#include <stdlib.h>
#include <unistd.h>
-#include <values.h>
#include <errno.h>
-#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <libgen.h>
#include <sched.h>
+#include <linux/limits.h>
+#include <signal.h>
-#include "elf.h"
#include "capabilities.h"
+#include "elf.h"
+#include "fs.h"
+#include "jail.h"
+#include "log.h"
-#include <libubox/list.h>
#include <libubox/uloop.h>
#define STACK_SIZE (1024 * 1024)
-#define OPT_ARGS "P:S:C:n:r:w:d:psulo"
+#define OPT_ARGS "S:C:n:h:r:w:d:psuloc"
static struct {
- char *path;
char *name;
+ char *hostname;
char **jail_argv;
char *seccomp;
char *capabilities;
+ int no_new_privs;
int namespace;
int procfs;
int ronly;
int sysfs;
} opts;
-struct extra {
- struct list_head list;
-
- const char *path;
- const char *name;
- int readonly;
-};
-
-static LIST_HEAD(extras);
-
extern int pivot_root(const char *new_root, const char *put_old);
int debug = 0;
return 0;
if (ret)
- ERROR("mkdir failed on %s: %s\n", dir, strerror(errno));
+ ERROR("mkdir(%s, %d) failed: %s\n", dir, mask, strerror(errno));
return ret;
}
-static int mount_bind(const char *root, const char *path, const char *name, int readonly, int error)
+int mount_bind(const char *root, const char *path, int readonly, int error)
{
- const char *p = path;
struct stat s;
- char old[256];
- char new[256];
+ char new[PATH_MAX];
int fd;
- if (strstr(p, "local"))
- p = "/lib";
-
- snprintf(old, sizeof(old), "%s/%s", path, name);
- snprintf(new, sizeof(new), "%s%s", root, p);
-
- mkdir_p(new, 0755);
-
- snprintf(new, sizeof(new), "%s%s/%s", root, p, name);
-
- if (stat(old, &s)) {
- ERROR("%s does not exist\n", old);
+ if (stat(path, &s)) {
+ ERROR("stat(%s) failed: %s\n", path, strerror(errno));
return error;
}
+ snprintf(new, sizeof(new), "%s%s", root, path);
if (S_ISDIR(s.st_mode)) {
mkdir_p(new, 0755);
} else {
+ mkdir_p(dirname(new), 0755);
+ snprintf(new, sizeof(new), "%s%s", root, path);
fd = creat(new, 0644);
if (fd == -1) {
- ERROR("failed to create %s: %s\n", new, strerror(errno));
+ ERROR("creat(%s) failed: %s\n", new, strerror(errno));
return -1;
}
close(fd);
}
- if (mount(old, new, NULL, MS_BIND, NULL)) {
- ERROR("failed to mount -B %s %s: %s\n", old, new, strerror(errno));
+ if (mount(path, new, NULL, MS_BIND, NULL)) {
+ ERROR("failed to mount -B %s %s: %s\n", path, new, strerror(errno));
return -1;
}
return -1;
}
- DEBUG("mount -B %s %s\n", old, new);
+ DEBUG("mount -B %s %s (%s)\n", path, new, readonly?"ro":"rw");
return 0;
}
-static int build_jail_fs()
+static int build_jail_fs(void)
{
- struct library *l;
- struct extra *m;
-
- if (mount("tmpfs", opts.path, "tmpfs", MS_NOATIME, "mode=0755")) {
- ERROR("tmpfs mount failed %s\n", strerror(errno));
+ char jail_root[] = "/tmp/ujail-XXXXXX";
+ if (mkdtemp(jail_root) == NULL) {
+ ERROR("mkdtemp(%s) failed: %s\n", jail_root, strerror(errno));
return -1;
}
- if (chdir(opts.path)) {
- ERROR("failed to chdir() in the jail root\n");
+ /* oldroot can't be MS_SHARED else pivot_root() fails */
+ if (mount("none", "/", NULL, MS_REC|MS_PRIVATE, NULL)) {
+ ERROR("private mount failed %s\n", strerror(errno));
return -1;
}
- avl_init(&libraries, avl_strcmp, false, NULL);
- alloc_library_path("/lib64");
- alloc_library_path("/lib");
- alloc_library_path("/usr/lib");
- load_ldso_conf("/etc/ld.so.conf");
-
- if (elf_load_deps(*opts.jail_argv)) {
- ERROR("failed to load dependencies\n");
+ if (mount("tmpfs", jail_root, "tmpfs", MS_NOATIME, "mode=0755")) {
+ ERROR("tmpfs mount failed %s\n", strerror(errno));
return -1;
}
- if (opts.seccomp && elf_load_deps("libpreload-seccomp.so")) {
- ERROR("failed to load libpreload-seccomp.so\n");
+ if (chdir(jail_root)) {
+ ERROR("chdir(%s) (jail_root) failed: %s\n", jail_root, strerror(errno));
return -1;
}
- avl_for_each_element(&libraries, l, avl)
- if (mount_bind(opts.path, l->path, l->name, 1, -1))
- return -1;
+ if (mount_all(jail_root)) {
+ ERROR("mount_all() failed\n");
+ return -1;
+ }
- list_for_each_entry(m, &extras, list)
- if (mount_bind(opts.path, m->path, m->name, m->readonly, 0))
- return -1;
+ char dirbuf[sizeof(jail_root) + 4];
+ snprintf(dirbuf, sizeof(dirbuf), "%s/old", jail_root);
+ mkdir(dirbuf, 0755);
- char *mpoint;
- if (asprintf(&mpoint, "%s/old", opts.path) < 0) {
- ERROR("failed to alloc pivot path: %s\n", strerror(errno));
+ if (pivot_root(jail_root, dirbuf) == -1) {
+ ERROR("pivot_root(%s, %s) failed: %s\n", jail_root, dirbuf, strerror(errno));
return -1;
}
- mkdir_p(mpoint, 0755);
- if (pivot_root(opts.path, mpoint) == -1) {
- ERROR("pivot_root failed:%s\n", strerror(errno));
- free(mpoint);
+ if (chdir("/")) {
+ ERROR("chdir(/) (after pivot_root) failed: %s\n", strerror(errno));
return -1;
}
- free(mpoint);
+
+ snprintf(dirbuf, sizeof(dirbuf), "/old%s", jail_root);
+ rmdir(dirbuf);
umount2("/old", MNT_DETACH);
rmdir("/old");
+
if (opts.procfs) {
mkdir("/proc", 0755);
mount("proc", "/proc", "proc", MS_NOATIME | MS_NODEV | MS_NOEXEC | MS_NOSUID, 0);
static char** build_envp(const char *seccomp)
{
static char *envp[MAX_ENVP];
- static char preload_var[64];
- static char seccomp_var[64];
+ static char preload_var[PATH_MAX];
+ static char seccomp_var[PATH_MAX];
static char debug_var[] = "LD_DEBUG=all";
- char *preload_lib = find_lib("libpreload-seccomp.so");
+ const char *preload_lib = find_lib("libpreload-seccomp.so");
int count = 0;
if (seccomp && !preload_lib) {
fprintf(stderr, " -d <num>\tshow debug log (increase num to increase verbosity)\n");
fprintf(stderr, " -S <file>\tseccomp filter config\n");
fprintf(stderr, " -C <file>\tcapabilities drop config\n");
+ fprintf(stderr, " -c\t\tset PR_SET_NO_NEW_PRIVS\n");
fprintf(stderr, " -n <name>\tthe name of the jail\n");
fprintf(stderr, "namespace jail options:\n");
- fprintf(stderr, " -P <path>\tpath where the jail will be staged\n");
+ fprintf(stderr, " -h <hostname>\tchange the hostname of the jail\n");
fprintf(stderr, " -r <file>\treadonly files that should be staged\n");
fprintf(stderr, " -w <file>\twriteable files that should be staged\n");
fprintf(stderr, " -p\t\tjail has /proc\n");
and will only drop capabilities/apply seccomp filter.\n\n");
}
-static int exec_jail()
+static int exec_jail(void *_notused)
{
- char **envp = build_envp(opts.seccomp);
- if (!envp)
- exit(EXIT_FAILURE);
-
if (opts.capabilities && drop_capabilities(opts.capabilities))
exit(EXIT_FAILURE);
- INFO("exec-ing %s\n", *opts.jail_argv);
- execve(*opts.jail_argv, opts.jail_argv, envp);
- //we get there only if execve fails
- ERROR("failed to execve %s: %s\n", *opts.jail_argv, strerror(errno));
- exit(EXIT_FAILURE);
-}
+ if (opts.no_new_privs && prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) {
+ ERROR("prctl(PR_SET_NO_NEW_PRIVS) failed: %s\n", strerror(errno));
+ exit(EXIT_FAILURE);
+ }
-static int spawn_jail(void *arg)
-{
- if (opts.name && sethostname(opts.name, strlen(opts.name))) {
- ERROR("failed to sethostname: %s\n", strerror(errno));
+ if (opts.namespace && opts.hostname && strlen(opts.hostname) > 0
+ && sethostname(opts.hostname, strlen(opts.hostname))) {
+ ERROR("sethostname(%s) failed: %s\n", opts.hostname, strerror(errno));
+ exit(EXIT_FAILURE);
}
- if (build_jail_fs()) {
- ERROR("failed to build jail fs");
+ if (opts.namespace && build_jail_fs()) {
+ ERROR("failed to build jail fs\n");
exit(EXIT_FAILURE);
}
- return exec_jail();
+ char **envp = build_envp(opts.seccomp);
+ if (!envp)
+ exit(EXIT_FAILURE);
+
+ INFO("exec-ing %s\n", *opts.jail_argv);
+ execve(*opts.jail_argv, opts.jail_argv, envp);
+ /* we get there only if execve fails */
+ ERROR("failed to execve %s: %s\n", *opts.jail_argv, strerror(errno));
+ exit(EXIT_FAILURE);
}
static int jail_running = 1;
static int jail_return_code = 0;
+static void jail_process_timeout_cb(struct uloop_timeout *t);
+static struct uloop_timeout jail_process_timeout = {
+ .cb = jail_process_timeout_cb,
+};
+
static void jail_process_handler(struct uloop_process *c, int ret)
{
+ uloop_timeout_cancel(&jail_process_timeout);
if (WIFEXITED(ret)) {
jail_return_code = WEXITSTATUS(ret);
INFO("jail (%d) exited with exit: %d\n", c->pid, jail_return_code);
.cb = jail_process_handler,
};
-static void add_extra(char *name, int readonly)
+static void jail_process_timeout_cb(struct uloop_timeout *t)
{
- struct extra *f;
-
- if (*name != '/') {
- ERROR("%s is not an absolute path\n", name);
- return;
- }
-
- f = calloc(1, sizeof(struct extra));
-
- f->name = basename(name);
- f->path = dirname(strdup(name));
- f->readonly = readonly;
+ DEBUG("jail process failed to stop, sending SIGKILL\n");
+ kill(jail_process.pid, SIGKILL);
+}
- list_add_tail(&f->list, &extras);
+static void jail_handle_signal(int signo)
+{
+ DEBUG("forwarding signal %d to the jailed process\n", signo);
+ kill(jail_process.pid, signo);
}
int main(int argc, char **argv)
{
+ sigset_t sigmask;
uid_t uid = getuid();
char log[] = "/dev/log";
char ubus[] = "/var/run/ubus.sock";
- int ret = EXIT_SUCCESS;
- int ch;
+ int ch, i;
if (uid) {
ERROR("not root, aborting: %s\n", strerror(errno));
}
umask(022);
+ mount_list_init();
+ init_library_search();
while ((ch = getopt(argc, argv, OPT_ARGS)) != -1) {
switch (ch) {
break;
case 'S':
opts.seccomp = optarg;
- add_extra(optarg, 1);
+ add_mount(optarg, 1, -1);
break;
case 'C':
opts.capabilities = optarg;
- add_extra(optarg, 1);
break;
- case 'P':
- opts.namespace = 1;
- opts.path = optarg;
+ case 'c':
+ opts.no_new_privs = 1;
break;
case 'n':
opts.name = optarg;
break;
+ case 'h':
+ opts.hostname = optarg;
+ break;
case 'r':
opts.namespace = 1;
- add_extra(optarg, 1);
+ add_path_and_deps(optarg, 1, 0, 0);
break;
case 'w':
opts.namespace = 1;
- add_extra(optarg, 0);
+ add_path_and_deps(optarg, 0, 0, 0);
break;
case 'u':
opts.namespace = 1;
- add_extra(ubus, 0);
+ add_mount(ubus, 0, -1);
break;
case 'l':
opts.namespace = 1;
- add_extra(log, 0);
+ add_mount(log, 0, -1);
break;
}
}
- //no <binary> param found
+ /* no <binary> param found */
if (argc - optind < 1) {
usage();
return EXIT_FAILURE;
opts.jail_argv = &argv[optind];
+ if (opts.namespace && add_path_and_deps(*opts.jail_argv, 1, -1, 0)) {
+ ERROR("failed to load dependencies\n");
+ return -1;
+ }
+
+ if (opts.namespace && opts.seccomp && add_path_and_deps("libpreload-seccomp.so", 1, -1, 1)) {
+ ERROR("failed to load libpreload-seccomp.so\n");
+ return -1;
+ }
+
if (opts.name)
prctl(PR_SET_NAME, opts.name, NULL, NULL, NULL);
- if (opts.namespace && !opts.path && asprintf(&opts.path, "/tmp/%s", basename(*opts.jail_argv)) == -1) {
- ERROR("failed to asprintf root path: %s\n", strerror(errno));
- return EXIT_FAILURE;
- }
+ uloop_init();
- if (opts.namespace && mkdir(opts.path, 0755)) {
- ERROR("unable to create root path: %s (%s)\n", opts.path, strerror(errno));
- return EXIT_FAILURE;
+ sigfillset(&sigmask);
+ for (i = 0; i < _NSIG; i++) {
+ struct sigaction s = { 0 };
+
+ if (!sigismember(&sigmask, i))
+ continue;
+ if ((i == SIGCHLD) || (i == SIGPIPE))
+ continue;
+
+ s.sa_handler = jail_handle_signal;
+ sigaction(i, &s, NULL);
}
- uloop_init();
if (opts.namespace) {
- jail_process.pid = clone(spawn_jail,
- child_stack + STACK_SIZE,
- CLONE_NEWUTS | CLONE_NEWPID | CLONE_NEWNS | CLONE_NEWIPC | SIGCHLD, argv);
+ add_mount("/dev/full", 0, -1);
+ add_mount("/dev/null", 0, -1);
+ add_mount("/dev/urandom", 0, -1);
+ add_mount("/dev/zero", 0, -1);
+
+ int flags = CLONE_NEWPID | CLONE_NEWNS | CLONE_NEWIPC | SIGCHLD;
+ if (opts.hostname)
+ flags |= CLONE_NEWUTS;
+ jail_process.pid = clone(exec_jail, child_stack + STACK_SIZE, flags, NULL);
} else {
jail_process.pid = fork();
}
if (jail_process.pid > 0) {
- //parent process
+ /* parent process */
uloop_process_add(&jail_process);
uloop_run();
- uloop_done();
if (jail_running) {
DEBUG("uloop interrupted, killing jail process\n");
kill(jail_process.pid, SIGTERM);
- waitpid(jail_process.pid, NULL, 0);
+ uloop_timeout_set(&jail_process_timeout, 1000);
+ uloop_run();
}
+ uloop_done();
+ return jail_return_code;
} else if (jail_process.pid == 0) {
- //fork child process
- return exec_jail();
+ /* fork child process */
+ return exec_jail(NULL);
} else {
ERROR("failed to clone/fork: %s\n", strerror(errno));
- ret = EXIT_FAILURE;
- }
-
- if (opts.namespace && rmdir(opts.path)) {
- ERROR("Unable to remove root path: %s (%s)\n", opts.path, strerror(errno));
- ret = EXIT_FAILURE;
+ return EXIT_FAILURE;
}
-
- if (ret)
- return ret;
-
- return jail_return_code;
}
projects / project / procd.git / blobdiff