^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0-or-later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /* Key to pathname encoder
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Written by David Howells (dhowells@redhat.com)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include "internal.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) static const char cachefiles_charmap[64] =
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) "0123456789" /* 0 - 9 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) "abcdefghijklmnopqrstuvwxyz" /* 10 - 35 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) "ABCDEFGHIJKLMNOPQRSTUVWXYZ" /* 36 - 61 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) "_-" /* 62 - 63 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) ;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) static const char cachefiles_filecharmap[256] = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) /* we skip space and tab and control chars */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) [33 ... 46] = 1, /* '!' -> '.' */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) /* we skip '/' as it's significant to pathwalk */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) [48 ... 127] = 1, /* '0' -> '~' */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) * turn the raw key into something cooked
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) * - the raw key should include the length in the two bytes at the front
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) * - the key may be up to 514 bytes in length (including the length word)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) * - "base64" encode the strange keys, mapping 3 bytes of raw to four of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) * cooked
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) * - need to cut the cooked key into 252 char lengths (189 raw bytes)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) char *cachefiles_cook_key(const u8 *raw, int keylen, uint8_t type)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) unsigned char csum, ch;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) unsigned int acc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) char *key;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) int loop, len, max, seg, mark, print;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) _enter(",%d", keylen);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) BUG_ON(keylen < 2 || keylen > 514);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) csum = raw[0] + raw[1];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) print = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) for (loop = 2; loop < keylen; loop++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) ch = raw[loop];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) csum += ch;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) print &= cachefiles_filecharmap[ch];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) if (print) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) /* if the path is usable ASCII, then we render it directly */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) max = keylen - 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) max += 2; /* two base64'd length chars on the front */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) max += 5; /* @checksum/M */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) max += 3 * 2; /* maximum number of segment dividers (".../M")
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) * is ((514 + 251) / 252) = 3
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) max += 1; /* NUL on end */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) /* calculate the maximum length of the cooked key */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) keylen = (keylen + 2) / 3;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) max = keylen * 4;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) max += 5; /* @checksum/M */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) max += 3 * 2; /* maximum number of segment dividers (".../M")
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) * is ((514 + 188) / 189) = 3
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) max += 1; /* NUL on end */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) max += 1; /* 2nd NUL on end */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) _debug("max: %d", max);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) key = kmalloc(max, cachefiles_gfp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) if (!key)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) len = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) /* build the cooked key */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) sprintf(key, "@%02x%c+", (unsigned) csum, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) len = 5;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) mark = len - 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) if (print) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) acc = *(uint16_t *) raw;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) raw += 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) key[len + 1] = cachefiles_charmap[acc & 63];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) acc >>= 6;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) key[len] = cachefiles_charmap[acc & 63];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) len += 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) seg = 250;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) for (loop = keylen; loop > 0; loop--) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) if (seg <= 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) key[len++] = '\0';
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) mark = len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) key[len++] = '+';
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) seg = 252;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) key[len++] = *raw++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) ASSERT(len < max);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) switch (type) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) case FSCACHE_COOKIE_TYPE_INDEX: type = 'I'; break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) case FSCACHE_COOKIE_TYPE_DATAFILE: type = 'D'; break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) default: type = 'S'; break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) seg = 252;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) for (loop = keylen; loop > 0; loop--) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) if (seg <= 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) key[len++] = '\0';
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) mark = len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) key[len++] = '+';
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) seg = 252;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) acc = *raw++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) acc |= *raw++ << 8;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) acc |= *raw++ << 16;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) _debug("acc: %06x", acc);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) key[len++] = cachefiles_charmap[acc & 63];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) acc >>= 6;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) key[len++] = cachefiles_charmap[acc & 63];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) acc >>= 6;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) key[len++] = cachefiles_charmap[acc & 63];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) acc >>= 6;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) key[len++] = cachefiles_charmap[acc & 63];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) ASSERT(len < max);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) switch (type) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) case FSCACHE_COOKIE_TYPE_INDEX: type = 'J'; break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) case FSCACHE_COOKIE_TYPE_DATAFILE: type = 'E'; break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) default: type = 'T'; break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) key[mark] = type;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) key[len++] = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) key[len] = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) _leave(" = %p %d", key, len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) return key;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) }
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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