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-rw-r--r--man/systemd-nspawn.xml13
-rw-r--r--src/nspawn.c70
2 files changed, 77 insertions, 6 deletions
diff --git a/man/systemd-nspawn.xml b/man/systemd-nspawn.xml
index e1b33f72c5..03c39fc3de 100644
--- a/man/systemd-nspawn.xml
+++ b/man/systemd-nspawn.xml
@@ -139,6 +139,19 @@
used.</para></listitem>
</varlistentry>
+ <varlistentry>
+ <term><option>--user=</option></term>
+ <term><option>--u</option></term>
+
+ <listitem><para>Run the command
+ under specified user, create home
+ directory and cd into it. As rest
+ of systemd-nspawn, this is not
+ the security feature and limits
+ against accidental changes only.
+ </para></listitem>
+ </varlistentry>
+
</variablelist>
</refsect1>
diff --git a/src/nspawn.c b/src/nspawn.c
index 1ade6e25ef..bead9eea2b 100644
--- a/src/nspawn.c
+++ b/src/nspawn.c
@@ -36,6 +36,7 @@
#include <sys/epoll.h>
#include <termios.h>
#include <sys/signalfd.h>
+#include <grp.h>
#include "log.h"
#include "util.h"
@@ -45,13 +46,15 @@
#include "strv.h"
static char *arg_directory = NULL;
+static char *arg_user = NULL;
static int help(void) {
printf("%s [OPTIONS...] [PATH] [ARGUMENTS...]\n\n"
"Spawn a minimal namespace container for debugging, testing and building.\n\n"
" -h --help Show this help\n"
- " -D --directory=NAME Root directory for the container\n",
+ " -D --directory=NAME Root directory for the container\n"
+ " -u --user=USER Run the command under specified user or uid\n",
program_invocation_short_name);
return 0;
@@ -62,6 +65,7 @@ static int parse_argv(int argc, char *argv[]) {
static const struct option options[] = {
{ "help", no_argument, NULL, 'h' },
{ "directory", required_argument, NULL, 'D' },
+ { "user", optional_argument, NULL, 'u' },
{ NULL, 0, NULL, 0 }
};
@@ -70,7 +74,7 @@ static int parse_argv(int argc, char *argv[]) {
assert(argc >= 0);
assert(argv);
- while ((c = getopt_long(argc, argv, "+hD:", options, NULL)) >= 0) {
+ while ((c = getopt_long(argc, argv, "+hD:u:", options, NULL)) >= 0) {
switch (c) {
@@ -87,6 +91,15 @@ static int parse_argv(int argc, char *argv[]) {
break;
+ case 'u':
+ free(arg_user);
+ if (!(arg_user = strdup(optarg))) {
+ log_error("Failed to duplicate user name.");
+ return -ENOMEM;
+ }
+
+ break;
+
case '?':
return -EINVAL;
@@ -693,14 +706,19 @@ int main(int argc, char *argv[]) {
/* child */
const char *hn;
+ const char *home = NULL;
+ uid_t uid = (uid_t) -1;
+ gid_t gid = (gid_t) -1;
const char *envp[] = {
- "HOME=/root",
"PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
- NULL,
+ NULL, /* TERM */
+ NULL, /* HOME */
+ NULL, /* USER */
+ NULL, /* LOGNAME */
NULL
};
- envp[2] = strv_find_prefix(environ, "TERM=");
+ envp[1] = strv_find_prefix(environ, "TERM=");
close_nointr_nofail(master);
@@ -757,13 +775,53 @@ int main(int argc, char *argv[]) {
if (drop_capabilities() < 0)
goto child_fail;
+ if (arg_user) {
+
+ if (get_user_creds((const char**)&arg_user, &uid, &gid, &home) < 0) {
+ log_error("get_user_creds() failed: %m");
+ goto child_fail;
+ }
+
+ if (mkdir_parents(home, 0775) < 0) {
+ log_error("mkdir_parents() failed: %m");
+ goto child_fail;
+ }
+
+ if (safe_mkdir(home, 0775, uid, gid) < 0) {
+ log_error("safe_mkdir() failed: %m");
+ goto child_fail;
+ }
+
+ if (initgroups((const char*)arg_user, gid) < 0) {
+ log_error("initgroups() failed: %m");
+ goto child_fail;
+ }
+
+ if (setregid(gid, gid) < 0) {
+ log_error("setregid() failed: %m");
+ goto child_fail;
+ }
+
+ if (setreuid(uid, uid) < 0) {
+ log_error("setreuid() failed: %m");
+ goto child_fail;
+ }
+ }
+
+ if ((asprintf((char**)(envp + 2), "HOME=%s", home? home: "/root") < 0) ||
+ (asprintf((char**)(envp + 3), "USER=%s", arg_user? arg_user : "root") < 0) ||
+ (asprintf((char**)(envp + 4), "LOGNAME=%s", arg_user? arg_user : "root") < 0)) {
+ log_error("environment setup failed: %m");
+ goto child_fail;
+ }
+
if ((hn = file_name_from_path(arg_directory)))
sethostname(hn, strlen(hn));
if (argc > optind)
execvpe(argv[optind], argv + optind, (char**) envp);
else {
- chdir("/root");
+ chdir(home? home : "/root");
execle("/bin/bash", "-bash", NULL, (char**) envp);
}