Commit 1b0bbe9f authored by Brenden Blanco's avatar Brenden Blanco Committed by GitHub

Merge pull request #636 from iovisor/xdp-drop

Add xdp_drop_count example
parents 89ad9342 ae059841
......@@ -7,4 +7,5 @@ add_subdirectory(distributed_bridge)
add_subdirectory(neighbor_sharing)
add_subdirectory(vlan_learning)
add_subdirectory(tunnel_monitor)
add_subdirectory(http_filter)
\ No newline at end of file
add_subdirectory(http_filter)
add_subdirectory(xdp)
install(PROGRAMS xdp_drop_count.py DESTINATION share/bcc/examples/networking/xdp)
#!/usr/bin/env python
#
# xdp_drop_count.py Drop incoming packets on XDP layer and count for which
# protocol type
#
# Copyright (c) 2016 PLUMgrid
# Copyright (c) 2016 Jan Ruth
# Licensed under the Apache License, Version 2.0 (the "License")
from bcc import BPF
import pyroute2
import time
import sys
if len(sys.argv) != 2:
print("Usage: {0} <ifdev>\n\ne.g.: {0} eth0".format(sys.argv[0]))
exit(1)
device = sys.argv[1]
mode = BPF.XDP
#mode = BPF.SCHED_CLS
if mode == BPF.XDP:
ret = "XDP_DROP"
ctxtype = "xdp_md"
else:
ret = "TC_ACT_SHOT"
ctxtype = "__sk_buff"
# load BPF program
b = BPF(text = """
#define KBUILD_MODNAME "foo"
#include <uapi/linux/bpf.h>
#include <linux/in.h>
#include <linux/if_ether.h>
#include <linux/if_packet.h>
#include <linux/if_vlan.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
BPF_TABLE("percpu_array", uint32_t, long, dropcnt, 256);
static inline int parse_ipv4(void *data, u64 nh_off, void *data_end) {
struct iphdr *iph = data + nh_off;
if ((void*)&iph[1] > data_end)
return 0;
return iph->protocol;
}
static inline int parse_ipv6(void *data, u64 nh_off, void *data_end) {
struct ipv6hdr *ip6h = data + nh_off;
if ((void*)&ip6h[1] > data_end)
return 0;
return ip6h->nexthdr;
}
int xdp_prog1(struct CTXTYPE *ctx) {
void* data_end = (void*)(long)ctx->data_end;
void* data = (void*)(long)ctx->data;
struct ethhdr *eth = data;
// drop packets
int rc = RETURNCODE; // let pass XDP_PASS or redirect to tx via XDP_TX
long *value;
uint16_t h_proto;
uint64_t nh_off = 0;
uint32_t index;
nh_off = sizeof(*eth);
if (data + nh_off > data_end)
return rc;
h_proto = eth->h_proto;
if (h_proto == htons(ETH_P_8021Q) || h_proto == htons(ETH_P_8021AD)) {
struct vlan_hdr *vhdr;
vhdr = data + nh_off;
nh_off += sizeof(struct vlan_hdr);
if (data + nh_off > data_end)
return rc;
h_proto = vhdr->h_vlan_encapsulated_proto;
}
if (h_proto == htons(ETH_P_8021Q) || h_proto == htons(ETH_P_8021AD)) {
struct vlan_hdr *vhdr;
vhdr = data + nh_off;
nh_off += sizeof(struct vlan_hdr);
if (data + nh_off > data_end)
return rc;
h_proto = vhdr->h_vlan_encapsulated_proto;
}
if (h_proto == htons(ETH_P_IP))
index = parse_ipv4(data, nh_off, data_end);
else if (h_proto == htons(ETH_P_IPV6))
index = parse_ipv6(data, nh_off, data_end);
else
index = 0;
value = dropcnt.lookup(&index);
if (value)
*value += 1;
return rc;
}
""", cflags=["-w", "-DRETURNCODE=%s" % ret, "-DCTXTYPE=%s" % ctxtype])
fn = b.load_func("xdp_prog1", mode)
if mode == BPF.XDP:
b.attach_xdp(device, fn)
else:
ip = pyroute2.IPRoute()
ipdb = pyroute2.IPDB(nl=ip)
idx = ipdb.interfaces[device].index
ip.tc("add", "clsact", idx)
ip.tc("add-filter", "bpf", idx, ":1", fd=fn.fd, name=fn.name,
parent="ffff:fff2", classid=1, direct_action=True)
dropcnt = b.get_table("dropcnt")
prev = [0] * 256
print("Printing drops per IP protocol-number, hit CTRL+C to stop")
while 1:
try:
for k in dropcnt.keys():
val = dropcnt.sum(k).value
i = k.value
if val:
delta = val - prev[i]
prev[i] = val
print("{}: {} pkt/s".format(i, delta))
time.sleep(1)
except KeyboardInterrupt:
print("Removing filter from device")
break;
if mode == BPF.XDP:
b.remove_xdp(device)
else:
ip.tc("del", "clsact", idx)
ipdb.release()
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