Basic attaching of kprobes

src/bpftrace.cpp

+#include <iostream>
+
 #include "bpftrace.h"
+#include "libbpf.h"
 
 namespace ebpf {
 namespace bpftrace {
@@ -15,5 +18,88 @@ std::string typestr(Type t)
   }
 }
 
+std::string typestr(ProbeType t)
+{
+  switch (t)
+  {
+    case ProbeType::kprobe:    return "kprobe";    break;
+    case ProbeType::kretprobe: return "kretprobe"; break;
+    default: abort();
+  }
+}
+
+int BPFtrace::attach_probes()
+{
+  int err = 0;
+  for (Probe &probe : probes_) {
+    if (probe.type == ProbeType::kprobe ||
+        probe.type == ProbeType::kretprobe) {
+      err = attach_kprobe(probe);
+    }
+    else {
+      abort();
+    }
+
+    if (err) {
+      std::cerr << "Error attaching probe: " << typestr(probe.type) << ":" << probe.attach_point << std::endl;
+      return err;
+    }
+  }
+  return 0;
+}
+
+int BPFtrace::add_probe(ast::Probe &p)
+{
+  Probe probe;
+  probe.attach_point = p.attach_point;
+  if (p.type == "kprobe") {
+    probe.type = ProbeType::kprobe;
+  }
+  else if (p.type == "kretprobe") {
+    probe.type = ProbeType::kretprobe;
+  }
+  else {
+    return -1;
+  }
+  probes_.push_back(probe);
+  return 0;
+}
+
+int BPFtrace::attach_kprobe(Probe &probe)
+{
+  std::string event;
+  std::string event_desc;
+  int pid = -1;
+  int cpu = 0;
+  int group_fd = -1;
+  perf_reader_cb cb = nullptr;
+  void *cb_cookie = nullptr;
+
+  switch (probe.type) {
+    case ProbeType::kprobe:
+      event =  "p_" + probe.attach_point;
+      break;
+    case ProbeType::kretprobe:
+      event =  "r_" + probe.attach_point;
+      break;
+    default:
+      abort();
+  }
+
+  switch (probe.type) {
+    case ProbeType::kprobe:
+      event_desc =  "p:kprobes/" + event + " " + probe.attach_point;
+      break;
+    case ProbeType::kretprobe:
+      event_desc =  "r:kprobes/" + event + " " + probe.attach_point;
+      break;
+    default:
+      abort();
+  }
+
+  bpf_attach_kprobe(probe.progfd, event.c_str(), event_desc.c_str(),
+      pid, cpu, group_fd, cb, cb_cookie);
+}
+
 } // namespace bpftrace
 } // namespace ebpf

src/bpftrace.h

@@ -4,6 +4,7 @@
 #include <memory>
 #include <vector>
 
+#include "ast.h"
 #include "map.h"
 
 namespace ebpf {
@@ -17,14 +18,37 @@ enum class Type
   count,
 };
 
+enum class ProbeType
+{
+  kprobe,
+  kretprobe,
+};
+
 std::string typestr(Type t);
+std::string typestr(ProbeType t);
+
+class Probe
+{
+public:
+  ProbeType type;
+  std::string attach_point;
+  int progfd;
+};
 
 class BPFtrace
 {
 public:
+  int attach_probes();
+  int add_probe(ast::Probe &p);
+
   std::map<std::string, Type> map_val_;
   std::map<std::string, std::vector<Type>> map_args_;
   std::map<std::string, std::unique_ptr<ebpf::bpftrace::Map>> maps_;
+
+private:
+  std::vector<Probe> probes_;
+
+  int attach_kprobe(Probe &probe);
 };
 
 } // namespace bpftrace

src/semantic_analyser.cpp

@@ -169,6 +169,10 @@ void SemanticAnalyser::visit(Probe &probe)
   for (Statement *stmt : *probe.stmts) {
     stmt->accept(*this);
   }
+
+  if (bpftrace_.add_probe(probe)) {
+    err_ << "Invalid probe type: '" << probe.type << "'" << std::endl;
+  }
 }
 
 void SemanticAnalyser::visit(Program &program)