fix: WiFiClientSecure connection timeout (espressif#5398) (espressif#5418)

Closes espressif#5398 Using the same non-blocking socket connect pattern for respecting connection timeout, copied from WiFiClient::connect. WiFiClient::connect uses lwip_connect_r, whereas start_ssl_client uses lwip_connect. I haven't found what is the difference between them. I tested both, both work ok, so I kept lwip_connect.

Author: vlastahajek

libraries/WiFiClientSecure/src/ssl_client.cpp

@@ -76,30 +76,67 @@ int start_ssl_client(sslclient_context *ssl_client, const char *host, uint32_t p
  return -1;
  }
 
+ fcntl( ssl_client->socket, F_SETFL, fcntl( ssl_client->socket, F_GETFL, 0 ) | O_NONBLOCK );
  struct sockaddr_in serv_addr;
  memset(&serv_addr, 0, sizeof(serv_addr));
  serv_addr.sin_family = AF_INET;
  serv_addr.sin_addr.s_addr = srv;
  serv_addr.sin_port = htons(port);
 
- if (lwip_connect(ssl_client->socket, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) == 0) {
- if(timeout <= 0){
- timeout = 30000; // Milli seconds.
- }
- timeval so_timeout = { .tv_sec = timeout / 1000, .tv_usec = (timeout % 1000) * 1000 };
+ if(timeout <= 0){
+ timeout = 30000; // Milli seconds.
+ }
 
-#define ROE(x,msg) { if (((x)<0)) { log_e("LWIP Socket config of " msg " failed."); return -1; }}
- ROE(lwip_setsockopt(ssl_client->socket, SOL_SOCKET, SO_RCVTIMEO, &so_timeout, sizeof(so_timeout)),"SO_RCVTIMEO");
- ROE(lwip_setsockopt(ssl_client->socket, SOL_SOCKET, SO_SNDTIMEO, &so_timeout, sizeof(so_timeout)),"SO_SNDTIMEO");
+ fd_set fdset;
+ struct timeval tv;
+ FD_ZERO(&fdset);
+ FD_SET(ssl_client->socket, &fdset);
+ tv.tv_sec = timeout / 1000;
+ tv.tv_usec = (timeout % 1000) * 1000;
 
-  ROE(lwip_setsockopt(ssl_client->socket, IPPROTO_TCP, TCP_NODELAY, &enable, sizeof(enable)),"TCP_NODELAY");
-  ROE(lwip_setsockopt(ssl_client->socket, SOL_SOCKET, SO_KEEPALIVE, &enable, sizeof(enable)),"SO_KEEPALIVE");
- } else {
- log_e("Connect to Server failed!");
+ int res = lwip_connect(ssl_client->socket, (struct sockaddr*)&serv_addr, sizeof(serv_addr));
+ if (res < 0 && errno != EINPROGRESS) {
+  log_e("connect on fd %d, errno: %d, \"%s\"", ssl_client->socket, errno, strerror(errno));
+ close(ssl_client->socket);
  return -1;
  }
 
- fcntl( ssl_client->socket, F_SETFL, fcntl( ssl_client->socket, F_GETFL, 0 ) | O_NONBLOCK );
+ res = select(ssl_client->socket + 1, nullptr, &fdset, nullptr, timeout<0 ? nullptr : &tv);
+ if (res < 0) {
+ log_e("select on fd %d, errno: %d, \"%s\"", ssl_client->socket, errno, strerror(errno));
+ close(ssl_client->socket);
+ return -1;
+ } else if (res == 0) {
+ log_i("select returned due to timeout %d ms for fd %d", timeout, ssl_client->socket);
+ close(ssl_client->socket);
+ return -1;
+ } else {
+ int sockerr;
+ socklen_t len = (socklen_t)sizeof(int);
+ res = getsockopt(ssl_client->socket, SOL_SOCKET, SO_ERROR, &sockerr, &len);
+
+ if (res < 0) {
+ log_e("getsockopt on fd %d, errno: %d, \"%s\"", ssl_client->socket, errno, strerror(errno));
+ close(ssl_client->socket);
+ return -1;
+ }
+
+ if (sockerr != 0) {
+ log_e("socket error on fd %d, errno: %d, \"%s\"", ssl_client->socket, sockerr, strerror(sockerr));
+ close(ssl_client->socket);
+ return -1;
+ }
+ }
+
+
+#define ROE(x,msg) { if (((x)<0)) { log_e("LWIP Socket config of " msg " failed."); return -1; }}
+ ROE(lwip_setsockopt(ssl_client->socket, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv)),"SO_RCVTIMEO");
+ ROE(lwip_setsockopt(ssl_client->socket, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv)),"SO_SNDTIMEO");
+
+ ROE(lwip_setsockopt(ssl_client->socket, IPPROTO_TCP, TCP_NODELAY, &enable, sizeof(enable)),"TCP_NODELAY");
+ ROE(lwip_setsockopt(ssl_client->socket, SOL_SOCKET, SO_KEEPALIVE, &enable, sizeof(enable)),"SO_KEEPALIVE");
+
+
 
  log_v("Seeding the random number generator");
  mbedtls_entropy_init(&ssl_client->entropy_ctx);