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author | David S. Miller <davem@davemloft.net> | 2017-05-02 15:56:54 -0400 |
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committer | David S. Miller <davem@davemloft.net> | 2017-05-02 15:56:54 -0400 |
commit | 5d15af6778b8e4ed1fd41b040283af278e7a9a72 (patch) | |
tree | c52e9bc9f46009212362172962fe8f07e6fc6c76 | |
parent | b0e92279d3ec3656152c4dfa1c8b28fa40ca66d7 (diff) | |
parent | ec8a09fbbeff252c80daf62c7a78342003dddf9c (diff) | |
download | linux-5d15af6778b8e4ed1fd41b040283af278e7a9a72.tar.gz linux-5d15af6778b8e4ed1fd41b040283af278e7a9a72.tar.bz2 linux-5d15af6778b8e4ed1fd41b040283af278e7a9a72.zip |
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: David S. Miller <davem@davemloft.net>
-rw-r--r-- | net/tipc/socket.c | 266 |
1 files changed, 122 insertions, 144 deletions
diff --git a/net/tipc/socket.c b/net/tipc/socket.c index 8a4e9fe5f9eb..7e45ef938c18 100644 --- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -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 @@ exit: * * 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 }; |