From cf027261c8da69ef837affdc06f9d392d574e571 Mon Sep 17 00:00:00 2001
From: Quentin Dufour <quentin@deuxfleurs.fr>
Date: Mon, 12 Aug 2019 16:24:20 +0200
Subject: [PATCH] Fix packet handling bug

---
 src/algo_naive.c |  6 +++---
 src/packet.c     | 26 ++++++++++++++++++--------
 2 files changed, 21 insertions(+), 11 deletions(-)

diff --git a/src/algo_naive.c b/src/algo_naive.c
index fb85873..8b7a51e 100644
--- a/src/algo_naive.c
+++ b/src/algo_naive.c
@@ -11,7 +11,7 @@ int algo_naive_on_stream(struct evt_core_ctx* ctx, struct evt_core_fdinfo* fdinf
   struct algo_ctx* app_ctx = fdinfo->cat->app_ctx;
   union abstract_packet* ap = (union abstract_packet*) &bp->ip;
 
-  // 1. Find destination
+  if (ctx->verbose > 1) fprintf(stderr, "    [algo_naive] 1/2 Find destination\n");
   sprintf(url, "udp:write:127.0.0.1:%d", ap->fmt.content.udp_encapsulated.port);
   to_fdinfo = evt_core_get_from_url (ctx, url);
   if (to_fdinfo == NULL) {
@@ -20,7 +20,7 @@ int algo_naive_on_stream(struct evt_core_ctx* ctx, struct evt_core_fdinfo* fdinf
     return 1;
   }
 
-  // 2. Move buffer
+  if (ctx->verbose > 1) fprintf(stderr, "    [algo_naive] 2/2 Move buffer\n");
   mv_buffer_rtow (&app_ctx->br, fdinfo, to_fdinfo);
   main_on_udp_write(ctx, to_fdinfo);
 
@@ -36,7 +36,7 @@ int algo_naive_on_datagram(struct evt_core_ctx* ctx, struct evt_core_fdinfo* fdi
   to_fdinfo = cat->socklist->len > 0 ? g_array_index(cat->socklist, struct evt_core_fdinfo*, 0) : NULL;
   if (to_fdinfo == NULL) {
     fprintf(stderr, "No fd for cat %s in udp-read. Dropping packet :( \n", cat->name);
-    mv_buffer_wtof (&app_ctx->br, fdinfo);
+    mv_buffer_wtof(&app_ctx->br, fdinfo);
     return 1;
   }
   //printf("Pass packet from %s to %s\n", fdinfo->url, url);
diff --git a/src/packet.c b/src/packet.c
index 95dcd18..e96fe66 100644
--- a/src/packet.c
+++ b/src/packet.c
@@ -7,27 +7,34 @@ union abstract_packet* ap_next(union abstract_packet* ap) {
   return NULL;
 }
 
-union abstract_packet* buffer_last_ptr(struct buffer_packet* bp) {
+union abstract_packet* buffer_last_ap(struct buffer_packet* bp) {
   union abstract_packet* ap = (union abstract_packet*) &bp->ip, *apn = NULL;
   while ((apn = ap_next(ap)) != NULL) ap = apn;
 
   return ap;
 }
 
-union abstract_packet* buffer_free_ptr(struct buffer_packet* bp) {
-  union abstract_packet* ap = buffer_last_ptr (bp);
+union abstract_packet* buffer_free_ap(struct buffer_packet* bp) {
+  union abstract_packet* ap = buffer_last_ap (bp);
   ap = (union abstract_packet*)(&ap->raw + ap->fmt.headers.size);
 
   return ap;
 }
 
+size_t buffer_count_ap(struct buffer_packet* bp) {
+  size_t s = 1;
+  union abstract_packet* ap = (union abstract_packet*) &bp->ip;
+  while ((ap = ap_next(ap)) != NULL) s++;
+  return s;
+}
+
 size_t get_full_size(struct buffer_packet* bp) {
-  return &(buffer_free_ptr (bp))->raw - &bp->ip[0];
+  return &(buffer_free_ap (bp))->raw - &bp->ip[0];
 }
 
 void buffer_append_ap(struct buffer_packet* bp, union abstract_packet* ap) {
-  buffer_last_ptr(bp)->fmt.headers.flags |= FLAG_READ_NEXT;
-  memcpy(buffer_last_ptr(bp), ap, ap->fmt.headers.size);
+  buffer_last_ap(bp)->fmt.headers.flags |= FLAG_READ_NEXT;
+  memcpy(buffer_last_ap(bp), ap, ap->fmt.headers.size);
 }
 
 enum FD_STATE read_packet_from_tcp(struct evt_core_fdinfo* fdinfo, struct buffer_packet* bp) {
@@ -53,7 +60,10 @@ enum FD_STATE read_packet_from_tcp(struct evt_core_fdinfo* fdinfo, struct buffer
   }
 
   bp->ap_count++;
-  if (bp->ap_count != get_full_size (bp)) return FDS_AGAIN;
+  if (bp->ap_count != buffer_count_ap (bp)) {
+    printf("  Expected %ld packets in buffer, received %d\n", get_full_size(bp), bp->ap_count);
+    return FDS_AGAIN;
+  }
 
   bp->mode = BP_WRITING;
   bp->awrite = 0;
@@ -83,7 +93,7 @@ enum FD_STATE write_packet_to_tcp(struct evt_core_fdinfo* fdinfo, struct buffer_
 enum FD_STATE write_packet_to_udp(struct evt_core_fdinfo* fdinfo, struct buffer_packet* bp, struct udp_target* udp_t) {
   ssize_t nwrite;
   union abstract_packet* ap = (union abstract_packet*) (&bp->ip + bp->awrite);
-  union abstract_packet* end = buffer_free_ptr (bp);
+  union abstract_packet* end = buffer_free_ap(bp);
   if (bp->mode != BP_WRITING) return FDS_ERR;
 
   while (ap != end) {