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dns_client: fix ssl race condition issue.

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This commit is contained in:
Nick Peng
2020-09-02 22:03:24 +08:00
parent 7af6f475da
commit 2b81fffb7e
1 changed files with 96 additions and 20 deletions
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116
src/dns_client.c
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@@ -108,6 +108,7 @@ struct dns_server_info {
int ssl_write_len;
SSL_CTX *ssl_ctx;
SSL_SESSION *ssl_session;
pthread_mutex_t lock;
char skip_check_cert;
dns_server_status status;
@@ -249,6 +250,69 @@ static LIST_HEAD(pending_servers);
static pthread_mutex_t pending_server_mutex = PTHREAD_MUTEX_INITIALIZER;
static int dns_client_has_bootstrap_dns = 0;
int _ssl_read(struct dns_server_info *server, void *buff, int num)
{
int ret = 0;
pthread_mutex_lock(&server->lock);
ret = SSL_read(server->ssl, buff, num);
pthread_mutex_unlock(&server->lock);
return ret;
}
int _ssl_write(struct dns_server_info *server, const void *buff, int num)
{
int ret = 0;
pthread_mutex_lock(&server->lock);
ret = SSL_write(server->ssl, buff, num);
pthread_mutex_unlock(&server->lock);
return ret;
}
int _ssl_shutdown(struct dns_server_info *server)
{
int ret = 0;
pthread_mutex_lock(&server->lock);
ret = SSL_shutdown(server->ssl);
pthread_mutex_unlock(&server->lock);
return ret;
}
int _ssl_get_error(struct dns_server_info *server, int ret)
{
int err = 0;
pthread_mutex_lock(&server->lock);
err = SSL_get_error(server->ssl, ret);
pthread_mutex_unlock(&server->lock);
return err;
}
int _ssl_do_handshake(struct dns_server_info *server)
{
int err = 0;
pthread_mutex_lock(&server->lock);
err = SSL_do_handshake(server->ssl);
pthread_mutex_unlock(&server->lock);
return err;
}
int _ssl_session_reused(struct dns_server_info *server)
{
int err = 0;
pthread_mutex_lock(&server->lock);
err = SSL_session_reused(server->ssl);
pthread_mutex_unlock(&server->lock);
return err;
}
SSL_SESSION *_ssl_get1_session(struct dns_server_info *server)
{
SSL_SESSION *ret = 0;
pthread_mutex_lock(&server->lock);
ret = SSL_get1_session(server->ssl);
pthread_mutex_unlock(&server->lock);
return ret;
}
const char *_dns_server_get_type_string(dns_server_type_t type)
{
const char *type_str = "";
@@ -837,6 +901,7 @@ 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;
pthread_mutex_init(&server_info->lock, NULL);
memcpy(&server_info->flags, flags, sizeof(server_info->flags));
/* exclude this server from default group */
@@ -862,7 +927,7 @@ static int _dns_client_server_add(char *server_ip, char *server_host, int port,
SSL_CTX_set_options(server_info->ssl_ctx, SSL_OP_ALL | SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION);
SSL_CTX_set_session_cache_mode(server_info->ssl_ctx, SSL_SESS_CACHE_CLIENT);
SSL_CTX_sess_set_cache_size(server_info->ssl_ctx, 1);
SSL_CTX_sess_set_cache_size(server_info->ssl_ctx, 32);
if (_dns_client_set_trusted_cert(server_info->ssl_ctx) != 0) {
tlog(TLOG_WARN, "disable check certificate for %s.", server_info->ip);
server_info->skip_check_cert = 1;
@@ -916,6 +981,7 @@ errout:
server_info->ssl_ctx = NULL;
}
pthread_mutex_destroy(&server_info->lock);
free(server_info);
}
@@ -935,7 +1001,7 @@ static void _dns_client_close_socket(struct dns_server_info *server_info)
if (server_info->ssl) {
/* Shutdown ssl */
if (server_info->status == DNS_SERVER_STATUS_CONNECTED) {
SSL_shutdown(server_info->ssl);
_ssl_shutdown(server_info);
}
SSL_free(server_info->ssl);
server_info->ssl = NULL;
@@ -974,7 +1040,7 @@ static void _dns_client_shutdown_socket(struct dns_server_info *server_info)
if (server_info->ssl) {
/* Shutdown ssl */
if (server_info->status == DNS_SERVER_STATUS_CONNECTED) {
SSL_shutdown(server_info->ssl);
_ssl_shutdown(server_info);
}
shutdown(server_info->fd, SHUT_RDWR);
}
@@ -1015,6 +1081,7 @@ static void _dns_client_server_remove_all(void)
{
list_del(&server_info->list);
_dns_client_server_close(server_info);
pthread_mutex_destroy(&server_info->lock);
free(server_info);
}
pthread_mutex_unlock(&client.server_list_lock);
@@ -1782,23 +1849,23 @@ static int _dns_client_process_udp(struct dns_server_info *server_info, struct e
return 0;
}
static int _dns_client_socket_ssl_send(SSL *ssl, const void *buf, int num)
static int _dns_client_socket_ssl_send(struct dns_server_info *server, const void *buf, int num)
{
int ret = 0;
int ssl_ret = 0;
unsigned long ssl_err = 0;
if (ssl == NULL) {
if (server->ssl == NULL) {
errno = EINVAL;
return -1;
}
ret = SSL_write(ssl, buf, num);
ret = _ssl_write(server, buf, num);
if (ret > 0) {
return ret;
}
ssl_ret = SSL_get_error(ssl, ret);
ssl_ret = _ssl_get_error(server, ret);
switch (ssl_ret) {
case SSL_ERROR_NONE:
return 0;
@@ -1838,23 +1905,23 @@ static int _dns_client_socket_ssl_send(SSL *ssl, const void *buf, int num)
return ret;
}
static int _dns_client_socket_ssl_recv(SSL *ssl, void *buf, int num)
static int _dns_client_socket_ssl_recv(struct dns_server_info *server, void *buf, int num)
{
int ret = 0;
int ssl_ret = 0;
unsigned long ssl_err = 0;
if (ssl == NULL) {
if (server->ssl == NULL) {
errno = EFAULT;
return -1;
}
ret = SSL_read(ssl, buf, num);
ret = _ssl_read(server, buf, num);
if (ret >= 0) {
return ret;
}
ssl_ret = SSL_get_error(ssl, ret);
ssl_ret = _ssl_get_error(server, ret);
switch (ssl_ret) {
case SSL_ERROR_NONE:
case SSL_ERROR_ZERO_RETURN:
@@ -1915,7 +1982,7 @@ static int _dns_client_socket_send(struct dns_server_info *server_info)
write_len = server_info->ssl_write_len;
server_info->ssl_write_len = -1;
}
int ret = _dns_client_socket_ssl_send(server_info->ssl, server_info->send_buff.data, write_len);
int ret = _dns_client_socket_ssl_send(server_info, server_info->send_buff.data, write_len);
if (ret != 0) {
if (errno == EAGAIN) {
server_info->ssl_write_len = write_len;
@@ -1935,7 +2002,7 @@ static int _dns_client_socket_recv(struct dns_server_info *server_info)
return recv(server_info->fd, server_info->recv_buff.data + server_info->recv_buff.len,
DNS_TCP_BUFFER - server_info->recv_buff.len, 0);
} else if (server_info->type == DNS_SERVER_TLS || server_info->type == DNS_SERVER_HTTPS) {
return _dns_client_socket_ssl_recv(server_info->ssl, server_info->recv_buff.data + server_info->recv_buff.len,
return _dns_client_socket_ssl_recv(server_info, server_info->recv_buff.data + server_info->recv_buff.len,
DNS_TCP_BUFFER - server_info->recv_buff.len);
} else {
return -1;
@@ -2053,6 +2120,11 @@ static int _dns_client_process_tcp(struct dns_server_info *server_info, struct e
goto errout;
}
if (errno == ETIMEDOUT) {
tlog(TLOG_INFO, "recv failed, server %s:%d, %s\n", server_info->ip, server_info->port, strerror(errno));
goto errout;
}
tlog(TLOG_ERROR, "recv failed, server %s:%d, %s\n", server_info->ip, server_info->port, strerror(errno));
goto errout;
}
@@ -2221,8 +2293,10 @@ static int _dns_client_tls_verify(struct dns_server_info *server_info)
return -1;
}
pthread_mutex_lock(&server_info->lock);
cert = SSL_get_peer_certificate(server_info->ssl);
if (cert == NULL) {
pthread_mutex_unlock(&server_info->lock);
tlog(TLOG_ERROR, "get peer certificate failed.");
return -1;
}
@@ -2230,6 +2304,7 @@ static int _dns_client_tls_verify(struct dns_server_info *server_info)
if (server_info->skip_check_cert == 0) {
long res = SSL_get_verify_result(server_info->ssl);
if (res != X509_V_OK) {
pthread_mutex_unlock(&server_info->lock);
peer_CN[0] = '\0';
_dns_client_tls_get_cert_CN(cert, peer_CN, sizeof(peer_CN));
tlog(TLOG_WARN, "peer server %s certificate verify failed", server_info->ip);
@@ -2237,6 +2312,7 @@ static int _dns_client_tls_verify(struct dns_server_info *server_info)
goto errout;
}
}
pthread_mutex_unlock(&server_info->lock);
if (_dns_client_tls_get_cert_CN(cert, peer_CN, sizeof(peer_CN)) != 0) {
tlog(TLOG_ERROR, "get cert CN failed.");
@@ -2336,12 +2412,12 @@ static int _dns_client_process_tls(struct dns_server_info *server_info, struct e
if (server_info->status == DNS_SERVER_STATUS_CONNECTING) {
/* do SSL hand shake */
ret = SSL_do_handshake(server_info->ssl);
ret = _ssl_do_handshake(server_info);
if (ret == 0) {
goto errout;
} else if (ret < 0) {
memset(&fd_event, 0, sizeof(fd_event));
ssl_ret = SSL_get_error(server_info->ssl, ret);
ssl_ret = _ssl_get_error(server_info, ret);
if (ssl_ret == SSL_ERROR_WANT_READ) {
fd_event.events = EPOLLIN;
} else if (ssl_ret == SSL_ERROR_WANT_WRITE) {
@@ -2370,7 +2446,7 @@ static int _dns_client_process_tls(struct dns_server_info *server_info, struct e
tlog(TLOG_DEBUG, "tls server %s connected.\n", server_info->ip);
/* Was the stored session reused? */
if (SSL_session_reused(server_info->ssl)) {
if (_ssl_session_reused(server_info)) {
tlog(TLOG_DEBUG, "reused session");
} else {
tlog(TLOG_DEBUG, "new session");
@@ -2388,7 +2464,7 @@ static int _dns_client_process_tls(struct dns_server_info *server_info, struct e
}
/* save ssl session for next request */
server_info->ssl_session = SSL_get1_session(server_info->ssl);
server_info->ssl_session = _ssl_get1_session(server_info);
pthread_mutex_unlock(&client.server_list_lock);
}
@@ -2539,7 +2615,7 @@ static int _dns_client_send_tls(struct dns_server_info *server_info, void *packe
return -1;
}
send_len = _dns_client_socket_ssl_send(server_info->ssl, inpacket, len);
send_len = _dns_client_socket_ssl_send(server_info, inpacket, len);
if (send_len <= 0) {
if (errno == EAGAIN || errno == EPIPE || server_info->ssl == NULL) {
/* save data to buffer, and retry when EPOLLOUT is available */
@@ -2590,13 +2666,13 @@ static int _dns_client_send_https(struct dns_server_info *server_info, void *pac
return -1;
}
send_len = _dns_client_socket_ssl_send(server_info->ssl, inpacket, http_len);
send_len = _dns_client_socket_ssl_send(server_info, inpacket, http_len);
if (send_len <= 0) {
if (errno == EAGAIN || errno == EPIPE || server_info->ssl == NULL) {
/* save data to buffer, and retry when EPOLLOUT is available */
return _dns_client_send_data_to_buffer(server_info, inpacket, http_len);
} else if (server_info->ssl && errno != ENOMEM) {
SSL_set_shutdown(server_info->ssl, SSL_SENT_SHUTDOWN | SSL_RECEIVED_SHUTDOWN);
_ssl_shutdown(server_info);
}
return -1;
} else if (send_len < http_len) {