From c40a98c1d6ba9c669a04ed49455d1dffec893e28 Mon Sep 17 00:00:00 2001
From: Petr Baudis <pasky@ucw.cz>
Date: Thu, 1 Mar 2012 04:03:12 +0100
Subject: [PATCH] compctld recvmsg(): Allocate space for cmsg

---
 compctl.c  |  7 ++++---
 compctld.c | 16 ++++++++++++----
 2 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/compctl.c b/compctl.c
index ddeccc2..dd73291 100644
--- a/compctl.c
+++ b/compctl.c
@@ -30,9 +30,10 @@ connectd(void)
 	};
 
 	char cbuf[CMSG_SPACE(sizeof(cred))];
-	struct msghdr msg = {0};
-	msg.msg_control = cbuf;
-	msg.msg_controllen = sizeof(cbuf);
+	struct msghdr msg = {
+		.msg_control = cbuf,
+		.msg_controllen = sizeof(cbuf),
+	};
 
 	struct cmsghdr *cmsg = CMSG_FIRSTHDR(&msg);
 	cmsg->cmsg_level = SOL_SOCKET;
diff --git a/compctld.c b/compctld.c
index ad1283f..6ca9dfd 100644
--- a/compctld.c
+++ b/compctld.c
@@ -121,19 +121,27 @@ main(int argc, char *argv[])
 
 		/* Decode the message with credentials. */
 
-		struct msghdr msg;
+		struct ucred *cred;
+		char cbuf[CMSG_SPACE(sizeof(*cred))];
+		struct msghdr msg = {
+			.msg_control = cbuf,
+			.msg_controllen = sizeof(cbuf),
+		};
 		char *errmsg;
-		if (recvmsg(fd, &msg, MSG_WAITALL) <= 0) {
+recvagain:
+		if (recvmsg(fd, &msg, MSG_WAITALL) < 0) {
+			if (errno == EAGAIN)
+				goto recvagain;
 			errmsg = "recvmsg";
 sockerror:
 			logperror(errmsg);
 			close(fd);
 			continue;
 		}
-		struct ucred *cred;
 		struct cmsghdr *cmsg;
 		cmsg = CMSG_FIRSTHDR(&msg);
-		if (cmsg == NULL || cmsg->cmsg_len != CMSG_LEN(sizeof(struct ucred))) {
+		if (cmsg == NULL || cmsg->cmsg_len != CMSG_LEN(sizeof(*cred))) {
+			syslog(LOG_INFO, "want %lu", CMSG_LEN(sizeof(*cred)));
 			errmsg = "cmsg";
 			goto sockerror;
 		}
-- 
2.11.4.GIT