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-rw-r--r--src/shared/plugin.c245
1 files changed, 245 insertions, 0 deletions
diff --git a/src/shared/plugin.c b/src/shared/plugin.c
new file mode 100644
index 00000000..cce845fa
--- /dev/null
+++ b/src/shared/plugin.c
@@ -0,0 +1,245 @@
+/*
+ * plugin.c
+ * Simple plugin handler
+ */
+
+/*
+ * Copyright (c) 2007-2015 The OpenRC Authors.
+ * See the Authors file at the top-level directory of this distribution and
+ * https://github.com/OpenRC/openrc/blob/HEAD/AUTHORS
+ *
+ * This file is part of OpenRC. It is subject to the license terms in
+ * the LICENSE file found in the top-level directory of this
+ * distribution and at https://github.com/OpenRC/openrc/blob/HEAD/LICENSE
+ * This file may not be copied, modified, propagated, or distributed
+ * except according to the terms contained in the LICENSE file.
+ */
+
+#include <sys/types.h>
+#include <sys/wait.h>
+
+#include <dirent.h>
+#include <dlfcn.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "einfo.h"
+#include "queue.h"
+#include "rc.h"
+#include "misc.h"
+#include "plugin.h"
+
+#define RC_PLUGIN_HOOK "rc_plugin_hook"
+
+bool rc_in_plugin = false;
+
+typedef struct plugin
+{
+ char *name;
+ void *handle;
+ int (*hook)(RC_HOOK, const char *);
+ TAILQ_ENTRY(plugin) entries;
+} PLUGIN;
+TAILQ_HEAD(, plugin) plugins;
+
+#ifndef __FreeBSD__
+dlfunc_t
+dlfunc(void * __restrict handle, const char * __restrict symbol)
+{
+ union {
+ void *d;
+ dlfunc_t f;
+ } rv;
+
+ rv.d = dlsym(handle, symbol);
+ return rv.f;
+}
+#endif
+
+void
+rc_plugin_load(void)
+{
+ DIR *dp;
+ struct dirent *d;
+ PLUGIN *plugin;
+ char *file = NULL;
+ void *h;
+ int (*fptr)(RC_HOOK, const char *);
+
+ /* Don't load plugins if we're in one */
+ if (rc_in_plugin)
+ return;
+
+ TAILQ_INIT(&plugins);
+
+ if (!(dp = opendir(RC_PLUGINDIR)))
+ return;
+
+ while ((d = readdir(dp))) {
+ if (d->d_name[0] == '.')
+ continue;
+
+ xasprintf(&file, RC_PLUGINDIR "/%s", d->d_name);
+ h = dlopen(file, RTLD_LAZY);
+ free(file);
+ if (h == NULL) {
+ eerror("dlopen: %s", dlerror());
+ continue;
+ }
+
+ fptr = (int (*)(RC_HOOK, const char *))
+ dlfunc(h, RC_PLUGIN_HOOK);
+ if (fptr == NULL) {
+ eerror("%s: cannot find symbol `%s'",
+ d->d_name, RC_PLUGIN_HOOK);
+ dlclose(h);
+ } else {
+ plugin = xmalloc(sizeof(*plugin));
+ plugin->name = xstrdup(d->d_name);
+ plugin->handle = h;
+ plugin->hook = fptr;
+ TAILQ_INSERT_TAIL(&plugins, plugin, entries);
+ }
+ }
+ closedir(dp);
+}
+
+int
+rc_waitpid(pid_t pid)
+{
+ int status;
+
+ while (waitpid(pid, &status, 0) == -1) {
+ if (errno != EINTR) {
+ status = -1;
+ break;
+ }
+ }
+ return status;
+}
+
+void
+rc_plugin_run(RC_HOOK hook, const char *value)
+{
+ PLUGIN *plugin;
+ struct sigaction sa;
+ sigset_t empty;
+ sigset_t full;
+ sigset_t old;
+ int i;
+ int flags;
+ int pfd[2];
+ pid_t pid;
+ char *buffer;
+ char *token;
+ char *p;
+ ssize_t nr;
+ int retval;
+
+ /* Don't run plugins if we're in one */
+ if (rc_in_plugin)
+ return;
+
+ /* We need to block signals until we have forked */
+ memset(&sa, 0, sizeof(sa));
+ sa.sa_handler = SIG_DFL;
+ sigemptyset(&sa.sa_mask);
+ sigemptyset(&empty);
+ sigfillset(&full);
+
+ TAILQ_FOREACH(plugin, &plugins, entries) {
+ /* We create a pipe so that plugins can affect our environment
+ * vars, which in turn influence our scripts. */
+ if (pipe(pfd) == -1) {
+ eerror("pipe: %s", strerror(errno));
+ return;
+ }
+
+ /* Stop any scripts from inheriting us.
+ * This is actually quite important as without this, the splash
+ * plugin will probably hang when running in silent mode. */
+ for (i = 0; i < 2; i++)
+ if ((flags = fcntl (pfd[i], F_GETFD, 0)) < 0 ||
+ fcntl (pfd[i], F_SETFD, flags | FD_CLOEXEC) < 0)
+ eerror("fcntl: %s", strerror(errno));
+
+ sigprocmask(SIG_SETMASK, &full, &old);
+
+ /* We run the plugin in a new process so we never crash
+ * or otherwise affected by it */
+ if ((pid = fork()) == -1) {
+ eerror("fork: %s", strerror(errno));
+ break;
+ }
+
+ if (pid == 0) {
+ /* Restore default handlers */
+ sigaction(SIGCHLD, &sa, NULL);
+ sigaction(SIGHUP, &sa, NULL);
+ sigaction(SIGINT, &sa, NULL);
+ sigaction(SIGQUIT, &sa, NULL);
+ sigaction(SIGTERM, &sa, NULL);
+ sigaction(SIGUSR1, &sa, NULL);
+ sigaction(SIGWINCH, &sa, NULL);
+ sigprocmask(SIG_SETMASK, &old, NULL);
+
+ rc_in_plugin = true;
+ close(pfd[0]);
+ rc_environ_fd = fdopen(pfd[1], "w");
+ retval = plugin->hook(hook, value);
+ fclose(rc_environ_fd);
+ rc_environ_fd = NULL;
+
+ /* Just in case the plugin sets this to false */
+ rc_in_plugin = true;
+ exit(retval);
+ }
+
+ sigprocmask(SIG_SETMASK, &old, NULL);
+ close(pfd[1]);
+ buffer = xmalloc(sizeof(char) * BUFSIZ);
+ memset(buffer, 0, BUFSIZ);
+
+ while ((nr = read(pfd[0], buffer, BUFSIZ)) > 0) {
+ p = buffer;
+ while (*p && p - buffer < nr) {
+ token = strsep(&p, "=");
+ if (token) {
+ unsetenv(token);
+ if (*p) {
+ setenv(token, p, 1);
+ p += strlen(p) + 1;
+ } else
+ p++;
+ }
+ }
+ }
+
+ free(buffer);
+ close(pfd[0]);
+
+ rc_waitpid(pid);
+ }
+}
+
+void
+rc_plugin_unload(void)
+{
+ PLUGIN *plugin = TAILQ_FIRST(&plugins);
+ PLUGIN *next;
+
+ while (plugin) {
+ next = TAILQ_NEXT(plugin, entries);
+ dlclose(plugin->handle);
+ free(plugin->name);
+ free(plugin);
+ plugin = next;
+ }
+ TAILQ_INIT(&plugins);
+}