Added /etc/mdev.conf support. Adds about 1.9k to mdev.

2 files changed, 123 insertions, 16 deletions

diff --git a/util-linux/Config.in b/util-linux/Config.in
index 5ab54e038..bf3e13b2a 100644
--- a/util-linux/Config.in
+++ b/util-linux/Config.in
@@ -254,7 +254,7 @@ config CONFIG_MDEV
           have it handle hotplug events afterwards.  Device names are taken
           from sysfs.
 
-config CONFIG_FEATURE_MDEV_CONFIG
+config CONFIG_FEATURE_MDEV_CONF
         bool "  Support /etc/mdev.conf"
         default n
         depends on CONFIG_MDEV
diff --git a/util-linux/mdev.c b/util-linux/mdev.c
index 49904d17a..688100c3a 100644
--- a/util-linux/mdev.c
+++ b/util-linux/mdev.c
@@ -8,25 +8,31 @@
  * 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/types.h>
 #include <unistd.h>
+#include "busybox.h"
+#include "xregex.h"
 
-#define DEV_PATH        "/dev"
-#define DEV_MODE        0660
+#define DEV_PATH        "/tmp/dev"
 
 #include <busybox.h>
 
 /* 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;
+        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);
 
@@ -44,8 +50,8 @@ void make_device(char *path)
         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 == ':') {
+        for (s = temp; *s; s++) {
+                if (*s == ':') {
                         major = minor;
                         minor = 0;
                 } else {
@@ -54,14 +60,115 @@ void make_device(char *path)
                 }
         }
 
-/* Open config file here, look up permissions */        
+        /* 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("/etc/mdev.conf",O_RDONLY))) {
+                        len=lseek(fd,0,SEEK_END);
+                        conf=mmap(NULL,len,PROT_READ,MAP_SHARED,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;
+                                        }
+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);
+                }
+        }
 
         sprintf(temp, "%s/%s", DEV_PATH, device_name);
-        if(mknod(temp, DEV_MODE | type, makedev(major, minor)) && errno != EEXIST)
+        umask(0);
+        if (mknod(temp, mode | type, makedev(major, minor)) && errno != EEXIST)
                 bb_perror_msg_and_die("mknod %s failed", temp);
-        
-/* Perform shellout here */
 
+        if (ENABLE_FEATURE_MDEV_CONF) chown(temp,uid,gid);
+        
 end:
         RELEASE_CONFIG_BUFFER(temp);
 }
@@ -69,18 +176,18 @@ end:
 /* 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);
 
-        if(!(dir = opendir(path)))
+        if (!(dir = opendir(path)))
                 bb_perror_msg_and_die("No %s",path);
 
-        for(;;) {
+        for (;;) {
                 struct dirent *entry = readdir(dir);
                 
-                if(!entry) break;
+                if (!entry) break;
 
                 /* Skip "." and ".." (also skips hidden files, which is ok) */
 
@@ -103,7 +210,7 @@ void find_dev(char *path)
 int mdev_main(int argc, char *argv[])
 {
         if (argc > 1) {
-                if(argc == 2 && !strcmp(argv[1],"-s")) {
+                if (argc == 2 && !strcmp(argv[1],"-s")) {
                         RESERVE_CONFIG_BUFFER(temp,PATH_MAX);
                         strcpy(temp,"/sys/block");
                         find_dev(temp);