diff options
Diffstat (limited to 'lib/libarchive/archive_read.c')
| -rw-r--r-- | lib/libarchive/archive_read.c | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/lib/libarchive/archive_read.c b/lib/libarchive/archive_read.c index c92b20c..06a4e8c 100644 --- a/lib/libarchive/archive_read.c +++ b/lib/libarchive/archive_read.c @@ -55,6 +55,7 @@ __FBSDID("$FreeBSD$"); static int choose_decompressor(struct archive_read *, const void*, size_t); static int choose_format(struct archive_read *); +static off_t dummy_skip(struct archive_read *, off_t); /* * Allocate, initialize and return a struct archive object. @@ -191,6 +192,13 @@ archive_read_open2(struct archive *_a, void *client_data, if (e == ARCHIVE_OK) a->archive.state = ARCHIVE_STATE_HEADER; + /* + * If the decompressor didn't register a skip function, provide a + * dummy compression-layer skip function. + */ + if (a->compression_skip == NULL) + a->compression_skip = dummy_skip; + return (e); } @@ -244,6 +252,38 @@ choose_decompressor(struct archive_read *a, } /* + * Dummy skip function, for use if the compression layer doesn't provide + * one: This code just reads data and discards it. + */ +static off_t +dummy_skip(struct archive_read * a, off_t request) +{ + const void * dummy_buffer; + ssize_t bytes_read; + off_t bytes_skipped; + + for (bytes_skipped = 0; request > 0;) { + bytes_read = (a->compression_read_ahead)(a, &dummy_buffer, 1); + if (bytes_read < 0) + return (bytes_read); + if (bytes_read == 0) { + /* Premature EOF. */ + archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC, + "Truncated input file (need to skip %jd bytes)", + (intmax_t)request); + return (ARCHIVE_FATAL); + } + if (bytes_read > request) + bytes_read = request; + (a->compression_read_consume)(a, bytes_read); + request -= bytes_read; + bytes_skipped += bytes_read; + } + + return (bytes_skipped); +} + +/* * Read header of next entry. */ int |
