129 lines
2.9 KiB
C
129 lines
2.9 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/* Copyright (c) 2020, Tessares SA. */
|
|
/* Copyright (c) 2024, Kylin Software */
|
|
|
|
/* vmlinux.h, bpf_helpers.h and other 'define' */
|
|
#include "bpf_tracing_net.h"
|
|
#include "mptcp_bpf.h"
|
|
|
|
char _license[] SEC("license") = "GPL";
|
|
|
|
char cc[TCP_CA_NAME_MAX] = "reno";
|
|
int pid;
|
|
|
|
/* Associate a subflow counter to each token */
|
|
struct {
|
|
__uint(type, BPF_MAP_TYPE_HASH);
|
|
__uint(key_size, sizeof(__u32));
|
|
__uint(value_size, sizeof(__u32));
|
|
__uint(max_entries, 100);
|
|
} mptcp_sf SEC(".maps");
|
|
|
|
SEC("sockops")
|
|
int mptcp_subflow(struct bpf_sock_ops *skops)
|
|
{
|
|
__u32 init = 1, key, mark, *cnt;
|
|
struct mptcp_sock *msk;
|
|
struct bpf_sock *sk;
|
|
int err;
|
|
|
|
if (skops->op != BPF_SOCK_OPS_TCP_CONNECT_CB)
|
|
return 1;
|
|
|
|
sk = skops->sk;
|
|
if (!sk)
|
|
return 1;
|
|
|
|
msk = bpf_skc_to_mptcp_sock(sk);
|
|
if (!msk)
|
|
return 1;
|
|
|
|
key = msk->token;
|
|
cnt = bpf_map_lookup_elem(&mptcp_sf, &key);
|
|
if (cnt) {
|
|
/* A new subflow is added to an existing MPTCP connection */
|
|
__sync_fetch_and_add(cnt, 1);
|
|
mark = *cnt;
|
|
} else {
|
|
/* A new MPTCP connection is just initiated and this is its primary subflow */
|
|
bpf_map_update_elem(&mptcp_sf, &key, &init, BPF_ANY);
|
|
mark = init;
|
|
}
|
|
|
|
/* Set the mark of the subflow's socket based on appearance order */
|
|
err = bpf_setsockopt(skops, SOL_SOCKET, SO_MARK, &mark, sizeof(mark));
|
|
if (err < 0)
|
|
return 1;
|
|
if (mark == 2)
|
|
err = bpf_setsockopt(skops, SOL_TCP, TCP_CONGESTION, cc, TCP_CA_NAME_MAX);
|
|
|
|
return 1;
|
|
}
|
|
|
|
static int _check_getsockopt_subflow_mark(struct mptcp_sock *msk, struct bpf_sockopt *ctx)
|
|
{
|
|
struct mptcp_subflow_context *subflow;
|
|
int i = 0;
|
|
|
|
mptcp_for_each_subflow(msk, subflow) {
|
|
struct sock *ssk;
|
|
|
|
ssk = mptcp_subflow_tcp_sock(bpf_core_cast(subflow,
|
|
struct mptcp_subflow_context));
|
|
|
|
if (ssk->sk_mark != ++i) {
|
|
ctx->retval = -2;
|
|
break;
|
|
}
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
static int _check_getsockopt_subflow_cc(struct mptcp_sock *msk, struct bpf_sockopt *ctx)
|
|
{
|
|
struct mptcp_subflow_context *subflow;
|
|
|
|
mptcp_for_each_subflow(msk, subflow) {
|
|
struct inet_connection_sock *icsk;
|
|
struct sock *ssk;
|
|
|
|
ssk = mptcp_subflow_tcp_sock(bpf_core_cast(subflow,
|
|
struct mptcp_subflow_context));
|
|
icsk = bpf_core_cast(ssk, struct inet_connection_sock);
|
|
|
|
if (ssk->sk_mark == 2 &&
|
|
__builtin_memcmp(icsk->icsk_ca_ops->name, cc, TCP_CA_NAME_MAX)) {
|
|
ctx->retval = -2;
|
|
break;
|
|
}
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
SEC("cgroup/getsockopt")
|
|
int _getsockopt_subflow(struct bpf_sockopt *ctx)
|
|
{
|
|
struct bpf_sock *sk = ctx->sk;
|
|
struct mptcp_sock *msk;
|
|
|
|
if (bpf_get_current_pid_tgid() >> 32 != pid)
|
|
return 1;
|
|
|
|
if (!sk || sk->protocol != IPPROTO_MPTCP ||
|
|
(!(ctx->level == SOL_SOCKET && ctx->optname == SO_MARK) &&
|
|
!(ctx->level == SOL_TCP && ctx->optname == TCP_CONGESTION)))
|
|
return 1;
|
|
|
|
msk = bpf_core_cast(sk, struct mptcp_sock);
|
|
if (msk->pm.subflows != 1) {
|
|
ctx->retval = -1;
|
|
return 1;
|
|
}
|
|
|
|
if (ctx->optname == SO_MARK)
|
|
return _check_getsockopt_subflow_mark(msk, ctx);
|
|
return _check_getsockopt_subflow_cc(msk, ctx);
|
|
}
|