[Etherboot-developers] [PATCH 6/7] [ipv4] Free frag_buffer when its timer expires

[Michal K. <mku...@su...>]

In the frag_buffer timer expiry function, there was comment "Free the
fragment buffer" but no attempt to free it was actually done.

Signed-off-by: Michal Kubecek <mku...@su...>
---
 src/include/gpxe/ip.h |    3 +++
 src/net/ipv4.c        |   26 ++++++++++++++++++++++++--
 2 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/src/include/gpxe/ip.h b/src/include/gpxe/ip.h
index 4342a0c..29def10 100644
--- a/src/include/gpxe/ip.h
+++ b/src/include/gpxe/ip.h
@@ -34,6 +34,7 @@ struct net_protocol;
 
 #define IP_FRAG_IOB_SIZE	1500
 #define IP_FRAG_TIMEOUT		50
+#define IP_FRAG_EXPIRED		0x0001
 
 /** An IPv4 packet header */
 struct iphdr {
@@ -86,6 +87,8 @@ struct frag_buffer {
 	struct io_buffer *frag_iob;
 	/* Reassembly timer */
 	struct retry_timer frag_timer;
+	/* Flags */
+	uint16_t frag_flags;
 	/* List of fragment reassembly buffers */
 	struct list_head list;
 };
diff --git a/src/net/ipv4.c b/src/net/ipv4.c
index d698318..f20762f 100644
--- a/src/net/ipv4.c
+++ b/src/net/ipv4.c
@@ -139,11 +139,14 @@ static struct ipv4_miniroute * ipv4_route ( struct in_addr *dest ) {
  * @v timer	Retry timer
  * @v over	If asserted, the timer is greater than @c MAX_TIMEOUT 
  */
-static void ipv4_frag_expired ( struct retry_timer *timer __unused,
+static void ipv4_frag_expired ( struct retry_timer *timer,
 				int over ) {
 	if ( over ) {
+		struct frag_buffer *fragbuf;
 		DBG ( "Fragment reassembly timeout" );
-		/* Free the fragment buffer */
+		/* Mark the fragment buffer for cleanup */
+		fragbuf = container_of(timer, struct frag_buffer, frag_timer);
+		fragbuf->frag_flags |= IP_FRAG_EXPIRED;
 	}
 }
 
@@ -161,6 +164,21 @@ static void free_fragbuf ( struct frag_buffer *fragbuf ) {
 }
 
 /**
+ * Remove all expired fragment buffers
+ *
+ */
+static void ipv4_frag_cleanup ()
+{
+	struct frag_buffer *fragbuf;
+	struct frag_buffer *fragtmp;
+
+	list_for_each_entry_safe ( fragbuf, fragtmp, &frag_buffers, list ) {
+		if ( fragbuf->frag_flags & IP_FRAG_EXPIRED )
+			free_fragbuf ( fragbuf );
+	}
+}
+
+/**
  * Fragment reassembler
  *
  * @v iobuf		I/O buffer, fragment of the datagram
@@ -172,6 +190,9 @@ static struct io_buffer * ipv4_reassemble ( struct io_buffer * iobuf ) {
 	struct frag_buffer *fragbuf;
 	struct frag_buffer *fragtmp;
 	
+	/* Remove expired fragment buffers */
+	ipv4_frag_cleanup();
+
 	/**
 	 * Check if the fragment belongs to any fragment series
 	 */
@@ -228,6 +249,7 @@ static struct io_buffer * ipv4_reassemble ( struct io_buffer * iobuf ) {
 	
 		/** Create a new fragment buffer */
 		fragbuf = ( struct frag_buffer* ) malloc ( sizeof( *fragbuf ) );
+		fragbuf->frag_flags = 0;
 		fragbuf->ident = iphdr->ident;
 		fragbuf->src = iphdr->src;
 
-- 
1.7.7