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authorIsaac Dunham <ibid.ag@gmail.com>2014-06-01 13:50:39 -0500
committerIsaac Dunham <ibid.ag@gmail.com>2014-06-01 13:50:39 -0500
commit670626ab009f1d369be94def71f48be2e88f0106 (patch)
treecdf9e2e09148f68005e7ccc532e3f0191686fb86
parentc20fb908bb733a3d7c1dda77a3c1d22d5c3fafec (diff)
downloadtoybox-670626ab009f1d369be94def71f48be2e88f0106.tar.gz
cpio: archive more files
While writing tests for cpio, I found that cpio tries to open empty files if they're regular files, and fails to archive them if unreadable. This can be easily avoided, and is not the usual behavior.
-rwxr-xr-xscripts/test/cpio.test39
-rw-r--r--toys/posix/cpio.c4
2 files changed, 41 insertions, 2 deletions
diff --git a/scripts/test/cpio.test b/scripts/test/cpio.test
new file mode 100755
index 00000000..d0528e52
--- /dev/null
+++ b/scripts/test/cpio.test
@@ -0,0 +1,39 @@
+#!/bin/bash
+
+[ -f testing.sh ] && . testing.sh
+
+# We need to test name and file padding.
+# This means all possible values of strlen(name)+1 % 4,
+# plus file sizes of at least 0-4.
+
+touch a bb ccc dddd
+testing "cpio name padding" "cpio -o -H newc|cpio -it" "a\nbb\nccc\ndddd\n" "" "a\nbb\nccc\ndddd\n"
+rm a bb ccc dddd
+
+touch a
+printf '1' >b
+printf '22' >c
+printf '333' >d
+testing "cpio file padding" "cpio -o -H newc|cpio -it" "a\nb\nc\nd\n" "" "a\nb\nc\nd\n"
+rm a b c d
+
+touch a
+printf '1' >bb
+printf '22' >ccc
+printf '333' >dddd
+# With the proper padding, header length, and file length,
+# the relevant bit should be here:
+# 110*5 + 4*3 + 2 + 6*3 = 550 + 12 + 20 = 582
+# files are padded to n*4, names are padded to 2 + n*4 due to the header length
+testing "cpio archive length" "cpio -o -H newc|dd ibs=2 skip=291 count=5" "TRAILER!!!" "" "a\nbb\nccc\ndddd\n"
+testing "cpio archive magic" "cpio -o -H newc|dd ibs=2 count=3" "070701" "" "a\n"
+# check name length (8 bytes before the empty "crc")
+testing "cpio name length" "cpio -o -H newc|dd ibs=2 skip=47 count=4" "00000002" "" "a\n"
+rm a bb ccc dddd
+
+# archive dangling symlinks and empty files even if we cannot open them
+touch a; chmod a-rwx a; ln -s a/cant b
+testing "cpio archives unreadable empty files" "cpio -o -H newc|cpio -it" "a\nb\n" "" "a\nb\n"
+chmod u+rw a; rm -f a b
+
+
diff --git a/toys/posix/cpio.c b/toys/posix/cpio.c
index 958931e6..668f2ee9 100644
--- a/toys/posix/cpio.c
+++ b/toys/posix/cpio.c
@@ -202,8 +202,8 @@ void cpio_main(void)
if (len<1) break;
if (name[len-1] == '\n') name[--len] = 0;
nlen = len+1;
- if (lstat(name, &st)
- || (S_ISREG(st.st_mode) && (fd = open(name, O_RDONLY))<0))
+ if (lstat(name, &st) || (S_ISREG(st.st_mode)
+ && st.st_size && (fd = open(name, O_RDONLY))<0))
{
perror_msg("%s", name);
continue;