From: Serge Hallyn <serge.hallyn@ubuntu.com>
Date: Tue, 25 Mar 2014 20:50:06 +0000 (-0500)
Subject: commands: handle epipe
X-Git-Tag: lxc-1.1.0.alpha1~189
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6168ff15aac16bcccbcf22b4ba915870844e96a4;p=thirdparty%2Flxc.git

commands: handle epipe

If we start a lxc_wait on a container while it is exiting, it is
possible that we open the command socket, then the command socket
monitor closes all its mainloop sockets and exit, then we send our
credentials. Then we get killed by SIGPIPE.

Handle that case, recognizing that if we get sigpipe then the
container is (now) stopped.

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>
---

diff --git a/src/lxc/af_unix.c b/src/lxc/af_unix.c
index a2de73e86..46d8e50fc 100644
--- a/src/lxc/af_unix.c
+++ b/src/lxc/af_unix.c
@@ -158,7 +158,7 @@ int lxc_abstract_unix_send_fd(int fd, int sendfd, void *data, size_t size)
 	msg.msg_iov = &iov;
 	msg.msg_iovlen = 1;
 
-	return sendmsg(fd, &msg, 0);
+	return sendmsg(fd, &msg, MSG_NOSIGNAL);
 }
 
 int lxc_abstract_unix_recv_fd(int fd, int *recvfd, void *data, size_t size)
@@ -230,7 +230,7 @@ int lxc_abstract_unix_send_credential(int fd, void *data, size_t size)
 	msg.msg_iov = &iov;
 	msg.msg_iovlen = 1;
 
-	return sendmsg(fd, &msg, 0);
+	return sendmsg(fd, &msg, MSG_NOSIGNAL);
 }
 
 int lxc_abstract_unix_rcv_credential(int fd, void *data, size_t size)
diff --git a/src/lxc/commands.c b/src/lxc/commands.c
index 6b46c2ca7..b71274c3e 100644
--- a/src/lxc/commands.c
+++ b/src/lxc/commands.c
@@ -263,6 +263,8 @@ static int lxc_cmd(const char *name, struct lxc_cmd_rr *cmd, int *stopped,
 
 	ret = lxc_abstract_unix_send_credential(sock, &cmd->req, sizeof(cmd->req));
 	if (ret != sizeof(cmd->req)) {
+		if (errno == EPIPE)
+			goto epipe;
 		SYSERROR("command %s failed to send req to '@%s' %d",
 			 lxc_cmd_str(cmd->req.cmd), offset, ret);
 		if (ret >=0)
@@ -271,8 +273,10 @@ static int lxc_cmd(const char *name, struct lxc_cmd_rr *cmd, int *stopped,
 	}
 
 	if (cmd->req.datalen > 0) {
-		ret = send(sock, cmd->req.data, cmd->req.datalen, 0);
+		ret = send(sock, cmd->req.data, cmd->req.datalen, MSG_NOSIGNAL);
 		if (ret != cmd->req.datalen) {
+			if (errno == EPIPE)
+				goto epipe;
 			SYSERROR("command %s failed to send request data to '@%s' %d",
 				 lxc_cmd_str(cmd->req.cmd), offset, ret);
 			if (ret >=0)
@@ -289,6 +293,11 @@ out:
 		cmd->rsp.ret = sock;
 
 	return ret;
+
+epipe:
+	close(sock);
+	*stopped = 1;
+	return 0;
 }
 
 int lxc_try_cmd(const char *name, const char *lxcpath)