[lxc-devel] [PATCH] make [ug]id map ordering consistent with /proc/<nr>/[ug]id_map

[Dwight Engen]

The id ordering and case of u,g is also consistent with uidmapshift,
reducing confusion.

doc: Moved example to the the EXAMPLES section, and used values
corresponding to the defaults in the pending shadow-utils subuid patch.

Signed-off-by: Dwight Engen <dwight.engen at oracle.com>
---
 doc/lxc.conf.sgml.in | 30 ++++++++++++++++--------------
 src/lxc/conf.c       |  4 ++--
 src/lxc/confile.c    |  8 ++++----
 3 files changed, 22 insertions(+), 20 deletions(-)

diff --git a/doc/lxc.conf.sgml.in b/doc/lxc.conf.sgml.in
index ae91221..60e7baa 100644
--- a/doc/lxc.conf.sgml.in
+++ b/doc/lxc.conf.sgml.in
@@ -709,21 +709,12 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 	  <listitem>
 	    <para>
 	      Four values must be provided.  First a character, either
-	      'U', or 'G', to specify whether user or group ids are
-	      being mapped.  Next is the first userid as seen on the
-	      host.  Next is the userid to be mapped in the container.
-	      Finally, a range indicating the number of consecutive
-	      ids to map.  For instance
+	      'u', or 'g', to specify whether user or group ids are
+	      being mapped.  Next is the first userid as seen in the
+	      user namespace of the container.  Next is the userid as
+	      seen on the host.  Finally, a range indicating the number
+	      of consecutive ids to map.
 	     </para>
-<programlisting>
-	lxc.id_map = U 200000 0 20000
-	lxc.id_map = G 200000 0 20000
-</programlisting>
-	    <para>
-	      will map both user and group ids in the
-	      range 0-19999 in the container to the ids
-	      200000-219999 on the host.
-	    </para>
 	  </listitem>
 	</varlistentry>
       </variablelist>
@@ -953,6 +944,17 @@ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
     </refsect2>
 
     <refsect2>
+      <title>UID/GID mapping</title>
+      <para>This configuration will map both user and group ids in the
+        range 0-9999 in the container to the ids 100000-109999 on the host.
+      </para>
+      <programlisting>
+	lxc.id_map = u 0 100000 10000
+	lxc.id_map = g 0 100000 10000
+      </programlisting>
+    </refsect2>
+
+    <refsect2>
       <title>Control group</title>
       <para>This configuration will setup several control groups for
       the application, cpuset.cpus restricts usage of the defined cpu,
diff --git a/src/lxc/conf.c b/src/lxc/conf.c
index 97b4ae4..e2abc72 100644
--- a/src/lxc/conf.c
+++ b/src/lxc/conf.c
@@ -2447,7 +2447,7 @@ int lxc_assign_network(struct lxc_list *network, pid_t pid)
 	return 0;
 }
 
-int add_id_mapping(enum idtype idtype, pid_t pid, uid_t host_start, uid_t ns_start, int range)
+static int add_id_mapping(enum idtype idtype, pid_t pid, uid_t ns_start, uid_t host_start, int range)
 {
 	char path[PATH_MAX];
 	int ret, closeret;
@@ -2480,7 +2480,7 @@ int lxc_map_ids(struct lxc_list *idmap, pid_t pid)
 
 	lxc_list_for_each(iterator, idmap) {
 		map = iterator->elem;
-		ret = add_id_mapping(map->idtype, pid, map->hostid, map->nsid, map->range);
+		ret = add_id_mapping(map->idtype, pid, map->nsid, map->hostid, map->range);
 		if (ret)
 			break;
 	}
diff --git a/src/lxc/confile.c b/src/lxc/confile.c
index d350f01..59cedef 100644
--- a/src/lxc/confile.c
+++ b/src/lxc/confile.c
@@ -1049,13 +1049,13 @@ static int config_idmap(const char *key, const char *value, struct lxc_conf *lxc
 
 	lxc_list_add_tail(&lxc_conf->id_map, idmaplist);
 
-	ret = sscanf(value, "%c %d %d %d", &type, &hostid, &nsid, &range);
+	ret = sscanf(value, "%c %d %d %d", &type, &nsid, &hostid, &range);
 	if (ret != 4)
 		goto out;
-	INFO("read uid map: type %c hostid %d nsid %d range %d", type, hostid, nsid, range);
-	if (type == 'U')
+	INFO("read uid map: type %c nsid %d hostid %d range %d", type, nsid, hostid, range);
+	if (type == 'u')
 		idmap->idtype = ID_TYPE_UID;
-	else if (type == 'G')
+	else if (type == 'g')
 		idmap->idtype = ID_TYPE_GID;
 	else
 		goto out;
-- 
1.7.12.3