1 files changed, 40 insertions, 33 deletions

diff --git a/net/socket.c b/net/socket.c
index b1cbbcd..24a7740 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -1871,8 +1871,14 @@ SYSCALL_DEFINE2(shutdown, int, fd, int, how)
 #define COMPAT_NAMELEN(msg)	COMPAT_MSG(msg, msg_namelen)
 #define COMPAT_FLAGS(msg)	COMPAT_MSG(msg, msg_flags)
 
+struct used_address {
+	struct sockaddr_storage name;
+	unsigned int name_len;
+};
+
 static int __sys_sendmsg(struct socket *sock, struct msghdr __user *msg,
-			 struct msghdr *msg_sys, unsigned flags, int nosec)
+			 struct msghdr *msg_sys, unsigned flags,
+			 struct used_address *used_address)
 {
 	struct compat_msghdr __user *msg_compat =
 	    (struct compat_msghdr __user *)msg;
@@ -1953,8 +1959,28 @@ static int __sys_sendmsg(struct socket *sock, struct msghdr __user *msg,
 
 	if (sock->file->f_flags & O_NONBLOCK)
 		msg_sys->msg_flags |= MSG_DONTWAIT;
-	err = (nosec ? sock_sendmsg_nosec : sock_sendmsg)(sock, msg_sys,
-							  total_len);
+	/*
+	 * If this is sendmmsg() and current destination address is same as
+	 * previously succeeded address, omit asking LSM's decision.
+	 * used_address->name_len is initialized to UINT_MAX so that the first
+	 * destination address never matches.
+	 */
+	if (used_address && used_address->name_len == msg_sys->msg_namelen &&
+	    !memcmp(&used_address->name, msg->msg_name,
+		    used_address->name_len)) {
+		err = sock_sendmsg_nosec(sock, msg_sys, total_len);
+		goto out_freectl;
+	}
+	err = sock_sendmsg(sock, msg_sys, total_len);
+	/*
+	 * If this is sendmmsg() and sending to current destination address was
+	 * successful, remember it.
+	 */
+	if (used_address && err >= 0) {
+		used_address->name_len = msg_sys->msg_namelen;
+		memcpy(&used_address->name, msg->msg_name,
+		       used_address->name_len);
+	}
 
 out_freectl:
 	if (ctl_buf != ctl)
@@ -1979,7 +2005,7 @@ SYSCALL_DEFINE3(sendmsg, int, fd, struct msghdr __user *, msg, unsigned, flags)
 	if (!sock)
 		goto out;
 
-	err = __sys_sendmsg(sock, msg, &msg_sys, flags, 0);
+	err = __sys_sendmsg(sock, msg, &msg_sys, flags, NULL);
 
 	fput_light(sock->file, fput_needed);
 out:
@@ -1998,6 +2024,10 @@ int __sys_sendmmsg(int fd, struct mmsghdr __user *mmsg, unsigned int vlen,
 	struct mmsghdr __user *entry;
 	struct compat_mmsghdr __user *compat_entry;
 	struct msghdr msg_sys;
+	struct used_address used_address;
+
+	if (vlen > UIO_MAXIOV)
+		vlen = UIO_MAXIOV;
 
 	datagrams = 0;
 
@@ -2005,27 +2035,22 @@ int __sys_sendmmsg(int fd, struct mmsghdr __user *mmsg, unsigned int vlen,
 	if (!sock)
 		return err;
 
-	err = sock_error(sock->sk);
-	if (err)
-		goto out_put;
-
+	used_address.name_len = UINT_MAX;
 	entry = mmsg;
 	compat_entry = (struct compat_mmsghdr __user *)mmsg;
+	err = 0;
 
 	while (datagrams < vlen) {
-		/*
-		 * No need to ask LSM for more than the first datagram.
-		 */
 		if (MSG_CMSG_COMPAT & flags) {
 			err = __sys_sendmsg(sock, (struct msghdr __user *)compat_entry,
-					    &msg_sys, flags, datagrams);
+					    &msg_sys, flags, &used_address);
 			if (err < 0)
 				break;
 			err = __put_user(err, &compat_entry->msg_len);
 			++compat_entry;
 		} else {
 			err = __sys_sendmsg(sock, (struct msghdr __user *)entry,
-					    &msg_sys, flags, datagrams);
+					    &msg_sys, flags, &used_address);
 			if (err < 0)
 				break;
 			err = put_user(err, &entry->msg_len);
@@ -2037,29 +2062,11 @@ int __sys_sendmmsg(int fd, struct mmsghdr __user *mmsg, unsigned int vlen,
 		++datagrams;
 	}
 
-out_put:
 	fput_light(sock->file, fput_needed);
 
-	if (err == 0)
-		return datagrams;
-
-	if (datagrams != 0) {
-		/*
-		 * We may send less entries than requested (vlen) if the
-		 * sock is non blocking...
-		 */
-		if (err != -EAGAIN) {
-			/*
-			 * ... or if sendmsg returns an error after we
-			 * send some datagrams, where we record the
-			 * error to return on the next call or if the
-			 * app asks about it using getsockopt(SO_ERROR).
-			 */
-			sock->sk->sk_err = -err;
-		}
-
+	/* We only return an error if no datagrams were able to be sent */
+	if (datagrams != 0)
 		return datagrams;
-	}
 
 	return err;
 }