[Toybox] [PATCH] Added support for a fourth field in mdev.conf
Faustas Azuolas Bagdonas
afaustas at gmail.com
Tue Jul 24 01:11:00 PDT 2018
This brings toybox closer to being a drop-in replacement for busybox mdev
functionality.
---
toys.h | 1 +
toys/pending/mdev.c | 106 +++++++++++++++++++++++++++++++++++++++++-----------
2 files changed, 86 insertions(+), 21 deletions(-)
diff --git a/toys.h b/toys.h
index 0e8d468..fe9a16b 100644
--- a/toys.h
+++ b/toys.h
@@ -26,6 +26,7 @@
#include <stdarg.h>
#include <stddef.h>
#include <stdint.h>
+#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
diff --git a/toys/pending/mdev.c b/toys/pending/mdev.c
index cab51e1..8b31d2a 100644
--- a/toys/pending/mdev.c
+++ b/toys/pending/mdev.c
@@ -22,11 +22,14 @@ config MDEV_CONF
help
The mdev config file (/etc/mdev.conf) contains lines that look like:
hd[a-z][0-9]* 0:3 660
+ (sd[a-z]) root:disk 660 =usb_storage
Each line must contain three whitespace separated fields. The first
field is a regular expression matching one or more device names,
the second and third fields are uid:gid and file permissions for
- matching devies.
+ matching devices. Fourth field is optional. It could be used to change
+ device name (prefix '='), path (prefix '=' and postfix '/') or create a
+ symlink (prefix '>').
*/
#include "toys.h"
@@ -34,7 +37,8 @@ config MDEV_CONF
// mknod in /dev based on a path like "/sys/block/hda/hda1"
static void make_device(char *path)
{
- char *device_name = 0, *s, *temp;
+ char *device_name = 0, *custom_name = 0, *s, *temp;
+ bool create_symlink = false;
int major = 0, minor = 0, type, len, fd, mode = 0660;
uid_t uid = 0;
gid_t gid = 0;
@@ -79,6 +83,8 @@ static void make_device(char *path)
if (CFG_MDEV_CONF) {
char *conf, *pos, *end;
+ bool found_device = false;
+ bool optional_field_valid = false;
// mmap the config file
if (-1!=(fd = open("/etc/mdev.conf", O_RDONLY))) {
@@ -96,8 +102,9 @@ static void make_device(char *path)
// 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--) {
+ // Four fields (last is optional): regex, uid:gid, mode [, name|path ]
+ // For example: (sd[a-z])1 root:disk 660 =usb_storage_p1
+ for (field = 4; field; field--) {
// Skip whitespace
while (pos<end && isspace(*pos)) pos++;
if (pos==end || *pos=='#') break;
@@ -105,7 +112,7 @@ static void make_device(char *path)
end2<end && !isspace(*end2) && *end2!='#'; end2++);
switch(field) {
// Regex to match this device
- case 3:
+ case 4:
{
char *regex = strndup(pos, end2-pos);
regex_t match;
@@ -126,7 +133,7 @@ static void make_device(char *path)
break;
}
// uid:gid
- case 2:
+ case 3:
{
char *s2;
@@ -158,10 +165,43 @@ static void make_device(char *path)
break;
}
// mode
- case 1:
+ case 2:
{
+ char *beg_pos = pos;
mode = strtoul(pos, &pos, 8);
- if (pos!=end2) goto end_line;
+ if(pos == beg_pos) {
+ // The line is bad because mode setting could not be
+ // converted to numeric value.
+ goto end_line;
+ }
+ break;
+ }
+ // Try to look for name or path (optional field)
+ case 1:
+ {
+ if(pos < end2){
+ //char *name = strndup(pos, end2-pos);
+ char *name = malloc(end2-pos+1);
+ if(name){
+ strncpy(name, pos, end2-pos+1);
+ name[end2-pos] = '\0';
+ switch(name[0]){
+ case '>':
+ create_symlink = true;
+ case '=':
+ custom_name = strdup(&name[1]);
+ break;
+ case '!':
+ device_name = NULL;
+ break;
+ default:
+ free(name);
+ goto end_line;
+ }
+ free(name);
+ optional_field_valid = true;
+ }
+ }
goto found_device;
}
}
@@ -169,8 +209,9 @@ static void make_device(char *path)
}
end_line:
// Did everything parse happily?
- if (field && field!=3) error_exit("Bad line %d", line);
-
+ // Note: Last field is optional.
+ if ((field>1 || (field==1 && !optional_field_valid)) && field!=4)
+ error_exit("Bad line %d", line);
// Next line
pos = ++end;
}
@@ -180,21 +221,44 @@ found_device:
close(fd);
}
- sprintf(toybuf, "/dev/%s", device_name);
+ if(device_name) {
+ if(custom_name) {
+ sprintf(toybuf, "/dev/%s", custom_name);
+ if(custom_name[strlen(custom_name) - 1] == '/') {
+ DIR *dir;
+ dir = opendir(toybuf);
+ if(dir) closedir(dir);
+ else mkdir(toybuf, 0755);
+ }
+ }
+ else
+ sprintf(toybuf, "/dev/%s", device_name);
- if ((temp=getenv("ACTION")) && !strcmp(temp, "remove")) {
- unlink(toybuf);
- return;
- }
+ if ((temp=getenv("ACTION")) && !strcmp(temp, "remove")) {
+ unlink(toybuf);
+ return;
+ }
- if (strchr(device_name, '/')) mkpath(toybuf);
- if (mknod(toybuf, mode | type, dev_makedev(major, minor)) && errno != EEXIST)
- perror_exit("mknod %s failed", toybuf);
+ if (strchr(device_name, '/')) mkpath(toybuf);
+ if (mknod(toybuf, mode | type, dev_makedev(major, minor)) &&
+ errno != EEXIST)
+ perror_exit("mknod %s failed", toybuf);
+ if(create_symlink){
+ char *symlink_name = malloc(sizeof("/dev/") + strlen(device_name) + 1);
+ if(symlink_name == NULL)
+ perror_exit("malloc failed while creating symlink to %s", toybuf);
+ sprintf(symlink_name, "/dev/%s", device_name);
+ if(symlink(toybuf, symlink_name)){
+ free(symlink_name);
+ perror_exit("symlink creation failed for %s", toybuf);
+ }
+ free(symlink_name);
+ }
-
- if (type == S_IFBLK) close(open(toybuf, O_RDONLY)); // scan for partitions
+ if (type == S_IFBLK) close(open(toybuf, O_RDONLY)); // scan for partitions
- if (CFG_MDEV_CONF) mode=chown(toybuf, uid, gid);
+ if (CFG_MDEV_CONF) mode=chown(toybuf, uid, gid);
+ }
}
static int callback(struct dirtree *node)
--
2.7.4
More information about the Toybox
mailing list