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client: avoid retry query storm

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This commit is contained in:
Nick Peng
2022-04-09 11:12:00 +08:00
parent 92af4c05c0
commit 23e9021d30
2 changed files with 20 additions and 8 deletions
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12
src/dns.c
View File

@@ -836,15 +836,15 @@ int dns_get_SOA(struct dns_rrs *rrs, char *domain, int maxsize, int *ttl, struct
if (ptr - data + 20 > len) {
return -1;
}
soa->serial = *((unsigned int *)ptr);
memcpy(&soa->serial, ptr, 4);
ptr += 4;
soa->refresh = *((unsigned int *)ptr);
memcpy(&soa->refresh, ptr, 4);
ptr += 4;
soa->retry = *((unsigned int *)ptr);
memcpy(&soa->retry, ptr, 4);
ptr += 4;
soa->expire = *((unsigned int *)ptr);
memcpy(&soa->expire, ptr, 4);
ptr += 4;
soa->minimum = *((unsigned int *)ptr);
memcpy(&soa->minimum, ptr, 4);
ptr += 4;
return 0;
@@ -1537,7 +1537,7 @@ static int _dns_encode_opts(struct dns_packet *packet, struct dns_context *conte
return 0;
}
static int _dns_decode_opt(struct dns_context *context, dns_rr_type type, unsigned int ttl, int rr_len)
static int __attribute__((unused)) _dns_decode_opt(struct dns_context *context, dns_rr_type type, unsigned int ttl, int rr_len)
{
unsigned short opt_code;
unsigned short opt_len;

16
src/dns_client.c
View File

@@ -58,7 +58,7 @@
#define DNS_TCP_IDLE_TIMEOUT (60 * 10)
#define DNS_TCP_CONNECT_TIMEOUT (5)
#define DNS_QUERY_TIMEOUT (500)
#define DNS_QUERY_RETRY (6)
#define DNS_QUERY_RETRY (4)
#define DNS_PENDING_SERVER_RETRY 40
#define SOCKET_PRIORITY (6)
#define SOCKET_IP_TOS (IPTOS_LOWDELAY | IPTOS_RELIABILITY)
@@ -117,6 +117,7 @@ struct dns_server_info {
time_t last_send;
time_t last_recv;
int prohibit;
/* server addr info */
unsigned short ai_family;
@@ -1004,6 +1005,7 @@ static int _dns_client_server_add(char *server_ip, char *server_host, int port,
server_info->ttl = ttl;
server_info->ttl_range = 0;
server_info->skip_check_cert = skip_check_cert;
server_info->prohibit = 0;
pthread_mutex_init(&server_info->lock, NULL);
memcpy(&server_info->flags, flags, sizeof(server_info->flags));
@@ -2152,6 +2154,7 @@ static int _dns_client_process_tcp_buff(struct dns_server_info *server_info)
}
tlog(TLOG_DEBUG, "recv tcp packet from %s, len = %d", server_info->ip, len);
time(&server_info->last_recv);
/* process result */
if (_dns_client_recv(server_info, inpacket_data, dns_packet_len, &server_info->addr, server_info->ai_addrlen) !=
0) {
@@ -2230,7 +2233,6 @@ static int _dns_client_process_tcp(struct dns_server_info *server_info, struct e
return ret;
}
time(&server_info->last_recv);
server_info->recv_buff.len += len;
if (server_info->recv_buff.len <= 2) {
/* wait and recv */
@@ -2787,6 +2789,14 @@ static int _dns_client_send_packet(struct dns_query_struct *query, void *packet,
list_for_each_entry_safe(group_member, tmp, &query->server_group->head, list)
{
server_info = group_member->server;
if (server_info->prohibit) {
time_t now;
time(&now);
if ((now - 60 < server_info->last_send) && (now - 5 > server_info->last_recv)) {
continue;
}
server_info->prohibit = 0;
}
total_server++;
tlog(TLOG_DEBUG, "send query to server %s", server_info->ip);
if (server_info->fd <= 0) {
@@ -2838,6 +2848,8 @@ static int _dns_client_send_packet(struct dns_query_struct *query, void *packet,
time_t now;
time(&now);
if (now - 5 > server_info->last_recv || send_err != ENOMEM) {
server_info->prohibit = 1;
tlog(TLOG_INFO, "server %s not alive, prohibit", server_info->ip);
_dns_client_shutdown_socket(server_info);
}