/*** 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 "libudev.h" #include "libudev-private.h" /** * SECTION:libudev-util * @short_description: utils * * Utilities useful when dealing with devices and device node names. */ int util_delete_path(struct udev *udev, const char *path) { char p[UTIL_PATH_SIZE]; char *pos; int err = 0; if (path[0] == '/') while(path[1] == '/') path++; strscpy(p, sizeof(p), path); pos = strrchr(p, '/'); if (pos == p || pos == NULL) return 0; for (;;) { *pos = '\0'; pos = strrchr(p, '/'); /* don't remove the last one */ if ((pos == p) || (pos == NULL)) break; err = rmdir(p); if (err < 0) { if (errno == ENOENT) err = 0; break; } } return err; } uid_t util_lookup_user(struct udev *udev, const char *user) { char *endptr; struct passwd pwbuf; struct passwd *pw; uid_t uid; size_t buflen = sysconf(_SC_GETPW_R_SIZE_MAX); char *buf = alloca(buflen); if (streq(user, "root")) return 0; uid = strtoul(user, &endptr, 10); if (endptr[0] == '\0') return uid; errno = getpwnam_r(user, &pwbuf, buf, buflen, &pw); if (pw != NULL) return pw->pw_uid; if (errno == 0 || errno == ENOENT || errno == ESRCH) udev_err(udev, "specified user '%s' unknown\n", user); else udev_err(udev, "error resolving user '%s': %m\n", user); return 0; } gid_t util_lookup_group(struct udev *udev, const char *group) { char *endptr; struct group grbuf; struct group *gr; gid_t gid = 0; size_t buflen = sysconf(_SC_GETPW_R_SIZE_MAX); char *buf = NULL; if (streq(group, "root")) return 0; gid = strtoul(group, &endptr, 10); if (endptr[0] == '\0') return gid; gid = 0; for (;;) { char *newbuf; newbuf = realloc(buf, buflen); if (!newbuf) break; buf = newbuf; errno = getgrnam_r(group, &grbuf, buf, buflen, &gr); if (gr != NULL) { gid = gr->gr_gid; } else if (errno == ERANGE) { buflen *= 2; continue; } else if (errno == 0 || errno == ENOENT || errno == ESRCH) { udev_err(udev, "specified group '%s' unknown\n", group); } else { udev_err(udev, "error resolving group '%s': %m\n", group); } break; } free(buf); return gid; } /* 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'; udev_dbg(udev, "value '[%s/%s]%s' is '%s'\n", 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); udev_dbg(udev, "path '[%s/%s]%s' is '%s'\n", 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'; } if (base == NULL) return -EINVAL; strscpyl(base, size - (base - syspath), "/", &link_target[back * 3], NULL); return 0; } int util_log_priority(const char *priority) { char *endptr; int prio; prio = strtol(priority, &endptr, 10); if (endptr[0] == '\0' || isspace(endptr[0])) return prio; if (startswith(priority, "err")) return LOG_ERR; if (startswith(priority, "info")) return LOG_INFO; if (startswith(priority, "debug")) return LOG_DEBUG; return 0; } 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'; } /* count of characters used to encode one unicode char */ static int utf8_encoded_expected_len(const char *str) { unsigned char c = (unsigned char)str[0]; if (c < 0x80) return 1; if ((c & 0xe0) == 0xc0) return 2; if ((c & 0xf0) == 0xe0) return 3; if ((c & 0xf8) == 0xf0) return 4; if ((c & 0xfc) == 0xf8) return 5; if ((c & 0xfe) == 0xfc) return 6; return 0; } /* decode one unicode char */ static int utf8_encoded_to_unichar(const char *str) { int unichar; int len; int i; len = utf8_encoded_expected_len(str); switch (len) { case 1: return (int)str[0]; case 2: unichar = str[0] & 0x1f; break; case 3: unichar = (int)str[0] & 0x0f; break; case 4: unichar = (int)str[0] & 0x07; break; case 5: unichar = (int)str[0] & 0x03; break; case 6: unichar = (int)str[0] & 0x01; break; default: return -1; } for (i = 1; i < len; i++) { if (((int)str[i] & 0xc0) != 0x80) return -1; unichar <<= 6; unichar |= (int)str[i] & 0x3f; } return unichar; } /* expected size used to encode one unicode char */ static int utf8_unichar_to_encoded_len(int unichar) { if (unichar < 0x80) return 1; if (unichar < 0x800) return 2; if (unichar < 0x10000) return 3; if (unichar < 0x200000) return 4; if (unichar < 0x4000000) return 5; return 6; } /* check if unicode char has a valid numeric range */ static int utf8_unichar_valid_range(int unichar) { if (unichar > 0x10ffff) return 0; if ((unichar & 0xfffff800) == 0xd800) return 0; if ((unichar > 0xfdcf) && (unichar < 0xfdf0)) return 0; if ((unichar & 0xffff) == 0xffff) return 0; return 1; } /* validate one encoded unicode char and return its length */ static int utf8_encoded_valid_unichar(const char *str) { int len; int unichar; int i; len = utf8_encoded_expected_len(str); if (len == 0) return -1; /* ascii is valid */ if (len == 1) return 1; /* check if expected encoded chars are available */ for (i = 0; i < len; i++) if ((str[i] & 0x80) != 0x80) return -1; unichar = utf8_encoded_to_unichar(str); /* check if encoded length matches encoded value */ if (utf8_unichar_to_encoded_len(unichar) != len) return -1; /* check if value has valid range */ if (!utf8_unichar_valid_range(unichar)) return -1; return len; } 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; } static int is_whitelisted(char c, const char *white) { if ((c >= '0' && c <= '9') || (c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z') || strchr("#+-.:=@_", c) != NULL || (white != NULL && strchr(white, c) != NULL)) return 1; 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 (is_whitelisted(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) { size_t i, j; if (str == NULL || str_enc == NULL) return -1; for (i = 0, j = 0; str[i] != '\0'; i++) { int seqlen; seqlen = utf8_encoded_valid_unichar(&str[i]); if (seqlen > 1) { if (len-j < (size_t)seqlen) goto err; memcpy(&str_enc[j], &str[i], seqlen); j += seqlen; i += (seqlen-1); } else if (str[i] == '\\' || !is_whitelisted(str[i], NULL)) { if (len-j < 4) goto err; sprintf(&str_enc[j], "\\x%02x", (unsigned char) str[i]); j += 4; } else { if (len-j < 1) goto err; str_enc[j] = str[i]; j++; } } if (len-j < 1) goto err; str_enc[j] = '\0'; return 0; err: return -1; } /* * http://sites.google.com/site/murmurhash/ * * All code is released to the public domain. For business purposes, * Murmurhash is under the MIT license. * */ static unsigned int murmur_hash2(const char *key, size_t len, unsigned int seed) { /* * 'm' and 'r' are mixing constants generated offline. * They're not really 'magic', they just happen to work well. */ const unsigned int m = 0x5bd1e995; const int r = 24; /* initialize the hash to a 'random' value */ unsigned int h = seed ^ len; /* mix 4 bytes at a time into the hash */ const unsigned char * data = (const unsigned char *)key; while(len >= sizeof(unsigned int)) { unsigned int k; memcpy(&k, data, sizeof(k)); k *= m; k ^= k >> r; k *= m; h *= m; h ^= k; data += sizeof(k); len -= sizeof(k); } /* handle the last few bytes of the input array */ switch(len) { case 3: h ^= data[2] << 16; case 2: h ^= data[1] << 8; case 1: h ^= data[0]; h *= m; }; /* do a few final mixes of the hash to ensure the last few bytes are well-incorporated */ h ^= h >> 13; h *= m; h ^= h >> 15; return h; } unsigned int util_string_hash32(const char *str) { return murmur_hash2(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; } ssize_t print_kmsg(const char *fmt, ...) { int fd; va_list ap; char text[1024]; ssize_t len; ssize_t ret; fd = open("/dev/kmsg", O_WRONLY|O_NOCTTY|O_CLOEXEC); if (fd < 0) return -errno; len = snprintf(text, sizeof(text), "<30>systemd-udevd[%u]: ", getpid()); va_start(ap, fmt); len += vsnprintf(text + len, sizeof(text) - len, fmt, ap); va_end(ap); ret = write(fd, text, len); if (ret < 0) ret = -errno; close(fd); return ret; }