X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=util-linux%2Fmdev.c;h=f9f067dfe37c434153e81fd13e036a0617cdd964;hb=ae30210d909ba52328385b75891754b0c93ec780;hp=b8c0090fae72d34d21713933c48db010e7d1e240;hpb=c1ef7bdd8d002ae0889efcf883d0e1b7faa938d4;p=oweals%2Fbusybox.git

diff --git a/util-linux/mdev.c b/util-linux/mdev.c
index b8c0090fa..f9f067dfe 100644
--- a/util-linux/mdev.c
+++ b/util-linux/mdev.c
@@ -1,167 +1,198 @@
-/* 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 "xregex.h"
 
 #define DEV_PATH	"/dev"
 
-#include <busybox.h>
-
-/* mknod in /dev based on a path like "/sys/block/hda/hda1" */
-static void make_device(char *path)
+struct mdev_globals
 {
-	char *device_name,*s;
-	int major,minor,type,len,fd;
-	int mode=0660;
-	uid_t uid=0;
-	gid_t gid=0;
-
-	RESERVE_CONFIG_BUFFER(temp,PATH_MAX);
+	int root_major, root_minor;
+} mdev_globals;
 
-	/* Try to read major/minor string */
+#define bbg mdev_globals
 
-	snprintf(temp, PATH_MAX, "%s/dev", path);
-	fd = open(temp, O_RDONLY);
-	len = read(fd, temp, PATH_MAX-1);
-	if (len<1) goto end;
-	close(fd);
+/* mknod in /dev based on a path like "/sys/block/hda/hda1" */
+static void make_device(char *path, int delete)
+{
+	char *device_name;
+	int major, minor, type, len;
+	int mode = 0660;
+	uid_t uid = 0;
+	gid_t gid = 0;
+	char *temp = path + strlen(path);
+	char *command = NULL;
+
+	/* 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) {
+		strcat(path, "/dev");
+		len = open_read_close(path, temp + 1, 64);
+		*temp++ = 0;
+		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;
-	if(sscanf(temp, "%d:%d", &major, &minor) != 2) goto end;
+	type = path[5]=='c' ? S_IFCHR : S_IFBLK;
 
 	/* 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;
+		int line, fd;
 
 		/* 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_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;
-								goto found_device;
-							}
-						}
-						pos=end2;
+		fd = open("/etc/mdev.conf", O_RDONLY);
+		if (fd < 0)
+			goto end_parse;
+		len = xlseek(fd, 0, SEEK_END);
+		conf = mmap(NULL, len, PROT_READ, MAP_PRIVATE, fd, 0);
+		close(fd);
+		if (!conf)
+			goto end_parse;
+
+		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=0; field < (3 + ENABLE_FEATURE_MDEV_EXEC);
+					field++)
+			{
+				/* Skip whitespace */
+				while (pos<end && isspace(*pos)) pos++;
+				if (pos==end || *pos=='#') break;
+				for (end2=pos;
+					end2<end && !isspace(*end2) && *end2!='#'; end2++)
+					;
+
+				if (field == 0) {
+					/* Regex to match this device */
+
+					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))
+						break;
+				}
+				if (field == 1) {
+					/* uid:gid */
+
+					char *s, *s2;
+
+					/* Find : */
+					for (s=pos; s<end2 && *s!=':'; s++)
+						;
+					if (s == end2) break;
+
+					/* Parse UID */
+					uid = strtoul(pos, &s2, 10);
+					if (s != s2) {
+						struct passwd *pass;
+						pass = getpwnam(strndupa(pos, s-pos));
+						if (!pass) break;
+						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) break;
+						gid = grp->gr_gid;
 					}
-end_line:
-					/* Did everything parse happily? */
-					if (field && field!=3)
-							bb_error_msg_and_die("Bad line %d",line);
+				}
+				if (field == 2) {
+					/* mode */
 
-					/* Next line */
-					pos=++end;
+					mode = strtoul(pos, &pos, 8);
+					if (pos != end2) break;
 				}
-found_device:
-				munmap(conf,len);
+				if (ENABLE_FEATURE_MDEV_EXEC && field == 3) {
+					// Command to run
+					const char *s = "@$*";
+					const char *s2;
+					s2 = strchr(s, *pos++);
+					if (!s2) {
+						// Force error
+						field = 1;
+						break;
+					}
+					if ((s2-s+1) & (1<<delete))
+						command = xstrndup(pos, end-pos);
+				}
+
+				pos = end2;
 			}
-			close(fd);
+
+			/* Did everything parse happily? */
+
+			if (field > 2) break;
+			if (field) bb_error_msg_and_die("bad line %d",line);
+
+			/* Next line */
+			pos = ++end;
 		}
+		munmap(conf, len);
+ end_parse:	/* nothing */ ;
 	}
 
-	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) {
+		if (sscanf(temp, "%d:%d", &major, &minor) != 2) return;
+		if (mknod(device_name, mode | type, makedev(major, minor)) && errno != EEXIST)
+			bb_perror_msg_and_die("mknod %s", 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);
+	}
+	if (command) {
+		int rc;
+		char *s;
+
+		s = xasprintf("MDEV=%s", device_name);
+		putenv(s);
+		rc = system(command);
+		s[4] = 0;
+		putenv(s);
+		free(s);
+		free(command);
+		if (rc == -1) bb_perror_msg_and_die("cannot run %s", command);
+	}
+	if (delete) unlink(device_name);
 }
 
 /* Recursive search of /sys/block or /sys/class.  path must be a writeable
@@ -170,43 +201,52 @@ end:
 static void find_dev(char *path)
 {
 	DIR *dir;
-	int len=strlen(path);
-
-	if (!(dir = opendir(path)))
-		bb_perror_msg_and_die("No %s",path);
+	size_t len = strlen(path);
+	struct dirent *entry;
 
-	for (;;) {
-		struct dirent *entry = readdir(dir);
+	dir = opendir(path);
+	if (dir == NULL)
+		return;
 
-		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;
 
-		if (entry->d_type == DT_DIR) {
-			snprintf(path+len, PATH_MAX-len, "/%s", entry->d_name);
-			find_dev(path);
-			path[len] = 0;
-		}
+		// 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 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, 0);
 	}
 
 	closedir(dir);
 }
 
+int mdev_main(int argc, char *argv[]);
 int mdev_main(int argc, char *argv[])
 {
 	char *action;
 	char *env_path;
 	RESERVE_CONFIG_BUFFER(temp,PATH_MAX);
 
+	xchdir(DEV_PATH);
+
 	/* Scan */
 
 	if (argc == 2 && !strcmp(argv[1],"-s")) {
+		struct stat st;
+
+		xstat("/", &st);
+		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");
@@ -217,17 +257,14 @@ int mdev_main(int argc, char *argv[])
 	} 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")) {
-			sprintf(temp, "%s/%s", DEV_PATH, strrchr(env_path, '/') + 1);
-			unlink(temp);
-		}
+		if (!action || !env_path)
+			bb_show_usage();
+
+		sprintf(temp, "/sys%s", env_path);
+		if (!strcmp(action, "add")) make_device(temp,0);
+		else if (!strcmp(action, "remove")) make_device(temp,1);
 	}
 
-	if(ENABLE_FEATURE_CLEAN_UP) RELEASE_CONFIG_BUFFER(temp);
+	if (ENABLE_FEATURE_CLEAN_UP) RELEASE_CONFIG_BUFFER(temp);
 	return 0;
 }