sync w/ internal repo.

Summary:
in this sync:
1) updated kernel's includes
2) added support for ICMP "packet too big" generation if recved packet
is bigger then MAX_PCKT_SIZE (turned off by default as this requires
bpf_xdp_adjust_tail helper from 4.17)
3) unittests for #2
4) formating/renaming of few internal structs

build_bpf_modules_opensource.sh

@@ -28,5 +28,6 @@ cp ./katran/lib/Makefile-bpf ./deps/linux/bpfprog/Makefile
 cp -r ./katran/lib/bpf ./deps/linux/bpfprog/
 cp ./katran/lib/linux_includes/bpf_helpers.h ./deps/linux/bpfprog/include/
 cd ./deps/linux/bpfprog && LD_LIBRARY_PATH="${CLANG_PATH}/lib" make \
+  EXTRA_CFLAGS="$*" \
   LLC="${CLANG_PATH}/bin/llc" CLANG="${CLANG_PATH}/bin/clang"
 echo "BPF BUILD COMPLITED"

katran/lib/BpfAdapter.cpp

@@ -93,7 +93,7 @@ BpfAdapter::BpfAdapter(bool set_limits) {
     struct rlimit lck_mem = {};
     lck_mem.rlim_cur = RLIM_INFINITY;
     lck_mem.rlim_max = RLIM_INFINITY;
-    if(setrlimit(RLIMIT_MEMLOCK, &lck_mem)) {
+    if (setrlimit(RLIMIT_MEMLOCK, &lck_mem)) {
       LOG(ERROR) << "Can't change limit for locked memory";
       throw std::runtime_error("error while setting limit for locked memory");
     }
@@ -131,7 +131,7 @@ int BpfAdapter::createNamedBpfMap(
     int numa_node) {
   const char* name_ptr = !name.empty() ? name.c_str() : nullptr;
 
-  return bpf_create_map_node(
+  return ebpf_create_map_node(
       static_cast<enum bpf_map_type>(type),
       name_ptr,
       key_size,
@@ -154,43 +154,43 @@ int BpfAdapter::bpfUpdateMap(
     void* key,
     void* value,
     unsigned long long flags) {
-  auto bpfError = bpf_update_elem(map_fd, key, value, flags);
+  auto bpfError = ebpf_update_elem(map_fd, key, value, flags);
   if (bpfError) {
     VLOG(4) << "Error while updating value in map: " << std::strerror(errno);
   }
   return bpfError;
 }
 
 int BpfAdapter::bpfMapLookupElement(int map_fd, void* key, void* value) {
-  auto bpfError = bpf_lookup_elem(map_fd, key, value);
+  auto bpfError = ebpf_lookup_elem(map_fd, key, value);
   if (bpfError) {
     VLOG(4) << "Error while geting value from map: " << std::strerror(errno);
   }
   return bpfError;
 }
 
 int BpfAdapter::bpfMapDeleteElement(int map_fd, void* key) {
-  auto bpfError = bpf_delete_elem(map_fd, key);
+  auto bpfError = ebpf_delete_elem(map_fd, key);
   if (bpfError) {
     VLOG(4) << "Error while deleting key from map: " << std::strerror(errno);
   }
   return bpfError;
 }
 
 int BpfAdapter::bpfMapGetNextKey(int map_fd, void* key, void* next_key) {
-  auto bpfError = bpf_get_next_key(map_fd, key, next_key);
+  auto bpfError = ebpf_get_next_key(map_fd, key, next_key);
   if (bpfError) {
     VLOG(4) << "Error getting next key from map: " << std::strerror(errno);
   }
   return bpfError;
 }
 
 int BpfAdapter::pinBpfObject(int fd, const std::string& path) {
-  return bpf_obj_pin(fd, path.c_str());
+  return ebpf_obj_pin(fd, path.c_str());
 }
 
 int BpfAdapter::getPinnedBpfObject(const std::string& path) {
-  return bpf_obj_get(path.c_str());
+  return ebpf_obj_get(path.c_str());
 }
 
 int BpfAdapter::getInterfaceIndex(const std::string& interface_name) {
@@ -298,7 +298,7 @@ int BpfAdapter::testXdpProg(
     uint32_t* size_out,
     uint32_t* retval,
     uint32_t* duration) {
-  return bpf_prog_test_run(
+  return ebpf_prog_test_run(
       prog_fd, repeat, data, data_size, data_out, size_out, retval, duration);
 }
 
@@ -460,7 +460,14 @@ int BpfAdapter::modifyTcBpfFilter(
     const int prog_fd,
     const unsigned int ifindex,
     const std::string& bpf_name,
-    const int direction) {
+    const int direction)
+// TODO: T30063437 fix null-pointer-use undefined behavior
+#if defined(__has_feature)
+#if __has_feature(__address_sanitizer__)
+    __attribute__((__no_sanitize__("null")))
+#endif
+#endif
+{
   char buf[MNL_SOCKET_BUFFER_SIZE];
   struct nlmsghdr* nlh;
   struct tcmsg* tc;
@@ -572,7 +579,7 @@ int BpfAdapter::attachCgroupProg(
   SCOPE_EXIT {
     ::close(target_fd);
   };
-  return bpf_prog_attach(prog_fd, target_fd, type, flags);
+  return ebpf_prog_attach(prog_fd, target_fd, type, flags);
 }
 
 int BpfAdapter::detachCgroupProg(
@@ -585,7 +592,7 @@ int BpfAdapter::detachCgroupProg(
   SCOPE_EXIT {
     ::close(target_fd);
   };
-  return bpf_prog_detach(target_fd, type);
+  return ebpf_prog_detach(target_fd, type);
 }
 
 int BpfAdapter::detachCgroupProg(
@@ -599,7 +606,7 @@ int BpfAdapter::detachCgroupProg(
   SCOPE_EXIT {
     ::close(target_fd);
   };
-  return bpf_prog_detach2(prog_fd, target_fd, type);
+  return ebpf_prog_detach2(prog_fd, target_fd, type);
 }
 
 } // namespace katran

katran/lib/BpfAdapter.h

@@ -52,7 +52,7 @@ constexpr unsigned int kBpfMapTypeHashOfMaps = 13;
  */
 class BpfAdapter {
  public:
-  explicit BpfAdapter(bool set_limits=true);
+  explicit BpfAdapter(bool set_limits = true);
 
   // BpfAdapter is not thread safe.  Discourage unsafe use by disabling copy
   // construction/assignment.

katran/lib/BpfLoader.cpp

@@ -225,14 +225,14 @@ int BpfLoader::loadMaps(Elf* elf) {
                    << "map-in-map prototype";
         return 1;
       }
-      map_fd = bpf_create_map_in_map(
+      map_fd = ebpf_create_map_in_map(
           static_cast<enum bpf_map_type>(maps[i].type),
           maps[i].key_size,
           inner_map_fd,
           maps[i].max_entries,
           maps[i].map_flags);
     } else {
-      map_fd = bpf_create_map(
+      map_fd = ebpf_create_map(
           static_cast<enum bpf_map_type>(maps[i].type),
           maps[i].key_size,
           maps[i].value_size,
@@ -579,7 +579,7 @@ int BpfLoader::loadBpfProgs() {
             << "\nlicense: " << license_
             << "\nkernel version: " << kernelVersion_;
     std::string bpf_log_buf(kLogBufSize, '\0');
-    auto prog_fd = bpf_prog_load(
+    auto prog_fd = ebpf_prog_load(
         prog_iter.second.type,
         prog_iter.second.insns,
         prog_iter.second.size,
@@ -607,7 +607,7 @@ int BpfLoader::loadBpfFile(const std::string& path, const bpf_prog_type type) {
   int fd = -1;
   SCOPE_EXIT {
     elf_end(elf_);
-    if (0 < fd) {
+    if (fd > 0) {
       ::close(fd);
     }
   };

katran/lib/KatranLb.cpp

@@ -668,18 +668,19 @@ lb_stats KatranLb::getStatsForVip(const VipKey& vip) {
 }
 
 lb_stats KatranLb::getLruStats() {
-  uint32_t lru_cntr_pos = maxVips_ + kLruCntrOffset;
-  return getLbStats(lru_cntr_pos);
+  return getLbStats(maxVips_ + kLruCntrOffset);
 }
 
 lb_stats KatranLb::getLruMissStats() {
-  uint32_t lru_miss_pos = maxVips_ + kLruMissOffset;
-  return getLbStats(lru_miss_pos);
+  return getLbStats(maxVips_ + kLruMissOffset);
 }
 
 lb_stats KatranLb::getLruFallbackStats() {
-  uint32_t lru_fallback_pos = maxVips_ + kLruFallbackOffset;
-  return getLbStats(lru_fallback_pos);
+  return getLbStats(maxVips_ + kLruFallbackOffset);
+}
+
+lb_stats KatranLb::getIcmpTooBigStats() {
+  return getLbStats(maxVips_ + kIcmpTooBigOffset);
 }
 
 lb_stats KatranLb::getLbStats(uint32_t position) {

katran/lib/KatranLb.h

@@ -45,6 +45,7 @@ constexpr int kMainIntfPos = 3;
 constexpr uint32_t kLruCntrOffset = 0;
 constexpr uint32_t kLruMissOffset = 1;
 constexpr uint32_t kLruFallbackOffset = 3;
+constexpr uint32_t kIcmpTooBigOffset = 4;
 
 /**
  * LRU map related constants
@@ -213,7 +214,7 @@ class KatranLb {
    * @param VipKey vip
    * @return struct lb_stats w/ statistic for specified vip
    *
-   * helper function which return totall ammount of pkts and bytes which
+   * helper function which return total ammount of pkts and bytes which
    * has been sent to specified vip. it's up to external entity to calculate
    * actual speed in pps/bps
    */
@@ -222,7 +223,7 @@ class KatranLb {
   /**
    * @return struct lb_stats w/ statistics for lru misses
    *
-   * helper function which returns totall amount of processed packets and
+   * helper function which returns total amount of processed packets and
    * how much of em was lru misses (when we wasnt able to find entry in
    * connection table)
    */
@@ -231,19 +232,28 @@ class KatranLb {
   /**
    * @return struct lb_stats w/ statistic of the reasons for lru misses
    *
-   * helper function which return totall amount of tcp lru misses because of
+   * helper function which returns total amount of tcp lru misses because of
    * the tcp syns (v1) or non-syns (v2)
    */
   lb_stats getLruMissStats();
 
   /**
    * @return struct lb_stats w/ statistic of fallback lru hits
    *
-   * helper function which return totall amount of numbers when we fel back
+   * helper function which return total amount of numbers when we fel back
    * to fallback_lru (v1);
    */
   lb_stats getLruFallbackStats();
 
+  /**
+   * @return struct lb_stats w/ statistic of icmp packet too big packets
+   *
+   * helper function which returns how many icmpv4/icmpv6 packet too big
+   * has been generated after we have received packet, which is bigger then
+   * maximum supported size.
+   */
+  lb_stats getIcmpTooBigStats();
+
   /**
    * @param uint32_t somark of the packet
    * @param std::string dst for a packed w/ specified so_mark
@@ -473,7 +483,7 @@ class KatranLb {
   std::vector<int> lruMapsFd_;
 
   /**
-   * totall LRUs map size; each forwarding cpu/core will have
+   * total LRUs map size; each forwarding cpu/core will have
    * total_size/forwarding_cores entries
    */
   uint64_t totalLruSize_;