lxc_container.c 58.0 KB
Newer Older
1
/*
2
 * Copyright (C) 2008-2013 Red Hat, Inc.
3
 * Copyright (C) 2008 IBM Corp.
4 5 6 7 8
 *
 * lxc_container.c: file description
 *
 * Authors:
 *  David L. Leskovec <dlesko at linux.vnet.ibm.com>
9
 *  Daniel P. Berrange <berrange@redhat.com>
10 11 12 13 14 15 16 17 18 19 20 21
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
22
 * License along with this library.  If not, see
O
Osier Yang 已提交
23
 * <http://www.gnu.org/licenses/>.
24 25 26 27 28 29 30
 */

#include <config.h>

#include <fcntl.h>
#include <limits.h>
#include <stdlib.h>
31
#include <stdio.h>
32 33
#include <sys/ioctl.h>
#include <sys/mount.h>
34
#include <sys/wait.h>
35
#include <sys/stat.h>
36
#include <unistd.h>
37
#include <mntent.h>
38 39
#include <sys/reboot.h>
#include <linux/reboot.h>
40 41 42 43 44 45

/* Yes, we want linux private one, for _syscall2() macro */
#include <linux/unistd.h>

/* For MS_MOVE */
#include <linux/fs.h>
46

47
#if WITH_CAPNG
48
# include <cap-ng.h>
D
Daniel P. Berrange 已提交
49
#endif
50

51
#if WITH_BLKID
52 53 54
# include <blkid/blkid.h>
#endif

55 56 57 58
#if WITH_SELINUX
# include <selinux/selinux.h>
#endif

59
#include "virerror.h"
60
#include "virlog.h"
61
#include "lxc_container.h"
62
#include "viralloc.h"
63
#include "virnetdevveth.h"
64
#include "viruuid.h"
E
Eric Blake 已提交
65
#include "virfile.h"
66
#include "virusb.h"
67
#include "vircommand.h"
68
#include "virnetdev.h"
69
#include "virprocess.h"
70
#include "virstring.h"
71

72 73
#define VIR_FROM_THIS VIR_FROM_LXC

74 75 76 77 78 79
/*
 * GLibc headers are behind the kernel, so we define these
 * constants if they're not present already.
 */

#ifndef CLONE_NEWPID
80
# define CLONE_NEWPID  0x20000000
81 82
#endif
#ifndef CLONE_NEWUTS
83
# define CLONE_NEWUTS  0x04000000
84 85
#endif
#ifndef CLONE_NEWUSER
86
# define CLONE_NEWUSER 0x10000000
87 88
#endif
#ifndef CLONE_NEWIPC
89
# define CLONE_NEWIPC  0x08000000
90 91
#endif
#ifndef CLONE_NEWNET
92
# define CLONE_NEWNET  0x40000000 /* New network namespace */
93 94 95 96 97 98 99 100
#endif

/* messages between parent and container */
typedef char lxc_message_t;
#define LXC_CONTINUE_MSG 'c'

typedef struct __lxc_child_argv lxc_child_argv_t;
struct __lxc_child_argv {
101
    virDomainDefPtr config;
102
    virSecurityManagerPtr securityDriver;
103
    size_t nveths;
104
    char **veths;
105
    int monitor;
106 107
    size_t npassFDs;
    int *passFDs;
108
    size_t nttyPaths;
109
    char **ttyPaths;
110
    int handshakefd;
111 112
};

113 114 115
static int lxcContainerMountFSBlock(virDomainFSDefPtr fs,
                                    const char *srcprefix);

116

117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162
/*
 * reboot(LINUX_REBOOT_CMD_CAD_ON) will return -EINVAL
 * in a child pid namespace if container reboot support exists.
 * Otherwise, it will either succeed or return -EPERM.
 */
ATTRIBUTE_NORETURN static int
lxcContainerRebootChild(void *argv)
{
    int *cmd = argv;
    int ret;

    ret = reboot(*cmd);
    if (ret == -1 && errno == EINVAL)
        _exit(1);
    _exit(0);
}


static
int lxcContainerHasReboot(void)
{
    int flags = CLONE_NEWPID|CLONE_NEWNS|CLONE_NEWUTS|
        CLONE_NEWIPC|SIGCHLD;
    int cpid;
    char *childStack;
    char *stack;
    char *buf;
    int cmd, v;
    int status;
    char *tmp;

    if (virFileReadAll("/proc/sys/kernel/ctrl-alt-del", 10, &buf) < 0)
        return -1;

    if ((tmp = strchr(buf, '\n')))
        *tmp = '\0';

    if (virStrToLong_i(buf, NULL, 10, &v) < 0) {
        virReportError(VIR_ERR_INTERNAL_ERROR,
                       _("Malformed ctrl-alt-del setting '%s'"), buf);
        VIR_FREE(buf);
        return -1;
    }
    VIR_FREE(buf);
    cmd = v ? LINUX_REBOOT_CMD_CAD_ON : LINUX_REBOOT_CMD_CAD_OFF;

163
    if (VIR_ALLOC_N(stack, getpagesize() * 4) < 0)
164 165 166 167 168 169 170 171 172 173
        return -1;

    childStack = stack + (getpagesize() * 4);

    cpid = clone(lxcContainerRebootChild, childStack, flags, &cmd);
    VIR_FREE(stack);
    if (cpid < 0) {
        virReportSystemError(errno, "%s",
                             _("Unable to clone to check reboot support"));
        return -1;
174
    } else if (virProcessWait(cpid, &status) < 0) {
175 176 177 178 179 180 181 182 183 184 185 186 187 188
        return -1;
    }

    if (WEXITSTATUS(status) != 1) {
        VIR_DEBUG("Containerized reboot support is missing "
                  "(kernel probably too old < 3.4)");
        return 0;
    }

    VIR_DEBUG("Containerized reboot support is available");
    return 1;
}


189
/**
190
 * lxcContainerBuildInitCmd:
191
 * @vmDef: pointer to vm definition structure
192
 *
193
 * Build a virCommandPtr for launching the container 'init' process
194
 *
195
 * Returns a virCommandPtr
196
 */
197
static virCommandPtr lxcContainerBuildInitCmd(virDomainDefPtr vmDef)
198
{
199
    char uuidstr[VIR_UUID_STRING_BUFLEN];
200
    virCommandPtr cmd;
201 202 203

    virUUIDFormat(vmDef->uuid, uuidstr);

204 205
    cmd = virCommandNew(vmDef->os.init);

206 207 208
    if (vmDef->os.initargv && vmDef->os.initargv[0])
        virCommandAddArgSet(cmd, (const char **)vmDef->os.initargv);

209 210
    virCommandAddEnvString(cmd, "PATH=/bin:/sbin");
    virCommandAddEnvString(cmd, "TERM=linux");
211
    virCommandAddEnvString(cmd, "container=lxc-libvirt");
212
    virCommandAddEnvPair(cmd, "container_uuid", uuidstr);
213 214
    virCommandAddEnvPair(cmd, "LIBVIRT_LXC_UUID", uuidstr);
    virCommandAddEnvPair(cmd, "LIBVIRT_LXC_NAME", vmDef->name);
215 216
    if (vmDef->os.cmdline)
        virCommandAddEnvPair(cmd, "LIBVIRT_LXC_CMDLINE", vmDef->os.cmdline);
217

218
    return cmd;
219 220 221
}

/**
222
 * lxcContainerSetupFDs:
223 224
 * @control: control FD from parent
 * @ttyfd: FD of tty to set as the container console
225 226
 * @npassFDs: number of extra FDs
 * @passFDs: list of extra FDs
227
 *
228 229 230 231
 * Setup file descriptors in the container. @ttyfd is set to be
 * the container's stdin, stdout & stderr. Any FDs included in
 * @passFDs, will be dup()'d such that they start from stderr+1
 * with no gaps.
232 233 234
 *
 * Returns 0 on success or -1 in case of error
 */
235 236
static int lxcContainerSetupFDs(int *ttyfd,
                                size_t npassFDs, int *passFDs)
237 238
{
    int rc = -1;
239 240
    int open_max;
    int fd;
241 242 243
    int last_fd;
    size_t i;
    size_t j;
244 245

    if (setsid() < 0) {
246
        virReportSystemError(errno, "%s",
247
                             _("setsid failed"));
248
        goto cleanup;
249 250
    }

251
    if (ioctl(*ttyfd, TIOCSCTTY, NULL) < 0) {
252
        virReportSystemError(errno, "%s",
253
                             _("ioctl(TIOCSTTY) failed"));
254 255 256
        goto cleanup;
    }

257
    if (dup2(*ttyfd, STDIN_FILENO) < 0) {
J
John Ferlan 已提交
258
        virReportSystemError(errno, "%s",
259
                             _("dup2(stdin) failed"));
J
John Ferlan 已提交
260 261
        goto cleanup;
    }
262

263
    if (dup2(*ttyfd, STDOUT_FILENO) < 0) {
264
        virReportSystemError(errno, "%s",
265
                             _("dup2(stdout) failed"));
266 267 268
        goto cleanup;
    }

269
    if (dup2(*ttyfd, STDERR_FILENO) < 0) {
270
        virReportSystemError(errno, "%s",
271
                             _("dup2(stderr) failed"));
272 273 274
        goto cleanup;
    }

275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333
    VIR_FORCE_CLOSE(*ttyfd);

    /* Any FDs in @passFDs need to be moved around so that
     * they are numbered, without gaps, starting from
     * STDERR_FILENO + 1
     */
    for (i = 0; i < npassFDs; i++) {
        int wantfd;

        wantfd = STDERR_FILENO + i + 1;
        VIR_DEBUG("Pass %d onto %d", passFDs[i], wantfd);

        /* If we already have desired FD number, life
         * is easy. Nothing needs renumbering */
        if (passFDs[i] == wantfd)
            continue;

        /*
         * Lets check to see if any later FDs are occupying
         * our desired FD number. If so, we must move them
         * out of the way
         */
        for (j = i + 1; j < npassFDs; j++) {
            if (passFDs[j] == wantfd) {
                VIR_DEBUG("Clash %zu", j);
                int newfd = dup(passFDs[j]);
                if (newfd < 0) {
                    virReportSystemError(errno,
                                         _("Cannot move fd %d out of the way"),
                                         passFDs[j]);
                    goto cleanup;
                }
                /* We're intentionally not closing the
                 * old value of passFDs[j], because we
                 * don't want later iterations of the
                 * loop to take it back. dup2() will
                 * cause it to be closed shortly anyway
                 */
                VIR_DEBUG("Moved clash onto %d", newfd);
                passFDs[j] = newfd;
            }
        }

        /* Finally we can move into our desired FD number */
        if (dup2(passFDs[i], wantfd) < 0) {
            virReportSystemError(errno,
                                 _("Cannot duplicate fd %d onto fd %d"),
                                 passFDs[i], wantfd);
            goto cleanup;
        }
        VIR_FORCE_CLOSE(passFDs[i]);
    }

    last_fd = STDERR_FILENO + npassFDs;

    /* Just in case someone forget to set FD_CLOEXEC, explicitly
     * close all remaining FDs before executing the container */
    open_max = sysconf(_SC_OPEN_MAX);
    if (open_max < 0) {
334
        virReportSystemError(errno, "%s",
335
                             _("sysconf(_SC_OPEN_MAX) failed"));
336 337 338
        goto cleanup;
    }

339 340 341 342 343
    for (fd = last_fd + 1; fd < open_max; fd++) {
        int tmpfd = fd;
        VIR_MASS_CLOSE(tmpfd);
    }

344 345 346
    rc = 0;

cleanup:
347
    VIR_DEBUG("rc=%d", rc);
348 349 350 351
    return rc;
}

/**
352
 * lxcContainerSendContinue:
353
 * @control: control FD to child
354
 *
355 356
 * Sends the continue message via the socket pair stored in the vm
 * structure.
357 358 359
 *
 * Returns 0 on success or -1 in case of error
 */
360
int lxcContainerSendContinue(int control)
361 362
{
    int rc = -1;
363 364
    lxc_message_t msg = LXC_CONTINUE_MSG;
    int writeCount = 0;
365

366
    VIR_DEBUG("Send continue on fd %d", control);
367 368 369
    writeCount = safewrite(control, &msg, sizeof(msg));
    if (writeCount != sizeof(msg)) {
        goto error_out;
370 371
    }

372 373 374
    rc = 0;
error_out:
    return rc;
375 376
}

377
/**
378
 * lxcContainerWaitForContinue:
379
 * @control: Control FD from parent
380 381 382 383 384 385 386
 *
 * This function will wait for the container continue message from the
 * parent process.  It will send this message on the socket pair stored in
 * the vm structure once it has completed the post clone container setup.
 *
 * Returns 0 on success or -1 in case of error
 */
387
int lxcContainerWaitForContinue(int control)
388 389 390 391
{
    lxc_message_t msg;
    int readLen;

392
    VIR_DEBUG("Wait continue on fd %d", control);
393
    readLen = saferead(control, &msg, sizeof(msg));
394
    VIR_DEBUG("Got continue on fd %d %d", control, readLen);
395 396 397 398 399 400 401
    if (readLen != sizeof(msg)) {
        if (readLen >= 0)
            errno = EIO;
        return -1;
    }
    if (msg != LXC_CONTINUE_MSG) {
        errno = EINVAL;
402
        return -1;
403 404
    }

405
    return 0;
406 407
}

408

409 410 411 412 413 414 415 416 417 418 419 420 421 422
/**
 * lxcContainerSetID:
 *
 * This function calls setuid and setgid to create proper
 * cred for tasks running in container.
 *
 * Returns 0 on success or -1 in case of error
 */
static int lxcContainerSetID(virDomainDefPtr def)
{
    /* Only call virSetUIDGID when user namespace is enabled
     * for this container. And user namespace is only enabled
     * when nuidmap&ngidmap is not zero */

423
    VIR_DEBUG("Set UID/GID to 0/0");
424
    if (def->idmap.nuidmap &&
425
        virSetUIDGID(0, 0, NULL, 0) < 0) {
426 427 428 429 430 431 432 433 434
        virReportSystemError(errno, "%s",
                             _("setuid or setgid failed"));
        return -1;
    }

    return 0;
}


435
/**
436
 * lxcContainerRenameAndEnableInterfaces:
437 438
 * @nveths: number of interfaces
 * @veths: interface names
439
 *
440 441 442
 * This function will rename the interfaces to ethN
 * with id ascending order from zero and enable the
 * renamed interfaces for this container.
443 444 445
 *
 * Returns 0 on success or nonzero in case of error
 */
446
static int lxcContainerRenameAndEnableInterfaces(bool privNet,
447
                                                 size_t nveths,
448
                                                 char **veths)
449 450
{
    int rc = 0;
451
    size_t i;
452
    char *newname = NULL;
453

454
    for (i = 0; i < nveths; i++) {
455
        if (virAsprintf(&newname, "eth%zu", i) < 0) {
456
            rc = -1;
457
            goto error_out;
458
        }
459

460
        VIR_DEBUG("Renaming %s to %s", veths[i], newname);
461
        rc = virNetDevSetName(veths[i], newname);
462
        if (rc < 0)
463 464
            goto error_out;

465
        VIR_DEBUG("Enabling %s", newname);
466
        rc = virNetDevSetOnline(newname, true);
467
        if (rc < 0)
468
            goto error_out;
469

470
        VIR_FREE(newname);
471 472 473
    }

    /* enable lo device only if there were other net devices */
474
    if (veths || privNet)
475
        rc = virNetDevSetOnline("lo", true);
476 477

error_out:
478
    VIR_FREE(newname);
479 480 481
    return rc;
}

482

483
/*_syscall2(int, pivot_root, char *, newroot, const char *, oldroot)*/
484 485 486 487 488 489 490
extern int pivot_root(const char * new_root,const char * put_old);

static int lxcContainerChildMountSort(const void *a, const void *b)
{
  const char **sa = (const char**)a;
  const char **sb = (const char**)b;

E
Eric Blake 已提交
491
  /* Deliberately reversed args - we need to unmount deepest
492 493 494 495
     children first */
  return strcmp(*sb, *sa);
}

496
#ifndef MS_REC
497
# define MS_REC          16384
498 499 500
#endif

#ifndef MNT_DETACH
501
# define MNT_DETACH      0x00000002
502 503 504
#endif

#ifndef MS_PRIVATE
505
# define MS_PRIVATE              (1<<18)
506 507 508
#endif

#ifndef MS_SLAVE
509
# define MS_SLAVE                (1<<19)
510 511
#endif

512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537
static int lxcContainerGetSubtree(const char *prefix,
                                  char ***mountsret,
                                  size_t *nmountsret)
{
    FILE *procmnt;
    struct mntent mntent;
    char mntbuf[1024];
    int ret = -1;
    char **mounts = NULL;
    size_t nmounts = 0;

    VIR_DEBUG("prefix=%s", prefix);

    *mountsret = NULL;
    *nmountsret = 0;

    if (!(procmnt = setmntent("/proc/mounts", "r"))) {
        virReportSystemError(errno, "%s",
                             _("Failed to read /proc/mounts"));
        return -1;
    }

    while (getmntent_r(procmnt, &mntent, mntbuf, sizeof(mntbuf)) != NULL) {
        if (!STRPREFIX(mntent.mnt_dir, prefix))
            continue;

538
        if (VIR_REALLOC_N(mounts, nmounts+1) < 0)
539
            goto cleanup;
540
        if (VIR_STRDUP(mounts[nmounts], mntent.mnt_dir) < 0)
541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570
            goto cleanup;
        nmounts++;
    }

    if (mounts)
        qsort(mounts, nmounts, sizeof(mounts[0]),
              lxcContainerChildMountSort);

    ret = 0;
cleanup:
    *mountsret = mounts;
    *nmountsret = nmounts;
    endmntent(procmnt);
    return ret;
}

static int lxcContainerUnmountSubtree(const char *prefix,
                                      bool isOldRootFS)
{
    char **mounts = NULL;
    size_t nmounts = 0;
    size_t i;
    int saveErrno;
    const char *failedUmount = NULL;
    int ret = -1;

    VIR_DEBUG("Unmount subtreee from %s", prefix);

    if (lxcContainerGetSubtree(prefix, &mounts, &nmounts) < 0)
        goto cleanup;
571
    for (i = 0; i < nmounts; i++) {
572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604
        VIR_DEBUG("Umount %s", mounts[i]);
        if (umount(mounts[i]) < 0) {
            char ebuf[1024];
            failedUmount = mounts[i];
            saveErrno = errno;
            VIR_WARN("Failed to unmount '%s', trying to detach subtree '%s': %s",
                     failedUmount, mounts[nmounts-1],
                     virStrerror(errno, ebuf, sizeof(ebuf)));
            break;
        }
    }

    if (failedUmount) {
        /* This detaches the subtree */
        if (umount2(mounts[nmounts-1], MNT_DETACH) < 0) {
            virReportSystemError(saveErrno,
                                 _("Failed to unmount '%s' and could not detach subtree '%s'"),
                                 failedUmount, mounts[nmounts-1]);
            goto cleanup;
        }
        /* This unmounts the tmpfs on which the old root filesystem was hosted */
        if (isOldRootFS &&
            umount(mounts[nmounts-1]) < 0) {
            virReportSystemError(saveErrno,
                                 _("Failed to unmount '%s' and could not unmount old root '%s'"),
                                 failedUmount, mounts[nmounts-1]);
            goto cleanup;
        }
    }

    ret = 0;

cleanup:
605
    for (i = 0; i < nmounts; i++)
606 607 608 609 610 611 612
        VIR_FREE(mounts[i]);
    VIR_FREE(mounts);

    return ret;
}


613 614 615 616 617 618
static int lxcContainerPrepareRoot(virDomainDefPtr def,
                                   virDomainFSDefPtr root)
{
    char *dst;
    char *tmp;

619 620
    VIR_DEBUG("Prepare root %d", root->type);

621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637
    if (root->type == VIR_DOMAIN_FS_TYPE_MOUNT)
        return 0;

    if (root->type == VIR_DOMAIN_FS_TYPE_FILE) {
        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
                       _("Unexpected root filesystem without loop device"));
        return -1;
    }

    if (root->type != VIR_DOMAIN_FS_TYPE_BLOCK) {
        virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
                       _("Unsupported root filesystem type %s"),
                       virDomainFSTypeToString(root->type));
        return -1;
    }

    if (virAsprintf(&dst, "%s/%s.root",
638
                    LXC_STATE_DIR, def->name) < 0)
639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657
        return -1;

    tmp = root->dst;
    root->dst = dst;

    if (lxcContainerMountFSBlock(root, "") < 0) {
        root->dst = tmp;
        VIR_FREE(dst);
        return -1;
    }

    root->dst = tmp;
    root->type = VIR_DOMAIN_FS_TYPE_MOUNT;
    VIR_FREE(root->src);
    root->src = dst;

    return 0;
}

658 659
static int lxcContainerPivotRoot(virDomainFSDefPtr root)
{
660
    int ret;
661
    char *oldroot = NULL, *newroot = NULL;
662

M
Mark McLoughlin 已提交
663 664
    ret = -1;

665 666
    VIR_DEBUG("Pivot via %s", root->src);

667 668
    /* root->parent must be private, so make / private. */
    if (mount("", "/", NULL, MS_PRIVATE|MS_REC, NULL) < 0) {
669
        virReportSystemError(errno, "%s",
670
                             _("Failed to make root private"));
671
        goto err;
672 673
    }

674
    if (virAsprintf(&oldroot, "%s/.oldroot", root->src) < 0)
675
        goto err;
676

677 678
    if (virFileMakePath(oldroot) < 0) {
        virReportSystemError(errno,
679
                             _("Failed to create %s"),
680
                             oldroot);
681 682 683 684 685
        goto err;
    }

    /* Create a tmpfs root since old and new roots must be
     * on separate filesystems */
686
    if (mount("tmprootfs", oldroot, "tmpfs", 0, NULL) < 0) {
687
        virReportSystemError(errno,
688
                             _("Failed to mount empty tmpfs at %s"),
689 690 691
                             oldroot);
        goto err;
    }
M
Mark McLoughlin 已提交
692

693
    /* Create a directory called 'new' in tmpfs */
694
    if (virAsprintf(&newroot, "%s/new", oldroot) < 0)
695 696
        goto err;

697 698
    if (virFileMakePath(newroot) < 0) {
        virReportSystemError(errno,
699
                             _("Failed to create %s"),
700 701 702 703 704 705
                             newroot);
        goto err;
    }

    /* ... and mount our root onto it */
    if (mount(root->src, newroot, NULL, MS_BIND|MS_REC, NULL) < 0) {
706
        virReportSystemError(errno,
707
                             _("Failed to bind new root %s into tmpfs"),
708 709 710 711
                             root->src);
        goto err;
    }

712 713 714 715 716 717 718 719 720
    if (root->readonly) {
        if (mount(root->src, newroot, NULL, MS_BIND|MS_REC|MS_RDONLY|MS_REMOUNT, NULL) < 0) {
            virReportSystemError(errno,
                                 _("Failed to make new root %s readonly"),
                                 root->src);
            goto err;
        }
    }

721
    /* Now we chdir into the tmpfs, then pivot into the
722
     * root->src bind-mounted onto '/new' */
723
    if (chdir(newroot) < 0) {
724
        virReportSystemError(errno,
725
                             _("Failed to chdir into %s"), newroot);
726
        goto err;
727 728 729 730
    }

    /* The old root directory will live at /.oldroot after
     * this and will soon be unmounted completely */
731
    if (pivot_root(".", ".oldroot") < 0) {
732
        virReportSystemError(errno, "%s",
733
                             _("Failed to pivot root"));
734
        goto err;
735 736 737
    }

    /* CWD is undefined after pivot_root, so go to / */
738 739 740
    if (chdir("/") < 0)
        goto err;

M
Mark McLoughlin 已提交
741 742 743
    ret = 0;

err:
744 745 746
    VIR_FREE(oldroot);
    VIR_FREE(newroot);

M
Mark McLoughlin 已提交
747
    return ret;
748 749
}

750

751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772
typedef struct {
    const char *src;
    const char *dst;
    const char *type;
    const char *opts;
    int mflags;
} virLXCBasicMountInfo;

static const virLXCBasicMountInfo lxcBasicMounts[] = {
    /* When we want to make a bind mount readonly, for unknown reasons,
     * it is currently necessary to bind it once, and then remount the
     * bind with the readonly flag. If this is not done, then the original
     * mount point in the main OS becomes readonly too which is not what
     * we want. Hence some things have two entries here.
     */
    { "proc", "/proc", "proc", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV },
    { "/proc/sys", "/proc/sys", NULL, NULL, MS_BIND },
    { "/proc/sys", "/proc/sys", NULL, NULL, MS_BIND|MS_REMOUNT|MS_RDONLY },
    { "sysfs", "/sys", "sysfs", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV },
    { "sysfs", "/sys", "sysfs", NULL, MS_BIND|MS_REMOUNT|MS_RDONLY },
    { "securityfs", "/sys/kernel/security", "securityfs", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV },
    { "securityfs", "/sys/kernel/security", "securityfs", NULL, MS_BIND|MS_REMOUNT|MS_RDONLY },
773
#if WITH_SELINUX
774 775
    { SELINUX_MOUNT, SELINUX_MOUNT, "selinuxfs", NULL, MS_NOSUID|MS_NOEXEC|MS_NODEV },
    { SELINUX_MOUNT, SELINUX_MOUNT, NULL, NULL, MS_BIND|MS_REMOUNT|MS_RDONLY },
776
#endif
777 778 779
};


780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847
static bool lxcIsBasicMountLocation(const char *path)
{
    size_t i;

    for (i = 0; i < ARRAY_CARDINALITY(lxcBasicMounts); i++) {
        if (STREQ(path, lxcBasicMounts[i].dst))
            return true;
    }

    return false;
}


static int lxcContainerSetReadOnly(void)
{
    FILE *procmnt;
    struct mntent mntent;
    char mntbuf[1024];
    int ret = -1;
    char **mounts = NULL;
    size_t nmounts = 0;
    size_t i;

    if (!(procmnt = setmntent("/proc/mounts", "r"))) {
        virReportSystemError(errno, "%s",
                             _("Failed to read /proc/mounts"));
        return -1;
    }

    while (getmntent_r(procmnt, &mntent, mntbuf, sizeof(mntbuf)) != NULL) {
        if (STREQ(mntent.mnt_dir, "/") ||
            STREQ(mntent.mnt_dir, "/.oldroot") ||
            STRPREFIX(mntent.mnt_dir, "/.oldroot/") ||
            lxcIsBasicMountLocation(mntent.mnt_dir))
            continue;

        if (VIR_REALLOC_N(mounts, nmounts + 1) < 0)
            goto cleanup;
        if (VIR_STRDUP(mounts[nmounts], mntent.mnt_dir) < 0)
            goto cleanup;
        nmounts++;
    }

    if (mounts)
        qsort(mounts, nmounts, sizeof(mounts[0]),
              lxcContainerChildMountSort);

    for (i = 0; i < nmounts; i++) {
        VIR_DEBUG("Bind readonly %s", mounts[i]);
        if (mount(mounts[i], mounts[i], NULL, MS_BIND|MS_REC|MS_RDONLY|MS_REMOUNT, NULL) < 0) {
            virReportSystemError(errno,
                                 _("Failed to make mount %s readonly"),
                                 mounts[i]);
            goto cleanup;
        }
    }

    ret = 0;
cleanup:
    for (i = 0; i < nmounts; i++)
        VIR_FREE(mounts[i]);
    VIR_FREE(mounts);
    endmntent(procmnt);
    return ret;

}


848 849
static int lxcContainerMountBasicFS(bool userns_enabled)
{
850 851
    size_t i;
    int rc = -1;
852

853
    VIR_DEBUG("Mounting basic filesystems");
854

855 856
    for (i = 0; i < ARRAY_CARDINALITY(lxcBasicMounts); i++) {
        virLXCBasicMountInfo const *mnt = &lxcBasicMounts[i];
857
        const char *srcpath = NULL;
858

859
        VIR_DEBUG("Processing %s -> %s",
860
                  mnt->src, mnt->dst);
861

862
        srcpath = mnt->src;
863 864 865

        /* Skip if mount doesn't exist in source */
        if ((srcpath[0] == '/') &&
866
            (access(srcpath, R_OK) < 0))
867 868
            continue;

869
#if WITH_SELINUX
870
        if (STREQ(mnt->src, SELINUX_MOUNT) &&
871
            (!is_selinux_enabled() || userns_enabled))
872 873 874
            continue;
#endif

875
        if (STREQ(mnt->src, "securityfs") && userns_enabled)
876 877
            continue;

878
        if (virFileMakePath(mnt->dst) < 0) {
879 880
            virReportSystemError(errno,
                                 _("Failed to mkdir %s"),
881
                                 mnt->src);
882 883 884
            goto cleanup;
        }

885
        VIR_DEBUG("Mount %s on %s type=%s flags=%x, opts=%s",
886 887
                  srcpath, mnt->dst, mnt->type, mnt->mflags, mnt->opts);
        if (mount(srcpath, mnt->dst, mnt->type, mnt->mflags, mnt->opts) < 0) {
888
            virReportSystemError(errno,
889
                                 _("Failed to mount %s on %s type %s flags=%x opts=%s"),
890 891
                                 srcpath, mnt->dst, NULLSTR(mnt->type),
                                 mnt->mflags, NULLSTR(mnt->opts));
892
            goto cleanup;
893
        }
894 895 896 897 898 899 900 901 902
    }

    rc = 0;

cleanup:
    VIR_DEBUG("rc=%d", rc);
    return rc;
}

903
#if WITH_FUSE
904 905
static int lxcContainerMountProcFuse(virDomainDefPtr def,
                                     const char *stateDir)
906 907 908 909
{
    int ret;
    char *meminfo_path = NULL;

910 911
    VIR_DEBUG("Mount /proc/meminfo stateDir=%s", stateDir);

912
    if ((ret = virAsprintf(&meminfo_path,
913
                           "/.oldroot/%s/%s.fuse/meminfo",
914
                           stateDir,
915 916 917 918 919 920 921 922 923 924 925 926 927 928
                           def->name)) < 0)
        return ret;

    if ((ret = mount(meminfo_path, "/proc/meminfo",
                     NULL, MS_BIND, NULL)) < 0) {
        virReportSystemError(errno,
                             _("Failed to mount %s on /proc/meminfo"),
                             meminfo_path);
    }

    VIR_FREE(meminfo_path);
    return ret;
}
#else
929 930
static int lxcContainerMountProcFuse(virDomainDefPtr def ATTRIBUTE_UNUSED,
                                     const char *stateDir ATTRIBUTE_UNUSED)
931 932 933 934
{
    return 0;
}
#endif
935

936 937 938
static int lxcContainerMountFSDev(virDomainDefPtr def,
                                  const char *stateDir)
{
939
    int ret = -1;
940 941 942 943 944 945 946 947
    char *path = NULL;

    VIR_DEBUG("Mount /dev/ stateDir=%s", stateDir);

    if ((ret = virAsprintf(&path, "/.oldroot/%s/%s.dev",
                           stateDir, def->name)) < 0)
        return ret;

948 949 950 951 952 953 954
    if (virFileMakePath("/dev") < 0) {
        virReportSystemError(errno, "%s",
                             _("Cannot create /dev"));
        goto cleanup;
    }

    VIR_DEBUG("Trying to move %s to /dev", path);
955

956
    if (mount(path, "/dev", NULL, MS_MOVE, NULL) < 0) {
957 958 959
        virReportSystemError(errno,
                             _("Failed to mount %s on /dev"),
                             path);
960
        goto cleanup;
961 962
    }

963 964 965
    ret = 0;

cleanup:
966 967 968 969
    VIR_FREE(path);
    return ret;
}

970 971
static int lxcContainerMountFSDevPTS(virDomainDefPtr def,
                                     const char *stateDir)
972
{
973 974
    int ret;
    char *path = NULL;
975

976 977
    VIR_DEBUG("Mount /dev/pts stateDir=%s", stateDir);

978
    if ((ret = virAsprintf(&path,
979
                           "/.oldroot/%s/%s.devpts",
980
                           stateDir,
981 982
                           def->name)) < 0)
        return ret;
983

984 985
    if (virFileMakePath("/dev/pts") < 0) {
        virReportSystemError(errno, "%s",
986
                             _("Cannot create /dev/pts"));
987
        goto cleanup;
988
    }
989

990 991 992 993 994 995 996
    VIR_DEBUG("Trying to move %s to /dev/pts", path);

    if ((ret = mount(path, "/dev/pts",
                     NULL, MS_MOVE, NULL)) < 0) {
        virReportSystemError(errno,
                             _("Failed to mount %s on /dev/pts"),
                             path);
997
        goto cleanup;
998
    }
999

1000 1001
cleanup:
    VIR_FREE(path);
1002

1003
    return ret;
1004 1005
}

1006
static int lxcContainerSetupDevices(char **ttyPaths, size_t nttyPaths)
1007
{
1008
    size_t i;
1009 1010 1011 1012 1013 1014 1015 1016 1017
    const struct {
        const char *src;
        const char *dst;
    } links[] = {
        { "/proc/self/fd/0", "/dev/stdin" },
        { "/proc/self/fd/1", "/dev/stdout" },
        { "/proc/self/fd/2", "/dev/stderr" },
        { "/proc/self/fd", "/dev/fd" },
    };
1018

1019
    for (i = 0; i < ARRAY_CARDINALITY(links); i++) {
1020 1021 1022 1023 1024 1025 1026 1027
        if (symlink(links[i].src, links[i].dst) < 0) {
            virReportSystemError(errno,
                                 _("Failed to symlink device %s to %s"),
                                 links[i].dst, links[i].src);
            return -1;
        }
    }

1028 1029 1030
    /* We have private devpts capability, so bind that */
    if (virFileTouch("/dev/ptmx", 0666) < 0)
        return -1;
1031

1032 1033 1034 1035
    if (mount("/dev/pts/ptmx", "/dev/ptmx", "ptmx", MS_BIND, NULL) < 0) {
        virReportSystemError(errno, "%s",
                             _("Failed to bind /dev/pts/ptmx on to /dev/ptmx"));
        return -1;
1036 1037
    }

1038
    for (i = 0; i < nttyPaths; i++) {
1039
        char *tty;
1040
        if (virAsprintf(&tty, "/dev/tty%zu", i+1) < 0)
1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056
            return -1;
        if (symlink(ttyPaths[i], tty) < 0) {
            VIR_FREE(tty);
            virReportSystemError(errno,
                                 _("Failed to symlink %s to %s"),
                                 ttyPaths[i], tty);
            return -1;
        }
        VIR_FREE(tty);
        if (i == 0 &&
            symlink(ttyPaths[i], "/dev/console") < 0) {
            virReportSystemError(errno,
                                 _("Failed to symlink %s to /dev/console"),
                                 ttyPaths[i]);
            return -1;
        }
1057
    }
1058 1059 1060 1061
    return 0;
}


1062 1063
static int lxcContainerMountFSBind(virDomainFSDefPtr fs,
                                   const char *srcprefix)
1064
{
1065 1066
    char *src = NULL;
    int ret = -1;
1067
    struct stat st;
1068

1069 1070
    VIR_DEBUG("src=%s dst=%s", fs->src, fs->dst);

1071
    if (virAsprintf(&src, "%s%s", srcprefix, fs->src) < 0)
1072 1073
        goto cleanup;

1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110
    if (stat(fs->dst, &st) < 0) {
        if (errno != ENOENT) {
            virReportSystemError(errno, _("Unable to stat bind target %s"),
                                 fs->dst);
            goto cleanup;
        }
        /* ENOENT => create the target dir or file */
        if (stat(src, &st) < 0) {
            virReportSystemError(errno, _("Unable to stat bind source %s"),
                                 src);
            goto cleanup;
        }
        if (S_ISDIR(st.st_mode)) {
            if (virFileMakePath(fs->dst) < 0) {
                virReportSystemError(errno,
                                     _("Failed to create %s"),
                                     fs->dst);
                goto cleanup;
            }
        } else {
            /* Create Empty file for target mount point */
            int fd = open(fs->dst, O_WRONLY|O_CREAT|O_NOCTTY|O_NONBLOCK, 0666);
            if (fd < 0) {
                if (errno != EEXIST) {
                    virReportSystemError(errno,
                                         _("Failed to create bind target %s"),
                                         fs->dst);
                    goto cleanup;
                }
            }
            if (VIR_CLOSE(fd) < 0) {
                virReportSystemError(errno,
                                     _("Failed to close bind target %s"),
                                     fs->dst);
                goto cleanup;
            }
        }
1111 1112 1113 1114 1115 1116 1117 1118 1119
    }

    if (mount(src, fs->dst, NULL, MS_BIND, NULL) < 0) {
        virReportSystemError(errno,
                             _("Failed to bind mount directory %s to %s"),
                             src, fs->dst);
        goto cleanup;
    }

1120 1121
    if (fs->readonly) {
        VIR_DEBUG("Binding %s readonly", fs->dst);
1122
        if (mount(src, fs->dst, NULL, MS_BIND|MS_REMOUNT|MS_RDONLY, NULL) < 0) {
1123 1124 1125
            virReportSystemError(errno,
                                 _("Failed to make directory %s readonly"),
                                 fs->dst);
1126
        }
1127 1128 1129 1130 1131 1132 1133
    } else {
        VIR_DEBUG("Binding %s readwrite", fs->dst);
        if (mount(src, fs->dst, NULL, MS_BIND|MS_REMOUNT, NULL) < 0) {
            virReportSystemError(errno,
                                 _("Failed to make directory %s readwrite"),
                                 fs->dst);
        }
1134 1135 1136 1137 1138 1139 1140 1141 1142 1143
    }

    ret = 0;

cleanup:
    VIR_FREE(src);
    return ret;
}


1144
#ifdef WITH_BLKID
1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201
static int
lxcContainerMountDetectFilesystem(const char *src, char **type)
{
    int fd;
    int ret = -1;
    int rc;
    const char *data = NULL;
    blkid_probe blkid = NULL;

    *type = NULL;

    if ((fd = open(src, O_RDONLY)) < 0) {
        virReportSystemError(errno,
                             _("Unable to open filesystem %s"), src);
        return -1;
    }

    if (!(blkid = blkid_new_probe())) {
        virReportSystemError(errno, "%s",
                             _("Unable to create blkid library handle"));
        goto cleanup;
    }
    if (blkid_probe_set_device(blkid, fd, 0, 0) < 0) {
        virReportSystemError(EINVAL,
                             _("Unable to associate device %s with blkid library"),
                             src);
        goto cleanup;
    }

    blkid_probe_enable_superblocks(blkid, 1);

    blkid_probe_set_superblocks_flags(blkid, BLKID_SUBLKS_TYPE);

    rc = blkid_do_safeprobe(blkid);
    if (rc != 0) {
        if (rc == 1) /* Nothing found, return success with *type == NULL */
            goto done;

        if (rc == -2) {
            virReportSystemError(EINVAL,
                                 _("Too many filesystems detected for %s"),
                                 src);
        } else {
            virReportSystemError(errno,
                                 _("Unable to detect filesystem for %s"),
                                 src);
        }
        goto cleanup;
    }

    if (blkid_probe_lookup_value(blkid, "TYPE", &data, NULL) < 0) {
        virReportSystemError(ENOENT,
                             _("Unable to find filesystem type for %s"),
                             src);
        goto cleanup;
    }

1202
    if (VIR_STRDUP(*type, data) < 0)
1203 1204 1205 1206 1207 1208 1209 1210 1211 1212
        goto cleanup;

done:
    ret = 0;
cleanup:
    VIR_FORCE_CLOSE(fd);
    if (blkid)
        blkid_free_probe(blkid);
    return ret;
}
1213
#else /* ! WITH_BLKID */
1214 1215 1216 1217 1218 1219 1220 1221
static int
lxcContainerMountDetectFilesystem(const char *src ATTRIBUTE_UNUSED,
                                  char **type)
{
    /* No libblkid, so just return success with no detected type */
    *type = NULL;
    return 0;
}
1222
#endif /* ! WITH_BLKID */
1223 1224

/*
C
Chen Hanxiao 已提交
1225
 * This function attempts to do automatic detection of filesystem
1226 1227 1228 1229 1230 1231 1232 1233
 * type following the same rules as the util-linux 'mount' binary.
 *
 * The main difference is that we don't (currently) try to use
 * libblkid to detect the format first. We go straight to using
 * /etc/filesystems, and then /proc/filesystems
 */
static int lxcContainerMountFSBlockAuto(virDomainFSDefPtr fs,
                                        int fsflags,
1234 1235
                                        const char *src,
                                        const char *srcprefix)
1236 1237 1238 1239 1240 1241 1242 1243 1244
{
    FILE *fp = NULL;
    int ret = -1;
    bool tryProc = false;
    bool gotStar = false;
    char *fslist = NULL;
    char *line = NULL;
    const char *type;

1245
    VIR_DEBUG("src=%s dst=%s srcprefix=%s", src, fs->dst, srcprefix);
1246 1247 1248

    /* First time around we use /etc/filesystems */
retry:
1249
    if (virAsprintf(&fslist, "%s%s", srcprefix,
1250
                    tryProc ? "/proc/filesystems" : "/etc/filesystems") < 0)
1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277
        goto cleanup;

    VIR_DEBUG("Open fslist %s", fslist);
    if (!(fp = fopen(fslist, "r"))) {
        /* If /etc/filesystems does not exist, then we need to retry
         * with /proc/filesystems next
         */
        if (errno == ENOENT &&
            !tryProc) {
            tryProc = true;
            VIR_FREE(fslist);
            goto retry;
        }

        virReportSystemError(errno,
                             _("Unable to read %s"),
                             fslist);
        goto cleanup;
    }

    while (!feof(fp)) {
        size_t n;
        VIR_FREE(line);
        if (getline(&line, &n, fp) <= 0) {
            if (feof(fp))
                break;

1278 1279 1280
            goto cleanup;
        }

1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293
        if (strstr(line, "nodev"))
            continue;

        type = strchr(line, '\n');
        if (type)
            line[type-line] = '\0';

        type = line;
        virSkipSpaces(&type);

        /*
         * /etc/filesystems is only allowed to contain '*' on the last line
         */
1294
        if (gotStar && !tryProc) {
1295 1296 1297
            virReportError(VIR_ERR_INTERNAL_ERROR,
                           _("%s has unexpected '*' before last line"),
                           fslist);
1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318
            goto cleanup;
        }

        /* An '*' on the last line in /etc/filesystems
         * means try /proc/filesystems next. We don't
         * jump immediately though, since we need to see
         * if any more lines follow
         */
        if (!tryProc &&
            STREQ(type, "*"))
            gotStar = true;

        VIR_DEBUG("Trying mount %s with %s", src, type);
        if (mount(src, fs->dst, type, fsflags, NULL) < 0) {
            /* These errnos indicate a bogus filesystem type for
             * the image we have, so skip to the next type
             */
            if (errno == EINVAL || errno == ENODEV)
                continue;

            virReportSystemError(errno,
1319
                                 _("Failed to mount device %s to %s"),
1320 1321 1322 1323 1324 1325
                                 src, fs->dst);
            goto cleanup;
        }

        ret = 0;
        break;
1326 1327
    }

1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339
    /* We've got to the end of /etc/filesystems and saw
     * a '*', so we must try /proc/filesystems next
     */
    if (ret != 0 &&
        !tryProc &&
        gotStar) {
        tryProc = true;
        VIR_FREE(fslist);
        VIR_FORCE_FCLOSE(fp);
        goto retry;
    }

1340 1341 1342 1343 1344 1345
    if (ret != 0) {
        virReportSystemError(ENODEV,
                             _("Failed to mount device %s to %s, unable to detect filesystem"),
                             src, fs->dst);
    }

1346 1347 1348 1349
    VIR_DEBUG("Done mounting filesystem ret=%d tryProc=%d", ret, tryProc);

cleanup:
    VIR_FREE(line);
1350
    VIR_FREE(fslist);
1351 1352 1353 1354 1355 1356 1357 1358 1359 1360
    VIR_FORCE_FCLOSE(fp);
    return ret;
}


/*
 * Mount a block device 'src' on fs->dst, automatically
 * probing for filesystem type
 */
static int lxcContainerMountFSBlockHelper(virDomainFSDefPtr fs,
1361 1362
                                          const char *src,
                                          const char *srcprefix)
1363 1364 1365
{
    int fsflags = 0;
    int ret = -1;
1366 1367
    char *format = NULL;

1368 1369 1370 1371 1372 1373 1374 1375 1376 1377
    if (fs->readonly)
        fsflags |= MS_RDONLY;

    if (virFileMakePath(fs->dst) < 0) {
        virReportSystemError(errno,
                             _("Failed to create %s"),
                             fs->dst);
        goto cleanup;
    }

1378 1379 1380 1381
    if (lxcContainerMountDetectFilesystem(src, &format) < 0)
        goto cleanup;

    if (format) {
1382 1383
        VIR_DEBUG("Mount '%s' on '%s' with detected format '%s'",
                  src, fs->dst, format);
1384 1385 1386 1387 1388 1389 1390 1391
        if (mount(src, fs->dst, format, fsflags, NULL) < 0) {
            virReportSystemError(errno,
                                 _("Failed to mount device %s to %s as %s"),
                                 src, fs->dst, format);
            goto cleanup;
        }
        ret = 0;
    } else {
1392
        ret = lxcContainerMountFSBlockAuto(fs, fsflags, src, srcprefix);
1393
    }
1394 1395

cleanup:
1396
    VIR_FREE(format);
1397 1398 1399 1400 1401 1402 1403 1404 1405 1406
    return ret;
}


static int lxcContainerMountFSBlock(virDomainFSDefPtr fs,
                                    const char *srcprefix)
{
    char *src = NULL;
    int ret = -1;

1407 1408
    VIR_DEBUG("src=%s dst=%s", fs->src, fs->dst);

1409
    if (virAsprintf(&src, "%s%s", srcprefix, fs->src) < 0)
1410 1411
        goto cleanup;

1412
    ret = lxcContainerMountFSBlockHelper(fs, src, srcprefix);
1413 1414 1415 1416 1417 1418 1419 1420 1421

    VIR_DEBUG("Done mounting filesystem ret=%d", ret);

cleanup:
    VIR_FREE(src);
    return ret;
}


1422 1423
static int lxcContainerMountFSTmpfs(virDomainFSDefPtr fs,
                                    char *sec_mount_options)
1424 1425 1426 1427
{
    int ret = -1;
    char *data = NULL;

1428 1429
    VIR_DEBUG("usage=%lld sec=%s", fs->usage, sec_mount_options);

1430
    if (virAsprintf(&data,
1431
                    "size=%lldk%s", fs->usage, sec_mount_options) < 0)
1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453
        goto cleanup;

    if (virFileMakePath(fs->dst) < 0) {
        virReportSystemError(errno,
                             _("Failed to create %s"),
                             fs->dst);
        goto cleanup;
    }

    if (mount("tmpfs", fs->dst, "tmpfs", MS_NOSUID|MS_NODEV, data) < 0) {
        virReportSystemError(errno,
                             _("Failed to mount directory %s as tmpfs"),
                             fs->dst);
        goto cleanup;
    }

    if (fs->readonly) {
        VIR_DEBUG("Binding %s readonly", fs->dst);
        if (mount(fs->dst, fs->dst, NULL, MS_BIND|MS_REMOUNT|MS_RDONLY, NULL) < 0) {
            virReportSystemError(errno,
                                 _("Failed to make directory %s readonly"),
                                 fs->dst);
1454
            goto cleanup;
1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465
        }
    }

    ret = 0;

cleanup:
    VIR_FREE(data);
    return ret;
}


1466
static int lxcContainerMountFS(virDomainFSDefPtr fs,
1467
                               char *sec_mount_options)
1468 1469 1470
{
    switch (fs->type) {
    case VIR_DOMAIN_FS_TYPE_MOUNT:
1471
        if (lxcContainerMountFSBind(fs, "/.oldroot") < 0)
1472 1473
            return -1;
        break;
1474
    case VIR_DOMAIN_FS_TYPE_BLOCK:
1475
        if (lxcContainerMountFSBlock(fs, "/.oldroot") < 0)
1476 1477
            return -1;
        break;
1478
    case VIR_DOMAIN_FS_TYPE_RAM:
1479
        if (lxcContainerMountFSTmpfs(fs, sec_mount_options) < 0)
1480 1481
            return -1;
        break;
1482 1483 1484 1485
    case VIR_DOMAIN_FS_TYPE_BIND:
        if (lxcContainerMountFSBind(fs, "") < 0)
            return -1;
        break;
1486
    case VIR_DOMAIN_FS_TYPE_FILE:
1487 1488 1489
        /* We do actually support this, but the lxc controller
         * should have associated the file with a loopback
         * device and changed this to TYPE_BLOCK for us */
1490 1491 1492
        virReportError(VIR_ERR_INTERNAL_ERROR,
                       _("Unexpected filesystem type %s"),
                       virDomainFSTypeToString(fs->type));
1493
        return -1;
1494
    default:
1495 1496 1497
        virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
                       _("Cannot mount filesystem type %s"),
                       virDomainFSTypeToString(fs->type));
1498
        return -1;
1499 1500 1501 1502 1503 1504
    }
    return 0;
}


static int lxcContainerMountAllFS(virDomainDefPtr vmDef,
1505
                                  char *sec_mount_options)
1506 1507
{
    size_t i;
1508
    VIR_DEBUG("Mounting all non-root filesystems");
1509 1510

    /* Pull in rest of container's mounts */
1511
    for (i = 0; i < vmDef->nfss; i++) {
1512
        if (STREQ(vmDef->fss[i]->dst, "/"))
1513 1514
            continue;

1515 1516 1517 1518
        if (lxcContainerUnmountSubtree(vmDef->fss[i]->dst,
                                       false) < 0)
            return -1;

1519
        if (lxcContainerMountFS(vmDef->fss[i], sec_mount_options) < 0)
1520 1521 1522
            return -1;
    }

1523
    VIR_DEBUG("Mounted all non-root filesystems");
1524 1525 1526 1527
    return 0;
}


1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553
int lxcContainerSetupHostdevCapsMakePath(const char *dev)
{
    int ret = -1;
    char *dir, *tmp;

    if (VIR_STRDUP(dir, dev) < 0)
        return -1;

    if ((tmp = strrchr(dir, '/'))) {
        *tmp = '\0';
        if (virFileMakePath(dir) < 0) {
            virReportSystemError(errno,
                                 _("Failed to create directory for '%s' dev '%s'"),
                                 dir, dev);
            goto cleanup;
        }
    }

    ret = 0;

cleanup:
    VIR_FREE(dir);
    return ret;
}


1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607
static int lxcContainerUnmountForSharedRoot(const char *stateDir,
                                            const char *domain)
{
    int ret = -1;
    char *tmp = NULL;

#if WITH_SELINUX
    /* Some versions of Linux kernel don't let you overmount
     * the selinux filesystem, so make sure we kill it first
     */
    /* Filed coverity bug for false positive 'USE_AFTER_FREE' due to swap
     * of root->src with root->dst and the VIR_FREE(root->src) prior to the
     * reset of root->src in lxcContainerPrepareRoot()
     */
    /* coverity[deref_arg] */
    if (lxcContainerUnmountSubtree(SELINUX_MOUNT, false) < 0)
        goto cleanup;
#endif

    /* These filesystems are created by libvirt temporarily, they
     * shouldn't appear in container. */
    if (virAsprintf(&tmp, "%s/%s.dev", stateDir, domain) < 0 ||
        lxcContainerUnmountSubtree(tmp, false) < 0)
        goto cleanup;

    VIR_FREE(tmp);
    if (virAsprintf(&tmp, "%s/%s.devpts", stateDir, domain) < 0 ||
        lxcContainerUnmountSubtree(tmp, false) < 0)
        goto cleanup;

#if WITH_FUSE
    VIR_FREE(tmp);
    if (virAsprintf(&tmp, "%s/%s.fuse", stateDir, domain) < 0 ||
        lxcContainerUnmountSubtree(tmp, false) < 0)
        goto cleanup;
#endif

    /* If we have the root source being '/', then we need to
     * get rid of any existing stuff under /proc, /sys & /tmp.
     * We need new namespace aware versions of those. We must
     * do /proc last otherwise we won't find /proc/mounts :-) */
    if (lxcContainerUnmountSubtree("/sys", false) < 0 ||
        lxcContainerUnmountSubtree("/dev", false) < 0 ||
        lxcContainerUnmountSubtree("/proc", false) < 0)
        goto cleanup;

    ret = 0;

cleanup:
    VIR_FREE(tmp);
    return ret;
}


1608 1609 1610 1611 1612
/* Got a FS mapped to /, we're going the pivot_root
 * approach to do a better-chroot-than-chroot
 * this is based on this thread http://lkml.org/lkml/2008/3/5/29
 */
static int lxcContainerSetupPivotRoot(virDomainDefPtr vmDef,
1613 1614
                                      virDomainFSDefPtr root,
                                      char **ttyPaths,
1615
                                      size_t nttyPaths,
1616
                                      virSecurityManagerPtr securityDriver)
1617
{
1618
    virCgroupPtr cgroup = NULL;
1619
    int ret = -1;
1620
    char *sec_mount_options;
1621
    char *stateDir = NULL;
1622

1623 1624
    VIR_DEBUG("Setup pivot root");

1625 1626
    if (!(sec_mount_options = virSecurityManagerGetMountOptions(securityDriver, vmDef)))
        return -1;
1627 1628 1629

    /* Before pivoting we need to identify any
     * cgroups controllers that are mounted */
1630
    if (virCgroupNewSelf(&cgroup) < 0)
1631
        goto cleanup;
1632

1633 1634 1635
    if (virFileResolveAllLinks(LXC_STATE_DIR, &stateDir) < 0)
        goto cleanup;

1636 1637 1638 1639
    /* Ensure the root filesystem is mounted */
    if (lxcContainerPrepareRoot(vmDef, root) < 0)
        goto cleanup;

1640
    /* Gives us a private root, leaving all parent OS mounts on /.oldroot */
1641
    if (lxcContainerPivotRoot(root) < 0)
1642
        goto cleanup;
1643

1644
    if (STREQ(root->src, "/") &&
1645
        lxcContainerUnmountForSharedRoot(stateDir, vmDef->name) < 0)
1646 1647
        goto cleanup;

1648
    /* Mounts the core /proc, /sys, etc filesystems */
1649
    if (lxcContainerMountBasicFS(vmDef->idmap.nuidmap) < 0)
1650 1651
        goto cleanup;

1652 1653 1654 1655 1656
    /* Ensure entire root filesystem (except /.oldroot) is readonly */
    if (root->readonly &&
        lxcContainerSetReadOnly() < 0)
        goto cleanup;

1657
    /* Mounts /proc/meminfo etc sysinfo */
1658
    if (lxcContainerMountProcFuse(vmDef, stateDir) < 0)
1659 1660
        goto cleanup;

1661 1662
    /* Now we can re-mount the cgroups controllers in the
     * same configuration as before */
1663
    if (virCgroupIsolateMount(cgroup, "/.oldroot/", sec_mount_options) < 0)
1664
        goto cleanup;
1665

1666 1667 1668 1669
    /* Mounts /dev */
    if (lxcContainerMountFSDev(vmDef, stateDir) < 0)
        goto cleanup;

1670
    /* Mounts /dev/pts */
1671
    if (lxcContainerMountFSDevPTS(vmDef, stateDir) < 0)
1672
        goto cleanup;
1673

1674 1675
    /* Setup device nodes in /dev/ */
    if (lxcContainerSetupDevices(ttyPaths, nttyPaths) < 0)
1676
        goto cleanup;
1677

1678
    /* Sets up any non-root mounts from guest config */
1679
    if (lxcContainerMountAllFS(vmDef, sec_mount_options) < 0)
1680
        goto cleanup;
1681

1682
   /* Gets rid of all remaining mounts from host OS, including /.oldroot itself */
1683
    if (lxcContainerUnmountSubtree("/.oldroot", true) < 0)
1684
        goto cleanup;
1685

1686 1687 1688
    ret = 0;

cleanup:
1689
    VIR_FREE(stateDir);
1690
    virCgroupFree(&cgroup);
1691
    VIR_FREE(sec_mount_options);
1692
    return ret;
1693 1694
}

1695

1696 1697 1698 1699
static int lxcContainerResolveSymlinks(virDomainDefPtr vmDef)
{
    char *newroot;
    size_t i;
1700
    char ebuf[1024];
1701

1702 1703
    VIR_DEBUG("Resolving symlinks");

1704
    for (i = 0; i < vmDef->nfss; i++) {
1705
        virDomainFSDefPtr fs = vmDef->fss[i];
1706 1707
        if (!fs->src)
            continue;
1708 1709 1710 1711 1712 1713 1714

        if (access(fs->src, F_OK)) {
            VIR_DEBUG("Failed to access '%s': %s", fs->src,
                      virStrerror(errno, ebuf, sizeof(ebuf)));
            return -1;
        }

1715
        VIR_DEBUG("Resolving '%s'", fs->src);
1716
        if (virFileResolveAllLinks(fs->src, &newroot) < 0) {
1717
            VIR_DEBUG("Failed to resolve symlink at %s", fs->src);
1718
            return -1;
1719
        }
1720 1721 1722 1723 1724 1725

        VIR_DEBUG("Resolved '%s' to %s", fs->src, newroot);

        VIR_FREE(fs->src);
        fs->src = newroot;
    }
1726
    VIR_DEBUG("Resolved all filesystem symlinks");
1727 1728 1729 1730

    return 0;
}

D
Daniel P. Berrange 已提交
1731
/*
C
Chen Hanxiao 已提交
1732
 * This is running as the 'init' process inside the container.
D
Daniel P. Berrange 已提交
1733 1734 1735
 * It removes some capabilities that could be dangerous to
 * host system, since they are not currently "containerized"
 */
1736
#if WITH_CAPNG
1737 1738
static int lxcContainerDropCapabilities(bool keepReboot)
{
D
Daniel P. Berrange 已提交
1739 1740 1741 1742 1743 1744 1745 1746 1747
    int ret;

    capng_get_caps_process();

    if ((ret = capng_updatev(CAPNG_DROP,
                             CAPNG_EFFECTIVE | CAPNG_PERMITTED |
                             CAPNG_INHERITABLE | CAPNG_BOUNDING_SET,
                             CAP_SYS_MODULE, /* No kernel module loading */
                             CAP_SYS_TIME, /* No changing the clock */
1748
                             CAP_MKNOD, /* No creating device nodes */
D
Daniel P. Berrange 已提交
1749 1750
                             CAP_AUDIT_CONTROL, /* No messing with auditing status */
                             CAP_MAC_ADMIN, /* No messing with LSM config */
1751
                             keepReboot ? -1 : CAP_SYS_BOOT, /* No use of reboot */
1752
                             -1)) < 0) {
1753 1754
        virReportError(VIR_ERR_INTERNAL_ERROR,
                       _("Failed to remove capabilities: %d"), ret);
D
Daniel P. Berrange 已提交
1755 1756
        return -1;
    }
1757

D
Daniel P. Berrange 已提交
1758
    if ((ret = capng_apply(CAPNG_SELECT_BOTH)) < 0) {
1759 1760
        virReportError(VIR_ERR_INTERNAL_ERROR,
                       _("Failed to apply capabilities: %d"), ret);
D
Daniel P. Berrange 已提交
1761
        return -1;
1762
    }
D
Daniel P. Berrange 已提交
1763

1764 1765 1766 1767 1768
    /* We do not need to call capng_lock() in this case. The bounding
     * set restriction will prevent them reacquiring sys_boot/module/time,
     * etc which is all that matters for the container. Once inside the
     * container it is fine for SECURE_NOROOT / SECURE_NO_SETUID_FIXUP to
     * be unmasked  - they can never escape the bounding set. */
D
Daniel P. Berrange 已提交
1769

1770 1771
    return 0;
}
D
Daniel P. Berrange 已提交
1772
#else
1773 1774
static int lxcContainerDropCapabilities(bool keepReboot ATTRIBUTE_UNUSED)
{
1775
    VIR_WARN("libcap-ng support not compiled in, unable to clear capabilities");
1776 1777
    return 0;
}
1778
#endif
1779 1780


1781
/**
1782 1783
 * lxcContainerChild:
 * @data: pointer to container arguments
1784 1785 1786 1787 1788 1789 1790 1791 1792
 *
 * This function is run in the process clone()'d in lxcStartContainer.
 * Perform a number of container setup tasks:
 *     Setup container file system
 *     mount container /proca
 * Then exec's the container init
 *
 * Returns 0 on success or -1 in case of error
 */
1793
static int lxcContainerChild(void *data)
1794
{
1795
    lxc_child_argv_t *argv = data;
1796
    virDomainDefPtr vmDef = argv->config;
1797
    int ttyfd = -1;
1798
    int ret = -1;
1799
    char *ttyPath = NULL;
1800
    virDomainFSDefPtr root;
1801
    virCommandPtr cmd = NULL;
1802
    int hasReboot;
1803 1804

    if (NULL == vmDef) {
1805 1806
        virReportError(VIR_ERR_INTERNAL_ERROR,
                       "%s", _("lxcChild() passed invalid vm definition"));
1807
        goto cleanup;
1808 1809
    }

1810 1811 1812 1813 1814 1815 1816 1817 1818 1819
    /* Wait for controller to finish setup tasks, including
     * things like move of network interfaces, uid/gid mapping
     */
    if (lxcContainerWaitForContinue(argv->monitor) < 0) {
        virReportSystemError(errno, "%s",
                             _("Failed to read the container continue message"));
        goto cleanup;
    }
    VIR_DEBUG("Received container continue message");

1820 1821 1822
    if ((hasReboot = lxcContainerHasReboot()) < 0)
        goto cleanup;

1823 1824 1825
    cmd = lxcContainerBuildInitCmd(vmDef);
    virCommandWriteArgLog(cmd, 1);

1826 1827 1828
    if (lxcContainerSetID(vmDef) < 0)
        goto cleanup;

1829
    root = virDomainGetRootFilesystem(vmDef);
1830

1831
    if (argv->nttyPaths) {
1832 1833 1834 1835
        const char *tty = argv->ttyPaths[0];
        if (STRPREFIX(tty, "/dev/pts/"))
            tty += strlen("/dev/pts/");
        if (virAsprintf(&ttyPath, "%s/%s.devpts/%s",
1836
                        LXC_STATE_DIR, vmDef->name, tty) < 0)
1837
            goto cleanup;
1838
    } else if (VIR_STRDUP(ttyPath, "/dev/null") < 0) {
1839
            goto cleanup;
1840
    }
1841

1842
    VIR_DEBUG("Container TTY path: %s", ttyPath);
1843 1844

    ttyfd = open(ttyPath, O_RDWR|O_NOCTTY);
1845
    if (ttyfd < 0) {
1846
        virReportSystemError(errno,
1847
                             _("Failed to open tty %s"),
1848
                             ttyPath);
1849
        goto cleanup;
1850
    }
1851

1852 1853 1854
    if (lxcContainerResolveSymlinks(vmDef) < 0)
        goto cleanup;

1855
    VIR_DEBUG("Setting up pivot");
1856 1857 1858
    if (lxcContainerSetupPivotRoot(vmDef, root,
                                   argv->ttyPaths, argv->nttyPaths,
                                   argv->securityDriver) < 0)
1859
        goto cleanup;
1860

1861 1862 1863 1864 1865 1866 1867
    if (!virFileExists(vmDef->os.init)) {
        virReportSystemError(errno,
                    _("cannot find init path '%s' relative to container root"),
                    vmDef->os.init);
        goto cleanup;
    }

1868
    /* rename and enable interfaces */
1869 1870 1871
    if (lxcContainerRenameAndEnableInterfaces(!!(vmDef->features &
                                                 (1 << VIR_DOMAIN_FEATURE_PRIVNET)),
                                              argv->nveths,
1872
                                              argv->veths) < 0) {
1873
        goto cleanup;
1874
    }
1875

1876
    /* drop a set of root capabilities */
1877
    if (lxcContainerDropCapabilities(!!hasReboot) < 0)
1878
        goto cleanup;
1879

1880 1881
    if (lxcContainerSendContinue(argv->handshakefd) < 0) {
        virReportSystemError(errno, "%s",
C
Chen Hanxiao 已提交
1882
                            _("Failed to send continue signal to controller"));
1883 1884 1885
        goto cleanup;
    }

1886 1887 1888 1889
    VIR_DEBUG("Setting up security labeling");
    if (virSecurityManagerSetProcessLabel(argv->securityDriver, vmDef) < 0)
        goto cleanup;

1890 1891 1892 1893
    VIR_FORCE_CLOSE(argv->handshakefd);
    VIR_FORCE_CLOSE(argv->monitor);
    if (lxcContainerSetupFDs(&ttyfd,
                             argv->npassFDs, argv->passFDs) < 0)
1894 1895
        goto cleanup;

1896
    ret = 0;
1897
cleanup:
1898 1899
    VIR_FREE(ttyPath);
    VIR_FORCE_CLOSE(ttyfd);
1900
    VIR_FORCE_CLOSE(argv->monitor);
1901
    VIR_FORCE_CLOSE(argv->handshakefd);
1902 1903

    if (ret == 0) {
E
Eric Blake 已提交
1904
        /* this function will only return if an error occurred */
1905 1906 1907
        ret = virCommandExec(cmd);
    }

1908 1909
    virCommandFree(cmd);
    return ret;
1910
}
1911

1912 1913 1914
static int userns_supported(void)
{
    return lxcContainerAvailable(LXC_CONTAINER_FEATURE_USER) == 0;
1915 1916 1917 1918 1919
}

static int userns_required(virDomainDefPtr def)
{
    return def->idmap.uidmap && def->idmap.gidmap;
1920 1921
}

1922
virArch lxcContainerGetAlt32bitArch(virArch arch)
1923 1924 1925
{
    /* Any Linux 64bit arch which has a 32bit
     * personality available should be listed here */
1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941
    if (arch == VIR_ARCH_X86_64)
        return VIR_ARCH_I686;
    if (arch == VIR_ARCH_S390X)
        return VIR_ARCH_S390;
    if (arch == VIR_ARCH_PPC64)
        return VIR_ARCH_PPC;
    if (arch == VIR_ARCH_PARISC64)
        return VIR_ARCH_PARISC;
    if (arch == VIR_ARCH_SPARC64)
        return VIR_ARCH_SPARC;
    if (arch == VIR_ARCH_MIPS64)
        return VIR_ARCH_MIPS;
    if (arch == VIR_ARCH_MIPS64EL)
        return VIR_ARCH_MIPSEL;

    return VIR_ARCH_NONE;
1942 1943 1944
}


1945 1946 1947 1948 1949 1950 1951 1952
static bool
lxcNeedNetworkNamespace(virDomainDefPtr def)
{
    size_t i;
    if (def->nets != NULL)
        return true;
    if (def->features & (1 << VIR_DOMAIN_FEATURE_PRIVNET))
        return true;
1953
    for (i = 0; i < def->nhostdevs; i++) {
1954 1955 1956 1957 1958 1959 1960
        if (def->hostdevs[i]->mode == VIR_DOMAIN_HOSTDEV_MODE_CAPABILITIES &&
            def->hostdevs[i]->source.caps.type == VIR_DOMAIN_HOSTDEV_CAPS_TYPE_NET)
            return true;
    }
    return false;
}

1961 1962
/**
 * lxcContainerStart:
1963 1964 1965 1966 1967
 * @def: pointer to virtual machine structure
 * @nveths: number of interfaces
 * @veths: interface names
 * @control: control FD to the container
 * @ttyPath: path of tty to set as the container console
1968 1969 1970 1971 1972
 *
 * Starts a container process by calling clone() with the namespace flags
 *
 * Returns PID of container on success or -1 in case of error
 */
1973
int lxcContainerStart(virDomainDefPtr def,
1974
                      virSecurityManagerPtr securityDriver,
1975
                      size_t nveths,
1976
                      char **veths,
1977 1978
                      size_t npassFDs,
                      int *passFDs,
1979
                      int control,
1980
                      int handshakefd,
1981 1982
                      size_t nttyPaths,
                      char **ttyPaths)
1983 1984
{
    pid_t pid;
E
Eric Blake 已提交
1985
    int cflags;
1986 1987
    int stacksize = getpagesize() * 4;
    char *stack, *stacktop;
1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999
    lxc_child_argv_t args = {
        .config = def,
        .securityDriver = securityDriver,
        .nveths = nveths,
        .veths = veths,
        .npassFDs = npassFDs,
        .passFDs = passFDs,
        .monitor = control,
        .nttyPaths = nttyPaths,
        .ttyPaths = ttyPaths,
        .handshakefd = handshakefd
    };
2000 2001

    /* allocate a stack for the container */
2002
    if (VIR_ALLOC_N(stack, stacksize) < 0)
2003 2004 2005
        return -1;
    stacktop = stack + stacksize;

E
Eric Blake 已提交
2006
    cflags = CLONE_NEWPID|CLONE_NEWNS|CLONE_NEWUTS|CLONE_NEWIPC|SIGCHLD;
2007

2008 2009 2010 2011 2012 2013 2014
    if (userns_required(def)) {
        if (userns_supported()) {
            VIR_DEBUG("Enable user namespace");
            cflags |= CLONE_NEWUSER;
        } else {
            virReportSystemError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
                                 _("Kernel doesn't support user namespace"));
2015
            VIR_FREE(stack);
2016 2017
            return -1;
        }
2018
    }
2019

2020
    if (lxcNeedNetworkNamespace(def)) {
2021
        VIR_DEBUG("Enable network namespaces");
E
Eric Blake 已提交
2022
        cflags |= CLONE_NEWNET;
2023
    }
2024

E
Eric Blake 已提交
2025
    pid = clone(lxcContainerChild, stacktop, cflags, &args);
2026
    VIR_FREE(stack);
2027
    VIR_DEBUG("clone() completed, new container PID is %d", pid);
2028 2029

    if (pid < 0) {
2030
        virReportSystemError(errno, "%s",
2031
                             _("Failed to run clone container"));
2032 2033 2034 2035 2036 2037
        return -1;
    }

    return pid;
}

2038 2039
ATTRIBUTE_NORETURN static int
lxcContainerDummyChild(void *argv ATTRIBUTE_UNUSED)
2040 2041 2042 2043 2044 2045
{
    _exit(0);
}

int lxcContainerAvailable(int features)
{
2046
    int flags = CLONE_NEWPID|CLONE_NEWNS|CLONE_NEWUTS|
2047 2048 2049 2050 2051
        CLONE_NEWIPC|SIGCHLD;
    int cpid;
    char *childStack;
    char *stack;

2052 2053 2054
    if (features & LXC_CONTAINER_FEATURE_USER)
        flags |= CLONE_NEWUSER;

2055 2056 2057 2058
    if (features & LXC_CONTAINER_FEATURE_NET)
        flags |= CLONE_NEWNET;

    if (VIR_ALLOC_N(stack, getpagesize() * 4) < 0) {
2059
        VIR_DEBUG("Unable to allocate stack");
2060 2061 2062 2063 2064 2065 2066 2067
        return -1;
    }

    childStack = stack + (getpagesize() * 4);

    cpid = clone(lxcContainerDummyChild, childStack, flags, NULL);
    VIR_FREE(stack);
    if (cpid < 0) {
2068
        char ebuf[1024] ATTRIBUTE_UNUSED;
2069
        VIR_DEBUG("clone call returned %s, container support is not enabled",
2070
                  virStrerror(errno, ebuf, sizeof(ebuf)));
2071
        return -1;
2072
    } else if (virProcessWait(cpid, NULL) < 0) {
E
Eric Blake 已提交
2073
        return -1;
2074 2075
    }

G
Gao feng 已提交
2076
    VIR_DEBUG("container support is enabled");
2077
    return 0;
2078
}
2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099

int lxcContainerChown(virDomainDefPtr def, const char *path)
{
    uid_t uid;
    gid_t gid;

    if (!def->idmap.uidmap)
        return 0;

    uid = def->idmap.uidmap[0].target;
    gid = def->idmap.gidmap[0].target;

    if (chown(path, uid, gid) < 0) {
        virReportSystemError(errno,
                             _("Failed to change owner of %s to %u:%u"),
                             path, uid, gid);
        return -1;
    }

    return 0;
}