7zip: Merge skip_sfx into get_data_offset

This removes the function skip_sfx which makes slurp_central_directory
and archive_read_format_7zip_bid use the same code now.

Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>

diff --git a/libarchive/archive_read_support_format_7zip.c b/libarchive/archive_read_support_format_7zip.c
index 8153d50506607d1073334be874a75cdc548ce660..3353bae5dc1a540c0c0febeb58ad1a90f72c1016 100644 (file)
--- a/libarchive/archive_read_support_format_7zip.c
+++ b/libarchive/archive_read_support_format_7zip.c
@@ -449,7 +449,6 @@ static ssize_t      read_stream(struct archive_read *, const void **, size_t,
                    size_t);
 static int     seek_pack(struct archive_read *);
 static int64_t skip_stream(struct archive_read *, size_t);
-static int     skip_sfx(struct archive_read *, const ssize_t);
 static int     get_data_offset(struct archive_read *, int64_t *);
 static ssize_t find_pe_overlay(struct archive_read *);
 static ssize_t find_elf_data_sec(struct archive_read *);
@@ -539,7 +538,7 @@ get_data_offset(struct archive_read *a, int64_t *data_offset)
        ssize_t window;
 
        if ((p = __archive_read_ahead(a, 6, NULL)) == NULL)
-               return (ARCHIVE_FATAL);
+               goto fail;
 
        /* If first six bytes are the 7-Zip signature,
         * return the offset right now. */
@@ -561,7 +560,7 @@ get_data_offset(struct archive_read *a, int64_t *data_offset)
        else if (memcmp(p, "\x7F\x45LF", 4) == 0)
                min_addr = find_elf_data_sec(a);
        else
-               return (ARCHIVE_FATAL);
+               goto fail;
 
        offset = min_addr;
        window = 4096;
@@ -573,7 +572,7 @@ get_data_offset(struct archive_read *a, int64_t *data_offset)
                        /* Remaining bytes are less than window. */
                        window >>= 1;
                        if (window < 0x40)
-                               return (ARCHIVE_FATAL);
+                               goto fail;
                        continue;
                }
                p = buff + offset;
@@ -587,6 +586,9 @@ get_data_offset(struct archive_read *a, int64_t *data_offset)
                }
                offset = p - buff;
        }
+fail:
+       archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
+           "Couldn't find out 7-Zip header");
        return (ARCHIVE_FATAL);
 }
 
@@ -631,63 +633,6 @@ check_7zip_header_in_sfx(const unsigned char *p)
        }
 }
 
-static int
-skip_sfx(struct archive_read *a, const ssize_t min_addr)
-{
-       const unsigned char *h, *p, *q;
-       size_t skip, offset;
-       ssize_t bytes, window;
-
-       if (__archive_read_seek(a, min_addr, SEEK_SET) < 0)
-               return (ARCHIVE_FATAL);
-
-       offset = 0;
-       window = 1;
-       while (offset + window <= SFX_MAX_ADDR - SFX_MIN_ADDR) {
-               h = __archive_read_ahead(a, window, &bytes);
-               if (h == NULL) {
-                       /* Remaining bytes are less than window. */
-                       window >>= 1;
-                       if (window < 0x40)
-                               goto fatal;
-                       continue;
-               }
-               if (bytes < 6) {
-                       /* This case might happen when window == 1. */
-                       window = 4096;
-                       continue;
-               }
-               p = h;
-               q = p + bytes;
-
-               /*
-                * Scan ahead until we find something that looks
-                * like the 7-Zip header.
-                */
-               while (p + 32 < q) {
-                       int step = check_7zip_header_in_sfx(p);
-                       if (step == 0) {
-                               struct _7zip *zip =
-                                   (struct _7zip *)a->format->data;
-                               skip = p - h;
-                               __archive_read_consume(a, skip);
-                               zip->seek_base = min_addr + offset + skip;
-                               return (ARCHIVE_OK);
-                       }
-                       p += step;
-               }
-               skip = p - h;
-               __archive_read_consume(a, skip);
-               offset += skip;
-               if (window == 1)
-                       window = 4096;
-       }
-fatal:
-       archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
-           "Couldn't find out 7-Zip header");
-       return (ARCHIVE_FATAL);
-}
-
 static ssize_t
 find_pe_overlay(struct archive_read *a)
 {
@@ -3255,22 +3200,17 @@ slurp_central_directory(struct archive_read *a, struct _7zip *zip,
        uint64_t next_header_size;
        uint32_t next_header_crc;
        ssize_t bytes_avail;
+       int64_t data_offset;
        int check_header_crc, r;
 
+       if (get_data_offset(a, &data_offset) < 0)
+               return (ARCHIVE_FATAL);
+       if (__archive_read_seek(a, data_offset, SEEK_SET) < 0)
+               return (ARCHIVE_FATAL);
        if ((p = __archive_read_ahead(a, 32, &bytes_avail)) == NULL)
                return (ARCHIVE_FATAL);
 
-       if ((p[0] == 'M' && p[1] == 'Z') || memcmp(p, "\x7F\x45LF", 4) == 0) {
-               /* This is an executable ? Must be self-extracting... */
-               const ssize_t min_addr = p[0] == 'M' ? find_pe_overlay(a) :
-                                                      find_elf_data_sec(a);
-               r = skip_sfx(a, min_addr);
-               if (r < ARCHIVE_WARN)
-                       return (r);
-               if ((p = __archive_read_ahead(a, 32, &bytes_avail)) == NULL)
-                       return (ARCHIVE_FATAL);
-       }
-       zip->seek_base += 32;
+       zip->seek_base = data_offset + 32;
 
        if (memcmp(p, _7ZIP_SIGNATURE, 6) != 0) {
                archive_set_error(&a->archive, -1, "Not 7-Zip archive file");