From 4d5dd554c5e715e7355c3672ef9985c67ee53667 Mon Sep 17 00:00:00 2001
From: Quentin Dufour <quentin@deuxfleurs.fr>
Date: Wed, 28 Aug 2019 11:35:43 +0200
Subject: [PATCH] Add unpad function

---
 src/algo_thunder.c | 34 +++++++++++++++++++++++++++++-----
 1 file changed, 29 insertions(+), 5 deletions(-)

diff --git a/src/algo_thunder.c b/src/algo_thunder.c
index 9e7072c..20e854a 100644
--- a/src/algo_thunder.c
+++ b/src/algo_thunder.c
@@ -8,15 +8,16 @@
 // A Tor cell size is 512 bytes but handle only 498 bytes of data
 #define TOR_CELL_SIZE 498
 #define ALLOWED_JITTER_MS 200
+#define MAX_LINKS 64
 
 struct thunder_ctx {
   uint16_t recv_id;
   uint16_t emit_id;
   uint8_t selected_link;
   uint8_t total_links;
-  uint8_t delta_t_per_link[64];
-  uint64_t received_pkts_on_link[64];
-  uint8_t blacklisted[64];
+  uint8_t delta_t_per_link[MAX_LINKS];
+  uint64_t received_pkts_on_link[MAX_LINKS];
+  uint8_t blacklisted[MAX_LINKS];
   size_t monit_pkt_size;
   struct timespec prev_link_time, prev_packet_time;
 };
@@ -193,8 +194,29 @@ void classify(struct evt_core_ctx* ctx, struct evt_core_fdinfo* fdinfo, struct b
   }
 }
 
-void unpad() {
+struct unpad_info {
+  union abstract_packet *ap_arr_pl[MAX_LINKS], *ap_arr_meta[MAX_LINKS];
+  uint8_t ap_arr_vals;
+};
 
+void unpad(struct evt_core_ctx* ctx, struct evt_core_fdinfo* fdinfo, struct buffer_packet* bp, struct unpad_info *ui) {
+  struct algo_ctx* app_ctx = fdinfo->cat->app_ctx;
+  struct thunder_ctx* thunderc = app_ctx->misc;
+
+  for (union abstract_packet* ap = buffer_first_ap (bp); ap != NULL; ap = ap_next(ap)) {
+    if (ap->fmt.headers.cmd != CMD_UDP_ENCAPSULATED) continue;
+
+    union abstract_packet* ap_meta = ap_next(ap);
+    if (ap_meta == NULL || ap_meta->fmt.headers.cmd != CMD_UDP_METADATA_THUNDER) {
+      fprintf(stderr, "Unexpected packet, expecting udp metadata\n");
+    }
+
+    if (ap_meta->fmt.content.udp_metadata_thunder.id > thunderc->recv_id) {
+      ui->ap_arr_pl[ui->ap_arr_vals] = ap;
+      ui->ap_arr_meta[ui->ap_arr_vals] = ap_meta;
+      ui->ap_arr_vals++;
+    }
+  }
 }
 
 void adapt() {
@@ -202,8 +224,10 @@ void adapt() {
 }
 
 int algo_thunder_on_stream(struct evt_core_ctx* ctx, struct evt_core_fdinfo* fdinfo, struct buffer_packet* bp) {
+  struct unpad_info ui = {0};
+
   classify(ctx, fdinfo, bp);
-  unpad();
+  unpad(ctx, fdinfo, bp, &ui);
   adapt();
   return 0;
 }