X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=util-linux%2Fmdev.c;h=73a82314c3cf3ef572ffcdf7b697898c83c2c06f;hb=1449a2014a4e715a7a52b27caec528a9c802fa5f;hp=830939b92d63f85724d1f396b28137c705453c15;hpb=9bdd742dd2f5fda08e6431ee58b15e1923fb3f64;p=oweals%2Fbusybox.git

diff --git a/util-linux/mdev.c b/util-linux/mdev.c
index 830939b92..73a82314c 100644
--- a/util-linux/mdev.c
+++ b/util-linux/mdev.c
@@ -1,7 +1,7 @@
 /* vi:set ts=4:
- * 
+ *
  * mdev - Mini udev for busybox
- * 
+ *
  * Copyright 2005 Rob Landley <rob@landley.net>
  * Copyright 2005 Frank Sorenson <frank@tuxrocks.com>
  *
@@ -16,96 +16,102 @@
 #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 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" */
 static void make_device(char *path)
 {
-	char *device_name,*s;
-	int major,minor,type,len,fd;
-	int mode=0660;
-	uid_t uid=0;
-	gid_t gid=0;
+	char *device_name, *s;
+	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;
+		char *conf, *pos, *end;
 
 		/* mmap the config file */
-		if (-1!=(fd=open("/etc/mdev.conf",O_RDONLY))) {
-			len=lseek(fd,0,SEEK_END);
-			conf=mmap(NULL,len,PROT_READ,MAP_SHARED,fd,0);
+		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;
+				int line = 0;
 
 				/* Loop through lines in mmaped file*/
-				for (pos=conf;pos-conf<len;) {
+				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++);
+					for(end=pos; end-conf<len && *end!='\n'; end++)
+						;
 
 					/* Three fields: regex, uid:gid, mode */
-					for (field=3;field;field--) {
+					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) {
+						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);
+								char *regex = strndupa(pos,end2-pos);
 								regex_t match;
 								regmatch_t off;
 								int result;
 
-								/* Is this it? */	
+								/* Is this it? */
 								xregcomp(&match,regex,REG_EXTENDED);
-								result=regexec(&match,device_name,1,&off,0);
+								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;
+								if (result || off.rm_so || off.rm_eo!=strlen(device_name))
+									goto end_line;
 
 								break;
 							}
@@ -115,62 +121,67 @@ static void make_device(char *path)
 								char *s2;
 
 								/* Find : */
-								for(s=pos;s<end2 && *s!=':';s++);
-								if(s==end2) goto end_line;
+								for(s=pos; s<end2 && *s!=':'; s++)
+									;
+								if (s == end2)
+									goto end_line;
 
 								/* Parse UID */
-								uid=strtoul(pos,&s2,10);
-								if(s!=s2) {
+								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;
+									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) {
+								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;
+									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;
-								goto found_device;
+								mode = strtoul(pos,&pos,8);
+								if (pos != end2)
+									goto end_line;
+								else
+									goto found_device;
 							}
 						}
-						pos=end2;
+						pos = end2;
 					}
 end_line:
 					/* Did everything parse happily? */
 					if (field && field!=3)
-							bb_error_msg_and_die("Bad line %d",line);
+						bb_error_msg_and_die("Bad line %d",line);
 
 					/* Next line */
-					pos=++end;
+					pos = ++end;
 				}
 found_device:
-				munmap(conf,len);
+				munmap(conf, len);
 			}
 			close(fd);
 		}
 	}
 
-	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 (mknod(device_name, mode | type, makedev(major, minor)) && errno != EEXIST)
+		bb_perror_msg_and_die("mknod %s failed", device_name);
 
-	if (ENABLE_FEATURE_MDEV_CONF) chown(temp,uid,gid);
+	if (major==bbg.root_major && minor==bbg.root_minor)
+		symlink(device_name, "root");
 	
-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
@@ -179,50 +190,71 @@ end:
 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;
 }