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Diff for /src/usr.bin/ssh/channels.c between version 1.57.2.5 and 1.58

version 1.57.2.5, 2001/03/21 18:52:38

version 1.58, 2000/05/17 08:20:15

Line 1

* channels.c

* Author: Tatu Ylonen <ylo@cs.hut.fi>

* Created: Fri Mar 24 16:35:24 1995 ylo

* This file contains functions for generic socket connection forwarding.

* There is also code for initiating connection forwarding for X11 connections,

* arbitrary tcp/ip connections, and the authentication agent connection.

* 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".

* SSH2 support added by Markus Friedl.

* 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("$OpenBSD$");

RCSID("$Id$");

#include <openssl/rsa.h>

#include <openssl/dsa.h>

#include "ssh.h"

#include "ssh1.h"

#include "ssh2.h"

#include "packet.h"

#include "xmalloc.h"

#include "buffer.h"

#include "authfd.h"

#include "uidswap.h"

#include "log.h"

#include "readconf.h"

#include "misc.h"

#include "servconf.h"

#include "channels.h"

#include "nchan.h"

#include "compat.h"

#include "canohost.h"

#include "key.h"

#include "authfd.h"

#include "ssh2.h"

/* Maximum number of fake X11 displays to try. */

#define MAX_DISPLAYS 1000

/* Max len of agent socket */

#define MAX_SOCKET_NAME 100

/* default window/packet sizes for tcp/x11-fwd-channel */

#define CHAN_TCP_WINDOW_DEFAULT (8*1024)

#define CHAN_TCP_PACKET_DEFAULT (CHAN_TCP_WINDOW_DEFAULT/2)

#define CHAN_X11_WINDOW_DEFAULT (4*1024)

#define CHAN_X11_PACKET_DEFAULT (CHAN_X11_WINDOW_DEFAULT/2)

* Pointer to an array containing all allocated channels. The array is

* dynamically extended as needed.

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* Maximum file descriptor value used in any of the channels. This is

* updated in channel_allocate.

static int channel_max_fd = 0;

static int channel_max_fd_value = 0;

/* Name and directory of socket for authentication agent forwarding. */

static char *channel_forwarded_auth_socket_name = NULL;

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/* Saved X11 authentication data. This is the real data. */

char *x11_saved_data = NULL;

u_int x11_saved_data_len = 0;

unsigned int x11_saved_data_len = 0;

* Fake X11 authentication data. This is what the server will be sending us;

* we should replace any occurrences of this by the real data.

char *x11_fake_data = NULL;

u_int x11_fake_data_len;

unsigned int x11_fake_data_len;

* Data structure for storing which hosts are permitted for forward requests.

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/* This is set to true if both sides support SSH_PROTOFLAG_HOST_IN_FWD_OPEN. */

static int have_hostname_in_open = 0;

/* AF_UNSPEC or AF_INET or AF_INET6 */

extern int IPv4or6;

/* Sets specific protocol options. */

void

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have_hostname_in_open = hostname_in_open;

}

* Permits opening to any host/port in SSH_MSG_PORT_OPEN. This is usually

* called by the server, because the user could connect to any port anyway,

* and the server has no way to know but to trust the client anyway.

void

channel_permit_all_opens()

{

all_opens_permitted = 1;

}

/* lookup channel by id */

Channel *

channel_lookup(int id)

{

Channel *c;

if (id < 0 || id > channels_alloc) {

if (id < 0 && id > channels_alloc) {

log("channel_lookup: %d: bad id", id);

return NULL;

}

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void

channel_register_fds(Channel *c, int rfd, int wfd, int efd,

channel_register_fds(Channel *c, int rfd, int wfd, int efd, int extusage)

int extusage, int nonblock)

{

/* Update the maximum file descriptor value. */

channel_max_fd = MAX(channel_max_fd, rfd);

if (rfd > channel_max_fd_value)

channel_max_fd = MAX(channel_max_fd, wfd);

channel_max_fd_value = rfd;

channel_max_fd = MAX(channel_max_fd, efd);

if (wfd > channel_max_fd_value)

channel_max_fd_value = wfd;

if (efd > channel_max_fd_value)

channel_max_fd_value = efd;

/* XXX set close-on-exec -markus */

c->rfd = rfd;

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c->sock = (rfd == wfd) ? rfd : -1;

c->efd = efd;

c->extended_usage = extusage;

if (rfd != -1)

/* XXX ugly hack: nonblock is only set by the server */

set_nonblock(rfd);

if (nonblock && isatty(c->rfd)) {

if (wfd != -1)

debug("channel %d: rfd %d isatty", c->self, c->rfd);

set_nonblock(wfd);

c->isatty = 1;

if (efd != -1)

if (!isatty(c->wfd)) {

set_nonblock(efd);

error("channel %d: wfd %d is not a tty?",

c->self, c->wfd);

}

} else {

c->isatty = 0;

}

/* enable nonblocking mode */

if (nonblock) {

if (rfd != -1)

set_nonblock(rfd);

if (wfd != -1)

set_nonblock(wfd);

if (efd != -1)

set_nonblock(efd);

}

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int

channel_new(char *ctype, int type, int rfd, int wfd, int efd,

int window, int maxpack, int extusage, char *remote_name, int nonblock)

int window, int maxpack, int extusage, char *remote_name)

{

int i, found;

Channel *c;

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/* There are no free slots. Take last+1 slot and expand the array. */

found = channels_alloc;

channels_alloc += 10;

debug2("channel: expanding %d", channels_alloc);

debug("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;

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buffer_init(&c->output);

buffer_init(&c->extended);

chan_init_iostates(c);

channel_register_fds(c, rfd, wfd, efd, extusage, nonblock);

channel_register_fds(c, rfd, wfd, efd, extusage);

c->self = found;

c->type = type;

c->ctype = ctype;

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c->cb_arg = NULL;

c->cb_event = 0;

c->dettach_user = NULL;

c->input_filter = NULL;

debug("channel %d: new [%s]", found, remote_name);

return found;

}

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int

channel_allocate(int type, int sock, char *remote_name)

{

return channel_new("", type, sock, sock, -1, 0, 0, 0, remote_name, 1);

return channel_new("", type, sock, sock, -1, 0, 0, 0, remote_name);

}

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channel_free(int id)

{

Channel *c = channel_lookup(id);

char *s = channel_open_message();

if (c == NULL)

packet_disconnect("channel free: bad local channel %d", id);

debug("channel_free: channel %d: status: %s", id, s);

debug("channel_free: channel %d: status: %s", id, channel_open_message());

xfree(s);

if (c->dettach_user != NULL) {

debug("channel_free: channel %d: dettaching channel user", id);

c->dettach_user(c->self, NULL);

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}

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())

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int

x11_open_helper(Channel *c)

{

u_char *ucp;

unsigned char *ucp;

u_int proto_len, data_len;

unsigned int proto_len, data_len;

/* Check if the fixed size part of the packet is in buffer. */

if (buffer_len(&c->output) < 12)

return 0;

/* Parse the lengths of variable-length fields. */

ucp = (u_char *) buffer_ptr(&c->output);

ucp = (unsigned char *) buffer_ptr(&c->output);

if (ucp[0] == 0x42) { /* Byte order MSB first. */

proto_len = 256 * ucp[6] + ucp[7];

data_len = 256 * ucp[8] + ucp[9];

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* We have received an X11 connection that has bad

* authentication information.

log("X11 connection rejected because of wrong authentication.");

log("X11 connection rejected because of wrong authentication.\r\n");

buffer_clear(&c->input);

buffer_clear(&c->output);

close(c->sock);

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struct sockaddr addr;

int newsock, newch;

socklen_t addrlen;

char buf[16384], *remote_ipaddr;

char buf[16384], *remote_hostname;

int remote_port;

if (FD_ISSET(c->sock, readset)) {

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error("accept: %.100s", strerror(errno));

return;

}

remote_ipaddr = get_peer_ipaddr(newsock);

remote_hostname = get_remote_hostname(newsock);

remote_port = get_peer_port(newsock);

snprintf(buf, sizeof buf, "X11 connection from %.200s port %d",

remote_ipaddr, remote_port);

remote_hostname, remote_port);

newch = channel_new("x11",

SSH_CHANNEL_OPENING, newsock, newsock, -1,

c->local_window_max, c->local_maxpacket,

0, xstrdup(buf), 1);

0, xstrdup(buf));

if (compat20) {

packet_start(SSH2_MSG_CHANNEL_OPEN);

packet_put_cstring("x11");

packet_put_int(newch);

packet_put_int(c->local_window_max);

packet_put_int(c->local_maxpacket);

/* originator ipaddr and port */

/* originator host and port */

packet_put_cstring(remote_ipaddr);

packet_put_cstring(remote_hostname);

if (datafellows & SSH_BUG_X11FWD) {

debug("ssh2 x11 bug compat mode");

} else {

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packet_put_string(buf, strlen(buf));

packet_send();

}

xfree(remote_ipaddr);

xfree(remote_hostname);

}

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struct sockaddr addr;

int newsock, newch;

socklen_t addrlen;

char buf[1024], *remote_ipaddr, *rtype;

char buf[1024], *remote_hostname;

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.",

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error("accept: %.100s", strerror(errno));

return;

}

remote_ipaddr = get_peer_ipaddr(newsock);

remote_hostname = get_remote_hostname(newsock);

remote_port = get_peer_port(newsock);

snprintf(buf, sizeof buf,

"listen port %d for %.100s port %d, "

"connect from %.200s port %d",

c->listening_port, c->path, c->host_port,

remote_ipaddr, remote_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), 1);

0, xstrdup(buf));

if (compat20) {

packet_start(SSH2_MSG_CHANNEL_OPEN);

packet_put_cstring(rtype);

packet_put_cstring("direct-tcpip");

packet_put_int(newch);

packet_put_int(c->local_window_max);

packet_put_int(c->local_maxpacket);

if (c->type == SSH_CHANNEL_RPORT_LISTENER) {

/* target host and port */

/* listen address, port */

packet_put_string(c->path, strlen(c->path));

packet_put_int(c->host_port);

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_ipaddr);

packet_put_cstring(remote_hostname);

packet_put_int(remote_port);

packet_send();

} else {

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}

packet_send();

}

xfree(remote_ipaddr);

xfree(remote_hostname);

}

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error("accept from auth socket: %.100s", strerror(errno));

return;

}

newch = channel_new("accepted auth socket",

newch = channel_allocate(SSH_CHANNEL_OPENING, newsock,

SSH_CHANNEL_OPENING, newsock, newsock, -1,

xstrdup("accepted auth socket"));

c->local_window_max, c->local_maxpacket,

packet_start(SSH_SMSG_AGENT_OPEN);

0, xstrdup("accepted auth socket"), 1);

packet_put_int(newch);

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)

{

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}

return -1;

}

if(c->input_filter != NULL) {

buffer_append(&c->input, buf, len);

if (c->input_filter(c, buf, len) == -1) {

debug("filter stops channel %d", 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. */

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}

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;

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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",

debug("channel %d: written %d to efd %d",

c->self, len, c->efd);

if (len < 0 && (errno == EINTR || errno == EAGAIN))

if (len > 0) {

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",

debug("channel %d: read %d from efd %d",

c->self, len, c->efd);

if (len < 0 && (errno == EINTR || errno == EAGAIN))

if (len == 0) {

return 1;

debug("channel %d: closing efd %d",

if (len <= 0) {

debug2("channel %d: closing read-efd %d",

c->self, c->efd);

close(c->efd);

c->efd = -1;

} else {

} else if (len > 0)

buffer_append(&c->extended, buf, len);

}

return 1;

}

int

channel_check_window(Channel *c)

channel_check_window(Channel *c, fd_set * readset, fd_set * writeset)

{

if (!(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD)) &&

c->local_window < c->local_window_max/2 &&

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packet_put_int(c->remote_id);

packet_put_int(c->local_consumed);

packet_send();

debug2("channel %d: window %d sent adjust %d",

debug("channel %d: window %d sent adjust %d",

c->self, c->local_window,

c->local_consumed);

c->local_window += c->local_consumed;

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channel_handle_rfd(c, readset, writeset);

channel_handle_wfd(c, readset, writeset);

channel_handle_efd(c, readset, writeset);

channel_check_window(c, readset, writeset);

channel_check_window(c);

}

void

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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

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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

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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

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if (ftab[c->type] == NULL)

continue;

(*ftab[c->type])(c, readset, writeset);

if (chan_is_dead(c)) {

chan_delete_if_full_closed(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->self);

}

void

channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp)

channel_prepare_select(fd_set * readset, fd_set * writeset)

{

int n;

channel_handler(channel_pre, readset, writeset);

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);

channel_handler(channel_pre, *readsetp, *writesetp);

}

void

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channel_handler(channel_post, readset, writeset);

}

/* If there is data to send to the connection, enqueue some of it now. */

/* If there is data to send to the connection, send some of it now. */

void

channel_output_poll()

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} else {

if (c->type != SSH_CHANNEL_OPEN)

continue;

if (c->istate != CHAN_INPUT_OPEN &&

c->istate != CHAN_INPUT_WAIT_DRAIN)

continue;

}

if (compat20 &&

(c->flags & (CHAN_CLOSE_SENT|CHAN_CLOSE_RCVD))) {

/* XXX is this true? */

debug("channel: %d: no data after CLOSE", c->self);

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 ||

len = buffer_len(&c->input);

c->istate == CHAN_INPUT_WAIT_DRAIN) &&

if (len > 0) {

(len = buffer_len(&c->input)) > 0) {

/* Send some data for the other side over the secure connection. */

if (compat20) {

if (len > c->remote_window)

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packet_send();

buffer_consume(&c->input, len);

c->remote_window -= len;

debug("channel %d: send data len %d", c->self, len);

}

} else if (c->istate == CHAN_INPUT_WAIT_DRAIN) {

if (compat13)

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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)

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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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void

channel_input_data(int type, int plen, void *ctxt)

channel_input_data(int type, int plen)

{

int id;

char *data;

u_int data_len;

unsigned int data_len;

Channel *c;

/* Get the channel number and verify it. */

Line 1175

Line 1015

xfree(data);

}

void

channel_input_extended_data(int type, int plen, void *ctxt)

channel_input_extended_data(int type, int plen)

{

int id;

int tcode;

char *data;

u_int data_len;

unsigned int data_len;

Channel *c;

/* Get the channel number and verify it. */

Line 1208

Line 1048

xfree(data);

return;

}

debug2("channel %d: rcvd ext data %d", c->self, data_len);

debug("channel %d: rcvd ext data %d", c->self, data_len);

c->local_window -= data_len;

buffer_append(&c->extended, data, data_len);

xfree(data);

Line 1223

Line 1063

int

channel_not_very_much_buffered_data()

{

u_int i;

unsigned int i;

Channel *c;

for (i = 0; i < channels_alloc; i++) {

Line 1245

Line 1085

}

void

channel_input_ieof(int type, int plen, void *ctxt)

channel_input_ieof(int type, int plen)

{

int id;

Channel *c;

Line 1260

Line 1100

}

void

channel_input_close(int type, int plen, void *ctxt)

channel_input_close(int type, int plen)

{

int id;

Channel *c;

Line 1299

Line 1139

/* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */

void

channel_input_oclose(int type, int plen, void *ctxt)

channel_input_oclose(int type, int plen)

{

int id = packet_get_int();

Channel *c = channel_lookup(id);

Line 1310

Line 1150

}

void

channel_input_close_confirmation(int type, int plen, void *ctxt)

channel_input_close_confirmation(int type, int plen)

{

int id = packet_get_int();

Channel *c = channel_lookup(id);

Line 1326

Line 1166

}

void

channel_input_open_confirmation(int type, int plen, void *ctxt)

channel_input_open_confirmation(int type, int plen)

{

int id, remote_id;

Channel *c;

Line 1350

Line 1190

c->remote_maxpacket = packet_get_int();

packet_done();

if (c->cb_fn != NULL && c->cb_event == type) {

debug2("callback start");

debug("callback start");

c->cb_fn(c->self, c->cb_arg);

debug2("callback done");

debug("callback done");

}

debug("channel %d: open confirm rwindow %d rmax %d", c->self,

c->remote_window, c->remote_maxpacket);

Line 1360

Line 1200

}

void

channel_input_open_failure(int type, int plen, void *ctxt)

channel_input_open_failure(int type, int plen)

{

int id, reason;

int id;

char *msg = NULL, *lang = NULL;

Channel *c;

if (!compat20)

Line 1376

Line 1215

packet_disconnect("Received open failure for "

"non-opening channel %d.", id);

if (compat20) {

reason = packet_get_int();

int reason = packet_get_int();

if (packet_remaining() > 0) {

char *msg = packet_get_string(NULL);

msg = packet_get_string(NULL);

char *lang = packet_get_string(NULL);

lang = packet_get_string(NULL);

log("channel_open_failure: %d: reason %d: %s", id, reason, msg);

}

packet_done();

log("channel_open_failure: %d: reason %d %s", id,

xfree(msg);

reason, msg ? msg : "<no additional info>");

xfree(lang);

if (msg != NULL)

xfree(msg);

if (lang != NULL)

xfree(lang);

}

/* Free the channel. This will also close the socket. */

channel_free(id);

}

void

channel_input_channel_request(int type, int plen, void *ctxt)

channel_input_channel_request(int type, int plen)

{

int id;

Channel *c;

Line 1407

Line 1241

packet_disconnect("Received request for "

"non-open channel %d.", id);

if (c->cb_fn != NULL && c->cb_event == type) {

debug2("callback start");

debug("callback start");

c->cb_fn(c->self, c->cb_arg);

debug2("callback done");

debug("callback done");

} else {

char *service = packet_get_string(NULL);

debug("channel %d: rcvd request for %s", c->self, service);

debug("channel: %d rcvd request for %s", c->self, service);

debug("cb_fn %p cb_event %d", c->cb_fn , c->cb_event);

xfree(service);

}

void

channel_input_window_adjust(int type, int plen, void *ctxt)

channel_input_window_adjust(int type, int plen)

{

Channel *c;

int id, adjust;

Line 1438

Line 1272

}

adjust = packet_get_int();

packet_done();

debug2("channel %d: rcvd adjust %d", id, adjust);

debug("channel %d: rcvd adjust %d", id, adjust);

c->remote_window += adjust;

}

Line 1455

Line 1289

switch (channels[i].type) {

case SSH_CHANNEL_AUTH_SOCKET:

close(channels[i].sock);

unlink(channels[i].path);

remove(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);

Line 1484

Line 1317

channel_close_fds(&channels[i]);

}

/* Returns the maximum file descriptor number used by the channels. */

int

channel_max_fd()

{

return channel_max_fd_value;

}

/* Returns true if any channel is still open. */

int

channel_still_open()

{

u_int i;

unsigned int i;

for (i = 0; i < channels_alloc; i++)

switch (channels[i].type) {

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)

Line 1542

Line 1381

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:

Line 1576

Line 1413

* Initiate forwarding of connections to local port "port" through the secure

* channel to host:port from remote side.

int

channel_request_local_forwarding(u_short listen_port, const char *host_to_connect,

u_short port_to_connect, int gateway_ports)

{

return channel_request_forwarding(

NULL, listen_port,

host_to_connect, port_to_connect,

gateway_ports, /*remote_fwd*/ 0);

}

void

* If 'remote_fwd' is true we have a '-R style' listener for protocol 2

channel_request_local_forwarding(u_short port, const char *host,

* (SSH_CHANNEL_RPORT_LISTENER).

u_short host_port, int gateway_ports)

int

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, ctype;

int success, ch, sock, on = 1;

struct addrinfo hints, *ai, *aitop;

char ntop[NI_MAXHOST], strport[NI_MAXSERV];

const char *host;

struct linger linger;

success = 0;

if (strlen(host) > sizeof(channels[0].path) - 1)

packet_disconnect("Forward host name too long.");

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) {

error("Forward host name too long.");

return success;

}

/* 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

Line 1626

Line 1434

hints.ai_family = IPv4or6;

hints.ai_flags = gateway_ports ? AI_PASSIVE : 0;

hints.ai_socktype = SOCK_STREAM;

snprintf(strport, sizeof strport, "%d", listen_port);

snprintf(strport, sizeof strport, "%d", port);

if (getaddrinfo(NULL, strport, &hints, &aitop) != 0)

packet_disconnect("getaddrinfo: fatal error");

success = 0;

for (ai = aitop; ai; ai = ai->ai_next) {

if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)

continue;

if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),

strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {

error("channel_request_forwarding: getnameinfo failed");

error("channel_request_local_forwarding: getnameinfo failed");

continue;

}

/* Create a port to listen for the host. */

Line 1669

Line 1478

continue;

}

/* Allocate a channel number for the socket. */

ch = channel_new("port listener", ctype, sock, sock, -1,

ch = channel_new(

"port listener", SSH_CHANNEL_PORT_LISTENER,

sock, sock, -1,

CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,

0, xstrdup("port listener"), 1);

0, xstrdup("port listener"));

strlcpy(channels[ch].path, host, sizeof(channels[ch].path));

channels[ch].host_port = port_to_connect;

channels[ch].host_port = host_port;

channels[ch].listening_port = listen_port;

channels[ch].listening_port = port;

success = 1;

}

if (success == 0)

error("channel_request_forwarding: cannot listen to port: %d",

packet_disconnect("cannot listen port: %d", port);

listen_port);

freeaddrinfo(aitop);

return success;

}

Line 1690

Line 1499

void

channel_request_remote_forwarding(u_short listen_port,

channel_request_remote_forwarding(u_short listen_port, const char *host_to_connect,

const char *host_to_connect, u_short port_to_connect)

u_short port_to_connect)

{

int payload_len, type, success = 0;

int payload_len;

/* 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";

Line 1707

Line 1520

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);

Line 1718

Line 1527

packet_put_int(port_to_connect);

packet_send();

packet_write_wait();

/* Wait for response from the remote side. */

* Wait for response from the remote side. It will send a disconnect

type = packet_read(&payload_len);

* message on failure, and we will never see it here.

switch (type) {

case SSH_SMSG_SUCCESS:

packet_read_expect(&payload_len, 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++;

}

Line 1766

Line 1559

if (port < IPPORT_RESERVED && !is_root)

packet_disconnect("Requested forwarding of port %d but user is not root.",

port);

/* Initiate forwarding */

* Initiate forwarding,

channel_request_local_forwarding(port, hostname, host_port, gateway_ports);

/* Free the argument string. */

xfree(hostname);

}

/* XXX move to aux.c */

* Permits opening to any host/port if permitted_opens[] is empty. This is

* usually called by the server, because the user could connect to any port

* anyway, and the server has no way to know but to trust the client anyway.

void

channel_permit_all_opens()

{

if (num_permitted_opens == 0)

all_opens_permitted = 1;

}

void

channel_add_permitted_opens(char *host, int port)

{

if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)

fatal("channel_request_remote_forwarding: too many forwards");

debug("allow port forwarding to host %s port %d", host, port);

permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);

permitted_opens[num_permitted_opens].port_to_connect = port;

num_permitted_opens++;

all_opens_permitted = 0;

}

void

channel_clear_permitted_opens(void)

{

int i;

for (i = 0; i < num_permitted_opens; i++)

xfree(permitted_opens[i].host_to_connect);

num_permitted_opens = 0;

}

/* return socket to remote host, port */

int

connect_to(const char *host, u_short port)

channel_connect_to(const char *host, u_short host_port)

{

struct addrinfo hints, *ai, *aitop;

char ntop[NI_MAXHOST], strport[NI_MAXSERV];

Line 1823

Line 1580

memset(&hints, 0, sizeof(hints));

hints.ai_family = IPv4or6;

hints.ai_socktype = SOCK_STREAM;

snprintf(strport, sizeof strport, "%d", port);

snprintf(strport, sizeof strport, "%d", host_port);

if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {

error("connect_to %.100s: unknown host (%s)", host,

error("%.100s: unknown host (%s)", host, gai_strerror(gaierr));

gai_strerror(gaierr));

return -1;

}

for (ai = aitop; ai; ai = ai->ai_next) {

Line 1834

Line 1590

continue;

if (getnameinfo(ai->ai_addr, ai->ai_addrlen, ntop, sizeof(ntop),

strport, sizeof(strport), NI_NUMERICHOST|NI_NUMERICSERV) != 0) {

error("connect_to: getnameinfo failed");

error("channel_connect_to: getnameinfo failed");

continue;

}

/* Create the socket. */

sock = socket(ai->ai_family, SOCK_STREAM, 0);

if (sock < 0) {

error("socket: %.100s", strerror(errno));

continue;

}

if (fcntl(sock, F_SETFL, O_NONBLOCK) < 0)

/* Connect to the host/port. */

fatal("connect_to: F_SETFL: %s", strerror(errno));

if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {

if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 &&

error("connect %.100s port %s: %.100s", ntop, strport,

errno != EINPROGRESS) {

error("connect_to %.100s port %s: %.100s", ntop, strport,

strerror(errno));

close(sock);

continue; /* fail -- try next */

}

break; /* success */

}

freeaddrinfo(aitop);

if (!ai) {

error("connect_to %.100s port %d: failed.", host, port);

error("connect %.100s port %d: failed.", host, host_port);

return -1;

}

/* 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 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;

}

/* Check if connecting to that port is permitted and connect. */

int

channel_connect_to(const char *host, u_short port)

{

int i, permit;

permit = all_opens_permitted;

if (!permit) {

for (i = 0; i < num_permitted_opens; i++)

if (permitted_opens[i].port_to_connect == port &&

strcmp(permitted_opens[i].host_to_connect, host) == 0)

permit = 1;

}

if (!permit) {

log("Received request to connect to host %.100s port %d, "

"but the request was denied.", host, port);

return -1;

}

return connect_to(host, port);

}

* This is called after receiving PORT_OPEN message. This attempts to

* connect to the given host:port, and sends back CHANNEL_OPEN_CONFIRMATION

Line 1907

Line 1624

void

channel_input_port_open(int type, int plen, void *ctxt)

channel_input_port_open(int type, int plen)

{

u_short host_port;

char *host, *originator_string;

int remote_channel, sock = -1, newch;

int remote_channel, sock = -1, newch, i, denied;

unsigned int host_len, originator_len;

/* Get remote channel number. */

remote_channel = packet_get_int();

host = packet_get_string(NULL);

/* Get host name to connect to. */

host = packet_get_string(&host_len);

/* Get port to connect to. */

host_port = packet_get_int();

/* Get remote originator name. */

if (have_hostname_in_open) {

originator_string = packet_get_string(NULL);

originator_string = packet_get_string(&originator_len);

originator_len += 4; /* size of packet_int */

} else {

originator_string = xstrdup("unknown (remote did not supply name)");

originator_len = 0; /* no originator supplied */

}

packet_done();

sock = channel_connect_to(host, host_port);

packet_integrity_check(plen,

if (sock != -1) {

4 + 4 + host_len + 4 + originator_len, SSH_MSG_PORT_OPEN);

newch = channel_allocate(SSH_CHANNEL_CONNECTING,

sock, originator_string);

/* Check if opening that port is permitted. */

denied = 0;

if (!all_opens_permitted) {

/* Go trough all permitted ports. */

for (i = 0; i < num_permitted_opens; i++)

if (permitted_opens[i].port_to_connect == host_port &&

strcmp(permitted_opens[i].host_to_connect, host) == 0)

break;

/* Check if we found the requested port among those permitted. */

if (i >= num_permitted_opens) {

/* The port is not permitted. */

log("Received request to connect to %.100s:%d, but the request was denied.",

host, host_port);

denied = 1;

}

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);

channels[newch].remote_id = remote_channel;

/*XXX delay answer? */

packet_start(SSH_MSG_CHANNEL_OPEN_CONFIRMATION);

packet_put_int(remote_channel);

packet_put_int(newch);

Line 1997

Line 1742

if (num_socks == NUM_SOCKS)

break;

}

freeaddrinfo(aitop);

if (num_socks > 0)

break;

}

Line 2028

Line 1772

(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"), 1);

0, xstrdup("X11 inet listener"));

}

/* Return a suitable value for the DISPLAY environment variable. */

Line 2041

Line 1785

static

int

connect_local_xsocket(u_int dnr)

connect_local_xsocket(unsigned int dnr)

{

static const char *const x_sockets[] = {

X_UNIX_PATH "%u",

Line 2170

Line 1914

void

x11_input_open(int type, int plen, void *ctxt)

x11_input_open(int type, int plen)

{

int remote_channel, sock = 0, newch;

char *remote_host;

u_int remote_len;

unsigned int remote_len;

/* Get remote channel number. */

remote_channel = packet_get_int();

Line 2214

Line 1958

}

/* 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.

Line 2245

Line 1967

x11_request_forwarding_with_spoofing(int client_session_id,

const char *proto, const char *data)

{

u_int data_len = (u_int) strlen(data) / 2;

unsigned int data_len = (unsigned int) strlen(data) / 2;

u_int i, value, len;

unsigned int i, value;

char *new_data;

int screen_number;

const char *cp;

Line 2284

Line 2006

x11_fake_data_len = data_len;

/* Convert the fake data into hex. */

len = 2 * data_len + 1;

new_data = xmalloc(2 * data_len + 1);

new_data = xmalloc(len);

for (i = 0; i < data_len; i++)

snprintf(new_data + 2 * i, len - 2 * i,

sprintf(new_data + 2 * i, "%02x", (unsigned char) x11_fake_data[i]);

"%02x", (u_char) x11_fake_data[i]);

/* Send the request packet. */

if (compat20) {

Line 2332

Line 2052

void

cleanup_socket(void)

{

unlink(channel_forwarded_auth_socket_name);

remove(channel_forwarded_auth_socket_name);

rmdir(channel_forwarded_auth_socket_dir);

}

* This is called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.

* This if called to process SSH_CMSG_AGENT_REQUEST_FORWARDING on the server.

* This starts forwarding authentication requests.

int

void

auth_input_request_forwarding(struct passwd * pw)

{

int sock, newch;

Line 2359

Line 2079

strlcpy(channel_forwarded_auth_socket_dir, "/tmp/ssh-XXXXXXXX", MAX_SOCKET_NAME);

/* Create private directory for socket */

if (mkdtemp(channel_forwarded_auth_socket_dir) == NULL) {

if (mkdtemp(channel_forwarded_auth_socket_dir) == NULL)

packet_send_debug("Agent forwarding disabled: mkdtemp() failed: %.100s",

packet_disconnect("mkdtemp: %.100s", strerror(errno));

strerror(errno));

restore_uid();

xfree(channel_forwarded_auth_socket_name);

xfree(channel_forwarded_auth_socket_dir);

channel_forwarded_auth_socket_name = NULL;

channel_forwarded_auth_socket_dir = NULL;

return 0;

}

snprintf(channel_forwarded_auth_socket_name, MAX_SOCKET_NAME, "%s/agent.%d",

channel_forwarded_auth_socket_dir, (int) getpid());

Line 2399

Line 2111

packet_disconnect("listen: %.100s", strerror(errno));

/* Allocate a channel for the authentication agent socket. */

newch = channel_new("auth socket",

newch = channel_allocate(SSH_CHANNEL_AUTH_SOCKET, sock,

SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,

xstrdup("auth socket"));

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;

}

/* This is called to process an SSH_SMSG_AGENT_OPEN message. */

void

auth_input_open_request(int type, int plen, void *ctxt)

auth_input_open_request(int type, int plen)

{

int remch, sock, newch;

char *dummyname;

Line 2533

Line 2241

}

c->dettach_user = NULL;

}

void

channel_register_filter(int id, channel_filter_fn *fn)

{

Channel *c = channel_lookup(id);

if (c == NULL) {

log("channel_register_filter: %d: bad id", id);

return;

}

c->input_filter = fn;

}

void

channel_set_fds(int id, int rfd, int wfd, int efd,

channel_set_fds(int id, int rfd, int wfd, int efd, int extusage)

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, nonblock);

channel_register_fds(c, rfd, wfd, efd, extusage);

c->type = SSH_CHANNEL_OPEN;

/* XXX window size? */

c->local_window = c->local_window_max = c->local_maxpacket * 2;

c->local_window = c->local_window_max = c->local_maxpacket/2;

packet_start(SSH2_MSG_CHANNEL_WINDOW_ADJUST);

packet_put_int(c->remote_id);

packet_put_int(c->local_window);