From 9cb736e11d82bf5cfe8085ae4bf3dccda91b5ee3 Mon Sep 17 00:00:00 2001
From: amarsri28 <38097938+amarsri28@users.noreply.github.com>
Date: Thu, 3 Mar 2022 01:56:40 +0530
Subject: [PATCH] Fix division by zero crash when doing metering (#529)

* Revert "Workaround for division by zero crash (#385)"

This reverts commit 103b19842673b1557b47a5e103b786518cd24058.

* Revert "QoS: Use params to profile map, carry pointer"

This reverts commit d2c079317b8cc9878c957a101287323e0fa9f286.

Co-authored-by: Maximilian Pudelko <pudelkoM@users.noreply.github.com>
---
 core/modules/qos.cc | 59 +++++++++++++--------------------------------
 core/modules/qos.h  | 21 +---------------
 2 files changed, 18 insertions(+), 62 deletions(-)

diff --git a/core/modules/qos.cc b/core/modules/qos.cc
index 84ecbf454..7eb0d6806 100644
--- a/core/modules/qos.cc
+++ b/core/modules/qos.cc
@@ -161,27 +161,19 @@ void Qos::ProcessBatch(Context *ctx, bess::PacketBatch *batch) {
 
     // meter if ogate is 0
     if (ogate == METER_GATE) {
-      if (val[j]->p->cir_period == 0 || val[j]->p->pir_period == 0) {
-        // FIXME: https://github.com/omec-project/upf-epc/issues/376
-        DLOG(INFO) << "Detected pir/cir_period zero in rte_meter_trtcm_profile,"
-                   << " BUG? Setting METER_GREEN_GATE to prevent crash"
-                   << std::endl;
+      uint64_t time = rte_rdtsc();
+      uint32_t pkt_len = pkt->total_len() - val[j]->deduct_len;
+      uint8_t color = rte_meter_trtcm_color_blind_check(&val[j]->m, &val[j]->p,
+                                                        time, pkt_len);
+
+      DLOG(INFO) << "color : " << color << std::endl;
+      // update ogate to color specific gate
+      if (color == RTE_COLOR_GREEN) {
         ogate = METER_GREEN_GATE;
-      } else {
-        uint64_t time = rte_rdtsc();
-        uint32_t pkt_len = pkt->total_len() - val[j]->deduct_len;
-        uint8_t color = rte_meter_trtcm_color_blind_check(&val[j]->m, val[j]->p,
-                                                          time, pkt_len);
-
-        DLOG(INFO) << "color : " << color << std::endl;
-        // update ogate to color specific gate
-        if (color == RTE_COLOR_GREEN) {
-          ogate = METER_GREEN_GATE;
-        } else if (color == RTE_COLOR_YELLOW) {
-          ogate = METER_YELLOW_GATE;
-        } else if (color == RTE_COLOR_RED) {
-          ogate = METER_RED_GATE;
-        }
+      } else if (color == RTE_COLOR_YELLOW) {
+        ogate = METER_YELLOW_GATE;
+      } else if (color == RTE_COLOR_RED) {
+        ogate = METER_RED_GATE;
       }
     }
 
@@ -386,28 +378,12 @@ CommandResponse Qos::CommandAdd(const bess::pb::QosCommandAddArg &arg) {
     struct rte_meter_trtcm_params app_trtcm_params = {
         .cir = cir, .pir = pir, .cbs = cbs, .pbs = pbs};
 
-    auto *result = params_map_.Find(app_trtcm_params);
-
-    if (result == nullptr) {
-      struct rte_meter_trtcm_profile p;
-
-      int ret = rte_meter_trtcm_profile_config(&p, &app_trtcm_params);
-      if (ret)
-        return CommandFailure(
-            ret,
-            "Insert Failed - rte_meter_trtcm_profile_config creation failed");
-
-      result = params_map_.Insert(app_trtcm_params, p);
-      if (result == nullptr) {
-        return CommandFailure(
-            ret,
-            "Insert Failed - rte_meter_trtcm_profile_config map insert failed");
-      }
-    }
-
-    v.p = &result->second;
+    int ret = rte_meter_trtcm_profile_config(&v.p, &app_trtcm_params);
+    if (ret)
+      return CommandFailure(
+          ret, "Insert Failed - rte_meter_trtcm_profile_config failed");
 
-    int ret = rte_meter_trtcm_config(&v.m, v.p);
+    ret = rte_meter_trtcm_config(&v.m, &v.p);
     if (ret) {
       return CommandFailure(ret,
                             "Insert Failed - rte_meter_trtcm_config failed");
@@ -433,7 +409,6 @@ CommandResponse Qos::CommandClear(__attribute__((unused))
 
 void Qos::Clear() {
   table_.Clear();
-  params_map_.Clear();
 }
 
 void Qos::DeInit() {
diff --git a/core/modules/qos.h b/core/modules/qos.h
index d5a329f7a..e2ff8be52 100644
--- a/core/modules/qos.h
+++ b/core/modules/qos.h
@@ -13,10 +13,8 @@
 #include <rte_hash_crc.h>
 
 #include "../pb/module_msg.pb.h"
-#include "../utils/cuckoo_map.h"
 #include "../utils/metering.h"
 
-using bess::utils::CuckooMap;
 using bess::utils::Metering;
 using bess::utils::MeteringKey;
 
@@ -40,7 +38,7 @@ enum { FieldType = 0, ValueType };
 struct value {
   gate_idx_t ogate;
   int64_t deduct_len;
-  struct rte_meter_trtcm_profile *p;
+  struct rte_meter_trtcm_profile p;
   struct rte_meter_trtcm m;
   MeteringKey Data;
 } __attribute__((packed));
@@ -56,21 +54,6 @@ class Qos final : public Module {
 
   static const Commands cmds;
 
-  struct Hash {
-    bess::utils::HashResult operator()(
-        const rte_meter_trtcm_params &key) const {
-      return rte_hash_crc(&key, sizeof(rte_meter_trtcm_params), 0);
-    }
-  };
-
-  struct EqualTo {
-    bool operator()(const rte_meter_trtcm_params &p1,
-                    const rte_meter_trtcm_params &p2) const {
-      return (p1.cir == p2.cir) && (p1.pir == p2.pir) && (p1.cbs == p2.cbs) &&
-             (p1.pbs == p2.pbs);
-    }
-  };
-
   Qos() : Module(), default_gate_(), total_key_size_(), fields_() {
     max_allowed_workers_ = Worker::kMaxWorkers;
     size_t len = sizeof(mask) / sizeof(uint64_t);
@@ -106,8 +89,6 @@ class Qos final : public Module {
   std::vector<struct MeteringField> values_;
   Metering<value> table_;
   uint64_t mask[MAX_FIELDS];
-  CuckooMap<rte_meter_trtcm_params, rte_meter_trtcm_profile, Hash, EqualTo>
-      params_map_;
 };
 
 #endif  // BESS_MODULES_QOS_H