cc: add support for prog table

Signed-off-by: Mauricio Vasquez B <mauricio.vasquez@polito.it>

src/cc/BPF.cc

@@ -482,6 +482,13 @@ std::string BPF::get_kprobe_event(const std::string& kernel_func,
   return res;
 }
 
+BPFProgTable BPF::get_prog_table(const std::string& name) {
+  TableStorage::iterator it;
+  if (bpf_module_->table_storage().Find(Path({bpf_module_->id(), name}), it))
+    return BPFProgTable(it->second);
+  return BPFProgTable({});
+}
+
 std::string BPF::get_uprobe_event(const std::string& binary_path,
                                   uint64_t offset, bpf_probe_attach_type type) {
   std::string res = attach_type_prefix(type) + "_";

src/cc/BPF.h

@@ -106,6 +106,8 @@ public:
     return BPFHashTable<KeyType, ValueType>({});
   }
 
+  BPFProgTable get_prog_table(const std::string& name);
+
   BPFStackTable get_stack_table(const std::string& name) {
     TableStorage::iterator it;
     if (bpf_module_->table_storage().Find(Path({bpf_module_->id(), name}), it))

src/cc/BPFTable.h

@@ -202,4 +202,20 @@ class BPFPerfBuffer : protected BPFTableBase<int, int> {
   std::unique_ptr<epoll_event[]> ep_events_;
 };
 
+class BPFProgTable : protected BPFTableBase<int, int> {
+public:
+  BPFProgTable(const TableDesc& desc)
+      : BPFTableBase<int, int>(desc) {
+    if (desc.type != BPF_MAP_TYPE_PROG_ARRAY)
+      throw std::invalid_argument("Table '" + desc.name + "' is not a prog table");
+  }
+
+  // updates an element
+  StatusTuple update_value(const int& index, const int& value) {
+    if (!this->update(const_cast<int*>(&index), const_cast<int*>(&value)))
+      return StatusTuple(-1, "Error updating value: %s", std::strerror(errno));
+    return StatusTuple(0);
+  }
+};
+
 }  // namespace ebpf