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author | Dean Camera <dean@fourwalledcubicle.com> | 2010-05-07 06:40:47 +0000 |
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committer | Dean Camera <dean@fourwalledcubicle.com> | 2010-05-07 06:40:47 +0000 |
commit | 27eb17cb934dcd3807bacdfe87f853e32f0cfdb4 (patch) | |
tree | 4c463e3cd8bf5cb7b56f0e21c2238ead5b9ef6f6 /Projects/Webserver/Lib/uip/uip.c | |
parent | 842e219bf3341020b9e3a5f04fe67dabd796e82d (diff) | |
download | lufa-27eb17cb934dcd3807bacdfe87f853e32f0cfdb4.tar.gz lufa-27eb17cb934dcd3807bacdfe87f853e32f0cfdb4.tar.bz2 lufa-27eb17cb934dcd3807bacdfe87f853e32f0cfdb4.zip |
Change over unix line-endings to dos line endings.
Diffstat (limited to 'Projects/Webserver/Lib/uip/uip.c')
-rw-r--r-- | Projects/Webserver/Lib/uip/uip.c | 3876 |
1 files changed, 1938 insertions, 1938 deletions
diff --git a/Projects/Webserver/Lib/uip/uip.c b/Projects/Webserver/Lib/uip/uip.c index 22a72043f..b2c422825 100644 --- a/Projects/Webserver/Lib/uip/uip.c +++ b/Projects/Webserver/Lib/uip/uip.c @@ -1,1938 +1,1938 @@ -#define DEBUG_PRINTF(...) /*printf(__VA_ARGS__)*/ - -/** - * \addtogroup uip - * @{ - */ - -/** - * \file - * The uIP TCP/IP stack code. - * \author Adam Dunkels <adam@dunkels.com> - */ - -/* - * Copyright (c) 2001-2003, Adam Dunkels. - * All rights reserved. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * 1. Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * 2. Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in the - * documentation and/or other materials provided with the distribution. - * 3. The name of the author may not be used to endorse or promote - * products derived from this software without specific prior - * written permission. - * - * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS - * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED - * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE - * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY - * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL - * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE - * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS - * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, - * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING - * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS - * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. - * - * This file is part of the uIP TCP/IP stack. - * - * $Id: uip.c,v 1.15 2008/10/15 08:08:32 adamdunkels Exp $ - * - */ - -/* - * uIP is a small implementation of the IP, UDP and TCP protocols (as - * well as some basic ICMP stuff). The implementation couples the IP, - * UDP, TCP and the application layers very tightly. To keep the size - * of the compiled code down, this code frequently uses the goto - * statement. While it would be possible to break the uip_process() - * function into many smaller functions, this would increase the code - * size because of the overhead of parameter passing and the fact that - * the optimier would not be as efficient. - * - * The principle is that we have a small buffer, called the uip_buf, - * in which the device driver puts an incoming packet. The TCP/IP - * stack parses the headers in the packet, and calls the - * application. If the remote host has sent data to the application, - * this data is present in the uip_buf and the application read the - * data from there. It is up to the application to put this data into - * a byte stream if needed. The application will not be fed with data - * that is out of sequence. - * - * If the application whishes to send data to the peer, it should put - * its data into the uip_buf. The uip_appdata pointer points to the - * first available byte. The TCP/IP stack will calculate the - * checksums, and fill in the necessary header fields and finally send - * the packet back to the peer. -*/ - -#include "uip.h" -#include "uipopt.h" -#include "uip_arp.h" - -#if !UIP_CONF_IPV6 /* If UIP_CONF_IPV6 is defined, we compile the - uip6.c file instead of this one. Therefore - this #ifndef removes the entire compilation - output of the uip.c file */ - - -#if UIP_CONF_IPV6 -#include "net/uip-neighbor.h" -#endif /* UIP_CONF_IPV6 */ - -#include <string.h> - -/*---------------------------------------------------------------------------*/ -/* Variable definitions. */ - - -/* The IP address of this host. If it is defined to be fixed (by - setting UIP_FIXEDADDR to 1 in uipopt.h), the address is set - here. Otherwise, the address */ -#if UIP_FIXEDADDR > 0 -const uip_ipaddr_t uip_hostaddr = - { UIP_IPADDR0, UIP_IPADDR1, UIP_IPADDR2, UIP_IPADDR3 }; -const uip_ipaddr_t uip_draddr = - { UIP_DRIPADDR0, UIP_DRIPADDR1, UIP_DRIPADDR2, UIP_DRIPADDR3 }; -const uip_ipaddr_t uip_netmask = - { UIP_NETMASK0, UIP_NETMASK1, UIP_NETMASK2, UIP_NETMASK3 }; -#else -uip_ipaddr_t uip_hostaddr, uip_draddr, uip_netmask; -#endif /* UIP_FIXEDADDR */ - -const uip_ipaddr_t uip_broadcast_addr = -#if UIP_CONF_IPV6 - { { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, - 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff } }; -#else /* UIP_CONF_IPV6 */ - { { 0xff, 0xff, 0xff, 0xff } }; -#endif /* UIP_CONF_IPV6 */ -const uip_ipaddr_t uip_all_zeroes_addr = { { 0x0, /* rest is 0 */ } }; - -#if UIP_FIXEDETHADDR -const struct uip_eth_addr uip_ethaddr = {{UIP_ETHADDR0, - UIP_ETHADDR1, - UIP_ETHADDR2, - UIP_ETHADDR3, - UIP_ETHADDR4, - UIP_ETHADDR5}}; -#else -struct uip_eth_addr uip_ethaddr = {{0,0,0,0,0,0}}; -#endif - -#ifndef UIP_CONF_EXTERNAL_BUFFER -u8_t uip_buf[UIP_BUFSIZE + 2]; /* The packet buffer that contains - incoming packets. */ -#endif /* UIP_CONF_EXTERNAL_BUFFER */ - -void *uip_appdata; /* The uip_appdata pointer points to - application data. */ -void *uip_sappdata; /* The uip_appdata pointer points to - the application data which is to - be sent. */ -#if UIP_URGDATA > 0 -void *uip_urgdata; /* The uip_urgdata pointer points to - urgent data (out-of-band data), if - present. */ -u16_t uip_urglen, uip_surglen; -#endif /* UIP_URGDATA > 0 */ - -u16_t uip_len, uip_slen; - /* The uip_len is either 8 or 16 bits, - depending on the maximum packet - size. */ - -u8_t uip_flags; /* The uip_flags variable is used for - communication between the TCP/IP stack - and the application program. */ -struct uip_conn *uip_conn; /* uip_conn always points to the current - connection. */ - -struct uip_conn uip_conns[UIP_CONNS]; - /* The uip_conns array holds all TCP - connections. */ -u16_t uip_listenports[UIP_LISTENPORTS]; - /* The uip_listenports list all currently - listning ports. */ -#if UIP_UDP -struct uip_udp_conn *uip_udp_conn; -struct uip_udp_conn uip_udp_conns[UIP_UDP_CONNS]; -#endif /* UIP_UDP */ - -static u16_t ipid; /* Ths ipid variable is an increasing - number that is used for the IP ID - field. */ - -void uip_setipid(u16_t id) { ipid = id; } - -static u8_t iss[4]; /* The iss variable is used for the TCP - initial sequence number. */ - -#if UIP_ACTIVE_OPEN -static u16_t lastport; /* Keeps track of the last port used for - a new connection. */ -#endif /* UIP_ACTIVE_OPEN */ - -/* Temporary variables. */ -u8_t uip_acc32[4]; -static u8_t c, opt; -static u16_t tmp16; - -/* Structures and definitions. */ -#define TCP_FIN 0x01 -#define TCP_SYN 0x02 -#define TCP_RST 0x04 -#define TCP_PSH 0x08 -#define TCP_ACK 0x10 -#define TCP_URG 0x20 -#define TCP_CTL 0x3f - -#define TCP_OPT_END 0 /* End of TCP options list */ -#define TCP_OPT_NOOP 1 /* "No-operation" TCP option */ -#define TCP_OPT_MSS 2 /* Maximum segment size TCP option */ - -#define TCP_OPT_MSS_LEN 4 /* Length of TCP MSS option. */ - -#define ICMP_ECHO_REPLY 0 -#define ICMP_ECHO 8 - -#define ICMP_DEST_UNREACHABLE 3 -#define ICMP_PORT_UNREACHABLE 3 - -#define ICMP6_ECHO_REPLY 129 -#define ICMP6_ECHO 128 -#define ICMP6_NEIGHBOR_SOLICITATION 135 -#define ICMP6_NEIGHBOR_ADVERTISEMENT 136 - -#define ICMP6_FLAG_S (1 << 6) - -#define ICMP6_OPTION_SOURCE_LINK_ADDRESS 1 -#define ICMP6_OPTION_TARGET_LINK_ADDRESS 2 - - -/* Macros. */ -#define BUF ((struct uip_tcpip_hdr *)&uip_buf[UIP_LLH_LEN]) -#define FBUF ((struct uip_tcpip_hdr *)&uip_reassbuf[0]) -#define ICMPBUF ((struct uip_icmpip_hdr *)&uip_buf[UIP_LLH_LEN]) -#define UDPBUF ((struct uip_udpip_hdr *)&uip_buf[UIP_LLH_LEN]) - - -#if UIP_STATISTICS == 1 -struct uip_stats uip_stat; -#define UIP_STAT(s) s -#else -#define UIP_STAT(s) -#endif /* UIP_STATISTICS == 1 */ - -#if UIP_LOGGING == 1 -#include <stdio.h> -void uip_log(char *msg); -#define UIP_LOG(m) uip_log(m) -#else -#define UIP_LOG(m) -#endif /* UIP_LOGGING == 1 */ - -#if ! UIP_ARCH_ADD32 -void -uip_add32(u8_t *op32, u16_t op16) -{ - uip_acc32[3] = op32[3] + (op16 & 0xff); - uip_acc32[2] = op32[2] + (op16 >> 8); - uip_acc32[1] = op32[1]; - uip_acc32[0] = op32[0]; - - if(uip_acc32[2] < (op16 >> 8)) { - ++uip_acc32[1]; - if(uip_acc32[1] == 0) { - ++uip_acc32[0]; - } - } - - - if(uip_acc32[3] < (op16 & 0xff)) { - ++uip_acc32[2]; - if(uip_acc32[2] == 0) { - ++uip_acc32[1]; - if(uip_acc32[1] == 0) { - ++uip_acc32[0]; - } - } - } -} - -#endif /* UIP_ARCH_ADD32 */ - -#if ! UIP_ARCH_CHKSUM -/*---------------------------------------------------------------------------*/ -static u16_t -chksum(u16_t sum, const u8_t *data, u16_t len) -{ - u16_t t; - const u8_t *dataptr; - const u8_t *last_byte; - - dataptr = data; - last_byte = data + len - 1; - - while(dataptr < last_byte) { /* At least two more bytes */ - t = (dataptr[0] << 8) + dataptr[1]; - sum += t; - if(sum < t) { - sum++; /* carry */ - } - dataptr += 2; - } - - if(dataptr == last_byte) { - t = (dataptr[0] << 8) + 0; - sum += t; - if(sum < t) { - sum++; /* carry */ - } - } - - /* Return sum in host byte order. */ - return sum; -} -/*---------------------------------------------------------------------------*/ -u16_t -uip_chksum(u16_t *data, u16_t len) -{ - return htons(chksum(0, (u8_t *)data, len)); -} -/*---------------------------------------------------------------------------*/ -#ifndef UIP_ARCH_IPCHKSUM -u16_t -uip_ipchksum(void) -{ - u16_t sum; - - sum = chksum(0, &uip_buf[UIP_LLH_LEN], UIP_IPH_LEN); - DEBUG_PRINTF("uip_ipchksum: sum 0x%04x\n", sum); - return (sum == 0) ? 0xffff : htons(sum); -} -#endif -/*---------------------------------------------------------------------------*/ -static u16_t -upper_layer_chksum(u8_t proto) -{ - u16_t upper_layer_len; - u16_t sum; - -#if UIP_CONF_IPV6 - upper_layer_len = (((u16_t)(BUF->len[0]) << 8) + BUF->len[1]); -#else /* UIP_CONF_IPV6 */ - upper_layer_len = (((u16_t)(BUF->len[0]) << 8) + BUF->len[1]) - UIP_IPH_LEN; -#endif /* UIP_CONF_IPV6 */ - - /* First sum pseudoheader. */ - - /* IP protocol and length fields. This addition cannot carry. */ - sum = upper_layer_len + proto; - /* Sum IP source and destination addresses. */ - sum = chksum(sum, (u8_t *)&BUF->srcipaddr, 2 * sizeof(uip_ipaddr_t)); - - /* Sum TCP header and data. */ - sum = chksum(sum, &uip_buf[UIP_IPH_LEN + UIP_LLH_LEN], - upper_layer_len); - - return (sum == 0) ? 0xffff : htons(sum); -} -/*---------------------------------------------------------------------------*/ -#if UIP_CONF_IPV6 -u16_t -uip_icmp6chksum(void) -{ - return upper_layer_chksum(UIP_PROTO_ICMP6); - -} -#endif /* UIP_CONF_IPV6 */ -/*---------------------------------------------------------------------------*/ -u16_t -uip_tcpchksum(void) -{ - return upper_layer_chksum(UIP_PROTO_TCP); -} -/*---------------------------------------------------------------------------*/ -#if UIP_UDP_CHECKSUMS -u16_t -uip_udpchksum(void) -{ - return upper_layer_chksum(UIP_PROTO_UDP); -} -#endif /* UIP_UDP_CHECKSUMS */ -#endif /* UIP_ARCH_CHKSUM */ -/*---------------------------------------------------------------------------*/ -void -uip_init(void) -{ - for(c = 0; c < UIP_LISTENPORTS; ++c) { - uip_listenports[c] = 0; - } - for(c = 0; c < UIP_CONNS; ++c) { - uip_conns[c].tcpstateflags = UIP_CLOSED; - } -#if UIP_ACTIVE_OPEN - lastport = 1024; -#endif /* UIP_ACTIVE_OPEN */ - -#if UIP_UDP - for(c = 0; c < UIP_UDP_CONNS; ++c) { - uip_udp_conns[c].lport = 0; - } -#endif /* UIP_UDP */ - - - /* IPv4 initialization. */ -#if UIP_FIXEDADDR == 0 - /* uip_hostaddr[0] = uip_hostaddr[1] = 0;*/ -#endif /* UIP_FIXEDADDR */ - -} -/*---------------------------------------------------------------------------*/ -#if UIP_ACTIVE_OPEN -struct uip_conn * -uip_connect(uip_ipaddr_t *ripaddr, u16_t rport) -{ - register struct uip_conn *conn, *cconn; - - /* Find an unused local port. */ - again: - ++lastport; - - if(lastport >= 32000) { - lastport = 4096; - } - - /* Check if this port is already in use, and if so try to find - another one. */ - for(c = 0; c < UIP_CONNS; ++c) { - conn = &uip_conns[c]; - if(conn->tcpstateflags != UIP_CLOSED && - conn->lport == htons(lastport)) { - goto again; - } - } - - conn = 0; - for(c = 0; c < UIP_CONNS; ++c) { - cconn = &uip_conns[c]; - if(cconn->tcpstateflags == UIP_CLOSED) { - conn = cconn; - break; - } - if(cconn->tcpstateflags == UIP_TIME_WAIT) { - if(conn == 0 || - cconn->timer > conn->timer) { - conn = cconn; - } - } - } - - if(conn == 0) { - return 0; - } - - conn->tcpstateflags = UIP_SYN_SENT; - - conn->snd_nxt[0] = iss[0]; - conn->snd_nxt[1] = iss[1]; - conn->snd_nxt[2] = iss[2]; - conn->snd_nxt[3] = iss[3]; - - conn->initialmss = conn->mss = UIP_TCP_MSS; - - conn->len = 1; /* TCP length of the SYN is one. */ - conn->nrtx = 0; - conn->timer = 1; /* Send the SYN next time around. */ - conn->rto = UIP_RTO; - conn->sa = 0; - conn->sv = 16; /* Initial value of the RTT variance. */ - conn->lport = htons(lastport); - conn->rport = rport; - uip_ipaddr_copy(&conn->ripaddr, ripaddr); - - return conn; -} -#endif /* UIP_ACTIVE_OPEN */ -/*---------------------------------------------------------------------------*/ -#if UIP_UDP -struct uip_udp_conn * -uip_udp_new(const uip_ipaddr_t *ripaddr, u16_t rport) -{ - register struct uip_udp_conn *conn; - - /* Find an unused local port. */ - again: - ++lastport; - - if(lastport >= 32000) { - lastport = 4096; - } - - for(c = 0; c < UIP_UDP_CONNS; ++c) { - if(uip_udp_conns[c].lport == htons(lastport)) { - goto again; - } - } - - - conn = 0; - for(c = 0; c < UIP_UDP_CONNS; ++c) { - if(uip_udp_conns[c].lport == 0) { - conn = &uip_udp_conns[c]; - break; - } - } - - if(conn == 0) { - return 0; - } - - conn->lport = HTONS(lastport); - conn->rport = rport; - if(ripaddr == NULL) { - memset(&conn->ripaddr, 0, sizeof(uip_ipaddr_t)); - } else { - uip_ipaddr_copy(&conn->ripaddr, ripaddr); - } - conn->ttl = UIP_TTL; - - return conn; -} -#endif /* UIP_UDP */ -/*---------------------------------------------------------------------------*/ -void -uip_unlisten(u16_t port) -{ - for(c = 0; c < UIP_LISTENPORTS; ++c) { - if(uip_listenports[c] == port) { - uip_listenports[c] = 0; - return; - } - } -} -/*---------------------------------------------------------------------------*/ -void -uip_listen(u16_t port) -{ - for(c = 0; c < UIP_LISTENPORTS; ++c) { - if(uip_listenports[c] == 0) { - uip_listenports[c] = port; - return; - } - } -} -/*---------------------------------------------------------------------------*/ -/* XXX: IP fragment reassembly: not well-tested. */ - -#if UIP_REASSEMBLY && !UIP_CONF_IPV6 -#define UIP_REASS_BUFSIZE (UIP_BUFSIZE - UIP_LLH_LEN) -static u8_t uip_reassbuf[UIP_REASS_BUFSIZE]; -static u8_t uip_reassbitmap[UIP_REASS_BUFSIZE / (8 * 8)]; -static const u8_t bitmap_bits[8] = {0xff, 0x7f, 0x3f, 0x1f, - 0x0f, 0x07, 0x03, 0x01}; -static u16_t uip_reasslen; -static u8_t uip_reassflags; -#define UIP_REASS_FLAG_LASTFRAG 0x01 -static u8_t uip_reasstmr; - -#define IP_MF 0x20 - -static u8_t -uip_reass(void) -{ - u16_t offset, len; - u16_t i; - - /* If ip_reasstmr is zero, no packet is present in the buffer, so we - write the IP header of the fragment into the reassembly - buffer. The timer is updated with the maximum age. */ - if(uip_reasstmr == 0) { - memcpy(uip_reassbuf, &BUF->vhl, UIP_IPH_LEN); - uip_reasstmr = UIP_REASS_MAXAGE; - uip_reassflags = 0; - /* Clear the bitmap. */ - memset(uip_reassbitmap, 0, sizeof(uip_reassbitmap)); - } - - /* Check if the incoming fragment matches the one currently present - in the reasembly buffer. If so, we proceed with copying the - fragment into the buffer. */ - if(BUF->srcipaddr[0] == FBUF->srcipaddr[0] && - BUF->srcipaddr[1] == FBUF->srcipaddr[1] && - BUF->destipaddr[0] == FBUF->destipaddr[0] && - BUF->destipaddr[1] == FBUF->destipaddr[1] && - BUF->ipid[0] == FBUF->ipid[0] && - BUF->ipid[1] == FBUF->ipid[1]) { - - len = (BUF->len[0] << 8) + BUF->len[1] - (BUF->vhl & 0x0f) * 4; - offset = (((BUF->ipoffset[0] & 0x3f) << 8) + BUF->ipoffset[1]) * 8; - - /* If the offset or the offset + fragment length overflows the - reassembly buffer, we discard the entire packet. */ - if(offset > UIP_REASS_BUFSIZE || - offset + len > UIP_REASS_BUFSIZE) { - uip_reasstmr = 0; - goto nullreturn; - } - - /* Copy the fragment into the reassembly buffer, at the right - offset. */ - memcpy(&uip_reassbuf[UIP_IPH_LEN + offset], - (char *)BUF + (int)((BUF->vhl & 0x0f) * 4), - len); - - /* Update the bitmap. */ - if(offset / (8 * 8) == (offset + len) / (8 * 8)) { - /* If the two endpoints are in the same byte, we only update - that byte. */ - - uip_reassbitmap[offset / (8 * 8)] |= - bitmap_bits[(offset / 8 ) & 7] & - ~bitmap_bits[((offset + len) / 8 ) & 7]; - } else { - /* If the two endpoints are in different bytes, we update the - bytes in the endpoints and fill the stuff inbetween with - 0xff. */ - uip_reassbitmap[offset / (8 * 8)] |= - bitmap_bits[(offset / 8 ) & 7]; - for(i = 1 + offset / (8 * 8); i < (offset + len) / (8 * 8); ++i) { - uip_reassbitmap[i] = 0xff; - } - uip_reassbitmap[(offset + len) / (8 * 8)] |= - ~bitmap_bits[((offset + len) / 8 ) & 7]; - } - - /* If this fragment has the More Fragments flag set to zero, we - know that this is the last fragment, so we can calculate the - size of the entire packet. We also set the - IP_REASS_FLAG_LASTFRAG flag to indicate that we have received - the final fragment. */ - - if((BUF->ipoffset[0] & IP_MF) == 0) { - uip_reassflags |= UIP_REASS_FLAG_LASTFRAG; - uip_reasslen = offset + len; - } - - /* Finally, we check if we have a full packet in the buffer. We do - this by checking if we have the last fragment and if all bits - in the bitmap are set. */ - if(uip_reassflags & UIP_REASS_FLAG_LASTFRAG) { - /* Check all bytes up to and including all but the last byte in - the bitmap. */ - for(i = 0; i < uip_reasslen / (8 * 8) - 1; ++i) { - if(uip_reassbitmap[i] != 0xff) { - goto nullreturn; - } - } - /* Check the last byte in the bitmap. It should contain just the - right amount of bits. */ - if(uip_reassbitmap[uip_reasslen / (8 * 8)] != - (u8_t)~bitmap_bits[uip_reasslen / 8 & 7]) { - goto nullreturn; - } - - /* If we have come this far, we have a full packet in the - buffer, so we allocate a pbuf and copy the packet into it. We - also reset the timer. */ - uip_reasstmr = 0; - memcpy(BUF, FBUF, uip_reasslen); - - /* Pretend to be a "normal" (i.e., not fragmented) IP packet - from now on. */ - BUF->ipoffset[0] = BUF->ipoffset[1] = 0; - BUF->len[0] = uip_reasslen >> 8; - BUF->len[1] = uip_reasslen & 0xff; - BUF->ipchksum = 0; - BUF->ipchksum = ~(uip_ipchksum()); - - return uip_reasslen; - } - } - - nullreturn: - return 0; -} -#endif /* UIP_REASSEMBLY */ -/*---------------------------------------------------------------------------*/ -static void -uip_add_rcv_nxt(u16_t n) -{ - uip_add32(uip_conn->rcv_nxt, n); - uip_conn->rcv_nxt[0] = uip_acc32[0]; - uip_conn->rcv_nxt[1] = uip_acc32[1]; - uip_conn->rcv_nxt[2] = uip_acc32[2]; - uip_conn->rcv_nxt[3] = uip_acc32[3]; -} -/*---------------------------------------------------------------------------*/ -void -uip_process(u8_t flag) -{ - register struct uip_conn *uip_connr = uip_conn; - -#if UIP_UDP - if(flag == UIP_UDP_SEND_CONN) { - goto udp_send; - } -#endif /* UIP_UDP */ - - uip_sappdata = uip_appdata = &uip_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN]; - - /* Check if we were invoked because of a poll request for a - particular connection. */ - if(flag == UIP_POLL_REQUEST) { - if((uip_connr->tcpstateflags & UIP_TS_MASK) == UIP_ESTABLISHED && - !uip_outstanding(uip_connr)) { - uip_len = uip_slen = 0; - uip_flags = UIP_POLL; - UIP_APPCALL(); - goto appsend; - } - goto drop; - - /* Check if we were invoked because of the perodic timer fireing. */ - } else if(flag == UIP_TIMER) { -#if UIP_REASSEMBLY - if(uip_reasstmr != 0) { - --uip_reasstmr; - } -#endif /* UIP_REASSEMBLY */ - /* Increase the initial sequence number. */ - if(++iss[3] == 0) { - if(++iss[2] == 0) { - if(++iss[1] == 0) { - ++iss[0]; - } - } - } - - /* Reset the length variables. */ - uip_len = 0; - uip_slen = 0; - - /* Check if the connection is in a state in which we simply wait - for the connection to time out. If so, we increase the - connection's timer and remove the connection if it times - out. */ - if(uip_connr->tcpstateflags == UIP_TIME_WAIT || - uip_connr->tcpstateflags == UIP_FIN_WAIT_2) { - ++(uip_connr->timer); - if(uip_connr->timer == UIP_TIME_WAIT_TIMEOUT) { - uip_connr->tcpstateflags = UIP_CLOSED; - } - } else if(uip_connr->tcpstateflags != UIP_CLOSED) { - /* If the connection has outstanding data, we increase the - connection's timer and see if it has reached the RTO value - in which case we retransmit. */ - if(uip_outstanding(uip_connr)) { - if(uip_connr->timer-- == 0) { - if(uip_connr->nrtx == UIP_MAXRTX || - ((uip_connr->tcpstateflags == UIP_SYN_SENT || - uip_connr->tcpstateflags == UIP_SYN_RCVD) && - uip_connr->nrtx == UIP_MAXSYNRTX)) { - uip_connr->tcpstateflags = UIP_CLOSED; - - /* We call UIP_APPCALL() with uip_flags set to - UIP_TIMEDOUT to inform the application that the - connection has timed out. */ - uip_flags = UIP_TIMEDOUT; - UIP_APPCALL(); - - /* We also send a reset packet to the remote host. */ - BUF->flags = TCP_RST | TCP_ACK; - goto tcp_send_nodata; - } - - /* Exponential backoff. */ - uip_connr->timer = UIP_RTO << (uip_connr->nrtx > 4? - 4: - uip_connr->nrtx); - ++(uip_connr->nrtx); - - /* Ok, so we need to retransmit. We do this differently - depending on which state we are in. In ESTABLISHED, we - call upon the application so that it may prepare the - data for the retransmit. In SYN_RCVD, we resend the - SYNACK that we sent earlier and in LAST_ACK we have to - retransmit our FINACK. */ - UIP_STAT(++uip_stat.tcp.rexmit); - switch(uip_connr->tcpstateflags & UIP_TS_MASK) { - case UIP_SYN_RCVD: - /* In the SYN_RCVD state, we should retransmit our - SYNACK. */ - goto tcp_send_synack; - -#if UIP_ACTIVE_OPEN - case UIP_SYN_SENT: - /* In the SYN_SENT state, we retransmit out SYN. */ - BUF->flags = 0; - goto tcp_send_syn; -#endif /* UIP_ACTIVE_OPEN */ - - case UIP_ESTABLISHED: - /* In the ESTABLISHED state, we call upon the application - to do the actual retransmit after which we jump into - the code for sending out the packet (the apprexmit - label). */ - uip_flags = UIP_REXMIT; - UIP_APPCALL(); - goto apprexmit; - - case UIP_FIN_WAIT_1: - case UIP_CLOSING: - case UIP_LAST_ACK: - /* In all these states we should retransmit a FINACK. */ - goto tcp_send_finack; - - } - } - } else if((uip_connr->tcpstateflags & UIP_TS_MASK) == UIP_ESTABLISHED) { - /* If there was no need for a retransmission, we poll the - application for new data. */ - uip_len = uip_slen = 0; - uip_flags = UIP_POLL; - UIP_APPCALL(); - goto appsend; - } - } - goto drop; - } -#if UIP_UDP - if(flag == UIP_UDP_TIMER) { - if(uip_udp_conn->lport != 0) { - uip_conn = NULL; - uip_sappdata = uip_appdata = &uip_buf[UIP_LLH_LEN + UIP_IPUDPH_LEN]; - uip_len = uip_slen = 0; - uip_flags = UIP_POLL; - UIP_UDP_APPCALL(); - goto udp_send; - } else { - goto drop; - } - } -#endif - - /* This is where the input processing starts. */ - UIP_STAT(++uip_stat.ip.recv); - - /* Start of IP input header processing code. */ - -#if UIP_CONF_IPV6 - /* Check validity of the IP header. */ - if((BUF->vtc & 0xf0) != 0x60) { /* IP version and header length. */ - UIP_STAT(++uip_stat.ip.drop); - UIP_STAT(++uip_stat.ip.vhlerr); - UIP_LOG("ipv6: invalid version."); - goto drop; - } -#else /* UIP_CONF_IPV6 */ - /* Check validity of the IP header. */ - if(BUF->vhl != 0x45) { /* IP version and header length. */ - UIP_STAT(++uip_stat.ip.drop); - UIP_STAT(++uip_stat.ip.vhlerr); - UIP_LOG("ip: invalid version or header length."); - goto drop; - } -#endif /* UIP_CONF_IPV6 */ - - /* Check the size of the packet. If the size reported to us in - uip_len is smaller the size reported in the IP header, we assume - that the packet has been corrupted in transit. If the size of - uip_len is larger than the size reported in the IP packet header, - the packet has been padded and we set uip_len to the correct - value.. */ - - if((BUF->len[0] << 8) + BUF->len[1] <= uip_len) { - uip_len = (BUF->len[0] << 8) + BUF->len[1]; -#if UIP_CONF_IPV6 - uip_len += 40; /* The length reported in the IPv6 header is the - length of the payload that follows the - header. However, uIP uses the uip_len variable - for holding the size of the entire packet, - including the IP header. For IPv4 this is not a - problem as the length field in the IPv4 header - contains the length of the entire packet. But - for IPv6 we need to add the size of the IPv6 - header (40 bytes). */ -#endif /* UIP_CONF_IPV6 */ - } else { - UIP_LOG("ip: packet shorter than reported in IP header."); - goto drop; - } - -#if !UIP_CONF_IPV6 - /* Check the fragment flag. */ - if((BUF->ipoffset[0] & 0x3f) != 0 || - BUF->ipoffset[1] != 0) { -#if UIP_REASSEMBLY - uip_len = uip_reass(); - if(uip_len == 0) { - goto drop; - } -#else /* UIP_REASSEMBLY */ - UIP_STAT(++uip_stat.ip.drop); - UIP_STAT(++uip_stat.ip.fragerr); - UIP_LOG("ip: fragment dropped."); - goto drop; -#endif /* UIP_REASSEMBLY */ - } -#endif /* UIP_CONF_IPV6 */ - - if(uip_ipaddr_cmp(&uip_hostaddr, &uip_all_zeroes_addr)) { - /* If we are configured to use ping IP address configuration and - hasn't been assigned an IP address yet, we accept all ICMP - packets. */ -#if UIP_PINGADDRCONF && !UIP_CONF_IPV6 - if(BUF->proto == UIP_PROTO_ICMP) { - UIP_LOG("ip: possible ping config packet received."); - goto icmp_input; - } else { - UIP_LOG("ip: packet dropped since no address assigned."); - goto drop; - } -#endif /* UIP_PINGADDRCONF */ - - } else { - /* If IP broadcast support is configured, we check for a broadcast - UDP packet, which may be destined to us. */ -#if UIP_BROADCAST - DEBUG_PRINTF("UDP IP checksum 0x%04x\n", uip_ipchksum()); - if(BUF->proto == UIP_PROTO_UDP && - uip_ipaddr_cmp(&BUF->destipaddr, &uip_broadcast_addr) - /*&& - uip_ipchksum() == 0xffff*/) { - goto udp_input; - } -#endif /* UIP_BROADCAST */ - - /* Check if the packet is destined for our IP address. */ -#if !UIP_CONF_IPV6 - if(!uip_ipaddr_cmp(&BUF->destipaddr, &uip_hostaddr)) { - UIP_STAT(++uip_stat.ip.drop); - goto drop; - } -#else /* UIP_CONF_IPV6 */ - /* For IPv6, packet reception is a little trickier as we need to - make sure that we listen to certain multicast addresses (all - hosts multicast address, and the solicited-node multicast - address) as well. However, we will cheat here and accept all - multicast packets that are sent to the ff02::/16 addresses. */ - if(!uip_ipaddr_cmp(&BUF->destipaddr, &uip_hostaddr) && - BUF->destipaddr.u16[0] != HTONS(0xff02)) { - UIP_STAT(++uip_stat.ip.drop); - goto drop; - } -#endif /* UIP_CONF_IPV6 */ - } - -#if !UIP_CONF_IPV6 - if(uip_ipchksum() != 0xffff) { /* Compute and check the IP header - checksum. */ - UIP_STAT(++uip_stat.ip.drop); - UIP_STAT(++uip_stat.ip.chkerr); - UIP_LOG("ip: bad checksum."); - goto drop; - } -#endif /* UIP_CONF_IPV6 */ - - if(BUF->proto == UIP_PROTO_TCP) { /* Check for TCP packet. If so, - proceed with TCP input - processing. */ - goto tcp_input; - } - -#if UIP_UDP - if(BUF->proto == UIP_PROTO_UDP) { - goto udp_input; - } -#endif /* UIP_UDP */ - -#if !UIP_CONF_IPV6 - /* ICMPv4 processing code follows. */ - if(BUF->proto != UIP_PROTO_ICMP) { /* We only allow ICMP packets from - here. */ - UIP_STAT(++uip_stat.ip.drop); - UIP_STAT(++uip_stat.ip.protoerr); - UIP_LOG("ip: neither tcp nor icmp."); - goto drop; - } - -#if UIP_PINGADDRCONF - icmp_input: -#endif /* UIP_PINGADDRCONF */ - UIP_STAT(++uip_stat.icmp.recv); - - /* ICMP echo (i.e., ping) processing. This is simple, we only change - the ICMP type from ECHO to ECHO_REPLY and adjust the ICMP - checksum before we return the packet. */ - if(ICMPBUF->type != ICMP_ECHO) { - UIP_STAT(++uip_stat.icmp.drop); - UIP_STAT(++uip_stat.icmp.typeerr); - UIP_LOG("icmp: not icmp echo."); - goto drop; - } - - /* If we are configured to use ping IP address assignment, we use - the destination IP address of this ping packet and assign it to - ourself. */ -#if UIP_PINGADDRCONF - if(uip_ipaddr_cmp(&uip_hostaddr, &uip_all_zeroes_addr)) { - uip_hostaddr = BUF->destipaddr; - } -#endif /* UIP_PINGADDRCONF */ - - ICMPBUF->type = ICMP_ECHO_REPLY; - - if(ICMPBUF->icmpchksum >= HTONS(0xffff - (ICMP_ECHO << 8))) { - ICMPBUF->icmpchksum += HTONS(ICMP_ECHO << 8) + 1; - } else { - ICMPBUF->icmpchksum += HTONS(ICMP_ECHO << 8); - } - - /* Swap IP addresses. */ - uip_ipaddr_copy(&BUF->destipaddr, &BUF->srcipaddr); - uip_ipaddr_copy(&BUF->srcipaddr, &uip_hostaddr); - - UIP_STAT(++uip_stat.icmp.sent); - BUF->ttl = UIP_TTL; - goto ip_send_nolen; - - /* End of IPv4 input header processing code. */ -#else /* !UIP_CONF_IPV6 */ - - /* This is IPv6 ICMPv6 processing code. */ - DEBUG_PRINTF("icmp6_input: length %d\n", uip_len); - - if(BUF->proto != UIP_PROTO_ICMP6) { /* We only allow ICMPv6 packets from - here. */ - UIP_STAT(++uip_stat.ip.drop); - UIP_STAT(++uip_stat.ip.protoerr); - UIP_LOG("ip: neither tcp nor icmp6."); - goto drop; - } - - UIP_STAT(++uip_stat.icmp.recv); - - /* If we get a neighbor solicitation for our address we should send - a neighbor advertisement message back. */ - if(ICMPBUF->type == ICMP6_NEIGHBOR_SOLICITATION) { - if(uip_ipaddr_cmp(&ICMPBUF->icmp6data, &uip_hostaddr)) { - - if(ICMPBUF->options[0] == ICMP6_OPTION_SOURCE_LINK_ADDRESS) { - /* Save the sender's address in our neighbor list. */ - uip_neighbor_add(&ICMPBUF->srcipaddr, &(ICMPBUF->options[2])); - } - - /* We should now send a neighbor advertisement back to where the - neighbor solicication came from. */ - ICMPBUF->type = ICMP6_NEIGHBOR_ADVERTISEMENT; - ICMPBUF->flags = ICMP6_FLAG_S; /* Solicited flag. */ - - ICMPBUF->reserved1 = ICMPBUF->reserved2 = ICMPBUF->reserved3 = 0; - - uip_ipaddr_copy(&ICMPBUF->destipaddr, &ICMPBUF->srcipaddr); - uip_ipaddr_copy(&ICMPBUF->srcipaddr, &uip_hostaddr); - ICMPBUF->options[0] = ICMP6_OPTION_TARGET_LINK_ADDRESS; - ICMPBUF->options[1] = 1; /* Options length, 1 = 8 bytes. */ - memcpy(&(ICMPBUF->options[2]), &uip_ethaddr, sizeof(uip_ethaddr)); - ICMPBUF->icmpchksum = 0; - ICMPBUF->icmpchksum = ~uip_icmp6chksum(); - - goto send; - - } - goto drop; - } else if(ICMPBUF->type == ICMP6_ECHO) { - /* ICMP echo (i.e., ping) processing. This is simple, we only - change the ICMP type from ECHO to ECHO_REPLY and update the - ICMP checksum before we return the packet. */ - - ICMPBUF->type = ICMP6_ECHO_REPLY; - - uip_ipaddr_copy(&BUF->destipaddr, &BUF->srcipaddr); - uip_ipaddr_copy(&BUF->srcipaddr, &uip_hostaddr); - ICMPBUF->icmpchksum = 0; - ICMPBUF->icmpchksum = ~uip_icmp6chksum(); - - UIP_STAT(++uip_stat.icmp.sent); - goto send; - } else { - DEBUG_PRINTF("Unknown icmp6 message type %d\n", ICMPBUF->type); - UIP_STAT(++uip_stat.icmp.drop); - UIP_STAT(++uip_stat.icmp.typeerr); - UIP_LOG("icmp: unknown ICMP message."); - goto drop; - } - - /* End of IPv6 ICMP processing. */ - -#endif /* !UIP_CONF_IPV6 */ - -#if UIP_UDP - /* UDP input processing. */ - udp_input: - /* UDP processing is really just a hack. We don't do anything to the - UDP/IP headers, but let the UDP application do all the hard - work. If the application sets uip_slen, it has a packet to - send. */ -#if UIP_UDP_CHECKSUMS - uip_len = uip_len - UIP_IPUDPH_LEN; - uip_appdata = &uip_buf[UIP_LLH_LEN + UIP_IPUDPH_LEN]; - if(UDPBUF->udpchksum != 0 && uip_udpchksum() != 0xffff) { - UIP_STAT(++uip_stat.udp.drop); - UIP_STAT(++uip_stat.udp.chkerr); - UIP_LOG("udp: bad checksum."); - goto drop; - } -#else /* UIP_UDP_CHECKSUMS */ - uip_len = uip_len - UIP_IPUDPH_LEN; -#endif /* UIP_UDP_CHECKSUMS */ - - /* Demultiplex this UDP packet between the UDP "connections". */ - for(uip_udp_conn = &uip_udp_conns[0]; - uip_udp_conn < &uip_udp_conns[UIP_UDP_CONNS]; - ++uip_udp_conn) { - /* If the local UDP port is non-zero, the connection is considered - to be used. If so, the local port number is checked against the - destination port number in the received packet. If the two port - numbers match, the remote port number is checked if the - connection is bound to a remote port. Finally, if the - connection is bound to a remote IP address, the source IP - address of the packet is checked. */ - if(uip_udp_conn->lport != 0 && - UDPBUF->destport == uip_udp_conn->lport && - (uip_udp_conn->rport == 0 || - UDPBUF->srcport == uip_udp_conn->rport) && - (uip_ipaddr_cmp(&uip_udp_conn->ripaddr, &uip_all_zeroes_addr) || - uip_ipaddr_cmp(&uip_udp_conn->ripaddr, &uip_broadcast_addr) || - uip_ipaddr_cmp(&BUF->srcipaddr, &uip_udp_conn->ripaddr))) { - goto udp_found; - } - } - UIP_LOG("udp: no matching connection found"); -#if UIP_CONF_ICMP_DEST_UNREACH && !UIP_CONF_IPV6 - /* Copy fields from packet header into payload of this ICMP packet. */ - memcpy(&(ICMPBUF->payload[0]), ICMPBUF, UIP_IPH_LEN + 8); - - /* Set the ICMP type and code. */ - ICMPBUF->type = ICMP_DEST_UNREACHABLE; - ICMPBUF->icode = ICMP_PORT_UNREACHABLE; - - /* Calculate the ICMP checksum. */ - ICMPBUF->icmpchksum = 0; - ICMPBUF->icmpchksum = ~uip_chksum((u16_t *)&(ICMPBUF->type), 36); - - /* Set the IP destination address to be the source address of the - original packet. */ - uip_ipaddr_copy(&BUF->destipaddr, &BUF->srcipaddr); - - /* Set our IP address as the source address. */ - uip_ipaddr_copy(&BUF->srcipaddr, &uip_hostaddr); - - /* The size of the ICMP destination unreachable packet is 36 + the - size of the IP header (20) = 56. */ - uip_len = 36 + UIP_IPH_LEN; - ICMPBUF->len[0] = 0; - ICMPBUF->len[1] = (u8_t)uip_len; - ICMPBUF->ttl = UIP_TTL; - ICMPBUF->proto = UIP_PROTO_ICMP; - - goto ip_send_nolen; -#else /* UIP_CONF_ICMP_DEST_UNREACH */ - goto drop; -#endif /* UIP_CONF_ICMP_DEST_UNREACH */ - - udp_found: - uip_conn = NULL; - uip_flags = UIP_NEWDATA; - uip_sappdata = uip_appdata = &uip_buf[UIP_LLH_LEN + UIP_IPUDPH_LEN]; - uip_slen = 0; - UIP_UDP_APPCALL(); - - udp_send: - if(uip_slen == 0) { - goto drop; - } - uip_len = uip_slen + UIP_IPUDPH_LEN; - -#if UIP_CONF_IPV6 - /* For IPv6, the IP length field does not include the IPv6 IP header - length. */ - BUF->len[0] = ((uip_len - UIP_IPH_LEN) >> 8); - BUF->len[1] = ((uip_len - UIP_IPH_LEN) & 0xff); -#else /* UIP_CONF_IPV6 */ - BUF->len[0] = (uip_len >> 8); - BUF->len[1] = (uip_len & 0xff); -#endif /* UIP_CONF_IPV6 */ - - BUF->ttl = uip_udp_conn->ttl; - BUF->proto = UIP_PROTO_UDP; - - UDPBUF->udplen = HTONS(uip_slen + UIP_UDPH_LEN); - UDPBUF->udpchksum = 0; - - BUF->srcport = uip_udp_conn->lport; - BUF->destport = uip_udp_conn->rport; - - uip_ipaddr_copy(&BUF->srcipaddr, &uip_hostaddr); - uip_ipaddr_copy(&BUF->destipaddr, &uip_udp_conn->ripaddr); - - uip_appdata = &uip_buf[UIP_LLH_LEN + UIP_IPTCPH_LEN]; - -#if UIP_UDP_CHECKSUMS - /* Calculate UDP checksum. */ - UDPBUF->udpchksum = ~(uip_udpchksum()); - if(UDPBUF->udpchksum == 0) { - UDPBUF->udpchksum = 0xffff; - } -#endif /* UIP_UDP_CHECKSUMS */ - - goto ip_send_nolen; -#endif /* UIP_UDP */ - - /* TCP input processing. */ - tcp_input: - UIP_STAT(++uip_stat.tcp.recv); - - /* Start of TCP input header processing code. */ - - if(uip_tcpchksum() != 0xffff) { /* Compute and check the TCP - checksum. */ - UIP_STAT(++uip_stat.tcp.drop); - UIP_STAT(++uip_stat.tcp.chkerr); - UIP_LOG("tcp: bad checksum."); - goto drop; - } - - /* Demultiplex this segment. */ - /* First check any active connections. */ - for(uip_connr = &uip_conns[0]; uip_connr <= &uip_conns[UIP_CONNS - 1]; - ++uip_connr) { - if(uip_connr->tcpstateflags != UIP_CLOSED && - BUF->destport == uip_connr->lport && - BUF->srcport == uip_connr->rport && - uip_ipaddr_cmp(&BUF->srcipaddr, &uip_connr->ripaddr)) { - goto found; - } - } - - /* If we didn't find and active connection that expected the packet, - either this packet is an old duplicate, or this is a SYN packet - destined for a connection in LISTEN. If the SYN flag isn't set, - it is an old packet and we send a RST. */ - if((BUF->flags & TCP_CTL) != TCP_SYN) { - goto reset; - } - - tmp16 = BUF->destport; - /* Next, check listening connections. */ - for(c = 0; c < UIP_LISTENPORTS; ++c) { - if(tmp16 == uip_listenports[c]) { - goto found_listen; - } - } - - /* No matching connection found, so we send a RST packet. */ - UIP_STAT(++uip_stat.tcp.synrst); - - reset: - /* We do not send resets in response to resets. */ - if(BUF->flags & TCP_RST) { - goto drop; - } - - UIP_STAT(++uip_stat.tcp.rst); - - BUF->flags = TCP_RST | TCP_ACK; - uip_len = UIP_IPTCPH_LEN; - BUF->tcpoffset = 5 << 4; - - /* Flip the seqno and ackno fields in the TCP header. */ - c = BUF->seqno[3]; - BUF->seqno[3] = BUF->ackno[3]; - BUF->ackno[3] = c; - - c = BUF->seqno[2]; - BUF->seqno[2] = BUF->ackno[2]; - BUF->ackno[2] = c; - - c = BUF->seqno[1]; - BUF->seqno[1] = BUF->ackno[1]; - BUF->ackno[1] = c; - - c = BUF->seqno[0]; - BUF->seqno[0] = BUF->ackno[0]; - BUF->ackno[0] = c; - - /* We also have to increase the sequence number we are - acknowledging. If the least significant byte overflowed, we need - to propagate the carry to the other bytes as well. */ - if(++BUF->ackno[3] == 0) { - if(++BUF->ackno[2] == 0) { - if(++BUF->ackno[1] == 0) { - ++BUF->ackno[0]; - } - } - } - - /* Swap port numbers. */ - tmp16 = BUF->srcport; - BUF->srcport = BUF->destport; - BUF->destport = tmp16; - - /* Swap IP addresses. */ - uip_ipaddr_copy(&BUF->destipaddr, &BUF->srcipaddr); - uip_ipaddr_copy(&BUF->srcipaddr, &uip_hostaddr); - - /* And send out the RST packet! */ - goto tcp_send_noconn; - - /* This label will be jumped to if we matched the incoming packet - with a connection in LISTEN. In that case, we should create a new - connection and send a SYNACK in return. */ - found_listen: - /* First we check if there are any connections avaliable. Unused - connections are kept in the same table as used connections, but - unused ones have the tcpstate set to CLOSED. Also, connections in - TIME_WAIT are kept track of and we'll use the oldest one if no - CLOSED connections are found. Thanks to Eddie C. Dost for a very - nice algorithm for the TIME_WAIT search. */ - uip_connr = 0; - for(c = 0; c < UIP_CONNS; ++c) { - if(uip_conns[c].tcpstateflags == UIP_CLOSED) { - uip_connr = &uip_conns[c]; - break; - } - if(uip_conns[c].tcpstateflags == UIP_TIME_WAIT) { - if(uip_connr == 0 || - uip_conns[c].timer > uip_connr->timer) { - uip_connr = &uip_conns[c]; - } - } - } - - if(uip_connr == 0) { - /* All connections are used already, we drop packet and hope that - the remote end will retransmit the packet at a time when we - have more spare connections. */ - UIP_STAT(++uip_stat.tcp.syndrop); - UIP_LOG("tcp: found no unused connections."); - goto drop; - } - uip_conn = uip_connr; - - /* Fill in the necessary fields for the new connection. */ - uip_connr->rto = uip_connr->timer = UIP_RTO; - uip_connr->sa = 0; - uip_connr->sv = 4; - uip_connr->nrtx = 0; - uip_connr->lport = BUF->destport; - uip_connr->rport = BUF->srcport; - uip_ipaddr_copy(&uip_connr->ripaddr, &BUF->srcipaddr); - uip_connr->tcpstateflags = UIP_SYN_RCVD; - - uip_connr->snd_nxt[0] = iss[0]; - uip_connr->snd_nxt[1] = iss[1]; - uip_connr->snd_nxt[2] = iss[2]; - uip_connr->snd_nxt[3] = iss[3]; - uip_connr->len = 1; - - /* rcv_nxt should be the seqno from the incoming packet + 1. */ - uip_connr->rcv_nxt[3] = BUF->seqno[3]; - uip_connr->rcv_nxt[2] = BUF->seqno[2]; - uip_connr->rcv_nxt[1] = BUF->seqno[1]; - uip_connr->rcv_nxt[0] = BUF->seqno[0]; - uip_add_rcv_nxt(1); - - /* Parse the TCP MSS option, if present. */ - if((BUF->tcpoffset & 0xf0) > 0x50) { - for(c = 0; c < ((BUF->tcpoffset >> 4) - 5) << 2 ;) { - opt = uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + c]; - if(opt == TCP_OPT_END) { - /* End of options. */ - break; - } else if(opt == TCP_OPT_NOOP) { - ++c; - /* NOP option. */ - } else if(opt == TCP_OPT_MSS && - uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c] == TCP_OPT_MSS_LEN) { - /* An MSS option with the right option length. */ - tmp16 = ((u16_t)uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 2 + c] << 8) | - (u16_t)uip_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN + 3 + c]; - uip_connr->initialmss = uip_connr->mss = - tmp16 > UIP_TCP_MSS? UIP_TCP_MSS: tmp16; - - /* And we are done processing options. */ - break; - } else { - /* All other options have a length field, so that we easily - can skip past them. */ - if(uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c] == 0) { - /* If the length field is zero, the options are malformed - and we don't process them further. */ - break; - } - c += uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c]; - } - } - } - - /* Our response will be a SYNACK. */ -#if UIP_ACTIVE_OPEN - tcp_send_synack: - BUF->flags = TCP_ACK; - - tcp_send_syn: - BUF->flags |= TCP_SYN; -#else /* UIP_ACTIVE_OPEN */ - tcp_send_synack: - BUF->flags = TCP_SYN | TCP_ACK; -#endif /* UIP_ACTIVE_OPEN */ - - /* We send out the TCP Maximum Segment Size option with our - SYNACK. */ - BUF->optdata[0] = TCP_OPT_MSS; - BUF->optdata[1] = TCP_OPT_MSS_LEN; - BUF->optdata[2] = (UIP_TCP_MSS) / 256; - BUF->optdata[3] = (UIP_TCP_MSS) & 255; - uip_len = UIP_IPTCPH_LEN + TCP_OPT_MSS_LEN; - BUF->tcpoffset = ((UIP_TCPH_LEN + TCP_OPT_MSS_LEN) / 4) << 4; - goto tcp_send; - - /* This label will be jumped to if we found an active connection. */ - found: - uip_conn = uip_connr; - uip_flags = 0; - /* We do a very naive form of TCP reset processing; we just accept - any RST and kill our connection. We should in fact check if the - sequence number of this reset is wihtin our advertised window - before we accept the reset. */ - if(BUF->flags & TCP_RST) { - uip_connr->tcpstateflags = UIP_CLOSED; - UIP_LOG("tcp: got reset, aborting connection."); - uip_flags = UIP_ABORT; - UIP_APPCALL(); - goto drop; - } - /* Calculate the length of the data, if the application has sent - any data to us. */ - c = (BUF->tcpoffset >> 4) << 2; - /* uip_len will contain the length of the actual TCP data. This is - calculated by subtracing the length of the TCP header (in - c) and the length of the IP header (20 bytes). */ - uip_len = uip_len - c - UIP_IPH_LEN; - - /* First, check if the sequence number of the incoming packet is - what we're expecting next. If not, we send out an ACK with the - correct numbers in. */ - if(!(((uip_connr->tcpstateflags & UIP_TS_MASK) == UIP_SYN_SENT) && - ((BUF->flags & TCP_CTL) == (TCP_SYN | TCP_ACK)))) { - if((uip_len > 0 || ((BUF->flags & (TCP_SYN | TCP_FIN)) != 0)) && - (BUF->seqno[0] != uip_connr->rcv_nxt[0] || - BUF->seqno[1] != uip_connr->rcv_nxt[1] || - BUF->seqno[2] != uip_connr->rcv_nxt[2] || - BUF->seqno[3] != uip_connr->rcv_nxt[3])) { - goto tcp_send_ack; - } - } - - /* Next, check if the incoming segment acknowledges any outstanding - data. If so, we update the sequence number, reset the length of - the outstanding data, calculate RTT estimations, and reset the - retransmission timer. */ - if((BUF->flags & TCP_ACK) && uip_outstanding(uip_connr)) { - uip_add32(uip_connr->snd_nxt, uip_connr->len); - - if(BUF->ackno[0] == uip_acc32[0] && - BUF->ackno[1] == uip_acc32[1] && - BUF->ackno[2] == uip_acc32[2] && - BUF->ackno[3] == uip_acc32[3]) { - /* Update sequence number. */ - uip_connr->snd_nxt[0] = uip_acc32[0]; - uip_connr->snd_nxt[1] = uip_acc32[1]; - uip_connr->snd_nxt[2] = uip_acc32[2]; - uip_connr->snd_nxt[3] = uip_acc32[3]; - - /* Do RTT estimation, unless we have done retransmissions. */ - if(uip_connr->nrtx == 0) { - signed char m; - m = uip_connr->rto - uip_connr->timer; - /* This is taken directly from VJs original code in his paper */ - m = m - (uip_connr->sa >> 3); - uip_connr->sa += m; - if(m < 0) { - m = -m; - } - m = m - (uip_connr->sv >> 2); - uip_connr->sv += m; - uip_connr->rto = (uip_connr->sa >> 3) + uip_connr->sv; - - } - /* Set the acknowledged flag. */ - uip_flags = UIP_ACKDATA; - /* Reset the retransmission timer. */ - uip_connr->timer = uip_connr->rto; - - /* Reset length of outstanding data. */ - uip_connr->len = 0; - } - - } - - /* Do different things depending on in what state the connection is. */ - switch(uip_connr->tcpstateflags & UIP_TS_MASK) { - /* CLOSED and LISTEN are not handled here. CLOSE_WAIT is not - implemented, since we force the application to close when the - peer sends a FIN (hence the application goes directly from - ESTABLISHED to LAST_ACK). */ - case UIP_SYN_RCVD: - /* In SYN_RCVD we have sent out a SYNACK in response to a SYN, and - we are waiting for an ACK that acknowledges the data we sent - out the last time. Therefore, we want to have the UIP_ACKDATA - flag set. If so, we enter the ESTABLISHED state. */ - if(uip_flags & UIP_ACKDATA) { - uip_connr->tcpstateflags = UIP_ESTABLISHED; - uip_flags = UIP_CONNECTED; - uip_connr->len = 0; - if(uip_len > 0) { - uip_flags |= UIP_NEWDATA; - uip_add_rcv_nxt(uip_len); - } - uip_slen = 0; - UIP_APPCALL(); - goto appsend; - } - goto drop; -#if UIP_ACTIVE_OPEN - case UIP_SYN_SENT: - /* In SYN_SENT, we wait for a SYNACK that is sent in response to - our SYN. The rcv_nxt is set to sequence number in the SYNACK - plus one, and we send an ACK. We move into the ESTABLISHED - state. */ - if((uip_flags & UIP_ACKDATA) && - (BUF->flags & TCP_CTL) == (TCP_SYN | TCP_ACK)) { - - /* Parse the TCP MSS option, if present. */ - if((BUF->tcpoffset & 0xf0) > 0x50) { - for(c = 0; c < ((BUF->tcpoffset >> 4) - 5) << 2 ;) { - opt = uip_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN + c]; - if(opt == TCP_OPT_END) { - /* End of options. */ - break; - } else if(opt == TCP_OPT_NOOP) { - ++c; - /* NOP option. */ - } else if(opt == TCP_OPT_MSS && - uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c] == TCP_OPT_MSS_LEN) { - /* An MSS option with the right option length. */ - tmp16 = (uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 2 + c] << 8) | - uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 3 + c]; - uip_connr->initialmss = - uip_connr->mss = tmp16 > UIP_TCP_MSS? UIP_TCP_MSS: tmp16; - - /* And we are done processing options. */ - break; - } else { - /* All other options have a length field, so that we easily - can skip past them. */ - if(uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c] == 0) { - /* If the length field is zero, the options are malformed - and we don't process them further. */ - break; - } - c += uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c]; - } - } - } - uip_connr->tcpstateflags = UIP_ESTABLISHED; - uip_connr->rcv_nxt[0] = BUF->seqno[0]; - uip_connr->rcv_nxt[1] = BUF->seqno[1]; - uip_connr->rcv_nxt[2] = BUF->seqno[2]; - uip_connr->rcv_nxt[3] = BUF->seqno[3]; - uip_add_rcv_nxt(1); - uip_flags = UIP_CONNECTED | UIP_NEWDATA; - uip_connr->len = 0; - uip_len = 0; - uip_slen = 0; - UIP_APPCALL(); - goto appsend; - } - /* Inform the application that the connection failed */ - uip_flags = UIP_ABORT; - UIP_APPCALL(); - /* The connection is closed after we send the RST */ - uip_conn->tcpstateflags = UIP_CLOSED; - goto reset; -#endif /* UIP_ACTIVE_OPEN */ - - case UIP_ESTABLISHED: - /* In the ESTABLISHED state, we call upon the application to feed - data into the uip_buf. If the UIP_ACKDATA flag is set, the - application should put new data into the buffer, otherwise we are - retransmitting an old segment, and the application should put that - data into the buffer. - - If the incoming packet is a FIN, we should close the connection on - this side as well, and we send out a FIN and enter the LAST_ACK - state. We require that there is no outstanding data; otherwise the - sequence numbers will be screwed up. */ - - if(BUF->flags & TCP_FIN && !(uip_connr->tcpstateflags & UIP_STOPPED)) { - if(uip_outstanding(uip_connr)) { - goto drop; - } - uip_add_rcv_nxt(1 + uip_len); - uip_flags |= UIP_CLOSE; - if(uip_len > 0) { - uip_flags |= UIP_NEWDATA; - } - UIP_APPCALL(); - uip_connr->len = 1; - uip_connr->tcpstateflags = UIP_LAST_ACK; - uip_connr->nrtx = 0; - tcp_send_finack: - BUF->flags = TCP_FIN | TCP_ACK; - goto tcp_send_nodata; - } - - /* Check the URG flag. If this is set, the segment carries urgent - data that we must pass to the application. */ - if((BUF->flags & TCP_URG) != 0) { -#if UIP_URGDATA > 0 - uip_urglen = (BUF->urgp[0] << 8) | BUF->urgp[1]; - if(uip_urglen > uip_len) { - /* There is more urgent data in the next segment to come. */ - uip_urglen = uip_len; - } - uip_add_rcv_nxt(uip_urglen); - uip_len -= uip_urglen; - uip_urgdata = uip_appdata; - uip_appdata += uip_urglen; - } else { - uip_urglen = 0; -#else /* UIP_URGDATA > 0 */ - uip_appdata = ((char *)uip_appdata) + ((BUF->urgp[0] << 8) | BUF->urgp[1]); - uip_len -= (BUF->urgp[0] << 8) | BUF->urgp[1]; -#endif /* UIP_URGDATA > 0 */ - } - - /* If uip_len > 0 we have TCP data in the packet, and we flag this - by setting the UIP_NEWDATA flag and update the sequence number - we acknowledge. If the application has stopped the dataflow - using uip_stop(), we must not accept any data packets from the - remote host. */ - if(uip_len > 0 && !(uip_connr->tcpstateflags & UIP_STOPPED)) { - uip_flags |= UIP_NEWDATA; - uip_add_rcv_nxt(uip_len); - } - - /* Check if the available buffer space advertised by the other end - is smaller than the initial MSS for this connection. If so, we - set the current MSS to the window size to ensure that the - application does not send more data than the other end can - handle. - - If the remote host advertises a zero window, we set the MSS to - the initial MSS so that the application will send an entire MSS - of data. This data will not be acknowledged by the receiver, - and the application will retransmit it. This is called the - "persistent timer" and uses the retransmission mechanim. - */ - tmp16 = ((u16_t)BUF->wnd[0] << 8) + (u16_t)BUF->wnd[1]; - if(tmp16 > uip_connr->initialmss || - tmp16 == 0) { - tmp16 = uip_connr->initialmss; - } - uip_connr->mss = tmp16; - - /* If this packet constitutes an ACK for outstanding data (flagged - by the UIP_ACKDATA flag, we should call the application since it - might want to send more data. If the incoming packet had data - from the peer (as flagged by the UIP_NEWDATA flag), the - application must also be notified. - - When the application is called, the global variable uip_len - contains the length of the incoming data. The application can - access the incoming data through the global pointer - uip_appdata, which usually points UIP_IPTCPH_LEN + UIP_LLH_LEN - bytes into the uip_buf array. - - If the application wishes to send any data, this data should be - put into the uip_appdata and the length of the data should be - put into uip_len. If the application don't have any data to - send, uip_len must be set to 0. */ - if(uip_flags & (UIP_NEWDATA | UIP_ACKDATA)) { - uip_slen = 0; - UIP_APPCALL(); - - appsend: - - if(uip_flags & UIP_ABORT) { - uip_slen = 0; - uip_connr->tcpstateflags = UIP_CLOSED; - BUF->flags = TCP_RST | TCP_ACK; - goto tcp_send_nodata; - } - - if(uip_flags & UIP_CLOSE) { - uip_slen = 0; - uip_connr->len = 1; - uip_connr->tcpstateflags = UIP_FIN_WAIT_1; - uip_connr->nrtx = 0; - BUF->flags = TCP_FIN | TCP_ACK; - goto tcp_send_nodata; - } - - /* If uip_slen > 0, the application has data to be sent. */ - if(uip_slen > 0) { - - /* If the connection has acknowledged data, the contents of - the ->len variable should be discarded. */ - if((uip_flags & UIP_ACKDATA) != 0) { - uip_connr->len = 0; - } - - /* If the ->len variable is non-zero the connection has - already data in transit and cannot send anymore right - now. */ - if(uip_connr->len == 0) { - - /* The application cannot send more than what is allowed by - the mss (the minumum of the MSS and the available - window). */ - if(uip_slen > uip_connr->mss) { - uip_slen = uip_connr->mss; - } - - /* Remember how much data we send out now so that we know - when everything has been acknowledged. */ - uip_connr->len = uip_slen; - } else { - - /* If the application already had unacknowledged data, we - make sure that the application does not send (i.e., - retransmit) out more than it previously sent out. */ - uip_slen = uip_connr->len; - } - } - uip_connr->nrtx = 0; - apprexmit: - uip_appdata = uip_sappdata; - - /* If the application has data to be sent, or if the incoming - packet had new data in it, we must send out a packet. */ - if(uip_slen > 0 && uip_connr->len > 0) { - /* Add the length of the IP and TCP headers. */ - uip_len = uip_connr->len + UIP_TCPIP_HLEN; - /* We always set the ACK flag in response packets. */ - BUF->flags = TCP_ACK | TCP_PSH; - /* Send the packet. */ - goto tcp_send_noopts; - } - /* If there is no data to send, just send out a pure ACK if - there is newdata. */ - if(uip_flags & UIP_NEWDATA) { - uip_len = UIP_TCPIP_HLEN; - BUF->flags = TCP_ACK; - goto tcp_send_noopts; - } - } - goto drop; - case UIP_LAST_ACK: - /* We can close this connection if the peer has acknowledged our - FIN. This is indicated by the UIP_ACKDATA flag. */ - if(uip_flags & UIP_ACKDATA) { - uip_connr->tcpstateflags = UIP_CLOSED; - uip_flags = UIP_CLOSE; - UIP_APPCALL(); - } - break; - - case UIP_FIN_WAIT_1: - /* The application has closed the connection, but the remote host - hasn't closed its end yet. Thus we do nothing but wait for a - FIN from the other side. */ - if(uip_len > 0) { - uip_add_rcv_nxt(uip_len); - } - if(BUF->flags & TCP_FIN) { - if(uip_flags & UIP_ACKDATA) { - uip_connr->tcpstateflags = UIP_TIME_WAIT; - uip_connr->timer = 0; - uip_connr->len = 0; - } else { - uip_connr->tcpstateflags = UIP_CLOSING; - } - uip_add_rcv_nxt(1); - uip_flags = UIP_CLOSE; - UIP_APPCALL(); - goto tcp_send_ack; - } else if(uip_flags & UIP_ACKDATA) { - uip_connr->tcpstateflags = UIP_FIN_WAIT_2; - uip_connr->len = 0; - goto drop; - } - if(uip_len > 0) { - goto tcp_send_ack; - } - goto drop; - - case UIP_FIN_WAIT_2: - if(uip_len > 0) { - uip_add_rcv_nxt(uip_len); - } - if(BUF->flags & TCP_FIN) { - uip_connr->tcpstateflags = UIP_TIME_WAIT; - uip_connr->timer = 0; - uip_add_rcv_nxt(1); - uip_flags = UIP_CLOSE; - UIP_APPCALL(); - goto tcp_send_ack; - } - if(uip_len > 0) { - goto tcp_send_ack; - } - goto drop; - - case UIP_TIME_WAIT: - goto tcp_send_ack; - - case UIP_CLOSING: - if(uip_flags & UIP_ACKDATA) { - uip_connr->tcpstateflags = UIP_TIME_WAIT; - uip_connr->timer = 0; - } - } - goto drop; - - /* We jump here when we are ready to send the packet, and just want - to set the appropriate TCP sequence numbers in the TCP header. */ - tcp_send_ack: - BUF->flags = TCP_ACK; - - tcp_send_nodata: - uip_len = UIP_IPTCPH_LEN; - - tcp_send_noopts: - BUF->tcpoffset = (UIP_TCPH_LEN / 4) << 4; - - /* We're done with the input processing. We are now ready to send a - reply. Our job is to fill in all the fields of the TCP and IP - headers before calculating the checksum and finally send the - packet. */ - tcp_send: - BUF->ackno[0] = uip_connr->rcv_nxt[0]; - BUF->ackno[1] = uip_connr->rcv_nxt[1]; - BUF->ackno[2] = uip_connr->rcv_nxt[2]; - BUF->ackno[3] = uip_connr->rcv_nxt[3]; - - BUF->seqno[0] = uip_connr->snd_nxt[0]; - BUF->seqno[1] = uip_connr->snd_nxt[1]; - BUF->seqno[2] = uip_connr->snd_nxt[2]; - BUF->seqno[3] = uip_connr->snd_nxt[3]; - - BUF->proto = UIP_PROTO_TCP; - - BUF->srcport = uip_connr->lport; - BUF->destport = uip_connr->rport; - - uip_ipaddr_copy(&BUF->srcipaddr, &uip_hostaddr); - uip_ipaddr_copy(&BUF->destipaddr, &uip_connr->ripaddr); - - if(uip_connr->tcpstateflags & UIP_STOPPED) { - /* If the connection has issued uip_stop(), we advertise a zero - window so that the remote host will stop sending data. */ - BUF->wnd[0] = BUF->wnd[1] = 0; - } else { - BUF->wnd[0] = ((UIP_RECEIVE_WINDOW) >> 8); - BUF->wnd[1] = ((UIP_RECEIVE_WINDOW) & 0xff); - } - - tcp_send_noconn: - BUF->ttl = UIP_TTL; -#if UIP_CONF_IPV6 - /* For IPv6, the IP length field does not include the IPv6 IP header - length. */ - BUF->len[0] = ((uip_len - UIP_IPH_LEN) >> 8); - BUF->len[1] = ((uip_len - UIP_IPH_LEN) & 0xff); -#else /* UIP_CONF_IPV6 */ - BUF->len[0] = (uip_len >> 8); - BUF->len[1] = (uip_len & 0xff); -#endif /* UIP_CONF_IPV6 */ - - BUF->urgp[0] = BUF->urgp[1] = 0; - - /* Calculate TCP checksum. */ - BUF->tcpchksum = 0; - BUF->tcpchksum = ~(uip_tcpchksum()); - - ip_send_nolen: -#if UIP_CONF_IPV6 - BUF->vtc = 0x60; - BUF->tcflow = 0x00; - BUF->flow = 0x00; -#else /* UIP_CONF_IPV6 */ - BUF->vhl = 0x45; - BUF->tos = 0; - BUF->ipoffset[0] = BUF->ipoffset[1] = 0; - ++ipid; - BUF->ipid[0] = ipid >> 8; - BUF->ipid[1] = ipid & 0xff; - /* Calculate IP checksum. */ - BUF->ipchksum = 0; - BUF->ipchksum = ~(uip_ipchksum()); - DEBUG_PRINTF("uip ip_send_nolen: chkecum 0x%04x\n", uip_ipchksum()); -#endif /* UIP_CONF_IPV6 */ - UIP_STAT(++uip_stat.tcp.sent); -#if UIP_CONF_IPV6 - send: -#endif /* UIP_CONF_IPV6 */ - DEBUG_PRINTF("Sending packet with length %d (%d)\n", uip_len, - (BUF->len[0] << 8) | BUF->len[1]); - - UIP_STAT(++uip_stat.ip.sent); - /* Return and let the caller do the actual transmission. */ - uip_flags = 0; - return; - - drop: - uip_len = 0; - uip_flags = 0; - return; -} -/*---------------------------------------------------------------------------*/ -u16_t -htons(u16_t val) -{ - return HTONS(val); -} - -u32_t -htonl(u32_t val) -{ - return HTONL(val); -} -/*---------------------------------------------------------------------------*/ -void -uip_send(const void *data, int len) -{ - int copylen; -#define MIN(a,b) ((a) < (b)? (a): (b)) - copylen = MIN(len, UIP_BUFSIZE - UIP_LLH_LEN - UIP_TCPIP_HLEN - - (int)((char *)uip_sappdata - (char *)&uip_buf[UIP_LLH_LEN + UIP_TCPIP_HLEN])); - if(copylen > 0) { - uip_slen = copylen; - if(data != uip_sappdata) { - memcpy(uip_sappdata, (data), uip_slen); - } - } -} -/*---------------------------------------------------------------------------*/ -/** @} */ -#endif /* UIP_CONF_IPV6 */ +#define DEBUG_PRINTF(...) /*printf(__VA_ARGS__)*/
+
+/**
+ * \addtogroup uip
+ * @{
+ */
+
+/**
+ * \file
+ * The uIP TCP/IP stack code.
+ * \author Adam Dunkels <adam@dunkels.com>
+ */
+
+/*
+ * Copyright (c) 2001-2003, Adam Dunkels.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote
+ * products derived from this software without specific prior
+ * written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
+ * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
+ * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * This file is part of the uIP TCP/IP stack.
+ *
+ * $Id: uip.c,v 1.15 2008/10/15 08:08:32 adamdunkels Exp $
+ *
+ */
+
+/*
+ * uIP is a small implementation of the IP, UDP and TCP protocols (as
+ * well as some basic ICMP stuff). The implementation couples the IP,
+ * UDP, TCP and the application layers very tightly. To keep the size
+ * of the compiled code down, this code frequently uses the goto
+ * statement. While it would be possible to break the uip_process()
+ * function into many smaller functions, this would increase the code
+ * size because of the overhead of parameter passing and the fact that
+ * the optimier would not be as efficient.
+ *
+ * The principle is that we have a small buffer, called the uip_buf,
+ * in which the device driver puts an incoming packet. The TCP/IP
+ * stack parses the headers in the packet, and calls the
+ * application. If the remote host has sent data to the application,
+ * this data is present in the uip_buf and the application read the
+ * data from there. It is up to the application to put this data into
+ * a byte stream if needed. The application will not be fed with data
+ * that is out of sequence.
+ *
+ * If the application whishes to send data to the peer, it should put
+ * its data into the uip_buf. The uip_appdata pointer points to the
+ * first available byte. The TCP/IP stack will calculate the
+ * checksums, and fill in the necessary header fields and finally send
+ * the packet back to the peer.
+*/
+
+#include "uip.h"
+#include "uipopt.h"
+#include "uip_arp.h"
+
+#if !UIP_CONF_IPV6 /* If UIP_CONF_IPV6 is defined, we compile the
+ uip6.c file instead of this one. Therefore
+ this #ifndef removes the entire compilation
+ output of the uip.c file */
+
+
+#if UIP_CONF_IPV6
+#include "net/uip-neighbor.h"
+#endif /* UIP_CONF_IPV6 */
+
+#include <string.h>
+
+/*---------------------------------------------------------------------------*/
+/* Variable definitions. */
+
+
+/* The IP address of this host. If it is defined to be fixed (by
+ setting UIP_FIXEDADDR to 1 in uipopt.h), the address is set
+ here. Otherwise, the address */
+#if UIP_FIXEDADDR > 0
+const uip_ipaddr_t uip_hostaddr =
+ { UIP_IPADDR0, UIP_IPADDR1, UIP_IPADDR2, UIP_IPADDR3 };
+const uip_ipaddr_t uip_draddr =
+ { UIP_DRIPADDR0, UIP_DRIPADDR1, UIP_DRIPADDR2, UIP_DRIPADDR3 };
+const uip_ipaddr_t uip_netmask =
+ { UIP_NETMASK0, UIP_NETMASK1, UIP_NETMASK2, UIP_NETMASK3 };
+#else
+uip_ipaddr_t uip_hostaddr, uip_draddr, uip_netmask;
+#endif /* UIP_FIXEDADDR */
+
+const uip_ipaddr_t uip_broadcast_addr =
+#if UIP_CONF_IPV6
+ { { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff } };
+#else /* UIP_CONF_IPV6 */
+ { { 0xff, 0xff, 0xff, 0xff } };
+#endif /* UIP_CONF_IPV6 */
+const uip_ipaddr_t uip_all_zeroes_addr = { { 0x0, /* rest is 0 */ } };
+
+#if UIP_FIXEDETHADDR
+const struct uip_eth_addr uip_ethaddr = {{UIP_ETHADDR0,
+ UIP_ETHADDR1,
+ UIP_ETHADDR2,
+ UIP_ETHADDR3,
+ UIP_ETHADDR4,
+ UIP_ETHADDR5}};
+#else
+struct uip_eth_addr uip_ethaddr = {{0,0,0,0,0,0}};
+#endif
+
+#ifndef UIP_CONF_EXTERNAL_BUFFER
+u8_t uip_buf[UIP_BUFSIZE + 2]; /* The packet buffer that contains
+ incoming packets. */
+#endif /* UIP_CONF_EXTERNAL_BUFFER */
+
+void *uip_appdata; /* The uip_appdata pointer points to
+ application data. */
+void *uip_sappdata; /* The uip_appdata pointer points to
+ the application data which is to
+ be sent. */
+#if UIP_URGDATA > 0
+void *uip_urgdata; /* The uip_urgdata pointer points to
+ urgent data (out-of-band data), if
+ present. */
+u16_t uip_urglen, uip_surglen;
+#endif /* UIP_URGDATA > 0 */
+
+u16_t uip_len, uip_slen;
+ /* The uip_len is either 8 or 16 bits,
+ depending on the maximum packet
+ size. */
+
+u8_t uip_flags; /* The uip_flags variable is used for
+ communication between the TCP/IP stack
+ and the application program. */
+struct uip_conn *uip_conn; /* uip_conn always points to the current
+ connection. */
+
+struct uip_conn uip_conns[UIP_CONNS];
+ /* The uip_conns array holds all TCP
+ connections. */
+u16_t uip_listenports[UIP_LISTENPORTS];
+ /* The uip_listenports list all currently
+ listning ports. */
+#if UIP_UDP
+struct uip_udp_conn *uip_udp_conn;
+struct uip_udp_conn uip_udp_conns[UIP_UDP_CONNS];
+#endif /* UIP_UDP */
+
+static u16_t ipid; /* Ths ipid variable is an increasing
+ number that is used for the IP ID
+ field. */
+
+void uip_setipid(u16_t id) { ipid = id; }
+
+static u8_t iss[4]; /* The iss variable is used for the TCP
+ initial sequence number. */
+
+#if UIP_ACTIVE_OPEN
+static u16_t lastport; /* Keeps track of the last port used for
+ a new connection. */
+#endif /* UIP_ACTIVE_OPEN */
+
+/* Temporary variables. */
+u8_t uip_acc32[4];
+static u8_t c, opt;
+static u16_t tmp16;
+
+/* Structures and definitions. */
+#define TCP_FIN 0x01
+#define TCP_SYN 0x02
+#define TCP_RST 0x04
+#define TCP_PSH 0x08
+#define TCP_ACK 0x10
+#define TCP_URG 0x20
+#define TCP_CTL 0x3f
+
+#define TCP_OPT_END 0 /* End of TCP options list */
+#define TCP_OPT_NOOP 1 /* "No-operation" TCP option */
+#define TCP_OPT_MSS 2 /* Maximum segment size TCP option */
+
+#define TCP_OPT_MSS_LEN 4 /* Length of TCP MSS option. */
+
+#define ICMP_ECHO_REPLY 0
+#define ICMP_ECHO 8
+
+#define ICMP_DEST_UNREACHABLE 3
+#define ICMP_PORT_UNREACHABLE 3
+
+#define ICMP6_ECHO_REPLY 129
+#define ICMP6_ECHO 128
+#define ICMP6_NEIGHBOR_SOLICITATION 135
+#define ICMP6_NEIGHBOR_ADVERTISEMENT 136
+
+#define ICMP6_FLAG_S (1 << 6)
+
+#define ICMP6_OPTION_SOURCE_LINK_ADDRESS 1
+#define ICMP6_OPTION_TARGET_LINK_ADDRESS 2
+
+
+/* Macros. */
+#define BUF ((struct uip_tcpip_hdr *)&uip_buf[UIP_LLH_LEN])
+#define FBUF ((struct uip_tcpip_hdr *)&uip_reassbuf[0])
+#define ICMPBUF ((struct uip_icmpip_hdr *)&uip_buf[UIP_LLH_LEN])
+#define UDPBUF ((struct uip_udpip_hdr *)&uip_buf[UIP_LLH_LEN])
+
+
+#if UIP_STATISTICS == 1
+struct uip_stats uip_stat;
+#define UIP_STAT(s) s
+#else
+#define UIP_STAT(s)
+#endif /* UIP_STATISTICS == 1 */
+
+#if UIP_LOGGING == 1
+#include <stdio.h>
+void uip_log(char *msg);
+#define UIP_LOG(m) uip_log(m)
+#else
+#define UIP_LOG(m)
+#endif /* UIP_LOGGING == 1 */
+
+#if ! UIP_ARCH_ADD32
+void
+uip_add32(u8_t *op32, u16_t op16)
+{
+ uip_acc32[3] = op32[3] + (op16 & 0xff);
+ uip_acc32[2] = op32[2] + (op16 >> 8);
+ uip_acc32[1] = op32[1];
+ uip_acc32[0] = op32[0];
+
+ if(uip_acc32[2] < (op16 >> 8)) {
+ ++uip_acc32[1];
+ if(uip_acc32[1] == 0) {
+ ++uip_acc32[0];
+ }
+ }
+
+
+ if(uip_acc32[3] < (op16 & 0xff)) {
+ ++uip_acc32[2];
+ if(uip_acc32[2] == 0) {
+ ++uip_acc32[1];
+ if(uip_acc32[1] == 0) {
+ ++uip_acc32[0];
+ }
+ }
+ }
+}
+
+#endif /* UIP_ARCH_ADD32 */
+
+#if ! UIP_ARCH_CHKSUM
+/*---------------------------------------------------------------------------*/
+static u16_t
+chksum(u16_t sum, const u8_t *data, u16_t len)
+{
+ u16_t t;
+ const u8_t *dataptr;
+ const u8_t *last_byte;
+
+ dataptr = data;
+ last_byte = data + len - 1;
+
+ while(dataptr < last_byte) { /* At least two more bytes */
+ t = (dataptr[0] << 8) + dataptr[1];
+ sum += t;
+ if(sum < t) {
+ sum++; /* carry */
+ }
+ dataptr += 2;
+ }
+
+ if(dataptr == last_byte) {
+ t = (dataptr[0] << 8) + 0;
+ sum += t;
+ if(sum < t) {
+ sum++; /* carry */
+ }
+ }
+
+ /* Return sum in host byte order. */
+ return sum;
+}
+/*---------------------------------------------------------------------------*/
+u16_t
+uip_chksum(u16_t *data, u16_t len)
+{
+ return htons(chksum(0, (u8_t *)data, len));
+}
+/*---------------------------------------------------------------------------*/
+#ifndef UIP_ARCH_IPCHKSUM
+u16_t
+uip_ipchksum(void)
+{
+ u16_t sum;
+
+ sum = chksum(0, &uip_buf[UIP_LLH_LEN], UIP_IPH_LEN);
+ DEBUG_PRINTF("uip_ipchksum: sum 0x%04x\n", sum);
+ return (sum == 0) ? 0xffff : htons(sum);
+}
+#endif
+/*---------------------------------------------------------------------------*/
+static u16_t
+upper_layer_chksum(u8_t proto)
+{
+ u16_t upper_layer_len;
+ u16_t sum;
+
+#if UIP_CONF_IPV6
+ upper_layer_len = (((u16_t)(BUF->len[0]) << 8) + BUF->len[1]);
+#else /* UIP_CONF_IPV6 */
+ upper_layer_len = (((u16_t)(BUF->len[0]) << 8) + BUF->len[1]) - UIP_IPH_LEN;
+#endif /* UIP_CONF_IPV6 */
+
+ /* First sum pseudoheader. */
+
+ /* IP protocol and length fields. This addition cannot carry. */
+ sum = upper_layer_len + proto;
+ /* Sum IP source and destination addresses. */
+ sum = chksum(sum, (u8_t *)&BUF->srcipaddr, 2 * sizeof(uip_ipaddr_t));
+
+ /* Sum TCP header and data. */
+ sum = chksum(sum, &uip_buf[UIP_IPH_LEN + UIP_LLH_LEN],
+ upper_layer_len);
+
+ return (sum == 0) ? 0xffff : htons(sum);
+}
+/*---------------------------------------------------------------------------*/
+#if UIP_CONF_IPV6
+u16_t
+uip_icmp6chksum(void)
+{
+ return upper_layer_chksum(UIP_PROTO_ICMP6);
+
+}
+#endif /* UIP_CONF_IPV6 */
+/*---------------------------------------------------------------------------*/
+u16_t
+uip_tcpchksum(void)
+{
+ return upper_layer_chksum(UIP_PROTO_TCP);
+}
+/*---------------------------------------------------------------------------*/
+#if UIP_UDP_CHECKSUMS
+u16_t
+uip_udpchksum(void)
+{
+ return upper_layer_chksum(UIP_PROTO_UDP);
+}
+#endif /* UIP_UDP_CHECKSUMS */
+#endif /* UIP_ARCH_CHKSUM */
+/*---------------------------------------------------------------------------*/
+void
+uip_init(void)
+{
+ for(c = 0; c < UIP_LISTENPORTS; ++c) {
+ uip_listenports[c] = 0;
+ }
+ for(c = 0; c < UIP_CONNS; ++c) {
+ uip_conns[c].tcpstateflags = UIP_CLOSED;
+ }
+#if UIP_ACTIVE_OPEN
+ lastport = 1024;
+#endif /* UIP_ACTIVE_OPEN */
+
+#if UIP_UDP
+ for(c = 0; c < UIP_UDP_CONNS; ++c) {
+ uip_udp_conns[c].lport = 0;
+ }
+#endif /* UIP_UDP */
+
+
+ /* IPv4 initialization. */
+#if UIP_FIXEDADDR == 0
+ /* uip_hostaddr[0] = uip_hostaddr[1] = 0;*/
+#endif /* UIP_FIXEDADDR */
+
+}
+/*---------------------------------------------------------------------------*/
+#if UIP_ACTIVE_OPEN
+struct uip_conn *
+uip_connect(uip_ipaddr_t *ripaddr, u16_t rport)
+{
+ register struct uip_conn *conn, *cconn;
+
+ /* Find an unused local port. */
+ again:
+ ++lastport;
+
+ if(lastport >= 32000) {
+ lastport = 4096;
+ }
+
+ /* Check if this port is already in use, and if so try to find
+ another one. */
+ for(c = 0; c < UIP_CONNS; ++c) {
+ conn = &uip_conns[c];
+ if(conn->tcpstateflags != UIP_CLOSED &&
+ conn->lport == htons(lastport)) {
+ goto again;
+ }
+ }
+
+ conn = 0;
+ for(c = 0; c < UIP_CONNS; ++c) {
+ cconn = &uip_conns[c];
+ if(cconn->tcpstateflags == UIP_CLOSED) {
+ conn = cconn;
+ break;
+ }
+ if(cconn->tcpstateflags == UIP_TIME_WAIT) {
+ if(conn == 0 ||
+ cconn->timer > conn->timer) {
+ conn = cconn;
+ }
+ }
+ }
+
+ if(conn == 0) {
+ return 0;
+ }
+
+ conn->tcpstateflags = UIP_SYN_SENT;
+
+ conn->snd_nxt[0] = iss[0];
+ conn->snd_nxt[1] = iss[1];
+ conn->snd_nxt[2] = iss[2];
+ conn->snd_nxt[3] = iss[3];
+
+ conn->initialmss = conn->mss = UIP_TCP_MSS;
+
+ conn->len = 1; /* TCP length of the SYN is one. */
+ conn->nrtx = 0;
+ conn->timer = 1; /* Send the SYN next time around. */
+ conn->rto = UIP_RTO;
+ conn->sa = 0;
+ conn->sv = 16; /* Initial value of the RTT variance. */
+ conn->lport = htons(lastport);
+ conn->rport = rport;
+ uip_ipaddr_copy(&conn->ripaddr, ripaddr);
+
+ return conn;
+}
+#endif /* UIP_ACTIVE_OPEN */
+/*---------------------------------------------------------------------------*/
+#if UIP_UDP
+struct uip_udp_conn *
+uip_udp_new(const uip_ipaddr_t *ripaddr, u16_t rport)
+{
+ register struct uip_udp_conn *conn;
+
+ /* Find an unused local port. */
+ again:
+ ++lastport;
+
+ if(lastport >= 32000) {
+ lastport = 4096;
+ }
+
+ for(c = 0; c < UIP_UDP_CONNS; ++c) {
+ if(uip_udp_conns[c].lport == htons(lastport)) {
+ goto again;
+ }
+ }
+
+
+ conn = 0;
+ for(c = 0; c < UIP_UDP_CONNS; ++c) {
+ if(uip_udp_conns[c].lport == 0) {
+ conn = &uip_udp_conns[c];
+ break;
+ }
+ }
+
+ if(conn == 0) {
+ return 0;
+ }
+
+ conn->lport = HTONS(lastport);
+ conn->rport = rport;
+ if(ripaddr == NULL) {
+ memset(&conn->ripaddr, 0, sizeof(uip_ipaddr_t));
+ } else {
+ uip_ipaddr_copy(&conn->ripaddr, ripaddr);
+ }
+ conn->ttl = UIP_TTL;
+
+ return conn;
+}
+#endif /* UIP_UDP */
+/*---------------------------------------------------------------------------*/
+void
+uip_unlisten(u16_t port)
+{
+ for(c = 0; c < UIP_LISTENPORTS; ++c) {
+ if(uip_listenports[c] == port) {
+ uip_listenports[c] = 0;
+ return;
+ }
+ }
+}
+/*---------------------------------------------------------------------------*/
+void
+uip_listen(u16_t port)
+{
+ for(c = 0; c < UIP_LISTENPORTS; ++c) {
+ if(uip_listenports[c] == 0) {
+ uip_listenports[c] = port;
+ return;
+ }
+ }
+}
+/*---------------------------------------------------------------------------*/
+/* XXX: IP fragment reassembly: not well-tested. */
+
+#if UIP_REASSEMBLY && !UIP_CONF_IPV6
+#define UIP_REASS_BUFSIZE (UIP_BUFSIZE - UIP_LLH_LEN)
+static u8_t uip_reassbuf[UIP_REASS_BUFSIZE];
+static u8_t uip_reassbitmap[UIP_REASS_BUFSIZE / (8 * 8)];
+static const u8_t bitmap_bits[8] = {0xff, 0x7f, 0x3f, 0x1f,
+ 0x0f, 0x07, 0x03, 0x01};
+static u16_t uip_reasslen;
+static u8_t uip_reassflags;
+#define UIP_REASS_FLAG_LASTFRAG 0x01
+static u8_t uip_reasstmr;
+
+#define IP_MF 0x20
+
+static u8_t
+uip_reass(void)
+{
+ u16_t offset, len;
+ u16_t i;
+
+ /* If ip_reasstmr is zero, no packet is present in the buffer, so we
+ write the IP header of the fragment into the reassembly
+ buffer. The timer is updated with the maximum age. */
+ if(uip_reasstmr == 0) {
+ memcpy(uip_reassbuf, &BUF->vhl, UIP_IPH_LEN);
+ uip_reasstmr = UIP_REASS_MAXAGE;
+ uip_reassflags = 0;
+ /* Clear the bitmap. */
+ memset(uip_reassbitmap, 0, sizeof(uip_reassbitmap));
+ }
+
+ /* Check if the incoming fragment matches the one currently present
+ in the reasembly buffer. If so, we proceed with copying the
+ fragment into the buffer. */
+ if(BUF->srcipaddr[0] == FBUF->srcipaddr[0] &&
+ BUF->srcipaddr[1] == FBUF->srcipaddr[1] &&
+ BUF->destipaddr[0] == FBUF->destipaddr[0] &&
+ BUF->destipaddr[1] == FBUF->destipaddr[1] &&
+ BUF->ipid[0] == FBUF->ipid[0] &&
+ BUF->ipid[1] == FBUF->ipid[1]) {
+
+ len = (BUF->len[0] << 8) + BUF->len[1] - (BUF->vhl & 0x0f) * 4;
+ offset = (((BUF->ipoffset[0] & 0x3f) << 8) + BUF->ipoffset[1]) * 8;
+
+ /* If the offset or the offset + fragment length overflows the
+ reassembly buffer, we discard the entire packet. */
+ if(offset > UIP_REASS_BUFSIZE ||
+ offset + len > UIP_REASS_BUFSIZE) {
+ uip_reasstmr = 0;
+ goto nullreturn;
+ }
+
+ /* Copy the fragment into the reassembly buffer, at the right
+ offset. */
+ memcpy(&uip_reassbuf[UIP_IPH_LEN + offset],
+ (char *)BUF + (int)((BUF->vhl & 0x0f) * 4),
+ len);
+
+ /* Update the bitmap. */
+ if(offset / (8 * 8) == (offset + len) / (8 * 8)) {
+ /* If the two endpoints are in the same byte, we only update
+ that byte. */
+
+ uip_reassbitmap[offset / (8 * 8)] |=
+ bitmap_bits[(offset / 8 ) & 7] &
+ ~bitmap_bits[((offset + len) / 8 ) & 7];
+ } else {
+ /* If the two endpoints are in different bytes, we update the
+ bytes in the endpoints and fill the stuff inbetween with
+ 0xff. */
+ uip_reassbitmap[offset / (8 * 8)] |=
+ bitmap_bits[(offset / 8 ) & 7];
+ for(i = 1 + offset / (8 * 8); i < (offset + len) / (8 * 8); ++i) {
+ uip_reassbitmap[i] = 0xff;
+ }
+ uip_reassbitmap[(offset + len) / (8 * 8)] |=
+ ~bitmap_bits[((offset + len) / 8 ) & 7];
+ }
+
+ /* If this fragment has the More Fragments flag set to zero, we
+ know that this is the last fragment, so we can calculate the
+ size of the entire packet. We also set the
+ IP_REASS_FLAG_LASTFRAG flag to indicate that we have received
+ the final fragment. */
+
+ if((BUF->ipoffset[0] & IP_MF) == 0) {
+ uip_reassflags |= UIP_REASS_FLAG_LASTFRAG;
+ uip_reasslen = offset + len;
+ }
+
+ /* Finally, we check if we have a full packet in the buffer. We do
+ this by checking if we have the last fragment and if all bits
+ in the bitmap are set. */
+ if(uip_reassflags & UIP_REASS_FLAG_LASTFRAG) {
+ /* Check all bytes up to and including all but the last byte in
+ the bitmap. */
+ for(i = 0; i < uip_reasslen / (8 * 8) - 1; ++i) {
+ if(uip_reassbitmap[i] != 0xff) {
+ goto nullreturn;
+ }
+ }
+ /* Check the last byte in the bitmap. It should contain just the
+ right amount of bits. */
+ if(uip_reassbitmap[uip_reasslen / (8 * 8)] !=
+ (u8_t)~bitmap_bits[uip_reasslen / 8 & 7]) {
+ goto nullreturn;
+ }
+
+ /* If we have come this far, we have a full packet in the
+ buffer, so we allocate a pbuf and copy the packet into it. We
+ also reset the timer. */
+ uip_reasstmr = 0;
+ memcpy(BUF, FBUF, uip_reasslen);
+
+ /* Pretend to be a "normal" (i.e., not fragmented) IP packet
+ from now on. */
+ BUF->ipoffset[0] = BUF->ipoffset[1] = 0;
+ BUF->len[0] = uip_reasslen >> 8;
+ BUF->len[1] = uip_reasslen & 0xff;
+ BUF->ipchksum = 0;
+ BUF->ipchksum = ~(uip_ipchksum());
+
+ return uip_reasslen;
+ }
+ }
+
+ nullreturn:
+ return 0;
+}
+#endif /* UIP_REASSEMBLY */
+/*---------------------------------------------------------------------------*/
+static void
+uip_add_rcv_nxt(u16_t n)
+{
+ uip_add32(uip_conn->rcv_nxt, n);
+ uip_conn->rcv_nxt[0] = uip_acc32[0];
+ uip_conn->rcv_nxt[1] = uip_acc32[1];
+ uip_conn->rcv_nxt[2] = uip_acc32[2];
+ uip_conn->rcv_nxt[3] = uip_acc32[3];
+}
+/*---------------------------------------------------------------------------*/
+void
+uip_process(u8_t flag)
+{
+ register struct uip_conn *uip_connr = uip_conn;
+
+#if UIP_UDP
+ if(flag == UIP_UDP_SEND_CONN) {
+ goto udp_send;
+ }
+#endif /* UIP_UDP */
+
+ uip_sappdata = uip_appdata = &uip_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN];
+
+ /* Check if we were invoked because of a poll request for a
+ particular connection. */
+ if(flag == UIP_POLL_REQUEST) {
+ if((uip_connr->tcpstateflags & UIP_TS_MASK) == UIP_ESTABLISHED &&
+ !uip_outstanding(uip_connr)) {
+ uip_len = uip_slen = 0;
+ uip_flags = UIP_POLL;
+ UIP_APPCALL();
+ goto appsend;
+ }
+ goto drop;
+
+ /* Check if we were invoked because of the perodic timer fireing. */
+ } else if(flag == UIP_TIMER) {
+#if UIP_REASSEMBLY
+ if(uip_reasstmr != 0) {
+ --uip_reasstmr;
+ }
+#endif /* UIP_REASSEMBLY */
+ /* Increase the initial sequence number. */
+ if(++iss[3] == 0) {
+ if(++iss[2] == 0) {
+ if(++iss[1] == 0) {
+ ++iss[0];
+ }
+ }
+ }
+
+ /* Reset the length variables. */
+ uip_len = 0;
+ uip_slen = 0;
+
+ /* Check if the connection is in a state in which we simply wait
+ for the connection to time out. If so, we increase the
+ connection's timer and remove the connection if it times
+ out. */
+ if(uip_connr->tcpstateflags == UIP_TIME_WAIT ||
+ uip_connr->tcpstateflags == UIP_FIN_WAIT_2) {
+ ++(uip_connr->timer);
+ if(uip_connr->timer == UIP_TIME_WAIT_TIMEOUT) {
+ uip_connr->tcpstateflags = UIP_CLOSED;
+ }
+ } else if(uip_connr->tcpstateflags != UIP_CLOSED) {
+ /* If the connection has outstanding data, we increase the
+ connection's timer and see if it has reached the RTO value
+ in which case we retransmit. */
+ if(uip_outstanding(uip_connr)) {
+ if(uip_connr->timer-- == 0) {
+ if(uip_connr->nrtx == UIP_MAXRTX ||
+ ((uip_connr->tcpstateflags == UIP_SYN_SENT ||
+ uip_connr->tcpstateflags == UIP_SYN_RCVD) &&
+ uip_connr->nrtx == UIP_MAXSYNRTX)) {
+ uip_connr->tcpstateflags = UIP_CLOSED;
+
+ /* We call UIP_APPCALL() with uip_flags set to
+ UIP_TIMEDOUT to inform the application that the
+ connection has timed out. */
+ uip_flags = UIP_TIMEDOUT;
+ UIP_APPCALL();
+
+ /* We also send a reset packet to the remote host. */
+ BUF->flags = TCP_RST | TCP_ACK;
+ goto tcp_send_nodata;
+ }
+
+ /* Exponential backoff. */
+ uip_connr->timer = UIP_RTO << (uip_connr->nrtx > 4?
+ 4:
+ uip_connr->nrtx);
+ ++(uip_connr->nrtx);
+
+ /* Ok, so we need to retransmit. We do this differently
+ depending on which state we are in. In ESTABLISHED, we
+ call upon the application so that it may prepare the
+ data for the retransmit. In SYN_RCVD, we resend the
+ SYNACK that we sent earlier and in LAST_ACK we have to
+ retransmit our FINACK. */
+ UIP_STAT(++uip_stat.tcp.rexmit);
+ switch(uip_connr->tcpstateflags & UIP_TS_MASK) {
+ case UIP_SYN_RCVD:
+ /* In the SYN_RCVD state, we should retransmit our
+ SYNACK. */
+ goto tcp_send_synack;
+
+#if UIP_ACTIVE_OPEN
+ case UIP_SYN_SENT:
+ /* In the SYN_SENT state, we retransmit out SYN. */
+ BUF->flags = 0;
+ goto tcp_send_syn;
+#endif /* UIP_ACTIVE_OPEN */
+
+ case UIP_ESTABLISHED:
+ /* In the ESTABLISHED state, we call upon the application
+ to do the actual retransmit after which we jump into
+ the code for sending out the packet (the apprexmit
+ label). */
+ uip_flags = UIP_REXMIT;
+ UIP_APPCALL();
+ goto apprexmit;
+
+ case UIP_FIN_WAIT_1:
+ case UIP_CLOSING:
+ case UIP_LAST_ACK:
+ /* In all these states we should retransmit a FINACK. */
+ goto tcp_send_finack;
+
+ }
+ }
+ } else if((uip_connr->tcpstateflags & UIP_TS_MASK) == UIP_ESTABLISHED) {
+ /* If there was no need for a retransmission, we poll the
+ application for new data. */
+ uip_len = uip_slen = 0;
+ uip_flags = UIP_POLL;
+ UIP_APPCALL();
+ goto appsend;
+ }
+ }
+ goto drop;
+ }
+#if UIP_UDP
+ if(flag == UIP_UDP_TIMER) {
+ if(uip_udp_conn->lport != 0) {
+ uip_conn = NULL;
+ uip_sappdata = uip_appdata = &uip_buf[UIP_LLH_LEN + UIP_IPUDPH_LEN];
+ uip_len = uip_slen = 0;
+ uip_flags = UIP_POLL;
+ UIP_UDP_APPCALL();
+ goto udp_send;
+ } else {
+ goto drop;
+ }
+ }
+#endif
+
+ /* This is where the input processing starts. */
+ UIP_STAT(++uip_stat.ip.recv);
+
+ /* Start of IP input header processing code. */
+
+#if UIP_CONF_IPV6
+ /* Check validity of the IP header. */
+ if((BUF->vtc & 0xf0) != 0x60) { /* IP version and header length. */
+ UIP_STAT(++uip_stat.ip.drop);
+ UIP_STAT(++uip_stat.ip.vhlerr);
+ UIP_LOG("ipv6: invalid version.");
+ goto drop;
+ }
+#else /* UIP_CONF_IPV6 */
+ /* Check validity of the IP header. */
+ if(BUF->vhl != 0x45) { /* IP version and header length. */
+ UIP_STAT(++uip_stat.ip.drop);
+ UIP_STAT(++uip_stat.ip.vhlerr);
+ UIP_LOG("ip: invalid version or header length.");
+ goto drop;
+ }
+#endif /* UIP_CONF_IPV6 */
+
+ /* Check the size of the packet. If the size reported to us in
+ uip_len is smaller the size reported in the IP header, we assume
+ that the packet has been corrupted in transit. If the size of
+ uip_len is larger than the size reported in the IP packet header,
+ the packet has been padded and we set uip_len to the correct
+ value.. */
+
+ if((BUF->len[0] << 8) + BUF->len[1] <= uip_len) {
+ uip_len = (BUF->len[0] << 8) + BUF->len[1];
+#if UIP_CONF_IPV6
+ uip_len += 40; /* The length reported in the IPv6 header is the
+ length of the payload that follows the
+ header. However, uIP uses the uip_len variable
+ for holding the size of the entire packet,
+ including the IP header. For IPv4 this is not a
+ problem as the length field in the IPv4 header
+ contains the length of the entire packet. But
+ for IPv6 we need to add the size of the IPv6
+ header (40 bytes). */
+#endif /* UIP_CONF_IPV6 */
+ } else {
+ UIP_LOG("ip: packet shorter than reported in IP header.");
+ goto drop;
+ }
+
+#if !UIP_CONF_IPV6
+ /* Check the fragment flag. */
+ if((BUF->ipoffset[0] & 0x3f) != 0 ||
+ BUF->ipoffset[1] != 0) {
+#if UIP_REASSEMBLY
+ uip_len = uip_reass();
+ if(uip_len == 0) {
+ goto drop;
+ }
+#else /* UIP_REASSEMBLY */
+ UIP_STAT(++uip_stat.ip.drop);
+ UIP_STAT(++uip_stat.ip.fragerr);
+ UIP_LOG("ip: fragment dropped.");
+ goto drop;
+#endif /* UIP_REASSEMBLY */
+ }
+#endif /* UIP_CONF_IPV6 */
+
+ if(uip_ipaddr_cmp(&uip_hostaddr, &uip_all_zeroes_addr)) {
+ /* If we are configured to use ping IP address configuration and
+ hasn't been assigned an IP address yet, we accept all ICMP
+ packets. */
+#if UIP_PINGADDRCONF && !UIP_CONF_IPV6
+ if(BUF->proto == UIP_PROTO_ICMP) {
+ UIP_LOG("ip: possible ping config packet received.");
+ goto icmp_input;
+ } else {
+ UIP_LOG("ip: packet dropped since no address assigned.");
+ goto drop;
+ }
+#endif /* UIP_PINGADDRCONF */
+
+ } else {
+ /* If IP broadcast support is configured, we check for a broadcast
+ UDP packet, which may be destined to us. */
+#if UIP_BROADCAST
+ DEBUG_PRINTF("UDP IP checksum 0x%04x\n", uip_ipchksum());
+ if(BUF->proto == UIP_PROTO_UDP &&
+ uip_ipaddr_cmp(&BUF->destipaddr, &uip_broadcast_addr)
+ /*&&
+ uip_ipchksum() == 0xffff*/) {
+ goto udp_input;
+ }
+#endif /* UIP_BROADCAST */
+
+ /* Check if the packet is destined for our IP address. */
+#if !UIP_CONF_IPV6
+ if(!uip_ipaddr_cmp(&BUF->destipaddr, &uip_hostaddr)) {
+ UIP_STAT(++uip_stat.ip.drop);
+ goto drop;
+ }
+#else /* UIP_CONF_IPV6 */
+ /* For IPv6, packet reception is a little trickier as we need to
+ make sure that we listen to certain multicast addresses (all
+ hosts multicast address, and the solicited-node multicast
+ address) as well. However, we will cheat here and accept all
+ multicast packets that are sent to the ff02::/16 addresses. */
+ if(!uip_ipaddr_cmp(&BUF->destipaddr, &uip_hostaddr) &&
+ BUF->destipaddr.u16[0] != HTONS(0xff02)) {
+ UIP_STAT(++uip_stat.ip.drop);
+ goto drop;
+ }
+#endif /* UIP_CONF_IPV6 */
+ }
+
+#if !UIP_CONF_IPV6
+ if(uip_ipchksum() != 0xffff) { /* Compute and check the IP header
+ checksum. */
+ UIP_STAT(++uip_stat.ip.drop);
+ UIP_STAT(++uip_stat.ip.chkerr);
+ UIP_LOG("ip: bad checksum.");
+ goto drop;
+ }
+#endif /* UIP_CONF_IPV6 */
+
+ if(BUF->proto == UIP_PROTO_TCP) { /* Check for TCP packet. If so,
+ proceed with TCP input
+ processing. */
+ goto tcp_input;
+ }
+
+#if UIP_UDP
+ if(BUF->proto == UIP_PROTO_UDP) {
+ goto udp_input;
+ }
+#endif /* UIP_UDP */
+
+#if !UIP_CONF_IPV6
+ /* ICMPv4 processing code follows. */
+ if(BUF->proto != UIP_PROTO_ICMP) { /* We only allow ICMP packets from
+ here. */
+ UIP_STAT(++uip_stat.ip.drop);
+ UIP_STAT(++uip_stat.ip.protoerr);
+ UIP_LOG("ip: neither tcp nor icmp.");
+ goto drop;
+ }
+
+#if UIP_PINGADDRCONF
+ icmp_input:
+#endif /* UIP_PINGADDRCONF */
+ UIP_STAT(++uip_stat.icmp.recv);
+
+ /* ICMP echo (i.e., ping) processing. This is simple, we only change
+ the ICMP type from ECHO to ECHO_REPLY and adjust the ICMP
+ checksum before we return the packet. */
+ if(ICMPBUF->type != ICMP_ECHO) {
+ UIP_STAT(++uip_stat.icmp.drop);
+ UIP_STAT(++uip_stat.icmp.typeerr);
+ UIP_LOG("icmp: not icmp echo.");
+ goto drop;
+ }
+
+ /* If we are configured to use ping IP address assignment, we use
+ the destination IP address of this ping packet and assign it to
+ ourself. */
+#if UIP_PINGADDRCONF
+ if(uip_ipaddr_cmp(&uip_hostaddr, &uip_all_zeroes_addr)) {
+ uip_hostaddr = BUF->destipaddr;
+ }
+#endif /* UIP_PINGADDRCONF */
+
+ ICMPBUF->type = ICMP_ECHO_REPLY;
+
+ if(ICMPBUF->icmpchksum >= HTONS(0xffff - (ICMP_ECHO << 8))) {
+ ICMPBUF->icmpchksum += HTONS(ICMP_ECHO << 8) + 1;
+ } else {
+ ICMPBUF->icmpchksum += HTONS(ICMP_ECHO << 8);
+ }
+
+ /* Swap IP addresses. */
+ uip_ipaddr_copy(&BUF->destipaddr, &BUF->srcipaddr);
+ uip_ipaddr_copy(&BUF->srcipaddr, &uip_hostaddr);
+
+ UIP_STAT(++uip_stat.icmp.sent);
+ BUF->ttl = UIP_TTL;
+ goto ip_send_nolen;
+
+ /* End of IPv4 input header processing code. */
+#else /* !UIP_CONF_IPV6 */
+
+ /* This is IPv6 ICMPv6 processing code. */
+ DEBUG_PRINTF("icmp6_input: length %d\n", uip_len);
+
+ if(BUF->proto != UIP_PROTO_ICMP6) { /* We only allow ICMPv6 packets from
+ here. */
+ UIP_STAT(++uip_stat.ip.drop);
+ UIP_STAT(++uip_stat.ip.protoerr);
+ UIP_LOG("ip: neither tcp nor icmp6.");
+ goto drop;
+ }
+
+ UIP_STAT(++uip_stat.icmp.recv);
+
+ /* If we get a neighbor solicitation for our address we should send
+ a neighbor advertisement message back. */
+ if(ICMPBUF->type == ICMP6_NEIGHBOR_SOLICITATION) {
+ if(uip_ipaddr_cmp(&ICMPBUF->icmp6data, &uip_hostaddr)) {
+
+ if(ICMPBUF->options[0] == ICMP6_OPTION_SOURCE_LINK_ADDRESS) {
+ /* Save the sender's address in our neighbor list. */
+ uip_neighbor_add(&ICMPBUF->srcipaddr, &(ICMPBUF->options[2]));
+ }
+
+ /* We should now send a neighbor advertisement back to where the
+ neighbor solicication came from. */
+ ICMPBUF->type = ICMP6_NEIGHBOR_ADVERTISEMENT;
+ ICMPBUF->flags = ICMP6_FLAG_S; /* Solicited flag. */
+
+ ICMPBUF->reserved1 = ICMPBUF->reserved2 = ICMPBUF->reserved3 = 0;
+
+ uip_ipaddr_copy(&ICMPBUF->destipaddr, &ICMPBUF->srcipaddr);
+ uip_ipaddr_copy(&ICMPBUF->srcipaddr, &uip_hostaddr);
+ ICMPBUF->options[0] = ICMP6_OPTION_TARGET_LINK_ADDRESS;
+ ICMPBUF->options[1] = 1; /* Options length, 1 = 8 bytes. */
+ memcpy(&(ICMPBUF->options[2]), &uip_ethaddr, sizeof(uip_ethaddr));
+ ICMPBUF->icmpchksum = 0;
+ ICMPBUF->icmpchksum = ~uip_icmp6chksum();
+
+ goto send;
+
+ }
+ goto drop;
+ } else if(ICMPBUF->type == ICMP6_ECHO) {
+ /* ICMP echo (i.e., ping) processing. This is simple, we only
+ change the ICMP type from ECHO to ECHO_REPLY and update the
+ ICMP checksum before we return the packet. */
+
+ ICMPBUF->type = ICMP6_ECHO_REPLY;
+
+ uip_ipaddr_copy(&BUF->destipaddr, &BUF->srcipaddr);
+ uip_ipaddr_copy(&BUF->srcipaddr, &uip_hostaddr);
+ ICMPBUF->icmpchksum = 0;
+ ICMPBUF->icmpchksum = ~uip_icmp6chksum();
+
+ UIP_STAT(++uip_stat.icmp.sent);
+ goto send;
+ } else {
+ DEBUG_PRINTF("Unknown icmp6 message type %d\n", ICMPBUF->type);
+ UIP_STAT(++uip_stat.icmp.drop);
+ UIP_STAT(++uip_stat.icmp.typeerr);
+ UIP_LOG("icmp: unknown ICMP message.");
+ goto drop;
+ }
+
+ /* End of IPv6 ICMP processing. */
+
+#endif /* !UIP_CONF_IPV6 */
+
+#if UIP_UDP
+ /* UDP input processing. */
+ udp_input:
+ /* UDP processing is really just a hack. We don't do anything to the
+ UDP/IP headers, but let the UDP application do all the hard
+ work. If the application sets uip_slen, it has a packet to
+ send. */
+#if UIP_UDP_CHECKSUMS
+ uip_len = uip_len - UIP_IPUDPH_LEN;
+ uip_appdata = &uip_buf[UIP_LLH_LEN + UIP_IPUDPH_LEN];
+ if(UDPBUF->udpchksum != 0 && uip_udpchksum() != 0xffff) {
+ UIP_STAT(++uip_stat.udp.drop);
+ UIP_STAT(++uip_stat.udp.chkerr);
+ UIP_LOG("udp: bad checksum.");
+ goto drop;
+ }
+#else /* UIP_UDP_CHECKSUMS */
+ uip_len = uip_len - UIP_IPUDPH_LEN;
+#endif /* UIP_UDP_CHECKSUMS */
+
+ /* Demultiplex this UDP packet between the UDP "connections". */
+ for(uip_udp_conn = &uip_udp_conns[0];
+ uip_udp_conn < &uip_udp_conns[UIP_UDP_CONNS];
+ ++uip_udp_conn) {
+ /* If the local UDP port is non-zero, the connection is considered
+ to be used. If so, the local port number is checked against the
+ destination port number in the received packet. If the two port
+ numbers match, the remote port number is checked if the
+ connection is bound to a remote port. Finally, if the
+ connection is bound to a remote IP address, the source IP
+ address of the packet is checked. */
+ if(uip_udp_conn->lport != 0 &&
+ UDPBUF->destport == uip_udp_conn->lport &&
+ (uip_udp_conn->rport == 0 ||
+ UDPBUF->srcport == uip_udp_conn->rport) &&
+ (uip_ipaddr_cmp(&uip_udp_conn->ripaddr, &uip_all_zeroes_addr) ||
+ uip_ipaddr_cmp(&uip_udp_conn->ripaddr, &uip_broadcast_addr) ||
+ uip_ipaddr_cmp(&BUF->srcipaddr, &uip_udp_conn->ripaddr))) {
+ goto udp_found;
+ }
+ }
+ UIP_LOG("udp: no matching connection found");
+#if UIP_CONF_ICMP_DEST_UNREACH && !UIP_CONF_IPV6
+ /* Copy fields from packet header into payload of this ICMP packet. */
+ memcpy(&(ICMPBUF->payload[0]), ICMPBUF, UIP_IPH_LEN + 8);
+
+ /* Set the ICMP type and code. */
+ ICMPBUF->type = ICMP_DEST_UNREACHABLE;
+ ICMPBUF->icode = ICMP_PORT_UNREACHABLE;
+
+ /* Calculate the ICMP checksum. */
+ ICMPBUF->icmpchksum = 0;
+ ICMPBUF->icmpchksum = ~uip_chksum((u16_t *)&(ICMPBUF->type), 36);
+
+ /* Set the IP destination address to be the source address of the
+ original packet. */
+ uip_ipaddr_copy(&BUF->destipaddr, &BUF->srcipaddr);
+
+ /* Set our IP address as the source address. */
+ uip_ipaddr_copy(&BUF->srcipaddr, &uip_hostaddr);
+
+ /* The size of the ICMP destination unreachable packet is 36 + the
+ size of the IP header (20) = 56. */
+ uip_len = 36 + UIP_IPH_LEN;
+ ICMPBUF->len[0] = 0;
+ ICMPBUF->len[1] = (u8_t)uip_len;
+ ICMPBUF->ttl = UIP_TTL;
+ ICMPBUF->proto = UIP_PROTO_ICMP;
+
+ goto ip_send_nolen;
+#else /* UIP_CONF_ICMP_DEST_UNREACH */
+ goto drop;
+#endif /* UIP_CONF_ICMP_DEST_UNREACH */
+
+ udp_found:
+ uip_conn = NULL;
+ uip_flags = UIP_NEWDATA;
+ uip_sappdata = uip_appdata = &uip_buf[UIP_LLH_LEN + UIP_IPUDPH_LEN];
+ uip_slen = 0;
+ UIP_UDP_APPCALL();
+
+ udp_send:
+ if(uip_slen == 0) {
+ goto drop;
+ }
+ uip_len = uip_slen + UIP_IPUDPH_LEN;
+
+#if UIP_CONF_IPV6
+ /* For IPv6, the IP length field does not include the IPv6 IP header
+ length. */
+ BUF->len[0] = ((uip_len - UIP_IPH_LEN) >> 8);
+ BUF->len[1] = ((uip_len - UIP_IPH_LEN) & 0xff);
+#else /* UIP_CONF_IPV6 */
+ BUF->len[0] = (uip_len >> 8);
+ BUF->len[1] = (uip_len & 0xff);
+#endif /* UIP_CONF_IPV6 */
+
+ BUF->ttl = uip_udp_conn->ttl;
+ BUF->proto = UIP_PROTO_UDP;
+
+ UDPBUF->udplen = HTONS(uip_slen + UIP_UDPH_LEN);
+ UDPBUF->udpchksum = 0;
+
+ BUF->srcport = uip_udp_conn->lport;
+ BUF->destport = uip_udp_conn->rport;
+
+ uip_ipaddr_copy(&BUF->srcipaddr, &uip_hostaddr);
+ uip_ipaddr_copy(&BUF->destipaddr, &uip_udp_conn->ripaddr);
+
+ uip_appdata = &uip_buf[UIP_LLH_LEN + UIP_IPTCPH_LEN];
+
+#if UIP_UDP_CHECKSUMS
+ /* Calculate UDP checksum. */
+ UDPBUF->udpchksum = ~(uip_udpchksum());
+ if(UDPBUF->udpchksum == 0) {
+ UDPBUF->udpchksum = 0xffff;
+ }
+#endif /* UIP_UDP_CHECKSUMS */
+
+ goto ip_send_nolen;
+#endif /* UIP_UDP */
+
+ /* TCP input processing. */
+ tcp_input:
+ UIP_STAT(++uip_stat.tcp.recv);
+
+ /* Start of TCP input header processing code. */
+
+ if(uip_tcpchksum() != 0xffff) { /* Compute and check the TCP
+ checksum. */
+ UIP_STAT(++uip_stat.tcp.drop);
+ UIP_STAT(++uip_stat.tcp.chkerr);
+ UIP_LOG("tcp: bad checksum.");
+ goto drop;
+ }
+
+ /* Demultiplex this segment. */
+ /* First check any active connections. */
+ for(uip_connr = &uip_conns[0]; uip_connr <= &uip_conns[UIP_CONNS - 1];
+ ++uip_connr) {
+ if(uip_connr->tcpstateflags != UIP_CLOSED &&
+ BUF->destport == uip_connr->lport &&
+ BUF->srcport == uip_connr->rport &&
+ uip_ipaddr_cmp(&BUF->srcipaddr, &uip_connr->ripaddr)) {
+ goto found;
+ }
+ }
+
+ /* If we didn't find and active connection that expected the packet,
+ either this packet is an old duplicate, or this is a SYN packet
+ destined for a connection in LISTEN. If the SYN flag isn't set,
+ it is an old packet and we send a RST. */
+ if((BUF->flags & TCP_CTL) != TCP_SYN) {
+ goto reset;
+ }
+
+ tmp16 = BUF->destport;
+ /* Next, check listening connections. */
+ for(c = 0; c < UIP_LISTENPORTS; ++c) {
+ if(tmp16 == uip_listenports[c]) {
+ goto found_listen;
+ }
+ }
+
+ /* No matching connection found, so we send a RST packet. */
+ UIP_STAT(++uip_stat.tcp.synrst);
+
+ reset:
+ /* We do not send resets in response to resets. */
+ if(BUF->flags & TCP_RST) {
+ goto drop;
+ }
+
+ UIP_STAT(++uip_stat.tcp.rst);
+
+ BUF->flags = TCP_RST | TCP_ACK;
+ uip_len = UIP_IPTCPH_LEN;
+ BUF->tcpoffset = 5 << 4;
+
+ /* Flip the seqno and ackno fields in the TCP header. */
+ c = BUF->seqno[3];
+ BUF->seqno[3] = BUF->ackno[3];
+ BUF->ackno[3] = c;
+
+ c = BUF->seqno[2];
+ BUF->seqno[2] = BUF->ackno[2];
+ BUF->ackno[2] = c;
+
+ c = BUF->seqno[1];
+ BUF->seqno[1] = BUF->ackno[1];
+ BUF->ackno[1] = c;
+
+ c = BUF->seqno[0];
+ BUF->seqno[0] = BUF->ackno[0];
+ BUF->ackno[0] = c;
+
+ /* We also have to increase the sequence number we are
+ acknowledging. If the least significant byte overflowed, we need
+ to propagate the carry to the other bytes as well. */
+ if(++BUF->ackno[3] == 0) {
+ if(++BUF->ackno[2] == 0) {
+ if(++BUF->ackno[1] == 0) {
+ ++BUF->ackno[0];
+ }
+ }
+ }
+
+ /* Swap port numbers. */
+ tmp16 = BUF->srcport;
+ BUF->srcport = BUF->destport;
+ BUF->destport = tmp16;
+
+ /* Swap IP addresses. */
+ uip_ipaddr_copy(&BUF->destipaddr, &BUF->srcipaddr);
+ uip_ipaddr_copy(&BUF->srcipaddr, &uip_hostaddr);
+
+ /* And send out the RST packet! */
+ goto tcp_send_noconn;
+
+ /* This label will be jumped to if we matched the incoming packet
+ with a connection in LISTEN. In that case, we should create a new
+ connection and send a SYNACK in return. */
+ found_listen:
+ /* First we check if there are any connections avaliable. Unused
+ connections are kept in the same table as used connections, but
+ unused ones have the tcpstate set to CLOSED. Also, connections in
+ TIME_WAIT are kept track of and we'll use the oldest one if no
+ CLOSED connections are found. Thanks to Eddie C. Dost for a very
+ nice algorithm for the TIME_WAIT search. */
+ uip_connr = 0;
+ for(c = 0; c < UIP_CONNS; ++c) {
+ if(uip_conns[c].tcpstateflags == UIP_CLOSED) {
+ uip_connr = &uip_conns[c];
+ break;
+ }
+ if(uip_conns[c].tcpstateflags == UIP_TIME_WAIT) {
+ if(uip_connr == 0 ||
+ uip_conns[c].timer > uip_connr->timer) {
+ uip_connr = &uip_conns[c];
+ }
+ }
+ }
+
+ if(uip_connr == 0) {
+ /* All connections are used already, we drop packet and hope that
+ the remote end will retransmit the packet at a time when we
+ have more spare connections. */
+ UIP_STAT(++uip_stat.tcp.syndrop);
+ UIP_LOG("tcp: found no unused connections.");
+ goto drop;
+ }
+ uip_conn = uip_connr;
+
+ /* Fill in the necessary fields for the new connection. */
+ uip_connr->rto = uip_connr->timer = UIP_RTO;
+ uip_connr->sa = 0;
+ uip_connr->sv = 4;
+ uip_connr->nrtx = 0;
+ uip_connr->lport = BUF->destport;
+ uip_connr->rport = BUF->srcport;
+ uip_ipaddr_copy(&uip_connr->ripaddr, &BUF->srcipaddr);
+ uip_connr->tcpstateflags = UIP_SYN_RCVD;
+
+ uip_connr->snd_nxt[0] = iss[0];
+ uip_connr->snd_nxt[1] = iss[1];
+ uip_connr->snd_nxt[2] = iss[2];
+ uip_connr->snd_nxt[3] = iss[3];
+ uip_connr->len = 1;
+
+ /* rcv_nxt should be the seqno from the incoming packet + 1. */
+ uip_connr->rcv_nxt[3] = BUF->seqno[3];
+ uip_connr->rcv_nxt[2] = BUF->seqno[2];
+ uip_connr->rcv_nxt[1] = BUF->seqno[1];
+ uip_connr->rcv_nxt[0] = BUF->seqno[0];
+ uip_add_rcv_nxt(1);
+
+ /* Parse the TCP MSS option, if present. */
+ if((BUF->tcpoffset & 0xf0) > 0x50) {
+ for(c = 0; c < ((BUF->tcpoffset >> 4) - 5) << 2 ;) {
+ opt = uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + c];
+ if(opt == TCP_OPT_END) {
+ /* End of options. */
+ break;
+ } else if(opt == TCP_OPT_NOOP) {
+ ++c;
+ /* NOP option. */
+ } else if(opt == TCP_OPT_MSS &&
+ uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c] == TCP_OPT_MSS_LEN) {
+ /* An MSS option with the right option length. */
+ tmp16 = ((u16_t)uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 2 + c] << 8) |
+ (u16_t)uip_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN + 3 + c];
+ uip_connr->initialmss = uip_connr->mss =
+ tmp16 > UIP_TCP_MSS? UIP_TCP_MSS: tmp16;
+
+ /* And we are done processing options. */
+ break;
+ } else {
+ /* All other options have a length field, so that we easily
+ can skip past them. */
+ if(uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c] == 0) {
+ /* If the length field is zero, the options are malformed
+ and we don't process them further. */
+ break;
+ }
+ c += uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c];
+ }
+ }
+ }
+
+ /* Our response will be a SYNACK. */
+#if UIP_ACTIVE_OPEN
+ tcp_send_synack:
+ BUF->flags = TCP_ACK;
+
+ tcp_send_syn:
+ BUF->flags |= TCP_SYN;
+#else /* UIP_ACTIVE_OPEN */
+ tcp_send_synack:
+ BUF->flags = TCP_SYN | TCP_ACK;
+#endif /* UIP_ACTIVE_OPEN */
+
+ /* We send out the TCP Maximum Segment Size option with our
+ SYNACK. */
+ BUF->optdata[0] = TCP_OPT_MSS;
+ BUF->optdata[1] = TCP_OPT_MSS_LEN;
+ BUF->optdata[2] = (UIP_TCP_MSS) / 256;
+ BUF->optdata[3] = (UIP_TCP_MSS) & 255;
+ uip_len = UIP_IPTCPH_LEN + TCP_OPT_MSS_LEN;
+ BUF->tcpoffset = ((UIP_TCPH_LEN + TCP_OPT_MSS_LEN) / 4) << 4;
+ goto tcp_send;
+
+ /* This label will be jumped to if we found an active connection. */
+ found:
+ uip_conn = uip_connr;
+ uip_flags = 0;
+ /* We do a very naive form of TCP reset processing; we just accept
+ any RST and kill our connection. We should in fact check if the
+ sequence number of this reset is wihtin our advertised window
+ before we accept the reset. */
+ if(BUF->flags & TCP_RST) {
+ uip_connr->tcpstateflags = UIP_CLOSED;
+ UIP_LOG("tcp: got reset, aborting connection.");
+ uip_flags = UIP_ABORT;
+ UIP_APPCALL();
+ goto drop;
+ }
+ /* Calculate the length of the data, if the application has sent
+ any data to us. */
+ c = (BUF->tcpoffset >> 4) << 2;
+ /* uip_len will contain the length of the actual TCP data. This is
+ calculated by subtracing the length of the TCP header (in
+ c) and the length of the IP header (20 bytes). */
+ uip_len = uip_len - c - UIP_IPH_LEN;
+
+ /* First, check if the sequence number of the incoming packet is
+ what we're expecting next. If not, we send out an ACK with the
+ correct numbers in. */
+ if(!(((uip_connr->tcpstateflags & UIP_TS_MASK) == UIP_SYN_SENT) &&
+ ((BUF->flags & TCP_CTL) == (TCP_SYN | TCP_ACK)))) {
+ if((uip_len > 0 || ((BUF->flags & (TCP_SYN | TCP_FIN)) != 0)) &&
+ (BUF->seqno[0] != uip_connr->rcv_nxt[0] ||
+ BUF->seqno[1] != uip_connr->rcv_nxt[1] ||
+ BUF->seqno[2] != uip_connr->rcv_nxt[2] ||
+ BUF->seqno[3] != uip_connr->rcv_nxt[3])) {
+ goto tcp_send_ack;
+ }
+ }
+
+ /* Next, check if the incoming segment acknowledges any outstanding
+ data. If so, we update the sequence number, reset the length of
+ the outstanding data, calculate RTT estimations, and reset the
+ retransmission timer. */
+ if((BUF->flags & TCP_ACK) && uip_outstanding(uip_connr)) {
+ uip_add32(uip_connr->snd_nxt, uip_connr->len);
+
+ if(BUF->ackno[0] == uip_acc32[0] &&
+ BUF->ackno[1] == uip_acc32[1] &&
+ BUF->ackno[2] == uip_acc32[2] &&
+ BUF->ackno[3] == uip_acc32[3]) {
+ /* Update sequence number. */
+ uip_connr->snd_nxt[0] = uip_acc32[0];
+ uip_connr->snd_nxt[1] = uip_acc32[1];
+ uip_connr->snd_nxt[2] = uip_acc32[2];
+ uip_connr->snd_nxt[3] = uip_acc32[3];
+
+ /* Do RTT estimation, unless we have done retransmissions. */
+ if(uip_connr->nrtx == 0) {
+ signed char m;
+ m = uip_connr->rto - uip_connr->timer;
+ /* This is taken directly from VJs original code in his paper */
+ m = m - (uip_connr->sa >> 3);
+ uip_connr->sa += m;
+ if(m < 0) {
+ m = -m;
+ }
+ m = m - (uip_connr->sv >> 2);
+ uip_connr->sv += m;
+ uip_connr->rto = (uip_connr->sa >> 3) + uip_connr->sv;
+
+ }
+ /* Set the acknowledged flag. */
+ uip_flags = UIP_ACKDATA;
+ /* Reset the retransmission timer. */
+ uip_connr->timer = uip_connr->rto;
+
+ /* Reset length of outstanding data. */
+ uip_connr->len = 0;
+ }
+
+ }
+
+ /* Do different things depending on in what state the connection is. */
+ switch(uip_connr->tcpstateflags & UIP_TS_MASK) {
+ /* CLOSED and LISTEN are not handled here. CLOSE_WAIT is not
+ implemented, since we force the application to close when the
+ peer sends a FIN (hence the application goes directly from
+ ESTABLISHED to LAST_ACK). */
+ case UIP_SYN_RCVD:
+ /* In SYN_RCVD we have sent out a SYNACK in response to a SYN, and
+ we are waiting for an ACK that acknowledges the data we sent
+ out the last time. Therefore, we want to have the UIP_ACKDATA
+ flag set. If so, we enter the ESTABLISHED state. */
+ if(uip_flags & UIP_ACKDATA) {
+ uip_connr->tcpstateflags = UIP_ESTABLISHED;
+ uip_flags = UIP_CONNECTED;
+ uip_connr->len = 0;
+ if(uip_len > 0) {
+ uip_flags |= UIP_NEWDATA;
+ uip_add_rcv_nxt(uip_len);
+ }
+ uip_slen = 0;
+ UIP_APPCALL();
+ goto appsend;
+ }
+ goto drop;
+#if UIP_ACTIVE_OPEN
+ case UIP_SYN_SENT:
+ /* In SYN_SENT, we wait for a SYNACK that is sent in response to
+ our SYN. The rcv_nxt is set to sequence number in the SYNACK
+ plus one, and we send an ACK. We move into the ESTABLISHED
+ state. */
+ if((uip_flags & UIP_ACKDATA) &&
+ (BUF->flags & TCP_CTL) == (TCP_SYN | TCP_ACK)) {
+
+ /* Parse the TCP MSS option, if present. */
+ if((BUF->tcpoffset & 0xf0) > 0x50) {
+ for(c = 0; c < ((BUF->tcpoffset >> 4) - 5) << 2 ;) {
+ opt = uip_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN + c];
+ if(opt == TCP_OPT_END) {
+ /* End of options. */
+ break;
+ } else if(opt == TCP_OPT_NOOP) {
+ ++c;
+ /* NOP option. */
+ } else if(opt == TCP_OPT_MSS &&
+ uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c] == TCP_OPT_MSS_LEN) {
+ /* An MSS option with the right option length. */
+ tmp16 = (uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 2 + c] << 8) |
+ uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 3 + c];
+ uip_connr->initialmss =
+ uip_connr->mss = tmp16 > UIP_TCP_MSS? UIP_TCP_MSS: tmp16;
+
+ /* And we are done processing options. */
+ break;
+ } else {
+ /* All other options have a length field, so that we easily
+ can skip past them. */
+ if(uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c] == 0) {
+ /* If the length field is zero, the options are malformed
+ and we don't process them further. */
+ break;
+ }
+ c += uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c];
+ }
+ }
+ }
+ uip_connr->tcpstateflags = UIP_ESTABLISHED;
+ uip_connr->rcv_nxt[0] = BUF->seqno[0];
+ uip_connr->rcv_nxt[1] = BUF->seqno[1];
+ uip_connr->rcv_nxt[2] = BUF->seqno[2];
+ uip_connr->rcv_nxt[3] = BUF->seqno[3];
+ uip_add_rcv_nxt(1);
+ uip_flags = UIP_CONNECTED | UIP_NEWDATA;
+ uip_connr->len = 0;
+ uip_len = 0;
+ uip_slen = 0;
+ UIP_APPCALL();
+ goto appsend;
+ }
+ /* Inform the application that the connection failed */
+ uip_flags = UIP_ABORT;
+ UIP_APPCALL();
+ /* The connection is closed after we send the RST */
+ uip_conn->tcpstateflags = UIP_CLOSED;
+ goto reset;
+#endif /* UIP_ACTIVE_OPEN */
+
+ case UIP_ESTABLISHED:
+ /* In the ESTABLISHED state, we call upon the application to feed
+ data into the uip_buf. If the UIP_ACKDATA flag is set, the
+ application should put new data into the buffer, otherwise we are
+ retransmitting an old segment, and the application should put that
+ data into the buffer.
+
+ If the incoming packet is a FIN, we should close the connection on
+ this side as well, and we send out a FIN and enter the LAST_ACK
+ state. We require that there is no outstanding data; otherwise the
+ sequence numbers will be screwed up. */
+
+ if(BUF->flags & TCP_FIN && !(uip_connr->tcpstateflags & UIP_STOPPED)) {
+ if(uip_outstanding(uip_connr)) {
+ goto drop;
+ }
+ uip_add_rcv_nxt(1 + uip_len);
+ uip_flags |= UIP_CLOSE;
+ if(uip_len > 0) {
+ uip_flags |= UIP_NEWDATA;
+ }
+ UIP_APPCALL();
+ uip_connr->len = 1;
+ uip_connr->tcpstateflags = UIP_LAST_ACK;
+ uip_connr->nrtx = 0;
+ tcp_send_finack:
+ BUF->flags = TCP_FIN | TCP_ACK;
+ goto tcp_send_nodata;
+ }
+
+ /* Check the URG flag. If this is set, the segment carries urgent
+ data that we must pass to the application. */
+ if((BUF->flags & TCP_URG) != 0) {
+#if UIP_URGDATA > 0
+ uip_urglen = (BUF->urgp[0] << 8) | BUF->urgp[1];
+ if(uip_urglen > uip_len) {
+ /* There is more urgent data in the next segment to come. */
+ uip_urglen = uip_len;
+ }
+ uip_add_rcv_nxt(uip_urglen);
+ uip_len -= uip_urglen;
+ uip_urgdata = uip_appdata;
+ uip_appdata += uip_urglen;
+ } else {
+ uip_urglen = 0;
+#else /* UIP_URGDATA > 0 */
+ uip_appdata = ((char *)uip_appdata) + ((BUF->urgp[0] << 8) | BUF->urgp[1]);
+ uip_len -= (BUF->urgp[0] << 8) | BUF->urgp[1];
+#endif /* UIP_URGDATA > 0 */
+ }
+
+ /* If uip_len > 0 we have TCP data in the packet, and we flag this
+ by setting the UIP_NEWDATA flag and update the sequence number
+ we acknowledge. If the application has stopped the dataflow
+ using uip_stop(), we must not accept any data packets from the
+ remote host. */
+ if(uip_len > 0 && !(uip_connr->tcpstateflags & UIP_STOPPED)) {
+ uip_flags |= UIP_NEWDATA;
+ uip_add_rcv_nxt(uip_len);
+ }
+
+ /* Check if the available buffer space advertised by the other end
+ is smaller than the initial MSS for this connection. If so, we
+ set the current MSS to the window size to ensure that the
+ application does not send more data than the other end can
+ handle.
+
+ If the remote host advertises a zero window, we set the MSS to
+ the initial MSS so that the application will send an entire MSS
+ of data. This data will not be acknowledged by the receiver,
+ and the application will retransmit it. This is called the
+ "persistent timer" and uses the retransmission mechanim.
+ */
+ tmp16 = ((u16_t)BUF->wnd[0] << 8) + (u16_t)BUF->wnd[1];
+ if(tmp16 > uip_connr->initialmss ||
+ tmp16 == 0) {
+ tmp16 = uip_connr->initialmss;
+ }
+ uip_connr->mss = tmp16;
+
+ /* If this packet constitutes an ACK for outstanding data (flagged
+ by the UIP_ACKDATA flag, we should call the application since it
+ might want to send more data. If the incoming packet had data
+ from the peer (as flagged by the UIP_NEWDATA flag), the
+ application must also be notified.
+
+ When the application is called, the global variable uip_len
+ contains the length of the incoming data. The application can
+ access the incoming data through the global pointer
+ uip_appdata, which usually points UIP_IPTCPH_LEN + UIP_LLH_LEN
+ bytes into the uip_buf array.
+
+ If the application wishes to send any data, this data should be
+ put into the uip_appdata and the length of the data should be
+ put into uip_len. If the application don't have any data to
+ send, uip_len must be set to 0. */
+ if(uip_flags & (UIP_NEWDATA | UIP_ACKDATA)) {
+ uip_slen = 0;
+ UIP_APPCALL();
+
+ appsend:
+
+ if(uip_flags & UIP_ABORT) {
+ uip_slen = 0;
+ uip_connr->tcpstateflags = UIP_CLOSED;
+ BUF->flags = TCP_RST | TCP_ACK;
+ goto tcp_send_nodata;
+ }
+
+ if(uip_flags & UIP_CLOSE) {
+ uip_slen = 0;
+ uip_connr->len = 1;
+ uip_connr->tcpstateflags = UIP_FIN_WAIT_1;
+ uip_connr->nrtx = 0;
+ BUF->flags = TCP_FIN | TCP_ACK;
+ goto tcp_send_nodata;
+ }
+
+ /* If uip_slen > 0, the application has data to be sent. */
+ if(uip_slen > 0) {
+
+ /* If the connection has acknowledged data, the contents of
+ the ->len variable should be discarded. */
+ if((uip_flags & UIP_ACKDATA) != 0) {
+ uip_connr->len = 0;
+ }
+
+ /* If the ->len variable is non-zero the connection has
+ already data in transit and cannot send anymore right
+ now. */
+ if(uip_connr->len == 0) {
+
+ /* The application cannot send more than what is allowed by
+ the mss (the minumum of the MSS and the available
+ window). */
+ if(uip_slen > uip_connr->mss) {
+ uip_slen = uip_connr->mss;
+ }
+
+ /* Remember how much data we send out now so that we know
+ when everything has been acknowledged. */
+ uip_connr->len = uip_slen;
+ } else {
+
+ /* If the application already had unacknowledged data, we
+ make sure that the application does not send (i.e.,
+ retransmit) out more than it previously sent out. */
+ uip_slen = uip_connr->len;
+ }
+ }
+ uip_connr->nrtx = 0;
+ apprexmit:
+ uip_appdata = uip_sappdata;
+
+ /* If the application has data to be sent, or if the incoming
+ packet had new data in it, we must send out a packet. */
+ if(uip_slen > 0 && uip_connr->len > 0) {
+ /* Add the length of the IP and TCP headers. */
+ uip_len = uip_connr->len + UIP_TCPIP_HLEN;
+ /* We always set the ACK flag in response packets. */
+ BUF->flags = TCP_ACK | TCP_PSH;
+ /* Send the packet. */
+ goto tcp_send_noopts;
+ }
+ /* If there is no data to send, just send out a pure ACK if
+ there is newdata. */
+ if(uip_flags & UIP_NEWDATA) {
+ uip_len = UIP_TCPIP_HLEN;
+ BUF->flags = TCP_ACK;
+ goto tcp_send_noopts;
+ }
+ }
+ goto drop;
+ case UIP_LAST_ACK:
+ /* We can close this connection if the peer has acknowledged our
+ FIN. This is indicated by the UIP_ACKDATA flag. */
+ if(uip_flags & UIP_ACKDATA) {
+ uip_connr->tcpstateflags = UIP_CLOSED;
+ uip_flags = UIP_CLOSE;
+ UIP_APPCALL();
+ }
+ break;
+
+ case UIP_FIN_WAIT_1:
+ /* The application has closed the connection, but the remote host
+ hasn't closed its end yet. Thus we do nothing but wait for a
+ FIN from the other side. */
+ if(uip_len > 0) {
+ uip_add_rcv_nxt(uip_len);
+ }
+ if(BUF->flags & TCP_FIN) {
+ if(uip_flags & UIP_ACKDATA) {
+ uip_connr->tcpstateflags = UIP_TIME_WAIT;
+ uip_connr->timer = 0;
+ uip_connr->len = 0;
+ } else {
+ uip_connr->tcpstateflags = UIP_CLOSING;
+ }
+ uip_add_rcv_nxt(1);
+ uip_flags = UIP_CLOSE;
+ UIP_APPCALL();
+ goto tcp_send_ack;
+ } else if(uip_flags & UIP_ACKDATA) {
+ uip_connr->tcpstateflags = UIP_FIN_WAIT_2;
+ uip_connr->len = 0;
+ goto drop;
+ }
+ if(uip_len > 0) {
+ goto tcp_send_ack;
+ }
+ goto drop;
+
+ case UIP_FIN_WAIT_2:
+ if(uip_len > 0) {
+ uip_add_rcv_nxt(uip_len);
+ }
+ if(BUF->flags & TCP_FIN) {
+ uip_connr->tcpstateflags = UIP_TIME_WAIT;
+ uip_connr->timer = 0;
+ uip_add_rcv_nxt(1);
+ uip_flags = UIP_CLOSE;
+ UIP_APPCALL();
+ goto tcp_send_ack;
+ }
+ if(uip_len > 0) {
+ goto tcp_send_ack;
+ }
+ goto drop;
+
+ case UIP_TIME_WAIT:
+ goto tcp_send_ack;
+
+ case UIP_CLOSING:
+ if(uip_flags & UIP_ACKDATA) {
+ uip_connr->tcpstateflags = UIP_TIME_WAIT;
+ uip_connr->timer = 0;
+ }
+ }
+ goto drop;
+
+ /* We jump here when we are ready to send the packet, and just want
+ to set the appropriate TCP sequence numbers in the TCP header. */
+ tcp_send_ack:
+ BUF->flags = TCP_ACK;
+
+ tcp_send_nodata:
+ uip_len = UIP_IPTCPH_LEN;
+
+ tcp_send_noopts:
+ BUF->tcpoffset = (UIP_TCPH_LEN / 4) << 4;
+
+ /* We're done with the input processing. We are now ready to send a
+ reply. Our job is to fill in all the fields of the TCP and IP
+ headers before calculating the checksum and finally send the
+ packet. */
+ tcp_send:
+ BUF->ackno[0] = uip_connr->rcv_nxt[0];
+ BUF->ackno[1] = uip_connr->rcv_nxt[1];
+ BUF->ackno[2] = uip_connr->rcv_nxt[2];
+ BUF->ackno[3] = uip_connr->rcv_nxt[3];
+
+ BUF->seqno[0] = uip_connr->snd_nxt[0];
+ BUF->seqno[1] = uip_connr->snd_nxt[1];
+ BUF->seqno[2] = uip_connr->snd_nxt[2];
+ BUF->seqno[3] = uip_connr->snd_nxt[3];
+
+ BUF->proto = UIP_PROTO_TCP;
+
+ BUF->srcport = uip_connr->lport;
+ BUF->destport = uip_connr->rport;
+
+ uip_ipaddr_copy(&BUF->srcipaddr, &uip_hostaddr);
+ uip_ipaddr_copy(&BUF->destipaddr, &uip_connr->ripaddr);
+
+ if(uip_connr->tcpstateflags & UIP_STOPPED) {
+ /* If the connection has issued uip_stop(), we advertise a zero
+ window so that the remote host will stop sending data. */
+ BUF->wnd[0] = BUF->wnd[1] = 0;
+ } else {
+ BUF->wnd[0] = ((UIP_RECEIVE_WINDOW) >> 8);
+ BUF->wnd[1] = ((UIP_RECEIVE_WINDOW) & 0xff);
+ }
+
+ tcp_send_noconn:
+ BUF->ttl = UIP_TTL;
+#if UIP_CONF_IPV6
+ /* For IPv6, the IP length field does not include the IPv6 IP header
+ length. */
+ BUF->len[0] = ((uip_len - UIP_IPH_LEN) >> 8);
+ BUF->len[1] = ((uip_len - UIP_IPH_LEN) & 0xff);
+#else /* UIP_CONF_IPV6 */
+ BUF->len[0] = (uip_len >> 8);
+ BUF->len[1] = (uip_len & 0xff);
+#endif /* UIP_CONF_IPV6 */
+
+ BUF->urgp[0] = BUF->urgp[1] = 0;
+
+ /* Calculate TCP checksum. */
+ BUF->tcpchksum = 0;
+ BUF->tcpchksum = ~(uip_tcpchksum());
+
+ ip_send_nolen:
+#if UIP_CONF_IPV6
+ BUF->vtc = 0x60;
+ BUF->tcflow = 0x00;
+ BUF->flow = 0x00;
+#else /* UIP_CONF_IPV6 */
+ BUF->vhl = 0x45;
+ BUF->tos = 0;
+ BUF->ipoffset[0] = BUF->ipoffset[1] = 0;
+ ++ipid;
+ BUF->ipid[0] = ipid >> 8;
+ BUF->ipid[1] = ipid & 0xff;
+ /* Calculate IP checksum. */
+ BUF->ipchksum = 0;
+ BUF->ipchksum = ~(uip_ipchksum());
+ DEBUG_PRINTF("uip ip_send_nolen: chkecum 0x%04x\n", uip_ipchksum());
+#endif /* UIP_CONF_IPV6 */
+ UIP_STAT(++uip_stat.tcp.sent);
+#if UIP_CONF_IPV6
+ send:
+#endif /* UIP_CONF_IPV6 */
+ DEBUG_PRINTF("Sending packet with length %d (%d)\n", uip_len,
+ (BUF->len[0] << 8) | BUF->len[1]);
+
+ UIP_STAT(++uip_stat.ip.sent);
+ /* Return and let the caller do the actual transmission. */
+ uip_flags = 0;
+ return;
+
+ drop:
+ uip_len = 0;
+ uip_flags = 0;
+ return;
+}
+/*---------------------------------------------------------------------------*/
+u16_t
+htons(u16_t val)
+{
+ return HTONS(val);
+}
+
+u32_t
+htonl(u32_t val)
+{
+ return HTONL(val);
+}
+/*---------------------------------------------------------------------------*/
+void
+uip_send(const void *data, int len)
+{
+ int copylen;
+#define MIN(a,b) ((a) < (b)? (a): (b))
+ copylen = MIN(len, UIP_BUFSIZE - UIP_LLH_LEN - UIP_TCPIP_HLEN -
+ (int)((char *)uip_sappdata - (char *)&uip_buf[UIP_LLH_LEN + UIP_TCPIP_HLEN]));
+ if(copylen > 0) {
+ uip_slen = copylen;
+ if(data != uip_sappdata) {
+ memcpy(uip_sappdata, (data), uip_slen);
+ }
+ }
+}
+/*---------------------------------------------------------------------------*/
+/** @} */
+#endif /* UIP_CONF_IPV6 */
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