From 98a717c7ed5f63c2727e5b0856af2c69a6ae9315 Mon Sep 17 00:00:00 2001
From: Andy Green <andy@warmcat.com>
Date: Sun, 6 Mar 2011 13:14:15 +0000
Subject: [PATCH] callback each active extension on packet rx pre parse

Signed-off-by: Andy Green <andy@warmcat.com>
---
 lib/libwebsockets.c        | 64 ++++++++++++++++++++++++++++++++++++++--------
 lib/libwebsockets.h        |  1 +
 libwebsockets-api-doc.html |  2 +-
 3 files changed, 55 insertions(+), 12 deletions(-)

diff --git a/lib/libwebsockets.c b/lib/libwebsockets.c
index b7c9705..a8f2cf1 100644
--- a/lib/libwebsockets.c
+++ b/lib/libwebsockets.c
@@ -448,6 +448,8 @@ libwebsocket_service_fd(struct libwebsocket_context *context,
 	char *p = &pkt[0];
 	const char *pc;
 	int okay = 0;
+	struct lws_tokens eff_buf;
+	int more = 1;
 #ifdef LWS_OPENSSL_SUPPORT
 	char ssl_err_buf[512];
 #endif
@@ -1417,30 +1419,70 @@ bail2:
 
 #ifdef LWS_OPENSSL_SUPPORT
 		if (wsi->ssl)
-			n = SSL_read(wsi->ssl, buf, sizeof buf);
+			eff_buf.token_len = SSL_read(wsi->ssl, buf, sizeof buf);
 		else
 #endif
-			n = recv(pollfd->fd, buf, sizeof buf, 0);
+			eff_buf.token_len =
+					   recv(pollfd->fd, buf, sizeof buf, 0);
 
-		if (n < 0) {
-			fprintf(stderr, "Socket read returned %d\n", n);
+		if (eff_buf.token_len < 0) {
+			fprintf(stderr, "Socket read returned %d\n",
+							    eff_buf.token_len);
 			break;
 		}
-		if (!n) {
+		if (!eff_buf.token_len) {
 			libwebsocket_close_and_free_session(context, wsi,
 						     LWS_CLOSE_STATUS_NOSTATUS);
 			return 1;
 		}
 
-		/* service incoming data */
+		/*
+		 * give any active extensions a chance to munge the buffer
+		 * before parse.  We pass in a pointer to an lws_tokens struct
+		 * prepared with the default buffer and content length that's in
+		 * there.  Rather than rewrite the default buffer, extensions
+		 * that expect to grow the buffer can adapt .token to
+		 * point to their own per-connection buffer in the extension
+		 * user allocation.  By default with no extensions or no
+		 * extension callback handling, just the normal input buffer is
+		 * used then so it is efficient.
+		 */
 
-		n = libwebsocket_read(context, wsi, buf, n);
-		if (n >= 0)
-			break;
+		eff_buf.token = (char *)buf;
+
+		more = 1;
+		while (more) {
+
+			more = 0;
+
+			for (n = 0; n < wsi->count_active_extensions; n++) {
+				m = wsi->active_extensions[n]->callback(context, wsi,
+					LWS_EXT_CALLBACK_PACKET_RX_PREPARSE,
+				     wsi->active_extensions_user[n], &eff_buf, 0);
+				if (m < 0) {
+					fprintf(stderr, "Extension reports fatal error\n");
+					libwebsocket_close_and_free_session(context, wsi,
+							     LWS_CLOSE_STATUS_NOSTATUS);
+					return 1;
+				}
+				if (m)
+					more = 1;
+			}
 
-		/* we closed wsi */
+			/* service incoming data */
 
-		return 1;
+			if (eff_buf.token_len) {
+				n = libwebsocket_read(context, wsi,
+				     (unsigned char *)eff_buf.token, eff_buf.token_len);
+				if (n < 0)
+					/* we closed wsi */
+					return 1;
+			}
+
+			eff_buf.token = NULL;
+			eff_buf.token_len = 0;
+		}
+		break;
 	}
 
 	return 0;
diff --git a/lib/libwebsockets.h b/lib/libwebsockets.h
index eded025..a9627ad 100644
--- a/lib/libwebsockets.h
+++ b/lib/libwebsockets.h
@@ -74,6 +74,7 @@ enum libwebsocket_callback_reasons {
 enum libwebsocket_extension_callback_reasons {
 	LWS_EXT_CALLBACK_CONSTRUCT,
 	LWS_EXT_CALLBACK_DESTROY,
+	LWS_EXT_CALLBACK_PACKET_RX_PREPARSE,
 };
 
 enum libwebsocket_write_protocol {
diff --git a/libwebsockets-api-doc.html b/libwebsockets-api-doc.html
index 0a039e9..0169b58 100644
--- a/libwebsockets-api-doc.html
+++ b/libwebsockets-api-doc.html
@@ -760,7 +760,7 @@ allows as many protocols as you like to be handled by one server.
 <h2>struct libwebsocket_extension - An extension we know how to cope with</h2>
 <b>struct libwebsocket_extension</b> {<br>
 &nbsp; &nbsp; <i>const char *</i> <b>name</b>;<br>
-&nbsp; &nbsp; <i>int (*</i><b>callback</b>) <i>(struct libwebsocket_context *context,struct libwebsocket *wsi,enum libwebsocket_callback_reasons reason, void *user,void *in, size_t len)</i>;<br>
+&nbsp; &nbsp; <i>int (*</i><b>callback</b>) <i>(struct libwebsocket_context *context,struct libwebsocket *wsi,enum libwebsocket_extension_callback_reasons reason,void *user, void *in, size_t len)</i>;<br>
 &nbsp; &nbsp; <i>size_t</i> <b>per_session_data_size</b>;<br>
 };<br>
 <h3>Members</h3>
-- 
2.7.4