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-rw-r--r--jail/jail.c459
1 files changed, 0 insertions, 459 deletions
diff --git a/jail/jail.c b/jail/jail.c
deleted file mode 100644
index 56dc9ca..0000000
--- a/jail/jail.c
+++ /dev/null
@@ -1,459 +0,0 @@
-/*
- * Copyright (C) 2015 John Crispin <blogic@openwrt.org>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU Lesser General Public License version 2.1
- * as published by the Free Software Foundation
- *
- * This program 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 General Public License for more details.
- */
-
-#define _GNU_SOURCE
-#include <sys/mount.h>
-#include <sys/prctl.h>
-#include <sys/wait.h>
-
-#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 "elf.h"
-#include "capabilities.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"
-
-static struct {
- char *path;
- char *name;
- char **jail_argv;
- char *seccomp;
- char *capabilities;
- 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;
-
-static char child_stack[STACK_SIZE];
-
-static int mkdir_p(char *dir, mode_t mask)
-{
- char *l = strrchr(dir, '/');
- int ret;
-
- if (!l)
- return 0;
-
- *l = '\0';
-
- if (mkdir_p(dir, mask))
- return -1;
-
- *l = '/';
-
- ret = mkdir(dir, mask);
- if (ret && errno == EEXIST)
- return 0;
-
- if (ret)
- ERROR("mkdir failed on %s: %s\n", dir, strerror(errno));
-
- return ret;
-}
-
-static int mount_bind(const char *root, const char *path, const char *name, int readonly, int error)
-{
- const char *p = path;
- struct stat s;
- char old[256];
- char new[256];
- 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);
- return error;
- }
-
- if (S_ISDIR(s.st_mode)) {
- mkdir_p(new, 0755);
- } else {
- fd = creat(new, 0644);
- if (fd == -1) {
- ERROR("failed to create %s: %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));
- return -1;
- }
-
- if (readonly && mount(NULL, new, NULL, MS_BIND | MS_REMOUNT | MS_RDONLY, NULL)) {
- ERROR("failed to remount ro %s: %s\n", new, strerror(errno));
- return -1;
- }
-
- DEBUG("mount -B %s %s\n", old, new);
-
- return 0;
-}
-
-static int build_jail_fs()
-{
- struct library *l;
- struct extra *m;
-
- if (mount("tmpfs", opts.path, "tmpfs", MS_NOATIME, "mode=0755")) {
- ERROR("tmpfs mount failed %s\n", strerror(errno));
- return -1;
- }
-
- if (chdir(opts.path)) {
- ERROR("failed to chdir() in the jail root\n");
- 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");
- return -1;
- }
-
- if (opts.seccomp && elf_load_deps("libpreload-seccomp.so")) {
- ERROR("failed to load libpreload-seccomp.so\n");
- return -1;
- }
-
- avl_for_each_element(&libraries, l, avl)
- if (mount_bind(opts.path, l->path, l->name, 1, -1))
- return -1;
-
- list_for_each_entry(m, &extras, list)
- if (mount_bind(opts.path, m->path, m->name, m->readonly, 0))
- return -1;
-
- char *mpoint;
- if (asprintf(&mpoint, "%s/old", opts.path) < 0) {
- ERROR("failed to alloc pivot path: %s\n", 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);
- return -1;
- }
- free(mpoint);
- 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);
- }
- if (opts.sysfs) {
- mkdir("/sys", 0755);
- mount("sysfs", "/sys", "sysfs", MS_NOATIME | MS_NODEV | MS_NOEXEC | MS_NOSUID, 0);
- }
- if (opts.ronly)
- mount(NULL, "/", NULL, MS_RDONLY | MS_REMOUNT, 0);
-
- return 0;
-}
-
-#define MAX_ENVP 8
-static char** build_envp(const char *seccomp)
-{
- static char *envp[MAX_ENVP];
- static char preload_var[64];
- static char seccomp_var[64];
- static char debug_var[] = "LD_DEBUG=all";
- char *preload_lib = find_lib("libpreload-seccomp.so");
- int count = 0;
-
- if (seccomp && !preload_lib) {
- ERROR("failed to add preload-lib to env\n");
- return NULL;
- }
- if (seccomp) {
- snprintf(seccomp_var, sizeof(seccomp_var), "SECCOMP_FILE=%s", seccomp);
- envp[count++] = seccomp_var;
- snprintf(preload_var, sizeof(preload_var), "LD_PRELOAD=%s", preload_lib);
- envp[count++] = preload_var;
- }
- if (debug > 1)
- envp[count++] = debug_var;
-
- return envp;
-}
-
-static void usage(void)
-{
- fprintf(stderr, "ujail <options> -- <binary> <params ...>\n");
- 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, " -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, " -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");
- fprintf(stderr, " -s\t\tjail has /sys\n");
- fprintf(stderr, " -l\t\tjail has /dev/log\n");
- fprintf(stderr, " -u\t\tjail has a ubus socket\n");
- fprintf(stderr, " -o\t\tremont jail root (/) read only\n");
- fprintf(stderr, "\nWarning: by default root inside the jail is the same\n\
-and he has the same powers as root outside the jail,\n\
-thus he can escape the jail and/or break stuff.\n\
-Please use seccomp/capabilities (-S/-C) to restrict his powers\n\n\
-If you use none of the namespace jail options,\n\
-ujail will not use namespace/build a jail,\n\
-and will only drop capabilities/apply seccomp filter.\n\n");
-}
-
-static int exec_jail()
-{
- 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);
-}
-
-static int spawn_jail(void *arg)
-{
- if (opts.name && sethostname(opts.name, strlen(opts.name))) {
- ERROR("failed to sethostname: %s\n", strerror(errno));
- }
-
- if (build_jail_fs()) {
- ERROR("failed to build jail fs");
- exit(EXIT_FAILURE);
- }
-
- return exec_jail();
-}
-
-static int jail_running = 1;
-static int jail_return_code = 0;
-
-static void jail_process_handler(struct uloop_process *c, int ret)
-{
- if (WIFEXITED(ret)) {
- jail_return_code = WEXITSTATUS(ret);
- INFO("jail (%d) exited with exit: %d\n", c->pid, jail_return_code);
- } else {
- jail_return_code = WTERMSIG(ret);
- INFO("jail (%d) exited with signal: %d\n", c->pid, jail_return_code);
- }
- jail_running = 0;
- uloop_end();
-}
-
-static struct uloop_process jail_process = {
- .cb = jail_process_handler,
-};
-
-static void add_extra(char *name, int readonly)
-{
- 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;
-
- list_add_tail(&f->list, &extras);
-}
-
-int main(int argc, char **argv)
-{
- uid_t uid = getuid();
- char log[] = "/dev/log";
- char ubus[] = "/var/run/ubus.sock";
- int ret = EXIT_SUCCESS;
- int ch;
-
- if (uid) {
- ERROR("not root, aborting: %s\n", strerror(errno));
- return EXIT_FAILURE;
- }
-
- umask(022);
-
- while ((ch = getopt(argc, argv, OPT_ARGS)) != -1) {
- switch (ch) {
- case 'd':
- debug = atoi(optarg);
- break;
- case 'p':
- opts.namespace = 1;
- opts.procfs = 1;
- break;
- case 'o':
- opts.namespace = 1;
- opts.ronly = 1;
- break;
- case 's':
- opts.namespace = 1;
- opts.sysfs = 1;
- break;
- case 'S':
- opts.seccomp = optarg;
- add_extra(optarg, 1);
- break;
- case 'C':
- opts.capabilities = optarg;
- add_extra(optarg, 1);
- break;
- case 'P':
- opts.namespace = 1;
- opts.path = optarg;
- break;
- case 'n':
- opts.name = optarg;
- break;
- case 'r':
- opts.namespace = 1;
- add_extra(optarg, 1);
- break;
- case 'w':
- opts.namespace = 1;
- add_extra(optarg, 0);
- break;
- case 'u':
- opts.namespace = 1;
- add_extra(ubus, 0);
- break;
- case 'l':
- opts.namespace = 1;
- add_extra(log, 0);
- break;
- }
- }
-
- //no <binary> param found
- if (argc - optind < 1) {
- usage();
- return EXIT_FAILURE;
- }
- if (!(opts.namespace||opts.capabilities||opts.seccomp)) {
- ERROR("Not using namespaces, capabilities or seccomp !!!\n\n");
- usage();
- return EXIT_FAILURE;
- }
- DEBUG("Using namespaces(%d), capabilities(%d), seccomp(%d)\n",
- opts.namespace,
- opts.capabilities != 0,
- opts.seccomp != 0);
-
- opts.jail_argv = &argv[optind];
-
- 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;
- }
-
- if (opts.namespace && mkdir(opts.path, 0755)) {
- ERROR("unable to create root path: %s (%s)\n", opts.path, strerror(errno));
- return EXIT_FAILURE;
- }
-
- 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);
- } else {
- jail_process.pid = fork();
- }
-
- if (jail_process.pid > 0) {
- //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);
- }
- } else if (jail_process.pid == 0) {
- //fork child process
- return exec_jail();
- } 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;
- }
-
- if (ret)
- return ret;
-
- return jail_return_code;
-}
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-27 20:21:53 +0200