From: Hwankyu Jhun <h.jhun@samsung.com>
Date: Wed, 21 Jul 2021 01:53:47 +0000 (+0900)
Subject: Add an exception handling about recvmsg()
X-Git-Tag: accepted/tizen/unified/20210722.124938~2
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=e2004809f8be5ebaf8c1a1063f053d554e0bde98;p=platform%2Fcore%2Fappfw%2Faul-1.git

Add an exception handling about recvmsg()

When calling the recvmsg(), the function returns a negative error value
immediately if the receive is interrupted by delivering of a signal.
This patch adds an exception handling for the error case.
If the errno is EINTR, calling the recvmsg() is tried for receiving the message
from the socket fd again.

Change-Id: I78ffc49bb9b128d14db489db95881fb48f009186
Signed-off-by: Hwankyu Jhun <h.jhun@samsung.com>
---

diff --git a/src/aul_sock.c b/src/aul_sock.c
index ae0a1cd..c4e7359 100644
--- a/src/aul_sock.c
+++ b/src/aul_sock.c
@@ -677,6 +677,7 @@ static int __recv_message(int sock, struct iovec *vec, int vec_max_size, int *ve
 	char buff[CMSG_SPACE(sizeof(int) * MAX_NR_OF_DESCRIPTORS) + CMSG_SPACE(50)] = {0};
 	struct msghdr msg = {0};
 	struct cmsghdr *cmsg = NULL;
+	bool is_blocking;
 	int ret;
 
 	if (vec == NULL || vec_max_size < 1 || vec_size == NULL)
@@ -687,9 +688,31 @@ static int __recv_message(int sock, struct iovec *vec, int vec_max_size, int *ve
 	msg.msg_control = buff;
 	msg.msg_controllen = sizeof(buff);
 
+	if (fcntl(sock, F_GETFL, 0) & O_NONBLOCK)
+		is_blocking = false;
+	else
+		is_blocking = true;
+
+retry:
 	ret = recvmsg(sock, &msg, 0);
-	if (ret < 0)
-		return -errno;
+	if (ret == 0) {
+		_W("Socket was disconnected. fd(%d)", sock);
+		return -ECOMM;
+	} else if (ret < 0) {
+		if (errno == EINTR || errno == EAGAIN) {
+			if (is_blocking && errno == EAGAIN) {
+				_E("recvmsg timeout. fd(%d)", sock);
+				return -EAGAIN;
+			}
+
+			goto retry;
+		}
+
+		ret = -errno;
+		_E("recvmsg error. fd(%d), errno(%d)", sock, errno);
+		return ret;
+	}
+
 	*vec_size = msg.msg_iovlen;
 
 	/* get the ANCILLARY data */