[systemd-commits] src/hostname src/libsystemd src/locale src/login src/systemd src/timedate
Lennart Poettering
lennart at kemper.freedesktop.org
Fri Aug 15 11:17:27 PDT 2014
src/hostname/hostnamed.c | 12 ++++---
src/libsystemd/sd-bus/bus-convenience.c | 53 ++++++++++++++++++++++++++++++++
src/libsystemd/sd-bus/bus-objects.c | 25 ++-------------
src/libsystemd/sd-bus/bus-util.c | 24 +++-----------
src/libsystemd/sd-bus/bus-util.h | 4 +-
src/locale/localed.c | 7 ++--
src/login/logind-dbus.c | 17 ++++++----
src/systemd/sd-bus.h | 1
src/timedate/timedated.c | 8 ++--
9 files changed, 91 insertions(+), 60 deletions(-)
New commits:
commit def9a7aa0182e5ecca3ac61b26f75136a5c4f103
Author: Lennart Poettering <lennart at poettering.net>
Date: Fri Aug 15 20:08:51 2014 +0200
sd-bus: add API to check if a client has privileges
This is a generalization of the vtable privilege check we already have,
but exported, and hence useful when preparing for a polkit change.
This will deal with the complexity that on dbus1 one cannot trust the
capability field we retrieve via the bus, since it is read via
/proc/$$/stat (and thus might be out-of-date) rather than directly from
the message (like on kdbus) or bus connection (as for uid creds on
dbus1).
Also, port over all code to this new API.
diff --git a/src/hostname/hostnamed.c b/src/hostname/hostnamed.c
index 4acdb72..dae73b3 100644
--- a/src/hostname/hostnamed.c
+++ b/src/hostname/hostnamed.c
@@ -23,6 +23,7 @@
#include <string.h>
#include <unistd.h>
#include <sys/utsname.h>
+#include <sys/capability.h>
#include "util.h"
#include "strv.h"
@@ -425,7 +426,7 @@ static int method_set_hostname(sd_bus *bus, sd_bus_message *m, void *userdata, s
if (streq_ptr(name, c->data[PROP_HOSTNAME]))
return sd_bus_reply_method_return(m, NULL);
- r = bus_verify_polkit_async(bus, &c->polkit_registry, m, "org.freedesktop.hostname1.set-hostname", interactive, error, method_set_hostname, c);
+ r = bus_verify_polkit_async(bus, &c->polkit_registry, m, CAP_SYS_ADMIN, "org.freedesktop.hostname1.set-hostname", interactive, error, method_set_hostname, c);
if (r < 0)
return r;
if (r == 0)
@@ -467,7 +468,7 @@ static int method_set_static_hostname(sd_bus *bus, sd_bus_message *m, void *user
if (streq_ptr(name, c->data[PROP_STATIC_HOSTNAME]))
return sd_bus_reply_method_return(m, NULL);
- r = bus_verify_polkit_async(bus, &c->polkit_registry, m, "org.freedesktop.hostname1.set-static-hostname", interactive, error, method_set_static_hostname, c);
+ r = bus_verify_polkit_async(bus, &c->polkit_registry, m, CAP_SYS_ADMIN, "org.freedesktop.hostname1.set-static-hostname", interactive, error, method_set_static_hostname, c);
if (r < 0)
return r;
if (r == 0)
@@ -532,9 +533,10 @@ static int set_machine_info(Context *c, sd_bus *bus, sd_bus_message *m, int prop
* same time as the static one, use the same policy action for
* both... */
- r = bus_verify_polkit_async(bus, &c->polkit_registry, m, prop == PROP_PRETTY_HOSTNAME ?
- "org.freedesktop.hostname1.set-static-hostname" :
- "org.freedesktop.hostname1.set-machine-info", interactive, error, cb, c);
+ r = bus_verify_polkit_async(bus, &c->polkit_registry, m, CAP_SYS_ADMIN,
+ prop == PROP_PRETTY_HOSTNAME ?
+ "org.freedesktop.hostname1.set-static-hostname" :
+ "org.freedesktop.hostname1.set-machine-info", interactive, error, cb, c);
if (r < 0)
return r;
if (r == 0)
diff --git a/src/libsystemd/sd-bus/bus-convenience.c b/src/libsystemd/sd-bus/bus-convenience.c
index c5b9cd4..f88836b 100644
--- a/src/libsystemd/sd-bus/bus-convenience.c
+++ b/src/libsystemd/sd-bus/bus-convenience.c
@@ -472,3 +472,56 @@ _public_ int sd_bus_query_sender_creds(sd_bus_message *call, uint64_t mask, sd_b
return bus_creds_extend_by_pid(c, mask, creds);
}
+
+_public_ int sd_bus_query_sender_privilege(sd_bus_message *call, int capability) {
+ _cleanup_bus_creds_unref_ sd_bus_creds *creds = NULL;
+ uid_t our_uid;
+ int r;
+
+ assert_return(call, -EINVAL);
+ assert_return(call->sealed, -EPERM);
+ assert_return(call->bus, -EINVAL);
+ assert_return(!bus_pid_changed(call->bus), -ECHILD);
+
+ if (!BUS_IS_OPEN(call->bus->state))
+ return -ENOTCONN;
+
+ /* We only trust the effective capability set if this is
+ * kdbus. On classic dbus1 we cannot retrieve the value
+ * without races. Since this function is supposed to be useful
+ * for authentication decision we hence avoid requesting and
+ * using that information. */
+ if (call->bus->is_kernel && capability >= 0) {
+ r = sd_bus_query_sender_creds(call, SD_BUS_CREDS_UID|SD_BUS_CREDS_EFFECTIVE_CAPS, &creds);
+ if (r < 0)
+ return r;
+
+ r = sd_bus_creds_has_effective_cap(creds, capability);
+ if (r > 0)
+ return 1;
+ } else {
+ r = sd_bus_query_sender_creds(call, SD_BUS_CREDS_UID, &creds);
+ if (r < 0)
+ return r;
+ }
+
+ /* Now, check the UID, but only if the capability check wasn't
+ * sufficient */
+ our_uid = getuid();
+ if (our_uid != 0 || !call->bus->is_kernel || capability < 0) {
+ uid_t sender_uid;
+
+ r = sd_bus_creds_get_uid(creds, &sender_uid);
+ if (r >= 0) {
+ /* Sender has same UID as us, then let's grant access */
+ if (sender_uid == our_uid)
+ return 1;
+
+ /* Sender is root, we are not root. */
+ if (our_uid != 0 && sender_uid == 0)
+ return 1;
+ }
+ }
+
+ return 0;
+}
diff --git a/src/libsystemd/sd-bus/bus-objects.c b/src/libsystemd/sd-bus/bus-objects.c
index dbb04e5..78dab80 100644
--- a/src/libsystemd/sd-bus/bus-objects.c
+++ b/src/libsystemd/sd-bus/bus-objects.c
@@ -289,7 +289,6 @@ static int node_callbacks_run(
static int check_access(sd_bus *bus, sd_bus_message *m, struct vtable_member *c, sd_bus_error *error) {
_cleanup_bus_creds_unref_ sd_bus_creds *creds = NULL;
uint64_t cap;
- uid_t uid;
int r;
assert(bus);
@@ -304,17 +303,6 @@ static int check_access(sd_bus *bus, sd_bus_message *m, struct vtable_member *c,
if (c->vtable->flags & SD_BUS_VTABLE_UNPRIVILEGED)
return 0;
- /* If we are not connected to kdbus we cannot retrieve the
- * effective capability set without race. Since we need this
- * for a security decision we cannot use racy data, hence
- * don't request it. */
- if (bus->is_kernel)
- r = sd_bus_query_sender_creds(m, SD_BUS_CREDS_UID|SD_BUS_CREDS_EFFECTIVE_CAPS, &creds);
- else
- r = sd_bus_query_sender_creds(m, SD_BUS_CREDS_UID, &creds);
- if (r < 0)
- return r;
-
/* Check have the caller has the requested capability
* set. Note that the flags value contains the capability
* number plus one, which we need to subtract here. We do this
@@ -328,16 +316,11 @@ static int check_access(sd_bus *bus, sd_bus_message *m, struct vtable_member *c,
else
cap --;
- r = sd_bus_creds_has_effective_cap(creds, cap);
+ r = sd_bus_query_sender_privilege(m, cap);
+ if (r < 0)
+ return r;
if (r > 0)
- return 1;
-
- /* Caller has same UID as us, then let's grant access */
- r = sd_bus_creds_get_uid(creds, &uid);
- if (r >= 0) {
- if (uid == getuid())
- return 1;
- }
+ return 0;
return sd_bus_error_setf(error, SD_BUS_ERROR_ACCESS_DENIED, "Access to %s.%s() not permitted.", c->interface, c->member);
}
diff --git a/src/libsystemd/sd-bus/bus-util.c b/src/libsystemd/sd-bus/bus-util.c
index 32c5368..0ab11c3 100644
--- a/src/libsystemd/sd-bus/bus-util.c
+++ b/src/libsystemd/sd-bus/bus-util.c
@@ -186,28 +186,22 @@ int bus_name_has_owner(sd_bus *c, const char *name, sd_bus_error *error) {
int bus_verify_polkit(
sd_bus *bus,
sd_bus_message *m,
+ int capability,
const char *action,
bool interactive,
bool *_challenge,
sd_bus_error *e) {
- _cleanup_bus_creds_unref_ sd_bus_creds *creds = NULL;
- uid_t uid;
int r;
assert(bus);
assert(m);
assert(action);
- r = sd_bus_query_sender_creds(m, SD_BUS_CREDS_UID, &creds);
+ r = sd_bus_query_sender_privilege(m, capability);
if (r < 0)
return r;
-
- r = sd_bus_creds_get_uid(creds, &uid);
- if (r < 0)
- return r;
-
- if (uid == 0)
+ if (r > 0)
return 1;
#ifdef ENABLE_POLKIT
@@ -325,6 +319,7 @@ int bus_verify_polkit_async(
sd_bus *bus,
Hashmap **registry,
sd_bus_message *m,
+ int capability,
const char *action,
bool interactive,
sd_bus_error *error,
@@ -336,8 +331,6 @@ int bus_verify_polkit_async(
AsyncPolkitQuery *q;
const char *sender;
#endif
- _cleanup_bus_creds_unref_ sd_bus_creds *creds = NULL;
- uid_t uid;
int r;
assert(bus);
@@ -383,15 +376,10 @@ int bus_verify_polkit_async(
}
#endif
- r = sd_bus_query_sender_creds(m, SD_BUS_CREDS_UID, &creds);
+ r = sd_bus_query_sender_privilege(m, capability);
if (r < 0)
return r;
-
- r = sd_bus_creds_get_uid(creds, &uid);
- if (r < 0)
- return r;
-
- if (uid == 0)
+ if (r > 0)
return 1;
#ifdef ENABLE_POLKIT
diff --git a/src/libsystemd/sd-bus/bus-util.h b/src/libsystemd/sd-bus/bus-util.h
index af50553..f760a1e 100644
--- a/src/libsystemd/sd-bus/bus-util.h
+++ b/src/libsystemd/sd-bus/bus-util.h
@@ -62,9 +62,9 @@ int bus_name_has_owner(sd_bus *c, const char *name, sd_bus_error *error);
int bus_check_peercred(sd_bus *c);
-int bus_verify_polkit(sd_bus *bus, sd_bus_message *m, const char *action, bool interactive, bool *_challenge, sd_bus_error *e);
+int bus_verify_polkit(sd_bus *bus, sd_bus_message *m, int capability, const char *action, bool interactive, bool *_challenge, sd_bus_error *e);
-int bus_verify_polkit_async(sd_bus *bus, Hashmap **registry, sd_bus_message *m, const char *action, bool interactive, sd_bus_error *error, sd_bus_message_handler_t callback, void *userdata);
+int bus_verify_polkit_async(sd_bus *bus, Hashmap **registry, sd_bus_message *m, int capability, const char *action, bool interactive, sd_bus_error *error, sd_bus_message_handler_t callback, void *userdata);
void bus_verify_polkit_async_registry_free(sd_bus *bus, Hashmap *registry);
int bus_open_system_systemd(sd_bus **_bus);
diff --git a/src/locale/localed.c b/src/locale/localed.c
index 3cfc2ea..0870667 100644
--- a/src/locale/localed.c
+++ b/src/locale/localed.c
@@ -23,6 +23,7 @@
#include <errno.h>
#include <string.h>
#include <unistd.h>
+#include <sys/capability.h>
#include "sd-bus.h"
@@ -876,7 +877,7 @@ static int method_set_locale(sd_bus *bus, sd_bus_message *m, void *userdata, sd_
}
if (modified) {
- r = bus_verify_polkit_async(bus, &c->polkit_registry, m,
+ r = bus_verify_polkit_async(bus, &c->polkit_registry, m, CAP_SYS_ADMIN,
"org.freedesktop.locale1.set-locale", interactive,
error, method_set_locale, c);
if (r < 0)
@@ -954,7 +955,7 @@ static int method_set_vc_keyboard(sd_bus *bus, sd_bus_message *m, void *userdata
(keymap_toggle && (!filename_is_safe(keymap_toggle) || !string_is_safe(keymap_toggle))))
return sd_bus_error_set_errnof(error, -EINVAL, "Received invalid keymap data");
- r = bus_verify_polkit_async(bus, &c->polkit_registry, m,
+ r = bus_verify_polkit_async(bus, &c->polkit_registry, m, CAP_SYS_ADMIN,
"org.freedesktop.locale1.set-keyboard",
interactive, error, method_set_vc_keyboard, c);
if (r < 0)
@@ -1026,7 +1027,7 @@ static int method_set_x11_keyboard(sd_bus *bus, sd_bus_message *m, void *userdat
(options && !string_is_safe(options)))
return sd_bus_error_set_errnof(error, -EINVAL, "Received invalid keyboard data");
- r = bus_verify_polkit_async(bus, &c->polkit_registry, m,
+ r = bus_verify_polkit_async(bus, &c->polkit_registry, m, CAP_SYS_ADMIN,
"org.freedesktop.locale1.set-keyboard",
interactive, error, method_set_x11_keyboard, c);
if (r < 0)
diff --git a/src/login/logind-dbus.c b/src/login/logind-dbus.c
index 1a363c2..bcfcba2 100644
--- a/src/login/logind-dbus.c
+++ b/src/login/logind-dbus.c
@@ -1032,6 +1032,7 @@ static int method_set_user_linger(sd_bus *bus, sd_bus_message *message, void *us
r = bus_verify_polkit_async(bus,
&m->polkit_registry,
message,
+ CAP_SYS_ADMIN,
"org.freedesktop.login1.set-user-linger",
interactive,
error,
@@ -1204,6 +1205,7 @@ static int method_attach_device(sd_bus *bus, sd_bus_message *message, void *user
r = bus_verify_polkit_async(bus,
&m->polkit_registry,
message,
+ CAP_SYS_ADMIN,
"org.freedesktop.login1.attach-device",
interactive,
error,
@@ -1235,6 +1237,7 @@ static int method_flush_devices(sd_bus *bus, sd_bus_message *message, void *user
r = bus_verify_polkit_async(bus,
&m->polkit_registry,
message,
+ CAP_SYS_ADMIN,
"org.freedesktop.login1.flush-devices",
interactive,
error,
@@ -1532,7 +1535,7 @@ static int method_do_shutdown_or_sleep(
blocked = manager_is_inhibited(m, w, INHIBIT_BLOCK, NULL, false, true, uid, NULL);
if (multiple_sessions) {
- r = bus_verify_polkit_async(m->bus, &m->polkit_registry, message,
+ r = bus_verify_polkit_async(m->bus, &m->polkit_registry, message, CAP_SYS_BOOT,
action_multiple_sessions, interactive, error, method, m);
if (r < 0)
return r;
@@ -1541,7 +1544,7 @@ static int method_do_shutdown_or_sleep(
}
if (blocked) {
- r = bus_verify_polkit_async(m->bus, &m->polkit_registry, message,
+ r = bus_verify_polkit_async(m->bus, &m->polkit_registry, message, CAP_SYS_BOOT,
action_ignore_inhibit, interactive, error, method, m);
if (r < 0)
return r;
@@ -1550,7 +1553,7 @@ static int method_do_shutdown_or_sleep(
}
if (!multiple_sessions && !blocked) {
- r = bus_verify_polkit_async(m->bus, &m->polkit_registry, message,
+ r = bus_verify_polkit_async(m->bus, &m->polkit_registry, message, CAP_SYS_BOOT,
action, interactive, error, method, m);
if (r < 0)
return r;
@@ -1688,7 +1691,7 @@ static int method_can_shutdown_or_sleep(
blocked = manager_is_inhibited(m, w, INHIBIT_BLOCK, NULL, false, true, uid, NULL);
if (multiple_sessions) {
- r = bus_verify_polkit(m->bus, message, action_multiple_sessions, false, &challenge, error);
+ r = bus_verify_polkit(m->bus, message, CAP_SYS_BOOT, action_multiple_sessions, false, &challenge, error);
if (r < 0)
return r;
@@ -1701,7 +1704,7 @@ static int method_can_shutdown_or_sleep(
}
if (blocked) {
- r = bus_verify_polkit(m->bus, message, action_ignore_inhibit, false, &challenge, error);
+ r = bus_verify_polkit(m->bus, message, CAP_SYS_BOOT, action_ignore_inhibit, false, &challenge, error);
if (r < 0)
return r;
@@ -1717,7 +1720,7 @@ static int method_can_shutdown_or_sleep(
/* If neither inhibit nor multiple sessions
* apply then just check the normal policy */
- r = bus_verify_polkit(m->bus, message, action, false, &challenge, error);
+ r = bus_verify_polkit(m->bus, message, CAP_SYS_BOOT, action, false, &challenge, error);
if (r < 0)
return r;
@@ -1837,7 +1840,7 @@ static int method_inhibit(sd_bus *bus, sd_bus_message *message, void *userdata,
if (m->action_what & w)
return sd_bus_error_setf(error, BUS_ERROR_OPERATION_IN_PROGRESS, "The operation inhibition has been requested for is already running");
- r = bus_verify_polkit_async(bus, &m->polkit_registry, message,
+ r = bus_verify_polkit_async(bus, &m->polkit_registry, message, CAP_SYS_BOOT,
w == INHIBIT_SHUTDOWN ? (mm == INHIBIT_BLOCK ? "org.freedesktop.login1.inhibit-block-shutdown" : "org.freedesktop.login1.inhibit-delay-shutdown") :
w == INHIBIT_SLEEP ? (mm == INHIBIT_BLOCK ? "org.freedesktop.login1.inhibit-block-sleep" : "org.freedesktop.login1.inhibit-delay-sleep") :
w == INHIBIT_IDLE ? "org.freedesktop.login1.inhibit-block-idle" :
diff --git a/src/systemd/sd-bus.h b/src/systemd/sd-bus.h
index 79566d2..3eedb44 100644
--- a/src/systemd/sd-bus.h
+++ b/src/systemd/sd-bus.h
@@ -282,6 +282,7 @@ int sd_bus_emit_interfaces_removed_strv(sd_bus *bus, const char *path, char **in
int sd_bus_emit_interfaces_removed(sd_bus *bus, const char *path, const char *interface, ...) _sd_sentinel_;
int sd_bus_query_sender_creds(sd_bus_message *call, uint64_t mask, sd_bus_creds **creds);
+int sd_bus_query_sender_privilege(sd_bus_message *call, int capability);
/* Credential handling */
diff --git a/src/timedate/timedated.c b/src/timedate/timedated.c
index 791e2b4..f037175 100644
--- a/src/timedate/timedated.c
+++ b/src/timedate/timedated.c
@@ -395,7 +395,7 @@ static int method_set_timezone(sd_bus *bus, sd_bus_message *m, void *userdata, s
if (streq_ptr(z, c->zone))
return sd_bus_reply_method_return(m, NULL);
- r = bus_verify_polkit_async(bus, &c->polkit_registry, m, "org.freedesktop.timedate1.set-timezone", interactive, error, method_set_timezone, c);
+ r = bus_verify_polkit_async(bus, &c->polkit_registry, m, CAP_SYS_TIME, "org.freedesktop.timedate1.set-timezone", interactive, error, method_set_timezone, c);
if (r < 0)
return r;
if (r == 0)
@@ -456,7 +456,7 @@ static int method_set_local_rtc(sd_bus *bus, sd_bus_message *m, void *userdata,
if (lrtc == c->local_rtc)
return sd_bus_reply_method_return(m, NULL);
- r = bus_verify_polkit_async(bus, &c->polkit_registry, m, "org.freedesktop.timedate1.set-local-rtc", interactive, error, method_set_local_rtc, c);
+ r = bus_verify_polkit_async(bus, &c->polkit_registry, m, CAP_SYS_TIME, "org.freedesktop.timedate1.set-local-rtc", interactive, error, method_set_local_rtc, c);
if (r < 0)
return r;
if (r == 0)
@@ -561,7 +561,7 @@ static int method_set_time(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bu
} else
timespec_store(&ts, (usec_t) utc);
- r = bus_verify_polkit_async(bus, &c->polkit_registry, m, "org.freedesktop.timedate1.set-time", interactive, error, method_set_time, c);
+ r = bus_verify_polkit_async(bus, &c->polkit_registry, m, CAP_SYS_TIME, "org.freedesktop.timedate1.set-time", interactive, error, method_set_time, c);
if (r < 0)
return r;
if (r == 0)
@@ -601,7 +601,7 @@ static int method_set_ntp(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus
if ((bool)ntp == c->use_ntp)
return sd_bus_reply_method_return(m, NULL);
- r = bus_verify_polkit_async(bus, &c->polkit_registry, m, "org.freedesktop.timedate1.set-ntp", interactive, error, method_set_ntp, c);
+ r = bus_verify_polkit_async(bus, &c->polkit_registry, m, CAP_SYS_TIME, "org.freedesktop.timedate1.set-ntp", interactive, error, method_set_ntp, c);
if (r < 0)
return r;
if (r == 0)
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