On Thu, May 23, 2013 at 12:06:48PM +0800, Gao feng wrote:
> This patch introduces new helper function
> virLXCControllerSetupUserns, in this function,
> we set the files uid_map and gid_map of the init
> task of container.
>
> lxcContainerSetID is used for creating cred for
> tasks running in container. Since after setuid/setgid,
> we may be a new user. This patch calls lxcContainerSetUserns
> at first to make sure the new created files belong to
> right user.
>
> Signed-off-by: Gao feng <gaofeng@xxxxxxxxxxxxxx>
> ---
> src/lxc/lxc_container.c | 63 ++++++++++++++++++++++++++++++++--------------
> src/lxc/lxc_controller.c | 65 ++++++++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 110 insertions(+), 18 deletions(-)
>
> diff --git a/src/lxc/lxc_container.c b/src/lxc/lxc_container.c
> index 618252c..52fcf39 100644
> --- a/src/lxc/lxc_container.c
> +++ b/src/lxc/lxc_container.c
> @@ -335,6 +335,30 @@ int lxcContainerWaitForContinue(int control)
>
>
> /**
> + * 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 */
> +
> + if (def->idmap.nuidmap && virSetUIDGID(0, 0) < 0) {
> + virReportSystemError(errno, "%s",
> + _("setuid or setgid failed"));
> + return -1;
> + }
> +
> + return 0;
> +}
> +
> +
> +/**
> * lxcContainerRenameAndEnableInterfaces:
> * @nveths: number of interfaces
> * @veths: interface names
> @@ -1937,6 +1961,27 @@ static int lxcContainerChild(void *data)
> cmd = lxcContainerBuildInitCmd(vmDef);
> virCommandWriteArgLog(cmd, 1);
>
> + if (lxcContainerResolveSymlinks(vmDef) < 0)
> + goto cleanup;
> +
> + if (!virFileExists(vmDef->os.init)) {
> + virReportSystemError(errno,
> + _("cannot find init path '%s' relative to container root"),
> + vmDef->os.init);
> + goto cleanup;
> + }
> +
> + /* Wait for interface devices to show up */
> + if (lxcContainerWaitForContinue(argv->monitor) < 0) {
> + virReportSystemError(errno, "%s",
> + _("Failed to read the container continue message"));
> + goto cleanup;
> + }
> + VIR_DEBUG("Received container continue message");
> +
> + if (lxcContainerSetID(vmDef) < 0)
> + goto cleanup;
> +
> root = virDomainGetRootFilesystem(vmDef);
>
> if (argv->nttyPaths) {
> @@ -1962,29 +2007,11 @@ static int lxcContainerChild(void *data)
> goto cleanup;
> }
>
> - if (lxcContainerResolveSymlinks(vmDef) < 0)
> - goto cleanup;
> -
> if (lxcContainerSetupPivotRoot(vmDef, root,
> argv->ttyPaths, argv->nttyPaths,
> argv->securityDriver) < 0)
> goto cleanup;
>
> - if (!virFileExists(vmDef->os.init)) {
> - virReportSystemError(errno,
> - _("cannot find init path '%s' relative to container root"),
> - vmDef->os.init);
> - goto cleanup;
> - }
> -
> - /* Wait for interface devices to show up */
> - if (lxcContainerWaitForContinue(argv->monitor) < 0) {
> - virReportSystemError(errno, "%s",
> - _("Failed to read the container continue message"));
> - goto cleanup;
> - }
> - VIR_DEBUG("Received container continue message");
Why did you need to move these functions before the lxcContainerSetID
call ?
> diff --git a/src/lxc/lxc_controller.c b/src/lxc/lxc_controller.c
> index dfe686b..0a2e3ac 100644
> --- a/src/lxc/lxc_controller.c
> +++ b/src/lxc/lxc_controller.c
> @@ -1122,6 +1122,68 @@ cleanup2:
> }
>
>
> +static int
> +virLXCControllerSetupUsernsMap(virDomainIdMapEntryPtr map,
> + char *path,
> + int num)
> +{
> + virBuffer map_value = VIR_BUFFER_INITIALIZER;
> + int i, ret = -1;
> +
> + for (i = 0; i < num; i++)
> + virBufferAsprintf(&map_value, "%u %u %u\n",
> + map[i].start, map[i].target, map[i].count);
> +
You need to check
virBufferError()
to see if OOM has occured here.
> + if (virFileWriteStr(path, virBufferCurrentContent(&map_value), 0) < 0) {
> + virReportSystemError(errno, _("unable write to %s"), path);
> + goto cleanup;
> + }
> + ret = 0;
> +
> +cleanup:
> + virBufferFreeAndReset(&map_value);
> + return ret;
> +}
Daniel
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