diff options
Diffstat (limited to 'ctrl/facemgr/src/interfaces/bonjour/mdns')
| -rw-r--r-- | ctrl/facemgr/src/interfaces/bonjour/mdns/LICENSE | 24 | ||||
| -rw-r--r-- | ctrl/facemgr/src/interfaces/bonjour/mdns/README.md | 9 | ||||
| -rw-r--r-- | ctrl/facemgr/src/interfaces/bonjour/mdns/mdns.c | 192 | ||||
| -rw-r--r-- | ctrl/facemgr/src/interfaces/bonjour/mdns/mdns.h | 879 |
4 files changed, 1104 insertions, 0 deletions
diff --git a/ctrl/facemgr/src/interfaces/bonjour/mdns/LICENSE b/ctrl/facemgr/src/interfaces/bonjour/mdns/LICENSE new file mode 100644 index 000000000..cf1ab25da --- /dev/null +++ b/ctrl/facemgr/src/interfaces/bonjour/mdns/LICENSE @@ -0,0 +1,24 @@ +This is free and unencumbered software released into the public domain. + +Anyone is free to copy, modify, publish, use, compile, sell, or +distribute this software, either in source code form or as a compiled +binary, for any purpose, commercial or non-commercial, and by any +means. + +In jurisdictions that recognize copyright laws, the author or authors +of this software dedicate any and all copyright interest in the +software to the public domain. We make this dedication for the benefit +of the public at large and to the detriment of our heirs and +successors. We intend this dedication to be an overt act of +relinquishment in perpetuity of all present and future rights to this +software under copyright law. + +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 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. + +For more information, please refer to <http://unlicense.org> diff --git a/ctrl/facemgr/src/interfaces/bonjour/mdns/README.md b/ctrl/facemgr/src/interfaces/bonjour/mdns/README.md new file mode 100644 index 000000000..1bee49c08 --- /dev/null +++ b/ctrl/facemgr/src/interfaces/bonjour/mdns/README.md @@ -0,0 +1,9 @@ +# Public domain mDNS/DNS-SD library in C + +This library provides a cross-platform mDNS and DNS-DS library in C. The latest source code is always available at + +https://github.com/mjansson/mdns + +This library is put in the public domain; you can redistribute it and/or modify it without any restrictions. + +Created by Mattias Jansson ([@maniccoder](https://twitter.com/maniccoder)) diff --git a/ctrl/facemgr/src/interfaces/bonjour/mdns/mdns.c b/ctrl/facemgr/src/interfaces/bonjour/mdns/mdns.c new file mode 100644 index 000000000..a8e97e8e0 --- /dev/null +++ b/ctrl/facemgr/src/interfaces/bonjour/mdns/mdns.c @@ -0,0 +1,192 @@ + +#ifdef _WIN32 +# define _CRT_SECURE_NO_WARNINGS 1 +#endif + +#include "mdns.h" + +#include <stdio.h> +#include <errno.h> + +#ifdef _WIN32 +# define sleep(x) Sleep(x * 1000) +#else +# include <netdb.h> +#endif + +static char addrbuffer[64]; +static char namebuffer[256]; +static mdns_record_txt_t txtbuffer[128]; + +static mdns_string_t +ipv4_address_to_string(char* buffer, size_t capacity, const struct sockaddr_in* addr) { + char host[NI_MAXHOST] = {0}; + char service[NI_MAXSERV] = {0}; + int ret = getnameinfo((const struct sockaddr*)addr, sizeof(struct sockaddr_in), + host, NI_MAXHOST, service, NI_MAXSERV, + NI_NUMERICSERV | NI_NUMERICHOST); + int len = 0; + if (ret == 0) { + if (addr->sin_port != 0) + len = snprintf(buffer, capacity, "%s:%s", host, service); + else + len = snprintf(buffer, capacity, "%s", host); + } + if (len >= (int)capacity) + len = (int)capacity - 1; + mdns_string_t str = {buffer, len}; + return str; +} + +static mdns_string_t +ipv6_address_to_string(char* buffer, size_t capacity, const struct sockaddr_in6* addr) { + char host[NI_MAXHOST] = {0}; + char service[NI_MAXSERV] = {0}; + int ret = getnameinfo((const struct sockaddr*)addr, sizeof(struct sockaddr_in6), + host, NI_MAXHOST, service, NI_MAXSERV, + NI_NUMERICSERV | NI_NUMERICHOST); + int len = 0; + if (ret == 0) { + if (addr->sin6_port != 0) + len = snprintf(buffer, capacity, "[%s]:%s", host, service); + else + len = snprintf(buffer, capacity, "%s", host); + } + if (len >= (int)capacity) + len = (int)capacity - 1; + mdns_string_t str = {buffer, len}; + return str; +} + +static mdns_string_t +ip_address_to_string(char* buffer, size_t capacity, const struct sockaddr* addr) { + if (addr->sa_family == AF_INET6) + return ipv6_address_to_string(buffer, capacity, (const struct sockaddr_in6*)addr); + return ipv4_address_to_string(buffer, capacity, (const struct sockaddr_in*)addr); +} + +static int +callback(const struct sockaddr* from, + mdns_entry_type_t entry, uint16_t type, + uint16_t rclass, uint32_t ttl, + const void* data, size_t size, size_t offset, size_t length, + void* user_data) { + mdns_string_t fromaddrstr = ip_address_to_string(addrbuffer, sizeof(addrbuffer), from); + const char* entrytype = (entry == MDNS_ENTRYTYPE_ANSWER) ? "answer" : + ((entry == MDNS_ENTRYTYPE_AUTHORITY) ? "authority" : "additional"); + if (type == MDNS_RECORDTYPE_PTR) { + mdns_string_t namestr = mdns_record_parse_ptr(data, size, offset, length, + namebuffer, sizeof(namebuffer)); + INFO("%.*s : %s PTR %.*s type %u rclass 0x%x ttl %u length %d\n", + MDNS_STRING_FORMAT(fromaddrstr), entrytype, + MDNS_STRING_FORMAT(namestr), type, rclass, ttl, (int)length); + } + else if (type == MDNS_RECORDTYPE_SRV) { + mdns_record_srv_t srv = mdns_record_parse_srv(data, size, offset, length, + namebuffer, sizeof(namebuffer)); + INFO("%.*s : %s SRV %.*s priority %d weight %d port %d\n", + MDNS_STRING_FORMAT(fromaddrstr), entrytype, + MDNS_STRING_FORMAT(srv.name), srv.priority, srv.weight, srv.port); + } + else if (type == MDNS_RECORDTYPE_A) { + struct sockaddr_in addr; + mdns_record_parse_a(data, size, offset, length, &addr); + mdns_string_t addrstr = ipv4_address_to_string(namebuffer, sizeof(namebuffer), &addr); + INFO("%.*s : %s A %.*s\n", + MDNS_STRING_FORMAT(fromaddrstr), entrytype, + MDNS_STRING_FORMAT(addrstr)); + } + else if (type == MDNS_RECORDTYPE_AAAA) { + struct sockaddr_in6 addr; + mdns_record_parse_aaaa(data, size, offset, length, &addr); + mdns_string_t addrstr = ipv6_address_to_string(namebuffer, sizeof(namebuffer), &addr); + INFO("%.*s : %s AAAA %.*s\n", + MDNS_STRING_FORMAT(fromaddrstr), entrytype, + MDNS_STRING_FORMAT(addrstr)); + } + else if (type == MDNS_RECORDTYPE_TXT) { + size_t parsed = mdns_record_parse_txt(data, size, offset, length, + txtbuffer, sizeof(txtbuffer) / sizeof(mdns_record_txt_t)); + for (size_t itxt = 0; itxt < parsed; ++itxt) { + if (txtbuffer[itxt].value.length) { + INFO("%.*s : %s TXT %.*s = %.*s\n", + MDNS_STRING_FORMAT(fromaddrstr), entrytype, + MDNS_STRING_FORMAT(txtbuffer[itxt].key), + MDNS_STRING_FORMAT(txtbuffer[itxt].value)); + } + else { + INFO("%.*s : %s TXT %.*s\n", + MDNS_STRING_FORMAT(fromaddrstr), entrytype, + MDNS_STRING_FORMAT(txtbuffer[itxt].key)); + } + } + } + else { + INFO("%.*s : %s type %u rclass 0x%x ttl %u length %d\n", + MDNS_STRING_FORMAT(fromaddrstr), entrytype, + type, rclass, ttl, (int)length); + } + return 0; +} + +int +main() { + size_t capacity = 2048; + void* buffer = 0; + void* user_data = 0; + size_t records; + +#ifdef _WIN32 + WORD versionWanted = MAKEWORD(1, 1); + WSADATA wsaData; + WSAStartup(versionWanted, &wsaData); +#endif + + int sock = mdns_socket_open_ipv4(); + if (sock < 0) { + INFO("Failed to open socket: %s\n", strerror(errno)); + return -1; + } + INFO("Opened IPv4 socket for mDNS/DNS-SD\n"); + buffer = malloc(capacity); +/* + INFO("Sending DNS-SD discovery\n"); + if (mdns_discovery_send(sock)) { + INFO("Failed to send DNS-DS discovery: %s\n", strerror(errno)); + goto quit; + } + + INFO("Reading DNS-SD replies\n"); + for (int i = 0; i < 10; ++i) { + records = mdns_discovery_recv(sock, buffer, capacity, callback, + user_data); + sleep(1); + } + */ + + INFO("Sending mDNS query\n"); + if (mdns_query_send(sock, MDNS_RECORDTYPE_PTR, + MDNS_STRING_CONST("_hicn._udp.local."), + buffer, capacity)) { + INFO("Failed to send mDNS query: %s\n", strerror(errno)); + goto quit; + } + + INFO("Reading mDNS replies\n"); + for (int i = 0; i < 10; ++i) { + records = mdns_query_recv(sock, buffer, capacity, callback, user_data, 1); + sleep(1); + } + +quit: + free(buffer); + + mdns_socket_close(sock); + INFO("Closed socket\n"); + +#ifdef _WIN32 + WSACleanup(); +#endif + + return 0; +} diff --git a/ctrl/facemgr/src/interfaces/bonjour/mdns/mdns.h b/ctrl/facemgr/src/interfaces/bonjour/mdns/mdns.h new file mode 100644 index 000000000..ff04b5d72 --- /dev/null +++ b/ctrl/facemgr/src/interfaces/bonjour/mdns/mdns.h @@ -0,0 +1,879 @@ +/* mdns.h - mDNS/DNS-SD library - Public Domain - 2017 Mattias Jansson + * + * This library provides a cross-platform mDNS and DNS-SD library in C. + * The implementation is based on RFC 6762 and RFC 6763. + * + * The latest source code is always available at + * + * https://github.com/mjansson/mdns + * + * This library is put in the public domain; you can redistribute it and/or modify it without any restrictions. + * + */ + +#pragma once + +#include <stdint.h> +#include <stddef.h> +#include <stdlib.h> +#include <string.h> + +#include <fcntl.h> +#ifdef _WIN32 +#include <Winsock2.h> +#include <Ws2tcpip.h> +#define strncasecmp _strnicmp +#else +#include <unistd.h> +#include <sys/socket.h> +#include <netinet/in.h> +#endif + +#define MDNS_INVALID_POS ((size_t)-1) + +#define MDNS_STRING_CONST(s) (s), (sizeof((s))-1) +#define MDNS_STRING_FORMAT(s) (int)((s).length), s.str + +enum mdns_record_type { + MDNS_RECORDTYPE_IGNORE = 0, + //Address + MDNS_RECORDTYPE_A = 1, + //Domain Name pointer + MDNS_RECORDTYPE_PTR = 12, + //Arbitrary text string + MDNS_RECORDTYPE_TXT = 16, + //IP6 Address [Thomson] + MDNS_RECORDTYPE_AAAA = 28, + //Server Selection [RFC2782] + MDNS_RECORDTYPE_SRV = 33 +}; + +enum mdns_entry_type { + MDNS_ENTRYTYPE_ANSWER = 1, + MDNS_ENTRYTYPE_AUTHORITY = 2, + MDNS_ENTRYTYPE_ADDITIONAL = 3 +}; + +enum mdns_class { + MDNS_CLASS_IN = 1 +}; + +typedef enum mdns_record_type mdns_record_type_t; +typedef enum mdns_entry_type mdns_entry_type_t; +typedef enum mdns_class mdns_class_t; + +typedef int (* mdns_record_callback_fn)(const struct sockaddr* from, + mdns_entry_type_t entry, uint16_t type, + uint16_t rclass, uint32_t ttl, + const void* data, size_t size, size_t offset, size_t length, + void* user_data); + +typedef struct mdns_string_t mdns_string_t; +typedef struct mdns_string_pair_t mdns_string_pair_t; +typedef struct mdns_record_srv_t mdns_record_srv_t; +typedef struct mdns_record_txt_t mdns_record_txt_t; + +struct mdns_string_t { + const char* str; + size_t length; +}; + +struct mdns_string_pair_t { + size_t offset; + size_t length; + int ref; +}; + +struct mdns_record_srv_t { + uint16_t priority; + uint16_t weight; + uint16_t port; + mdns_string_t name; +}; + +struct mdns_record_txt_t { + mdns_string_t key; + mdns_string_t value; +}; + +static int +mdns_socket_open_ipv4(void); + +static int +mdns_socket_setup_ipv4(int sock); + +#if 0 +static int +mdns_socket_open_ipv6(void); + + + +static int +mdns_socket_setup_ipv6(int sock); +#endif + +static void +mdns_socket_close(int sock); + +#if 0 +static int +mdns_discovery_send(int sock); + + +static size_t +mdns_discovery_recv(int sock, void* buffer, size_t capacity, + mdns_record_callback_fn callback, void* user_data); +#endif + +static int +mdns_query_send(int sock, mdns_record_type_t type, const char* name, size_t length, + void* buffer, size_t capacity); + +static size_t +mdns_query_recv(int sock, void* buffer, size_t capacity, + mdns_record_callback_fn callback, void* user_data, + uint8_t one_shot); + +static mdns_string_t +mdns_string_extract(const void* buffer, size_t size, size_t* offset, + char* str, size_t capacity); + +static int +mdns_string_skip(const void* buffer, size_t size, size_t* offset); + +#if 0 +static int +mdns_string_equal(const void* buffer_lhs, size_t size_lhs, size_t* ofs_lhs, + const void* buffer_rhs, size_t size_rhs, size_t* ofs_rhs); +#endif + +static void* +mdns_string_make(void* data, size_t capacity, const char* name, size_t length); + +static mdns_string_t +mdns_record_parse_ptr(const void* buffer, size_t size, size_t offset, size_t length, + char* strbuffer, size_t capacity); + +static mdns_record_srv_t +mdns_record_parse_srv(const void* buffer, size_t size, size_t offset, size_t length, + char* strbuffer, size_t capacity); + +static struct sockaddr_in* +mdns_record_parse_a(const void* buffer, size_t size, size_t offset, size_t length, + struct sockaddr_in* addr); + +static struct sockaddr_in6* +mdns_record_parse_aaaa(const void* buffer, size_t size, size_t offset, size_t length, + struct sockaddr_in6* addr); + +static size_t +mdns_record_parse_txt(const void* buffer, size_t size, size_t offset, size_t length, + mdns_record_txt_t* records, size_t capacity); + +// Implementations + +static int +mdns_socket_open_ipv4(void) { + int sock = (int)socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP); + if (sock < 0) + return -1; + if (mdns_socket_setup_ipv4(sock)) { + mdns_socket_close(sock); + return -1; + } + return sock; +} + +static int +mdns_socket_setup_ipv4(int sock) { + struct sockaddr_in saddr; + memset(&saddr, 0, sizeof(saddr)); + saddr.sin_family = AF_INET; + saddr.sin_addr.s_addr = INADDR_ANY; +#ifdef __APPLE__ + saddr.sin_len = sizeof(saddr); +#endif + + if (bind(sock, (struct sockaddr*)&saddr, sizeof(saddr))) + return -1; + +#ifdef _WIN32 + unsigned long param = 1; + ioctlsocket(sock, FIONBIO, ¶m); +#else + const int flags = fcntl(sock, F_GETFL, 0); + fcntl(sock, F_SETFL, flags | O_NONBLOCK); +#endif + + unsigned char ttl = 1; + unsigned char loopback = 1; + struct ip_mreq req; + + setsockopt(sock, IPPROTO_IP, IP_MULTICAST_TTL, (const char*)&ttl, sizeof(ttl)); + setsockopt(sock, IPPROTO_IP, IP_MULTICAST_LOOP, (const char*)&loopback, sizeof(loopback)); + + memset(&req, 0, sizeof(req)); + req.imr_multiaddr.s_addr = htonl((((uint32_t)224U) << 24U) | ((uint32_t)251U)); + req.imr_interface.s_addr = INADDR_ANY; + if (setsockopt(sock, IPPROTO_IP, IP_ADD_MEMBERSHIP, (char*)&req, sizeof(req))) + return -1; + + return 0; +} + +#if 0 +static int +mdns_socket_open_ipv6(void) { + int sock = (int)socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP); + if (sock < 0) + return -1; + if (mdns_socket_setup_ipv6(sock)) { + mdns_socket_close(sock); + return -1; + } + return sock; +} + + +static int +mdns_socket_setup_ipv6(int sock) { + struct sockaddr_in6 saddr; + memset(&saddr, 0, sizeof(saddr)); + saddr.sin6_family = AF_INET6; + saddr.sin6_addr = in6addr_any; +#ifdef __APPLE__ + saddr.sin6_len = sizeof(saddr); +#endif + + if (bind(sock, (struct sockaddr*)&saddr, sizeof(saddr))) + return -1; + +#ifdef _WIN32 + unsigned long param = 1; + ioctlsocket(sock, FIONBIO, ¶m); +#else + const int flags = fcntl(sock, F_GETFL, 0); + fcntl(sock, F_SETFL, flags | O_NONBLOCK); +#endif + + int hops = 1; + unsigned int loopback = 1; + struct ipv6_mreq req; + + setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, (const char*)&hops, sizeof(hops)); + setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, (const char*)&loopback, sizeof(loopback)); + + memset(&req, 0, sizeof(req)); + req.ipv6mr_multiaddr.s6_addr[0] = 0xFF; + req.ipv6mr_multiaddr.s6_addr[1] = 0x02; + req.ipv6mr_multiaddr.s6_addr[15] = 0xFB; + if (setsockopt(sock, IPPROTO_IPV6, IPV6_JOIN_GROUP, (char*)&req, sizeof(req))) + return -1; + + return 0; +} +#endif + +static void +mdns_socket_close(int sock) { +#ifdef _WIN32 + closesocket(sock); +#else + close(sock); +#endif +} + +static int +mdns_is_string_ref(uint8_t val) { + return (0xC0 == (val & 0xC0)); +} + +static mdns_string_pair_t +mdns_get_next_substring(const void* rawdata, size_t size, size_t offset) { + const uint8_t* buffer = rawdata; + mdns_string_pair_t pair = {MDNS_INVALID_POS, 0, 0}; + if (!buffer[offset]) { + pair.offset = offset; + return pair; + } + if (mdns_is_string_ref(buffer[offset])) { + if (size < offset + 2) + return pair; + + offset = (((size_t)(0x3f & buffer[offset]) << 8) | (size_t)buffer[offset + 1]); + if (offset >= size) + return pair; + + pair.ref = 1; + } + + size_t length = (size_t)buffer[offset++]; + if (size < offset + length) + return pair; + + pair.offset = offset; + pair.length = length; + + return pair; +} + +static int +mdns_string_skip(const void* buffer, size_t size, size_t* offset) { + size_t cur = *offset; + mdns_string_pair_t substr; + do { + substr = mdns_get_next_substring(buffer, size, cur); + if (substr.offset == MDNS_INVALID_POS) + return 0; + if (substr.ref) { + *offset = cur + 2; + return 1; + } + cur = substr.offset + substr.length; + } + while (substr.length); + + *offset = cur + 1; + return 1; +} + +#if 0 +static int +mdns_string_equal(const void* buffer_lhs, size_t size_lhs, size_t* ofs_lhs, + const void* buffer_rhs, size_t size_rhs, size_t* ofs_rhs) { + size_t lhs_cur = *ofs_lhs; + size_t rhs_cur = *ofs_rhs; + size_t lhs_end = MDNS_INVALID_POS; + size_t rhs_end = MDNS_INVALID_POS; + mdns_string_pair_t lhs_substr; + mdns_string_pair_t rhs_substr; + do { + lhs_substr = mdns_get_next_substring(buffer_lhs, size_lhs, lhs_cur); + rhs_substr = mdns_get_next_substring(buffer_rhs, size_rhs, rhs_cur); + if ((lhs_substr.offset == MDNS_INVALID_POS) || (rhs_substr.offset == MDNS_INVALID_POS)) + return 0; + if (lhs_substr.length != rhs_substr.length) + return 0; + if (strncasecmp((const char*)buffer_rhs + rhs_substr.offset, + (const char*)buffer_lhs + lhs_substr.offset, rhs_substr.length)) + return 0; + if (lhs_substr.ref && (lhs_end == MDNS_INVALID_POS)) + lhs_end = lhs_cur + 2; + if (rhs_substr.ref && (rhs_end == MDNS_INVALID_POS)) + rhs_end = rhs_cur + 2; + lhs_cur = lhs_substr.offset + lhs_substr.length; + rhs_cur = rhs_substr.offset + rhs_substr.length; + } + while (lhs_substr.length); + + if (lhs_end == MDNS_INVALID_POS) + lhs_end = lhs_cur + 1; + *ofs_lhs = lhs_end; + + if (rhs_end == MDNS_INVALID_POS) + rhs_end = rhs_cur + 1; + *ofs_rhs = rhs_end; + + return 1; +} +#endif + +static mdns_string_t +mdns_string_extract(const void* buffer, size_t size, size_t* offset, + char* str, size_t capacity) { + size_t cur = *offset; + size_t end = MDNS_INVALID_POS; + mdns_string_pair_t substr; + mdns_string_t result = {str, 0}; + char* dst = str; + size_t remain = capacity; + do { + substr = mdns_get_next_substring(buffer, size, cur); + if (substr.offset == MDNS_INVALID_POS) + return result; + if (substr.ref && (end == MDNS_INVALID_POS)) + end = cur + 2; + if (substr.length) { + size_t to_copy = (substr.length < remain) ? substr.length : remain; + memcpy(dst, (const char*)buffer + substr.offset, to_copy); + dst += to_copy; + remain -= to_copy; + if (remain) { + *dst++ = '.'; + --remain; + } + } + cur = substr.offset + substr.length; + } + while (substr.length); + + if (end == MDNS_INVALID_POS) + end = cur + 1; + *offset = end; + + result.length = capacity - remain; + return result; +} + +static size_t +mdns_string_find(const char* str, size_t length, char c, size_t offset) { + const void* found; + if (offset >= length) + return MDNS_INVALID_POS; + found = memchr(str + offset, c, length - offset); + if (found) + return (size_t)((const char*)found - str); + return MDNS_INVALID_POS; +} + +static void* +mdns_string_make(void* data, size_t capacity, const char* name, size_t length) { + size_t pos = 0; + size_t last_pos = 0; + size_t remain = capacity; + unsigned char* dest = data; + while ((last_pos < length) && ((pos = mdns_string_find(name, length, '.', last_pos)) != MDNS_INVALID_POS)) { + size_t sublength = pos - last_pos; + if (sublength < remain) { + *dest = (unsigned char)sublength; + memcpy(dest + 1, name + last_pos, sublength); + dest += sublength + 1; + remain -= sublength + 1; + } + else { + return 0; + } + last_pos = pos + 1; + } + if (last_pos < length) { + size_t sublength = length - last_pos; + if (sublength < capacity) { + *dest = (unsigned char)sublength; + memcpy(dest + 1, name + last_pos, sublength); + dest += sublength + 1; + remain -= sublength + 1; + } + else { + return 0; + } + } + if (!remain) + return 0; + *dest++ = 0; + return dest; +} + +static size_t +mdns_records_parse(const struct sockaddr* from, const void* buffer, size_t size, size_t* offset, + mdns_entry_type_t type, size_t records, mdns_record_callback_fn callback, + void* user_data) { + size_t parsed = 0; + int do_callback = 1; + for (size_t i = 0; i < records; ++i) { + mdns_string_skip(buffer, size, offset); + const uint16_t* data = (const uint16_t*)((const char*)buffer + (*offset)); + + uint16_t rtype = ntohs(*data++); + uint16_t rclass = ntohs(*data++); + uint32_t ttl = ntohs(*(const uint32_t*)(const void*)data); data += 2; + uint16_t length = ntohs(*data++); + + *offset += 10; + + if (do_callback) { + ++parsed; + if (callback(from, type, rtype, rclass, ttl, buffer, size, *offset, length, + user_data)) + do_callback = 0; + } + + *offset += length; + } + return parsed; +} + +static const uint8_t mdns_services_query[] = { + // Transaction ID + 0x00, 0x00, + // Flags + 0x00, 0x00, + // 1 question + 0x00, 0x01, + // No answer, authority or additional RRs + 0x00, 0x00, + 0x00, 0x00, + 0x00, 0x00, + // _services._dns-sd._udp.local. + 0x09, '_', 's', 'e', 'r', 'v', 'i', 'c', 'e', 's', + 0x07, '_', 'd', 'n', 's', '-', 's', 'd', + 0x04, '_', 'u', 'd', 'p', + 0x05, 'l', 'o', 'c', 'a', 'l', + 0x00, + // PTR record + 0x00, MDNS_RECORDTYPE_PTR, + // QU (unicast response) and class IN + 0x80, MDNS_CLASS_IN +}; + +#if 0 +static int +mdns_discovery_send(int sock) { + struct sockaddr_storage addr_storage; + struct sockaddr_in addr; + struct sockaddr_in6 addr6; + struct sockaddr* saddr = (struct sockaddr*)&addr_storage; + socklen_t saddrlen = sizeof(struct sockaddr_storage); + if (getsockname(sock, saddr, &saddrlen)) + return -1; + if (saddr->sa_family == AF_INET6) { + memset(&addr6, 0, sizeof(struct sockaddr_in6)); + addr6.sin6_family = AF_INET6; +#ifdef __APPLE__ + addr6.sin6_len = sizeof(struct sockaddr_in6); +#endif + addr6.sin6_addr.s6_addr[0] = 0xFF; + addr6.sin6_addr.s6_addr[1] = 0x02; + addr6.sin6_addr.s6_addr[15] = 0xFB; + addr6.sin6_port = htons((unsigned short)5353); + saddr = (struct sockaddr*)&addr6; + saddrlen = sizeof(struct sockaddr_in6); + } + else { + memset(&addr, 0, sizeof(struct sockaddr_in)); + addr.sin_family = AF_INET; +#ifdef __APPLE__ + addr.sin_len = sizeof(struct sockaddr_in); +#endif + addr.sin_addr.s_addr = htonl((((uint32_t)224U) << 24U) | ((uint32_t)251U)); + addr.sin_port = htons((unsigned short)5353); + saddr = (struct sockaddr*)&addr; + saddrlen = sizeof(struct sockaddr_in); + } + + if (sendto(sock, mdns_services_query, sizeof(mdns_services_query), 0, + saddr, saddrlen) < 0) + return -1; + return 0; +} + +static size_t +mdns_discovery_recv(int sock, void* buffer, size_t capacity, + mdns_record_callback_fn callback, void* user_data) { + struct sockaddr_in6 addr; + struct sockaddr* saddr = (struct sockaddr*)&addr; + memset(&addr, 0, sizeof(addr)); + saddr->sa_family = AF_INET; +#ifdef __APPLE__ + saddr->sa_len = sizeof(addr); +#endif + socklen_t addrlen = sizeof(addr); + int ret = recvfrom(sock, buffer, capacity, 0, + saddr, &addrlen); + if (ret <= 0) + return 0; + + size_t data_size = (size_t)ret; + size_t records = 0; + uint16_t* data = (uint16_t*)buffer; + + uint16_t transaction_id = ntohs(*data++); + uint16_t flags = ntohs(*data++); + uint16_t questions = ntohs(*data++); + uint16_t answer_rrs = ntohs(*data++); + uint16_t authority_rrs = ntohs(*data++); + uint16_t additional_rrs = ntohs(*data++); + + if (transaction_id || (flags != 0x8400)) + return 0; //Not a reply to our question + + if (questions > 1) + return 0; + + int i; + for (i = 0; i < questions; ++i) { + size_t ofs = (size_t)((char*)data - (char*)buffer); + size_t verify_ofs = 12; + //Verify it's our question, _services._dns-sd._udp.local. + if (!mdns_string_equal(buffer, data_size, &ofs, + mdns_services_query, sizeof(mdns_services_query), &verify_ofs)) + return 0; + data = (uint16_t*)((char*)buffer + ofs); + + uint16_t type = ntohs(*data++); + uint16_t rclass = ntohs(*data++); + + //Make sure we get a reply based on our PTR question for class IN + if ((type != MDNS_RECORDTYPE_PTR) || ((rclass & 0x7FFF) != MDNS_CLASS_IN)) + return 0; + } + + int do_callback = 1; + for (i = 0; i < answer_rrs; ++i) { + size_t ofs = (size_t)((char*)data - (char*)buffer); + size_t verify_ofs = 12; + //Verify it's an answer to our question, _services._dns-sd._udp.local. + int is_answer = mdns_string_equal(buffer, data_size, &ofs, + mdns_services_query, sizeof(mdns_services_query), &verify_ofs); + data = (uint16_t*)((char*)buffer + ofs); + + uint16_t type = ntohs(*data++); + uint16_t rclass = ntohs(*data++); + uint32_t ttl = ntohl(*(uint32_t*)(void*)data); data += 2; + uint16_t length = ntohs(*data++); + + if (is_answer && do_callback) { + ++records; + if (callback(saddr, MDNS_ENTRYTYPE_ANSWER, type, rclass, ttl, buffer, + data_size, (size_t)((char*)data - (char*)buffer), length, + user_data)) + do_callback = 0; + } + data = (void*)((char*)data + length); + } + + size_t offset = (size_t)((char*)data - (char*)buffer); + records += mdns_records_parse(saddr, buffer, data_size, &offset, + MDNS_ENTRYTYPE_AUTHORITY, authority_rrs, + callback, user_data); + records += mdns_records_parse(saddr, buffer, data_size, &offset, + MDNS_ENTRYTYPE_ADDITIONAL, additional_rrs, + callback, user_data); + + return records; +} +#endif + +static uint16_t mdns_transaction_id = 0; + +static int +mdns_query_send(int sock, mdns_record_type_t type, const char* name, size_t length, + void* buffer, size_t capacity) { + if (capacity < (17 + length)) + return -1; + + uint16_t* data = buffer; + //Transaction ID + *data++ = htons(++mdns_transaction_id); + //Flags + *data++ = 0; + //Questions + *data++ = htons(1); + //No answer, authority or additional RRs + *data++ = 0; + *data++ = 0; + *data++ = 0; + //Name string + data = mdns_string_make(data, capacity - 17, name, length); + if (!data) + return -1; + //Record type + *data++ = htons(type); + //! Unicast response, class IN + *data++ = htons(0x8000U | MDNS_CLASS_IN); + + struct sockaddr_storage addr_storage; + struct sockaddr_in addr; + struct sockaddr_in6 addr6; + struct sockaddr* saddr = (struct sockaddr*)&addr_storage; + socklen_t saddrlen = sizeof(struct sockaddr_storage); + if (getsockname(sock, saddr, &saddrlen)) + return -1; + if (saddr->sa_family == AF_INET6) { + memset(&addr6, 0, sizeof(struct sockaddr_in6)); + addr6.sin6_family = AF_INET6; +#ifdef __APPLE__ + addr6.sin6_len = sizeof(struct sockaddr_in6); +#endif + addr6.sin6_addr.s6_addr[0] = 0xFF; + addr6.sin6_addr.s6_addr[1] = 0x02; + addr6.sin6_addr.s6_addr[15] = 0xFB; + addr6.sin6_port = htons((unsigned short)5353); + saddr = (struct sockaddr*)&addr6; + saddrlen = sizeof(struct sockaddr_in6); + } + else { + memset(&addr, 0, sizeof(struct sockaddr_in)); + addr.sin_family = AF_INET; +#ifdef __APPLE__ + addr.sin_len = sizeof(struct sockaddr_in); +#endif + addr.sin_addr.s_addr = htonl((((uint32_t)224U) << 24U) | ((uint32_t)251U)); + addr.sin_port = htons((unsigned short)5353); + saddr = (struct sockaddr*)&addr; + saddrlen = sizeof(struct sockaddr_in); + } + + if (sendto(sock, buffer, (char*)data - (char*)buffer, 0, + saddr, saddrlen) < 0) + return -1; + return 0; +} + +static size_t +mdns_query_recv(int sock, void* buffer, size_t capacity, + mdns_record_callback_fn callback, void* user_data, + uint8_t one_shot) { + struct sockaddr_in6 addr; + struct sockaddr* saddr = (struct sockaddr*)&addr; + memset(&addr, 0, sizeof(addr)); + saddr->sa_family = AF_INET; +#ifdef __APPLE__ + saddr->sa_len = sizeof(addr); +#endif + socklen_t addrlen = sizeof(addr); + int ret = recvfrom(sock, buffer, capacity, 0, + saddr, &addrlen); + if (ret <= 0) + return 0; + + size_t data_size = (size_t)ret; + uint16_t* data = (uint16_t*)buffer; + + uint16_t transaction_id = ntohs(*data++); + ++data;// uint16_t flags = ntohs(*data++); + uint16_t questions = ntohs(*data++); + uint16_t answer_rrs = ntohs(*data++); + uint16_t authority_rrs = ntohs(*data++); + uint16_t additional_rrs = ntohs(*data++); + + if (one_shot && transaction_id != mdns_transaction_id)// || (flags != 0x8400)) + return 0; //Not a reply to our last question + + if (questions > 1) + return 0; + + //Skip questions part + int i; + for (i = 0; i < questions; ++i) { + size_t ofs = (size_t)((char*)data - (char*)buffer); + if (!mdns_string_skip(buffer, data_size, &ofs)) + return 0; + data = (void*)((char*)buffer + ofs); + ++data; + ++data; + } + + size_t records = 0; + size_t offset = (size_t)((char*)data - (char*)buffer); + records += mdns_records_parse(saddr, buffer, data_size, &offset, + MDNS_ENTRYTYPE_ANSWER, answer_rrs, + callback, user_data); + records += mdns_records_parse(saddr, buffer, data_size, &offset, + MDNS_ENTRYTYPE_AUTHORITY, authority_rrs, + callback, user_data); + records += mdns_records_parse(saddr, buffer, data_size, &offset, + MDNS_ENTRYTYPE_ADDITIONAL, additional_rrs, + callback, user_data); + return records; +} + +static mdns_string_t +mdns_record_parse_ptr(const void* buffer, size_t size, size_t offset, size_t length, + char* strbuffer, size_t capacity) { + //PTR record is just a string + if ((size >= offset + length) && (length >= 2)) + return mdns_string_extract(buffer, size, &offset, strbuffer, capacity); + mdns_string_t empty = {0, 0}; + return empty; +} + +static mdns_record_srv_t +mdns_record_parse_srv(const void* buffer, size_t size, size_t offset, size_t length, + char* strbuffer, size_t capacity) { + mdns_record_srv_t srv; + memset(&srv, 0, sizeof(mdns_record_srv_t)); + // Read the priority, weight, port number and the discovery name + // SRV record format (http://www.ietf.org/rfc/rfc2782.txt): + // 2 bytes network-order unsigned priority + // 2 bytes network-order unsigned weight + // 2 bytes network-order unsigned port + // string: discovery (domain) name, minimum 2 bytes when compressed + if ((size >= offset + length) && (length >= 8)) { + const uint16_t* recorddata = (const uint16_t*)((const char*)buffer + offset); + srv.priority = ntohs(*recorddata++); + srv.weight = ntohs(*recorddata++); + srv.port = ntohs(*recorddata++); + offset += 6; + srv.name = mdns_string_extract(buffer, size, &offset, strbuffer, capacity); + } + return srv; +} + +static struct sockaddr_in* +mdns_record_parse_a(const void* buffer, size_t size, size_t offset, size_t length, + struct sockaddr_in* addr) { + memset(addr, 0, sizeof(struct sockaddr_in)); + addr->sin_family = AF_INET; +#ifdef __APPLE__ + addr->sin_len = sizeof(struct sockaddr_in); +#endif + if ((size >= offset + length) && (length == 4)) + addr->sin_addr.s_addr = *(const uint32_t*)((const char*)buffer + offset); + return addr; +} + +static struct sockaddr_in6* +mdns_record_parse_aaaa(const void* buffer, size_t size, size_t offset, size_t length, + struct sockaddr_in6* addr) { + memset(addr, 0, sizeof(struct sockaddr_in6)); + addr->sin6_family = AF_INET6; +#ifdef __APPLE__ + addr->sin6_len = sizeof(struct sockaddr_in6); +#endif + if ((size >= offset + length) && (length == 16)) + addr->sin6_addr = *(const struct in6_addr*)((const char*)buffer + offset); + return addr; +} + +static size_t +mdns_record_parse_txt(const void* buffer, size_t size, size_t offset, size_t length, + mdns_record_txt_t* records, size_t capacity) { + size_t parsed = 0; + const char* strdata; + size_t separator, sublength; + size_t end = offset + length; + + if (size < end) + end = size; + + while ((offset < end) && (parsed < capacity)) { + strdata = (const char*)buffer + offset; + sublength = *(const unsigned char*)strdata; + + ++strdata; + offset += sublength + 1; + + separator = 0; + for (size_t c = 0; c < sublength; ++c) { + //DNS-SD TXT record keys MUST be printable US-ASCII, [0x20, 0x7E] + if ((strdata[c] < 0x20) || (strdata[c] > 0x7E)) + break; + if (strdata[c] == '=') { + separator = c; + break; + } + } + + if (!separator) + continue; + + if (separator < sublength) { + records[parsed].key.str = strdata; + records[parsed].key.length = separator; + records[parsed].value.str = strdata + separator + 1; + records[parsed].value.length = sublength - (separator + 1); + } + else { + records[parsed].key.str = strdata; + records[parsed].key.length = sublength; + } + + ++parsed; + } + + return parsed; +} + +#ifdef _WIN32 +#undef strncasecmp +#endif |