From 515db1ecc4afd8d2a75ffdea031dd71aa6821342 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Tue, 7 Nov 2023 13:42:50 +1100 Subject: tcp_splice: Simplify selection of socket and pipe sides in socket handler tcp_splice_sock_handler() uses the tcp_splice_dir() helper to select which of the socket, pipe and counter fields to use depending on which side of the connection the socket event is coming from. Now that we are using arrays for the two sides, rather than separate named fields, we can instead just use a variable indicating the side and use that to index the arrays whever we need a particular side's field. Signed-off-by: David Gibson Signed-off-by: Stefano Brivio --- tcp_splice.c | 81 +++++++++++++++++------------------------------------------- 1 file changed, 22 insertions(+), 59 deletions(-) diff --git a/tcp_splice.c b/tcp_splice.c index 9f84d4f..a5c1332 100644 --- a/tcp_splice.c +++ b/tcp_splice.c @@ -438,29 +438,6 @@ static int tcp_splice_new(const struct ctx *c, struct tcp_splice_conn *conn, return tcp_splice_connect(c, conn, s, port); } -/** - * tcp_splice_dir() - Set sockets/pipe pointers reflecting flow direction - * @conn: Connection pointers - * @ref_sock: Socket returned as reference from epoll - * @reverse: Reverse direction: @ref_sock is used as destination - * @from: Destination socket pointer to set - * @to: Source socket pointer to set - * @pipes: Pipe set, assigned on return - */ -static void tcp_splice_dir(struct tcp_splice_conn *conn, int ref_sock, - int reverse, int *from, int *to, int **pipes) -{ - if (!reverse) { - *from = ref_sock; - *to = (*from == conn->s[0]) ? conn->s[1] : conn->s[0]; - } else { - *to = ref_sock; - *from = (*to == conn->s[0]) ? conn->s[1] : conn->s[0]; - } - - *pipes = *from == conn->s[0] ? conn->pipe[0] : conn->pipe[1]; -} - /** * tcp_splice_conn_from_sock() - Attempt to init state for a spliced connection * @c: Execution context @@ -521,8 +498,7 @@ void tcp_splice_sock_handler(struct ctx *c, struct tcp_splice_conn *conn, int s, uint32_t events) { uint8_t lowat_set_flag, lowat_act_flag; - int from, to, *pipes, eof, never_read; - uint32_t *seq_read, *seq_write; + int fromside, eof, never_read; if (conn->events == SPLICE_CLOSED) return; @@ -538,14 +514,15 @@ void tcp_splice_sock_handler(struct ctx *c, struct tcp_splice_conn *conn, } if (events & EPOLLOUT) { - if (s == conn->s[0]) + if (s == conn->s[0]) { conn_event(c, conn, ~OUT_WAIT_0); - else + fromside = 1; + } else { conn_event(c, conn, ~OUT_WAIT_1); - - tcp_splice_dir(conn, s, 1, &from, &to, &pipes); + fromside = 0; + } } else { - tcp_splice_dir(conn, s, 0, &from, &to, &pipes); + fromside = s == conn->s[0] ? 0 : 1; } if (events & EPOLLRDHUP) { @@ -566,24 +543,16 @@ swap: eof = 0; never_read = 1; - if (from == conn->s[0]) { - seq_read = &conn->read[0]; - seq_write = &conn->written[0]; - lowat_set_flag = RCVLOWAT_SET_0; - lowat_act_flag = RCVLOWAT_ACT_0; - } else { - seq_read = &conn->read[1]; - seq_write = &conn->written[1]; - lowat_set_flag = RCVLOWAT_SET_1; - lowat_act_flag = RCVLOWAT_ACT_1; - } + lowat_set_flag = fromside == 0 ? RCVLOWAT_SET_0 : RCVLOWAT_SET_1; + lowat_act_flag = fromside == 0 ? RCVLOWAT_ACT_0 : RCVLOWAT_ACT_1; while (1) { ssize_t readlen, to_write = 0, written; int more = 0; retry: - readlen = splice(from, NULL, pipes[1], NULL, c->tcp.pipe_size, + readlen = splice(conn->s[fromside], NULL, + conn->pipe[fromside][1], NULL, c->tcp.pipe_size, SPLICE_F_MOVE | SPLICE_F_NONBLOCK); trace("TCP (spliced): %li from read-side call", readlen); if (readlen < 0) { @@ -608,7 +577,8 @@ retry: } eintr: - written = splice(pipes[0], NULL, to, NULL, to_write, + written = splice(conn->pipe[fromside][0], NULL, + conn->s[!fromside], NULL, to_write, SPLICE_F_MOVE | more | SPLICE_F_NONBLOCK); trace("TCP (spliced): %li from write-side call (passed %lu)", written, to_write); @@ -622,8 +592,8 @@ eintr: readlen > (long)c->tcp.pipe_size / 10) { int lowat = c->tcp.pipe_size / 4; - setsockopt(from, SOL_SOCKET, SO_RCVLOWAT, - &lowat, sizeof(lowat)); + setsockopt(conn->s[fromside], SOL_SOCKET, + SO_RCVLOWAT, &lowat, sizeof(lowat)); conn_flag(c, conn, lowat_set_flag); conn_flag(c, conn, lowat_act_flag); @@ -632,8 +602,8 @@ eintr: break; } - *seq_read += readlen > 0 ? readlen : 0; - *seq_write += written > 0 ? written : 0; + conn->read[fromside] += readlen > 0 ? readlen : 0; + conn->written[fromside] += written > 0 ? written : 0; if (written < 0) { if (errno == EINTR) @@ -645,10 +615,8 @@ eintr: if (never_read) break; - if (to == conn->s[0]) - conn_event(c, conn, OUT_WAIT_0); - else - conn_event(c, conn, OUT_WAIT_1); + conn_event(c, conn, + fromside == 0 ? OUT_WAIT_1 : OUT_WAIT_0); break; } @@ -665,14 +633,14 @@ eintr: } if ((conn->events & FIN_RCVD_0) && !(conn->events & FIN_SENT_1)) { - if (*seq_read == *seq_write && eof) { + if (conn->read[fromside] == conn->written[fromside] && eof) { shutdown(conn->s[1], SHUT_WR); conn_event(c, conn, FIN_SENT_1); } } if ((conn->events & FIN_RCVD_1) && !(conn->events & FIN_SENT_0)) { - if (*seq_read == *seq_write && eof) { + if (conn->read[fromside] == conn->written[fromside] && eof) { shutdown(conn->s[0], SHUT_WR); conn_event(c, conn, FIN_SENT_0); } @@ -684,12 +652,7 @@ eintr: if ((events & (EPOLLIN | EPOLLOUT)) == (EPOLLIN | EPOLLOUT)) { events = EPOLLIN; - SWAP(from, to); - if (pipes == conn->pipe[0]) - pipes = conn->pipe[1]; - else - pipes = conn->pipe[0]; - + fromside = !fromside; goto swap; } -- cgit v1.2.3