| /* vi:set 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. |
| */ |
| |
| #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" |
| #define MDEV_CONF "/etc/mdev.conf" |
| |
| #include <busybox.h> |
| |
| /* 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; |
| |
| RESERVE_CONFIG_BUFFER(temp, PATH_MAX); |
| |
| /* 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); |
| close(fd); |
| if (len < 1) goto end; |
| |
| /* 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; |
| |
| /* 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(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; |
| else |
| 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); |
| umask(0); |
| if (mknod(temp, mode | type, makedev(major, minor)) && errno != EEXIST) |
| bb_perror_msg_and_die("mknod %s failed", temp); |
| |
| if (ENABLE_FEATURE_MDEV_CONF) chown(temp,uid,gid); |
| |
| end: |
| RELEASE_CONFIG_BUFFER(temp); |
| } |
| |
| /* 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; |
| size_t len = strlen(path); |
| struct dirent *entry; |
| |
| if ((dir = opendir(path)) == NULL) |
| return; |
| |
| while ((entry = readdir(dir)) != NULL) { |
| |
| /* Skip "." and ".." (also skips hidden files, which is ok) */ |
| |
| 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); |
| } |
| |
| /* 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[]) |
| { |
| char *action; |
| char *env_path; |
| RESERVE_CONFIG_BUFFER(temp,PATH_MAX); |
| |
| /* Scan */ |
| |
| if (argc == 2 && !strcmp(argv[1],"-s")) { |
| 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")) { |
| sprintf(temp, "%s/%s", DEV_PATH, strrchr(env_path, '/') + 1); |
| unlink(temp); |
| } |
| } |
| |
| if (ENABLE_FEATURE_CLEAN_UP) RELEASE_CONFIG_BUFFER(temp); |
| return 0; |
| } |