From: David Vašek <david.vasek@nic.cz>
Date: Thu, 5 Mar 2020 13:57:27 +0000 (+0100)
Subject: contrib/net: when sending data, reflect other transient errors as well
X-Git-Tag: embedded_lmdb~17
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=58045d51e5ea83defa2b058f4e35061d796402aa;p=thirdparty%2Fknot-dns.git

contrib/net: when sending data, reflect other transient errors as well
---

diff --git a/src/contrib/net.c b/src/contrib/net.c
index 666a8c04ca..93963e0f29 100644
--- a/src/contrib/net.c
+++ b/src/contrib/net.c
@@ -321,13 +321,13 @@ static int poll_one(int fd, int events, int timeout_ms)
  */
 static bool io_should_wait(int error)
 {
-	/* socket data not ready */
-	if (error == EAGAIN || error == EWOULDBLOCK) {
+	if (error == EAGAIN || error == EWOULDBLOCK ||	/* Socket data not ready. */
+	    error == ENOMEM || error == ENOBUFS) {	/* Insufficient resources. */
 		return true;
 	}
 
 #ifndef __linux__
-	/* FreeBSD: connection in progress */
+	/* FreeBSD: connection in progress. */
 	if (error == ENOTCONN) {
 		return true;
 	}
@@ -336,6 +336,20 @@ static bool io_should_wait(int error)
 	return false;
 }
 
+/*!
+ * \brief Check if we should wait again.
+ *
+ * \param error  \a errno set by the failed wait operation.
+ */
+static bool wait_should_retry(int error)
+{
+	if (error == EINTR ||				/* System call interrupted. */
+	    error == EAGAIN || error == ENOMEM) {	/* Insufficient resources. */
+		return true;
+	}
+	return false;
+}
+
 /*!
  * \brief I/O operation callbacks.
  */
@@ -430,9 +444,9 @@ static ssize_t io_exec(const struct io *io, int fd, struct msghdr *msg,
 					TIMEOUT_CTX_UPDATE
 					/* Ready, retry process. */
 					break;
-				} else if (ret == -1 && errno == EINTR) {
+				} else if (ret == -1 && wait_should_retry(errno)) {
 					TIMEOUT_CTX_UPDATE
-					/* Interrupted, continue waiting. */
+					/* Interrupted or transient error, continue waiting. */
 					continue;
 				} else if (ret == 0) {
 					/* Timeouted, exit. */