[SCTP]: Beginning of sin_port fixes.

That's going to be a long series.  Introduced temporary helpers
doing copy-and-convert for sctp_addr; they are used to kill
flip-in-place in global data structures and will be used
to gradually push host-endian uses of sctp_addr out of existence.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 34 insertions, 17 deletions

diff --git a/include/net/sctp/structs.h b/include/net/sctp/structs.h
index ca77bc5b7ff5..2aa61ac9a9f3 100644
--- a/include/net/sctp/structs.h
+++ b/include/net/sctp/structs.h
@@ -74,6 +74,28 @@ union sctp_addr {
         struct sockaddr sa;
 };
 
+static inline void flip_to_n(union sctp_addr *to, const union sctp_addr *from)
+{
+        size_t len;
+        if (from->sa.sa_family == AF_INET6)
+                len = sizeof(struct sockaddr_in6);
+        else
+                len = sizeof(struct sockaddr);
+        memcpy(to, from, len);
+        to->v4.sin_port = htons(from->v4.sin_port);
+}
+
+static inline void flip_to_h(union sctp_addr *to, const union sctp_addr *from)
+{
+        size_t len;
+        if (from->sa.sa_family == AF_INET6)
+                len = sizeof(struct sockaddr_in6);
+        else
+                len = sizeof(struct sockaddr);
+        memcpy(to, from, len);
+        to->v4.sin_port = ntohs(from->v4.sin_port);
+}
+
 /* Forward declarations for data structures. */
 struct sctp_globals;
 struct sctp_endpoint;
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 935bc9187fd8..f4d13ab79f49 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -228,12 +228,12 @@ static struct sctp_transport *sctp_addr_id2transport(struct sock *sk,
         struct sctp_association *addr_asoc = NULL, *id_asoc = NULL;
         struct sctp_transport *transport;
         union sctp_addr *laddr = (union sctp_addr *)addr;
+        union sctp_addr tmp;
 
-        laddr->v4.sin_port = ntohs(laddr->v4.sin_port);
+        flip_to_h(&tmp, laddr);
         addr_asoc = sctp_endpoint_lookup_assoc(sctp_sk(sk)->ep,
-                                               (union sctp_addr *)addr,
+                                               &tmp,
                                                &transport);
-        laddr->v4.sin_port = htons(laddr->v4.sin_port);
 
         if (!addr_asoc)
                 return NULL;
@@ -313,6 +313,7 @@ SCTP_STATIC int sctp_do_bind(struct sock *sk, union sctp_addr *addr, int len)
         struct sctp_af *af;
         unsigned short snum;
         int ret = 0;
+        union sctp_addr tmp;
 
         /* Common sockaddr verification. */
         af = sctp_sockaddr_af(sp, addr, len);
@@ -368,9 +369,8 @@ SCTP_STATIC int sctp_do_bind(struct sock *sk, union sctp_addr *addr, int len)
         sctp_write_lock(&ep->base.addr_lock);
 
         /* Use GFP_ATOMIC since BHs are disabled.  */
-        addr->v4.sin_port = ntohs(addr->v4.sin_port);
-        ret = sctp_add_bind_addr(bp, addr, 1, GFP_ATOMIC);
-        addr->v4.sin_port = htons(addr->v4.sin_port);
+        flip_to_h(&tmp, addr);
+        ret = sctp_add_bind_addr(bp, &tmp, 1, GFP_ATOMIC);
         sctp_write_unlock(&ep->base.addr_lock);
         sctp_local_bh_enable();
 
@@ -4194,12 +4194,8 @@ static int sctp_getsockopt_primary_addr(struct sock *sk, int len,
         if (!asoc->peer.primary_path)
                 return -ENOTCONN;
         
-        asoc->peer.primary_path->ipaddr.v4.sin_port =
-                htons(asoc->peer.primary_path->ipaddr.v4.sin_port);
-        memcpy(&prim.ssp_addr, &asoc->peer.primary_path->ipaddr,
-               sizeof(union sctp_addr));
-        asoc->peer.primary_path->ipaddr.v4.sin_port =
-                ntohs(asoc->peer.primary_path->ipaddr.v4.sin_port);
+        flip_to_n((union sctp_addr *)&prim.ssp_addr,
+                  &asoc->peer.primary_path->ipaddr);
 
         sctp_get_pf_specific(sk->sk_family)->addr_v4map(sp,
                         (union sctp_addr *)&prim.ssp_addr);
@@ -4642,12 +4638,12 @@ static long sctp_get_port_local(struct sock *sk, union sctp_addr *addr)
 {
         struct sctp_bind_hashbucket *head; /* hash list */
         struct sctp_bind_bucket *pp; /* hash list port iterator */
+        union sctp_addr tmp;
         unsigned short snum;
         int ret;
 
-        /* NOTE:  Remember to put this back to net order. */
-        addr->v4.sin_port = ntohs(addr->v4.sin_port);
-        snum = addr->v4.sin_port;
+        flip_to_h(&tmp, addr);
+        snum = ntohs(addr->v4.sin_port);
 
         SCTP_DEBUG_PRINTK("sctp_get_port() begins, snum=%d\n", snum);
         sctp_local_bh_disable();
@@ -4744,7 +4740,7 @@ pp_found:
                         if (reuse && sk2->sk_reuse)
                                 continue;
 
-                        if (sctp_bind_addr_match(&ep2->base.bind_addr, addr,
+                        if (sctp_bind_addr_match(&ep2->base.bind_addr, &tmp,
                                                  sctp_sk(sk))) {
                                 ret = (long)sk2;
                                 goto fail_unlock;
@@ -4784,7 +4780,6 @@ fail_unlock:
 
 fail:
         sctp_local_bh_enable();
-        addr->v4.sin_port = htons(addr->v4.sin_port);
         return ret;
 }