New hooks for reading/writing archives to/from a FILE * or

an in-memory buffer.

PR: bin/86742

1 files changed, 147 insertions, 0 deletions

diff --git a/lib/libarchive/archive_read_open_memory.c b/lib/libarchive/archive_read_open_memory.c
new file mode 100644
index 0000000..a639d85
--- /dev/null
+++ b/lib/libarchive/archive_read_open_memory.c
@@ -0,0 +1,147 @@
+/*-
+ * Copyright (c) 2003-2006 Tim Kientzle
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "archive_platform.h"
+__FBSDID("$FreeBSD$");
+
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "archive.h"
+
+/*
+ * Glue to read an archive from a block of memory.
+ *
+ * This is mostly a huge help in building test harnesses;
+ * test programs can build archives in memory and read them
+ * back again without having to mess with files on disk.
+ */
+
+struct read_memory_data {
+	unsigned char	*buffer;
+	unsigned char	*end;
+	ssize_t	 read_size;
+};
+
+static int	memory_read_close(struct archive *, void *);
+static int	memory_read_open(struct archive *, void *);
+static ssize_t	memory_read_skip(struct archive *, void *, size_t request);
+static ssize_t	memory_read(struct archive *, void *, const void **buff);
+
+int
+archive_read_open_memory(struct archive *a, void *buff, size_t size)
+{
+	return archive_read_open_memory2(a, buff, size, size);
+}
+
+/*
+ * Don't use _open_memory2() in production code; the archive_read_open_memory()
+ * version is the one you really want.  This is just here so that
+ * test harnesses can exercise block operations inside the library.
+ */
+int
+archive_read_open_memory2(struct archive *a, void *buff,
+    size_t size, size_t read_size)
+{
+	struct read_memory_data *mine;
+
+	mine = (struct read_memory_data *)malloc(sizeof(*mine));
+	if (mine == NULL) {
+		archive_set_error(a, ENOMEM, "No memory");
+		return (ARCHIVE_FATAL);
+	}
+	memset(mine, 0, sizeof(*mine));
+	mine->buffer = (unsigned char *)buff;
+	mine->end = mine->buffer + size;
+	mine->read_size = read_size;
+	return (archive_read_open2(a, mine, memory_read_open,
+		    memory_read, memory_read_skip, memory_read_close));
+}
+
+/*
+ * There's nothing to open.
+ */
+static int
+memory_read_open(struct archive *a, void *client_data)
+{
+	(void)a; /* UNUSED */
+	(void)client_data; /* UNUSED */
+	return (ARCHIVE_OK);
+}
+
+/*
+ * This is scary simple:  Just advance a pointer.  Limiting
+ * to read_size is not technically necessary, but it exercises
+ * more of the internal logic when used with a small block size
+ * in a test harness.  Production use should not specify a block
+ * size; then this is much faster.
+ */
+static ssize_t
+memory_read(struct archive *a, void *client_data, const void **buff)
+{
+	struct read_memory_data *mine = (struct read_memory_data *)client_data;
+	ssize_t size;
+
+	(void)a; /* UNUSED */
+	*buff = mine->buffer;
+	size = mine->end - mine->buffer;
+	if (size > mine->read_size)
+		size = mine->read_size;
+        mine->buffer += size;
+	return (size);
+}
+
+/*
+ * Advancing is just as simple.  Again, this is doing more than
+ * necessary in order to better exercise internal code when used
+ * as a test harness.
+ */
+static ssize_t
+memory_read_skip(struct archive *a, void *client_data, size_t skip)
+{
+	struct read_memory_data *mine = (struct read_memory_data *)client_data;
+
+	(void)a; /* UNUSED */
+	if (mine->buffer + skip > mine->end)
+		skip = mine->end - mine->buffer;
+	/* Round down to block size. */
+	skip /= mine->read_size;
+	skip *= mine->read_size;
+	mine->buffer += skip;
+	return (skip);
+}
+
+/*
+ * Close is just cleaning up our one small bit of data.
+ */
+static int
+memory_read_close(struct archive *a, void *client_data)
+{
+	struct read_memory_data *mine = (struct read_memory_data *)client_data;
+	(void)a; /* UNUSED */
+	free(mine);
+	return (ARCHIVE_OK);
+}