Merge pull request #542 from mbertrone/master

http_filter fixes

examples/networking/http_filter/http-parse-complete.c

@@ -54,7 +54,7 @@ int http_filter(struct __sk_buff *skb) {
 	u32  payload_offset = 0;
 	u32  payload_length = 0;
 	struct Key 	key;
-	struct Leaf leaf;
+	struct Leaf zero = {0};
 
 	struct tcp_t *tcp = cursor_advance(cursor, sizeof(*tcp));
 
@@ -135,9 +135,7 @@ int http_filter(struct __sk_buff *skb) {
 	//keep the packet and send it to userspace retruning -1
 	HTTP_MATCH:
 	//if not already present, insert into map <Key, Leaf>
-	leaf.timestamp = 0;
-	sessions.lookup_or_init(&key, &leaf);
-	sessions.update(&key,&leaf);
+	sessions.lookup_or_init(&key,&zero);
 
 	//send packet to userspace returning -1
 	KEEP:

examples/networking/http_filter/http-parse-complete.py

@@ -16,6 +16,7 @@ from __future__ import print_function
 from bcc import BPF
 from ctypes import *
 from struct import *
+from sys import argv
 
 import sys
 import socket
@@ -27,7 +28,6 @@ import time
 CLEANUP_N_PACKETS  = 50       #run cleanup every CLEANUP_N_PACKETS packets received
 MAX_URL_STRING_LEN = 8192     #max url string len (usually 8K)
 MAX_AGE_SECONDS    = 30       #max age entry in bpf_sessions map
-#-----FUNCTIONS-BEGIN----------------------#
 
 #convert a bin string into a string of hex char
 #helper function to print raw packet in hex
@@ -73,8 +73,45 @@ def cleanup():
         print("cleanup exception.")
     return 
 
-#-----FUNCTIONS-END-------------------------#
+#args
+def usage():
+    print("USAGE: %s [-i <if_name>]" % argv[0])
+    print("")
+    print("Try '%s -h' for more options." % argv[0])
+    exit()
+
+#help
+def help():
+    print("USAGE: %s [-i <if_name>]" % argv[0])
+    print("")
+    print("optional arguments:")
+    print("   -h                       print this help")
+    print("   -i if_name               select interface if_name. Default is eth0")
+    print("")
+    print("examples:")
+    print("    http-parse              # bind socket to eth0")
+    print("    http-parse -i wlan0     # bind socket to wlan0")
+    exit()
+
+#arguments
+interface="eth0"
+
+if len(argv) == 2:
+  if str(argv[1]) == '-h':
+    help()
+  else:
+    usage()
+
+if len(argv) == 3:
+  if str(argv[1]) == '-i':
+    interface = argv[2]
+  else:
+    usage()
+
+if len(argv) > 3:
+  usage()
 
+print ("binding socket to '%s'" % interface)
 
 # initialize BPF - load source code from http-parse-complete.c
 bpf = BPF(src_file = "http-parse-complete.c",debug = 0)
@@ -84,9 +121,9 @@ bpf = BPF(src_file = "http-parse-complete.c",debug = 0)
 #http://man7.org/linux/man-pages/man2/bpf.2.html
 function_http_filter = bpf.load_func("http_filter", BPF.SOCKET_FILTER)
 
-#create raw socket, bind it to eth0
+#create raw socket, bind it to interface
 #attach bpf program to socket created
-BPF.attach_raw_socket(function_http_filter, "eth0")
+BPF.attach_raw_socket(function_http_filter, interface)
 
 #get file descriptor of the socket previously created inside BPF.attach_raw_socket
 socket_fd = function_http_filter.sock

examples/networking/http_filter/http-parse-simple.py

@@ -14,11 +14,52 @@
 
 from __future__ import print_function
 from bcc import BPF
+from sys import argv
 
 import sys
 import socket
 import os
 
+#args
+def usage():
+    print("USAGE: %s [-i <if_name>]" % argv[0])
+    print("")
+    print("Try '%s -h' for more options." % argv[0])
+    exit()
+
+#help
+def help():
+    print("USAGE: %s [-i <if_name>]" % argv[0])
+    print("")
+    print("optional arguments:")
+    print("   -h                       print this help")
+    print("   -i if_name               select interface if_name. Default is eth0")
+    print("")
+    print("examples:")
+    print("    http-parse              # bind socket to eth0")
+    print("    http-parse -i wlan0     # bind socket to wlan0")
+    exit()
+
+#arguments
+interface="eth0"
+
+if len(argv) == 2:
+  if str(argv[1]) == '-h':
+    help()
+  else:
+    usage()
+
+if len(argv) == 3:
+  if str(argv[1]) == '-i':
+    interface = argv[2]
+  else:
+    usage()
+
+if len(argv) > 3:
+  usage()
+
+print ("binding socket to '%s'" % interface)
+
 # initialize BPF - load source code from http-parse-simple.c
 bpf = BPF(src_file = "http-parse-simple.c",debug = 0)
 
@@ -27,9 +68,9 @@ bpf = BPF(src_file = "http-parse-simple.c",debug = 0)
 #http://man7.org/linux/man-pages/man2/bpf.2.html
 function_http_filter = bpf.load_func("http_filter", BPF.SOCKET_FILTER)
 
-#create raw socket, bind it to eth0
+#create raw socket, bind it to interface
 #attach bpf program to socket created
-BPF.attach_raw_socket(function_http_filter, "eth0")
+BPF.attach_raw_socket(function_http_filter, interface)
 
 #get file descriptor of the socket previously created inside BPF.attach_raw_socket
 socket_fd = function_http_filter.sock