[Devel] [PATCH v2 1/8] host uid and gid parameters

[Glauber Costa]

When running with an upstream Linux kernel that supports user namespaces,
we will run the container using an unprivileged user in the system. That
can be any user, and it serves as base to a 1:1 mapping between users in
the container and users in the host.

By default, the value 100000 will be used for both uid and gid.

Signed-off-by: Glauber Costa <glommer at parallels.com>
---
 include/res.h         |  8 ++++++++
 include/vzctl_param.h |  3 +++
 src/lib/config.c      | 32 ++++++++++++++++++++++++++++++++
 3 files changed, 43 insertions(+)

diff --git a/include/res.h b/include/res.h
index e07060d..47c36da 100644
--- a/include/res.h
+++ b/include/res.h
@@ -47,6 +47,12 @@ struct env_param {
 };
 typedef struct env_param env_param_t;
 
+/*
+ * When running upstream kernels, we will need host-side UID and GID. Those
+ * are configurable, but if none is specified, those are used.
+ */
+#define VZ_DEFAULT_UID		100000
+#define VZ_DEFAULT_GID		100000
 typedef struct {
 	list_head_t userpw;
 	list_head_t nameserver;
@@ -56,6 +62,8 @@ typedef struct {
 	int onboot;
 	unsigned long *bootorder;
 	int wait;
+	unsigned long *local_uid;
+	unsigned long *local_gid;
 } misc_param;
 
 struct mod_action;
diff --git a/include/vzctl_param.h b/include/vzctl_param.h
index 3034a13..e583540 100644
--- a/include/vzctl_param.h
+++ b/include/vzctl_param.h
@@ -149,5 +149,8 @@
 #define PARAM_MOUNT_OPTS	396
 
 
+#define PARAM_LOCAL_UID		397
+#define PARAM_LOCAL_GID		398
+
 #define PARAM_LINE		"e:p:f:t:i:l:k:a:b:n:x:h"
 #endif
diff --git a/src/lib/config.c b/src/lib/config.c
index cf5f352..cc4c1cc 100644
--- a/src/lib/config.c
+++ b/src/lib/config.c
@@ -128,6 +128,10 @@ static vps_config config[] = {
 {"CONFIGFILE",	NULL, PARAM_CONFIG},
 {"ORIGIN_SAMPLE",NULL,PARAM_CONFIG_SAMPLE},
 {"DISABLED",	NULL, PARAM_DISABLED},
+#ifdef HAVE_UPSTREAM
+{"LOCAL_UID",	NULL, PARAM_LOCAL_UID},
+{"LOCAL_GID",	NULL, PARAM_LOCAL_GID},
+#endif
 /* quota */
 {"DISK_QUOTA",	NULL, PARAM_DISK_QUOTA},
 {"DISKSPACE",	NULL, PARAM_DISKSPACE},
@@ -1363,6 +1367,12 @@ static int store_misc(vps_param *old_p, vps_param *vps_p, vps_config *conf,
 		ret = conf_store_strlist(conf_h, conf->name,
 			&misc->searchdomain, 0);
 		break;
+	case PARAM_LOCAL_UID:
+		ret = conf_store_ulong(conf_h, conf->name, misc->local_uid);
+		break;
+	case PARAM_LOCAL_GID:
+		ret = conf_store_ulong(conf_h, conf->name, misc->local_gid);
+		break;
 	}
 	return ret;
 }
@@ -1996,6 +2006,13 @@ static int parse(envid_t veid, vps_param *vps_p, char *val, int id)
 	case PARAM_IPTABLES:
 		ret = parse_iptables(&vps_p->res.env, val);
 		break;
+
+	case PARAM_LOCAL_UID:
+		conf_parse_ulong(&vps_p->res.misc.local_uid, val);
+		break;
+	case PARAM_LOCAL_GID:
+		conf_parse_ulong(&vps_p->res.misc.local_gid, val);
+		break;
 	case PARAM_LOCKEDPAGES:
 	case PARAM_PRIVVMPAGES:
 	case PARAM_SHMPAGES:
@@ -2697,6 +2714,8 @@ static void free_misc(misc_param *misc)
 	FREE_P(misc->hostname)
 	FREE_P(misc->description)
 	FREE_P(misc->bootorder)
+	FREE_P(misc->local_uid)
+	FREE_P(misc->local_gid)
 }
 
 static void free_net(net_param *net)
@@ -2789,6 +2808,17 @@ void free_vps_param(vps_param *param)
 		*dst->x = *src->x;					\
 	}
 
+#define MERGE_P_DEFAULT(x, dfl)						\
+	if ((src->x) != NULL) {						\
+		if ((dst->x) == NULL)					\
+			dst->x = malloc(sizeof(*(dst->x)));		\
+		*dst->x = *src->x;					\
+	}								\
+	if ((dst->x) == NULL) {						\
+		dst->x = malloc(sizeof(*(dst->x)));			\
+		*dst->x = (unsigned long)(dfl);				\
+	}
+
 #define MERGE_P2(x)							\
 	if ((src->x) != NULL) {						\
 		if ((dst->x) == NULL)					\
@@ -2865,6 +2895,8 @@ static void merge_misc(misc_param *dst, misc_param *src)
 	MERGE_STR(hostname)
 	MERGE_STR(description)
 	MERGE_INT(onboot)
+	MERGE_P_DEFAULT(local_uid, VZ_DEFAULT_UID)
+	MERGE_P_DEFAULT(local_gid, VZ_DEFAULT_GID)
 	MERGE_P(bootorder)
 	MERGE_INT(wait)
 }
-- 
1.7.11.7