projects / thirdparty / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| acb4ea95 NS |
1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | /* | |
| 3 | * Copyright (c) 2018 Facebook | |
| 4 | * | |
| 5 | * BPF program to automatically reflect TOS option from received syn packet | |
| 6 | * | |
| ea9b6362 | 7 | * Use "bpftool cgroup attach $cg sock_ops $prog" to load this BPF program. |
| acb4ea95 NS |
8 | */ |
| 9 | ||
| 10 | #include <uapi/linux/bpf.h> | |
| 11 | #include <uapi/linux/tcp.h> | |
| 12 | #include <uapi/linux/if_ether.h> | |
| 13 | #include <uapi/linux/if_packet.h> | |
| 14 | #include <uapi/linux/ip.h> | |
| 15 | #include <uapi/linux/ipv6.h> | |
| 16 | #include <uapi/linux/in.h> | |
| 17 | #include <linux/socket.h> | |
| 7cf245a3 THJ |
18 | #include <bpf/bpf_helpers.h> |
| 19 | #include <bpf/bpf_endian.h> | |
| acb4ea95 NS |
20 | |
| 21 | #define DEBUG 1 | |
| 22 | ||
| acb4ea95 NS |
23 | SEC("sockops") |
| 24 | int bpf_basertt(struct bpf_sock_ops *skops) | |
| 25 | { | |
| 26 | char header[sizeof(struct ipv6hdr)]; | |
| 27 | struct ipv6hdr *hdr6; | |
| 28 | struct iphdr *hdr; | |
| 29 | int hdr_size = 0; | |
| 30 | int save_syn = 1; | |
| 31 | int tos = 0; | |
| 32 | int rv = 0; | |
| 33 | int op; | |
| 34 | ||
| 35 | op = (int) skops->op; | |
| 36 | ||
| 37 | #ifdef DEBUG | |
| 38 | bpf_printk("BPF command: %d\n", op); | |
| 39 | #endif | |
| 40 | switch (op) { | |
| 41 | case BPF_SOCK_OPS_TCP_LISTEN_CB: | |
| 42 | rv = bpf_setsockopt(skops, SOL_TCP, TCP_SAVE_SYN, | |
| 43 | &save_syn, sizeof(save_syn)); | |
| 44 | break; | |
| 45 | case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB: | |
| 46 | if (skops->family == AF_INET) | |
| 47 | hdr_size = sizeof(struct iphdr); | |
| 48 | else | |
| 49 | hdr_size = sizeof(struct ipv6hdr); | |
| 50 | rv = bpf_getsockopt(skops, SOL_TCP, TCP_SAVED_SYN, | |
| 51 | header, hdr_size); | |
| 52 | if (!rv) { | |
| 53 | if (skops->family == AF_INET) { | |
| 54 | hdr = (struct iphdr *) header; | |
| 55 | tos = hdr->tos; | |
| 56 | if (tos != 0) | |
| 57 | bpf_setsockopt(skops, SOL_IP, IP_TOS, | |
| 58 | &tos, sizeof(tos)); | |
| 59 | } else { | |
| 60 | hdr6 = (struct ipv6hdr *) header; | |
| 61 | tos = ((hdr6->priority) << 4 | | |
| 62 | (hdr6->flow_lbl[0]) >> 4); | |
| 63 | if (tos) | |
| 64 | bpf_setsockopt(skops, SOL_IPV6, | |
| 65 | IPV6_TCLASS, | |
| 66 | &tos, sizeof(tos)); | |
| 67 | } | |
| 68 | rv = 0; | |
| 69 | } | |
| 70 | break; | |
| 71 | default: | |
| 72 | rv = -1; | |
| 73 | } | |
| 74 | #ifdef DEBUG | |
| 75 | bpf_printk("Returning %d\n", rv); | |
| 76 | #endif | |
| 77 | skops->reply = rv; | |
| 78 | return 1; | |
| 79 | } | |
| 80 | char _license[] SEC("license") = "GPL"; |