net: bpf: Implement bpf iterator for udp (5788b3a0) · Commits · 戴 / test

net/ipv4/udp.c

+116 −0

Original line number	Diff line number	Diff line
		@@ -2968,6 +2968,67 @@ int udp4_seq_show(struct seq_file seq, void v)
		return 0;
		}

		#ifdef CONFIG_BPF_SYSCALL
		struct bpf_iter__udp {
		__bpf_md_ptr(struct bpf_iter_meta *, meta);
		__bpf_md_ptr(struct udp_sock *, udp_sk);
		uid_t uid __aligned(8);
		int bucket __aligned(8);
		};

		static int udp_prog_seq_show(struct bpf_prog prog, struct bpf_iter_meta meta,
		struct udp_sock *udp_sk, uid_t uid, int bucket)
		{
		struct bpf_iter__udp ctx;

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

		static int bpf_iter_udp_seq_show(struct seq_file seq, void v)
		{
		struct udp_iter_state *state = seq->private;
		struct bpf_iter_meta meta;
		struct bpf_prog *prog;
		struct sock *sk = v;
		uid_t uid;

		if (v == SEQ_START_TOKEN)
		return 0;

		uid = from_kuid_munged(seq_user_ns(seq), sock_i_uid(sk));
		meta.seq = seq;
		prog = bpf_iter_get_info(&meta, false);
		return udp_prog_seq_show(prog, &meta, v, uid, state->bucket);
		}

		static void bpf_iter_udp_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)udp_prog_seq_show(prog, &meta, v, 0, 0);
		}

		udp_seq_stop(seq, v);
		}

		static const struct seq_operations bpf_iter_udp_seq_ops = {
		.start = udp_seq_start,
		.next = udp_seq_next,
		.stop = bpf_iter_udp_seq_stop,
		.show = bpf_iter_udp_seq_show,
		};
		#endif

		const struct seq_operations udp_seq_ops = {
		.start = udp_seq_start,
		.next = udp_seq_next,
		@@ -3085,6 +3146,57 @@ static struct pernet_operations __net_initdata udp_sysctl_ops = {
		.init = udp_sysctl_init,
		};

		#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
		DEFINE_BPF_ITER_FUNC(udp, struct bpf_iter_meta *meta,
		struct udp_sock *udp_sk, uid_t uid, int bucket)

		static int bpf_iter_init_udp(void *priv_data)
		{
		struct udp_iter_state *st = priv_data;
		struct udp_seq_afinfo *afinfo;
		int ret;

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

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

		static void bpf_iter_fini_udp(void *priv_data)
		{
		struct udp_iter_state *st = priv_data;

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

		static const struct bpf_iter_reg udp_reg_info = {
		.target = "udp",
		.seq_ops = &bpf_iter_udp_seq_ops,
		.init_seq_private = bpf_iter_init_udp,
		.fini_seq_private = bpf_iter_fini_udp,
		.seq_priv_size = sizeof(struct udp_iter_state),
		.ctx_arg_info_size = 1,
		.ctx_arg_info = {
		{ offsetof(struct bpf_iter__udp, udp_sk),
		PTR_TO_BTF_ID_OR_NULL },
		},
		};

		static void __init bpf_iter_register(void)
		{
		if (bpf_iter_reg_target(&udp_reg_info))
		pr_warn("Warning: could not register bpf iterator udp\n");
		}
		#endif

		void __init udp_init(void)
		{
		unsigned long limit;
		@@ -3110,4 +3222,8 @@ void __init udp_init(void)

		if (register_pernet_subsys(&udp_sysctl_ops))
		panic("UDP: failed to init sysctl parameters.\n");

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

Admin message