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authorLennart Poettering <lennart@poettering.net>2015-07-09 14:46:20 -0300
committerLennart Poettering <lennart@poettering.net>2015-07-09 14:46:20 -0300
commitc01ff965b48bb9693dcd77cbc748b5d8676766b0 (patch)
tree63e50e4f3d4b6e6d3217fa2bf7f700eb19c258de /src/machine
parent43694a8cc70667498f3ffc5d9325b7d0428558e5 (diff)
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.
Diffstat (limited to 'src/machine')
-rw-r--r--src/machine/machined-dbus.c231
-rw-r--r--src/machine/org.freedesktop.machine1.conf16
2 files changed, 246 insertions, 1 deletions
diff --git a/src/machine/machined-dbus.c b/src/machine/machined-dbus.c
index 0e971a6789..3637815fc9 100644
--- a/src/machine/machined-dbus.c
+++ b/src/machine/machined-dbus.c
@@ -31,12 +31,13 @@
#include "bus-common-errors.h"
#include "cgroup-util.h"
#include "btrfs-util.h"
+#include "formats-util.h"
+#include "process-util.h"
#include "machine-image.h"
#include "machine-pool.h"
#include "image-dbus.h"
#include "machined.h"
#include "machine-dbus.h"
-#include "formats-util.h"
static int property_get_pool_path(
sd_bus *bus,
@@ -840,6 +841,230 @@ static int method_set_image_limit(sd_bus_message *message, void *userdata, sd_bu
return bus_image_method_set_limit(message, i, error);
}
+static int method_map_from_machine_user(sd_bus_message *message, void *userdata, sd_bus_error *error) {
+ _cleanup_fclose_ FILE *f = NULL;
+ Manager *m = userdata;
+ const char *name, *p;
+ Machine *machine;
+ uint32_t uid;
+ int r;
+
+ r = sd_bus_message_read(message, "su", &name, &uid);
+ if (r < 0)
+ return r;
+
+ if (UID_IS_INVALID(uid))
+ return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid user ID " UID_FMT, uid);
+
+ machine = hashmap_get(m->machines, name);
+ if (!machine)
+ return sd_bus_error_setf(error, BUS_ERROR_NO_SUCH_MACHINE, "No machine '%s' known", name);
+
+ p = procfs_file_alloca(machine->leader, "uid_map");
+ f = fopen(p, "re");
+ if (!f)
+ return -errno;
+
+ for (;;) {
+ uid_t uid_base, uid_shift, uid_range, converted;
+ int k;
+
+ errno = 0;
+ k = fscanf(f, UID_FMT " " UID_FMT " " UID_FMT, &uid_base, &uid_shift, &uid_range);
+ if (k < 0 && feof(f))
+ break;
+ if (k != 3) {
+ if (ferror(f) && errno != 0)
+ return -errno;
+
+ return -EIO;
+ }
+
+ if (uid < uid_base || uid >= uid_base + uid_range)
+ continue;
+
+ converted = uid - uid_base + uid_shift;
+ if (UID_IS_INVALID(converted))
+ return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid user ID " UID_FMT, uid);
+
+ return sd_bus_reply_method_return(message, "u", (uint32_t) converted);
+ }
+
+ return sd_bus_error_setf(error, BUS_ERROR_NO_SUCH_USER_MAPPING, "Machine '%s' has no matching user mappings.", name);
+}
+
+static int method_map_to_machine_user(sd_bus_message *message, void *userdata, sd_bus_error *error) {
+ Manager *m = userdata;
+ Machine *machine;
+ uid_t uid;
+ Iterator i;
+ int r;
+
+ r = sd_bus_message_read(message, "u", &uid);
+ if (r < 0)
+ return r;
+ if (UID_IS_INVALID(uid))
+ return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid user ID " UID_FMT, uid);
+ if (uid < 0x10000)
+ return sd_bus_error_setf(error, BUS_ERROR_NO_SUCH_USER_MAPPING, "User " UID_FMT " belongs to host UID range", uid);
+
+ HASHMAP_FOREACH(machine, m->machines, i) {
+ _cleanup_fclose_ FILE *f = NULL;
+ char p[strlen("/proc//uid_map") + DECIMAL_STR_MAX(pid_t) + 1];
+
+ xsprintf(p, "/proc/" UID_FMT "/uid_map", machine->leader);
+ f = fopen(p, "re");
+ if (!f) {
+ log_warning_errno(errno, "Failed top open %s, ignoring,", p);
+ continue;
+ }
+
+ for (;;) {
+ _cleanup_free_ char *o = NULL;
+ uid_t uid_base, uid_shift, uid_range, converted;
+ int k;
+
+ errno = 0;
+ k = fscanf(f, UID_FMT " " UID_FMT " " UID_FMT, &uid_base, &uid_shift, &uid_range);
+ if (k < 0 && feof(f))
+ break;
+ if (k != 3) {
+ if (ferror(f) && errno != 0)
+ return -errno;
+
+ return -EIO;
+ }
+
+ if (uid < uid_shift || uid >= uid_shift + uid_range)
+ continue;
+
+ converted = (uid - uid_shift + uid_base);
+ if (UID_IS_INVALID(converted))
+ return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid user ID " UID_FMT, uid);
+
+ o = machine_bus_path(machine);
+ if (!o)
+ return -ENOMEM;
+
+ return sd_bus_reply_method_return(message, "sou", machine->name, o, (uint32_t) converted);
+ }
+ }
+
+ return sd_bus_error_setf(error, BUS_ERROR_NO_SUCH_USER_MAPPING, "No matching user mapping for " UID_FMT ".", uid);
+}
+
+static int method_map_from_machine_group(sd_bus_message *message, void *groupdata, sd_bus_error *error) {
+ _cleanup_fclose_ FILE *f = NULL;
+ Manager *m = groupdata;
+ const char *name, *p;
+ Machine *machine;
+ uint32_t gid;
+ int r;
+
+ r = sd_bus_message_read(message, "su", &name, &gid);
+ if (r < 0)
+ return r;
+
+ if (GID_IS_INVALID(gid))
+ return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid group ID " GID_FMT, gid);
+
+ machine = hashmap_get(m->machines, name);
+ if (!machine)
+ return sd_bus_error_setf(error, BUS_ERROR_NO_SUCH_MACHINE, "No machine '%s' known", name);
+
+ p = procfs_file_alloca(machine->leader, "gid_map");
+ f = fopen(p, "re");
+ if (!f)
+ return -errno;
+
+ for (;;) {
+ gid_t gid_base, gid_shift, gid_range, converted;
+ int k;
+
+ errno = 0;
+ k = fscanf(f, GID_FMT " " GID_FMT " " GID_FMT, &gid_base, &gid_shift, &gid_range);
+ if (k < 0 && feof(f))
+ break;
+ if (k != 3) {
+ if (ferror(f) && errno != 0)
+ return -errno;
+
+ return -EIO;
+ }
+
+ if (gid < gid_base || gid >= gid_base + gid_range)
+ continue;
+
+ converted = gid - gid_base + gid_shift;
+ if (GID_IS_INVALID(converted))
+ return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid group ID " GID_FMT, gid);
+
+ return sd_bus_reply_method_return(message, "u", (uint32_t) converted);
+ }
+
+ return sd_bus_error_setf(error, BUS_ERROR_NO_SUCH_GROUP_MAPPING, "Machine '%s' has no matching group mappings.", name);
+}
+
+static int method_map_to_machine_group(sd_bus_message *message, void *groupdata, sd_bus_error *error) {
+ Manager *m = groupdata;
+ Machine *machine;
+ gid_t gid;
+ Iterator i;
+ int r;
+
+ r = sd_bus_message_read(message, "u", &gid);
+ if (r < 0)
+ return r;
+ if (GID_IS_INVALID(gid))
+ return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid group ID " GID_FMT, gid);
+ if (gid < 0x10000)
+ return sd_bus_error_setf(error, BUS_ERROR_NO_SUCH_GROUP_MAPPING, "Group " GID_FMT " belongs to host GID range", gid);
+
+ HASHMAP_FOREACH(machine, m->machines, i) {
+ _cleanup_fclose_ FILE *f = NULL;
+ char p[strlen("/proc//gid_map") + DECIMAL_STR_MAX(pid_t) + 1];
+
+ xsprintf(p, "/proc/" GID_FMT "/gid_map", machine->leader);
+ f = fopen(p, "re");
+ if (!f) {
+ log_warning_errno(errno, "Failed top open %s, ignoring,", p);
+ continue;
+ }
+
+ for (;;) {
+ _cleanup_free_ char *o = NULL;
+ gid_t gid_base, gid_shift, gid_range, converted;
+ int k;
+
+ errno = 0;
+ k = fscanf(f, GID_FMT " " GID_FMT " " GID_FMT, &gid_base, &gid_shift, &gid_range);
+ if (k < 0 && feof(f))
+ break;
+ if (k != 3) {
+ if (ferror(f) && errno != 0)
+ return -errno;
+
+ return -EIO;
+ }
+
+ if (gid < gid_shift || gid >= gid_shift + gid_range)
+ continue;
+
+ converted = (gid - gid_shift + gid_base);
+ if (GID_IS_INVALID(converted))
+ return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid group ID " GID_FMT, gid);
+
+ o = machine_bus_path(machine);
+ if (!o)
+ return -ENOMEM;
+
+ return sd_bus_reply_method_return(message, "sou", machine->name, o, (uint32_t) converted);
+ }
+ }
+
+ return sd_bus_error_setf(error, BUS_ERROR_NO_SUCH_GROUP_MAPPING, "No matching group mapping for " GID_FMT ".", gid);
+}
+
const sd_bus_vtable manager_vtable[] = {
SD_BUS_VTABLE_START(0),
SD_BUS_PROPERTY("PoolPath", "s", property_get_pool_path, 0, 0),
@@ -869,6 +1094,10 @@ const sd_bus_vtable manager_vtable[] = {
SD_BUS_METHOD("MarkImageReadOnly", "sb", NULL, method_mark_image_read_only, SD_BUS_VTABLE_UNPRIVILEGED),
SD_BUS_METHOD("SetPoolLimit", "t", NULL, method_set_pool_limit, SD_BUS_VTABLE_UNPRIVILEGED),
SD_BUS_METHOD("SetImageLimit", "st", NULL, method_set_image_limit, SD_BUS_VTABLE_UNPRIVILEGED),
+ SD_BUS_METHOD("MapFromMachineUser", "su", "u", method_map_from_machine_user, SD_BUS_VTABLE_UNPRIVILEGED),
+ SD_BUS_METHOD("MapToMachineUser", "u", "sou", method_map_to_machine_user, SD_BUS_VTABLE_UNPRIVILEGED),
+ SD_BUS_METHOD("MapFromMachineGroup", "su", "u", method_map_from_machine_group, SD_BUS_VTABLE_UNPRIVILEGED),
+ SD_BUS_METHOD("MapToMachineGroup", "u", "sou", method_map_to_machine_group, SD_BUS_VTABLE_UNPRIVILEGED),
SD_BUS_SIGNAL("MachineNew", "so", 0),
SD_BUS_SIGNAL("MachineRemoved", "so", 0),
SD_BUS_VTABLE_END
diff --git a/src/machine/org.freedesktop.machine1.conf b/src/machine/org.freedesktop.machine1.conf
index 93aaf6a377..d58f01507b 100644
--- a/src/machine/org.freedesktop.machine1.conf
+++ b/src/machine/org.freedesktop.machine1.conf
@@ -113,6 +113,22 @@
send_member="SetImageLimit"/>
<allow send_destination="org.freedesktop.machine1"
+ send_interface="org.freedesktop.machine1.Manager"
+ send_member="MapFromMachineUser"/>
+
+ <allow send_destination="org.freedesktop.machine1"
+ send_interface="org.freedesktop.machine1.Manager"
+ send_member="MapToMachineUser"/>
+
+ <allow send_destination="org.freedesktop.machine1"
+ send_interface="org.freedesktop.machine1.Manager"
+ send_member="MapFromMachineGroup"/>
+
+ <allow send_destination="org.freedesktop.machine1"
+ send_interface="org.freedesktop.machine1.Manager"
+ send_member="MapToMachineGroup"/>
+
+ <allow send_destination="org.freedesktop.machine1"
send_interface="org.freedesktop.machine1.Machine"
send_member="GetAddresses"/>