Commit 5d15af67 authored by David S. Miller's avatar David S. Miller

Merge branch 'tipc-refactor-socket-receive-functions'

Jon Maloy says:

====================
tipc: refactor socket receive functions

We try to make the functions tipc_sk_recvmsg() and
tipc_sk_recvstream() more readable.
====================
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents b0e92279 ec8a09fb
......@@ -51,6 +51,7 @@
#define TIPC_FWD_MSG 1
#define TIPC_MAX_PORT 0xffffffff
#define TIPC_MIN_PORT 1
#define TIPC_ACK_RATE 4 /* ACK at 1/4 of of rcv window size */
enum {
TIPC_LISTEN = TCP_LISTEN,
......@@ -1290,7 +1291,7 @@ static int tipc_wait_for_rcvmsg(struct socket *sock, long *timeop)
/**
* tipc_recvmsg - receive packet-oriented message
* @m: descriptor for message info
* @buf_len: total size of user buffer area
* @buflen: length of user buffer area
* @flags: receive flags
*
* Used for SOCK_DGRAM, SOCK_RDM, and SOCK_SEQPACKET messages.
......@@ -1298,95 +1299,85 @@ static int tipc_wait_for_rcvmsg(struct socket *sock, long *timeop)
*
* Returns size of returned message data, errno otherwise
*/
static int tipc_recvmsg(struct socket *sock, struct msghdr *m, size_t buf_len,
int flags)
static int tipc_recvmsg(struct socket *sock, struct msghdr *m,
size_t buflen, int flags)
{
struct sock *sk = sock->sk;
struct tipc_sock *tsk = tipc_sk(sk);
struct sk_buff *buf;
struct tipc_msg *msg;
bool is_connectionless = tipc_sk_type_connectionless(sk);
long timeo;
unsigned int sz;
u32 err;
int res, hlen;
struct sk_buff *skb;
struct tipc_msg *hdr;
bool connected = !tipc_sk_type_connectionless(sk);
int rc, err, hlen, dlen, copy;
long timeout;
/* Catch invalid receive requests */
if (unlikely(!buf_len))
if (unlikely(!buflen))
return -EINVAL;
lock_sock(sk);
if (!is_connectionless && unlikely(sk->sk_state == TIPC_OPEN)) {
res = -ENOTCONN;
if (unlikely(connected && sk->sk_state == TIPC_OPEN)) {
rc = -ENOTCONN;
goto exit;
}
timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
restart:
/* Look for a message in receive queue; wait if necessary */
res = tipc_wait_for_rcvmsg(sock, &timeo);
if (res)
goto exit;
/* Look at first message in receive queue */
buf = skb_peek(&sk->sk_receive_queue);
msg = buf_msg(buf);
sz = msg_data_sz(msg);
hlen = msg_hdr_sz(msg);
err = msg_errcode(msg);
/* Discard an empty non-errored message & try again */
if ((!sz) && (!err)) {
do {
/* Look at first msg in receive queue; wait if necessary */
rc = tipc_wait_for_rcvmsg(sock, &timeout);
if (unlikely(rc))
goto exit;
skb = skb_peek(&sk->sk_receive_queue);
hdr = buf_msg(skb);
dlen = msg_data_sz(hdr);
hlen = msg_hdr_sz(hdr);
err = msg_errcode(hdr);
if (likely(dlen || err))
break;
tsk_advance_rx_queue(sk);
goto restart;
}
/* Capture sender's address (optional) */
set_orig_addr(m, msg);
} while (1);
/* Capture ancillary data (optional) */
res = tipc_sk_anc_data_recv(m, msg, tsk);
if (res)
/* Collect msg meta data, including error code and rejected data */
set_orig_addr(m, hdr);
rc = tipc_sk_anc_data_recv(m, hdr, tsk);
if (unlikely(rc))
goto exit;
/* Capture message data (if valid) & compute return value (always) */
if (!err) {
if (unlikely(buf_len < sz)) {
sz = buf_len;
/* Capture data if non-error msg, otherwise just set return value */
if (likely(!err)) {
copy = min_t(int, dlen, buflen);
if (unlikely(copy != dlen))
m->msg_flags |= MSG_TRUNC;
}
res = skb_copy_datagram_msg(buf, hlen, m, sz);
if (res)
goto exit;
res = sz;
rc = skb_copy_datagram_msg(skb, hlen, m, copy);
} else {
if (is_connectionless || err == TIPC_CONN_SHUTDOWN ||
m->msg_control)
res = 0;
else
res = -ECONNRESET;
copy = 0;
rc = 0;
if (err != TIPC_CONN_SHUTDOWN && connected && !m->msg_control)
rc = -ECONNRESET;
}
if (unlikely(rc))
goto exit;
/* Caption of data or error code/rejected data was successful */
if (unlikely(flags & MSG_PEEK))
goto exit;
if (likely(!is_connectionless)) {
tsk->rcv_unacked += tsk_inc(tsk, hlen + sz);
if (unlikely(tsk->rcv_unacked >= (tsk->rcv_win / 4)))
tipc_sk_send_ack(tsk);
}
tsk_advance_rx_queue(sk);
if (likely(!connected))
goto exit;
/* Send connection flow control ack when applicable */
tsk->rcv_unacked += tsk_inc(tsk, hlen + dlen);
if (tsk->rcv_unacked >= tsk->rcv_win / TIPC_ACK_RATE)
tipc_sk_send_ack(tsk);
exit:
release_sock(sk);
return res;
return rc ? rc : copy;
}
/**
* tipc_recv_stream - receive stream-oriented data
* tipc_recvstream - receive stream-oriented data
* @m: descriptor for message info
* @buf_len: total size of user buffer area
* @buflen: total size of user buffer area
* @flags: receive flags
*
* Used for SOCK_STREAM messages only. If not enough data is available
......@@ -1394,111 +1385,98 @@ static int tipc_recvmsg(struct socket *sock, struct msghdr *m, size_t buf_len,
*
* Returns size of returned message data, errno otherwise
*/
static int tipc_recv_stream(struct socket *sock, struct msghdr *m,
size_t buf_len, int flags)
static int tipc_recvstream(struct socket *sock, struct msghdr *m,
size_t buflen, int flags)
{
struct sock *sk = sock->sk;
struct tipc_sock *tsk = tipc_sk(sk);
struct sk_buff *buf;
struct tipc_msg *msg;
long timeo;
unsigned int sz;
int target;
int sz_copied = 0;
u32 err;
int res = 0, hlen;
struct sk_buff *skb;
struct tipc_msg *hdr;
struct tipc_skb_cb *skb_cb;
bool peek = flags & MSG_PEEK;
int offset, required, copy, copied = 0;
int hlen, dlen, err, rc;
long timeout;
/* Catch invalid receive attempts */
if (unlikely(!buf_len))
if (unlikely(!buflen))
return -EINVAL;
lock_sock(sk);
if (unlikely(sk->sk_state == TIPC_OPEN)) {
res = -ENOTCONN;
goto exit;
}
target = sock_rcvlowat(sk, flags & MSG_WAITALL, buf_len);
timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
restart:
/* Look for a message in receive queue; wait if necessary */
res = tipc_wait_for_rcvmsg(sock, &timeo);
if (res)
rc = -ENOTCONN;
goto exit;
/* Look at first message in receive queue */
buf = skb_peek(&sk->sk_receive_queue);
msg = buf_msg(buf);
sz = msg_data_sz(msg);
hlen = msg_hdr_sz(msg);
err = msg_errcode(msg);
/* Discard an empty non-errored message & try again */
if ((!sz) && (!err)) {
tsk_advance_rx_queue(sk);
goto restart;
}
/* Optionally capture sender's address & ancillary data of first msg */
if (sz_copied == 0) {
set_orig_addr(m, msg);
res = tipc_sk_anc_data_recv(m, msg, tsk);
if (res)
goto exit;
}
required = sock_rcvlowat(sk, flags & MSG_WAITALL, buflen);
timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
/* Capture message data (if valid) & compute return value (always) */
if (!err) {
u32 offset = TIPC_SKB_CB(buf)->bytes_read;
u32 needed;
int sz_to_copy;
sz -= offset;
needed = (buf_len - sz_copied);
sz_to_copy = min(sz, needed);
res = skb_copy_datagram_msg(buf, hlen + offset, m, sz_to_copy);
if (res)
goto exit;
do {
/* Look at first msg in receive queue; wait if necessary */
rc = tipc_wait_for_rcvmsg(sock, &timeout);
if (unlikely(rc))
break;
skb = skb_peek(&sk->sk_receive_queue);
skb_cb = TIPC_SKB_CB(skb);
hdr = buf_msg(skb);
dlen = msg_data_sz(hdr);
hlen = msg_hdr_sz(hdr);
err = msg_errcode(hdr);
/* Discard any empty non-errored (SYN-) message */
if (unlikely(!dlen && !err)) {
tsk_advance_rx_queue(sk);
continue;
}
sz_copied += sz_to_copy;
/* Collect msg meta data, incl. error code and rejected data */
if (!copied) {
set_orig_addr(m, hdr);
rc = tipc_sk_anc_data_recv(m, hdr, tsk);
if (rc)
break;
}
if (sz_to_copy < sz) {
if (!(flags & MSG_PEEK))
TIPC_SKB_CB(buf)->bytes_read =
offset + sz_to_copy;
goto exit;
/* Copy data if msg ok, otherwise return error/partial data */
if (likely(!err)) {
offset = skb_cb->bytes_read;
copy = min_t(int, dlen - offset, buflen - copied);
rc = skb_copy_datagram_msg(skb, hlen + offset, m, copy);
if (unlikely(rc))
break;
copied += copy;
offset += copy;
if (unlikely(offset < dlen)) {
if (!peek)
skb_cb->bytes_read = offset;
break;
}
} else {
rc = 0;
if ((err != TIPC_CONN_SHUTDOWN) && !m->msg_control)
rc = -ECONNRESET;
if (copied || rc)
break;
}
} else {
if (sz_copied != 0)
goto exit; /* can't add error msg to valid data */
if ((err == TIPC_CONN_SHUTDOWN) || m->msg_control)
res = 0;
else
res = -ECONNRESET;
}
if (unlikely(peek))
break;
if (unlikely(flags & MSG_PEEK))
goto exit;
tsk_advance_rx_queue(sk);
tsk->rcv_unacked += tsk_inc(tsk, hlen + msg_data_sz(msg));
if (unlikely(tsk->rcv_unacked >= (tsk->rcv_win / 4)))
tipc_sk_send_ack(tsk);
tsk_advance_rx_queue(sk);
/* Send connection flow control advertisement when applicable */
tsk->rcv_unacked += tsk_inc(tsk, hlen + dlen);
if (unlikely(tsk->rcv_unacked >= tsk->rcv_win / TIPC_ACK_RATE))
tipc_sk_send_ack(tsk);
/* Loop around if more data is required */
if ((sz_copied < buf_len) && /* didn't get all requested data */
(!skb_queue_empty(&sk->sk_receive_queue) ||
(sz_copied < target)) && /* and more is ready or required */
(!err)) /* and haven't reached a FIN */
goto restart;
/* Exit if all requested data or FIN/error received */
if (copied == buflen || err)
break;
} while (!skb_queue_empty(&sk->sk_receive_queue) || copied < required);
exit:
release_sock(sk);
return sz_copied ? sz_copied : res;
return copied ? copied : rc;
}
/**
......@@ -2593,7 +2571,7 @@ static const struct proto_ops stream_ops = {
.setsockopt = tipc_setsockopt,
.getsockopt = tipc_getsockopt,
.sendmsg = tipc_sendstream,
.recvmsg = tipc_recv_stream,
.recvmsg = tipc_recvstream,
.mmap = sock_no_mmap,
.sendpage = sock_no_sendpage
};
......
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