X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=util-linux%2Fmdev.c;h=b4042c07ecaeda7bbabc2a9ad5c4707d36a13caf;hb=dd8adde3866ac22bd510348b733bb29e1662ac6d;hp=99e487532f20df41a758e5b2a832fe30fdc76587;hpb=aa0a12d5495a9cc8612e026ea5787eee4b019095;p=oweals%2Fbusybox.git

diff --git a/util-linux/mdev.c b/util-linux/mdev.c
index 99e487532..b4042c07e 100644
--- a/util-linux/mdev.c
+++ b/util-linux/mdev.c
@@ -64,11 +64,8 @@
 struct globals {
 	int root_major, root_minor;
 	char *subsystem;
-};
+} FIX_ALIASING;
 #define G (*(struct globals*)&bb_common_bufsiz1)
-#define root_major (G.root_major)
-#define root_minor (G.root_minor)
-#define subsystem  (G.subsystem )
 
 /* Prevent infinite loops in /sys symlinks */
 #define MAX_SYSFS_DEPTH 3
@@ -101,13 +98,17 @@ static char *build_alias(char *alias, const char *device_name)
 	return alias;
 }
 
-/* mknod in /dev based on a path like "/sys/block/hda/hda1" */
-/* NB: "mdev -s" may call us many times, do not leak memory/fds! */
+/* mknod in /dev based on a path like "/sys/block/hda/hda1"
+ * NB1: path parameter needs to have SCRATCH_SIZE scratch bytes
+ * after NUL, but we promise to not mangle (IOW: to restore if needed)
+ * path string.
+ * NB2: "mdev -s" may call us many times, do not leak memory/fds!
+ */
 static void make_device(char *path, int delete)
 {
-	char *device_name;
+	char *device_name, *subsystem_slash_devname;
 	int major, minor, type, len;
-	int mode;
+	mode_t mode;
 	parser_t *parser;
 
 	/* Try to read major/minor string.  Note that the kernel puts \n after
@@ -136,17 +137,29 @@ static void make_device(char *path, int delete)
 	device_name = (char*) bb_basename(path);
 	/* http://kernel.org/doc/pending/hotplug.txt says that only
 	 * "/sys/block/..." is for block devices. "/sys/bus" etc is not.
-	 * But since 2.6.25 block devices are also in /sys/class/block,
-	 * we use strstr("/block/") to forestall future surprises. */
+	 * But since 2.6.25 block devices are also in /sys/class/block.
+	 * We use strstr("/block/") to forestall future surprises. */
 	type = S_IFCHR;
-	if (strstr(path, "/block/"))
+	if (strstr(path, "/block/") || (G.subsystem && strncmp(G.subsystem, "block", 5) == 0))
 		type = S_IFBLK;
 
 	/* Make path point to "subsystem/device_name" */
-	if (path[5] == 'b') /* legacy /sys/block? */
+	subsystem_slash_devname = NULL;
+	/* Check for coldplug invocations first */
+	if (strncmp(path, "/sys/block/", 11) == 0) /* legacy case */
 		path += sizeof("/sys/") - 1;
-	else
+	else if (strncmp(path, "/sys/class/", 11) == 0)
 		path += sizeof("/sys/class/") - 1;
+	else {
+		/* Example of a hotplug invocation:
+		 * SUBSYSTEM="block"
+		 * DEVPATH="/sys" + "/devices/virtual/mtd/mtd3/mtdblock3"
+		 * ("/sys" is added by mdev_main)
+		 * - path does not contain subsystem
+		 */
+		subsystem_slash_devname = concat_path_file(G.subsystem, device_name);
+		path = subsystem_slash_devname;
+	}
 
 	/* If we have config file, look up user settings */
 	if (ENABLE_FEATURE_MDEV_CONF)
@@ -191,7 +204,8 @@ static void make_device(char *path, int delete)
 				if (major < 0)
 					continue; /* no dev, no match */
 				sc = sscanf(val, "@%u,%u-%u", &cmaj, &cmin0, &cmin1);
-				if (sc < 1 || major != cmaj
+				if (sc < 1
+				 || major != cmaj
 				 || (sc == 2 && minor != cmin0)
 				 || (sc == 3 && (minor < cmin0 || minor > cmin1))
 				) {
@@ -230,7 +244,8 @@ static void make_device(char *path, int delete)
 
 				/* If no match, skip rest of line */
 				/* (regexec returns whole pattern as "range" 0) */
-				if (result || off[0].rm_so
+				if (result
+				 || off[0].rm_so
 				 || ((int)off[0].rm_eo != (int)strlen(str_to_match))
 				) {
 					continue; /* this line doesn't match */
@@ -242,30 +257,37 @@ static void make_device(char *path, int delete)
 
 			/* 2nd field: uid:gid - device ownership */
 			if (get_uidgid(&ugid, tokens[1], 1) == 0)
-				bb_error_msg("unknown user/group %s", tokens[1]);
+				bb_error_msg("unknown user/group %s on line %d", tokens[1], parser->lineno);
 
 			/* 3rd field: mode - device permissions */
-			mode = strtoul(tokens[2], NULL, 8);
+			bb_parse_mode(tokens[2], &mode);
 
 			val = tokens[3];
-			/* 4th field (opt): >|=alias */
+			/* 4th field (opt): ">|=alias" or "!" to not create the node */
 
 			if (ENABLE_FEATURE_MDEV_RENAME && val) {
-				aliaslink = val[0];
-				if (aliaslink == '>' || aliaslink == '=') {
-					char *a, *s, *st;
-					char *p;
-					unsigned i, n;
-
-					a = val;
-					s = strchrnul(val, ' ');
-					st = strchrnul(val, '\t');
-					if (st < s)
-						s = st;
-					val = (s[0] && s[1]) ? s+1 : NULL;
+				char *a, *s, *st;
+
+				a = val;
+				s = strchrnul(val, ' ');
+				st = strchrnul(val, '\t');
+				if (st < s)
+					s = st;
+				st = (s[0] && s[1]) ? s+1 : NULL;
+
+				aliaslink = a[0];
+				if (aliaslink == '!' && s == a+1) {
+					val = st;
+					/* "!": suppress node creation/deletion */
+					major = -1;
+				}
+				else if (aliaslink == '>' || aliaslink == '=') {
+					val = st;
 					s[0] = '\0';
-
 					if (ENABLE_FEATURE_MDEV_RENAME_REGEXP) {
+						char *p;
+						unsigned i, n;
+
 						/* substitute %1..9 with off[1..9], if any */
 						n = 0;
 						s = a;
@@ -299,67 +321,74 @@ static void make_device(char *path, int delete)
 				const char *s = "$@*";
 				const char *s2 = strchr(s, val[0]);
 
-				if (!s2)
-					bb_error_msg_and_die("bad line %u", parser->lineno);
+				if (!s2) {
+					bb_error_msg("bad line %u", parser->lineno);
+					if (ENABLE_FEATURE_MDEV_RENAME)
+						free(alias);
+					continue;
+				}
 
 				/* Are we running this command now?
 				 * Run $cmd on delete, @cmd on create, *cmd on both
 				 */
-				if (s2-s != delete)
+				if (s2 - s != delete) {
+					/* We are here if: '*',
+					 * or: '@' and delete = 0,
+					 * or: '$' and delete = 1
+					 */
 					command = xstrdup(val + 1);
+				}
 			}
 		}
 
 		/* End of field parsing */
 
 		/* "Execute" the line we found */
-
-		if (!delete && major >= 0) {
-			if (ENABLE_FEATURE_MDEV_RENAME)
-				unlink(device_name);
-			if (mknod(device_name, mode | type, makedev(major, minor)) && errno != EEXIST)
-				bb_perror_msg_and_die("mknod %s", device_name);
-			if (major == root_major && minor == root_minor)
-				symlink(device_name, "root");
-			if (ENABLE_FEATURE_MDEV_CONF) {
-				chmod(device_name, mode);
-				chown(device_name, ugid.uid, ugid.gid);
-			}
-			if (ENABLE_FEATURE_MDEV_RENAME && alias) {
-				alias = build_alias(alias, device_name);
-				/* move the device, and optionally
-				 * make a symlink to moved device node */
-				if (rename(device_name, alias) == 0 && aliaslink == '>')
-					symlink(alias, device_name);
-				free(alias);
+		{
+			const char *node_name;
+
+			node_name = device_name;
+			if (ENABLE_FEATURE_MDEV_RENAME && alias)
+				node_name = alias = build_alias(alias, device_name);
+
+			if (!delete && major >= 0) {
+				if (mknod(node_name, mode | type, makedev(major, minor)) && errno != EEXIST)
+					bb_perror_msg("can't create '%s'", node_name);
+				if (major == G.root_major && minor == G.root_minor)
+					symlink(node_name, "root");
+				if (ENABLE_FEATURE_MDEV_CONF) {
+					chmod(node_name, mode);
+					chown(node_name, ugid.uid, ugid.gid);
+				}
+				if (ENABLE_FEATURE_MDEV_RENAME && alias) {
+					if (aliaslink == '>')
+						symlink(node_name, device_name);
+				}
 			}
-		}
 
-		if (ENABLE_FEATURE_MDEV_EXEC && command) {
-			/* setenv will leak memory, use putenv/unsetenv/free */
-			char *s = xasprintf("%s=%s", "MDEV", device_name);
-			char *s1 = xasprintf("%s=%s", "SUBSYSTEM", subsystem);
-			putenv(s);
-			putenv(s1);
-			if (system(command) == -1)
-				bb_perror_msg_and_die("can't run '%s'", command);
-			unsetenv("SUBSYSTEM");
-			free(s1);
-			unsetenv("MDEV");
-			free(s);
-			free(command);
-		}
+			if (ENABLE_FEATURE_MDEV_EXEC && command) {
+				/* setenv will leak memory, use putenv/unsetenv/free */
+				char *s = xasprintf("%s=%s", "MDEV", node_name);
+				char *s1 = xasprintf("%s=%s", "SUBSYSTEM", G.subsystem);
+				putenv(s);
+				putenv(s1);
+				if (system(command) == -1)
+					bb_perror_msg("can't run '%s'", command);
+				bb_unsetenv_and_free(s1);
+				bb_unsetenv_and_free(s);
+				free(command);
+			}
 
-		if (delete) {
-			unlink(device_name);
-			/* At creation time, device might have been moved
-			 * and a symlink might have been created. Undo that. */
+			if (delete && major >= 0) {
+				if (ENABLE_FEATURE_MDEV_RENAME && alias) {
+					if (aliaslink == '>')
+						unlink(device_name);
+				}
+				unlink(node_name);
+			}
 
-			if (ENABLE_FEATURE_MDEV_RENAME && alias) {
-				alias = build_alias(alias, device_name);
-				unlink(alias);
+			if (ENABLE_FEATURE_MDEV_RENAME)
 				free(alias);
-			}
 		}
 
 		/* We found matching line.
@@ -372,6 +401,7 @@ static void make_device(char *path, int delete)
 
 	if (ENABLE_FEATURE_MDEV_CONF)
 		config_close(parser);
+	free(subsystem_slash_devname);
 }
 
 /* File callback for /sys/ traversal */
@@ -389,7 +419,7 @@ static int FAST_FUNC fileAction(const char *fileName,
 
 	strcpy(scratch, fileName);
 	scratch[len] = '\0';
-	make_device(scratch, 0);
+	make_device(scratch, /*delete:*/ 0);
 
 	return TRUE;
 }
@@ -403,10 +433,10 @@ static int FAST_FUNC dirAction(const char *fileName UNUSED_PARAM,
 	/* Extract device subsystem -- the name of the directory
 	 * under /sys/class/ */
 	if (1 == depth) {
-		free(subsystem);
-		subsystem = strrchr(fileName, '/');
-		if (subsystem)
-			subsystem = xstrdup(subsystem + 1);
+		free(G.subsystem);
+		G.subsystem = strrchr(fileName, '/');
+		if (G.subsystem)
+			G.subsystem = xstrdup(G.subsystem + 1);
 	}
 
 	return (depth >= MAX_SYSFS_DEPTH ? SKIP : TRUE);
@@ -491,8 +521,8 @@ int mdev_main(int argc UNUSED_PARAM, char **argv)
 		struct stat st;
 
 		xstat("/", &st);
-		root_major = major(st.st_dev);
-		root_minor = minor(st.st_dev);
+		G.root_major = major(st.st_dev);
+		G.root_minor = minor(st.st_dev);
 
 		/* ACTION_FOLLOWLINKS is needed since in newer kernels
 		 * /sys/block/loop* (for example) are symlinks to dirs,
@@ -518,6 +548,9 @@ int mdev_main(int argc UNUSED_PARAM, char **argv)
 		char *seq;
 		char *action;
 		char *env_path;
+		static const char keywords[] ALIGN1 = "remove\0add\0";
+		enum { OP_remove = 0, OP_add };
+		smalluint op;
 
 		/* Hotplug:
 		 * env ACTION=... DEVPATH=... SUBSYSTEM=... [SEQNUM=...] mdev
@@ -526,11 +559,11 @@ int mdev_main(int argc UNUSED_PARAM, char **argv)
 		 */
 		action = getenv("ACTION");
 		env_path = getenv("DEVPATH");
-		subsystem = getenv("SUBSYSTEM");
-		if (!action || !env_path /*|| !subsystem*/)
+		G.subsystem = getenv("SUBSYSTEM");
+		if (!action || !env_path /*|| !G.subsystem*/)
 			bb_show_usage();
 		fw = getenv("FIRMWARE");
-
+		op = index_in_strings(keywords, action);
 		/* If it exists, does /dev/mdev.seq match $SEQNUM?
 		 * If it does not match, earlier mdev is running
 		 * in parallel, and we need to wait */
@@ -557,18 +590,15 @@ int mdev_main(int argc UNUSED_PARAM, char **argv)
 		}
 
 		snprintf(temp, PATH_MAX, "/sys%s", env_path);
-		if (strcmp(action, "remove") == 0) {
+		if (op == OP_remove) {
 			/* Ignoring "remove firmware". It was reported
 			 * to happen and to cause erroneous deletion
 			 * of device nodes. */
 			if (!fw)
-				make_device(temp, 1);
+				make_device(temp, /*delete:*/ 1);
 		}
-		else if (strcmp(action, "add") == 0) {
-			/* make_device mangles its parameter, use a copy */
-			char *s = xstrdup(temp);
-			make_device(s, 0);
-			free(s);
+		else if (op == OP_add) {
+			make_device(temp, /*delete:*/ 0);
 			if (ENABLE_FEATURE_MDEV_LOAD_FIRMWARE) {
 				if (fw)
 					load_firmware(fw, temp);