lxc_controller.c 55.0 KB
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/*
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 * Copyright (C) 2010-2011 Red Hat, Inc.
 * Copyright IBM Corp. 2008
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 *
 * lxc_controller.c: linux container process controller
 *
 * Authors:
 *  David L. Leskovec <dlesko at linux.vnet.ibm.com>
 *
 * 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
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include <config.h>

#include <sys/epoll.h>
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#include <sys/wait.h>
#include <sys/socket.h>
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#include <sys/types.h>
#include <sys/un.h>
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#include <sys/utsname.h>
#include <sys/personality.h>
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#include <unistd.h>
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#include <paths.h>
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#include <errno.h>
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#include <fcntl.h>
#include <signal.h>
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#include <getopt.h>
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#include <sys/mount.h>
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#include <locale.h>
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#include <linux/loop.h>
#include <dirent.h>
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#include <grp.h>
#include <sys/stat.h>
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#include <time.h>
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#if HAVE_CAPNG
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# include <cap-ng.h>
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#endif

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#if HAVE_NUMACTL
# define NUMA_VERSION1_COMPATIBILITY 1
# include <numa.h>
#endif

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#include "virterror_internal.h"
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#include "logging.h"
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#include "util.h"

#include "lxc_conf.h"
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#include "lxc_container.h"
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#include "virnetdev.h"
#include "virnetdevveth.h"
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#include "memory.h"
#include "util.h"
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#include "virfile.h"
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#include "virpidfile.h"
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#include "command.h"
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#include "processinfo.h"
#include "nodeinfo.h"
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#include "virrandom.h"
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#define VIR_FROM_THIS VIR_FROM_LXC

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struct cgroup_device_policy {
    char type;
    int major;
    int minor;
};

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typedef struct _virLXCController virLXCController;
typedef virLXCController *virLXCControllerPtr;
struct _virLXCController {
    char *name;
    virDomainDefPtr def;
};

static void virLXCControllerFree(virLXCControllerPtr ctrl);

static virLXCControllerPtr virLXCControllerNew(const char *name)
{
    virLXCControllerPtr ctrl = NULL;
    virCapsPtr caps = NULL;
    char *configFile = NULL;

    if (VIR_ALLOC(ctrl) < 0)
        goto no_memory;

    if (!(ctrl->name = strdup(name)))
        goto no_memory;

    if ((caps = lxcCapsInit(NULL)) == NULL)
        goto error;

    if ((configFile = virDomainConfigFile(LXC_STATE_DIR,
                                          ctrl->name)) == NULL)
        goto error;

    if ((ctrl->def = virDomainDefParseFile(caps,
                                           configFile,
                                           1 << VIR_DOMAIN_VIRT_LXC,
                                           0)) == NULL)
        goto error;

cleanup:
    VIR_FREE(configFile);
    virCapabilitiesFree(caps);
    return ctrl;

no_memory:
    virReportOOMError();
error:
    virLXCControllerFree(ctrl);
    ctrl = NULL;
    goto cleanup;
}

static void virLXCControllerFree(virLXCControllerPtr ctrl)
{
    if (!ctrl)
        return;

    virDomainDefFree(ctrl->def);
    VIR_FREE(ctrl->name);

    VIR_FREE(ctrl);
}

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static int lxcGetLoopFD(char **dev_name)
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{
    int fd = -1;
    DIR *dh = NULL;
    struct dirent *de;
    char *looppath;
    struct loop_info64 lo;

    VIR_DEBUG("Looking for loop devices in /dev");

    if (!(dh = opendir("/dev"))) {
        virReportSystemError(errno, "%s",
                             _("Unable to read /dev"));
        goto cleanup;
    }

    while ((de = readdir(dh)) != NULL) {
        if (!STRPREFIX(de->d_name, "loop"))
            continue;

        if (virAsprintf(&looppath, "/dev/%s", de->d_name) < 0) {
            virReportOOMError();
            goto cleanup;
        }

        VIR_DEBUG("Checking up on device %s", looppath);
        if ((fd = open(looppath, O_RDWR)) < 0) {
            virReportSystemError(errno,
                                 _("Unable to open %s"), looppath);
            goto cleanup;
        }

        if (ioctl(fd, LOOP_GET_STATUS64, &lo) < 0) {
            /* Got a free device, return the fd */
            if (errno == ENXIO)
                goto cleanup;

            VIR_FORCE_CLOSE(fd);
            virReportSystemError(errno,
                                 _("Unable to get loop status on %s"),
                                 looppath);
            goto cleanup;
        }

        /* Oh well, try the next device */
        VIR_FORCE_CLOSE(fd);
        VIR_FREE(looppath);
    }

    lxcError(VIR_ERR_INTERNAL_ERROR, "%s",
             _("Unable to find a free loop device in /dev"));

cleanup:
    if (fd != -1) {
        VIR_DEBUG("Got free loop device %s %d", looppath, fd);
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        *dev_name = looppath;
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    } else {
        VIR_DEBUG("No free loop devices available");
        VIR_FREE(looppath);
    }
    if (dh)
        closedir(dh);
    return fd;
}

static int lxcSetupLoopDevice(virDomainFSDefPtr fs)
{
    int lofd = -1;
    int fsfd = -1;
    struct loop_info64 lo;
    char *loname = NULL;
    int ret = -1;

    if ((lofd = lxcGetLoopFD(&loname)) < 0)
        return -1;

    memset(&lo, 0, sizeof(lo));
    lo.lo_flags = LO_FLAGS_AUTOCLEAR;

    if ((fsfd = open(fs->src, O_RDWR)) < 0) {
        virReportSystemError(errno,
                             _("Unable to open %s"), fs->src);
        goto cleanup;
    }

    if (ioctl(lofd, LOOP_SET_FD, fsfd) < 0) {
        virReportSystemError(errno,
                             _("Unable to attach %s to loop device"),
                             fs->src);
        goto cleanup;
    }

    if (ioctl(lofd, LOOP_SET_STATUS64, &lo) < 0) {
        virReportSystemError(errno, "%s",
                             _("Unable to mark loop device as autoclear"));

        if (ioctl(lofd, LOOP_CLR_FD, 0) < 0)
            VIR_WARN("Unable to detach %s from loop device", fs->src);
        goto cleanup;
    }

    VIR_DEBUG("Attached loop device  %s %d to %s", fs->src, lofd, loname);
    /*
     * We now change it into a block device type, so that
     * the rest of container setup 'just works'
     */
    fs->type = VIR_DOMAIN_FS_TYPE_BLOCK;
    VIR_FREE(fs->src);
    fs->src = loname;
    loname = NULL;

    ret = 0;

cleanup:
    VIR_FREE(loname);
    VIR_FORCE_CLOSE(fsfd);
    if (ret == -1)
        VIR_FORCE_CLOSE(lofd);
    return lofd;
}


static int lxcSetupLoopDevices(virDomainDefPtr def, size_t *nloopDevs, int **loopDevs)
{
    size_t i;
    int ret = -1;

    for (i = 0 ; i < def->nfss ; i++) {
        int fd;

        if (def->fss[i]->type != VIR_DOMAIN_FS_TYPE_FILE)
            continue;

        fd = lxcSetupLoopDevice(def->fss[i]);
        if (fd < 0)
            goto cleanup;

        VIR_DEBUG("Saving loop fd %d", fd);
        if (VIR_REALLOC_N(*loopDevs, *nloopDevs+1) < 0) {
            VIR_FORCE_CLOSE(fd);
            virReportOOMError();
            goto cleanup;
        }
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        (*loopDevs)[(*nloopDevs)++] = fd;
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    }

    VIR_DEBUG("Setup all loop devices");
    ret = 0;

cleanup:
    return ret;
}

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#if HAVE_NUMACTL
static int lxcSetContainerNUMAPolicy(virDomainDefPtr def)
{
    nodemask_t mask;
    int mode = -1;
    int node = -1;
    int ret = -1;
    int i = 0;
    int maxnode = 0;
    bool warned = false;

    if (!def->numatune.memory.nodemask)
        return 0;

    VIR_DEBUG("Setting NUMA memory policy");

    if (numa_available() < 0) {
        lxcError(VIR_ERR_CONFIG_UNSUPPORTED,
                 "%s", _("Host kernel is not aware of NUMA."));
        return -1;
    }

    maxnode = numa_max_node() + 1;

    /* Convert nodemask to NUMA bitmask. */
    nodemask_zero(&mask);
    for (i = 0; i < VIR_DOMAIN_CPUMASK_LEN; i++) {
        if (def->numatune.memory.nodemask[i]) {
            if (i > NUMA_NUM_NODES) {
                lxcError(VIR_ERR_CONFIG_UNSUPPORTED,
                         _("Host cannot support NUMA node %d"), i);
                return -1;
            }
            if (i > maxnode && !warned) {
                VIR_WARN("nodeset is out of range, there is only %d NUMA "
                         "nodes on host", maxnode);
                warned = true;
            }
            nodemask_set(&mask, i);
        }
    }

    mode = def->numatune.memory.mode;

    if (mode == VIR_DOMAIN_NUMATUNE_MEM_STRICT) {
        numa_set_bind_policy(1);
        numa_set_membind(&mask);
        numa_set_bind_policy(0);
    } else if (mode == VIR_DOMAIN_NUMATUNE_MEM_PREFERRED) {
        int nnodes = 0;
        for (i = 0; i < NUMA_NUM_NODES; i++) {
            if (nodemask_isset(&mask, i)) {
                node = i;
                nnodes++;
            }
        }

        if (nnodes != 1) {
            lxcError(VIR_ERR_CONFIG_UNSUPPORTED,
                     "%s", _("NUMA memory tuning in 'preferred' mode "
                             "only supports single node"));
            goto cleanup;
        }

        numa_set_bind_policy(0);
        numa_set_preferred(node);
    } else if (mode == VIR_DOMAIN_NUMATUNE_MEM_INTERLEAVE) {
        numa_set_interleave_mask(&mask);
    } else {
        lxcError(VIR_ERR_CONFIG_UNSUPPORTED,
                 _("Unable to set NUMA policy %s"),
                 virDomainNumatuneMemModeTypeToString(mode));
        goto cleanup;
    }

    ret = 0;

cleanup:
    return ret;
}
#else
static int lxcSetContainerNUMAPolicy(virDomainDefPtr def)
{
    if (def->numatune.memory.nodemask) {
        lxcError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
                 _("NUMA policy is not available on this platform"));
        return -1;
    }

    return 0;
}
#endif

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/*
 * To be run while still single threaded
 */
static int lxcSetContainerCpuAffinity(virDomainDefPtr def)
{
    int i, hostcpus, maxcpu = CPU_SETSIZE;
    virNodeInfo nodeinfo;
    unsigned char *cpumap;
    int cpumaplen;

    VIR_DEBUG("Setting CPU affinity");

    if (nodeGetInfo(NULL, &nodeinfo) < 0)
        return -1;

    /* setaffinity fails if you set bits for CPUs which
     * aren't present, so we have to limit ourselves */
    hostcpus = VIR_NODEINFO_MAXCPUS(nodeinfo);
    if (maxcpu > hostcpus)
        maxcpu = hostcpus;

    cpumaplen = VIR_CPU_MAPLEN(maxcpu);
    if (VIR_ALLOC_N(cpumap, cpumaplen) < 0) {
        virReportOOMError();
        return -1;
    }

    if (def->cpumask) {
        /* XXX why don't we keep 'cpumask' in the libvirt cpumap
         * format to start with ?!?! */
        for (i = 0 ; i < maxcpu && i < def->cpumasklen ; i++)
            if (def->cpumask[i])
                VIR_USE_CPU(cpumap, i);
    } else {
        /* You may think this is redundant, but we can't assume libvirtd
         * itself is running on all pCPUs, so we need to explicitly set
         * the spawned LXC instance to all pCPUs if no map is given in
         * its config file */
        for (i = 0 ; i < maxcpu ; i++)
            VIR_USE_CPU(cpumap, i);
    }

    /* We are pressuming we are running between fork/exec of LXC
     * so use '0' to indicate our own process ID. No threads are
     * running at this point
     */
    if (virProcessInfoSetAffinity(0, /* Self */
                                  cpumap, cpumaplen, maxcpu) < 0) {
        VIR_FREE(cpumap);
        return -1;
    }
    VIR_FREE(cpumap);

    return 0;
}


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static int lxcSetContainerCpuTune(virCgroupPtr cgroup, virDomainDefPtr def)
{
    int ret = -1;
    if (def->cputune.shares != 0) {
        int rc = virCgroupSetCpuShares(cgroup, def->cputune.shares);
        if (rc != 0) {
            virReportSystemError(-rc,
                                 _("Unable to set io cpu shares for domain %s"),
                                 def->name);
            goto cleanup;
        }
    }
    if (def->cputune.quota != 0) {
        int rc = virCgroupSetCpuCfsQuota(cgroup, def->cputune.quota);
        if (rc != 0) {
            virReportSystemError(-rc,
                                 _("Unable to set io cpu quota for domain %s"),
                                 def->name);
            goto cleanup;
        }
    }
    if (def->cputune.period != 0) {
        int rc = virCgroupSetCpuCfsPeriod(cgroup, def->cputune.period);
        if (rc != 0) {
            virReportSystemError(-rc,
                                 _("Unable to set io cpu period for domain %s"),
                                 def->name);
            goto cleanup;
        }
    }
    ret = 0;
cleanup:
    return ret;
}


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static int lxcSetContainerBlkioTune(virCgroupPtr cgroup, virDomainDefPtr def)
{
    int ret = -1;

    if (def->blkio.weight) {
        int rc = virCgroupSetBlkioWeight(cgroup, def->blkio.weight);
        if (rc != 0) {
            virReportSystemError(-rc,
                                 _("Unable to set Blkio weight for domain %s"),
                                 def->name);
            goto cleanup;
        }
    }

    ret = 0;
cleanup:
    return ret;
}


501
static int lxcSetContainerMemTune(virCgroupPtr cgroup, virDomainDefPtr def)
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{
503 504
    int ret = -1;
    int rc;
505

506
    rc = virCgroupSetMemory(cgroup, def->mem.max_balloon);
507
    if (rc != 0) {
508
        virReportSystemError(-rc,
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                             _("Unable to set memory limit for domain %s"),
                             def->name);
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        goto cleanup;
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    }
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514
    if (def->mem.hard_limit) {
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        rc = virCgroupSetMemoryHardLimit(cgroup, def->mem.hard_limit);
        if (rc != 0) {
            virReportSystemError(-rc,
                                 _("Unable to set memory hard limit for domain %s"),
                                 def->name);
            goto cleanup;
        }
    }

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    if (def->mem.soft_limit) {
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        rc = virCgroupSetMemorySoftLimit(cgroup, def->mem.soft_limit);
        if (rc != 0) {
            virReportSystemError(-rc,
                                 _("Unable to set memory soft limit for domain %s"),
                                 def->name);
            goto cleanup;
        }
    }

534
    if (def->mem.swap_hard_limit) {
535
        rc = virCgroupSetMemSwapHardLimit(cgroup, def->mem.swap_hard_limit);
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        if (rc != 0) {
            virReportSystemError(-rc,
                                 _("Unable to set swap hard limit for domain %s"),
                                 def->name);
            goto cleanup;
        }
    }

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    ret = 0;
cleanup:
    return ret;
}


static int lxcSetContainerDeviceACL(virCgroupPtr cgroup, virDomainDefPtr def)
{
    int ret = -1;
    int rc;
    size_t i;
    static const struct cgroup_device_policy devices[] = {
        {'c', LXC_DEV_MAJ_MEMORY, LXC_DEV_MIN_NULL},
        {'c', LXC_DEV_MAJ_MEMORY, LXC_DEV_MIN_ZERO},
        {'c', LXC_DEV_MAJ_MEMORY, LXC_DEV_MIN_FULL},
        {'c', LXC_DEV_MAJ_MEMORY, LXC_DEV_MIN_RANDOM},
        {'c', LXC_DEV_MAJ_MEMORY, LXC_DEV_MIN_URANDOM},
        {'c', LXC_DEV_MAJ_TTY, LXC_DEV_MIN_TTY},
        {'c', LXC_DEV_MAJ_TTY, LXC_DEV_MIN_PTMX},
        {0,   0, 0}};

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    rc = virCgroupDenyAllDevices(cgroup);
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    if (rc != 0) {
567
        virReportSystemError(-rc,
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                             _("Unable to deny devices for domain %s"),
                             def->name);
        goto cleanup;
    }
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    for (i = 0; devices[i].type != 0; i++) {
574
        const struct cgroup_device_policy *dev = &devices[i];
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        rc = virCgroupAllowDevice(cgroup,
                                  dev->type,
                                  dev->major,
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                                  dev->minor,
                                  VIR_CGROUP_DEVICE_RWM);
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        if (rc != 0) {
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            virReportSystemError(-rc,
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                                 _("Unable to allow device %c:%d:%d for domain %s"),
                                 dev->type, dev->major, dev->minor, def->name);
            goto cleanup;
        }
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    }

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    for (i = 0 ; i < def->nfss ; i++) {
        if (def->fss[i]->type != VIR_DOMAIN_FS_TYPE_BLOCK)
            continue;

        rc = virCgroupAllowDevicePath(cgroup,
                                      def->fss[i]->src,
                                      def->fss[i]->readonly ?
                                      VIR_CGROUP_DEVICE_READ :
                                      VIR_CGROUP_DEVICE_RW);
        if (rc != 0) {
            virReportSystemError(-rc,
                                 _("Unable to allow device %s for domain %s"),
                                 def->fss[i]->src, def->name);
            goto cleanup;
        }
    }

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    rc = virCgroupAllowDeviceMajor(cgroup, 'c', LXC_DEV_MAJ_PTY,
                                   VIR_CGROUP_DEVICE_RWM);
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    if (rc != 0) {
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        virReportSystemError(-rc,
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                             _("Unable to allow PTY devices for domain %s"),
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                             def->name);
        goto cleanup;
    }
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    ret = 0;
cleanup:
    return ret;
}


/**
 * lxcSetContainerResources
 * @def: pointer to virtual machine structure
 *
 * Creates a cgroup for the container, moves the task inside,
 * and sets resource limits
 *
 * Returns 0 on success or -1 in case of error
 */
static int lxcSetContainerResources(virDomainDefPtr def)
{
    virCgroupPtr driver;
    virCgroupPtr cgroup;
    int rc = -1;

    if (lxcSetContainerCpuAffinity(def) < 0)
        return -1;

    if (lxcSetContainerNUMAPolicy(def) < 0)
        return -1;

    rc = virCgroupForDriver("lxc", &driver, 1, 0);
    if (rc != 0) {
        /* Skip all if no driver cgroup is configured */
        if (rc == -ENXIO || rc == -ENOENT)
            return 0;

        virReportSystemError(-rc, "%s",
                             _("Unable to get cgroup for driver"));
        return rc;
    }

    rc = virCgroupForDomain(driver, def->name, &cgroup, 1);
    if (rc != 0) {
        virReportSystemError(-rc,
                             _("Unable to create cgroup for domain %s"),
                             def->name);
        goto cleanup;
    }

    if (lxcSetContainerCpuTune(cgroup, def) < 0)
        goto cleanup;

    if (lxcSetContainerBlkioTune(cgroup, def) < 0)
        goto cleanup;

    if (lxcSetContainerMemTune(cgroup, def) < 0)
        goto cleanup;

    if (lxcSetContainerDeviceACL(cgroup, def) < 0)
        goto cleanup;

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    rc = virCgroupAddTask(cgroup, getpid());
    if (rc != 0) {
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        virReportSystemError(-rc,
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                             _("Unable to add task %d to cgroup for domain %s"),
                             getpid(), def->name);
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    }

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cleanup:
    virCgroupFree(&driver);
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    virCgroupFree(&cgroup);

    return rc;
}

686
static char*lxcMonitorPath(virLXCControllerPtr ctrl)
687 688
{
    char *sockpath;
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    if (virAsprintf(&sockpath, "%s/%s.sock",
691
                    LXC_STATE_DIR, ctrl->def->name) < 0)
692
        virReportOOMError();
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    return sockpath;
}

static int lxcMonitorServer(const char *sockpath)
{
    int fd;
    struct sockaddr_un addr;

    if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) {
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        virReportSystemError(errno,
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                             _("failed to create server socket '%s'"),
                             sockpath);
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        goto error;
    }

    unlink(sockpath);
    memset(&addr, 0, sizeof(addr));
    addr.sun_family = AF_UNIX;
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    if (virStrcpyStatic(addr.sun_path, sockpath) == NULL) {
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        lxcError(VIR_ERR_INTERNAL_ERROR,
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                 _("Socket path %s too long for destination"), sockpath);
        goto error;
    }
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    if (bind(fd, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
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        virReportSystemError(errno,
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                             _("failed to bind server socket '%s'"),
                             sockpath);
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        goto error;
    }
    if (listen(fd, 30 /* backlog */ ) < 0) {
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        virReportSystemError(errno,
725 726
                             _("failed to listen server socket %s"),
                             sockpath);
727 728 729 730 731 732
        goto error;
    }

    return fd;

error:
733
    VIR_FORCE_CLOSE(fd);
734 735
    return -1;
}
736

D
Daniel P. Berrange 已提交
737 738 739 740 741 742 743 744 745

static int lxcControllerClearCapabilities(void)
{
#if HAVE_CAPNG
    int ret;

    capng_clear(CAPNG_SELECT_BOTH);

    if ((ret = capng_apply(CAPNG_SELECT_BOTH)) < 0) {
746
        lxcError(VIR_ERR_INTERNAL_ERROR,
D
Daniel P. Berrange 已提交
747 748 749 750
                 _("failed to apply capabilities: %d"), ret);
        return -1;
    }
#else
751
    VIR_WARN("libcap-ng support not compiled in, unable to clear capabilities");
D
Daniel P. Berrange 已提交
752 753 754 755
#endif
    return 0;
}

756 757 758
/* Return true if it is ok to ignore an accept-after-epoll syscall
   that fails with the specified errno value.  Else false.  */
static bool
759
ignorable_accept_errno(int errnum)
760 761 762 763 764 765 766
{
  return (errnum == EINVAL
          || errnum == ECONNABORTED
          || errnum == EAGAIN
          || errnum == EWOULDBLOCK);
}

767 768 769 770 771 772 773 774 775 776 777 778
static bool quit = false;
static virMutex lock;
static int sigpipe[2];

static void lxcSignalChildHandler(int signum ATTRIBUTE_UNUSED)
{
    ignore_value(write(sigpipe[1], "1", 1));
}

static void lxcSignalChildIO(int watch ATTRIBUTE_UNUSED,
                             int fd ATTRIBUTE_UNUSED,
                             int events ATTRIBUTE_UNUSED, void *opaque)
779
{
780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798
    char buf[1];
    int ret;
    int *container = opaque;

    ignore_value(read(sigpipe[0], buf, 1));
    ret = waitpid(-1, NULL, WNOHANG);
    if (ret == *container) {
        virMutexLock(&lock);
        quit = true;
        virMutexUnlock(&lock);
    }
}


struct lxcConsole {

    int hostWatch;
    int hostFd;  /* PTY FD in the host OS */
    bool hostClosed;
799 800 801
    int hostEpoll;
    bool hostBlocking;

802 803 804
    int contWatch;
    int contFd;  /* PTY FD in the container */
    bool contClosed;
805 806 807 808 809
    int contEpoll;
    bool contBlocking;

    int epollWatch;
    int epollFd; /* epoll FD for dealing with EOF */
810 811 812 813 814 815 816 817 818 819 820 821 822

    size_t fromHostLen;
    char fromHostBuf[1024];
    size_t fromContLen;
    char fromContBuf[1024];
};

struct lxcMonitor {
    int serverWatch;
    int serverFd;  /* Server listen socket */
    int clientWatch;
    int clientFd;  /* Current client FD (if any) */
};
823 824


825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904
static void lxcClientIO(int watch ATTRIBUTE_UNUSED, int fd, int events, void *opaque)
{
    struct lxcMonitor *monitor = opaque;
    char buf[1024];
    ssize_t ret;

    if (events & (VIR_EVENT_HANDLE_HANGUP |
                  VIR_EVENT_HANDLE_ERROR)) {
        virEventRemoveHandle(monitor->clientWatch);
        monitor->clientWatch = -1;
        return;
    }

reread:
    ret = read(fd, buf, sizeof(buf));
    if (ret == -1 && errno == EINTR)
        goto reread;
    if (ret == -1 && errno == EAGAIN)
        return;
    if (ret == -1) {
        lxcError(VIR_ERR_INTERNAL_ERROR, "%s",
                 _("Unable to read from monitor client"));
        virMutexLock(&lock);
        quit = true;
        virMutexUnlock(&lock);
        return;
    }
    if (ret == 0) {
        VIR_DEBUG("Client %d gone", fd);
        VIR_FORCE_CLOSE(monitor->clientFd);
        virEventRemoveHandle(monitor->clientWatch);
        monitor->clientWatch = -1;
    }
}


static void lxcServerAccept(int watch ATTRIBUTE_UNUSED, int fd, int events ATTRIBUTE_UNUSED, void *opaque)
{
    struct lxcMonitor *monitor = opaque;
    int client;

    if ((client = accept(fd, NULL, NULL)) < 0) {
        /* First reflex may be simply to declare accept failure
           to be a fatal error.  However, accept may fail when
           a client quits between the above poll and here.
           That case is not fatal, but rather to be expected,
           if not common, so ignore it.  */
        if (ignorable_accept_errno(errno))
            return;
        virReportSystemError(errno, "%s",
                             _("Unable to accept monitor client"));
        virMutexLock(&lock);
        quit = true;
        virMutexUnlock(&lock);
        return;
    }
    VIR_DEBUG("New client %d (old %d)\n", client, monitor->clientFd);
    VIR_FORCE_CLOSE(monitor->clientFd);
    virEventRemoveHandle(monitor->clientWatch);

    monitor->clientFd = client;
    if ((monitor->clientWatch = virEventAddHandle(monitor->clientFd,
                                                  VIR_EVENT_HANDLE_READABLE,
                                                  lxcClientIO,
                                                  monitor,
                                                  NULL)) < 0) {
        lxcError(VIR_ERR_INTERNAL_ERROR, "%s",
                 _("Unable to watch client socket"));
        virMutexLock(&lock);
        quit = true;
        virMutexUnlock(&lock);
        return;
    }
}

static void lxcConsoleUpdateWatch(struct lxcConsole *console)
{
    int hostEvents = 0;
    int contEvents = 0;

905
    if (!console->hostClosed || (!console->hostBlocking && console->fromContLen)) {
906 907 908 909 910
        if (console->fromHostLen < sizeof(console->fromHostBuf))
            hostEvents |= VIR_EVENT_HANDLE_READABLE;
        if (console->fromContLen)
            hostEvents |= VIR_EVENT_HANDLE_WRITABLE;
    }
911
    if (!console->contClosed || (!console->contBlocking && console->fromHostLen)) {
912 913 914 915 916 917
        if (console->fromContLen < sizeof(console->fromContBuf))
            contEvents |= VIR_EVENT_HANDLE_READABLE;
        if (console->fromHostLen)
            contEvents |= VIR_EVENT_HANDLE_WRITABLE;
    }

918 919 920
    VIR_DEBUG("Container watch %d=%d host watch %d=%d",
              console->contWatch, contEvents,
              console->hostWatch, hostEvents);
921 922
    virEventUpdateHandle(console->contWatch, contEvents);
    virEventUpdateHandle(console->hostWatch, hostEvents);
923

924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959
    if (console->hostClosed) {
        int events = EPOLLIN | EPOLLET;
        if (console->hostBlocking)
            events |= EPOLLOUT;

        if (events != console->hostEpoll) {
            struct epoll_event event;
            int action = EPOLL_CTL_ADD;
            if (console->hostEpoll)
                action = EPOLL_CTL_MOD;

            VIR_DEBUG("newHostEvents=%x oldHostEvents=%x", events, console->hostEpoll);

            event.events = events;
            event.data.fd = console->hostFd;
            if (epoll_ctl(console->epollFd, action, console->hostFd, &event) < 0) {
                VIR_DEBUG(":fail");
                virReportSystemError(errno, "%s",
                                     _("Unable to add epoll fd"));
                quit = true;
                goto cleanup;
            }
            console->hostEpoll = events;
            VIR_DEBUG("newHostEvents=%x oldHostEvents=%x", events, console->hostEpoll);
        }
    } else if (console->hostEpoll) {
        VIR_DEBUG("Stop epoll oldContEvents=%x", console->hostEpoll);
        if (epoll_ctl(console->epollFd, EPOLL_CTL_DEL, console->hostFd, NULL) < 0) {
            virReportSystemError(errno, "%s",
                                 _("Unable to remove epoll fd"));
                VIR_DEBUG(":fail");
            quit = true;
            goto cleanup;
        }
        console->hostEpoll = 0;
    }
960

961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999
    if (console->contClosed) {
        int events = EPOLLIN | EPOLLET;
        if (console->contBlocking)
            events |= EPOLLOUT;

        if (events != console->contEpoll) {
            struct epoll_event event;
            int action = EPOLL_CTL_ADD;
            if (console->contEpoll)
                action = EPOLL_CTL_MOD;

            VIR_DEBUG("newContEvents=%x oldContEvents=%x", events, console->contEpoll);

            event.events = events;
            event.data.fd = console->contFd;
            if (epoll_ctl(console->epollFd, action, console->contFd, &event) < 0) {
                virReportSystemError(errno, "%s",
                                     _("Unable to add epoll fd"));
                VIR_DEBUG(":fail");
                quit = true;
                goto cleanup;
            }
            console->contEpoll = events;
            VIR_DEBUG("newHostEvents=%x oldHostEvents=%x", events, console->contEpoll);
        }
    } else if (console->contEpoll) {
        VIR_DEBUG("Stop epoll oldContEvents=%x", console->contEpoll);
        if (epoll_ctl(console->epollFd, EPOLL_CTL_DEL, console->contFd, NULL) < 0) {
            virReportSystemError(errno, "%s",
                                 _("Unable to remove epoll fd"));
                VIR_DEBUG(":fail");
            quit = true;
            goto cleanup;
        }
        console->contEpoll = 0;
    }
cleanup:
    return;
}
1000 1001


1002
static void lxcEpollIO(int watch, int fd, int events, void *opaque)
1003
{
1004
    struct lxcConsole *console = opaque;
1005

1006 1007 1008 1009 1010 1011 1012 1013 1014 1015
    virMutexLock(&lock);
    VIR_DEBUG("IO event watch=%d fd=%d events=%d fromHost=%zu fromcont=%zu",
              watch, fd, events,
              console->fromHostLen,
              console->fromContLen);

    while (1) {
        struct epoll_event event;
        int ret;
        ret = epoll_wait(console->epollFd, &event, 1, 0);
1016
        if (ret < 0) {
S
Stefan Berger 已提交
1017
            if (errno == EINTR)
1018 1019 1020 1021 1022 1023 1024
                continue;
            virReportSystemError(errno, "%s",
                                 _("Unable to wait on epoll"));
            quit = true;
            goto cleanup;
        }

1025 1026 1027 1028 1029 1030 1031
        if (ret == 0)
            break;

        VIR_DEBUG("fd=%d hostFd=%d contFd=%d hostEpoll=%x contEpoll=%x",
                  event.data.fd, console->hostFd, console->contFd,
                  console->hostEpoll, console->contEpoll);

1032 1033 1034
        /* If we get HUP+dead PID, we just re-enable the main loop
         * which will see the PID has died and exit */
        if ((event.events & EPOLLIN)) {
1035 1036
            if (event.data.fd == console->hostFd) {
                console->hostClosed = false;
1037
            } else {
1038
                console->contClosed = false;
1039
            }
1040
            lxcConsoleUpdateWatch(console);
1041 1042 1043 1044 1045
            break;
        }
    }

cleanup:
1046
    virMutexUnlock(&lock);
1047 1048 1049 1050 1051 1052 1053
}

static void lxcConsoleIO(int watch, int fd, int events, void *opaque)
{
    struct lxcConsole *console = opaque;

    virMutexLock(&lock);
1054 1055 1056 1057
    VIR_DEBUG("IO event watch=%d fd=%d events=%d fromHost=%zu fromcont=%zu",
              watch, fd, events,
              console->fromHostLen,
              console->fromContLen);
1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 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 1111 1112 1113
    if (events & VIR_EVENT_HANDLE_READABLE) {
        char *buf;
        size_t *len;
        size_t avail;
        ssize_t done;
        if (watch == console->hostWatch) {
            buf = console->fromHostBuf;
            len = &console->fromHostLen;
            avail = sizeof(console->fromHostBuf) - *len;
        } else {
            buf = console->fromContBuf;
            len = &console->fromContLen;
            avail = sizeof(console->fromContBuf) - *len;
        }
    reread:
        done = read(fd, buf + *len, avail);
        if (done == -1 && errno == EINTR)
            goto reread;
        if (done == -1 && errno != EAGAIN) {
            virReportSystemError(errno, "%s",
                                 _("Unable to read container pty"));
            goto error;
        }
        if (done > 0) {
            *len += done;
        } else {
            VIR_DEBUG("Read fd %d done %d errno %d", fd, (int)done, errno);
        }
    }

    if (events & VIR_EVENT_HANDLE_WRITABLE) {
        char *buf;
        size_t *len;
        ssize_t done;
        if (watch == console->hostWatch) {
            buf = console->fromContBuf;
            len = &console->fromContLen;
        } else {
            buf = console->fromHostBuf;
            len = &console->fromHostLen;
        }

    rewrite:
        done = write(fd, buf, *len);
        if (done == -1 && errno == EINTR)
            goto rewrite;
        if (done == -1 && errno != EAGAIN) {
            virReportSystemError(errno, "%s",
                                 _("Unable to write to container pty"));
            goto error;
        }
        if (done > 0) {
            memmove(buf, buf + done, (*len - done));
            *len -= done;
        } else {
            VIR_DEBUG("Write fd %d done %d errno %d", fd, (int)done, errno);
1114 1115 1116 1117
            if (watch == console->hostWatch)
                console->hostBlocking = true;
            else
                console->contBlocking = true;
1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142
        }
    }

    if (events & VIR_EVENT_HANDLE_HANGUP) {
        if (watch == console->hostWatch) {
            console->hostClosed = true;
        } else {
            console->contClosed = true;
        }
        VIR_DEBUG("Got EOF on %d %d", watch, fd);
    }

    lxcConsoleUpdateWatch(console);
    virMutexUnlock(&lock);
    return;

error:
    virEventRemoveHandle(console->contWatch);
    virEventRemoveHandle(console->hostWatch);
    console->contWatch = console->hostWatch = -1;
    quit = true;
    virMutexUnlock(&lock);
}


1143
/**
1144
 * lxcControllerMain
1145 1146 1147 1148
 * @serverFd: server socket fd to accept client requests
 * @clientFd: initial client which is the libvirtd daemon
 * @hostFd: open fd for application facing Pty
 * @contFd: open fd for container facing Pty
1149
 *
1150
 * Processes I/O on consoles and the monitor
1151 1152 1153
 *
 * Returns 0 on success or -1 in case of error
 */
1154 1155
static int lxcControllerMain(int serverFd,
                             int clientFd,
1156 1157 1158
                             int *hostFds,
                             int *contFds,
                             size_t nFds,
1159
                             pid_t container)
1160
{
S
Stefan Berger 已提交
1161
    struct lxcConsole *consoles = NULL;
1162 1163 1164 1165 1166
    struct lxcMonitor monitor = {
        .serverFd = serverFd,
        .clientFd = clientFd,
    };
    virErrorPtr err;
1167
    int rc = -1;
1168
    size_t i;
1169 1170 1171 1172 1173

    if (virMutexInit(&lock) < 0)
        goto cleanup2;

    if (pipe2(sigpipe, O_CLOEXEC|O_NONBLOCK) < 0) {
1174
        virReportSystemError(errno, "%s",
1175
                             _("Cannot create signal pipe"));
1176 1177 1178
        goto cleanup;
    }

1179 1180 1181 1182 1183 1184 1185
    if (virEventAddHandle(sigpipe[0],
                          VIR_EVENT_HANDLE_READABLE,
                          lxcSignalChildIO,
                          &container,
                          NULL) < 0) {
        lxcError(VIR_ERR_INTERNAL_ERROR, "%s",
                 _("Unable to watch signal pipe"));
1186 1187
        goto cleanup;
    }
1188 1189

    if (signal(SIGCHLD, lxcSignalChildHandler) == SIG_ERR) {
1190
        virReportSystemError(errno, "%s",
1191
                             _("Cannot install signal handler"));
1192 1193 1194
        goto cleanup;
    }

1195 1196
    VIR_DEBUG("serverFd=%d clientFd=%d",
              serverFd, clientFd);
1197 1198 1199 1200 1201 1202 1203 1204 1205
    virResetLastError();

    if ((monitor.serverWatch = virEventAddHandle(monitor.serverFd,
                                                 VIR_EVENT_HANDLE_READABLE,
                                                 lxcServerAccept,
                                                 &monitor,
                                                 NULL)) < 0) {
        lxcError(VIR_ERR_INTERNAL_ERROR, "%s",
                 _("Unable to watch monitor socket"));
1206 1207 1208
        goto cleanup;
    }

1209 1210 1211 1212 1213 1214 1215 1216
    if (monitor.clientFd != -1 &&
        (monitor.clientWatch = virEventAddHandle(monitor.clientFd,
                                                 VIR_EVENT_HANDLE_READABLE,
                                                 lxcClientIO,
                                                 &monitor,
                                                 NULL)) < 0) {
        lxcError(VIR_ERR_INTERNAL_ERROR, "%s",
                 _("Unable to watch client socket"));
1217 1218 1219
        goto cleanup;
    }

1220 1221
    if (VIR_ALLOC_N(consoles, nFds) < 0) {
        virReportOOMError();
1222 1223
        goto cleanup;
    }
1224

1225 1226 1227 1228 1229 1230 1231
    for (i = 0 ; i < nFds ; i++) {
        consoles[i].epollFd = -1;
        consoles[i].epollWatch = -1;
        consoles[i].hostWatch = -1;
        consoles[i].contWatch = -1;
    }

1232 1233 1234 1235
    for (i = 0 ; i < nFds ; i++) {
        consoles[i].hostFd = hostFds[i];
        consoles[i].contFd = contFds[i];

1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251
        if ((consoles[i].epollFd = epoll_create1(EPOLL_CLOEXEC)) < 0) {
            virReportSystemError(errno, "%s",
                                 _("Unable to create epoll fd"));
            goto cleanup;
        }

        if ((consoles[i].epollWatch = virEventAddHandle(consoles[i].epollFd,
                                                        VIR_EVENT_HANDLE_READABLE,
                                                        lxcEpollIO,
                                                        &consoles[i],
                                                        NULL)) < 0) {
            lxcError(VIR_ERR_INTERNAL_ERROR, "%s",
                     _("Unable to watch epoll FD"));
            goto cleanup;
        }

1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270
        if ((consoles[i].hostWatch = virEventAddHandle(consoles[i].hostFd,
                                                       VIR_EVENT_HANDLE_READABLE,
                                                       lxcConsoleIO,
                                                       &consoles[i],
                                                       NULL)) < 0) {
            lxcError(VIR_ERR_INTERNAL_ERROR, "%s",
                     _("Unable to watch host console PTY"));
            goto cleanup;
        }

        if ((consoles[i].contWatch = virEventAddHandle(consoles[i].contFd,
                                                       VIR_EVENT_HANDLE_READABLE,
                                                       lxcConsoleIO,
                                                       &consoles[i],
                                                       NULL)) < 0) {
            lxcError(VIR_ERR_INTERNAL_ERROR, "%s",
                     _("Unable to watch host console PTY"));
            goto cleanup;
        }
1271
    }
1272

1273 1274 1275 1276
    virMutexLock(&lock);
    while (!quit) {
        virMutexUnlock(&lock);
        if (virEventRunDefaultImpl() < 0)
1277
            goto cleanup;
1278
        virMutexLock(&lock);
1279
    }
1280
    virMutexUnlock(&lock);
1281

1282 1283 1284
    err = virGetLastError();
    if (!err || err->code == VIR_ERR_OK)
        rc = 0;
1285 1286

cleanup:
1287 1288 1289 1290 1291
    virMutexDestroy(&lock);
    signal(SIGCHLD, SIG_DFL);
cleanup2:
    VIR_FORCE_CLOSE(monitor.serverFd);
    VIR_FORCE_CLOSE(monitor.clientFd);
1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302

    for (i = 0 ; i < nFds ; i++) {
        if (consoles[i].epollWatch != -1)
            virEventRemoveHandle(consoles[i].epollWatch);
        VIR_FORCE_CLOSE(consoles[i].epollFd);
        if (consoles[i].contWatch != -1)
            virEventRemoveHandle(consoles[i].contWatch);
        if (consoles[i].hostWatch != -1)
            virEventRemoveHandle(consoles[i].hostWatch);
    }

1303
    VIR_FREE(consoles);
1304 1305 1306
    return rc;
}

1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324


/**
 * lxcControllerMoveInterfaces
 * @nveths: number of interfaces
 * @veths: interface names
 * @container: pid of container
 *
 * Moves network interfaces into a container's namespace
 *
 * Returns 0 on success or -1 in case of error
 */
static int lxcControllerMoveInterfaces(unsigned int nveths,
                                       char **veths,
                                       pid_t container)
{
    unsigned int i;
    for (i = 0 ; i < nveths ; i++)
1325
        if (virNetDevSetNamespace(veths[i], container) < 0)
1326 1327 1328 1329 1330 1331 1332 1333
            return -1;

    return 0;
}


/**
 * lxcCleanupInterfaces:
1334 1335
 * @nveths: number of interfaces
 * @veths: interface names
1336 1337 1338 1339 1340 1341 1342 1343 1344 1345
 *
 * Cleans up the container interfaces by deleting the veth device pairs.
 *
 * Returns 0 on success or -1 in case of error
 */
static int lxcControllerCleanupInterfaces(unsigned int nveths,
                                          char **veths)
{
    unsigned int i;
    for (i = 0 ; i < nveths ; i++)
1346
        ignore_value(virNetDevVethDelete(veths[i]));
1347 1348 1349 1350

    return 0;
}

1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369
static int lxcSetPersonality(virDomainDefPtr def)
{
    struct utsname utsname;
    const char *altArch;

    uname(&utsname);

    altArch = lxcContainerGetAlt32bitArch(utsname.machine);
    if (altArch &&
        STREQ(def->os.arch, altArch)) {
        if (personality(PER_LINUX32) < 0) {
            virReportSystemError(errno, _("Unable to request personality for %s on %s"),
                                 altArch, utsname.machine);
            return -1;
        }
    }
    return 0;
}

1370
#ifndef MS_REC
1371
# define MS_REC          16384
1372 1373 1374
#endif

#ifndef MS_SLAVE
1375
# define MS_SLAVE              (1<<19)
1376
#endif
1377

1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421
/* Create a private tty using the private devpts at PTMX, returning
 * the master in *TTYMASTER and the name of the slave, _from the
 * perspective of the guest after remounting file systems_, in
 * *TTYNAME.  Heavily borrowed from glibc, but doesn't require that
 * devpts == "/dev/pts" */
static int
lxcCreateTty(char *ptmx, int *ttymaster, char **ttyName)
{
    int ret = -1;
    int ptyno;
    int unlock = 0;

    if ((*ttymaster = open(ptmx, O_RDWR|O_NOCTTY|O_NONBLOCK)) < 0)
        goto cleanup;

    if (ioctl(*ttymaster, TIOCSPTLCK, &unlock) < 0)
        goto cleanup;

    if (ioctl(*ttymaster, TIOCGPTN, &ptyno) < 0)
        goto cleanup;

    /* If mount() succeeded at honoring newinstance, then the kernel
     * was new enough to also honor the mode=0620,gid=5 options, which
     * guarantee that the new pty already has correct permissions; so
     * while glibc has to fstat(), fchmod(), and fchown() for older
     * kernels, we can skip those steps.  ptyno shouldn't currently be
     * anything other than 0, but let's play it safe.  */
    if (virAsprintf(ttyName, "/dev/pts/%d", ptyno) < 0) {
        virReportOOMError();
        errno = ENOMEM;
        goto cleanup;
    }

    ret = 0;

cleanup:
    if (ret != 0) {
        VIR_FORCE_CLOSE(*ttymaster);
        VIR_FREE(*ttyName);
    }

    return ret;
}

1422
static int
1423 1424 1425 1426 1427 1428 1429 1430 1431
virLXCControllerRun(virLXCControllerPtr ctrl,
                    virSecurityManagerPtr securityDriver,
                    unsigned int nveths,
                    char **veths,
                    int monitor,
                    int client,
                    int *ttyFDs,
                    size_t nttyFDs,
                    int handshakefd)
1432 1433 1434
{
    int rc = -1;
    int control[2] = { -1, -1};
1435
    int containerhandshake[2] = { -1, -1 };
1436 1437
    int *containerTtyFDs = NULL;
    char **containerTtyPaths = NULL;
1438
    pid_t container = -1;
1439 1440 1441
    virDomainFSDefPtr root;
    char *devpts = NULL;
    char *devptmx = NULL;
1442 1443 1444
    size_t nloopDevs = 0;
    int *loopDevs = NULL;
    size_t i;
1445
    char *mount_options = NULL;
1446

1447 1448 1449 1450 1451 1452 1453 1454 1455
    if (VIR_ALLOC_N(containerTtyFDs, nttyFDs) < 0) {
        virReportOOMError();
        goto cleanup;
    }
    if (VIR_ALLOC_N(containerTtyPaths, nttyFDs) < 0) {
        virReportOOMError();
        goto cleanup;
    }

1456
    if (socketpair(PF_UNIX, SOCK_STREAM, 0, control) < 0) {
1457
        virReportSystemError(errno, "%s",
1458
                             _("sockpair failed"));
1459 1460 1461
        goto cleanup;
    }

1462 1463 1464 1465 1466 1467
    if (socketpair(PF_UNIX, SOCK_STREAM, 0, containerhandshake) < 0) {
        virReportSystemError(errno, "%s",
                             _("socketpair failed"));
        goto cleanup;
    }

1468
    if (lxcSetupLoopDevices(ctrl->def, &nloopDevs, &loopDevs) < 0)
1469 1470
        goto cleanup;

1471
    root = virDomainGetRootFilesystem(ctrl->def);
1472

1473
    if (lxcSetContainerResources(ctrl->def) < 0)
1474 1475
        goto cleanup;

1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496
    /*
     * If doing a chroot style setup, we need to prepare
     * a private /dev/pts for the child now, which they
     * will later move into position.
     *
     * This is complex because 'virsh console' needs to
     * use /dev/pts from the host OS, and the guest OS
     * needs to use /dev/pts from the guest.
     *
     * This means that we (libvirt_lxc) need to see and
     * use both /dev/pts instances. We're running in the
     * host OS context though and don't want to expose
     * the guest OS /dev/pts there.
     *
     * Thus we call unshare(CLONE_NS) so that we can see
     * the guest's new /dev/pts, without it becoming
     * visible to the host OS. We also put the root FS
     * into slave mode, just in case it was currently
     * marked as shared
     */
    if (root) {
1497
        mount_options = virSecurityManagerGetMountOptions(securityDriver, ctrl->def);
1498
        char *opts;
1499
        VIR_DEBUG("Setting up private /dev/pts");
1500 1501 1502 1503 1504 1505 1506 1507

        if (!virFileExists(root->src)) {
            virReportSystemError(errno,
                                 _("root source %s does not exist"),
                                 root->src);
            goto cleanup;
        }

1508
        if (unshare(CLONE_NEWNS) < 0) {
1509
            virReportSystemError(errno, "%s",
1510
                                 _("Cannot unshare mount namespace"));
1511 1512 1513 1514
            goto cleanup;
        }

        if (mount("", "/", NULL, MS_SLAVE|MS_REC, NULL) < 0) {
1515
            virReportSystemError(errno, "%s",
1516
                                 _("Failed to switch root mount into slave mode"));
1517 1518 1519 1520 1521
            goto cleanup;
        }

        if (virAsprintf(&devpts, "%s/dev/pts", root->src) < 0 ||
            virAsprintf(&devptmx, "%s/dev/pts/ptmx", root->src) < 0) {
1522
            virReportOOMError();
1523 1524 1525
            goto cleanup;
        }

1526
        if (virFileMakePath(devpts) < 0) {
1527
            virReportSystemError(errno,
1528
                                 _("Failed to make path %s"),
1529 1530 1531 1532
                                 devpts);
            goto cleanup;
        }

1533 1534
        /* XXX should we support gid=X for X!=5 for distros which use
         * a different gid for tty?  */
1535 1536
        if (virAsprintf(&opts, "newinstance,ptmxmode=0666,mode=0620,gid=5%s",
                        (mount_options ? mount_options : "")) < 0) {
1537 1538 1539 1540 1541 1542 1543 1544
            virReportOOMError();
            goto cleanup;
        }

        VIR_DEBUG("Mount devpts on %s type=tmpfs flags=%x, opts=%s",
                  devpts, MS_NOSUID, opts);
        if (mount("devpts", devpts, "devpts", MS_NOSUID, opts) < 0) {
            VIR_FREE(opts);
1545
            virReportSystemError(errno,
1546
                                 _("Failed to mount devpts on %s"),
1547 1548 1549
                                 devpts);
            goto cleanup;
        }
1550
        VIR_FREE(opts);
1551 1552

        if (access(devptmx, R_OK) < 0) {
1553
            VIR_WARN("Kernel does not support private devpts, using shared devpts");
1554 1555 1556
            VIR_FREE(devptmx);
        }
    } else {
1557 1558 1559
        if (nttyFDs != 1) {
            lxcError(VIR_ERR_CONFIG_UNSUPPORTED,
                     _("Expected exactly one TTY fd, but got %zu"), nttyFDs);
1560 1561 1562 1563
            goto cleanup;
        }
    }

1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585
    for (i = 0 ; i < nttyFDs ; i++) {
        if (devptmx) {
            VIR_DEBUG("Opening tty on private %s", devptmx);
            if (lxcCreateTty(devptmx,
                             &containerTtyFDs[i],
                             &containerTtyPaths[i]) < 0) {
                virReportSystemError(errno, "%s",
                                     _("Failed to allocate tty"));
                goto cleanup;
            }
        } else {
            VIR_DEBUG("Opening tty on shared /dev/ptmx");
            if (virFileOpenTty(&containerTtyFDs[i],
                               &containerTtyPaths[i],
                               0) < 0) {
                virReportSystemError(errno, "%s",
                                     _("Failed to allocate tty"));
                goto cleanup;
            }
        }
    }

1586
    if (lxcSetPersonality(ctrl->def) < 0)
1587
        goto cleanup;
1588

1589
    if ((container = lxcContainerStart(ctrl->def,
1590
                                       securityDriver,
1591 1592 1593
                                       nveths,
                                       veths,
                                       control[1],
1594
                                       containerhandshake[1],
1595 1596
                                       containerTtyPaths,
                                       nttyFDs)) < 0)
1597
        goto cleanup;
1598
    VIR_FORCE_CLOSE(control[1]);
1599
    VIR_FORCE_CLOSE(containerhandshake[1]);
1600 1601 1602 1603

    if (lxcControllerMoveInterfaces(nveths, veths, container) < 0)
        goto cleanup;

1604 1605 1606
    if (lxcContainerSendContinue(control[0]) < 0) {
        virReportSystemError(errno, "%s",
                             _("Unable to send container continue message"));
1607
        goto cleanup;
1608
    }
1609

1610 1611 1612 1613 1614 1615
    if (lxcContainerWaitForContinue(containerhandshake[0]) < 0) {
        virReportSystemError(errno, "%s",
                             _("error receiving signal from container"));
        goto cleanup;
    }

1616 1617 1618 1619 1620 1621 1622 1623
    /* Now the container is fully setup... */

    /* ...we can close the loop devices... */

    for (i = 0 ; i < nloopDevs ; i++)
        VIR_FORCE_CLOSE(loopDevs[i]);

    /* ...and reduce our privileges */
D
Daniel P. Berrange 已提交
1624 1625 1626
    if (lxcControllerClearCapabilities() < 0)
        goto cleanup;

1627 1628 1629 1630 1631 1632 1633
    if (lxcContainerSendContinue(handshakefd) < 0) {
        virReportSystemError(errno, "%s",
                             _("error sending continue signal to parent"));
        goto cleanup;
    }
    VIR_FORCE_CLOSE(handshakefd);

1634
    if (virSetBlocking(monitor, false) < 0 ||
1635
        virSetBlocking(client, false) < 0) {
1636
        virReportSystemError(errno, "%s",
1637
                             _("Unable to set file descriptor non-blocking"));
1638 1639
        goto cleanup;
    }
1640 1641 1642 1643
    for (i = 0 ; i < nttyFDs ; i++) {
        if (virSetBlocking(ttyFDs[i], false) < 0 ||
            virSetBlocking(containerTtyFDs[i], false) < 0) {
            virReportSystemError(errno, "%s",
1644
                                 _("Unable to set file descriptor non-blocking"));
1645 1646 1647
            goto cleanup;
        }
    }
1648

1649 1650
    rc = lxcControllerMain(monitor, client, ttyFDs, containerTtyFDs, nttyFDs, container);
    monitor = client = -1;
1651 1652

cleanup:
1653
    VIR_FREE(mount_options);
1654 1655
    VIR_FREE(devptmx);
    VIR_FREE(devpts);
1656 1657
    VIR_FORCE_CLOSE(control[0]);
    VIR_FORCE_CLOSE(control[1]);
1658
    VIR_FORCE_CLOSE(handshakefd);
1659 1660
    VIR_FORCE_CLOSE(containerhandshake[0]);
    VIR_FORCE_CLOSE(containerhandshake[1]);
1661

1662 1663 1664 1665 1666 1667
    for (i = 0 ; i < nttyFDs ; i++)
        VIR_FREE(containerTtyPaths[i]);
    VIR_FREE(containerTtyPaths);
    for (i = 0 ; i < nttyFDs ; i++)
        VIR_FORCE_CLOSE(containerTtyFDs[i]);
    VIR_FREE(containerTtyFDs);
1668

1669 1670
    for (i = 0 ; i < nloopDevs ; i++)
        VIR_FORCE_CLOSE(loopDevs[i]);
1671 1672
    VIR_FREE(loopDevs);

1673 1674
    virPidAbort(container);

1675 1676 1677 1678
    return rc;
}


1679
int main(int argc, char *argv[])
1680 1681
{
    pid_t pid;
1682
    int rc = 1;
1683
    int client;
1684 1685 1686 1687
    char *name = NULL;
    int nveths = 0;
    char **veths = NULL;
    int monitor = -1;
1688
    int handshakefd = -1;
1689 1690
    int bg = 0;
    char *sockpath = NULL;
1691
    const struct option options[] = {
1692 1693 1694 1695
        { "background", 0, NULL, 'b' },
        { "name",   1, NULL, 'n' },
        { "veth",   1, NULL, 'v' },
        { "console", 1, NULL, 'c' },
1696
        { "handshakefd", 1, NULL, 's' },
1697
        { "security", 1, NULL, 'S' },
1698 1699 1700
        { "help", 0, NULL, 'h' },
        { 0, 0, 0, 0 },
    };
1701 1702
    int *ttyFDs = NULL;
    size_t nttyFDs = 0;
1703
    virSecurityManagerPtr securityDriver = NULL;
1704
    virLXCControllerPtr ctrl = NULL;
1705

E
Eric Blake 已提交
1706 1707
    if (setlocale(LC_ALL, "") == NULL ||
        bindtextdomain(PACKAGE, LOCALEDIR) == NULL ||
1708 1709
        textdomain(PACKAGE) == NULL ||
        virRandomInitialize(time(NULL) ^ getpid())) {
E
Eric Blake 已提交
1710 1711 1712 1713
        fprintf(stderr, _("%s: initialization failed\n"), argv[0]);
        exit(EXIT_FAILURE);
    }

1714 1715 1716
    /* Initialize logging */
    virLogSetFromEnv();

1717 1718
    while (1) {
        int c;
1719

1720
        c = getopt_long(argc, argv, "dn:v:m:c:s:h:S:",
1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732
                       options, NULL);

        if (c == -1)
            break;

        switch (c) {
        case 'b':
            bg = 1;
            break;

        case 'n':
            if ((name = strdup(optarg)) == NULL) {
1733
                virReportOOMError();
1734
                goto cleanup;
1735
            }
1736 1737 1738 1739
            break;

        case 'v':
            if (VIR_REALLOC_N(veths, nveths+1) < 0) {
1740
                virReportOOMError();
1741
                goto cleanup;
1742
            }
1743
            if ((veths[nveths++] = strdup(optarg)) == NULL) {
1744
                virReportOOMError();
1745
                goto cleanup;
1746
            }
1747 1748 1749
            break;

        case 'c':
1750 1751 1752 1753 1754
            if (VIR_REALLOC_N(ttyFDs, nttyFDs + 1) < 0) {
                virReportOOMError();
                goto cleanup;
            }
            if (virStrToLong_i(optarg, NULL, 10, &ttyFDs[nttyFDs++]) < 0) {
1755 1756 1757 1758 1759
                fprintf(stderr, "malformed --console argument '%s'", optarg);
                goto cleanup;
            }
            break;

1760 1761 1762 1763 1764 1765 1766 1767
        case 's':
            if (virStrToLong_i(optarg, NULL, 10, &handshakefd) < 0) {
                fprintf(stderr, "malformed --handshakefd argument '%s'",
                        optarg);
                goto cleanup;
            }
            break;

1768
        case 'S':
1769 1770 1771
            if (!(securityDriver = virSecurityManagerNew(optarg,
                                                         LXC_DRIVER_NAME,
                                                         false, false, false))) {
1772 1773 1774 1775 1776 1777
                fprintf(stderr, "Cannot create security manager '%s'",
                        optarg);
                goto cleanup;
            }
            break;

1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788
        case 'h':
        case '?':
            fprintf(stderr, "\n");
            fprintf(stderr, "syntax: %s [OPTIONS]\n", argv[0]);
            fprintf(stderr, "\n");
            fprintf(stderr, "Options\n");
            fprintf(stderr, "\n");
            fprintf(stderr, "  -b, --background\n");
            fprintf(stderr, "  -n NAME, --name NAME\n");
            fprintf(stderr, "  -c FD, --console FD\n");
            fprintf(stderr, "  -v VETH, --veth VETH\n");
1789
            fprintf(stderr, "  -s FD, --handshakefd FD\n");
1790
            fprintf(stderr, "  -S NAME, --security NAME\n");
1791 1792 1793
            fprintf(stderr, "  -h, --help\n");
            fprintf(stderr, "\n");
            goto cleanup;
1794 1795 1796
        }
    }

1797
    if (securityDriver == NULL) {
1798 1799 1800
        if (!(securityDriver = virSecurityManagerNew("none",
                                                     LXC_DRIVER_NAME,
                                                     false, false, false))) {
1801 1802 1803 1804 1805
            fprintf(stderr, "%s: cannot initialize nop security manager", argv[0]);
            goto cleanup;
        }
    }

1806

1807 1808 1809 1810 1811
    if (name == NULL) {
        fprintf(stderr, "%s: missing --name argument for configuration\n", argv[0]);
        goto cleanup;
    }

1812 1813 1814 1815 1816 1817
    if (handshakefd < 0) {
        fprintf(stderr, "%s: missing --handshake argument for container PTY\n",
                argv[0]);
        goto cleanup;
    }

1818
    if (getuid() != 0) {
1819 1820 1821
        fprintf(stderr, "%s: must be run as the 'root' user\n", argv[0]);
        goto cleanup;
    }
1822

1823 1824
    virEventRegisterDefaultImpl();

1825
    if (!(ctrl = virLXCControllerNew(name)))
1826
        goto cleanup;
1827

1828
    VIR_DEBUG("Security model %s type %s label %s imagelabel %s",
1829 1830 1831 1832
              NULLSTR(ctrl->def->seclabel.model),
              virDomainSeclabelTypeToString(ctrl->def->seclabel.type),
              NULLSTR(ctrl->def->seclabel.label),
              NULLSTR(ctrl->def->seclabel.imagelabel));
1833

1834
    if (ctrl->def->nnets != nveths) {
1835
        fprintf(stderr, "%s: expecting %d veths, but got %d\n",
1836
                argv[0], ctrl->def->nnets, nveths);
1837
        goto cleanup;
1838 1839
    }

1840
    if ((sockpath = lxcMonitorPath(ctrl)) == NULL)
1841
        goto cleanup;
1842

1843 1844
    if ((monitor = lxcMonitorServer(sockpath)) < 0)
        goto cleanup;
1845

1846 1847 1848
    if (bg) {
        if ((pid = fork()) < 0)
            goto cleanup;
1849

1850
        if (pid > 0) {
1851
            if ((rc = virPidFileWrite(LXC_STATE_DIR, name, pid)) < 0) {
1852
                virReportSystemError(-rc,
1853 1854
                                     _("Unable to write pid file '%s/%s.pid'"),
                                     LXC_STATE_DIR, name);
1855 1856
                _exit(1);
            }
1857

1858 1859 1860 1861
            /* First child now exits, allowing original caller
             * (ie libvirtd's LXC driver to complete their
             * waitpid & continue */
            _exit(0);
1862 1863
        }

1864 1865
        /* Don't hold onto any cwd we inherit from libvirtd either */
        if (chdir("/") < 0) {
1866
            virReportSystemError(errno, "%s",
1867
                                 _("Unable to change to root dir"));
1868 1869 1870 1871
            goto cleanup;
        }

        if (setsid() < 0) {
1872
            virReportSystemError(errno, "%s",
1873
                                 _("Unable to become session leader"));
1874 1875 1876
            goto cleanup;
        }
    }
1877 1878

    /* Accept initial client which is the libvirtd daemon */
1879
    if ((client = accept(monitor, NULL, 0)) < 0) {
1880
        virReportSystemError(errno, "%s",
1881
                             _("Failed to accept a connection from driver"));
1882
        goto cleanup;
1883 1884
    }

1885 1886 1887
    rc = virLXCControllerRun(ctrl, securityDriver,
                             nveths, veths, monitor, client,
                             ttyFDs, nttyFDs, handshakefd);
1888

1889
cleanup:
1890
    virPidFileDelete(LXC_STATE_DIR, name);
1891
    lxcControllerCleanupInterfaces(nveths, veths);
J
Jim Meyering 已提交
1892 1893
    if (sockpath)
        unlink(sockpath);
1894
    VIR_FREE(sockpath);
1895
    virLXCControllerFree(ctrl);
1896

1897
    return rc ? EXIT_FAILURE : EXIT_SUCCESS;
1898
}