Import libsparse sources
[project/make_ext4fs.git] / libsparse / sparse_read.c
diff --git a/libsparse/sparse_read.c b/libsparse/sparse_read.c
new file mode 100644 (file)
index 0000000..9b10293
--- /dev/null
@@ -0,0 +1,505 @@
+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define _GNU_SOURCE
+#define _FILE_OFFSET_BITS 64
+#define _LARGEFILE64_SOURCE 1
+
+#include <fcntl.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <sparse/sparse.h>
+
+#include "defs.h"
+#include "output_file.h"
+#include "sparse_crc32.h"
+#include "sparse_file.h"
+#include "sparse_format.h"
+
+#if defined(__APPLE__) && defined(__MACH__)
+#define lseek64 lseek
+#define off64_t off_t
+#endif
+
+#define SPARSE_HEADER_MAJOR_VER 1
+#define SPARSE_HEADER_LEN       (sizeof(sparse_header_t))
+#define CHUNK_HEADER_LEN (sizeof(chunk_header_t))
+
+#define COPY_BUF_SIZE (1024U*1024U)
+static char *copybuf;
+
+#define min(a, b) \
+       ({ typeof(a) _a = (a); typeof(b) _b = (b); (_a < _b) ? _a : _b; })
+
+static void verbose_error(bool verbose, int err, const char *fmt, ...)
+{
+       char *s = "";
+       char *at = "";
+       if (fmt) {
+               va_list argp;
+               int size;
+
+               va_start(argp, fmt);
+               size = vsnprintf(NULL, 0, fmt, argp);
+               va_end(argp);
+
+               if (size < 0) {
+                       return;
+               }
+
+               at = malloc(size + 1);
+               if (at == NULL) {
+                       return;
+               }
+
+               va_start(argp, fmt);
+               vsnprintf(at, size, fmt, argp);
+               va_end(argp);
+               at[size] = 0;
+               s = " at ";
+       }
+       if (verbose) {
+#ifndef USE_MINGW
+               if (err == -EOVERFLOW) {
+                       sparse_print_verbose("EOF while reading file%s%s\n", s, at);
+               } else
+#endif
+               if (err == -EINVAL) {
+                       sparse_print_verbose("Invalid sparse file format%s%s\n", s, at);
+               } else if (err == -ENOMEM) {
+                       sparse_print_verbose("Failed allocation while reading file%s%s\n",
+                                       s, at);
+               } else {
+                       sparse_print_verbose("Unknown error %d%s%s\n", err, s, at);
+               }
+       }
+       if (fmt) {
+               free(at);
+       }
+}
+
+static int process_raw_chunk(struct sparse_file *s, unsigned int chunk_size,
+               int fd, int64_t offset, unsigned int blocks, unsigned int block,
+               uint32_t *crc32)
+{
+       int ret;
+       int chunk;
+       unsigned int len = blocks * s->block_size;
+
+       if (chunk_size % s->block_size != 0) {
+               return -EINVAL;
+       }
+
+       if (chunk_size / s->block_size != blocks) {
+               return -EINVAL;
+       }
+
+       ret = sparse_file_add_fd(s, fd, offset, len, block);
+       if (ret < 0) {
+               return ret;
+       }
+
+       if (crc32) {
+               while (len) {
+                       chunk = min(len, COPY_BUF_SIZE);
+                       ret = read_all(fd, copybuf, chunk);
+                       if (ret < 0) {
+                               return ret;
+                       }
+                       *crc32 = sparse_crc32(*crc32, copybuf, chunk);
+                       len -= chunk;
+               }
+       } else {
+               lseek64(fd, len, SEEK_CUR);
+       }
+
+       return 0;
+}
+
+static int process_fill_chunk(struct sparse_file *s, unsigned int chunk_size,
+               int fd, unsigned int blocks, unsigned int block, uint32_t *crc32)
+{
+       int ret;
+       int chunk;
+       int64_t len = (int64_t)blocks * s->block_size;
+       uint32_t fill_val;
+       uint32_t *fillbuf;
+       unsigned int i;
+
+       if (chunk_size != sizeof(fill_val)) {
+               return -EINVAL;
+       }
+
+       ret = read_all(fd, &fill_val, sizeof(fill_val));
+       if (ret < 0) {
+               return ret;
+       }
+
+       ret = sparse_file_add_fill(s, fill_val, len, block);
+       if (ret < 0) {
+               return ret;
+       }
+
+       if (crc32) {
+               /* Fill copy_buf with the fill value */
+               fillbuf = (uint32_t *)copybuf;
+               for (i = 0; i < (COPY_BUF_SIZE / sizeof(fill_val)); i++) {
+                       fillbuf[i] = fill_val;
+               }
+
+               while (len) {
+                       chunk = min(len, COPY_BUF_SIZE);
+                       *crc32 = sparse_crc32(*crc32, copybuf, chunk);
+                       len -= chunk;
+               }
+       }
+
+       return 0;
+}
+
+static int process_skip_chunk(struct sparse_file *s, unsigned int chunk_size,
+               int fd __unused, unsigned int blocks,
+               unsigned int block __unused, uint32_t *crc32)
+{
+       if (chunk_size != 0) {
+               return -EINVAL;
+       }
+
+       if (crc32) {
+               int64_t len = (int64_t)blocks * s->block_size;
+               memset(copybuf, 0, COPY_BUF_SIZE);
+
+               while (len) {
+                       int chunk = min(len, COPY_BUF_SIZE);
+                       *crc32 = sparse_crc32(*crc32, copybuf, chunk);
+                       len -= chunk;
+               }
+       }
+
+       return 0;
+}
+
+static int process_crc32_chunk(int fd, unsigned int chunk_size, uint32_t crc32)
+{
+       uint32_t file_crc32;
+       int ret;
+
+       if (chunk_size != sizeof(file_crc32)) {
+               return -EINVAL;
+       }
+
+       ret = read_all(fd, &file_crc32, sizeof(file_crc32));
+       if (ret < 0) {
+               return ret;
+       }
+
+       if (file_crc32 != crc32) {
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+static int process_chunk(struct sparse_file *s, int fd, off64_t offset,
+               unsigned int chunk_hdr_sz, chunk_header_t *chunk_header,
+               unsigned int cur_block, uint32_t *crc_ptr)
+{
+       int ret;
+       unsigned int chunk_data_size;
+
+       chunk_data_size = chunk_header->total_sz - chunk_hdr_sz;
+
+       switch (chunk_header->chunk_type) {
+               case CHUNK_TYPE_RAW:
+                       ret = process_raw_chunk(s, chunk_data_size, fd, offset,
+                                       chunk_header->chunk_sz, cur_block, crc_ptr);
+                       if (ret < 0) {
+                               verbose_error(s->verbose, ret, "data block at %lld", offset);
+                               return ret;
+                       }
+                       return chunk_header->chunk_sz;
+               case CHUNK_TYPE_FILL:
+                       ret = process_fill_chunk(s, chunk_data_size, fd,
+                                       chunk_header->chunk_sz, cur_block, crc_ptr);
+                       if (ret < 0) {
+                               verbose_error(s->verbose, ret, "fill block at %lld", offset);
+                               return ret;
+                       }
+                       return chunk_header->chunk_sz;
+               case CHUNK_TYPE_DONT_CARE:
+                       ret = process_skip_chunk(s, chunk_data_size, fd,
+                                       chunk_header->chunk_sz, cur_block, crc_ptr);
+                       if (chunk_data_size != 0) {
+                               if (ret < 0) {
+                                       verbose_error(s->verbose, ret, "skip block at %lld", offset);
+                                       return ret;
+                               }
+                       }
+                       return chunk_header->chunk_sz;
+               case CHUNK_TYPE_CRC32:
+                       ret = process_crc32_chunk(fd, chunk_data_size, *crc_ptr);
+                       if (ret < 0) {
+                               verbose_error(s->verbose, -EINVAL, "crc block at %lld",
+                                               offset);
+                               return ret;
+                       }
+                       return 0;
+               default:
+                       verbose_error(s->verbose, -EINVAL, "unknown block %04X at %lld",
+                                       chunk_header->chunk_type, offset);
+       }
+
+       return 0;
+}
+
+static int sparse_file_read_sparse(struct sparse_file *s, int fd, bool crc)
+{
+       int ret;
+       unsigned int i;
+       sparse_header_t sparse_header;
+       chunk_header_t chunk_header;
+       uint32_t crc32 = 0;
+       uint32_t *crc_ptr = 0;
+       unsigned int cur_block = 0;
+       off64_t offset;
+
+       if (!copybuf) {
+               copybuf = malloc(COPY_BUF_SIZE);
+       }
+
+       if (!copybuf) {
+               return -ENOMEM;
+       }
+
+       if (crc) {
+               crc_ptr = &crc32;
+       }
+
+       ret = read_all(fd, &sparse_header, sizeof(sparse_header));
+       if (ret < 0) {
+               return ret;
+       }
+
+       if (sparse_header.magic != SPARSE_HEADER_MAGIC) {
+               return -EINVAL;
+       }
+
+       if (sparse_header.major_version != SPARSE_HEADER_MAJOR_VER) {
+               return -EINVAL;
+       }
+
+       if (sparse_header.file_hdr_sz < SPARSE_HEADER_LEN) {
+               return -EINVAL;
+       }
+
+       if (sparse_header.chunk_hdr_sz < sizeof(chunk_header)) {
+               return -EINVAL;
+       }
+
+       if (sparse_header.file_hdr_sz > SPARSE_HEADER_LEN) {
+               /* Skip the remaining bytes in a header that is longer than
+                * we expected.
+                */
+               lseek64(fd, sparse_header.file_hdr_sz - SPARSE_HEADER_LEN, SEEK_CUR);
+       }
+
+       for (i = 0; i < sparse_header.total_chunks; i++) {
+               ret = read_all(fd, &chunk_header, sizeof(chunk_header));
+               if (ret < 0) {
+                       return ret;
+               }
+
+               if (sparse_header.chunk_hdr_sz > CHUNK_HEADER_LEN) {
+                       /* Skip the remaining bytes in a header that is longer than
+                        * we expected.
+                        */
+                       lseek64(fd, sparse_header.chunk_hdr_sz - CHUNK_HEADER_LEN, SEEK_CUR);
+               }
+
+               offset = lseek64(fd, 0, SEEK_CUR);
+
+               ret = process_chunk(s, fd, offset, sparse_header.chunk_hdr_sz, &chunk_header,
+                               cur_block, crc_ptr);
+               if (ret < 0) {
+                       return ret;
+               }
+
+               cur_block += ret;
+       }
+
+       if (sparse_header.total_blks != cur_block) {
+               return -EINVAL;
+       }
+
+       return 0;
+}
+
+static int sparse_file_read_normal(struct sparse_file *s, int fd)
+{
+       int ret;
+       uint32_t *buf = malloc(s->block_size);
+       unsigned int block = 0;
+       int64_t remain = s->len;
+       int64_t offset = 0;
+       unsigned int to_read;
+       unsigned int i;
+       bool sparse_block;
+
+       if (!buf) {
+               return -ENOMEM;
+       }
+
+       while (remain > 0) {
+               to_read = min(remain, s->block_size);
+               ret = read_all(fd, buf, to_read);
+               if (ret < 0) {
+                       error("failed to read sparse file");
+                       return ret;
+               }
+
+               if (to_read == s->block_size) {
+                       sparse_block = true;
+                       for (i = 1; i < s->block_size / sizeof(uint32_t); i++) {
+                               if (buf[0] != buf[i]) {
+                                       sparse_block = false;
+                                       break;
+                               }
+                       }
+               } else {
+                       sparse_block = false;
+               }
+
+               if (sparse_block) {
+                       /* TODO: add flag to use skip instead of fill for buf[0] == 0 */
+                       sparse_file_add_fill(s, buf[0], to_read, block);
+               } else {
+                       sparse_file_add_fd(s, fd, offset, to_read, block);
+               }
+
+               remain -= to_read;
+               offset += to_read;
+               block++;
+       }
+
+       return 0;
+}
+
+int sparse_file_read(struct sparse_file *s, int fd, bool sparse, bool crc)
+{
+       if (crc && !sparse) {
+               return -EINVAL;
+       }
+
+       if (sparse) {
+               return sparse_file_read_sparse(s, fd, crc);
+       } else {
+               return sparse_file_read_normal(s, fd);
+       }
+}
+
+struct sparse_file *sparse_file_import(int fd, bool verbose, bool crc)
+{
+       int ret;
+       sparse_header_t sparse_header;
+       int64_t len;
+       struct sparse_file *s;
+
+       ret = read_all(fd, &sparse_header, sizeof(sparse_header));
+       if (ret < 0) {
+               verbose_error(verbose, ret, "header");
+               return NULL;
+       }
+
+       if (sparse_header.magic != SPARSE_HEADER_MAGIC) {
+               verbose_error(verbose, -EINVAL, "header magic");
+               return NULL;
+       }
+
+       if (sparse_header.major_version != SPARSE_HEADER_MAJOR_VER) {
+               verbose_error(verbose, -EINVAL, "header major version");
+               return NULL;
+       }
+
+       if (sparse_header.file_hdr_sz < SPARSE_HEADER_LEN) {
+               return NULL;
+       }
+
+       if (sparse_header.chunk_hdr_sz < sizeof(chunk_header_t)) {
+               return NULL;
+       }
+
+       len = (int64_t)sparse_header.total_blks * sparse_header.blk_sz;
+       s = sparse_file_new(sparse_header.blk_sz, len);
+       if (!s) {
+               verbose_error(verbose, -EINVAL, NULL);
+               return NULL;
+       }
+
+       ret = lseek64(fd, 0, SEEK_SET);
+       if (ret < 0) {
+               verbose_error(verbose, ret, "seeking");
+               sparse_file_destroy(s);
+               return NULL;
+       }
+
+       s->verbose = verbose;
+
+       ret = sparse_file_read(s, fd, true, crc);
+       if (ret < 0) {
+               sparse_file_destroy(s);
+               return NULL;
+       }
+
+       return s;
+}
+
+struct sparse_file *sparse_file_import_auto(int fd, bool crc, bool verbose)
+{
+       struct sparse_file *s;
+       int64_t len;
+       int ret;
+
+       s = sparse_file_import(fd, verbose, crc);
+       if (s) {
+               return s;
+       }
+
+       len = lseek64(fd, 0, SEEK_END);
+       if (len < 0) {
+               return NULL;
+       }
+
+       lseek64(fd, 0, SEEK_SET);
+
+       s = sparse_file_new(4096, len);
+       if (!s) {
+               return NULL;
+       }
+
+       ret = sparse_file_read_normal(s, fd);
+       if (ret < 0) {
+               sparse_file_destroy(s);
+               return NULL;
+       }
+
+       return s;
+}