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putty/ssh2connection.c

1724 строки
60 KiB
C
Исходник Ответственный История

/*
* Packet protocol layer for the SSH-2 connection protocol (RFC 4254).
*/
#include <assert.h>
#include "putty.h"
#include "ssh.h"
#include "sshbpp.h"
#include "sshppl.h"
#include "sshchan.h"
#include "sshcr.h"
#include "ssh2connection.h"
static void ssh2_connection_free(PacketProtocolLayer *);
static void ssh2_connection_process_queue(PacketProtocolLayer *);
static bool ssh2_connection_get_specials(
PacketProtocolLayer *ppl, add_special_fn_t add_special, void *ctx);
static void ssh2_connection_special_cmd(PacketProtocolLayer *ppl,
SessionSpecialCode code, int arg);
static bool ssh2_connection_want_user_input(PacketProtocolLayer *ppl);
static void ssh2_connection_got_user_input(PacketProtocolLayer *ppl);
static void ssh2_connection_reconfigure(PacketProtocolLayer *ppl, Conf *conf);
static const struct PacketProtocolLayerVtable ssh2_connection_vtable = {
ssh2_connection_free,
ssh2_connection_process_queue,
ssh2_connection_get_specials,
ssh2_connection_special_cmd,
ssh2_connection_want_user_input,
ssh2_connection_got_user_input,
ssh2_connection_reconfigure,
"ssh-connection",
};
static SshChannel *ssh2_lportfwd_open(
ConnectionLayer *cl, const char *hostname, int port,
const char *description, const SocketPeerInfo *pi, Channel *chan);
static struct X11FakeAuth *ssh2_add_x11_display(
ConnectionLayer *cl, int authtype, struct X11Display *x11disp);
static struct X11FakeAuth *ssh2_add_sharing_x11_display(
ConnectionLayer *cl, int authtype, ssh_sharing_connstate *share_cs,
share_channel *share_chan);
static void ssh2_remove_sharing_x11_display(ConnectionLayer *cl,
struct X11FakeAuth *auth);
static void ssh2_send_packet_from_downstream(
ConnectionLayer *cl, unsigned id, int type,
const void *pkt, int pktlen, const char *additional_log_text);
static unsigned ssh2_alloc_sharing_channel(
ConnectionLayer *cl, ssh_sharing_connstate *connstate);
static void ssh2_delete_sharing_channel(
ConnectionLayer *cl, unsigned localid);
static void ssh2_sharing_queue_global_request(
ConnectionLayer *cl, ssh_sharing_connstate *share_ctx);
static void ssh2_sharing_no_more_downstreams(ConnectionLayer *cl);
static bool ssh2_agent_forwarding_permitted(ConnectionLayer *cl);
static void ssh2_terminal_size(ConnectionLayer *cl, int width, int height);
static void ssh2_stdout_unthrottle(ConnectionLayer *cl, size_t bufsize);
static size_t ssh2_stdin_backlog(ConnectionLayer *cl);
static void ssh2_throttle_all_channels(ConnectionLayer *cl, bool throttled);
static bool ssh2_ldisc_option(ConnectionLayer *cl, int option);
static void ssh2_set_ldisc_option(ConnectionLayer *cl, int option, bool value);
static void ssh2_enable_x_fwd(ConnectionLayer *cl);
static void ssh2_enable_agent_fwd(ConnectionLayer *cl);
static void ssh2_set_wants_user_input(ConnectionLayer *cl, bool wanted);
static const struct ConnectionLayerVtable ssh2_connlayer_vtable = {
ssh2_rportfwd_alloc,
ssh2_rportfwd_remove,
ssh2_lportfwd_open,
ssh2_session_open,
ssh2_serverside_x11_open,
ssh2_serverside_agent_open,
ssh2_add_x11_display,
ssh2_add_sharing_x11_display,
ssh2_remove_sharing_x11_display,
ssh2_send_packet_from_downstream,
ssh2_alloc_sharing_channel,
ssh2_delete_sharing_channel,
ssh2_sharing_queue_global_request,
ssh2_sharing_no_more_downstreams,
ssh2_agent_forwarding_permitted,
ssh2_terminal_size,
ssh2_stdout_unthrottle,
ssh2_stdin_backlog,
ssh2_throttle_all_channels,
ssh2_ldisc_option,
ssh2_set_ldisc_option,
ssh2_enable_x_fwd,
ssh2_enable_agent_fwd,
ssh2_set_wants_user_input,
};
static char *ssh2_channel_open_failure_error_text(PktIn *pktin)
{
static const char *const reasons[] = {
NULL,
"Administratively prohibited",
"Connect failed",
"Unknown channel type",
"Resource shortage",
};
unsigned reason_code;
const char *reason_code_string;
char reason_code_buf[256];
ptrlen reason;
reason_code = get_uint32(pktin);
if (reason_code < lenof(reasons) && reasons[reason_code]) {
reason_code_string = reasons[reason_code];
} else {
reason_code_string = reason_code_buf;
sprintf(reason_code_buf, "unknown reason code %#x", reason_code);
}
reason = get_string(pktin);
return dupprintf("%s [%.*s]", reason_code_string, PTRLEN_PRINTF(reason));
}
static size_t ssh2channel_write(
SshChannel *c, bool is_stderr, const void *buf, size_t len);
static void ssh2channel_write_eof(SshChannel *c);
static void ssh2channel_initiate_close(SshChannel *c, const char *err);
static void ssh2channel_unthrottle(SshChannel *c, size_t bufsize);
static Conf *ssh2channel_get_conf(SshChannel *c);
static void ssh2channel_window_override_removed(SshChannel *c);
static void ssh2channel_x11_sharing_handover(
SshChannel *c, ssh_sharing_connstate *share_cs, share_channel *share_chan,
const char *peer_addr, int peer_port, int endian,
int protomajor, int protominor, const void *initial_data, int initial_len);
static void ssh2channel_hint_channel_is_simple(SshChannel *c);
static const struct SshChannelVtable ssh2channel_vtable = {
ssh2channel_write,
ssh2channel_write_eof,
ssh2channel_initiate_close,
ssh2channel_unthrottle,
ssh2channel_get_conf,
ssh2channel_window_override_removed,
ssh2channel_x11_sharing_handover,
ssh2channel_send_exit_status,
ssh2channel_send_exit_signal,
ssh2channel_send_exit_signal_numeric,
ssh2channel_request_x11_forwarding,
ssh2channel_request_agent_forwarding,
ssh2channel_request_pty,
ssh2channel_send_env_var,
ssh2channel_start_shell,
ssh2channel_start_command,
ssh2channel_start_subsystem,
ssh2channel_send_serial_break,
ssh2channel_send_signal,
ssh2channel_send_terminal_size_change,
ssh2channel_hint_channel_is_simple,
};
static void ssh2_channel_check_close(struct ssh2_channel *c);
static void ssh2_channel_try_eof(struct ssh2_channel *c);
static void ssh2_set_window(struct ssh2_channel *c, int newwin);
static size_t ssh2_try_send(struct ssh2_channel *c);
static void ssh2_try_send_and_unthrottle(struct ssh2_channel *c);
static void ssh2_channel_check_throttle(struct ssh2_channel *c);
static void ssh2_channel_close_local(struct ssh2_channel *c,
const char *reason);
static void ssh2_channel_destroy(struct ssh2_channel *c);
static void ssh2_check_termination(struct ssh2_connection_state *s);
struct outstanding_global_request {
gr_handler_fn_t handler;
void *ctx;
struct outstanding_global_request *next;
};
void ssh2_queue_global_request_handler(
struct ssh2_connection_state *s, gr_handler_fn_t handler, void *ctx)
{
struct outstanding_global_request *ogr =
snew(struct outstanding_global_request);
ogr->handler = handler;
ogr->ctx = ctx;
if (s->globreq_tail)
s->globreq_tail->next = ogr;
else
s->globreq_head = ogr;
s->globreq_tail = ogr;
}
static int ssh2_channelcmp(void *av, void *bv)
{
const struct ssh2_channel *a = (const struct ssh2_channel *) av;
const struct ssh2_channel *b = (const struct ssh2_channel *) bv;
if (a->localid < b->localid)
return -1;
if (a->localid > b->localid)
return +1;
return 0;
}
static int ssh2_channelfind(void *av, void *bv)
{
const unsigned *a = (const unsigned *) av;
const struct ssh2_channel *b = (const struct ssh2_channel *) bv;
if (*a < b->localid)
return -1;
if (*a > b->localid)
return +1;
return 0;
}
/*
* Each channel has a queue of outstanding CHANNEL_REQUESTS and their
* handlers.
*/
struct outstanding_channel_request {
cr_handler_fn_t handler;
void *ctx;
struct outstanding_channel_request *next;
};
static void ssh2_channel_free(struct ssh2_channel *c)
{
bufchain_clear(&c->outbuffer);
bufchain_clear(&c->errbuffer);
while (c->chanreq_head) {
struct outstanding_channel_request *chanreq = c->chanreq_head;
c->chanreq_head = c->chanreq_head->next;
sfree(chanreq);
}
if (c->chan) {
struct ssh2_connection_state *s = c->connlayer;
if (s->mainchan_sc == &c->sc) {
s->mainchan = NULL;
s->mainchan_sc = NULL;
}
chan_free(c->chan);
}
sfree(c);
}
PacketProtocolLayer *ssh2_connection_new(
Ssh *ssh, ssh_sharing_state *connshare, bool is_simple,
Conf *conf, const char *peer_verstring, ConnectionLayer **cl_out)
{
struct ssh2_connection_state *s = snew(struct ssh2_connection_state);
memset(s, 0, sizeof(*s));
s->ppl.vt = &ssh2_connection_vtable;
s->conf = conf_copy(conf);
s->ssh_is_simple = is_simple;
/*
* If the ssh_no_shell option is enabled, we disable the usual
* termination check, so that we persist even in the absence of
* any at all channels (because our purpose is probably to be a
* background port forwarder).
*/
s->persistent = conf_get_bool(s->conf, CONF_ssh_no_shell);
s->connshare = connshare;
s->peer_verstring = dupstr(peer_verstring);
s->channels = newtree234(ssh2_channelcmp);
s->x11authtree = newtree234(x11_authcmp);
/* Need to get the log context for s->cl now, because we won't be
* helpfully notified when a copy is written into s->ppl by our
* owner. */
s->cl.vt = &ssh2_connlayer_vtable;
s->cl.logctx = ssh_get_logctx(ssh);
s->portfwdmgr = portfwdmgr_new(&s->cl);
*cl_out = &s->cl;
if (s->connshare)
ssh_connshare_provide_connlayer(s->connshare, &s->cl);
return &s->ppl;
}
static void ssh2_connection_free(PacketProtocolLayer *ppl)
{
struct ssh2_connection_state *s =
container_of(ppl, struct ssh2_connection_state, ppl);
struct X11FakeAuth *auth;
struct ssh2_channel *c;
struct ssh_rportfwd *rpf;
sfree(s->peer_verstring);
conf_free(s->conf);
while ((c = delpos234(s->channels, 0)) != NULL)
ssh2_channel_free(c);
freetree234(s->channels);
while ((auth = delpos234(s->x11authtree, 0)) != NULL) {
if (auth->disp)
x11_free_display(auth->disp);
x11_free_fake_auth(auth);
}
freetree234(s->x11authtree);
if (s->rportfwds) {
while ((rpf = delpos234(s->rportfwds, 0)) != NULL)
free_rportfwd(rpf);
freetree234(s->rportfwds);
}
portfwdmgr_free(s->portfwdmgr);
sfree(s);
}
static bool ssh2_connection_filter_queue(struct ssh2_connection_state *s)
{
PktIn *pktin;
PktOut *pktout;
ptrlen type, data;
struct ssh2_channel *c;
struct outstanding_channel_request *ocr;
unsigned localid, remid, winsize, pktsize, ext_type;
bool want_reply, reply_success, expect_halfopen;
ChanopenResult chanopen_result;
PacketProtocolLayer *ppl = &s->ppl; /* for ppl_logevent */
while (1) {
if (ssh2_common_filter_queue(&s->ppl))
return true;
if ((pktin = pq_peek(s->ppl.in_pq)) == NULL)
return false;
switch (pktin->type) {
case SSH2_MSG_GLOBAL_REQUEST:
type = get_string(pktin);
want_reply = get_bool(pktin);
reply_success = ssh2_connection_parse_global_request(
s, type, pktin);
if (want_reply) {
int type = (reply_success ? SSH2_MSG_REQUEST_SUCCESS :
SSH2_MSG_REQUEST_FAILURE);
pktout = ssh_bpp_new_pktout(s->ppl.bpp, type);
pq_push(s->ppl.out_pq, pktout);
}
pq_pop(s->ppl.in_pq);
break;
case SSH2_MSG_REQUEST_SUCCESS:
case SSH2_MSG_REQUEST_FAILURE:
if (!s->globreq_head) {
ssh_proto_error(
s->ppl.ssh,
"Received %s with no outstanding global request",
ssh2_pkt_type(s->ppl.bpp->pls->kctx, s->ppl.bpp->pls->actx,
pktin->type));
return true;
}
s->globreq_head->handler(s, pktin, s->globreq_head->ctx);
{
struct outstanding_global_request *tmp = s->globreq_head;
s->globreq_head = s->globreq_head->next;
sfree(tmp);
}
pq_pop(s->ppl.in_pq);
break;
case SSH2_MSG_CHANNEL_OPEN:
type = get_string(pktin);
c = snew(struct ssh2_channel);
c->connlayer = s;
c->chan = NULL;
remid = get_uint32(pktin);
winsize = get_uint32(pktin);
pktsize = get_uint32(pktin);
chanopen_result = ssh2_connection_parse_channel_open(
s, type, pktin, &c->sc);
if (chanopen_result.outcome == CHANOPEN_RESULT_DOWNSTREAM) {
/*
* This channel-open request needs to go to a
* connection-sharing downstream, so abandon our own
* channel-open procedure and just pass the message on
* to sshshare.c.
*/
share_got_pkt_from_server(
chanopen_result.u.downstream.share_ctx, pktin->type,
BinarySource_UPCAST(pktin)->data,
BinarySource_UPCAST(pktin)->len);
sfree(c);
break;
}
c->remoteid = remid;
c->halfopen = false;
if (chanopen_result.outcome == CHANOPEN_RESULT_FAILURE) {
pktout = ssh_bpp_new_pktout(
s->ppl.bpp, SSH2_MSG_CHANNEL_OPEN_FAILURE);
put_uint32(pktout, c->remoteid);
put_uint32(pktout, chanopen_result.u.failure.reason_code);
put_stringz(pktout, chanopen_result.u.failure.wire_message);
put_stringz(pktout, "en"); /* language tag */
pq_push(s->ppl.out_pq, pktout);
ppl_logevent("Rejected channel open: %s",
chanopen_result.u.failure.wire_message);
sfree(chanopen_result.u.failure.wire_message);
sfree(c);
} else {
c->chan = chanopen_result.u.success.channel;
ssh2_channel_init(c);
c->remwindow = winsize;
c->remmaxpkt = pktsize;
if (c->chan->initial_fixed_window_size) {
c->locwindow = c->locmaxwin = c->remlocwin =
c->chan->initial_fixed_window_size;
}
pktout = ssh_bpp_new_pktout(
s->ppl.bpp, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
put_uint32(pktout, c->remoteid);
put_uint32(pktout, c->localid);
put_uint32(pktout, c->locwindow);
put_uint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
pq_push(s->ppl.out_pq, pktout);
}
pq_pop(s->ppl.in_pq);
break;
case SSH2_MSG_CHANNEL_DATA:
case SSH2_MSG_CHANNEL_EXTENDED_DATA:
case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
case SSH2_MSG_CHANNEL_REQUEST:
case SSH2_MSG_CHANNEL_EOF:
case SSH2_MSG_CHANNEL_CLOSE:
case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
case SSH2_MSG_CHANNEL_OPEN_FAILURE:
case SSH2_MSG_CHANNEL_SUCCESS:
case SSH2_MSG_CHANNEL_FAILURE:
/*
* Common preliminary code for all the messages from the
* server that cite one of our channel ids: look up that
* channel id, check it exists, and if it's for a sharing
* downstream, pass it on.
*/
localid = get_uint32(pktin);
c = find234(s->channels, &localid, ssh2_channelfind);
if (c && c->sharectx) {
share_got_pkt_from_server(c->sharectx, pktin->type,
BinarySource_UPCAST(pktin)->data,
BinarySource_UPCAST(pktin)->len);
pq_pop(s->ppl.in_pq);
break;
}
expect_halfopen = (
pktin->type == SSH2_MSG_CHANNEL_OPEN_CONFIRMATION ||
pktin->type == SSH2_MSG_CHANNEL_OPEN_FAILURE);
if (!c || c->halfopen != expect_halfopen) {
ssh_proto_error(s->ppl.ssh,
"Received %s for %s channel %u",
ssh2_pkt_type(s->ppl.bpp->pls->kctx,
s->ppl.bpp->pls->actx,
pktin->type),
(!c ? "nonexistent" :
c->halfopen ? "half-open" : "open"),
localid);
return true;
}
switch (pktin->type) {
case SSH2_MSG_CHANNEL_OPEN_CONFIRMATION:
assert(c->halfopen);
c->remoteid = get_uint32(pktin);
c->halfopen = false;
c->remwindow = get_uint32(pktin);
c->remmaxpkt = get_uint32(pktin);
chan_open_confirmation(c->chan);
/*
* Now that the channel is fully open, it's possible
* in principle to immediately close it. Check whether
* it wants us to!
*
* This can occur if a local socket error occurred
* between us sending out CHANNEL_OPEN and receiving
* OPEN_CONFIRMATION. If that happens, all we can do
* is immediately initiate close proceedings now that
* we know the server's id to put in the close
* message. We'll have handled that in this code by
* having already turned c->chan into a zombie, so its
* want_close method (which ssh2_channel_check_close
* will consult) will already be returning true.
*/
ssh2_channel_check_close(c);
if (c->pending_eof)
ssh2_channel_try_eof(c); /* in case we had a pending EOF */
break;
case SSH2_MSG_CHANNEL_OPEN_FAILURE:
assert(c->halfopen);
{
char *err = ssh2_channel_open_failure_error_text(pktin);
chan_open_failed(c->chan, err);
sfree(err);
}
del234(s->channels, c);
ssh2_channel_free(c);
break;
case SSH2_MSG_CHANNEL_DATA:
case SSH2_MSG_CHANNEL_EXTENDED_DATA:
ext_type = (pktin->type == SSH2_MSG_CHANNEL_DATA ? 0 :
get_uint32(pktin));
data = get_string(pktin);
if (!get_err(pktin)) {
int bufsize;
c->locwindow -= data.len;
c->remlocwin -= data.len;
if (ext_type != 0 && ext_type != SSH2_EXTENDED_DATA_STDERR)
data.len = 0; /* ignore unknown extended data */
bufsize = chan_send(
c->chan, ext_type == SSH2_EXTENDED_DATA_STDERR,
data.ptr, data.len);
/*
* If it looks like the remote end hit the end of
* its window, and we didn't want it to do that,
* think about using a larger window.
*/
if (c->remlocwin <= 0 &&
c->throttle_state == UNTHROTTLED &&
c->locmaxwin < 0x40000000)
c->locmaxwin += OUR_V2_WINSIZE;
/*
* If we are not buffering too much data, enlarge
* the window again at the remote side. If we are
* buffering too much, we may still need to adjust
* the window if the server's sent excess data.
*/
if (bufsize < c->locmaxwin)
ssh2_set_window(c, c->locmaxwin - bufsize);
/*
* If we're either buffering way too much data, or
* if we're buffering anything at all and we're in
* "simple" mode, throttle the whole channel.
*/
if ((bufsize > c->locmaxwin ||
(s->ssh_is_simple && bufsize>0)) &&
!c->throttling_conn) {
c->throttling_conn = true;
ssh_throttle_conn(s->ppl.ssh, +1);
}
}
break;
case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
if (!(c->closes & CLOSES_SENT_EOF)) {
c->remwindow += get_uint32(pktin);
ssh2_try_send_and_unthrottle(c);
}
break;
case SSH2_MSG_CHANNEL_REQUEST:
type = get_string(pktin);
want_reply = get_bool(pktin);
reply_success = false;
if (c->closes & CLOSES_SENT_CLOSE) {
/*
* We don't reply to channel requests after we've
* sent CHANNEL_CLOSE for the channel, because our
* reply might cross in the network with the other
* side's CHANNEL_CLOSE and arrive after they have
* wound the channel up completely.
*/
want_reply = false;
}
/*
* Try every channel request name we recognise, no
* matter what the channel, and see if the Channel
* instance will accept it.
*/
if (ptrlen_eq_string(type, "exit-status")) {
int exitcode = toint(get_uint32(pktin));
reply_success = chan_rcvd_exit_status(c->chan, exitcode);
} else if (ptrlen_eq_string(type, "exit-signal")) {
ptrlen signame;
int signum;
bool core = false;
ptrlen errmsg;
int format;
/*
* ICK: older versions of OpenSSH (e.g. 3.4p1)
* provide an `int' for the signal, despite its
* having been a `string' in the drafts of RFC
* 4254 since at least 2001. (Fixed in session.c
* 1.147.) Try to infer which we can safely parse
* it as.
*/
size_t startpos = BinarySource_UPCAST(pktin)->pos;
for (format = 0; format < 2; format++) {
BinarySource_UPCAST(pktin)->pos = startpos;
BinarySource_UPCAST(pktin)->err = BSE_NO_ERROR;
/* placate compiler warnings about unin */
signame = make_ptrlen(NULL, 0);
signum = 0;
if (format == 0) /* standard string-based format */
signame = get_string(pktin);
else /* nonstandard integer format */
signum = toint(get_uint32(pktin));
core = get_bool(pktin);
errmsg = get_string(pktin); /* error message */
get_string(pktin); /* language tag */
if (!get_err(pktin) && get_avail(pktin) == 0)
break; /* successful parse */
}
switch (format) {
case 0:
reply_success = chan_rcvd_exit_signal(
c->chan, signame, core, errmsg);
break;
case 1:
reply_success = chan_rcvd_exit_signal_numeric(
c->chan, signum, core, errmsg);
break;
default:
/* Couldn't parse this message in either format */
reply_success = false;
break;
}
} else if (ptrlen_eq_string(type, "shell")) {
reply_success = chan_run_shell(c->chan);
} else if (ptrlen_eq_string(type, "exec")) {
ptrlen command = get_string(pktin);
reply_success = chan_run_command(c->chan, command);
} else if (ptrlen_eq_string(type, "subsystem")) {
ptrlen subsys = get_string(pktin);
reply_success = chan_run_subsystem(c->chan, subsys);
} else if (ptrlen_eq_string(type, "x11-req")) {
bool oneshot = get_bool(pktin);
ptrlen authproto = get_string(pktin);
ptrlen authdata = get_string(pktin);
unsigned screen_number = get_uint32(pktin);
reply_success = chan_enable_x11_forwarding(
c->chan, oneshot, authproto, authdata, screen_number);
} else if (ptrlen_eq_string(type,
"auth-agent-req@openssh.com")) {
reply_success = chan_enable_agent_forwarding(c->chan);
} else if (ptrlen_eq_string(type, "pty-req")) {
ptrlen termtype = get_string(pktin);
unsigned width = get_uint32(pktin);
unsigned height = get_uint32(pktin);
unsigned pixwidth = get_uint32(pktin);
unsigned pixheight = get_uint32(pktin);
ptrlen encoded_modes = get_string(pktin);
BinarySource bs_modes[1];
struct ssh_ttymodes modes;
BinarySource_BARE_INIT_PL(bs_modes, encoded_modes);
modes = read_ttymodes_from_packet(bs_modes, 2);
if (get_err(bs_modes) || get_avail(bs_modes) > 0) {
ppl_logevent("Unable to decode terminal mode string");
reply_success = false;
} else {
reply_success = chan_allocate_pty(
c->chan, termtype, width, height,
pixwidth, pixheight, modes);
}
} else if (ptrlen_eq_string(type, "env")) {
ptrlen var = get_string(pktin);
ptrlen value = get_string(pktin);
reply_success = chan_set_env(c->chan, var, value);
} else if (ptrlen_eq_string(type, "break")) {
unsigned length = get_uint32(pktin);
reply_success = chan_send_break(c->chan, length);
} else if (ptrlen_eq_string(type, "signal")) {
ptrlen signame = get_string(pktin);
reply_success = chan_send_signal(c->chan, signame);
} else if (ptrlen_eq_string(type, "window-change")) {
unsigned width = get_uint32(pktin);
unsigned height = get_uint32(pktin);
unsigned pixwidth = get_uint32(pktin);
unsigned pixheight = get_uint32(pktin);
reply_success = chan_change_window_size(
c->chan, width, height, pixwidth, pixheight);
}
if (want_reply) {
int type = (reply_success ? SSH2_MSG_CHANNEL_SUCCESS :
SSH2_MSG_CHANNEL_FAILURE);
pktout = ssh_bpp_new_pktout(s->ppl.bpp, type);
put_uint32(pktout, c->remoteid);
pq_push(s->ppl.out_pq, pktout);
}
break;
case SSH2_MSG_CHANNEL_SUCCESS:
case SSH2_MSG_CHANNEL_FAILURE:
ocr = c->chanreq_head;
if (!ocr) {
ssh_proto_error(
s->ppl.ssh,
"Received %s for channel %d with no outstanding "
"channel request",
ssh2_pkt_type(s->ppl.bpp->pls->kctx,
s->ppl.bpp->pls->actx, pktin->type));
return true;
}
ocr->handler(c, pktin, ocr->ctx);
c->chanreq_head = ocr->next;
sfree(ocr);
/*
* We may now initiate channel-closing procedures, if
* that CHANNEL_REQUEST was the last thing outstanding
* before we send CHANNEL_CLOSE.
*/
ssh2_channel_check_close(c);
break;
case SSH2_MSG_CHANNEL_EOF:
if (!(c->closes & CLOSES_RCVD_EOF)) {
c->closes |= CLOSES_RCVD_EOF;
chan_send_eof(c->chan);
ssh2_channel_check_close(c);
}
break;
case SSH2_MSG_CHANNEL_CLOSE:
/*
* When we receive CLOSE on a channel, we assume it
* comes with an implied EOF if we haven't seen EOF
* yet.
*/
if (!(c->closes & CLOSES_RCVD_EOF)) {
c->closes |= CLOSES_RCVD_EOF;
chan_send_eof(c->chan);
}
if (!(s->ppl.remote_bugs & BUG_SENDS_LATE_REQUEST_REPLY)) {
/*
* It also means we stop expecting to see replies
* to any outstanding channel requests, so clean
* those up too. (ssh_chanreq_init will enforce by
* assertion that we don't subsequently put
* anything back on this list.)
*/
while (c->chanreq_head) {
struct outstanding_channel_request *ocr =
c->chanreq_head;
ocr->handler(c, NULL, ocr->ctx);
c->chanreq_head = ocr->next;
sfree(ocr);
}
}
/*
* And we also send an outgoing EOF, if we haven't
* already, on the assumption that CLOSE is a pretty
* forceful announcement that the remote side is doing
* away with the entire channel. (If it had wanted to
* send us EOF and continue receiving data from us, it
* would have just sent CHANNEL_EOF.)
*/
if (!(c->closes & CLOSES_SENT_EOF)) {
/*
* Abandon any buffered data we still wanted to
* send to this channel. Receiving a CHANNEL_CLOSE
* is an indication that the server really wants
* to get on and _destroy_ this channel, and it
* isn't going to send us any further
* WINDOW_ADJUSTs to permit us to send pending
* stuff.
*/
bufchain_clear(&c->outbuffer);
bufchain_clear(&c->errbuffer);
/*
* Send outgoing EOF.
*/
sshfwd_write_eof(&c->sc);
/*
* Make sure we don't read any more from whatever
* our local data source is for this channel.
* (This will pick up on the changes made by
* sshfwd_write_eof.)
*/
ssh2_channel_check_throttle(c);
}
/*
* Now process the actual close.
*/
if (!(c->closes & CLOSES_RCVD_CLOSE)) {
c->closes |= CLOSES_RCVD_CLOSE;
ssh2_channel_check_close(c);
}
break;
}
pq_pop(s->ppl.in_pq);
break;
default:
return false;
}
}
}
static void ssh2_handle_winadj_response(struct ssh2_channel *c,
PktIn *pktin, void *ctx)
{
unsigned *sizep = ctx;
/*
* Winadj responses should always be failures. However, at least
* one server ("boks_sshd") is known to return SUCCESS for channel
* requests it's never heard of, such as "winadj@putty". Raised
* with foxt.com as bug 090916-090424, but for the sake of a quiet
* life, we don't worry about what kind of response we got.
*/
c->remlocwin += *sizep;
sfree(sizep);
/*
* winadj messages are only sent when the window is fully open, so
* if we get an ack of one, we know any pending unthrottle is
* complete.
*/
if (c->throttle_state == UNTHROTTLING)
c->throttle_state = UNTHROTTLED;
}
static void ssh2_set_window(struct ssh2_channel *c, int newwin)
{
struct ssh2_connection_state *s = c->connlayer;
/*
* Never send WINDOW_ADJUST for a channel that the remote side has
* already sent EOF on; there's no point, since it won't be
* sending any more data anyway. Ditto if _we've_ already sent
* CLOSE.
*/
if (c->closes & (CLOSES_RCVD_EOF | CLOSES_SENT_CLOSE))
return;
/*
* If the client-side Channel is in an initial setup phase with a
* fixed window size, e.g. for an X11 channel when we're still
* waiting to see its initial auth and may yet hand it off to a
* downstream, don't send any WINDOW_ADJUST either.
*/
if (c->chan->initial_fixed_window_size)
return;
/*
* If the remote end has a habit of ignoring maxpkt, limit the
* window so that it has no choice (assuming it doesn't ignore the
* window as well).
*/
if ((s->ppl.remote_bugs & BUG_SSH2_MAXPKT) && newwin > OUR_V2_MAXPKT)
newwin = OUR_V2_MAXPKT;
/*
* Only send a WINDOW_ADJUST if there's significantly more window
* available than the other end thinks there is. This saves us
* sending a WINDOW_ADJUST for every character in a shell session.
*
* "Significant" is arbitrarily defined as half the window size.
*/
if (newwin / 2 >= c->locwindow) {
PktOut *pktout;
unsigned *up;
/*
* In order to keep track of how much window the client
* actually has available, we'd like it to acknowledge each
* WINDOW_ADJUST. We can't do that directly, so we accompany
* it with a CHANNEL_REQUEST that has to be acknowledged.
*
* This is only necessary if we're opening the window wide.
* If we're not, then throughput is being constrained by
* something other than the maximum window size anyway.
*/
if (newwin == c->locmaxwin &&
!(s->ppl.remote_bugs & BUG_CHOKES_ON_WINADJ)) {
up = snew(unsigned);
*up = newwin - c->locwindow;
pktout = ssh2_chanreq_init(c, "winadj@putty.projects.tartarus.org",
ssh2_handle_winadj_response, up);
pq_push(s->ppl.out_pq, pktout);
if (c->throttle_state != UNTHROTTLED)
c->throttle_state = UNTHROTTLING;
} else {
/* Pretend the WINDOW_ADJUST was acked immediately. */
c->remlocwin = newwin;
c->throttle_state = THROTTLED;
}
pktout = ssh_bpp_new_pktout(s->ppl.bpp, SSH2_MSG_CHANNEL_WINDOW_ADJUST);
put_uint32(pktout, c->remoteid);
put_uint32(pktout, newwin - c->locwindow);
pq_push(s->ppl.out_pq, pktout);
c->locwindow = newwin;
}
}
static PktIn *ssh2_connection_pop(struct ssh2_connection_state *s)
{
ssh2_connection_filter_queue(s);
return pq_pop(s->ppl.in_pq);
}
static void ssh2_connection_process_queue(PacketProtocolLayer *ppl)
{
struct ssh2_connection_state *s =
container_of(ppl, struct ssh2_connection_state, ppl);
PktIn *pktin;
if (ssh2_connection_filter_queue(s)) /* no matter why we were called */
return;
crBegin(s->crState);
if (s->connshare)
share_activate(s->connshare, s->peer_verstring);
/*
* Signal the seat that authentication is done, so that it can
* deploy spoofing defences. If it doesn't have any, deploy our
* own fallback one.
*
* We do this here rather than at the end of userauth, because we
* might not have gone through userauth at all (if we're a
* connection-sharing downstream).
*/
if (ssh2_connection_need_antispoof_prompt(s)) {
s->antispoof_prompt = new_prompts();
s->antispoof_prompt->to_server = true;
s->antispoof_prompt->from_server = false;
s->antispoof_prompt->name = dupstr("Authentication successful");
add_prompt(
s->antispoof_prompt,
dupstr("Access granted. Press Return to begin session. "), false);
s->antispoof_ret = seat_get_userpass_input(
s->ppl.seat, s->antispoof_prompt, NULL);
while (1) {
while (s->antispoof_ret < 0 &&
bufchain_size(s->ppl.user_input) > 0)
s->antispoof_ret = seat_get_userpass_input(
s->ppl.seat, s->antispoof_prompt, s->ppl.user_input);
if (s->antispoof_ret >= 0)
break;
s->want_user_input = true;
crReturnV;
s->want_user_input = false;
}
free_prompts(s->antispoof_prompt);
}
/*
* Enable port forwardings.
*/
portfwdmgr_config(s->portfwdmgr, s->conf);
s->portfwdmgr_configured = true;
/*
* Create the main session channel, if any.
*/
s->mainchan = mainchan_new(
&s->ppl, &s->cl, s->conf, s->term_width, s->term_height,
s->ssh_is_simple, &s->mainchan_sc);
/*
* Transfer data!
*/
while (1) {
if ((pktin = ssh2_connection_pop(s)) != NULL) {
/*
* _All_ the connection-layer packets we expect to
* receive are now handled by the dispatch table.
* Anything that reaches here must be bogus.
*/
ssh_proto_error(s->ppl.ssh, "Received unexpected connection-layer "
"packet, type %d (%s)", pktin->type,
ssh2_pkt_type(s->ppl.bpp->pls->kctx,
s->ppl.bpp->pls->actx,
pktin->type));
return;
}
crReturnV;
}
crFinishV;
}
static void ssh2_channel_check_close(struct ssh2_channel *c)
{
struct ssh2_connection_state *s = c->connlayer;
PktOut *pktout;
if (c->halfopen) {
/*
* If we've sent out our own CHANNEL_OPEN but not yet seen
* either OPEN_CONFIRMATION or OPEN_FAILURE in response, then
* it's too early to be sending close messages of any kind.
*/
return;
}
if (chan_want_close(c->chan, (c->closes & CLOSES_SENT_EOF),
(c->closes & CLOSES_RCVD_EOF)) &&
!c->chanreq_head &&
!(c->closes & CLOSES_SENT_CLOSE)) {
/*
* We have both sent and received EOF (or the channel is a
* zombie), and we have no outstanding channel requests, which
* means the channel is in final wind-up. But we haven't sent
* CLOSE, so let's do so now.
*/
pktout = ssh_bpp_new_pktout(s->ppl.bpp, SSH2_MSG_CHANNEL_CLOSE);
put_uint32(pktout, c->remoteid);
pq_push(s->ppl.out_pq, pktout);
c->closes |= CLOSES_SENT_EOF | CLOSES_SENT_CLOSE;
}
if (!((CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE) & ~c->closes)) {
assert(c->chanreq_head == NULL);
/*
* We have both sent and received CLOSE, which means we're
* completely done with the channel.
*/
ssh2_channel_destroy(c);
}
}
static void ssh2_channel_try_eof(struct ssh2_channel *c)
{
struct ssh2_connection_state *s = c->connlayer;
PktOut *pktout;
assert(c->pending_eof); /* precondition for calling us */
if (c->halfopen)
return; /* can't close: not even opened yet */
if (bufchain_size(&c->outbuffer) > 0 || bufchain_size(&c->errbuffer) > 0)
return; /* can't send EOF: pending outgoing data */
c->pending_eof = false; /* we're about to send it */
pktout = ssh_bpp_new_pktout(s->ppl.bpp, SSH2_MSG_CHANNEL_EOF);
put_uint32(pktout, c->remoteid);
pq_push(s->ppl.out_pq, pktout);
c->closes |= CLOSES_SENT_EOF;
ssh2_channel_check_close(c);
}
/*
* Attempt to send data on an SSH-2 channel.
*/
static size_t ssh2_try_send(struct ssh2_channel *c)
{
struct ssh2_connection_state *s = c->connlayer;
PktOut *pktout;
size_t bufsize;
if (!c->halfopen) {
while (c->remwindow > 0 &&
(bufchain_size(&c->outbuffer) > 0 ||
bufchain_size(&c->errbuffer) > 0)) {
bufchain *buf = (bufchain_size(&c->errbuffer) > 0 ?
&c->errbuffer : &c->outbuffer);
ptrlen data = bufchain_prefix(buf);
if (data.len > c->remwindow)
data.len = c->remwindow;
if (data.len > c->remmaxpkt)
data.len = c->remmaxpkt;
if (buf == &c->errbuffer) {
pktout = ssh_bpp_new_pktout(
s->ppl.bpp, SSH2_MSG_CHANNEL_EXTENDED_DATA);
put_uint32(pktout, c->remoteid);
put_uint32(pktout, SSH2_EXTENDED_DATA_STDERR);
} else {
pktout = ssh_bpp_new_pktout(s->ppl.bpp, SSH2_MSG_CHANNEL_DATA);
put_uint32(pktout, c->remoteid);
}
put_stringpl(pktout, data);
pq_push(s->ppl.out_pq, pktout);
bufchain_consume(buf, data.len);
c->remwindow -= data.len;
}
}
/*
* After having sent as much data as we can, return the amount
* still buffered.
*/
bufsize = bufchain_size(&c->outbuffer) + bufchain_size(&c->errbuffer);
/*
* And if there's no data pending but we need to send an EOF, send
* it.
*/
if (!bufsize && c->pending_eof)
ssh2_channel_try_eof(c);
return bufsize;
}
static void ssh2_try_send_and_unthrottle(struct ssh2_channel *c)
{
int bufsize;
if (c->closes & CLOSES_SENT_EOF)
return; /* don't send on channels we've EOFed */
bufsize = ssh2_try_send(c);
if (bufsize == 0) {
c->throttled_by_backlog = false;
ssh2_channel_check_throttle(c);
}
}
static void ssh2_channel_check_throttle(struct ssh2_channel *c)
{
/*
* We don't want this channel to read further input if this
* particular channel has a backed-up SSH window, or if the
* outgoing side of the whole SSH connection is currently
* throttled, or if this channel already has an outgoing EOF
* either sent or pending.
*/
chan_set_input_wanted(c->chan,
!c->throttled_by_backlog &&
!c->connlayer->all_channels_throttled &&
!c->pending_eof &&
!(c->closes & CLOSES_SENT_EOF));
}
/*
* Close any local socket and free any local resources associated with
* a channel. This converts the channel into a zombie.
*/
static void ssh2_channel_close_local(struct ssh2_channel *c,
const char *reason)
{
struct ssh2_connection_state *s = c->connlayer;
PacketProtocolLayer *ppl = &s->ppl; /* for ppl_logevent */
char *msg = NULL;
if (c->sharectx)
return;
msg = chan_log_close_msg(c->chan);
if (msg)
ppl_logevent("%s%s%s", msg, reason ? " " : "", reason ? reason : "");
sfree(msg);
chan_free(c->chan);
c->chan = zombiechan_new();
}
static void ssh2_check_termination_callback(void *vctx)
{
struct ssh2_connection_state *s = (struct ssh2_connection_state *)vctx;
ssh2_check_termination(s);
}
static void ssh2_channel_destroy(struct ssh2_channel *c)
{
struct ssh2_connection_state *s = c->connlayer;
assert(c->chanreq_head == NULL);
ssh2_channel_close_local(c, NULL);
del234(s->channels, c);
ssh2_channel_free(c);
/*
* If that was the last channel left open, we might need to
* terminate. But we'll be a bit cautious, by doing that in a
* toplevel callback, just in case anything on the current call
* stack objects to this entire PPL being freed.
*/
queue_toplevel_callback(ssh2_check_termination_callback, s);
}
static void ssh2_check_termination(struct ssh2_connection_state *s)
{
/*
* Decide whether we should terminate the SSH connection now.
* Called after a channel or a downstream goes away. The general
* policy is that we terminate when none of either is left.
*/
if (s->persistent)
return; /* persistent mode: never proactively terminate */
if (count234(s->channels) == 0 &&
!(s->connshare && share_ndownstreams(s->connshare) > 0)) {
/*
* We used to send SSH_MSG_DISCONNECT here, because I'd
* believed that _every_ conforming SSH-2 connection had to
* end with a disconnect being sent by at least one side;
* apparently I was wrong and it's perfectly OK to
* unceremoniously slam the connection shut when you're done,
* and indeed OpenSSH feels this is more polite than sending a
* DISCONNECT. So now we don't.
*/
ssh_user_close(s->ppl.ssh, "All channels closed");
return;
}
}
/*
* Set up most of a new ssh2_channel. Nulls out sharectx, but leaves
* chan untouched (since it will sometimes have been filled in before
* calling this).
*/
void ssh2_channel_init(struct ssh2_channel *c)
{
struct ssh2_connection_state *s = c->connlayer;
c->closes = 0;
c->pending_eof = false;
c->throttling_conn = false;
c->throttled_by_backlog = false;
c->sharectx = NULL;
c->locwindow = c->locmaxwin = c->remlocwin =
s->ssh_is_simple ? OUR_V2_BIGWIN : OUR_V2_WINSIZE;
c->chanreq_head = NULL;
c->throttle_state = UNTHROTTLED;
bufchain_init(&c->outbuffer);
bufchain_init(&c->errbuffer);
c->sc.vt = &ssh2channel_vtable;
c->sc.cl = &s->cl;
c->localid = alloc_channel_id(s->channels, struct ssh2_channel);
add234(s->channels, c);
}
/*
* Construct the common parts of a CHANNEL_OPEN.
*/
PktOut *ssh2_chanopen_init(struct ssh2_channel *c, const char *type)
{
struct ssh2_connection_state *s = c->connlayer;
PktOut *pktout;
pktout = ssh_bpp_new_pktout(s->ppl.bpp, SSH2_MSG_CHANNEL_OPEN);
put_stringz(pktout, type);
put_uint32(pktout, c->localid);
put_uint32(pktout, c->locwindow); /* our window size */
put_uint32(pktout, OUR_V2_MAXPKT); /* our max pkt size */
return pktout;
}
/*
* Construct the common parts of a CHANNEL_REQUEST. If handler is not
* NULL then a reply will be requested and the handler will be called
* when it arrives. The returned packet is ready to have any
* request-specific data added and be sent. Note that if a handler is
* provided, it's essential that the request actually be sent.
*
* The handler will usually be passed the response packet in pktin. If
* pktin is NULL, this means that no reply will ever be forthcoming
* (e.g. because the entire connection is being destroyed, or because
* the server initiated channel closure before we saw the response)
* and the handler should free any storage it's holding.
*/
PktOut *ssh2_chanreq_init(struct ssh2_channel *c, const char *type,
cr_handler_fn_t handler, void *ctx)
{
struct ssh2_connection_state *s = c->connlayer;
PktOut *pktout;
assert(!(c->closes & (CLOSES_SENT_CLOSE | CLOSES_RCVD_CLOSE)));
pktout = ssh_bpp_new_pktout(s->ppl.bpp, SSH2_MSG_CHANNEL_REQUEST);
put_uint32(pktout, c->remoteid);
put_stringz(pktout, type);
put_bool(pktout, handler != NULL);
if (handler != NULL) {
struct outstanding_channel_request *ocr =
snew(struct outstanding_channel_request);
ocr->handler = handler;
ocr->ctx = ctx;
ocr->next = NULL;
if (!c->chanreq_head)
c->chanreq_head = ocr;
else
c->chanreq_tail->next = ocr;
c->chanreq_tail = ocr;
}
return pktout;
}
static Conf *ssh2channel_get_conf(SshChannel *sc)
{
struct ssh2_channel *c = container_of(sc, struct ssh2_channel, sc);
struct ssh2_connection_state *s = c->connlayer;
return s->conf;
}
static void ssh2channel_write_eof(SshChannel *sc)
{
struct ssh2_channel *c = container_of(sc, struct ssh2_channel, sc);
if (c->closes & CLOSES_SENT_EOF)
return;
c->pending_eof = true;
ssh2_channel_try_eof(c);
}
static void ssh2channel_initiate_close(SshChannel *sc, const char *err)
{
struct ssh2_channel *c = container_of(sc, struct ssh2_channel, sc);
char *reason;
reason = err ? dupprintf("due to local error: %s", err) : NULL;
ssh2_channel_close_local(c, reason);
sfree(reason);
c->pending_eof = false; /* this will confuse a zombie channel */
ssh2_channel_check_close(c);
}
static void ssh2channel_unthrottle(SshChannel *sc, size_t bufsize)
{
struct ssh2_channel *c = container_of(sc, struct ssh2_channel, sc);
struct ssh2_connection_state *s = c->connlayer;
size_t buflimit;
buflimit = s->ssh_is_simple ? 0 : c->locmaxwin;
if (bufsize < buflimit)
ssh2_set_window(c, buflimit - bufsize);
if (c->throttling_conn && bufsize <= buflimit) {
c->throttling_conn = false;
ssh_throttle_conn(s->ppl.ssh, -1);
}
}
static size_t ssh2channel_write(
SshChannel *sc, bool is_stderr, const void *buf, size_t len)
{
struct ssh2_channel *c = container_of(sc, struct ssh2_channel, sc);
assert(!(c->closes & CLOSES_SENT_EOF));
bufchain_add(is_stderr ? &c->errbuffer : &c->outbuffer, buf, len);
return ssh2_try_send(c);
}
static void ssh2channel_x11_sharing_handover(
SshChannel *sc, ssh_sharing_connstate *share_cs, share_channel *share_chan,
const char *peer_addr, int peer_port, int endian,
int protomajor, int protominor, const void *initial_data, int initial_len)
{
struct ssh2_channel *c = container_of(sc, struct ssh2_channel, sc);
/*
* This function is called when we've just discovered that an X
* forwarding channel on which we'd been handling the initial auth
* ourselves turns out to be destined for a connection-sharing
* downstream. So we turn the channel into a sharing one, meaning
* that we completely stop tracking windows and buffering data and
* just pass more or less unmodified SSH messages back and forth.
*/
c->sharectx = share_cs;
share_setup_x11_channel(share_cs, share_chan,
c->localid, c->remoteid, c->remwindow,
c->remmaxpkt, c->locwindow,
peer_addr, peer_port, endian,
protomajor, protominor,
initial_data, initial_len);
chan_free(c->chan);
c->chan = NULL;
}
static void ssh2channel_window_override_removed(SshChannel *sc)
{
struct ssh2_channel *c = container_of(sc, struct ssh2_channel, sc);
struct ssh2_connection_state *s = c->connlayer;
/*
* This function is called when a client-side Channel has just
* stopped requiring an initial fixed-size window.
*/
assert(!c->chan->initial_fixed_window_size);
ssh2_set_window(c, s->ssh_is_simple ? OUR_V2_BIGWIN : OUR_V2_WINSIZE);
}
static void ssh2channel_hint_channel_is_simple(SshChannel *sc)
{
struct ssh2_channel *c = container_of(sc, struct ssh2_channel, sc);
struct ssh2_connection_state *s = c->connlayer;
PktOut *pktout = ssh2_chanreq_init(
c, "simple@putty.projects.tartarus.org", NULL, NULL);
pq_push(s->ppl.out_pq, pktout);
}
static SshChannel *ssh2_lportfwd_open(
ConnectionLayer *cl, const char *hostname, int port,
const char *description, const SocketPeerInfo *pi, Channel *chan)
{
struct ssh2_connection_state *s =
container_of(cl, struct ssh2_connection_state, cl);
struct ssh2_channel *c = snew(struct ssh2_channel);
PktOut *pktout;
c->connlayer = s;
ssh2_channel_init(c);
c->halfopen = true;
c->chan = chan;
pktout = ssh2_portfwd_chanopen(s, c, hostname, port, description, pi);
pq_push(s->ppl.out_pq, pktout);
return &c->sc;
}
static void ssh2_sharing_globreq_response(
struct ssh2_connection_state *s, PktIn *pktin, void *ctx)
{
ssh_sharing_connstate *cs = (ssh_sharing_connstate *)ctx;
share_got_pkt_from_server(cs, pktin->type,
BinarySource_UPCAST(pktin)->data,
BinarySource_UPCAST(pktin)->len);
}
static void ssh2_sharing_queue_global_request(
ConnectionLayer *cl, ssh_sharing_connstate *cs)
{
struct ssh2_connection_state *s =
container_of(cl, struct ssh2_connection_state, cl);
ssh2_queue_global_request_handler(s, ssh2_sharing_globreq_response, cs);
}
static void ssh2_sharing_no_more_downstreams(ConnectionLayer *cl)
{
struct ssh2_connection_state *s =
container_of(cl, struct ssh2_connection_state, cl);
queue_toplevel_callback(ssh2_check_termination_callback, s);
}
static struct X11FakeAuth *ssh2_add_x11_display(
ConnectionLayer *cl, int authtype, struct X11Display *disp)
{
struct ssh2_connection_state *s =
container_of(cl, struct ssh2_connection_state, cl);
struct X11FakeAuth *auth = x11_invent_fake_auth(s->x11authtree, authtype);
auth->disp = disp;
return auth;
}
static struct X11FakeAuth *ssh2_add_sharing_x11_display(
ConnectionLayer *cl, int authtype, ssh_sharing_connstate *share_cs,
share_channel *share_chan)
{
struct ssh2_connection_state *s =
container_of(cl, struct ssh2_connection_state, cl);
struct X11FakeAuth *auth;
/*
* Make up a new set of fake X11 auth data, and add it to the tree
* of currently valid ones with an indication of the sharing
* context that it's relevant to.
*/
auth = x11_invent_fake_auth(s->x11authtree, authtype);
auth->share_cs = share_cs;
auth->share_chan = share_chan;
return auth;
}
static void ssh2_remove_sharing_x11_display(
ConnectionLayer *cl, struct X11FakeAuth *auth)
{
struct ssh2_connection_state *s =
container_of(cl, struct ssh2_connection_state, cl);
del234(s->x11authtree, auth);
x11_free_fake_auth(auth);
}
static unsigned ssh2_alloc_sharing_channel(
ConnectionLayer *cl, ssh_sharing_connstate *connstate)
{
struct ssh2_connection_state *s =
container_of(cl, struct ssh2_connection_state, cl);
struct ssh2_channel *c = snew(struct ssh2_channel);
c->connlayer = s;
ssh2_channel_init(c);
c->chan = NULL;
c->sharectx = connstate;
return c->localid;
}
static void ssh2_delete_sharing_channel(ConnectionLayer *cl, unsigned localid)
{
struct ssh2_connection_state *s =
container_of(cl, struct ssh2_connection_state, cl);
struct ssh2_channel *c = find234(s->channels, &localid, ssh2_channelfind);
if (c)
ssh2_channel_destroy(c);
}
static void ssh2_send_packet_from_downstream(
ConnectionLayer *cl, unsigned id, int type,
const void *data, int datalen, const char *additional_log_text)
{
struct ssh2_connection_state *s =
container_of(cl, struct ssh2_connection_state, cl);
PktOut *pkt = ssh_bpp_new_pktout(s->ppl.bpp, type);
pkt->downstream_id = id;
pkt->additional_log_text = additional_log_text;
put_data(pkt, data, datalen);
pq_push(s->ppl.out_pq, pkt);
}
static bool ssh2_agent_forwarding_permitted(ConnectionLayer *cl)
{
struct ssh2_connection_state *s =
container_of(cl, struct ssh2_connection_state, cl);
return conf_get_bool(s->conf, CONF_agentfwd) && agent_exists();
}
static bool ssh2_connection_get_specials(
PacketProtocolLayer *ppl, add_special_fn_t add_special, void *ctx)
{
struct ssh2_connection_state *s =
container_of(ppl, struct ssh2_connection_state, ppl);
bool toret = false;
if (s->mainchan) {
mainchan_get_specials(s->mainchan, add_special, ctx);
toret = true;
}
/*
* Don't bother offering IGNORE if we've decided the remote
* won't cope with it, since we wouldn't bother sending it if
* asked anyway.
*/
if (!(s->ppl.remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
if (toret)
add_special(ctx, NULL, SS_SEP, 0);
add_special(ctx, "IGNORE message", SS_NOP, 0);
toret = true;
}
return toret;
}
static void ssh2_connection_special_cmd(PacketProtocolLayer *ppl,
SessionSpecialCode code, int arg)
{
struct ssh2_connection_state *s =
container_of(ppl, struct ssh2_connection_state, ppl);
PktOut *pktout;
if (code == SS_PING || code == SS_NOP) {
if (!(s->ppl.remote_bugs & BUG_CHOKES_ON_SSH2_IGNORE)) {
pktout = ssh_bpp_new_pktout(s->ppl.bpp, SSH2_MSG_IGNORE);
put_stringz(pktout, "");
pq_push(s->ppl.out_pq, pktout);
}
} else if (s->mainchan) {
mainchan_special_cmd(s->mainchan, code, arg);
}
}
static void ssh2_terminal_size(ConnectionLayer *cl, int width, int height)
{
struct ssh2_connection_state *s =
container_of(cl, struct ssh2_connection_state, cl);
s->term_width = width;
s->term_height = height;
if (s->mainchan)
mainchan_terminal_size(s->mainchan, width, height);
}
static void ssh2_stdout_unthrottle(ConnectionLayer *cl, size_t bufsize)
{
struct ssh2_connection_state *s =
container_of(cl, struct ssh2_connection_state, cl);
if (s->mainchan)
sshfwd_unthrottle(s->mainchan_sc, bufsize);
}
static size_t ssh2_stdin_backlog(ConnectionLayer *cl)
{
struct ssh2_connection_state *s =
container_of(cl, struct ssh2_connection_state, cl);
struct ssh2_channel *c;
if (!s->mainchan)
return 0;
c = container_of(s->mainchan_sc, struct ssh2_channel, sc);
return s->mainchan ?
bufchain_size(&c->outbuffer) + bufchain_size(&c->errbuffer) : 0;
}
static void ssh2_throttle_all_channels(ConnectionLayer *cl, bool throttled)
{
struct ssh2_connection_state *s =
container_of(cl, struct ssh2_connection_state, cl);
struct ssh2_channel *c;
int i;
s->all_channels_throttled = throttled;
for (i = 0; NULL != (c = index234(s->channels, i)); i++)
if (!c->sharectx)
ssh2_channel_check_throttle(c);
}
static bool ssh2_ldisc_option(ConnectionLayer *cl, int option)
{
struct ssh2_connection_state *s =
container_of(cl, struct ssh2_connection_state, cl);
return s->ldisc_opts[option];
}
static void ssh2_set_ldisc_option(ConnectionLayer *cl, int option, bool value)
{
struct ssh2_connection_state *s =
container_of(cl, struct ssh2_connection_state, cl);
s->ldisc_opts[option] = value;
}
static void ssh2_enable_x_fwd(ConnectionLayer *cl)
{
struct ssh2_connection_state *s =
container_of(cl, struct ssh2_connection_state, cl);
s->X11_fwd_enabled = true;
}
static void ssh2_enable_agent_fwd(ConnectionLayer *cl)
{
struct ssh2_connection_state *s =
container_of(cl, struct ssh2_connection_state, cl);
s->agent_fwd_enabled = true;
}
static void ssh2_set_wants_user_input(ConnectionLayer *cl, bool wanted)
{
struct ssh2_connection_state *s =
container_of(cl, struct ssh2_connection_state, cl);
s->want_user_input = wanted;
}
static bool ssh2_connection_want_user_input(PacketProtocolLayer *ppl)
{
struct ssh2_connection_state *s =
container_of(ppl, struct ssh2_connection_state, ppl);
return s->want_user_input;
}
static void ssh2_connection_got_user_input(PacketProtocolLayer *ppl)
{
struct ssh2_connection_state *s =
container_of(ppl, struct ssh2_connection_state, ppl);
while (s->mainchan && bufchain_size(s->ppl.user_input) > 0) {
/*
* Add user input to the main channel's buffer.
*/
ptrlen data = bufchain_prefix(s->ppl.user_input);
sshfwd_write(s->mainchan_sc, data.ptr, data.len);
bufchain_consume(s->ppl.user_input, data.len);
}
}
static void ssh2_connection_reconfigure(PacketProtocolLayer *ppl, Conf *conf)
{
struct ssh2_connection_state *s =
container_of(ppl, struct ssh2_connection_state, ppl);
conf_free(s->conf);
s->conf = conf_copy(conf);
if (s->portfwdmgr_configured)
portfwdmgr_config(s->portfwdmgr, s->conf);
}
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