Annotation of src/usr.bin/ssh/serverloop.c, Revision 1.226
1.226 ! djm 1: /* $OpenBSD: serverloop.c,v 1.225 2021/01/27 10:05:28 djm Exp $ */
1.1 deraadt 2: /*
1.11 deraadt 3: * Author: Tatu Ylonen <ylo@cs.hut.fi>
4: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5: * All rights reserved
6: * Server main loop for handling the interactive session.
1.28 deraadt 7: *
8: * As far as I am concerned, the code I have written for this software
9: * can be used freely for any purpose. Any derived versions of this
10: * software must be clearly marked as such, and if the derived work is
11: * incompatible with the protocol description in the RFC file, it must be
12: * called by a name other than "ssh" or "Secure Shell".
13: *
1.17 markus 14: * SSH2 support by Markus Friedl.
1.71 markus 15: * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
1.28 deraadt 16: *
17: * Redistribution and use in source and binary forms, with or without
18: * modification, are permitted provided that the following conditions
19: * are met:
20: * 1. Redistributions of source code must retain the above copyright
21: * notice, this list of conditions and the following disclaimer.
22: * 2. Redistributions in binary form must reproduce the above copyright
23: * notice, this list of conditions and the following disclaimer in the
24: * documentation and/or other materials provided with the distribution.
25: *
26: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
27: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
28: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
29: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
30: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
31: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
32: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
33: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
35: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.17 markus 36: */
1.1 deraadt 37:
1.126 stevesk 38: #include <sys/types.h>
39: #include <sys/wait.h>
1.136 stevesk 40: #include <sys/socket.h>
1.142 stevesk 41: #include <sys/time.h>
1.149 djm 42: #include <sys/queue.h>
1.136 stevesk 43:
44: #include <netinet/in.h>
1.125 stevesk 45:
1.139 stevesk 46: #include <errno.h>
1.138 stevesk 47: #include <fcntl.h>
1.137 stevesk 48: #include <pwd.h>
1.211 djm 49: #include <limits.h>
1.127 stevesk 50: #include <signal.h>
1.141 stevesk 51: #include <string.h>
1.125 stevesk 52: #include <termios.h>
1.140 stevesk 53: #include <unistd.h>
1.144 deraadt 54: #include <stdarg.h>
1.33 djm 55:
1.1 deraadt 56: #include "xmalloc.h"
57: #include "packet.h"
1.207 markus 58: #include "sshbuf.h"
1.42 markus 59: #include "log.h"
1.172 millert 60: #include "misc.h"
1.1 deraadt 61: #include "servconf.h"
1.104 stevesk 62: #include "canohost.h"
1.54 djm 63: #include "sshpty.h"
1.67 markus 64: #include "channels.h"
1.16 markus 65: #include "compat.h"
1.17 markus 66: #include "ssh2.h"
1.208 markus 67: #include "sshkey.h"
1.144 deraadt 68: #include "cipher.h"
69: #include "kex.h"
70: #include "hostfile.h"
1.40 markus 71: #include "auth.h"
1.17 markus 72: #include "session.h"
1.16 markus 73: #include "dispatch.h"
1.26 markus 74: #include "auth-options.h"
1.42 markus 75: #include "serverloop.h"
1.177 djm 76: #include "ssherr.h"
1.210 djm 77:
1.32 markus 78: extern ServerOptions options;
79:
1.56 markus 80: /* XXX */
1.111 markus 81: extern Authctxt *the_authctxt;
1.205 djm 82: extern struct sshauthopt *auth_opts;
1.121 djm 83: extern int use_privsep;
1.56 markus 84:
1.152 djm 85: static int no_more_sessions = 0; /* Disallow further sessions. */
1.1 deraadt 86:
1.12 markus 87: /*
88: * This SIGCHLD kludge is used to detect when the child exits. The server
89: * will exit after that, as soon as forwarded connections have terminated.
90: */
1.70 itojun 91:
1.84 markus 92: static volatile sig_atomic_t child_terminated = 0; /* The child has terminated. */
1.1 deraadt 93:
1.121 djm 94: /* Cleanup on signals (!use_privsep case only) */
95: static volatile sig_atomic_t received_sigterm = 0;
96:
1.70 itojun 97: /* prototypes */
1.211 djm 98: static void server_init_dispatch(struct ssh *);
1.16 markus 99:
1.199 djm 100: /* requested tunnel forwarding interface(s), shared with session.c */
101: char *tun_fwd_ifnames = NULL;
1.209 dtucker 102:
103: /* returns 1 if bind to specified port by specified user is permitted */
104: static int
105: bind_permitted(int port, uid_t uid)
106: {
107: if (use_privsep)
108: return 1; /* allow system to decide */
109: if (port < IPPORT_RESERVED && uid != 0)
110: return 0;
111: return 1;
112: }
1.199 djm 113:
1.87 markus 114: /*
115: * we write to this pipe if a SIGCHLD is caught in order to avoid
116: * the race between select() and child_terminated
117: */
118: static int notify_pipe[2];
119: static void
120: notify_setup(void)
121: {
1.216 deraadt 122: if (pipe(notify_pipe) == -1) {
1.87 markus 123: error("pipe(notify_pipe) failed %s", strerror(errno));
1.160 djm 124: } else if ((fcntl(notify_pipe[0], F_SETFD, FD_CLOEXEC) == -1) ||
125: (fcntl(notify_pipe[1], F_SETFD, FD_CLOEXEC) == -1)) {
1.87 markus 126: error("fcntl(notify_pipe, F_SETFD) failed %s", strerror(errno));
127: close(notify_pipe[0]);
128: close(notify_pipe[1]);
129: } else {
130: set_nonblock(notify_pipe[0]);
131: set_nonblock(notify_pipe[1]);
132: return;
133: }
134: notify_pipe[0] = -1; /* read end */
135: notify_pipe[1] = -1; /* write end */
136: }
137: static void
138: notify_parent(void)
139: {
140: if (notify_pipe[1] != -1)
1.166 dtucker 141: (void)write(notify_pipe[1], "", 1);
1.87 markus 142: }
143: static void
144: notify_prepare(fd_set *readset)
145: {
146: if (notify_pipe[0] != -1)
147: FD_SET(notify_pipe[0], readset);
148: }
149: static void
150: notify_done(fd_set *readset)
151: {
152: char c;
153:
154: if (notify_pipe[0] != -1 && FD_ISSET(notify_pipe[0], readset))
155: while (read(notify_pipe[0], &c, 1) != -1)
1.224 djm 156: debug2_f("reading");
1.87 markus 157: }
158:
1.131 deraadt 159: /*ARGSUSED*/
1.70 itojun 160: static void
1.10 markus 161: sigchld_handler(int sig)
1.1 deraadt 162: {
1.10 markus 163: int save_errno = errno;
1.68 markus 164: child_terminated = 1;
1.87 markus 165: notify_parent();
1.10 markus 166: errno = save_errno;
1.1 deraadt 167: }
168:
1.131 deraadt 169: /*ARGSUSED*/
1.121 djm 170: static void
171: sigterm_handler(int sig)
172: {
173: received_sigterm = sig;
174: }
175:
1.79 markus 176: static void
1.197 djm 177: client_alive_check(struct ssh *ssh)
1.79 markus 178: {
1.200 dtucker 179: char remote_id[512];
1.211 djm 180: int r, channel_id;
1.94 markus 181:
1.79 markus 182: /* timeout, check to see how many we have had */
1.221 djm 183: if (options.client_alive_count_max > 0 &&
184: ssh_packet_inc_alive_timeouts(ssh) >
1.211 djm 185: options.client_alive_count_max) {
1.200 dtucker 186: sshpkt_fmt_connection_id(ssh, remote_id, sizeof(remote_id));
187: logit("Timeout, client not responding from %s", remote_id);
1.145 markus 188: cleanup_exit(255);
189: }
1.79 markus 190:
191: /*
1.114 markus 192: * send a bogus global/channel request with "wantreply",
1.79 markus 193: * we should get back a failure
194: */
1.197 djm 195: if ((channel_id = channel_find_open(ssh)) == -1) {
1.211 djm 196: if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
197: (r = sshpkt_put_cstring(ssh, "keepalive@openssh.com"))
198: != 0 ||
199: (r = sshpkt_put_u8(ssh, 1)) != 0) /* boolean: want reply */
1.224 djm 200: fatal_fr(r, "compose");
1.114 markus 201: } else {
1.197 djm 202: channel_request_start(ssh, channel_id,
203: "keepalive@openssh.com", 1);
1.114 markus 204: }
1.211 djm 205: if ((r = sshpkt_send(ssh)) != 0)
1.224 djm 206: fatal_fr(r, "send");
1.79 markus 207: }
208:
1.11 deraadt 209: /*
210: * Sleep in select() until we can do something. This will initialize the
211: * select masks. Upon return, the masks will indicate which descriptors
212: * have data or can accept data. Optionally, a maximum time can be specified
213: * for the duration of the wait (0 = infinite).
214: */
1.70 itojun 215: static void
1.197 djm 216: wait_until_can_do_something(struct ssh *ssh,
217: int connection_in, int connection_out,
1.185 markus 218: fd_set **readsetp, fd_set **writesetp, int *maxfdp,
1.183 djm 219: u_int *nallocp, u_int64_t max_time_ms)
1.1 deraadt 220: {
1.10 markus 221: struct timeval tv, *tvp;
222: int ret;
1.162 djm 223: time_t minwait_secs = 0;
1.61 beck 224: int client_alive_scheduled = 0;
1.214 dtucker 225: /* time we last heard from the client OR sent a keepalive */
1.194 dtucker 226: static time_t last_client_time;
1.61 beck 227:
1.161 djm 228: /* Allocate and update select() masks for channel descriptors. */
1.197 djm 229: channel_prepare_select(ssh, readsetp, writesetp, maxfdp,
1.196 djm 230: nallocp, &minwait_secs);
1.161 djm 231:
1.183 djm 232: /* XXX need proper deadline system for rekey/client alive */
1.161 djm 233: if (minwait_secs != 0)
1.186 deraadt 234: max_time_ms = MINIMUM(max_time_ms, (u_int)minwait_secs * 1000);
1.161 djm 235:
1.61 beck 236: /*
1.86 deraadt 237: * if using client_alive, set the max timeout accordingly,
1.61 beck 238: * and indicate that this particular timeout was for client
239: * alive by setting the client_alive_scheduled flag.
240: *
241: * this could be randomized somewhat to make traffic
1.86 deraadt 242: * analysis more difficult, but we're not doing it yet.
1.61 beck 243: */
1.185 markus 244: if (options.client_alive_interval) {
1.183 djm 245: uint64_t keepalive_ms =
246: (uint64_t)options.client_alive_interval * 1000;
247:
1.215 djm 248: if (max_time_ms == 0 || max_time_ms > keepalive_ms) {
1.183 djm 249: max_time_ms = keepalive_ms;
1.215 djm 250: client_alive_scheduled = 1;
251: }
1.223 djm 252: if (last_client_time == 0)
253: last_client_time = monotime();
1.75 markus 254: }
1.10 markus 255:
1.78 markus 256: #if 0
1.185 markus 257: /* wrong: bad condition XXX */
258: if (channel_not_very_much_buffered_data())
1.78 markus 259: #endif
1.185 markus 260: FD_SET(connection_in, *readsetp);
1.87 markus 261: notify_prepare(*readsetp);
1.10 markus 262:
1.12 markus 263: /*
264: * If we have buffered packet data going to the client, mark that
265: * descriptor.
266: */
1.211 djm 267: if (ssh_packet_have_data_to_write(ssh))
1.43 markus 268: FD_SET(connection_out, *writesetp);
1.10 markus 269:
1.12 markus 270: /*
271: * If child has terminated and there is enough buffer space to read
272: * from it, then read as much as is available and exit.
273: */
1.211 djm 274: if (child_terminated && ssh_packet_not_very_much_data_to_write(ssh))
1.183 djm 275: if (max_time_ms == 0 || client_alive_scheduled)
276: max_time_ms = 100;
1.10 markus 277:
1.183 djm 278: if (max_time_ms == 0)
1.10 markus 279: tvp = NULL;
280: else {
1.183 djm 281: tv.tv_sec = max_time_ms / 1000;
282: tv.tv_usec = 1000 * (max_time_ms % 1000);
1.10 markus 283: tvp = &tv;
284: }
285:
286: /* Wait for something to happen, or the timeout to expire. */
1.43 markus 287: ret = select((*maxfdp)+1, *readsetp, *writesetp, NULL, tvp);
1.10 markus 288:
1.61 beck 289: if (ret == -1) {
1.83 markus 290: memset(*readsetp, 0, *nallocp);
291: memset(*writesetp, 0, *nallocp);
1.10 markus 292: if (errno != EINTR)
293: error("select: %.100s", strerror(errno));
1.194 dtucker 294: } else if (client_alive_scheduled) {
295: time_t now = monotime();
296:
1.214 dtucker 297: /*
298: * If the select timed out, or returned for some other reason
299: * but we haven't heard from the client in time, send keepalive.
300: */
301: if (ret == 0 || (last_client_time != 0 && last_client_time +
302: options.client_alive_interval <= now)) {
1.197 djm 303: client_alive_check(ssh);
1.214 dtucker 304: last_client_time = now;
1.194 dtucker 305: } else if (FD_ISSET(connection_in, *readsetp)) {
306: last_client_time = now;
307: }
308: }
1.87 markus 309:
310: notify_done(*readsetp);
1.1 deraadt 311: }
312:
1.11 deraadt 313: /*
314: * Processes input from the client and the program. Input data is stored
315: * in buffers and processed later.
316: */
1.185 markus 317: static int
1.197 djm 318: process_input(struct ssh *ssh, fd_set *readset, int connection_in)
1.1 deraadt 319: {
1.211 djm 320: int r, len;
1.10 markus 321: char buf[16384];
1.1 deraadt 322:
1.10 markus 323: /* Read and buffer any input data from the client. */
324: if (FD_ISSET(connection_in, readset)) {
1.181 markus 325: len = read(connection_in, buf, sizeof(buf));
1.10 markus 326: if (len == 0) {
1.184 djm 327: verbose("Connection closed by %.100s port %d",
328: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1.185 markus 329: return -1;
1.216 deraadt 330: } else if (len == -1) {
1.224 djm 331: if (errno == EINTR || errno == EAGAIN)
332: return 0;
333: verbose("Read error from remote host %s port %d: %s",
334: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
335: strerror(errno));
336: cleanup_exit(255);
1.10 markus 337: }
1.224 djm 338: /* Buffer any received data. */
339: if ((r = ssh_packet_process_incoming(ssh, buf, len)) != 0)
340: fatal_fr(r, "ssh_packet_process_incoming");
1.10 markus 341: }
1.185 markus 342: return 0;
1.1 deraadt 343: }
344:
1.11 deraadt 345: /*
346: * Sends data from internal buffers to client program stdin.
347: */
1.70 itojun 348: static void
1.211 djm 349: process_output(struct ssh *ssh, fd_set *writeset, int connection_out)
1.1 deraadt 350: {
1.211 djm 351: int r;
352:
1.10 markus 353: /* Send any buffered packet data to the client. */
1.211 djm 354: if (FD_ISSET(connection_out, writeset)) {
1.222 djm 355: if ((r = ssh_packet_write_poll(ssh)) != 0) {
356: sshpkt_fatal(ssh, r, "%s: ssh_packet_write_poll",
357: __func__);
358: }
1.211 djm 359: }
1.1 deraadt 360: }
361:
1.70 itojun 362: static void
1.197 djm 363: process_buffered_input_packets(struct ssh *ssh)
1.16 markus 364: {
1.197 djm 365: ssh_dispatch_run_fatal(ssh, DISPATCH_NONBLOCK, NULL);
1.16 markus 366: }
367:
1.82 markus 368: static void
1.197 djm 369: collect_children(struct ssh *ssh)
1.82 markus 370: {
371: pid_t pid;
372: sigset_t oset, nset;
373: int status;
374:
375: /* block SIGCHLD while we check for dead children */
376: sigemptyset(&nset);
377: sigaddset(&nset, SIGCHLD);
378: sigprocmask(SIG_BLOCK, &nset, &oset);
379: if (child_terminated) {
1.128 djm 380: debug("Received SIGCHLD.");
1.101 markus 381: while ((pid = waitpid(-1, &status, WNOHANG)) > 0 ||
1.216 deraadt 382: (pid == -1 && errno == EINTR))
1.101 markus 383: if (pid > 0)
1.197 djm 384: session_close_by_pid(ssh, pid, status);
1.82 markus 385: child_terminated = 0;
386: }
387: sigprocmask(SIG_SETMASK, &oset, NULL);
388: }
389:
1.19 markus 390: void
1.197 djm 391: server_loop2(struct ssh *ssh, Authctxt *authctxt)
1.17 markus 392: {
1.43 markus 393: fd_set *readset = NULL, *writeset = NULL;
1.182 djm 394: int max_fd;
1.185 markus 395: u_int nalloc = 0, connection_in, connection_out;
1.165 dtucker 396: u_int64_t rekey_timeout_ms = 0;
1.17 markus 397:
398: debug("Entering interactive session for SSH2.");
399:
1.219 dtucker 400: ssh_signal(SIGCHLD, sigchld_handler);
1.17 markus 401: child_terminated = 0;
1.211 djm 402: connection_in = ssh_packet_get_connection_in(ssh);
403: connection_out = ssh_packet_get_connection_out(ssh);
1.43 markus 404:
1.121 djm 405: if (!use_privsep) {
1.219 dtucker 406: ssh_signal(SIGTERM, sigterm_handler);
407: ssh_signal(SIGINT, sigterm_handler);
408: ssh_signal(SIGQUIT, sigterm_handler);
1.121 djm 409: }
410:
1.87 markus 411: notify_setup();
412:
1.186 deraadt 413: max_fd = MAXIMUM(connection_in, connection_out);
414: max_fd = MAXIMUM(max_fd, notify_pipe[0]);
1.87 markus 415:
1.211 djm 416: server_init_dispatch(ssh);
1.17 markus 417:
418: for (;;) {
1.197 djm 419: process_buffered_input_packets(ssh);
1.58 markus 420:
1.197 djm 421: if (!ssh_packet_is_rekeying(ssh) &&
1.211 djm 422: ssh_packet_not_very_much_data_to_write(ssh))
1.197 djm 423: channel_output_poll(ssh);
1.211 djm 424: if (options.rekey_interval > 0 &&
425: !ssh_packet_is_rekeying(ssh)) {
426: rekey_timeout_ms = ssh_packet_get_rekey_timeout(ssh) *
427: 1000;
428: } else {
1.165 dtucker 429: rekey_timeout_ms = 0;
1.211 djm 430: }
1.165 dtucker 431:
1.197 djm 432: wait_until_can_do_something(ssh, connection_in, connection_out,
1.185 markus 433: &readset, &writeset, &max_fd, &nalloc, rekey_timeout_ms);
1.121 djm 434:
435: if (received_sigterm) {
1.164 dtucker 436: logit("Exiting on signal %d", (int)received_sigterm);
1.121 djm 437: /* Clean up sessions, utmp, etc. */
438: cleanup_exit(255);
439: }
1.81 markus 440:
1.197 djm 441: collect_children(ssh);
442: if (!ssh_packet_is_rekeying(ssh))
443: channel_after_select(ssh, readset, writeset);
444: if (process_input(ssh, readset, connection_in) < 0)
1.60 markus 445: break;
1.211 djm 446: process_output(ssh, writeset, connection_out);
1.43 markus 447: }
1.197 djm 448: collect_children(ssh);
1.82 markus 449:
1.167 djm 450: free(readset);
451: free(writeset);
1.43 markus 452:
1.81 markus 453: /* free all channels, no more reads and writes */
1.197 djm 454: channel_free_all(ssh);
1.81 markus 455:
1.82 markus 456: /* free remaining sessions, e.g. remove wtmp entries */
1.197 djm 457: session_destroy_all(ssh, NULL);
1.17 markus 458: }
459:
1.174 markus 460: static int
1.192 markus 461: server_input_keep_alive(int type, u_int32_t seq, struct ssh *ssh)
1.61 beck 462: {
1.114 markus 463: debug("Got %d/%u for keepalive", type, seq);
1.86 deraadt 464: /*
1.62 markus 465: * reset timeout, since we got a sane answer from the client.
1.61 beck 466: * even if this was generated by something other than
467: * the bogus CHANNEL_REQUEST we send for keepalives.
468: */
1.211 djm 469: ssh_packet_set_alive_timeouts(ssh, 0);
1.174 markus 470: return 0;
1.61 beck 471: }
472:
1.70 itojun 473: static Channel *
1.197 djm 474: server_request_direct_tcpip(struct ssh *ssh, int *reason, const char **errmsg)
1.17 markus 475: {
1.163 djm 476: Channel *c = NULL;
1.211 djm 477: char *target = NULL, *originator = NULL;
478: u_int target_port = 0, originator_port = 0;
479: int r;
480:
481: if ((r = sshpkt_get_cstring(ssh, &target, NULL)) != 0 ||
482: (r = sshpkt_get_u32(ssh, &target_port)) != 0 ||
483: (r = sshpkt_get_cstring(ssh, &originator, NULL)) != 0 ||
484: (r = sshpkt_get_u32(ssh, &originator_port)) != 0 ||
485: (r = sshpkt_get_end(ssh)) != 0)
486: sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
487: if (target_port > 0xFFFF) {
1.224 djm 488: error_f("invalid target port");
1.211 djm 489: *reason = SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED;
490: goto out;
491: }
492: if (originator_port > 0xFFFF) {
1.224 djm 493: error_f("invalid originator port");
1.211 djm 494: *reason = SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED;
495: goto out;
496: }
1.17 markus 497:
1.224 djm 498: debug_f("originator %s port %u, target %s port %u",
1.205 djm 499: originator, originator_port, target, target_port);
1.26 markus 500:
1.163 djm 501: /* XXX fine grained permissions */
502: if ((options.allow_tcp_forwarding & FORWARD_LOCAL) != 0 &&
1.205 djm 503: auth_opts->permit_port_forwarding_flag &&
504: !options.disable_forwarding) {
1.197 djm 505: c = channel_connect_to_port(ssh, target, target_port,
1.191 dtucker 506: "direct-tcpip", "direct-tcpip", reason, errmsg);
1.163 djm 507: } else {
508: logit("refused local port forward: "
509: "originator %s port %d, target %s port %d",
510: originator, originator_port, target, target_port);
1.191 dtucker 511: if (reason != NULL)
512: *reason = SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED;
1.163 djm 513: }
1.150 djm 514:
1.211 djm 515: out:
1.167 djm 516: free(originator);
517: free(target);
1.64 markus 518: return c;
1.35 markus 519: }
520:
1.70 itojun 521: static Channel *
1.197 djm 522: server_request_direct_streamlocal(struct ssh *ssh)
1.172 millert 523: {
524: Channel *c = NULL;
1.211 djm 525: char *target = NULL, *originator = NULL;
526: u_int originator_port = 0;
1.190 djm 527: struct passwd *pw = the_authctxt->pw;
1.211 djm 528: int r;
1.190 djm 529:
530: if (pw == NULL || !the_authctxt->valid)
1.224 djm 531: fatal_f("no/invalid user");
1.172 millert 532:
1.211 djm 533: if ((r = sshpkt_get_cstring(ssh, &target, NULL)) != 0 ||
534: (r = sshpkt_get_cstring(ssh, &originator, NULL)) != 0 ||
535: (r = sshpkt_get_u32(ssh, &originator_port)) != 0 ||
536: (r = sshpkt_get_end(ssh)) != 0)
537: sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
538: if (originator_port > 0xFFFF) {
1.224 djm 539: error_f("invalid originator port");
1.211 djm 540: goto out;
541: }
1.172 millert 542:
1.224 djm 543: debug_f("originator %s port %d, target %s",
1.172 millert 544: originator, originator_port, target);
545:
546: /* XXX fine grained permissions */
547: if ((options.allow_streamlocal_forwarding & FORWARD_LOCAL) != 0 &&
1.205 djm 548: auth_opts->permit_port_forwarding_flag &&
549: !options.disable_forwarding && (pw->pw_uid == 0 || use_privsep)) {
1.197 djm 550: c = channel_connect_to_path(ssh, target,
1.172 millert 551: "direct-streamlocal@openssh.com", "direct-streamlocal");
552: } else {
553: logit("refused streamlocal port forward: "
554: "originator %s port %d, target %s",
555: originator, originator_port, target);
556: }
557:
1.211 djm 558: out:
1.172 millert 559: free(originator);
560: free(target);
561: return c;
562: }
563:
564: static Channel *
1.197 djm 565: server_request_tun(struct ssh *ssh)
1.122 reyk 566: {
567: Channel *c = NULL;
1.211 djm 568: u_int mode, tun;
569: int r, sock;
1.199 djm 570: char *tmp, *ifname = NULL;
1.122 reyk 571:
1.211 djm 572: if ((r = sshpkt_get_u32(ssh, &mode)) != 0)
573: sshpkt_fatal(ssh, r, "%s: parse mode", __func__);
1.123 reyk 574: switch (mode) {
575: case SSH_TUNMODE_POINTOPOINT:
576: case SSH_TUNMODE_ETHERNET:
577: break;
578: default:
1.211 djm 579: ssh_packet_send_debug(ssh, "Unsupported tunnel device mode.");
1.123 reyk 580: return NULL;
581: }
582: if ((options.permit_tun & mode) == 0) {
1.211 djm 583: ssh_packet_send_debug(ssh, "Server has rejected tunnel device "
1.123 reyk 584: "forwarding");
1.122 reyk 585: return NULL;
586: }
587:
1.211 djm 588: if ((r = sshpkt_get_u32(ssh, &tun)) != 0)
589: sshpkt_fatal(ssh, r, "%s: parse device", __func__);
590: if (tun > INT_MAX) {
1.224 djm 591: debug_f("invalid tun");
1.211 djm 592: goto done;
593: }
1.205 djm 594: if (auth_opts->force_tun_device != -1) {
1.211 djm 595: if (tun != SSH_TUNID_ANY &&
596: auth_opts->force_tun_device != (int)tun)
1.122 reyk 597: goto done;
1.205 djm 598: tun = auth_opts->force_tun_device;
1.122 reyk 599: }
1.199 djm 600: sock = tun_open(tun, mode, &ifname);
1.122 reyk 601: if (sock < 0)
602: goto done;
1.199 djm 603: debug("Tunnel forwarding using interface %s", ifname);
604:
1.197 djm 605: c = channel_new(ssh, "tun", SSH_CHANNEL_OPEN, sock, sock, -1,
1.122 reyk 606: CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1);
607: c->datagram = 1;
1.199 djm 608:
609: /*
610: * Update the list of names exposed to the session
611: * XXX remove these if the tunnels are closed (won't matter
612: * much if they are already in the environment though)
613: */
614: tmp = tun_fwd_ifnames;
615: xasprintf(&tun_fwd_ifnames, "%s%s%s",
616: tun_fwd_ifnames == NULL ? "" : tun_fwd_ifnames,
617: tun_fwd_ifnames == NULL ? "" : ",",
618: ifname);
619: free(tmp);
620: free(ifname);
1.122 reyk 621:
622: done:
623: if (c == NULL)
1.211 djm 624: ssh_packet_send_debug(ssh, "Failed to open the tunnel device.");
1.122 reyk 625: return c;
626: }
627:
628: static Channel *
1.197 djm 629: server_request_session(struct ssh *ssh)
1.35 markus 630: {
1.64 markus 631: Channel *c;
1.211 djm 632: int r;
1.35 markus 633:
634: debug("input_session_request");
1.211 djm 635: if ((r = sshpkt_get_end(ssh)) != 0)
636: sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
1.152 djm 637:
638: if (no_more_sessions) {
1.213 djm 639: ssh_packet_disconnect(ssh, "Possible attack: attempt to open a "
1.211 djm 640: "session after additional sessions disabled");
1.152 djm 641: }
642:
1.35 markus 643: /*
644: * A server session has no fd to read or write until a
645: * CHANNEL_REQUEST for a shell is made, so we set the type to
646: * SSH_CHANNEL_LARVAL. Additionally, a callback for handling all
647: * CHANNEL_REQUEST messages is registered.
648: */
1.197 djm 649: c = channel_new(ssh, "session", SSH_CHANNEL_LARVAL,
1.64 markus 650: -1, -1, -1, /*window size*/0, CHAN_SES_PACKET_DEFAULT,
1.108 markus 651: 0, "server-session", 1);
1.111 markus 652: if (session_open(the_authctxt, c->self) != 1) {
1.64 markus 653: debug("session open failed, free channel %d", c->self);
1.197 djm 654: channel_free(ssh, c);
1.64 markus 655: return NULL;
1.35 markus 656: }
1.197 djm 657: channel_register_cleanup(ssh, c->self, session_close_by_channel, 0);
1.64 markus 658: return c;
1.17 markus 659: }
660:
1.174 markus 661: static int
1.192 markus 662: server_input_channel_open(int type, u_int32_t seq, struct ssh *ssh)
1.17 markus 663: {
664: Channel *c = NULL;
1.211 djm 665: char *ctype = NULL;
1.191 dtucker 666: const char *errmsg = NULL;
1.211 djm 667: int r, reason = SSH2_OPEN_CONNECT_FAILED;
1.218 dtucker 668: u_int rchan = 0, rmaxpack = 0, rwindow = 0;
1.17 markus 669:
1.211 djm 670: if ((r = sshpkt_get_cstring(ssh, &ctype, NULL)) != 0 ||
671: (r = sshpkt_get_u32(ssh, &rchan)) != 0 ||
672: (r = sshpkt_get_u32(ssh, &rwindow)) != 0 ||
673: (r = sshpkt_get_u32(ssh, &rmaxpack)) != 0)
674: sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
1.224 djm 675: debug_f("ctype %s rchan %u win %u max %u",
1.218 dtucker 676: ctype, rchan, rwindow, rmaxpack);
1.17 markus 677:
1.220 djm 678: if (strcmp(ctype, "session") == 0) {
1.197 djm 679: c = server_request_session(ssh);
1.17 markus 680: } else if (strcmp(ctype, "direct-tcpip") == 0) {
1.197 djm 681: c = server_request_direct_tcpip(ssh, &reason, &errmsg);
1.172 millert 682: } else if (strcmp(ctype, "direct-streamlocal@openssh.com") == 0) {
1.197 djm 683: c = server_request_direct_streamlocal(ssh);
1.122 reyk 684: } else if (strcmp(ctype, "tun@openssh.com") == 0) {
1.197 djm 685: c = server_request_tun(ssh);
1.17 markus 686: }
687: if (c != NULL) {
1.224 djm 688: debug_f("confirm %s", ctype);
1.220 djm 689: c->remote_id = rchan;
1.198 djm 690: c->have_remote_id = 1;
1.17 markus 691: c->remote_window = rwindow;
692: c->remote_maxpacket = rmaxpack;
1.65 markus 693: if (c->type != SSH_CHANNEL_CONNECTING) {
1.211 djm 694: if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION)) != 0 ||
695: (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
696: (r = sshpkt_put_u32(ssh, c->self)) != 0 ||
697: (r = sshpkt_put_u32(ssh, c->local_window)) != 0 ||
698: (r = sshpkt_put_u32(ssh, c->local_maxpacket)) != 0 ||
699: (r = sshpkt_send(ssh)) != 0) {
700: sshpkt_fatal(ssh, r,
701: "%s: send open confirm", __func__);
702: }
1.65 markus 703: }
1.17 markus 704: } else {
1.224 djm 705: debug_f("failure %s", ctype);
1.211 djm 706: if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE)) != 0 ||
707: (r = sshpkt_put_u32(ssh, rchan)) != 0 ||
708: (r = sshpkt_put_u32(ssh, reason)) != 0 ||
709: (r = sshpkt_put_cstring(ssh, errmsg ? errmsg : "open failed")) != 0 ||
710: (r = sshpkt_put_cstring(ssh, "")) != 0 ||
711: (r = sshpkt_send(ssh)) != 0) {
712: sshpkt_fatal(ssh, r,
713: "%s: send open failure", __func__);
714: }
1.17 markus 715: }
1.167 djm 716: free(ctype);
1.174 markus 717: return 0;
1.17 markus 718: }
719:
1.174 markus 720: static int
1.197 djm 721: server_input_hostkeys_prove(struct ssh *ssh, struct sshbuf **respp)
1.177 djm 722: {
723: struct sshbuf *resp = NULL;
724: struct sshbuf *sigbuf = NULL;
725: struct sshkey *key = NULL, *key_pub = NULL, *key_prv = NULL;
1.202 djm 726: int r, ndx, kexsigtype, use_kexsigtype, success = 0;
1.177 djm 727: const u_char *blob;
728: u_char *sig = 0;
729: size_t blen, slen;
730:
731: if ((resp = sshbuf_new()) == NULL || (sigbuf = sshbuf_new()) == NULL)
1.224 djm 732: fatal_f("sshbuf_new");
1.177 djm 733:
1.202 djm 734: kexsigtype = sshkey_type_plain(
735: sshkey_type_from_name(ssh->kex->hostkey_alg));
1.177 djm 736: while (ssh_packet_remaining(ssh) > 0) {
737: sshkey_free(key);
738: key = NULL;
739: if ((r = sshpkt_get_string_direct(ssh, &blob, &blen)) != 0 ||
740: (r = sshkey_from_blob(blob, blen, &key)) != 0) {
1.224 djm 741: error_fr(r, "parse key");
1.177 djm 742: goto out;
743: }
744: /*
745: * Better check that this is actually one of our hostkeys
746: * before attempting to sign anything with it.
747: */
748: if ((ndx = ssh->kex->host_key_index(key, 1, ssh)) == -1) {
1.224 djm 749: error_f("unknown host %s key", sshkey_type(key));
1.177 djm 750: goto out;
751: }
752: /*
753: * XXX refactor: make kex->sign just use an index rather
754: * than passing in public and private keys
755: */
756: if ((key_prv = get_hostkey_by_index(ndx)) == NULL &&
757: (key_pub = get_hostkey_public_by_index(ndx, ssh)) == NULL) {
1.224 djm 758: error_f("can't retrieve hostkey %d", ndx);
1.177 djm 759: goto out;
760: }
761: sshbuf_reset(sigbuf);
762: free(sig);
763: sig = NULL;
1.202 djm 764: /*
765: * For RSA keys, prefer to use the signature type negotiated
766: * during KEX to the default (SHA1).
767: */
768: use_kexsigtype = kexsigtype == KEY_RSA &&
769: sshkey_type_plain(key->type) == KEY_RSA;
1.178 djm 770: if ((r = sshbuf_put_cstring(sigbuf,
771: "hostkeys-prove-00@openssh.com")) != 0 ||
1.225 djm 772: (r = sshbuf_put_stringb(sigbuf,
773: ssh->kex->session_id)) != 0 ||
1.177 djm 774: (r = sshkey_puts(key, sigbuf)) != 0 ||
1.212 djm 775: (r = ssh->kex->sign(ssh, key_prv, key_pub, &sig, &slen,
1.201 djm 776: sshbuf_ptr(sigbuf), sshbuf_len(sigbuf),
1.212 djm 777: use_kexsigtype ? ssh->kex->hostkey_alg : NULL)) != 0 ||
1.177 djm 778: (r = sshbuf_put_string(resp, sig, slen)) != 0) {
1.224 djm 779: error_fr(r, "assemble signature");
1.177 djm 780: goto out;
781: }
782: }
783: /* Success */
784: *respp = resp;
785: resp = NULL; /* don't free it */
786: success = 1;
787: out:
788: free(sig);
789: sshbuf_free(resp);
790: sshbuf_free(sigbuf);
791: sshkey_free(key);
792: return success;
793: }
794:
795: static int
1.192 markus 796: server_input_global_request(int type, u_int32_t seq, struct ssh *ssh)
1.35 markus 797: {
1.211 djm 798: char *rtype = NULL;
799: u_char want_reply = 0;
1.177 djm 800: int r, success = 0, allocated_listen_port = 0;
1.211 djm 801: u_int port = 0;
1.177 djm 802: struct sshbuf *resp = NULL;
1.190 djm 803: struct passwd *pw = the_authctxt->pw;
1.211 djm 804: struct Forward fwd;
1.190 djm 805:
1.211 djm 806: memset(&fwd, 0, sizeof(fwd));
1.190 djm 807: if (pw == NULL || !the_authctxt->valid)
1.224 djm 808: fatal_f("no/invalid user");
1.35 markus 809:
1.211 djm 810: if ((r = sshpkt_get_cstring(ssh, &rtype, NULL)) != 0 ||
811: (r = sshpkt_get_u8(ssh, &want_reply)) != 0)
812: sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
1.224 djm 813: debug_f("rtype %s want_reply %d", rtype, want_reply);
1.45 stevesk 814:
1.55 markus 815: /* -R style forwarding */
1.35 markus 816: if (strcmp(rtype, "tcpip-forward") == 0) {
1.211 djm 817: if ((r = sshpkt_get_cstring(ssh, &fwd.listen_host, NULL)) != 0 ||
818: (r = sshpkt_get_u32(ssh, &port)) != 0)
819: sshpkt_fatal(ssh, r, "%s: parse tcpip-forward", __func__);
1.224 djm 820: debug_f("tcpip-forward listen %s port %u",
1.211 djm 821: fwd.listen_host, port);
822: if (port <= INT_MAX)
823: fwd.listen_port = (int)port;
1.35 markus 824: /* check permissions */
1.211 djm 825: if (port > INT_MAX ||
826: (options.allow_tcp_forwarding & FORWARD_REMOTE) == 0 ||
1.205 djm 827: !auth_opts->permit_port_forwarding_flag ||
828: options.disable_forwarding ||
1.172 millert 829: (!want_reply && fwd.listen_port == 0) ||
1.187 dtucker 830: (fwd.listen_port != 0 &&
1.226 ! djm 831: !bind_permitted(fwd.listen_port, pw->pw_uid))) {
1.35 markus 832: success = 0;
1.211 djm 833: ssh_packet_send_debug(ssh, "Server has disabled port forwarding.");
1.35 markus 834: } else {
835: /* Start listening on the port */
1.197 djm 836: success = channel_setup_remote_fwd_listener(ssh, &fwd,
1.172 millert 837: &allocated_listen_port, &options.fwd_opts);
1.35 markus 838: }
1.177 djm 839: if ((resp = sshbuf_new()) == NULL)
1.224 djm 840: fatal_f("sshbuf_new");
1.179 djm 841: if (allocated_listen_port != 0 &&
842: (r = sshbuf_put_u32(resp, allocated_listen_port)) != 0)
1.224 djm 843: fatal_fr(r, "sshbuf_put_u32");
1.116 djm 844: } else if (strcmp(rtype, "cancel-tcpip-forward") == 0) {
1.211 djm 845: if ((r = sshpkt_get_cstring(ssh, &fwd.listen_host, NULL)) != 0 ||
846: (r = sshpkt_get_u32(ssh, &port)) != 0)
847: sshpkt_fatal(ssh, r, "%s: parse cancel-tcpip-forward", __func__);
1.116 djm 848:
1.224 djm 849: debug_f("cancel-tcpip-forward addr %s port %d",
1.211 djm 850: fwd.listen_host, port);
851: if (port <= INT_MAX) {
852: fwd.listen_port = (int)port;
853: success = channel_cancel_rport_listener(ssh, &fwd);
854: }
1.172 millert 855: } else if (strcmp(rtype, "streamlocal-forward@openssh.com") == 0) {
1.211 djm 856: if ((r = sshpkt_get_cstring(ssh, &fwd.listen_path, NULL)) != 0)
857: sshpkt_fatal(ssh, r, "%s: parse streamlocal-forward@openssh.com", __func__);
1.224 djm 858: debug_f("streamlocal-forward listen path %s",
1.172 millert 859: fwd.listen_path);
860:
861: /* check permissions */
862: if ((options.allow_streamlocal_forwarding & FORWARD_REMOTE) == 0
1.205 djm 863: || !auth_opts->permit_port_forwarding_flag ||
864: options.disable_forwarding ||
1.190 djm 865: (pw->pw_uid != 0 && !use_privsep)) {
1.172 millert 866: success = 0;
1.211 djm 867: ssh_packet_send_debug(ssh, "Server has disabled "
1.190 djm 868: "streamlocal forwarding.");
1.172 millert 869: } else {
870: /* Start listening on the socket */
1.197 djm 871: success = channel_setup_remote_fwd_listener(ssh,
1.172 millert 872: &fwd, NULL, &options.fwd_opts);
873: }
874: } else if (strcmp(rtype, "cancel-streamlocal-forward@openssh.com") == 0) {
1.211 djm 875: if ((r = sshpkt_get_cstring(ssh, &fwd.listen_path, NULL)) != 0)
876: sshpkt_fatal(ssh, r, "%s: parse cancel-streamlocal-forward@openssh.com", __func__);
1.224 djm 877: debug_f("cancel-streamlocal-forward path %s",
1.172 millert 878: fwd.listen_path);
1.116 djm 879:
1.197 djm 880: success = channel_cancel_rport_listener(ssh, &fwd);
1.152 djm 881: } else if (strcmp(rtype, "no-more-sessions@openssh.com") == 0) {
882: no_more_sessions = 1;
883: success = 1;
1.178 djm 884: } else if (strcmp(rtype, "hostkeys-prove-00@openssh.com") == 0) {
1.197 djm 885: success = server_input_hostkeys_prove(ssh, &resp);
1.35 markus 886: }
1.211 djm 887: /* XXX sshpkt_get_end() */
1.35 markus 888: if (want_reply) {
1.211 djm 889: if ((r = sshpkt_start(ssh, success ?
890: SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE)) != 0 ||
891: (success && resp != NULL && (r = sshpkt_putb(ssh, resp)) != 0) ||
892: (r = sshpkt_send(ssh)) != 0 ||
893: (r = ssh_packet_write_wait(ssh)) != 0)
894: sshpkt_fatal(ssh, r, "%s: send reply", __func__);
1.35 markus 895: }
1.211 djm 896: free(fwd.listen_host);
897: free(fwd.listen_path);
1.167 djm 898: free(rtype);
1.177 djm 899: sshbuf_free(resp);
1.174 markus 900: return 0;
1.35 markus 901: }
1.133 deraadt 902:
1.174 markus 903: static int
1.192 markus 904: server_input_channel_req(int type, u_int32_t seq, struct ssh *ssh)
1.97 markus 905: {
906: Channel *c;
1.211 djm 907: int r, success = 0;
908: char *rtype = NULL;
909: u_char want_reply = 0;
910: u_int id = 0;
911:
912: if ((r = sshpkt_get_u32(ssh, &id)) != 0 ||
913: (r = sshpkt_get_cstring(ssh, &rtype, NULL)) != 0 ||
914: (r = sshpkt_get_u8(ssh, &want_reply)) != 0)
915: sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
916:
917: debug("server_input_channel_req: channel %u request %s reply %d",
918: id, rtype, want_reply);
1.97 markus 919:
1.213 djm 920: if (id >= INT_MAX || (c = channel_lookup(ssh, (int)id)) == NULL) {
921: ssh_packet_disconnect(ssh, "%s: unknown channel %d",
922: __func__, id);
923: }
1.151 markus 924: if (!strcmp(rtype, "eow@openssh.com")) {
1.211 djm 925: if ((r = sshpkt_get_end(ssh)) != 0)
926: sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
1.197 djm 927: chan_rcvd_eow(ssh, c);
1.153 djm 928: } else if ((c->type == SSH_CHANNEL_LARVAL ||
929: c->type == SSH_CHANNEL_OPEN) && strcmp(c->ctype, "session") == 0)
1.197 djm 930: success = session_input_channel_req(ssh, c, rtype);
1.211 djm 931: if (want_reply && !(c->flags & CHAN_CLOSE_SENT)) {
1.198 djm 932: if (!c->have_remote_id)
1.224 djm 933: fatal_f("channel %d: no remote_id", c->self);
1.211 djm 934: if ((r = sshpkt_start(ssh, success ?
935: SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE)) != 0 ||
936: (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
937: (r = sshpkt_send(ssh)) != 0)
938: sshpkt_fatal(ssh, r, "%s: send reply", __func__);
1.97 markus 939: }
1.167 djm 940: free(rtype);
1.174 markus 941: return 0;
1.97 markus 942: }
1.35 markus 943:
1.70 itojun 944: static void
1.211 djm 945: server_init_dispatch(struct ssh *ssh)
1.17 markus 946: {
1.185 markus 947: debug("server_init_dispatch");
1.211 djm 948: ssh_dispatch_init(ssh, &dispatch_protocol_error);
949: ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
950: ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_DATA, &channel_input_data);
951: ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
952: ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
953: ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_OPEN, &server_input_channel_open);
954: ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
955: ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
956: ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_REQUEST, &server_input_channel_req);
957: ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
958: ssh_dispatch_set(ssh, SSH2_MSG_GLOBAL_REQUEST, &server_input_global_request);
1.61 beck 959: /* client_alive */
1.211 djm 960: ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_SUCCESS, &server_input_keep_alive);
961: ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_FAILURE, &server_input_keep_alive);
962: ssh_dispatch_set(ssh, SSH2_MSG_REQUEST_SUCCESS, &server_input_keep_alive);
963: ssh_dispatch_set(ssh, SSH2_MSG_REQUEST_FAILURE, &server_input_keep_alive);
1.56 markus 964: /* rekeying */
1.211 djm 965: ssh_dispatch_set(ssh, SSH2_MSG_KEXINIT, &kex_input_kexinit);
1.1 deraadt 966: }
![[BACK]](/icons/back.gif){kind=icon}
Return to serverloop.c CVS log ![[TXT]](/icons/text.gif){kind=icon}
![[DIR]](/icons/dir.gif){kind=icon}
Up to [local] / src / usr.bin / ssh