diff options
Diffstat (limited to 'libsparse/sparse_read.cpp')
| -rw-r--r-- | libsparse/sparse_read.cpp | 192 |
1 files changed, 154 insertions, 38 deletions
diff --git a/libsparse/sparse_read.cpp b/libsparse/sparse_read.cpp index 437963527..d6a68b3c7 100644 --- a/libsparse/sparse_read.cpp +++ b/libsparse/sparse_read.cpp @@ -58,6 +58,114 @@ static std::string ErrorString(int err) return android::base::StringPrintf("Unknown error %d", err); } +class SparseFileSource { +public: + /* Seeks the source ahead by the given offset. */ + virtual void Seek(int64_t offset) = 0; + + /* Return the current offset. */ + virtual int64_t GetOffset() = 0; + + /* Set the current offset. Return 0 if successful. */ + virtual int SetOffset(int64_t offset) = 0; + + /* Adds the given length from the current offset of the source to the file at the given + * block. Return 0 if successful. */ + virtual int AddToSparseFile(struct sparse_file *s, int64_t len, unsigned int block) = 0; + + /* Get data of fixed size from the current offset and seek len bytes. + * Return 0 if successful. */ + virtual int ReadValue(void *ptr, int len) = 0; + + /* Find the crc32 of the next len bytes and seek ahead len bytes. Return 0 if successful. */ + virtual int GetCrc32(uint32_t *crc32, int64_t len) = 0; + + virtual ~SparseFileSource() {}; +}; + +class SparseFileFdSource : public SparseFileSource { +private: + int fd; +public: + SparseFileFdSource(int fd) : fd(fd) {} + ~SparseFileFdSource() override {} + + void Seek(int64_t off) override { + lseek64(fd, off, SEEK_CUR); + } + + int64_t GetOffset() override { + return lseek64(fd, 0, SEEK_CUR); + } + + int SetOffset(int64_t offset) override { + return lseek64(fd, offset, SEEK_SET) == offset ? 0 : -errno; + } + + int AddToSparseFile(struct sparse_file *s, int64_t len, unsigned int block) override { + return sparse_file_add_fd(s, fd, GetOffset(), len, block); + } + + int ReadValue(void *ptr, int len) override { + return read_all(fd, ptr, len); + } + + int GetCrc32(uint32_t *crc32, int64_t len) override { + int chunk; + int ret; + while (len) { + chunk = std::min(len, COPY_BUF_SIZE); + ret = read_all(fd, copybuf, chunk); + if (ret < 0) { + return ret; + } + *crc32 = sparse_crc32(*crc32, copybuf, chunk); + len -= chunk; + } + return 0; + } +}; + +class SparseFileBufSource : public SparseFileSource { +private: + char *buf; + int64_t offset; +public: + SparseFileBufSource(char *buf) : buf(buf), offset(0) {} + ~SparseFileBufSource() override {} + + void Seek(int64_t off) override { + buf += off; + offset += off; + } + + int64_t GetOffset() override { + return offset; + } + + int SetOffset(int64_t off) override { + buf += off - offset; + offset = off; + return 0; + } + + int AddToSparseFile(struct sparse_file *s, int64_t len, unsigned int block) override { + return sparse_file_add_data(s, buf, len, block); + } + + int ReadValue(void *ptr, int len) override { + memcpy(ptr, buf, len); + Seek(len); + return 0; + } + + int GetCrc32(uint32_t *crc32, int64_t len) override { + *crc32 = sparse_crc32(*crc32, buf, len); + Seek(len); + return 0; + } +}; + static void verbose_error(bool verbose, int err, const char *fmt, ...) { if (!verbose) return; @@ -74,11 +182,10 @@ static void verbose_error(bool verbose, int err, const char *fmt, ...) } static int process_raw_chunk(struct sparse_file *s, unsigned int chunk_size, - int fd, int64_t offset, unsigned int blocks, unsigned int block, + SparseFileSource *source, unsigned int blocks, unsigned int block, uint32_t *crc32) { int ret; - int chunk; int64_t len = blocks * s->block_size; if (chunk_size % s->block_size != 0) { @@ -89,30 +196,25 @@ static int process_raw_chunk(struct sparse_file *s, unsigned int chunk_size, return -EINVAL; } - ret = sparse_file_add_fd(s, fd, offset, len, block); + ret = source->AddToSparseFile(s, len, block); if (ret < 0) { return ret; } if (crc32) { - while (len) { - chunk = std::min(len, COPY_BUF_SIZE); - ret = read_all(fd, copybuf, chunk); - if (ret < 0) { - return ret; - } - *crc32 = sparse_crc32(*crc32, copybuf, chunk); - len -= chunk; + ret = source->GetCrc32(crc32, len); + if (ret < 0) { + return ret; } } else { - lseek64(fd, len, SEEK_CUR); + source->Seek(len); } 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) + SparseFileSource *source, unsigned int blocks, unsigned int block, uint32_t *crc32) { int ret; int chunk; @@ -125,7 +227,7 @@ static int process_fill_chunk(struct sparse_file *s, unsigned int chunk_size, return -EINVAL; } - ret = read_all(fd, &fill_val, sizeof(fill_val)); + ret = source->ReadValue(&fill_val, sizeof(fill_val)); if (ret < 0) { return ret; } @@ -153,7 +255,7 @@ static int process_fill_chunk(struct sparse_file *s, unsigned int chunk_size, } static int process_skip_chunk(struct sparse_file *s, unsigned int chunk_size, - int fd __unused, unsigned int blocks, + SparseFileSource *source __unused, unsigned int blocks, unsigned int block __unused, uint32_t *crc32) { if (chunk_size != 0) { @@ -161,7 +263,7 @@ static int process_skip_chunk(struct sparse_file *s, unsigned int chunk_size, } if (crc32) { - int64_t len = (int64_t)blocks * s->block_size; + int64_t len = (int64_t)blocks * s->block_size; memset(copybuf, 0, COPY_BUF_SIZE); while (len) { @@ -174,16 +276,15 @@ static int process_skip_chunk(struct sparse_file *s, unsigned int chunk_size, return 0; } -static int process_crc32_chunk(int fd, unsigned int chunk_size, uint32_t *crc32) +static int process_crc32_chunk(SparseFileSource *source, 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)); + int ret = source->ReadValue(&file_crc32, sizeof(file_crc32)); if (ret < 0) { return ret; } @@ -195,18 +296,19 @@ static int process_crc32_chunk(int fd, unsigned int chunk_size, uint32_t *crc32) return 0; } -static int process_chunk(struct sparse_file *s, int fd, off64_t offset, +static int process_chunk(struct sparse_file *s, SparseFileSource *source, 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; + int64_t offset = source->GetOffset(); 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, + ret = process_raw_chunk(s, chunk_data_size, source, chunk_header->chunk_sz, cur_block, crc_ptr); if (ret < 0) { verbose_error(s->verbose, ret, "data block at %" PRId64, offset); @@ -214,7 +316,7 @@ static int process_chunk(struct sparse_file *s, int fd, off64_t offset, } return chunk_header->chunk_sz; case CHUNK_TYPE_FILL: - ret = process_fill_chunk(s, chunk_data_size, fd, + ret = process_fill_chunk(s, chunk_data_size, source, chunk_header->chunk_sz, cur_block, crc_ptr); if (ret < 0) { verbose_error(s->verbose, ret, "fill block at %" PRId64, offset); @@ -222,7 +324,7 @@ static int process_chunk(struct sparse_file *s, int fd, off64_t offset, } return chunk_header->chunk_sz; case CHUNK_TYPE_DONT_CARE: - ret = process_skip_chunk(s, chunk_data_size, fd, + ret = process_skip_chunk(s, chunk_data_size, source, chunk_header->chunk_sz, cur_block, crc_ptr); if (chunk_data_size != 0) { if (ret < 0) { @@ -232,7 +334,7 @@ static int process_chunk(struct sparse_file *s, int fd, off64_t offset, } return chunk_header->chunk_sz; case CHUNK_TYPE_CRC32: - ret = process_crc32_chunk(fd, chunk_data_size, crc_ptr); + ret = process_crc32_chunk(source, chunk_data_size, crc_ptr); if (ret < 0) { verbose_error(s->verbose, -EINVAL, "crc block at %" PRId64, offset); @@ -247,7 +349,7 @@ static int process_chunk(struct sparse_file *s, int fd, off64_t offset, return 0; } -static int sparse_file_read_sparse(struct sparse_file *s, int fd, bool crc) +static int sparse_file_read_sparse(struct sparse_file *s, SparseFileSource *source, bool crc) { int ret; unsigned int i; @@ -256,7 +358,6 @@ static int sparse_file_read_sparse(struct sparse_file *s, int fd, bool crc) uint32_t crc32 = 0; uint32_t *crc_ptr = 0; unsigned int cur_block = 0; - off64_t offset; if (!copybuf) { copybuf = (char *)malloc(COPY_BUF_SIZE); @@ -270,7 +371,7 @@ static int sparse_file_read_sparse(struct sparse_file *s, int fd, bool crc) crc_ptr = &crc32; } - ret = read_all(fd, &sparse_header, sizeof(sparse_header)); + ret = source->ReadValue(&sparse_header, sizeof(sparse_header)); if (ret < 0) { return ret; } @@ -295,11 +396,11 @@ static int sparse_file_read_sparse(struct sparse_file *s, int fd, bool crc) /* 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); + source->Seek(sparse_header.file_hdr_sz - SPARSE_HEADER_LEN); } for (i = 0; i < sparse_header.total_chunks; i++) { - ret = read_all(fd, &chunk_header, sizeof(chunk_header)); + ret = source->ReadValue(&chunk_header, sizeof(chunk_header)); if (ret < 0) { return ret; } @@ -308,12 +409,10 @@ static int sparse_file_read_sparse(struct sparse_file *s, int fd, bool crc) /* 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); + source->Seek(sparse_header.chunk_hdr_sz - CHUNK_HEADER_LEN); } - offset = lseek64(fd, 0, SEEK_CUR); - - ret = process_chunk(s, fd, offset, sparse_header.chunk_hdr_sz, &chunk_header, + ret = process_chunk(s, source, sparse_header.chunk_hdr_sz, &chunk_header, cur_block, crc_ptr); if (ret < 0) { return ret; @@ -388,20 +487,27 @@ int sparse_file_read(struct sparse_file *s, int fd, bool sparse, bool crc) } if (sparse) { - return sparse_file_read_sparse(s, fd, crc); + SparseFileFdSource source(fd); + return sparse_file_read_sparse(s, &source, crc); } else { return sparse_file_read_normal(s, fd); } } -struct sparse_file *sparse_file_import(int fd, bool verbose, bool crc) +int sparse_file_read_buf(struct sparse_file *s, char *buf, bool crc) +{ + SparseFileBufSource source(buf); + return sparse_file_read_sparse(s, &source, crc); +} + +static struct sparse_file *sparse_file_import_source(SparseFileSource *source, 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)); + ret = source->ReadValue(&sparse_header, sizeof(sparse_header)); if (ret < 0) { verbose_error(verbose, ret, "header"); return NULL; @@ -432,7 +538,7 @@ struct sparse_file *sparse_file_import(int fd, bool verbose, bool crc) return NULL; } - ret = lseek64(fd, 0, SEEK_SET); + ret = source->SetOffset(0); if (ret < 0) { verbose_error(verbose, ret, "seeking"); sparse_file_destroy(s); @@ -441,7 +547,7 @@ struct sparse_file *sparse_file_import(int fd, bool verbose, bool crc) s->verbose = verbose; - ret = sparse_file_read(s, fd, true, crc); + ret = sparse_file_read_sparse(s, source, crc); if (ret < 0) { sparse_file_destroy(s); return NULL; @@ -450,6 +556,16 @@ struct sparse_file *sparse_file_import(int fd, bool verbose, bool crc) return s; } +struct sparse_file *sparse_file_import(int fd, bool verbose, bool crc) { + SparseFileFdSource source(fd); + return sparse_file_import_source(&source, verbose, crc); +} + +struct sparse_file *sparse_file_import_buf(char* buf, bool verbose, bool crc) { + SparseFileBufSource source(buf); + return sparse_file_import_source(&source, verbose, crc); +} + struct sparse_file *sparse_file_import_auto(int fd, bool crc, bool verbose) { struct sparse_file *s; |