1 // SPDX-License-Identifier: GPL-2.0 2 // Copyright (c) 2024 Meta 3 4 #include "vmlinux.h" 5 #include <bpf/bpf_helpers.h> 6 #include <bpf/bpf_core_read.h> 7 #include <bpf/bpf_endian.h> 8 #include "bpf_tracing_net.h" 9 #include "bpf_kfuncs.h" 10 11 #define ATTR __always_inline 12 #include "test_jhash.h" 13 14 static bool ipv6_addr_loopback(const struct in6_addr *a) 15 { 16 return (a->s6_addr32[0] | a->s6_addr32[1] | 17 a->s6_addr32[2] | (a->s6_addr32[3] ^ bpf_htonl(1))) == 0; 18 } 19 20 volatile const __u16 ports[2]; 21 unsigned int bucket[2]; 22 23 SEC("iter/tcp") 24 int iter_tcp_soreuse(struct bpf_iter__tcp *ctx) 25 { 26 struct sock *sk = (struct sock *)ctx->sk_common; 27 struct inet_hashinfo *hinfo; 28 unsigned int hash; 29 struct net *net; 30 int idx; 31 32 if (!sk) 33 return 0; 34 35 sk = bpf_rdonly_cast(sk, bpf_core_type_id_kernel(struct sock)); 36 if (sk->sk_family != AF_INET6 || 37 sk->sk_state != TCP_LISTEN || 38 !ipv6_addr_loopback(&sk->sk_v6_rcv_saddr)) 39 return 0; 40 41 if (sk->sk_num == ports[0]) 42 idx = 0; 43 else if (sk->sk_num == ports[1]) 44 idx = 1; 45 else 46 return 0; 47 48 /* bucket selection as in inet_lhash2_bucket_sk() */ 49 net = sk->sk_net.net; 50 hash = jhash2(sk->sk_v6_rcv_saddr.s6_addr32, 4, net->hash_mix); 51 hash ^= sk->sk_num; 52 hinfo = net->ipv4.tcp_death_row.hashinfo; 53 bucket[idx] = hash & hinfo->lhash2_mask; 54 bpf_seq_write(ctx->meta->seq, &idx, sizeof(idx)); 55 56 return 0; 57 } 58 59 #define udp_sk(ptr) container_of(ptr, struct udp_sock, inet.sk) 60 61 SEC("iter/udp") 62 int iter_udp_soreuse(struct bpf_iter__udp *ctx) 63 { 64 struct sock *sk = (struct sock *)ctx->udp_sk; 65 struct udp_table *udptable; 66 int idx; 67 68 if (!sk) 69 return 0; 70 71 sk = bpf_rdonly_cast(sk, bpf_core_type_id_kernel(struct sock)); 72 if (sk->sk_family != AF_INET6 || 73 !ipv6_addr_loopback(&sk->sk_v6_rcv_saddr)) 74 return 0; 75 76 if (sk->sk_num == ports[0]) 77 idx = 0; 78 else if (sk->sk_num == ports[1]) 79 idx = 1; 80 else 81 return 0; 82 83 /* bucket selection as in udp_hashslot2() */ 84 udptable = sk->sk_net.net->ipv4.udp_table; 85 bucket[idx] = udp_sk(sk)->udp_portaddr_hash & udptable->mask; 86 bpf_seq_write(ctx->meta->seq, &idx, sizeof(idx)); 87 88 return 0; 89 } 90 91 char _license[] SEC("license") = "GPL"; 92