MFp4 @1189139:

Get rid of the msg_peek() function, which has a problem.  If there was less
data in the socket buffer than requested by the caller, the function would busy
loop, as select(2) will always return immediately.

We can just receive nvlhdr now, because some time ago we splitted receive of
data from the receive of descriptors.

MFC after:	1 week

3 files changed, 5 insertions, 29 deletions

diff --git a/lib/libnv/msgio.c b/lib/libnv/msgio.c
index a37d1cd0bcf5..0a0bd7ff4d88 100644
--- a/lib/libnv/msgio.c
+++ b/lib/libnv/msgio.c
@@ -113,30 +113,6 @@ fd_wait(int fd, bool doread)
 	    NULL, NULL);
 }
 
-int
-msg_peek(int sock, void *buf, size_t size)
-{
-	ssize_t done;
-
-	PJDLOG_ASSERT(sock >= 0);
-	PJDLOG_ASSERT(size > 0);
-
-	do {
-		fd_wait(sock, true);
-		done = recv(sock, buf, size, MSG_PEEK | MSG_WAITALL);
-		if (done == -1) {
-			if (errno == EAGAIN || errno == EINTR)
-				continue;
-			return (-1);
-		} else if (done == 0) {
-			errno = ENOTCONN;
-			return (-1);
-		}
-	} while (done != (ssize_t)size);
-
-	return (0);
-}
-
 static int
 msg_recv(int sock, struct msghdr *msg)
 {
diff --git a/lib/libnv/msgio.h b/lib/libnv/msgio.h
index c6de92de10d7..fd5e462af0d0 100644
--- a/lib/libnv/msgio.h
+++ b/lib/libnv/msgio.h
@@ -38,8 +38,6 @@ struct cmsgcred;
 struct iovec;
 struct msghdr;
 
-int msg_peek(int sock, void *buf, size_t size);
-
 int cred_send(int sock);
 int cred_recv(int sock, struct cmsgcred *cred);
 
diff --git a/lib/libnv/nvlist.c b/lib/libnv/nvlist.c
index 323b2c8d6307..299d60e8a0f2 100644
--- a/lib/libnv/nvlist.c
+++ b/lib/libnv/nvlist.c
@@ -724,11 +724,11 @@ nvlist_recv(int sock)
 {
 	struct nvlist_header nvlhdr;
 	nvlist_t *nvl, *ret;
+	unsigned char *buf;
 	size_t nfds, size;
-	void *buf;
 	int serrno, *fds;
 
-	if (msg_peek(sock, &nvlhdr, sizeof(nvlhdr)) == -1)
+	if (buf_recv(sock, &nvlhdr, sizeof(nvlhdr)) == -1)
 		return (NULL);
 
 	if (!nvlist_check_header(&nvlhdr))
@@ -741,10 +741,12 @@ nvlist_recv(int sock)
 	if (buf == NULL)
 		return (NULL);
 
+	memcpy(buf, &nvlhdr, sizeof(nvlhdr));
+
 	ret = NULL;
 	fds = NULL;
 
-	if (buf_recv(sock, buf, size) == -1)
+	if (buf_recv(sock, buf + sizeof(nvlhdr), size - sizeof(nvlhdr)) == -1)
 		goto out;
 
 	if (nfds > 0) {