dnsdist: Implement proper parameters handling in the XDP helper

diff --git a/contrib/xdp.py b/contrib/xdp.py
index d6ef369708e92b699ab2b3afb853fade511bdc9a..089e68d9b1b1a3584f55fcf14241c14b3822319d 100644 (file)
--- a/contrib/xdp.py
+++ b/contrib/xdp.py
@@ -1,10 +1,11 @@
 #!/usr/bin/env python3
-
-from bcc import BPF
+import argparse
 import ctypes as ct
 import netaddr
 import socket
 
+from bcc import BPF
+
 # Constants
 QTYPES = {'LOC': 29, '*': 255, 'IXFR': 251, 'UINFO': 100, 'NSEC3': 50, 'AAAA': 28, 'CNAME': 5, 'MINFO': 14, 'EID': 31, 'GPOS': 27, 'X25': 19, 'HINFO': 13, 'CAA': 257, 'NULL': 10, 'DNSKEY': 48, 'DS': 43, 'ISDN': 20, 'SOA': 6, 'RP': 17, 'UID': 101, 'TALINK': 58, 'TKEY': 249, 'PX': 26, 'NSAP-PTR': 23, 'TXT': 16, 'IPSECKEY': 45, 'DNAME': 39, 'MAILA': 254, 'AFSDB': 18, 'SSHFP': 44, 'NS': 2, 'PTR': 12, 'SPF': 99, 'TA': 32768, 'A': 1, 'NXT': 30, 'AXFR': 252, 'RKEY': 57, 'KEY': 25, 'NIMLOC': 32, 'A6': 38, 'TLSA': 52, 'MG': 8, 'HIP': 55, 'NSEC': 47, 'GID': 102, 'SRV': 33, 'DLV': 32769, 'NSEC3PARAM': 51, 'UNSPEC': 103, 'TSIG': 250, 'ATMA': 34, 'RRSIG': 46, 'OPT': 41, 'MD': 3, 'NAPTR': 35, 'MF': 4, 'MB': 7, 'DHCID': 49, 'MX': 15, 'MAILB': 253, 'CERT': 37, 'NINFO': 56, 'APL': 42, 'MR': 9, 'SIG': 24, 'WKS': 11, 'KX': 36, 'NSAP': 22, 'RT': 21, 'SINK': 40}
 INV_QTYPES = {v: k for k, v in QTYPES.items()}
@@ -13,9 +14,6 @@ ACTIONS = {1 : 'DROP', 2 : 'TC'}
 DROP_ACTION = 1
 TC_ACTION = 2
 
-# The interface on wich the filter will be attached
-DEV = "eth1"
-
 # The list of blocked IPv4, IPv6 and QNames
 # IP format : (IPAddress, Action)
 # CIDR format : (IPAddress/cidr, Action)
@@ -27,19 +25,26 @@ blocked_cidr6 = [("2001:db8::1/128", TC_ACTION)]
 blocked_qnames = [("localhost", "A", DROP_ACTION), ("test.com", "*", TC_ACTION)]
 
 # Main
-useXsk = True
+parser = argparse.ArgumentParser(description='XDP helper for DNSDist')
+parser.add_argument('--xsk', action='store_true', help='Enable XSK (AF_XDP) mode', default=False)
+parser.add_argument('--interface', '-i', type=str, default='eth0', help='The interface on which the filter will be attached')
+
+parameters = parser.parse_args()
 cflag = []
-if useXsk:
+if parameters.xsk:
+  print(f'Enabling XSK (AF_XDP) on {parameters.interface}..')
   cflag.append("-DUseXsk")
 else:
   Ports = [53]
+  portsStr = ', '.join(str(port) for port in Ports)
+  print(f'Enabling XDP on {parameters.interface} and ports {portsStr}..')
   IN_DNS_PORT_SET = "||".join("COMPARE_PORT((x),"+str(i)+")" for i in Ports)
   cflag.append(r"-DIN_DNS_PORT_SET(x)=(" + IN_DNS_PORT_SET + r")")
 
 xdp = BPF(src_file="xdp-filter.ebpf.src", cflags=cflag)
 
 fn = xdp.load_func("xdp_dns_filter", BPF.XDP)
-xdp.attach_xdp(DEV, fn, 0)
+xdp.attach_xdp(parameters.interface, fn, 0)
 
 v4filter = xdp.get_table("v4filter")
 v6filter = xdp.get_table("v6filter")
@@ -47,7 +52,7 @@ cidr4filter = xdp.get_table("cidr4filter")
 cidr6filter = xdp.get_table("cidr6filter")
 qnamefilter = xdp.get_table("qnamefilter")
 
-if useXsk:
+if parameters.xsk:
   xskDestinations = xdp.get_table("xskDestinationsV4")
 
 for ip in blocked_ipv4:
@@ -108,7 +113,8 @@ for qname in blocked_qnames:
   leaf.action = qname[2]
   qnamefilter[key] = leaf
 
-print("Filter is ready")
+print(f"Filter is ready on {parameters.interface}")
+
 try:
   xdp.trace_print()
 except KeyboardInterrupt:
@@ -126,4 +132,4 @@ for item in cidr6filter.items():
 for item in qnamefilter.items():
   print(f"{''.join(map(chr, item[0].qname)).strip()}/{INV_QTYPES[item[0].qtype]} ({ACTIONS[item[1].action]}): {item[1].counter}")
 
-xdp.remove_xdp(DEV, 0)
+xdp.remove_xdp(parameters.interface, 0)