mirror of
https://git.tartarus.org/simon/putty.git
synced 2025-01-09 17:38:00 +00:00
2160205aee
In commit09954a87cI introduced the portfwdmgr_connect_socket() system, which opened a port forwarding given a callback to create the Socket itself, with the aim of using it to make forwardings to Unix- domain sockets and Windows named pipes (both initially for agent forwarding). But I forgot that a year and a bit ago, in commit834396170, I already introduced a similar low-level system for creating a PortForwarding around an unusual kind of socket: the portfwd_raw_new() system, which in place of a callback uses a two-phase setup protocol (you create the socket in between the two setup calls, and can roll it back if the socket can't be created). There's really no need to have _both_ these systems! So now I'm merging them, which is to say, I'm enhancing portfwd_raw_new to have the one new feature it needs, and throwing away the newer system completely. The new feature is to be able to control the initial state of the 'ready' flag: portfwd_raw_new was always used for initiating port forwardings in response to an incoming local connection, which means you need to start off with ready=false and set it true when the other end of the SSH connection sends back OPEN_CONFIRMATION. Now it's being used for initiating port forwardings in response to a CHANNEL_OPEN, we need to be able to start with ready=true. This commit reverts09954a87c2and its followup fix12aa06ccc9, and simplifies the agent_connect system down to a single trivial function that makes a Socket given a Plug.
501 lines
15 KiB
C
501 lines
15 KiB
C
/*
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* Client-specific parts of the SSH-2 connection layer.
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*/
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#include <assert.h>
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#include "putty.h"
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#include "ssh.h"
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#include "sshbpp.h"
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#include "sshppl.h"
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#include "sshchan.h"
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#include "sshcr.h"
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#include "ssh2connection.h"
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static ChanopenResult chan_open_x11(
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struct ssh2_connection_state *s, SshChannel *sc,
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ptrlen peeraddr, int peerport)
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{
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PacketProtocolLayer *ppl = &s->ppl; /* for ppl_logevent */
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char *peeraddr_str;
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Channel *ch;
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ppl_logevent("Received X11 connect request from %.*s:%d",
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PTRLEN_PRINTF(peeraddr), peerport);
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if (!s->X11_fwd_enabled && !s->connshare) {
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CHANOPEN_RETURN_FAILURE(
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SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED,
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("X11 forwarding is not enabled"));
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}
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peeraddr_str = peeraddr.ptr ? mkstr(peeraddr) : NULL;
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ch = x11_new_channel(
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s->x11authtree, sc, peeraddr_str, peerport, s->connshare != NULL);
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sfree(peeraddr_str);
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ppl_logevent("Opened X11 forward channel");
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CHANOPEN_RETURN_SUCCESS(ch);
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}
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static ChanopenResult chan_open_forwarded_tcpip(
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struct ssh2_connection_state *s, SshChannel *sc,
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ptrlen fwdaddr, int fwdport, ptrlen peeraddr, int peerport)
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{
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PacketProtocolLayer *ppl = &s->ppl; /* for ppl_logevent */
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struct ssh_rportfwd pf, *realpf;
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Channel *ch;
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char *err;
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ppl_logevent("Received remote port %.*s:%d open request from %.*s:%d",
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PTRLEN_PRINTF(fwdaddr), fwdport,
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PTRLEN_PRINTF(peeraddr), peerport);
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pf.shost = mkstr(fwdaddr);
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pf.sport = fwdport;
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realpf = find234(s->rportfwds, &pf, NULL);
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sfree(pf.shost);
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if (realpf == NULL) {
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CHANOPEN_RETURN_FAILURE(
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SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED,
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("Remote port is not recognised"));
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}
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if (realpf->share_ctx) {
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/*
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* This port forwarding is on behalf of a connection-sharing
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* downstream.
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*/
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CHANOPEN_RETURN_DOWNSTREAM(realpf->share_ctx);
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}
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err = portfwdmgr_connect(
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s->portfwdmgr, &ch, realpf->dhost, realpf->dport,
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sc, realpf->addressfamily);
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ppl_logevent("Attempting to forward remote port to %s:%d",
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realpf->dhost, realpf->dport);
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if (err != NULL) {
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ppl_logevent("Port open failed: %s", err);
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sfree(err);
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CHANOPEN_RETURN_FAILURE(
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SSH2_OPEN_CONNECT_FAILED,
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("Port open failed"));
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}
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ppl_logevent("Forwarded port opened successfully");
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CHANOPEN_RETURN_SUCCESS(ch);
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}
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static ChanopenResult chan_open_auth_agent(
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struct ssh2_connection_state *s, SshChannel *sc)
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{
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if (!s->agent_fwd_enabled) {
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CHANOPEN_RETURN_FAILURE(
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SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED,
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("Agent forwarding is not enabled"));
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}
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/*
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* If possible, make a stream-oriented connection to the agent and
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* set up an ordinary port-forwarding type channel over it.
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*/
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Plug *plug;
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Channel *ch = portfwd_raw_new(&s->cl, &plug, true);
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Socket *skt = agent_connect(plug);
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if (!sk_socket_error(skt)) {
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portfwd_raw_setup(ch, skt, sc);
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CHANOPEN_RETURN_SUCCESS(ch);
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} else {
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portfwd_raw_free(ch);
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/*
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* Otherwise, fall back to the old-fashioned system of parsing the
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* forwarded data stream ourselves for message boundaries, and
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* passing each individual message to the one-off agent_query().
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*/
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CHANOPEN_RETURN_SUCCESS(agentf_new(sc));
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}
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}
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ChanopenResult ssh2_connection_parse_channel_open(
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struct ssh2_connection_state *s, ptrlen type,
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PktIn *pktin, SshChannel *sc)
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{
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if (ptrlen_eq_string(type, "x11")) {
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ptrlen peeraddr = get_string(pktin);
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int peerport = get_uint32(pktin);
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return chan_open_x11(s, sc, peeraddr, peerport);
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} else if (ptrlen_eq_string(type, "forwarded-tcpip")) {
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ptrlen fwdaddr = get_string(pktin);
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int fwdport = toint(get_uint32(pktin));
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ptrlen peeraddr = get_string(pktin);
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int peerport = toint(get_uint32(pktin));
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return chan_open_forwarded_tcpip(
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s, sc, fwdaddr, fwdport, peeraddr, peerport);
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} else if (ptrlen_eq_string(type, "auth-agent@openssh.com")) {
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return chan_open_auth_agent(s, sc);
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} else {
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CHANOPEN_RETURN_FAILURE(
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SSH2_OPEN_UNKNOWN_CHANNEL_TYPE,
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("Unsupported channel type requested"));
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}
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}
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bool ssh2_connection_parse_global_request(
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struct ssh2_connection_state *s, ptrlen type, PktIn *pktin)
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{
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/*
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* We don't know of any global requests that an SSH client needs
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* to honour.
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*/
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return false;
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}
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PktOut *ssh2_portfwd_chanopen(
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struct ssh2_connection_state *s, struct ssh2_channel *c,
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const char *hostname, int port,
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const char *description, const SocketPeerInfo *peerinfo)
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{
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PacketProtocolLayer *ppl = &s->ppl; /* for ppl_logevent */
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PktOut *pktout;
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/*
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* In client mode, this function is called by portfwdmgr in
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* response to PortListeners that were set up in
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* portfwdmgr_config, which means that the hostname and port
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* parameters will indicate the host we want to tell the server to
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* connect _to_.
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*/
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ppl_logevent("Opening connection to %s:%d for %s",
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hostname, port, description);
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pktout = ssh2_chanopen_init(c, "direct-tcpip");
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{
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char *trimmed_host = host_strduptrim(hostname);
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put_stringz(pktout, trimmed_host);
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sfree(trimmed_host);
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}
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put_uint32(pktout, port);
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/*
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* We make up values for the originator data; partly it's too much
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* hassle to keep track, and partly I'm not convinced the server
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* should be told details like that about my local network
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* configuration. The "originator IP address" is syntactically a
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* numeric IP address, and some servers (e.g., Tectia) get upset
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* if it doesn't match this syntax.
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*/
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put_stringz(pktout, "0.0.0.0");
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put_uint32(pktout, 0);
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return pktout;
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}
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static int ssh2_rportfwd_cmp(void *av, void *bv)
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{
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struct ssh_rportfwd *a = (struct ssh_rportfwd *) av;
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struct ssh_rportfwd *b = (struct ssh_rportfwd *) bv;
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int i;
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if ( (i = strcmp(a->shost, b->shost)) != 0)
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return i < 0 ? -1 : +1;
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if (a->sport > b->sport)
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return +1;
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if (a->sport < b->sport)
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return -1;
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return 0;
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}
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static void ssh2_rportfwd_globreq_response(struct ssh2_connection_state *s,
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PktIn *pktin, void *ctx)
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{
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PacketProtocolLayer *ppl = &s->ppl; /* for ppl_logevent */
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struct ssh_rportfwd *rpf = (struct ssh_rportfwd *)ctx;
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if (pktin->type == SSH2_MSG_REQUEST_SUCCESS) {
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ppl_logevent("Remote port forwarding from %s enabled",
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rpf->log_description);
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} else {
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ppl_logevent("Remote port forwarding from %s refused",
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rpf->log_description);
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struct ssh_rportfwd *realpf = del234(s->rportfwds, rpf);
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assert(realpf == rpf);
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portfwdmgr_close(s->portfwdmgr, rpf->pfr);
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free_rportfwd(rpf);
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}
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}
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struct ssh_rportfwd *ssh2_rportfwd_alloc(
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ConnectionLayer *cl,
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const char *shost, int sport, const char *dhost, int dport,
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int addressfamily, const char *log_description, PortFwdRecord *pfr,
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ssh_sharing_connstate *share_ctx)
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{
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struct ssh2_connection_state *s =
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container_of(cl, struct ssh2_connection_state, cl);
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struct ssh_rportfwd *rpf = snew(struct ssh_rportfwd);
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if (!s->rportfwds)
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s->rportfwds = newtree234(ssh2_rportfwd_cmp);
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rpf->shost = dupstr(shost);
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rpf->sport = sport;
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rpf->dhost = dupstr(dhost);
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rpf->dport = dport;
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rpf->addressfamily = addressfamily;
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rpf->log_description = dupstr(log_description);
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rpf->pfr = pfr;
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rpf->share_ctx = share_ctx;
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if (add234(s->rportfwds, rpf) != rpf) {
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free_rportfwd(rpf);
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return NULL;
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}
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if (!rpf->share_ctx) {
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PktOut *pktout = ssh_bpp_new_pktout(
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s->ppl.bpp, SSH2_MSG_GLOBAL_REQUEST);
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put_stringz(pktout, "tcpip-forward");
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put_bool(pktout, true); /* want reply */
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put_stringz(pktout, rpf->shost);
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put_uint32(pktout, rpf->sport);
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pq_push(s->ppl.out_pq, pktout);
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ssh2_queue_global_request_handler(
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s, ssh2_rportfwd_globreq_response, rpf);
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}
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return rpf;
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}
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void ssh2_rportfwd_remove(ConnectionLayer *cl, struct ssh_rportfwd *rpf)
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{
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struct ssh2_connection_state *s =
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container_of(cl, struct ssh2_connection_state, cl);
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if (rpf->share_ctx) {
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/*
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* We don't manufacture a cancel-tcpip-forward message for
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* remote port forwardings being removed on behalf of a
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* downstream; we just pass through the one the downstream
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* sent to us.
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*/
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} else {
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PktOut *pktout = ssh_bpp_new_pktout(
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s->ppl.bpp, SSH2_MSG_GLOBAL_REQUEST);
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put_stringz(pktout, "cancel-tcpip-forward");
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put_bool(pktout, false); /* _don't_ want reply */
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put_stringz(pktout, rpf->shost);
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put_uint32(pktout, rpf->sport);
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pq_push(s->ppl.out_pq, pktout);
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}
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assert(s->rportfwds);
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struct ssh_rportfwd *realpf = del234(s->rportfwds, rpf);
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assert(realpf == rpf);
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free_rportfwd(rpf);
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}
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SshChannel *ssh2_session_open(ConnectionLayer *cl, Channel *chan)
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{
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struct ssh2_connection_state *s =
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container_of(cl, struct ssh2_connection_state, cl);
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PacketProtocolLayer *ppl = &s->ppl; /* for ppl_logevent */
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struct ssh2_channel *c = snew(struct ssh2_channel);
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PktOut *pktout;
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c->connlayer = s;
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ssh2_channel_init(c);
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c->halfopen = true;
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c->chan = chan;
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ppl_logevent("Opening main session channel");
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pktout = ssh2_chanopen_init(c, "session");
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pq_push(s->ppl.out_pq, pktout);
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return &c->sc;
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}
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SshChannel *ssh2_serverside_x11_open(
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ConnectionLayer *cl, Channel *chan, const SocketPeerInfo *pi)
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{
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unreachable("Should never be called in the client");
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}
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SshChannel *ssh2_serverside_agent_open(ConnectionLayer *cl, Channel *chan)
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{
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unreachable("Should never be called in the client");
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}
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static void ssh2_channel_response(
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struct ssh2_channel *c, PktIn *pkt, void *ctx)
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{
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chan_request_response(c->chan, pkt->type == SSH2_MSG_CHANNEL_SUCCESS);
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}
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void ssh2channel_start_shell(SshChannel *sc, bool want_reply)
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{
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struct ssh2_channel *c = container_of(sc, struct ssh2_channel, sc);
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struct ssh2_connection_state *s = c->connlayer;
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PktOut *pktout = ssh2_chanreq_init(
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c, "shell", want_reply ? ssh2_channel_response : NULL, NULL);
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pq_push(s->ppl.out_pq, pktout);
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}
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void ssh2channel_start_command(
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SshChannel *sc, bool want_reply, const char *command)
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{
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struct ssh2_channel *c = container_of(sc, struct ssh2_channel, sc);
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struct ssh2_connection_state *s = c->connlayer;
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PktOut *pktout = ssh2_chanreq_init(
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c, "exec", want_reply ? ssh2_channel_response : NULL, NULL);
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put_stringz(pktout, command);
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pq_push(s->ppl.out_pq, pktout);
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}
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bool ssh2channel_start_subsystem(
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SshChannel *sc, bool want_reply, const char *subsystem)
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{
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struct ssh2_channel *c = container_of(sc, struct ssh2_channel, sc);
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struct ssh2_connection_state *s = c->connlayer;
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PktOut *pktout = ssh2_chanreq_init(
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c, "subsystem", want_reply ? ssh2_channel_response : NULL, NULL);
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put_stringz(pktout, subsystem);
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pq_push(s->ppl.out_pq, pktout);
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return true;
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}
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void ssh2channel_send_exit_status(SshChannel *sc, int status)
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{
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unreachable("Should never be called in the client");
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}
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void ssh2channel_send_exit_signal(
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SshChannel *sc, ptrlen signame, bool core_dumped, ptrlen msg)
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{
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unreachable("Should never be called in the client");
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}
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void ssh2channel_send_exit_signal_numeric(
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SshChannel *sc, int signum, bool core_dumped, ptrlen msg)
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{
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unreachable("Should never be called in the client");
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}
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void ssh2channel_request_x11_forwarding(
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SshChannel *sc, bool want_reply, const char *authproto,
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const char *authdata, int screen_number, bool oneshot)
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{
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struct ssh2_channel *c = container_of(sc, struct ssh2_channel, sc);
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struct ssh2_connection_state *s = c->connlayer;
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PktOut *pktout = ssh2_chanreq_init(
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c, "x11-req", want_reply ? ssh2_channel_response : NULL, NULL);
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put_bool(pktout, oneshot);
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put_stringz(pktout, authproto);
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put_stringz(pktout, authdata);
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put_uint32(pktout, screen_number);
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pq_push(s->ppl.out_pq, pktout);
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}
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void ssh2channel_request_agent_forwarding(SshChannel *sc, bool want_reply)
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{
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struct ssh2_channel *c = container_of(sc, struct ssh2_channel, sc);
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struct ssh2_connection_state *s = c->connlayer;
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PktOut *pktout = ssh2_chanreq_init(
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c, "auth-agent-req@openssh.com",
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want_reply ? ssh2_channel_response : NULL, NULL);
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pq_push(s->ppl.out_pq, pktout);
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}
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void ssh2channel_request_pty(
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SshChannel *sc, bool want_reply, Conf *conf, int w, int h)
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{
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struct ssh2_channel *c = container_of(sc, struct ssh2_channel, sc);
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struct ssh2_connection_state *s = c->connlayer;
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strbuf *modebuf;
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PktOut *pktout = ssh2_chanreq_init(
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c, "pty-req", want_reply ? ssh2_channel_response : NULL, NULL);
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put_stringz(pktout, conf_get_str(conf, CONF_termtype));
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put_uint32(pktout, w);
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put_uint32(pktout, h);
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put_uint32(pktout, 0); /* pixel width */
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put_uint32(pktout, 0); /* pixel height */
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modebuf = strbuf_new();
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write_ttymodes_to_packet(
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BinarySink_UPCAST(modebuf), 2,
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get_ttymodes_from_conf(s->ppl.seat, conf));
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put_stringsb(pktout, modebuf);
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pq_push(s->ppl.out_pq, pktout);
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}
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bool ssh2channel_send_env_var(
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SshChannel *sc, bool want_reply, const char *var, const char *value)
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{
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struct ssh2_channel *c = container_of(sc, struct ssh2_channel, sc);
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struct ssh2_connection_state *s = c->connlayer;
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PktOut *pktout = ssh2_chanreq_init(
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c, "env", want_reply ? ssh2_channel_response : NULL, NULL);
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put_stringz(pktout, var);
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put_stringz(pktout, value);
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pq_push(s->ppl.out_pq, pktout);
|
|
|
|
return true;
|
|
}
|
|
|
|
bool ssh2channel_send_serial_break(SshChannel *sc, bool want_reply, int length)
|
|
{
|
|
struct ssh2_channel *c = container_of(sc, struct ssh2_channel, sc);
|
|
struct ssh2_connection_state *s = c->connlayer;
|
|
|
|
PktOut *pktout = ssh2_chanreq_init(
|
|
c, "break", want_reply ? ssh2_channel_response : NULL, NULL);
|
|
put_uint32(pktout, length);
|
|
pq_push(s->ppl.out_pq, pktout);
|
|
|
|
return true;
|
|
}
|
|
|
|
bool ssh2channel_send_signal(
|
|
SshChannel *sc, bool want_reply, const char *signame)
|
|
{
|
|
struct ssh2_channel *c = container_of(sc, struct ssh2_channel, sc);
|
|
struct ssh2_connection_state *s = c->connlayer;
|
|
|
|
PktOut *pktout = ssh2_chanreq_init(
|
|
c, "signal", want_reply ? ssh2_channel_response : NULL, NULL);
|
|
put_stringz(pktout, signame);
|
|
pq_push(s->ppl.out_pq, pktout);
|
|
|
|
return true;
|
|
}
|
|
|
|
void ssh2channel_send_terminal_size_change(SshChannel *sc, int w, int h)
|
|
{
|
|
struct ssh2_channel *c = container_of(sc, struct ssh2_channel, sc);
|
|
struct ssh2_connection_state *s = c->connlayer;
|
|
|
|
PktOut *pktout = ssh2_chanreq_init(c, "window-change", NULL, NULL);
|
|
put_uint32(pktout, w);
|
|
put_uint32(pktout, h);
|
|
put_uint32(pktout, 0); /* pixel width */
|
|
put_uint32(pktout, 0); /* pixel height */
|
|
pq_push(s->ppl.out_pq, pktout);
|
|
}
|
|
|
|
bool ssh2_connection_need_antispoof_prompt(struct ssh2_connection_state *s)
|
|
{
|
|
return !seat_set_trust_status(s->ppl.seat, false);
|
|
}
|