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author | John Fastabend <john.fastabend@gmail.com> | 2017-08-16 08:33:32 +0300 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2017-08-16 21:27:53 +0300 |
commit | 69e8cc134bcbf0ccfcf852c400b8e6788d1d0038 (patch) | |
tree | 181f7fc9d1a8204f93aa705e2725e7c5b766610c /samples/sockmap/sockmap_kern.c | |
parent | 8a31db5615667956c513d205cfb06885c3ec6d0b (diff) | |
download | linux-69e8cc134bcbf0ccfcf852c400b8e6788d1d0038.tar.xz |
bpf: sockmap sample program
This program binds a program to a cgroup and then matches hard
coded IP addresses and adds these to a sockmap.
This will receive messages from the backend and send them to
the client.
client:X <---> frontend:10000 client:X <---> backend:10001
To keep things simple this is only designed for 1:1 connections
using hard coded values. A more complete example would allow many
backends and clients.
To run,
# sockmap <cgroup2_dir>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'samples/sockmap/sockmap_kern.c')
-rw-r--r-- | samples/sockmap/sockmap_kern.c | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/samples/sockmap/sockmap_kern.c b/samples/sockmap/sockmap_kern.c new file mode 100644 index 000000000000..6ff986f7059b --- /dev/null +++ b/samples/sockmap/sockmap_kern.c @@ -0,0 +1,110 @@ +/* Copyright (c) 2017 Covalent IO, Inc. http://covalent.io + * + * 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. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + */ +#include <uapi/linux/bpf.h> +#include <uapi/linux/if_ether.h> +#include <uapi/linux/if_packet.h> +#include <uapi/linux/ip.h> +#include "../../tools/testing/selftests/bpf/bpf_helpers.h" +#include "../../tools/testing/selftests/bpf/bpf_endian.h" + +/* Sockmap sample program connects a client and a backend together + * using cgroups. + * + * client:X <---> frontend:80 client:X <---> backend:80 + * + * For simplicity we hard code values here and bind 1:1. The hard + * coded values are part of the setup in sockmap.sh script that + * is associated with this BPF program. + * + * The bpf_printk is verbose and prints information as connections + * are established and verdicts are decided. + */ + +#define bpf_printk(fmt, ...) \ +({ \ + char ____fmt[] = fmt; \ + bpf_trace_printk(____fmt, sizeof(____fmt), \ + ##__VA_ARGS__); \ +}) + +struct bpf_map_def SEC("maps") sock_map = { + .type = BPF_MAP_TYPE_SOCKMAP, + .key_size = sizeof(int), + .value_size = sizeof(int), + .max_entries = 20, +}; + +SEC("sk_skb1") +int bpf_prog1(struct __sk_buff *skb) +{ + return skb->len; +} + +SEC("sk_skb2") +int bpf_prog2(struct __sk_buff *skb) +{ + __u32 lport = skb->local_port; + __u32 rport = skb->remote_port; + int ret = 0; + + if (lport == 10000) + ret = 10; + else + ret = 1; + + bpf_printk("sockmap: %d -> %d @ %d\n", lport, bpf_ntohl(rport), ret); + return bpf_sk_redirect_map(&sock_map, ret, 0); +} + +SEC("sockops") +int bpf_sockmap(struct bpf_sock_ops *skops) +{ + __u32 lport, rport; + int op, err = 0, index, key, ret; + + + op = (int) skops->op; + + switch (op) { + case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB: + lport = skops->local_port; + rport = skops->remote_port; + + if (lport == 10000) { + ret = 1; + err = bpf_sock_map_update(skops, &sock_map, &ret, + BPF_NOEXIST, + BPF_SOCKMAP_STRPARSER); + bpf_printk("passive(%i -> %i) map ctx update err: %d\n", + lport, bpf_ntohl(rport), err); + } + break; + case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB: + lport = skops->local_port; + rport = skops->remote_port; + + if (bpf_ntohl(rport) == 10001) { + ret = 10; + err = bpf_sock_map_update(skops, &sock_map, &ret, + BPF_NOEXIST, + BPF_SOCKMAP_STRPARSER); + bpf_printk("active(%i -> %i) map ctx update err: %d\n", + lport, bpf_ntohl(rport), err); + } + break; + default: + break; + } + + return 0; +} +char _license[] SEC("license") = "GPL"; |