^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) /* Copyright (c) 2016 Thomas Graf <tgraf@tgraf.ch>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * This program is free software; you can redistribute it and/or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) * modify it under the terms of version 2 of the GNU General Public
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * License as published by the Free Software Foundation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * This program is distributed in the hope that it will be useful, but
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) * WITHOUT ANY WARRANTY; without even the implied warranty of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) * General Public License for more details.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <stdint.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <stddef.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/bpf.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <linux/ip.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <linux/in.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include <linux/in6.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include <linux/tcp.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #include <linux/udp.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) #include <linux/icmpv6.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) #include <linux/if_ether.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) #include <bpf/bpf_helpers.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) #include <string.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) # define printk(fmt, ...) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) ({ \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) char ____fmt[] = fmt; \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) bpf_trace_printk(____fmt, sizeof(____fmt), \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) ##__VA_ARGS__); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) })
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) #define CB_MAGIC 1234
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) /* Test: Pass all packets through */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) SEC("nop")
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) int do_nop(struct __sk_buff *skb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) return BPF_OK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) /* Test: Verify context information can be accessed */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) SEC("test_ctx")
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) int do_test_ctx(struct __sk_buff *skb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) skb->cb[0] = CB_MAGIC;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) printk("len %d hash %d protocol %d\n", skb->len, skb->hash,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) skb->protocol);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) printk("cb %d ingress_ifindex %d ifindex %d\n", skb->cb[0],
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) skb->ingress_ifindex, skb->ifindex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) return BPF_OK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) /* Test: Ensure skb->cb[] buffer is cleared */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) SEC("test_cb")
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) int do_test_cb(struct __sk_buff *skb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) printk("cb0: %x cb1: %x cb2: %x\n", skb->cb[0], skb->cb[1],
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) skb->cb[2]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) printk("cb3: %x cb4: %x\n", skb->cb[3], skb->cb[4]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) return BPF_OK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) /* Test: Verify skb data can be read */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) SEC("test_data")
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) int do_test_data(struct __sk_buff *skb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) void *data = (void *)(long)skb->data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) void *data_end = (void *)(long)skb->data_end;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) struct iphdr *iph = data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) if (data + sizeof(*iph) > data_end) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) printk("packet truncated\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) return BPF_DROP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) printk("src: %x dst: %x\n", iph->saddr, iph->daddr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) return BPF_OK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) #define IP_CSUM_OFF offsetof(struct iphdr, check)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) #define IP_DST_OFF offsetof(struct iphdr, daddr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) #define IP_SRC_OFF offsetof(struct iphdr, saddr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) #define IP_PROTO_OFF offsetof(struct iphdr, protocol)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) #define TCP_CSUM_OFF offsetof(struct tcphdr, check)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) #define UDP_CSUM_OFF offsetof(struct udphdr, check)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) #define IS_PSEUDO 0x10
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) static inline int rewrite(struct __sk_buff *skb, uint32_t old_ip,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) uint32_t new_ip, int rw_daddr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) int ret, off = 0, flags = IS_PSEUDO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) uint8_t proto;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) ret = bpf_skb_load_bytes(skb, IP_PROTO_OFF, &proto, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) if (ret < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) printk("bpf_l4_csum_replace failed: %d\n", ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) return BPF_DROP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) switch (proto) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) case IPPROTO_TCP:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) off = TCP_CSUM_OFF;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) case IPPROTO_UDP:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) off = UDP_CSUM_OFF;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) flags |= BPF_F_MARK_MANGLED_0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) case IPPROTO_ICMPV6:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) off = offsetof(struct icmp6hdr, icmp6_cksum);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) if (off) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) ret = bpf_l4_csum_replace(skb, off, old_ip, new_ip,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) flags | sizeof(new_ip));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) if (ret < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) printk("bpf_l4_csum_replace failed: %d\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) return BPF_DROP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) ret = bpf_l3_csum_replace(skb, IP_CSUM_OFF, old_ip, new_ip, sizeof(new_ip));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) if (ret < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) printk("bpf_l3_csum_replace failed: %d\n", ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) return BPF_DROP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) if (rw_daddr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) ret = bpf_skb_store_bytes(skb, IP_DST_OFF, &new_ip, sizeof(new_ip), 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) ret = bpf_skb_store_bytes(skb, IP_SRC_OFF, &new_ip, sizeof(new_ip), 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) if (ret < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) printk("bpf_skb_store_bytes() failed: %d\n", ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) return BPF_DROP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) return BPF_OK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) /* Test: Verify skb data can be modified */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) SEC("test_rewrite")
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) int do_test_rewrite(struct __sk_buff *skb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) uint32_t old_ip, new_ip = 0x3fea8c0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) ret = bpf_skb_load_bytes(skb, IP_DST_OFF, &old_ip, 4);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) if (ret < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) printk("bpf_skb_load_bytes failed: %d\n", ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) return BPF_DROP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) if (old_ip == 0x2fea8c0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) printk("out: rewriting from %x to %x\n", old_ip, new_ip);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) return rewrite(skb, old_ip, new_ip, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) return BPF_OK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) static inline int __do_push_ll_and_redirect(struct __sk_buff *skb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) uint64_t smac = SRC_MAC, dmac = DST_MAC;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) int ret, ifindex = DST_IFINDEX;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) struct ethhdr ehdr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) ret = bpf_skb_change_head(skb, 14, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) if (ret < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) printk("skb_change_head() failed: %d\n", ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) ehdr.h_proto = __constant_htons(ETH_P_IP);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) memcpy(&ehdr.h_source, &smac, 6);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) memcpy(&ehdr.h_dest, &dmac, 6);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) ret = bpf_skb_store_bytes(skb, 0, &ehdr, sizeof(ehdr), 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) if (ret < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) printk("skb_store_bytes() failed: %d\n", ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) return BPF_DROP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) return bpf_redirect(ifindex, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) SEC("push_ll_and_redirect_silent")
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) int do_push_ll_and_redirect_silent(struct __sk_buff *skb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) return __do_push_ll_and_redirect(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) SEC("push_ll_and_redirect")
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) int do_push_ll_and_redirect(struct __sk_buff *skb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) int ret, ifindex = DST_IFINDEX;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) ret = __do_push_ll_and_redirect(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) if (ret >= 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) printk("redirected to %d\n", ifindex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) static inline void __fill_garbage(struct __sk_buff *skb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) uint64_t f = 0xFFFFFFFFFFFFFFFF;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) bpf_skb_store_bytes(skb, 0, &f, sizeof(f), 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) bpf_skb_store_bytes(skb, 8, &f, sizeof(f), 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) bpf_skb_store_bytes(skb, 16, &f, sizeof(f), 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) bpf_skb_store_bytes(skb, 24, &f, sizeof(f), 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) bpf_skb_store_bytes(skb, 32, &f, sizeof(f), 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) bpf_skb_store_bytes(skb, 40, &f, sizeof(f), 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) bpf_skb_store_bytes(skb, 48, &f, sizeof(f), 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) bpf_skb_store_bytes(skb, 56, &f, sizeof(f), 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) bpf_skb_store_bytes(skb, 64, &f, sizeof(f), 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) bpf_skb_store_bytes(skb, 72, &f, sizeof(f), 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) bpf_skb_store_bytes(skb, 80, &f, sizeof(f), 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) bpf_skb_store_bytes(skb, 88, &f, sizeof(f), 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) SEC("fill_garbage")
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) int do_fill_garbage(struct __sk_buff *skb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) __fill_garbage(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) printk("Set initial 96 bytes of header to FF\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) return BPF_OK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) SEC("fill_garbage_and_redirect")
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) int do_fill_garbage_and_redirect(struct __sk_buff *skb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) int ifindex = DST_IFINDEX;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) __fill_garbage(skb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) printk("redirected to %d\n", ifindex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) return bpf_redirect(ifindex, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) /* Drop all packets */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) SEC("drop_all")
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) int do_drop_all(struct __sk_buff *skb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) printk("dropping with: %d\n", BPF_DROP);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) return BPF_DROP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) char _license[] SEC("license") = "GPL";
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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