sctp: factor out sctp_sendmsg_get_daddr from sctp_sendmsg

This patch is to move the codes for trying to get daddr from
msg->msg_name into sctp_sendmsg_get_daddr.

Note that after adding 'daddr', 'to' and 'msg_name' can be
deleted.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 93cff9963614506716d144be9b657e9f0db978ca..68691d2b31679a0b6ce194dae7941e2d714660f3 100644 (file)
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -1814,14 +1814,35 @@ static int sctp_sendmsg_to_asoc(struct sctp_association *asoc,
        return err;
 }
 
+static union sctp_addr *sctp_sendmsg_get_daddr(struct sock *sk,
+                                              const struct msghdr *msg,
+                                              struct sctp_cmsgs *cmsgs)
+{
+       union sctp_addr *daddr = NULL;
+       int err;
+
+       if (!sctp_style(sk, UDP_HIGH_BANDWIDTH) && msg->msg_name) {
+               int len = msg->msg_namelen;
+
+               if (len > sizeof(*daddr))
+                       len = sizeof(*daddr);
+
+               daddr = (union sctp_addr *)msg->msg_name;
+
+               err = sctp_verify_addr(sk, daddr, len);
+               if (err)
+                       return ERR_PTR(err);
+       }
+
+       return daddr;
+}
+
 static int sctp_sendmsg(struct sock *sk, struct msghdr *msg, size_t msg_len)
 {
        struct sctp_sock *sp;
        struct sctp_endpoint *ep;
        struct sctp_association *new_asoc = NULL, *asoc = NULL;
        struct sctp_transport *transport, *chunk_tp;
-       union sctp_addr to;
-       struct sockaddr *msg_name = NULL;
        struct sctp_sndrcvinfo default_sinfo;
        struct sctp_sndrcvinfo *sinfo;
        struct sctp_initmsg *sinit;
@@ -1829,6 +1850,7 @@ static int sctp_sendmsg(struct sock *sk, struct msghdr *msg, size_t msg_len)
        struct sctp_cmsgs cmsgs = { NULL };
        bool fill_sinfo_ttl = false;
        __u16 sinfo_flags = 0;
+       union sctp_addr *daddr;
        int err;
 
        err = 0;
@@ -1851,23 +1873,11 @@ static int sctp_sendmsg(struct sock *sk, struct msghdr *msg, size_t msg_len)
                goto out_nounlock;
        }
 
-       /* Fetch the destination address for this packet.  This
-        * address only selects the association--it is not necessarily
-        * the address we will send to.
-        * For a peeled-off socket, msg_name is ignored.
-        */
-       if (!sctp_style(sk, UDP_HIGH_BANDWIDTH) && msg->msg_name) {
-               int msg_namelen = msg->msg_namelen;
-
-               err = sctp_verify_addr(sk, (union sctp_addr *)msg->msg_name,
-                                      msg_namelen);
-               if (err)
-                       return err;
-
-               if (msg_namelen > sizeof(to))
-                       msg_namelen = sizeof(to);
-               memcpy(&to, msg->msg_name, msg_namelen);
-               msg_name = msg->msg_name;
+       /* Get daddr from msg */
+       daddr = sctp_sendmsg_get_daddr(sk, msg, &cmsgs);
+       if (IS_ERR(daddr)) {
+               err = PTR_ERR(daddr);
+               goto out_nounlock;
        }
 
        sinit = cmsgs.init;
@@ -1925,9 +1935,9 @@ static int sctp_sendmsg(struct sock *sk, struct msghdr *msg, size_t msg_len)
        lock_sock(sk);
 
        /* If a msg_name has been specified, assume this is to be used.  */
-       if (msg_name) {
+       if (daddr) {
                /* Look for a matching association on the endpoint. */
-               asoc = sctp_endpoint_lookup_assoc(ep, &to, &transport);
+               asoc = sctp_endpoint_lookup_assoc(ep, daddr, &transport);
        } else {
                asoc = sctp_id2assoc(sk, associd);
                if (!asoc) {
@@ -1945,7 +1955,7 @@ static int sctp_sendmsg(struct sock *sk, struct msghdr *msg, size_t msg_len)
 
        /* Do we need to create the association?  */
        if (!asoc) {
-               err = sctp_sendmsg_new_asoc(sk, sinfo_flags, &cmsgs, &to,
+               err = sctp_sendmsg_new_asoc(sk, sinfo_flags, &cmsgs, daddr,
                                            &transport);
                if (err)
                        goto out_unlock;
@@ -1989,9 +1999,9 @@ static int sctp_sendmsg(struct sock *sk, struct msghdr *msg, size_t msg_len)
         * to override the primary destination address in the TCP model, or
         * when SCTP_ADDR_OVER flag is set in the UDP model.
         */
-       if ((sctp_style(sk, TCP) && msg_name) ||
+       if ((sctp_style(sk, TCP) && daddr) ||
            (sinfo_flags & SCTP_ADDR_OVER)) {
-               chunk_tp = sctp_assoc_lookup_paddr(asoc, &to);
+               chunk_tp = sctp_assoc_lookup_paddr(asoc, daddr);
                if (!chunk_tp) {
                        err = -EINVAL;
                        goto out_free;