1 /* SPDX-License-Identifier: GPL-2.0 */
2 // Copyright (c) 2018 Covalent IO, Inc. http://covalent.io
8 #include <linux/if_ether.h>
11 #include <linux/ipv6.h>
12 #include <linux/pkt_cls.h>
13 #include <linux/tcp.h>
14 #include <sys/socket.h>
15 #include "bpf_helpers.h"
16 #include "bpf_endian.h"
18 int _version SEC("version") = 1;
19 char _license[] SEC("license") = "GPL";
21 /* Fill 'tuple' with L3 info, and attempt to find L4. On fail, return NULL. */
22 static struct bpf_sock_tuple *get_tuple(void *data, __u64 nh_off,
23 void *data_end, __u16 eth_proto,
26 struct bpf_sock_tuple *result;
30 if (eth_proto == bpf_htons(ETH_P_IP)) {
31 struct iphdr *iph = (struct iphdr *)(data + nh_off);
33 if (iph + 1 > data_end)
35 ihl_len = iph->ihl * 4;
36 proto = iph->protocol;
38 result = (struct bpf_sock_tuple *)&iph->saddr;
39 } else if (eth_proto == bpf_htons(ETH_P_IPV6)) {
40 struct ipv6hdr *ip6h = (struct ipv6hdr *)(data + nh_off);
42 if (ip6h + 1 > data_end)
44 ihl_len = sizeof(*ip6h);
45 proto = ip6h->nexthdr;
47 result = (struct bpf_sock_tuple *)&ip6h->saddr;
50 if (data + nh_off + ihl_len > data_end || proto != IPPROTO_TCP)
56 SEC("sk_lookup_success")
57 int bpf_sk_lookup_test0(struct __sk_buff *skb)
59 void *data_end = (void *)(long)skb->data_end;
60 void *data = (void *)(long)skb->data;
61 struct ethhdr *eth = (struct ethhdr *)(data);
62 struct bpf_sock_tuple *tuple;
67 if (eth + 1 > data_end)
70 tuple = get_tuple(data, sizeof(*eth), data_end, eth->h_proto, &ipv4);
71 if (!tuple || tuple + sizeof *tuple > data_end)
74 tuple_len = ipv4 ? sizeof(tuple->ipv4) : sizeof(tuple->ipv6);
75 sk = bpf_sk_lookup_tcp(skb, tuple, tuple_len, BPF_F_CURRENT_NETNS, 0);
78 return sk ? TC_ACT_OK : TC_ACT_UNSPEC;
81 SEC("sk_lookup_success_simple")
82 int bpf_sk_lookup_test1(struct __sk_buff *skb)
84 struct bpf_sock_tuple tuple = {};
87 sk = bpf_sk_lookup_tcp(skb, &tuple, sizeof(tuple), BPF_F_CURRENT_NETNS, 0);
93 SEC("fail_use_after_free")
94 int bpf_sk_lookup_uaf(struct __sk_buff *skb)
96 struct bpf_sock_tuple tuple = {};
100 sk = bpf_sk_lookup_tcp(skb, &tuple, sizeof(tuple), BPF_F_CURRENT_NETNS, 0);
108 SEC("fail_modify_sk_pointer")
109 int bpf_sk_lookup_modptr(struct __sk_buff *skb)
111 struct bpf_sock_tuple tuple = {};
115 sk = bpf_sk_lookup_tcp(skb, &tuple, sizeof(tuple), BPF_F_CURRENT_NETNS, 0);
123 SEC("fail_modify_sk_or_null_pointer")
124 int bpf_sk_lookup_modptr_or_null(struct __sk_buff *skb)
126 struct bpf_sock_tuple tuple = {};
130 sk = bpf_sk_lookup_tcp(skb, &tuple, sizeof(tuple), BPF_F_CURRENT_NETNS, 0);
137 SEC("fail_no_release")
138 int bpf_sk_lookup_test2(struct __sk_buff *skb)
140 struct bpf_sock_tuple tuple = {};
142 bpf_sk_lookup_tcp(skb, &tuple, sizeof(tuple), BPF_F_CURRENT_NETNS, 0);
146 SEC("fail_release_twice")
147 int bpf_sk_lookup_test3(struct __sk_buff *skb)
149 struct bpf_sock_tuple tuple = {};
152 sk = bpf_sk_lookup_tcp(skb, &tuple, sizeof(tuple), BPF_F_CURRENT_NETNS, 0);
158 SEC("fail_release_unchecked")
159 int bpf_sk_lookup_test4(struct __sk_buff *skb)
161 struct bpf_sock_tuple tuple = {};
164 sk = bpf_sk_lookup_tcp(skb, &tuple, sizeof(tuple), BPF_F_CURRENT_NETNS, 0);
169 void lookup_no_release(struct __sk_buff *skb)
171 struct bpf_sock_tuple tuple = {};
172 bpf_sk_lookup_tcp(skb, &tuple, sizeof(tuple), BPF_F_CURRENT_NETNS, 0);
175 SEC("fail_no_release_subcall")
176 int bpf_sk_lookup_test5(struct __sk_buff *skb)
178 lookup_no_release(skb);