sctp: fix the issue that flags are ignored when using kernel_connect

commit 644fbdeacf1d3edd366e44b8ba214de9d1dd66a9 upstream.

Now sctp uses inet_dgram_connect as its proto_ops .connect, and the flags
param can't be passed into its proto .connect where this flags is really
needed.

sctp works around it by getting flags from socket file in __sctp_connect.
It works for connecting from userspace, as inherently the user sock has
socket file and it passes f_flags as the flags param into the proto_ops
.connect.

However, the sock created by sock_create_kern doesn't have a socket file,
and it passes the flags (like O_NONBLOCK) by using the flags param in
kernel_connect, which calls proto_ops .connect later.

So to fix it, this patch defines a new proto_ops .connect for sctp,
sctp_inet_connect, which calls __sctp_connect() directly with this
flags param. After this, the sctp's proto .connect can be removed.

Note that sctp_inet_connect doesn't need to do some checks that are not
needed for sctp, which makes thing better than with inet_dgram_connect.

Suggested-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Reviewed-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h
index d33b17b..8a71f4d 100644 (file)
--- a/include/net/sctp/sctp.h
+++ b/include/net/sctp/sctp.h
@@ -98,6 +98,8 @@ void sctp_addr_wq_mgmt(struct net *, struct sctp_sockaddr_entry *, int);
 /*
  * sctp/socket.c
  */
+int sctp_inet_connect(struct socket *sock, struct sockaddr *uaddr,
+                     int addr_len, int flags);
 int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb);
 int sctp_inet_listen(struct socket *sock, int backlog);
 void sctp_write_space(struct sock *sk);

diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c
index 9fa0b0d..ae619cf 100644 (file)
--- a/net/sctp/ipv6.c
+++ b/net/sctp/ipv6.c
@@ -970,7 +970,7 @@ static const struct proto_ops inet6_seqpacket_ops = {
        .owner             = THIS_MODULE,
        .release           = inet6_release,
        .bind              = inet6_bind,
-       .connect           = inet_dgram_connect,
+       .connect           = sctp_inet_connect,
        .socketpair        = sock_no_socketpair,
        .accept            = inet_accept,
        .getname           = sctp_getname,

diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
index 07c54b2..8816e49 100644 (file)
--- a/net/sctp/protocol.c
+++ b/net/sctp/protocol.c
@@ -1012,7 +1012,7 @@ static const struct proto_ops inet_seqpacket_ops = {
        .owner             = THIS_MODULE,
        .release           = inet_release,      /* Needs to be wrapped... */
        .bind              = inet_bind,
-       .connect           = inet_dgram_connect,
+       .connect           = sctp_inet_connect,
        .socketpair        = sock_no_socketpair,
        .accept            = inet_accept,
        .getname           = inet_getname,      /* Semantics are different.  */

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 191fd25..05350b6 100644 (file)
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -1072,7 +1072,7 @@ out:
  */
 static int __sctp_connect(struct sock *sk,
                          struct sockaddr *kaddrs,
-                         int addrs_size,
+                         int addrs_size, int flags,
                          sctp_assoc_t *assoc_id)
 {
        struct net *net = sock_net(sk);
@@ -1090,7 +1090,6 @@ static int __sctp_connect(struct sock *sk,
        union sctp_addr *sa_addr = NULL;
        void *addr_buf;
        unsigned short port;
-       unsigned int f_flags = 0;
 
        sp = sctp_sk(sk);
        ep = sp->ep;
@@ -1238,13 +1237,7 @@ static int __sctp_connect(struct sock *sk,
        sp->pf->to_sk_daddr(sa_addr, sk);
        sk->sk_err = 0;
 
-       /* in-kernel sockets don't generally have a file allocated to them
-        * if all they do is call sock_create_kern().
-        */
-       if (sk->sk_socket->file)
-               f_flags = sk->sk_socket->file->f_flags;
-
-       timeo = sock_sndtimeo(sk, f_flags & O_NONBLOCK);
+       timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
 
        if (assoc_id)
                *assoc_id = asoc->assoc_id;
@@ -1340,7 +1333,7 @@ static int __sctp_setsockopt_connectx(struct sock *sk,
 {
        struct sockaddr *kaddrs;
        gfp_t gfp = GFP_KERNEL;
-       int err = 0;
+       int err = 0, flags = 0;
 
        pr_debug("%s: sk:%p addrs:%p addrs_size:%d\n",
                 __func__, sk, addrs, addrs_size);
@@ -1360,11 +1353,18 @@ static int __sctp_setsockopt_connectx(struct sock *sk,
                return -ENOMEM;
 
        if (__copy_from_user(kaddrs, addrs, addrs_size)) {
-               err = -EFAULT;
-       } else {
-               err = __sctp_connect(sk, kaddrs, addrs_size, assoc_id);
+               kfree(kaddrs);
+               return -EFAULT;
        }
 
+       /* in-kernel sockets don't generally have a file allocated to them
+        * if all they do is call sock_create_kern().
+        */
+       if (sk->sk_socket->file)
+               flags = sk->sk_socket->file->f_flags;
+
+       err = __sctp_connect(sk, kaddrs, addrs_size, flags, assoc_id);
+
        kfree(kaddrs);
 
        return err;
@@ -3895,16 +3895,26 @@ out_nounlock:
  * len: the size of the address.
  */
 static int sctp_connect(struct sock *sk, struct sockaddr *addr,
-                       int addr_len)
+                       int addr_len, int flags)
 {
-       int err = 0;
+       struct inet_sock *inet = inet_sk(sk);
        struct sctp_af *af;
+       int err = 0;
 
        lock_sock(sk);
 
        pr_debug("%s: sk:%p, sockaddr:%p, addr_len:%d\n", __func__, sk,
                 addr, addr_len);
 
+       /* We may need to bind the socket. */
+       if (!inet->inet_num) {
+               if (sk->sk_prot->get_port(sk, 0)) {
+                       release_sock(sk);
+                       return -EAGAIN;
+               }
+               inet->inet_sport = htons(inet->inet_num);
+       }
+
        /* Validate addr_len before calling common connect/connectx routine. */
        af = sctp_get_af_specific(addr->sa_family);
        if (!af || addr_len < af->sockaddr_len) {
@@ -3913,13 +3923,25 @@ 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, NULL);
+               err = __sctp_connect(sk, addr, af->sockaddr_len, flags, NULL);
        }
 
        release_sock(sk);
        return err;
 }
 
+int sctp_inet_connect(struct socket *sock, struct sockaddr *uaddr,
+                     int addr_len, int flags)
+{
+       if (addr_len < sizeof(uaddr->sa_family))
+               return -EINVAL;
+
+       if (uaddr->sa_family == AF_UNSPEC)
+               return -EOPNOTSUPP;
+
+       return sctp_connect(sock->sk, uaddr, addr_len, flags);
+}
+
 /* FIXME: Write comments. */
 static int sctp_disconnect(struct sock *sk, int flags)
 {
@@ -7428,7 +7450,6 @@ struct proto sctp_prot = {
        .name        =  "SCTP",
        .owner       =  THIS_MODULE,
        .close       =  sctp_close,
-       .connect     =  sctp_connect,
        .disconnect  =  sctp_disconnect,
        .accept      =  sctp_accept,
        .ioctl       =  sctp_ioctl,
@@ -7467,7 +7488,6 @@ struct proto sctpv6_prot = {
        .name           = "SCTPv6",
        .owner          = THIS_MODULE,
        .close          = sctp_close,
-       .connect        = sctp_connect,
        .disconnect     = sctp_disconnect,
        .accept         = sctp_accept,
        .ioctl          = sctp_ioctl,