compression: fix lzxpress-compress

Signed-off-by: Matt Suiche <msuiche@comae.com>
Reviewed-by: Joseph Sutton <josephsutton@catalyst.net.nz>
Reviewed-by: Douglas Bagnall <douglas.bagnall@catalyst.net.nz>

diff --git a/lib/compression/lzxpress.c b/lib/compression/lzxpress.c
index 4b2ffbda0f2d84c917f44f5c5900b4f1479dfd51..a428d0397c80137a8bb1aa0de07d6ae17a0e2605 100644 (file)
--- a/lib/compression/lzxpress.c
+++ b/lib/compression/lzxpress.c
@@ -57,6 +57,17 @@
 ))
 #endif
 
+#define __CHECK_BYTES(__size, __index, __needed) do { \
+       if (unlikely(__index >= __size)) { \
+               return -1; \
+       } else { \
+               uint32_t __avail = __size - __index; \
+               if (unlikely(__needed > __avail)) { \
+                       return -1; \
+               } \
+       } \
+} while(0)
+
 ssize_t lzxpress_compress(const uint8_t *uncompressed,
                          uint32_t uncompressed_size,
                          uint8_t *compressed,
@@ -65,7 +76,7 @@ ssize_t lzxpress_compress(const uint8_t *uncompressed,
        uint32_t uncompressed_pos, compressed_pos, byte_left;
        uint32_t max_offset, best_offset;
        int32_t offset;
-       uint32_t max_len, len, best_len;
+       uint32_t max_len, len, best_len, match_len;
        const uint8_t *str1, *str2;
        uint32_t indic;
        uint8_t *indic_pos;
@@ -92,7 +103,8 @@ ssize_t lzxpress_compress(const uint8_t *uncompressed,
        if (uncompressed_pos > XPRESS_BLOCK_SIZE)
                return 0;
 
-       do {
+       while ((uncompressed_pos < uncompressed_size) &&
+              (compressed_pos < max_compressed_size)) {
                bool found = false;
 
                max_offset = uncompressed_pos;
@@ -109,7 +121,7 @@ ssize_t lzxpress_compress(const uint8_t *uncompressed,
                        str2 = &str1[-offset];
 
                        /* maximum len we can encode into metadata */
-                       max_len = MIN((255 + 15 + 7 + 3), byte_left);
+                       max_len = MIN(0x1FFF, byte_left);
 
                        for (len = 0; (len < max_len) && (str1[len] == str2[len]); len++);
 
@@ -124,112 +136,128 @@ ssize_t lzxpress_compress(const uint8_t *uncompressed,
                        }
                }
 
-               if (found) {
+               if (!found) {
+                       __CHECK_BYTES(uncompressed_size, uncompressed_pos, sizeof(uint8_t));
+                       __CHECK_BYTES(max_compressed_size, compressed_pos, sizeof(uint8_t));
+                       compressed[compressed_pos++] = uncompressed[uncompressed_pos++];
+                       byte_left--;
+
+                       indic <<= 1;
+                       indic_bit += 1;
+
+                       if (indic_bit == 32) {
+                               SIVAL(indic_pos, 0, indic);
+                               indic_bit = 0;
+                               __CHECK_BYTES(max_compressed_size, compressed_pos, sizeof(uint32_t));
+                               indic_pos = &compressed[compressed_pos];
+                               compressed_pos += sizeof(uint32_t);
+                       }
+               } else {
                        metadata_size = 0;
+                       match_len = best_len;
+                       __CHECK_BYTES(max_compressed_size, compressed_pos, sizeof(uint16_t));
                        dest = (uint16_t *)&compressed[compressed_pos];
 
-                       if (best_len < 10) {
+                       match_len -= 3;
+                       best_offset -= 1;
+
+                       if (match_len < 7) {
                                /* Classical meta-data */
-                               metadata = (uint16_t)(((best_offset - 1) << 3) | (best_len - 3));
+                               __CHECK_BYTES(max_compressed_size, compressed_pos, sizeof(uint16_t));
+                               metadata = (uint16_t)((best_offset  << 3) + match_len);
                                SSVAL(dest, metadata_size / sizeof(uint16_t), metadata);
                                metadata_size += sizeof(uint16_t);
                        } else {
-                               metadata = (uint16_t)(((best_offset - 1) << 3) | 7);
+                               bool has_extra = false;
+                               __CHECK_BYTES(max_compressed_size, compressed_pos, sizeof(uint16_t));
+                               metadata = (uint16_t)(best_offset << 3) | 7;
                                SSVAL(dest, metadata_size / sizeof(uint16_t), metadata);
-                               metadata_size = sizeof(uint16_t);
+                               metadata_size += sizeof(uint16_t);
+
+                               match_len -= 7;
 
-                               if (best_len < (15 + 7 + 3)) {
-                                       /* Shared byte */
-                                       if (!nibble_index) {
-                                               compressed[compressed_pos + metadata_size] = (best_len - (3 + 7)) & 0xF;
+                               if (!nibble_index) {
+                                       nibble_index = compressed_pos;
+                                       if (match_len < 15) {
+                                               __CHECK_BYTES(max_compressed_size, compressed_pos + metadata_size, sizeof(uint8_t));
+                                               compressed[compressed_pos + metadata_size] = match_len & 0xFF;;
                                                metadata_size += sizeof(uint8_t);
                                        } else {
-                                               compressed[nibble_index] &= 0xF;
-                                               compressed[nibble_index] |= (best_len - (3 + 7)) * 16;
-                                       }
-                               } else if (best_len < (3 + 7 + 15 + 255)) {
-                                       /* Shared byte */
-                                       if (!nibble_index) {
+                                               __CHECK_BYTES(max_compressed_size, compressed_pos + metadata_size, sizeof(uint8_t));
                                                compressed[compressed_pos + metadata_size] = 15;
                                                metadata_size += sizeof(uint8_t);
-                                       } else {
-                                               compressed[nibble_index] &= 0xF;
-                                               compressed[nibble_index] |= (15 * 16);
+                                               has_extra = true;
                                        }
-
-                                       /* Additional best_len */
-                                       compressed[compressed_pos + metadata_size] = (best_len - (3 + 7 + 15)) & 0xFF;
-                                       metadata_size += sizeof(uint8_t);
                                } else {
-                                       /* Shared byte */
-                                       if (!nibble_index) {
-                                               compressed[compressed_pos + metadata_size] |= 15;
-                                               metadata_size += sizeof(uint8_t);
+                                       if (match_len < 15) {
+                                               // compressed[nibble_index] &= 0xF;
+                                               __CHECK_BYTES(max_compressed_size, nibble_index, sizeof(uint8_t));
+                                               compressed[nibble_index] |= (match_len << 4) & 0xFF;
+                                               nibble_index = 0;
                                        } else {
-                                               compressed[nibble_index] |= 15 << 4;
+                                               __CHECK_BYTES(max_compressed_size, nibble_index, sizeof(uint8_t));
+                                               compressed[nibble_index] |= (15 << 4);
+                                               nibble_index = 0;
+                                               has_extra = true;
                                        }
+                               }
 
-                                       /* Additional best_len */
-                                       compressed[compressed_pos + metadata_size] = 255;
+                               if (has_extra) {
+                                       match_len -= 15;
 
-                                       metadata_size += sizeof(uint8_t);
+                                       if (match_len < 255) {
+                                               __CHECK_BYTES(max_compressed_size, compressed_pos + metadata_size, sizeof(uint8_t));
+                                               compressed[compressed_pos + metadata_size] = match_len & 0xFF;
+                                               metadata_size += sizeof(uint8_t);
+                                       } else {
+                                               /* Additional match_len */
+                                               __CHECK_BYTES(max_compressed_size, compressed_pos + metadata_size, sizeof(uint8_t));
+                                               compressed[compressed_pos + metadata_size] = 255;
+                                               metadata_size += sizeof(uint8_t);
 
-                                       compressed[compressed_pos + metadata_size] = (best_len - 3) & 0xFF;
-                                       compressed[compressed_pos + metadata_size + 1] = ((best_len - 3) >> 8) & 0xFF;
-                                       metadata_size += sizeof(uint16_t);
+                                               match_len += 7 + 15;
+
+                                               if (match_len < (1 << 16)) {
+                                                       __CHECK_BYTES(max_compressed_size, compressed_pos + metadata_size, sizeof(uint16_t));
+                                                       compressed[compressed_pos + metadata_size] = match_len & 0xFF;
+                                                       compressed[compressed_pos + metadata_size + 1] = (match_len >> 8);
+                                                       metadata_size += sizeof(uint16_t);
+                                               } else {
+                                                       __CHECK_BYTES(max_compressed_size, compressed_pos + metadata_size, sizeof(uint16_t) + sizeof(uint32_t));
+                                                       compressed[compressed_pos + metadata_size] = 0;
+                                                       compressed[compressed_pos + metadata_size + 1] = 0;
+                                                       metadata_size += sizeof(uint16_t);
+
+                                                       compressed[compressed_pos + metadata_size] = match_len & 0xFF;
+                                                       compressed[compressed_pos + metadata_size + 1] = (match_len >> 8) & 0xFF;
+                                                       compressed[compressed_pos + metadata_size + 2] = (match_len >> 16) & 0xFF;
+                                                       compressed[compressed_pos + metadata_size + 3] = (match_len >> 24) & 0xFF;
+                                                       metadata_size += sizeof(uint32_t);
+                                               }
+                                       }
                                }
                        }
 
-                       indic |= 1U << (32 - ((indic_bit % 32) + 1));
+                       indic = (indic << 1) | 1;
+                       indic_bit += 1;
 
-                       if (best_len > 9) {
-                               if (nibble_index == 0) {
-                                       nibble_index = compressed_pos + sizeof(uint16_t);
-                               } else {
-                                       nibble_index = 0;
-                               }
+                       if (indic_bit == 32) {
+                               SIVAL(indic_pos, 0, indic);
+                               indic_bit = 0;
+                               indic_pos = &compressed[compressed_pos];
+                               compressed_pos += sizeof(uint32_t);
                        }
 
                        compressed_pos += metadata_size;
                        uncompressed_pos += best_len;
                        byte_left -= best_len;
-               } else {
-                       compressed[compressed_pos++] = uncompressed[uncompressed_pos++];
-                       byte_left--;
-               }
-               indic_bit++;
-
-               if ((indic_bit - 1) % 32 > (indic_bit % 32)) {
-                       SIVAL(indic_pos, 0, indic);
-                       indic = 0;
-                       indic_pos = &compressed[compressed_pos];
-                       compressed_pos += sizeof(uint32_t);
-               }
-       } while (byte_left > 3);
-
-       do {
-               compressed[compressed_pos] = uncompressed[uncompressed_pos];
-               indic_bit++;
-
-               uncompressed_pos++;
-               compressed_pos++;
-                if (((indic_bit - 1) % 32) > (indic_bit % 32)){
-                       SIVAL(indic_pos, 0, indic);
-                       indic = 0;
-                       indic_pos = &compressed[compressed_pos];
-                       compressed_pos += sizeof(uint32_t);
                }
-       } while (uncompressed_pos < uncompressed_size);
-
-       if ((indic_bit % 32) > 0) {
-               for (; (indic_bit % 32) != 0; indic_bit++)
-                       indic |= 1U << (32 - ((indic_bit % 32) + 1));
-
-               SIVAL(compressed, compressed_pos, 0);
-               SIVAL(indic_pos, 0, indic);
-               compressed_pos += sizeof(uint32_t);
        }
 
+       indic <<= 32 - indic_bit;
+       indic |= (1 << (32 - indic_bit)) - 1;
+       SIVAL(indic_pos, 0, indic);
+
        return compressed_pos;
 }
 
@@ -253,16 +281,6 @@ ssize_t lzxpress_decompress(const uint8_t *input,
        offset = 0;
        nibble_index = 0;
 
-#define __CHECK_BYTES(__size, __index, __needed) do { \
-       if (unlikely(__index >= __size)) { \
-               return -1; \
-       } else { \
-               uint32_t __avail = __size - __index; \
-               if (unlikely(__needed > __avail)) { \
-                       return -1; \
-               } \
-       } \
-} while(0)
 #define CHECK_INPUT_BYTES(__needed) \
        __CHECK_BYTES(input_size, input_index, __needed)
 #define CHECK_OUTPUT_BYTES(__needed) \

diff --git a/selftest/knownfail.d/lzxpress b/selftest/knownfail.d/lzxpress
deleted file mode 100644 (file)
index bdfe64d..0000000
--- a/selftest/knownfail.d/lzxpress
+++ /dev/null
@@ -1,3 +0,0 @@
-samba4.local.compression.lzxpress
-samba4.local.compression.lzxpress2
-samba4.local.compression.lzxpress3