refactor channels.c

Move static state to a "struct ssh_channels" that is allocated at
runtime and tracked as a member of struct ssh.

Explicitly pass "struct ssh" to all channels functions.

Replace use of the legacy packet APIs in channels.c.

Rework sshd_config PermitOpen handling: previously the configuration
parser would call directly into the channels layer. After the refactor
this is not possible, as the channels structures are allocated at
connection time and aren't available when the configuration is parsed.
The server config parser now tracks PermitOpen itself and explicitly
configures the channels code later.

ok markus@

1 files changed, 48 insertions, 40 deletions

diff --git a/usr.bin/ssh/ssh.c b/usr.bin/ssh/ssh.c
index 3733dfbfe09..2451dfd9758 100644
--- a/usr.bin/ssh/ssh.c
+++ b/usr.bin/ssh/ssh.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh.c,v 1.462 2017/08/12 06:46:01 djm Exp $ */
+/* $OpenBSD: ssh.c,v 1.463 2017/09/12 06:32:07 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -192,7 +192,7 @@ usage(void)
 	exit(255);
 }
 
-static int ssh_session2(void);
+static int ssh_session2(struct ssh *);
 static void load_public_identity_files(void);
 static void main_sigchld_handler(int);
 
@@ -565,6 +565,14 @@ main(int ac, char **av)
 	 */
 	initialize_options(&options);
 
+	/*
+	 * Prepare main ssh transport/connection structures
+	 */
+	if ((ssh = ssh_alloc_session_state()) == NULL)
+		fatal("Couldn't allocate session state");
+	channel_init_channels(ssh);
+	active_state = ssh; /* XXX legacy API compat */
+
 	/* Parse command-line arguments. */
 	host = NULL;
 	use_syslog = 0;
@@ -1077,7 +1085,7 @@ main(int ac, char **av)
 
 	if (options.port == 0)
 		options.port = default_ssh_port();
-	channel_set_af(options.address_family);
+	channel_set_af(ssh, options.address_family);
 
 	/* Tidy and check options */
 	if (options.host_key_alias != NULL)
@@ -1219,8 +1227,7 @@ main(int ac, char **av)
 	if (options.control_path != NULL) {
 		int sock;
 		if ((sock = muxclient(options.control_path)) >= 0) {
-			packet_set_connection(sock, sock);
-			ssh = active_state; /* XXX */
+			ssh_packet_set_connection(ssh, sock, sock);
 			packet_set_mux();
 			goto skip_connect;
 		}
@@ -1240,7 +1247,7 @@ main(int ac, char **av)
 	timeout_ms = options.connection_timeout * 1000;
 
 	/* Open a connection to the remote host. */
-	if (ssh_connect(host, addrs, &hostaddr, options.port,
+	if (ssh_connect(ssh, host, addrs, &hostaddr, options.port,
 	    options.address_family, options.connection_attempts,
 	    &timeout_ms, options.tcp_keep_alive,
 	    options.use_privileged_port) != 0)
@@ -1407,7 +1414,7 @@ main(int ac, char **av)
 	}
 
  skip_connect:
-	exit_status = ssh_session2();
+	exit_status = ssh_session2(ssh);
 	packet_close();
 
 	if (options.control_path != NULL && muxserver_sock != -1)
@@ -1480,7 +1487,7 @@ fork_postauth(void)
 
 /* Callback for remote forward global requests */
 static void
-ssh_confirm_remote_forward(int type, u_int32_t seq, void *ctxt)
+ssh_confirm_remote_forward(struct ssh *ssh, int type, u_int32_t seq, void *ctxt)
 {
 	struct Forward *rfwd = (struct Forward *)ctxt;
 
@@ -1498,10 +1505,10 @@ ssh_confirm_remote_forward(int type, u_int32_t seq, void *ctxt)
 			logit("Allocated port %u for remote forward to %s:%d",
 			    rfwd->allocated_port,
 			    rfwd->connect_host, rfwd->connect_port);
-			channel_update_permitted_opens(rfwd->handle,
-			    rfwd->allocated_port);
+			channel_update_permitted_opens(ssh,
+			    rfwd->handle, rfwd->allocated_port);
 		} else {
-			channel_update_permitted_opens(rfwd->handle, -1);
+			channel_update_permitted_opens(ssh, rfwd->handle, -1);
 		}
 	}
 	
@@ -1530,21 +1537,21 @@ ssh_confirm_remote_forward(int type, u_int32_t seq, void *ctxt)
 }
 
 static void
-client_cleanup_stdio_fwd(int id, void *arg)
+client_cleanup_stdio_fwd(struct ssh *ssh, int id, void *arg)
 {
 	debug("stdio forwarding: done");
 	cleanup_exit(0);
 }
 
 static void
-ssh_stdio_confirm(int id, int success, void *arg)
+ssh_stdio_confirm(struct ssh *ssh, int id, int success, void *arg)
 {
 	if (!success)
 		fatal("stdio forwarding failed");
 }
 
 static void
-ssh_init_stdio_forwarding(void)
+ssh_init_stdio_forwarding(struct ssh *ssh)
 {
 	Channel *c;
 	int in, out;
@@ -1558,15 +1565,15 @@ ssh_init_stdio_forwarding(void)
 	if ((in = dup(STDIN_FILENO)) < 0 ||
 	    (out = dup(STDOUT_FILENO)) < 0)
 		fatal("channel_connect_stdio_fwd: dup() in/out failed");
-	if ((c = channel_connect_stdio_fwd(options.stdio_forward_host,
+	if ((c = channel_connect_stdio_fwd(ssh, options.stdio_forward_host,
 	    options.stdio_forward_port, in, out)) == NULL)
 		fatal("%s: channel_connect_stdio_fwd failed", __func__);
-	channel_register_cleanup(c->self, client_cleanup_stdio_fwd, 0);
-	channel_register_open_confirm(c->self, ssh_stdio_confirm, NULL);
+	channel_register_cleanup(ssh, c->self, client_cleanup_stdio_fwd, 0);
+	channel_register_open_confirm(ssh, c->self, ssh_stdio_confirm, NULL);
 }
 
 static void
-ssh_init_forwarding(void)
+ssh_init_forwarding(struct ssh *ssh)
 {
 	int success = 0;
 	int i;
@@ -1585,7 +1592,7 @@ ssh_init_forwarding(void)
 		    options.local_forwards[i].connect_path :
 		    options.local_forwards[i].connect_host,
 		    options.local_forwards[i].connect_port);
-		success += channel_setup_local_fwd_listener(
+		success += channel_setup_local_fwd_listener(ssh,
 		    &options.local_forwards[i], &options.fwd_opts);
 	}
 	if (i > 0 && success != i && options.exit_on_forward_failure)
@@ -1607,7 +1614,7 @@ ssh_init_forwarding(void)
 		    options.remote_forwards[i].connect_host,
 		    options.remote_forwards[i].connect_port);
 		options.remote_forwards[i].handle =
-		    channel_request_remote_forwarding(
+		    channel_request_remote_forwarding(ssh,
 		    &options.remote_forwards[i]);
 		if (options.remote_forwards[i].handle < 0) {
 			if (options.exit_on_forward_failure)
@@ -1616,14 +1623,15 @@ ssh_init_forwarding(void)
 				logit("Warning: Could not request remote "
 				    "forwarding.");
 		} else {
-			client_register_global_confirm(ssh_confirm_remote_forward,
+			client_register_global_confirm(
+			    ssh_confirm_remote_forward,
 			    &options.remote_forwards[i]);
 		}
 	}
 
 	/* Initiate tunnel forwarding. */
 	if (options.tun_open != SSH_TUNMODE_NO) {
-		if (client_request_tun_fwd(options.tun_open,
+		if (client_request_tun_fwd(ssh, options.tun_open,
 		    options.tun_local, options.tun_remote) == -1) {
 			if (options.exit_on_forward_failure)
 				fatal("Could not request tunnel forwarding.");
@@ -1650,7 +1658,7 @@ check_agent_present(void)
 }
 
 static void
-ssh_session2_setup(int id, int success, void *arg)
+ssh_session2_setup(struct ssh *ssh, int id, int success, void *arg)
 {
 	extern char **environ;
 	const char *display;
@@ -1663,15 +1671,15 @@ ssh_session2_setup(int id, int success, void *arg)
 	display = getenv("DISPLAY");
 	if (display == NULL && options.forward_x11)
 		debug("X11 forwarding requested but DISPLAY not set");
-	if (options.forward_x11 && client_x11_get_proto(display,
+	if (options.forward_x11 && client_x11_get_proto(ssh, display,
 	    options.xauth_location, options.forward_x11_trusted,
 	    options.forward_x11_timeout, &proto, &data) == 0) {
 		/* Request forwarding with authentication spoofing. */
 		debug("Requesting X11 forwarding with authentication "
 		    "spoofing.");
-		x11_request_forwarding_with_spoofing(id, display, proto,
+		x11_request_forwarding_with_spoofing(ssh, id, display, proto,
 		    data, 1);
-		client_expect_confirm(id, "X11 forwarding", CONFIRM_WARN);
+		client_expect_confirm(ssh, id, "X11 forwarding", CONFIRM_WARN);
 		/* XXX exit_on_forward_failure */
 		interactive = 1;
 	}
@@ -1679,7 +1687,7 @@ ssh_session2_setup(int id, int success, void *arg)
 	check_agent_present();
 	if (options.forward_agent) {
 		debug("Requesting authentication agent forwarding.");
-		channel_request_start(id, "auth-agent-req@openssh.com", 0);
+		channel_request_start(ssh, id, "auth-agent-req@openssh.com", 0);
 		packet_send();
 	}
 
@@ -1687,13 +1695,13 @@ ssh_session2_setup(int id, int success, void *arg)
 	packet_set_interactive(interactive,
 	    options.ip_qos_interactive, options.ip_qos_bulk);
 
-	client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"),
+	client_session2_setup(ssh, id, tty_flag, subsystem_flag, getenv("TERM"),
 	    NULL, fileno(stdin), &command, environ);
 }
 
 /* open new channel for a session */
 static int
-ssh_session2_open(void)
+ssh_session2_open(struct ssh *ssh)
 {
 	Channel *c;
 	int window, packetmax, in, out, err;
@@ -1723,34 +1731,34 @@ ssh_session2_open(void)
 		window >>= 1;
 		packetmax >>= 1;
 	}
-	c = channel_new(
+	c = channel_new(ssh,
 	    "session", SSH_CHANNEL_OPENING, in, out, err,
 	    window, packetmax, CHAN_EXTENDED_WRITE,
 	    "client-session", /*nonblock*/0);
 
-	debug3("ssh_session2_open: channel_new: %d", c->self);
+	debug3("%s: channel_new: %d", __func__, c->self);
 
-	channel_send_open(c->self);
+	channel_send_open(ssh, c->self);
 	if (!no_shell_flag)
-		channel_register_open_confirm(c->self,
+		channel_register_open_confirm(ssh, c->self,
 		    ssh_session2_setup, NULL);
 
 	return c->self;
 }
 
 static int
-ssh_session2(void)
+ssh_session2(struct ssh *ssh)
 {
 	int id = -1;
 
 	/* XXX should be pre-session */
 	if (!options.control_persist)
-		ssh_init_stdio_forwarding();
-	ssh_init_forwarding();
+		ssh_init_stdio_forwarding(ssh);
+	ssh_init_forwarding(ssh);
 
 	/* Start listening for multiplex clients */
 	if (!packet_get_mux())
-		muxserver_listen();
+		muxserver_listen(ssh);
 
  	/*
 	 * If we are in control persist mode and have a working mux listen
@@ -1778,10 +1786,10 @@ ssh_session2(void)
 	 * stdio forward setup that we skipped earlier.
 	 */
 	if (options.control_persist && muxserver_sock == -1)
-		ssh_init_stdio_forwarding();
+		ssh_init_stdio_forwarding(ssh);
 
 	if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN))
-		id = ssh_session2_open();
+		id = ssh_session2_open(ssh);
 	else {
 		packet_set_interactive(
 		    options.control_master == SSHCTL_MASTER_NO,
@@ -1816,7 +1824,7 @@ ssh_session2(void)
 			fork_postauth();
 	}
 
-	return client_loop(tty_flag, tty_flag ?
+	return client_loop(ssh, tty_flag, tty_flag ?
 	    options.escape_char : SSH_ESCAPECHAR_NONE, id);
 }