X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=util-linux%2Fmdev.c;h=a4c0520ac302179d7ee58a77de0b68b8f8a2cc9e;hb=67075bb95f23233c49628a624cc6ba86c3462dcb;hp=aef84ac458204fbe5ab0d62f4684951d6ea9c18e;hpb=a421ba8203df8cd8a09d4bfb158057d9e717648f;p=oweals%2Fbusybox.git

diff --git a/util-linux/mdev.c b/util-linux/mdev.c
index aef84ac45..a4c0520ac 100644
--- a/util-linux/mdev.c
+++ b/util-linux/mdev.c
@@ -1,243 +1,463 @@
-/* vi:set ts=4:
+/* vi: set sw=4 ts=4: */
+/*
  *
  * mdev - Mini udev for busybox
  *
  * Copyright 2005 Rob Landley <rob@landley.net>
  * Copyright 2005 Frank Sorenson <frank@tuxrocks.com>
  *
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ * Licensed under GPL version 2, see file LICENSE in this tarball for details.
  */
 
-#include <ctype.h>
-#include <dirent.h>
-#include <errno.h>
-#include <fcntl.h>
-#include <stdio.h>
-#include <string.h>
-#include <sys/mman.h>
-#include <sys/stat.h>
-#include <sys/types.h>
-#include <unistd.h>
-#include <stdlib.h>
-#include "busybox.h"
+#include "libbb.h"
 #include "xregex.h"
 
-#define DEV_PATH	"/dev"
-#define MDEV_CONF	"/etc/mdev.conf"
+struct globals {
+	int root_major, root_minor;
+};
+#define G (*(struct globals*)&bb_common_bufsiz1)
+#define root_major (G.root_major)
+#define root_minor (G.root_minor)
 
-#include <busybox.h>
+/* Prevent infinite loops in /sys symlinks */
+#define MAX_SYSFS_DEPTH 3
+
+/* We use additional 64+ bytes in make_device() */
+#define SCRATCH_SIZE 80
+
+static char *next_field(char *s)
+{
+	char *end = skip_non_whitespace(s);
+	s = skip_whitespace(end);
+	*end = '\0';
+	if (*s == '\0')
+		s = NULL;
+	return s;
+}
 
 /* mknod in /dev based on a path like "/sys/block/hda/hda1" */
-static void make_device(char *path)
+/* NB: "mdev -s" may call us many times, do not leak memory/fds! */
+static void make_device(char *path, int delete)
 {
-	char *device_name, *s;
-	int major, minor, type, len, fd;
+	const char *device_name;
+	int major, minor, type, len;
 	int mode = 0660;
 	uid_t uid = 0;
 	gid_t gid = 0;
+	char *dev_maj_min = path + strlen(path);
+	char *command = NULL;
+	char *alias = NULL;
+	char aliaslink = aliaslink; /* for compiler */
 
-	RESERVE_CONFIG_BUFFER(temp, PATH_MAX);
-
-	/* Try to read major/minor string */
+	/* Force the configuration file settings exactly. */
+	umask(0);
 
-	snprintf(temp, PATH_MAX, "%s/dev", path);
-	fd = open(temp, O_RDONLY);
-	len = read(fd, temp, PATH_MAX-1);
-	close(fd);
-	if (len < 1) goto end;
+	/* Try to read major/minor string.  Note that the kernel puts \n after
+	 * the data, so we don't need to worry about null terminating the string
+	 * because sscanf() will stop at the first nondigit, which \n is.  We
+	 * also depend on path having writeable space after it.
+	 */
+	if (!delete) {
+		strcpy(dev_maj_min, "/dev");
+		len = open_read_close(path, dev_maj_min + 1, 64);
+		*dev_maj_min++ = '\0';
+		if (len < 1) {
+			if (!ENABLE_FEATURE_MDEV_EXEC)
+				return;
+			/* no "dev" file, so just try to run script */
+			*dev_maj_min = '\0';
+		}
+	}
 
 	/* Determine device name, type, major and minor */
+	device_name = bb_basename(path);
+	/* http://kernel.org/doc/pending/hotplug.txt says that only
+	 * "/sys/block/..." is for block devices. "/sys/bus" etc is not!
+	 * Since kernel 2.6.25 block devices are also in /sys/class/block. */
+	/* TODO: would it be acceptable to just use strstr(path, "/block/")? */
+	if (strncmp(&path[5], "class/block/"+6, 6) != 0
+	 && strncmp(&path[5], "class/block/", 12) != 0)
+	        type = S_IFCHR;
+	else
+	        type = S_IFBLK;
 
-	device_name = strrchr(path, '/') + 1;
-	type = strncmp(path+5, "block/", 6) ? S_IFCHR : S_IFBLK;
-	if (sscanf(temp, "%d:%d", &major, &minor) != 2)
-		goto end;
+	if (ENABLE_FEATURE_MDEV_CONF) {
+		FILE *fp;
+		char *line, *val, *next;
+		unsigned lineno = 0;
+
+		/* If we have config file, look up user settings */
+		fp = fopen_or_warn("/etc/mdev.conf", "r");
+		if (!fp)
+			goto end_parse;
+
+		while ((line = xmalloc_fgetline(fp)) != NULL) {
+			regmatch_t off[1+9*ENABLE_FEATURE_MDEV_RENAME_REGEXP];
+
+			++lineno;
+			trim(line);
+			if (!line[0])
+				goto next_line;
+
+			/* Fields: regex uid:gid mode [alias] [cmd] */
+
+			/* 1st field: regex to match this device */
+			next = next_field(line);
+			{
+				regex_t match;
+				int result;
+
+				/* Is this it? */
+				xregcomp(&match, line, REG_EXTENDED);
+				result = regexec(&match, device_name, ARRAY_SIZE(off), off, 0);
+				regfree(&match);
+
+				//bb_error_msg("matches:");
+				//for (int i = 0; i < ARRAY_SIZE(off); i++) {
+				//	if (off[i].rm_so < 0) continue;
+				//	bb_error_msg("match %d: '%.*s'\n", i,
+				//		(int)(off[i].rm_eo - off[i].rm_so),
+				//		device_name + off[i].rm_so);
+				//}
+
+				/* If not this device, skip rest of line */
+				/* (regexec returns whole pattern as "range" 0) */
+				if (result || off[0].rm_so
+				 || ((int)off[0].rm_eo != (int)strlen(device_name))
+				) {
+					goto next_line;
+				}
+			}
 
-	/* If we have a config file, look up permissions for this device */
+			/* This line matches: stop parsing the file
+			 * after parsing the rest of fields */
+
+			/* 2nd field: uid:gid - device ownership */
+			if (!next) /* field must exist */
+				bb_error_msg_and_die("bad line %u", lineno);
+			val = next;
+			next = next_field(val);
+			{
+				struct passwd *pass;
+				struct group *grp;
+				char *str_uid = val;
+				char *str_gid = strchrnul(val, ':');
+
+				if (*str_gid)
+					*str_gid++ = '\0';
+				/* Parse UID */
+				pass = getpwnam(str_uid);
+				if (pass)
+					uid = pass->pw_uid;
+				else
+					uid = strtoul(str_uid, NULL, 10);
+				/* Parse GID */
+				grp = getgrnam(str_gid);
+				if (grp)
+					gid = grp->gr_gid;
+				else
+					gid = strtoul(str_gid, NULL, 10);
+			}
 
-	if (ENABLE_FEATURE_MDEV_CONF) {
-		char *conf, *pos, *end;
-
-		/* mmap the config file */
-		if (-1 != (fd=open(MDEV_CONF,O_RDONLY))) {
-			len = lseek(fd, 0, SEEK_END);
-			conf = mmap(NULL, len, PROT_READ, MAP_PRIVATE, fd, 0);
-			if (conf) {
-				int line = 0;
-
-				/* Loop through lines in mmaped file*/
-				for (pos=conf; pos-conf<len;) {
-					int field;
-					char *end2;
-
-					line++;
-					/* find end of this line */
-					for(end=pos; end-conf<len && *end!='\n'; end++)
-						;
-
-					/* Three fields: regex, uid:gid, mode */
-					for (field=3; field; field--) {
-						/* Skip whitespace */
-						while (pos<end && isspace(*pos))
-							pos++;
-						if (pos==end || *pos=='#')
-							break;
-						for (end2=pos; end2<end && !isspace(*end2) && *end2!='#'; end2++)
-							;
-
-						switch (field) {
-							/* Regex to match this device */
-							case 3:
-							{
-								char *regex = strndupa(pos,end2-pos);
-								regex_t match;
-								regmatch_t off;
-								int result;
-
-								/* Is this it? */
-								xregcomp(&match,regex,REG_EXTENDED);
-								result = regexec(&match,device_name,1,&off,0);
-								regfree(&match);
-
-								/* If not this device, skip rest of line */
-								if (result || off.rm_so || off.rm_eo!=strlen(device_name))
-									goto end_line;
-
-								break;
-							}
-							/* uid:gid */
-							case 2:
-							{
-								char *s2;
-
-								/* Find : */
-								for(s=pos; s<end2 && *s!=':'; s++)
-									;
-								if (s == end2)
-									goto end_line;
-
-								/* Parse UID */
-								uid = strtoul(pos,&s2,10);
-								if (s != s2) {
-									struct passwd *pass;
-									pass = getpwnam(strndupa(pos,s-pos));
-									if (!pass)
-										goto end_line;
-									uid = pass->pw_uid;
-								}
-								s++;
-								/* parse GID */
-								gid = strtoul(s,&s2,10);
-								if (end2 != s2) {
-									struct group *grp;
-									grp = getgrnam(strndupa(s,end2-s));
-									if (!grp)
-										goto end_line;
-									gid = grp->gr_gid;
-								}
-								break;
-							}
-							/* mode */
-							case 1:
-							{
-								mode = strtoul(pos,&pos,8);
-								if (pos != end2)
-									goto end_line;
-								else
-									goto found_device;
-							}
+			/* 3rd field: mode - device permissions */
+			if (!next) /* field must exist */
+				bb_error_msg_and_die("bad line %u", lineno);
+			val = next;
+			next = next_field(val);
+			mode = strtoul(val, NULL, 8);
+
+			/* 4th field (opt): >alias */
+#if ENABLE_FEATURE_MDEV_RENAME
+			if (!next)
+				break;
+			if (*next == '>' || *next == '=') {
+#if ENABLE_FEATURE_MDEV_RENAME_REGEXP
+				char *s, *p;
+				unsigned i, n;
+
+				aliaslink = *next;
+				val = next;
+				next = next_field(val);
+				/* substitute %1..9 with off[1..9], if any */
+				n = 0;
+				s = val;
+				while (*s)
+					if (*s++ == '%')
+						n++;
+
+				p = alias = xzalloc(strlen(val) + n * strlen(device_name));
+				s = val + 1;
+				while (*s) {
+					*p = *s;
+					if ('%' == *s) {
+						i = (s[1] - '0');
+						if (i <= 9 && off[i].rm_so >= 0) {
+							n = off[i].rm_eo - off[i].rm_so;
+							strncpy(p, device_name + off[i].rm_so, n);
+							p += n - 1;
+							s++;
 						}
-						pos = end2;
 					}
-end_line:
-					/* Did everything parse happily? */
-					if (field && field!=3)
-						bb_error_msg_and_die("Bad line %d",line);
-
-					/* Next line */
-					pos = ++end;
+					p++;
+					s++;
 				}
-found_device:
-				munmap(conf, len);
+#else
+				aliaslink = *next;
+				val = next;
+				next = next_field(val);
+				alias = xstrdup(val + 1);
+#endif
 			}
-			close(fd);
-		}
+#endif /* ENABLE_FEATURE_MDEV_RENAME */
+
+			/* The rest (opt): command to run */
+			if (!next)
+				break;
+			val = next;
+			if (ENABLE_FEATURE_MDEV_EXEC) {
+				const char *s = "@$*";
+				const char *s2 = strchr(s, *val);
+
+				if (!s2)
+					bb_error_msg_and_die("bad line %u", lineno);
+
+				/* Correlate the position in the "@$*" with the delete
+				 * step so that we get the proper behavior:
+				 * @cmd: run on create
+				 * $cmd: run on delete
+				 * *cmd: run on both
+				 */
+				if ((s2 - s + 1) /*1/2/3*/ & /*1/2*/ (1 + delete)) {
+					command = xstrdup(val + 1);
+				}
+			}
+			/* end of field parsing */
+			break; /* we found matching line, stop */
+ next_line:
+			free(line);
+		} /* end of "while line is read from /etc/mdev.conf" */
+
+		free(line); /* in case we used "break" to get here */
+		fclose(fp);
 	}
+ end_parse:
 
-	sprintf(temp, "%s/%s", DEV_PATH, device_name);
-	umask(0);
-	if (mknod(temp, mode | type, makedev(major, minor)) && errno != EEXIST)
-		bb_perror_msg_and_die("mknod %s failed", temp);
+	if (!delete && sscanf(dev_maj_min, "%u:%u", &major, &minor) == 2) {
 
-	if (ENABLE_FEATURE_MDEV_CONF) chown(temp,uid,gid);
+		if (ENABLE_FEATURE_MDEV_RENAME)
+			unlink(device_name);
 
-end:
-	RELEASE_CONFIG_BUFFER(temp);
-}
-
-/* Recursive search of /sys/block or /sys/class.  path must be a writeable
- * buffer of size PATH_MAX containing the directory string to start at. */
+		if (mknod(device_name, mode | type, makedev(major, minor)) && errno != EEXIST)
+			bb_perror_msg_and_die("mknod %s", device_name);
 
-static void find_dev(char *path)
-{
-	DIR *dir;
-	size_t len = strlen(path);
-	struct dirent *entry;
+		if (major == root_major && minor == root_minor)
+			symlink(device_name, "root");
 
-	if ((dir = opendir(path)) == NULL)
-		return;
+		if (ENABLE_FEATURE_MDEV_CONF) {
+			chown(device_name, uid, gid);
 
-	while ((entry = readdir(dir)) != NULL) {
+			if (ENABLE_FEATURE_MDEV_RENAME && alias) {
+				char *dest;
 
-		/* Skip "." and ".." (also skips hidden files, which is ok) */
+				/* ">bar/": rename to bar/device_name */
+				/* ">bar[/]baz": rename to bar[/]baz */
+				dest = strrchr(alias, '/');
+				if (dest) { /* ">bar/[baz]" ? */
+					*dest = '\0'; /* mkdir bar */
+					bb_make_directory(alias, 0755, FILEUTILS_RECUR);
+					*dest = '/';
+					if (dest[1] == '\0') { /* ">bar/" => ">bar/device_name" */
+						dest = alias;
+						alias = concat_path_file(alias, device_name);
+						free(dest);
+					}
+				}
 
-		if (entry->d_name[0] == '.')
-			continue;
+				/* move the device, and optionally
+				 * make a symlink to moved device node */
+				if (rename(device_name, alias) == 0 && aliaslink == '>')
+					symlink(alias, device_name);
 
-		if (entry->d_type == DT_DIR) {
-			snprintf(path+len, PATH_MAX-len, "/%s", entry->d_name);
-			find_dev(path);
+				free(alias);
+			}
 		}
+	}
 
-		/* If there's a dev entry, mknod it */
-
-		if (!strcmp(entry->d_name, "dev")) make_device(path);
+	if (ENABLE_FEATURE_MDEV_EXEC && command) {
+		/* setenv will leak memory, use putenv/unsetenv/free */
+		char *s = xasprintf("MDEV=%s", device_name);
+		putenv(s);
+		if (system(command) == -1)
+			bb_perror_msg_and_die("can't run '%s'", command);
+		s[4] = '\0';
+		unsetenv(s);
+		free(s);
+		free(command);
 	}
 
-	closedir(dir);
+	if (delete)
+		unlink(device_name);
 }
 
-int mdev_main(int argc, char *argv[])
+/* File callback for /sys/ traversal */
+static int FAST_FUNC fileAction(const char *fileName,
+		struct stat *statbuf UNUSED_PARAM,
+		void *userData,
+		int depth UNUSED_PARAM)
 {
-	char *action;
-	char *env_path;
-	RESERVE_CONFIG_BUFFER(temp,PATH_MAX);
+	size_t len = strlen(fileName) - 4; /* can't underflow */
+	char *scratch = userData;
 
-	/* Scan */
+	/* len check is for paranoid reasons */
+	if (strcmp(fileName + len, "/dev") || len >= PATH_MAX)
+		return FALSE;
 
-	if (argc == 2 && !strcmp(argv[1],"-s")) {
-		strcpy(temp,"/sys/block");
-		find_dev(temp);
-		strcpy(temp,"/sys/class");
-		find_dev(temp);
+	strcpy(scratch, fileName);
+	scratch[len] = '\0';
+	make_device(scratch, 0);
 
-	/* Hotplug */
+	return TRUE;
+}
+
+/* Directory callback for /sys/ traversal */
+static int FAST_FUNC dirAction(const char *fileName UNUSED_PARAM,
+		struct stat *statbuf UNUSED_PARAM,
+		void *userData UNUSED_PARAM,
+		int depth)
+{
+	return (depth >= MAX_SYSFS_DEPTH ? SKIP : TRUE);
+}
+
+/* For the full gory details, see linux/Documentation/firmware_class/README
+ *
+ * Firmware loading works like this:
+ * - kernel sets FIRMWARE env var
+ * - userspace checks /lib/firmware/$FIRMWARE
+ * - userspace waits for /sys/$DEVPATH/loading to appear
+ * - userspace writes "1" to /sys/$DEVPATH/loading
+ * - userspace copies /lib/firmware/$FIRMWARE into /sys/$DEVPATH/data
+ * - userspace writes "0" (worked) or "-1" (failed) to /sys/$DEVPATH/loading
+ * - kernel loads firmware into device
+ */
+static void load_firmware(const char *const firmware, const char *const sysfs_path)
+{
+	int cnt;
+	int firmware_fd, loading_fd, data_fd;
+
+	/* check for /lib/firmware/$FIRMWARE */
+	xchdir("/lib/firmware");
+	firmware_fd = xopen(firmware, O_RDONLY);
+
+	/* in case we goto out ... */
+	data_fd = -1;
+
+	/* check for /sys/$DEVPATH/loading ... give 30 seconds to appear */
+	xchdir(sysfs_path);
+	for (cnt = 0; cnt < 30; ++cnt) {
+		loading_fd = open("loading", O_WRONLY);
+		if (loading_fd != -1)
+			goto loading;
+		sleep(1);
+	}
+	goto out;
+
+ loading:
+	/* tell kernel we're loading by `echo 1 > /sys/$DEVPATH/loading` */
+	if (full_write(loading_fd, "1", 1) != 1)
+		goto out;
+
+	/* load firmware by `cat /lib/firmware/$FIRMWARE > /sys/$DEVPATH/data */
+	data_fd = open("data", O_WRONLY);
+	if (data_fd == -1)
+		goto out;
+	cnt = bb_copyfd_eof(firmware_fd, data_fd);
+
+	/* tell kernel result by `echo [0|-1] > /sys/$DEVPATH/loading` */
+	if (cnt > 0)
+		full_write(loading_fd, "0", 1);
+	else
+		full_write(loading_fd, "-1", 2);
+
+ out:
+	if (ENABLE_FEATURE_CLEAN_UP) {
+		close(firmware_fd);
+		close(loading_fd);
+		close(data_fd);
+	}
+}
 
+int mdev_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int mdev_main(int argc, char **argv)
+{
+	char *action;
+	char *env_path;
+	RESERVE_CONFIG_BUFFER(temp, PATH_MAX + SCRATCH_SIZE);
+
+	/* We can be called as hotplug helper */
+	/* Kernel cannot provide suitable stdio fds for us, do it ourself */
+#if 1
+	bb_sanitize_stdio();
+#else
+	/* Debug code */
+	/* Replace LOGFILE by other file or device name if you need */
+#define LOGFILE "/dev/console"
+	/* Just making sure fd 0 is not closed,
+	 * we don't really intend to read from it */
+	xmove_fd(xopen("/", O_RDONLY), STDIN_FILENO);
+	xmove_fd(xopen(LOGFILE, O_WRONLY|O_APPEND), STDOUT_FILENO);
+	xmove_fd(xopen(LOGFILE, O_WRONLY|O_APPEND), STDERR_FILENO);
+#endif
+
+	xchdir("/dev");
+
+	if (argc == 2 && !strcmp(argv[1], "-s")) {
+		/* Scan:
+		 * mdev -s
+		 */
+		struct stat st;
+
+		xstat("/", &st);
+		root_major = major(st.st_dev);
+		root_minor = minor(st.st_dev);
+
+		/* ACTION_FOLLOWLINKS is needed since in newer kernels
+		 * /sys/block/loop* (for example) are symlinks to dirs,
+		 * not real directories.
+		 * (kernel's CONFIG_SYSFS_DEPRECATED makes them real dirs,
+		 * but we can't enforce that on users) */
+		recursive_action("/sys/block",
+			ACTION_RECURSE | ACTION_FOLLOWLINKS,
+			fileAction, dirAction, temp, 0);
+		recursive_action("/sys/class",
+			ACTION_RECURSE | ACTION_FOLLOWLINKS,
+			fileAction, dirAction, temp, 0);
 	} else {
+		/* Hotplug:
+		 * env ACTION=... DEVPATH=... mdev
+		 * ACTION can be "add" or "remove"
+		 * DEVPATH is like "/block/sda" or "/class/input/mice"
+		 */
 		action = getenv("ACTION");
 		env_path = getenv("DEVPATH");
-	    if (!action || !env_path)
+		if (!action || !env_path)
 			bb_show_usage();
 
-		if (!strcmp(action, "add")) {
-			sprintf(temp, "/sys%s", env_path);
-			make_device(temp);
-		} else if (!strcmp(action, "remove")) {
-			sprintf(temp, "%s/%s", DEV_PATH, strrchr(env_path, '/') + 1);
-			unlink(temp);
+		snprintf(temp, PATH_MAX, "/sys%s", env_path);
+		if (!strcmp(action, "remove"))
+			make_device(temp, 1);
+		else if (!strcmp(action, "add")) {
+			make_device(temp, 0);
+
+			if (ENABLE_FEATURE_MDEV_LOAD_FIRMWARE) {
+				char *fw = getenv("FIRMWARE");
+				if (fw)
+					load_firmware(fw, temp);
+			}
 		}
 	}
 
-	if (ENABLE_FEATURE_CLEAN_UP) RELEASE_CONFIG_BUFFER(temp);
+	if (ENABLE_FEATURE_CLEAN_UP)
+		RELEASE_CONFIG_BUFFER(temp);
+
 	return 0;
 }