From 37385fcd836bcc086b56b8dc7089d5038c203f13 Mon Sep 17 00:00:00 2001
From: Matthias Schiffer <mschiffer@universe-factory.net>
Date: Sat, 15 Sep 2012 06:01:11 +0200
Subject: Rework some parts of the AES128-GCM method

These changes improve the performance of the AES128-GCM method by ~10% on my
Intel CPU when compiled with -O2.

Furthermore, the AES and the GHASH parts are separated now, allowing to switch
to other implementations of the algorithms more easily.
---
 src/fastd.c | 44 ++++++++++++++++++++++++++++++++++++++------
 1 file changed, 38 insertions(+), 6 deletions(-)

(limited to 'src/fastd.c')

diff --git a/src/fastd.c b/src/fastd.c
index dadcd17..3bbf30f 100644
--- a/src/fastd.c
+++ b/src/fastd.c
@@ -264,7 +264,7 @@ static size_t methods_min_encrypt_head_space(fastd_context *ctx) {
 			ret = s;
 	}
 
-	return ret;
+	return ALIGN(ret, 8);
 }
 
 static size_t methods_min_decrypt_head_space(fastd_context *ctx) {
@@ -280,6 +280,38 @@ static size_t methods_min_decrypt_head_space(fastd_context *ctx) {
 			ret = s;
 	}
 
+	return ALIGN(ret, 8);
+}
+
+static size_t methods_min_encrypt_tail_space(fastd_context *ctx) {
+	size_t ret = ctx->conf->methods[0]->min_encrypt_tail_space(ctx);
+
+	int i;
+	for (i = 0; i < MAX_METHODS; i++) {
+		if (!ctx->conf->methods[i])
+			break;
+
+		size_t s = ctx->conf->methods[i]->min_encrypt_tail_space(ctx);
+		if (s > ret)
+			ret = s;
+	}
+
+	return ret;
+}
+
+static size_t methods_min_decrypt_tail_space(fastd_context *ctx) {
+	size_t ret = ctx->conf->methods[0]->min_decrypt_tail_space(ctx);
+
+	int i;
+	for (i = 0; i < MAX_METHODS; i++) {
+		if (!ctx->conf->methods[i])
+			break;
+
+		size_t s = ctx->conf->methods[i]->min_decrypt_tail_space(ctx);
+		if (s > ret)
+			ret = s;
+	}
+
 	return ret;
 }
 
@@ -360,7 +392,7 @@ void fastd_handle_receive(fastd_context *ctx, fastd_peer *peer, fastd_buffer buf
 			fastd_peer *dest_peer;
 			for (dest_peer = ctx->peers; dest_peer; dest_peer = dest_peer->next) {
 				if (dest_peer != peer && fastd_peer_is_established(dest_peer)) {
-					fastd_buffer send_buffer = fastd_buffer_alloc(buffer.len, methods_min_encrypt_head_space(ctx), 0);
+					fastd_buffer send_buffer = fastd_buffer_alloc(buffer.len, methods_min_encrypt_head_space(ctx), methods_min_encrypt_tail_space(ctx));
 					memcpy(send_buffer.data, buffer.data, buffer.len);
 					ctx->conf->protocol->send(ctx, dest_peer, send_buffer);
 				}
@@ -479,7 +511,7 @@ static void handle_tasks(fastd_context *ctx) {
 
 		case TASK_KEEPALIVE:
 			pr_debug(ctx, "sending keepalive to %P", task->peer);
-			ctx->conf->protocol->send(ctx, task->peer, fastd_buffer_alloc(0, methods_min_encrypt_head_space(ctx), 0));
+			ctx->conf->protocol->send(ctx, task->peer, fastd_buffer_alloc(0, methods_min_encrypt_head_space(ctx), methods_min_encrypt_tail_space(ctx)));
 			break;
 
 		default:
@@ -492,7 +524,7 @@ static void handle_tasks(fastd_context *ctx) {
 
 static void handle_tun(fastd_context *ctx) {
 	size_t max_len = fastd_max_packet_size(ctx);
-	fastd_buffer buffer = fastd_buffer_alloc(max_len, methods_min_encrypt_head_space(ctx), 0);
+	fastd_buffer buffer = fastd_buffer_alloc(max_len, methods_min_encrypt_head_space(ctx), methods_min_encrypt_tail_space(ctx));
 
 	ssize_t len = read(ctx->tunfd, buffer.data, max_len);
 	if (len < 0) {
@@ -529,7 +561,7 @@ static void handle_tun(fastd_context *ctx) {
 	if (peer == NULL) {
 		for (peer = ctx->peers; peer; peer = peer->next) {
 			if (fastd_peer_is_established(peer)) {
-				fastd_buffer send_buffer = fastd_buffer_alloc(len, methods_min_encrypt_head_space(ctx), 0);
+				fastd_buffer send_buffer = fastd_buffer_alloc(len, methods_min_encrypt_head_space(ctx), methods_min_encrypt_tail_space(ctx));
 				memcpy(send_buffer.data, buffer.data, len);
 				ctx->conf->protocol->send(ctx, peer, send_buffer);
 			}
@@ -541,7 +573,7 @@ static void handle_tun(fastd_context *ctx) {
 
 static void handle_socket(fastd_context *ctx, int sockfd) {
 	size_t max_len = PACKET_TYPE_LEN + methods_max_packet_size(ctx);
-	fastd_buffer buffer = fastd_buffer_alloc(max_len, ALIGN8(methods_min_decrypt_head_space(ctx)), 0);
+	fastd_buffer buffer = fastd_buffer_alloc(max_len, methods_min_decrypt_head_space(ctx), methods_min_decrypt_tail_space(ctx));
 	uint8_t *packet_type;
 
 	fastd_peer_address recvaddr;
-- 
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