net: bpf: Implement bpf iterator for tcp (52d87d5f) · Commits · 戴 / test

net/ipv4/tcp_ipv4.c

+123 −0

Original line number	Diff line number	Diff line
		@@ -2613,6 +2613,74 @@ out:
		return 0;
		}

		#ifdef CONFIG_BPF_SYSCALL
		struct bpf_iter__tcp {
		__bpf_md_ptr(struct bpf_iter_meta *, meta);
		__bpf_md_ptr(struct sock_common *, sk_common);
		uid_t uid __aligned(8);
		};

		static int tcp_prog_seq_show(struct bpf_prog prog, struct bpf_iter_meta meta,
		struct sock_common *sk_common, uid_t uid)
		{
		struct bpf_iter__tcp ctx;

		meta->seq_num--; /* skip SEQ_START_TOKEN */
		ctx.meta = meta;
		ctx.sk_common = sk_common;
		ctx.uid = uid;
		return bpf_iter_run_prog(prog, &ctx);
		}

		static int bpf_iter_tcp_seq_show(struct seq_file seq, void v)
		{
		struct bpf_iter_meta meta;
		struct bpf_prog *prog;
		struct sock *sk = v;
		uid_t uid;

		if (v == SEQ_START_TOKEN)
		return 0;

		if (sk->sk_state == TCP_TIME_WAIT) {
		uid = 0;
		} else if (sk->sk_state == TCP_NEW_SYN_RECV) {
		const struct request_sock *req = v;

		uid = from_kuid_munged(seq_user_ns(seq),
		sock_i_uid(req->rsk_listener));
		} else {
		uid = from_kuid_munged(seq_user_ns(seq), sock_i_uid(sk));
		}

		meta.seq = seq;
		prog = bpf_iter_get_info(&meta, false);
		return tcp_prog_seq_show(prog, &meta, v, uid);
		}

		static void bpf_iter_tcp_seq_stop(struct seq_file seq, void v)
		{
		struct bpf_iter_meta meta;
		struct bpf_prog *prog;

		if (!v) {
		meta.seq = seq;
		prog = bpf_iter_get_info(&meta, true);
		if (prog)
		(void)tcp_prog_seq_show(prog, &meta, v, 0);
		}

		tcp_seq_stop(seq, v);
		}

		static const struct seq_operations bpf_iter_tcp_seq_ops = {
		.show = bpf_iter_tcp_seq_show,
		.start = tcp_seq_start,
		.next = tcp_seq_next,
		.stop = bpf_iter_tcp_seq_stop,
		};
		#endif

		static const struct seq_operations tcp4_seq_ops = {
		.show = tcp4_seq_show,
		.start = tcp_seq_start,
		@@ -2844,8 +2912,63 @@ static struct pernet_operations __net_initdata tcp_sk_ops = {
		.exit_batch = tcp_sk_exit_batch,
		};

		#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
		DEFINE_BPF_ITER_FUNC(tcp, struct bpf_iter_meta *meta,
		struct sock_common *sk_common, uid_t uid)

		static int bpf_iter_init_tcp(void *priv_data)
		{
		struct tcp_iter_state *st = priv_data;
		struct tcp_seq_afinfo *afinfo;
		int ret;

		afinfo = kmalloc(sizeof(*afinfo), GFP_USER \| __GFP_NOWARN);
		if (!afinfo)
		return -ENOMEM;

		afinfo->family = AF_UNSPEC;
		st->bpf_seq_afinfo = afinfo;
		ret = bpf_iter_init_seq_net(priv_data);
		if (ret)
		kfree(afinfo);
		return ret;
		}

		static void bpf_iter_fini_tcp(void *priv_data)
		{
		struct tcp_iter_state *st = priv_data;

		kfree(st->bpf_seq_afinfo);
		bpf_iter_fini_seq_net(priv_data);
		}

		static const struct bpf_iter_reg tcp_reg_info = {
		.target = "tcp",
		.seq_ops = &bpf_iter_tcp_seq_ops,
		.init_seq_private = bpf_iter_init_tcp,
		.fini_seq_private = bpf_iter_fini_tcp,
		.seq_priv_size = sizeof(struct tcp_iter_state),
		.ctx_arg_info_size = 1,
		.ctx_arg_info = {
		{ offsetof(struct bpf_iter__tcp, sk_common),
		PTR_TO_BTF_ID_OR_NULL },
		},
		};

		static void __init bpf_iter_register(void)
		{
		if (bpf_iter_reg_target(&tcp_reg_info))
		pr_warn("Warning: could not register bpf iterator tcp\n");
		}

		#endif

		void __init tcp_v4_init(void)
		{
		if (register_pernet_subsys(&tcp_sk_ops))
		panic("Failed to create the TCP control socket.\n");

		#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
		bpf_iter_register();
		#endif
		}

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