diff options
Diffstat (limited to 'image/main.c')
| -rw-r--r-- | image/main.c | 208 |
1 files changed, 166 insertions, 42 deletions
diff --git a/image/main.c b/image/main.c index 80588e81..4cffbdba 100644 --- a/image/main.c +++ b/image/main.c @@ -338,61 +338,146 @@ static u64 logical_to_physical(struct mdrestore_struct *mdres, u64 logical, return fs_chunk->physical + offset; } +/* + * Reverse CRC-32C table + */ +static const u32 crc32c_rev_table[256] = { + 0x00000000L,0x05EC76F1L,0x0BD8EDE2L,0x0E349B13L, + 0x17B1DBC4L,0x125DAD35L,0x1C693626L,0x198540D7L, + 0x2F63B788L,0x2A8FC179L,0x24BB5A6AL,0x21572C9BL, + 0x38D26C4CL,0x3D3E1ABDL,0x330A81AEL,0x36E6F75FL, + 0x5EC76F10L,0x5B2B19E1L,0x551F82F2L,0x50F3F403L, + 0x4976B4D4L,0x4C9AC225L,0x42AE5936L,0x47422FC7L, + 0x71A4D898L,0x7448AE69L,0x7A7C357AL,0x7F90438BL, + 0x6615035CL,0x63F975ADL,0x6DCDEEBEL,0x6821984FL, + 0xBD8EDE20L,0xB862A8D1L,0xB65633C2L,0xB3BA4533L, + 0xAA3F05E4L,0xAFD37315L,0xA1E7E806L,0xA40B9EF7L, + 0x92ED69A8L,0x97011F59L,0x9935844AL,0x9CD9F2BBL, + 0x855CB26CL,0x80B0C49DL,0x8E845F8EL,0x8B68297FL, + 0xE349B130L,0xE6A5C7C1L,0xE8915CD2L,0xED7D2A23L, + 0xF4F86AF4L,0xF1141C05L,0xFF208716L,0xFACCF1E7L, + 0xCC2A06B8L,0xC9C67049L,0xC7F2EB5AL,0xC21E9DABL, + 0xDB9BDD7CL,0xDE77AB8DL,0xD043309EL,0xD5AF466FL, + 0x7EF1CAB1L,0x7B1DBC40L,0x75292753L,0x70C551A2L, + 0x69401175L,0x6CAC6784L,0x6298FC97L,0x67748A66L, + 0x51927D39L,0x547E0BC8L,0x5A4A90DBL,0x5FA6E62AL, + 0x4623A6FDL,0x43CFD00CL,0x4DFB4B1FL,0x48173DEEL, + 0x2036A5A1L,0x25DAD350L,0x2BEE4843L,0x2E023EB2L, + 0x37877E65L,0x326B0894L,0x3C5F9387L,0x39B3E576L, + 0x0F551229L,0x0AB964D8L,0x048DFFCBL,0x0161893AL, + 0x18E4C9EDL,0x1D08BF1CL,0x133C240FL,0x16D052FEL, + 0xC37F1491L,0xC6936260L,0xC8A7F973L,0xCD4B8F82L, + 0xD4CECF55L,0xD122B9A4L,0xDF1622B7L,0xDAFA5446L, + 0xEC1CA319L,0xE9F0D5E8L,0xE7C44EFBL,0xE228380AL, + 0xFBAD78DDL,0xFE410E2CL,0xF075953FL,0xF599E3CEL, + 0x9DB87B81L,0x98540D70L,0x96609663L,0x938CE092L, + 0x8A09A045L,0x8FE5D6B4L,0x81D14DA7L,0x843D3B56L, + 0xB2DBCC09L,0xB737BAF8L,0xB90321EBL,0xBCEF571AL, + 0xA56A17CDL,0xA086613CL,0xAEB2FA2FL,0xAB5E8CDEL, + 0xFDE39562L,0xF80FE393L,0xF63B7880L,0xF3D70E71L, + 0xEA524EA6L,0xEFBE3857L,0xE18AA344L,0xE466D5B5L, + 0xD28022EAL,0xD76C541BL,0xD958CF08L,0xDCB4B9F9L, + 0xC531F92EL,0xC0DD8FDFL,0xCEE914CCL,0xCB05623DL, + 0xA324FA72L,0xA6C88C83L,0xA8FC1790L,0xAD106161L, + 0xB49521B6L,0xB1795747L,0xBF4DCC54L,0xBAA1BAA5L, + 0x8C474DFAL,0x89AB3B0BL,0x879FA018L,0x8273D6E9L, + 0x9BF6963EL,0x9E1AE0CFL,0x902E7BDCL,0x95C20D2DL, + 0x406D4B42L,0x45813DB3L,0x4BB5A6A0L,0x4E59D051L, + 0x57DC9086L,0x5230E677L,0x5C047D64L,0x59E80B95L, + 0x6F0EFCCAL,0x6AE28A3BL,0x64D61128L,0x613A67D9L, + 0x78BF270EL,0x7D5351FFL,0x7367CAECL,0x768BBC1DL, + 0x1EAA2452L,0x1B4652A3L,0x1572C9B0L,0x109EBF41L, + 0x091BFF96L,0x0CF78967L,0x02C31274L,0x072F6485L, + 0x31C993DAL,0x3425E52BL,0x3A117E38L,0x3FFD08C9L, + 0x2678481EL,0x23943EEFL,0x2DA0A5FCL,0x284CD30DL, + 0x83125FD3L,0x86FE2922L,0x88CAB231L,0x8D26C4C0L, + 0x94A38417L,0x914FF2E6L,0x9F7B69F5L,0x9A971F04L, + 0xAC71E85BL,0xA99D9EAAL,0xA7A905B9L,0xA2457348L, + 0xBBC0339FL,0xBE2C456EL,0xB018DE7DL,0xB5F4A88CL, + 0xDDD530C3L,0xD8394632L,0xD60DDD21L,0xD3E1ABD0L, + 0xCA64EB07L,0xCF889DF6L,0xC1BC06E5L,0xC4507014L, + 0xF2B6874BL,0xF75AF1BAL,0xF96E6AA9L,0xFC821C58L, + 0xE5075C8FL,0xE0EB2A7EL,0xEEDFB16DL,0xEB33C79CL, + 0x3E9C81F3L,0x3B70F702L,0x35446C11L,0x30A81AE0L, + 0x292D5A37L,0x2CC12CC6L,0x22F5B7D5L,0x2719C124L, + 0x11FF367BL,0x1413408AL,0x1A27DB99L,0x1FCBAD68L, + 0x064EEDBFL,0x03A29B4EL,0x0D96005DL,0x087A76ACL, + 0x605BEEE3L,0x65B79812L,0x6B830301L,0x6E6F75F0L, + 0x77EA3527L,0x720643D6L,0x7C32D8C5L,0x79DEAE34L, + 0x4F38596BL,0x4AD42F9AL,0x44E0B489L,0x410CC278L, + 0x588982AFL,0x5D65F45EL,0x53516F4DL,0x56BD19BCL +}; -static char *find_collision(struct metadump_struct *md, char *name, - u32 name_len) +/* + * Calculate a 4-byte suffix to match desired CRC32C + * + * @current_crc: CRC32C checksum of all bytes before the suffix + * @desired_crc: the checksum that we want to get after adding the suffix + * + * Outputs: @suffix: pointer to where the suffix will be written (4-bytes) + */ +static void find_collision_calc_suffix(unsigned long current_crc, + unsigned long desired_crc, + char *suffix) { - struct name *val; - struct rb_node *entry; - struct name tmp; - unsigned long checksum; - int found = 0; int i; - tmp.val = name; - tmp.len = name_len; - entry = tree_search(&md->name_tree, &tmp.n, name_cmp, 0); - if (entry) { - val = rb_entry(entry, struct name, n); - free(name); - return val->sub; - } - - val = malloc(sizeof(struct name)); - if (!val) { - error("cannot sanitize name, not enough memory"); - free(name); - return NULL; + for(i = 3; i >= 0; i--) { + desired_crc = (desired_crc << 8) + ^ crc32c_rev_table[desired_crc >> 24 & 0xFF] + ^ ((current_crc >> i * 8) & 0xFF); } + for (i = 0; i < 4; i++) + suffix[i] = (desired_crc >> i * 8) & 0xFF; +} - memset(val, 0, sizeof(*val)); +/* + * Check if suffix is valid according to our file name conventions + */ +static int find_collision_is_suffix_valid(const char *suffix) +{ + int i; + char c; - val->val = name; - val->len = name_len; - val->sub = malloc(name_len); - if (!val->sub) { - error("cannot sanitize name, not enough memory"); - free(val); - free(name); - return NULL; + for (i = 0; i < 4; i++) { + c = suffix[i]; + if (c < ' ' || c > 126 || c == '/') + return 0; } + return 1; +} + +static int find_collision_reverse_crc32c(struct name *val, u32 name_len) +{ + unsigned long checksum; + unsigned long current_checksum; + int found = 0; + int i; + /* There are no same length collisions of 4 or less bytes */ + if (name_len <= 4) + return 0; checksum = crc32c(~1, val->val, name_len); + name_len -= 4; memset(val->sub, ' ', name_len); i = 0; while (1) { - if (crc32c(~1, val->sub, name_len) == checksum && + current_checksum = crc32c(~1, val->sub, name_len); + find_collision_calc_suffix(current_checksum, + checksum, + val->sub + name_len); + if (find_collision_is_suffix_valid(val->sub + name_len) && memcmp(val->sub, val->val, val->len)) { found = 1; break; } - if (val->sub[i] == 127) { + if (val->sub[i] == 126) { do { i++; if (i >= name_len) break; - } while (val->sub[i] == 127); + } while (val->sub[i] == 126); if (i >= name_len) break; @@ -408,6 +493,47 @@ static char *find_collision(struct metadump_struct *md, char *name, val->sub[i]++; } } + return found; +} + +static char *find_collision(struct metadump_struct *md, char *name, + u32 name_len) +{ + struct name *val; + struct rb_node *entry; + struct name tmp; + int found; + int i; + + tmp.val = name; + tmp.len = name_len; + entry = tree_search(&md->name_tree, &tmp.n, name_cmp, 0); + if (entry) { + val = rb_entry(entry, struct name, n); + free(name); + return val->sub; + } + + val = malloc(sizeof(struct name)); + if (!val) { + error("cannot sanitize name, not enough memory"); + free(name); + return NULL; + } + + memset(val, 0, sizeof(*val)); + + val->val = name; + val->len = name_len; + val->sub = malloc(name_len); + if (!val->sub) { + error("cannot sanitize name, not enough memory"); + free(val); + free(name); + return NULL; + } + + found = find_collision_reverse_crc32c(val, name_len); if (!found) { warning( @@ -919,7 +1045,6 @@ static int flush_pending(struct metadump_struct *md, int done) { struct async_work *async = NULL; struct extent_buffer *eb; - u64 blocksize = md->root->fs_info->nodesize; u64 start = 0; u64 size; size_t offset; @@ -972,9 +1097,10 @@ static int flush_pending(struct metadump_struct *md, int done) } while (!md->data && size > 0) { - u64 this_read = min(blocksize, size); - eb = read_tree_block(md->root->fs_info, start, - this_read, 0); + u64 this_read = min((u64)md->root->fs_info->nodesize, + size); + + eb = read_tree_block(md->root->fs_info, start, 0); if (!extent_buffer_uptodate(eb)) { free(async->buffer); free(async); @@ -1029,7 +1155,7 @@ static int add_extent(u64 start, u64 size, struct metadump_struct *md, return ret; md->pending_start = start; } - readahead_tree_block(md->root->fs_info, start, size, 0); + readahead_tree_block(md->root->fs_info, start, 0); md->pending_size += size; md->data = data; return 0; @@ -1105,8 +1231,7 @@ static int copy_tree_blocks(struct btrfs_root *root, struct extent_buffer *eb, continue; ri = btrfs_item_ptr(eb, i, struct btrfs_root_item); bytenr = btrfs_disk_root_bytenr(eb, ri); - tmp = read_tree_block(fs_info, bytenr, - fs_info->nodesize, 0); + tmp = read_tree_block(fs_info, bytenr, 0); if (!extent_buffer_uptodate(tmp)) { error("unable to read log root block"); return -EIO; @@ -1117,8 +1242,7 @@ static int copy_tree_blocks(struct btrfs_root *root, struct extent_buffer *eb, return ret; } else { bytenr = btrfs_node_blockptr(eb, i); - tmp = read_tree_block(fs_info, bytenr, - fs_info->nodesize, 0); + tmp = read_tree_block(fs_info, bytenr, 0); if (!extent_buffer_uptodate(tmp)) { error("unable to read log root block"); return -EIO; |