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Commit 468b3fde authored by John Fastabend's avatar John Fastabend Committed by Daniel Borkmann
Browse files

bpf: sockmap sample support for bpf_msg_cork_bytes() 



Add sample application support for the bpf_msg_cork_bytes helper. This
lets the user specify how many bytes each verdict should apply to.

Similar to apply_bytes() tests these can be run as a stand-alone test
when used without other options or inline with other tests by using
the txmsg_cork option along with any of the basic tests txmsg,
txmsg_redir, txmsg_drop.

Signed-off-by: default avatarJohn Fastabend <john.fastabend@gmail.com>
Acked-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parent 1c16c312

samples/sockmap/sockmap_kern.c

+45 −8
Original line number Diff line number Diff line
@@ -64,6 +64,13 @@ struct bpf_map_def SEC("maps") sock_apply_bytes = { 
	.max_entries = 1

};



struct bpf_map_def SEC("maps") sock_cork_bytes = {

	.type = BPF_MAP_TYPE_ARRAY,

	.key_size = sizeof(int),

	.value_size = sizeof(int),

	.max_entries = 1

};



SEC("sk_skb1")

int bpf_prog1(struct __sk_buff *skb)

{
@@ -135,6 +142,9 @@ int bpf_prog4(struct sk_msg_md *msg) 
	bytes = bpf_map_lookup_elem(&sock_apply_bytes, &zero);

	if (bytes)

		bpf_msg_apply_bytes(msg, *bytes);

	bytes = bpf_map_lookup_elem(&sock_cork_bytes, &zero);

	if (bytes)

		bpf_msg_cork_bytes(msg, *bytes);

	return SK_PASS;

}
@@ -143,13 +153,16 @@ int bpf_prog5(struct sk_msg_md *msg) 
{

	void *data_end = (void *)(long) msg->data_end;

	void *data = (void *)(long) msg->data;

	int *bytes, err = 0, zero = 0;

	int *bytes, err1 = -1, err2 = -1, zero = 0;



	bytes = bpf_map_lookup_elem(&sock_apply_bytes, &zero);

	if (bytes)

		err = bpf_msg_apply_bytes(msg, *bytes);

	bpf_printk("sk_msg2: data length %i err %i\n",

		   (__u64)data_end - (__u64)data, err);

		err1 = bpf_msg_apply_bytes(msg, *bytes);

	bytes = bpf_map_lookup_elem(&sock_cork_bytes, &zero);

	if (bytes)

		err2 = bpf_msg_cork_bytes(msg, *bytes);

	bpf_printk("sk_msg2: data length %i err1 %i err2 %i\n",

		   (__u64)data_end - (__u64)data, err1, err2);

	return SK_PASS;

}
@@ -163,6 +176,9 @@ int bpf_prog6(struct sk_msg_md *msg) 
	bytes = bpf_map_lookup_elem(&sock_apply_bytes, &zero);

	if (bytes)

		bpf_msg_apply_bytes(msg, *bytes);

	bytes = bpf_map_lookup_elem(&sock_cork_bytes, &zero);

	if (bytes)

		bpf_msg_cork_bytes(msg, *bytes);

	return bpf_msg_redirect_map(msg, &sock_map_redir, zero, 0);

}
@@ -171,13 +187,17 @@ int bpf_prog7(struct sk_msg_md *msg) 
{

	void *data_end = (void *)(long) msg->data_end;

	void *data = (void *)(long) msg->data;

	int *bytes, err = 0, zero = 0;

	int *bytes, err1 = 0, err2 = 0, zero = 0;



	bytes = bpf_map_lookup_elem(&sock_apply_bytes, &zero);

	if (bytes)

		err = bpf_msg_apply_bytes(msg, *bytes);

	bpf_printk("sk_msg3: redirect(%iB) err=%i\n",

		   (__u64)data_end - (__u64)data, err);

		err1 = bpf_msg_apply_bytes(msg, *bytes);

	bytes = bpf_map_lookup_elem(&sock_cork_bytes, &zero);

	if (bytes)

		err2 = bpf_msg_cork_bytes(msg, *bytes);



	bpf_printk("sk_msg3: redirect(%iB) err1=%i err2=%i\n",

		   (__u64)data_end - (__u64)data, err1, err2);

	return bpf_msg_redirect_map(msg, &sock_map_redir, zero, 0);

}
@@ -198,5 +218,22 @@ int bpf_prog8(struct sk_msg_md *msg) 
	}

	return SK_PASS;

}

SEC("sk_msg6")

int bpf_prog9(struct sk_msg_md *msg)

{

	void *data_end = (void *)(long) msg->data_end;

	void *data = (void *)(long) msg->data;

	int ret = 0, *bytes, zero = 0;



	bytes = bpf_map_lookup_elem(&sock_cork_bytes, &zero);

	if (bytes) {

		if (((__u64)data_end - (__u64)data) >= *bytes)

			return SK_PASS;

		ret = bpf_msg_cork_bytes(msg, *bytes);

		if (ret)

			return SK_DROP;

	}

	return SK_PASS;

}



char _license[] SEC("license") = "GPL";

samples/sockmap/sockmap_user.c

+19 −0
Original line number Diff line number Diff line
@@ -60,6 +60,7 @@ int txmsg_noisy; 
int txmsg_redir;

int txmsg_redir_noisy;

int txmsg_apply;

int txmsg_cork;



static const struct option long_options[] = {

	{"help",	no_argument,		NULL, 'h' },
@@ -75,6 +76,7 @@ static const struct option long_options[] = { 
	{"txmsg_redir",		no_argument,	&txmsg_redir, 1  },

	{"txmsg_redir_noisy",	no_argument,	&txmsg_redir_noisy, 1},

	{"txmsg_apply",	required_argument,	NULL, 'a'},

	{"txmsg_cork",	required_argument,	NULL, 'k'},

	{0, 0, NULL, 0 }

};
@@ -551,6 +553,9 @@ int main(int argc, char **argv) 
		case 'a':

			txmsg_apply = atoi(optarg);

			break;

		case 'k':

			txmsg_cork = atoi(optarg);

			break;

		case 'c':

			cg_fd = open(optarg, O_DIRECTORY, O_RDONLY);

			if (cg_fd < 0) {
@@ -671,6 +676,8 @@ int main(int argc, char **argv) 
		tx_prog_fd = prog_fd[6];

	else if (txmsg_apply)

		tx_prog_fd = prog_fd[7];

	else if (txmsg_cork)

		tx_prog_fd = prog_fd[8];

	else

		tx_prog_fd = 0;
@@ -716,6 +723,18 @@ int main(int argc, char **argv) 
				return err;

			}

		}



		if (txmsg_cork) {

			err = bpf_map_update_elem(map_fd[4],

						  &i, &txmsg_cork, BPF_ANY);

			if (err) {

				fprintf(stderr,

					"ERROR: bpf_map_update_elem (cork_bytes):  %d (%s\n",

					err, strerror(errno));

				return err;

			}

		}



	}

	if (test == PING_PONG)

		err = forever_ping_pong(rate, &options);

tools/include/uapi/linux/bpf.h

+2 −1
Original line number Diff line number Diff line
@@ -792,7 +792,8 @@ union bpf_attr { 
	FN(override_return),		\

	FN(sock_ops_cb_flags_set),	\

	FN(msg_redirect_map),		\

	FN(msg_apply_bytes),

	FN(msg_apply_bytes),		\

	FN(msg_cork_bytes),



/* integer value in 'imm' field of BPF_CALL instruction selects which helper

 * function eBPF program intends to call

tools/testing/selftests/bpf/bpf_helpers.h

+2 −0
Original line number Diff line number Diff line
@@ -90,6 +90,8 @@ static int (*bpf_msg_redirect_map)(void *ctx, void *map, int key, int flags) = 
	(void *) BPF_FUNC_msg_redirect_map;

static int (*bpf_msg_apply_bytes)(void *ctx, int len) =

	(void *) BPF_FUNC_msg_apply_bytes;

static int (*bpf_msg_cork_bytes)(void *ctx, int len) =

	(void *) BPF_FUNC_msg_cork_bytes;



/* llvm builtin functions that eBPF C program may use to

 * emit BPF_LD_ABS and BPF_LD_IND instructions