dns_client: make DNS query ID random

src/dns_client.c

@@ -47,6 +47,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <sys/epoll.h>
+#include <sys/random.h>
 #include <sys/socket.h>
 #include <sys/stat.h>
 #include <sys/types.h>
@@ -254,7 +255,6 @@ struct dns_query_struct {
 };
 
 static struct dns_client client;
-static atomic_t dns_client_sid = ATOMIC_INIT(0);
 static LIST_HEAD(pending_servers);
 static pthread_mutex_t pending_server_mutex = PTHREAD_MUTEX_INITIALIZER;
 static int dns_client_has_bootstrap_dns = 0;
@@ -1525,7 +1525,7 @@ static void _dns_client_check_tcp(void)
 	pthread_mutex_unlock(&client.server_list_lock);
 }
 
-static struct dns_query_struct *_dns_client_get_request(unsigned short sid, char *domain)
+static struct dns_query_struct *_dns_client_get_request(char *domain, int qtype, unsigned short sid)
 {
 	struct dns_query_struct *query = NULL;
 	struct dns_query_struct *query_result = NULL;
@@ -1535,6 +1535,7 @@ static struct dns_query_struct *_dns_client_get_request(unsigned short sid, char
 	/* get query by hash key : id + domain */
 	key = hash_string(domain);
 	key = jhash(&sid, sizeof(sid), key);
+	key = jhash(&qtype, sizeof(qtype), key);
 	pthread_mutex_lock(&client.domain_map_lock);
 	hash_for_each_possible_safe(client.domain_map, query, tmp, domain_node, key)
 	{
@@ -1542,6 +1543,10 @@ static struct dns_query_struct *_dns_client_get_request(unsigned short sid, char
 			continue;
 		}
 
+		if (qtype != query->qtype) {
+			continue;
+		}
+
 		if (strncmp(query->domain, domain, DNS_MAX_CNAME_LEN) != 0) {
 			continue;
 		}
@@ -1643,7 +1648,7 @@ static int _dns_client_recv(struct dns_server_info *server_info, unsigned char *
 	}
 
 	/* get query reference */
-	query = _dns_client_get_request(packet->head.id, domain);
+	query = _dns_client_get_request(domain, qtype, packet->head.id);
 	if (query == NULL) {
 		return 0;
 	}
@@ -3495,6 +3500,7 @@ int dns_client_query(const char *domain, int qtype, dns_client_callback callback
 	struct dns_query_struct *query = NULL;
 	int ret = 0;
 	uint32_t key = 0;
+	int unused __attribute__((unused));
 
 	if (domain == NULL) {
 		goto errout;
@@ -3518,7 +3524,9 @@ int dns_client_query(const char *domain, int qtype, dns_client_callback callback
 	query->qtype = qtype;
 	query->send_tick = 0;
 	query->has_result = 0;
-	query->sid = atomic_inc_return(&dns_client_sid);
+	if (getrandom(&query->sid, sizeof(query->sid), GRND_NONBLOCK) != sizeof(query->sid)) {
+		query->sid = random();
+	}
 	query->server_group = _dns_client_get_dnsserver_group(group_name);
 	if (query->server_group == NULL) {
 		tlog(TLOG_ERROR, "get dns server group %s failed.", group_name);
@@ -3534,6 +3542,7 @@ int dns_client_query(const char *domain, int qtype, dns_client_callback callback
 	/* add query to hashtable */
 	key = hash_string(domain);
 	key = jhash(&query->sid, sizeof(query->sid), key);
+	key = jhash(&query->qtype, sizeof(query->qtype), key);
 	pthread_mutex_lock(&client.domain_map_lock);
 	hash_add(client.domain_map, &query->domain_node, key);
 	pthread_mutex_unlock(&client.domain_map_lock);
@@ -3946,6 +3955,8 @@ int dns_client_init(void)
 		return -1;
 	}
 
+	srandom(time(NULL));
+
 	memset(&client, 0, sizeof(client));
 	pthread_attr_init(&attr);
 	atomic_set(&client.dns_server_num, 0);

src/fast_ping.c

@@ -569,7 +569,7 @@ static int _fast_ping_sendping_v4(struct ping_host_struct *ping_host)
 	len = sendto(ping.fd_icmp, packet, sizeof(struct fast_ping_packet), 0, &ping_host->addr, ping_host->addr_len);
 	if (len < 0 || len != sizeof(struct fast_ping_packet)) {
 		int err = errno;
-		if (errno == ENETUNREACH || errno == EINVAL || errno == EADDRNOTAVAIL) {
+		if (errno == ENETUNREACH || errno == EINVAL || errno == EADDRNOTAVAIL || errno == EPERM || errno == EACCES) {
 			goto errout;
 		}
 		char ping_host_name[PING_MAX_HOSTLEN];
@@ -621,7 +621,7 @@ static int _fast_ping_sendping_udp(struct ping_host_struct *ping_host)
 	len = sendto(fd, &dns_head, sizeof(dns_head), 0, &ping_host->addr, ping_host->addr_len);
 	if (len < 0 || len != sizeof(dns_head)) {
 		int err = errno;
-		if (errno == ENETUNREACH || errno == EINVAL || errno == EADDRNOTAVAIL) {
+		if (errno == ENETUNREACH || errno == EINVAL || errno == EADDRNOTAVAIL || errno == EPERM || errno == EACCES) {
 			goto errout;
 		}
 		char ping_host_name[PING_MAX_HOSTLEN];
@@ -672,7 +672,7 @@ static int _fast_ping_sendping_tcp(struct ping_host_struct *ping_host)
 				goto errout;
 			}
 
-			if (errno == EACCES) {
+			if (errno == EACCES || errno == EPERM) {
 				if (bool_print_log == 0) {
 					goto errout;
 				}