--- /dev/null
+/*
+ * Copyright (C) 2021 Daniel Golle <daniel@makrotopia.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/inotify.h>
+#include <sys/types.h>
+
+#include <assert.h>
+#include <dirent.h>
+#include <errno.h>
+#include <glob.h>
+#include <limits.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <libubox/avl.h>
+#include <libubox/avl-cmp.h>
+#include <libubox/list.h>
+#include <libubox/uloop.h>
+#include <libubus.h>
+
+#include "procd.h"
+
+#define HOTPLUG_BASEDIR "/etc/hotplug.d"
+#define HOTPLUG_OBJECT_PREFIX "hotplug."
+
+#define INOTIFY_SZ (sizeof(struct inotify_event) + PATH_MAX + 1)
+
+struct ubus_context *ctx;
+static char *inotify_buffer;
+static struct uloop_fd fd_inotify_read;
+
+static LIST_HEAD(subsystems);
+
+extern char **environ;
+
+struct hotplug_subsys {
+ struct list_head list;
+ struct ubus_object ubus;
+};
+
+struct envlist {
+ struct avl_node avl;
+ char *env;
+};
+
+struct hotplug_process {
+ struct ubus_object *ubus;
+ char **envp;
+ struct uloop_timeout timeout;
+ struct uloop_process process;
+ glob_t globbuf;
+ unsigned int cnt;
+ int ret;
+};
+
+static void env_free(char **envp)
+{
+ char **tmp;
+
+ tmp = envp;
+ while (*tmp)
+ free(*(tmp++));
+ free(envp);
+}
+
+static void hotplug_free(struct hotplug_process *pc)
+{
+ env_free(pc->envp);
+ globfree(&pc->globbuf);
+ free(pc);
+}
+
+static void hotplug_done(struct uloop_process *c, int ret)
+{
+ struct hotplug_process *pc = container_of(c, struct hotplug_process, process);
+
+ pc->ret = ret;
+
+ uloop_timeout_set(&pc->timeout, 50);
+}
+
+static void hotplug_exec(struct uloop_timeout *t)
+{
+ struct hotplug_process *pc = container_of(t, struct hotplug_process, timeout);
+ char *script;
+ char *exec_argv[4];
+ /* we have reached the last entry in the globbuf */
+ if (pc->cnt == pc->globbuf.gl_pathc) {
+ hotplug_free(pc);
+ return;
+ }
+
+ asprintf(&script, ". /lib/functions.sh\n. %s\n", pc->globbuf.gl_pathv[pc->cnt++]);
+ /* prepare for execve() */
+ exec_argv[0] = "/bin/sh";
+ exec_argv[1] = "-c";
+ exec_argv[2] = script;
+ exec_argv[3] = NULL;
+
+ /* set callback in uloop_process */
+ pc->process.cb = hotplug_done;
+ pc->process.pid = fork();
+ if (pc->process.pid == 0) {
+ /* child */
+ exit(execve(exec_argv[0], exec_argv, pc->envp));
+ } else if (pc->process.pid < 0) {
+ /* fork error */
+ hotplug_free(pc);
+ return;
+ }
+ /* parent */
+ free(script);
+ uloop_process_add(&pc->process);
+}
+
+static int avl_envcmp(const void *k1, const void *k2, void *ptr)
+{
+ const char *tmp;
+
+ tmp = strchr(k1, '=');
+ if (!tmp)
+ return -1;
+
+ /*
+ * compare the variable name only, ie. limit strncmp to check
+ * only up to and including the '=' sign
+ */
+ return strncmp(k1, k2, (tmp - (char *)k1) + 1);
+}
+
+/* validate NULL-terminated environment variable name */
+static int validate_envvarname(const char *envvarname)
+{
+ const char *tmp = envvarname;
+
+ /* check for illegal characters in env variable name */
+ while (tmp[0] != '\0') {
+ if (!((tmp[0] >= 'a' && tmp[0] <= 'z') ||
+ (tmp[0] >= 'A' && tmp[0] <= 'Z') ||
+ (tmp[0] == '_') ||
+ /* allow numbers unless they are at the first character */
+ ((tmp != envvarname) && tmp[0] >= '0' && tmp[0] <= '9')))
+ return EINVAL;
+ ++tmp;
+ }
+
+ return 0;
+}
+
+enum {
+ HOTPLUG_ENV,
+ __HOTPLUG_MAX
+};
+
+static const struct blobmsg_policy hotplug_policy[__HOTPLUG_MAX] = {
+ [HOTPLUG_ENV] = { .name = "env", .type = BLOBMSG_TYPE_ARRAY },
+};
+
+static int hotplug_call(struct ubus_context *ctx, struct ubus_object *obj,
+ struct ubus_request_data *req, const char *method,
+ struct blob_attr *msg)
+{
+ const char *subsys = &obj->name[strlen(HOTPLUG_OBJECT_PREFIX)];
+ struct blob_attr *tb[__HOTPLUG_MAX], *cur;
+ AVL_TREE(env, avl_envcmp, false, NULL);
+ struct envlist *envle, *p;
+ int rem;
+ char **envp, *globstr, *tmp, **tmpenv;
+ size_t envz = 0;
+ struct hotplug_process *pc;
+ bool async = true;
+
+ blobmsg_parse(hotplug_policy, __HOTPLUG_MAX, tb, blobmsg_data(msg), blobmsg_len(msg));
+
+ if (!tb[HOTPLUG_ENV])
+ return UBUS_STATUS_INVALID_ARGUMENT;
+
+ tmpenv = environ;
+
+ /* first adding existing environment to avl_tree */
+ while (*tmpenv) {
+ envle = calloc(1, sizeof(struct envlist));
+ assert(envle != NULL);
+ envle->env = strdup(*tmpenv);
+ envle->avl.key = envle->env;
+ avl_insert(&env, &envle->avl);
+ ++tmpenv;
+ }
+
+ /* then adding additional variables from ubus call */
+ blobmsg_for_each_attr(cur, tb[HOTPLUG_ENV], rem) {
+ char *enve = blobmsg_get_string(cur);
+ if (!enve)
+ continue;
+
+ if (!strncmp(enve, "LD_", 3))
+ continue;
+
+ if (!strcmp(enve, "PATH"))
+ continue;
+
+ if (strlen(enve) < 3)
+ continue;
+
+ if (!(tmp = strchr(enve, '=')))
+ continue;
+
+ *tmp = '\0';
+ if (validate_envvarname(enve))
+ continue;
+ *tmp = '=';
+
+ if (!strlen(++tmp))
+ continue;
+
+ if (!strcmp(enve, "ASYNC=0"))
+ async = false;
+
+ envle = calloc(1, sizeof(struct envlist));
+ assert(envle != NULL);
+ envle->env = strdup(enve);
+ envle->avl.key = envle->env;
+ if (avl_insert(&env, &envle->avl)) {
+ free((void*)envle->env);
+ free(envle);
+ }
+ ++tmpenv;
+ }
+
+ /* allocating new environment */
+ avl_for_each_element(&env, envle, avl)
+ ++envz;
+
+ envp = calloc(envz + 1, sizeof(char *));
+ assert(envp != NULL);
+
+ /* populating new environment */
+ envz = 0;
+ avl_for_each_element_safe(&env, envle, avl, p) {
+ envp[envz++] = envle->env;
+ avl_delete(&env, &envle->avl);
+ free(envle);
+ }
+
+ /* glob'ing for hotplug scripts */
+ if (asprintf(&globstr, "%s/%s/*", HOTPLUG_BASEDIR, subsys) == -1) {
+ env_free(envp);
+ return UBUS_STATUS_UNKNOWN_ERROR;
+ }
+
+ /* synchronous calls are unsupported for now */
+ if (!async) {
+ env_free(envp);
+ return UBUS_STATUS_NOT_SUPPORTED;
+ }
+
+ pc = calloc(1, sizeof(struct hotplug_process));
+ assert(pc != NULL);
+ pc->timeout.cb = hotplug_exec;
+ pc->envp = envp;
+ pc->cnt = 0;
+ pc->ubus = obj;
+
+ if (glob(globstr, GLOB_DOOFFS, NULL, &pc->globbuf)) {
+ free(globstr);
+ hotplug_free(pc);
+ return UBUS_STATUS_OK;
+ }
+
+ free(globstr);
+
+ /* asynchronous call to hotplug_exec() */
+ uloop_timeout_set(&pc->timeout, 50);
+
+ return UBUS_STATUS_OK;
+}
+
+static const struct ubus_method hotplug_methods[] = {
+ UBUS_METHOD("call", hotplug_call, hotplug_policy),
+};
+
+static struct ubus_object_type hotplug_object_type =
+ UBUS_OBJECT_TYPE("hotplug", hotplug_methods);
+
+static void add_subsystem(int nlen, char *newname)
+{
+ struct hotplug_subsys *nh = calloc(1, sizeof(struct hotplug_subsys));
+ char *name;
+
+ asprintf(&name, "%s%.*s", HOTPLUG_OBJECT_PREFIX, nlen, newname);
+
+ /* prepare and add ubus object */
+ nh->ubus.name = name;
+ nh->ubus.type = &hotplug_object_type;
+ nh->ubus.methods = hotplug_object_type.methods;
+ nh->ubus.n_methods = hotplug_object_type.n_methods;
+ list_add(&nh->list, &subsystems);
+ ubus_add_object(ctx, &nh->ubus);
+}
+
+static void remove_subsystem(int nlen, char *name)
+{
+ struct hotplug_subsys *n, *h;
+
+ /* find match subsystem object by name or any if not given */
+ list_for_each_entry_safe(h, n, &subsystems, list) {
+ if (nlen && (strlen(h->ubus.name) != strnlen(name, nlen) + strlen(HOTPLUG_OBJECT_PREFIX)))
+ continue;
+ if (nlen && (strncmp(name, &h->ubus.name[strlen(HOTPLUG_OBJECT_PREFIX)], nlen)))
+ continue;
+
+ list_del(&h->list);
+ ubus_remove_object(ctx, &h->ubus);
+ free((void*)h->ubus.name);
+ free(h);
+ }
+}
+
+static int init_subsystems(void)
+{
+ DIR *dir;
+ struct dirent *dirent;
+
+ dir = opendir(HOTPLUG_BASEDIR);
+ if (dir == NULL)
+ return ENOENT;
+
+ while ((dirent = readdir(dir))) {
+ /* skip everything but directories */
+ if (dirent->d_type != DT_DIR)
+ continue;
+
+ /* skip '.' and '..' as well as hidden files */
+ if (dirent->d_name[0] == '.')
+ continue;
+
+ add_subsystem(strlen(dirent->d_name), dirent->d_name);
+ }
+ closedir(dir);
+
+ return 0;
+}
+
+static void inotify_read_handler(struct uloop_fd *u, unsigned int events)
+{
+ int rc;
+ char *p;
+ struct inotify_event *in;
+
+ /* read inotify events */
+ while ((rc = read(u->fd, inotify_buffer, INOTIFY_SZ)) == -1 && errno == EINTR);
+
+ if (rc <= 0)
+ return;
+
+ /* process events from buffer */
+ for (p = inotify_buffer;
+ rc - (p - inotify_buffer) >= (int)sizeof(struct inotify_event);
+ p += sizeof(struct inotify_event) + in->len) {
+ in = (struct inotify_event*)p;
+
+ /* skip everything but directories */
+ if (!(in->mask & IN_ISDIR))
+ continue;
+
+ if (in->len < 1)
+ continue;
+
+ /* skip hidden files */
+ if (in->name[0] == '.')
+ continue;
+
+ /* add/remove subsystem objects */
+ if (in->mask & (IN_CREATE | IN_MOVED_TO))
+ add_subsystem(in->len, in->name);
+ else if (in->mask & (IN_DELETE | IN_MOVED_FROM))
+ remove_subsystem(in->len, in->name);
+ }
+}
+
+void ubus_init_hotplug(struct ubus_context *newctx)
+{
+ ctx = newctx;
+ remove_subsystem(0, NULL);
+ if (init_subsystems()) {
+ printf("failed to initialize hotplug subsystems from %s\n", HOTPLUG_BASEDIR);
+ return;
+ }
+ fd_inotify_read.fd = inotify_init1(IN_NONBLOCK | IN_CLOEXEC);
+ fd_inotify_read.cb = inotify_read_handler;
+ assert(fd_inotify_read.fd != -1);
+
+ inotify_buffer = calloc(1, INOTIFY_SZ);
+ assert(inotify_buffer != NULL);
+ inotify_add_watch(fd_inotify_read.fd, HOTPLUG_BASEDIR, IN_CREATE | IN_MOVED_TO | IN_DELETE | IN_MOVED_FROM | IN_ONLYDIR);
+ uloop_fd_add(&fd_inotify_read, ULOOP_READ);
+}
projects / project / procd.git / blobdiff