X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=udev%2Flib%2Flibudev-monitor.c;h=33a0605492a128f174b080b2b84b6206907fc81c;hb=1e03b754aef576a5cb75f01b1805cdc1f9cc292f;hp=a0f93546f7f8fb7c035c01f3ee03a49a3e88d26d;hpb=c7dff03e057a7548bc2f2adbd5d2798d209b56e6;p=elogind.git

diff --git a/udev/lib/libudev-monitor.c b/udev/lib/libudev-monitor.c
index a0f93546f..33a060549 100644
--- a/udev/lib/libudev-monitor.c
+++ b/udev/lib/libudev-monitor.c
@@ -1,7 +1,7 @@
 /*
  * libudev - interface to udev device information
  *
- * Copyright (C) 2008 Kay Sievers <kay.sievers@vrfy.org>
+ * Copyright (C) 2008-2009 Kay Sievers <kay.sievers@vrfy.org>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -32,15 +32,17 @@ struct udev_monitor {
 	int refcount;
 	int sock;
 	struct sockaddr_nl snl;
-	struct sockaddr_nl snl_peer;
+	struct sockaddr_nl snl_trusted_sender;
+	struct sockaddr_nl snl_destination;
 	struct sockaddr_un sun;
 	socklen_t addrlen;
 	struct udev_list_node filter_subsystem_list;
 };
 
 enum udev_monitor_netlink_group {
-	UDEV_MONITOR_KERNEL	= 1,
-	UDEV_MONITOR_UDEV	= 2,
+	UDEV_MONITOR_NONE,
+	UDEV_MONITOR_KERNEL,
+	UDEV_MONITOR_UDEV,
 };
 
 #define UDEV_MONITOR_MAGIC		0xcafe1dea
@@ -56,11 +58,12 @@ struct udev_monitor_netlink_header {
 	unsigned short properties_off;
 	unsigned short properties_len;
 	/*
-	 * hashes of some common device propertie strings to filter with socket filters in
+	 * hashes of some common device properties strings to filter with socket filters in
 	 * the client used in the kernel from socket filter rules; needs to be stored in
 	 * network order
 	 */
 	unsigned int filter_subsystem;
+	unsigned int filter_devtype;
 };
 
 static struct udev_monitor *udev_monitor_new(struct udev *udev)
@@ -112,16 +115,16 @@ struct udev_monitor *udev_monitor_new_from_socket(struct udev *udev, const char
 	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));
+		util_strscpy(udev_monitor->sun.sun_path, sizeof(udev_monitor->sun.sun_path), socket_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));
+		util_strscpy(udev_monitor->sun.sun_path, sizeof(udev_monitor->sun.sun_path), socket_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);
+		util_strscpy(&udev_monitor->sun.sun_path[1], sizeof(udev_monitor->sun.sun_path)-1, socket_path);
 		udev_monitor->addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(socket_path)+1;
 	}
 	udev_monitor->sock = socket(AF_LOCAL, SOCK_DGRAM, 0);
@@ -170,11 +173,11 @@ struct udev_monitor *udev_monitor_new_from_netlink(struct udev *udev, const char
 		return NULL;
 
 	if (name == NULL)
-		return NULL;
-	if (strcmp(name, "kernel") == 0)
-		group = UDEV_MONITOR_KERNEL;
+		group = UDEV_MONITOR_NONE;
 	else if (strcmp(name, "udev") == 0)
 		group = UDEV_MONITOR_UDEV;
+	else if (strcmp(name, "kernel") == 0)
+		group = UDEV_MONITOR_KERNEL;
 	else
 		return NULL;
 
@@ -192,8 +195,10 @@ struct udev_monitor *udev_monitor_new_from_netlink(struct udev *udev, const char
 
 	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;
+
+	/* default destination for sending */
+	udev_monitor->snl_destination.nl_family = AF_NETLINK;
+	udev_monitor->snl_destination.nl_groups = UDEV_MONITOR_UDEV;
 
 	dbg(udev, "monitor %p created with NETLINK_KOBJECT_UEVENT (%u)\n", udev_monitor, group);
 	return udev_monitor;
@@ -222,7 +227,7 @@ static inline void bpf_jmp(struct sock_filter *inss, unsigned int *i,
 	(*i)++;
 }
 
-static int filter_apply(struct udev_monitor *udev_monitor)
+int udev_monitor_filter_update(struct udev_monitor *udev_monitor)
 {
 	static struct sock_filter ins[256];
 	static struct sock_fprog filter;
@@ -236,23 +241,34 @@ static int filter_apply(struct udev_monitor *udev_monitor)
 	memset(ins, 0x00, sizeof(ins));
 	i = 0;
 
-	/* load magic in accu */
+	/* load magic in A */
 	bpf_stmt(ins, &i, BPF_LD|BPF_W|BPF_ABS, offsetof(struct udev_monitor_netlink_header, magic));
 	/* jump if magic matches */
 	bpf_jmp(ins, &i, BPF_JMP|BPF_JEQ|BPF_K, UDEV_MONITOR_MAGIC, 1, 0);
-	/* wrong magic, drop packet */
-	bpf_stmt(ins, &i, BPF_RET|BPF_K, 0);
+	/* wrong magic, pass packet */
+	bpf_stmt(ins, &i, BPF_RET|BPF_K, 0xffffffff);
 
-	/* load filter_subsystem value in accu */
-	bpf_stmt(ins, &i, BPF_LD|BPF_W|BPF_ABS, offsetof(struct udev_monitor_netlink_header, filter_subsystem));
 	/* add all subsystem match values */
 	udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_monitor->filter_subsystem_list)) {
-		const char *subsys = udev_list_entry_get_name(list_entry);
 		unsigned int hash;
 
-		hash = util_string_hash32(subsys);
-		/* jump if value does not match */
-		bpf_jmp(ins, &i, BPF_JMP|BPF_JEQ|BPF_K, hash, 0, 1);
+		/* load filter_subsystem value in A */
+		bpf_stmt(ins, &i, BPF_LD|BPF_W|BPF_ABS, offsetof(struct udev_monitor_netlink_header, filter_subsystem));
+		hash = util_string_hash32(udev_list_entry_get_name(list_entry));
+		if (udev_list_entry_get_value(list_entry) == NULL) {
+			/* jump if subsystem does not match */
+			bpf_jmp(ins, &i, BPF_JMP|BPF_JEQ|BPF_K, hash, 0, 1);
+		} else {
+			/* jump if subsystem does not match */
+			bpf_jmp(ins, &i, BPF_JMP|BPF_JEQ|BPF_K, hash, 0, 3);
+
+			/* load filter_devtype value in A */
+			bpf_stmt(ins, &i, BPF_LD|BPF_W|BPF_ABS, offsetof(struct udev_monitor_netlink_header, filter_devtype));
+			/* jump if value does not match */
+			hash = util_string_hash32(udev_list_entry_get_value(list_entry));
+			bpf_jmp(ins, &i, BPF_JMP|BPF_JEQ|BPF_K, hash, 0, 1);
+		}
+
 		/* matched, pass packet */
 		bpf_stmt(ins, &i, BPF_RET|BPF_K, 0xffffffff);
 
@@ -269,6 +285,12 @@ static int filter_apply(struct udev_monitor *udev_monitor)
 	return err;
 }
 
+int udev_monitor_allow_unicast_sender(struct udev_monitor *udev_monitor, struct udev_monitor *sender)
+{
+	udev_monitor->snl_trusted_sender.nl_pid = sender->snl.nl_pid;
+	return 0;
+}
+
 int udev_monitor_enable_receiving(struct udev_monitor *udev_monitor)
 {
 	int err;
@@ -278,9 +300,22 @@ int udev_monitor_enable_receiving(struct udev_monitor *udev_monitor)
 		err = bind(udev_monitor->sock,
 			   (struct sockaddr *)&udev_monitor->sun, udev_monitor->addrlen);
 	} else if (udev_monitor->snl.nl_family != 0) {
-		filter_apply(udev_monitor);
+		udev_monitor_filter_update(udev_monitor);
 		err = bind(udev_monitor->sock,
 			   (struct sockaddr *)&udev_monitor->snl, sizeof(struct sockaddr_nl));
+		if (err == 0) {
+			struct sockaddr_nl snl;
+			socklen_t addrlen;
+
+			/*
+			 * get the address the kernel has assigned us
+			 * it is usually, but not neccessarily the pid
+			 */
+			addrlen = sizeof(struct sockaddr_nl);
+			err = getsockname(udev_monitor->sock, (struct sockaddr *)&snl, &addrlen);
+			if (err == 0)
+				udev_monitor->snl.nl_pid = snl.nl_pid;
+		}
 	} else {
 		return -EINVAL;
 	}
@@ -302,6 +337,15 @@ int udev_monitor_set_receive_buffer_size(struct udev_monitor *udev_monitor, int
 	return setsockopt(udev_monitor->sock, SOL_SOCKET, SO_RCVBUFFORCE, &size, sizeof(size));
 }
 
+int udev_monitor_disconnect(struct udev_monitor *udev_monitor)
+{
+	int err;
+
+	err = close(udev_monitor->sock);
+	udev_monitor->sock = -1;
+	return err;
+}
+
 /**
  * udev_monitor_ref:
  * @udev_monitor: udev monitor
@@ -374,20 +418,29 @@ int udev_monitor_get_fd(struct udev_monitor *udev_monitor)
 static int passes_filter(struct udev_monitor *udev_monitor, struct udev_device *udev_device)
 {
 	struct udev_list_entry *list_entry;
-	int pass = 0;
 
 	if (udev_list_get_entry(&udev_monitor->filter_subsystem_list) == NULL)
 		return 1;
 
 	udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_monitor->filter_subsystem_list)) {
-		const char *subsys = udev_device_get_subsystem(udev_device);
+		const char *subsys = udev_list_entry_get_name(list_entry);
+		const char *dsubsys = udev_device_get_subsystem(udev_device);
+		const char *devtype;
+		const char *ddevtype;
 
-		if (strcmp(udev_list_entry_get_name(list_entry), subsys) == 0) {
-			pass= 1;
-			break;
-		}
+		if (strcmp(dsubsys, subsys) != 0)
+			continue;
+
+		devtype = udev_list_entry_get_value(list_entry);
+		if (devtype == NULL)
+			return 1;
+		ddevtype = udev_device_get_devtype(udev_device);
+		if (ddevtype == NULL)
+			continue;
+		if (strcmp(ddevtype, devtype) == 0)
+			return 1;
 	}
-	return pass;
+	return 0;
 }
 
 /**
@@ -424,6 +477,7 @@ struct udev_device *udev_monitor_receive_device(struct udev_monitor *udev_monito
 	int action_set = 0;
 	int maj = 0;
 	int min = 0;
+	int is_kernel = 0;
 
 retry:
 	if (udev_monitor == NULL)
@@ -456,12 +510,18 @@ retry:
 
 	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;
+			/* unicast message, check if we trust the sender */
+			if (udev_monitor->snl_trusted_sender.nl_pid == 0 ||
+			    snl.nl_pid != udev_monitor->snl_trusted_sender.nl_pid) {
+				info(udev_monitor->udev, "unicast netlink message ignored\n");
+				return NULL;
+			}
+		} else if (snl.nl_groups == UDEV_MONITOR_KERNEL) {
+			if (snl.nl_pid > 0) {
+				info(udev_monitor->udev, "multicast kernel netlink message from pid %d ignored\n", snl.nl_pid);
+				return NULL;
+			}
+			is_kernel = 1;
 		}
 	}
 
@@ -520,8 +580,7 @@ retry:
 		if (strncmp(key, "DEVPATH=", 8) == 0) {
 			char path[UTIL_PATH_SIZE];
 
-			util_strlcpy(path, udev_get_sys_path(udev_monitor->udev), sizeof(path));
-			util_strlcat(path, &key[8], sizeof(path));
+			util_strscpyl(path, sizeof(path), udev_get_sys_path(udev_monitor->udev), &key[8], NULL);
 			udev_device_set_syspath(udev_device, path);
 			devpath_set = 1;
 		} else if (strncmp(key, "SUBSYSTEM=", 10) == 0) {
@@ -530,13 +589,16 @@ retry:
 		} else if (strncmp(key, "DEVTYPE=", 8) == 0) {
 			udev_device_set_devtype(udev_device, &key[8]);
 		} else if (strncmp(key, "DEVNAME=", 8) == 0) {
-			udev_device_set_devnode(udev_device, &key[8]);
+			if (is_kernel)
+				udev_device_set_knodename(udev_device, &key[8]);
+			else
+				udev_device_set_devnode(udev_device, &key[8]);
 		} else if (strncmp(key, "DEVLINKS=", 9) == 0) {
 			char devlinks[UTIL_PATH_SIZE];
 			char *slink;
 			char *next;
 
-			util_strlcpy(devlinks, &key[9], sizeof(devlinks));
+			util_strscpy(devlinks, sizeof(devlinks), &key[9]);
 			slink = devlinks;
 			next = strchr(slink, ' ');
 			while (next != NULL) {
@@ -558,15 +620,10 @@ retry:
 			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);
 		}
@@ -599,7 +656,8 @@ retry:
 	return udev_device;
 }
 
-int udev_monitor_send_device(struct udev_monitor *udev_monitor, struct udev_device *udev_device)
+int udev_monitor_send_device(struct udev_monitor *udev_monitor,
+			     struct udev_monitor *destination, struct udev_device *udev_device)
 {
 	struct msghdr smsg;
 	struct iovec iov[2];
@@ -614,19 +672,17 @@ int udev_monitor_send_device(struct udev_monitor *udev_monitor, struct udev_devi
 	if (udev_monitor->sun.sun_family != 0) {
 		const char *action;
 		char header[2048];
-		size_t hlen;
+		char *s;
 
 		/* header <action>@<devpath> */
 		action = udev_device_get_action(udev_device);
 		if (action == NULL)
 			return -EINVAL;
-		util_strlcpy(header, action, sizeof(header));
-		util_strlcat(header, "@", sizeof(header));
-		hlen = util_strlcat(header, udev_device_get_devpath(udev_device), sizeof(header))+1;
-		if (hlen >= sizeof(header))
+		s = header;
+		if (util_strpcpyl(&s, sizeof(header), action, "@", udev_device_get_devpath(udev_device), NULL) == 0)
 			return -EINVAL;
 		iov[0].iov_base = header;
-		iov[0].iov_len = hlen;
+		iov[0].iov_len = (s - header)+1;
 
 		/* add properties list */
 		iov[1].iov_base = (char *)buf;
@@ -644,10 +700,13 @@ int udev_monitor_send_device(struct udev_monitor *udev_monitor, struct udev_devi
 
 		/* add versioned header */
 		memset(&nlh, 0x00, sizeof(struct udev_monitor_netlink_header));
-		util_strlcpy(nlh.version, "udev-" VERSION, sizeof(nlh.version));
+		util_strscpy(nlh.version, sizeof(nlh.version), "udev-" VERSION);
 		nlh.magic = htonl(UDEV_MONITOR_MAGIC);
 		val = udev_device_get_subsystem(udev_device);
 		nlh.filter_subsystem = htonl(util_string_hash32(val));
+		val = udev_device_get_devtype(udev_device);
+		if (val != NULL)
+			nlh.filter_devtype = htonl(util_string_hash32(val));
 		iov[0].iov_base = &nlh;
 		iov[0].iov_len = sizeof(struct udev_monitor_netlink_header);
 
@@ -660,8 +719,16 @@ int udev_monitor_send_device(struct udev_monitor *udev_monitor, struct udev_devi
 		memset(&smsg, 0x00, sizeof(struct msghdr));
 		smsg.msg_iov = iov;
 		smsg.msg_iovlen = 2;
-		/* no destination besides the muticast group, we will always get ECONNREFUSED */
-		smsg.msg_name = &udev_monitor->snl_peer;
+		/*
+		 * Use custom address for target, or the default one.
+		 *
+		 * If we send to a muticast group, we will get
+		 * ECONNREFUSED, which is expected.
+		 */
+		if (destination != NULL)
+			smsg.msg_name = &destination->snl;
+		else
+			smsg.msg_name = &udev_monitor->snl_destination;
 		smsg.msg_namelen = sizeof(struct sockaddr_nl);
 	} else {
 		return -1;
@@ -672,14 +739,22 @@ int udev_monitor_send_device(struct udev_monitor *udev_monitor, struct udev_devi
 	return count;
 }
 
-int udev_monitor_filter_add_match_subsystem(struct udev_monitor *udev_monitor, const char *subsystem)
+int udev_monitor_filter_add_match_subsystem_devtype(struct udev_monitor *udev_monitor, const char *subsystem, const char *devtype)
 {
 	if (udev_monitor == NULL)
 		return -EINVAL;
 	if (subsystem == NULL)
 		return 0;
 	if (udev_list_entry_add(udev_monitor->udev,
-				&udev_monitor->filter_subsystem_list, subsystem, NULL, 1, 0) == NULL)
+				&udev_monitor->filter_subsystem_list, subsystem, devtype, 0, 0) == NULL)
 		return -ENOMEM;
 	return 0;
 }
+
+int udev_monitor_filter_remove(struct udev_monitor *udev_monitor)
+{
+	static struct sock_fprog filter = { 0, NULL };
+
+	udev_list_cleanup_entries(udev_monitor->udev, &udev_monitor->filter_subsystem_list);
+	return setsockopt(udev_monitor->sock, SOL_SOCKET, SO_ATTACH_FILTER, &filter, sizeof(filter));
+}