diff options
Diffstat (limited to 'src/nxt_isolation.c')
| -rw-r--r-- | src/nxt_isolation.c | 1012 |
1 files changed, 1012 insertions, 0 deletions
diff --git a/src/nxt_isolation.c b/src/nxt_isolation.c new file mode 100644 index 00000000..ac7a37e8 --- /dev/null +++ b/src/nxt_isolation.c @@ -0,0 +1,1012 @@ +/* + * Copyright (C) NGINX, Inc. + */ + +#include <nxt_main.h> +#include <nxt_application.h> +#include <nxt_process.h> +#include <nxt_isolation.h> + +#if (NXT_HAVE_PIVOT_ROOT) +#include <mntent.h> +#endif + + +static nxt_int_t nxt_isolation_set(nxt_task_t *task, + nxt_conf_value_t *isolation, nxt_process_t *process); + +#if (NXT_HAVE_CLONE) +static nxt_int_t nxt_isolation_set_namespaces(nxt_task_t *task, + nxt_conf_value_t *isolation, nxt_process_t *process); +static nxt_int_t nxt_isolation_clone_flags(nxt_task_t *task, + nxt_conf_value_t *namespaces, nxt_clone_t *clone); +#endif + +#if (NXT_HAVE_CLONE_NEWUSER) +static nxt_int_t nxt_isolation_set_creds(nxt_task_t *task, + nxt_conf_value_t *isolation, nxt_process_t *process); +static nxt_int_t nxt_isolation_credential_map(nxt_task_t *task, + nxt_mp_t *mem_pool, nxt_conf_value_t *map_array, + nxt_clone_credential_map_t *map); +static nxt_int_t nxt_isolation_vldt_creds(nxt_task_t *task, + nxt_process_t *process); +#endif + +#if (NXT_HAVE_ISOLATION_ROOTFS) +static nxt_int_t nxt_isolation_set_rootfs(nxt_task_t *task, + nxt_conf_value_t *isolation, nxt_process_t *process); +static nxt_int_t nxt_isolation_set_automount(nxt_task_t *task, + nxt_conf_value_t *isolation, nxt_process_t *process); +static nxt_int_t nxt_isolation_set_mounts(nxt_task_t *task, + nxt_process_t *process, nxt_str_t *app_type); +static nxt_int_t nxt_isolation_set_lang_mounts(nxt_task_t *task, + nxt_process_t *process, nxt_array_t *syspaths); +static void nxt_isolation_unmount_all(nxt_task_t *task, nxt_process_t *process); + +#if (NXT_HAVE_PIVOT_ROOT) && (NXT_HAVE_CLONE_NEWNS) +static nxt_int_t nxt_isolation_pivot_root(nxt_task_t *task, const char *rootfs); +static nxt_int_t nxt_isolation_make_private_mount(nxt_task_t *task, + const char *rootfs); +nxt_inline int nxt_pivot_root(const char *new_root, const char *old_root); +#endif + +static nxt_int_t nxt_isolation_chroot(nxt_task_t *task, const char *path); +#endif + +#if (NXT_HAVE_PR_SET_NO_NEW_PRIVS) +static nxt_int_t nxt_isolation_set_new_privs(nxt_task_t *task, + nxt_conf_value_t *isolation, nxt_process_t *process); +#endif + + +nxt_int_t +nxt_isolation_main_prefork(nxt_task_t *task, nxt_process_t *process, + nxt_mp_t *mp) +{ + nxt_int_t cap_setid; + nxt_int_t ret; + nxt_runtime_t *rt; + nxt_common_app_conf_t *app_conf; + + rt = task->thread->runtime; + app_conf = process->data.app; + cap_setid = rt->capabilities.setid; + + if (app_conf->isolation != NULL) { + ret = nxt_isolation_set(task, app_conf->isolation, process); + if (nxt_slow_path(ret != NXT_OK)) { + return ret; + } + } + +#if (NXT_HAVE_CLONE_NEWUSER) + if (nxt_is_clone_flag_set(process->isolation.clone.flags, NEWUSER)) { + cap_setid = 1; + } +#endif + +#if (NXT_HAVE_ISOLATION_ROOTFS) + if (process->isolation.rootfs != NULL) { + ret = nxt_isolation_set_mounts(task, process, &app_conf->type); + if (nxt_slow_path(ret != NXT_OK)) { + return ret; + } + } +#endif + + if (cap_setid) { + ret = nxt_process_creds_set(task, process, &app_conf->user, + &app_conf->group); + + if (nxt_slow_path(ret != NXT_OK)) { + return ret; + } + + } else { + if (!nxt_str_eq(&app_conf->user, (u_char *) rt->user_cred.user, + nxt_strlen(rt->user_cred.user))) + { + nxt_alert(task, "cannot set user \"%V\" for app \"%V\": " + "missing capabilities", &app_conf->user, &app_conf->name); + + return NXT_ERROR; + } + + if (app_conf->group.length > 0 + && !nxt_str_eq(&app_conf->group, (u_char *) rt->group, + nxt_strlen(rt->group))) + { + nxt_alert(task, "cannot set group \"%V\" for app \"%V\": " + "missing capabilities", &app_conf->group, + &app_conf->name); + + return NXT_ERROR; + } + } + +#if (NXT_HAVE_CLONE_NEWUSER) + ret = nxt_isolation_vldt_creds(task, process); + if (nxt_slow_path(ret != NXT_OK)) { + return ret; + } +#endif + + return NXT_OK; +} + + +static nxt_int_t +nxt_isolation_set(nxt_task_t *task, nxt_conf_value_t *isolation, + nxt_process_t *process) +{ +#if (NXT_HAVE_CLONE) + if (nxt_slow_path(nxt_isolation_set_namespaces(task, isolation, process) + != NXT_OK)) + { + return NXT_ERROR; + } +#endif + +#if (NXT_HAVE_CLONE_NEWUSER) + if (nxt_slow_path(nxt_isolation_set_creds(task, isolation, process) + != NXT_OK)) + { + return NXT_ERROR; + } +#endif + +#if (NXT_HAVE_ISOLATION_ROOTFS) + if (nxt_slow_path(nxt_isolation_set_rootfs(task, isolation, process) + != NXT_OK)) + { + return NXT_ERROR; + } + + if (nxt_slow_path(nxt_isolation_set_automount(task, isolation, process) + != NXT_OK)) + { + return NXT_ERROR; + } +#endif + +#if (NXT_HAVE_PR_SET_NO_NEW_PRIVS) + if (nxt_slow_path(nxt_isolation_set_new_privs(task, isolation, process) + != NXT_OK)) + { + return NXT_ERROR; + } +#endif + + return NXT_OK; +} + + +#if (NXT_HAVE_CLONE) + +static nxt_int_t +nxt_isolation_set_namespaces(nxt_task_t *task, nxt_conf_value_t *isolation, + nxt_process_t *process) +{ + nxt_int_t ret; + nxt_conf_value_t *obj; + + static nxt_str_t nsname = nxt_string("namespaces"); + + obj = nxt_conf_get_object_member(isolation, &nsname, NULL); + if (obj != NULL) { + ret = nxt_isolation_clone_flags(task, obj, &process->isolation.clone); + if (nxt_slow_path(ret != NXT_OK)) { + return NXT_ERROR; + } + } + + return NXT_OK; +} + +#endif + + +#if (NXT_HAVE_CLONE_NEWUSER) + +static nxt_int_t +nxt_isolation_set_creds(nxt_task_t *task, nxt_conf_value_t *isolation, + nxt_process_t *process) +{ + nxt_int_t ret; + nxt_clone_t *clone; + nxt_conf_value_t *array; + + static nxt_str_t uidname = nxt_string("uidmap"); + static nxt_str_t gidname = nxt_string("gidmap"); + + clone = &process->isolation.clone; + + array = nxt_conf_get_object_member(isolation, &uidname, NULL); + if (array != NULL) { + ret = nxt_isolation_credential_map(task, process->mem_pool, array, + &clone->uidmap); + + if (nxt_slow_path(ret != NXT_OK)) { + return NXT_ERROR; + } + } + + array = nxt_conf_get_object_member(isolation, &gidname, NULL); + if (array != NULL) { + ret = nxt_isolation_credential_map(task, process->mem_pool, array, + &clone->gidmap); + + if (nxt_slow_path(ret != NXT_OK)) { + return NXT_ERROR; + } + } + + return NXT_OK; +} + + +static nxt_int_t +nxt_isolation_credential_map(nxt_task_t *task, nxt_mp_t *mp, + nxt_conf_value_t *map_array, nxt_clone_credential_map_t *map) +{ + nxt_int_t ret; + nxt_uint_t i; + nxt_conf_value_t *obj; + + static nxt_conf_map_t nxt_clone_map_entry_conf[] = { + { + nxt_string("container"), + NXT_CONF_MAP_INT, + offsetof(nxt_clone_map_entry_t, container), + }, + + { + nxt_string("host"), + NXT_CONF_MAP_INT, + offsetof(nxt_clone_map_entry_t, host), + }, + + { + nxt_string("size"), + NXT_CONF_MAP_INT, + offsetof(nxt_clone_map_entry_t, size), + }, + }; + + map->size = nxt_conf_array_elements_count(map_array); + + if (map->size == 0) { + return NXT_OK; + } + + map->map = nxt_mp_alloc(mp, map->size * sizeof(nxt_clone_map_entry_t)); + if (nxt_slow_path(map->map == NULL)) { + return NXT_ERROR; + } + + for (i = 0; i < map->size; i++) { + obj = nxt_conf_get_array_element(map_array, i); + + ret = nxt_conf_map_object(mp, obj, nxt_clone_map_entry_conf, + nxt_nitems(nxt_clone_map_entry_conf), + map->map + i); + if (nxt_slow_path(ret != NXT_OK)) { + nxt_alert(task, "clone map entry map error"); + return NXT_ERROR; + } + } + + return NXT_OK; +} + + +static nxt_int_t +nxt_isolation_vldt_creds(nxt_task_t *task, nxt_process_t *process) +{ + nxt_int_t ret; + nxt_clone_t *clone; + nxt_credential_t *creds; + + clone = &process->isolation.clone; + creds = process->user_cred; + + if (clone->uidmap.size == 0 && clone->gidmap.size == 0) { + return NXT_OK; + } + + if (!nxt_is_clone_flag_set(clone->flags, NEWUSER)) { + if (nxt_slow_path(clone->uidmap.size > 0)) { + nxt_log(task, NXT_LOG_ERR, "\"uidmap\" is set but " + "\"isolation.namespaces.credential\" is false or unset"); + + return NXT_ERROR; + } + + if (nxt_slow_path(clone->gidmap.size > 0)) { + nxt_log(task, NXT_LOG_ERR, "\"gidmap\" is set but " + "\"isolation.namespaces.credential\" is false or unset"); + + return NXT_ERROR; + } + + return NXT_OK; + } + + ret = nxt_clone_vldt_credential_uidmap(task, &clone->uidmap, creds); + if (nxt_slow_path(ret != NXT_OK)) { + return NXT_ERROR; + } + + return nxt_clone_vldt_credential_gidmap(task, &clone->gidmap, creds); +} + +#endif + + +#if (NXT_HAVE_CLONE) + +static nxt_int_t +nxt_isolation_clone_flags(nxt_task_t *task, nxt_conf_value_t *namespaces, + nxt_clone_t *clone) +{ + uint32_t index; + nxt_str_t name; + nxt_int_t flag; + nxt_conf_value_t *value; + + index = 0; + + for ( ;; ) { + value = nxt_conf_next_object_member(namespaces, &name, &index); + + if (value == NULL) { + break; + } + + flag = 0; + +#if (NXT_HAVE_CLONE_NEWUSER) + if (nxt_str_eq(&name, "credential", 10)) { + flag = CLONE_NEWUSER; + } +#endif + +#if (NXT_HAVE_CLONE_NEWPID) + if (nxt_str_eq(&name, "pid", 3)) { + flag = CLONE_NEWPID; + } +#endif + +#if (NXT_HAVE_CLONE_NEWNET) + if (nxt_str_eq(&name, "network", 7)) { + flag = CLONE_NEWNET; + } +#endif + +#if (NXT_HAVE_CLONE_NEWUTS) + if (nxt_str_eq(&name, "uname", 5)) { + flag = CLONE_NEWUTS; + } +#endif + +#if (NXT_HAVE_CLONE_NEWNS) + if (nxt_str_eq(&name, "mount", 5)) { + flag = CLONE_NEWNS; + } +#endif + +#if (NXT_HAVE_CLONE_NEWCGROUP) + if (nxt_str_eq(&name, "cgroup", 6)) { + flag = CLONE_NEWCGROUP; + } +#endif + + if (!flag) { + nxt_alert(task, "unknown namespace flag: \"%V\"", &name); + return NXT_ERROR; + } + + if (nxt_conf_get_boolean(value)) { + clone->flags |= flag; + } + } + + return NXT_OK; +} + +#endif + + +#if (NXT_HAVE_ISOLATION_ROOTFS) + +static nxt_int_t +nxt_isolation_set_rootfs(nxt_task_t *task, nxt_conf_value_t *isolation, + nxt_process_t *process) +{ + nxt_str_t str; + nxt_conf_value_t *obj; + + static nxt_str_t rootfs_name = nxt_string("rootfs"); + + obj = nxt_conf_get_object_member(isolation, &rootfs_name, NULL); + if (obj != NULL) { + nxt_conf_get_string(obj, &str); + + if (nxt_slow_path(str.length <= 1 || str.start[0] != '/')) { + nxt_log(task, NXT_LOG_ERR, "rootfs requires an absolute path other " + "than \"/\" but given \"%V\"", &str); + + return NXT_ERROR; + } + + if (str.start[str.length - 1] == '/') { + str.length--; + } + + process->isolation.rootfs = nxt_mp_alloc(process->mem_pool, + str.length + 1); + + if (nxt_slow_path(process->isolation.rootfs == NULL)) { + return NXT_ERROR; + } + + nxt_memcpy(process->isolation.rootfs, str.start, str.length); + + process->isolation.rootfs[str.length] = '\0'; + } + + return NXT_OK; +} + + +static nxt_int_t +nxt_isolation_set_automount(nxt_task_t *task, nxt_conf_value_t *isolation, + nxt_process_t *process) +{ + nxt_conf_value_t *conf, *value; + nxt_process_automount_t *automount; + + static nxt_str_t automount_name = nxt_string("automount"); + static nxt_str_t langdeps_name = nxt_string("language_deps"); + + automount = &process->isolation.automount; + + automount->language_deps = 1; + + conf = nxt_conf_get_object_member(isolation, &automount_name, NULL); + if (conf != NULL) { + value = nxt_conf_get_object_member(conf, &langdeps_name, NULL); + if (value != NULL) { + automount->language_deps = nxt_conf_get_boolean(value); + } + } + + return NXT_OK; +} + + +static nxt_int_t +nxt_isolation_set_mounts(nxt_task_t *task, nxt_process_t *process, + nxt_str_t *app_type) +{ + nxt_int_t ret, cap_chroot; + nxt_runtime_t *rt; + nxt_app_lang_module_t *lang; + + rt = task->thread->runtime; + cap_chroot = rt->capabilities.chroot; + lang = nxt_app_lang_module(rt, app_type); + + nxt_assert(lang != NULL); + +#if (NXT_HAVE_CLONE_NEWUSER) + if (nxt_is_clone_flag_set(process->isolation.clone.flags, NEWUSER)) { + cap_chroot = 1; + } +#endif + + if (!cap_chroot) { + nxt_log(task, NXT_LOG_ERR, "The \"rootfs\" field requires privileges"); + return NXT_ERROR; + } + + ret = nxt_isolation_set_lang_mounts(task, process, lang->mounts); + if (nxt_slow_path(ret != NXT_OK)) { + return NXT_ERROR; + } + + process->isolation.cleanup = nxt_isolation_unmount_all; + + return NXT_OK; +} + + +static nxt_int_t +nxt_isolation_set_lang_mounts(nxt_task_t *task, nxt_process_t *process, + nxt_array_t *lang_mounts) +{ + u_char *p; + size_t i, n, rootfs_len, len; + nxt_mp_t *mp; + nxt_array_t *mounts; + const u_char *rootfs; + nxt_fs_mount_t *mnt, *lang_mnt; + + mp = process->mem_pool; + + /* copy to init mem pool */ + mounts = nxt_array_copy(mp, NULL, lang_mounts); + if (mounts == NULL) { + return NXT_ERROR; + } + + n = mounts->nelts; + mnt = mounts->elts; + lang_mnt = lang_mounts->elts; + + rootfs = process->isolation.rootfs; + rootfs_len = nxt_strlen(rootfs); + + for (i = 0; i < n; i++) { + len = nxt_strlen(lang_mnt[i].dst); + + mnt[i].dst = nxt_mp_alloc(mp, rootfs_len + len + 1); + if (nxt_slow_path(mnt[i].dst == NULL)) { + return NXT_ERROR; + } + + p = nxt_cpymem(mnt[i].dst, rootfs, rootfs_len); + p = nxt_cpymem(p, lang_mnt[i].dst, len); + *p = '\0'; + } + + mnt = nxt_array_add(mounts); + if (nxt_slow_path(mnt == NULL)) { + return NXT_ERROR; + } + + mnt->src = (u_char *) "tmpfs"; + mnt->fstype = (u_char *) "tmpfs"; + mnt->flags = NXT_MS_NOSUID | NXT_MS_NODEV | NXT_MS_NOEXEC | NXT_MS_RELATIME; + mnt->data = (u_char *) "size=1m,mode=777"; + mnt->builtin = 1; + + mnt->dst = nxt_mp_nget(mp, rootfs_len + nxt_length("/tmp") + 1); + if (nxt_slow_path(mnt->dst == NULL)) { + return NXT_ERROR; + } + + p = nxt_cpymem(mnt->dst, rootfs, rootfs_len); + p = nxt_cpymem(p, "/tmp", 4); + *p = '\0'; + +#if (NXT_HAVE_CLONE_NEWPID) && (NXT_HAVE_CLONE_NEWNS) + + if (nxt_is_clone_flag_set(process->isolation.clone.flags, NEWPID) + && nxt_is_clone_flag_set(process->isolation.clone.flags, NEWNS)) + { + mnt = nxt_array_add(mounts); + if (nxt_slow_path(mnt == NULL)) { + return NXT_ERROR; + } + + mnt->fstype = (u_char *) "proc"; + mnt->src = (u_char *) "proc"; + + mnt->dst = nxt_mp_nget(mp, rootfs_len + nxt_length("/proc") + 1); + if (nxt_slow_path(mnt->dst == NULL)) { + return NXT_ERROR; + } + + p = nxt_cpymem(mnt->dst, rootfs, rootfs_len); + p = nxt_cpymem(p, "/proc", 5); + *p = '\0'; + + mnt->data = (u_char *) ""; + mnt->flags = 0; + } +#endif + + process->isolation.mounts = mounts; + + return NXT_OK; +} + + +void +nxt_isolation_unmount_all(nxt_task_t *task, nxt_process_t *process) +{ + size_t i, n; + nxt_array_t *mounts; + nxt_fs_mount_t *mnt; + nxt_process_automount_t *automount; + + nxt_debug(task, "unmount all (%s)", process->name); + + automount = &process->isolation.automount; + mounts = process->isolation.mounts; + n = mounts->nelts; + mnt = mounts->elts; + + for (i = 0; i < n; i++) { + if (mnt[i].builtin && !automount->language_deps) { + continue; + } + + nxt_fs_unmount(mnt[i].dst); + } +} + + +nxt_int_t +nxt_isolation_prepare_rootfs(nxt_task_t *task, nxt_process_t *process) +{ + size_t i, n; + nxt_int_t ret; + struct stat st; + nxt_array_t *mounts; + const u_char *dst; + nxt_fs_mount_t *mnt; + nxt_process_automount_t *automount; + + automount = &process->isolation.automount; + mounts = process->isolation.mounts; + + n = mounts->nelts; + mnt = mounts->elts; + + for (i = 0; i < n; i++) { + dst = mnt[i].dst; + + if (mnt[i].builtin && !automount->language_deps) { + continue; + } + + if (nxt_slow_path(nxt_memcmp(mnt[i].fstype, "bind", 4) == 0 + && stat((const char *) mnt[i].src, &st) != 0)) + { + nxt_log(task, NXT_LOG_WARN, "host path not found: %s", mnt[i].src); + continue; + } + + ret = nxt_fs_mkdir_all(dst, S_IRWXU | S_IRWXG | S_IRWXO); + if (nxt_slow_path(ret != NXT_OK)) { + nxt_alert(task, "mkdir(%s) %E", dst, nxt_errno); + goto undo; + } + + ret = nxt_fs_mount(task, &mnt[i]); + if (nxt_slow_path(ret != NXT_OK)) { + goto undo; + } + } + + return NXT_OK; + +undo: + + n = i + 1; + + for (i = 0; i < n; i++) { + nxt_fs_unmount(mnt[i].dst); + } + + return NXT_ERROR; +} + + +#if (NXT_HAVE_PIVOT_ROOT) && (NXT_HAVE_CLONE_NEWNS) + +nxt_int_t +nxt_isolation_change_root(nxt_task_t *task, nxt_process_t *process) +{ + char *rootfs; + nxt_int_t ret; + + rootfs = (char *) process->isolation.rootfs; + + nxt_debug(task, "change root: %s", rootfs); + + if (nxt_is_clone_flag_set(process->isolation.clone.flags, NEWNS)) { + ret = nxt_isolation_pivot_root(task, rootfs); + + } else { + ret = nxt_isolation_chroot(task, rootfs); + } + + if (nxt_fast_path(ret == NXT_OK)) { + if (nxt_slow_path(chdir("/") < 0)) { + nxt_alert(task, "chdir(\"/\") %E", nxt_errno); + return NXT_ERROR; + } + } + + return ret; +} + + +/* + * pivot_root(2) can only be safely used with containers, otherwise it can + * umount(2) the global root filesystem and screw up the machine. + */ + +static nxt_int_t +nxt_isolation_pivot_root(nxt_task_t *task, const char *path) +{ + /* + * This implementation makes use of a kernel trick that works for ages + * and now documented in Linux kernel 5. + * https://lore.kernel.org/linux-man/87r24piwhm.fsf@x220.int.ebiederm.org/T/ + */ + + if (nxt_slow_path(mount("", "/", "", MS_SLAVE|MS_REC, "") != 0)) { + nxt_alert(task, "mount(\"/\", MS_SLAVE|MS_REC) failed: %E", nxt_errno); + return NXT_ERROR; + } + + if (nxt_slow_path(nxt_isolation_make_private_mount(task, path) != NXT_OK)) { + return NXT_ERROR; + } + + if (nxt_slow_path(mount(path, path, "bind", MS_BIND|MS_REC, "") != 0)) { + nxt_alert(task, "error bind mounting rootfs %E", nxt_errno); + return NXT_ERROR; + } + + if (nxt_slow_path(chdir(path) != 0)) { + nxt_alert(task, "failed to chdir(%s) %E", path, nxt_errno); + return NXT_ERROR; + } + + if (nxt_slow_path(nxt_pivot_root(".", ".") != 0)) { + nxt_alert(task, "failed to pivot_root %E", nxt_errno); + return NXT_ERROR; + } + + /* + * Demote the oldroot mount to avoid unmounts getting propagated to + * the host. + */ + if (nxt_slow_path(mount("", ".", "", MS_SLAVE | MS_REC, NULL) != 0)) { + nxt_alert(task, "failed to bind mount rootfs %E", nxt_errno); + return NXT_ERROR; + } + + if (nxt_slow_path(umount2(".", MNT_DETACH) != 0)) { + nxt_alert(task, "failed to umount old root directory %E", nxt_errno); + return NXT_ERROR; + } + + return NXT_OK; +} + + +static nxt_int_t +nxt_isolation_make_private_mount(nxt_task_t *task, const char *rootfs) +{ + char *parent_mnt; + FILE *procfile; + u_char **mounts; + size_t len; + uint8_t *shared; + nxt_int_t ret, index, nmounts; + struct mntent *ent; + + static const char *mount_path = "/proc/self/mounts"; + + ret = NXT_ERROR; + ent = NULL; + shared = NULL; + procfile = NULL; + parent_mnt = NULL; + + nmounts = 256; + + mounts = nxt_malloc(nmounts * sizeof(uintptr_t)); + if (nxt_slow_path(mounts == NULL)) { + goto fail; + } + + shared = nxt_malloc(nmounts); + if (nxt_slow_path(shared == NULL)) { + goto fail; + } + + procfile = setmntent(mount_path, "r"); + if (nxt_slow_path(procfile == NULL)) { + nxt_alert(task, "failed to open %s %E", mount_path, nxt_errno); + + goto fail; + } + + index = 0; + +again: + + for ( ; index < nmounts; index++) { + ent = getmntent(procfile); + if (ent == NULL) { + nmounts = index; + break; + } + + mounts[index] = (u_char *) strdup(ent->mnt_dir); + shared[index] = hasmntopt(ent, "shared") != NULL; + } + + if (ent != NULL) { + /* there are still entries to be read */ + + nmounts *= 2; + mounts = nxt_realloc(mounts, nmounts); + if (nxt_slow_path(mounts == NULL)) { + goto fail; + } + + shared = nxt_realloc(shared, nmounts); + if (nxt_slow_path(shared == NULL)) { + goto fail; + } + + goto again; + } + + for (index = 0; index < nmounts; index++) { + if (nxt_strcmp(mounts[index], rootfs) == 0) { + parent_mnt = (char *) rootfs; + break; + } + } + + if (parent_mnt == NULL) { + len = nxt_strlen(rootfs); + + parent_mnt = nxt_malloc(len + 1); + if (parent_mnt == NULL) { + goto fail; + } + + nxt_memcpy(parent_mnt, rootfs, len); + parent_mnt[len] = '\0'; + + if (parent_mnt[len - 1] == '/') { + parent_mnt[len - 1] = '\0'; + len--; + } + + for ( ;; ) { + for (index = 0; index < nmounts; index++) { + if (nxt_strcmp(mounts[index], parent_mnt) == 0) { + goto found; + } + } + + if (len == 1 && parent_mnt[0] == '/') { + nxt_alert(task, "parent mount not found"); + goto fail; + } + + /* parent dir */ + while (parent_mnt[len - 1] != '/' && len > 0) { + len--; + } + + if (nxt_slow_path(len == 0)) { + nxt_alert(task, "parent mount not found"); + goto fail; + } + + if (len == 1) { + parent_mnt[len] = '\0'; /* / */ + } else { + parent_mnt[len - 1] = '\0'; /* /<path> */ + } + } + } + +found: + + if (shared[index]) { + if (nxt_slow_path(mount("", parent_mnt, "", MS_PRIVATE, "") != 0)) { + nxt_alert(task, "mount(\"\", \"%s\", MS_PRIVATE) %E", parent_mnt, + nxt_errno); + + goto fail; + } + } + + ret = NXT_OK; + +fail: + + if (procfile != NULL) { + endmntent(procfile); + } + + if (mounts != NULL) { + for (index = 0; index < nmounts; index++) { + nxt_free(mounts[index]); + } + + nxt_free(mounts); + } + + if (shared != NULL) { + nxt_free(shared); + } + + if (parent_mnt != NULL && parent_mnt != rootfs) { + nxt_free(parent_mnt); + } + + return ret; +} + + +nxt_inline int +nxt_pivot_root(const char *new_root, const char *old_root) +{ + return syscall(__NR_pivot_root, new_root, old_root); +} + + +#else /* !(NXT_HAVE_PIVOT_ROOT) || !(NXT_HAVE_CLONE_NEWNS) */ + + +nxt_int_t +nxt_isolation_change_root(nxt_task_t *task, nxt_process_t *process) +{ + char *rootfs; + + rootfs = (char *) process->isolation.rootfs; + + nxt_debug(task, "change root: %s", rootfs); + + if (nxt_fast_path(nxt_isolation_chroot(task, rootfs) == NXT_OK)) { + if (nxt_slow_path(chdir("/") < 0)) { + nxt_alert(task, "chdir(\"/\") %E", nxt_errno); + return NXT_ERROR; + } + + return NXT_OK; + } + + return NXT_ERROR; +} + +#endif + + +static nxt_int_t +nxt_isolation_chroot(nxt_task_t *task, const char *path) +{ + if (nxt_slow_path(chroot(path) < 0)) { + nxt_alert(task, "chroot(%s) %E", path, nxt_errno); + return NXT_ERROR; + } + + return NXT_OK; +} + +#endif /* NXT_HAVE_ISOLATION_ROOTFS */ + + +#if (NXT_HAVE_PR_SET_NO_NEW_PRIVS) + +static nxt_int_t +nxt_isolation_set_new_privs(nxt_task_t *task, nxt_conf_value_t *isolation, + nxt_process_t *process) +{ + nxt_conf_value_t *obj; + + static nxt_str_t new_privs_name = nxt_string("new_privs"); + + obj = nxt_conf_get_object_member(isolation, &new_privs_name, NULL); + if (obj != NULL) { + process->isolation.new_privs = nxt_conf_get_boolean(obj); + } + + return NXT_OK; +} + +#endif |