interesting
/
getdns
mirror of https://github.com/getdnsapi/getdns.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

First version of the MDNS multicast client that actually works.

This commit is contained in:
Christian Huitema 2017-03-03 16:52:02 -08:00
parent 03307a7b71
commit 4058529081
1 changed files with 429 additions and 84 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

513
src/mdns.c
View File

@ -85,6 +85,10 @@ static uint8_t mdns_suffix_b_e_f_ip6_arpa[] = {
3, 'i', 'p', '6', 3, 'i', 'p', '6',
4, 'a', 'r', 'p', 'a', 0 }; 4, 'a', 'r', 'p', 'a', 0 };
#define MDNS_PACKET_INDEX_QCODE 2
#define MDNS_PACKET_INDEX_QUERY 4
#define MDNS_PACKET_INDEX_ANSWER 6
/* /*
* MDNS cache management using LRU Hash. * MDNS cache management using LRU Hash.
* *
@ -607,6 +611,19 @@ static void msdn_cache_deldata(void* vdata, void* vcontext)
GETDNS_FREE(((struct getdns_context *) vcontext)->mf, vdata); GETDNS_FREE(((struct getdns_context *) vcontext)->mf, vdata);
} }
/*
* Read the number of answers in a cached record
*/
static int
mdns_cache_nb_records_in_entry(uint8_t * cached_data)
{
int message_index = sizeof(getdns_mdns_cached_record_header);
int nb_answers = (cached_data[message_index + MDNS_PACKET_INDEX_ANSWER] << 8) |
cached_data[message_index + MDNS_PACKET_INDEX_ANSWER + 1];
return nb_answers;
}
/* /*
* Create a key in preallocated buffer * Create a key in preallocated buffer
* the allocated size of key should be >= sizeof(getdns_mdns_cached_key_header) + name_len * the allocated size of key should be >= sizeof(getdns_mdns_cached_key_header) + name_len
@ -663,6 +680,7 @@ static uint8_t * mdns_cache_create_data(
header->netreq_first = NULL; header->netreq_first = NULL;
current_index = sizeof(getdns_mdns_cached_record_header); current_index = sizeof(getdns_mdns_cached_record_header);
memset(data + current_index, 0, 12); memset(data + current_index, 0, 12);
data[current_index + MDNS_PACKET_INDEX_QUERY + 1] = 1; /* 1 query present by default */
current_index += 12; current_index += 12;
memcpy(data + current_index, name, name_len); memcpy(data + current_index, name, name_len);
current_index += name_len; current_index += name_len;
@ -691,13 +709,13 @@ mdns_add_record_to_cache_entry(struct getdns_context *context,
uint32_t record_length = 2 + 2 + 2 + 4 + 2 + record_data_len; uint32_t record_length = 2 + 2 + 2 + 4 + 2 + record_data_len;
uint32_t current_length = header->content_len; uint32_t current_length = header->content_len;
/* update the number of records */ /* update the number of records */
uint8_t *start_answer_code = old_record + sizeof(getdns_mdns_cached_record_header) + 2 + 2; uint8_t *start_answer_code = old_record + sizeof(getdns_mdns_cached_record_header) + MDNS_PACKET_INDEX_ANSWER;
uint16_t nb_answers = (start_answer_code[0] << 8) + start_answer_code[1]; uint16_t nb_answers = (start_answer_code[0] << 8) + start_answer_code[1];
nb_answers++; nb_answers++;
start_answer_code[0] = (uint8_t)(nb_answers >> 8); start_answer_code[0] = (uint8_t)(nb_answers >> 8);
start_answer_code[1] = (uint8_t)(nb_answers&0xFF); start_answer_code[1] = (uint8_t)(nb_answers&0xFF);
/* Update the content length */ /* Update the content length and reallocate memory if needed */
header->content_len += record_length; header->content_len += record_length;
if (header->content_len > header->allocated_length) if (header->content_len > header->allocated_length)
{ {
@ -722,7 +740,7 @@ mdns_add_record_to_cache_entry(struct getdns_context *context,
/* copy the record */ /* copy the record */
/* First, point name relative to beginning of DNS message */ /* First, point name relative to beginning of DNS message */
(*new_record)[current_length++] = 0xC0; (*new_record)[current_length++] = 0xC0;
(*new_record)[current_length++] = 0x12; (*new_record)[current_length++] = 12;
/* encode the components of the per record header */ /* encode the components of the per record header */
(*new_record)[current_length++] = (uint8_t)((record_type >> 8) & 0xFF); (*new_record)[current_length++] = (uint8_t)((record_type >> 8) & 0xFF);
(*new_record)[current_length++] = (uint8_t)((record_type)& 0xFF); (*new_record)[current_length++] = (uint8_t)((record_type)& 0xFF);
@ -735,6 +753,7 @@ mdns_add_record_to_cache_entry(struct getdns_context *context,
(*new_record)[current_length++] = (uint8_t)((record_data_len >> 8) & 0xFF); (*new_record)[current_length++] = (uint8_t)((record_data_len >> 8) & 0xFF);
(*new_record)[current_length++] = (uint8_t)((record_data_len) & 0xFF); (*new_record)[current_length++] = (uint8_t)((record_data_len) & 0xFF);
memcpy(*new_record + current_length, record_data, record_data_len); memcpy(*new_record + current_length, record_data, record_data_len);
} }
return ret; return ret;
@ -765,14 +784,17 @@ mdns_update_cache_ttl_and_prune(struct getdns_context *context,
int current_record_match; int current_record_match;
int last_copied_index; int last_copied_index;
int current_hole_index = 0; int current_hole_index = 0;
int record_name_length = 0;
int record_ttl_index = 0;
/* /*
* Skip the query * Skip the query
*/ */
message_index = sizeof(getdns_mdns_cached_record_header); message_index = sizeof(getdns_mdns_cached_record_header);
nb_answers = (old_record[message_index + 4] << 8) | old_record[message_index + 5]; nb_answers = (old_record[message_index + MDNS_PACKET_INDEX_ANSWER] << 8) |
old_record[message_index + MDNS_PACKET_INDEX_ANSWER + 1];
nb_answers_left = nb_answers; nb_answers_left = nb_answers;
answer_index = mdns_util_skip_query(old_record + message_index + 12); answer_index = message_index + 12 + mdns_util_skip_query(old_record + message_index + 12);
last_copied_index = answer_index; last_copied_index = answer_index;
/* /*
@ -780,19 +802,22 @@ mdns_update_cache_ttl_and_prune(struct getdns_context *context,
*/ */
for (int i = 0; i < nb_answers; i++) for (int i = 0; i < nb_answers; i++)
{ {
current_record_ttl = (old_record[answer_index + 2 + 2 + 2] << 24) record_name_length = mdns_util_skip_name(old_record + answer_index);
| (old_record[answer_index + 2 + 2 + 2 + 1] << 16) record_ttl_index = answer_index + record_name_length + 2 + 2;
| (old_record[answer_index + 2 + 2 + 2 + 2] << 8)
| (old_record[answer_index + 2 + 2 + 2 + 3]);
current_record_data_len = (old_record[answer_index + 2 + 2 + 2 + 4] << 8) current_record_ttl = (old_record[record_ttl_index] << 24)
| (old_record[answer_index + 2 + 2 + 2 + 4 + 1]); | (old_record[record_ttl_index + 1] << 16)
| (old_record[record_ttl_index + 2] << 8)
| (old_record[record_ttl_index + 3]);
current_record_length = 2 + 2 + 2 + 4 + 2 + current_record_data_len; current_record_data_len = (old_record[record_ttl_index + 4] << 8)
| (old_record[record_ttl_index + 5]);
current_record_length = record_name_length + 2 + 2 + 4 + 2 + current_record_data_len;
if (not_matched_yet && if (not_matched_yet &&
current_record_data_len == record_data_len && current_record_data_len == record_data_len &&
memcmp(old_record + answer_index + 2 + 2 + 2 + 4 + 2, record_data, record_data_len) == 0) memcmp(old_record + record_ttl_index + 4 + 2, record_data, record_data_len) == 0)
{ {
current_record_match = 1; current_record_match = 1;
not_matched_yet = 0; not_matched_yet = 0;
@ -813,7 +838,7 @@ mdns_update_cache_ttl_and_prune(struct getdns_context *context,
} }
} }
if (current_record_ttl != 0) if (current_record_ttl == 0)
{ {
nb_answers_left--; nb_answers_left--;
@ -833,42 +858,43 @@ mdns_update_cache_ttl_and_prune(struct getdns_context *context,
last_copied_index += answer_index - current_hole_index; last_copied_index += answer_index - current_hole_index;
} }
/* in all cases, the current hole begins after the message's encoding */ /* extend the current hole */
current_hole_index = answer_index + current_record_length; current_hole_index = answer_index + current_record_length;
} }
else else
{ {
/* keeping this record, but updating the TTL */ /* keeping this record, but updating the TTL */
old_record[answer_index + 2 + 2 + 2] = (uint8_t)(current_record_ttl >> 24); old_record[record_ttl_index] = (uint8_t)(current_record_ttl >> 24);
old_record[answer_index + 2 + 2 + 2 + 1] = (uint8_t)(current_record_ttl >> 16); old_record[record_ttl_index + 1] = (uint8_t)(current_record_ttl >> 16);
old_record[answer_index + 2 + 2 + 2 + 2] = (uint8_t)(current_record_ttl >> 8); old_record[record_ttl_index + 2] = (uint8_t)(current_record_ttl >> 8);
old_record[answer_index + 2 + 2 + 2 + 3] = (uint8_t)(current_record_ttl); old_record[record_ttl_index + 3] = (uint8_t)(current_record_ttl);
} }
/* progress to the next record */ /* progress to the next record */
answer_index += current_record_length; answer_index += current_record_length;
} }
/* if necessary, copy the pending data */ /* if necessary, copy the pending data */
if (current_hole_index != answer_index) if (current_hole_index != answer_index && current_hole_index != 0)
{ {
/* copy the data from hole to last answer */ /* copy the data from hole to last answer */
memmove(old_record + last_copied_index, old_record + current_hole_index, memmove(old_record + last_copied_index, old_record + current_hole_index,
answer_index - current_hole_index); answer_index - current_hole_index);
last_copied_index += answer_index - current_hole_index; last_copied_index += answer_index - current_hole_index;
answer_index = last_copied_index;
} }
/* if some records were deleted, update the record headers */ /* if some records were deleted, update the record headers */
if (nb_answers != nb_answers_left) if (nb_answers != nb_answers_left)
{ {
header->content_len = last_copied_index; header->content_len = last_copied_index;
old_record[message_index + 4] = (uint8_t)(nb_answers >> 8); old_record[message_index + MDNS_PACKET_INDEX_ANSWER] = (uint8_t)(nb_answers_left >> 8);
old_record[message_index + 5] = (uint8_t)(nb_answers); old_record[message_index + MDNS_PACKET_INDEX_ANSWER + 1] = (uint8_t)(nb_answers_left);
} }
/* /*
* if the update was never seen, ask for an addition * if the update was never seen, ask for an addition
*/ */
if (ttl == 0 && not_matched_yet) if (ttl > 0 && not_matched_yet)
{ {
mdns_add_record_to_cache_entry(context, old_record, new_record, mdns_add_record_to_cache_entry(context, old_record, new_record,
record_type, record_class, ttl, record_data, record_data_len); record_type, record_class, ttl, record_data, record_data_len);
@ -882,15 +908,30 @@ mdns_update_cache_ttl_and_prune(struct getdns_context *context,
return ret; return ret;
} }
static int /*
mdns_cache_nb_records_in_entry(uint8_t * cached_data) * Get a cached entry by name and record type .
*/
static struct lruhash_entry *
mdns_access_cached_entry_by_name(
struct getdns_context *context,
uint8_t * name, int name_len,
int record_type, int record_class)
{ {
int message_index = sizeof(getdns_mdns_cached_record_header); uint8_t temp_key[256 + sizeof(getdns_mdns_cached_key_header)];
int nb_answers = (cached_data[message_index + 4] << 8) | cached_data[message_index + 5]; hashvalue_type hash;
struct lruhash_entry *entry;
return nb_answers; msdn_cache_create_key_in_buffer(temp_key, name, name_len, record_type, record_class);
/* TODO: make hash init value a random number in the context, for defense against DOS */
hash = hashlittle(temp_key, name_len + sizeof(getdns_mdns_cached_key_header), 0xCAC8E);
entry = lruhash_lookup(context->mdns_cache, hash, temp_key, 1);
return entry;
} }
/* /*
* Add entry function for the MDNS record cache. * Add entry function for the MDNS record cache.
*/ */
@ -982,11 +1023,16 @@ mdns_propose_entry_to_cache(
netreq->mdns_netreq_next = header->netreq_first; netreq->mdns_netreq_next = header->netreq_first;
header->netreq_first = netreq; header->netreq_first = netreq;
} }
else
/* if the entry is empty, move it to the bottom of the LRU */
if (mdns_cache_nb_records_in_entry((uint8_t*)(entry->data)) == 0)
{ {
lru_demote(context->mdns_cache, entry); header = (getdns_mdns_cached_record_header *)entry->data;
/* if the entry is empty, move it to the bottom of the LRU */
if (mdns_cache_nb_records_in_entry((uint8_t*)(entry->data)) == 0 &&
header->netreq_first == NULL)
{
lru_demote(context->mdns_cache, entry);
}
} }
/* then, unlock the entry */ /* then, unlock the entry */
@ -996,6 +1042,90 @@ mdns_propose_entry_to_cache(
return ret; return ret;
} }
/*
* Serve a request from the cached value
*/
static int
mdns_complete_query_from_cache_entry(
getdns_network_req *netreq,
struct lruhash_entry *entry)
{
int ret = 0;
uint8_t *packet = ((uint8_t *)entry->data) + sizeof(getdns_mdns_cached_record_header);
getdns_mdns_cached_record_header * header = (getdns_mdns_cached_record_header*)entry->data;
size_t packet_length = header->content_len - sizeof(getdns_mdns_cached_record_header);
getdns_network_req **prev_netreq;
int found = 0;
int nb_answers = mdns_cache_nb_records_in_entry((uint8_t *)entry->data);
/* Clear the event associated to the query */
GETDNS_CLEAR_EVENT(netreq->owner->loop, &netreq->event);
/* remove the completed query from the waiting list */
prev_netreq = &header->netreq_first;
while (*prev_netreq != NULL)
{
if (*prev_netreq == netreq)
{
*prev_netreq = netreq->mdns_netreq_next;
netreq->mdns_netreq_next = NULL;
found = 1;
break;
}
else
{
prev_netreq = &((*prev_netreq)->mdns_netreq_next);
}
}
if (found)
{
if (nb_answers == 0)
{
}
else
{
/* copy the returned value in the response field */
if (packet_length > netreq->wire_data_sz)
{
netreq->response = GETDNS_XREALLOC(
netreq->owner->context->mf, netreq->response, uint8_t, packet_length);
}
if (netreq->response != NULL)
{
memcpy(netreq->response, packet, packet_length);
netreq->response[MDNS_PACKET_INDEX_QCODE] = 0x84;
netreq->response_len = packet_length;
netreq->debug_end_time = _getdns_get_time_as_uintt64();
netreq->state = NET_REQ_FINISHED;
_getdns_check_dns_req_complete(netreq->owner);
}
else
{
/* Fail the query? */
netreq->response_len = 0;
netreq->debug_end_time = _getdns_get_time_as_uintt64();
netreq->state = NET_REQ_ERRORED;
_getdns_check_dns_req_complete(netreq->owner);
}
}
}
else
{
/* Failure */
netreq->response_len = 0;
netreq->debug_end_time = _getdns_get_time_as_uintt64();
netreq->state = NET_REQ_ERRORED;
_getdns_check_dns_req_complete(netreq->owner);
}
return ret;
}
/* /*
* Processing of requests after cache update. * Processing of requests after cache update.
* This is coded as synchronous processing, under lock. This is probably wrong. * This is coded as synchronous processing, under lock. This is probably wrong.
@ -1010,55 +1140,21 @@ mdns_cache_complete_queries(
{ {
int ret = 0; int ret = 0;
size_t required_memory = 0; size_t required_memory = 0;
uint8_t temp_key[256 + sizeof(getdns_mdns_cached_key_header)];
hashvalue_type hash;
struct lruhash_entry *entry; struct lruhash_entry *entry;
uint8_t *packet;
int packet_length;
getdns_mdns_cached_record_header * header; getdns_mdns_cached_record_header * header;
getdns_network_req * netreq; getdns_network_req * netreq;
msdn_cache_create_key_in_buffer(temp_key, name, name_len, record_type, record_class); entry = mdns_access_cached_entry_by_name(context, name, name_len, record_type, record_class);
if (entry != NULL)
/* TODO: make hash init value a random number in the context, for defense against DOS */
hash = hashlittle(temp_key, name_len + sizeof(getdns_mdns_cached_key_header), 0xCAC8E);
entry = lruhash_lookup(context->mdns_cache, hash, temp_key, 1);
if (entry != NULL && entry->data != NULL)
{ {
header = (getdns_mdns_cached_record_header *)entry->data; if (entry->data != NULL)
packet = ((uint8_t *)entry->data) + sizeof(getdns_mdns_cached_record_header);
packet_length = header->content_len; /* TODO: check that */
while ((netreq = header->netreq_first) != NULL)
{ {
header->netreq_first = netreq->mdns_netreq_next; header = (getdns_mdns_cached_record_header *)entry->data;
netreq->mdns_netreq_next = NULL;
/* TODO: copy the returned value in the response field */
if (packet_length > netreq->wire_data_sz)
{
/* TODO: allocation. */
}
if (netreq->response != NULL) while ((netreq = header->netreq_first) != NULL)
{ {
memcpy(netreq->response, packet, packet_length); mdns_complete_query_from_cache_entry(netreq, entry);
/* TODO: process the query */
netreq->response_len = packet_length;
netreq->debug_end_time = _getdns_get_time_as_uintt64();
netreq->state = NET_REQ_FINISHED;
_getdns_check_dns_req_complete(netreq->owner);
}
else
{
/* Fail the query? */
netreq->response_len = 0;
netreq->debug_end_time = _getdns_get_time_as_uintt64();
netreq->state = NET_REQ_ERRORED;
_getdns_check_dns_req_complete(netreq->owner);
} }
} }
lock_rw_unlock(entry->lock); lock_rw_unlock(entry->lock);
@ -1067,6 +1163,57 @@ mdns_cache_complete_queries(
return ret; return ret;
} }
/*
* Timeout of multicast MDNS query
*/
static void
mdns_mcast_timeout_cb(void *userarg)
{
getdns_network_req *netreq = (getdns_network_req *)userarg;
getdns_dns_req *dnsreq = netreq->owner;
getdns_context *context = dnsreq->context;
int ret = 0;
size_t required_memory = 0;
uint8_t temp_key[256 + sizeof(getdns_mdns_cached_key_header)];
hashvalue_type hash;
struct lruhash_entry *entry;
int found = 0;
DEBUG_MDNS("%s %-35s: MSG: %p\n",
MDNS_DEBUG_CLEANUP, __FUNCTION__, netreq);
msdn_cache_create_key_in_buffer(temp_key, dnsreq->name, dnsreq->name_len,
netreq->request_type, dnsreq->request_class);
/* TODO: make hash init value a random number in the context, for defense against DOS */
hash = hashlittle(temp_key, dnsreq->name_len + sizeof(getdns_mdns_cached_key_header), 0xCAC8E);
/* Open the corresponding cache entry */
entry = lruhash_lookup(context->mdns_cache, hash, temp_key, 1);
if (entry != NULL)
{
if (entry->data != NULL)
{
/* Remove entry from chain and serve the query */
found = 1;
mdns_complete_query_from_cache_entry(netreq, entry);
}
lock_rw_unlock(entry->lock);
}
if (!found)
{
/* Fail the request on timeout */
netreq->response_len = 0;
netreq->debug_end_time = _getdns_get_time_as_uintt64();
netreq->state = NET_REQ_ERRORED;
_getdns_check_dns_req_complete(netreq->owner);
}
}
/* /*
* Multicast receive event callback * Multicast receive event callback
*/ */
@ -1145,7 +1292,8 @@ mdns_udp_multicast_read_cb(void *userarg)
/* Parse the record header */ /* Parse the record header */
record_type = (cnx->response[current_index++] << 8); record_type = (cnx->response[current_index++] << 8);
record_type |= (cnx->response[current_index++]); record_type |= (cnx->response[current_index++]);
record_class = (cnx->response[current_index++] << 8); /* TODO: handle the cache flush bit! */
record_class = (cnx->response[current_index++] << 8)&0x7F;
record_class |= (cnx->response[current_index++]); record_class |= (cnx->response[current_index++]);
record_ttl = (cnx->response[current_index++] << 24); record_ttl = (cnx->response[current_index++] << 24);
record_ttl |= (cnx->response[current_index++] << 16); record_ttl |= (cnx->response[current_index++] << 16);
@ -1154,7 +1302,7 @@ mdns_udp_multicast_read_cb(void *userarg)
record_data_len = (cnx->response[current_index++] << 8); record_data_len = (cnx->response[current_index++] << 8);
record_data_len |= (cnx->response[current_index++]); record_data_len |= (cnx->response[current_index++]);
if (current_index + record_data_len < read) if (current_index + record_data_len <= read)
{ {
/* /*
* Set the record to canonical form. This is required, since * Set the record to canonical form. This is required, since
@ -1244,7 +1392,7 @@ static int mdns_open_ipv4_multicast(SOCKADDR_STORAGE* mcast_dest, int* mcast_des
uint8_t ttl = 255; uint8_t ttl = 255;
IP_MREQ mreq4; IP_MREQ mreq4;
memset(&mcast_dest, 0, sizeof(SOCKADDR_STORAGE)); memset(mcast_dest, 0, sizeof(SOCKADDR_STORAGE));
*mcast_dest_len = 0; *mcast_dest_len = 0;
memset(&ipv4_dest, 0, sizeof(ipv4_dest)); memset(&ipv4_dest, 0, sizeof(ipv4_dest));
memset(&ipv4_port, 0, sizeof(ipv4_dest)); memset(&ipv4_port, 0, sizeof(ipv4_dest));
@ -1299,7 +1447,7 @@ static int mdns_open_ipv4_multicast(SOCKADDR_STORAGE* mcast_dest, int* mcast_des
if (ret == 0) if (ret == 0)
{ {
memcpy(&mcast_dest, &ipv4_dest, sizeof(ipv4_dest)); memcpy(mcast_dest, &ipv4_dest, sizeof(ipv4_dest));
*mcast_dest_len = sizeof(ipv4_dest); *mcast_dest_len = sizeof(ipv4_dest);
} }
@ -1316,7 +1464,7 @@ static int mdns_open_ipv6_multicast(SOCKADDR_STORAGE* mcast_dest, int* mcast_des
uint8_t ttl = 255; uint8_t ttl = 255;
IPV6_MREQ mreq6; IPV6_MREQ mreq6;
memset(&mcast_dest, 0, sizeof(SOCKADDR_STORAGE)); memset(mcast_dest, 0, sizeof(SOCKADDR_STORAGE));
*mcast_dest_len = 0; *mcast_dest_len = 0;
memset(&ipv6_dest, 0, sizeof(ipv6_dest)); memset(&ipv6_dest, 0, sizeof(ipv6_dest));
memset(&ipv6_port, 0, sizeof(ipv6_dest)); memset(&ipv6_port, 0, sizeof(ipv6_dest));
@ -1374,7 +1522,7 @@ static int mdns_open_ipv6_multicast(SOCKADDR_STORAGE* mcast_dest, int* mcast_des
if (ret == 0) if (ret == 0)
{ {
memcpy(&mcast_dest, &ipv6_dest, sizeof(ipv6_dest)); memcpy(mcast_dest, &ipv6_dest, sizeof(ipv6_dest));
*mcast_dest_len = sizeof(ipv6_dest); *mcast_dest_len = sizeof(ipv6_dest);
} }
return fd6; return fd6;
@ -1414,9 +1562,11 @@ static getdns_return_t mdns_delayed_network_init(struct getdns_context *context)
context->mdns_connection[0].fd = mdns_open_ipv4_multicast( context->mdns_connection[0].fd = mdns_open_ipv4_multicast(
&context->mdns_connection[0].addr_mcast &context->mdns_connection[0].addr_mcast
, &context->mdns_connection[0].addr_mcast_len); , &context->mdns_connection[0].addr_mcast_len);
context->mdns_connection[0].context = context;
context->mdns_connection[1].fd = mdns_open_ipv6_multicast( context->mdns_connection[1].fd = mdns_open_ipv6_multicast(
&context->mdns_connection[0].addr_mcast &context->mdns_connection[1].addr_mcast
, &context->mdns_connection[0].addr_mcast_len); , &context->mdns_connection[1].addr_mcast_len);
context->mdns_connection[1].context = context;
if (context->mdns_connection[0].fd == -1 || if (context->mdns_connection[0].fd == -1 ||
context->mdns_connection[1].fd == -1) context->mdns_connection[1].fd == -1)
@ -1479,7 +1629,7 @@ static getdns_return_t mdns_delayed_network_init(struct getdns_context *context)
*/ */
static getdns_return_t mdns_initialize_continuous_request(getdns_network_req *netreq) static getdns_return_t mdns_initialize_continuous_request(getdns_network_req *netreq)
{ {
int ret = 0; getdns_return_t ret = 0;
getdns_dns_req *dnsreq = netreq->owner; getdns_dns_req *dnsreq = netreq->owner;
struct getdns_context *context = dnsreq->context; struct getdns_context *context = dnsreq->context;
@ -1521,6 +1671,15 @@ static getdns_return_t mdns_initialize_continuous_request(getdns_network_req *ne
if (ret == 0) if (ret == 0)
{ {
/* If the query is not actually complete, are a per query timer. */
if (netreq->state < NET_REQ_FINISHED)
{
GETDNS_CLEAR_EVENT(dnsreq->loop, &netreq->event);
GETDNS_SCHEDULE_EVENT(
dnsreq->loop, -1, dnsreq->context->timeout,
getdns_eventloop_event_init(&netreq->event, netreq,
NULL, NULL, mdns_mcast_timeout_cb));
}
/* If the entry was created less than 1 sec ago, send a query */ /* If the entry was created less than 1 sec ago, send a query */
if (context->mdns_connection_nb <= 0) if (context->mdns_connection_nb <= 0)
@ -1532,12 +1691,13 @@ static getdns_return_t mdns_initialize_continuous_request(getdns_network_req *ne
{ {
/* TODO? Set TTL=255 for compliance with RFC 6762 */ /* TODO? Set TTL=255 for compliance with RFC 6762 */
int fd_index = context->mdns_connection_nb - 1; int fd_index = context->mdns_connection_nb - 1;
int sent = sendto(
if ((ssize_t)pkt_len != sendto(
context->mdns_connection[fd_index].fd context->mdns_connection[fd_index].fd
, (const void *)netreq->query, pkt_len, 0 , (const void *)netreq->query, pkt_len, 0
, (SOCKADDR*)&context->mdns_connection[fd_index].addr_mcast , (SOCKADDR*)&context->mdns_connection[fd_index].addr_mcast
, context->mdns_connection[fd_index].addr_mcast_len)) , context->mdns_connection[fd_index].addr_mcast_len);
if (pkt_len != sent)
{ {
ret = GETDNS_RETURN_GENERIC_ERROR; ret = GETDNS_RETURN_GENERIC_ERROR;
} }
@ -1900,3 +2060,188 @@ _getdns_mdns_namespace_check(
} }
#endif /* HAVE_MDNS_SUPPORT */ #endif /* HAVE_MDNS_SUPPORT */
#ifdef MDNS_UNIT_TEST
/*
* Test adding data to the LRU Cache
*/
static BYTE mdns_exampleRRAM[] = {
0, 0, /* Transaction ID = 0 */
0x84, 0, /* Answer: QR=1 (80), AA=1 (04) */
0, 0, /* QD Count = 0 */
0, 1, /* AN Count = 1 */
0, 0, /* NS Count = 0 */
0, 0, /* AD Count = 0 */
7, /* length of "example" name part */
'e', 'x', 'a', 'm', 'p', 'l', 'e',
5, /* length of "local" name part */
'l', 'o', 'c', 'a', 'l',
0, /* length of the root name part */
0, 1, /* QTYPE = 1, A record */
0, 1, /* QCLASS = 1, IN */
0, 0, 0, 255, /* TTL: 255 sec */
0, 4, /* length of RDATA */
10, 0, 0, 1 /* Value of RDATA (some IPv4 address) */
};
uint8_t mdns_test_name[] = {
7, /* length of "example" name part */
't', 'e', 's', 't', 'i', 'n', 'g',
5, /* length of "local" name part */
'l', 'o', 'c', 'a', 'l',
0, /* length of the root name part */
};
uint8_t mdns_test_first_address[4] = { 10, 0, 0, 1 };
uint8_t mdns_test_second_address[4] = { 10, 0, 0, 2 };
uint8_t mdns_test_third_address[4] = { 10, 0, 0, 3 };
int mdns_finalize_lru_test(struct getdns_context* context,
uint8_t * name, int name_len, int record_type, int record_class,
int expected_nb_records,
uint8_t * buffer, size_t buffer_max, size_t* entry_length)
{
int ret = 0;
/* verify that the entry is there */
struct lruhash_entry * entry =
mdns_access_cached_entry_by_name(context, name, name_len, record_type, record_class);
*entry_length = 0;
if (entry == NULL)
{
if (expected_nb_records != 0)
ret = -1;
}
else
{
int nbanswers = mdns_cache_nb_records_in_entry((uint8_t*)entry->data);
if (nbanswers != expected_nb_records)
{
ret = -2;
}
if (buffer != NULL)
{
getdns_mdns_cached_record_header * header =
(getdns_mdns_cached_record_header*)entry->data;
size_t record_length = header->content_len - sizeof(getdns_mdns_cached_record_header);
if (record_length > buffer_max)
{
ret = -3;
}
else
{
memcpy(buffer, ((uint8_t *)entry->data) + sizeof(getdns_mdns_cached_record_header),
record_length);
*entry_length = record_length;
}
}
lock_rw_unlock(entry->lock);
}
return ret;
}
int mdns_addition_test(struct getdns_context* context,
uint8_t * buffer, size_t buffer_max, size_t* entry_length)
{
int ret =
mdns_propose_entry_to_cache(context, mdns_test_name, sizeof(mdns_test_name), 1, 1, 255,
mdns_test_first_address, 4, NULL, _getdns_get_time_as_uintt64());
if (ret == 0)
{
ret = mdns_finalize_lru_test(context, &mdns_exampleRRAM[12], 15, 1, 1,
1, buffer, buffer_max, entry_length);
}
return ret;
}
int mdns_addition_test2(struct getdns_context* context,
uint8_t * buffer, size_t buffer_max, size_t* entry_length)
{
int ret =
mdns_propose_entry_to_cache(context, mdns_test_name, sizeof(mdns_test_name), 1, 1, 255,
mdns_test_first_address, 4, NULL, _getdns_get_time_as_uintt64());
if (ret == 0)
{
/* add a second entry, with a different value */
ret =
mdns_propose_entry_to_cache(context, mdns_test_name, sizeof(mdns_test_name), 1, 1, 255,
mdns_test_second_address, 4, NULL, _getdns_get_time_as_uintt64());
}
if (ret == 0)
{
/* add a third entry, with a different value */
ret =
mdns_propose_entry_to_cache(context, mdns_test_name, sizeof(mdns_test_name), 1, 1, 255,
mdns_test_third_address, 4, NULL, _getdns_get_time_as_uintt64());
}
if (ret == 0)
{
ret = mdns_finalize_lru_test(context, mdns_test_name, sizeof(mdns_test_name), 1, 1,
3, buffer, buffer_max, entry_length);
}
return ret;
}
int mdns_deletion_test(struct getdns_context* context,
uint8_t * buffer, size_t buffer_max, size_t* entry_length)
{
/* insert data with TTL = 0 to trigger suppression */
int ret =
mdns_propose_entry_to_cache(context, mdns_test_name, sizeof(mdns_test_name), 1, 1, 0,
mdns_test_second_address, 4, NULL, _getdns_get_time_as_uintt64());
if (ret == 0)
{
ret = mdns_finalize_lru_test(context, mdns_test_name, sizeof(mdns_test_name), 1, 1,
2, buffer, buffer_max, entry_length);
}
return ret;
}
int mdns_deletion_test2(struct getdns_context* context,
uint8_t * buffer, size_t buffer_max, size_t* entry_length)
{
/* insert data with TTL = 0 to trigger suppression */
int ret =
mdns_propose_entry_to_cache(context, mdns_test_name, sizeof(mdns_test_name), 1, 1, 0,
mdns_test_first_address, 4, NULL, _getdns_get_time_as_uintt64());
if (ret == 0)
{
ret =
mdns_propose_entry_to_cache(context, mdns_test_name, sizeof(mdns_test_name), 1, 1, 0,
mdns_test_third_address, 4, NULL, _getdns_get_time_as_uintt64());
}
if (ret == 0)
{
ret = mdns_finalize_lru_test(context, mdns_test_name, sizeof(mdns_test_name), 1, 1,
0, buffer, buffer_max, entry_length);
}
return ret;
}
int mdns_test_prepare(struct getdns_context* context)
{
return mdns_delayed_network_init(context);
}
#endif