From c01ff965b48bb9693dcd77cbc748b5d8676766b0 Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Thu, 9 Jul 2015 14:46:20 -0300
Subject: nss-mymachines: map userns users of containers to real user names

Given a container "foo", that maps user id $UID to container user, using
user namespaces, this NSS module extenstion will now map the $UID to a
name "vu-foo-$TUID" for the translated UID $UID.

Similar, userns groups are mapped to "vg-foo-$TGID" for translated GIDs
of $GID.

This simple change should make userns users more discoverable. Also,
given that many tools like "adduser" check NSS before allocating a UID,
should lower the chance of UID range conflicts between tools.
---
 src/shared/nss-util.h | 33 +++++++++++++++++++++++++++++++--
 1 file changed, 31 insertions(+), 2 deletions(-)

(limited to 'src/shared')

diff --git a/src/shared/nss-util.h b/src/shared/nss-util.h
index 230a986040..3657aa5d9c 100644
--- a/src/shared/nss-util.h
+++ b/src/shared/nss-util.h
@@ -24,6 +24,9 @@
 #include <nss.h>
 #include <netdb.h>
 #include <resolv.h>
+#include <pwd.h>
+#include <grp.h>
+
 
 #define NSS_GETHOSTBYNAME_PROTOTYPES(module)            \
 enum nss_status _nss_##module##_gethostbyname4_r(       \
@@ -109,7 +112,8 @@ enum nss_status _nss_##module##_gethostbyname_r(        \
                         NULL,                           \
                         NULL);                          \
        return ret;                                      \
-}
+}                                                       \
+struct __useless_struct_to_allow_trailing_semicolon__
 
 #define NSS_GETHOSTBYADDR_FALLBACKS(module)             \
 enum nss_status _nss_##module##_gethostbyaddr_r(        \
@@ -125,4 +129,29 @@ enum nss_status _nss_##module##_gethostbyaddr_r(        \
                         buffer, buflen,                 \
                         errnop, h_errnop,               \
                         NULL);                          \
-}
+}                                                       \
+struct __useless_struct_to_allow_trailing_semicolon__
+
+#define NSS_GETPW_PROTOTYPES(module)                    \
+enum nss_status _nss_##module##_getpwnam_r(             \
+                const char *name,                       \
+                struct passwd *pwd,                     \
+                char *buffer, size_t buflen,            \
+                int *errnop) _public_;                  \
+enum nss_status _nss_mymachines_getpwuid_r(             \
+                uid_t uid,                              \
+                struct passwd *pwd,                     \
+                char *buffer, size_t buflen,            \
+                int *errnop) _public_
+
+#define NSS_GETGR_PROTOTYPES(module)                    \
+enum nss_status _nss_##module##_getgrnam_r(             \
+                const char *name,                       \
+                struct group *gr,                       \
+                char *buffer, size_t buflen,            \
+                int *errnop) _public_;                  \
+enum nss_status _nss_##module##_getgrgid_r(             \
+                gid_t gid,                              \
+                struct group *gr,                       \
+                char *buffer, size_t buflen,            \
+                int *errnop) _public_
-- 
cgit v1.2.3-54-g00ecf