Commit 0dcbbf67 authored by John Fastabend's avatar John Fastabend Committed by Daniel Borkmann
Browse files

bpf: sockmap sample test for bpf_msg_pull_data 



This adds an option to test the msg_pull_data helper. This
uses two options txmsg_start and txmsg_end to let the user
specify start and end bytes to pull.

The options can be used with txmsg_apply, txmsg_cork options
as well as with any of the basic tests, txmsg, txmsg_redir and
txmsg_drop (plus noisy variants) to run pull_data inline with
those tests. By giving user direct control over the variables
we can easily do negative testing as well as positive tests.

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 e6373ce7

samples/sockmap/sockmap_kern.c

+65 −14
Original line number Diff line number Diff line
@@ -71,6 +71,14 @@ struct bpf_map_def SEC("maps") sock_cork_bytes = { 
	.max_entries = 1

};



struct bpf_map_def SEC("maps") sock_pull_bytes = {

	.type = BPF_MAP_TYPE_ARRAY,

	.key_size = sizeof(int),

	.value_size = sizeof(int),

	.max_entries = 2

};





SEC("sk_skb1")

int bpf_prog1(struct __sk_buff *skb)

{
@@ -137,7 +145,8 @@ int bpf_sockmap(struct bpf_sock_ops *skops) 
SEC("sk_msg1")

int bpf_prog4(struct sk_msg_md *msg)

{

	int *bytes, zero = 0;

	int *bytes, zero = 0, one = 1;

	int *start, *end;



	bytes = bpf_map_lookup_elem(&sock_apply_bytes, &zero);

	if (bytes)
@@ -145,15 +154,18 @@ int bpf_prog4(struct sk_msg_md *msg) 
	bytes = bpf_map_lookup_elem(&sock_cork_bytes, &zero);

	if (bytes)

		bpf_msg_cork_bytes(msg, *bytes);

	start = bpf_map_lookup_elem(&sock_pull_bytes, &zero);

	end = bpf_map_lookup_elem(&sock_pull_bytes, &one);

	if (start && end)

		bpf_msg_pull_data(msg, *start, *end, 0);

	return SK_PASS;

}



SEC("sk_msg2")

int bpf_prog5(struct sk_msg_md *msg)

{

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

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

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

	int err1 = -1, err2 = -1, zero = 0, one = 1;

	int *bytes, *start, *end, len1, len2;



	bytes = bpf_map_lookup_elem(&sock_apply_bytes, &zero);

	if (bytes)
@@ -161,17 +173,32 @@ int bpf_prog5(struct sk_msg_md *msg) 
	bytes = bpf_map_lookup_elem(&sock_cork_bytes, &zero);

	if (bytes)

		err2 = bpf_msg_cork_bytes(msg, *bytes);

	len1 = (__u64)msg->data_end - (__u64)msg->data;

	start = bpf_map_lookup_elem(&sock_pull_bytes, &zero);

	end = bpf_map_lookup_elem(&sock_pull_bytes, &one);

	if (start && end) {

		int err;



		bpf_printk("sk_msg2: pull(%i:%i)\n",

			   start ? *start : 0, end ? *end : 0);

		err = bpf_msg_pull_data(msg, *start, *end, 0);

		if (err)

			bpf_printk("sk_msg2: pull_data err %i\n",

				   err);

		len2 = (__u64)msg->data_end - (__u64)msg->data;

		bpf_printk("sk_msg2: length update %i->%i\n",

			   len1, len2);

	}

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

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

		   len1, err1, err2);

	return SK_PASS;

}



SEC("sk_msg3")

int bpf_prog6(struct sk_msg_md *msg)

{

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

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

	int *bytes, zero = 0;

	int *bytes, zero = 0, one = 1;

	int *start, *end;



	bytes = bpf_map_lookup_elem(&sock_apply_bytes, &zero);

	if (bytes)
@@ -179,15 +206,18 @@ int bpf_prog6(struct sk_msg_md *msg) 
	bytes = bpf_map_lookup_elem(&sock_cork_bytes, &zero);

	if (bytes)

		bpf_msg_cork_bytes(msg, *bytes);

	start = bpf_map_lookup_elem(&sock_pull_bytes, &zero);

	end = bpf_map_lookup_elem(&sock_pull_bytes, &one);

	if (start && end)

		bpf_msg_pull_data(msg, *start, *end, 0);

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

}



SEC("sk_msg4")

int bpf_prog7(struct sk_msg_md *msg)

{

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

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

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

	int err1 = 0, err2 = 0, zero = 0, one = 1;

	int *bytes, *start, *end, len1, len2;



	bytes = bpf_map_lookup_elem(&sock_apply_bytes, &zero);

	if (bytes)
@@ -195,9 +225,24 @@ int bpf_prog7(struct sk_msg_md *msg) 
	bytes = bpf_map_lookup_elem(&sock_cork_bytes, &zero);

	if (bytes)

		err2 = bpf_msg_cork_bytes(msg, *bytes);



	len1 = (__u64)msg->data_end - (__u64)msg->data;

	start = bpf_map_lookup_elem(&sock_pull_bytes, &zero);

	end = bpf_map_lookup_elem(&sock_pull_bytes, &one);

	if (start && end) {

		int err;



		bpf_printk("sk_msg2: pull(%i:%i)\n",

			   start ? *start : 0, end ? *end : 0);

		err = bpf_msg_pull_data(msg, *start, *end, 0);

		if (err)

			bpf_printk("sk_msg2: pull_data err %i\n",

				   err);

		len2 = (__u64)msg->data_end - (__u64)msg->data;

		bpf_printk("sk_msg2: length update %i->%i\n",

			   len1, len2);

	}

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

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

		   len1, err1, err2);

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

}
@@ -239,7 +284,8 @@ int bpf_prog9(struct sk_msg_md *msg) 
SEC("sk_msg7")

int bpf_prog10(struct sk_msg_md *msg)

{

	int *bytes, zero = 0;

	int *bytes, zero = 0, one = 1;

	int *start, *end;



	bytes = bpf_map_lookup_elem(&sock_apply_bytes, &zero);

	if (bytes)
@@ -247,6 +293,11 @@ int bpf_prog10(struct sk_msg_md *msg) 
	bytes = bpf_map_lookup_elem(&sock_cork_bytes, &zero);

	if (bytes)

		bpf_msg_cork_bytes(msg, *bytes);

	start = bpf_map_lookup_elem(&sock_pull_bytes, &zero);

	end = bpf_map_lookup_elem(&sock_pull_bytes, &one);

	if (start && end)

		bpf_msg_pull_data(msg, *start, *end, 0);



	return SK_DROP;

}

samples/sockmap/sockmap_user.c

+32 −0
Original line number Diff line number Diff line
@@ -62,6 +62,8 @@ int txmsg_redir_noisy; 
int txmsg_drop;

int txmsg_apply;

int txmsg_cork;

int txmsg_start;

int txmsg_end;



static const struct option long_options[] = {

	{"help",	no_argument,		NULL, 'h' },
@@ -79,6 +81,8 @@ static const struct option long_options[] = { 
	{"txmsg_drop",		no_argument,	&txmsg_drop, 1 },

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

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

	{"txmsg_start", required_argument,	NULL, 's'},

	{"txmsg_end",	required_argument,	NULL, 'e'},

	{0, 0, NULL, 0 }

};
@@ -572,6 +576,12 @@ int main(int argc, char **argv) 
	while ((opt = getopt_long(argc, argv, ":dhvc:r:i:l:t:",

				  long_options, &longindex)) != -1) {

		switch (opt) {

		case 's':

			txmsg_start = atoi(optarg);

			break;

		case 'e':

			txmsg_end = atoi(optarg);

			break;

		case 'a':

			txmsg_apply = atoi(optarg);

			break;
@@ -761,6 +771,28 @@ run: 
			}

		}



		if (txmsg_start) {

			err = bpf_map_update_elem(map_fd[5],

						  &i, &txmsg_start, BPF_ANY);

			if (err) {

				fprintf(stderr,

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

					err, strerror(errno));

				return err;

			}

		}



		if (txmsg_end) {

			i = 1;

			err = bpf_map_update_elem(map_fd[5],

						  &i, &txmsg_end, BPF_ANY);

			if (err) {

				fprintf(stderr,

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

					err, strerror(errno));

				return err;

			}

		}

	}



	if (txmsg_drop)

tools/include/uapi/linux/bpf.h

+2 −1
Original line number Diff line number Diff line
@@ -793,7 +793,8 @@ union bpf_attr { 
	FN(sock_ops_cb_flags_set),	\

	FN(msg_redirect_map),		\

	FN(msg_apply_bytes),		\

	FN(msg_cork_bytes),

	FN(msg_cork_bytes),		\

	FN(msg_pull_data),



/* 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
@@ -92,6 +92,8 @@ 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;

static int (*bpf_msg_pull_data)(void *ctx, int start, int end, int flags) =

	(void *) BPF_FUNC_msg_pull_data;



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

 * emit BPF_LD_ABS and BPF_LD_IND instructions

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