sctp: Support the new specification of sctp_connectx()

The specification of sctp_connectx() has been changed to return
an association id.  We've added a new socket option that will
return the association id as the return value from the setsockopt()
call.  The library that implements sctp_connectx() interface will
implement both socket options.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 59 insertions, 11 deletions

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 66985871401b..81600eea05d2 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -956,7 +956,8 @@ out:
  */
 static int __sctp_connect(struct sock* sk,
                           struct sockaddr *kaddrs,
-                          int addrs_size)
+                          int addrs_size,
+                          sctp_assoc_t *assoc_id)
 {
         struct sctp_sock *sp;
         struct sctp_endpoint *ep;
@@ -1111,6 +1112,8 @@ static int __sctp_connect(struct sock* sk,
         timeo = sock_sndtimeo(sk, f_flags & O_NONBLOCK);
 
         err = sctp_wait_for_connect(asoc, &timeo);
+        if (!err && assoc_id)
+                *assoc_id = asoc->assoc_id;
 
         /* Don't free association on exit. */
         asoc = NULL;
@@ -1128,7 +1131,8 @@ out_free:
 /* Helper for tunneling sctp_connectx() requests through sctp_setsockopt()
  *
  * API 8.9
- * int sctp_connectx(int sd, struct sockaddr *addrs, int addrcnt);
+ * int sctp_connectx(int sd, struct sockaddr *addrs, int addrcnt,
+ *                      sctp_assoc_t *asoc);
  *
  * If sd is an IPv4 socket, the addresses passed must be IPv4 addresses.
  * If the sd is an IPv6 socket, the addresses passed can either be IPv4
@@ -1144,8 +1148,10 @@ out_free:
  * representation is termed a "packed array" of addresses). The caller
  * specifies the number of addresses in the array with addrcnt.
  *
- * On success, sctp_connectx() returns 0. On failure, sctp_connectx() returns
- * -1, and sets errno to the appropriate error code.
+ * On success, sctp_connectx() returns 0. It also sets the assoc_id to
+ * the association id of the new association.  On failure, sctp_connectx()
+ * returns -1, and sets errno to the appropriate error code.  The assoc_id
+ * is not touched by the kernel.
  *
  * For SCTP, the port given in each socket address must be the same, or
  * sctp_connectx() will fail, setting errno to EINVAL.
@@ -1182,11 +1188,12 @@ out_free:
  * addrs     The pointer to the addresses in user land
  * addrssize Size of the addrs buffer
  *
- * Returns 0 if ok, <0 errno code on error.
+ * Returns >=0 if ok, <0 errno code on error.
  */
-SCTP_STATIC int sctp_setsockopt_connectx(struct sock* sk,
+SCTP_STATIC int __sctp_setsockopt_connectx(struct sock* sk,
                                       struct sockaddr __user *addrs,
-                                      int addrs_size)
+                                      int addrs_size,
+                                      sctp_assoc_t *assoc_id)
 {
         int err = 0;
         struct sockaddr *kaddrs;
@@ -1209,13 +1216,46 @@ SCTP_STATIC int sctp_setsockopt_connectx(struct sock* sk,
         if (__copy_from_user(kaddrs, addrs, addrs_size)) {
                 err = -EFAULT;
         } else {
-                err = __sctp_connect(sk, kaddrs, addrs_size);
+                err = __sctp_connect(sk, kaddrs, addrs_size, assoc_id);
         }
 
         kfree(kaddrs);
+
         return err;
 }
 
+/*
+ * This is an older interface.  It's kept for backward compatibility
+ * to the option that doesn't provide association id.
+ */
+SCTP_STATIC int sctp_setsockopt_connectx_old(struct sock* sk,
+                                      struct sockaddr __user *addrs,
+                                      int addrs_size)
+{
+        return __sctp_setsockopt_connectx(sk, addrs, addrs_size, NULL);
+}
+
+/*
+ * New interface for the API.  The since the API is done with a socket
+ * option, to make it simple we feed back the association id is as a return
+ * indication to the call.  Error is always negative and association id is
+ * always positive.
+ */
+SCTP_STATIC int sctp_setsockopt_connectx(struct sock* sk,
+                                      struct sockaddr __user *addrs,
+                                      int addrs_size)
+{
+        sctp_assoc_t assoc_id = 0;
+        int err = 0;
+
+        err = __sctp_setsockopt_connectx(sk, addrs, addrs_size, &assoc_id);
+
+        if (err)
+                return err;
+        else
+                return assoc_id;
+}
+
 /* API 3.1.4 close() - UDP Style Syntax
  * Applications use close() to perform graceful shutdown (as described in
  * Section 10.1 of [SCTP]) on ALL the associations currently represented
@@ -3206,10 +3246,18 @@ SCTP_STATIC int sctp_setsockopt(struct sock *sk, int level, int optname,
                                                optlen, SCTP_BINDX_REM_ADDR);
                 break;
 
+        case SCTP_SOCKOPT_CONNECTX_OLD:
+                /* 'optlen' is the size of the addresses buffer. */
+                retval = sctp_setsockopt_connectx_old(sk,
+                                            (struct sockaddr __user *)optval,
+                                            optlen);
+                break;
+
         case SCTP_SOCKOPT_CONNECTX:
                 /* 'optlen' is the size of the addresses buffer. */
-                retval = sctp_setsockopt_connectx(sk, (struct sockaddr __user *)optval,
-                                               optlen);
+                retval = sctp_setsockopt_connectx(sk,
+                                            (struct sockaddr __user *)optval,
+                                            optlen);
                 break;
 
         case SCTP_DISABLE_FRAGMENTS:
@@ -3336,7 +3384,7 @@ SCTP_STATIC int sctp_connect(struct sock *sk, struct sockaddr *addr,
                 /* Pass correct addr len to common routine (so it knows there
                  * is only one address being passed.
                  */
-                err = __sctp_connect(sk, addr, af->sockaddr_len);
+                err = __sctp_connect(sk, addr, af->sockaddr_len, NULL);
         }
 
         sctp_release_sock(sk);