From: Patrick Lam Date: Sun, 28 Aug 2005 05:20:23 +0000 (+0000) Subject: Emit and verify machine signature (sizeof (stuff) + endianness) in cache X-Git-Tag: fc-2_3_90~21 X-Git-Url: https://git.wh0rd.org/?a=commitdiff_plain;h=2dbe759762c3b7b779dbe52ef0d6ca50e51d4bf1;p=fontconfig.git Emit and verify machine signature (sizeof (stuff) + endianness) in cache files. Fix bugs in FcCacheBankToIndex. --- diff --git a/src/fccache.c b/src/fccache.c index 58adcb9..2255b3b 100644 --- a/src/fccache.c +++ b/src/fccache.c @@ -28,6 +28,12 @@ #include #include "fcint.h" +#define ENDIAN_TEST 0x12345678 +#define MACHINE_SIGNATURE_SIZE 9 + 5*19 + 1 + +static char * +FcCacheProduceMachineSignature (void); + /* * POSIX has broken stdio so that getc must do thread-safe locking, * this is a serious performance problem for applications doing large @@ -1025,28 +1031,13 @@ FcCacheNextOffset(off_t w) return ((w / PAGESIZE)+1)*PAGESIZE; } -/* get the current arch name */ -/* caller is responsible for freeing returned pointer */ -static char * -FcCacheGetCurrentArch (void) -{ - struct utsname b; - char * current_arch_machine_name; - - if (uname(&b) == -1) - return FcFalse; - current_arch_machine_name = strdup(b.machine); - /* if (getenv ("FAKE_ARCH")) // testing purposes - current_arch_machine_name = strdup(getenv("FAKE_ARCH")); */ - return current_arch_machine_name; -} - /* return the address of the segment for the provided arch, * or -1 if arch not found */ static off_t FcCacheSkipToArch (int fd, const char * arch) { - char candidate_arch_machine_name[64], bytes_to_skip[7]; + char candidate_arch_machine_name_count[MACHINE_SIGNATURE_SIZE + 9]; + char * candidate_arch; off_t current_arch_start = 0; /* skip arches that are not the current arch */ @@ -1055,21 +1046,20 @@ FcCacheSkipToArch (int fd, const char * arch) long bs; lseek (fd, current_arch_start, SEEK_SET); - if (FcCacheReadString2 (fd, candidate_arch_machine_name, - sizeof (candidate_arch_machine_name)) == 0) - break; - if (FcCacheReadString2 (fd, bytes_to_skip, 7) == 0) - break; - bs = a64l(bytes_to_skip); - if (bs == 0) + if (FcCacheReadString2 (fd, candidate_arch_machine_name_count, + sizeof (candidate_arch_machine_name_count)) == 0) break; + if (!strlen(candidate_arch_machine_name_count)) + return -1; + bs = strtol(candidate_arch_machine_name_count, &candidate_arch, 16); + candidate_arch++; /* skip leading space */ - if (strcmp (candidate_arch_machine_name, arch)==0) + if (strcmp (candidate_arch, arch)==0) break; current_arch_start += bs; } - if (strcmp (candidate_arch_machine_name, arch)!=0) + if (strcmp (candidate_arch, arch)!=0) return -1; return current_arch_start; @@ -1084,7 +1074,7 @@ static FcBool FcCacheMoveDown (int fd, off_t start) { char * buf = malloc (BUF_SIZE); - char candidate_arch_machine_name[64], bytes_to_skip[7]; + char candidate_arch_machine_name[MACHINE_SIGNATURE_SIZE + 9]; long bs; int c, bytes_skipped; @@ -1095,10 +1085,10 @@ FcCacheMoveDown (int fd, off_t start) if (FcCacheReadString2 (fd, candidate_arch_machine_name, sizeof (candidate_arch_machine_name)) == 0) goto done; - if (FcCacheReadString2 (fd, bytes_to_skip, 7) == 0) + if (!strlen(candidate_arch_machine_name)) goto done; - bs = a64l(bytes_to_skip); + bs = strtol(candidate_arch_machine_name, 0, 16); if (bs == 0) goto done; @@ -1237,11 +1227,7 @@ FcCacheReadDirs (FcConfig * config, FcGlobalCache * cache, } } closedir (d); - if (FcDirCacheValid (dir)) - { - FcDirCacheRead (set, dir); - } - else + if (!FcDirCacheValid (dir) || !FcDirCacheRead (set, dir)) { if (FcDebug () & FC_DBG_FONTSET) printf ("scan dir %s\n", dir); @@ -1293,7 +1279,7 @@ FcDirCacheRead (FcFontSet * set, const FcChar8 *dir) FcCache metadata; void * current_dir_block; char * current_arch_machine_name; - char candidate_arch_machine_name[64], bytes_in_block[7]; + char candidate_arch_machine_name[9+MACHINE_SIGNATURE_SIZE]; off_t current_arch_start = 0; if (force) @@ -1301,10 +1287,10 @@ FcDirCacheRead (FcFontSet * set, const FcChar8 *dir) if (!cache_file) goto bail; - current_arch_machine_name = FcCacheGetCurrentArch(); + current_arch_machine_name = FcCacheProduceMachineSignature(); fd = open(cache_file, O_RDONLY); if (fd == -1) - goto bail0; + goto bail; current_arch_start = FcCacheSkipToArch(fd, current_arch_machine_name); if (current_arch_start < 0) @@ -1314,35 +1300,30 @@ FcDirCacheRead (FcFontSet * set, const FcChar8 *dir) if (FcCacheReadString2 (fd, candidate_arch_machine_name, sizeof (candidate_arch_machine_name)) == 0) goto bail1; - if (FcCacheReadString2 (fd, bytes_in_block, 7) == 0) - goto bail1; // sanity check for endianness issues read(fd, &metadata, sizeof(FcCache)); if (metadata.magic != FC_CACHE_MAGIC) goto bail1; - if (metadata.count) - { - off_t pos = FcCacheNextOffset (lseek(fd, 0, SEEK_CUR)); - current_dir_block = mmap (0, metadata.count, - PROT_READ, MAP_SHARED, fd, pos); - if (current_dir_block == MAP_FAILED) - perror(""); - - if (!FcFontSetUnserialize (metadata, set, current_dir_block)) - goto bail1; - } + if (!metadata.count) + goto bail1; + + off_t pos = FcCacheNextOffset (lseek(fd, 0, SEEK_CUR)); + current_dir_block = mmap (0, metadata.count, + PROT_READ, MAP_SHARED, fd, pos); + if (current_dir_block == MAP_FAILED) + perror(""); + + if (!FcFontSetUnserialize (metadata, set, current_dir_block)) + goto bail1; close(fd); - free (current_arch_machine_name); free (cache_file); return FcTrue; bail1: close(fd); - bail0: - free (current_arch_machine_name); bail: free (cache_file); return FcFalse; @@ -1356,7 +1337,7 @@ FcDirCacheWrite (int bank, FcFontSet *set, const FcChar8 *dir) int fd, bytes_to_write, metadata_bytes; FcCache metadata; off_t current_arch_start = 0, truncate_to; - char * current_arch_machine_name, bytes_written[7] = "dedbef"; + char * current_arch_machine_name, * header; void * current_dir_block, *final_dir_block; if (!cache_file) @@ -1380,18 +1361,21 @@ FcDirCacheWrite (int bank, FcFontSet *set, const FcChar8 *dir) if (!current_dir_block) goto bail; final_dir_block = FcFontSetDistributeBytes (&metadata, current_dir_block); + + if ((char *)current_dir_block + bytes_to_write != final_dir_block) + goto bail; if (!FcFontSetSerialize (bank, set)) - return FcFalse; + goto bail; if (FcDebug () & FC_DBG_CACHE) printf ("FcDirCacheWriteDir cache_file \"%s\"\n", cache_file); fd = open(cache_file, O_RDWR | O_CREAT, 0666); if (fd == -1) - return FcFalse; + goto bail; - current_arch_machine_name = FcCacheGetCurrentArch(); + current_arch_machine_name = FcCacheProduceMachineSignature (); current_arch_start = FcCacheSkipToArch(fd, current_arch_machine_name); if (current_arch_start < 0) current_arch_start = FcCacheNextOffset (lseek(fd, 0, SEEK_END)); @@ -1403,15 +1387,13 @@ FcDirCacheWrite (int bank, FcFontSet *set, const FcChar8 *dir) if (ftruncate (fd, current_arch_start) == -1) goto bail1; - /* reserve space for arch, count & metadata */ - if (!FcCacheWriteString2 (fd, current_arch_machine_name)) - goto bail1; - /* now write the address of the next offset */ - truncate_to = FcCacheNextOffset(current_arch_start + bytes_to_write + metadata_bytes) - - current_arch_start; - strcpy (bytes_written, l64a(truncate_to)); - if (!FcCacheWriteString2 (fd, bytes_written)) + truncate_to = FcCacheNextOffset (FcCacheNextOffset (current_arch_start + metadata_bytes) + bytes_to_write) - current_arch_start; + + header = malloc (10 + strlen (current_arch_machine_name)); + sprintf (header, "%8x ", (int)truncate_to); + strcat (header, current_arch_machine_name); + if (!FcCacheWriteString2 (fd, header)) goto bail1; metadata.magic = FC_CACHE_MAGIC; @@ -1419,7 +1401,7 @@ FcDirCacheWrite (int bank, FcFontSet *set, const FcChar8 *dir) lseek (fd, FcCacheNextOffset (lseek(fd, 0, SEEK_END)), SEEK_SET); write (fd, current_dir_block, bytes_to_write); - /* this actually serves to pad out the cache file */ + /* this actually serves to pad out the cache file, if needed */ if (ftruncate (fd, current_arch_start + truncate_to) == -1) goto bail1; @@ -1435,6 +1417,40 @@ FcDirCacheWrite (int bank, FcFontSet *set, const FcChar8 *dir) return FcFalse; } +static char * +FcCacheProduceMachineSignature () +{ + static char buf[MACHINE_SIGNATURE_SIZE]; + int magic = ENDIAN_TEST; + char * m = (char *)&magic; + + sprintf (buf, "%2x%2x%2x%2x " + "%4x %4x %4x %4x %4x %4x %4x %4x %4x %4x %4x %4x " + "%4x %4x %4x %4x %4x %4x %4x\n", + m[0], m[1], m[2], m[3], + sizeof (char), + sizeof (char *), + sizeof (int), + sizeof (FcPattern), + sizeof (FcPatternEltPtr), + sizeof (struct _FcPatternElt *), + sizeof (FcPatternElt), + sizeof (FcObjectPtr), + sizeof (FcValueListPtr), + sizeof (FcValue), + sizeof (FcValueBinding), + sizeof (struct _FcValueList *), + sizeof (FcCharSet), + sizeof (FcCharLeaf **), + sizeof (FcChar16 *), + sizeof (FcChar16), + sizeof (FcCharLeaf), + sizeof (FcChar32), + sizeof (FcCache)); + + return buf; +} + /* if true, ignore the cache file */ void FcCacheForce (FcBool f) @@ -1480,9 +1496,9 @@ FcCacheBankToIndex (int bank) if (bankId[i] == bank) return i; - if (banks_ptr <= banks_alloc) + if (banks_ptr >= banks_alloc) { - b = realloc (bankId, banks_alloc + 4); + b = realloc (bankId, (banks_alloc + 4) * sizeof(int)); if (!b) return -1; diff --git a/src/fcint.h b/src/fcint.h index 446e164..e78fef7 100644 --- a/src/fcint.h +++ b/src/fcint.h @@ -323,7 +323,7 @@ typedef struct _FcCaseFold { * cache which is then rewritten to the users home directory */ -#define FC_CACHE_MAGIC 0x12345678 +#define FC_CACHE_MAGIC 0xFC20FC20 #define FC_GLOBAL_CACHE_DIR_HASH_SIZE 37 #define FC_GLOBAL_CACHE_FILE_HASH_SIZE 67