From ffa3a443b9f01d3ea0fcb3c4fc6928a5c695cf4a Mon Sep 17 00:00:00 2001
From: Guus Sliepen <guus@tinc-vpn.org>
Date: Sat, 14 May 2011 22:30:23 +0200
Subject: [PATCH] Several fixes for the buffer code.

---
 src/buffer.c | 17 +++++++++++++----
 src/buffer.h |  1 +
 src/meta.c   |  5 +++--
 3 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/src/buffer.c b/src/buffer.c
index fc4fac0f..72888b50 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -22,6 +22,14 @@
 #include "buffer.h"
 #include "xalloc.h"
 
+void buffer_compact(buffer_t *buffer) {
+	if(buffer->offset / 7 > buffer->len / 8) {
+		memmove(buffer->data, buffer->data + buffer->offset, buffer->len - buffer->offset);
+		buffer->len -= buffer->offset;
+		buffer->offset = 0;
+	}
+}
+
 // Make sure we can add size bytes to the buffer, and return a pointer to the start of those bytes.
 
 char *buffer_prepare(buffer_t *buffer, int size) {
@@ -41,8 +49,11 @@ char *buffer_prepare(buffer_t *buffer, int size) {
 		}
 	}
 
+	char *start = buffer->data + buffer->len;
+
 	buffer->len += size;
-	return buffer->data + buffer->offset;
+
+	return start;
 }
 
 // Copy data into the buffer.
@@ -61,8 +72,6 @@ static char *buffer_consume(buffer_t *buffer, int size) {
 	if(buffer->offset >= buffer->len) {
 		buffer->offset = 0;
 		buffer->len = 0;
-	} else {
-		buffer->offset += size;
 	}
 
 	return start;
@@ -76,7 +85,7 @@ char *buffer_readline(buffer_t *buffer) {
 	if(!newline)
 		return NULL;
 
-	int len = newline + 1 - buffer->data + buffer->offset;
+	int len = newline + 1 - (buffer->data + buffer->offset);
 	*newline = 0;
 	return buffer_consume(buffer, len);
 }
diff --git a/src/buffer.h b/src/buffer.h
index 4d6f6726..db22ac4f 100644
--- a/src/buffer.h
+++ b/src/buffer.h
@@ -8,6 +8,7 @@ typedef struct buffer_t {
 	int offset;
 } buffer_t;
 
+extern void buffer_compact(buffer_t *buffer);
 extern char *buffer_prepare(buffer_t *buffer, int size);
 extern char *buffer_add(buffer_t *buffer, const char *data, int size);
 extern char *buffer_readline(buffer_t *buffer);
diff --git a/src/meta.c b/src/meta.c
index 726dcca9..1fbd22c2 100644
--- a/src/meta.c
+++ b/src/meta.c
@@ -42,10 +42,9 @@ bool send_meta(connection_t *c, const char *buffer, int length) {
 
 	/* Add our data to buffer */
 	if(c->status.encryptout) {
-		char outbuf[length];
 		size_t outlen = length;
 
-		if(!cipher_encrypt(&c->outcipher, outbuf, length, buffer_prepare(&c->outbuf, length), &outlen, false) || outlen != length) {
+		if(!cipher_encrypt(&c->outcipher, buffer, length, buffer_prepare(&c->outbuf, length), &outlen, false) || outlen != length) {
 			logger(LOG_ERR, "Error while encrypting metadata to %s (%s)",
 					c->name, c->hostname);
 			return false;
@@ -152,5 +151,7 @@ bool receive_meta(connection_t *c) {
 		}
 	} while(inlen);
 
+	buffer_compact(&c->inbuf);
+
 	return true;
 }
-- 
2.39.2