src/lxc/terminal.c

   1 /*
   2  * lxc: linux Container library
   3  *
   4  * (C) Copyright IBM Corp. 2007, 2008
   5  *
   6  * Authors:
   7  * Daniel Lezcano <daniel.lezcano at free.fr>
   8  *
   9  * This library is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public
  11  * License as published by the Free Software Foundation; either
  12  * version 2.1 of the License, or (at your option) any later version.
  13  *
  14  * This library is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with this library; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  22  */
  23
  24 #define _GNU_SOURCE
  25 #include <errno.h>
  26 #include <fcntl.h>
  27 #include <lxc/lxccontainer.h>
  28 #include <pthread.h>
  29 #include <signal.h>
  30 #include <stdio.h>
  31 #include <stdlib.h>
  32 #include <sys/epoll.h>
  33 #include <sys/types.h>
  34 #include <termios.h>
  35 #include <unistd.h>
  36
  37 #include "af_unix.h"
  38 #include "caps.h"
  39 #include "commands.h"
  40 #include "conf.h"
  41 #include "config.h"
  42 #include "log.h"
  43 #include "lxclock.h"
  44 #include "mainloop.h"
  45 #include "start.h"
  46 #include "terminal.h"
  47 #include "utils.h"
  48
  49 #if HAVE_PTY_H
  50 #include <pty.h>
  51 #else
  52 #include <../include/openpty.h>
  53 #endif
  54
  55 #define LXC_TERMINAL_BUFFER_SIZE 1024
  56
  57 lxc_log_define(terminal, lxc);
  58
  59 static struct lxc_list lxc_ttys;
  60
  61 typedef void (*sighandler_t)(int);
  62
  63 __attribute__((constructor)) void lxc_terminal_init_global(void)
  64 {
  65         lxc_list_init(&lxc_ttys);
  66 }
  67
  68 void lxc_terminal_winsz(int srcfd, int dstfd)
  69 {
  70         int ret;
  71         struct winsize wsz;
  72
  73         if (!isatty(srcfd))
  74                 return;
  75
  76         ret = ioctl(srcfd, TIOCGWINSZ, &wsz);
  77         if (ret < 0) {
  78                 WARN("Failed to get window size");
  79                 return;
  80         }
  81
  82         ret = ioctl(dstfd, TIOCSWINSZ, &wsz);
  83         if (ret < 0)
  84                 WARN("Failed to set window size");
  85         else
  86                 DEBUG("Set window size to %d columns and %d rows", wsz.ws_col,
  87                       wsz.ws_row);
  88
  89         return;
  90 }
  91
  92 static void lxc_terminal_winch(struct lxc_terminal_state *ts)
  93 {
  94         lxc_terminal_winsz(ts->stdinfd, ts->masterfd);
  95
  96         if (ts->winch_proxy)
  97                 lxc_cmd_terminal_winch(ts->winch_proxy, ts->winch_proxy_lxcpath);
  98 }
  99
 100 void lxc_terminal_sigwinch(int sig)
 101 {
 102         struct lxc_list *it;
 103         struct lxc_terminal_state *ts;
 104
 105         lxc_list_for_each(it, &lxc_ttys) {
 106                 ts = it->elem;
 107                 lxc_terminal_winch(ts);
 108         }
 109 }
 110
 111 int lxc_terminal_signalfd_cb(int fd, uint32_t events, void *cbdata,
 112                              struct lxc_epoll_descr *descr)
 113 {
 114         ssize_t ret;
 115         struct signalfd_siginfo siginfo;
 116         struct lxc_terminal_state *ts = cbdata;
 117
 118         ret = read(fd, &siginfo, sizeof(siginfo));
 119         if (ret < 0 || (size_t)ret < sizeof(siginfo)) {
 120                 ERROR("Failed to read signal info");
 121                 return LXC_MAINLOOP_ERROR;
 122         }
 123
 124         if (siginfo.ssi_signo == SIGTERM) {
 125                 DEBUG("Received SIGTERM. Detaching from the terminal");
 126                 return LXC_MAINLOOP_CLOSE;
 127         }
 128
 129         if (siginfo.ssi_signo == SIGWINCH)
 130                 lxc_terminal_winch(ts);
 131
 132         return LXC_MAINLOOP_CONTINUE;
 133 }
 134
 135 struct lxc_terminal_state *lxc_terminal_signal_init(int srcfd, int dstfd)
 136 {
 137         int ret;
 138         bool istty = false;
 139         sigset_t mask;
 140         struct lxc_terminal_state *ts;
 141
 142         ts = malloc(sizeof(*ts));
 143         if (!ts)
 144                 return NULL;
 145
 146         memset(ts, 0, sizeof(*ts));
 147         ts->stdinfd = srcfd;
 148         ts->masterfd = dstfd;
 149         ts->sigfd = -1;
 150
 151         ret = sigemptyset(&mask);
 152         if (ret < 0) {
 153                 SYSERROR("Failed to initialize an empty signal set");
 154                 goto on_error;
 155         }
 156
 157         istty = (isatty(srcfd) == 1);
 158         if (!istty) {
 159                 INFO("fd %d does not refer to a tty device", srcfd);
 160         } else {
 161                 /* Add tty to list to be scanned at SIGWINCH time. */
 162                 lxc_list_add_elem(&ts->node, ts);
 163                 lxc_list_add_tail(&lxc_ttys, &ts->node);
 164                 ret = sigaddset(&mask, SIGWINCH);
 165                 if (ret < 0)
 166                         SYSNOTICE("Failed to add SIGWINCH to signal set");
 167         }
 168
 169         /* Exit the mainloop cleanly on SIGTERM. */
 170         ret = sigaddset(&mask, SIGTERM);
 171         if (ret < 0) {
 172                 SYSERROR("Failed to add SIGWINCH to signal set");
 173                 goto on_error;
 174         }
 175
 176         ret = pthread_sigmask(SIG_BLOCK, &mask, &ts->oldmask);
 177         if (ret < 0) {
 178                 WARN("Failed to block signals");
 179                 goto on_error;
 180         }
 181
 182         ts->sigfd = signalfd(-1, &mask, SFD_CLOEXEC);
 183         if (ts->sigfd < 0) {
 184                 WARN("Failed to create signal fd");
 185                 (void)pthread_sigmask(SIG_SETMASK, &ts->oldmask, NULL);
 186                 goto on_error;
 187         }
 188
 189         DEBUG("Created signal fd %d", ts->sigfd);
 190         return ts;
 191
 192 on_error:
 193         ERROR("Failed to create signal fd");
 194         if (ts->sigfd >= 0) {
 195                 close(ts->sigfd);
 196                 ts->sigfd = -1;
 197         }
 198
 199         if (istty)
 200                 lxc_list_del(&ts->node);
 201
 202         return ts;
 203 }
 204
 205 void lxc_terminal_signal_fini(struct lxc_terminal_state *ts)
 206 {
 207         if (ts->sigfd >= 0) {
 208                 close(ts->sigfd);
 209
 210                 if (pthread_sigmask(SIG_SETMASK, &ts->oldmask, NULL) < 0)
 211                         SYSWARN("Failed to restore signal mask");
 212         }
 213
 214         if (isatty(ts->stdinfd))
 215                 lxc_list_del(&ts->node);
 216
 217         free(ts);
 218 }
 219
 220 static int lxc_terminal_truncate_log_file(struct lxc_terminal *terminal)
 221 {
 222         /* be very certain things are kosher */
 223         if (!terminal->log_path || terminal->log_fd < 0)
 224                 return -EBADF;
 225
 226         return lxc_unpriv(ftruncate(terminal->log_fd, 0));
 227 }
 228
 229 static int lxc_terminal_rotate_log_file(struct lxc_terminal *terminal)
 230 {
 231         int ret;
 232         size_t len;
 233         char *tmp;
 234
 235         if (!terminal->log_path || terminal->log_rotate == 0)
 236                 return -EOPNOTSUPP;
 237
 238         /* be very certain things are kosher */
 239         if (terminal->log_fd < 0)
 240                 return -EBADF;
 241
 242         len = strlen(terminal->log_path) + sizeof(".1");
 243         tmp = alloca(len);
 244
 245         ret = snprintf(tmp, len, "%s.1", terminal->log_path);
 246         if (ret < 0 || (size_t)ret >= len)
 247                 return -EFBIG;
 248
 249         close(terminal->log_fd);
 250         terminal->log_fd = -1;
 251         ret = lxc_unpriv(rename(terminal->log_path, tmp));
 252         if (ret < 0)
 253                 return ret;
 254
 255         return lxc_terminal_create_log_file(terminal);
 256 }
 257
 258 static int lxc_terminal_write_log_file(struct lxc_terminal *terminal, char *buf,
 259                                        int bytes_read)
 260 {
 261         int ret;
 262         struct stat st;
 263         int64_t space_left = -1;
 264
 265         if (terminal->log_fd < 0)
 266                 return 0;
 267
 268         /* A log size <= 0 means that there's no limit on the size of the log
 269          * file at which point we simply ignore whether the log is supposed to
 270          * be rotated or not.
 271          */
 272         if (terminal->log_size <= 0)
 273                 return lxc_write_nointr(terminal->log_fd, buf, bytes_read);
 274
 275         /* Get current size of the log file. */
 276         ret = fstat(terminal->log_fd, &st);
 277         if (ret < 0) {
 278                 SYSERROR("Failed to stat the terminal log file descriptor");
 279                 return -1;
 280         }
 281
 282         /* handle non-regular files */
 283         if ((st.st_mode & S_IFMT) != S_IFREG) {
 284                 /* This isn't a regular file. so rotating the file seems a
 285                  * dangerous thing to do, size limits are also very
 286                  * questionable. Let's not risk anything and tell the user that
 287                  * he's requesting us to do weird stuff.
 288                  */
 289                 if (terminal->log_rotate > 0 || terminal->log_size > 0)
 290                         return -EINVAL;
 291
 292                 /* I mean, sure log wherever you want to. */
 293                 return lxc_write_nointr(terminal->log_fd, buf, bytes_read);
 294         }
 295
 296         space_left = terminal->log_size - st.st_size;
 297
 298         /* User doesn't want to rotate the log file and there's no more space
 299          * left so simply truncate it.
 300          */
 301         if (space_left <= 0 && terminal->log_rotate <= 0) {
 302                 ret = lxc_terminal_truncate_log_file(terminal);
 303                 if (ret < 0)
 304                         return ret;
 305
 306                 if (bytes_read <= terminal->log_size)
 307                         return lxc_write_nointr(terminal->log_fd, buf, bytes_read);
 308
 309                 /* Write as much as we can into the buffer and loose the rest. */
 310                 return lxc_write_nointr(terminal->log_fd, buf, terminal->log_size);
 311         }
 312
 313         /* There's enough space left. */
 314         if (bytes_read <= space_left)
 315                 return lxc_write_nointr(terminal->log_fd, buf, bytes_read);
 316
 317         /* There's not enough space left but at least write as much as we can
 318          * into the old log file.
 319          */
 320         ret = lxc_write_nointr(terminal->log_fd, buf, space_left);
 321         if (ret < 0)
 322                 return -1;
 323
 324         /* Calculate how many bytes we still need to write. */
 325         bytes_read -= space_left;
 326
 327         /* There'd be more to write but we aren't instructed to rotate the log
 328          * file so simply return. There's no error on our side here.
 329          */
 330         if (terminal->log_rotate > 0)
 331                 ret = lxc_terminal_rotate_log_file(terminal);
 332         else
 333                 ret = lxc_terminal_truncate_log_file(terminal);
 334         if (ret < 0)
 335                 return ret;
 336
 337         if (terminal->log_size < bytes_read) {
 338                 /* Well, this is unfortunate because it means that there is more
 339                  * to write than the user has granted us space. There are
 340                  * multiple ways to handle this but let's use the simplest one:
 341                  * write as much as we can, tell the user that there was more
 342                  * stuff to write and move on.
 343                  * Note that this scenario shouldn't actually happen with the
 344                  * standard pty-based terminal that LXC allocates since it will
 345                  * be switched into raw mode. In raw mode only 1 byte at a time
 346                  * should be read and written.
 347                  */
 348                 WARN("Size of terminal log file is smaller than the bytes to write");
 349                 ret = lxc_write_nointr(terminal->log_fd, buf, terminal->log_size);
 350                 if (ret < 0)
 351                         return -1;
 352                 bytes_read -= ret;
 353                 return bytes_read;
 354         }
 355
 356         /* Yay, we made it. */
 357         ret = lxc_write_nointr(terminal->log_fd, buf, bytes_read);
 358         if (ret < 0)
 359                 return -1;
 360         bytes_read -= ret;
 361         return bytes_read;
 362 }
 363
 364 int lxc_terminal_io_cb(int fd, uint32_t events, void *data,
 365                        struct lxc_epoll_descr *descr)
 366 {
 367         struct lxc_terminal *terminal = data;
 368         char buf[LXC_TERMINAL_BUFFER_SIZE];
 369         int r, w, w_log, w_rbuf;
 370
 371         w = r = lxc_read_nointr(fd, buf, sizeof(buf));
 372         if (r <= 0) {
 373                 INFO("Terminal client on fd %d has exited", fd);
 374                 lxc_mainloop_del_handler(descr, fd);
 375
 376                 if (fd == terminal->master) {
 377                         terminal->master = -EBADF;
 378                 } else if (fd == terminal->peer) {
 379                         if (terminal->tty_state) {
 380                                 lxc_terminal_signal_fini(terminal->tty_state);
 381                                 terminal->tty_state = NULL;
 382                         }
 383                         terminal->peer = -EBADF;
 384                 } else {
 385                         ERROR("Handler received unexpected file descriptor");
 386                 }
 387                 close(fd);
 388
 389                 return LXC_MAINLOOP_CLOSE;
 390         }
 391
 392         if (fd == terminal->peer)
 393                 w = lxc_write_nointr(terminal->master, buf, r);
 394
 395         w_rbuf = w_log = 0;
 396         if (fd == terminal->master) {
 397                 /* write to peer first */
 398                 if (terminal->peer >= 0)
 399                         w = lxc_write_nointr(terminal->peer, buf, r);
 400
 401                 /* write to terminal ringbuffer */
 402                 if (terminal->buffer_size > 0)
 403                         w_rbuf = lxc_ringbuf_write(&terminal->ringbuf, buf, r);
 404
 405                 /* write to terminal log */
 406                 if (terminal->log_fd >= 0)
 407                         w_log = lxc_terminal_write_log_file(terminal, buf, r);
 408         }
 409
 410         if (w != r)
 411                 WARN("Short write on terminal r:%d != w:%d", r, w);
 412
 413         if (w_rbuf < 0) {
 414                 errno = -w_rbuf;
 415                 SYSTRACE("Failed to write %d bytes to terminal ringbuffer", r);
 416         }
 417
 418         if (w_log < 0)
 419                 TRACE("Failed to write %d bytes to terminal log", r);
 420
 421         return LXC_MAINLOOP_CONTINUE;
 422 }
 423
 424 static int lxc_terminal_mainloop_add_peer(struct lxc_terminal *terminal)
 425 {
 426         int ret;
 427
 428         if (terminal->peer >= 0) {
 429                 ret = lxc_mainloop_add_handler(terminal->descr, terminal->peer,
 430                                                lxc_terminal_io_cb, terminal);
 431                 if (ret < 0) {
 432                         WARN("Failed to add terminal peer handler to mainloop");
 433                         return -1;
 434                 }
 435         }
 436
 437         if (!terminal->tty_state || terminal->tty_state->sigfd < 0)
 438                 return 0;
 439
 440         ret = lxc_mainloop_add_handler(terminal->descr, terminal->tty_state->sigfd,
 441                                        lxc_terminal_signalfd_cb, terminal->tty_state);
 442         if (ret < 0) {
 443                 WARN("Failed to add signal handler to mainloop");
 444                 return -1;
 445         }
 446
 447         return 0;
 448 }
 449
 450 int lxc_terminal_mainloop_add(struct lxc_epoll_descr *descr,
 451                               struct lxc_terminal *terminal)
 452 {
 453         int ret;
 454
 455         if (terminal->master < 0) {
 456                 INFO("Terminal is not initialized");
 457                 return 0;
 458         }
 459
 460         ret = lxc_mainloop_add_handler(descr, terminal->master,
 461                                        lxc_terminal_io_cb, terminal);
 462         if (ret < 0) {
 463                 ERROR("Failed to add handler for terminal master fd %d to "
 464                       "mainloop", terminal->master);
 465                 return -1;
 466         }
 467
 468         /* We cache the descr so that we can add an fd to it when someone
 469          * does attach to it in lxc_terminal_allocate().
 470          */
 471         terminal->descr = descr;
 472
 473         return lxc_terminal_mainloop_add_peer(terminal);
 474 }
 475
 476 int lxc_setup_tios(int fd, struct termios *oldtios)
 477 {
 478         int ret;
 479         struct termios newtios;
 480
 481         if (!isatty(fd)) {
 482                 ERROR("File descriptor %d does not refert to a terminal", fd);
 483                 return -1;
 484         }
 485
 486         /* Get current termios. */
 487         ret = tcgetattr(fd, oldtios);
 488         if (ret < 0) {
 489                 SYSERROR("Failed to get current terminal settings");
 490                 return -1;
 491         }
 492
 493         /* ensure we don't end up in an endless loop:
 494          * The kernel might fire SIGTTOU while an
 495          * ioctl() in tcsetattr() is executed. When the ioctl()
 496          * is resumed and retries, the signal handler interrupts it again.
 497          */
 498         signal (SIGTTIN, SIG_IGN);
 499         signal (SIGTTOU, SIG_IGN);
 500
 501         newtios = *oldtios;
 502
 503         /* We use the same settings that ssh does. */
 504         newtios.c_iflag |= IGNPAR;
 505         newtios.c_iflag &= ~(ISTRIP | INLCR | IGNCR | ICRNL | IXON | IXANY | IXOFF);
 506 #ifdef IUCLC
 507         newtios.c_iflag &= ~IUCLC;
 508 #endif
 509         newtios.c_lflag &= ~(TOSTOP | ISIG | ICANON | ECHO | ECHOE | ECHOK | ECHONL);
 510 #ifdef IEXTEN
 511         newtios.c_lflag &= ~IEXTEN;
 512 #endif
 513         newtios.c_oflag &= ~ONLCR;
 514         newtios.c_oflag |= OPOST;
 515         newtios.c_cc[VMIN] = 1;
 516         newtios.c_cc[VTIME] = 0;
 517
 518         /* Set new attributes. */
 519         ret = tcsetattr(fd, TCSAFLUSH, &newtios);
 520         if (ret < 0) {
 521                 ERROR("Failed to set new terminal settings");
 522                 return -1;
 523         }
 524
 525         return 0;
 526 }
 527
 528 static void lxc_terminal_peer_proxy_free(struct lxc_terminal *terminal)
 529 {
 530         if (terminal->tty_state) {
 531                 lxc_terminal_signal_fini(terminal->tty_state);
 532                 terminal->tty_state = NULL;
 533         }
 534
 535         close(terminal->proxy.master);
 536         terminal->proxy.master = -1;
 537
 538         close(terminal->proxy.slave);
 539         terminal->proxy.slave = -1;
 540
 541         terminal->proxy.busy = -1;
 542
 543         terminal->proxy.name[0] = '\0';
 544
 545         terminal->peer = -1;
 546 }
 547
 548 static int lxc_terminal_peer_proxy_alloc(struct lxc_terminal *terminal,
 549                                          int sockfd)
 550 {
 551         int ret;
 552         struct termios oldtermio;
 553         struct lxc_terminal_state *ts;
 554
 555         if (terminal->master < 0) {
 556                 ERROR("Terminal not set up");
 557                 return -1;
 558         }
 559
 560         if (terminal->proxy.busy != -1 || terminal->peer != -1) {
 561                 NOTICE("Terminal already in use");
 562                 return -1;
 563         }
 564
 565         if (terminal->tty_state) {
 566                 ERROR("Terminal has already been initialized");
 567                 return -1;
 568         }
 569
 570         /* This is the proxy terminal that will be given to the client, and
 571          * that the real terminal master will send to / recv from.
 572          */
 573         ret = openpty(&terminal->proxy.master, &terminal->proxy.slave,
 574                       terminal->proxy.name, NULL, NULL);
 575         if (ret < 0) {
 576                 SYSERROR("Failed to open proxy terminal");
 577                 return -1;
 578         }
 579
 580         ret = lxc_setup_tios(terminal->proxy.slave, &oldtermio);
 581         if (ret < 0)
 582                 goto on_error;
 583
 584         ts = lxc_terminal_signal_init(terminal->proxy.master, terminal->master);
 585         if (!ts)
 586                 goto on_error;
 587
 588         terminal->tty_state = ts;
 589         terminal->peer = terminal->proxy.slave;
 590         terminal->proxy.busy = sockfd;
 591         ret = lxc_terminal_mainloop_add_peer(terminal);
 592         if (ret < 0)
 593                 goto on_error;
 594
 595         NOTICE("Opened proxy terminal with master fd %d and slave fd %d",
 596                terminal->proxy.master, terminal->proxy.slave);
 597         return 0;
 598
 599 on_error:
 600         lxc_terminal_peer_proxy_free(terminal);
 601         return -1;
 602 }
 603
 604 int lxc_terminal_allocate(struct lxc_conf *conf, int sockfd, int *ttyreq)
 605 {
 606         int ttynum;
 607         int masterfd = -1;
 608         struct lxc_tty_info *ttys = &conf->ttys;
 609         struct lxc_terminal *terminal = &conf->console;
 610
 611         if (*ttyreq == 0) {
 612                 int ret;
 613
 614                 ret = lxc_terminal_peer_proxy_alloc(terminal, sockfd);
 615                 if (ret < 0)
 616                         goto out;
 617
 618                 masterfd = terminal->proxy.master;
 619                 goto out;
 620         }
 621
 622         if (*ttyreq > 0) {
 623                 if (*ttyreq > ttys->max)
 624                         goto out;
 625
 626                 if (ttys->tty[*ttyreq - 1].busy)
 627                         goto out;
 628
 629                 /* The requested tty is available. */
 630                 ttynum = *ttyreq;
 631                 goto out_tty;
 632         }
 633
 634         /* Search for next available tty, fixup index tty1 => [0]. */
 635         for (ttynum = 1; ttynum <= ttys->max && ttys->tty[ttynum - 1].busy; ttynum++) {
 636                 ;
 637         }
 638
 639         /* We didn't find any available slot for tty. */
 640         if (ttynum > ttys->max)
 641                 goto out;
 642
 643         *ttyreq = ttynum;
 644
 645 out_tty:
 646         ttys->tty[ttynum - 1].busy = sockfd;
 647         masterfd = ttys->tty[ttynum - 1].master;
 648
 649 out:
 650         return masterfd;
 651 }
 652
 653 void lxc_terminal_free(struct lxc_conf *conf, int fd)
 654 {
 655         int i;
 656         struct lxc_tty_info *ttys = &conf->ttys;
 657         struct lxc_terminal *terminal = &conf->console;
 658
 659         for (i = 0; i < ttys->max; i++)
 660                 if (ttys->tty[i].busy == fd)
 661                         ttys->tty[i].busy = 0;
 662
 663         if (terminal->proxy.busy != fd)
 664                 return;
 665
 666         lxc_mainloop_del_handler(terminal->descr, terminal->proxy.slave);
 667         lxc_terminal_peer_proxy_free(terminal);
 668 }
 669
 670 static int lxc_terminal_peer_default(struct lxc_terminal *terminal)
 671 {
 672         struct lxc_terminal_state *ts;
 673         const char *path;
 674         int ret = 0;
 675
 676         if (terminal->path)
 677                 path = terminal->path;
 678         else
 679                 path = "/dev/tty";
 680
 681         terminal->peer = lxc_unpriv(open(path, O_RDWR | O_CLOEXEC));
 682         if (terminal->peer < 0) {
 683                 if (!terminal->path) {
 684                         errno = ENODEV;
 685                         SYSDEBUG("The process does not have a controlling terminal");
 686                         goto on_succes;
 687                 }
 688
 689                 SYSERROR("Failed to open proxy terminal \"%s\"", path);
 690                 return -ENOTTY;
 691         }
 692         DEBUG("Using terminal \"%s\" as proxy", path);
 693
 694         if (!isatty(terminal->peer)) {
 695                 ERROR("File descriptor for \"%s\" does not refer to a terminal", path);
 696                 goto on_error_free_tios;
 697         }
 698
 699         ts = lxc_terminal_signal_init(terminal->peer, terminal->master);
 700         terminal->tty_state = ts;
 701         if (!ts) {
 702                 WARN("Failed to install signal handler");
 703                 goto on_error_free_tios;
 704         }
 705
 706         lxc_terminal_winsz(terminal->peer, terminal->master);
 707
 708         terminal->tios = malloc(sizeof(*terminal->tios));
 709         if (!terminal->tios)
 710                 goto on_error_free_tios;
 711
 712         ret = lxc_setup_tios(terminal->peer, terminal->tios);
 713         if (ret < 0)
 714                 goto on_error_close_peer;
 715         else
 716                 goto on_succes;
 717
 718 on_error_free_tios:
 719         free(terminal->tios);
 720         terminal->tios = NULL;
 721
 722 on_error_close_peer:
 723         close(terminal->peer);
 724         terminal->peer = -1;
 725         ret = -ENOTTY;
 726
 727 on_succes:
 728         return ret;
 729 }
 730
 731 int lxc_terminal_write_ringbuffer(struct lxc_terminal *terminal)
 732 {
 733         char *r_addr;
 734         ssize_t ret;
 735         uint64_t used;
 736         struct lxc_ringbuf *buf = &terminal->ringbuf;
 737
 738         /* There's not log file where we can dump the ringbuffer to. */
 739         if (terminal->log_fd < 0)
 740                 return 0;
 741
 742         used = lxc_ringbuf_used(buf);
 743         if (used == 0)
 744                 return 0;
 745
 746         ret = lxc_terminal_truncate_log_file(terminal);
 747         if (ret < 0)
 748                 return ret;
 749
 750         /* Write as much as we can without exceeding the limit. */
 751         if (terminal->log_size < used)
 752                 used = terminal->log_size;
 753
 754         r_addr = lxc_ringbuf_get_read_addr(buf);
 755         ret = lxc_write_nointr(terminal->log_fd, r_addr, used);
 756         if (ret < 0)
 757                 return -EIO;
 758
 759         return 0;
 760 }
 761
 762 void lxc_terminal_delete(struct lxc_terminal *terminal)
 763 {
 764         int ret;
 765
 766         ret = lxc_terminal_write_ringbuffer(terminal);
 767         if (ret < 0)
 768                 WARN("Failed to write terminal log to disk");
 769
 770         if (terminal->tios && terminal->peer >= 0) {
 771                 ret = tcsetattr(terminal->peer, TCSAFLUSH, terminal->tios);
 772                 if (ret < 0)
 773                         SYSWARN("Failed to set old terminal settings");
 774         }
 775         free(terminal->tios);
 776         terminal->tios = NULL;
 777
 778         if (terminal->peer >= 0)
 779                 close(terminal->peer);
 780         terminal->peer = -1;
 781
 782         if (terminal->master >= 0)
 783                 close(terminal->master);
 784         terminal->master = -1;
 785
 786         if (terminal->slave >= 0)
 787                 close(terminal->slave);
 788         terminal->slave = -1;
 789
 790         if (terminal->log_fd >= 0)
 791                 close(terminal->log_fd);
 792         terminal->log_fd = -1;
 793 }
 794
 795 /**
 796  * Note that this function needs to run before the mainloop starts. Since we
 797  * register a handler for the terminal's masterfd when we create the mainloop
 798  * the terminal handler needs to see an allocated ringbuffer.
 799  */
 800 static int lxc_terminal_create_ringbuf(struct lxc_terminal *terminal)
 801 {
 802         int ret;
 803         struct lxc_ringbuf *buf = &terminal->ringbuf;
 804         uint64_t size = terminal->buffer_size;
 805
 806         /* no ringbuffer previously allocated and no ringbuffer requested */
 807         if (!buf->addr && size <= 0)
 808                 return 0;
 809
 810         /* ringbuffer allocated but no new ringbuffer requested */
 811         if (buf->addr && size <= 0) {
 812                 lxc_ringbuf_release(buf);
 813                 buf->addr = NULL;
 814                 buf->r_off = 0;
 815                 buf->w_off = 0;
 816                 buf->size = 0;
 817                 TRACE("Deallocated terminal ringbuffer");
 818                 return 0;
 819         }
 820
 821         if (size <= 0)
 822                 return 0;
 823
 824         /* check wether the requested size for the ringbuffer has changed */
 825         if (buf->addr && buf->size != size) {
 826                 TRACE("Terminal ringbuffer size changed from %" PRIu64
 827                       " to %" PRIu64 " bytes. Deallocating terminal ringbuffer",
 828                       buf->size, size);
 829                 lxc_ringbuf_release(buf);
 830         }
 831
 832         ret = lxc_ringbuf_create(buf, size);
 833         if (ret < 0) {
 834                 ERROR("Failed to setup %" PRIu64 " byte terminal ringbuffer", size);
 835                 return -1;
 836         }
 837
 838         TRACE("Allocated %" PRIu64 " byte terminal ringbuffer", size);
 839         return 0;
 840 }
 841
 842 /**
 843  * This is the terminal log file. Please note that the terminal log file is
 844  * (implementation wise not content wise) independent of the terminal ringbuffer.
 845  */
 846 int lxc_terminal_create_log_file(struct lxc_terminal *terminal)
 847 {
 848         if (!terminal->log_path)
 849                 return 0;
 850
 851         terminal->log_fd = lxc_unpriv(open(terminal->log_path, O_CLOEXEC | O_RDWR | O_CREAT | O_APPEND, 0600));
 852         if (terminal->log_fd < 0) {
 853                 SYSERROR("Failed to open terminal log file \"%s\"", terminal->log_path);
 854                 return -1;
 855         }
 856
 857         DEBUG("Using \"%s\" as terminal log file", terminal->log_path);
 858         return 0;
 859 }
 860
 861 int lxc_terminal_create(struct lxc_terminal *terminal)
 862 {
 863         int ret;
 864
 865         ret = openpty(&terminal->master, &terminal->slave, terminal->name, NULL, NULL);
 866         if (ret < 0) {
 867                 SYSERROR("Failed to open terminal");
 868                 return -1;
 869         }
 870
 871         ret = fcntl(terminal->master, F_SETFD, FD_CLOEXEC);
 872         if (ret < 0) {
 873                 SYSERROR("Failed to set FD_CLOEXEC flag on terminal master");
 874                 goto err;
 875         }
 876
 877         ret = fcntl(terminal->slave, F_SETFD, FD_CLOEXEC);
 878         if (ret < 0) {
 879                 SYSERROR("Failed to set FD_CLOEXEC flag on terminal slave");
 880                 goto err;
 881         }
 882
 883         ret = lxc_terminal_peer_default(terminal);
 884         if (ret < 0) {
 885                 ERROR("Failed to allocate proxy terminal");
 886                 goto err;
 887         }
 888
 889         return 0;
 890
 891 err:
 892         lxc_terminal_delete(terminal);
 893         return -ENODEV;
 894 }
 895
 896 int lxc_terminal_setup(struct lxc_conf *conf)
 897 {
 898         int ret;
 899         struct lxc_terminal *terminal = &conf->console;
 900         struct termios oldtios;
 901
 902         if (terminal->path && strcmp(terminal->path, "none") == 0) {
 903                 INFO("No terminal requested");
 904                 return 0;
 905         }
 906
 907         ret = lxc_terminal_create(terminal);
 908         if (ret < 0)
 909                 return -1;
 910
 911         ret = lxc_setup_tios(terminal->master, &oldtios);
 912         if (ret < 0)
 913                 return -1;
 914
 915         ret = lxc_terminal_create_log_file(terminal);
 916         if (ret < 0)
 917                 goto err;
 918
 919         ret = lxc_terminal_create_ringbuf(terminal);
 920         if (ret < 0)
 921                 goto err;
 922
 923         return 0;
 924
 925 err:
 926         lxc_terminal_delete(terminal);
 927         return -ENODEV;
 928 }
 929
 930 static bool __terminal_dup2(int duplicate, int original)
 931 {
 932         int ret;
 933
 934         if (!isatty(original))
 935                 return true;
 936
 937         ret = dup2(duplicate, original);
 938         if (ret < 0) {
 939                 SYSERROR("Failed to dup2(%d, %d)", duplicate, original);
 940                 return false;
 941         }
 942
 943         return true;
 944 }
 945
 946 int lxc_terminal_set_stdfds(int fd)
 947 {
 948         int i;
 949
 950         if (fd < 0)
 951                 return 0;
 952
 953         for (i = 0; i < 3; i++)
 954                 if (!__terminal_dup2(fd, (int[]){STDIN_FILENO, STDOUT_FILENO,
 955                                                  STDERR_FILENO}[i]))
 956                         return -1;
 957
 958         return 0;
 959 }
 960
 961 int lxc_terminal_stdin_cb(int fd, uint32_t events, void *cbdata,
 962                           struct lxc_epoll_descr *descr)
 963 {
 964         int ret;
 965         char c;
 966         struct lxc_terminal_state *ts = cbdata;
 967
 968         if (fd != ts->stdinfd)
 969                 return LXC_MAINLOOP_CLOSE;
 970
 971         ret = lxc_read_nointr(ts->stdinfd, &c, 1);
 972         if (ret <= 0)
 973                 return LXC_MAINLOOP_CLOSE;
 974
 975         if (ts->escape >= 1) {
 976                 /* we want to exit the terminal with Ctrl+a q */
 977                 if (c == ts->escape && !ts->saw_escape) {
 978                         ts->saw_escape = 1;
 979                         return LXC_MAINLOOP_CONTINUE;
 980                 }
 981
 982                 if (c == 'q' && ts->saw_escape)
 983                         return LXC_MAINLOOP_CLOSE;
 984
 985                 ts->saw_escape = 0;
 986         }
 987
 988         ret = lxc_write_nointr(ts->masterfd, &c, 1);
 989         if (ret <= 0)
 990                 return LXC_MAINLOOP_CLOSE;
 991
 992         return LXC_MAINLOOP_CONTINUE;
 993 }
 994
 995 int lxc_terminal_master_cb(int fd, uint32_t events, void *cbdata,
 996                            struct lxc_epoll_descr *descr)
 997 {
 998         int r, w;
 999         char buf[LXC_TERMINAL_BUFFER_SIZE];
1000         struct lxc_terminal_state *ts = cbdata;
1001
1002         if (fd != ts->masterfd)
1003                 return LXC_MAINLOOP_CLOSE;
1004
1005         r = lxc_read_nointr(fd, buf, sizeof(buf));
1006         if (r <= 0)
1007                 return LXC_MAINLOOP_CLOSE;
1008
1009         w = lxc_write_nointr(ts->stdoutfd, buf, r);
1010         if (w <= 0 || w != r)
1011                 return LXC_MAINLOOP_CLOSE;
1012
1013         return LXC_MAINLOOP_CONTINUE;
1014 }
1015
1016 int lxc_terminal_getfd(struct lxc_container *c, int *ttynum, int *masterfd)
1017 {
1018         return lxc_cmd_console(c->name, ttynum, masterfd, c->config_path);
1019 }
1020
1021 int lxc_console(struct lxc_container *c, int ttynum,
1022                 int stdinfd, int stdoutfd, int stderrfd,
1023                 int escape)
1024 {
1025         int masterfd, ret, ttyfd;
1026         struct lxc_epoll_descr descr;
1027         struct termios oldtios;
1028         struct lxc_terminal_state *ts;
1029         int istty = 0;
1030
1031         ttyfd = lxc_cmd_console(c->name, &ttynum, &masterfd, c->config_path);
1032         if (ttyfd < 0)
1033                 return -1;
1034
1035         ret = setsid();
1036         if (ret < 0)
1037                 TRACE("Process is already group leader");
1038
1039         ts = lxc_terminal_signal_init(stdinfd, masterfd);
1040         if (!ts) {
1041                 ret = -1;
1042                 goto close_fds;
1043         }
1044         ts->escape = escape;
1045         ts->winch_proxy = c->name;
1046         ts->winch_proxy_lxcpath = c->config_path;
1047         ts->stdoutfd = stdoutfd;
1048
1049         istty = isatty(stdinfd);
1050         if (istty) {
1051                 lxc_terminal_winsz(stdinfd, masterfd);
1052                 lxc_cmd_terminal_winch(ts->winch_proxy, ts->winch_proxy_lxcpath);
1053         } else {
1054                 INFO("File descriptor %d does not refer to a terminal", stdinfd);
1055         }
1056
1057         ret = lxc_mainloop_open(&descr);
1058         if (ret) {
1059                 ERROR("Failed to create mainloop");
1060                 goto sigwinch_fini;
1061         }
1062
1063         if (ts->sigfd != -1) {
1064                 ret = lxc_mainloop_add_handler(&descr, ts->sigfd,
1065                                                lxc_terminal_signalfd_cb, ts);
1066                 if (ret < 0) {
1067                         ERROR("Failed to add signal handler to mainloop");
1068                         goto close_mainloop;
1069                 }
1070         }
1071
1072         ret = lxc_mainloop_add_handler(&descr, ts->stdinfd,
1073                                        lxc_terminal_stdin_cb, ts);
1074         if (ret < 0) {
1075                 ERROR("Failed to add stdin handler");
1076                 goto close_mainloop;
1077         }
1078
1079         ret = lxc_mainloop_add_handler(&descr, ts->masterfd,
1080                                        lxc_terminal_master_cb, ts);
1081         if (ret < 0) {
1082                 ERROR("Failed to add master handler");
1083                 goto close_mainloop;
1084         }
1085
1086         if (ts->escape >= 1) {
1087                 fprintf(stderr,
1088                         "\n"
1089                         "Connected to tty %1$d\n"
1090                         "Type <Ctrl+%2$c q> to exit the console, "
1091                         "<Ctrl+%2$c Ctrl+%2$c> to enter Ctrl+%2$c itself\n",
1092                         ttynum, 'a' + escape - 1);
1093         }
1094
1095         if (istty) {
1096                 ret = lxc_setup_tios(stdinfd, &oldtios);
1097                 if (ret < 0)
1098                         goto close_mainloop;
1099         }
1100
1101         ret = lxc_mainloop(&descr, -1);
1102         if (ret < 0) {
1103                 ERROR("The mainloop returned an error");
1104                 goto restore_tios;
1105         }
1106
1107         ret = 0;
1108
1109 restore_tios:
1110         if (istty) {
1111                 istty = tcsetattr(stdinfd, TCSAFLUSH, &oldtios);
1112                 if (istty < 0)
1113                         SYSWARN("Failed to restore terminal properties");
1114         }
1115
1116 close_mainloop:
1117         lxc_mainloop_close(&descr);
1118
1119 sigwinch_fini:
1120         lxc_terminal_signal_fini(ts);
1121
1122 close_fds:
1123         close(masterfd);
1124         close(ttyfd);
1125
1126         return ret;
1127 }
1128
1129 int lxc_make_controlling_terminal(int fd)
1130 {
1131         int ret;
1132
1133         setsid();
1134
1135         ret = ioctl(fd, TIOCSCTTY, (char *)NULL);
1136         if (ret < 0)
1137                 return -1;
1138
1139         return 0;
1140 }
1141
1142 int lxc_terminal_prepare_login(int fd)
1143 {
1144         int ret;
1145
1146         ret = lxc_make_controlling_terminal(fd);
1147         if (ret < 0)
1148                 return -1;
1149
1150         ret = lxc_terminal_set_stdfds(fd);
1151         if (ret < 0)
1152                 return -1;
1153
1154         if (fd > STDERR_FILENO)
1155                 close(fd);
1156
1157         return 0;
1158 }
1159
1160 void lxc_terminal_info_init(struct lxc_terminal_info *terminal)
1161 {
1162         terminal->name[0] = '\0';
1163         terminal->master = -EBADF;
1164         terminal->slave = -EBADF;
1165         terminal->busy = -1;
1166 }
1167
1168 void lxc_terminal_init(struct lxc_terminal *terminal)
1169 {
1170         memset(terminal, 0, sizeof(*terminal));
1171         terminal->slave = -EBADF;
1172         terminal->master = -EBADF;
1173         terminal->peer = -EBADF;
1174         terminal->log_fd = -EBADF;
1175         lxc_terminal_info_init(&terminal->proxy);
1176 }
1177
1178 void lxc_terminal_conf_free(struct lxc_terminal *terminal)
1179 {
1180         free(terminal->log_path);
1181         free(terminal->path);
1182         if (terminal->buffer_size > 0 && terminal->ringbuf.addr)
1183                 lxc_ringbuf_release(&terminal->ringbuf);
1184 }
1185
1186 int lxc_terminal_map_ids(struct lxc_conf *c, struct lxc_terminal *terminal)
1187 {
1188         int ret;
1189
1190         if (lxc_list_empty(&c->id_map))
1191                 return 0;
1192
1193         if (strcmp(terminal->name, "") == 0)
1194                 return 0;
1195
1196         ret = chown_mapped_root(terminal->name, c);
1197         if (ret < 0) {
1198                 ERROR("Failed to chown terminal \"%s\"", terminal->name);
1199                 return -1;
1200         }
1201
1202         TRACE("Chowned terminal \"%s\"", terminal->name);
1203
1204         return 0;
1205 }