[libvirt] [PATCH] Updated to deal with specifying user IDs to that do not map to usernames

[Roy Keene]

Patch to libvirt master to avoid failing when a user ID is specified, 
e.g. for <seclabel type='dac'>, that does not map to a user name.

This is useful if you want to run each VM as a separate user and not 
bother creating an /etc/passwd entry for each UID.

It compiles but is as yet untested.

---
  src/util/virutil.c | 69 
+++++++++++++++++++++++++++++++++++++++---------------
  1 file changed, 50 insertions(+), 19 deletions(-)

diff --git a/src/util/virutil.c b/src/util/virutil.c
index d80d994..ae95237 100644
--- a/src/util/virutil.c
+++ b/src/util/virutil.c
@@ -790,26 +790,57 @@ virGetUserEnt(uid_t uid, char **name, gid_t 
*group, char **dir)
          if (VIR_RESIZE_N(strbuf, strbuflen, strbuflen, strbuflen) < 0)
              goto cleanup;
      }
-    if (rc != 0) {
-        virReportSystemError(rc,
-                             _("Failed to find user record for uid '%u'"),
-                             (unsigned int) uid);
-        goto cleanup;
-    } else if (pw == NULL) {
-        virReportError(VIR_ERR_SYSTEM_ERROR,
-                       _("Failed to find user record for uid '%u'"),
-                       (unsigned int) uid);
-        goto cleanup;
-    }

-    if (name && VIR_STRDUP(*name, pw->pw_name) < 0)
-        goto cleanup;
-    if (group)
-        *group = pw->pw_gid;
-    if (dir && VIR_STRDUP(*dir, pw->pw_dir) < 0) {
-        if (name)
-            VIR_FREE(*name);
-        goto cleanup;
+    if (rc != 0 || pw == NULL) {
+        /*
+         * If the user does not exist or its data is not present, return
+         * a created username.
+         */
+         VIR_FREE(strbuf);
+
+         strbuflen = 128;
+
+         if (VIR_ALLOC_N(strbuf, strbuflen) < 0) {
+             return(-1);
+         }
+
+         /*
+          * Fake user home directory: /
+          */
+         if (dir) {
+             if (VIR_STRDUP(*dir, "/") < 0) {
+                 goto cleanup;
+             }
+         }
+
+         /*
+          * Fake user GID: Same as UID
+          */
+         if (group) {
+             *group = (gid_t) uid;
+         }
+
+         /*
+          * Fake user name: Same as UID (in string)
+          */
+         snprintf(strbuf, strbuflen, "%llu", (unsigned long long) uid);
+
+         if (name && VIR_STRDUP(*name, strbuf) < 0) {
+             if (dir) {
+                 VIR_FREE(*dir);
+             }
+             goto cleanup;
+         }
+    } else {
+        if (name && VIR_STRDUP(*name, pw->pw_name) < 0)
+            goto cleanup;
+        if (group)
+            *group = pw->pw_gid;
+        if (dir && VIR_STRDUP(*dir, pw->pw_dir) < 0) {
+            if (name)
+                VIR_FREE(*name);
+            goto cleanup;
+        }
      }

      ret = 0;
-- 
2.7.4

-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/pkcs7-signature
Size: 3455 bytes
Desc: S/MIME Cryptographic Signature
URL: <http://listman.redhat.com/archives/libvir-list/attachments/20160606/371a7f1a/attachment-0001.p7s>