/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
*
* As far as I am concerned, the code I have written for this software
* can be used freely for any purpose. Any derived versions of this
* software must be clearly marked as such, and if the derived work is
* incompatible with the protocol description in the RFC file, it must be
* called by a name other than "ssh" or "Secure Shell".
*
*
* Copyright (c) 2001 Markus Friedl. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "includes.h"
RCSID("$OpenBSD: channel-core.c,v 1.1 2001/05/30 12:55:07 markus Exp $");
#include "ssh1.h"
#include "ssh2.h"
#include "packet.h"
#include "xmalloc.h"
#include "log.h"
#include "channel.h"
#include "compat.h"
#include "canohost.h"
extern int channels_alloc;
extern int channel_max_fd;
extern Channel **channels;
void port_open_helper(Channel *c, char *rtype);
/*
* 'channel_pre*' are called just before select() to add any bits relevant to
* channels in the select bitmasks.
*/
/*
* 'channel_post*': perform any appropriate operations for channels which
* have events pending.
*/
typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset);
chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
void
channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset)
{
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)
{
if (buffer_len(&c->input) < packet_get_maxsize())
FD_SET(c->sock, readset);
if (buffer_len(&c->output) > 0)
FD_SET(c->sock, writeset);
}
void
channel_pre_open_15(Channel *c, fd_set * readset, fd_set * writeset)
{
/* test whether sockets are 'alive' for read/write */
if (c->istate == CHAN_INPUT_OPEN)
if (buffer_len(&c->input) < packet_get_maxsize())
FD_SET(c->sock, readset);
if (c->ostate == CHAN_OUTPUT_OPEN ||
c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
if (buffer_len(&c->output) > 0) {
FD_SET(c->sock, writeset);
} else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
chan_obuf_empty(c);
}
}
}
void
channel_pre_open_20(Channel *c, fd_set * readset, fd_set * writeset)
{
if (c->istate == CHAN_INPUT_OPEN &&
c->remote_window > 0 &&
buffer_len(&c->input) < c->remote_window)
FD_SET(c->rfd, readset);
if (c->ostate == CHAN_OUTPUT_OPEN ||
c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
if (buffer_len(&c->output) > 0) {
FD_SET(c->wfd, writeset);
} else if (c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
chan_obuf_empty(c);
}
}
/** XXX check close conditions, too */
if (c->efd != -1) {
if (c->extended_usage == CHAN_EXTENDED_WRITE &&
buffer_len(&c->extended) > 0)
FD_SET(c->efd, writeset);
else if (c->extended_usage == CHAN_EXTENDED_READ &&
buffer_len(&c->extended) < c->remote_window)
FD_SET(c->efd, readset);
}
}
void
channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset)
{
if (buffer_len(&c->input) == 0) {
packet_start(SSH_MSG_CHANNEL_CLOSE);
packet_put_int(c->remote_id);
packet_send();
c->type = SSH_CHANNEL_CLOSED;
debug("channel %d: closing after input drain.", c->self);
}
}
void
channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset)
{
if (buffer_len(&c->output) == 0)
chan_mark_dead(c);
else
FD_SET(c->sock, writeset);
}
void
channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset)
{
int ret = x11_check_cookie(&c->output);
if (ret == 1) {
/* Start normal processing for the channel. */
c->type = SSH_CHANNEL_OPEN;
channel_pre_open_13(c, readset, writeset);
} else if (ret == -1) {
/*
* We have received an X11 connection that has bad
* authentication information.
*/
log("X11 connection rejected because of wrong authentication.");
buffer_clear(&c->input);
buffer_clear(&c->output);
close(c->sock);
c->sock = -1;
c->type = SSH_CHANNEL_CLOSED;
packet_start(SSH_MSG_CHANNEL_CLOSE);
packet_put_int(c->remote_id);
packet_send();
}
}
void
channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset)
{
int ret = x11_check_cookie(&c->output);
if (ret == 1) {
c->type = SSH_CHANNEL_OPEN;
if (compat20)
channel_pre_open_20(c, readset, writeset);
else
channel_pre_open_15(c, readset, writeset);
} else if (ret == -1) {
debug("X11 rejected %d i%d/o%d", c->self, c->istate, c->ostate);
chan_read_failed(c); /** force close? */
chan_write_failed(c);
debug("X11 closed %d i%d/o%d", c->self, c->istate, c->ostate);
}
}
/* try to decode a socks4 header */
int
channel_decode_socks4(Channel *c, fd_set * readset, fd_set * writeset)
{
u_char *p, *host;
int len, have, i, found;
char username[256];
struct {
u_int8_t version;
u_int8_t command;
u_int16_t dest_port;
struct in_addr dest_addr;
} s4_req, s4_rsp;
debug2("channel %d: decode socks4", c->self);
have = buffer_len(&c->input);
len = sizeof(s4_req);
if (have < len)
return 0;
p = buffer_ptr(&c->input);
for (found = 0, i = len; i < have; i++) {
if (p[i] == '\0') {
found = 1;
break;
}
if (i > 1024) {
/* the peer is probably sending garbage */
debug("channel %d: decode socks4: too long",
c->self);
return -1;
}
}
if (!found)
return 0;
buffer_get(&c->input, (char *)&s4_req.version, 1);
buffer_get(&c->input, (char *)&s4_req.command, 1);
buffer_get(&c->input, (char *)&s4_req.dest_port, 2);
buffer_get(&c->input, (char *)&s4_req.dest_addr, 4);
have = buffer_len(&c->input);
p = buffer_ptr(&c->input);
len = strlen(p);
debug2("channel %d: decode socks4: user %s/%d", c->self, p, len);
if (len > have)
fatal("channel %d: decode socks4: len %d > have %d",
c->self, len, have);
strlcpy(username, p, sizeof(username));
buffer_consume(&c->input, len);
buffer_consume(&c->input, 1); /* trailing '\0' */
host = inet_ntoa(s4_req.dest_addr);
strlcpy(c->path, host, sizeof(c->path));
c->host_port = ntohs(s4_req.dest_port);
debug("channel %d: dynamic request: socks4 host %s port %u command %u",
c->self, host, c->host_port, s4_req.command);
if (s4_req.command != 1) {
debug("channel %d: cannot handle: socks4 cn %d",
c->self, s4_req.command);
return -1;
}
s4_rsp.version = 0; /* vn: 0 for reply */
s4_rsp.command = 90; /* cd: req granted */
s4_rsp.dest_port = 0; /* ignored */
s4_rsp.dest_addr.s_addr = INADDR_ANY; /* ignored */
buffer_append(&c->output, (char *)&s4_rsp, sizeof(s4_rsp));
return 1;
}
/* dynamic port forwarding */
void
channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset)
{
u_char *p;
int have, ret;
have = buffer_len(&c->input);
debug2("channel %d: pre_dynamic: have %d", c->self, have);
/* buffer_dump(&c->input); */
/* check if the fixed size part of the packet is in buffer. */
if (have < 4) {
/* need more */
FD_SET(c->sock, readset);
return;
}
/* try to guess the protocol */
p = buffer_ptr(&c->input);
switch (p[0]) {
case 0x04:
ret = channel_decode_socks4(c, readset, writeset);
break;
default:
ret = -1;
break;
}
if (ret < 0) {
chan_mark_dead(c);
} else if (ret == 0) {
debug2("channel %d: pre_dynamic: need more", c->self);
/* need more */
FD_SET(c->sock, readset);
} else {
/* switch to the next state */
c->type = SSH_CHANNEL_OPENING;
port_open_helper(c, "direct-tcpip");
}
}
/* This is our fake X11 server socket. */
void
channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset)
{
Channel *nc;
struct sockaddr addr;
int newsock;
socklen_t addrlen;
char buf[16384], *remote_ipaddr;
int remote_port;
if (FD_ISSET(c->sock, readset)) {
debug("X11 connection requested.");
addrlen = sizeof(addr);
newsock = accept(c->sock, &addr, &addrlen);
if (newsock < 0) {
error("accept: %.100s", strerror(errno));
return;
}
remote_ipaddr = get_peer_ipaddr(newsock);
remote_port = get_peer_port(newsock);
snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",
remote_ipaddr, remote_port);
nc = channel_new("accepted x11 socket",
SSH_CHANNEL_OPENING, newsock, newsock, -1,
c->local_window_max, c->local_maxpacket,
0, xstrdup(buf), 1);
if (nc == NULL) {
close(newsock);
xfree(remote_ipaddr);
return;
}
if (compat20) {
packet_start(SSH2_MSG_CHANNEL_OPEN);
packet_put_cstring("x11");
packet_put_int(nc->self);
packet_put_int(c->local_window_max);
packet_put_int(c->local_maxpacket);
/* originator ipaddr and port */
packet_put_cstring(remote_ipaddr);
if (datafellows & SSH_BUG_X11FWD) {
debug("ssh2 x11 bug compat mode");
} else {
packet_put_int(remote_port);
}
packet_send();
} else {
packet_start(SSH_SMSG_X11_OPEN);
packet_put_int(nc->self);
if (packet_get_protocol_flags() &
SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
packet_put_string(buf, strlen(buf));
packet_send();
}
xfree(remote_ipaddr);
}
}
void
port_open_helper(Channel *c, char *rtype)
{
int direct;
char buf[1024];
char *remote_ipaddr = get_peer_ipaddr(c->sock);
u_short remote_port = get_peer_port(c->sock);
direct = (strcmp(rtype, "direct-tcpip") == 0);
snprintf(buf, sizeof buf,
"%s: listening port %d for %.100s port %d, "
"connect from %.200s port %d",
rtype, c->listening_port, c->path, c->host_port,
remote_ipaddr, remote_port);
xfree(c->remote_name);
c->remote_name = xstrdup(buf);
if (compat20) {
packet_start(SSH2_MSG_CHANNEL_OPEN);
packet_put_cstring(rtype);
packet_put_int(c->self);
packet_put_int(c->local_window_max);
packet_put_int(c->local_maxpacket);
if (direct) {
/* target host, port */
packet_put_cstring(c->path);
packet_put_int(c->host_port);
} else {
/* listen address, port */
packet_put_cstring(c->path);
packet_put_int(c->listening_port);
}
/* originator host and port */
packet_put_cstring(remote_ipaddr);
packet_put_int(remote_port);
packet_send();
} else {
packet_start(SSH_MSG_PORT_OPEN);
packet_put_int(c->self);
packet_put_cstring(c->path);
packet_put_int(c->host_port);
if (packet_get_protocol_flags() &
SSH_PROTOFLAG_HOST_IN_FWD_OPEN)
packet_put_cstring(c->remote_name);
packet_send();
}
xfree(remote_ipaddr);
}
/*
* This socket is listening for connections to a forwarded TCP/IP port.
*/
void
channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset)
{
Channel *nc;
struct sockaddr addr;
int newsock, nextstate;
socklen_t addrlen;
char *rtype;
if (FD_ISSET(c->sock, readset)) {
debug("Connection to port %d forwarding "
"to %.100s port %d requested.",
c->listening_port, c->path, c->host_port);
rtype = (c->type == SSH_CHANNEL_RPORT_LISTENER) ?
"forwarded-tcpip" : "direct-tcpip";
nextstate = (c->host_port == 0 &&
c->type != SSH_CHANNEL_RPORT_LISTENER) ?
SSH_CHANNEL_DYNAMIC : SSH_CHANNEL_OPENING;
addrlen = sizeof(addr);
newsock = accept(c->sock, &addr, &addrlen);
if (newsock < 0) {
error("accept: %.100s", strerror(errno));
return;
}
nc = channel_new(rtype,
nextstate, newsock, newsock, -1,
c->local_window_max, c->local_maxpacket,
0, xstrdup(rtype), 1);
if (nc == NULL) {
error("channel_post_port_listener: no new channel:");
close(newsock);
return;
}
nc->listening_port = c->listening_port;
nc->host_port = c->host_port;
strlcpy(nc->path, c->path, sizeof(nc->path));
if (nextstate != SSH_CHANNEL_DYNAMIC)
port_open_helper(nc, rtype);
}
}
/*
* This is the authentication agent socket listening for connections from
* clients.
*/
void
channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset)
{
Channel *nc;
char *name;
int newsock;
struct sockaddr addr;
socklen_t addrlen;
if (FD_ISSET(c->sock, readset)) {
addrlen = sizeof(addr);
newsock = accept(c->sock, &addr, &addrlen);
if (newsock < 0) {
error("accept from auth socket: %.100s", strerror(errno));
return;
}
name = xstrdup("accepted auth socket");
nc = channel_new("accepted auth socket",
SSH_CHANNEL_OPENING, newsock, newsock, -1,
c->local_window_max, c->local_maxpacket,
0, name, 1);
if (nc == NULL) {
error("channel_post_auth_listener: channel_new failed");
xfree(name);
close(newsock);
}
if (compat20) {
packet_start(SSH2_MSG_CHANNEL_OPEN);
packet_put_cstring("auth-agent@openssh.com");
packet_put_int(nc->self);
packet_put_int(c->local_window_max);
packet_put_int(c->local_maxpacket);
} else {
packet_start(SSH_SMSG_AGENT_OPEN);
packet_put_int(nc->self);
}
packet_send();
}
}
void
channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset)
{
int err = 0;
int sz = sizeof(err);
if (FD_ISSET(c->sock, writeset)) {
if (getsockopt(c->sock, SOL_SOCKET, SO_ERROR, (char *)&err,
&sz) < 0) {
err = errno;
error("getsockopt SO_ERROR failed");
}
if (err == 0) {
debug("channel %d: connected", c->self);
c->type = SSH_CHANNEL_OPEN;
if (compat20) {
packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
packet_put_int(c->remote_id);
packet_put_int(c->self);
packet_put_int(c->local_window);
packet_put_int(c->local_maxpacket);
} else {
packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);
packet_put_int(c->remote_id);
packet_put_int(c->self);
}
} else {
debug("channel %d: not connected: %s",
c->self, strerror(err));
if (compat20) {
packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
packet_put_int(c->remote_id);
packet_put_int(SSH2_OPEN_CONNECT_FAILED);
if (!(datafellows & SSH_BUG_OPENFAILURE)) {
packet_put_cstring(strerror(err));
packet_put_cstring("");
}
} else {
packet_start(SSH_MSG_CHANNEL_OPEN_FAILURE);
packet_put_int(c->remote_id);
}
chan_mark_dead(c);
}
packet_send();
}
}
int
channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
{
char buf[16*1024];
int len;
if (c->rfd != -1 &&
FD_ISSET(c->rfd, readset)) {
len = read(c->rfd, buf, sizeof(buf));
if (len < 0 && (errno == EINTR || errno == EAGAIN))
return 1;
if (len <= 0) {
debug("channel %d: read<=0 rfd %d len %d",
c->self, c->rfd, len);
if (c->type != SSH_CHANNEL_OPEN) {
debug("channel %d: not open", c->self);
chan_mark_dead(c);
return -1;
} else if (compat13) {
buffer_consume(&c->output, buffer_len(&c->output));
c->type = SSH_CHANNEL_INPUT_DRAINING;
debug("channel %d: input draining.", c->self);
} else {
chan_read_failed(c);
}
return -1;
}
if(c->input_filter != NULL) {
if (c->input_filter(c, buf, len) == -1) {
debug("channel %d: filter stops", c->self);
chan_read_failed(c);
}
} else {
buffer_append(&c->input, buf, len);
}
}
return 1;
}
int
channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
{
struct termios tio;
int len;
/* Send buffered output data to the socket. */
if (c->wfd != -1 &&
FD_ISSET(c->wfd, writeset) &&
buffer_len(&c->output) > 0) {
len = write(c->wfd, buffer_ptr(&c->output),
buffer_len(&c->output));
if (len < 0 && (errno == EINTR || errno == EAGAIN))
return 1;
if (len <= 0) {
if (c->type != SSH_CHANNEL_OPEN) {
debug("channel %d: not open", c->self);
chan_mark_dead(c);
return -1;
} else if (compat13) {
buffer_consume(&c->output, buffer_len(&c->output));
debug("channel %d: input draining.", c->self);
c->type = SSH_CHANNEL_INPUT_DRAINING;
} else {
chan_write_failed(c);
}
return -1;
}
if (compat20 && c->isatty) {
if (tcgetattr(c->wfd, &tio) == 0 &&
!(tio.c_lflag & ECHO) && (tio.c_lflag & ICANON)) {
/*
* Simulate echo to reduce the impact of
* traffic analysis. We need to match the
* size of a SSH2_MSG_CHANNEL_DATA message
* (4 byte channel id + data)
*/
packet_send_ignore(4 + len);
packet_send();
}
}
buffer_consume(&c->output, len);
if (compat20 && len > 0) {
c->local_consumed += len;
}
}
return 1;
}
int
channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset)
{
char buf[16*1024];
int len;
/** XXX handle drain efd, too */
if (c->efd != -1) {
if (c->extended_usage == CHAN_EXTENDED_WRITE &&
FD_ISSET(c->efd, writeset) &&
buffer_len(&c->extended) > 0) {
len = write(c->efd, buffer_ptr(&c->extended),
buffer_len(&c->extended));
debug2("channel %d: written %d to efd %d",
c->self, len, c->efd);
if (len < 0 && (errno == EINTR || errno == EAGAIN))
return 1;
if (len <= 0) {
debug2("channel %d: closing write-efd %d",
c->self, c->efd);
close(c->efd);
c->efd = -1;
} else {
buffer_consume(&c->extended, len);
c->local_consumed += len;
}
} else if (c->extended_usage == CHAN_EXTENDED_READ &&
FD_ISSET(c->efd, readset)) {
len = read(c->efd, buf, sizeof(buf));
debug2("channel %d: read %d from efd %d",
c->self, len, c->efd);
if (len < 0 && (errno == EINTR || errno == EAGAIN))
return 1;
if (len <= 0) {
debug2("channel %d: closing read-efd %d",
c->self, c->efd);
close(c->efd);
c->efd = -1;
} else {
buffer_append(&c->extended, buf, len);
}
}
}
return 1;
}
int
channel_check_window(Channel *c)
{
if (c->type == SSH_CHANNEL_OPEN &&
!(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&
c->local_window < c->local_window_max/2 &&
c->local_consumed > 0) {
packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
packet_put_int(c->remote_id);
packet_put_int(c->local_consumed);
packet_send();
debug2("channel %d: window %d sent adjust %d",
c->self, c->local_window,
c->local_consumed);
c->local_window += c->local_consumed;
c->local_consumed = 0;
}
return 1;
}
void
channel_post_open_1(Channel *c, fd_set * readset, fd_set * writeset)
{
channel_handle_rfd(c, readset, writeset);
channel_handle_wfd(c, readset, writeset);
}
void
channel_post_open_2(Channel *c, fd_set * readset, fd_set * writeset)
{
channel_handle_rfd(c, readset, writeset);
channel_handle_wfd(c, readset, writeset);
channel_handle_efd(c, readset, writeset);
channel_check_window(c);
}
void
channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset)
{
int len;
/* Send buffered output data to the socket. */
if (FD_ISSET(c->sock, writeset) && buffer_len(&c->output) > 0) {
len = write(c->sock, buffer_ptr(&c->output),
buffer_len(&c->output));
if (len <= 0)
buffer_consume(&c->output, buffer_len(&c->output));
else
buffer_consume(&c->output, len);
}
}
void
channel_handler_init_20(void)
{
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_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
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;
channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_2;
}
void
channel_handler_init_13(void)
{
channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_13;
channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open_13;
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_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_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
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;
channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_1;
}
void
channel_handler_init_15(void)
{
channel_pre[SSH_CHANNEL_OPEN] = &channel_pre_open_15;
channel_pre[SSH_CHANNEL_X11_OPEN] = &channel_pre_x11_open;
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_pre[SSH_CHANNEL_DYNAMIC] = &channel_pre_dynamic;
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;
channel_post[SSH_CHANNEL_DYNAMIC] = &channel_post_open_1;
}
void
channel_handler_init(void)
{
int i;
for(i = 0; i < SSH_CHANNEL_MAX_TYPE; i++) {
channel_pre[i] = NULL;
channel_post[i] = NULL;
}
if (compat20)
channel_handler_init_20();
else if (compat13)
channel_handler_init_13();
else
channel_handler_init_15();
}
void
channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)
{
static int did_init = 0;
int i;
Channel *c;
if (!did_init) {
channel_handler_init();
did_init = 1;
}
for (i = 0; i < channels_alloc; i++) {
c = channels[i];
if (c == NULL)
continue;
if (ftab[c->type] != NULL)
(*ftab[c->type])(c, readset, writeset);
if (chan_is_dead(c)) {
/*
* we have to remove the fd's from the select mask
* before the channels are free'd and the fd's are
* closed
*/
if (c->wfd != -1)
FD_CLR(c->wfd, writeset);
if (c->rfd != -1)
FD_CLR(c->rfd, readset);
if (c->efd != -1) {
if (c->extended_usage == CHAN_EXTENDED_READ)
FD_CLR(c->efd, readset);
if (c->extended_usage == CHAN_EXTENDED_WRITE)
FD_CLR(c->efd, writeset);
}
channel_free(c);
}
}
}
/*
* Allocate/update select bitmasks and add any bits relevant to channels in
* select bitmasks.
*/
void
channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
int rekeying)
{
int n;
u_int sz;
n = MAX(*maxfdp, channel_max_fd);
sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
if (*readsetp == NULL || n > *maxfdp) {
if (*readsetp)
xfree(*readsetp);
if (*writesetp)
xfree(*writesetp);
*readsetp = xmalloc(sz);
*writesetp = xmalloc(sz);
*maxfdp = n;
}
memset(*readsetp, 0, sz);
memset(*writesetp, 0, sz);
if (!rekeying)
channel_handler(channel_pre, *readsetp, *writesetp);
}
/*
* After select, perform any appropriate operations for channels which have
* events pending.
*/
void
channel_after_select(fd_set * readset, fd_set * writeset)
{
channel_handler(channel_post, readset, writeset);
}
/* If there is data to send to the connection, enqueue some of it now. */
void
channel_output_poll()
{
int len, i;
Channel *c;
for (i = 0; i < channels_alloc; i++) {
c = channels[i];
if (c == NULL)
continue;
/*
* We are only interested in channels that can have buffered
* incoming data.
*/
if (compat13) {
if (c->type != SSH_CHANNEL_OPEN &&
c->type != SSH_CHANNEL_INPUT_DRAINING)
continue;
} else {
if (c->type != SSH_CHANNEL_OPEN)
continue;
}
if (compat20 &&
(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {
/* XXX is this true? */
debug2("channel %d: no data after CLOSE", c->self);
continue;
}
/* Get the amount of buffered data for this channel. */
if ((c->istate == CHAN_INPUT_OPEN ||
c->istate == CHAN_INPUT_WAIT_DRAIN) &&
(len = buffer_len(&c->input)) > 0) {
/*
* Send some data for the other side over the secure
* connection.
*/
if (compat20) {
if (len > c->remote_window)
len = c->remote_window;
if (len > c->remote_maxpacket)
len = c->remote_maxpacket;
} else {
if (packet_is_interactive()) {
if (len > 1024)
len = 512;
} else {
/* Keep the packets at reasonable size. */
if (len > packet_get_maxsize()/2)
len = packet_get_maxsize()/2;
}
}
if (len > 0) {
packet_start(compat20 ?
SSH2_MSG_CHANNEL_DATA : SSH_MSG_CHANNEL_DATA);
packet_put_int(c->remote_id);
packet_put_string(buffer_ptr(&c->input), len);
packet_send();
buffer_consume(&c->input, len);
c->remote_window -= len;
}
} else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {
if (compat13)
fatal("cannot happen: istate == INPUT_WAIT_DRAIN for proto 1.3");
/*
* input-buffer is empty and read-socket shutdown:
* tell peer, that we will not send more data: send IEOF
*/
chan_ibuf_empty(c);
}
/* Send extended data, i.e. stderr */
if (compat20 &&
c->remote_window > 0 &&
(len = buffer_len(&c->extended)) > 0 &&
c->extended_usage == CHAN_EXTENDED_READ) {
debug2("channel %d: rwin %d elen %d euse %d",
c->self, c->remote_window, buffer_len(&c->extended),
c->extended_usage);
if (len > c->remote_window)
len = c->remote_window;
if (len > c->remote_maxpacket)
len = c->remote_maxpacket;
packet_start(SSH2_MSG_CHANNEL_EXTENDED_DATA);
packet_put_int(c->remote_id);
packet_put_int(SSH2_EXTENDED_DATA_STDERR);
packet_put_string(buffer_ptr(&c->extended), len);
packet_send();
buffer_consume(&c->extended, len);
c->remote_window -= len;
debug2("channel %d: sent ext data %d", c->self, len);
}
}
}
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