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linux/samples/bpf/parse_varlen.c

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samples/bpf: add 'pointer to packet' tests parse_simple.c - packet parser exapmle with single length check that filters out udp packets for port 9 parse_varlen.c - variable length parser that understand multiple vlan headers, ipip, ipip6 and ip options to filter out udp or tcp packets on port 9. The packet is parsed layer by layer with multitple length checks. parse_ldabs.c - classic style of packet parsing using LD_ABS instruction. Same functionality as parse_simple. simple = 24.1Mpps per core varlen = 22.7Mpps ldabs = 21.4Mpps Parser with LD_ABS instructions is slower than full direct access parser which does more packet accesses and checks. These examples demonstrate the choice bpf program authors can make between flexibility of the parser vs speed. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-06 10:49:14 +08:00
/* Copyright (c) 2016 Facebook
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*/
bpf: fix samples to add fake KBUILD_MODNAME Some of the sample files are causing issues when they are loaded with tc and cls_bpf, meaning tc bails out while trying to parse the resulting ELF file as program/map/etc sections are not present, which can be easily spotted with readelf(1). Currently, BPF samples are including some of the kernel headers and mid term we should change them to refrain from this, really. When dynamic debugging is enabled, we bail out due to undeclared KBUILD_MODNAME, which is easily overlooked in the build as clang spills this along with other noisy warnings from various header includes, and llc still generates an ELF file with mentioned characteristics. For just playing around with BPF examples, this can be a bit of a hurdle to take. Just add a fake KBUILD_MODNAME as a band-aid to fix the issue, same is done in xdp*_kern samples already. Fixes: 65d472fb007d ("samples/bpf: add 'pointer to packet' tests") Fixes: 6afb1e28b859 ("samples/bpf: Add tunnel set/get tests.") Fixes: a3f74617340b ("cgroup: bpf: Add an example to do cgroup checking in BPF") Reported-by: Chandrasekar Kannan <ckannan@console.to> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-26 06:37:53 +08:00
#define KBUILD_MODNAME "foo"
samples/bpf: add 'pointer to packet' tests parse_simple.c - packet parser exapmle with single length check that filters out udp packets for port 9 parse_varlen.c - variable length parser that understand multiple vlan headers, ipip, ipip6 and ip options to filter out udp or tcp packets on port 9. The packet is parsed layer by layer with multitple length checks. parse_ldabs.c - classic style of packet parsing using LD_ABS instruction. Same functionality as parse_simple. simple = 24.1Mpps per core varlen = 22.7Mpps ldabs = 21.4Mpps Parser with LD_ABS instructions is slower than full direct access parser which does more packet accesses and checks. These examples demonstrate the choice bpf program authors can make between flexibility of the parser vs speed. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-06 10:49:14 +08:00
#include <linux/if_ether.h>
samples/bpf: add missing <linux/if_vlan.h> This fixes build error regarding redefinition: CLANG-bpf samples/bpf/parse_varlen.o samples/bpf/parse_varlen.c:111:8: error: redefinition of 'vlan_hdr' struct vlan_hdr { ^ ./include/linux/if_vlan.h:38:8: note: previous definition is here So remove duplicate 'struct vlan_hdr' in sample code and include if_vlan.h Signed-off-by: Taeung Song <treeze.taeung@gmail.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-04 21:36:36 +08:00
#include <linux/if_vlan.h>
samples/bpf: add 'pointer to packet' tests parse_simple.c - packet parser exapmle with single length check that filters out udp packets for port 9 parse_varlen.c - variable length parser that understand multiple vlan headers, ipip, ipip6 and ip options to filter out udp or tcp packets on port 9. The packet is parsed layer by layer with multitple length checks. parse_ldabs.c - classic style of packet parsing using LD_ABS instruction. Same functionality as parse_simple. simple = 24.1Mpps per core varlen = 22.7Mpps ldabs = 21.4Mpps Parser with LD_ABS instructions is slower than full direct access parser which does more packet accesses and checks. These examples demonstrate the choice bpf program authors can make between flexibility of the parser vs speed. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-06 10:49:14 +08:00
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/in.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <uapi/linux/bpf.h>
#include <net/ip.h>
samples/bpf: Use consistent include paths for libbpf Fix all files in samples/bpf to include libbpf header files with the bpf/ prefix, to be consistent with external users of the library. Also ensure that all includes of exported libbpf header files (those that are exported on 'make install' of the library) use bracketed includes instead of quoted. To make sure no new files are introduced that doesn't include the bpf/ prefix in its include, remove tools/lib/bpf from the include path entirely, and use tools/lib instead. Fixes: 6910d7d3867a ("selftests/bpf: Ensure bpf_helper_defs.h are taken from selftests dir") Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/157952560911.1683545.8795966751309534150.stgit@toke.dk
2020-01-20 21:06:49 +08:00
#include <bpf/bpf_helpers.h>
samples/bpf: add 'pointer to packet' tests parse_simple.c - packet parser exapmle with single length check that filters out udp packets for port 9 parse_varlen.c - variable length parser that understand multiple vlan headers, ipip, ipip6 and ip options to filter out udp or tcp packets on port 9. The packet is parsed layer by layer with multitple length checks. parse_ldabs.c - classic style of packet parsing using LD_ABS instruction. Same functionality as parse_simple. simple = 24.1Mpps per core varlen = 22.7Mpps ldabs = 21.4Mpps Parser with LD_ABS instructions is slower than full direct access parser which does more packet accesses and checks. These examples demonstrate the choice bpf program authors can make between flexibility of the parser vs speed. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-06 10:49:14 +08:00
#define DEFAULT_PKTGEN_UDP_PORT 9
#define DEBUG 0
static int tcp(void *data, uint64_t tp_off, void *data_end)
{
struct tcphdr *tcp = data + tp_off;
if (tcp + 1 > data_end)
return 0;
if (tcp->dest == htons(80) || tcp->source == htons(80))
return TC_ACT_SHOT;
return 0;
}
static int udp(void *data, uint64_t tp_off, void *data_end)
{
struct udphdr *udp = data + tp_off;
if (udp + 1 > data_end)
return 0;
if (udp->dest == htons(DEFAULT_PKTGEN_UDP_PORT) ||
udp->source == htons(DEFAULT_PKTGEN_UDP_PORT)) {
if (DEBUG) {
char fmt[] = "udp port 9 indeed\n";
bpf_trace_printk(fmt, sizeof(fmt));
}
return TC_ACT_SHOT;
}
return 0;
}
static int parse_ipv4(void *data, uint64_t nh_off, void *data_end)
{
struct iphdr *iph;
uint64_t ihl_len;
iph = data + nh_off;
if (iph + 1 > data_end)
return 0;
if (ip_is_fragment(iph))
return 0;
ihl_len = iph->ihl * 4;
if (iph->protocol == IPPROTO_IPIP) {
iph = data + nh_off + ihl_len;
if (iph + 1 > data_end)
return 0;
ihl_len += iph->ihl * 4;
}
if (iph->protocol == IPPROTO_TCP)
return tcp(data, nh_off + ihl_len, data_end);
else if (iph->protocol == IPPROTO_UDP)
return udp(data, nh_off + ihl_len, data_end);
return 0;
}
static int parse_ipv6(void *data, uint64_t nh_off, void *data_end)
{
struct ipv6hdr *ip6h;
struct iphdr *iph;
uint64_t ihl_len = sizeof(struct ipv6hdr);
uint64_t nexthdr;
ip6h = data + nh_off;
if (ip6h + 1 > data_end)
return 0;
nexthdr = ip6h->nexthdr;
if (nexthdr == IPPROTO_IPIP) {
iph = data + nh_off + ihl_len;
if (iph + 1 > data_end)
return 0;
ihl_len += iph->ihl * 4;
nexthdr = iph->protocol;
} else if (nexthdr == IPPROTO_IPV6) {
ip6h = data + nh_off + ihl_len;
if (ip6h + 1 > data_end)
return 0;
ihl_len += sizeof(struct ipv6hdr);
nexthdr = ip6h->nexthdr;
}
if (nexthdr == IPPROTO_TCP)
return tcp(data, nh_off + ihl_len, data_end);
else if (nexthdr == IPPROTO_UDP)
return udp(data, nh_off + ihl_len, data_end);
return 0;
}
SEC("varlen")
int handle_ingress(struct __sk_buff *skb)
{
void *data = (void *)(long)skb->data;
struct ethhdr *eth = data;
void *data_end = (void *)(long)skb->data_end;
uint64_t h_proto, nh_off;
nh_off = sizeof(*eth);
if (data + nh_off > data_end)
return 0;
h_proto = eth->h_proto;
if (h_proto == ETH_P_8021Q || h_proto == ETH_P_8021AD) {
struct vlan_hdr *vhdr;
vhdr = data + nh_off;
nh_off += sizeof(struct vlan_hdr);
if (data + nh_off > data_end)
return 0;
h_proto = vhdr->h_vlan_encapsulated_proto;
}
if (h_proto == ETH_P_8021Q || h_proto == ETH_P_8021AD) {
struct vlan_hdr *vhdr;
vhdr = data + nh_off;
nh_off += sizeof(struct vlan_hdr);
if (data + nh_off > data_end)
return 0;
h_proto = vhdr->h_vlan_encapsulated_proto;
}
if (h_proto == htons(ETH_P_IP))
return parse_ipv4(data, nh_off, data_end);
else if (h_proto == htons(ETH_P_IPV6))
return parse_ipv6(data, nh_off, data_end);
return 0;
}
char _license[] SEC("license") = "GPL";
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