*
* Connection Manager
*
- * Copyright (C) 2007-2010 Intel Corporation. All rights reserved.
+ * Copyright (C) 2007-2012 Intel Corporation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
#endif
#include <errno.h>
+#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <stdint.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
+#include <resolv.h>
+#include <gweb/gresolv.h>
#include <glib.h>
gpointer resp;
gsize resplen;
struct listener_data *ifdata;
+ gboolean append_domain;
};
struct listener_data {
guint tcp_listener_watch;
};
+struct cache_data {
+ time_t inserted;
+ time_t valid_until;
+ time_t cache_until;
+ int timeout;
+ uint16_t type;
+ uint16_t answers;
+ unsigned int data_len;
+ unsigned char *data; /* contains DNS header + body */
+};
+
+struct cache_entry {
+ char *key;
+ int want_refresh;
+ int hits;
+ struct cache_data *ipv4;
+ struct cache_data *ipv6;
+};
+
+struct domain_question {
+ uint16_t type;
+ uint16_t class;
+} __attribute__ ((packed));
+
+struct domain_rr {
+ uint16_t type;
+ uint16_t class;
+ uint32_t ttl;
+ uint16_t rdlen;
+} __attribute__ ((packed));
+
+/*
+ * We limit how long the cached DNS entry stays in the cache.
+ * By default the TTL (time-to-live) of the DNS response is used
+ * when setting the cache entry life time. The value is in seconds.
+ */
+#define MAX_CACHE_TTL (60 * 30)
+/*
+ * Also limit the other end, cache at least for 30 seconds.
+ */
+#define MIN_CACHE_TTL (30)
+
+/*
+ * We limit the cache size to some sane value so that cached data does
+ * not occupy too much memory. Each cached entry occupies on average
+ * about 100 bytes memory (depending on DNS name length).
+ * Example: caching www.connman.net uses 97 bytes memory.
+ * The value is the max amount of cached DNS responses (count).
+ */
+#define MAX_CACHE_SIZE 256
+
+static int cache_size;
+static GHashTable *cache;
+static int cache_refcount;
static GSList *server_list = NULL;
static GSList *request_list = NULL;
static GSList *request_pending_list = NULL;
-static guint16 request_id = 0x0000;
static GHashTable *listener_table = NULL;
+static time_t next_refresh;
+
+static guint16 get_id()
+{
+ return random();
+}
static int protocol_offset(int protocol)
{
}
+/*
+ * There is a power and efficiency benefit to have entries
+ * in our cache expire at the same time. To this extend,
+ * we round down the cache valid time to common boundaries.
+ */
+static time_t round_down_ttl(time_t end_time, int ttl)
+{
+ if (ttl < 15)
+ return end_time;
+
+ /* Less than 5 minutes, round to 10 second boundary */
+ if (ttl < 300) {
+ end_time = end_time / 10;
+ end_time = end_time * 10;
+ } else { /* 5 or more minutes, round to 30 seconds */
+ end_time = end_time / 30;
+ end_time = end_time * 30;
+ }
+ return end_time;
+}
+
static struct request_data *find_request(guint16 id)
{
GSList *list;
return NULL;
}
+/* we can keep using the same resolve's */
+static GResolv *ipv4_resolve;
+static GResolv *ipv6_resolve;
+
+static void dummy_resolve_func(GResolvResultStatus status,
+ char **results, gpointer user_data)
+{
+}
+
+/*
+ * Refresh a DNS entry, but also age the hit count a bit */
+static void refresh_dns_entry(struct cache_entry *entry, char *name)
+{
+ int age = 1;
+
+ if (ipv4_resolve == NULL) {
+ ipv4_resolve = g_resolv_new(0);
+ g_resolv_set_address_family(ipv4_resolve, AF_INET);
+ g_resolv_add_nameserver(ipv4_resolve, "127.0.0.1", 53, 0);
+ }
+
+ if (ipv6_resolve == NULL) {
+ ipv6_resolve = g_resolv_new(0);
+ g_resolv_set_address_family(ipv6_resolve, AF_INET6);
+ g_resolv_add_nameserver(ipv6_resolve, "127.0.0.1", 53, 0);
+ }
+
+ if (entry->ipv4 == NULL) {
+ DBG("Refresing A record for %s", name);
+ g_resolv_lookup_hostname(ipv4_resolve, name,
+ dummy_resolve_func, NULL);
+ age = 4;
+ }
+
+ if (entry->ipv6 == NULL) {
+ DBG("Refresing AAAA record for %s", name);
+ g_resolv_lookup_hostname(ipv6_resolve, name,
+ dummy_resolve_func, NULL);
+ age = 4;
+ }
+
+ entry->hits -= age;
+ if (entry->hits < 0)
+ entry->hits = 0;
+}
+
+static int dns_name_length(unsigned char *buf)
+{
+ if ((buf[0] & NS_CMPRSFLGS) == NS_CMPRSFLGS) /* compressed name */
+ return 2;
+ return strlen((char *)buf);
+}
+
+static void update_cached_ttl(unsigned char *buf, int len, int new_ttl)
+{
+ unsigned char *c;
+ uint32_t *i;
+ uint16_t *w;
+ int l;
+
+ /* skip the header */
+ c = buf + 12;
+ len -= 12;
+
+ /* skip the query, which is a name and 2 16 bit words */
+ l = dns_name_length(c);
+ c += l;
+ len -= l;
+ c += 4;
+ len -= 4;
+
+ /* now we get the answer records */
+
+ while (len > 0) {
+ /* first a name */
+ l = dns_name_length(c);
+ c += l;
+ len -= l;
+ if (len < 0)
+ break;
+ /* then type + class, 2 bytes each */
+ c += 4;
+ len -= 4;
+ if (len < 0)
+ break;
+
+ /* now the 4 byte TTL field */
+ i = (uint32_t *)c;
+ *i = htonl(new_ttl);
+ c += 4;
+ len -= 4;
+ if (len < 0)
+ break;
+
+ /* now the 2 byte rdlen field */
+ w = (uint16_t *)c;
+ c += ntohs(*w) + 2;
+ len -= ntohs(*w) + 2;
+ }
+}
+
+static void send_cached_response(int sk, unsigned char *buf, int len,
+ const struct sockaddr *to, socklen_t tolen,
+ int protocol, int id, uint16_t answers, int ttl)
+{
+ struct domain_hdr *hdr;
+ int err, offset = protocol_offset(protocol);
+
+ if (offset < 0)
+ return;
+
+ if (len < 12)
+ return;
+
+ hdr = (void *) (buf + offset);
+
+ hdr->id = id;
+ hdr->qr = 1;
+ hdr->rcode = 0;
+ hdr->ancount = htons(answers);
+ hdr->nscount = 0;
+ hdr->arcount = 0;
+
+ /* if this is a negative reply, we are authorative */
+ if (answers == 0)
+ hdr->aa = 1;
+ else
+ update_cached_ttl(buf, len, ttl);
+
+ DBG("id 0x%04x answers %d", hdr->id, answers);
+
+ err = sendto(sk, buf, len, 0, to, tolen);
+ if (err < 0) {
+ connman_error("Cannot send cached DNS response: %s",
+ strerror(errno));
+ return;
+ }
+}
static void send_response(int sk, unsigned char *buf, int len,
const struct sockaddr *to, socklen_t tolen,
if (offset < 0)
return;
- if (len < 12)
+ if (len < 12)
+ return;
+
+ hdr = (void *) (buf + offset);
+
+ DBG("id 0x%04x qr %d opcode %d", hdr->id, hdr->qr, hdr->opcode);
+
+ hdr->qr = 1;
+ hdr->rcode = 2;
+
+ hdr->ancount = 0;
+ hdr->nscount = 0;
+ hdr->arcount = 0;
+
+ err = sendto(sk, buf, len, 0, to, tolen);
+ if (err < 0) {
+ connman_error("Failed to send DNS response: %s",
+ strerror(errno));
+ return;
+ }
+}
+
+static gboolean request_timeout(gpointer user_data)
+{
+ struct request_data *req = user_data;
+ struct listener_data *ifdata;
+
+ DBG("id 0x%04x", req->srcid);
+
+ if (req == NULL)
+ return FALSE;
+
+ ifdata = req->ifdata;
+
+ request_list = g_slist_remove(request_list, req);
+ req->numserv--;
+
+ if (req->resplen > 0 && req->resp != NULL) {
+ int sk, err;
+
+ sk = g_io_channel_unix_get_fd(ifdata->udp_listener_channel);
+
+ err = sendto(sk, req->resp, req->resplen, 0,
+ &req->sa, req->sa_len);
+ if (err < 0)
+ return FALSE;
+ } else if (req->request && req->numserv == 0) {
+ struct domain_hdr *hdr;
+
+ if (req->protocol == IPPROTO_TCP) {
+ hdr = (void *) (req->request + 2);
+ hdr->id = req->srcid;
+ send_response(req->client_sk, req->request,
+ req->request_len, NULL, 0, IPPROTO_TCP);
+
+ } else if (req->protocol == IPPROTO_UDP) {
+ int sk;
+
+ hdr = (void *) (req->request);
+ hdr->id = req->srcid;
+ sk = g_io_channel_unix_get_fd(
+ ifdata->udp_listener_channel);
+ send_response(sk, req->request, req->request_len,
+ &req->sa, req->sa_len, IPPROTO_UDP);
+ }
+ }
+
+ g_free(req->resp);
+ g_free(req);
+
+ return FALSE;
+}
+
+static int append_query(unsigned char *buf, unsigned int size,
+ const char *query, const char *domain)
+{
+ unsigned char *ptr = buf;
+ int len;
+
+ DBG("query %s domain %s", query, domain);
+
+ while (query != NULL) {
+ const char *tmp;
+
+ tmp = strchr(query, '.');
+ if (tmp == NULL) {
+ len = strlen(query);
+ if (len == 0)
+ break;
+ *ptr = len;
+ memcpy(ptr + 1, query, len);
+ ptr += len + 1;
+ break;
+ }
+
+ *ptr = tmp - query;
+ memcpy(ptr + 1, query, tmp - query);
+ ptr += tmp - query + 1;
+
+ query = tmp + 1;
+ }
+
+ while (domain != NULL) {
+ const char *tmp;
+
+ tmp = strchr(domain, '.');
+ if (tmp == NULL) {
+ len = strlen(domain);
+ if (len == 0)
+ break;
+ *ptr = len;
+ memcpy(ptr + 1, domain, len);
+ ptr += len + 1;
+ break;
+ }
+
+ *ptr = tmp - domain;
+ memcpy(ptr + 1, domain, tmp - domain);
+ ptr += tmp - domain + 1;
+
+ domain = tmp + 1;
+ }
+
+ *ptr++ = 0x00;
+
+ return ptr - buf;
+}
+
+static gboolean cache_check_is_valid(struct cache_data *data,
+ time_t current_time)
+{
+ if (data == NULL)
+ return FALSE;
+
+ if (data->cache_until < current_time)
+ return FALSE;
+
+ return TRUE;
+}
+
+/*
+ * remove stale cached entries so that they can be refreshed
+ */
+static void cache_enforce_validity(struct cache_entry *entry)
+{
+ time_t current_time = time(NULL);
+
+ if (cache_check_is_valid(entry->ipv4, current_time) == FALSE
+ && entry->ipv4) {
+ DBG("cache timeout \"%s\" type A", entry->key);
+ g_free(entry->ipv4->data);
+ g_free(entry->ipv4);
+ entry->ipv4 = NULL;
+
+ }
+
+ if (cache_check_is_valid(entry->ipv6, current_time) == FALSE
+ && entry->ipv6) {
+ DBG("cache timeout \"%s\" type AAAA", entry->key);
+ g_free(entry->ipv6->data);
+ g_free(entry->ipv6);
+ entry->ipv6 = NULL;
+ }
+}
+
+static uint16_t cache_check_validity(char *question, uint16_t type,
+ struct cache_entry *entry)
+{
+ time_t current_time = time(NULL);
+ int want_refresh = 0;
+
+ /*
+ * if we have a popular entry, we want a refresh instead of
+ * total destruction of the entry.
+ */
+ if (entry->hits > 2)
+ want_refresh = 1;
+
+ cache_enforce_validity(entry);
+
+ switch (type) {
+ case 1: /* IPv4 */
+ if (cache_check_is_valid(entry->ipv4, current_time) == FALSE) {
+ DBG("cache %s \"%s\" type A", entry->ipv4 ?
+ "timeout" : "entry missing", question);
+
+ if (want_refresh)
+ entry->want_refresh = 1;
+
+ /*
+ * We do not remove cache entry if there is still
+ * valid IPv6 entry found in the cache.
+ */
+ if (cache_check_is_valid(entry->ipv6, current_time)
+ == FALSE && want_refresh == FALSE) {
+ g_hash_table_remove(cache, question);
+ type = 0;
+ }
+ }
+ break;
+
+ case 28: /* IPv6 */
+ if (cache_check_is_valid(entry->ipv6, current_time) == FALSE) {
+ DBG("cache %s \"%s\" type AAAA", entry->ipv6 ?
+ "timeout" : "entry missing", question);
+
+ if (want_refresh)
+ entry->want_refresh = 1;
+
+ if (cache_check_is_valid(entry->ipv4, current_time)
+ == FALSE && want_refresh == FALSE) {
+ g_hash_table_remove(cache, question);
+ type = 0;
+ }
+ }
+ break;
+ }
+
+ return type;
+}
+
+static struct cache_entry *cache_check(gpointer request, int *qtype)
+{
+ char *question = request + 12;
+ struct cache_entry *entry;
+ struct domain_question *q;
+ uint16_t type;
+ int offset;
+
+ offset = strlen(question) + 1;
+ q = (void *) (question + offset);
+ type = ntohs(q->type);
+
+ /* We only cache either A (1) or AAAA (28) requests */
+ if (type != 1 && type != 28)
+ return NULL;
+
+ entry = g_hash_table_lookup(cache, question);
+ if (entry == NULL)
+ return NULL;
+
+ type = cache_check_validity(question, type, entry);
+ if (type == 0)
+ return NULL;
+
+ *qtype = type;
+ return entry;
+}
+
+/*
+ * Get a label/name from DNS resource record. The function decompresses the
+ * label if necessary. The function does not convert the name to presentation
+ * form. This means that the result string will contain label lengths instead
+ * of dots between labels. We intentionally do not want to convert to dotted
+ * format so that we can cache the wire format string directly.
+ */
+static int get_name(int counter,
+ unsigned char *pkt, unsigned char *start, unsigned char *max,
+ unsigned char *output, int output_max, int *output_len,
+ unsigned char **end, char *name, int *name_len)
+{
+ unsigned char *p;
+
+ /* Limit recursion to 10 (this means up to 10 labels in domain name) */
+ if (counter > 10)
+ return -EINVAL;
+
+ p = start;
+ while (*p) {
+ if ((*p & NS_CMPRSFLGS) == NS_CMPRSFLGS) {
+ uint16_t offset = (*p & 0x3F) * 256 + *(p + 1);
+
+ if (offset >= max - pkt)
+ return -ENOBUFS;
+
+ if (*end == NULL)
+ *end = p + 2;
+
+ return get_name(counter + 1, pkt, pkt + offset, max,
+ output, output_max, output_len, end,
+ name, name_len);
+ } else {
+ unsigned label_len = *p;
+
+ if (pkt + label_len > max)
+ return -ENOBUFS;
+
+ if (*output_len > output_max)
+ return -ENOBUFS;
+
+ /*
+ * We need the original name in order to check
+ * if this answer is the correct one.
+ */
+ name[(*name_len)++] = label_len;
+ memcpy(name + *name_len, p + 1, label_len + 1);
+ *name_len += label_len;
+
+ /* We compress the result */
+ output[0] = NS_CMPRSFLGS;
+ output[1] = 0x0C;
+ *output_len = 2;
+
+ p += label_len + 1;
+
+ if (*end == NULL)
+ *end = p;
+
+ if (p >= max)
+ return -ENOBUFS;
+ }
+ }
+
+ return 0;
+}
+
+static int parse_rr(unsigned char *buf, unsigned char *start,
+ unsigned char *max,
+ unsigned char *response, unsigned int *response_size,
+ uint16_t *type, uint16_t *class, int *ttl, int *rdlen,
+ unsigned char **end,
+ char *name)
+{
+ struct domain_rr *rr;
+ int err, offset;
+ int name_len = 0, output_len = 0, max_rsp = *response_size;
+
+ err = get_name(0, buf, start, max, response, max_rsp,
+ &output_len, end, name, &name_len);
+ if (err < 0)
+ return err;
+
+ offset = output_len;
+
+ if ((unsigned int) offset > *response_size)
+ return -ENOBUFS;
+
+ rr = (void *) (*end);
+
+ if (rr == NULL)
+ return -EINVAL;
+
+ *type = ntohs(rr->type);
+ *class = ntohs(rr->class);
+ *ttl = ntohl(rr->ttl);
+ *rdlen = ntohs(rr->rdlen);
+
+ if (*ttl < 0)
+ return -EINVAL;
+
+ memcpy(response + offset, *end, sizeof(struct domain_rr));
+
+ offset += sizeof(struct domain_rr);
+ *end += sizeof(struct domain_rr);
+
+ if ((unsigned int) (offset + *rdlen) > *response_size)
+ return -ENOBUFS;
+
+ memcpy(response + offset, *end, *rdlen);
+
+ *end += *rdlen;
+
+ *response_size = offset + *rdlen;
+
+ return 0;
+}
+
+static gboolean check_alias(GSList *aliases, char *name)
+{
+ GSList *list;
+
+ if (aliases != NULL) {
+ for (list = aliases; list; list = list->next) {
+ int len = strlen((char *)list->data);
+ if (strncmp((char *)list->data, name, len) == 0)
+ return TRUE;
+ }
+ }
+
+ return FALSE;
+}
+
+static int parse_response(unsigned char *buf, int buflen,
+ char *question, int qlen,
+ uint16_t *type, uint16_t *class, int *ttl,
+ unsigned char *response, unsigned int *response_len,
+ uint16_t *answers)
+{
+ struct domain_hdr *hdr = (void *) buf;
+ struct domain_question *q;
+ unsigned char *ptr;
+ uint16_t qdcount = ntohs(hdr->qdcount);
+ uint16_t ancount = ntohs(hdr->ancount);
+ int err, i;
+ uint16_t qtype, qclass;
+ unsigned char *next = NULL;
+ unsigned int maxlen = *response_len;
+ GSList *aliases = NULL, *list;
+ char name[NS_MAXDNAME + 1];
+
+ if (buflen < 12)
+ return -EINVAL;
+
+ DBG("qr %d qdcount %d", hdr->qr, qdcount);
+
+ /* We currently only cache responses where question count is 1 */
+ if (hdr->qr != 1 || qdcount != 1)
+ return -EINVAL;
+
+ ptr = buf + sizeof(struct domain_hdr);
+
+ strncpy(question, (char *) ptr, qlen);
+ qlen = strlen(question);
+ ptr += qlen + 1; /* skip \0 */
+
+ q = (void *) ptr;
+ qtype = ntohs(q->type);
+
+ /* We cache only A and AAAA records */
+ if (qtype != 1 && qtype != 28)
+ return -ENOMSG;
+
+ qclass = ntohs(q->class);
+
+ ptr += 2 + 2; /* ptr points now to answers */
+
+ err = -ENOMSG;
+ *response_len = 0;
+ *answers = 0;
+
+ /*
+ * We have a bunch of answers (like A, AAAA, CNAME etc) to
+ * A or AAAA question. We traverse the answers and parse the
+ * resource records. Only A and AAAA records are cached, all
+ * the other records in answers are skipped.
+ */
+ for (i = 0; i < ancount; i++) {
+ /*
+ * Get one address at a time to this buffer.
+ * The max size of the answer is
+ * 2 (pointer) + 2 (type) + 2 (class) +
+ * 4 (ttl) + 2 (rdlen) + addr (16 or 4) = 28
+ * for A or AAAA record.
+ * For CNAME the size can be bigger.
+ */
+ unsigned char rsp[NS_MAXCDNAME];
+ unsigned int rsp_len = sizeof(rsp) - 1;
+ int ret, rdlen;
+
+ memset(rsp, 0, sizeof(rsp));
+
+ ret = parse_rr(buf, ptr, buf + buflen, rsp, &rsp_len,
+ type, class, ttl, &rdlen, &next, name);
+ if (ret != 0) {
+ err = ret;
+ goto out;
+ }
+
+ /*
+ * Now rsp contains compressed or uncompressed resource
+ * record. Next we check if this record answers the question.
+ * The name var contains the uncompressed label.
+ * One tricky bit is the CNAME records as they alias
+ * the name we might be interested in.
+ */
+
+ /*
+ * Go to next answer if the class is not the one we are
+ * looking for.
+ */
+ if (*class != qclass) {
+ ptr = next;
+ next = NULL;
+ continue;
+ }
+
+ /*
+ * Try to resolve aliases also, type is CNAME(5).
+ * This is important as otherwise the aliased names would not
+ * be cached at all as the cache would not contain the aliased
+ * question.
+ *
+ * If any CNAME is found in DNS packet, then we cache the alias
+ * IP address instead of the question (as the server
+ * said that question has only an alias).
+ * This means in practice that if e.g., ipv6.google.com is
+ * queried, DNS server returns CNAME of that name which is
+ * ipv6.l.google.com. We then cache the address of the CNAME
+ * but return the question name to client. So the alias
+ * status of the name is not saved in cache and thus not
+ * returned to the client. We do not return DNS packets from
+ * cache to client saying that ipv6.google.com is an alias to
+ * ipv6.l.google.com but we return instead a DNS packet that
+ * says ipv6.google.com has address xxx which is in fact the
+ * address of ipv6.l.google.com. For caching purposes this
+ * should not cause any issues.
+ */
+ if (*type == 5 && strncmp(question, name, qlen) == 0) {
+ /*
+ * So now the alias answered the question. This is
+ * not very useful from caching point of view as
+ * the following A or AAAA records will not match the
+ * question. We need to find the real A/AAAA record
+ * of the alias and cache that.
+ */
+ unsigned char *end = NULL;
+ int name_len = 0, output_len;
+
+ memset(rsp, 0, sizeof(rsp));
+ rsp_len = sizeof(rsp) - 1;
+
+ /*
+ * Alias is in rdata part of the message,
+ * and next-rdlen points to it. So we need to get
+ * the real name of the alias.
+ */
+ ret = get_name(0, buf, next - rdlen, buf + buflen,
+ rsp, rsp_len, &output_len, &end,
+ name, &name_len);
+ if (ret != 0) {
+ /* just ignore the error at this point */
+ ptr = next;
+ next = NULL;
+ continue;
+ }
+
+ /*
+ * We should now have the alias of the entry we might
+ * want to cache. Just remember it for a while.
+ * We check the alias list when we have parsed the
+ * A or AAAA record.
+ */
+ aliases = g_slist_prepend(aliases, g_strdup(name));
+
+ ptr = next;
+ next = NULL;
+ continue;
+ }
+
+ if (*type == qtype) {
+ /*
+ * We found correct type (A or AAAA)
+ */
+ if (check_alias(aliases, name) == TRUE ||
+ (aliases == NULL && strncmp(question, name,
+ qlen) == 0)) {
+ /*
+ * We found an alias or the name of the rr
+ * matches the question. If so, we append
+ * the compressed label to the cache.
+ * The end result is a response buffer that
+ * will contain one or more cached and
+ * compressed resource records.
+ */
+ if (*response_len + rsp_len > maxlen) {
+ err = -ENOBUFS;
+ goto out;
+ }
+ memcpy(response + *response_len, rsp, rsp_len);
+ *response_len += rsp_len;
+ (*answers)++;
+ err = 0;
+ }
+ }
+
+ ptr = next;
+ next = NULL;
+ }
+
+out:
+ for (list = aliases; list; list = list->next)
+ g_free(list->data);
+ g_slist_free(aliases);
+
+ return err;
+}
+
+struct cache_timeout {
+ time_t current_time;
+ int max_timeout;
+ int try_harder;
+};
+
+static gboolean cache_check_entry(gpointer key, gpointer value,
+ gpointer user_data)
+{
+ struct cache_timeout *data = user_data;
+ struct cache_entry *entry = value;
+ int max_timeout;
+
+ /* Scale the number of hits by half as part of cache aging */
+
+ entry->hits /= 2;
+
+ /*
+ * If either IPv4 or IPv6 cached entry has expired, we
+ * remove both from the cache.
+ */
+
+ if (entry->ipv4 != NULL && entry->ipv4->timeout > 0) {
+ max_timeout = entry->ipv4->cache_until;
+ if (max_timeout > data->max_timeout)
+ data->max_timeout = max_timeout;
+
+ if (entry->ipv4->cache_until < data->current_time)
+ return TRUE;
+ }
+
+ if (entry->ipv6 != NULL && entry->ipv6->timeout > 0) {
+ max_timeout = entry->ipv6->cache_until;
+ if (max_timeout > data->max_timeout)
+ data->max_timeout = max_timeout;
+
+ if (entry->ipv6->cache_until < data->current_time)
+ return TRUE;
+ }
+
+ /*
+ * if we're asked to try harder, also remove entries that have
+ * few hits
+ */
+ if (data->try_harder && entry->hits < 4)
+ return TRUE;
+
+ return FALSE;
+}
+
+static void cache_cleanup(void)
+{
+ static int max_timeout;
+ struct cache_timeout data;
+ int count = 0;
+
+ data.current_time = time(NULL);
+ data.max_timeout = 0;
+ data.try_harder = 0;
+
+ /*
+ * In the first pass, we only remove entries that have timed out.
+ * We use a cache of the first time to expire to do this only
+ * when it makes sense.
+ */
+ if (max_timeout <= data.current_time) {
+ count = g_hash_table_foreach_remove(cache, cache_check_entry,
+ &data);
+ }
+ DBG("removed %d in the first pass", count);
+
+ /*
+ * In the second pass, if the first pass turned up blank,
+ * we also expire entries with a low hit count,
+ * while aging the hit count at the same time.
+ */
+ data.try_harder = 1;
+ if (count == 0)
+ count = g_hash_table_foreach_remove(cache, cache_check_entry,
+ &data);
+
+ if (count == 0)
+ /*
+ * If we could not remove anything, then remember
+ * what is the max timeout and do nothing if we
+ * have not yet reached it. This will prevent
+ * constant traversal of the cache if it is full.
+ */
+ max_timeout = data.max_timeout;
+ else
+ max_timeout = 0;
+}
+
+static gboolean cache_invalidate_entry(gpointer key, gpointer value,
+ gpointer user_data)
+{
+ struct cache_entry *entry = value;
+
+ /* first, delete any expired elements */
+ cache_enforce_validity(entry);
+
+ /* if anything is not expired, mark the entry for refresh */
+ if (entry->hits > 0 && (entry->ipv4 || entry->ipv6))
+ entry->want_refresh = 1;
+
+ /* delete the cached data */
+ if (entry->ipv4) {
+ g_free(entry->ipv4->data);
+ g_free(entry->ipv4);
+ entry->ipv4 = NULL;
+ }
+
+ if (entry->ipv6) {
+ g_free(entry->ipv6->data);
+ g_free(entry->ipv6);
+ entry->ipv6 = NULL;
+ }
+
+ /* keep the entry if we want it refreshed, delete it otherwise */
+ if (entry->want_refresh)
+ return FALSE;
+ else
+ return TRUE;
+}
+
+/*
+ * cache_invalidate is called from places where the DNS landscape
+ * has changed, say because connections are added or we entered a VPN.
+ * The logic is to wipe all cache data, but mark all non-expired
+ * parts of the cache for refresh rather than deleting the whole cache.
+ */
+static void cache_invalidate(void)
+{
+ DBG("Invalidating the DNS cache %p", cache);
+
+ if (cache == NULL)
return;
- hdr = (void *) (buf + offset);
+ g_hash_table_foreach_remove(cache, cache_invalidate_entry, NULL);
+}
- DBG("id 0x%04x qr %d opcode %d", hdr->id, hdr->qr, hdr->opcode);
+static void cache_refresh_entry(struct cache_entry *entry)
+{
- hdr->qr = 1;
- hdr->rcode = 2;
+ cache_enforce_validity(entry);
+
+ if (entry->hits > 2 && entry->ipv4 == NULL)
+ entry->want_refresh = 1;
+ if (entry->hits > 2 && entry->ipv6 == NULL)
+ entry->want_refresh = 1;
+
+ if (entry->want_refresh) {
+ char *c;
+ char dns_name[NS_MAXDNAME + 1];
+ entry->want_refresh = 0;
+
+ /* turn a DNS name into a hostname with dots */
+ strncpy(dns_name, entry->key, NS_MAXDNAME);
+ c = dns_name;
+ while (c && *c) {
+ int jump;
+ jump = *c;
+ *c = '.';
+ c += jump + 1;
+ }
+ DBG("Refreshing %s\n", dns_name);
+ /* then refresh the hostname */
+ refresh_dns_entry(entry, &dns_name[1]);
+ }
+}
- hdr->ancount = 0;
- hdr->nscount = 0;
- hdr->arcount = 0;
+static void cache_refresh_iterator(gpointer key, gpointer value,
+ gpointer user_data)
+{
+ struct cache_entry *entry = value;
- err = sendto(sk, buf, len, 0, to, tolen);
- if (err < 0) {
- connman_error("Failed to send DNS response: %s",
- strerror(errno));
+ cache_refresh_entry(entry);
+}
+
+static void cache_refresh(void)
+{
+ if (cache == NULL)
return;
- }
+
+ g_hash_table_foreach(cache, cache_refresh_iterator, NULL);
}
-static gboolean request_timeout(gpointer user_data)
+static int reply_query_type(unsigned char *msg, int len)
{
- struct request_data *req = user_data;
- struct listener_data *ifdata;
+ unsigned char *c;
+ uint16_t *w;
+ int l;
+ int type;
- DBG("id 0x%04x", req->srcid);
+ /* skip the header */
+ c = msg + sizeof(struct domain_hdr);
+ len -= sizeof(struct domain_hdr);
- if (req == NULL)
- return FALSE;
+ if (len < 0)
+ return 0;
- ifdata = req->ifdata;
+ /* now the query, which is a name and 2 16 bit words */
+ l = dns_name_length(c) + 1;
+ c += l;
+ w = (uint16_t *) c;
+ type = ntohs(*w);
- request_list = g_slist_remove(request_list, req);
- req->numserv--;
+ return type;
+}
- if (req->resplen > 0 && req->resp != NULL) {
- int sk, err;
+static int cache_update(struct server_data *srv, unsigned char *msg,
+ unsigned int msg_len)
+{
+ int offset = protocol_offset(srv->protocol);
+ int err, qlen, ttl = 0;
+ uint16_t answers = 0, type = 0, class = 0;
+ struct domain_question *q;
+ struct cache_entry *entry;
+ struct cache_data *data;
+ char question[NS_MAXDNAME + 1];
+ unsigned char response[NS_MAXDNAME + 1];
+ unsigned char *ptr;
+ unsigned int rsplen;
+ gboolean new_entry = TRUE;
+ time_t current_time;
+
+ if (cache_size >= MAX_CACHE_SIZE) {
+ cache_cleanup();
+ if (cache_size >= MAX_CACHE_SIZE)
+ return 0;
+ }
- sk = g_io_channel_unix_get_fd(ifdata->udp_listener_channel);
+ current_time = time(NULL);
- err = sendto(sk, req->resp, req->resplen, 0,
- &req->sa, req->sa_len);
- if (err < 0)
- return FALSE;
- } else if (req->request && req->numserv == 0) {
- struct domain_hdr *hdr;
+ /* don't do a cache refresh more than twice a minute */
+ if (next_refresh < current_time) {
+ cache_refresh();
+ next_refresh = current_time + 30;
+ }
- if (req->protocol == IPPROTO_TCP) {
- hdr = (void *) (req->request + 2);
- hdr->id = req->srcid;
- send_response(req->client_sk, req->request,
- req->request_len, NULL, 0, IPPROTO_TCP);
- } else if (req->protocol == IPPROTO_UDP) {
- int sk;
+ /* Continue only if response code is 0 (=ok) */
+ if (msg[3] & 0x0f)
+ return 0;
- hdr = (void *) (req->request);
- hdr->id = req->srcid;
- sk = g_io_channel_unix_get_fd(
- ifdata->udp_listener_channel);
- send_response(sk, req->request, req->request_len,
- &req->sa, req->sa_len, IPPROTO_UDP);
+ if (offset < 0)
+ return 0;
+
+ rsplen = sizeof(response) - 1;
+ question[sizeof(question) - 1] = '\0';
+
+ err = parse_response(msg + offset, msg_len - offset,
+ question, sizeof(question) - 1,
+ &type, &class, &ttl,
+ response, &rsplen, &answers);
+
+ /*
+ * special case: if we do a ipv6 lookup and get no result
+ * for a record that's already in our ipv4 cache.. we want
+ * to cache the negative response.
+ */
+ if ((err == -ENOMSG || err == -ENOBUFS) &&
+ reply_query_type(msg, msg_len) == 28) {
+ entry = g_hash_table_lookup(cache, question);
+ if (entry && entry->ipv4 && entry->ipv6 == NULL) {
+ data = g_try_new(struct cache_data, 1);
+ if (data == NULL)
+ return -ENOMEM;
+ data->inserted = entry->ipv4->inserted;
+ data->type = type;
+ data->answers = msg[5];
+ data->timeout = entry->ipv4->timeout;
+ data->data_len = msg_len;
+ data->data = ptr = g_malloc(msg_len);
+ data->valid_until = entry->ipv4->valid_until;
+ data->cache_until = entry->ipv4->cache_until;
+ memcpy(data->data, msg, msg_len);
+ entry->ipv6 = data;
+ /*
+ * we will get a "hit" when we serve the response
+ * out of the cache
+ */
+ entry->hits--;
+ if (entry->hits < 0)
+ entry->hits = 0;
+ return 0;
}
}
- g_free(req->resp);
- g_free(req);
+ if (err < 0 || ttl == 0)
+ return 0;
- return FALSE;
-}
+ qlen = strlen(question);
+
+ /*
+ * If the cache contains already data, check if the
+ * type of the cached data is the same and do not add
+ * to cache if data is already there.
+ * This is needed so that we can cache both A and AAAA
+ * records for the same name.
+ */
+ entry = g_hash_table_lookup(cache, question);
+ if (entry == NULL) {
+ entry = g_try_new(struct cache_entry, 1);
+ if (entry == NULL)
+ return -ENOMEM;
-static int append_query(unsigned char *buf, unsigned int size,
- const char *query, const char *domain)
-{
- unsigned char *ptr = buf;
- char *offset;
+ data = g_try_new(struct cache_data, 1);
+ if (data == NULL) {
+ g_free(entry);
+ return -ENOMEM;
+ }
- DBG("query %s domain %s", query, domain);
+ entry->key = g_strdup(question);
+ entry->ipv4 = entry->ipv6 = NULL;
+ entry->want_refresh = 0;
+ entry->hits = 0;
+
+ if (type == 1)
+ entry->ipv4 = data;
+ else
+ entry->ipv6 = data;
+ } else {
+ if (type == 1 && entry->ipv4 != NULL)
+ return 0;
- offset = (char *) query;
- while (offset != NULL) {
- char *tmp;
+ if (type == 28 && entry->ipv6 != NULL)
+ return 0;
- tmp = strchr(offset, '.');
- if (tmp == NULL) {
- if (strlen(offset) == 0)
- break;
- *ptr = strlen(offset);
- memcpy(ptr + 1, offset, strlen(offset));
- ptr += strlen(offset) + 1;
- break;
- }
+ data = g_try_new(struct cache_data, 1);
+ if (data == NULL)
+ return -ENOMEM;
- *ptr = tmp - offset;
- memcpy(ptr + 1, offset, tmp - offset);
- ptr += tmp - offset + 1;
+ if (type == 1)
+ entry->ipv4 = data;
+ else
+ entry->ipv6 = data;
+
+ /*
+ * compensate for the hit we'll get for serving
+ * the response out of the cache
+ */
+ entry->hits--;
+ if (entry->hits < 0)
+ entry->hits = 0;
- offset = tmp + 1;
+ new_entry = FALSE;
}
- offset = (char *) domain;
- while (offset != NULL) {
- char *tmp;
+ if (ttl < MIN_CACHE_TTL)
+ ttl = MIN_CACHE_TTL;
- tmp = strchr(offset, '.');
- if (tmp == NULL) {
- if (strlen(offset) == 0)
- break;
- *ptr = strlen(offset);
- memcpy(ptr + 1, offset, strlen(offset));
- ptr += strlen(offset) + 1;
- break;
- }
+ data->inserted = current_time;
+ data->type = type;
+ data->answers = answers;
+ data->timeout = ttl;
+ data->data_len = 12 + qlen + 1 + 2 + 2 + rsplen;
+ data->data = ptr = g_malloc(data->data_len);
+ data->valid_until = current_time + ttl;
+
+ /*
+ * Restrict the cached DNS record TTL to some sane value
+ * in order to prevent data staying in the cache too long.
+ */
+ if (ttl > MAX_CACHE_TTL)
+ ttl = MAX_CACHE_TTL;
+
+ data->cache_until = round_down_ttl(current_time + ttl, ttl);
+
+ if (data->data == NULL) {
+ g_free(entry->key);
+ g_free(data);
+ g_free(entry);
+ return -ENOMEM;
+ }
+
+ memcpy(ptr, msg, 12);
+ memcpy(ptr + 12, question, qlen + 1); /* copy also the \0 */
- *ptr = tmp - offset;
- memcpy(ptr + 1, offset, tmp - offset);
- ptr += tmp - offset + 1;
+ q = (void *) (ptr + 12 + qlen + 1);
+ q->type = htons(type);
+ q->class = htons(class);
+ memcpy(ptr + 12 + qlen + 1 + sizeof(struct domain_question),
+ response, rsplen);
- offset = tmp + 1;
+ if (new_entry == TRUE) {
+ g_hash_table_replace(cache, entry->key, entry);
+ cache_size++;
}
- *ptr++ = 0x00;
+ DBG("cache %d %squestion \"%s\" type %d ttl %d size %zd",
+ cache_size, new_entry ? "new " : "old ",
+ question, type, ttl,
+ sizeof(*entry) + sizeof(*data) + data->data_len + qlen);
- return ptr - buf;
+ return 0;
}
static int ns_resolv(struct server_data *server, struct request_data *req,
gpointer request, gpointer name)
{
GList *list;
- int sk, err;
+ int sk, err, type = 0;
char *dot, *lookup = (char *) name;
+ struct cache_entry *entry;
+
+ entry = cache_check(request, &type);
+ if (entry != NULL) {
+ int ttl_left = 0;
+ struct cache_data *data;
+
+ DBG("cache hit %s type %s", lookup, type == 1 ? "A" : "AAAA");
+ if (type == 1)
+ data = entry->ipv4;
+ else
+ data = entry->ipv6;
+
+ if (data) {
+ ttl_left = data->valid_until - time(NULL);
+ entry->hits++;
+ }
+
+ if (data != NULL && req->protocol == IPPROTO_TCP) {
+ send_cached_response(req->client_sk, data->data,
+ data->data_len, NULL, 0, IPPROTO_TCP,
+ req->srcid, data->answers, ttl_left);
+ return 1;
+ }
+
+ if (data != NULL && req->protocol == IPPROTO_UDP) {
+ int sk;
+ sk = g_io_channel_unix_get_fd(
+ req->ifdata->udp_listener_channel);
+
+ send_cached_response(sk, data->data,
+ data->data_len, &req->sa, req->sa_len,
+ IPPROTO_UDP, req->srcid, data->answers,
+ ttl_left);
+ return 1;
+ }
+ }
sk = g_io_channel_unix_get_fd(server->channel);
err = send(sk, request, req->request_len, 0);
+ if (err < 0)
+ return -EIO;
req->numserv++;
if (dot != NULL && dot != lookup + strlen(lookup) - 1)
return 0;
+ if (server->domains != NULL && server->domains->data != NULL)
+ req->append_domain = TRUE;
+
for (list = server->domains; list; list = list->next) {
char *domain;
unsigned char alt[1024];
memcpy(alt + offset + altlen,
request + offset + altlen - domlen,
- req->request_len - altlen + domlen);
+ req->request_len - altlen - offset + domlen);
if (server->protocol == IPPROTO_TCP) {
- int req_len = req->request_len + domlen - 1;
+ int req_len = req->request_len + domlen - 2;
alt[0] = (req_len >> 8) & 0xff;
alt[1] = req_len & 0xff;
}
- err = send(sk, alt, req->request_len + domlen + 1, 0);
+ err = send(sk, alt, req->request_len + domlen, 0);
if (err < 0)
return -EIO;
return 0;
}
-static int forward_dns_reply(unsigned char *reply, int reply_len, int protocol)
+static void destroy_request_data(struct request_data *req)
+{
+ if (req->timeout > 0)
+ g_source_remove(req->timeout);
+
+ g_free(req->resp);
+ g_free(req->request);
+ g_free(req->name);
+ g_free(req);
+}
+
+static int forward_dns_reply(unsigned char *reply, int reply_len, int protocol,
+ struct server_data *data)
{
struct domain_hdr *hdr;
struct request_data *req;
req->numresp++;
if (hdr->rcode == 0 || req->resp == NULL) {
+
+ /*
+ * If the domain name was append
+ * remove it before forwarding the reply.
+ */
+ if (req->append_domain == TRUE) {
+ unsigned char *ptr;
+ uint8_t host_len;
+ unsigned int domain_len;
+
+ /*
+ * ptr points to the first char of the hostname.
+ * ->hostname.domain.net
+ */
+ ptr = reply + offset + sizeof(struct domain_hdr);
+ host_len = *ptr;
+ domain_len = strlen((const char *)ptr + host_len + 1);
+
+ /*
+ * Remove the domain name and replace it by the end
+ * of reply. Check if the domain is really there
+ * before trying to copy the data. The domain_len can
+ * be 0 because if the original query did not contain
+ * a domain name, then we are sending two packets,
+ * first without the domain name and the second packet
+ * with domain name. The append_domain is set to true
+ * even if we sent the first packet without domain
+ * name. In this case we end up in this branch.
+ */
+ if (domain_len > 0) {
+ /*
+ * Note that we must use memmove() here,
+ * because the memory areas can overlap.
+ */
+ memmove(ptr + host_len + 1,
+ ptr + host_len + domain_len + 1,
+ reply_len - (ptr - reply + domain_len));
+
+ reply_len = reply_len - domain_len;
+ }
+ }
+
g_free(req->resp);
req->resplen = 0;
memcpy(req->resp, reply, reply_len);
req->resplen = reply_len;
+
+ cache_update(data, reply, reply_len);
}
if (hdr->rcode > 0 && req->numresp < req->numserv)
return err;
}
+static void cache_element_destroy(gpointer value)
+{
+ struct cache_entry *entry = value;
+
+ if (entry == NULL)
+ return;
+
+ if (entry->ipv4 != NULL) {
+ g_free(entry->ipv4->data);
+ g_free(entry->ipv4);
+ }
+
+ if (entry->ipv6 != NULL) {
+ g_free(entry->ipv6->data);
+ g_free(entry->ipv6);
+ }
+
+ g_free(entry->key);
+ g_free(entry);
+
+ if (--cache_size < 0)
+ cache_size = 0;
+}
+
+static gboolean try_remove_cache(gpointer user_data)
+{
+ if (__sync_fetch_and_sub(&cache_refcount, 1) == 1) {
+ DBG("No cache users, removing it.");
+
+ g_hash_table_destroy(cache);
+ cache = NULL;
+ }
+
+ return FALSE;
+}
+
static void destroy_server(struct server_data *server)
{
GList *list;
g_io_channel_unref(server->channel);
if (server->protocol == IPPROTO_UDP)
- connman_info("Removing DNS server %s", server->server);
+ DBG("Removing DNS server %s", server->server);
g_free(server->incoming_reply);
g_free(server->server);
g_free(domain);
}
g_free(server->interface);
+
+ /*
+ * We do not remove cache right away but delay it few seconds.
+ * The idea is that when IPv6 DNS server is added via RDNSS, it has a
+ * lifetime. When the lifetime expires we decrease the refcount so it
+ * is possible that the cache is then removed. Because a new DNS server
+ * is usually created almost immediately we would then loose the cache
+ * without any good reason. The small delay allows the new RDNSS to
+ * create a new DNS server instance and the refcount does not go to 0.
+ */
+ g_timeout_add_seconds(3, try_remove_cache, NULL);
+
g_free(server);
}
{
unsigned char buf[4096];
int sk, err, len;
+ struct server_data *data = user_data;
if (condition & (G_IO_NVAL | G_IO_ERR | G_IO_HUP)) {
- struct server_data *data = user_data;
-
connman_error("Error with UDP server %s", data->server);
data->watch = 0;
return FALSE;
if (len < 12)
return TRUE;
- err = forward_dns_reply(buf, len, IPPROTO_UDP);
+ err = forward_dns_reply(buf, len, IPPROTO_UDP, data);
if (err < 0)
return TRUE;
if ((condition & G_IO_OUT) && !server->connected) {
GSList *list;
GList *domains;
+ int no_request_sent = TRUE;
struct server_data *udp_server;
udp_server = find_server(server->interface, server->server,
server->timeout = 0;
}
- for (list = request_list; list; list = list->next) {
+ for (list = request_list; list; ) {
struct request_data *req = list->data;
+ int status;
- if (req->protocol == IPPROTO_UDP)
+ if (req->protocol == IPPROTO_UDP) {
+ list = list->next;
continue;
+ }
DBG("Sending req %s over TCP", (char *)req->name);
+ status = ns_resolv(server, req,
+ req->request, req->name);
+ if (status > 0) {
+ /*
+ * A cached result was sent,
+ * so the request can be released
+ */
+ list = list->next;
+ request_list = g_slist_remove(request_list, req);
+ destroy_request_data(req);
+ continue;
+ }
+
+ if (status < 0) {
+ list = list->next;
+ continue;
+ }
+
+ no_request_sent = FALSE;
+
if (req->timeout > 0)
g_source_remove(req->timeout);
req->timeout = g_timeout_add_seconds(30,
request_timeout, req);
- ns_resolv(server, req, req->request, req->name);
+ list = list->next;
+ }
+
+ if (no_request_sent == TRUE) {
+ destroy_server(server);
+ return FALSE;
}
} else if (condition & G_IO_IN) {
reply->received += bytes_recv;
}
- forward_dns_reply(reply->buf, reply->received, IPPROTO_TCP);
+ forward_dns_reply(reply->buf, reply->received, IPPROTO_TCP,
+ server);
g_free(reply);
server->incoming_reply = NULL;
}
}
+ if (__sync_fetch_and_add(&cache_refcount, 1) == 0)
+ cache = g_hash_table_new_full(g_str_hash,
+ g_str_equal,
+ NULL,
+ cache_element_destroy);
+
if (protocol == IPPROTO_UDP) {
/* Enable new servers by default */
data->enabled = TRUE;
- connman_info("Adding DNS server %s", data->server);
+ DBG("Adding DNS server %s", data->server);
server_list = g_slist_append(server_list, data);
-
- return data;
}
- return NULL;
+ return data;
}
static gboolean resolv(struct request_data *req,
G_IO_IN | G_IO_NVAL | G_IO_ERR | G_IO_HUP,
udp_server_event, data);
- if (ns_resolv(data, req, request, name) < 0)
- continue;
+ if (ns_resolv(data, req, request, name) > 0)
+ return TRUE;
}
- return TRUE;
+ return FALSE;
}
static void append_domain(const char *interface, const char *domain)
struct server_data *data = list->data;
if (enabled == FALSE) {
- connman_info("Enabling DNS server %s", data->server);
+ DBG("Enabling DNS server %s", data->server);
data->enabled = TRUE;
+ cache_invalidate();
+ cache_refresh();
} else {
- connman_info("Disabling DNS server %s", data->server);
+ DBG("Disabling DNS server %s", data->server);
data->enabled = FALSE;
+ cache_invalidate();
}
}
}
DBG("service %p", service);
+ /* DNS has changed, invalidate the cache */
+ cache_invalidate();
+
if (service == NULL) {
/* When no services are active, then disable DNS proxying */
dnsproxy_offline_mode(TRUE);
struct server_data *data = list->data;
if (g_strcmp0(data->interface, interface) == 0) {
- connman_info("Enabling DNS server %s", data->server);
+ DBG("Enabling DNS server %s", data->server);
data->enabled = TRUE;
} else {
- connman_info("Disabling DNS server %s", data->server);
+ DBG("Disabling DNS server %s", data->server);
data->enabled = FALSE;
}
}
g_free(interface);
+ cache_refresh();
}
static struct connman_notifier dnsproxy_notifier = {
if (hdr->qr != 0 || qdcount != 1)
return -EINVAL;
- memset(name, 0, size);
+ name[0] = '\0';
ptr = buf + sizeof(struct domain_hdr);
remain = len - sizeof(struct domain_hdr);
socklen_t client_addr_len = sizeof(client_addr);
GSList *list;
struct listener_data *ifdata = user_data;
+ int waiting_for_connect = FALSE;
DBG("condition 0x%x", condition);
req->client_sk = client_sk;
req->protocol = IPPROTO_TCP;
- request_id += 2;
- if (request_id == 0x0000 || request_id == 0xffff)
- request_id += 2;
-
req->srcid = buf[2] | (buf[3] << 8);
- req->dstid = request_id;
- req->altid = request_id + 1;
+ req->dstid = get_id();
+ req->altid = get_id();
req->request_len = len;
buf[2] = req->dstid & 0xff;
req->numserv = 0;
req->ifdata = (struct listener_data *) ifdata;
- request_list = g_slist_append(request_list, req);
+ req->append_domain = FALSE;
for (list = server_list; list; list = list->next) {
struct server_data *data = list->data;
server = create_server(data->interface, NULL,
data->server, IPPROTO_TCP);
-
- /*
- * If server is NULL, we're not connected yet.
- * Copy the relevant buffers and continue with
- * the next nameserver.
- * The request will actually be sent once we're
- * properly connected over TCP to this nameserver.
- */
- if (server == NULL) {
- req->request = g_try_malloc0(req->request_len);
- if (req->request == NULL)
- return TRUE;
-
- memcpy(req->request, buf, req->request_len);
-
- req->name = g_try_malloc0(sizeof(query));
- if (req->name == NULL) {
- g_free(req->request);
- return TRUE;
- }
- memcpy(req->name, query, sizeof(query));
-
+ if (server == NULL)
continue;
- }
-
- if (req->timeout > 0)
- g_source_remove(req->timeout);
for (domains = data->domains; domains;
domains = domains->next) {
g_strdup(dom));
}
- req->timeout = g_timeout_add_seconds(30, request_timeout, req);
- ns_resolv(server, req, buf, query);
+ waiting_for_connect = TRUE;
+ }
+
+ if (waiting_for_connect == FALSE) {
+ /* No server is waiting for connect */
+ send_response(client_sk, buf, len, NULL, 0, IPPROTO_TCP);
+ g_free(req);
+ return TRUE;
+ }
+
+ /*
+ * The server is not connected yet.
+ * Copy the relevant buffers.
+ * The request will actually be sent once we're
+ * properly connected over TCP to the nameserver.
+ */
+ req->request = g_try_malloc0(req->request_len);
+ if (req->request == NULL) {
+ send_response(client_sk, buf, len, NULL, 0, IPPROTO_TCP);
+ g_free(req);
+ return TRUE;
+ }
+ memcpy(req->request, buf, req->request_len);
+
+ req->name = g_try_malloc0(sizeof(query));
+ if (req->name == NULL) {
+ send_response(client_sk, buf, len, NULL, 0, IPPROTO_TCP);
+ g_free(req->request);
+ g_free(req);
+ return TRUE;
}
+ memcpy(req->name, query, sizeof(query));
+
+ req->timeout = g_timeout_add_seconds(30, request_timeout, req);
+
+ request_list = g_slist_append(request_list, req);
return TRUE;
}
req->client_sk = 0;
req->protocol = IPPROTO_UDP;
- request_id += 2;
- if (request_id == 0x0000 || request_id == 0xffff)
- request_id += 2;
-
req->srcid = buf[0] | (buf[1] << 8);
- req->dstid = request_id;
- req->altid = request_id + 1;
+ req->dstid = get_id();
+ req->altid = get_id();
req->request_len = len;
buf[0] = req->dstid & 0xff;
req->numserv = 0;
req->ifdata = (struct listener_data *) ifdata;
+ req->append_domain = FALSE;
+
+ if (resolv(req, buf, query) == TRUE) {
+ /* a cached result was sent, so the request can be released */
+ g_free(req);
+ return TRUE;
+ }
+
req->timeout = g_timeout_add_seconds(5, request_timeout, req);
request_list = g_slist_append(request_list, req);
- return resolv(req, buf, query);
+ return TRUE;
}
-static int create_dns_listener(int protocol, const char *ifname)
+static int create_dns_listener(int protocol, struct listener_data *ifdata)
{
GIOChannel *channel;
const char *proto;
socklen_t slen;
int sk, type, v6only = 0;
int family = AF_INET6;
- struct listener_data *ifdata;
- DBG("interface %s", ifname);
- ifdata = g_hash_table_lookup(listener_table, ifname);
- if (ifdata == NULL)
- return -ENODEV;
+ DBG("interface %s", ifdata->ifname);
switch (protocol) {
case IPPROTO_UDP:
proto = "UDP";
- type = SOCK_DGRAM;
+ type = SOCK_DGRAM | SOCK_CLOEXEC;
break;
case IPPROTO_TCP:
proto = "TCP";
- type = SOCK_STREAM;
+ type = SOCK_STREAM | SOCK_CLOEXEC;
break;
default:
}
if (setsockopt(sk, SOL_SOCKET, SO_BINDTODEVICE,
- ifname, strlen(ifname) + 1) < 0) {
+ ifdata->ifname,
+ strlen(ifdata->ifname) + 1) < 0) {
connman_error("Failed to bind %s listener interface", proto);
close(sk);
return -EIO;
return 0;
}
-static void destroy_udp_listener(const char *interface)
+static void destroy_udp_listener(struct listener_data *ifdata)
{
- struct listener_data *ifdata;
-
- DBG("interface %s", interface);
-
- ifdata = g_hash_table_lookup(listener_table, interface);
- if (ifdata == NULL)
- return;
+ DBG("interface %s", ifdata->ifname);
if (ifdata->udp_listener_watch > 0)
g_source_remove(ifdata->udp_listener_watch);
g_io_channel_unref(ifdata->udp_listener_channel);
}
-static void destroy_tcp_listener(const char *interface)
+static void destroy_tcp_listener(struct listener_data *ifdata)
{
- struct listener_data *ifdata;
-
- DBG("interface %s", interface);
-
- ifdata = g_hash_table_lookup(listener_table, interface);
- if (ifdata == NULL)
- return;
+ DBG("interface %s", ifdata->ifname);
if (ifdata->tcp_listener_watch > 0)
g_source_remove(ifdata->tcp_listener_watch);
g_io_channel_unref(ifdata->tcp_listener_channel);
}
-static int create_listener(const char *interface)
+static int create_listener(struct listener_data *ifdata)
{
int err;
- err = create_dns_listener(IPPROTO_UDP, interface);
+ err = create_dns_listener(IPPROTO_UDP, ifdata);
if (err < 0)
return err;
- err = create_dns_listener(IPPROTO_TCP, interface);
+ err = create_dns_listener(IPPROTO_TCP, ifdata);
if (err < 0) {
- destroy_udp_listener(interface);
+ destroy_udp_listener(ifdata);
return err;
}
- if (g_strcmp0(interface, "lo") == 0)
+ if (g_strcmp0(ifdata->ifname, "lo") == 0)
__connman_resolvfile_append("lo", NULL, "127.0.0.1");
return 0;
}
-static void destroy_listener(const char *interface)
+static void destroy_listener(struct listener_data *ifdata)
{
GSList *list;
- if (interface == NULL)
- return;
-
- if (g_strcmp0(interface, "lo") == 0)
+ if (g_strcmp0(ifdata->ifname, "lo") == 0)
__connman_resolvfile_remove("lo", NULL, "127.0.0.1");
for (list = request_pending_list; list; list = list->next) {
DBG("Dropping pending request (id 0x%04x -> 0x%04x)",
req->srcid, req->dstid);
-
- g_free(req->resp);
- g_free(req->request);
- g_free(req->name);
- g_free(req);
+ destroy_request_data(req);
list->data = NULL;
}
DBG("Dropping request (id 0x%04x -> 0x%04x)",
req->srcid, req->dstid);
-
- g_free(req->resp);
- g_free(req->request);
- g_free(req->name);
- g_free(req);
+ destroy_request_data(req);
list->data = NULL;
}
g_slist_free(request_list);
request_list = NULL;
- destroy_tcp_listener(interface);
- destroy_udp_listener(interface);
+ destroy_tcp_listener(ifdata);
+ destroy_udp_listener(ifdata);
}
int __connman_dnsproxy_add_listener(const char *interface)
ifdata->tcp_listener_channel = NULL;
ifdata->tcp_listener_watch = 0;
- err = create_listener(interface);
+ err = create_listener(ifdata);
if (err < 0) {
connman_error("Couldn't create listener for %s err %d",
interface, err);
void __connman_dnsproxy_remove_listener(const char *interface)
{
+ struct listener_data *ifdata;
+
DBG("interface %s", interface);
- destroy_listener(interface);
+ ifdata = g_hash_table_lookup(listener_table, interface);
+ if (ifdata == NULL)
+ return;
+
+ destroy_listener(ifdata);
g_hash_table_remove(listener_table, interface);
}
static void remove_listener(gpointer key, gpointer value, gpointer user_data)
{
- __connman_dnsproxy_remove_listener(key);
+ const char *interface = key;
+ struct listener_data *ifdata = value;
+
+ DBG("interface %s", interface);
+
+ destroy_listener(ifdata);
}
int __connman_dnsproxy_init(void)
DBG("");
+ srandom(time(NULL));
+
listener_table = g_hash_table_new_full(g_str_hash, g_str_equal,
g_free, g_free);
err = __connman_dnsproxy_add_listener("lo");
projects / framework / connectivity / connman.git / blobdiff