plugins: refactor, break out inotify watcher to src/iwatch.[ch]

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

plugins/pidfile.c

@@ -25,8 +25,6 @@
 #include <glob.h>
 #include <limits.h>
 #include <paths.h>
-#include <lite/queue.h>
-#include <sys/inotify.h>
 
 #include "finit.h"
 #include "cond.h"
@@ -34,28 +32,15 @@
 #include "pid.h"
 #include "plugin.h"
 #include "service.h"
-
+#include "iwatch.h"
-struct iwatch_path {
-	TAILQ_ENTRY(iwatch_path) link;
-	char *path;
-	int wd;
-};
-
-struct iwatch {
-	int fd;
-	TAILQ_HEAD(, iwatch_path) iwp_list;
-};
 
 static struct iwatch iw_pidfile;
 
-static int iwatch_add(struct iwatch *iw, char *path)
-{
-	struct iwatch_path *iwp;
-	uint32_t mask = IN_ONLYDIR | IN_CREATE | IN_ATTRIB | IN_DELETE | IN_MODIFY | IN_MOVED_TO;
-	char *ptr;
-	int wd;
 
-	_d("pidfile: Adding new watcher for path %s", path);
+static int pidfile_add_path(struct iwatch *iw, char *path)
+{
+	char *ptr;
+
 	ptr = strstr(path, "run/");
 	if (ptr) {
 		char *slash;
@@ -66,44 +51,16 @@ static int iwatch_add(struct iwatch *iw, char *path)
 			ptr = slash++;
 			slash = strchr(ptr, '/');
 			if (slash) {
-				_d("pidfile: Path too deep, skipping.");
+				_d("Path too deep, skipping.");
 				return -1;
 			}
 		}
 	}
 
-	wd = inotify_add_watch(iw->fd, path, mask);
+	return iwatch_add(iw, path, IN_ONLYDIR);
-	if (wd < 0) {
-		_pe("inotify_add_watch()");
-		return -1;
-	}
-
-	iwp = malloc(sizeof(struct iwatch_path));
-	if (!iwp) {
-		_pe("Failed allocating new `struct iwatch_path`");
-		inotify_rm_watch(iw->fd, wd);
-		return -1;
-	}
-
-	iwp->path = path;
-	iwp->wd = wd;
-	TAILQ_INSERT_HEAD(&iw->iwp_list, iwp, link);
-
-	return 0;
 }
 
-static int iwatch_del(struct iwatch *iw, struct iwatch_path *iwp)
+static void pidfile_update_conds(char *dir, char *name, uint32_t mask)
-{
-	_d("pidfile: Removing watcher for removed path %s", iwp->path);
-	TAILQ_REMOVE(&iw->iwp_list, iwp, link);
-	inotify_rm_watch(iw->fd, iwp->wd);
-	free(iwp->path);
-	free(iwp);
-
-	return 0;
-}
-
-static void update_conds(char *dir, char *name, uint32_t mask)
 {
 	char cond[MAX_COND_LEN];
 	char fn[PATH_MAX];
@@ -114,11 +71,11 @@ static void update_conds(char *dir, char *name, uint32_t mask)
 
 	svc = svc_find_by_pidfile(fn);
 	if (!svc) {
-		_d("pidfile: No matching svc for %s", fn);
+		_d("No matching svc for %s", fn);
 		return;
 	}
 
-	_d("pidfile: Found svc %s for %s with pid %d", svc->name, fn, svc->pid);
+	_d("Found svc %s for %s with pid %d", svc->name, fn, svc->pid);
 
 	mkcond(svc, cond, sizeof(cond));
 	if (mask & (IN_CREATE | IN_ATTRIB | IN_MODIFY | IN_MOVED_TO)) {
@@ -138,7 +95,7 @@ static void update_conds(char *dir, char *name, uint32_t mask)
 }
 
 /* synthesize events in case of new run dirs */
-static void scan_for_pidfiles(struct iwatch *iw, char *dir, int len)
+static void pidfile_scandir(struct iwatch *iw, char *dir, int len)
 {
 	glob_t gl;
 	size_t i;
@@ -157,47 +114,33 @@ static void scan_for_pidfiles(struct iwatch *iw, char *dir, int len)
 
 	for (i = 0; i < gl.gl_pathc; i++) {
 		_d("scan found %s", gl.gl_pathv[i]);
-		update_conds(dir, gl.gl_pathv[i], IN_CREATE);
+		pidfile_update_conds(dir, gl.gl_pathv[i], IN_CREATE);
 	}
 	globfree(&gl);
 }
 
-static void handle_dir(struct iwatch *iw, struct iwatch_path *iwp, char *name, int mask)
+/*
+ * create/remove sub-directory in monitored directory
+ */
+static void pidfile_handle_dir(struct iwatch *iw, char *dir, char *name, int mask)
 {
-	char *path;
+	char path[strlen(dir) + strlen(name) + 2];
-	int plen;
+	struct iwatch_path *iwp;
-	int exist = 0;
 
-	plen = snprintf(NULL, 0, "%s/%s", iwp->path, name) + 1;
+	snprintf(path, sizeof(path), "%s/%s", dir, name);
-	path = malloc(plen);
+	_d("path: %s", path);
-	if (!path) {
-		_pe("Failed allocating path buffer for watcher");
-		return;
-	}
-	snprintf(path, plen, "%s/%s", iwp->path, name);
-	_d("pidfile: path is %s", path);
 
-	TAILQ_FOREACH(iwp, &iw->iwp_list, link) {
+	iwp = iwatch_find_by_path(iw, path);
-		if (!strcmp(iwp->path, path)) {
-			exist = 1;
-			break;
-		}
-	}
 
 	if (mask & IN_CREATE) {
-		if (!exist) {
+		if (!iwp) {
-			int rc = iwatch_add(iw, path);
+			pidfile_add_path(iw, path);
-
+			pidfile_scandir(iw, path, sizeof(path));
-			scan_for_pidfiles(iw, path, plen);
-			if (!rc)
-				return;
 		}
 	} else if (mask & IN_DELETE) {
-		if (exist)
+		if (iwp)
 			iwatch_del(&iw_pidfile, iwp);
 	}
-
-	free(path);
 }
 
 static void pidfile_callback(void *arg, int fd, int events)
@@ -213,14 +156,14 @@ static void pidfile_callback(void *arg, int fd, int events)
 		return;
 	}
 
-	_d("pidfile: Entering ... reading %zu bytes into ev_buf[]", buflen - 1);
+	_d("Entering ... reading %zu bytes into ev_buf[]", buflen - 1);
 	sz = read(fd, buf, buflen - 1);
 	if (sz <= 0) {
 		_pe("invalid inotify event");
 		goto done;
 	}
 	buf[sz] = 0;
-	_d("pidfile: Read %zd bytes, processing ...", sz);
+	_d("Read %zd bytes, processing ...", sz);
 
 	off = 0;
 	for (off = 0; off < sz; off += sizeof(*ev) + ev->len) {
@@ -228,18 +171,17 @@ static void pidfile_callback(void *arg, int fd, int events)
 
 		ev = (struct inotify_event *)&buf[off];
 
-		_d("pidfile: path %s, event: 0x%08x", ev->name, ev->mask);
+		_d("path %s, event: 0x%08x", ev->name, ev->mask);
 		if (!ev->mask)
 			continue;
 
 		/* Find base path for this event */
-		TAILQ_FOREACH(iwp, &iw_pidfile.iwp_list, link) {
+		iwp = iwatch_find_by_wd(&iw_pidfile, ev->wd);
-			if (iwp->wd == ev->wd)
+		if (!iwp)
-				break;
+			continue;
-		}
 
 		if (ev->mask & IN_ISDIR) {
-			handle_dir(&iw_pidfile, iwp, ev->name, ev->mask);
+			pidfile_handle_dir(&iw_pidfile, iwp->path, ev->name, ev->mask);
 			continue;
 		}
 
@@ -249,7 +191,7 @@ static void pidfile_callback(void *arg, int fd, int events)
 		}
 
 		if (ev->mask & (IN_CREATE | IN_ATTRIB | IN_MODIFY | IN_MOVED_TO))
-			update_conds(iwp->path, ev->name, ev->mask);
+			pidfile_update_conds(iwp->path, ev->name, ev->mask);
 	}
 done:
 	free(buf);
@@ -305,14 +247,10 @@ static void pidfile_init(void *arg)
 		return;
 	}
 
-	TAILQ_INIT(&iw_pidfile.iwp_list);
+	if (pidfile_add_path(&iw_pidfile, path))
-	if (iwatch_add(&iw_pidfile, path))
+		iwatch_exit(&iw_pidfile);
-		close(iw_pidfile.fd);
-	_d("pidfile monitor active");
 }
 
-static struct iwatch iw_pidfile;
-
 /*
  * When performing an `initctl reload` with one (unchanged) service
  * depending on, e.g. `net/iface/lo`, its condition will not be set
@@ -340,27 +278,19 @@ static plugin_t plugin = {
 
 PLUGIN_INIT(plugin_init)
 {
-	iw_pidfile.fd = inotify_init1(IN_NONBLOCK | IN_CLOEXEC);
+	int fd;
-	if (iw_pidfile.fd < 0) {
-		_pe("inotify_init()");
-		return;
-	}
 
-	plugin.io.fd = iw_pidfile.fd;
+	fd = iwatch_init(&iw_pidfile);
+	if (fd < 0)
+		return;
+
+	plugin.io.fd = fd;
 	plugin_register(&plugin);
 }
 
 PLUGIN_EXIT(plugin_exit)
 {
-	struct iwatch_path *iwp, *tmp;
+	iwatch_exit(&iw_pidfile);
-
-	TAILQ_FOREACH_SAFE(iwp, &iw_pidfile.iwp_list, link, tmp) {
-		inotify_rm_watch(iw_pidfile.fd, iwp->wd);
-		free(iwp->path);
-		free(iwp);
-	}
-	close(iw_pidfile.fd);
-
 	plugin_unregister(&plugin);
 }
 

src/Makefile.am

@@ -26,6 +26,7 @@ finit_SOURCES      = api.c	cgroup.c	cgroup.h	\
 		     exec.c	finit.c		finit.h		\
 		     getty.c	stty.c				\
 		     helpers.c	helpers.h			\
+		     iwatch.c   iwatch.h			\
 		     log.c	log.h				\
 		     mdadm.c	mount.c				\
 		     pid.c      pid.h				\

src/iwatch.c

@@ -0,0 +1,118 @@
+#include <errno.h>
+
+#include "finit.h"
+#include "iwatch.h"
+#include "log.h"
+
+
+int iwatch_init(struct iwatch *iw)
+{
+	if (!iw) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	TAILQ_INIT(&iw->iwp_list);
+
+	iw->fd = inotify_init1(IN_NONBLOCK | IN_CLOEXEC);
+	if (iw->fd < 0) {
+		_pe("inotify_init()");
+		return -1;
+	}
+
+	return iw->fd;
+}
+
+void iwatch_exit(struct iwatch *iw)
+{
+	struct iwatch_path *iwp, *tmp;
+
+	TAILQ_FOREACH_SAFE(iwp, &iw->iwp_list, link, tmp) {
+		TAILQ_REMOVE(&iw->iwp_list, iwp, link);
+		inotify_rm_watch(iw->fd, iwp->wd);
+		free(iwp->path);
+		free(iwp);
+	}
+
+	close(iw->fd);
+}
+
+int iwatch_add(struct iwatch *iw, char *file, uint32_t mask)
+{
+	struct iwatch_path *iwp;
+	char *path;
+	int wd;
+
+	_d("Adding new watcher for path %s", file);
+
+	path = strdup(file);
+	if (!path) {
+		_pe("Out of memory");
+		return -1;
+	}
+
+	wd = inotify_add_watch(iw->fd, path, IWATCH_MASK | mask);
+	if (wd < 0) {
+		_pe("inotify_add_watch(%s)", path);
+		free(path);
+		return -1;
+	}
+
+	iwp = malloc(sizeof(struct iwatch_path));
+	if (!iwp) {
+		_pe("Failed allocating new `struct iwatch_path`");
+		inotify_rm_watch(iw->fd, wd);
+		free(path);
+		return -1;
+	}
+
+	iwp->path = path;
+	iwp->wd = wd;
+	TAILQ_INSERT_HEAD(&iw->iwp_list, iwp, link);
+
+	return 0;
+}
+
+int iwatch_del(struct iwatch *iw, struct iwatch_path *iwp)
+{
+	_d("Removing watcher for removed path %s", iwp->path);
+
+	TAILQ_REMOVE(&iw->iwp_list, iwp, link);
+	inotify_rm_watch(iw->fd, iwp->wd);
+	free(iwp->path);
+	free(iwp);
+
+	return 0;
+}
+
+struct iwatch_path *iwatch_find_by_wd(struct iwatch *iw, int wd)
+{
+	struct iwatch_path *iwp;
+
+	TAILQ_FOREACH(iwp, &iw->iwp_list, link) {
+		if (iwp->wd == wd)
+			return iwp;
+	}
+
+	return NULL;
+}
+
+struct iwatch_path *iwatch_find_by_path(struct iwatch *iw, const char *path)
+{
+	struct iwatch_path *iwp;
+
+	TAILQ_FOREACH(iwp, &iw->iwp_list, link) {
+		if (!strcmp(iwp->path, path))
+			return iwp;
+	}
+
+	return NULL;
+}
+
+/**
+ * Local Variables:
+ *  indent-tabs-mode: t
+ *  c-file-style: "linux"
+ * End:
+ */
+

src/iwatch.h

@@ -0,0 +1,64 @@
+/* inotify watcher for files or directories
+ *
+ * Copyright (c) 2015-2016  Tobias Waldekranz <tobias@waldekranz.com>
+ * Copyright (c) 2016-2021  Joachim Wiberg <troglobit@gmail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef FINIT_IWATCH_H_
+#define FINIT_IWATCH_H_
+
+#include <stdint.h>
+#include <lite/queue.h>
+#include <sys/inotify.h>
+
+
+/* Monitors changes to both directories and files by default */
+#define IWATCH_MASK (IN_CREATE | IN_DELETE | IN_MODIFY | IN_ATTRIB | IN_MOVE)
+
+struct iwatch_path {
+	TAILQ_ENTRY(iwatch_path) link;
+	char *path;
+	int wd;
+};
+
+struct iwatch {
+	int fd;
+	TAILQ_HEAD(, iwatch_path) iwp_list;
+};
+
+
+int  iwatch_init (struct iwatch *iw);
+void iwatch_exit (struct iwatch *iw);
+
+int  iwatch_add  (struct iwatch *iw, char *file, uint32_t mask);
+int  iwatch_del  (struct iwatch *iw, struct iwatch_path *iwp);
+
+struct iwatch_path *iwatch_find_by_wd   (struct iwatch *iw, int wd);
+struct iwatch_path *iwatch_find_by_path (struct iwatch *iw, const char *path);
+
+#endif /* FINIT_IWATCH_H_ */
+
+/**
+ * Local Variables:
+ *  indent-tabs-mode: t
+ *  c-file-style: "linux"
+ * End:
+ */