/*** This file is part of systemd. Copyright 2008-2012 Kay Sievers <kay@vrfy.org> systemd is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. systemd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ #include <stdio.h> #include <stdlib.h> #include <stddef.h> #include <unistd.h> #include <errno.h> #include <string.h> #include <dirent.h> #include <ctype.h> #include <fcntl.h> #include <time.h> #include <pwd.h> #include <grp.h> #include <sys/stat.h> #include <sys/param.h> #include "device-nodes.h" #include "libudev.h" #include "libudev-private.h" #include "utf8.h" #include "MurmurHash2.h" /** * SECTION:libudev-util * @short_description: utils * * Utilities useful when dealing with devices and device node names. */ /* handle "[<SUBSYSTEM>/<KERNEL>]<attribute>" format */ int util_resolve_subsys_kernel(struct udev *udev, const char *string, char *result, size_t maxsize, int read_value) { char temp[UTIL_PATH_SIZE]; char *subsys; char *sysname; struct udev_device *dev; char *attr; if (string[0] != '[') return -1; strscpy(temp, sizeof(temp), string); subsys = &temp[1]; sysname = strchr(subsys, '/'); if (sysname == NULL) return -1; sysname[0] = '\0'; sysname = &sysname[1]; attr = strchr(sysname, ']'); if (attr == NULL) return -1; attr[0] = '\0'; attr = &attr[1]; if (attr[0] == '/') attr = &attr[1]; if (attr[0] == '\0') attr = NULL; if (read_value && attr == NULL) return -1; dev = udev_device_new_from_subsystem_sysname(udev, subsys, sysname); if (dev == NULL) return -1; if (read_value) { const char *val; val = udev_device_get_sysattr_value(dev, attr); if (val != NULL) strscpy(result, maxsize, val); else result[0] = '\0'; log_debug("value '[%s/%s]%s' is '%s'", subsys, sysname, attr, result); } else { size_t l; char *s; s = result; l = strpcpyl(&s, maxsize, udev_device_get_syspath(dev), NULL); if (attr != NULL) strpcpyl(&s, l, "/", attr, NULL); log_debug("path '[%s/%s]%s' is '%s'", subsys, sysname, attr, result); } udev_device_unref(dev); return 0; } ssize_t util_get_sys_core_link_value(struct udev *udev, const char *slink, const char *syspath, char *value, size_t size) { char path[UTIL_PATH_SIZE]; char target[UTIL_PATH_SIZE]; ssize_t len; const char *pos; strscpyl(path, sizeof(path), syspath, "/", slink, NULL); len = readlink(path, target, sizeof(target)); if (len <= 0 || len == (ssize_t)sizeof(target)) return -1; target[len] = '\0'; pos = strrchr(target, '/'); if (pos == NULL) return -1; pos = &pos[1]; return strscpy(value, size, pos); } int util_resolve_sys_link(struct udev *udev, char *syspath, size_t size) { char link_target[UTIL_PATH_SIZE]; ssize_t len; int i; int back; char *base = NULL; len = readlink(syspath, link_target, sizeof(link_target)); if (len <= 0 || len == (ssize_t)sizeof(link_target)) return -1; link_target[len] = '\0'; for (back = 0; startswith(&link_target[back * 3], "../"); back++) ; for (i = 0; i <= back; i++) { base = strrchr(syspath, '/'); if (base == NULL) return -EINVAL; base[0] = '\0'; } strscpyl(base, size - (base - syspath), "/", &link_target[back * 3], NULL); return 0; } int util_log_priority(const char *priority) { char *endptr; int prio; prio = strtoul(priority, &endptr, 10); if (endptr[0] == '\0' || isspace(endptr[0])) { if (prio >= 0 && prio <= 7) return prio; else return -ERANGE; } return log_level_from_string(priority); } size_t util_path_encode(const char *src, char *dest, size_t size) { size_t i, j; for (i = 0, j = 0; src[i] != '\0'; i++) { if (src[i] == '/') { if (j+4 >= size) { j = 0; break; } memcpy(&dest[j], "\\x2f", 4); j += 4; } else if (src[i] == '\\') { if (j+4 >= size) { j = 0; break; } memcpy(&dest[j], "\\x5c", 4); j += 4; } else { if (j+1 >= size) { j = 0; break; } dest[j] = src[i]; j++; } } dest[j] = '\0'; return j; } void util_remove_trailing_chars(char *path, char c) { size_t len; if (path == NULL) return; len = strlen(path); while (len > 0 && path[len-1] == c) path[--len] = '\0'; } int util_replace_whitespace(const char *str, char *to, size_t len) { size_t i, j; /* strip trailing whitespace */ len = strnlen(str, len); while (len && isspace(str[len-1])) len--; /* strip leading whitespace */ i = 0; while (isspace(str[i]) && (i < len)) i++; j = 0; while (i < len) { /* substitute multiple whitespace with a single '_' */ if (isspace(str[i])) { while (isspace(str[i])) i++; to[j++] = '_'; } to[j++] = str[i++]; } to[j] = '\0'; return 0; } /* allow chars in whitelist, plain ascii, hex-escaping and valid utf8 */ int util_replace_chars(char *str, const char *white) { size_t i = 0; int replaced = 0; while (str[i] != '\0') { int len; if (whitelisted_char_for_devnode(str[i], white)) { i++; continue; } /* accept hex encoding */ if (str[i] == '\\' && str[i+1] == 'x') { i += 2; continue; } /* accept valid utf8 */ len = utf8_encoded_valid_unichar(&str[i]); if (len > 1) { i += len; continue; } /* if space is allowed, replace whitespace with ordinary space */ if (isspace(str[i]) && white != NULL && strchr(white, ' ') != NULL) { str[i] = ' '; i++; replaced++; continue; } /* everything else is replaced with '_' */ str[i] = '_'; i++; replaced++; } return replaced; } /** * udev_util_encode_string: * @str: input string to be encoded * @str_enc: output string to store the encoded input string * @len: maximum size of the output string, which may be * four times as long as the input string * * Encode all potentially unsafe characters of a string to the * corresponding 2 char hex value prefixed by '\x'. * * Returns: 0 if the entire string was copied, non-zero otherwise. **/ _public_ int udev_util_encode_string(const char *str, char *str_enc, size_t len) { return encode_devnode_name(str, str_enc, len); } unsigned int util_string_hash32(const char *str) { return MurmurHash2(str, strlen(str), 0); } /* get a bunch of bit numbers out of the hash, and set the bits in our bit field */ uint64_t util_string_bloom64(const char *str) { uint64_t bits = 0; unsigned int hash = util_string_hash32(str); bits |= 1LLU << (hash & 63); bits |= 1LLU << ((hash >> 6) & 63); bits |= 1LLU << ((hash >> 12) & 63); bits |= 1LLU << ((hash >> 18) & 63); return bits; }