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-rw-r--r--ctrl/facemgr/src/interfaces/bonjour/mdns/mdns.h879
1 files changed, 879 insertions, 0 deletions
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, &param);
+#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, &param);
+#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