X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=udev%2Flib%2Flibudev-monitor.c;h=e68bdf5bac208b1c5db84e7c269fd20dd54614c6;hp=5f63d2d4016768ad53e59b12274940396d59e5d2;hb=ff109b8ded61ad1241843090dea2a367572ac375;hpb=c4f5f942d7dd904e53374c10de319feb41968561

diff --git a/udev/lib/libudev-monitor.c b/udev/lib/libudev-monitor.c
index 5f63d2d40..e68bdf5ba 100644
--- a/udev/lib/libudev-monitor.c
+++ b/udev/lib/libudev-monitor.c
@@ -3,22 +3,12 @@
  *
  * Copyright (C) 2008 Kay Sievers <kay.sievers@vrfy.org>
  *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 2 of the License, or
- * (at your option) any later version.
- *
- * 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.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
  */
 
-#include "config.h"
-
 #include <stdio.h>
 #include <stdlib.h>
 #include <stddef.h>
@@ -29,66 +19,150 @@
 #include <sys/stat.h>
 #include <sys/socket.h>
 #include <sys/un.h>
+#include <linux/netlink.h>
 
 #include "libudev.h"
 #include "libudev-private.h"
-#include "../udev.h"
 
 struct udev_monitor {
 	struct udev *udev;
 	int refcount;
 	int sock;
-	struct sockaddr_un saddr;
+	struct sockaddr_nl snl;
+	struct sockaddr_nl snl_peer;
+	struct sockaddr_un sun;
 	socklen_t addrlen;
 };
 
+enum udev_monitor_netlink_group {
+	UDEV_MONITOR_KERNEL	= 1,
+	UDEV_MONITOR_UDEV	= 2,
+};
+
 /**
  * udev_monitor_new_from_socket:
  * @udev: udev library context
  * @socket_path: unix socket path
  *
- * Create new udev monitor, setup and connect to a specified socket. The
- * path to a socket can point to an existing socket file, or it will be
- * created if needed. If neccessary, the permissions adjustment as well as
- * the later cleanup of the socket file, needs to be done by the caller.
- * If the socket path starts with a '@' character, an abstract namespace
+ * Create new udev monitor and connect to a specified socket. The
+ * path to a socket either points to an existing socket file, or if
+ * the socket path starts with a '@' character, an abstract namespace
  * socket will be used.
  *
+ * A socket file will not be created. If it does not already exist,
+ * it will fall-back and connect to an abstract namespace socket with
+ * the given path. The permissions adjustment of a socket file, as
+ * well as the later cleanup, needs to be done by the caller.
+ *
  * The initial refcount is 1, and needs to be decremented to
- * release the ressources of the udev monitor.
+ * release the resources of the udev monitor.
  *
  * Returns: a new udev monitor, or #NULL, in case of an error
  **/
 struct udev_monitor *udev_monitor_new_from_socket(struct udev *udev, const char *socket_path)
 {
 	struct udev_monitor *udev_monitor;
+	struct stat statbuf;
 
 	if (udev == NULL)
 		return NULL;
 	if (socket_path == NULL)
 		return NULL;
-	udev_monitor = malloc(sizeof(struct udev_monitor));
+	udev_monitor = calloc(1, sizeof(struct udev_monitor));
 	if (udev_monitor == NULL)
 		return NULL;
-	memset(udev_monitor, 0x00, sizeof(struct udev_monitor));
 	udev_monitor->refcount = 1;
 	udev_monitor->udev = udev;
 
-	udev_monitor->saddr.sun_family = AF_LOCAL;
-	strcpy(udev_monitor->saddr.sun_path, socket_path);
-	udev_monitor->addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(udev_monitor->saddr.sun_path);
+	udev_monitor->sun.sun_family = AF_LOCAL;
+	if (socket_path[0] == '@') {
+		/* translate leading '@' to abstract namespace */
+		util_strlcpy(udev_monitor->sun.sun_path, socket_path, sizeof(udev_monitor->sun.sun_path));
+		udev_monitor->sun.sun_path[0] = '\0';
+		udev_monitor->addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(socket_path);
+	} else if (stat(socket_path, &statbuf) == 0 && S_ISSOCK(statbuf.st_mode)) {
+		/* existing socket file */
+		util_strlcpy(udev_monitor->sun.sun_path, socket_path, sizeof(udev_monitor->sun.sun_path));
+		udev_monitor->addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(socket_path);
+	} else {
+		/* no socket file, assume abstract namespace socket */
+		util_strlcpy(&udev_monitor->sun.sun_path[1], socket_path, sizeof(udev_monitor->sun.sun_path)-1);
+		udev_monitor->addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(socket_path)+1;
+	}
+	udev_monitor->sock = socket(AF_LOCAL, SOCK_DGRAM, 0);
+	if (udev_monitor->sock == -1) {
+		err(udev, "error getting socket: %m\n");
+		free(udev_monitor);
+		return NULL;
+	}
+	util_set_fd_cloexec(udev_monitor->sock);
 
-	/* translate leading '@' to abstract namespace */
-	if (udev_monitor->saddr.sun_path[0] == '@')
-		udev_monitor->saddr.sun_path[0] = '\0';
+	dbg(udev, "monitor %p created with '%s'\n", udev_monitor, socket_path);
+	return udev_monitor;
+}
 
-	udev_monitor->sock = socket(AF_LOCAL, SOCK_DGRAM, 0);
+/**
+ * udev_monitor_new_from_netlink:
+ * @udev: udev library context
+ * @name: name of event source
+ *
+ * Create new udev monitor and connect to a specified event
+ * source. Valid sources identifiers are "udev" and "kernel".
+ *
+ * Applications should usually not connect directly to the
+ * "kernel" events, because the devices might not be useable
+ * at that time, before udev has configured them, and created
+ * device nodes.
+ *
+ * Accessing devices at the same time as udev, might result
+ * in unpredictable behavior.
+ *
+ * The "udev" events are sent out after udev has finished its
+ * event processing, all rules have been processed, and needed
+ * device nodes are created.
+ *
+ * The initial refcount is 1, and needs to be decremented to
+ * release the resources of the udev monitor.
+ *
+ * Returns: a new udev monitor, or #NULL, in case of an error
+ **/
+struct udev_monitor *udev_monitor_new_from_netlink(struct udev *udev, const char *name)
+{
+	struct udev_monitor *udev_monitor;
+	unsigned int group;
+
+	if (udev == NULL)
+		return NULL;
+
+	if (name == NULL)
+		return NULL;
+	if (strcmp(name, "kernel") == 0)
+		group = UDEV_MONITOR_KERNEL;
+	else if (strcmp(name, "udev") == 0)
+		group = UDEV_MONITOR_UDEV;
+	else
+		return NULL;
+
+	udev_monitor = calloc(1, sizeof(struct udev_monitor));
+	if (udev_monitor == NULL)
+		return NULL;
+	udev_monitor->refcount = 1;
+	udev_monitor->udev = udev;
+
+	udev_monitor->sock = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT);
 	if (udev_monitor->sock == -1) {
-		err(udev, "error getting socket: %s\n", strerror(errno));
+		err(udev, "error getting socket: %m\n");
 		free(udev_monitor);
 		return NULL;
 	}
-	info(udev, "monitor %p created with '%s'\n", udev_monitor, socket_path);
+	util_set_fd_cloexec(udev_monitor->sock);
+
+	udev_monitor->snl.nl_family = AF_NETLINK;
+	udev_monitor->snl.nl_groups = group;
+	udev_monitor->snl_peer.nl_family = AF_NETLINK;
+	udev_monitor->snl_peer.nl_groups = UDEV_MONITOR_UDEV;
+
+	dbg(udev, "monitor %p created with NETLINK_KOBJECT_UEVENT (%u)\n", udev_monitor, group);
 	return udev_monitor;
 }
 
@@ -97,18 +171,32 @@ int udev_monitor_enable_receiving(struct udev_monitor *udev_monitor)
 	int err;
 	const int on = 1;
 
-	err = bind(udev_monitor->sock, (struct sockaddr *)&udev_monitor->saddr, udev_monitor->addrlen);
+	if (udev_monitor->sun.sun_family != 0)
+		err = bind(udev_monitor->sock,
+			   (struct sockaddr *)&udev_monitor->sun, udev_monitor->addrlen);
+	else if (udev_monitor->snl.nl_family != 0)
+		err = bind(udev_monitor->sock,
+			   (struct sockaddr *)&udev_monitor->snl, sizeof(struct sockaddr_nl));
+	else
+		return -EINVAL;
+
 	if (err < 0) {
-		err(udev_monitor->udev, "bind failed: %s\n", strerror(errno));
+		err(udev_monitor->udev, "bind failed: %m\n");
 		return err;
 	}
 
-	/* enable receiving of the sender credentials */
+	/* enable receiving of sender credentials */
 	setsockopt(udev_monitor->sock, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on));
-	info(udev_monitor->udev, "monitor %p listening\n", udev_monitor);
 	return 0;
 }
 
+int udev_monitor_set_receive_buffer_size(struct udev_monitor *udev_monitor, int size)
+{
+	if (udev_monitor == NULL)
+		return -1;
+	return setsockopt(udev_monitor->sock, SOL_SOCKET, SO_RCVBUFFORCE, &size, sizeof(size));
+}
+
 /**
  * udev_monitor_ref:
  * @udev_monitor: udev monitor
@@ -129,8 +217,8 @@ struct udev_monitor *udev_monitor_ref(struct udev_monitor *udev_monitor)
  * udev_monitor_unref:
  * @udev_monitor: udev monitor
  *
- * Drop a reference ofa udev monitor. If the refcount reaches zero,
- * the bound socket will be closed, and the ressources of the monitor
+ * Drop a reference of a udev monitor. If the refcount reaches zero,
+ * the bound socket will be closed, and the resources of the monitor
  * will be released.
  *
  **/
@@ -143,7 +231,7 @@ void udev_monitor_unref(struct udev_monitor *udev_monitor)
 		return;
 	if (udev_monitor->sock >= 0)
 		close(udev_monitor->sock);
-	info(udev_monitor->udev, "monitor %p released\n", udev_monitor);
+	dbg(udev_monitor->udev, "monitor %p released\n", udev_monitor);
 	free(udev_monitor);
 }
 
@@ -185,11 +273,11 @@ int udev_monitor_get_fd(struct udev_monitor *udev_monitor)
  * device, fill in the received data, and return the device.
  *
  * Only socket connections with uid=0 are accepted. The caller
- * needs to make sure, that there is data to read from the socket,
- * the call will block until the socket becomes readable.
+ * needs to make sure that there is data to read from the socket.
+ * The call will block until the socket becomes readable.
  *
  * The initial refcount is 1, and needs to be decremented to
- * release the ressources of the udev device.
+ * release the resources of the udev device.
  *
  * Returns: a new udev device, or #NULL, in case of an error
  **/
@@ -197,12 +285,18 @@ struct udev_device *udev_monitor_receive_device(struct udev_monitor *udev_monito
 {
 	struct udev_device *udev_device;
 	struct msghdr smsg;
-	struct cmsghdr *cmsg;
 	struct iovec iov;
-	struct ucred *cred;
 	char cred_msg[CMSG_SPACE(sizeof(struct ucred))];
+	struct cmsghdr *cmsg;
+	struct sockaddr_nl snl;
+	struct ucred *cred;
 	char buf[4096];
 	size_t bufpos;
+	int devpath_set = 0;
+	int subsystem_set = 0;
+	int action_set = 0;
+	int maj = 0;
+	int min = 0;
 
 	if (udev_monitor == NULL)
 		return NULL;
@@ -215,38 +309,54 @@ struct udev_device *udev_monitor_receive_device(struct udev_monitor *udev_monito
 	smsg.msg_control = cred_msg;
 	smsg.msg_controllen = sizeof(cred_msg);
 
+	if (udev_monitor->snl.nl_family != 0) {
+		smsg.msg_name = &snl;
+		smsg.msg_namelen = sizeof snl;
+	}
+
 	if (recvmsg(udev_monitor->sock, &smsg, 0) < 0) {
 		if (errno != EINTR)
-			info(udev_monitor->udev, "unable to receive message");
+			info(udev_monitor->udev, "unable to receive message\n");
 		return NULL;
 	}
-	cmsg = CMSG_FIRSTHDR(&smsg);
-	cred = (struct ucred *)CMSG_DATA (cmsg);
 
+	if (udev_monitor->snl.nl_family != 0) {
+		if (snl.nl_groups == 0) {
+			info(udev_monitor->udev, "unicast netlink message ignored\n");
+			return NULL;
+		}
+		if ((snl.nl_groups == UDEV_MONITOR_KERNEL) && (snl.nl_pid > 0)) {
+			info(udev_monitor->udev, "multicast kernel netlink message from pid %d ignored\n", snl.nl_pid);
+			return NULL;
+		}
+	}
+
+	cmsg = CMSG_FIRSTHDR(&smsg);
 	if (cmsg == NULL || cmsg->cmsg_type != SCM_CREDENTIALS) {
-		info(udev_monitor->udev, "no sender credentials received, message ignored");
+		info(udev_monitor->udev, "no sender credentials received, message ignored\n");
 		return NULL;
 	}
 
+	cred = (struct ucred *)CMSG_DATA(cmsg);
 	if (cred->uid != 0) {
-		info(udev_monitor->udev, "sender uid=%d, message ignored", cred->uid);
+		info(udev_monitor->udev, "sender uid=%d, message ignored\n", cred->uid);
 		return NULL;
 	}
 
 	/* skip header */
 	bufpos = strlen(buf) + 1;
 	if (bufpos < sizeof("a@/d") || bufpos >= sizeof(buf)) {
-		info(udev_monitor->udev, "invalid message length");
+		info(udev_monitor->udev, "invalid message length\n");
 		return NULL;
 	}
 
 	/* check message header */
 	if (strstr(buf, "@/") == NULL) {
-		info(udev_monitor->udev, "unrecognized message header");
+		info(udev_monitor->udev, "unrecognized message header\n");
 		return NULL;
 	}
 
-	udev_device = device_init(udev_monitor->udev);
+	udev_device = device_new(udev_monitor->udev);
 	if (udev_device == NULL) {
 		return NULL;
 	}
@@ -262,26 +372,93 @@ struct udev_device *udev_monitor_receive_device(struct udev_monitor *udev_monito
 		bufpos += keylen + 1;
 
 		if (strncmp(key, "DEVPATH=", 8) == 0) {
-			device_set_devpath(udev_device, &key[8]);
+			char path[UTIL_PATH_SIZE];
+
+			util_strlcpy(path, udev_get_sys_path(udev_monitor->udev), sizeof(path));
+			util_strlcat(path, &key[8], sizeof(path));
+			udev_device_set_syspath(udev_device, path);
+			devpath_set = 1;
 		} else if (strncmp(key, "SUBSYSTEM=", 10) == 0) {
-			device_set_subsystem(udev_device, &key[10]);
+			udev_device_set_subsystem(udev_device, &key[10]);
+			subsystem_set = 1;
+		} else if (strncmp(key, "DEVTYPE=", 8) == 0) {
+			udev_device_set_devtype(udev_device, &key[8]);
 		} else if (strncmp(key, "DEVNAME=", 8) == 0) {
-			device_set_devname(udev_device, &key[8]);
+			udev_device_set_devnode(udev_device, &key[8]);
 		} else if (strncmp(key, "DEVLINKS=", 9) == 0) {
-			char *slink = &key[9];
-			char *next = strchr(slink, ' ');
+			char devlinks[UTIL_PATH_SIZE];
+			char *slink;
+			char *next;
 
+			util_strlcpy(devlinks, &key[9], sizeof(devlinks));
+			slink = devlinks;
+			next = strchr(slink, ' ');
 			while (next != NULL) {
 				next[0] = '\0';
-				device_add_devlink(udev_device, slink);
+				udev_device_add_devlink(udev_device, slink);
 				slink = &next[1];
 				next = strchr(slink, ' ');
 			}
 			if (slink[0] != '\0')
-				device_add_devlink(udev_device, slink);
+				udev_device_add_devlink(udev_device, slink);
+		} else if (strncmp(key, "DRIVER=", 7) == 0) {
+			udev_device_set_driver(udev_device, &key[7]);
+		} else if (strncmp(key, "ACTION=", 7) == 0) {
+			udev_device_set_action(udev_device, &key[7]);
+			action_set = 1;
+		} else if (strncmp(key, "MAJOR=", 6) == 0) {
+			maj = strtoull(&key[6], NULL, 10);
+		} else if (strncmp(key, "MINOR=", 6) == 0) {
+			min = strtoull(&key[6], NULL, 10);
+		} else if (strncmp(key, "DEVPATH_OLD=", 12) == 0) {
+			udev_device_set_devpath_old(udev_device, &key[12]);
+		} else if (strncmp(key, "PHYSDEVPATH=", 12) == 0) {
+			udev_device_set_physdevpath(udev_device, &key[12]);
+		} else if (strncmp(key, "SEQNUM=", 7) == 0) {
+			udev_device_set_seqnum(udev_device, strtoull(&key[7], NULL, 10));
+		} else if (strncmp(key, "TIMEOUT=", 8) == 0) {
+			udev_device_set_timeout(udev_device, strtoull(&key[8], NULL, 10));
+		} else if (strncmp(key, "PHYSDEV", 7) == 0) {
+			/* skip deprecated values */
+			continue;
+		} else {
+			udev_device_add_property_from_string(udev_device, key);
 		}
-		device_add_property(udev_device, key);
 	}
-
+	if (!devpath_set || !subsystem_set || !action_set) {
+		info(udev_monitor->udev, "missing values, skip\n");
+		udev_device_unref(udev_device);
+		return NULL;
+	}
+	if (maj > 0)
+		udev_device_set_devnum(udev_device, makedev(maj, min));
+	udev_device_set_info_loaded(udev_device);
 	return udev_device;
 }
+
+int udev_monitor_send_device(struct udev_monitor *udev_monitor, struct udev_device *udev_device)
+{
+	const char *buf;
+	ssize_t len;
+	ssize_t count;
+
+	len = udev_device_get_properties_monitor_buf(udev_device, &buf);
+	if (len < 32)
+		return -1;
+	if (udev_monitor->sun.sun_family != 0)
+		count = sendto(udev_monitor->sock,
+			       buf, len, 0,
+			       (struct sockaddr *)&udev_monitor->sun,
+			       udev_monitor->addrlen);
+	else if (udev_monitor->snl.nl_family != 0)
+		/* no destination besides the muticast group, we will always get ECONNREFUSED */
+		count = sendto(udev_monitor->sock,
+			       buf, len, 0,
+			       (struct sockaddr *)&udev_monitor->snl_peer,
+			       sizeof(struct sockaddr_nl));
+	else
+		return -1;
+
+	info(udev_monitor->udev, "passed %zi bytes to monitor %p\n", count, udev_monitor);
+	return count;
+}