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-rw-r--r--src/core/execute.c6
l---------src/nss-systemd/Makefile1
-rw-r--r--src/nss-systemd/nss-systemd.c332
-rw-r--r--src/nss-systemd/nss-systemd.sym17
4 files changed, 356 insertions, 0 deletions
diff --git a/src/core/execute.c b/src/core/execute.c
index c186f2a705..26e9cd5339 100644
--- a/src/core/execute.c
+++ b/src/core/execute.c
@@ -1670,6 +1670,12 @@ static int exec_child(
if (context->dynamic_user && dcreds) {
+ /* Make sure we bypass our own NSS module for any NSS checks */
+ if (putenv((char*) "SYSTEMD_NSS_DYNAMIC_BYPASS=1") != 0) {
+ *exit_status = EXIT_USER;
+ return -errno;
+ }
+
r = dynamic_creds_realize(dcreds, &uid, &gid);
if (r < 0) {
*exit_status = EXIT_USER;
diff --git a/src/nss-systemd/Makefile b/src/nss-systemd/Makefile
new file mode 120000
index 0000000000..d0b0e8e008
--- /dev/null
+++ b/src/nss-systemd/Makefile
@@ -0,0 +1 @@
+../Makefile \ No newline at end of file
diff --git a/src/nss-systemd/nss-systemd.c b/src/nss-systemd/nss-systemd.c
new file mode 100644
index 0000000000..e7a4393bb0
--- /dev/null
+++ b/src/nss-systemd/nss-systemd.c
@@ -0,0 +1,332 @@
+/***
+ This file is part of systemd.
+
+ Copyright 2016 Lennart Poettering
+
+ systemd is free software; you can redistribute it and/or modify it
+ under the terms of the GNU Lesser General Public License as published by
+ the Free Software Foundation; either version 2.1 of the License, or
+ (at your option) any later version.
+
+ systemd is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <nss.h>
+
+#include "sd-bus.h"
+
+#include "bus-common-errors.h"
+#include "env-util.h"
+#include "macro.h"
+#include "nss-util.h"
+#include "signal-util.h"
+#include "user-util.h"
+#include "util.h"
+
+NSS_GETPW_PROTOTYPES(systemd);
+NSS_GETGR_PROTOTYPES(systemd);
+
+enum nss_status _nss_systemd_getpwnam_r(
+ const char *name,
+ struct passwd *pwd,
+ char *buffer, size_t buflen,
+ int *errnop) {
+
+ _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+ _cleanup_(sd_bus_message_unrefp) sd_bus_message* reply = NULL;
+ _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
+ uint32_t translated;
+ size_t l;
+ int r;
+
+ BLOCK_SIGNALS(NSS_SIGNALS_BLOCK);
+
+ assert(name);
+ assert(pwd);
+
+ /* Make sure that we don't go in circles when allocating a dynamic UID by checking our own database */
+ if (getenv_bool("SYSTEMD_NSS_DYNAMIC_BYPASS") > 0)
+ goto not_found;
+
+ r = sd_bus_open_system(&bus);
+ if (r < 0)
+ goto fail;
+
+ r = sd_bus_call_method(bus,
+ "org.freedesktop.systemd1",
+ "/org/freedesktop/systemd1",
+ "org.freedesktop.systemd1.Manager",
+ "LookupDynamicUserByName",
+ &error,
+ &reply,
+ "s",
+ name);
+ if (r < 0) {
+ if (sd_bus_error_has_name(&error, BUS_ERROR_NO_SUCH_DYNAMIC_USER))
+ goto not_found;
+
+ goto fail;
+ }
+
+ r = sd_bus_message_read(reply, "u", &translated);
+ if (r < 0)
+ goto fail;
+
+ l = strlen(name);
+ if (buflen < l+1) {
+ *errnop = ENOMEM;
+ return NSS_STATUS_TRYAGAIN;
+ }
+
+ memcpy(buffer, name, l+1);
+
+ pwd->pw_name = buffer;
+ pwd->pw_uid = (uid_t) translated;
+ pwd->pw_gid = (uid_t) translated;
+ pwd->pw_gecos = (char*) "Dynamic User";
+ pwd->pw_passwd = (char*) "*"; /* locked */
+ pwd->pw_dir = (char*) "/";
+ pwd->pw_shell = (char*) "/sbin/nologin";
+
+ *errnop = 0;
+ return NSS_STATUS_SUCCESS;
+
+not_found:
+ *errnop = 0;
+ return NSS_STATUS_NOTFOUND;
+
+fail:
+ *errnop = -r;
+ return NSS_STATUS_UNAVAIL;
+}
+
+enum nss_status _nss_systemd_getpwuid_r(
+ uid_t uid,
+ struct passwd *pwd,
+ char *buffer, size_t buflen,
+ int *errnop) {
+
+ _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+ _cleanup_(sd_bus_message_unrefp) sd_bus_message* reply = NULL;
+ _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
+ const char *translated;
+ size_t l;
+ int r;
+
+ BLOCK_SIGNALS(NSS_SIGNALS_BLOCK);
+
+ if (!uid_is_valid(uid)) {
+ r = -EINVAL;
+ goto fail;
+ }
+
+ if (uid <= SYSTEM_UID_MAX)
+ goto not_found;
+
+ if (getenv_bool("SYSTEMD_NSS_DYNAMIC_BYPASS") > 0)
+ goto not_found;
+
+ r = sd_bus_open_system(&bus);
+ if (r < 0)
+ goto fail;
+
+ r = sd_bus_call_method(bus,
+ "org.freedesktop.systemd1",
+ "/org/freedesktop/systemd1",
+ "org.freedesktop.systemd1.Manager",
+ "LookupDynamicUserByUID",
+ &error,
+ &reply,
+ "u",
+ (uint32_t) uid);
+ if (r < 0) {
+ if (sd_bus_error_has_name(&error, BUS_ERROR_NO_SUCH_DYNAMIC_USER))
+ goto not_found;
+
+ goto fail;
+ }
+
+ r = sd_bus_message_read(reply, "s", &translated);
+ if (r < 0)
+ goto fail;
+
+ l = strlen(translated) + 1;
+ if (buflen < l) {
+ *errnop = ENOMEM;
+ return NSS_STATUS_TRYAGAIN;
+ }
+
+ memcpy(buffer, translated, l);
+
+ pwd->pw_name = buffer;
+ pwd->pw_uid = uid;
+ pwd->pw_gid = uid;
+ pwd->pw_gecos = (char*) "Dynamic User";
+ pwd->pw_passwd = (char*) "*"; /* locked */
+ pwd->pw_dir = (char*) "/";
+ pwd->pw_shell = (char*) "/sbin/nologin";
+
+ *errnop = 0;
+ return NSS_STATUS_SUCCESS;
+
+not_found:
+ *errnop = 0;
+ return NSS_STATUS_NOTFOUND;
+
+fail:
+ *errnop = -r;
+ return NSS_STATUS_UNAVAIL;
+}
+
+enum nss_status _nss_systemd_getgrnam_r(
+ const char *name,
+ struct group *gr,
+ char *buffer, size_t buflen,
+ int *errnop) {
+
+ _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+ _cleanup_(sd_bus_message_unrefp) sd_bus_message* reply = NULL;
+ _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
+ uint32_t translated;
+ size_t l;
+ int r;
+
+ BLOCK_SIGNALS(NSS_SIGNALS_BLOCK);
+
+ assert(name);
+ assert(gr);
+
+ if (getenv_bool("SYSTEMD_NSS_DYNAMIC_BYPASS") > 0)
+ goto not_found;
+
+ r = sd_bus_open_system(&bus);
+ if (r < 0)
+ goto fail;
+
+ r = sd_bus_call_method(bus,
+ "org.freedesktop.systemd1",
+ "/org/freedesktop/systemd1",
+ "org.freedesktop.systemd1.Manager",
+ "LookupDynamicUserByName",
+ &error,
+ &reply,
+ "s",
+ name);
+ if (r < 0) {
+ if (sd_bus_error_has_name(&error, BUS_ERROR_NO_SUCH_DYNAMIC_USER))
+ goto not_found;
+
+ goto fail;
+ }
+
+ r = sd_bus_message_read(reply, "u", &translated);
+ if (r < 0)
+ goto fail;
+
+ l = sizeof(char*) + strlen(name) + 1;
+ if (buflen < l) {
+ *errnop = ENOMEM;
+ return NSS_STATUS_TRYAGAIN;
+ }
+
+ memzero(buffer, sizeof(char*));
+ strcpy(buffer + sizeof(char*), name);
+
+ gr->gr_name = buffer + sizeof(char*);
+ gr->gr_gid = (gid_t) translated;
+ gr->gr_passwd = (char*) "*"; /* locked */
+ gr->gr_mem = (char**) buffer;
+
+ *errnop = 0;
+ return NSS_STATUS_SUCCESS;
+
+not_found:
+ *errnop = 0;
+ return NSS_STATUS_NOTFOUND;
+
+fail:
+ *errnop = -r;
+ return NSS_STATUS_UNAVAIL;
+}
+
+enum nss_status _nss_systemd_getgrgid_r(
+ gid_t gid,
+ struct group *gr,
+ char *buffer, size_t buflen,
+ int *errnop) {
+
+ _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+ _cleanup_(sd_bus_message_unrefp) sd_bus_message* reply = NULL;
+ _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
+ const char *translated;
+ size_t l;
+ int r;
+
+ BLOCK_SIGNALS(NSS_SIGNALS_BLOCK);
+
+ if (!gid_is_valid(gid)) {
+ r = -EINVAL;
+ goto fail;
+ }
+
+ if (gid <= SYSTEM_GID_MAX)
+ goto not_found;
+
+ if (getenv_bool("SYSTEMD_NSS_DYNAMIC_BYPASS") > 0)
+ goto not_found;
+
+ r = sd_bus_open_system(&bus);
+ if (r < 0)
+ goto fail;
+
+ r = sd_bus_call_method(bus,
+ "org.freedesktop.systemd1",
+ "/org/freedesktop/systemd1",
+ "org.freedesktop.systemd1.Manager",
+ "LookupDynamicUserByUID",
+ &error,
+ &reply,
+ "u",
+ (uint32_t) gid);
+ if (r < 0) {
+ if (sd_bus_error_has_name(&error, BUS_ERROR_NO_SUCH_DYNAMIC_USER))
+ goto not_found;
+
+ goto fail;
+ }
+
+ r = sd_bus_message_read(reply, "s", &translated);
+ if (r < 0)
+ goto fail;
+
+ l = sizeof(char*) + strlen(translated) + 1;
+ if (buflen < l) {
+ *errnop = ENOMEM;
+ return NSS_STATUS_TRYAGAIN;
+ }
+
+ memzero(buffer, sizeof(char*));
+ strcpy(buffer + sizeof(char*), translated);
+
+ gr->gr_name = buffer + sizeof(char*);
+ gr->gr_gid = gid;
+ gr->gr_passwd = (char*) "*"; /* locked */
+ gr->gr_mem = (char**) buffer;
+
+ *errnop = 0;
+ return NSS_STATUS_SUCCESS;
+
+not_found:
+ *errnop = 0;
+ return NSS_STATUS_NOTFOUND;
+
+fail:
+ *errnop = -r;
+ return NSS_STATUS_UNAVAIL;
+}
diff --git a/src/nss-systemd/nss-systemd.sym b/src/nss-systemd/nss-systemd.sym
new file mode 100644
index 0000000000..955078788a
--- /dev/null
+++ b/src/nss-systemd/nss-systemd.sym
@@ -0,0 +1,17 @@
+/***
+ This file is part of systemd.
+
+ systemd is free software; you can redistribute it and/or modify it
+ under the terms of the GNU Lesser General Public License as published by
+ the Free Software Foundation; either version 2.1 of the License, or
+ (at your option) any later version.
+***/
+
+{
+global:
+ _nss_systemd_getpwnam_r;
+ _nss_systemd_getpwuid_r;
+ _nss_systemd_getgrnam_r;
+ _nss_systemd_getgrgid_r;
+local: *;
+};