less: document -S flag and make it independently configurable

[oweals/busybox.git] / archival / libarchive / get_header_tar.c

diff --git a/archival/libarchive/get_header_tar.c b/archival/libarchive/get_header_tar.c
index 54d910431038945fecff7be2ec557512f2f9b974..fb68673b900fdf82a69b42fcd55cce4ee2e07c34 100644 (file)
--- a/archival/libarchive/get_header_tar.c
+++ b/archival/libarchive/get_header_tar.c
@@ -17,36 +17,6 @@
 typedef uint32_t aliased_uint32_t FIX_ALIASING;
 typedef off_t    aliased_off_t    FIX_ALIASING;
 
-
-const char* FAST_FUNC strip_unsafe_prefix(const char *str)
-{
-       const char *cp = str;
-       while (1) {
-               char *cp2;
-               if (*cp == '/') {
-                       cp++;
-                       continue;
-               }
-               if (strncmp(cp, "/../"+1, 3) == 0) {
-                       cp += 3;
-                       continue;
-               }
-               cp2 = strstr(cp, "/../");
-               if (!cp2)
-                       break;
-               cp = cp2 + 4;
-       }
-       if (cp != str) {
-               static smallint warned = 0;
-               if (!warned) {
-                       warned = 1;
-                       bb_error_msg("removing leading '%.*s' from member names",
-                               (int)(cp - str), str);
-               }
-       }
-       return cp;
-}
-
 /* NB: _DESTROYS_ str[len] character! */
 static unsigned long long getOctal(char *str, int len)
 {
@@ -135,7 +105,7 @@ static void process_pax_hdr(archive_handle_t *archive_handle, unsigned sz, int g
                value = end + 1;
 
 #if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
-               if (!global && strncmp(value, "path=", sizeof("path=") - 1) == 0) {
+               if (!global && is_prefixed_with(value, "path=")) {
                        value += sizeof("path=") - 1;
                        free(archive_handle->tar__longname);
                        archive_handle->tar__longname = xstrdup(value);
@@ -148,7 +118,7 @@ static void process_pax_hdr(archive_handle_t *archive_handle, unsigned sz, int g
                 * This is what Red Hat's patched version of tar uses.
                 */
 # define SELINUX_CONTEXT_KEYWORD "RHT.security.selinux"
-               if (strncmp(value, SELINUX_CONTEXT_KEYWORD"=", sizeof(SELINUX_CONTEXT_KEYWORD"=") - 1) == 0) {
+               if (is_prefixed_with(value, SELINUX_CONTEXT_KEYWORD"=")) {
                        value += sizeof(SELINUX_CONTEXT_KEYWORD"=") - 1;
                        free(archive_handle->tar__sctx[global]);
                        archive_handle->tar__sctx[global] = xstrdup(value);
@@ -232,7 +202,7 @@ char FAST_FUNC get_header_tar(archive_handle_t *archive_handle)
 
        /* Check header has valid magic, "ustar" is for the proper tar,
         * five NULs are for the old tar format  */
-       if (strncmp(tar.magic, "ustar", 5) != 0
+       if (!is_prefixed_with(tar.magic, "ustar")
         && (!ENABLE_FEATURE_TAR_OLDGNU_COMPATIBILITY
             || memcmp(tar.magic, "\0\0\0\0", 5) != 0)
        ) {
@@ -243,7 +213,7 @@ char FAST_FUNC get_header_tar(archive_handle_t *archive_handle)
                 * or not first block (false positive, it's not .gz/.bz2!) */
                if (lseek(archive_handle->src_fd, -i, SEEK_CUR) != 0)
                        goto err;
-               if (setup_unzip_on_fd(archive_handle->src_fd, /*fail_if_not_detected:*/ 0) != 0)
+               if (setup_unzip_on_fd(archive_handle->src_fd, /*fail_if_not_compressed:*/ 0) != 0)
  err:
                        bb_error_msg_and_die("invalid tar magic");
                archive_handle->offset = 0;
@@ -380,7 +350,14 @@ char FAST_FUNC get_header_tar(archive_handle_t *archive_handle)
        case '6':
                file_header->mode |= S_IFIFO;
                goto size0;
+       case 'g':       /* pax global header */
+       case 'x': {     /* pax extended header */
+               if ((uoff_t)file_header->size > 0xfffff) /* paranoia */
+                       goto skip_ext_hdr;
+               process_pax_hdr(archive_handle, file_header->size, (tar.typeflag == 'g'));
+               goto again_after_align;
 #if ENABLE_FEATURE_TAR_GNU_EXTENSIONS
+/* See http://www.gnu.org/software/tar/manual/html_node/Extensions.html */
        case 'L':
                /* free: paranoia: tar with several consecutive longnames */
                free(p_longname);
@@ -400,18 +377,17 @@ char FAST_FUNC get_header_tar(archive_handle_t *archive_handle)
                archive_handle->offset += file_header->size;
                /* return get_header_tar(archive_handle); */
                goto again;
-       case 'D':       /* GNU dump dir */
-       case 'M':       /* Continuation of multi volume archive */
-       case 'N':       /* Old GNU for names > 100 characters */
-       case 'S':       /* Sparse file */
-       case 'V':       /* Volume header */
+/*
+ *     case 'S':       // Sparse file
+ * Was seen in the wild. Not supported (yet?).
+ * See https://www.gnu.org/software/tar/manual/html_section/tar_92.html
+ * for the format. (An "Old GNU Format" was seen, not PAX formats).
+ */
+//     case 'D':       /* GNU dump dir */
+//     case 'M':       /* Continuation of multi volume archive */
+//     case 'N':       /* Old GNU for names > 100 characters */
+//     case 'V':       /* Volume header */
 #endif
-       case 'g':       /* pax global header */
-       case 'x': {     /* pax extended header */
-               if ((uoff_t)file_header->size > 0xfffff) /* paranoia */
-                       goto skip_ext_hdr;
-               process_pax_hdr(archive_handle, file_header->size, (tar.typeflag == 'g'));
-               goto again_after_align;
        }
  skip_ext_hdr:
        {