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author | Hannes Frederic Sowa <hannes@stressinduktion.org> | 2015-05-21 18:00:01 +0300 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2015-05-25 07:06:59 +0300 |
commit | 2b514574f7e88c8498027ee366fd6e7aae5aa4b5 (patch) | |
tree | 1fd7303692dfbbf1c9c3348cb79961ceb5078cd1 /net | |
parent | a60e3cc7c92973a31fad0fd04dc5cf4355d3d1ef (diff) | |
download | linux-2b514574f7e88c8498027ee366fd6e7aae5aa4b5.tar.xz |
net: af_unix: implement splice for stream af_unix sockets
unix_stream_recvmsg is refactored to unix_stream_read_generic in this
patch and enhanced to deal with pipe splicing. The refactoring is
inneglible, we mostly have to deal with a non-existing struct msghdr
argument.
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r-- | net/core/skbuff.c | 1 | ||||
-rw-r--r-- | net/unix/af_unix.c | 140 |
2 files changed, 120 insertions, 21 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 02769fa4f5c8..9bac0e6f8dfa 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -1942,6 +1942,7 @@ done: return ret; } +EXPORT_SYMBOL_GPL(skb_splice_bits); /** * skb_store_bits - store bits from kernel buffer to skb diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 7762c0b46721..b8c44076c776 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -520,6 +520,9 @@ 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 *, @@ -561,6 +564,7 @@ static const struct proto_ops unix_stream_ops = { .recvmsg = unix_stream_recvmsg, .mmap = sock_no_mmap, .sendpage = unix_stream_sendpage, + .splice_read = unix_stream_splice_read, .set_peek_off = unix_set_peek_off, }; @@ -1957,8 +1961,9 @@ 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); @@ -1966,7 +1971,9 @@ 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) || @@ -1990,38 +1997,50 @@ 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 @@ -2037,6 +2056,7 @@ static int unix_stream_recvmsg(struct socket *sock, struct msghdr *msg, unix_state_lock(sk); last = skb = skb_peek(&sk->sk_receive_queue); + last_len = last ? last->len : 0; again: if (skb == NULL) { unix_sk(sk)->recursion_level = 0; @@ -2059,16 +2079,17 @@ 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; } @@ -2077,6 +2098,7 @@ 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; @@ -2093,18 +2115,20 @@ again: } 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; + 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; @@ -2142,11 +2166,85 @@ 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; |