diff options
| -rw-r--r-- | tcp.c | 37 |
1 files changed, 33 insertions, 4 deletions
@@ -1388,7 +1388,34 @@ static int tcp_send_flag(const struct ctx *c, struct tcp_tap_conn *conn, } /** - * tcp_rst_do() - Reset a tap connection: send RST segment to tap, close socket + * tcp_sock_rst() - Close TCP connection forcing RST on socket side + * @c: Execution context + * @conn: Connection pointer + */ +static void tcp_sock_rst(const struct ctx *c, struct tcp_tap_conn *conn) +{ + const struct linger linger0 = { + .l_onoff = 1, + .l_linger = 0, + }; + + /* Force RST on socket to inform the peer + * + * We do this by setting SO_LINGER with 0 timeout, which means that + * close() will send an RST (unless the connection is already closed in + * both directions). + */ + if (setsockopt(conn->sock, SOL_SOCKET, + SO_LINGER, &linger0, sizeof(linger0)) < 0) { + flow_dbg_perror(conn, + "SO_LINGER failed, may not send RST to peer"); + } + + conn_event(c, conn, CLOSED); +} + +/** + * tcp_rst_do() - Reset a tap connection: send RST segment on both sides, close * @c: Execution context * @conn: Connection pointer */ @@ -1397,8 +1424,10 @@ void tcp_rst_do(const struct ctx *c, struct tcp_tap_conn *conn) if (conn->events == CLOSED) return; + /* Send RST on tap */ tcp_send_flag(c, conn, RST); - conn_event(c, conn, CLOSED); + + tcp_sock_rst(c, conn); } /** @@ -1874,7 +1903,7 @@ static int tcp_data_from_tap(const struct ctx *c, struct tcp_tap_conn *conn, return -1; if (th->rst) { - conn_event(c, conn, CLOSED); + tcp_sock_rst(c, conn); return 1; } @@ -2238,7 +2267,7 @@ int tcp_tap_handler(const struct ctx *c, uint8_t pif, sa_family_t af, flow_trace(conn, "packet length %zu from tap", l4len); if (th->rst) { - conn_event(c, conn, CLOSED); + tcp_sock_rst(c, conn); return 1; } |