5 * Copyright (C) 2007-2012 Intel Corporation. All rights reserved.
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
31 #include <arpa/inet.h>
32 #include <netinet/in.h>
33 #include <sys/types.h>
34 #include <sys/socket.h>
37 #include <gweb/gresolv.h>
43 #if __BYTE_ORDER == __LITTLE_ENDIAN
58 } __attribute__ ((packed));
59 #elif __BYTE_ORDER == __BIG_ENDIAN
74 } __attribute__ ((packed));
76 #error "Unknown byte order"
79 struct partial_reply {
95 struct partial_reply *incoming_reply;
100 struct sockaddr_in6 __sin6; /* Only for the length */
118 struct listener_data *ifdata;
119 gboolean append_domain;
122 struct listener_data {
124 GIOChannel *udp_listener_channel;
125 guint udp_listener_watch;
126 GIOChannel *tcp_listener_channel;
127 guint tcp_listener_watch;
137 unsigned int data_len;
138 unsigned char *data; /* contains DNS header + body */
145 struct cache_data *ipv4;
146 struct cache_data *ipv6;
149 struct domain_question {
152 } __attribute__ ((packed));
159 } __attribute__ ((packed));
162 * We limit how long the cached DNS entry stays in the cache.
163 * By default the TTL (time-to-live) of the DNS response is used
164 * when setting the cache entry life time. The value is in seconds.
166 #define MAX_CACHE_TTL (60 * 30)
168 * Also limit the other end, cache at least for 30 seconds.
170 #define MIN_CACHE_TTL (30)
173 * We limit the cache size to some sane value so that cached data does
174 * not occupy too much memory. Each cached entry occupies on average
175 * about 100 bytes memory (depending on DNS name length).
176 * Example: caching www.connman.net uses 97 bytes memory.
177 * The value is the max amount of cached DNS responses (count).
179 #define MAX_CACHE_SIZE 256
181 static int cache_size;
182 static GHashTable *cache;
183 static int cache_refcount;
184 static GSList *server_list = NULL;
185 static GSList *request_list = NULL;
186 static GHashTable *listener_table = NULL;
187 static time_t next_refresh;
189 static guint16 get_id()
194 static int protocol_offset(int protocol)
210 * There is a power and efficiency benefit to have entries
211 * in our cache expire at the same time. To this extend,
212 * we round down the cache valid time to common boundaries.
214 static time_t round_down_ttl(time_t end_time, int ttl)
219 /* Less than 5 minutes, round to 10 second boundary */
221 end_time = end_time / 10;
222 end_time = end_time * 10;
223 } else { /* 5 or more minutes, round to 30 seconds */
224 end_time = end_time / 30;
225 end_time = end_time * 30;
230 static struct request_data *find_request(guint16 id)
234 for (list = request_list; list; list = list->next) {
235 struct request_data *req = list->data;
237 if (req->dstid == id || req->altid == id)
244 static struct server_data *find_server(const char *interface,
250 DBG("interface %s server %s", interface, server);
252 for (list = server_list; list; list = list->next) {
253 struct server_data *data = list->data;
255 if (interface == NULL && data->interface == NULL &&
256 g_str_equal(data->server, server) == TRUE &&
257 data->protocol == protocol)
260 if (interface == NULL ||
261 data->interface == NULL || data->server == NULL)
264 if (g_str_equal(data->interface, interface) == TRUE &&
265 g_str_equal(data->server, server) == TRUE &&
266 data->protocol == protocol)
273 /* we can keep using the same resolve's */
274 static GResolv *ipv4_resolve;
275 static GResolv *ipv6_resolve;
277 static void dummy_resolve_func(GResolvResultStatus status,
278 char **results, gpointer user_data)
283 * Refresh a DNS entry, but also age the hit count a bit */
284 static void refresh_dns_entry(struct cache_entry *entry, char *name)
288 if (ipv4_resolve == NULL) {
289 ipv4_resolve = g_resolv_new(0);
290 g_resolv_set_address_family(ipv4_resolve, AF_INET);
291 g_resolv_add_nameserver(ipv4_resolve, "127.0.0.1", 53, 0);
294 if (ipv6_resolve == NULL) {
295 ipv6_resolve = g_resolv_new(0);
296 g_resolv_set_address_family(ipv6_resolve, AF_INET6);
297 g_resolv_add_nameserver(ipv6_resolve, "127.0.0.1", 53, 0);
300 if (entry->ipv4 == NULL) {
301 DBG("Refresing A record for %s", name);
302 g_resolv_lookup_hostname(ipv4_resolve, name,
303 dummy_resolve_func, NULL);
307 if (entry->ipv6 == NULL) {
308 DBG("Refresing AAAA record for %s", name);
309 g_resolv_lookup_hostname(ipv6_resolve, name,
310 dummy_resolve_func, NULL);
319 static int dns_name_length(unsigned char *buf)
321 if ((buf[0] & NS_CMPRSFLGS) == NS_CMPRSFLGS) /* compressed name */
323 return strlen((char *)buf);
326 static void update_cached_ttl(unsigned char *buf, int len, int new_ttl)
333 /* skip the header */
337 /* skip the query, which is a name and 2 16 bit words */
338 l = dns_name_length(c);
344 /* now we get the answer records */
348 l = dns_name_length(c);
353 /* then type + class, 2 bytes each */
359 /* now the 4 byte TTL field */
367 /* now the 2 byte rdlen field */
370 len -= ntohs(*w) + 2;
374 static void send_cached_response(int sk, unsigned char *buf, int len,
375 const struct sockaddr *to, socklen_t tolen,
376 int protocol, int id, uint16_t answers, int ttl)
378 struct domain_hdr *hdr;
379 unsigned char *ptr = buf;
380 int err, offset, dns_len, adj_len = len - 2;
383 * The cached packet contains always the TCP offset (two bytes)
384 * so skip them for UDP.
395 dns_len = ptr[0] * 256 + ptr[1];
404 hdr = (void *) (ptr + offset);
409 hdr->ancount = htons(answers);
413 /* if this is a negative reply, we are authorative */
417 update_cached_ttl((unsigned char *)hdr, adj_len, ttl);
419 DBG("sk %d id 0x%04x answers %d ptr %p length %d dns %d",
420 sk, hdr->id, answers, ptr, len, dns_len);
422 err = sendto(sk, ptr, len, MSG_NOSIGNAL, to, tolen);
424 connman_error("Cannot send cached DNS response: %s",
429 if (err != len || (dns_len != (len - 2) && protocol == IPPROTO_TCP) ||
430 (dns_len != len && protocol == IPPROTO_UDP))
431 DBG("Packet length mismatch, sent %d wanted %d dns %d",
435 static void send_response(int sk, unsigned char *buf, int len,
436 const struct sockaddr *to, socklen_t tolen,
439 struct domain_hdr *hdr;
440 int err, offset = protocol_offset(protocol);
450 hdr = (void *) (buf + offset);
452 DBG("id 0x%04x qr %d opcode %d", hdr->id, hdr->qr, hdr->opcode);
461 err = sendto(sk, buf, len, MSG_NOSIGNAL, to, tolen);
463 connman_error("Failed to send DNS response: %s",
469 static gboolean request_timeout(gpointer user_data)
471 struct request_data *req = user_data;
472 struct listener_data *ifdata;
474 DBG("id 0x%04x", req->srcid);
479 ifdata = req->ifdata;
481 request_list = g_slist_remove(request_list, req);
484 if (req->resplen > 0 && req->resp != NULL) {
487 sk = g_io_channel_unix_get_fd(ifdata->udp_listener_channel);
489 err = sendto(sk, req->resp, req->resplen, MSG_NOSIGNAL,
490 &req->sa, req->sa_len);
493 } else if (req->request && req->numserv == 0) {
494 struct domain_hdr *hdr;
496 if (req->protocol == IPPROTO_TCP) {
497 hdr = (void *) (req->request + 2);
498 hdr->id = req->srcid;
499 send_response(req->client_sk, req->request,
500 req->request_len, NULL, 0, IPPROTO_TCP);
502 } else if (req->protocol == IPPROTO_UDP) {
505 hdr = (void *) (req->request);
506 hdr->id = req->srcid;
507 sk = g_io_channel_unix_get_fd(
508 ifdata->udp_listener_channel);
509 send_response(sk, req->request, req->request_len,
510 &req->sa, req->sa_len, IPPROTO_UDP);
520 static int append_query(unsigned char *buf, unsigned int size,
521 const char *query, const char *domain)
523 unsigned char *ptr = buf;
526 DBG("query %s domain %s", query, domain);
528 while (query != NULL) {
531 tmp = strchr(query, '.');
537 memcpy(ptr + 1, query, len);
543 memcpy(ptr + 1, query, tmp - query);
544 ptr += tmp - query + 1;
549 while (domain != NULL) {
552 tmp = strchr(domain, '.');
554 len = strlen(domain);
558 memcpy(ptr + 1, domain, len);
564 memcpy(ptr + 1, domain, tmp - domain);
565 ptr += tmp - domain + 1;
575 static gboolean cache_check_is_valid(struct cache_data *data,
581 if (data->cache_until < current_time)
588 * remove stale cached entries so that they can be refreshed
590 static void cache_enforce_validity(struct cache_entry *entry)
592 time_t current_time = time(NULL);
594 if (cache_check_is_valid(entry->ipv4, current_time) == FALSE
596 DBG("cache timeout \"%s\" type A", entry->key);
597 g_free(entry->ipv4->data);
603 if (cache_check_is_valid(entry->ipv6, current_time) == FALSE
605 DBG("cache timeout \"%s\" type AAAA", entry->key);
606 g_free(entry->ipv6->data);
612 static uint16_t cache_check_validity(char *question, uint16_t type,
613 struct cache_entry *entry)
615 time_t current_time = time(NULL);
616 int want_refresh = 0;
619 * if we have a popular entry, we want a refresh instead of
620 * total destruction of the entry.
625 cache_enforce_validity(entry);
629 if (cache_check_is_valid(entry->ipv4, current_time) == FALSE) {
630 DBG("cache %s \"%s\" type A", entry->ipv4 ?
631 "timeout" : "entry missing", question);
634 entry->want_refresh = 1;
637 * We do not remove cache entry if there is still
638 * valid IPv6 entry found in the cache.
640 if (cache_check_is_valid(entry->ipv6, current_time)
641 == FALSE && want_refresh == FALSE) {
642 g_hash_table_remove(cache, question);
649 if (cache_check_is_valid(entry->ipv6, current_time) == FALSE) {
650 DBG("cache %s \"%s\" type AAAA", entry->ipv6 ?
651 "timeout" : "entry missing", question);
654 entry->want_refresh = 1;
656 if (cache_check_is_valid(entry->ipv4, current_time)
657 == FALSE && want_refresh == FALSE) {
658 g_hash_table_remove(cache, question);
668 static struct cache_entry *cache_check(gpointer request, int *qtype)
670 char *question = request + 12;
671 struct cache_entry *entry;
672 struct domain_question *q;
676 offset = strlen(question) + 1;
677 q = (void *) (question + offset);
678 type = ntohs(q->type);
680 /* We only cache either A (1) or AAAA (28) requests */
681 if (type != 1 && type != 28)
684 entry = g_hash_table_lookup(cache, question);
688 type = cache_check_validity(question, type, entry);
697 * Get a label/name from DNS resource record. The function decompresses the
698 * label if necessary. The function does not convert the name to presentation
699 * form. This means that the result string will contain label lengths instead
700 * of dots between labels. We intentionally do not want to convert to dotted
701 * format so that we can cache the wire format string directly.
703 static int get_name(int counter,
704 unsigned char *pkt, unsigned char *start, unsigned char *max,
705 unsigned char *output, int output_max, int *output_len,
706 unsigned char **end, char *name, int *name_len)
710 /* Limit recursion to 10 (this means up to 10 labels in domain name) */
716 if ((*p & NS_CMPRSFLGS) == NS_CMPRSFLGS) {
717 uint16_t offset = (*p & 0x3F) * 256 + *(p + 1);
719 if (offset >= max - pkt)
725 return get_name(counter + 1, pkt, pkt + offset, max,
726 output, output_max, output_len, end,
729 unsigned label_len = *p;
731 if (pkt + label_len > max)
734 if (*output_len > output_max)
738 * We need the original name in order to check
739 * if this answer is the correct one.
741 name[(*name_len)++] = label_len;
742 memcpy(name + *name_len, p + 1, label_len + 1);
743 *name_len += label_len;
745 /* We compress the result */
746 output[0] = NS_CMPRSFLGS;
763 static int parse_rr(unsigned char *buf, unsigned char *start,
765 unsigned char *response, unsigned int *response_size,
766 uint16_t *type, uint16_t *class, int *ttl, int *rdlen,
770 struct domain_rr *rr;
772 int name_len = 0, output_len = 0, max_rsp = *response_size;
774 err = get_name(0, buf, start, max, response, max_rsp,
775 &output_len, end, name, &name_len);
781 if ((unsigned int) offset > *response_size)
784 rr = (void *) (*end);
789 *type = ntohs(rr->type);
790 *class = ntohs(rr->class);
791 *ttl = ntohl(rr->ttl);
792 *rdlen = ntohs(rr->rdlen);
797 memcpy(response + offset, *end, sizeof(struct domain_rr));
799 offset += sizeof(struct domain_rr);
800 *end += sizeof(struct domain_rr);
802 if ((unsigned int) (offset + *rdlen) > *response_size)
805 memcpy(response + offset, *end, *rdlen);
809 *response_size = offset + *rdlen;
814 static gboolean check_alias(GSList *aliases, char *name)
818 if (aliases != NULL) {
819 for (list = aliases; list; list = list->next) {
820 int len = strlen((char *)list->data);
821 if (strncmp((char *)list->data, name, len) == 0)
829 static int parse_response(unsigned char *buf, int buflen,
830 char *question, int qlen,
831 uint16_t *type, uint16_t *class, int *ttl,
832 unsigned char *response, unsigned int *response_len,
835 struct domain_hdr *hdr = (void *) buf;
836 struct domain_question *q;
838 uint16_t qdcount = ntohs(hdr->qdcount);
839 uint16_t ancount = ntohs(hdr->ancount);
841 uint16_t qtype, qclass;
842 unsigned char *next = NULL;
843 unsigned int maxlen = *response_len;
844 GSList *aliases = NULL, *list;
845 char name[NS_MAXDNAME + 1];
850 DBG("qr %d qdcount %d", hdr->qr, qdcount);
852 /* We currently only cache responses where question count is 1 */
853 if (hdr->qr != 1 || qdcount != 1)
856 ptr = buf + sizeof(struct domain_hdr);
858 strncpy(question, (char *) ptr, qlen);
859 qlen = strlen(question);
860 ptr += qlen + 1; /* skip \0 */
863 qtype = ntohs(q->type);
865 /* We cache only A and AAAA records */
866 if (qtype != 1 && qtype != 28)
869 qclass = ntohs(q->class);
871 ptr += 2 + 2; /* ptr points now to answers */
878 * We have a bunch of answers (like A, AAAA, CNAME etc) to
879 * A or AAAA question. We traverse the answers and parse the
880 * resource records. Only A and AAAA records are cached, all
881 * the other records in answers are skipped.
883 for (i = 0; i < ancount; i++) {
885 * Get one address at a time to this buffer.
886 * The max size of the answer is
887 * 2 (pointer) + 2 (type) + 2 (class) +
888 * 4 (ttl) + 2 (rdlen) + addr (16 or 4) = 28
889 * for A or AAAA record.
890 * For CNAME the size can be bigger.
892 unsigned char rsp[NS_MAXCDNAME];
893 unsigned int rsp_len = sizeof(rsp) - 1;
896 memset(rsp, 0, sizeof(rsp));
898 ret = parse_rr(buf, ptr, buf + buflen, rsp, &rsp_len,
899 type, class, ttl, &rdlen, &next, name);
906 * Now rsp contains compressed or uncompressed resource
907 * record. Next we check if this record answers the question.
908 * The name var contains the uncompressed label.
909 * One tricky bit is the CNAME records as they alias
910 * the name we might be interested in.
914 * Go to next answer if the class is not the one we are
917 if (*class != qclass) {
924 * Try to resolve aliases also, type is CNAME(5).
925 * This is important as otherwise the aliased names would not
926 * be cached at all as the cache would not contain the aliased
929 * If any CNAME is found in DNS packet, then we cache the alias
930 * IP address instead of the question (as the server
931 * said that question has only an alias).
932 * This means in practice that if e.g., ipv6.google.com is
933 * queried, DNS server returns CNAME of that name which is
934 * ipv6.l.google.com. We then cache the address of the CNAME
935 * but return the question name to client. So the alias
936 * status of the name is not saved in cache and thus not
937 * returned to the client. We do not return DNS packets from
938 * cache to client saying that ipv6.google.com is an alias to
939 * ipv6.l.google.com but we return instead a DNS packet that
940 * says ipv6.google.com has address xxx which is in fact the
941 * address of ipv6.l.google.com. For caching purposes this
942 * should not cause any issues.
944 if (*type == 5 && strncmp(question, name, qlen) == 0) {
946 * So now the alias answered the question. This is
947 * not very useful from caching point of view as
948 * the following A or AAAA records will not match the
949 * question. We need to find the real A/AAAA record
950 * of the alias and cache that.
952 unsigned char *end = NULL;
953 int name_len = 0, output_len;
955 memset(rsp, 0, sizeof(rsp));
956 rsp_len = sizeof(rsp) - 1;
959 * Alias is in rdata part of the message,
960 * and next-rdlen points to it. So we need to get
961 * the real name of the alias.
963 ret = get_name(0, buf, next - rdlen, buf + buflen,
964 rsp, rsp_len, &output_len, &end,
967 /* just ignore the error at this point */
974 * We should now have the alias of the entry we might
975 * want to cache. Just remember it for a while.
976 * We check the alias list when we have parsed the
979 aliases = g_slist_prepend(aliases, g_strdup(name));
986 if (*type == qtype) {
988 * We found correct type (A or AAAA)
990 if (check_alias(aliases, name) == TRUE ||
991 (aliases == NULL && strncmp(question, name,
994 * We found an alias or the name of the rr
995 * matches the question. If so, we append
996 * the compressed label to the cache.
997 * The end result is a response buffer that
998 * will contain one or more cached and
999 * compressed resource records.
1001 if (*response_len + rsp_len > maxlen) {
1005 memcpy(response + *response_len, rsp, rsp_len);
1006 *response_len += rsp_len;
1017 for (list = aliases; list; list = list->next)
1019 g_slist_free(aliases);
1024 struct cache_timeout {
1025 time_t current_time;
1030 static gboolean cache_check_entry(gpointer key, gpointer value,
1033 struct cache_timeout *data = user_data;
1034 struct cache_entry *entry = value;
1037 /* Scale the number of hits by half as part of cache aging */
1042 * If either IPv4 or IPv6 cached entry has expired, we
1043 * remove both from the cache.
1046 if (entry->ipv4 != NULL && entry->ipv4->timeout > 0) {
1047 max_timeout = entry->ipv4->cache_until;
1048 if (max_timeout > data->max_timeout)
1049 data->max_timeout = max_timeout;
1051 if (entry->ipv4->cache_until < data->current_time)
1055 if (entry->ipv6 != NULL && entry->ipv6->timeout > 0) {
1056 max_timeout = entry->ipv6->cache_until;
1057 if (max_timeout > data->max_timeout)
1058 data->max_timeout = max_timeout;
1060 if (entry->ipv6->cache_until < data->current_time)
1065 * if we're asked to try harder, also remove entries that have
1068 if (data->try_harder && entry->hits < 4)
1074 static void cache_cleanup(void)
1076 static int max_timeout;
1077 struct cache_timeout data;
1080 data.current_time = time(NULL);
1081 data.max_timeout = 0;
1082 data.try_harder = 0;
1085 * In the first pass, we only remove entries that have timed out.
1086 * We use a cache of the first time to expire to do this only
1087 * when it makes sense.
1089 if (max_timeout <= data.current_time) {
1090 count = g_hash_table_foreach_remove(cache, cache_check_entry,
1093 DBG("removed %d in the first pass", count);
1096 * In the second pass, if the first pass turned up blank,
1097 * we also expire entries with a low hit count,
1098 * while aging the hit count at the same time.
1100 data.try_harder = 1;
1102 count = g_hash_table_foreach_remove(cache, cache_check_entry,
1107 * If we could not remove anything, then remember
1108 * what is the max timeout and do nothing if we
1109 * have not yet reached it. This will prevent
1110 * constant traversal of the cache if it is full.
1112 max_timeout = data.max_timeout;
1117 static gboolean cache_invalidate_entry(gpointer key, gpointer value,
1120 struct cache_entry *entry = value;
1122 /* first, delete any expired elements */
1123 cache_enforce_validity(entry);
1125 /* if anything is not expired, mark the entry for refresh */
1126 if (entry->hits > 0 && (entry->ipv4 || entry->ipv6))
1127 entry->want_refresh = 1;
1129 /* delete the cached data */
1131 g_free(entry->ipv4->data);
1132 g_free(entry->ipv4);
1137 g_free(entry->ipv6->data);
1138 g_free(entry->ipv6);
1142 /* keep the entry if we want it refreshed, delete it otherwise */
1143 if (entry->want_refresh)
1150 * cache_invalidate is called from places where the DNS landscape
1151 * has changed, say because connections are added or we entered a VPN.
1152 * The logic is to wipe all cache data, but mark all non-expired
1153 * parts of the cache for refresh rather than deleting the whole cache.
1155 static void cache_invalidate(void)
1157 DBG("Invalidating the DNS cache %p", cache);
1162 g_hash_table_foreach_remove(cache, cache_invalidate_entry, NULL);
1165 static void cache_refresh_entry(struct cache_entry *entry)
1168 cache_enforce_validity(entry);
1170 if (entry->hits > 2 && entry->ipv4 == NULL)
1171 entry->want_refresh = 1;
1172 if (entry->hits > 2 && entry->ipv6 == NULL)
1173 entry->want_refresh = 1;
1175 if (entry->want_refresh) {
1177 char dns_name[NS_MAXDNAME + 1];
1178 entry->want_refresh = 0;
1180 /* turn a DNS name into a hostname with dots */
1181 strncpy(dns_name, entry->key, NS_MAXDNAME);
1189 DBG("Refreshing %s\n", dns_name);
1190 /* then refresh the hostname */
1191 refresh_dns_entry(entry, &dns_name[1]);
1195 static void cache_refresh_iterator(gpointer key, gpointer value,
1198 struct cache_entry *entry = value;
1200 cache_refresh_entry(entry);
1203 static void cache_refresh(void)
1208 g_hash_table_foreach(cache, cache_refresh_iterator, NULL);
1211 static int reply_query_type(unsigned char *msg, int len)
1218 /* skip the header */
1219 c = msg + sizeof(struct domain_hdr);
1220 len -= sizeof(struct domain_hdr);
1225 /* now the query, which is a name and 2 16 bit words */
1226 l = dns_name_length(c) + 1;
1234 static int cache_update(struct server_data *srv, unsigned char *msg,
1235 unsigned int msg_len)
1237 int offset = protocol_offset(srv->protocol);
1238 int err, qlen, ttl = 0;
1239 uint16_t answers = 0, type = 0, class = 0;
1240 struct domain_question *q;
1241 struct cache_entry *entry;
1242 struct cache_data *data;
1243 char question[NS_MAXDNAME + 1];
1244 unsigned char response[NS_MAXDNAME + 1];
1246 unsigned int rsplen;
1247 gboolean new_entry = TRUE;
1248 time_t current_time;
1250 if (cache_size >= MAX_CACHE_SIZE) {
1252 if (cache_size >= MAX_CACHE_SIZE)
1256 current_time = time(NULL);
1258 /* don't do a cache refresh more than twice a minute */
1259 if (next_refresh < current_time) {
1261 next_refresh = current_time + 30;
1265 /* Continue only if response code is 0 (=ok) */
1272 rsplen = sizeof(response) - 1;
1273 question[sizeof(question) - 1] = '\0';
1275 err = parse_response(msg + offset, msg_len - offset,
1276 question, sizeof(question) - 1,
1277 &type, &class, &ttl,
1278 response, &rsplen, &answers);
1281 * special case: if we do a ipv6 lookup and get no result
1282 * for a record that's already in our ipv4 cache.. we want
1283 * to cache the negative response.
1285 if ((err == -ENOMSG || err == -ENOBUFS) &&
1286 reply_query_type(msg, msg_len) == 28) {
1287 entry = g_hash_table_lookup(cache, question);
1288 if (entry && entry->ipv4 && entry->ipv6 == NULL) {
1289 data = g_try_new(struct cache_data, 1);
1292 data->inserted = entry->ipv4->inserted;
1294 data->answers = msg[5];
1295 data->timeout = entry->ipv4->timeout;
1296 data->data_len = msg_len;
1297 data->data = ptr = g_malloc(msg_len);
1298 data->valid_until = entry->ipv4->valid_until;
1299 data->cache_until = entry->ipv4->cache_until;
1300 memcpy(data->data, msg, msg_len);
1303 * we will get a "hit" when we serve the response
1307 if (entry->hits < 0)
1313 if (err < 0 || ttl == 0)
1316 qlen = strlen(question);
1319 * If the cache contains already data, check if the
1320 * type of the cached data is the same and do not add
1321 * to cache if data is already there.
1322 * This is needed so that we can cache both A and AAAA
1323 * records for the same name.
1325 entry = g_hash_table_lookup(cache, question);
1326 if (entry == NULL) {
1327 entry = g_try_new(struct cache_entry, 1);
1331 data = g_try_new(struct cache_data, 1);
1337 entry->key = g_strdup(question);
1338 entry->ipv4 = entry->ipv6 = NULL;
1339 entry->want_refresh = 0;
1347 if (type == 1 && entry->ipv4 != NULL)
1350 if (type == 28 && entry->ipv6 != NULL)
1353 data = g_try_new(struct cache_data, 1);
1363 * compensate for the hit we'll get for serving
1364 * the response out of the cache
1367 if (entry->hits < 0)
1373 if (ttl < MIN_CACHE_TTL)
1374 ttl = MIN_CACHE_TTL;
1376 data->inserted = current_time;
1378 data->answers = answers;
1379 data->timeout = ttl;
1381 * The "2" in start of the length is the TCP offset. We allocate it
1382 * here even for UDP packet because it simplifies the sending
1385 data->data_len = 2 + 12 + qlen + 1 + 2 + 2 + rsplen;
1386 data->data = ptr = g_malloc(data->data_len);
1387 data->valid_until = current_time + ttl;
1390 * Restrict the cached DNS record TTL to some sane value
1391 * in order to prevent data staying in the cache too long.
1393 if (ttl > MAX_CACHE_TTL)
1394 ttl = MAX_CACHE_TTL;
1396 data->cache_until = round_down_ttl(current_time + ttl, ttl);
1398 if (data->data == NULL) {
1406 * We cache the two extra bytes at the start of the message
1407 * in a TCP packet. When sending UDP packet, we skip the first
1408 * two bytes. This way we do not need to know the format
1409 * (UDP/TCP) of the cached message.
1411 ptr[0] = (data->data_len - 2) / 256;
1412 ptr[1] = (data->data_len - 2) - ptr[0] * 256;
1413 if (srv->protocol == IPPROTO_UDP)
1416 memcpy(ptr, msg, offset + 12);
1417 memcpy(ptr + offset + 12, question, qlen + 1); /* copy also the \0 */
1419 q = (void *) (ptr + offset + 12 + qlen + 1);
1420 q->type = htons(type);
1421 q->class = htons(class);
1422 memcpy(ptr + offset + 12 + qlen + 1 + sizeof(struct domain_question),
1425 if (new_entry == TRUE) {
1426 g_hash_table_replace(cache, entry->key, entry);
1430 DBG("cache %d %squestion \"%s\" type %d ttl %d size %zd packet %u "
1432 cache_size, new_entry ? "new " : "old ",
1433 question, type, ttl,
1434 sizeof(*entry) + sizeof(*data) + data->data_len + qlen,
1436 srv->protocol == IPPROTO_TCP ?
1437 (unsigned int)(data->data[0] * 256 + data->data[1]) :
1443 static int ns_resolv(struct server_data *server, struct request_data *req,
1444 gpointer request, gpointer name)
1447 int sk, err, type = 0;
1448 char *dot, *lookup = (char *) name;
1449 struct cache_entry *entry;
1451 entry = cache_check(request, &type);
1452 if (entry != NULL) {
1454 struct cache_data *data;
1456 DBG("cache hit %s type %s", lookup, type == 1 ? "A" : "AAAA");
1463 ttl_left = data->valid_until - time(NULL);
1467 if (data != NULL && req->protocol == IPPROTO_TCP) {
1468 send_cached_response(req->client_sk, data->data,
1469 data->data_len, NULL, 0, IPPROTO_TCP,
1470 req->srcid, data->answers, ttl_left);
1474 if (data != NULL && req->protocol == IPPROTO_UDP) {
1476 sk = g_io_channel_unix_get_fd(
1477 req->ifdata->udp_listener_channel);
1479 send_cached_response(sk, data->data,
1480 data->data_len, &req->sa, req->sa_len,
1481 IPPROTO_UDP, req->srcid, data->answers,
1487 sk = g_io_channel_unix_get_fd(server->channel);
1489 err = send(sk, request, req->request_len, MSG_NOSIGNAL);
1495 /* If we have more than one dot, we don't add domains */
1496 dot = strchr(lookup, '.');
1497 if (dot != NULL && dot != lookup + strlen(lookup) - 1)
1500 if (server->domains != NULL && server->domains->data != NULL)
1501 req->append_domain = TRUE;
1503 for (list = server->domains; list; list = list->next) {
1505 unsigned char alt[1024];
1506 struct domain_hdr *hdr = (void *) &alt;
1507 int altlen, domlen, offset;
1509 domain = list->data;
1514 offset = protocol_offset(server->protocol);
1518 domlen = strlen(domain) + 1;
1522 alt[offset] = req->altid & 0xff;
1523 alt[offset + 1] = req->altid >> 8;
1525 memcpy(alt + offset + 2, request + offset + 2, 10);
1526 hdr->qdcount = htons(1);
1528 altlen = append_query(alt + offset + 12, sizeof(alt) - 12,
1535 memcpy(alt + offset + altlen,
1536 request + offset + altlen - domlen,
1537 req->request_len - altlen - offset + domlen);
1539 if (server->protocol == IPPROTO_TCP) {
1540 int req_len = req->request_len + domlen - 2;
1542 alt[0] = (req_len >> 8) & 0xff;
1543 alt[1] = req_len & 0xff;
1546 err = send(sk, alt, req->request_len + domlen, MSG_NOSIGNAL);
1556 static void destroy_request_data(struct request_data *req)
1558 if (req->timeout > 0)
1559 g_source_remove(req->timeout);
1562 g_free(req->request);
1567 static int forward_dns_reply(unsigned char *reply, int reply_len, int protocol,
1568 struct server_data *data)
1570 struct domain_hdr *hdr;
1571 struct request_data *req;
1572 int dns_id, sk, err, offset = protocol_offset(protocol);
1573 struct listener_data *ifdata;
1578 hdr = (void *)(reply + offset);
1579 dns_id = reply[offset] | reply[offset + 1] << 8;
1581 DBG("Received %d bytes (id 0x%04x)", reply_len, dns_id);
1583 req = find_request(dns_id);
1587 DBG("id 0x%04x rcode %d", hdr->id, hdr->rcode);
1589 ifdata = req->ifdata;
1591 reply[offset] = req->srcid & 0xff;
1592 reply[offset + 1] = req->srcid >> 8;
1596 if (hdr->rcode == 0 || req->resp == NULL) {
1599 * If the domain name was append
1600 * remove it before forwarding the reply.
1602 if (req->append_domain == TRUE) {
1605 unsigned int domain_len;
1608 * ptr points to the first char of the hostname.
1609 * ->hostname.domain.net
1611 ptr = reply + offset + sizeof(struct domain_hdr);
1613 domain_len = strlen((const char *)ptr + host_len + 1);
1616 * Remove the domain name and replace it by the end
1617 * of reply. Check if the domain is really there
1618 * before trying to copy the data. The domain_len can
1619 * be 0 because if the original query did not contain
1620 * a domain name, then we are sending two packets,
1621 * first without the domain name and the second packet
1622 * with domain name. The append_domain is set to true
1623 * even if we sent the first packet without domain
1624 * name. In this case we end up in this branch.
1626 if (domain_len > 0) {
1628 * Note that we must use memmove() here,
1629 * because the memory areas can overlap.
1631 memmove(ptr + host_len + 1,
1632 ptr + host_len + domain_len + 1,
1633 reply_len - (ptr - reply + domain_len));
1635 reply_len = reply_len - domain_len;
1642 req->resp = g_try_malloc(reply_len);
1643 if (req->resp == NULL)
1646 memcpy(req->resp, reply, reply_len);
1647 req->resplen = reply_len;
1649 cache_update(data, reply, reply_len);
1652 if (hdr->rcode > 0 && req->numresp < req->numserv)
1655 request_list = g_slist_remove(request_list, req);
1657 if (protocol == IPPROTO_UDP) {
1658 sk = g_io_channel_unix_get_fd(ifdata->udp_listener_channel);
1659 err = sendto(sk, req->resp, req->resplen, 0,
1660 &req->sa, req->sa_len);
1662 sk = req->client_sk;
1663 err = send(sk, req->resp, req->resplen, MSG_NOSIGNAL);
1667 destroy_request_data(req);
1672 static void cache_element_destroy(gpointer value)
1674 struct cache_entry *entry = value;
1679 if (entry->ipv4 != NULL) {
1680 g_free(entry->ipv4->data);
1681 g_free(entry->ipv4);
1684 if (entry->ipv6 != NULL) {
1685 g_free(entry->ipv6->data);
1686 g_free(entry->ipv6);
1692 if (--cache_size < 0)
1696 static gboolean try_remove_cache(gpointer user_data)
1698 if (__sync_fetch_and_sub(&cache_refcount, 1) == 1) {
1699 DBG("No cache users, removing it.");
1701 g_hash_table_destroy(cache);
1708 static void destroy_server(struct server_data *server)
1712 DBG("interface %s server %s", server->interface, server->server);
1714 server_list = g_slist_remove(server_list, server);
1716 if (server->watch > 0)
1717 g_source_remove(server->watch);
1719 if (server->timeout > 0)
1720 g_source_remove(server->timeout);
1722 g_io_channel_unref(server->channel);
1724 if (server->protocol == IPPROTO_UDP)
1725 DBG("Removing DNS server %s", server->server);
1727 g_free(server->incoming_reply);
1728 g_free(server->server);
1729 for (list = server->domains; list; list = list->next) {
1730 char *domain = list->data;
1732 server->domains = g_list_remove(server->domains, domain);
1735 g_free(server->interface);
1738 * We do not remove cache right away but delay it few seconds.
1739 * The idea is that when IPv6 DNS server is added via RDNSS, it has a
1740 * lifetime. When the lifetime expires we decrease the refcount so it
1741 * is possible that the cache is then removed. Because a new DNS server
1742 * is usually created almost immediately we would then loose the cache
1743 * without any good reason. The small delay allows the new RDNSS to
1744 * create a new DNS server instance and the refcount does not go to 0.
1746 g_timeout_add_seconds(3, try_remove_cache, NULL);
1751 static gboolean udp_server_event(GIOChannel *channel, GIOCondition condition,
1754 unsigned char buf[4096];
1756 struct server_data *data = user_data;
1758 if (condition & (G_IO_NVAL | G_IO_ERR | G_IO_HUP)) {
1759 connman_error("Error with UDP server %s", data->server);
1764 sk = g_io_channel_unix_get_fd(channel);
1766 len = recv(sk, buf, sizeof(buf), 0);
1770 err = forward_dns_reply(buf, len, IPPROTO_UDP, data);
1777 static gboolean tcp_server_event(GIOChannel *channel, GIOCondition condition,
1781 struct server_data *server = user_data;
1783 sk = g_io_channel_unix_get_fd(channel);
1787 if (condition & (G_IO_NVAL | G_IO_ERR | G_IO_HUP)) {
1790 DBG("TCP server channel closed");
1793 * Discard any partial response which is buffered; better
1794 * to get a proper response from a working server.
1796 g_free(server->incoming_reply);
1797 server->incoming_reply = NULL;
1799 for (list = request_list; list; list = list->next) {
1800 struct request_data *req = list->data;
1801 struct domain_hdr *hdr;
1803 if (req->protocol == IPPROTO_UDP)
1806 if (req->request == NULL)
1810 * If we're not waiting for any further response
1811 * from another name server, then we send an error
1812 * response to the client.
1814 if (req->numserv && --(req->numserv))
1817 hdr = (void *) (req->request + 2);
1818 hdr->id = req->srcid;
1819 send_response(req->client_sk, req->request,
1820 req->request_len, NULL, 0, IPPROTO_TCP);
1822 request_list = g_slist_remove(request_list, req);
1825 destroy_server(server);
1830 if ((condition & G_IO_OUT) && !server->connected) {
1833 int no_request_sent = TRUE;
1834 struct server_data *udp_server;
1836 udp_server = find_server(server->interface, server->server,
1838 if (udp_server != NULL) {
1839 for (domains = udp_server->domains; domains;
1840 domains = domains->next) {
1841 char *dom = domains->data;
1843 DBG("Adding domain %s to %s",
1844 dom, server->server);
1846 server->domains = g_list_append(server->domains,
1851 server->connected = TRUE;
1852 server_list = g_slist_append(server_list, server);
1854 if (server->timeout > 0) {
1855 g_source_remove(server->timeout);
1856 server->timeout = 0;
1859 for (list = request_list; list; ) {
1860 struct request_data *req = list->data;
1863 if (req->protocol == IPPROTO_UDP) {
1868 DBG("Sending req %s over TCP", (char *)req->name);
1870 status = ns_resolv(server, req,
1871 req->request, req->name);
1874 * A cached result was sent,
1875 * so the request can be released
1878 request_list = g_slist_remove(request_list, req);
1879 destroy_request_data(req);
1888 no_request_sent = FALSE;
1890 if (req->timeout > 0)
1891 g_source_remove(req->timeout);
1893 req->timeout = g_timeout_add_seconds(30,
1894 request_timeout, req);
1898 if (no_request_sent == TRUE) {
1899 destroy_server(server);
1903 } else if (condition & G_IO_IN) {
1904 struct partial_reply *reply = server->incoming_reply;
1908 unsigned char reply_len_buf[2];
1911 bytes_recv = recv(sk, reply_len_buf, 2, MSG_PEEK);
1914 } else if (bytes_recv < 0) {
1915 if (errno == EAGAIN || errno == EWOULDBLOCK)
1918 connman_error("DNS proxy error %s",
1921 } else if (bytes_recv < 2)
1924 reply_len = reply_len_buf[1] | reply_len_buf[0] << 8;
1927 DBG("TCP reply %d bytes", reply_len);
1929 reply = g_try_malloc(sizeof(*reply) + reply_len + 2);
1933 reply->len = reply_len;
1934 reply->received = 0;
1936 server->incoming_reply = reply;
1939 while (reply->received < reply->len) {
1940 bytes_recv = recv(sk, reply->buf + reply->received,
1941 reply->len - reply->received, 0);
1943 connman_error("DNS proxy TCP disconnect");
1945 } else if (bytes_recv < 0) {
1946 if (errno == EAGAIN || errno == EWOULDBLOCK)
1949 connman_error("DNS proxy error %s",
1953 reply->received += bytes_recv;
1956 forward_dns_reply(reply->buf, reply->received, IPPROTO_TCP,
1960 server->incoming_reply = NULL;
1962 destroy_server(server);
1970 static gboolean tcp_idle_timeout(gpointer user_data)
1972 struct server_data *server = user_data;
1979 destroy_server(server);
1984 static struct server_data *create_server(const char *interface,
1985 const char *domain, const char *server,
1988 struct addrinfo hints, *rp;
1989 struct server_data *data;
1992 DBG("interface %s server %s", interface, server);
1994 memset(&hints, 0, sizeof(hints));
1998 hints.ai_socktype = SOCK_DGRAM;
2002 hints.ai_socktype = SOCK_STREAM;
2008 hints.ai_family = AF_UNSPEC;
2009 hints.ai_flags = AI_PASSIVE | AI_NUMERICSERV | AI_NUMERICHOST;
2011 ret = getaddrinfo(server, "53", &hints, &rp);
2013 connman_error("Failed to parse server %s address: %s\n",
2014 server, gai_strerror(ret));
2017 /* Do not blindly copy this code elsewhere; it doesn't loop over the
2018 results using ->ai_next as it should. That's OK in *this* case
2019 because it was a numeric lookup; we *know* there's only one. */
2021 sk = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
2023 connman_error("Failed to create server %s socket", server);
2028 if (interface != NULL) {
2029 if (setsockopt(sk, SOL_SOCKET, SO_BINDTODEVICE,
2030 interface, strlen(interface) + 1) < 0) {
2031 connman_error("Failed to bind server %s "
2040 data = g_try_new0(struct server_data, 1);
2042 connman_error("Failed to allocate server %s data", server);
2048 data->channel = g_io_channel_unix_new(sk);
2049 if (data->channel == NULL) {
2050 connman_error("Failed to create server %s channel", server);
2057 g_io_channel_set_close_on_unref(data->channel, TRUE);
2059 if (protocol == IPPROTO_TCP) {
2060 g_io_channel_set_flags(data->channel, G_IO_FLAG_NONBLOCK, NULL);
2061 data->watch = g_io_add_watch(data->channel,
2062 G_IO_OUT | G_IO_IN | G_IO_HUP | G_IO_NVAL | G_IO_ERR,
2063 tcp_server_event, data);
2064 data->timeout = g_timeout_add_seconds(30, tcp_idle_timeout,
2067 data->watch = g_io_add_watch(data->channel,
2068 G_IO_IN | G_IO_NVAL | G_IO_ERR | G_IO_HUP,
2069 udp_server_event, data);
2071 data->interface = g_strdup(interface);
2073 data->domains = g_list_append(data->domains, g_strdup(domain));
2074 data->server = g_strdup(server);
2075 data->protocol = protocol;
2077 ret = connect(sk, rp->ai_addr, rp->ai_addrlen);
2080 if ((protocol == IPPROTO_TCP && errno != EINPROGRESS) ||
2081 protocol == IPPROTO_UDP) {
2084 connman_error("Failed to connect to server %s", server);
2085 if (data->watch > 0)
2086 g_source_remove(data->watch);
2087 if (data->timeout > 0)
2088 g_source_remove(data->timeout);
2090 g_io_channel_unref(data->channel);
2093 g_free(data->server);
2094 g_free(data->interface);
2095 for (list = data->domains; list; list = list->next) {
2096 char *domain = list->data;
2098 data->domains = g_list_remove(data->domains,
2107 if (__sync_fetch_and_add(&cache_refcount, 1) == 0)
2108 cache = g_hash_table_new_full(g_str_hash,
2111 cache_element_destroy);
2113 if (protocol == IPPROTO_UDP) {
2114 /* Enable new servers by default */
2115 data->enabled = TRUE;
2116 DBG("Adding DNS server %s", data->server);
2118 server_list = g_slist_append(server_list, data);
2124 static gboolean resolv(struct request_data *req,
2125 gpointer request, gpointer name)
2129 for (list = server_list; list; list = list->next) {
2130 struct server_data *data = list->data;
2132 DBG("server %s enabled %d", data->server, data->enabled);
2134 if (data->enabled == FALSE)
2137 if (data->watch == 0 && data->protocol == IPPROTO_UDP)
2138 data->watch = g_io_add_watch(data->channel,
2139 G_IO_IN | G_IO_NVAL | G_IO_ERR | G_IO_HUP,
2140 udp_server_event, data);
2142 if (ns_resolv(data, req, request, name) > 0)
2149 static void append_domain(const char *interface, const char *domain)
2153 DBG("interface %s domain %s", interface, domain);
2158 for (list = server_list; list; list = list->next) {
2159 struct server_data *data = list->data;
2162 gboolean dom_found = FALSE;
2164 if (data->interface == NULL)
2167 if (g_str_equal(data->interface, interface) == FALSE)
2170 for (dom_list = data->domains; dom_list;
2171 dom_list = dom_list->next) {
2172 dom = dom_list->data;
2174 if (g_str_equal(dom, domain)) {
2180 if (dom_found == FALSE) {
2182 g_list_append(data->domains, g_strdup(domain));
2187 int __connman_dnsproxy_append(const char *interface, const char *domain,
2190 struct server_data *data;
2192 DBG("interface %s server %s", interface, server);
2194 if (server == NULL && domain == NULL)
2197 if (server == NULL) {
2198 append_domain(interface, domain);
2203 if (g_str_equal(server, "127.0.0.1") == TRUE)
2206 data = find_server(interface, server, IPPROTO_UDP);
2208 append_domain(interface, domain);
2212 data = create_server(interface, domain, server, IPPROTO_UDP);
2219 static void remove_server(const char *interface, const char *domain,
2220 const char *server, int protocol)
2222 struct server_data *data;
2224 data = find_server(interface, server, protocol);
2228 destroy_server(data);
2231 int __connman_dnsproxy_remove(const char *interface, const char *domain,
2234 DBG("interface %s server %s", interface, server);
2239 if (g_str_equal(server, "127.0.0.1") == TRUE)
2242 remove_server(interface, domain, server, IPPROTO_UDP);
2243 remove_server(interface, domain, server, IPPROTO_TCP);
2248 void __connman_dnsproxy_flush(void)
2252 list = request_list;
2254 struct request_data *req = list->data;
2258 if (resolv(req, req->request, req->name) == TRUE) {
2260 * A cached result was sent,
2261 * so the request can be released
2264 g_slist_remove(request_list, req);
2265 destroy_request_data(req);
2269 if (req->timeout > 0)
2270 g_source_remove(req->timeout);
2271 req->timeout = g_timeout_add_seconds(5, request_timeout, req);
2275 static void dnsproxy_offline_mode(connman_bool_t enabled)
2279 DBG("enabled %d", enabled);
2281 for (list = server_list; list; list = list->next) {
2282 struct server_data *data = list->data;
2284 if (enabled == FALSE) {
2285 DBG("Enabling DNS server %s", data->server);
2286 data->enabled = TRUE;
2290 DBG("Disabling DNS server %s", data->server);
2291 data->enabled = FALSE;
2297 static void dnsproxy_default_changed(struct connman_service *service)
2302 DBG("service %p", service);
2304 /* DNS has changed, invalidate the cache */
2307 if (service == NULL) {
2308 /* When no services are active, then disable DNS proxying */
2309 dnsproxy_offline_mode(TRUE);
2313 interface = connman_service_get_interface(service);
2314 if (interface == NULL)
2317 for (list = server_list; list; list = list->next) {
2318 struct server_data *data = list->data;
2320 if (g_strcmp0(data->interface, interface) == 0) {
2321 DBG("Enabling DNS server %s", data->server);
2322 data->enabled = TRUE;
2324 DBG("Disabling DNS server %s", data->server);
2325 data->enabled = FALSE;
2333 static struct connman_notifier dnsproxy_notifier = {
2335 .default_changed = dnsproxy_default_changed,
2336 .offline_mode = dnsproxy_offline_mode,
2339 static unsigned char opt_edns0_type[2] = { 0x00, 0x29 };
2341 static int parse_request(unsigned char *buf, int len,
2342 char *name, unsigned int size)
2344 struct domain_hdr *hdr = (void *) buf;
2345 uint16_t qdcount = ntohs(hdr->qdcount);
2346 uint16_t arcount = ntohs(hdr->arcount);
2348 char *last_label = NULL;
2349 unsigned int remain, used = 0;
2354 DBG("id 0x%04x qr %d opcode %d qdcount %d arcount %d",
2355 hdr->id, hdr->qr, hdr->opcode,
2358 if (hdr->qr != 0 || qdcount != 1)
2363 ptr = buf + sizeof(struct domain_hdr);
2364 remain = len - sizeof(struct domain_hdr);
2366 while (remain > 0) {
2370 last_label = (char *) (ptr + 1);
2374 if (used + len + 1 > size)
2377 strncat(name, (char *) (ptr + 1), len);
2386 if (last_label && arcount && remain >= 9 && last_label[4] == 0 &&
2387 !memcmp(last_label + 5, opt_edns0_type, 2)) {
2388 uint16_t edns0_bufsize;
2390 edns0_bufsize = last_label[7] << 8 | last_label[8];
2392 DBG("EDNS0 buffer size %u", edns0_bufsize);
2394 /* This is an evil hack until full TCP support has been
2397 * Somtimes the EDNS0 request gets send with a too-small
2398 * buffer size. Since glibc doesn't seem to crash when it
2399 * gets a response biffer then it requested, just bump
2400 * the buffer size up to 4KiB.
2402 if (edns0_bufsize < 0x1000) {
2403 last_label[7] = 0x10;
2404 last_label[8] = 0x00;
2408 DBG("query %s", name);
2413 static gboolean tcp_listener_event(GIOChannel *channel, GIOCondition condition,
2416 unsigned char buf[768];
2418 struct request_data *req;
2419 int sk, client_sk, len, err;
2420 struct sockaddr_in6 client_addr;
2421 socklen_t client_addr_len = sizeof(client_addr);
2423 struct listener_data *ifdata = user_data;
2424 int waiting_for_connect = FALSE;
2426 DBG("condition 0x%x", condition);
2428 if (condition & (G_IO_NVAL | G_IO_ERR | G_IO_HUP)) {
2429 if (ifdata->tcp_listener_watch > 0)
2430 g_source_remove(ifdata->tcp_listener_watch);
2431 ifdata->tcp_listener_watch = 0;
2433 connman_error("Error with TCP listener channel");
2438 sk = g_io_channel_unix_get_fd(channel);
2440 client_sk = accept(sk, (void *)&client_addr, &client_addr_len);
2441 if (client_sk < 0) {
2442 connman_error("Accept failure on TCP listener");
2443 ifdata->tcp_listener_watch = 0;
2447 len = recv(client_sk, buf, sizeof(buf), 0);
2451 DBG("Received %d bytes (id 0x%04x)", len, buf[2] | buf[3] << 8);
2453 err = parse_request(buf + 2, len - 2, query, sizeof(query));
2454 if (err < 0 || (g_slist_length(server_list) == 0)) {
2455 send_response(client_sk, buf, len, NULL, 0, IPPROTO_TCP);
2459 req = g_try_new0(struct request_data, 1);
2463 memcpy(&req->sa, &client_addr, client_addr_len);
2464 req->sa_len = client_addr_len;
2465 req->client_sk = client_sk;
2466 req->protocol = IPPROTO_TCP;
2468 req->srcid = buf[2] | (buf[3] << 8);
2469 req->dstid = get_id();
2470 req->altid = get_id();
2471 req->request_len = len;
2473 buf[2] = req->dstid & 0xff;
2474 buf[3] = req->dstid >> 8;
2477 req->ifdata = (struct listener_data *) ifdata;
2478 req->append_domain = FALSE;
2480 for (list = server_list; list; list = list->next) {
2481 struct server_data *data = list->data;
2483 if (data->protocol != IPPROTO_UDP || data->enabled == FALSE)
2486 if(create_server(data->interface, NULL,
2487 data->server, IPPROTO_TCP) == NULL)
2490 waiting_for_connect = TRUE;
2493 if (waiting_for_connect == FALSE) {
2494 /* No server is waiting for connect */
2495 send_response(client_sk, buf, len, NULL, 0, IPPROTO_TCP);
2501 * The server is not connected yet.
2502 * Copy the relevant buffers.
2503 * The request will actually be sent once we're
2504 * properly connected over TCP to the nameserver.
2506 req->request = g_try_malloc0(req->request_len);
2507 if (req->request == NULL) {
2508 send_response(client_sk, buf, len, NULL, 0, IPPROTO_TCP);
2512 memcpy(req->request, buf, req->request_len);
2514 req->name = g_try_malloc0(sizeof(query));
2515 if (req->name == NULL) {
2516 send_response(client_sk, buf, len, NULL, 0, IPPROTO_TCP);
2517 g_free(req->request);
2521 memcpy(req->name, query, sizeof(query));
2523 req->timeout = g_timeout_add_seconds(30, request_timeout, req);
2525 request_list = g_slist_append(request_list, req);
2530 static gboolean udp_listener_event(GIOChannel *channel, GIOCondition condition,
2533 unsigned char buf[768];
2535 struct request_data *req;
2536 struct sockaddr_in6 client_addr;
2537 socklen_t client_addr_len = sizeof(client_addr);
2539 struct listener_data *ifdata = user_data;
2541 if (condition & (G_IO_NVAL | G_IO_ERR | G_IO_HUP)) {
2542 connman_error("Error with UDP listener channel");
2543 ifdata->udp_listener_watch = 0;
2547 sk = g_io_channel_unix_get_fd(channel);
2549 memset(&client_addr, 0, client_addr_len);
2550 len = recvfrom(sk, buf, sizeof(buf), 0, (void *)&client_addr,
2555 DBG("Received %d bytes (id 0x%04x)", len, buf[0] | buf[1] << 8);
2557 err = parse_request(buf, len, query, sizeof(query));
2558 if (err < 0 || (g_slist_length(server_list) == 0)) {
2559 send_response(sk, buf, len, (void *)&client_addr,
2560 client_addr_len, IPPROTO_UDP);
2564 req = g_try_new0(struct request_data, 1);
2568 memcpy(&req->sa, &client_addr, client_addr_len);
2569 req->sa_len = client_addr_len;
2571 req->protocol = IPPROTO_UDP;
2573 req->srcid = buf[0] | (buf[1] << 8);
2574 req->dstid = get_id();
2575 req->altid = get_id();
2576 req->request_len = len;
2578 buf[0] = req->dstid & 0xff;
2579 buf[1] = req->dstid >> 8;
2582 req->ifdata = (struct listener_data *) ifdata;
2583 req->append_domain = FALSE;
2585 if (resolv(req, buf, query) == TRUE) {
2586 /* a cached result was sent, so the request can be released */
2591 req->timeout = g_timeout_add_seconds(5, request_timeout, req);
2592 request_list = g_slist_append(request_list, req);
2597 static int create_dns_listener(int protocol, struct listener_data *ifdata)
2599 GIOChannel *channel;
2603 struct sockaddr_in6 sin6;
2604 struct sockaddr_in sin;
2607 int sk, type, v6only = 0;
2608 int family = AF_INET6;
2611 DBG("interface %s", ifdata->ifname);
2616 type = SOCK_DGRAM | SOCK_CLOEXEC;
2621 type = SOCK_STREAM | SOCK_CLOEXEC;
2628 sk = socket(family, type, protocol);
2629 if (sk < 0 && family == AF_INET6 && errno == EAFNOSUPPORT) {
2630 connman_error("No IPv6 support; DNS proxy listening only on Legacy IP");
2632 sk = socket(family, type, protocol);
2635 connman_error("Failed to create %s listener socket", proto);
2639 if (setsockopt(sk, SOL_SOCKET, SO_BINDTODEVICE,
2641 strlen(ifdata->ifname) + 1) < 0) {
2642 connman_error("Failed to bind %s listener interface", proto);
2646 /* Ensure it accepts Legacy IP connections too */
2647 if (family == AF_INET6 &&
2648 setsockopt(sk, SOL_IPV6, IPV6_V6ONLY,
2649 &v6only, sizeof(v6only)) < 0) {
2650 connman_error("Failed to clear V6ONLY on %s listener socket",
2656 if (family == AF_INET) {
2657 memset(&s.sin, 0, sizeof(s.sin));
2658 s.sin.sin_family = AF_INET;
2659 s.sin.sin_port = htons(53);
2660 s.sin.sin_addr.s_addr = htonl(INADDR_ANY);
2661 slen = sizeof(s.sin);
2663 memset(&s.sin6, 0, sizeof(s.sin6));
2664 s.sin6.sin6_family = AF_INET6;
2665 s.sin6.sin6_port = htons(53);
2666 s.sin6.sin6_addr = in6addr_any;
2667 slen = sizeof(s.sin6);
2670 if (bind(sk, &s.sa, slen) < 0) {
2671 connman_error("Failed to bind %s listener socket", proto);
2676 if (protocol == IPPROTO_TCP && listen(sk, 10) < 0) {
2677 connman_error("Failed to listen on TCP socket");
2682 channel = g_io_channel_unix_new(sk);
2683 if (channel == NULL) {
2684 connman_error("Failed to create %s listener channel", proto);
2689 g_io_channel_set_close_on_unref(channel, TRUE);
2691 if (protocol == IPPROTO_TCP) {
2692 ifdata->tcp_listener_channel = channel;
2693 ifdata->tcp_listener_watch = g_io_add_watch(channel,
2694 G_IO_IN, tcp_listener_event, (gpointer) ifdata);
2696 ifdata->udp_listener_channel = channel;
2697 ifdata->udp_listener_watch = g_io_add_watch(channel,
2698 G_IO_IN, udp_listener_event, (gpointer) ifdata);
2704 static void destroy_udp_listener(struct listener_data *ifdata)
2706 DBG("interface %s", ifdata->ifname);
2708 if (ifdata->udp_listener_watch > 0)
2709 g_source_remove(ifdata->udp_listener_watch);
2711 g_io_channel_unref(ifdata->udp_listener_channel);
2714 static void destroy_tcp_listener(struct listener_data *ifdata)
2716 DBG("interface %s", ifdata->ifname);
2718 if (ifdata->tcp_listener_watch > 0)
2719 g_source_remove(ifdata->tcp_listener_watch);
2721 g_io_channel_unref(ifdata->tcp_listener_channel);
2724 static int create_listener(struct listener_data *ifdata)
2728 err = create_dns_listener(IPPROTO_UDP, ifdata);
2732 err = create_dns_listener(IPPROTO_TCP, ifdata);
2734 destroy_udp_listener(ifdata);
2738 if (g_strcmp0(ifdata->ifname, "lo") == 0)
2739 __connman_resolvfile_append("lo", NULL, "127.0.0.1");
2744 static void destroy_listener(struct listener_data *ifdata)
2748 if (g_strcmp0(ifdata->ifname, "lo") == 0)
2749 __connman_resolvfile_remove("lo", NULL, "127.0.0.1");
2751 for (list = request_list; list; list = list->next) {
2752 struct request_data *req = list->data;
2754 DBG("Dropping request (id 0x%04x -> 0x%04x)",
2755 req->srcid, req->dstid);
2756 destroy_request_data(req);
2760 g_slist_free(request_list);
2761 request_list = NULL;
2763 destroy_tcp_listener(ifdata);
2764 destroy_udp_listener(ifdata);
2767 int __connman_dnsproxy_add_listener(const char *interface)
2769 struct listener_data *ifdata;
2772 DBG("interface %s", interface);
2774 if (g_hash_table_lookup(listener_table, interface) != NULL)
2777 ifdata = g_try_new0(struct listener_data, 1);
2781 ifdata->ifname = g_strdup(interface);
2782 ifdata->udp_listener_channel = NULL;
2783 ifdata->udp_listener_watch = 0;
2784 ifdata->tcp_listener_channel = NULL;
2785 ifdata->tcp_listener_watch = 0;
2787 err = create_listener(ifdata);
2789 connman_error("Couldn't create listener for %s err %d",
2791 g_free(ifdata->ifname);
2795 g_hash_table_insert(listener_table, ifdata->ifname, ifdata);
2799 void __connman_dnsproxy_remove_listener(const char *interface)
2801 struct listener_data *ifdata;
2803 DBG("interface %s", interface);
2805 ifdata = g_hash_table_lookup(listener_table, interface);
2809 destroy_listener(ifdata);
2811 g_hash_table_remove(listener_table, interface);
2814 static void remove_listener(gpointer key, gpointer value, gpointer user_data)
2816 const char *interface = key;
2817 struct listener_data *ifdata = value;
2819 DBG("interface %s", interface);
2821 destroy_listener(ifdata);
2824 int __connman_dnsproxy_init(void)
2830 srandom(time(NULL));
2832 listener_table = g_hash_table_new_full(g_str_hash, g_str_equal,
2834 err = __connman_dnsproxy_add_listener("lo");
2838 err = connman_notifier_register(&dnsproxy_notifier);
2845 __connman_dnsproxy_remove_listener("lo");
2846 g_hash_table_destroy(listener_table);
2851 void __connman_dnsproxy_cleanup(void)
2855 connman_notifier_unregister(&dnsproxy_notifier);
2857 g_hash_table_foreach(listener_table, remove_listener, NULL);
2859 g_hash_table_destroy(listener_table);