Fix network connect poll interuption handling

When connecting to socket, it is possible to get EINTR. In such case,
there should be an another attempt to connect if we are not over the
timeout. The timeout should be adjusted accordingly in that case.

This fixes phpredis/phpredis#1881

Closes GH-16606

Author: bukka

NEWS

@@ -63,6 +63,9 @@ PHP                                                                        NEWS
   . Fixed bug GH-16905 (Internal iterator functions can't handle UNDEF
     properties). (nielsdos)
 
+- Streams:
+  . Fixed network connect poll interuption handling. (Jakub Zelenka)
+
 - Windows:
   . Fixed bug GH-16849 (Error dialog causes process to hang). (cmb)
 

main/network.c

@@ -299,6 +299,35 @@ typedef int php_non_blocking_flags_t;
 	 fcntl(sock, F_SETFL, save)
 #endif
 
+#if HAVE_GETTIMEOFDAY
+/* Subtract times */
+static inline void sub_times(struct timeval a, struct timeval b, struct timeval *result)
+{
+	result->tv_usec = a.tv_usec - b.tv_usec;
+	if (result->tv_usec < 0L) {
+		a.tv_sec--;
+		result->tv_usec += 1000000L;
+	}
+	result->tv_sec = a.tv_sec - b.tv_sec;
+	if (result->tv_sec < 0L) {
+		result->tv_sec++;
+		result->tv_usec -= 1000000L;
+	}
+}
+
+static inline void php_network_set_limit_time(struct timeval *limit_time,
+		struct timeval *timeout)
+{
+	gettimeofday(limit_time, NULL);
+	limit_time->tv_sec += timeout->tv_sec;
+	limit_time->tv_usec += timeout->tv_usec;
+	if (limit_time->tv_usec >= 1000000) {
+		limit_time->tv_usec -= 1000000;
+		limit_time->tv_sec++;
+	}
+}
+#endif
+
 /* Connect to a socket using an interruptible connect with optional timeout.
  * Optionally, the connect can be made asynchronously, which will implicitly
  * enable non-blocking mode on the socket.
@@ -351,25 +380,53 @@ PHPAPI int php_network_connect_socket(php_socket_t sockfd,
 	 * expected when a connection is actively refused. This way,
 	 * php_pollfd_for will return a mask with POLLOUT if the connection
 	 * is successful and with POLLPRI otherwise. */
-	if ((n = php_pollfd_for(sockfd, POLLOUT|POLLPRI, timeout)) == 0) {
+	int events = POLLOUT|POLLPRI;
 #else
-	if ((n = php_pollfd_for(sockfd, PHP_POLLREADABLE|POLLOUT, timeout)) == 0) {
+	int events = PHP_POLLREADABLE|POLLOUT;
+#endif
+	struct timeval working_timeout;
+#if HAVE_GETTIMEOFDAY
+	struct timeval limit_time, time_now;
+#endif
+	if (timeout) {
+		memcpy(&working_timeout, timeout, sizeof(working_timeout));
+#if HAVE_GETTIMEOFDAY
+		php_network_set_limit_time(&limit_time, &working_timeout);
 #endif
-		error = PHP_TIMEOUT_ERROR_VALUE;
 	}
 
-	if (n > 0) {
-		len = sizeof(error);
-		/*
-		   BSD-derived systems set errno correctly
-		   Solaris returns -1 from getsockopt in case of error
-		   */
-		if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, (char*)&error, &len) != 0) {
+	while (true) {
+		n = php_pollfd_for(sockfd, events, timeout ? &working_timeout : NULL);
+		if (n < 0) {
+			if (errno == EINTR) {
+#if HAVE_GETTIMEOFDAY
+				if (timeout) {
+					gettimeofday(&time_now, NULL);
+
+					if (!timercmp(&time_now, &limit_time, <)) {
+						/* time limit expired; no need for another poll */
+						error = PHP_TIMEOUT_ERROR_VALUE;
+						break;
+					} else {
+						/* work out remaining time */
+						sub_times(limit_time, time_now, &working_timeout);
+					}
+				}
+#endif
+				continue;
+			}
 			ret = -1;
+		} else if (n == 0) {
+			error = PHP_TIMEOUT_ERROR_VALUE;
+		} else {
+			len = sizeof(error);
+			/* BSD-derived systems set errno correctly.
+			 * Solaris returns -1 from getsockopt in case of error. */
+			if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, (char*)&error, &len) != 0) {
+				ret = -1;
+			}
 		}
-	} else {
-		/* whoops: sockfd has disappeared */
-		ret = -1;
+		break;
 	}
 
 ok:
@@ -392,22 +449,6 @@ PHPAPI int php_network_connect_socket(php_socket_t sockfd,
 }
 /* }}} */
 
-/* {{{ sub_times */
-static inline void sub_times(struct timeval a, struct timeval b, struct timeval *result)
-{
-	result->tv_usec = a.tv_usec - b.tv_usec;
-	if (result->tv_usec < 0L) {
-		a.tv_sec--;
-		result->tv_usec += 1000000L;
-	}
-	result->tv_sec = a.tv_sec - b.tv_sec;
-	if (result->tv_sec < 0L) {
-		result->tv_sec++;
-		result->tv_usec -= 1000000L;
-	}
-}
-/* }}} */
-
 /* Bind to a local IP address.
  * Returns the bound socket, or -1 on failure.
  * */
@@ -777,7 +818,6 @@ PHPAPI php_socket_t php_network_accept_incoming(php_socket_t srvsock,
 }
 /* }}} */
 
-
 /* Connect to a remote host using an interruptible connect with optional timeout.
  * Optionally, the connect can be made asynchronously, which will implicitly
  * enable non-blocking mode on the socket.
@@ -809,13 +849,7 @@ php_socket_t php_network_connect_socket_to_host(const char *host, unsigned short
 	if (timeout) {
 		memcpy(&working_timeout, timeout, sizeof(working_timeout));
 #if HAVE_GETTIMEOFDAY
-		gettimeofday(&limit_time, NULL);
-		limit_time.tv_sec += working_timeout.tv_sec;
-		limit_time.tv_usec += working_timeout.tv_usec;
-		if (limit_time.tv_usec >= 1000000) {
-			limit_time.tv_usec -= 1000000;
-			limit_time.tv_sec++;
-		}
+		php_network_set_limit_time(&limit_time, &working_timeout);
 #endif
 	}