Clarify why we're not using fseek(), use fseek() where applicable.

[oweals/opkg-lede.git] / libbb / unarchive.c

diff --git a/libbb/unarchive.c b/libbb/unarchive.c
index 03a63bdd958b7b2c872b99dce85491d9442f1313..62ca2674e4aec15024a0ee1fc91050c30580a12a 100644 (file)
--- a/libbb/unarchive.c
+++ b/libbb/unarchive.c
@@ -61,11 +61,15 @@ seek_by_read(FILE* fd, size_t len)
 }
 
 static void
-seek_sub_file(FILE *src_stream, const int count)
+seek_sub_file(FILE *fd, const int count)
 {
-       /* Try to fseek as faster */
        archive_offset += count;
-        seek_by_read(src_stream, count);
+
+       /* Do not use fseek() on a pipe. It may fail with ESPIPE, leaving the
+        * stream at an undefined location.
+        */
+        seek_by_read(fd, count);
+
        return;
 }
 
@@ -686,7 +690,12 @@ deb_extract(const char *package_filename, FILE *out_stream,
                                free_header_ar(ar_header);
                                break;
                        }
-                       seek_sub_file(deb_stream, ar_header->size);
+                       if (fseek(deb_stream, ar_header->size, SEEK_CUR) == -1) {
+                               opkg_perror(ERROR, "Couldn't fseek into %s", package_filename);
+                               *err = -1;
+                               free_header_ar(ar_header);
+                               goto cleanup;
+                       }
                        free_header_ar(ar_header);
                }
                goto cleanup;
@@ -696,7 +705,11 @@ deb_extract(const char *package_filename, FILE *out_stream,
                FILE *unzipped_opkg_stream;
                file_header_t *tar_header;
                archive_offset = 0;
-               fseek(deb_stream, 0, SEEK_SET);
+               if (fseek(deb_stream, 0, SEEK_SET) == -1) {
+                       opkg_perror(ERROR, "Couldn't fseek into %s", package_filename);
+                       *err = -1;
+                       goto cleanup;
+               }
                unzipped_opkg_stream = gz_open(deb_stream, &unzipped_opkg_pid);
                if (unzipped_opkg_stream == NULL) {
                        *err = -1;