X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=util-linux%2Fmdev.c;h=73a82314c3cf3ef572ffcdf7b697898c83c2c06f;hb=1449a2014a4e715a7a52b27caec528a9c802fa5f;hp=49904d17aa724d4c916457deda8b900670b630dc;hpb=70f7ef7be385f782e57106df523f1c5e16fbdc47;p=oweals%2Fbusybox.git

diff --git a/util-linux/mdev.c b/util-linux/mdev.c
index 49904d17a..73a82314c 100644
--- a/util-linux/mdev.c
+++ b/util-linux/mdev.c
@@ -1,121 +1,260 @@
 /* vi:set 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.
  */
 
+#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/sysmacros.h>
 #include <sys/types.h>
 #include <unistd.h>
+#include <stdlib.h>
+#include "busybox.h"
+#include "xregex.h"
 
 #define DEV_PATH	"/dev"
-#define DEV_MODE	0660
+#define MDEV_CONF	"/etc/mdev.conf"
 
 #include <busybox.h>
 
+struct mdev_globals
+{
+	int root_major, root_minor;
+} mdev_globals;
+
+#define bbg mdev_globals
+
 /* mknod in /dev based on a path like "/sys/block/hda/hda1" */
-void make_device(char *path)
+static void make_device(char *path)
 {
 	char *device_name, *s;
-	int major,minor,type,len,fd;
+	int major, minor, type, len, fd;
+	int mode = 0660;
+	uid_t uid = 0;
+	gid_t gid = 0;
+	char *temp = path + strlen(path);
 
-	RESERVE_CONFIG_BUFFER(temp,PATH_MAX);
+	/* 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. */
 
-	/* Try to read major/minor string */
-	
-	snprintf(temp, PATH_MAX, "%s/dev", path);
-	fd = open(temp, O_RDONLY);
-	len = read(fd, temp, PATH_MAX-1);
-	if (len<1) goto end;
-	temp[len] = 0;
+	strcat(path, "/dev");
+	fd = open(path, O_RDONLY);
+	len = read(fd, temp + 1, 64);
+	*temp++ = 0;
 	close(fd);
-	
+	if (len < 1) return;
+
 	/* Determine device name, type, major and minor */
-	
+
 	device_name = strrchr(path, '/') + 1;
-	type = strncmp(path+5, "block/" ,6) ? S_IFCHR : S_IFBLK;
-	major = minor = 0;
-	for(s = temp; *s; s++) {
-		if(*s == ':') {
-			major = minor;
-			minor = 0;
-		} else {
-			minor *= 10;
-			minor += (*s) - '0';
+	type = path[5]=='c' ? S_IFCHR : S_IFBLK;
+	if (sscanf(temp, "%d:%d", &major, &minor) != 2) return;
+
+	/* If we have a config file, look up permissions for this device */
+
+	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;
+							}
+						}
+						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;
+				}
+found_device:
+				munmap(conf, len);
+			}
+			close(fd);
 		}
 	}
 
-/* Open config file here, look up permissions */	
+	umask(0);
+	if (mknod(device_name, mode | type, makedev(major, minor)) && errno != EEXIST)
+		bb_perror_msg_and_die("mknod %s failed", device_name);
 
-	sprintf(temp, "%s/%s", DEV_PATH, device_name);
-	if(mknod(temp, DEV_MODE | type, makedev(major, minor)) && errno != EEXIST)
-		bb_perror_msg_and_die("mknod %s failed", temp);
+	if (major==bbg.root_major && minor==bbg.root_minor)
+		symlink(device_name, "root");
 	
-/* Perform shellout here */
-
-end:
-	RELEASE_CONFIG_BUFFER(temp);
+	if (ENABLE_FEATURE_MDEV_CONF) chown(device_name, uid, gid);
 }
 
 /* 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. */
 
-void find_dev(char *path)
+static void find_dev(char *path)
 {
 	DIR *dir;
-	int len=strlen(path);
+	size_t len = strlen(path);
+	struct dirent *entry;
 
-	if(!(dir = opendir(path)))
-		bb_perror_msg_and_die("No %s",path);
+	if ((dir = opendir(path)) == NULL)
+		return;
 
-	for(;;) {
-		struct dirent *entry = readdir(dir);
-		
-		if(!entry) break;
+	while ((entry = readdir(dir)) != NULL) {
+		struct stat st;
 
 		/* Skip "." and ".." (also skips hidden files, which is ok) */
 
-		if (entry->d_name[0]=='.') continue;
+		if (entry->d_name[0] == '.')
+			continue;
+
+		// uClibc doesn't fill out entry->d_type reliably. so we use lstat().
+
+		snprintf(path+len, PATH_MAX-len, "/%s", entry->d_name);
+		if (!lstat(path, &st) && S_ISDIR(st.st_mode)) find_dev(path);
+		path[len] = 0;
 
-		if (entry->d_type == DT_DIR) {
-			snprintf(path+len, PATH_MAX-len, "/%s", entry->d_name);
-			find_dev(path);
-			path[len] = 0;
-		}
-		
 		/* If there's a dev entry, mknod it */
-		
-		if (strcmp(entry->d_name, "dev")) make_device(path);
+
+		if (!strcmp(entry->d_name, "dev")) make_device(path);
 	}
-	
+
 	closedir(dir);
 }
 
 int mdev_main(int argc, char *argv[])
 {
-	if (argc > 1) {
-		if(argc == 2 && !strcmp(argv[1],"-s")) {
-			RESERVE_CONFIG_BUFFER(temp,PATH_MAX);
-			strcpy(temp,"/sys/block");
-			find_dev(temp);
-			strcpy(temp,"/sys/class");
-			find_dev(temp);
-			if(ENABLE_FEATURE_CLEAN_UP)
-				RELEASE_CONFIG_BUFFER(temp);
-			return 0;
-		} else bb_show_usage();
-	} 
-	
-/* hotplug support goes here */
-	
+	char *action;
+	char *env_path;
+	RESERVE_CONFIG_BUFFER(temp,PATH_MAX);
+
+	bb_xchdir(DEV_PATH);
+
+	/* Scan */
+
+	if (argc == 2 && !strcmp(argv[1],"-s")) {
+		struct stat st;
+
+		stat("/", &st);  // If this fails, we have bigger problems.
+		bbg.root_major=major(st.st_dev);
+		bbg.root_minor=minor(st.st_dev);
+		strcpy(temp,"/sys/block");
+		find_dev(temp);
+		strcpy(temp,"/sys/class");
+		find_dev(temp);
+
+	/* Hotplug */
+
+	} else {
+		action = getenv("ACTION");
+		env_path = getenv("DEVPATH");
+	    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")) {
+			unlink(strrchr(env_path, '/') + 1);
+		}
+	}
+
+	if (ENABLE_FEATURE_CLEAN_UP) RELEASE_CONFIG_BUFFER(temp);
 	return 0;
 }