--- /dev/null
+// SPDX-License-Identifier: ISC OR MIT
+/*
+ * rpcd - UBUS RPC server
+ *
+ * Copyright (C) 2020 Rafał Miłecki <rafal@milecki.pl>
+ */
+
+#include <dirent.h>
+#include <fcntl.h>
+#include <linux/limits.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+
+#include <libubox/blobmsg.h>
+#include <libubox/ulog.h>
+#include <libubox/uloop.h>
+#include <libubus.h>
+
+#include <rpcd/rc.h>
+
+#define RC_LIST_EXEC_TIMEOUT_MS 3000
+
+enum {
+ RC_INIT_NAME,
+ RC_INIT_ACTION,
+ __RC_INIT_MAX
+};
+
+static const struct blobmsg_policy rc_init_policy[] = {
+ [RC_INIT_NAME] = { "name", BLOBMSG_TYPE_STRING },
+ [RC_INIT_ACTION] = { "action", BLOBMSG_TYPE_STRING },
+};
+
+struct rc_list_context {
+ struct uloop_process process;
+ struct uloop_timeout timeout;
+ struct ubus_context *ctx;
+ struct ubus_request_data req;
+ struct blob_buf *buf;
+ DIR *dir;
+
+ /* Info about currently processed init.d entry */
+ struct {
+ char path[PATH_MAX];
+ const char *d_name;
+ unsigned int start;
+ unsigned int stop;
+ bool enabled;
+ bool running;
+ } entry;
+};
+
+static void rc_list_readdir(struct rc_list_context *c);
+
+/**
+ * rc_check_script - check if script is safe to execute as root
+ *
+ * Check if it's owned by root and if only root can modify it.
+ */
+static int rc_check_script(const char *path)
+{
+ struct stat s;
+
+ if (stat(path, &s))
+ return UBUS_STATUS_NOT_FOUND;
+
+ if (s.st_uid != 0 || s.st_gid != 0 || !(s.st_mode & S_IXUSR) || (s.st_mode & S_IWOTH))
+ return UBUS_STATUS_PERMISSION_DENIED;
+
+ return UBUS_STATUS_OK;
+}
+
+static void rc_list_add_table(struct rc_list_context *c)
+{
+ void *e;
+
+ e = blobmsg_open_table(c->buf, c->entry.d_name);
+
+ if (c->entry.start)
+ blobmsg_add_u16(c->buf, "start", c->entry.start);
+ if (c->entry.stop)
+ blobmsg_add_u16(c->buf, "stop", c->entry.stop);
+ blobmsg_add_u8(c->buf, "enabled", c->entry.enabled);
+ blobmsg_add_u8(c->buf, "running", c->entry.running);
+
+ blobmsg_close_table(c->buf, e);
+}
+
+static void rpc_list_exec_timeout_cb(struct uloop_timeout *t)
+{
+ struct rc_list_context *c = container_of(t, struct rc_list_context, timeout);
+
+ ULOG_WARN("Timeout waiting for %s\n", c->entry.path);
+
+ uloop_process_delete(&c->process);
+ kill(c->process.pid, SIGKILL);
+
+ rc_list_readdir(c);
+}
+
+/**
+ * rc_exec - execute a file and call callback on complete
+ */
+static int rc_list_exec(struct rc_list_context *c, const char *action, uloop_process_handler cb)
+{
+ pid_t pid;
+ int err;
+ int fd;
+
+ pid = fork();
+ switch (pid) {
+ case -1:
+ return -errno;
+ case 0:
+ /* Set stdin, stdout & stderr to /dev/null */
+ fd = open("/dev/null", O_RDWR);
+ if (fd >= 0) {
+ dup2(fd, 0);
+ dup2(fd, 1);
+ dup2(fd, 2);
+ if (fd > 2)
+ close(fd);
+ }
+
+ uloop_end();
+
+ execl(c->entry.path, c->entry.path, action, NULL);
+ exit(errno);
+ default:
+ c->process.pid = pid;
+ c->process.cb = cb;
+
+ err = uloop_process_add(&c->process);
+ if (err)
+ return err;
+
+ c->timeout.cb = rpc_list_exec_timeout_cb;
+ err = uloop_timeout_set(&c->timeout, RC_LIST_EXEC_TIMEOUT_MS);
+ if (err) {
+ uloop_process_delete(&c->process);
+ return err;
+ }
+
+ return 0;
+ }
+}
+
+static void rc_list_exec_running_cb(struct uloop_process *p, int stat)
+{
+ struct rc_list_context *c = container_of(p, struct rc_list_context, process);
+
+ uloop_timeout_cancel(&c->timeout);
+
+ c->entry.running = !stat;
+ rc_list_add_table(c);
+
+ rc_list_readdir(c);
+}
+
+static void rc_list_readdir(struct rc_list_context *c)
+{
+ struct dirent *e;
+ FILE *fp;
+
+ e = readdir(c->dir);
+ if (!e) {
+ closedir(c->dir);
+ ubus_send_reply(c->ctx, &c->req, c->buf->head);
+ ubus_complete_deferred_request(c->ctx, &c->req, UBUS_STATUS_OK);
+ return;
+ }
+
+ if (!strcmp(e->d_name, ".") || !strcmp(e->d_name, ".."))
+ goto next;
+
+ memset(&c->entry, 0, sizeof(c->entry));
+
+ snprintf(c->entry.path, sizeof(c->entry.path), "/etc/init.d/%s", e->d_name);
+ if (rc_check_script(c->entry.path))
+ goto next;
+
+ c->entry.d_name = e->d_name;
+
+ fp = fopen(c->entry.path, "r");
+ if (fp) {
+ struct stat s;
+ char path[PATH_MAX];
+ char line[32];
+ bool beginning;
+
+ beginning = true;
+ while (!c->entry.start && !c->entry.stop && fgets(line, sizeof(line), fp)) {
+ if (beginning) {
+ if (!strncmp(line, "START=", 6)) {
+ c->entry.start = strtoul(line + 6, NULL, 0);
+ } else if (!strncmp(line, "STOP=", 5)) {
+ c->entry.stop = strtoul(line + 5, NULL, 0);
+ }
+ }
+
+ beginning = !!strchr(line, '\n');
+ }
+ fclose(fp);
+
+ snprintf(path, sizeof(path), "/etc/rc.d/S%02d%s", c->entry.start, c->entry.d_name);
+ if (!stat(path, &s) && (s.st_mode & S_IXUSR))
+ c->entry.enabled = true;
+ }
+
+ if (rc_list_exec(c, "running", rc_list_exec_running_cb))
+ goto next;
+
+ return;
+next:
+ rc_list_readdir(c);
+}
+
+/**
+ * rc_list - allocate listing context and start reading directory
+ */
+static int rc_list(struct ubus_context *ctx, struct ubus_object *obj,
+ struct ubus_request_data *req, const char *method,
+ struct blob_attr *msg)
+{
+ static struct blob_buf buf;
+ struct rc_list_context *c;
+
+ blob_buf_init(&buf, 0);
+
+ c = calloc(1, sizeof(*c));
+ if (!c)
+ return UBUS_STATUS_UNKNOWN_ERROR;
+
+ c->ctx = ctx;
+ c->buf = &buf;
+ c->dir = opendir("/etc/init.d");
+ if (!c->dir) {
+ free(c);
+ return UBUS_STATUS_UNKNOWN_ERROR;
+ }
+
+ ubus_defer_request(ctx, req, &c->req);
+
+ rc_list_readdir(c);
+
+ return 0; /* Deferred */
+}
+
+struct rc_init_context {
+ struct uloop_process process;
+ struct ubus_context *ctx;
+ struct ubus_request_data req;
+};
+
+static void rc_init_cb(struct uloop_process *p, int stat)
+{
+ struct rc_init_context *c = container_of(p, struct rc_init_context, process);
+
+ ubus_complete_deferred_request(c->ctx, &c->req, UBUS_STATUS_OK);
+
+ free(c);
+}
+
+static int rc_init(struct ubus_context *ctx, struct ubus_object *obj,
+ struct ubus_request_data *req, const char *method,
+ struct blob_attr *msg)
+{
+ struct blob_attr *tb[__RC_INIT_MAX];
+ struct rc_init_context *c;
+ char path[PATH_MAX];
+ const char *action;
+ const char *name;
+ const char *chr;
+ pid_t pid;
+ int err;
+ int fd;
+
+ blobmsg_parse(rc_init_policy, __RC_INIT_MAX, tb, blobmsg_data(msg), blobmsg_data_len(msg));
+
+ if (!tb[RC_INIT_NAME] || !tb[RC_INIT_ACTION])
+ return UBUS_STATUS_INVALID_ARGUMENT;
+
+ name = blobmsg_get_string(tb[RC_INIT_NAME]);
+
+ /* Validate script name */
+ for (chr = name; (chr = strchr(chr, '.')); chr++) {
+ if (*(chr + 1) == '.')
+ return UBUS_STATUS_INVALID_ARGUMENT;
+ }
+ if (strchr(name, '/'))
+ return UBUS_STATUS_INVALID_ARGUMENT;
+
+ snprintf(path, sizeof(path), "/etc/init.d/%s", name);
+
+ /* Validate script privileges */
+ err = rc_check_script(path);
+ if (err)
+ return err;
+
+ action = blobmsg_get_string(tb[RC_INIT_ACTION]);
+ if (strcmp(action, "disable") &&
+ strcmp(action, "enable") &&
+ strcmp(action, "stop") &&
+ strcmp(action, "start") &&
+ strcmp(action, "restart") &&
+ strcmp(action, "reload"))
+ return UBUS_STATUS_INVALID_ARGUMENT;
+
+ c = calloc(1, sizeof(*c));
+ if (!c)
+ return UBUS_STATUS_UNKNOWN_ERROR;
+
+ pid = fork();
+ switch (pid) {
+ case -1:
+ free(c);
+ return UBUS_STATUS_UNKNOWN_ERROR;
+ case 0:
+ /* Set stdin, stdout & stderr to /dev/null */
+ fd = open("/dev/null", O_RDWR);
+ if (fd >= 0) {
+ dup2(fd, 0);
+ dup2(fd, 1);
+ dup2(fd, 2);
+ if (fd > 2)
+ close(fd);
+ }
+
+ uloop_end();
+
+ execl(path, path, action, NULL);
+ exit(errno);
+ default:
+ c->ctx = ctx;
+ c->process.pid = pid;
+ c->process.cb = rc_init_cb;
+ uloop_process_add(&c->process);
+
+ ubus_defer_request(ctx, req, &c->req);
+
+ return 0; /* Deferred */
+ }
+}
+
+int rpc_rc_api_init(struct ubus_context *ctx)
+{
+ static const struct ubus_method rc_methods[] = {
+ UBUS_METHOD_NOARG("list", rc_list),
+ UBUS_METHOD("init", rc_init, rc_init_policy),
+ };
+
+ static struct ubus_object_type rc_type =
+ UBUS_OBJECT_TYPE("rc", rc_methods);
+
+ static struct ubus_object obj = {
+ .name = "rc",
+ .type = &rc_type,
+ .methods = rc_methods,
+ .n_methods = ARRAY_SIZE(rc_methods),
+ };
+
+ return ubus_add_object(ctx, &obj);
+}
projects / project / rpcd.git / commitdiff