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create: pass --mapped-gid to templates next to --mapped-uid
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That way templates can fix group ownership alongside uid ownership.

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>
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@hallyn @stgraber
hallyn authored and stgraber committed Feb 4, 2014
1 parent 8ec981f commit 2133f58
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Showing 5 changed files with 61 additions and 18 deletions.
14 changes: 7 additions & 7 deletions src/lxc/conf.c
View file
Expand Up @@ -3177,29 +3177,29 @@ bool get_mapped_rootid(struct lxc_conf *conf, enum idtype idtype,
return false;
}

int mapped_hostid(int id, struct lxc_conf *conf)
int mapped_hostid(unsigned id, struct lxc_conf *conf, enum idtype idtype)
{
struct lxc_list *it;
struct id_map *map;
lxc_list_for_each(it, &conf->id_map) {
map = it->elem;
if (map->idtype != ID_TYPE_UID)
if (map->idtype != idtype)
continue;
if (id >= map->hostid && id < map->hostid + map->range)
return (id - map->hostid) + map->nsid;
}
return -1;
}

int find_unmapped_nsuid(struct lxc_conf *conf)
int find_unmapped_nsuid(struct lxc_conf *conf, enum idtype idtype)
{
struct lxc_list *it;
struct id_map *map;
uid_t freeid = 0;
unsigned int freeid = 0;
again:
lxc_list_for_each(it, &conf->id_map) {
map = it->elem;
if (map->idtype != ID_TYPE_UID)
if (map->idtype != idtype)
continue;
if (freeid >= map->nsid && freeid < map->nsid + map->range) {
freeid = map->nsid + map->range;
Expand Down Expand Up @@ -3992,7 +3992,7 @@ static int run_userns_fn(void *data)
*/
static struct lxc_list *idmap_add_id(struct lxc_conf *conf, uid_t uid)
{
int hostid_mapped = mapped_hostid(uid, conf);
int hostid_mapped = mapped_hostid(uid, conf, ID_TYPE_UID);
struct lxc_list *new = NULL, *tmp, *it, *next;
struct id_map *entry;

Expand All @@ -4004,7 +4004,7 @@ static struct lxc_list *idmap_add_id(struct lxc_conf *conf, uid_t uid)
lxc_list_init(new);

if (hostid_mapped < 0) {
hostid_mapped = find_unmapped_nsuid(conf);
hostid_mapped = find_unmapped_nsuid(conf, ID_TYPE_UID);
if (hostid_mapped < 0)
goto err;
tmp = malloc(sizeof(*tmp));
Expand Down
4 changes: 2 additions & 2 deletions src/lxc/conf.h
View file
Expand Up @@ -371,8 +371,8 @@ extern int lxc_setup(struct lxc_handler *handler);

extern void lxc_rename_phys_nics_on_shutdown(struct lxc_conf *conf);

extern int find_unmapped_nsuid(struct lxc_conf *conf);
extern int mapped_hostid(int id, struct lxc_conf *conf);
extern int find_unmapped_nsuid(struct lxc_conf *conf, enum idtype idtype);
extern int mapped_hostid(unsigned id, struct lxc_conf *conf, enum idtype idtype);
extern int chown_mapped_root(char *path, struct lxc_conf *conf);
extern int ttys_shift_ids(struct lxc_conf *c);
extern int userns_exec_1(struct lxc_conf *conf, int (*fn)(void *), void *data);
Expand Down
38 changes: 33 additions & 5 deletions src/lxc/lxccontainer.c
View file
Expand Up @@ -977,6 +977,7 @@ static bool create_run_template(struct lxc_container *c, char *tpath, bool quiet
if (geteuid() != 0 && !lxc_list_empty(&conf->id_map)) {
int n2args = 1;
char txtuid[20];
char txtgid[20];
char **n2 = malloc(n2args * sizeof(*n2));
struct lxc_list *it;
struct id_map *map;
Expand Down Expand Up @@ -1004,13 +1005,13 @@ static bool create_run_template(struct lxc_container *c, char *tpath, bool quiet
if (ret < 0 || ret >= 200)
exit(1);
}
int hostid_mapped = mapped_hostid(geteuid(), conf);
int hostid_mapped = mapped_hostid(geteuid(), conf, ID_TYPE_UID);
int extraargs = hostid_mapped >= 0 ? 1 : 3;
n2 = realloc(n2, (nargs + n2args + extraargs) * sizeof(char *));
if (!n2)
exit(1);
if (hostid_mapped < 0) {
hostid_mapped = find_unmapped_nsuid(conf);
hostid_mapped = find_unmapped_nsuid(conf, ID_TYPE_UID);
n2[n2args++] = "-m";
if (hostid_mapped < 0) {
ERROR("Could not find free uid to map");
Expand All @@ -1028,22 +1029,49 @@ static bool create_run_template(struct lxc_container *c, char *tpath, bool quiet
exit(1);
}
}
int hostgid_mapped = mapped_hostid(getegid(), conf, ID_TYPE_GID);
extraargs = hostgid_mapped >= 0 ? 1 : 3;
n2 = realloc(n2, (nargs + n2args + extraargs) * sizeof(char *));
if (!n2)
exit(1);
if (hostgid_mapped < 0) {
hostgid_mapped = find_unmapped_nsuid(conf, ID_TYPE_GID);
n2[n2args++] = "-m";
if (hostgid_mapped < 0) {
ERROR("Could not find free uid to map");
exit(1);
}
n2[n2args++] = malloc(200);
if (!n2[n2args-1]) {
SYSERROR("out of memory");
exit(1);
}
ret = snprintf(n2[n2args-1], 200, "g:%d:%d:1",
hostgid_mapped, getegid());
if (ret < 0 || ret >= 200) {
ERROR("string too long");
exit(1);
}
}
n2[n2args++] = "--";
for (i = 0; i < nargs; i++)
n2[i + n2args] = newargv[i];
n2args += nargs;
// Finally add "--mapped-uid $uid" to tell template what to chown
// cached images to
n2args += 2;
n2args += 4;
n2 = realloc(n2, n2args * sizeof(char *));
if (!n2) {
SYSERROR("out of memory");
exit(1);
}
// note n2[n2args-1] is NULL
n2[n2args-3] = "--mapped-uid";
n2[n2args-5] = "--mapped-uid";
snprintf(txtuid, 20, "%d", hostid_mapped);
n2[n2args-2] = txtuid;
n2[n2args-4] = txtuid;
n2[n2args-3] = "--mapped-gid";
snprintf(txtgid, 20, "%d", hostgid_mapped);
n2[n2args-2] = txtgid;
n2[n2args-1] = NULL;
free(newargv);
newargv = n2;
Expand Down
13 changes: 11 additions & 2 deletions templates/lxc-download.in
View file
Expand Up @@ -51,6 +51,7 @@ LXC_NAME=
LXC_PATH=
LXC_ROOTFS=
LXC_MAPPED_UID=
LXC_MAPPED_GID=

# Some useful functions
cleanup() {
Expand Down Expand Up @@ -175,14 +176,15 @@ LXC internal arguments (do not pass manually!):
[ --name <name> ]: The container name
[ --path <path> ]: The path to the container
[ --rootfs <rootfs> ]: The path to the container's rootfs
[ --mapped-uid <map> ]: A uid/gid map (user namespaces)
[ --mapped-uid <map> ]: A uid map (user namespaces)
[ --mapped-gid <map> ]: A gid map (user namespaces)
EOF
return 0
}

options=$(getopt -o d:r:a:hl -l dist:,release:,arch:,help,list,variant:,\
server:,keyid:,no-validate,flush-cache,force-cache,name:,path:,\
rootfs:,mapped-uid: -- "$@")
rootfs:,mapped-uid:,mapped-gid: -- "$@")

if [ $? -ne 0 ]; then
usage
Expand All @@ -207,6 +209,7 @@ while :; do
--path) LXC_PATH=$2; shift 2;;
--rootfs) LXC_ROOTFS=$2; shift 2;;
--mapped-uid) LXC_MAPPED_UID=$2; shift 2;;
--mapped-gid) LXC_MAPPED_GID=$2; shift 2;;
*) break;;
esac
done
Expand Down Expand Up @@ -434,6 +437,9 @@ if [ "$DOWNLOAD_USE_CACHE" = "false" ]; then
if [ -n "$LXC_MAPPED_UID" ] && [ "$LXC_MAPPED_UID" != "-1" ]; then
chown -R $LXC_MAPPED_UID $LXC_CACHE_BASE >/dev/null 2>&1 || true
fi
if [ -n "$LXC_MAPPED_GID" ] && [ "$LXC_MAPPED_GID" != "-1" ]; then
chgrp -R $LXC_MAPPED_GID $LXC_CACHE_BASE >/dev/null 2>&1 || true
fi
echo "The image cache is now ready"
fi
else
Expand Down Expand Up @@ -527,6 +533,9 @@ done
if [ -n "$LXC_MAPPED_UID" ] && [ "$LXC_MAPPED_UID" != "-1" ]; then
chown $LXC_MAPPED_UID $LXC_PATH/config $LXC_PATH/fstab >/dev/null 2>&1 || true
fi
if [ -n "$LXC_MAPPED_GID" ] && [ "$LXC_MAPPED_GID" != "-1" ]; then
chgrp $LXC_MAPPED_GID $LXC_PATH/config $LXC_PATH/fstab >/dev/null 2>&1 || true
fi

if [ -e "$(relevant_file create-message)" ]; then
echo ""
Expand Down
10 changes: 8 additions & 2 deletions templates/lxc-ubuntu-cloud.in
View file
Expand Up @@ -147,14 +147,15 @@ EOF
return 0
}

options=$(getopt -o a:hp:r:n:Fi:CLS:T:ds:u: -l arch:,help,rootfs:,path:,release:,name:,flush-cache,hostid:,auth-key:,cloud,no_locales,tarball:,debug,stream:,userdata:,mapped-uid: -- "$@")
options=$(getopt -o a:hp:r:n:Fi:CLS:T:ds:u: -l arch:,help,rootfs:,path:,release:,name:,flush-cache,hostid:,auth-key:,cloud,no_locales,tarball:,debug,stream:,userdata:,mapped-uid:,mapped-gid: -- "$@")
if [ $? -ne 0 ]; then
usage $(basename $0)
exit 1
fi
eval set -- "$options"

mapped_uid=-1
mapped_gid=-1
# default release is precise, or the systems release if recognized
release=precise
if [ -f /etc/lsb-release ]; then
Expand Down Expand Up @@ -216,12 +217,12 @@ do
-C|--cloud) cloneargs[${#cloneargs[@]}]="--cloud"; shift 1;;
-S|--auth-key) cloneargs[${#cloneargs[@]}]="--auth-key=$2"; shift 2;;
--mapped-uid) mapped_uid=$2; shift 2;;
--mapped-gid) mapped_gid=$2; shift 2;;
--) shift 1; break ;;
*) break ;;
esac
done

echo "mapped_uid is .$mapped_uid."
cloneargs=( "--name=$name" "${cloneargs[@]}" )

if [ $debug -eq 1 ]; then
Expand Down Expand Up @@ -390,6 +391,11 @@ if [ $mapped_uid -ne -1 ]; then
chown -R $mapped_uid $STATE_DIR
chown -R $mapped_uid $cache
fi
if [ $mapped_gid -ne -1 ]; then
chgrp $mapped_gid $path/config
chgrp -R $mapped_gid $STATE_DIR
chgrp -R $mapped_gid $cache
fi

echo "Container $name created."
exit 0
Expand Down

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