From 4cdc461996b6ef26c65e6dd3d2dc29a3ef62a08b Mon Sep 17 00:00:00 2001
From: Yuhan Li <1325861244@qq.com>
Date: Mon, 23 May 2022 14:12:11 +0800
Subject: [PATCH] =?UTF-8?q?=E5=A2=9E=E5=8A=A0=E8=B7=9F=E8=B8=AA=E9=A1=B9?=
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通过使用特定的语法来决定哪些跟踪项在哪些内核版本中启用. 并切换
__netif_receive_skb_core使用该功能来实现.

Signed-off-by: Yuhan Li <1325861244@qq.com>
---
 nettrace.py | 44 +++++++++++++++++---------------------------
 skb.yaml    |  7 ++++++-
 utils.py    | 26 ++++++++++++++++++++++++++
 3 files changed, 49 insertions(+), 28 deletions(-)

diff --git a/nettrace.py b/nettrace.py
index c97120e..40b94dd 100755
--- a/nettrace.py
+++ b/nettrace.py
@@ -23,15 +23,6 @@ class Tracer:
     _cata_enabled = []
     _cata_all = None
 
-    _v_tracer = {
-        '4.14': [
-            {'name': '__netif_receive_skb_core', 'skb': 0, 'level': 1},
-        ],
-        '5.4': [
-            {'name': '__netif_receive_skb_core', 'pskb': 0, 'level': 1},
-        ]
-    }
-
     @staticmethod
     def get_cata_all():
         if Tracer._cata_all:
@@ -139,22 +130,16 @@ def print_tracer(tracer, tab=''):
             Tracer.print_tracer(i, tab + '    ')
 
     @staticmethod
-    def fix_version():
-        import subprocess
-        code, ver_str = subprocess.getstatusoutput('uname -r')
-        if code != 0:
-            return
-        m = re.match(r'([0-9]+\.[0-9]+)\.', ver_str)
-        if not m:
-            return
-        ver = m.group(1)
-        if ver not in Tracer._v_tracer:
-            Helper.pr_warn('''kernel version not found! You can add your kernel
-version in '_v_tracer' of nettrace.py\n''')
-            return
-        for tracer in Tracer._v_tracer[ver]:
-            origin = Tracer.get_cata_or_tracer(tracer['name'])
-            origin.update(tracer)
+    def check_if(tracer):
+        if 'if' not in tracer:
+            return True
+        cond = tracer['if']
+        kernelVersion = kernel_version_cur()
+        cond = cond.replace('kernelVersion', str(kernelVersion))
+        ret = {'value': False}
+        cond = '''value = %s''' % cond
+        exec(cond, ret)
+        return ret['value']
 
     @staticmethod
     def prepare_cata(root=None):
@@ -192,7 +177,11 @@ def init_tracers():
             if not cata:
                 Helper.pr_warn('the tracer:%s not found' % cata_str)
                 continue
-            tracers += Tracer.get_tracers(cata)
+            for tracer in Tracer.get_tracers(cata):
+                if Tracer.check_if(tracer):
+                    tracers.append(tracer)
+                else:
+                    tracer['hidden'] = True
             catalogs.append(cata)
 
         for t in set(Helper.get_stack_tracer()):
@@ -221,7 +210,6 @@ def init_tracers():
         Tracer._tracer_enabled = tracers
         Tracer._cata_enabled = catalogs
         Tracer.bind_parent(Tracer.get_cata_all())
-        Tracer.fix_version()
 
         for t in tracers:
             p = t['parent']
@@ -447,6 +435,8 @@ def init_args():
         Helper._user_args = args
 
         if args.tracer == '?':
+            args.tracer = 'all'
+            Tracer.init_tracers()
             print('available tracer:')
             print('---------------------------------------------------\n')
             Tracer.print_tracer(Tracer.get_cata_all())
diff --git a/skb.yaml b/skb.yaml
index a4dae53..c9d8f44 100644
--- a/skb.yaml
+++ b/skb.yaml
@@ -11,13 +11,18 @@ children:
     children:
     - napi_gro_receive:1
     - enqueue_to_backlog:0
-    - __netif_receive_skb_core
     - name: do_xdp_generic
       regex: do_xdp_generic\..*
       skb: 1
     - xdp_do_generic_redirect:1
     - generic_xdp_tx:1
     - sch_handle_ingress:0
+    - name: __netif_receive_skb_core
+      skb: 0
+      if: kernelVersion < 504
+    - name: __netif_receive_skb_core
+      pskb: 0
+      if: kernelVersion >= 504
   - name: link-out
     desc: link layer (L2) of packet out
     visual: true
diff --git a/utils.py b/utils.py
index ea2200f..38afd3c 100644
--- a/utils.py
+++ b/utils.py
@@ -1,8 +1,13 @@
 import os
 import struct
 import socket
+import subprocess
+import re
+
+from numpy import mat
 
 cur_dir = os.path.dirname(os.path.abspath(__file__))
+_cur_version = None
 
 
 def project_file(name):
@@ -12,6 +17,27 @@ def project_file(name):
 def b2str(b):
     return 'true' if b else 'false'
 
+def kernel_version_num(version):
+    if not version:
+        return 0
+
+    match = re.match("([0-9]+)\.([0-9]+)\.", version)
+    if not match:
+        return None
+    return int(match.group(1)) * 100 + int(match.group(2))
+
+def kernel_version_cur():
+    return kernel_version_num(kernel_version())
+
+def kernel_version():
+    global _cur_version
+    if _cur_version:
+        return _cur_version
+    (code, result) = subprocess.getstatusoutput('uname -r')
+    if code != 0:
+        return None
+    _cur_version = result
+    return result
 
 class NetUtils: