* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
-#include "config.h"
-#include <stdio.h>
-#include <stdlib.h>
-#include <unistd.h>
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE 1
+#endif
+#include <errno.h>
+#include <fcntl.h>
+#include <grp.h>
+#include <libgen.h>
+#include <pwd.h>
#include <sched.h>
-#include <sys/syscall.h>
#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
#include <string.h>
-#include <errno.h>
-#include <libgen.h>
-#include <fcntl.h>
+#include <sys/mount.h>
#include <sys/stat.h>
+#include <sys/syscall.h>
#include <sys/types.h>
-#include <sys/mount.h>
#include <sys/wait.h>
-#include <sched.h>
-#include <pwd.h>
-#include <grp.h>
+#include <unistd.h>
#include "conf.h"
-#include "namespace.h"
+#include "config.h"
+#include "list.h"
+#include "log.h"
+#include "macro.h"
+#include "file_utils.h"
+#include "string_utils.h"
+#include "syscall_wrappers.h"
#include "utils.h"
-#ifndef MS_REC
-#define MS_REC 16384
-#endif
-
-#ifndef MS_SLAVE
-#define MS_SLAVE (1 << 19)
-#endif
-
extern int lxc_log_fd;
-int unshare(int flags);
-
static void usage(const char *name)
{
printf("usage: %s [-h] [-m <uid-maps>] -- [command [arg ..]]\n", name);
static void opentty(const char *tty, int which)
{
- int fd, flags;
+ int fd, flags, ret;
if (tty[0] == '\0')
return;
fd = open(tty, O_RDWR | O_NONBLOCK);
if (fd < 0) {
- printf("WARN: could not reopen tty: %s\n", strerror(errno));
+ CMD_SYSERROR("Failed to open tty");
return;
}
flags = fcntl(fd, F_GETFL);
flags &= ~O_NONBLOCK;
- if (fcntl(fd, F_SETFL, flags) < 0) {
- printf("WARN: could not set fd flags: %s\n", strerror(errno));
+ ret = fcntl(fd, F_SETFL, flags);
+ if (ret < 0) {
+ CMD_SYSINFO("Failed to remove O_NONBLOCK from file descriptor %d", fd);
close(fd);
return;
}
static int do_child(void *vargv)
{
+ int ret;
char **argv = (char **)vargv;
/* Assume we want to become root */
- if (setgid(0) < 0) {
- perror("setgid");
- return -1;
- }
- if (setuid(0) < 0) {
- perror("setuid");
+ if (!lxc_switch_uid_gid(0, 0))
return -1;
- }
- if (setgroups(0, NULL) < 0) {
- perror("setgroups");
+
+ if (!lxc_setgroups(0, NULL))
return -1;
- }
- if (unshare(CLONE_NEWNS) < 0) {
- perror("unshare CLONE_NEWNS");
+
+ ret = unshare(CLONE_NEWNS);
+ if (ret < 0) {
+ CMD_SYSERROR("Failed to unshare mount namespace");
return -1;
}
+
if (detect_shared_rootfs()) {
- if (mount(NULL, "/", NULL, MS_SLAVE|MS_REC, NULL)) {
- printf("Failed to make / rslave\n");
+ ret = mount(NULL, "/", NULL, MS_SLAVE | MS_REC, NULL);
+ if (ret < 0) {
+ CMD_SYSINFO("Failed to make \"/\" rslave");
return -1;
}
}
+
execvp(argv[0], argv);
- perror("execvpe");
+ CMD_SYSERROR("Failed to execute \"%s\"", argv[0]);
return -1;
}
static struct lxc_list active_map;
/*
- * given a string like "b:0:100000:10", map both uids and gids
- * 0-10 to 100000 to 100010
+ * Given a string like "b:0:100000:10", map both uids and gids 0-10 to 100000
+ * to 100010
*/
static int parse_map(char *map)
{
+ int i, ret;
+ long host_id, ns_id, range;
+ char which;
struct id_map *newmap;
- struct lxc_list *tmp = NULL;
- int ret;
- int i;
char types[2] = {'u', 'g'};
- char which;
- long host_id, ns_id, range;
+ struct lxc_list *tmp = NULL;
if (!map)
return -1;
}
/*
- * This is called if the user did not pass any uid ranges in
- * through -m flags. It's called once to get the default uid
- * map, and once for the default gid map.
- * Go through /etc/subuids and /etc/subgids to find this user's
- * allowed map. We only use the first one for each of uid and
- * gid, because otherwise we're not sure which entries the user
- * wanted.
+ * This is called if the user did not pass any uid ranges in through -m flags.
+ * It's called once to get the default uid map, and once for the default gid
+ * map.
+ * Go through /etc/subuids and /etc/subgids to find this user's allowed map. We
+ * only use the first one for each of uid and gid, because otherwise we're not
+ * sure which entries the user wanted.
*/
-static int read_default_map(char *fnam, int which, char *username)
+static int read_default_map(char *fnam, int which, char *user)
{
+ size_t len;
+ char *p1, *p2;
+ unsigned long ul1, ul2;
FILE *fin;
- char *line = NULL;
+ int ret = -1;
size_t sz = 0;
- struct id_map *newmap;
+ char *line = NULL;
struct lxc_list *tmp = NULL;
- char *p1, *p2;
+ struct id_map *newmap = NULL;
fin = fopen(fnam, "r");
if (!fin)
return -1;
+
+ len = strlen(user);
while (getline(&line, &sz, fin) != -1) {
- if (sz <= strlen(username) ||
- strncmp(line, username, strlen(username)) != 0 ||
- line[strlen(username)] != ':')
+ if (sz <= len || strncmp(line, user, len) != 0 || line[len] != ':')
continue;
+
p1 = strchr(line, ':');
if (!p1)
continue;
- p2 = strchr(p1+1, ':');
+
+ p2 = strchr(p1 + 1, ':');
if (!p2)
continue;
+
+ line[strlen(line) - 1] = '\0';
+ *p2 = '\0';
+
+ ret = lxc_safe_ulong(p1 + 1, &ul1);
+ if (ret < 0)
+ break;
+
+ ret = lxc_safe_ulong(p2 + 1, &ul2);
+ if (ret < 0)
+ break;
+
+ ret = -1;
newmap = malloc(sizeof(*newmap));
- if (!newmap) {
- fclose(fin);
- free(line);
- return -1;
- }
- newmap->hostid = atol(p1+1);
- newmap->range = atol(p2+1);
+ if (!newmap)
+ break;
+
newmap->nsid = 0;
newmap->idtype = which;
+ newmap->hostid = ul1;
+ newmap->range = ul2;
tmp = malloc(sizeof(*tmp));
if (!tmp) {
- fclose(fin);
- free(line);
free(newmap);
- return -1;
+ break;
}
tmp->elem = newmap;
lxc_list_add_tail(&active_map, tmp);
+
+ ret = 0;
break;
}
- free(line);
fclose(fin);
- return 0;
+ free(line);
+
+ return ret;
}
static int find_default_map(void)
{
+ size_t bufsize;
+ char *buf;
struct passwd pwent;
+ int ret = -1;
struct passwd *pwentp = NULL;
- char *buf;
- size_t bufsize;
- int ret;
bufsize = sysconf(_SC_GETPW_R_SIZE_MAX);
if (bufsize == -1)
ret = getpwuid_r(getuid(), &pwent, buf, bufsize, &pwentp);
if (!pwentp) {
if (ret == 0)
- printf("WARN: could not find matched password record\n");
+ CMD_SYSERROR("Failed to find matched password record");
- printf("Failed to get password record - %u\n", getuid());
- free(buf);
- return -1;
+ CMD_SYSERROR("Failed to get password record for uid %d", getuid());
+ ret = -1;
+ goto out;
}
- if (read_default_map(subuidfile, ID_TYPE_UID, pwent.pw_name) < 0) {
- free(buf);
- return -1;
- }
+ ret = read_default_map(subuidfile, ID_TYPE_UID, pwent.pw_name);
+ if (ret < 0)
+ goto out;
- if (read_default_map(subgidfile, ID_TYPE_GID, pwent.pw_name) < 0) {
- free(buf);
- return -1;
- }
+ ret = read_default_map(subgidfile, ID_TYPE_GID, pwent.pw_name);
+ if (ret < 0)
+ goto out;
+
+ ret = 0;
+out:
free(buf);
- return 0;
+
+ return ret;
}
int main(int argc, char *argv[])
{
- int c;
+ int c, pid, ret, status;
+ char buf[1];
+ int pipe_fds1[2], /* child tells parent it has unshared */
+ pipe_fds2[2]; /* parent tells child it is mapped and may proceed */
unsigned long flags = CLONE_NEWUSER | CLONE_NEWNS;
- char ttyname0[256], ttyname1[256], ttyname2[256];
- int status;
- int ret;
- int pid;
+ char ttyname0[256] = {0}, ttyname1[256] = {0}, ttyname2[256] = {0};
char *default_args[] = {"/bin/sh", NULL};
- char buf[1];
- int pipe_fds1[2], /* child tells parent it has unshared */
- pipe_fds2[2]; /* parent tells child it is mapped and may proceed */
lxc_log_fd = STDERR_FILENO;
- memset(ttyname0, '\0', sizeof(ttyname0));
- memset(ttyname1, '\0', sizeof(ttyname1));
- memset(ttyname2, '\0', sizeof(ttyname2));
- if (isatty(0)) {
+ if (isatty(STDIN_FILENO)) {
ret = readlink("/proc/self/fd/0", ttyname0, sizeof(ttyname0));
if (ret < 0) {
- perror("unable to open stdin.");
- exit(EXIT_FAILURE);
+ CMD_SYSERROR("Failed to open stdin");
+ _exit(EXIT_FAILURE);
}
+
ret = readlink("/proc/self/fd/1", ttyname1, sizeof(ttyname1));
if (ret < 0) {
- printf("Warning: unable to open stdout, continuing.\n");
- memset(ttyname1, '\0', sizeof(ttyname1));
+ CMD_SYSINFO("Failed to open stdout. Continuing");
+ ttyname1[0] = '\0';
}
+
ret = readlink("/proc/self/fd/2", ttyname2, sizeof(ttyname2));
if (ret < 0) {
- printf("Warning: unable to open stderr, continuing.\n");
- memset(ttyname2, '\0', sizeof(ttyname2));
+ CMD_SYSINFO("Failed to open stderr. Continuing");
+ ttyname2[0] = '\0';
}
}
while ((c = getopt(argc, argv, "m:h")) != EOF) {
switch (c) {
case 'm':
- if (parse_map(optarg)) {
+ ret = parse_map(optarg);
+ if (ret < 0) {
usage(argv[0]);
- exit(EXIT_FAILURE);
+ _exit(EXIT_FAILURE);
}
break;
case 'h':
usage(argv[0]);
- exit(EXIT_SUCCESS);
+ _exit(EXIT_SUCCESS);
default:
usage(argv[0]);
- exit(EXIT_FAILURE);
+ _exit(EXIT_FAILURE);
}
};
if (lxc_list_empty(&active_map)) {
- if (find_default_map()) {
- fprintf(stderr, "You have no allocated subuids or subgids\n");
- exit(EXIT_FAILURE);
+ ret = find_default_map();
+ if (ret < 0) {
+ fprintf(stderr, "Failed to find subuid or subgid allocation\n");
+ _exit(EXIT_FAILURE);
}
}
if (argc < 1)
argv = default_args;
- if (pipe2(pipe_fds1, O_CLOEXEC) < 0 || pipe2(pipe_fds2, O_CLOEXEC) < 0) {
- perror("pipe");
- exit(EXIT_FAILURE);
+ ret = pipe2(pipe_fds1, O_CLOEXEC);
+ if (ret < 0) {
+ CMD_SYSERROR("Failed to open new pipe");
+ _exit(EXIT_FAILURE);
}
+
+ ret = pipe2(pipe_fds2, O_CLOEXEC);
+ if (ret < 0) {
+ CMD_SYSERROR("Failed to open new pipe");
+ close(pipe_fds1[0]);
+ close(pipe_fds1[1]);
+ _exit(EXIT_FAILURE);
+ }
+
pid = fork();
- if (pid == 0) { /* Child. */
+ if (pid < 0) {
+ close(pipe_fds1[0]);
+ close(pipe_fds1[1]);
+ close(pipe_fds2[0]);
+ close(pipe_fds2[1]);
+ _exit(EXIT_FAILURE);
+ }
+
+ if (pid == 0) {
close(pipe_fds1[0]);
close(pipe_fds2[1]);
- opentty(ttyname0, 0);
- opentty(ttyname1, 1);
- opentty(ttyname2, 2);
+
+ opentty(ttyname0, STDIN_FILENO);
+ opentty(ttyname1, STDOUT_FILENO);
+ opentty(ttyname2, STDERR_FILENO);
ret = unshare(flags);
if (ret < 0) {
- perror("unshare");
- return 1;
+ CMD_SYSERROR("Failed to unshare mount and user namespace");
+ close(pipe_fds1[1]);
+ close(pipe_fds2[0]);
+ _exit(EXIT_FAILURE);
}
+
buf[0] = '1';
- if (lxc_write_nointr(pipe_fds1[1], buf, 1) < 1) {
- perror("write pipe");
- exit(EXIT_FAILURE);
- }
- if (lxc_read_nointr(pipe_fds2[0], buf, 1) < 1) {
- perror("read pipe");
- exit(EXIT_FAILURE);
+ ret = lxc_write_nointr(pipe_fds1[1], buf, 1);
+ if (ret != 1) {
+ CMD_SYSERROR("Failed to write to pipe file descriptor %d",
+ pipe_fds1[1]);
+ close(pipe_fds1[1]);
+ close(pipe_fds2[0]);
+ _exit(EXIT_FAILURE);
}
- if (buf[0] != '1') {
- fprintf(stderr, "parent had an error, child exiting\n");
- exit(EXIT_FAILURE);
+
+ ret = lxc_read_nointr(pipe_fds2[0], buf, 1);
+ if (ret != 1) {
+ CMD_SYSERROR("Failed to read from pipe file descriptor %d",
+ pipe_fds2[0]);
+ close(pipe_fds1[1]);
+ close(pipe_fds2[0]);
+ _exit(EXIT_FAILURE);
}
close(pipe_fds1[1]);
close(pipe_fds2[0]);
- return do_child((void *)argv);
+
+ if (buf[0] != '1') {
+ fprintf(stderr, "Received unexpected value from parent process\n");
+ _exit(EXIT_FAILURE);
+ }
+
+ ret = do_child((void *)argv);
+ if (ret < 0)
+ _exit(EXIT_FAILURE);
+
+ _exit(EXIT_SUCCESS);
}
close(pipe_fds1[1]);
close(pipe_fds2[0]);
- if (lxc_read_nointr(pipe_fds1[0], buf, 1) < 1) {
- perror("read pipe");
- exit(EXIT_FAILURE);
- }
+
+ ret = lxc_read_nointr(pipe_fds1[0], buf, 1);
+ if (ret <= 0)
+ CMD_SYSERROR("Failed to read from pipe file descriptor %d", pipe_fds1[0]);
buf[0] = '1';
- if (lxc_map_ids(&active_map, pid))
- fprintf(stderr, "error mapping child\n");
+ ret = lxc_map_ids(&active_map, pid);
+ if (ret < 0)
+ fprintf(stderr, "Failed to write id mapping for child process\n");
- if (lxc_write_nointr(pipe_fds2[1], buf, 1) < 0) {
- perror("write to pipe");
- exit(EXIT_FAILURE);
+ ret = lxc_write_nointr(pipe_fds2[1], buf, 1);
+ if (ret < 0) {
+ CMD_SYSERROR("Failed to write to pipe file descriptor %d", pipe_fds2[1]);
+ _exit(EXIT_FAILURE);
}
+
ret = waitpid(pid, &status, __WALL);
if (ret < 0) {
- printf("waitpid() returns %d, errno %d\n", ret, errno);
- exit(EXIT_FAILURE);
+ CMD_SYSERROR("Failed to wait on child process");
+ _exit(EXIT_FAILURE);
}
- exit(WEXITSTATUS(status));
+ _exit(WEXITSTATUS(status));
}
projects / mirror_lxc.git / blobdiff