[Cluster-devel] [PATCH] cman: Prevent libcman from causing SIGPIPE

[Christine Caulfield]

If corosync goes down/is shut down cman will return 0 from cman_dispatch 
and close the socket. However, if a cman write operation is issued 
before this happens then SIGPIPE can result from the writev() call to an 
open, but disconnected, FD.

This patch changes writev() to sendmg() so it can pass MSG_NOSIGNAL to 
the system call and prevent SIGPIPEs from occurring.

Signed-Off-By: Christine Caulfield <ccaul...@redhat.com>
diff --git a/cman/lib/libcman.c b/cman/lib/libcman.c
index a89c731..a99f5a0 100644
--- a/cman/lib/libcman.c
+++ b/cman/lib/libcman.c
@@ -204,10 +204,19 @@ static int loopy_writev(int fd, struct iovec *iovptr, size_t iovlen)
 {
 	size_t byte_cnt=0;
 	int len;
+	struct msghdr msg;
+
+	msg.msg_name = NULL;
+	msg.msg_namelen = 0;
+	msg.msg_control = NULL;
+	msg.msg_controllen = 0;
 
 	while (iovlen > 0)
 	{
-		len = writev(fd, iovptr, iovlen);
+	  msg.msg_iov = iovptr;
+	  msg.msg_iovlen = iovlen;
+
+	  len = sendmsg(fd, &msg, MSG_NOSIGNAL);
 		if (len <= 0)
 			return len;