diff options
Diffstat (limited to 'src')
-rw-r--r-- | src/core/execute.c | 6 | ||||
l--------- | src/nss-systemd/Makefile | 1 | ||||
-rw-r--r-- | src/nss-systemd/nss-systemd.c | 332 | ||||
-rw-r--r-- | src/nss-systemd/nss-systemd.sym | 17 |
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: *; +}; |