diff options
Diffstat (limited to 'tinyusb/lib/networking/dnserver.c')
| -rwxr-xr-x | tinyusb/lib/networking/dnserver.c | 200 |
1 files changed, 200 insertions, 0 deletions
diff --git a/tinyusb/lib/networking/dnserver.c b/tinyusb/lib/networking/dnserver.c new file mode 100755 index 00000000..6df0bd0c --- /dev/null +++ b/tinyusb/lib/networking/dnserver.c @@ -0,0 +1,200 @@ +/* + * The MIT License (MIT) + * + * Copyright (c) 2015 by Sergey Fetisov <fsenok@gmail.com> + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in all + * copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + */ + +/* + * version: 1.0 demo (7.02.2015) + * brief: tiny dns ipv4 server using lwip (pcb) + */ + +#include "dnserver.h" + +#define DNS_MAX_HOST_NAME_LEN 128 + +static struct udp_pcb *pcb = NULL; +dns_query_proc_t query_proc = NULL; + +#pragma pack(push, 1) +typedef struct +{ +#if BYTE_ORDER == LITTLE_ENDIAN + uint8_t rd: 1, /* Recursion Desired */ + tc: 1, /* Truncation Flag */ + aa: 1, /* Authoritative Answer Flag */ + opcode: 4, /* Operation code */ + qr: 1; /* Query/Response Flag */ + uint8_t rcode: 4, /* Response Code */ + z: 3, /* Zero */ + ra: 1; /* Recursion Available */ +#else + uint8_t qr: 1, /* Query/Response Flag */ + opcode: 4, /* Operation code */ + aa: 1, /* Authoritative Answer Flag */ + tc: 1, /* Truncation Flag */ + rd: 1; /* Recursion Desired */ + uint8_t ra: 1, /* Recursion Available */ + z: 3, /* Zero */ + rcode: 4; /* Response Code */ +#endif +} dns_header_flags_t; + +typedef struct +{ + uint16_t id; + dns_header_flags_t flags; + uint16_t n_record[4]; +} dns_header_t; + +typedef struct dns_answer +{ + uint16_t name; + uint16_t type; + uint16_t Class; + uint32_t ttl; + uint16_t len; + uint32_t addr; +} dns_answer_t; +#pragma pack(pop) + +typedef struct dns_query +{ + char name[DNS_MAX_HOST_NAME_LEN]; + uint16_t type; + uint16_t Class; +} dns_query_t; + +static uint16_t get_uint16(const uint8_t *pnt) +{ + uint16_t result; + memcpy(&result, pnt, sizeof(result)); + return result; +} + +static int parse_next_query(void *data, int size, dns_query_t *query) +{ + int len; + int lables; + uint8_t *ptr; + + len = 0; + lables = 0; + ptr = (uint8_t *)data; + + while (true) + { + uint8_t lable_len; + if (size <= 0) return -1; + lable_len = *ptr++; + size--; + if (lable_len == 0) break; + if (lables > 0) + { + if (len == DNS_MAX_HOST_NAME_LEN) return -2; + query->name[len++] = '.'; + } + if (lable_len > size) return -1; + if (len + lable_len >= DNS_MAX_HOST_NAME_LEN) return -2; + memcpy(&query->name[len], ptr, lable_len); + len += lable_len; + ptr += lable_len; + size -= lable_len; + lables++; + } + + if (size < 4) return -1; + query->name[len] = 0; + query->type = get_uint16(ptr); + ptr += 2; + query->Class = get_uint16(ptr); + ptr += 2; + return ptr - (uint8_t *)data; +} + +static void udp_recv_proc(void *arg, struct udp_pcb *upcb, struct pbuf *p, const ip_addr_t *addr, u16_t port) +{ + int len; + dns_header_t *header; + static dns_query_t query; + struct pbuf *out; + ip_addr_t host_addr; + dns_answer_t *answer; + + (void)arg; + + if (p->len <= sizeof(dns_header_t)) goto error; + header = (dns_header_t *)p->payload; + if (header->flags.qr != 0) goto error; + if (ntohs(header->n_record[0]) != 1) goto error; + + len = parse_next_query(header + 1, p->len - sizeof(dns_header_t), &query); + if (len < 0) goto error; + if (!query_proc(query.name, &host_addr)) goto error; + + len += sizeof(dns_header_t); + out = pbuf_alloc(PBUF_TRANSPORT, len + 16, PBUF_POOL); + if (out == NULL) goto error; + + memcpy(out->payload, p->payload, len); + header = (dns_header_t *)out->payload; + header->flags.qr = 1; + header->n_record[1] = htons(1); + answer = (struct dns_answer *)((uint8_t *)out->payload + len); + answer->name = htons(0xC00C); + answer->type = htons(1); + answer->Class = htons(1); + answer->ttl = htonl(32); + answer->len = htons(4); + answer->addr = host_addr.addr; + + udp_sendto(upcb, out, addr, port); + pbuf_free(out); + +error: + pbuf_free(p); +} + +err_t dnserv_init(const ip_addr_t *bind, uint16_t port, dns_query_proc_t qp) +{ + err_t err; + udp_init(); + dnserv_free(); + pcb = udp_new(); + if (pcb == NULL) + return ERR_MEM; + err = udp_bind(pcb, bind, port); + if (err != ERR_OK) + { + dnserv_free(); + return err; + } + udp_recv(pcb, udp_recv_proc, NULL); + query_proc = qp; + return ERR_OK; +} + +void dnserv_free() +{ + if (pcb == NULL) return; + udp_remove(pcb); + pcb = NULL; +} |