| /* vi: set sw=4 ts=4: */ |
| /* |
| * |
| * mdev - Mini udev for busybox |
| * |
| * Copyright 2005 Rob Landley <rob@landley.net> |
| * Copyright 2005 Frank Sorenson <frank@tuxrocks.com> |
| * |
| * Licensed under GPL version 2, see file LICENSE in this tarball for details. |
| */ |
| |
| #include "busybox.h" |
| #include "xregex.h" |
| |
| #define DEV_PATH "/dev" |
| |
| 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, int delete) |
| { |
| char *device_name; |
| int major, minor, type, len, fd; |
| int mode = 0660; |
| uid_t uid = 0; |
| gid_t gid = 0; |
| char *temp = path + strlen(path); |
| char *command = NULL; |
| |
| /* 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. */ |
| |
| if (!delete) { |
| 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 = path[5]=='c' ? S_IFCHR : S_IFBLK; |
| |
| /* 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_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=0; field < (3 + ENABLE_FEATURE_MDEV_EXEC); |
| field++) |
| { |
| /* Skip whitespace */ |
| while (pos<end && isspace(*pos)) pos++; |
| if (pos==end || *pos=='#') break; |
| for (end2=pos; |
| end2<end && !isspace(*end2) && *end2!='#'; end2++) |
| ; |
| |
| if (!field) { |
| /* Regex to match this device */ |
| |
| 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)) |
| break; |
| |
| } else if (field == 1) { |
| /* uid:gid */ |
| |
| char *s, *s2; |
| |
| /* Find : */ |
| for(s=pos; s<end2 && *s!=':'; s++) |
| ; |
| if (s == end2) break; |
| |
| /* Parse UID */ |
| uid = strtoul(pos,&s2,10); |
| if (s != s2) { |
| struct passwd *pass; |
| pass = getpwnam(strndupa(pos, s-pos)); |
| if (!pass) break; |
| 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) break; |
| gid = grp->gr_gid; |
| } |
| } else if (field == 2) { |
| /* mode */ |
| |
| mode = strtoul(pos, &pos, 8); |
| if (pos != end2) break; |
| } else if (ENABLE_FEATURE_MDEV_EXEC && field == 3) { |
| // Command to run |
| char *s = "@$*", *s2; |
| if (!(s2 = strchr(s, *pos++))) { |
| // Force error |
| field = 1; |
| break; |
| } |
| if ((s2-s+1) & (1<<delete)) |
| command = xstrndup(pos, end-pos); |
| } |
| |
| pos = end2; |
| } |
| |
| /* Did everything parse happily? */ |
| |
| if (field > 2) break; |
| if (field) bb_error_msg_and_die("Bad line %d",line); |
| |
| /* Next line */ |
| pos = ++end; |
| } |
| munmap(conf, len); |
| } |
| close(fd); |
| } |
| } |
| |
| umask(0); |
| if (!delete) { |
| if (sscanf(temp, "%d:%d", &major, &minor) != 2) return; |
| if (mknod(device_name, mode | type, makedev(major, minor)) && errno != EEXIST) |
| bb_perror_msg_and_die("mknod %s failed", device_name); |
| |
| if (major == bbg.root_major && minor == bbg.root_minor) |
| symlink(device_name, "root"); |
| |
| if (ENABLE_FEATURE_MDEV_CONF) chown(device_name, uid, gid); |
| } |
| if (command) { |
| int rc; |
| char *s; |
| |
| s=xasprintf("MDEV=%s",device_name); |
| putenv(s); |
| rc = system(command); |
| s[4]=0; |
| putenv(s); |
| free(s); |
| free(command); |
| if (rc == -1) bb_perror_msg_and_die("Couldn't run %s", command); |
| } |
| if (delete) unlink(device_name); |
| } |
| |
| /* 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) { |
| struct stat st; |
| |
| /* Skip "." and ".." (also skips hidden files, which is ok) */ |
| |
| 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 there's a dev entry, mknod it */ |
| |
| if (!strcmp(entry->d_name, "dev")) make_device(path, 0); |
| } |
| |
| closedir(dir); |
| } |
| |
| int mdev_main(int argc, char *argv[]) |
| { |
| char *action; |
| char *env_path; |
| RESERVE_CONFIG_BUFFER(temp,PATH_MAX); |
| |
| 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(); |
| |
| sprintf(temp, "/sys%s", env_path); |
| if (!strcmp(action, "add")) make_device(temp,0); |
| else if (!strcmp(action, "remove")) make_device(temp,1); |
| } |
| |
| if (ENABLE_FEATURE_CLEAN_UP) RELEASE_CONFIG_BUFFER(temp); |
| return 0; |
| } |