X-Git-Url: http://git.archive.openwrt.org/?p=project%2Fprocd.git;a=blobdiff_plain;f=jail%2Fjail.c;h=97ddaab6e7de109a35209cd0973157eb5efbac22;hp=ae096230338e8bf4b62c4745ef632e252eb460ad;hb=def4c1b9766cf04cfdf42ada9e27fff228d0dc19;hpb=321edb642dc6b7fef52c05d93de16ec47c96d1f0 diff --git a/jail/jail.c b/jail/jail.c index ae09623..97ddaab 100644 --- a/jail/jail.c +++ b/jail/jail.c @@ -18,46 +18,37 @@ #include #include -#include #include #include #include #include #include #include +#include -#include "elf.h" #include "capabilities.h" +#include "elf.h" +#include "fs.h" +#include "jail.h" #include "log.h" -#include #include #define STACK_SIZE (1024 * 1024) -#define OPT_ARGS "P:S:C:n:r:w:d:psulo" +#define OPT_ARGS "S:C:n:r:w:d:psuloc" static struct { - char *path; char *name; 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; @@ -89,32 +80,23 @@ static int mkdir_p(char *dir, mode_t mask) 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)); @@ -123,8 +105,8 @@ static int mount_bind(const char *root, const char *path, const char *name, int 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; } @@ -133,64 +115,58 @@ static int mount_bind(const char *root, const char *path, const char *name, int return -1; } - DEBUG("mount -B %s %s\n", old, new); + DEBUG("mount -B %s %s\n", path, new); return 0; } -static int build_jail_fs() +static int build_jail_fs(void) { - struct library *l; - struct extra *m; + char jail_root[] = "/tmp/ujail-XXXXXX"; + if (mkdtemp(jail_root) == NULL) { + ERROR("mkdtemp(jail_root) failed: %s\n", strerror(errno)); + return -1; + } - if (mount("tmpfs", opts.path, "tmpfs", MS_NOATIME, "mode=0755")) { + if (mount("tmpfs", jail_root, "tmpfs", MS_NOATIME, "mode=0755")) { ERROR("tmpfs mount failed %s\n", strerror(errno)); return -1; } - if (chdir(opts.path)) { + if (chdir(jail_root)) { 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)) { + if (add_path_and_deps(*opts.jail_argv, 1, -1, 0)) { ERROR("failed to load dependencies\n"); return -1; } - if (opts.seccomp && elf_load_deps("libpreload-seccomp.so")) { + if (opts.seccomp && add_path_and_deps("libpreload-seccomp.so", 1, -1, 1)) { 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)); + if (mount_all(jail_root)) { + ERROR("mount_all() failed\n"); return -1; } - mkdir_p(mpoint, 0755); - if (pivot_root(opts.path, mpoint) == -1) { - ERROR("pivot_root failed:%s\n", strerror(errno)); - free(mpoint); + + char dirbuf[sizeof(jail_root) + 4]; + snprintf(dirbuf, sizeof(dirbuf), "%s/old", jail_root); + mkdir(dirbuf, 0755); + + if (pivot_root(jail_root, dirbuf) == -1) { + ERROR("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); @@ -209,8 +185,8 @@ static int build_jail_fs() 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"; const char *preload_lib = find_lib("libpreload-seccomp.so"); int count = 0; @@ -237,9 +213,9 @@ static void usage(void) fprintf(stderr, " -d \tshow debug log (increase num to increase verbosity)\n"); fprintf(stderr, " -S \tseccomp filter config\n"); fprintf(stderr, " -C \tcapabilities drop config\n"); + fprintf(stderr, " -c\t\tset PR_SET_NO_NEW_PRIVS\n"); fprintf(stderr, " -n \tthe name of the jail\n"); fprintf(stderr, "namespace jail options:\n"); - fprintf(stderr, " -P \tpath where the jail will be staged\n"); fprintf(stderr, " -r \treadonly files that should be staged\n"); fprintf(stderr, " -w \twriteable files that should be staged\n"); fprintf(stderr, " -p\t\tjail has /proc\n"); @@ -256,7 +232,7 @@ ujail will not use namespace/build a jail,\n\ and will only drop capabilities/apply seccomp filter.\n\n"); } -static int exec_jail() +static int exec_jail(void) { char **envp = build_envp(opts.seccomp); if (!envp) @@ -265,9 +241,14 @@ static int exec_jail() if (opts.capabilities && drop_capabilities(opts.capabilities)) 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); + } + INFO("exec-ing %s\n", *opts.jail_argv); execve(*opts.jail_argv, opts.jail_argv, envp); - //we get there only if execve fails + /* we get there only if execve fails */ ERROR("failed to execve %s: %s\n", *opts.jail_argv, strerror(errno)); exit(EXIT_FAILURE); } @@ -306,30 +287,11 @@ 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) { @@ -338,6 +300,8 @@ int main(int argc, char **argv) } umask(022); + mount_list_init(); + init_library_search(); while ((ch = getopt(argc, argv, OPT_ARGS)) != -1) { switch (ch) { @@ -358,39 +322,38 @@ int main(int argc, char **argv) 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); + add_mount(optarg, 1, -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 '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 param found + /* no param found */ if (argc - optind < 1) { usage(); return EXIT_FAILURE; @@ -410,16 +373,6 @@ int main(int argc, char **argv) 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, @@ -430,7 +383,7 @@ int main(int argc, char **argv) } if (jail_process.pid > 0) { - //parent process + /* parent process */ uloop_process_add(&jail_process); uloop_run(); uloop_done(); @@ -439,21 +392,12 @@ int main(int argc, char **argv) kill(jail_process.pid, SIGTERM); waitpid(jail_process.pid, NULL, 0); } + return jail_return_code; } else if (jail_process.pid == 0) { - //fork child process + /* 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; + return EXIT_FAILURE; } - - if (ret) - return ret; - - return jail_return_code; }