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.
lxcContainerSetUserns 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 | 59 +++++++++++++++++++++++++++-------------
src/lxc/lxc_controller.c | 70 ++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 111 insertions(+), 18 deletions(-)
diff --git a/src/lxc/lxc_container.c b/src/lxc/lxc_container.c
index 094f205..eabaa34 100644
--- a/src/lxc/lxc_container.c
+++ b/src/lxc/lxc_container.c
@@ -331,6 +331,26 @@ int lxcContainerWaitForContinue(int control)
/**
+ * lxcContainerSetUserns:
+ *
+ * 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 lxcContainerSetUserns(virDomainDefPtr def)
+{
+ if (def->idmap.nuidmap && def->idmap.ngidmap && virSetUIDGID(0, 0) < 0) {
+ virReportSystemError(errno, "%s",
+ _("setuid or setgid failed"));
+ return -1;
+ }
+
+ return 0;
+}
+
+
+/**
* lxcContainerRenameAndEnableInterfaces:
* @nveths: number of interfaces
* @veths: interface names
@@ -1936,6 +1956,27 @@ 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 (lxcContainerSetUserns(vmDef) < 0)
+ goto cleanup;
+
root = virDomainGetRootFilesystem(vmDef);
if (argv->nttyPaths) {
@@ -1965,29 +2006,11 @@ 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");
-
/* rename and enable interfaces */
if (lxcContainerRenameAndEnableInterfaces(!!(vmDef->features &
(1 << VIR_DOMAIN_FEATURE_PRIVNET)),
diff --git a/src/lxc/lxc_controller.c b/src/lxc/lxc_controller.c
index 8c358c3..e9b90bf 100644
--- a/src/lxc/lxc_controller.c
+++ b/src/lxc/lxc_controller.c
@@ -1036,6 +1036,73 @@ cleanup2:
}
+static int virLXCControllerSetupUsernsMap(struct idmap *map,
+ char *path,
+ int num)
+{
+ char *map_value = NULL;
+ int i, ret = -1;
+
+ for (i = 0; i < num; i++) {
+ if (virAsprintf(&map_value, "%s %u %u %u\n",
+ map_value ? map_value : "",
+ map[i].start, map[i].target, map[i].count) < 0)
+ goto cleanup;
+ }
+
+ if (virFileWriteStr(path, map_value, 0) < 0) {
+ if (errno == -ENOENT)
+ virReportSystemError(errno,
+ _("%s doesn't exist, please disable userns"),
+ path);
+ virReportSystemError(errno, _("unable write to %s"), path);
+ goto cleanup;
+ }
+ ret = 0;
+
+cleanup:
+ VIR_FREE(map_value);
+ return ret;
+}
+
+/**
+ * virLXCControllerSetupUserns
+ *
+ * Set proc files for user namespace
+ *
+ * Returns 0 on success or -1 in case of error
+ */
+static int virLXCControllerSetupUserns(virLXCControllerPtr ctrl)
+{
+ char *uid_map = NULL;
+ char *gid_map = NULL;
+ int ret = -1;
+
+ if (ctrl->def->idmap.nuidmap == 0 || ctrl->def->idmap.ngidmap == 0)
+ return 0;
+
+ if (virAsprintf(&uid_map, "/proc/%d/uid_map", ctrl->initpid) < 0)
+ goto cleanup;
+
+ if (virLXCControllerSetupUsernsMap(ctrl->def->idmap.uidmap, uid_map,
+ ctrl->def->idmap.nuidmap) < 0)
+ goto cleanup;
+
+ if (virAsprintf(&gid_map, "/proc/%d/gid_map", ctrl->initpid) < 0)
+ goto cleanup;
+
+ if (virLXCControllerSetupUsernsMap(ctrl->def->idmap.gidmap, gid_map,
+ ctrl->def->idmap.ngidmap) < 0)
+ goto cleanup;
+
+ ret = 0;
+cleanup:
+ VIR_FREE(uid_map);
+ VIR_FREE(gid_map);
+ return ret;
+}
+
+
/**
* virLXCControllerMoveInterfaces
@@ -1467,6 +1534,9 @@ virLXCControllerRun(virLXCControllerPtr ctrl)
VIR_FORCE_CLOSE(control[1]);
VIR_FORCE_CLOSE(containerhandshake[1]);
+ if (virLXCControllerSetupUserns(ctrl) < 0)
+ goto cleanup;
+
if (virLXCControllerMoveInterfaces(ctrl) < 0)
goto cleanup;
--
1.8.1.4
--
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