diff options
| -rw-r--r-- | tcp.c | 53 |
1 files changed, 30 insertions, 23 deletions
@@ -165,12 +165,13 @@ * * - ESTABLISHED connection established, ready for data * - FIN from tap write shutdown > FIN_WAIT_1 - * - zero-sized socket read read shutdown, FIN to tap > ESTABLISHED_SOCK_FIN + * - EPOLLRDHUP/EPOLLHUP read shutdown > ESTABLISHED_SOCK_FIN * - socket error RST to tap, close socket > CLOSED * - data timeout FIN to tap > ESTABLISHED_SOCK_FIN * - RST from tap close socket > CLOSED * - * - ESTABLISHED_SOCK_FIN socket closing connection, FIN sent to tap + * - ESTABLISHED_SOCK_FIN socket closing connection, reading half closed + * - zero-sized socket read FIN, ACK to tap > CLOSE_WAIT * - ACK from tap > CLOSE_WAIT * - ACK timeout RST to tap, close socket > CLOSED * - RST from tap close socket > CLOSED @@ -1222,12 +1223,13 @@ static void tcp_rst(struct ctx *c, struct tcp_tap_conn *conn) /** * tcp_clamp_window() - Set window and scaling from option, clamp on socket * @conn: Connection pointer - * @th: TCP header, from tap - * @len: Buffer length, at L4 + * @th: TCP header, from tap, can be NULL if window is passed + * @len: Buffer length, at L4, can be 0 if no header is passed + * @window: Window value, host order, unscaled, if no header is passed * @init: Set if this is the very first segment from tap */ static void tcp_clamp_window(struct tcp_tap_conn *conn, struct tcphdr *th, - int len, int init) + int len, unsigned int window, int init) { if (init) { conn->ws = tcp_opt_get(th, len, OPT_WS, NULL, NULL); @@ -1241,7 +1243,10 @@ static void tcp_clamp_window(struct tcp_tap_conn *conn, struct tcphdr *th, conn->tap_window = ntohs(th->window); conn->window_clamped = 0; } else { - unsigned int window = ntohs(th->window) << conn->ws; + if (th) + window = ntohs(th->window) << conn->ws; + else + window <<= conn->ws; if (conn->window_clamped) { if (conn->tap_window == window) @@ -1376,7 +1381,7 @@ static void tcp_conn_from_tap(struct ctx *c, int af, void *addr, sl = sizeof(conn->mss_guest); setsockopt(s, SOL_TCP, TCP_MAXSEG, &conn->mss_guest, sl); - tcp_clamp_window(conn, th, len, 1); + tcp_clamp_window(conn, th, len, 0, 1); if (af == AF_INET) { sa = (struct sockaddr *)&addr4; @@ -1802,10 +1807,9 @@ err: zero_len: if (conn->state == FIN_WAIT_1) { tcp_tap_state(conn, FIN_WAIT_1_SOCK_FIN); - } else if (conn->state < ESTABLISHED_SOCK_FIN) { - tcp_tap_state(conn, ESTABLISHED_SOCK_FIN); - shutdown(conn->sock, SHUT_RD); + } else if (conn->state == ESTABLISHED_SOCK_FIN) { tcp_send_to_tap(c, conn, FIN | ACK, NULL, 0); + tcp_tap_state(conn, CLOSE_WAIT); } goto out_restore_iov; @@ -1838,7 +1842,7 @@ static void tcp_data_from_tap(struct ctx *c, struct tcp_tap_conn *conn, struct msghdr mh = { .msg_iov = tcp_tap_iov }; uint32_t max_ack_seq = conn->seq_ack_from_tap; uint32_t seq_from_tap = conn->seq_from_tap; - uint16_t max_ack_seq_wnd; + uint16_t max_ack_seq_wnd = WINDOW_DEFAULT; ssize_t len; for (i = 0, iov_i = 0; i < count; i++) { @@ -1938,6 +1942,8 @@ static void tcp_data_from_tap(struct ctx *c, struct tcp_tap_conn *conn, } } + tcp_clamp_window(conn, NULL, 0, max_ack_seq_wnd, 0); + if (ack) { conn->ts_ack_tap = *now; tcp_sock_consume(conn, max_ack_seq); @@ -1978,11 +1984,13 @@ static void tcp_data_from_tap(struct ctx *c, struct tcp_tap_conn *conn, tcp_send_to_tap(c, conn, 0, NULL, 0); fin: - if (conn->state == ESTABLISHED_SOCK_FIN && ack && - !tcp_data_from_sock(c, conn, now)) - tcp_tap_state(conn, CLOSE_WAIT); - - if (fin) { + if (conn->state == CLOSE_WAIT && fin && ack) { + tcp_data_from_sock(c, conn, now); + tcp_sock_consume(conn, conn->seq_ack_from_tap); + shutdown(conn->sock, SHUT_WR); + tcp_tap_state(conn, LAST_ACK); + tcp_send_to_tap(c, conn, ACK, NULL, 0); + } else if (fin) { shutdown(conn->sock, SHUT_WR); if (conn->state == ESTABLISHED) { tcp_tap_state(conn, FIN_WAIT_1); @@ -2034,8 +2042,6 @@ int tcp_tap_handler(struct ctx *c, int af, void *addr, return 1; } - tcp_clamp_window(conn, th, len, th->syn && th->ack); - conn->ts_tap = *now; switch (conn->state) { @@ -2045,6 +2051,8 @@ int tcp_tap_handler(struct ctx *c, int af, void *addr, return 1; } + tcp_clamp_window(conn, th, len, 0, 1); + conn->mss_guest = tcp_opt_get(th, len, OPT_MSS, NULL, NULL); if (conn->mss_guest < 0) conn->mss_guest = MSS_DEFAULT; @@ -2103,6 +2111,8 @@ int tcp_tap_handler(struct ctx *c, int af, void *addr, return 1; } + tcp_clamp_window(conn, th, len, 0, 0); + tcp_tap_state(conn, ESTABLISHED); break; case ESTABLISHED: @@ -2598,8 +2608,7 @@ void tcp_sock_handler(struct ctx *c, union epoll_ref ref, uint32_t events, } if (conn->state == SOCK_SYN_SENT) { - /* This can only be a socket error or a shutdown from remote */ - tcp_rst(c, conn); + /* This could also be a data packet already, don't reset yet. */ return; } @@ -2614,15 +2623,13 @@ void tcp_sock_handler(struct ctx *c, union epoll_ref ref, uint32_t events, return; } - if (conn->state == ESTABLISHED) + if (conn->state == ESTABLISHED || conn->state == ESTABLISHED_SOCK_FIN) tcp_data_from_sock(c, conn, now); if (events & (EPOLLRDHUP | EPOLLHUP)) { if (conn->state == ESTABLISHED) { tcp_tap_state(conn, ESTABLISHED_SOCK_FIN); shutdown(conn->sock, SHUT_RD); - tcp_data_from_sock(c, conn, now); - tcp_send_to_tap(c, conn, FIN | ACK, NULL, 0); } else if (conn->state == FIN_WAIT_1) { tcp_tap_state(conn, FIN_WAIT_1_SOCK_FIN); shutdown(conn->sock, SHUT_RD); |