1 files changed, 142 insertions, 0 deletions

diff --git a/test/packetdrill/open_memstream.c b/test/packetdrill/open_memstream.c
new file mode 100644
index 0000000..9114091
--- /dev/null
+++ b/test/packetdrill/open_memstream.c
@@ -0,0 +1,142 @@
+/*
+ * Copyright 2013 Google Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+/*
+ * Author: ncardwell@google.com (Neal Cardwell)
+ *
+ * FreeBSD does not have open_memstream(), so we roll our own minimalist
+ * implementation here.
+ */
+
+#include "types.h"
+
+#ifndef HAVE_OPEN_MEMSTREAM
+
+#include "assert.h"
+#include "open_memstream.h"
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+
+/* Our internal state for the memstream. */
+struct mem_stream {
+	char   **buf;		/* pointer to the output buffer pointer */
+	size_t  *sizeloc;	/* pointer to the output final buffer size */
+
+	size_t	buf_size;	/* currently allocated size of buffer */
+	size_t	offset;		/* current write offset */
+};
+
+#define INITIAL_BUF_SIZE    1024
+
+/* Grow buffer, if needed, to write "write_bytes" bytes at the current
+ * offset. We also have to take into account the extra '\0' that we
+ * maintain just past the end. Returns 0 on success, or -1 on failure.
+ */
+static int mem_stream_grow(struct mem_stream *stream, int write_bytes)
+{
+	char *new_buf = NULL;
+	size_t new_size = 0;
+	size_t needed_bytes = 0;
+
+	needed_bytes = stream->offset + write_bytes + 1;
+	if (needed_bytes <= stream->buf_size)
+		return 0;
+
+	if (stream->buf_size == 0)
+		new_size = INITIAL_BUF_SIZE;
+	else
+		new_size = 2 * stream->buf_size;
+
+	if (new_size < needed_bytes)
+		new_size = needed_bytes;
+
+	new_buf = (char *) realloc(*stream->buf, new_size);
+	if (new_buf == NULL)
+		return -1;
+
+	*stream->buf = new_buf;
+	stream->buf_size = new_size;
+
+	return 0;
+}
+
+/* Write the give data to our memstream, expanding our buffer if we
+ * need to. Per the specification in the Linux man pages, "A null byte
+ * is maintained at the end of the buffer. This byte is not included
+ * in the size value stored at sizeloc."
+ */
+static int write_memstream(void *cookie, const char *buf, int write_bytes)
+{
+	struct mem_stream *stream = (struct mem_stream *) cookie;
+
+	if (mem_stream_grow(stream, write_bytes) < 0)
+		return -1;
+
+	memcpy(*stream->buf + stream->offset, buf, write_bytes);
+	stream->offset += write_bytes;
+
+	*(*stream->buf + stream->offset) = '\0';
+
+	*stream->sizeloc = stream->offset;  /* size does not include '\0' */
+
+	return write_bytes;
+}
+
+/* Clean up */
+static int close_memstream(void *cookie)
+{
+	struct mem_stream *stream = (struct mem_stream *) cookie;
+
+	free(stream);
+
+	return 0;
+}
+
+/* Create a memstream. */
+FILE *open_memstream(char **ptr, size_t *sizeloc)
+{
+	FILE *f;
+	struct mem_stream *stream;
+
+	if (ptr == NULL || sizeloc == NULL) {
+		errno = EINVAL;
+		return NULL;
+	}
+
+	stream = (struct mem_stream *) calloc(1, sizeof(struct mem_stream));
+	if (stream == NULL)
+		return NULL;
+
+	f = funopen(stream, NULL, write_memstream, NULL, close_memstream);
+	if (f == NULL) {
+		free(stream);
+		return NULL;
+	}
+
+	*ptr = NULL;
+	*sizeloc = 0;
+
+	stream->buf = ptr;
+	stream->sizeloc = sizeloc;
+
+	return f;
+}
+
+#endif /* HAVE_OPEN_MEMSTREAM */