diff options
Diffstat (limited to 'channels.c')
-rw-r--r-- | channels.c | 164 |
1 files changed, 109 insertions, 55 deletions
@@ -1,4 +1,4 @@ -/* $OpenBSD: channels.c,v 1.311 2011/06/22 22:08:42 djm Exp $ */ +/* $OpenBSD: channels.c,v 1.312 2011/09/09 22:46:44 djm Exp $ */ /* * Author: Tatu Ylonen <ylo@cs.hut.fi> * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland @@ -302,6 +302,8 @@ channel_new(char *ctype, int type, int rfd, int wfd, int efd, buffer_init(&c->output); buffer_init(&c->extended); c->path = NULL; + c->listening_addr = NULL; + c->listening_port = 0; c->ostate = CHAN_OUTPUT_OPEN; c->istate = CHAN_INPUT_OPEN; c->flags = 0; @@ -411,6 +413,10 @@ channel_free(Channel *c) xfree(c->path); c->path = NULL; } + if (c->listening_addr) { + xfree(c->listening_addr); + c->listening_addr = NULL; + } while ((cc = TAILQ_FIRST(&c->status_confirms)) != NULL) { if (cc->abandon_cb != NULL) cc->abandon_cb(c, cc->ctx); @@ -2634,6 +2640,46 @@ channel_set_af(int af) IPv4or6 = af; } + +/* + * Determine whether or not a port forward listens to loopback, the + * specified address or wildcard. On the client, a specified bind + * address will always override gateway_ports. On the server, a + * gateway_ports of 1 (``yes'') will override the client's specification + * and force a wildcard bind, whereas a value of 2 (``clientspecified'') + * will bind to whatever address the client asked for. + * + * Special-case listen_addrs are: + * + * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR + * "" (empty string), "*" -> wildcard v4/v6 + * "localhost" -> loopback v4/v6 + */ +static const char * +channel_fwd_bind_addr(const char *listen_addr, int *wildcardp, + int is_client, int gateway_ports) +{ + const char *addr = NULL; + int wildcard = 0; + + if (listen_addr == NULL) { + /* No address specified: default to gateway_ports setting */ + if (gateway_ports) + wildcard = 1; + } else if (gateway_ports || is_client) { + if (((datafellows & SSH_OLD_FORWARD_ADDR) && + strcmp(listen_addr, "0.0.0.0") == 0 && is_client == 0) || + *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 || + (!is_client && gateway_ports == 1)) + wildcard = 1; + else if (strcmp(listen_addr, "localhost") != 0) + addr = listen_addr; + } + if (wildcardp != NULL) + *wildcardp = wildcard; + return addr; +} + static int channel_setup_fwd_listener(int type, const char *listen_addr, u_short listen_port, int *allocated_listen_port, @@ -2659,36 +2705,9 @@ channel_setup_fwd_listener(int type, const char *listen_addr, return 0; } - /* - * Determine whether or not a port forward listens to loopback, - * specified address or wildcard. On the client, a specified bind - * address will always override gateway_ports. On the server, a - * gateway_ports of 1 (``yes'') will override the client's - * specification and force a wildcard bind, whereas a value of 2 - * (``clientspecified'') will bind to whatever address the client - * asked for. - * - * Special-case listen_addrs are: - * - * "0.0.0.0" -> wildcard v4/v6 if SSH_OLD_FORWARD_ADDR - * "" (empty string), "*" -> wildcard v4/v6 - * "localhost" -> loopback v4/v6 - */ - addr = NULL; - if (listen_addr == NULL) { - /* No address specified: default to gateway_ports setting */ - if (gateway_ports) - wildcard = 1; - } else if (gateway_ports || is_client) { - if (((datafellows & SSH_OLD_FORWARD_ADDR) && - strcmp(listen_addr, "0.0.0.0") == 0 && is_client == 0) || - *listen_addr == '\0' || strcmp(listen_addr, "*") == 0 || - (!is_client && gateway_ports == 1)) - wildcard = 1; - else if (strcmp(listen_addr, "localhost") != 0) - addr = listen_addr; - } - + /* Determine the bind address, cf. channel_fwd_bind_addr() comment */ + addr = channel_fwd_bind_addr(listen_addr, &wildcard, + is_client, gateway_ports); debug3("channel_setup_fwd_listener: type %d wildcard %d addr %s", type, wildcard, (addr == NULL) ? "NULL" : addr); @@ -2793,6 +2812,7 @@ channel_setup_fwd_listener(int type, const char *listen_addr, c->path = xstrdup(host); c->host_port = port_to_connect; c->listening_port = listen_port; + c->listening_addr = addr == NULL ? NULL : xstrdup(addr); success = 1; } if (success == 0) @@ -2810,9 +2830,36 @@ channel_cancel_rport_listener(const char *host, u_short port) for (i = 0; i < channels_alloc; i++) { Channel *c = channels[i]; + if (c == NULL || c->type != SSH_CHANNEL_RPORT_LISTENER) + continue; + if (strcmp(c->path, host) == 0 && c->listening_port == port) { + debug2("%s: close channel %d", __func__, i); + channel_free(c); + found = 1; + } + } + + return (found); +} + +int +channel_cancel_lport_listener(const char *lhost, u_short lport, + u_short cport, int gateway_ports) +{ + u_int i; + int found = 0; + const char *addr = channel_fwd_bind_addr(lhost, NULL, 1, gateway_ports); - if (c != NULL && c->type == SSH_CHANNEL_RPORT_LISTENER && - strcmp(c->path, host) == 0 && c->listening_port == port) { + for (i = 0; i < channels_alloc; i++) { + Channel *c = channels[i]; + if (c == NULL || c->type != SSH_CHANNEL_PORT_LISTENER) + continue; + if (c->listening_port != lport || c->host_port != cport) + continue; + if ((c->listening_addr == NULL && addr != NULL) || + (c->listening_addr != NULL && addr == NULL)) + continue; + if (addr == NULL || strcmp(c->listening_addr, addr) == 0) { debug2("%s: close channel %d", __func__, i); channel_free(c); found = 1; @@ -2843,10 +2890,30 @@ channel_setup_remote_fwd_listener(const char *listen_address, } /* + * Translate the requested rfwd listen host to something usable for + * this server. + */ +static const char * +channel_rfwd_bind_host(const char *listen_host) +{ + if (listen_host == NULL) { + if (datafellows & SSH_BUG_RFWD_ADDR) + return "127.0.0.1"; + else + return "localhost"; + } else if (*listen_host == '\0' || strcmp(listen_host, "*") == 0) { + if (datafellows & SSH_BUG_RFWD_ADDR) + return "0.0.0.0"; + else + return ""; + } else + return listen_host; +} + +/* * Initiate forwarding of connections to port "port" on remote host through * the secure channel to host:port from local side. */ - int channel_request_remote_forwarding(const char *listen_host, u_short listen_port, const char *host_to_connect, u_short port_to_connect) @@ -2855,25 +2922,10 @@ channel_request_remote_forwarding(const char *listen_host, u_short listen_port, /* Send the forward request to the remote side. */ if (compat20) { - const char *address_to_bind; - if (listen_host == NULL) { - if (datafellows & SSH_BUG_RFWD_ADDR) - address_to_bind = "127.0.0.1"; - else - address_to_bind = "localhost"; - } else if (*listen_host == '\0' || - strcmp(listen_host, "*") == 0) { - if (datafellows & SSH_BUG_RFWD_ADDR) - address_to_bind = "0.0.0.0"; - else - address_to_bind = ""; - } else - address_to_bind = listen_host; - packet_start(SSH2_MSG_GLOBAL_REQUEST); packet_put_cstring("tcpip-forward"); - packet_put_char(1); /* boolean: want reply */ - packet_put_cstring(address_to_bind); + packet_put_char(1); /* boolean: want reply */ + packet_put_cstring(channel_rfwd_bind_host(listen_host)); packet_put_int(listen_port); packet_send(); packet_write_wait(); @@ -2917,13 +2969,13 @@ channel_request_remote_forwarding(const char *listen_host, u_short listen_port, * Request cancellation of remote forwarding of connection host:port from * local side. */ -void +int channel_request_rforward_cancel(const char *host, u_short port) { int i; if (!compat20) - return; + return -1; for (i = 0; i < num_permitted_opens; i++) { if (permitted_opens[i].host_to_connect != NULL && @@ -2932,12 +2984,12 @@ channel_request_rforward_cancel(const char *host, u_short port) } if (i >= num_permitted_opens) { debug("%s: requested forward not found", __func__); - return; + return -1; } packet_start(SSH2_MSG_GLOBAL_REQUEST); packet_put_cstring("cancel-tcpip-forward"); packet_put_char(0); - packet_put_cstring(host == NULL ? "" : host); + packet_put_cstring(channel_rfwd_bind_host(host)); packet_put_int(port); packet_send(); @@ -2945,6 +2997,8 @@ channel_request_rforward_cancel(const char *host, u_short port) permitted_opens[i].port_to_connect = 0; xfree(permitted_opens[i].host_to_connect); permitted_opens[i].host_to_connect = NULL; + + return 0; } /* |