From 6d24ad71f6fdb5345970fcfa7450cd5a50790d18 Mon Sep 17 00:00:00 2001
From: Alexandru Ardelean <ardeleanalex@gmail.com>
Date: Fri, 27 Jun 2014 19:11:40 +0300
Subject: [PATCH] ubus: increase message size limit and make it configurable at
 build-time

---
 CMakeLists.txt |  2 ++
 libubus-io.c   | 10 ++++++++++
 libubus.c      |  3 ++-
 libubus.h      |  1 +
 ubusmsg.h      |  2 +-
 5 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index e3b150b..cb2f420 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -9,8 +9,10 @@ OPTION(ENABLE_SYSTEMD "systemd support" ON)
 
 SET(CMAKE_SHARED_LIBRARY_LINK_C_FLAGS "")
 SET(UBUS_UNIX_SOCKET "/var/run/ubus.sock")
+SET(UBUS_MAX_MSGLEN 1048576)
 
 ADD_DEFINITIONS( -DUBUS_UNIX_SOCKET="${UBUS_UNIX_SOCKET}")
+ADD_DEFINITIONS( -DUBUS_MAX_MSGLEN=${UBUS_MAX_MSGLEN})
 
 IF(APPLE)
   INCLUDE_DIRECTORIES(/opt/local/include)
diff --git a/libubus-io.c b/libubus-io.c
index c63a920..48bb72d 100644
--- a/libubus-io.c
+++ b/libubus-io.c
@@ -233,6 +233,7 @@ static bool get_next_msg(struct ubus_context *ctx, int *recv_fd)
 		struct blob_attr data;
 	} hdrbuf;
 	struct iovec iov = STATIC_IOV(hdrbuf);
+	int len;
 	int r;
 
 	/* receive header + start attribute */
@@ -247,6 +248,15 @@ static bool get_next_msg(struct ubus_context *ctx, int *recv_fd)
 	if (!ubus_validate_hdr(&hdrbuf.hdr))
 		return false;
 
+	len = blob_raw_len(&hdrbuf.data);
+	if (len > ctx->msgbuf_data_len) {
+		ctx->msgbuf.data = realloc(ctx->msgbuf.data, len * sizeof(char));
+		if (ctx->msgbuf.data)
+			ctx->msgbuf_data_len = len;
+	}
+	if (!ctx->msgbuf.data)
+		return false;
+
 	memcpy(&ctx->msgbuf.hdr, &hdrbuf.hdr, sizeof(hdrbuf.hdr));
 	memcpy(ctx->msgbuf.data, &hdrbuf.data, sizeof(hdrbuf.data));
 
diff --git a/libubus.c b/libubus.c
index 83a2c43..be4e6ac 100644
--- a/libubus.c
+++ b/libubus.c
@@ -280,9 +280,10 @@ static int _ubus_connect(struct ubus_context *ctx, const char *path)
 	ctx->connection_lost = ubus_default_connection_lost;
 	ctx->pending_timer.cb = ubus_process_pending_msg;
 
-	ctx->msgbuf.data = calloc(UBUS_MAX_MSGLEN, sizeof(char));
+	ctx->msgbuf.data = calloc(UBUS_MSG_CHUNK_SIZE, sizeof(char));
 	if (!ctx->msgbuf.data)
 		return -1;
+	ctx->msgbuf_data_len = UBUS_MSG_CHUNK_SIZE;
 
 	INIT_LIST_HEAD(&ctx->requests);
 	INIT_LIST_HEAD(&ctx->pending);
diff --git a/libubus.h b/libubus.h
index 33a99aa..78ffa38 100644
--- a/libubus.h
+++ b/libubus.h
@@ -155,6 +155,7 @@ struct ubus_context {
 	void (*connection_lost)(struct ubus_context *ctx);
 
 	struct ubus_msghdr_buf msgbuf;
+	uint32_t msgbuf_data_len;
 };
 
 struct ubus_object_data {
diff --git a/ubusmsg.h b/ubusmsg.h
index c9b92e7..0a27b42 100644
--- a/ubusmsg.h
+++ b/ubusmsg.h
@@ -19,7 +19,7 @@
 
 #define __packetdata __attribute__((packed)) __attribute__((__aligned__(4)))
 
-#define UBUS_MAX_MSGLEN	65536
+#define UBUS_MSG_CHUNK_SIZE	65536
 
 #define UBUS_SYSTEM_OBJECT_EVENT	1
 #define UBUS_SYSTEM_OBJECT_MAX		1024