*/
#include "includes.h"
-RCSID("$OpenBSD: channels.c,v 1.69 2000/09/21 11:25:33 markus Exp $");
+RCSID("$OpenBSD: channels.c,v 1.75 2000/12/05 20:34:09 markus Exp $");
#include "ssh.h"
#include "packet.h"
*/
void
-channel_register_fds(Channel *c, int rfd, int wfd, int efd, int extusage)
+channel_register_fds(Channel *c, int rfd, int wfd, int efd,
+ int extusage, int nonblock)
{
/* Update the maximum file descriptor value. */
if (rfd > channel_max_fd_value)
c->sock = (rfd == wfd) ? rfd : -1;
c->efd = efd;
c->extended_usage = extusage;
- if (rfd != -1)
- set_nonblock(rfd);
- if (wfd != -1)
- set_nonblock(wfd);
- if (efd != -1)
- set_nonblock(efd);
+
+ /* enable nonblocking mode */
+ if (nonblock) {
+ if (rfd != -1)
+ set_nonblock(rfd);
+ if (wfd != -1)
+ set_nonblock(wfd);
+ if (efd != -1)
+ set_nonblock(efd);
+ }
}
/*
int
channel_new(char *ctype, int type, int rfd, int wfd, int efd,
- int window, int maxpack, int extusage, char *remote_name)
+ int window, int maxpack, int extusage, char *remote_name, int nonblock)
{
int i, found;
Channel *c;
/* There are no free slots. Take last+1 slot and expand the array. */
found = channels_alloc;
channels_alloc += 10;
- debug("channel: expanding %d", channels_alloc);
+ debug2("channel: expanding %d", channels_alloc);
channels = xrealloc(channels, channels_alloc * sizeof(Channel));
for (i = found; i < channels_alloc; i++)
channels[i].type = SSH_CHANNEL_FREE;
buffer_init(&c->output);
buffer_init(&c->extended);
chan_init_iostates(c);
- channel_register_fds(c, rfd, wfd, efd, extusage);
+ channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
c->self = found;
c->type = type;
c->ctype = ctype;
int
channel_allocate(int type, int sock, char *remote_name)
{
- return channel_new("", type, sock, sock, -1, 0, 0, 0, remote_name);
+ return channel_new("", type, sock, sock, -1, 0, 0, 0, remote_name, 1);
}
FD_SET(c->sock, readset);
}
+void
+channel_pre_connecting(Channel *c, fd_set * readset, fd_set * writeset)
+{
+ debug3("channel %d: waiting for connection", c->self);
+ FD_SET(c->sock, writeset);
+}
+
void
channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset)
{
newch = channel_new("x11",
SSH_CHANNEL_OPENING, newsock, newsock, -1,
c->local_window_max, c->local_maxpacket,
- 0, xstrdup(buf));
+ 0, xstrdup(buf), 1);
if (compat20) {
packet_start(SSH2_MSG_CHANNEL_OPEN);
packet_put_cstring("x11");
struct sockaddr addr;
int newsock, newch;
socklen_t addrlen;
- char buf[1024], *remote_hostname;
+ char buf[1024], *remote_hostname, *rtype;
int remote_port;
+ rtype = (c->type == SSH_CHANNEL_RPORT_LISTENER) ?
+ "forwarded-tcpip" : "direct-tcpip";
+
if (FD_ISSET(c->sock, readset)) {
debug("Connection to port %d forwarding "
"to %.100s port %d requested.",
"connect from %.200s port %d",
c->listening_port, c->path, c->host_port,
remote_hostname, remote_port);
- newch = channel_new("direct-tcpip",
+
+ newch = channel_new(rtype,
SSH_CHANNEL_OPENING, newsock, newsock, -1,
c->local_window_max, c->local_maxpacket,
- 0, xstrdup(buf));
+ 0, xstrdup(buf), 1);
if (compat20) {
packet_start(SSH2_MSG_CHANNEL_OPEN);
- packet_put_cstring("direct-tcpip");
+ packet_put_cstring(rtype);
packet_put_int(newch);
packet_put_int(c->local_window_max);
packet_put_int(c->local_maxpacket);
- /* target host and port */
- packet_put_string(c->path, strlen(c->path));
- packet_put_int(c->host_port);
+ if (c->type == SSH_CHANNEL_RPORT_LISTENER) {
+ /* listen address, port */
+ packet_put_string(c->path, strlen(c->path));
+ packet_put_int(c->listening_port);
+ } else {
+ /* target host, port */
+ packet_put_string(c->path, strlen(c->path));
+ packet_put_int(c->host_port);
+ }
/* originator host and port */
packet_put_cstring(remote_hostname);
packet_put_int(remote_port);
error("accept from auth socket: %.100s", strerror(errno));
return;
}
- newch = channel_allocate(SSH_CHANNEL_OPENING, newsock,
- xstrdup("accepted auth socket"));
- packet_start(SSH_SMSG_AGENT_OPEN);
- packet_put_int(newch);
+ newch = channel_new("accepted auth socket",
+ SSH_CHANNEL_OPENING, newsock, newsock, -1,
+ c->local_window_max, c->local_maxpacket,
+ 0, xstrdup("accepted auth socket"), 1);
+ if (compat20) {
+ packet_start(SSH2_MSG_CHANNEL_OPEN);
+ packet_put_cstring("auth-agent@openssh.com");
+ packet_put_int(newch);
+ packet_put_int(c->local_window_max);
+ packet_put_int(c->local_maxpacket);
+ } else {
+ packet_start(SSH_SMSG_AGENT_OPEN);
+ packet_put_int(newch);
+ }
packet_send();
}
}
+void
+channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset)
+{
+ if (FD_ISSET(c->sock, writeset)) {
+ int err = 0;
+ int sz = sizeof(err);
+ c->type = SSH_CHANNEL_OPEN;
+ if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, (char *)&err, &sz) < 0) {
+ debug("getsockopt SO_ERROR failed");
+ } else {
+ if (err == 0) {
+ debug("channel %d: connected)", c->self);
+ } else {
+ debug("channel %d: not connected: %s",
+ c->self, strerror(err));
+ chan_read_failed(c);
+ chan_write_failed(c);
+ }
+ }
+ }
+}
+
int
channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
{
buffer_len(&c->extended) > 0) {
len = write(c->efd, buffer_ptr(&c->extended),
buffer_len(&c->extended));
- debug("channel %d: written %d to efd %d",
+ debug2("channel %d: written %d to efd %d",
c->self, len, c->efd);
if (len > 0) {
buffer_consume(&c->extended, len);
} else if (c->extended_usage == CHAN_EXTENDED_READ &&
FD_ISSET(c->efd, readset)) {
len = read(c->efd, buf, sizeof(buf));
- debug("channel %d: read %d from efd %d",
+ debug2("channel %d: read %d from efd %d",
c->self, len, c->efd);
if (len == 0) {
debug("channel %d: closing efd %d",
packet_put_int(c->remote_id);
packet_put_int(c->local_consumed);
packet_send();
- debug("channel %d: window %d sent adjust %d",
+ debug2("channel %d: window %d sent adjust %d",
c->self, c->local_window,
c->local_consumed);
c->local_window += c->local_consumed;
channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_20;
channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
+ channel_pre[SSH_CHANNEL_RPORT_LISTENER] = &channel_pre_listener;
channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
+ channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
+ channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_2;
channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
+ channel_post[SSH_CHANNEL_RPORT_LISTENER] = &channel_post_port_listener;
channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
+ channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
+ channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
}
void
channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
channel_pre[SSH_CHANNEL_INPUT_DRAINING] = &channel_pre_input_draining;
channel_pre[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_pre_output_draining;
+ channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1;
channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
channel_post[SSH_CHANNEL_OUTPUT_DRAINING] = &channel_post_output_drain_13;
+ channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
}
void
channel_pre[SSH_CHANNEL_X11_LISTENER] = &channel_pre_listener;
channel_pre[SSH_CHANNEL_PORT_LISTENER] = &channel_pre_listener;
channel_pre[SSH_CHANNEL_AUTH_SOCKET] = &channel_pre_listener;
+ channel_pre[SSH_CHANNEL_CONNECTING] = &channel_pre_connecting;
channel_post[SSH_CHANNEL_X11_LISTENER] = &channel_post_x11_listener;
channel_post[SSH_CHANNEL_PORT_LISTENER] = &channel_post_port_listener;
channel_post[SSH_CHANNEL_AUTH_SOCKET] = &channel_post_auth_listener;
channel_post[SSH_CHANNEL_OPEN] = &channel_post_open_1;
+ channel_post[SSH_CHANNEL_CONNECTING] = &channel_post_connecting;
}
void
xfree(data);
return;
}
- debug("channel %d: rcvd ext data %d", c->self, data_len);
+ debug2("channel %d: rcvd ext data %d", c->self, data_len);
c->local_window -= data_len;
buffer_append(&c->extended, data, data_len);
xfree(data);
c->remote_maxpacket = packet_get_int();
packet_done();
if (c->cb_fn != NULL && c->cb_event == type) {
- debug("callback start");
+ debug2("callback start");
c->cb_fn(c->self, c->cb_arg);
- debug("callback done");
+ debug2("callback done");
}
debug("channel %d: open confirm rwindow %d rmax %d", c->self,
c->remote_window, c->remote_maxpacket);
packet_disconnect("Received request for "
"non-open channel %d.", id);
if (c->cb_fn != NULL && c->cb_event == type) {
- debug("callback start");
+ debug2("callback start");
c->cb_fn(c->self, c->cb_arg);
- debug("callback done");
+ debug2("callback done");
} else {
char *service = packet_get_string(NULL);
debug("channel: %d rcvd request for %s", c->self, service);
-debug("cb_fn %p cb_event %d", c->cb_fn , c->cb_event);
+ debug("cb_fn %p cb_event %d", c->cb_fn , c->cb_event);
xfree(service);
}
}
}
adjust = packet_get_int();
packet_done();
- debug("channel %d: rcvd adjust %d", id, adjust);
+ debug2("channel %d: rcvd adjust %d", id, adjust);
c->remote_window += adjust;
}
switch (channels[i].type) {
case SSH_CHANNEL_AUTH_SOCKET:
close(channels[i].sock);
- remove(channels[i].path);
+ unlink(channels[i].path);
channel_free(i);
break;
case SSH_CHANNEL_PORT_LISTENER:
+ case SSH_CHANNEL_RPORT_LISTENER:
case SSH_CHANNEL_X11_LISTENER:
close(channels[i].sock);
channel_free(i);
case SSH_CHANNEL_FREE:
case SSH_CHANNEL_X11_LISTENER:
case SSH_CHANNEL_PORT_LISTENER:
+ case SSH_CHANNEL_RPORT_LISTENER:
case SSH_CHANNEL_CLOSED:
case SSH_CHANNEL_AUTH_SOCKET:
+ case SSH_CHANNEL_CONNECTING: /* XXX ??? */
continue;
case SSH_CHANNEL_LARVAL:
if (!compat20)
case SSH_CHANNEL_FREE:
case SSH_CHANNEL_X11_LISTENER:
case SSH_CHANNEL_PORT_LISTENER:
+ case SSH_CHANNEL_RPORT_LISTENER:
case SSH_CHANNEL_CLOSED:
case SSH_CHANNEL_AUTH_SOCKET:
continue;
case SSH_CHANNEL_LARVAL:
case SSH_CHANNEL_OPENING:
+ case SSH_CHANNEL_CONNECTING:
case SSH_CHANNEL_OPEN:
case SSH_CHANNEL_X11_OPEN:
case SSH_CHANNEL_INPUT_DRAINING:
* Initiate forwarding of connections to local port "port" through the secure
* channel to host:port from remote side.
*/
+void
+channel_request_local_forwarding(u_short listen_port, const char *host_to_connect,
+ u_short port_to_connect, int gateway_ports)
+{
+ channel_request_forwarding(
+ NULL, listen_port,
+ host_to_connect, port_to_connect,
+ gateway_ports, /*remote_fwd*/ 0);
+}
+/*
+ * If 'remote_fwd' is true we have a '-R style' listener for protocol 2
+ * (SSH_CHANNEL_RPORT_LISTENER).
+ */
void
-channel_request_local_forwarding(u_short port, const char *host,
- u_short host_port, int gateway_ports)
+channel_request_forwarding(
+ const char *listen_address, u_short listen_port,
+ const char *host_to_connect, u_short port_to_connect,
+ int gateway_ports, int remote_fwd)
{
- int success, ch, sock, on = 1;
+ int success, ch, sock, on = 1, ctype;
struct addrinfo hints, *ai, *aitop;
char ntop[NI_MAXHOST], strport[NI_MAXSERV];
+ const char *host;
struct linger linger;
+ if (remote_fwd) {
+ host = listen_address;
+ ctype = SSH_CHANNEL_RPORT_LISTENER;
+ } else {
+ host = host_to_connect;
+ ctype =SSH_CHANNEL_PORT_LISTENER;
+ }
+
if (strlen(host) > sizeof(channels[0].path) - 1)
packet_disconnect("Forward host name too long.");
+ /* XXX listen_address is currently ignored */
/*
* getaddrinfo returns a loopback address if the hostname is
* set to NULL and hints.ai_flags is not AI_PASSIVE
hints.ai_family = IPv4or6;
hints.ai_flags = gateway_ports ? AI_PASSIVE : 0;
hints.ai_socktype = SOCK_STREAM;
- snprintf(strport, sizeof strport, "%d", port);
+ snprintf(strport, sizeof strport, "%d", listen_port);
if (getaddrinfo(NULL, strport, &hints, &aitop) != 0)
packet_disconnect("getaddrinfo: fatal error");
continue;
if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),
strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
- error("channel_request_local_forwarding: getnameinfo failed");
+ error("channel_request_forwarding: getnameinfo failed");
continue;
}
/* Create a port to listen for the host. */
continue;
}
/* Allocate a channel number for the socket. */
- ch = channel_new(
- "port listener", SSH_CHANNEL_PORT_LISTENER,
- sock, sock, -1,
+ ch = channel_new("port listener", ctype, sock, sock, -1,
CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
- 0, xstrdup("port listener"));
+ 0, xstrdup("port listener"), 1);
strlcpy(channels[ch].path, host, sizeof(channels[ch].path));
- channels[ch].host_port = host_port;
- channels[ch].listening_port = port;
+ channels[ch].host_port = port_to_connect;
+ channels[ch].listening_port = listen_port;
success = 1;
}
if (success == 0)
- packet_disconnect("cannot listen port: %d", port);
+ packet_disconnect("cannot listen port: %d", listen_port); /*XXX ?disconnect? */
freeaddrinfo(aitop);
}
*/
void
-channel_request_remote_forwarding(u_short listen_port, const char *host_to_connect,
- u_short port_to_connect)
+channel_request_remote_forwarding(u_short listen_port,
+ const char *host_to_connect, u_short port_to_connect)
{
- int payload_len;
+ int payload_len, type, success = 0;
+
/* Record locally that connection to this host/port is permitted. */
if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
fatal("channel_request_remote_forwarding: too many forwards");
- permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
- permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
- permitted_opens[num_permitted_opens].listen_port = listen_port;
- num_permitted_opens++;
-
/* Send the forward request to the remote side. */
if (compat20) {
const char *address_to_bind = "0.0.0.0";
packet_put_char(0); /* boolean: want reply */
packet_put_cstring(address_to_bind);
packet_put_int(listen_port);
+ packet_send();
+ packet_write_wait();
+ /* Assume that server accepts the request */
+ success = 1;
} else {
packet_start(SSH_CMSG_PORT_FORWARD_REQUEST);
packet_put_int(listen_port);
packet_put_int(port_to_connect);
packet_send();
packet_write_wait();
- /*
- * Wait for response from the remote side. It will send a disconnect
- * message on failure, and we will never see it here.
- */
- packet_read_expect(&payload_len, SSH_SMSG_SUCCESS);
+
+ /* Wait for response from the remote side. */
+ type = packet_read(&payload_len);
+ switch (type) {
+ case SSH_SMSG_SUCCESS:
+ success = 1;
+ break;
+ case SSH_SMSG_FAILURE:
+ log("Warning: Server denied remote port forwarding.");
+ break;
+ default:
+ /* Unknown packet */
+ packet_disconnect("Protocol error for port forward request:"
+ "received packet type %d.", type);
+ }
+ }
+ if (success) {
+ permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host_to_connect);
+ permitted_opens[num_permitted_opens].port_to_connect = port_to_connect;
+ permitted_opens[num_permitted_opens].listen_port = listen_port;
+ num_permitted_opens++;
}
}
packet_disconnect("Requested forwarding of port %d but user is not root.",
port);
#endif
- /*
- * Initiate forwarding,
- */
+ /* Initiate forwarding */
channel_request_local_forwarding(port, hostname, host_port, gateway_ports);
/* Free the argument string. */
error("socket: %.100s", strerror(errno));
continue;
}
+ if (fcntl(sock, F_SETFL, O_NDELAY) < 0)
+ fatal("connect_to: F_SETFL: %s", strerror(errno));
/* Connect to the host/port. */
- if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
+ if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&
+ errno != EINPROGRESS) {
error("connect %.100s port %s: %.100s", ntop, strport,
strerror(errno));
close(sock);
/* success */
return sock;
}
+int
+channel_connect_by_listen_adress(u_short listen_port)
+{
+ int i;
+ for (i = 0; i < num_permitted_opens; i++)
+ if (permitted_opens[i].listen_port == listen_port)
+ return channel_connect_to(
+ permitted_opens[i].host_to_connect,
+ permitted_opens[i].port_to_connect);
+ error("WARNING: Server requests forwarding for unknown listen_port %d",
+ listen_port);
+ return -1;
+}
/*
* This is called after receiving PORT_OPEN message. This attempts to
sock = denied ? -1 : channel_connect_to(host, host_port);
if (sock > 0) {
/* Allocate a channel for this connection. */
- newch = channel_allocate(SSH_CHANNEL_OPEN, sock, originator_string);
+ newch = channel_allocate(SSH_CHANNEL_CONNECTING,
+ sock, originator_string);
+/*XXX delay answer? */
channels[newch].remote_id = remote_channel;
packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
continue;
sock = socket(ai->ai_family, SOCK_STREAM, 0);
if (sock < 0) {
- if (errno != EINVAL) {
+ if ((errno != EINVAL) && (errno != EAFNOSUPPORT)) {
error("socket: %.100s", strerror(errno));
return NULL;
} else {
(void) channel_new("x11 listener",
SSH_CHANNEL_X11_LISTENER, sock, sock, -1,
CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
- 0, xstrdup("X11 inet listener"));
+ 0, xstrdup("X11 inet listener"), 1);
}
/* Return a suitable value for the DISPLAY environment variable. */
}
}
+/* dummy protocol handler that denies SSH-1 requests (agent/x11) */
+void
+deny_input_open(int type, int plen, void *ctxt)
+{
+ int rchan = packet_get_int();
+ switch(type){
+ case SSH_SMSG_AGENT_OPEN:
+ error("Warning: ssh server tried agent forwarding.");
+ break;
+ case SSH_SMSG_X11_OPEN:
+ error("Warning: ssh server tried X11 forwarding.");
+ break;
+ default:
+ error("deny_input_open: type %d plen %d", type, plen);
+ break;
+ }
+ error("Warning: this is probably a break in attempt by a malicious server.");
+ packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
+ packet_put_int(rchan);
+ packet_send();
+}
+
/*
* Requests forwarding of X11 connections, generates fake authentication
* data, and enables authentication spoofing.
void
cleanup_socket(void)
{
- remove(channel_forwarded_auth_socket_name);
+ unlink(channel_forwarded_auth_socket_name);
rmdir(channel_forwarded_auth_socket_dir);
}
packet_disconnect("listen: %.100s", strerror(errno));
/* Allocate a channel for the authentication agent socket. */
- newch = channel_allocate(SSH_CHANNEL_AUTH_SOCKET, sock,
- xstrdup("auth socket"));
+ newch = channel_new("auth socket",
+ SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
+ CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
+ 0, xstrdup("auth socket"), 1);
+
strlcpy(channels[newch].path, channel_forwarded_auth_socket_name,
sizeof(channels[newch].path));
return 1;
}
void
-channel_set_fds(int id, int rfd, int wfd, int efd, int extusage)
+channel_set_fds(int id, int rfd, int wfd, int efd,
+ int extusage, int nonblock)
{
Channel *c = channel_lookup(id);
if (c == NULL || c->type != SSH_CHANNEL_LARVAL)
fatal("channel_activate for non-larval channel %d.", id);
-
- channel_register_fds(c, rfd, wfd, efd, extusage);
+ channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);
c->type = SSH_CHANNEL_OPEN;
/* XXX window size? */
c->local_window = c->local_window_max = c->local_maxpacket * 2;
andersk / openssh.git / blobdiff