From 2f172ede7115d0a2730a3b689131042ba559e272 Mon Sep 17 00:00:00 2001 From: David Oberhollenzer Date: Wed, 19 Jun 2019 15:04:17 +0200 Subject: Split generic tar code off to static library Signed-off-by: David Oberhollenzer --- lib/tar/skip.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 lib/tar/skip.c (limited to 'lib/tar/skip.c') diff --git a/lib/tar/skip.c b/lib/tar/skip.c new file mode 100644 index 0000000..69208b2 --- /dev/null +++ b/lib/tar/skip.c @@ -0,0 +1,48 @@ +/* SPDX-License-Identifier: GPL-3.0-or-later */ +#include "util.h" +#include "tar.h" + +#include + +static int skip_bytes(int fd, uint64_t size) +{ + unsigned char buffer[1024]; + ssize_t ret; + size_t diff; + + while (size != 0) { + diff = sizeof(buffer); + if (diff > size) + diff = size; + + ret = read_retry(fd, buffer, diff); + + if (ret < 0) { + perror("reading tar record data"); + return -1; + } + + if ((size_t)ret < diff) { + fputs("unexpected end of file\n", stderr); + return -1; + } + + size -= diff; + } + + return 0; +} + +int skip_padding(int fd, uint64_t size) +{ + size_t tail = size % 512; + + return tail ? skip_bytes(fd, 512 - tail) : 0; +} + +int skip_entry(int fd, uint64_t size) +{ + size_t tail = size % 512; + + return skip_bytes(fd, tail ? (size + 512 - tail) : size); +} -- cgit v1.2.3