write_integrity_table(): Fix documented return values
[wimlib] / src / integrity.c
index 6711921..6d007fe 100644 (file)
  * along with wimlib; if not, see http://www.gnu.org/licenses/.
  */
 
-#include "wimlib_internal.h"
-#include "buffer_io.h"
-#include "sha1.h"
+#ifdef HAVE_CONFIG_H
+#  include "config.h"
+#endif
+
+#include "wimlib/assert.h"
+#include "wimlib/endianness.h"
+#include "wimlib/error.h"
+#include "wimlib/file_io.h"
+#include "wimlib/integrity.h"
+#include "wimlib/resource.h"
+#include "wimlib/sha1.h"
+#include "wimlib/wim.h"
 
 /* Size, in bytes, of each SHA1-summed chunk, when wimlib writes integrity
  * information. */
@@ -42,43 +51,32 @@ struct integrity_table {
        u32 size;
        u32 num_entries;
        u32 chunk_size;
-       u8  sha1sums[0][20];
-};
+       u8  sha1sums[][20];
+} _packed_attribute;
 
-static int calculate_chunk_sha1(FILE *fp, size_t this_chunk_size,
-                               off_t offset, u8 sha1_md[])
+static int
+calculate_chunk_sha1(struct filedes *in_fd, size_t this_chunk_size,
+                    off_t offset, u8 sha1_md[])
 {
-       int ret;
        u8 buf[BUFFER_SIZE];
        SHA_CTX ctx;
        size_t bytes_remaining;
        size_t bytes_to_read;
-       size_t bytes_read;
+       int ret;
 
-       ret = fseeko(fp, offset, SEEK_SET);
-       if (ret != 0) {
-               ERROR_WITH_ERRNO("Can't seek to offset "
-                                "%"PRIu64" in WIM", offset);
-               return WIMLIB_ERR_READ;
-       }
        bytes_remaining = this_chunk_size;
        sha1_init(&ctx);
        do {
                bytes_to_read = min(bytes_remaining, sizeof(buf));
-               bytes_read = fread(buf, 1, bytes_to_read, fp);
-               if (bytes_read != bytes_to_read) {
-                       if (feof(fp)) {
-                               ERROR("Unexpected EOF while calculating "
-                                     "integrity checksums");
-                       } else {
-                               ERROR_WITH_ERRNO("File stream error while "
-                                                "calculating integrity "
-                                                "checksums");
-                       }
-                       return WIMLIB_ERR_READ;
+               ret = full_pread(in_fd, buf, bytes_to_read, offset);
+               if (ret) {
+                       ERROR_WITH_ERRNO("Read error while calculating "
+                                        "integrity checksums");
+                       return ret;
                }
-               sha1_update(&ctx, buf, bytes_read);
-               bytes_remaining -= bytes_read;
+               sha1_update(&ctx, buf, bytes_to_read);
+               bytes_remaining -= bytes_to_read;
+               offset += bytes_to_read;
        } while (bytes_remaining);
        sha1_final(sha1_md, &ctx);
        return 0;
@@ -88,114 +86,69 @@ static int calculate_chunk_sha1(FILE *fp, size_t this_chunk_size,
 /*
  * read_integrity_table: -  Reads the integrity table from a WIM file.
  *
- * @res_entry:
- *     The resource entry that specifies the location of the integrity table.
- *     The integrity table must exist (i.e. res_entry->offset must not be 0).
- *
- * @fp:
- *     FILE * to the WIM file, opened for reading.
+ * @wim:
+ *     WIMStruct for the WIM file; @wim->hdr.integrity specifies the location
+ *     of the integrity table.  The integrity table must exist (i.e.
+ *     res_entry->offset must not be 0).  @wim->in_fd is expected to be a
+ *     seekable file descriptor to the WIM file opened for reading.
  *
  * @num_checked_bytes:
- *     Number of bytes of data that should be checked by the integrity table.
- *
- * @table ret:
- *     On success, a pointer to an in-memory structure containing the integrity
- *     information is written to this location.
- *
- * Returns 0 on success; nonzero on failure.  The possible error codes are:
- *
- *     * WIMLIB_ERR_INVALID_INTEGRITY_TABLE:  The integrity table is invalid.
- *     * WIMLIB_ERR_NOMEM:  Could not allocate memory to store the integrity
- *                                 data.
- *     * WIMLIB_ERR_READ:   Could not read the integrity data from the WIM file.
+ *     Number of bytes of data that should be checked by the integrity table.
+ *
+ * @table_ret:
+ *     On success, a pointer to an in-memory structure containing the integrity
+ *     information is written to this location.
+ *
+ * Return values:
+ *     WIMLIB_ERR_SUCCESS (0)
+ *     WIMLIB_ERR_INVALID_INTEGRITY_TABLE
+ *     WIMLIB_ERR_NOMEM
+ *     WIMLIB_ERR_READ
+ *     WIMLIB_ERR_UNEXPECTED_END_OF_FILE
  */
-static int read_integrity_table(const struct resource_entry *res_entry,
-                               FILE *fp,
-                               u64 num_checked_bytes,
-                               struct integrity_table **table_ret)
+static int
+read_integrity_table(WIMStruct *wim, u64 num_checked_bytes,
+                    struct integrity_table **table_ret)
 {
-       struct integrity_table *table = NULL;
-       int ret = 0;
-       u64 expected_size;
-       u64 expected_num_entries;
-
-       if (resource_is_compressed(res_entry)) {
-               ERROR("Didn't expect a compressed integrity table");
-               return WIMLIB_ERR_INVALID_INTEGRITY_TABLE;
-       }
-
-       if (res_entry->size < 8 || res_entry->size  > 0xffffffff) {
-               ERROR("Integrity table resource header is invalid");
-               return WIMLIB_ERR_INVALID_INTEGRITY_TABLE;
-       }
+       void *buf;
+       struct integrity_table *table;
+       int ret;
 
-       /* Read the integrity table into memory. */
-       if ((table = MALLOC(res_entry->size)) == NULL) {
-               ERROR("Can't allocate %"PRIu64" bytes for integrity table",
-                     (u64)res_entry->size);
-               return WIMLIB_ERR_NOMEM;
-       }
+       if (wim->hdr.integrity.size < 8)
+               goto invalid;
 
-       ret = read_uncompressed_resource(fp, res_entry->offset,
-                                        res_entry->size, (void*)table);
+       DEBUG("Reading integrity table (offset %"PRIu64", "
+             "original_size %"PRIu64")",
+             wim->hdr.integrity.offset, wim->hdr.integrity.original_size);
 
-       if (ret != 0) {
-               ERROR("Failed to read integrity table (size = %u, "
-                     " offset = %"PRIu64")",
-                     (unsigned)res_entry->size, res_entry->offset);
-               goto out;
-       }
+       ret = res_entry_to_data(&wim->hdr.integrity, wim, &buf);
+       if (ret)
+               return ret;
+       table = buf;
 
        table->size        = le32_to_cpu(table->size);
        table->num_entries = le32_to_cpu(table->num_entries);
        table->chunk_size  = le32_to_cpu(table->chunk_size);
 
-       if (table->size != res_entry->size) {
-               ERROR("Inconsistent integrity table sizes: Table header says "
-                     "%u bytes but resource entry says %u bytes",
-                     table->size, (unsigned)res_entry->size);
-               ret = WIMLIB_ERR_INVALID_INTEGRITY_TABLE;
-               goto out;
-       }
-
        DEBUG("table->size = %u, table->num_entries = %u, "
              "table->chunk_size = %u",
              table->size, table->num_entries, table->chunk_size);
 
-       expected_size = (u64)table->num_entries * SHA1_HASH_SIZE + 12;
-
-       if (table->size != expected_size) {
-               ERROR("Integrity table is %u bytes, but expected %"PRIu64" "
-                     "bytes to hold %u entries",
-                     table->size, expected_size, table->num_entries);
-               ret = WIMLIB_ERR_INVALID_INTEGRITY_TABLE;
-               goto out;
+       if (table->size != wim->hdr.integrity.original_size ||
+           table->size != (u64)table->num_entries * SHA1_HASH_SIZE + 12 ||
+           table->chunk_size == 0 ||
+           table->num_entries != DIV_ROUND_UP(num_checked_bytes, table->chunk_size))
+       {
+               FREE(table);
+               goto invalid;
        }
 
-       if (table->chunk_size == 0) {
-               ERROR("Cannot use integrity chunk size of 0");
-               ret = WIMLIB_ERR_INVALID_INTEGRITY_TABLE;
-               goto out;
-       }
+       *table_ret = table;
+       return 0;
 
-       expected_num_entries = DIV_ROUND_UP(num_checked_bytes, table->chunk_size);
-
-       if (table->num_entries != expected_num_entries) {
-               ERROR("%"PRIu64" integrity table entries would be required "
-                     "to checksum the %"PRIu64" bytes from the end of the "
-                     "header to the",
-                     expected_num_entries, num_checked_bytes);
-               ERROR("end of the lookup table with a chunk size of %u, but "
-                     "there were only %u entries",
-                     table->chunk_size, table->num_entries);
-               ret = WIMLIB_ERR_INVALID_INTEGRITY_TABLE;
-       }
-out:
-       if (ret == 0)
-               *table_ret = table;
-       else
-               FREE(table);
-       return ret;
+invalid:
+       ERROR("Integrity table is invalid");
+       return WIMLIB_ERR_INVALID_INTEGRITY_TABLE;
 }
 
 /*
@@ -204,39 +157,44 @@ out:
  * Calculates an integrity table for the data in a file beginning at offset 208
  * (WIM_HEADER_DISK_SIZE).
  *
- * @fp:
- *     FILE * for the file to be checked, opened for reading.  Does not need to
- *     be at any specific location in the file.
+ * @in_fd:
+ *     File descriptor for the file to be checked, opened for reading.  Does
+ *     not need to be at any specific location in the file.
  *
  * @new_check_end:
- *     Offset of byte after the last byte to be checked.
+ *     Offset of byte after the last byte to be checked.
  *
  * @old_table:
- *     If non-NULL, a pointer to the table containing the previously calculated
- *     integrity data for a prefix of this file.
+ *     If non-NULL, a pointer to the table containing the previously calculated
+ *     integrity data for a prefix of this file.
  *
  * @old_check_end:
- *     If @old_table is non-NULL, the byte after the last byte that was checked
- *     in the old table.  Must be less than or equal to new_check_end.
+ *     If @old_table is non-NULL, the byte after the last byte that was checked
+ *     in the old table.  Must be less than or equal to new_check_end.
  *
  * @progress_func:
- *     If non-NULL, a progress function that will be called after every
- *     calculated chunk.
+ *     If non-NULL, a progress function that will be called after every
+ *     calculated chunk.
  *
  * @integrity_table_ret:
- *     On success, a pointer to the calculated integrity table is written into
- *     this location.
- *
- * Returns 0 on success; nonzero on failure.
+ *     On success, a pointer to the calculated integrity table is written into
+ *     this location.
+ *
+ * Return values:
+ *     WIMLIB_ERR_SUCCESS (0)
+ *     WIMLIB_ERR_NOMEM
+ *     WIMLIB_ERR_READ
+ *     WIMLIB_ERR_UNEXPECTED_END_OF_FILE
  */
-static int calculate_integrity_table(FILE *fp,
-                                    off_t new_check_end,
-                                    const struct integrity_table *old_table,
-                                    off_t old_check_end,
-                                    wimlib_progress_func_t progress_func,
-                                    struct integrity_table **integrity_table_ret)
+static int
+calculate_integrity_table(struct filedes *in_fd,
+                         off_t new_check_end,
+                         const struct integrity_table *old_table,
+                         off_t old_check_end,
+                         wimlib_progress_func_t progress_func,
+                         struct integrity_table **integrity_table_ret)
 {
-       int ret = 0;
+       int ret;
        size_t chunk_size = INTEGRITY_CHUNK_SIZE;
 
        /* If an old table is provided, set the chunk size to be compatible with
@@ -298,10 +256,12 @@ static int calculate_integrity_table(FILE *fp,
                        copy_hash(new_table->sha1sums[i], old_table->sha1sums[i]);
                } else {
                        /* Calculate the SHA1 message digest of this chunk */
-                       ret = calculate_chunk_sha1(fp, this_chunk_size,
+                       ret = calculate_chunk_sha1(in_fd, this_chunk_size,
                                                   offset, new_table->sha1sums[i]);
-                       if (ret != 0)
-                               break;
+                       if (ret) {
+                               FREE(new_table);
+                               return ret;
+                       }
                }
                offset += this_chunk_size;
                if (progress_func) {
@@ -311,11 +271,8 @@ static int calculate_integrity_table(FILE *fp,
                                      &progress);
                }
        }
-       if (ret == 0)
-               *integrity_table_ret = new_table;
-       else
-               FREE(new_table);
-       return ret;
+       *integrity_table_ret = new_table;
+       return 0;
 }
 
 /*
@@ -332,56 +289,50 @@ static int calculate_integrity_table(FILE *fp,
  * cannot be read, a warning is printed and the integrity information is
  * re-calculated.
  *
- * @fp:
- *     FILE * to the WIM file, opened read-write, positioned at the location at
- *     which the integrity table is to be written.
- *
- * @integrity_res_entry:
- *     Resource entry which will be set to point to the integrity table on
- *     success.  In addition, if @old_lookup_table_end != 0, this initially
- *     must point to the resource entry for the old integrity table for the
- *     WIM.
+ * @wim:
+ *     WIMStruct for the WIM file.  @wim->out_fd must be a seekable descriptor
+ *     to the new WIM file, opened read-write, positioned at the location at
+ *     which the integrity table is to be written.  Furthermore,
+ *     @wim->hdr.integrity is expected to be a resource entry which will be set
+ *     to the integrity table information on success.  In addition, if
+ *     @old_lookup_table_end != 0, @wim->hdr.integrity must initially contain
+ *     information about the old integrity table, and @wim->in_fd must be a
+ *     seekable descriptor to the original WIM file opened for reading.
  *
  * @new_lookup_table_end:
- *     The offset of the byte directly following the lookup table in the WIM
- *     being written.
+ *     The offset of the byte directly following the lookup table in the WIM
+ *     being written.
  *
  * @old_lookup_table_end:
- *     If nonzero, the offset of the byte directly following the old lookup
- *     table in the WIM.
+ *     If nonzero, the offset of the byte directly following the old lookup
+ *     table in the WIM.
  *
  * @progress_func
- *     If non-NULL, a progress function that will be called after every
- *     calculated chunk.
- *
- * Returns:
- *     0 on success, nonzero on failure.  The possible error codes are:
- *        * WIMLIB_ERR_WRITE:  Could not write the integrity table.
- *        * WIMLIB_ERR_READ:   Could not read a chunk of data that needed
- *                             to be checked.
+ *     If non-NULL, a progress function that will be called after every
+ *     calculated chunk.
+ *
+ * Return values:
+ *     WIMLIB_ERR_SUCCESS (0)
+ *     WIMLIB_ERR_NOMEM
+ *     WIMLIB_ERR_UNEXPECTED_END_OF_FILE
+ *     WIMLIB_ERR_WRITE
  */
-int write_integrity_table(FILE *fp,
-                         struct resource_entry *integrity_res_entry,
-                         off_t new_lookup_table_end,
-                         off_t old_lookup_table_end,
-                         wimlib_progress_func_t progress_func)
+int
+write_integrity_table(WIMStruct *wim,
+                     off_t new_lookup_table_end,
+                     off_t old_lookup_table_end,
+                     wimlib_progress_func_t progress_func)
 {
        struct integrity_table *old_table;
        struct integrity_table *new_table;
        int ret;
-       off_t cur_offset;
        u32 new_table_size;
 
        wimlib_assert(old_lookup_table_end <= new_lookup_table_end);
 
-       cur_offset = ftello(fp);
-       if (cur_offset == -1)
-               return WIMLIB_ERR_WRITE;
-
-       if (integrity_res_entry->offset == 0 || old_lookup_table_end == 0) {
-               old_table = NULL;
-       } else {
-               ret = read_integrity_table(integrity_res_entry, fp,
+       old_table = NULL;
+       if (wim_has_integrity_table(wim) && old_lookup_table_end != 0) {
+               ret = read_integrity_table(wim,
                                           old_lookup_table_end - WIM_HEADER_DISK_SIZE,
                                           &old_table);
                if (ret == WIMLIB_ERR_INVALID_INTEGRITY_TABLE) {
@@ -393,10 +344,10 @@ int write_integrity_table(FILE *fp,
                }
        }
 
-       ret = calculate_integrity_table(fp, new_lookup_table_end,
+       ret = calculate_integrity_table(&wim->out_fd, new_lookup_table_end,
                                        old_table, old_lookup_table_end,
                                        progress_func, &new_table);
-       if (ret != 0)
+       if (ret)
                goto out_free_old_table;
 
        new_table_size = new_table->size;
@@ -405,24 +356,14 @@ int write_integrity_table(FILE *fp,
        new_table->num_entries = cpu_to_le32(new_table->num_entries);
        new_table->chunk_size  = cpu_to_le32(new_table->chunk_size);
 
-       if (fseeko(fp, cur_offset, SEEK_SET) != 0) {
-               ERROR_WITH_ERRNO("Failed to seek to byte %"PRIu64" of WIM to "
-                                "write integrity table", cur_offset);
-               ret = WIMLIB_ERR_WRITE;
-               goto out_free_new_table;
-       }
-
-       if (fwrite(new_table, 1, new_table_size, fp) != new_table_size) {
-               ERROR_WITH_ERRNO("Failed to write WIM integrity table");
-               ret = WIMLIB_ERR_WRITE;
-       } else {
-               integrity_res_entry->offset        = cur_offset;
-               integrity_res_entry->size          = new_table_size;
-               integrity_res_entry->original_size = new_table_size;
-               integrity_res_entry->flags         = 0;
-               ret = 0;
-       }
-out_free_new_table:
+       ret = write_wim_resource_from_buffer(new_table,
+                                            new_table_size,
+                                            0,
+                                            &wim->out_fd,
+                                            WIMLIB_COMPRESSION_TYPE_NONE,
+                                            &wim->hdr.integrity,
+                                            NULL,
+                                            0);
        FREE(new_table);
 out_free_old_table:
        FREE(old_table);
@@ -434,30 +375,31 @@ out_free_old_table:
  *
  * Checks a WIM for consistency with the integrity table.
  *
- * @fp:
- *     FILE * to the WIM file, opened for reading.
+ * @in_fd:
+ *     File descriptor to the WIM file, opened for reading.
  *
  * @table:
- *     The integrity table for the WIM, read into memory.
+ *     The integrity table for the WIM, read into memory.
  *
  * @bytes_to_check:
- *     Number of bytes in the WIM that need to be checked (offset of end of the
- *     lookup table minus offset of end of the header).
+ *     Number of bytes in the WIM that need to be checked (offset of end of the
+ *     lookup table minus offset of end of the header).
  *
  * @progress_func
- *     If non-NULL, a progress function that will be called after every
- *     verified chunk.
+ *     If non-NULL, a progress function that will be called after every
+ *     verified chunk.
  *
  * Returns:
- *     > 0 (WIMLIB_ERR_*) on error
- *     0 (WIM_INTEGRITY_OK) if the integrity was checked successfully and there
- *     were no inconsistencies.
- *     -1 (WIM_INTEGRITY_NOT_OK) if the WIM failed the integrity check.
+ *     > 0 (WIMLIB_ERR_READ, WIMLIB_ERR_UNEXPECTED_END_OF_FILE) on error
+ *     0 (WIM_INTEGRITY_OK) if the integrity was checked successfully and there
+ *     were no inconsistencies.
+ *     -1 (WIM_INTEGRITY_NOT_OK) if the WIM failed the integrity check.
  */
-static int verify_integrity(FILE *fp, const tchar *filename,
-                           const struct integrity_table *table,
-                           u64 bytes_to_check,
-                           wimlib_progress_func_t progress_func)
+static int
+verify_integrity(struct filedes *in_fd, const tchar *filename,
+                const struct integrity_table *table,
+                u64 bytes_to_check,
+                wimlib_progress_func_t progress_func)
 {
        int ret;
        u64 offset = WIM_HEADER_DISK_SIZE;
@@ -482,8 +424,8 @@ static int verify_integrity(FILE *fp, const tchar *filename,
                else
                        this_chunk_size = table->chunk_size;
 
-               ret = calculate_chunk_sha1(fp, this_chunk_size, offset, sha1_md);
-               if (ret != 0)
+               ret = calculate_chunk_sha1(in_fd, this_chunk_size, offset, sha1_md);
+               if (ret)
                        return ret;
 
                if (!hashes_equal(sha1_md, table->sha1sums[i]))
@@ -508,35 +450,37 @@ static int verify_integrity(FILE *fp, const tchar *filename,
  * ~10 MiB chunks of the WIM match up with the values given in the integrity
  * table.
  *
- * @w:
- *     The WIM, opened for reading, and with the header already read.
+ * @wim:
+ *     The WIM, opened for reading.
  *
  * @progress_func
- *     If non-NULL, a progress function that will be called after every
- *     verified chunk.
+ *     If non-NULL, a progress function that will be called after every
+ *     verified chunk.
  *
  * Returns:
- *     > 0 (WIMLIB_ERR_*) on error
- *     0 (WIM_INTEGRITY_OK) if the integrity was checked successfully and there
- *     were no inconsistencies.
- *     -1 (WIM_INTEGRITY_NOT_OK) if the WIM failed the integrity check.
- *     -2 (WIM_INTEGRITY_NONEXISTENT) if the WIM contains no integrity
- *     information.
+ *     > 0 (WIMLIB_ERR_INVALID_INTEGRITY_TABLE, WIMLIB_ERR_READ,
+ *          WIMLIB_ERR_UNEXPECTED_END_OF_FILE) on error
+ *     0 (WIM_INTEGRITY_OK) if the integrity was checked successfully and there
+ *     were no inconsistencies.
+ *     -1 (WIM_INTEGRITY_NOT_OK) if the WIM failed the integrity check.
+ *     -2 (WIM_INTEGRITY_NONEXISTENT) if the WIM contains no integrity
+ *     information.
  */
-int check_wim_integrity(WIMStruct *w, wimlib_progress_func_t progress_func)
+int
+check_wim_integrity(WIMStruct *wim, wimlib_progress_func_t progress_func)
 {
        int ret;
        u64 bytes_to_check;
        struct integrity_table *table;
        u64 end_lookup_table_offset;
 
-       if (w->hdr.integrity.offset == 0) {
+       if (!wim_has_integrity_table(wim)) {
                DEBUG("No integrity information.");
                return WIM_INTEGRITY_NONEXISTENT;
        }
 
-       end_lookup_table_offset = w->hdr.lookup_table_res_entry.offset +
-                                 w->hdr.lookup_table_res_entry.size;
+       end_lookup_table_offset = wim->hdr.lookup_table_res_entry.offset +
+                                 wim->hdr.lookup_table_res_entry.size;
 
        if (end_lookup_table_offset < WIM_HEADER_DISK_SIZE) {
                ERROR("WIM lookup table ends before WIM header ends!");
@@ -545,11 +489,10 @@ int check_wim_integrity(WIMStruct *w, wimlib_progress_func_t progress_func)
 
        bytes_to_check = end_lookup_table_offset - WIM_HEADER_DISK_SIZE;
 
-       ret = read_integrity_table(&w->hdr.integrity, w->fp,
-                                  bytes_to_check, &table);
-       if (ret != 0)
+       ret = read_integrity_table(wim, bytes_to_check, &table);
+       if (ret)
                return ret;
-       ret = verify_integrity(w->fp, w->filename, table,
+       ret = verify_integrity(&wim->in_fd, wim->filename, table,
                               bytes_to_check, progress_func);
        FREE(table);
        return ret;