src/usr.bin/ssh/channels.c - diff

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Diff for /src/usr.bin/ssh/channels.c between version 1.72 and 1.72.2.5

version 1.72, 2000/10/27 07:48:22

version 1.72.2.5, 2001/06/12 22:47:33

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#include "includes.h"

RCSID("$OpenBSD$");

#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 "bufaux.h"

#include "uidswap.h"

#include "readconf.h"

#include "log.h"

#include "servconf.h"

#include "misc.h"

#include "channels.h"

#include "nchan.h"

#include "compat.h"

#include "canohost.h"

#include "ssh2.h"

#include <openssl/rsa.h>

#include <openssl/dsa.h>

#include "key.h"

#include "authfd.h"

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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_value = 0;

static int channel_max_fd = 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;

unsigned int x11_saved_data_len = 0;

u_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;

unsigned int x11_fake_data_len;

u_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;

void port_open_helper(Channel *c, char *rtype);

/* 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 *

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int extusage, int nonblock)

{

/* Update the maximum file descriptor value. */

if (rfd > channel_max_fd_value)

channel_max_fd = MAX(channel_max_fd, rfd);

channel_max_fd_value = rfd;

channel_max_fd = MAX(channel_max_fd, wfd);

if (wfd > channel_max_fd_value)

channel_max_fd = MAX(channel_max_fd, efd);

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->efd = efd;

c->extended_usage = extusage;

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

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

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

c->isatty = 1;

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

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)

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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, channel_open_message());

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

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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packet_put_int(c->remote_id);

packet_send();

c->type = SSH_CHANNEL_CLOSED;

debug("Closing channel %d after input drain.", c->self);

debug("channel %d: closing after input drain.", c->self);

}

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int

x11_open_helper(Channel *c)

{

unsigned char *ucp;

u_char *ucp;

unsigned int proto_len, data_len;

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

ucp = (u_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.\r\n");

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

buffer_clear(&c->input);

buffer_clear(&c->output);

close(c->sock);

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}

/* 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) {

channel_free(c->self);

} 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)

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struct sockaddr addr;

int newsock, newch;

socklen_t addrlen;

char buf[16384], *remote_hostname;

char buf[16384], *remote_ipaddr;

int remote_port;

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

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

return;

}

remote_hostname = get_remote_hostname(newsock);

remote_ipaddr = get_peer_ipaddr(newsock);

remote_port = get_peer_port(newsock);

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

remote_hostname, remote_port);

remote_ipaddr, remote_port);

newch = channel_new("x11",

SSH_CHANNEL_OPENING, newsock, newsock, -1,

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packet_put_int(newch);

packet_put_int(c->local_window_max);

packet_put_int(c->local_maxpacket);

/* originator host and port */

/* originator ipaddr and port */

packet_put_cstring(remote_hostname);

packet_put_cstring(remote_ipaddr);

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_hostname);

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 (have_hostname_in_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, newch;

int newsock, newch, nextstate;

socklen_t addrlen;

char buf[1024], *remote_hostname;

char *rtype;

int remote_port;

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) ? SSH_CHANNEL_DYNAMIC :

SSH_CHANNEL_OPENING;

addrlen = sizeof(addr);

newsock = accept(c->sock, &addr, &addrlen);

if (newsock < 0) {

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

return;

}

remote_hostname = get_remote_hostname(newsock);

newch = channel_new(rtype,

remote_port = get_peer_port(newsock);

nextstate, newsock, newsock, -1,

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_hostname, remote_port);

newch = channel_new("direct-tcpip",

SSH_CHANNEL_OPENING, newsock, newsock, -1,

c->local_window_max, c->local_maxpacket,

0, xstrdup(buf), 1);

0, xstrdup(rtype), 1);

if (compat20) {

packet_start(SSH2_MSG_CHANNEL_OPEN);

nc = channel_lookup(newch);

packet_put_cstring("direct-tcpip");

if (nc == NULL) {

packet_put_int(newch);

error("xxx: no new channel:");

packet_put_int(c->local_window_max);

return;

packet_put_int(c->local_maxpacket);

/* target host and 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);

packet_send();

} else {

packet_start(SSH_MSG_PORT_OPEN);

packet_put_int(newch);

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

packet_put_int(c->host_port);

if (have_hostname_in_open) {

packet_put_string(buf, strlen(buf));

}

packet_send();

}

xfree(remote_hostname);

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);

}

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

return;

}

newch = channel_allocate(SSH_CHANNEL_OPENING, newsock,

newch = channel_new("accepted auth socket",

xstrdup("accepted auth socket"));

SSH_CHANNEL_OPENING, newsock, newsock, -1,

packet_start(SSH_SMSG_AGENT_OPEN);

c->local_window_max, c->local_maxpacket,

packet_put_int(newch);

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)

{

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if (len <= 0) {

debug("channel %d: read<=0 rfd %d len %d",

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

if (compat13) {

if (c->type != SSH_CHANNEL_OPEN) {

debug("channel %d: not open", c->self);

channel_free(c->self);

return -1;

} else if (compat13) {

buffer_consume(&c->output, buffer_len(&c->output));

c->type = SSH_CHANNEL_INPUT_DRAINING;

debug("Channel %d status set to input draining.", c->self);

debug("channel %d: status set to input draining.", c->self);

} else {

chan_read_failed(c);

}

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}

if(c->input_filter != NULL) {

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

debug("filter stops channel %d", c->self);

debug("channel %d: filter stops", c->self);

chan_read_failed(c);

}

} else {

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

return 1;

if (len <= 0) {

if (compat13) {

if (c->type != SSH_CHANNEL_OPEN) {

debug("channel %d: not open", c->self);

channel_free(c->self);

return -1;

} else if (compat13) {

buffer_consume(&c->output, buffer_len(&c->output));

debug("Channel %d status set to input draining.", c->self);

debug("channel %d: status set to 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;

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buffer_len(&c->extended));

debug2("channel %d: written %d to efd %d",

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

if (len > 0) {

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;

}

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len = read(c->efd, buf, sizeof(buf));

debug2("channel %d: read %d from efd %d",

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

if (len == 0) {

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

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

return 1;

if (len <= 0) {

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

c->self, c->efd);

close(c->efd);

c->efd = -1;

} else if (len > 0)

} else {

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

}

return 1;

}

int

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

channel_check_window(Channel *c)

{

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

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);

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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_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

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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_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

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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_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

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

continue;

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

chan_delete_if_full_closed(c);

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->self);

}

void

channel_prepare_select(fd_set * readset, fd_set * writeset)

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

int rekeying)

{

channel_handler(channel_pre, readset, writeset);

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);

}

void

Line 910

Line 1191

channel_handler(channel_post, readset, writeset);

}

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

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

void

channel_output_poll()

Line 929

Line 1210

} 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))) {

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

/* XXX is this true? */

debug2("channel %d: no data after CLOSE", c->self);

continue;

}

/* Get the amount of buffered data for this channel. */

len = buffer_len(&c->input);

if ((c->istate == CHAN_INPUT_OPEN ||

if (len > 0) {

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)

Line 981

Line 1261

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)

Line 992

Line 1275

packet_send();

buffer_consume(&c->extended, len);

c->remote_window -= len;

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

}

Line 1007

Line 1291

{

int id;

char *data;

unsigned int data_len;

u_int data_len;

Channel *c;

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

Line 1053

Line 1337

int id;

int tcode;

char *data;

unsigned int data_len;

u_int data_len;

Channel *c;

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

Line 1096

Line 1380

int

channel_not_very_much_buffered_data()

{

unsigned int i;

u_int i;

Channel *c;

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

Line 1235

Line 1519

void

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

{

int id;

int id, reason;

char *msg = NULL, *lang = NULL;

Channel *c;

if (!compat20)

Line 1248

Line 1533

packet_disconnect("Received open failure for "

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

if (compat20) {

int reason = packet_get_int();

reason = packet_get_int();

char *msg = packet_get_string(NULL);

if (packet_remaining() > 0) {

char *lang = packet_get_string(NULL);

msg = packet_get_string(NULL);

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

lang = packet_get_string(NULL);

}

packet_done();

xfree(msg);

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

xfree(lang);

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

if (msg != NULL)

xfree(msg);

if (lang != NULL)

xfree(lang);

}

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

channel_free(id);

Line 1279

Line 1569

debug2("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);

}

Line 1322

Line 1612

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);

Line 1350

Line 1641

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()

{

unsigned int i;

u_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_DYNAMIC:

case SSH_CHANNEL_CONNECTING: /* XXX ??? */

continue;

case SSH_CHANNEL_LARVAL:

if (!compat20)

Line 1392

Line 1678

return 0;

}

/* Returns the id of an open channel suitable for keepaliving */

int

channel_find_open()

{

u_int i;

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

switch (channels[i].type) {

case SSH_CHANNEL_CLOSED:

case SSH_CHANNEL_DYNAMIC:

case SSH_CHANNEL_FREE:

case SSH_CHANNEL_X11_LISTENER:

case SSH_CHANNEL_PORT_LISTENER:

case SSH_CHANNEL_RPORT_LISTENER:

case SSH_CHANNEL_OPENING:

continue;

case SSH_CHANNEL_LARVAL:

case SSH_CHANNEL_AUTH_SOCKET:

case SSH_CHANNEL_CONNECTING: /* XXX ??? */

case SSH_CHANNEL_OPEN:

case SSH_CHANNEL_X11_OPEN:

return i;

case SSH_CHANNEL_INPUT_DRAINING:

case SSH_CHANNEL_OUTPUT_DRAINING:

if (!compat13)

fatal("cannot happen: OUT_DRAIN");

return i;

default:

fatal("channel_find_open: bad channel type %d", channels[i].type);

/* NOTREACHED */

}

return -1;

}

* Returns a message describing the currently open forwarded connections,

* suitable for sending to the client. The message contains crlf pairs for

Line 1414

Line 1735

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_DYNAMIC:

case SSH_CHANNEL_OPEN:

case SSH_CHANNEL_X11_OPEN:

case SSH_CHANNEL_INPUT_DRAINING:

Line 1446

Line 1770

* 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

channel_request_local_forwarding(u_short port, const char *host,

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

u_short host_port, int gateway_ports)

* (SSH_CHANNEL_RPORT_LISTENER).

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;

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

success = 0;

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 1467

Line 1820

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");

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_local_forwarding: getnameinfo failed");

error("channel_request_forwarding: getnameinfo failed");

continue;

}

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

Line 1511

Line 1863

continue;

}

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

ch = channel_new(

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

"port listener", SSH_CHANNEL_PORT_LISTENER,

sock, sock, -1,

CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,

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

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

channels[ch].host_port = host_port;

channels[ch].host_port = port_to_connect;

channels[ch].listening_port = port;

channels[ch].listening_port = listen_port;

success = 1;

}

if (success == 0)

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

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

listen_port);

freeaddrinfo(aitop);

return success;

}

Line 1532

Line 1884

void

channel_request_remote_forwarding(u_short listen_port, const char *host_to_connect,

channel_request_remote_forwarding(u_short listen_port,

u_short port_to_connect)

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";

Line 1553

Line 1901

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 1560

Line 1912

packet_put_int(port_to_connect);

packet_send();

packet_write_wait();

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

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

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

type = packet_read(&payload_len);

switch (type) {

packet_read_expect(&payload_len, SSH_SMSG_SUCCESS);

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++;

}

Line 1592

Line 1960

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

channel_connect_to(const char *host, u_short host_port)

connect_to(const char *host, u_short port)

{

struct addrinfo hints, *ai, *aitop;

char ntop[NI_MAXHOST], strport[NI_MAXSERV];

Line 1613

Line 2017

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

hints.ai_family = IPv4or6;

hints.ai_socktype = SOCK_STREAM;

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

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

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

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

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

gai_strerror(gaierr));

return -1;

}

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

Line 1623

Line 2028

continue;

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

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

error("channel_connect_to: getnameinfo failed");

error("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;

}

/* Connect to the host/port. */

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

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

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

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

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

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

error("connect_to %.100s port %d: failed.", 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 1661

Line 2105

{

u_short host_port;

char *host, *originator_string;

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

int remote_channel, sock = -1, newch;

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(&originator_len);

originator_string = packet_get_string(NULL);

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();

packet_integrity_check(plen,

sock = channel_connect_to(host, host_port);

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

if (sock != -1) {

newch = channel_allocate(SSH_CHANNEL_CONNECTING,

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

sock, originator_string);

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 1775

Line 2191

if (num_socks == NUM_SOCKS)

break;

}

freeaddrinfo(aitop);

if (num_socks > 0)

break;

}

Line 1818

Line 2235

static

int

connect_local_xsocket(unsigned int dnr)

connect_local_xsocket(u_int dnr)

{

static const char *const x_sockets[] = {

X_UNIX_PATH "%u",

Line 1951

Line 2368

{

int remote_channel, sock = 0, newch;

char *remote_host;

unsigned int remote_len;

u_int remote_len;

/* Get remote channel number. */

remote_channel = packet_get_int();

Line 2022

Line 2439

x11_request_forwarding_with_spoofing(int client_session_id,

const char *proto, const char *data)

{

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

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

unsigned int i, value;

u_int i, value, len;

char *new_data;

int screen_number;

const char *cp;

Line 2061

Line 2478

x11_fake_data_len = data_len;

/* Convert the fake data into hex. */

new_data = xmalloc(2 * data_len + 1);

len = 2 * data_len + 1;

new_data = xmalloc(len);

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

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

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

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

/* Send the request packet. */

if (compat20) {

Line 2105

Line 2524

/* removes the agent forwarding socket */

void

cleanup_socket(void)

auth_sock_cleanup_proc(void *_pw)

{

remove(channel_forwarded_auth_socket_name);

struct passwd *pw = _pw;

rmdir(channel_forwarded_auth_socket_dir);

if (channel_forwarded_auth_socket_name) {

temporarily_use_uid(pw);

unlink(channel_forwarded_auth_socket_name);

rmdir(channel_forwarded_auth_socket_dir);

channel_forwarded_auth_socket_name = NULL;

restore_uid();

}

Line 2126

Line 2552

fatal("Protocol error: authentication forwarding requested twice.");

/* Temporarily drop privileged uid for mkdir/bind. */

temporarily_use_uid(pw->pw_uid);

temporarily_use_uid(pw);

/* Allocate a buffer for the socket name, and format the name. */

channel_forwarded_auth_socket_name = xmalloc(MAX_SOCKET_NAME);

Line 2147

Line 2573

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

channel_forwarded_auth_socket_dir, (int) getpid());

if (atexit(cleanup_socket) < 0) {

/* delete agent socket on fatal() */

int saved = errno;

fatal_add_cleanup(auth_sock_cleanup_proc, pw);

cleanup_socket();

packet_disconnect("socket: %.100s", strerror(saved));

}

/* Create the socket. */

sock = socket(AF_UNIX, SOCK_STREAM, 0);

if (sock < 0)

Line 2174

Line 2598

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

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

newch = channel_allocate(SSH_CHANNEL_AUTH_SOCKET, sock,

newch = channel_new("auth socket",

xstrdup("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;

Line 2305

Line 2732

}

c->dettach_user = NULL;

}

void

channel_register_filter(int id, channel_filter_fn *fn)

{

Channel *c = channel_lookup(id);