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Merge tag 'armsoc-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
[uclinux-h8/linux.git] / net / unix / af_unix.c
index 0643059..03ee4d3 100644 (file)
@@ -140,12 +140,17 @@ static struct hlist_head *unix_sockets_unbound(void *addr)
 #ifdef CONFIG_SECURITY_NETWORK
 static void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
 {
-       memcpy(UNIXSID(skb), &scm->secid, sizeof(u32));
+       UNIXCB(skb).secid = scm->secid;
 }
 
 static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb)
 {
-       scm->secid = *UNIXSID(skb);
+       scm->secid = UNIXCB(skb).secid;
+}
+
+static inline bool unix_secdata_eq(struct scm_cookie *scm, struct sk_buff *skb)
+{
+       return (scm->secid == UNIXCB(skb).secid);
 }
 #else
 static inline void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
@@ -153,6 +158,11 @@ static inline void unix_get_secdata(struct scm_cookie *scm, struct sk_buff *skb)
 
 static inline void unix_set_secdata(struct scm_cookie *scm, struct sk_buff *skb)
 { }
+
+static inline bool unix_secdata_eq(struct scm_cookie *scm, struct sk_buff *skb)
+{
+       return true;
+}
 #endif /* CONFIG_SECURITY_NETWORK */
 
 /*
@@ -518,6 +528,11 @@ static int unix_ioctl(struct socket *, unsigned int, unsigned long);
 static int unix_shutdown(struct socket *, int);
 static int unix_stream_sendmsg(struct socket *, struct msghdr *, size_t);
 static int unix_stream_recvmsg(struct socket *, struct msghdr *, size_t, int);
+static ssize_t unix_stream_sendpage(struct socket *, struct page *, int offset,
+                                   size_t size, int flags);
+static ssize_t unix_stream_splice_read(struct socket *,  loff_t *ppos,
+                                      struct pipe_inode_info *, size_t size,
+                                      unsigned int flags);
 static int unix_dgram_sendmsg(struct socket *, struct msghdr *, size_t);
 static int unix_dgram_recvmsg(struct socket *, struct msghdr *, size_t, int);
 static int unix_dgram_connect(struct socket *, struct sockaddr *,
@@ -558,7 +573,8 @@ static const struct proto_ops unix_stream_ops = {
        .sendmsg =      unix_stream_sendmsg,
        .recvmsg =      unix_stream_recvmsg,
        .mmap =         sock_no_mmap,
-       .sendpage =     sock_no_sendpage,
+       .sendpage =     unix_stream_sendpage,
+       .splice_read =  unix_stream_splice_read,
        .set_peek_off = unix_set_peek_off,
 };
 
@@ -620,7 +636,7 @@ static struct proto unix_proto = {
  */
 static struct lock_class_key af_unix_sk_receive_queue_lock_key;
 
-static struct sock *unix_create1(struct net *net, struct socket *sock)
+static struct sock *unix_create1(struct net *net, struct socket *sock, int kern)
 {
        struct sock *sk = NULL;
        struct unix_sock *u;
@@ -629,7 +645,7 @@ static struct sock *unix_create1(struct net *net, struct socket *sock)
        if (atomic_long_read(&unix_nr_socks) > 2 * get_max_files())
                goto out;
 
-       sk = sk_alloc(net, PF_UNIX, GFP_KERNEL, &unix_proto);
+       sk = sk_alloc(net, PF_UNIX, GFP_KERNEL, &unix_proto, kern);
        if (!sk)
                goto out;
 
@@ -688,7 +704,7 @@ static int unix_create(struct net *net, struct socket *sock, int protocol,
                return -ESOCKTNOSUPPORT;
        }
 
-       return unix_create1(net, sock) ? 0 : -ENOMEM;
+       return unix_create1(net, sock, kern) ? 0 : -ENOMEM;
 }
 
 static int unix_release(struct socket *sock)
@@ -1088,7 +1104,7 @@ static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr,
        err = -ENOMEM;
 
        /* create new sock for complete connection */
-       newsk = unix_create1(sock_net(sk), NULL);
+       newsk = unix_create1(sock_net(sk), NULL, 0);
        if (newsk == NULL)
                goto out;
 
@@ -1408,6 +1424,7 @@ static int unix_scm_to_skb(struct scm_cookie *scm, struct sk_buff *skb, bool sen
        UNIXCB(skb).uid = scm->creds.uid;
        UNIXCB(skb).gid = scm->creds.gid;
        UNIXCB(skb).fp = NULL;
+       unix_get_secdata(scm, skb);
        if (scm->fp && send_fds)
                err = unix_attach_fds(scm, skb);
 
@@ -1503,7 +1520,6 @@ static int unix_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
        if (err < 0)
                goto out_free;
        max_level = err + 1;
-       unix_get_secdata(&scm, skb);
 
        skb_put(skb, len - data_len);
        skb->data_len = data_len;
@@ -1720,6 +1736,101 @@ out_err:
        return sent ? : err;
 }
 
+static ssize_t unix_stream_sendpage(struct socket *socket, struct page *page,
+                                   int offset, size_t size, int flags)
+{
+       int err = 0;
+       bool send_sigpipe = true;
+       struct sock *other, *sk = socket->sk;
+       struct sk_buff *skb, *newskb = NULL, *tail = NULL;
+
+       if (flags & MSG_OOB)
+               return -EOPNOTSUPP;
+
+       other = unix_peer(sk);
+       if (!other || sk->sk_state != TCP_ESTABLISHED)
+               return -ENOTCONN;
+
+       if (false) {
+alloc_skb:
+               unix_state_unlock(other);
+               mutex_unlock(&unix_sk(other)->readlock);
+               newskb = sock_alloc_send_pskb(sk, 0, 0, flags & MSG_DONTWAIT,
+                                             &err, 0);
+               if (!newskb)
+                       return err;
+       }
+
+       /* we must acquire readlock as we modify already present
+        * skbs in the sk_receive_queue and mess with skb->len
+        */
+       err = mutex_lock_interruptible(&unix_sk(other)->readlock);
+       if (err) {
+               err = flags & MSG_DONTWAIT ? -EAGAIN : -ERESTARTSYS;
+               send_sigpipe = false;
+               goto err;
+       }
+
+       if (sk->sk_shutdown & SEND_SHUTDOWN) {
+               err = -EPIPE;
+               goto err_unlock;
+       }
+
+       unix_state_lock(other);
+
+       if (sock_flag(other, SOCK_DEAD) ||
+           other->sk_shutdown & RCV_SHUTDOWN) {
+               err = -EPIPE;
+               goto err_state_unlock;
+       }
+
+       skb = skb_peek_tail(&other->sk_receive_queue);
+       if (tail && tail == skb) {
+               skb = newskb;
+       } else if (!skb) {
+               if (newskb)
+                       skb = newskb;
+               else
+                       goto alloc_skb;
+       } else if (newskb) {
+               /* this is fast path, we don't necessarily need to
+                * call to kfree_skb even though with newskb == NULL
+                * this - does no harm
+                */
+               consume_skb(newskb);
+       }
+
+       if (skb_append_pagefrags(skb, page, offset, size)) {
+               tail = skb;
+               goto alloc_skb;
+       }
+
+       skb->len += size;
+       skb->data_len += size;
+       skb->truesize += size;
+       atomic_add(size, &sk->sk_wmem_alloc);
+
+       if (newskb)
+               __skb_queue_tail(&other->sk_receive_queue, newskb);
+
+       unix_state_unlock(other);
+       mutex_unlock(&unix_sk(other)->readlock);
+
+       other->sk_data_ready(other);
+
+       return size;
+
+err_state_unlock:
+       unix_state_unlock(other);
+err_unlock:
+       mutex_unlock(&unix_sk(other)->readlock);
+err:
+       kfree_skb(newskb);
+       if (send_sigpipe && !(flags & MSG_NOSIGNAL))
+               send_sig(SIGPIPE, current, 0);
+       return err;
+}
+
 static int unix_seqpacket_sendmsg(struct socket *sock, struct msghdr *msg,
                                  size_t len)
 {
@@ -1860,8 +1971,9 @@ out:
  *     Sleep until more data has arrived. But check for races..
  */
 static long unix_stream_data_wait(struct sock *sk, long timeo,
-                                 struct sk_buff *last)
+                                 struct sk_buff *last, unsigned int last_len)
 {
+       struct sk_buff *tail;
        DEFINE_WAIT(wait);
 
        unix_state_lock(sk);
@@ -1869,7 +1981,9 @@ static long unix_stream_data_wait(struct sock *sk, long timeo,
        for (;;) {
                prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
 
-               if (skb_peek_tail(&sk->sk_receive_queue) != last ||
+               tail = skb_peek_tail(&sk->sk_receive_queue);
+               if (tail != last ||
+                   (tail && tail->len != last_len) ||
                    sk->sk_err ||
                    (sk->sk_shutdown & RCV_SHUTDOWN) ||
                    signal_pending(current) ||
@@ -1897,38 +2011,50 @@ static unsigned int unix_skb_len(const struct sk_buff *skb)
        return skb->len - UNIXCB(skb).consumed;
 }
 
-static int unix_stream_recvmsg(struct socket *sock, struct msghdr *msg,
-                              size_t size, int flags)
+struct unix_stream_read_state {
+       int (*recv_actor)(struct sk_buff *, int, int,
+                         struct unix_stream_read_state *);
+       struct socket *socket;
+       struct msghdr *msg;
+       struct pipe_inode_info *pipe;
+       size_t size;
+       int flags;
+       unsigned int splice_flags;
+};
+
+static int unix_stream_read_generic(struct unix_stream_read_state *state)
 {
        struct scm_cookie scm;
+       struct socket *sock = state->socket;
        struct sock *sk = sock->sk;
        struct unix_sock *u = unix_sk(sk);
-       DECLARE_SOCKADDR(struct sockaddr_un *, sunaddr, msg->msg_name);
        int copied = 0;
+       int flags = state->flags;
        int noblock = flags & MSG_DONTWAIT;
-       int check_creds = 0;
+       bool check_creds = false;
        int target;
        int err = 0;
        long timeo;
        int skip;
+       size_t size = state->size;
+       unsigned int last_len;
 
        err = -EINVAL;
        if (sk->sk_state != TCP_ESTABLISHED)
                goto out;
 
        err = -EOPNOTSUPP;
-       if (flags&MSG_OOB)
+       if (flags & MSG_OOB)
                goto out;
 
-       target = sock_rcvlowat(sk, flags&MSG_WAITALL, size);
+       target = sock_rcvlowat(sk, flags & MSG_WAITALL, size);
        timeo = sock_rcvtimeo(sk, noblock);
 
+       memset(&scm, 0, sizeof(scm));
+
        /* Lock the socket to prevent queue disordering
         * while sleeps in memcpy_tomsg
         */
-
-       memset(&scm, 0, sizeof(scm));
-
        err = mutex_lock_interruptible(&u->readlock);
        if (unlikely(err)) {
                /* recvmsg() in non blocking mode is supposed to return -EAGAIN
@@ -1948,6 +2074,7 @@ static int unix_stream_recvmsg(struct socket *sock, struct msghdr *msg,
                        goto unlock;
                }
                last = skb = skb_peek(&sk->sk_receive_queue);
+               last_len = last ? last->len : 0;
 again:
                if (skb == NULL) {
                        unix_sk(sk)->recursion_level = 0;
@@ -1970,16 +2097,17 @@ again:
                                break;
                        mutex_unlock(&u->readlock);
 
-                       timeo = unix_stream_data_wait(sk, timeo, last);
+                       timeo = unix_stream_data_wait(sk, timeo, last,
+                                                     last_len);
 
-                       if (signal_pending(current)
-                           ||  mutex_lock_interruptible(&u->readlock)) {
+                       if (signal_pending(current) ||
+                           mutex_lock_interruptible(&u->readlock)) {
                                err = sock_intr_errno(timeo);
                                goto out;
                        }
 
                        continue;
- unlock:
+unlock:
                        unix_state_unlock(sk);
                        break;
                }
@@ -1988,6 +2116,7 @@ again:
                while (skip >= unix_skb_len(skb)) {
                        skip -= unix_skb_len(skb);
                        last = skb;
+                       last_len = skb->len;
                        skb = skb_peek_next(skb, &sk->sk_receive_queue);
                        if (!skb)
                                goto again;
@@ -1999,23 +2128,27 @@ again:
                        /* Never glue messages from different writers */
                        if ((UNIXCB(skb).pid  != scm.pid) ||
                            !uid_eq(UNIXCB(skb).uid, scm.creds.uid) ||
-                           !gid_eq(UNIXCB(skb).gid, scm.creds.gid))
+                           !gid_eq(UNIXCB(skb).gid, scm.creds.gid) ||
+                           !unix_secdata_eq(&scm, skb))
                                break;
                } else if (test_bit(SOCK_PASSCRED, &sock->flags)) {
                        /* Copy credentials */
                        scm_set_cred(&scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid);
-                       check_creds = 1;
+                       unix_set_secdata(&scm, skb);
+                       check_creds = true;
                }
 
                /* Copy address just once */
-               if (sunaddr) {
-                       unix_copy_addr(msg, skb->sk);
+               if (state->msg && state->msg->msg_name) {
+                       DECLARE_SOCKADDR(struct sockaddr_un *, sunaddr,
+                                        state->msg->msg_name);
+                       unix_copy_addr(state->msg, skb->sk);
                        sunaddr = NULL;
                }
 
                chunk = min_t(unsigned int, unix_skb_len(skb) - skip, size);
-               if (skb_copy_datagram_msg(skb, UNIXCB(skb).consumed + skip,
-                                         msg, chunk)) {
+               chunk = state->recv_actor(skb, skip, chunk, state);
+               if (chunk < 0) {
                        if (copied == 0)
                                copied = -EFAULT;
                        break;
@@ -2053,11 +2186,85 @@ again:
        } while (size);
 
        mutex_unlock(&u->readlock);
-       scm_recv(sock, msg, &scm, flags);
+       if (state->msg)
+               scm_recv(sock, state->msg, &scm, flags);
+       else
+               scm_destroy(&scm);
 out:
        return copied ? : err;
 }
 
+static int unix_stream_read_actor(struct sk_buff *skb,
+                                 int skip, int chunk,
+                                 struct unix_stream_read_state *state)
+{
+       int ret;
+
+       ret = skb_copy_datagram_msg(skb, UNIXCB(skb).consumed + skip,
+                                   state->msg, chunk);
+       return ret ?: chunk;
+}
+
+static int unix_stream_recvmsg(struct socket *sock, struct msghdr *msg,
+                              size_t size, int flags)
+{
+       struct unix_stream_read_state state = {
+               .recv_actor = unix_stream_read_actor,
+               .socket = sock,
+               .msg = msg,
+               .size = size,
+               .flags = flags
+       };
+
+       return unix_stream_read_generic(&state);
+}
+
+static ssize_t skb_unix_socket_splice(struct sock *sk,
+                                     struct pipe_inode_info *pipe,
+                                     struct splice_pipe_desc *spd)
+{
+       int ret;
+       struct unix_sock *u = unix_sk(sk);
+
+       mutex_unlock(&u->readlock);
+       ret = splice_to_pipe(pipe, spd);
+       mutex_lock(&u->readlock);
+
+       return ret;
+}
+
+static int unix_stream_splice_actor(struct sk_buff *skb,
+                                   int skip, int chunk,
+                                   struct unix_stream_read_state *state)
+{
+       return skb_splice_bits(skb, state->socket->sk,
+                              UNIXCB(skb).consumed + skip,
+                              state->pipe, chunk, state->splice_flags,
+                              skb_unix_socket_splice);
+}
+
+static ssize_t unix_stream_splice_read(struct socket *sock,  loff_t *ppos,
+                                      struct pipe_inode_info *pipe,
+                                      size_t size, unsigned int flags)
+{
+       struct unix_stream_read_state state = {
+               .recv_actor = unix_stream_splice_actor,
+               .socket = sock,
+               .pipe = pipe,
+               .size = size,
+               .splice_flags = flags,
+       };
+
+       if (unlikely(*ppos))
+               return -ESPIPE;
+
+       if (sock->file->f_flags & O_NONBLOCK ||
+           flags & SPLICE_F_NONBLOCK)
+               state.flags = MSG_DONTWAIT;
+
+       return unix_stream_read_generic(&state);
+}
+
 static int unix_shutdown(struct socket *sock, int mode)
 {
        struct sock *sk = sock->sk;