#include <libubox/uloop.h>
#define STACK_SIZE (1024 * 1024)
-#define OPT_ARGS "S:C:n:r:w:d:psuloc"
+#define OPT_ARGS "S:C:n:h:r:w:d:psuloc"
static struct {
char *name;
+ char *hostname;
char **jail_argv;
char *seccomp;
char *capabilities;
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;
}
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);
return -1;
}
- DEBUG("mount -B %s %s\n", path, new);
+ DEBUG("mount -B %s %s (%s)\n", path, new, readonly?"ro":"rw");
return 0;
}
{
char jail_root[] = "/tmp/ujail-XXXXXX";
if (mkdtemp(jail_root) == NULL) {
- ERROR("mkdtemp(jail_root) failed: %s\n", strerror(errno));
+ ERROR("mkdtemp(%s) failed: %s\n", jail_root, strerror(errno));
return -1;
}
- if (mount("tmpfs", jail_root, "tmpfs", MS_NOATIME, "mode=0755")) {
- ERROR("tmpfs mount failed %s\n", strerror(errno));
- return -1;
- }
-
- if (chdir(jail_root)) {
- 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;
}
- if (add_path_and_deps(*opts.jail_argv, 1, -1, 0)) {
- 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 && add_path_and_deps("libpreload-seccomp.so", 1, -1, 1)) {
- 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;
}
mkdir(dirbuf, 0755);
if (pivot_root(jail_root, dirbuf) == -1) {
- ERROR("pivot_root failed: %s\n", strerror(errno));
+ ERROR("pivot_root(%s, %s) failed: %s\n", jail_root, dirbuf, strerror(errno));
+ return -1;
+ }
+ if (chdir("/")) {
+ ERROR("chdir(/) (after pivot_root) failed: %s\n", strerror(errno));
return -1;
}
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, " -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(void)
+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);
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 spawn_jail(void *_notused)
-{
- 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;
break;
case 'C':
opts.capabilities = optarg;
- add_mount(optarg, 1, -1);
break;
case 'c':
opts.no_new_privs = 1;
case 'n':
opts.name = optarg;
break;
+ case 'h':
+ opts.hostname = optarg;
+ break;
case 'r':
opts.namespace = 1;
add_path_and_deps(optarg, 1, 0, 0);
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);
uloop_init();
if (opts.namespace) {
- jail_process.pid = clone(spawn_jail,
- child_stack + STACK_SIZE,
- CLONE_NEWUTS | CLONE_NEWPID | CLONE_NEWNS | CLONE_NEWIPC | SIGCHLD, NULL);
+ 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();
}
return jail_return_code;
} else if (jail_process.pid == 0) {
/* fork child process */
- return exec_jail();
+ return exec_jail(NULL);
} else {
ERROR("failed to clone/fork: %s\n", strerror(errno));
return EXIT_FAILURE;