/* vi:set ts=4:
- *
+ *
* mdev - Mini udev for busybox
- *
+ *
* Copyright 2005 Rob Landley <rob@landley.net>
* Copyright 2005 Frank Sorenson <frank@tuxrocks.com>
*
#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; // remove trailing \n
+ 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_PRIVATE,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;
}
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
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;
}