[py] Add support for CGROUP_SOCKOPT program type

Testing: Added a new test to test_clang that loads a program of type `CGROUP_SOCKOPT`

```
16: .
16: ----------------------------------------------------------------------
16: Ran 84 tests in 83.695s
16:
16: OK (skipped=4)
16: 0
16/41 Test iovisor#16: py_test_clang ....................   Passed   84.14 sec
```

src/python/bcc/__init__.py

@@ -188,6 +188,7 @@ class BPFProgType:
  SK_MSG = 16
  RAW_TRACEPOINT = 17
  CGROUP_SOCK_ADDR = 18
+ CGROUP_SOCKOPT = 25
  TRACING = 26
  LSM = 29
 

tests/python/test_clang.py

@@ -2,7 +2,7 @@
 # Copyright (c) PLUMgrid, Inc.
 # Licensed under the Apache License, Version 2.0 (the "License")
 
-from bcc import BPF
+from bcc import BPF, BPFAttachType, BPFProgType
 from bcc.libbcc import lib
 import ctypes as ct
 from unittest import main, skipUnless, TestCase
@@ -55,6 +55,16 @@ def test_probe_read1(self):
  b = BPF(text=text, debug=0)
  fn = b.load_func("count_sched", BPF.KPROBE)
 
+ def test_load_cgroup_sockopt_prog(self):
+ text = """
+int sockopt(struct bpf_sockopt* ctx){
+
+ return 0;
+}
+"""
+ b = BPF(text=text, debug=0)
+ fn = b.load_func("sockopt", BPFProgType.CGROUP_SOCKOPT, device = None, attach_type = BPFAttachType.CGROUP_SETSOCKOPT)
+
  def test_probe_read2(self):
  text = """
 #include <linux/sched.h>