diff options
Diffstat (limited to 'toys/mdev.c')
| -rw-r--r-- | toys/mdev.c | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/toys/mdev.c b/toys/mdev.c new file mode 100644 index 00000000..53be23e0 --- /dev/null +++ b/toys/mdev.c @@ -0,0 +1,196 @@ +/* vi:set ts=4: + * + * mdev - Mini udev for busybox + * + * Copyright 2005 Rob Landley <rob@landley.net> + * Copyright 2005 Frank Sorenson <frank@tuxrocks.com> + */ + +#include "toys.h" +#include "lib/xregcomp.h" + +// mknod in /dev based on a path like "/sys/block/hda/hda1" +static void make_device(char *path) +{ + char *device_name, *s, *temp; + int major, minor, type, len, fd; + int mode = 0660; + uid_t uid = 0; + gid_t gid = 0; + + // Try to read major/minor string + + temp = path+strlen(path); + strcpy(temp, "/dev"); + fd = open(path, O_RDONLY); + *temp=0; + temp++; + len = read(fd, temp, 64); + close(fd); + if (len<1) return; + temp[len] = 0; + + // Determine device name, type, major and minor + + device_name = strrchr(path, '/') + 1; + type = path[5]=='c' ? S_IFCHR : S_IFBLK; + major = minor = 0; + sscanf(temp, "%u:%u", &major, &minor); + + // If we have a config file, look up permissions for this device + + if (CFG_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_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; + } +end_line: + // Did everything parse happily? + if (field && field!=3) error_exit("Bad line %d", line); + + // Next line + pos = ++end; + } +found_device: + munmap(conf, len); + } + close(fd); + } + } + + sprintf(temp, "/dev/%s", device_name); + umask(0); + if (mknod(temp, mode | type, makedev(major, minor)) && errno != EEXIST) + perror_exit("mknod %s failed", temp); + + if (CFG_MDEV_CONF) chown(temp, uid, gid); +} + +// 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. + +static void find_dev(char *path) +{ + DIR *dir; + int len=strlen(path); + + if (!(dir = opendir(path))) + perror_exit("No %s",path); + + for (;;) { + struct dirent *entry = readdir(dir); + + if (!entry) break; + + // Skip "." and ".." (also skips hidden files, which is ok) + + if (entry->d_name[0]=='.') continue; + + if (entry->d_type == DT_DIR) { + snprintf(path+len, sizeof(toybuf)-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); + } + + closedir(dir); +} + +int mdev_main(int argc, char *argv[]) +{ + if (toys.optflags) { + strcpy(toybuf, "/sys/block"); + find_dev(toybuf); + strcpy(toybuf, "/sys/class"); + find_dev(toybuf); + return 0; + } + + // hotplug support goes here + + return 0; +} |