Properly pad symlinks when writing cpio "newc" format.

Thanks to: Jesse Barker for reporting this.
MFC after: 7 days

2 files changed, 49 insertions, 4 deletions

diff --git a/lib/libarchive/archive_write_set_format_cpio_newc.c b/lib/libarchive/archive_write_set_format_cpio_newc.c
index 37dd35a..6580b52 100644
--- a/lib/libarchive/archive_write_set_format_cpio_newc.c
+++ b/lib/libarchive/archive_write_set_format_cpio_newc.c
@@ -176,9 +176,15 @@ archive_write_newc_header(struct archive_write *a, struct archive_entry *entry)
 
 	cpio->entry_bytes_remaining = archive_entry_size(entry);
 	cpio->padding = 3 & (-cpio->entry_bytes_remaining);
+
 	/* Write the symlink now. */
-	if (p != NULL  &&  *p != '\0')
+	if (p != NULL  &&  *p != '\0') {
 		ret = (a->compressor.write)(a, p, strlen(p));
+		if (ret != ARCHIVE_OK)
+			return (ARCHIVE_FATAL);
+		pad = 0x3 & -strlen(p);
+		ret = (a->compressor.write)(a, "\0\0\0", pad);
+	}
 
 	return (ret);
 }
diff --git a/lib/libarchive/test/test_write_format_cpio_newc.c b/lib/libarchive/test/test_write_format_cpio_newc.c
index 733e4ab..9b16e47 100644
--- a/lib/libarchive/test/test_write_format_cpio_newc.c
+++ b/lib/libarchive/test/test_write_format_cpio_newc.c
@@ -68,6 +68,8 @@ DEFINE_TEST(test_write_format_cpio_newc)
 	 * Add various files to it.
 	 * TODO: Extend this to cover more filetypes.
 	 */
+
+	/* Regular file */
 	assert((entry = archive_entry_new()) != NULL);
 	archive_entry_set_mtime(entry, 1, 10);
 	archive_entry_set_pathname(entry, "file");
@@ -82,6 +84,7 @@ DEFINE_TEST(test_write_format_cpio_newc)
 	archive_entry_free(entry);
 	assertEqualIntA(a, 10, archive_write_data(a, "1234567890", 10));
 
+	/* Directory */
 	assert((entry = archive_entry_new()) != NULL);
 	archive_entry_set_mtime(entry, 2, 20);
 	archive_entry_set_pathname(entry, "dir");
@@ -92,6 +95,22 @@ DEFINE_TEST(test_write_format_cpio_newc)
 	archive_entry_free(entry);
 	assertEqualIntA(a, 0, archive_write_data(a, "1234567890", 10));
 
+	/* Symlink */
+	assert((entry = archive_entry_new()) != NULL);
+	archive_entry_set_mtime(entry, 3, 30);
+	archive_entry_set_pathname(entry, "lnk");
+	archive_entry_set_mode(entry, S_IFLNK | 0664);
+	archive_entry_set_size(entry, 0);
+	archive_entry_set_uid(entry, 83);
+	archive_entry_set_gid(entry, 93);
+	archive_entry_set_dev(entry, 13);
+	archive_entry_set_ino(entry, 88);
+	archive_entry_set_nlink(entry, 1);
+	archive_entry_set_symlink(entry,"a");
+	assertEqualIntA(a, 0, archive_write_header(a, entry));
+	archive_entry_free(entry);
+
+
 #if ARCHIVE_API_VERSION > 1
 	assert(0 == archive_write_finish(a));
 #else
@@ -122,7 +141,7 @@ DEFINE_TEST(test_write_format_cpio_newc)
 	assertEqualMem(e + 110, "file\0\0", 6); /* Name contents */
 	assertEqualMem(e + 116, "1234567890", 10); /* File body */
 	assertEqualMem(e + 126, "\0\0", 2); /* Pad to multiple of 4 */
-	e += 128;
+	e += 128; /* Must be multiple of four here! */
 
 	/* Second entry is "dir" */
 	assert(is_hex(e, 110));
@@ -142,7 +161,27 @@ DEFINE_TEST(test_write_format_cpio_newc)
 	assertEqualMem(e + 102, "00000000", 8); /* CRC */
 	assertEqualMem(e + 110, "dir\0", 4); /* name */
 	assertEqualMem(e + 114, "\0\0", 2); /* Pad to multiple of 4 */
-	e += 116;
+	e += 116; /* Must be multiple of four here! */
+
+	/* Third entry is "lnk" */
+	assert(is_hex(e, 110)); /* Entire header is hex digits. */
+	assertEqualMem(e + 0, "070701", 6); /* Magic */
+	assertEqualMem(e + 6, "00000058", 8); /* ino */
+	assertEqualMem(e + 14, "0000a1b4", 8); /* Mode */
+	assertEqualMem(e + 22, "00000053", 8); /* uid */
+	assertEqualMem(e + 30, "0000005d", 8); /* gid */
+	assertEqualMem(e + 38, "00000001", 8); /* nlink */
+	assertEqualMem(e + 46, "00000003", 8); /* mtime */
+	assertEqualMem(e + 54, "00000001", 8); /* File size */
+	assertEqualMem(e + 62, "00000000", 8); /* devmajor */
+	assertEqualMem(e + 70, "0000000d", 8); /* devminor */
+	assertEqualMem(e + 78, "00000000", 8); /* rdevmajor */
+	assertEqualMem(e + 86, "00000000", 8); /* rdevminor */
+	assertEqualMem(e + 94, "00000004", 8); /* Name size */
+	assertEqualMem(e + 102, "00000000", 8); /* CRC */
+	assertEqualMem(e + 110, "lnk\0\0\0", 6); /* Name contents */
+	assertEqualMem(e + 116, "a\0\0\0", 4); /* File body + pad */
+	e += 120; /* Must be multiple of four here! */
 
 	/* TODO: Verify other types of entries. */
 
@@ -164,7 +203,7 @@ DEFINE_TEST(test_write_format_cpio_newc)
 	assertEqualMem(e + 102, "00000000", 8); /* CRC */
 	assertEqualMem(e + 110, "TRAILER!!!\0", 11); /* Name */
 	assertEqualMem(e + 121, "\0\0\0", 3); /* Pad to multiple of 4 bytes */
-	e += 124;
+	e += 124; /* Must be multiple of four here! */
 
 	assertEqualInt(used, e - buff);