Fix WSAPoll (#1265)

gthess · web-flow · commit 75e8fd75391f · 2025-04-11T15:05:52.000+02:00
* Fix calling WSAPoll.

* fast_reload: explicitly set tcp_wouldblock on Windows when there is no
  command to read from the fast_reload thread.

* For poll(), also check for ENOMEM (Linux).

* Remove ifdefs for ENOMEM.
* Some systems return EAGAIN for poll.
diff --git a/daemon/remote.c b/daemon/remote.c
@@ -3899,6 +3899,7 @@ sock_poll_timeout(int fd, int timeout, int pollin, int pollout, int* event)
 {
 	int loopcount = 0;
 	/* Loop if the system call returns an errno to do so, like EINTR. */
+	log_assert(pollin || pollout);
 	while(1) {
 		struct pollfd p, *fds;
 		int nfds, ret;
@@ -3916,11 +3917,11 @@ sock_poll_timeout(int fd, int timeout, int pollin, int pollout, int* event)
 			nfds = 1;
 			memset(&p, 0, sizeof(p));
 			p.fd = fd;
-			p.events = POLLERR
 #ifndef USE_WINSOCK
+			p.events = POLLERR
 				| POLLHUP
-#endif
 				;
+#endif
 			if(pollin)
 				p.events |= POLLIN;
 			if(pollout)
@@ -3937,19 +3938,20 @@ sock_poll_timeout(int fd, int timeout, int pollin, int pollout, int* event)
 		}
 #endif
 		if(ret == -1) {
-			if(
 #ifndef USE_WINSOCK
+			if(
 				errno == EINTR || errno == EAGAIN
 #  ifdef EWOULDBLOCK
 				|| errno == EWOULDBLOCK
 #  endif
-#else
-				WSAGetLastError() == WSAEINTR ||
-				WSAGetLastError() == WSAEINPROGRESS ||
-				WSAGetLastError() == WSAEWOULDBLOCK
+			) continue; /* Try again. */
 #endif
-				)
-				continue; /* Try again. */
+			/* For WSAPoll we only get errors here:
+			 * o WSAENETDOWN
+			 * o WSAEFAULT
+			 * o WSAEINVAL
+			 * o WSAENOBUFS
+			 */
 			log_err("poll: %s", sock_strerror(errno));
 			if(event)
 				*event = 0;
@@ -7392,11 +7394,17 @@ fr_main_handle_cmd(struct fast_reload_thread* fr)
 #  endif
 #else
 			WSAGetLastError() == WSAEINTR ||
-			WSAGetLastError() == WSAEINPROGRESS ||
-			WSAGetLastError() == WSAEWOULDBLOCK
+			WSAGetLastError() == WSAEINPROGRESS
 #endif
 			)
 			return; /* Continue later. */
+#ifdef USE_WINSOCK
+		if(WSAGetLastError() == WSAEWOULDBLOCK) {
+			ub_winsock_tcp_wouldblock(fr->service_event,
+				UB_EV_READ);
+			return; /* Continue later. */
+		}
+#endif
 		log_err("read cmd from fast reload thread, recv: %s",
 			sock_strerror(errno));
 		return;
@@ -7428,10 +7436,23 @@ fr_check_cmd_from_thread(struct fast_reload_thread* fr)
 		if(!sock_poll_timeout(fr->commpair[0], 0, 1, 0, &inevent)) {
 			log_err("check for cmd from fast reload thread: "
 				"poll failed");
+#ifdef USE_WINSOCK
+			if(worker->daemon->fast_reload_thread)
+				ub_winsock_tcp_wouldblock(worker->daemon->
+					fast_reload_thread->service_event,
+					UB_EV_READ);
+#endif
 			return;
 		}
-		if(!inevent)
+		if(!inevent) {
+#ifdef USE_WINSOCK
+			if(worker->daemon->fast_reload_thread)
+				ub_winsock_tcp_wouldblock(worker->daemon->
+					fast_reload_thread->service_event,
+					UB_EV_READ);
+#endif
 			return;
+		}
 		fr_main_handle_cmd(fr);
 	}
 }
diff --git a/util/netevent.c b/util/netevent.c
@@ -456,9 +456,9 @@ comm_point_send_udp_msg(struct comm_point *c, sldns_buffer* packet,
 				int pret;
 				memset(&p, 0, sizeof(p));
 				p.fd = c->fd;
-				p.events = POLLOUT | POLLERR
+				p.events = POLLOUT
 #ifndef USE_WINSOCK
-					| POLLHUP
+					| POLLERR | POLLHUP
 #endif
 					;
 #  ifndef USE_WINSOCK
@@ -483,7 +483,7 @@ comm_point_send_udp_msg(struct comm_point *c, sldns_buffer* packet,
 #  ifdef EWOULDBLOCK
 					errno != EWOULDBLOCK &&
 #  endif
-					errno != ENOBUFS
+					errno != ENOMEM && errno != ENOBUFS
 #else
 					WSAGetLastError() != WSAEINPROGRESS &&
 					WSAGetLastError() != WSAEINTR &&
@@ -496,15 +496,19 @@ comm_point_send_udp_msg(struct comm_point *c, sldns_buffer* packet,
 					return 0;
 				} else if((pret < 0 &&
 #ifndef USE_WINSOCK
-					errno == ENOBUFS
+					( errno == ENOBUFS  /* Maybe some systems */
+					|| errno == ENOMEM  /* Linux */
+					|| errno == EAGAIN)  /* Macos, solaris, openbsd */
 #else
 					WSAGetLastError() == WSAENOBUFS
 #endif
 					) || (send_nobufs && retries > 0)) {
-					/* ENOBUFS, and poll returned without
+					/* ENOBUFS/ENOMEM/EAGAIN, and poll
+					 * returned without
 					 * a timeout. Or the retried send call
-					 * returned ENOBUFS. It is good to
-					 * wait a bit for the error to clear. */
+					 * returned ENOBUFS/ENOMEM/EAGAIN.
+					 * It is good to wait a bit for the
+					 * error to clear. */
 					/* The timeout is 20*(2^(retries+1)),
 					 * it increases exponentially, starting
 					 * at 40 msec. After 5 tries, 1240 msec
@@ -517,18 +521,15 @@ comm_point_send_udp_msg(struct comm_point *c, sldns_buffer* packet,
 					Sleep((SEND_BLOCKED_WAIT_TIMEOUT/10)<<(retries+1));
 					pret = 0;
 #endif
-					if(pret < 0 &&
+					if(pret < 0
 #ifndef USE_WINSOCK
-						errno != EAGAIN && errno != EINTR &&
+						&& errno != EAGAIN && errno != EINTR &&
 #  ifdef EWOULDBLOCK
 						errno != EWOULDBLOCK &&
 #  endif
-						errno != ENOBUFS
+						errno != ENOMEM && errno != ENOBUFS
 #else
-						WSAGetLastError() != WSAEINPROGRESS &&
-						WSAGetLastError() != WSAEINTR &&
-						WSAGetLastError() != WSAENOBUFS &&
-						WSAGetLastError() != WSAEWOULDBLOCK
+						/* Sleep does not error */
 #endif
 					) {
 						log_err("poll udp out timer failed: %s",
@@ -770,9 +771,9 @@ comm_point_send_udp_msg_if(struct comm_point *c, sldns_buffer* packet,
 				int pret;
 				memset(&p, 0, sizeof(p));
 				p.fd = c->fd;
-				p.events = POLLOUT | POLLERR
+				p.events = POLLOUT
 #ifndef USE_WINSOCK
-					| POLLHUP
+					| POLLERR | POLLHUP
 #endif
 					;
 #  ifndef USE_WINSOCK
@@ -797,7 +798,7 @@ comm_point_send_udp_msg_if(struct comm_point *c, sldns_buffer* packet,
 #  ifdef EWOULDBLOCK
 					errno != EWOULDBLOCK &&
 #  endif
-					errno != ENOBUFS
+					errno != ENOMEM && errno != ENOBUFS
 #else
 					WSAGetLastError() != WSAEINPROGRESS &&
 					WSAGetLastError() != WSAEINTR &&
@@ -810,15 +811,19 @@ comm_point_send_udp_msg_if(struct comm_point *c, sldns_buffer* packet,
 					return 0;
 				} else if((pret < 0 &&
 #ifndef USE_WINSOCK
-					errno == ENOBUFS
+					( errno == ENOBUFS  /* Maybe some systems */
+					|| errno == ENOMEM  /* Linux */
+					|| errno == EAGAIN)  /* Macos, solaris, openbsd */
 #else
 					WSAGetLastError() == WSAENOBUFS
 #endif
 					) || (send_nobufs && retries > 0)) {
-					/* ENOBUFS, and poll returned without
+					/* ENOBUFS/ENOMEM/EAGAIN, and poll
+					 * returned without
 					 * a timeout. Or the retried send call
-					 * returned ENOBUFS. It is good to
-					 * wait a bit for the error to clear. */
+					 * returned ENOBUFS/ENOMEM/EAGAIN.
+					 * It is good to wait a bit for the
+					 * error to clear. */
 					/* The timeout is 20*(2^(retries+1)),
 					 * it increases exponentially, starting
 					 * at 40 msec. After 5 tries, 1240 msec
@@ -831,18 +836,15 @@ comm_point_send_udp_msg_if(struct comm_point *c, sldns_buffer* packet,
 					Sleep((SEND_BLOCKED_WAIT_TIMEOUT/10)<<(retries+1));
 					pret = 0;
 #endif
-					if(pret < 0 &&
+					if(pret < 0
 #ifndef USE_WINSOCK
-						errno != EAGAIN && errno != EINTR &&
+						&& errno != EAGAIN && errno != EINTR &&
 #  ifdef EWOULDBLOCK
 						errno != EWOULDBLOCK &&
 #  endif
-						errno != ENOBUFS
-#else
-						WSAGetLastError() != WSAEINPROGRESS &&
-						WSAGetLastError() != WSAEINTR &&
-						WSAGetLastError() != WSAENOBUFS &&
-						WSAGetLastError() != WSAEWOULDBLOCK
+						errno != ENOMEM && errno != ENOBUFS
+#else  /* USE_WINSOCK */
+						/* Sleep does not error */
 #endif
 					) {
 						log_err("poll udp out timer failed: %s",
