Commit 6a32a44d authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'packet-fanout-unique-id' 



Mike Maloney says:

====================
packet: Add option to create new fanout group with unique id.

Fanout uses a per net global namespace. A process that intends to create a
new fanout group can accidentally join an existing group. It is
not possible to detect this.

Add a socket option to specify on the first call to
setsockopt(..., PACKET_FANOUT, ...) to ensure that a new group is created.
Also add tests.
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 69226896 28be04f5

include/uapi/linux/if_packet.h

+1 −0
Original line number Diff line number Diff line
@@ -66,6 +66,7 @@ struct sockaddr_ll { 
#define PACKET_FANOUT_CBPF		6

#define PACKET_FANOUT_EBPF		7

#define PACKET_FANOUT_FLAG_ROLLOVER	0x1000

#define PACKET_FANOUT_FLAG_UNIQUEID	0x2000

#define PACKET_FANOUT_FLAG_DEFRAG	0x8000



struct tpacket_stats {

net/packet/af_packet.c

+44 −0
Original line number Diff line number Diff line
@@ -1496,6 +1496,7 @@ static int packet_rcv_fanout(struct sk_buff *skb, struct net_device *dev, 
DEFINE_MUTEX(fanout_mutex);

EXPORT_SYMBOL_GPL(fanout_mutex);

static LIST_HEAD(fanout_list);

static u16 fanout_next_id;



static void __fanout_link(struct sock *sk, struct packet_sock *po)

{
@@ -1629,6 +1630,36 @@ static void fanout_release_data(struct packet_fanout *f) 
	};

}



static bool __fanout_id_is_free(struct sock *sk, u16 candidate_id)

{

	struct packet_fanout *f;



	list_for_each_entry(f, &fanout_list, list) {

		if (f->id == candidate_id &&

		    read_pnet(&f->net) == sock_net(sk)) {

			return false;

		}

	}

	return true;

}



static bool fanout_find_new_id(struct sock *sk, u16 *new_id)

{

	u16 id = fanout_next_id;



	do {

		if (__fanout_id_is_free(sk, id)) {

			*new_id = id;

			fanout_next_id = id + 1;

			return true;

		}



		id++;

	} while (id != fanout_next_id);



	return false;

}



static int fanout_add(struct sock *sk, u16 id, u16 type_flags)

{

	struct packet_rollover *rollover = NULL;
@@ -1676,6 +1707,19 @@ static int fanout_add(struct sock *sk, u16 id, u16 type_flags) 
		po->rollover = rollover;

	}



	if (type_flags & PACKET_FANOUT_FLAG_UNIQUEID) {

		if (id != 0) {

			err = -EINVAL;

			goto out;

		}

		if (!fanout_find_new_id(sk, &id)) {

			err = -ENOMEM;

			goto out;

		}

		/* ephemeral flag for the first socket in the group: drop it */

		flags &= ~(PACKET_FANOUT_FLAG_UNIQUEID >> 8);

	}



	match = NULL;

	list_for_each_entry(f, &fanout_list, list) {

		if (f->id == id &&

tools/testing/selftests/net/psock_fanout.c

+83 −10
Original line number Diff line number Diff line
@@ -71,7 +71,7 @@ 


/* Open a socket in a given fanout mode.

 * @return -1 if mode is bad, a valid socket otherwise */

static int sock_fanout_open(uint16_t typeflags, int num_packets)

static int sock_fanout_open(uint16_t typeflags, uint16_t group_id)

{

	int fd, val;
@@ -81,8 +81,7 @@ static int sock_fanout_open(uint16_t typeflags, int num_packets) 
		exit(1);

	}



	/* fanout group ID is always 0: tests whether old groups are deleted */

	val = ((int) typeflags) << 16;

	val = (((int) typeflags) << 16) | group_id;

	if (setsockopt(fd, SOL_PACKET, PACKET_FANOUT, &val, sizeof(val))) {

		if (close(fd)) {

			perror("close packet");
@@ -113,6 +112,20 @@ static void sock_fanout_set_cbpf(int fd) 
	}

}



static void sock_fanout_getopts(int fd, uint16_t *typeflags, uint16_t *group_id)

{

	int sockopt;

	socklen_t sockopt_len = sizeof(sockopt);



	if (getsockopt(fd, SOL_PACKET, PACKET_FANOUT,

		       &sockopt, &sockopt_len)) {

		perror("failed to getsockopt");

		exit(1);

	}

	*typeflags = sockopt >> 16;

	*group_id = sockopt & 0xfffff;

}



static void sock_fanout_set_ebpf(int fd)

{

	const int len_off = __builtin_offsetof(struct __sk_buff, len);
@@ -241,26 +254,26 @@ static void test_control_group(void) 


	fprintf(stderr, "test: control multiple sockets\n");



	fds[0] = sock_fanout_open(PACKET_FANOUT_HASH, 20);

	fds[0] = sock_fanout_open(PACKET_FANOUT_HASH, 0);

	if (fds[0] == -1) {

		fprintf(stderr, "ERROR: failed to open HASH socket\n");

		exit(1);

	}

	if (sock_fanout_open(PACKET_FANOUT_HASH |

			       PACKET_FANOUT_FLAG_DEFRAG, 10) != -1) {

			       PACKET_FANOUT_FLAG_DEFRAG, 0) != -1) {

		fprintf(stderr, "ERROR: joined group with wrong flag defrag\n");

		exit(1);

	}

	if (sock_fanout_open(PACKET_FANOUT_HASH |

			       PACKET_FANOUT_FLAG_ROLLOVER, 10) != -1) {

			       PACKET_FANOUT_FLAG_ROLLOVER, 0) != -1) {

		fprintf(stderr, "ERROR: joined group with wrong flag ro\n");

		exit(1);

	}

	if (sock_fanout_open(PACKET_FANOUT_CPU, 10) != -1) {

	if (sock_fanout_open(PACKET_FANOUT_CPU, 0) != -1) {

		fprintf(stderr, "ERROR: joined group with wrong mode\n");

		exit(1);

	}

	fds[1] = sock_fanout_open(PACKET_FANOUT_HASH, 20);

	fds[1] = sock_fanout_open(PACKET_FANOUT_HASH, 0);

	if (fds[1] == -1) {

		fprintf(stderr, "ERROR: failed to join group\n");

		exit(1);
@@ -271,6 +284,61 @@ static void test_control_group(void) 
	}

}



/* Test creating a unique fanout group ids */

static void test_unique_fanout_group_ids(void)

{

	int fds[3];

	uint16_t typeflags, first_group_id, second_group_id;



	fprintf(stderr, "test: unique ids\n");



	fds[0] = sock_fanout_open(PACKET_FANOUT_HASH |

				  PACKET_FANOUT_FLAG_UNIQUEID, 0);

	if (fds[0] == -1) {

		fprintf(stderr, "ERROR: failed to create a unique id group.\n");

		exit(1);

	}



	sock_fanout_getopts(fds[0], &typeflags, &first_group_id);

	if (typeflags != PACKET_FANOUT_HASH) {

		fprintf(stderr, "ERROR: unexpected typeflags %x\n", typeflags);

		exit(1);

	}



	if (sock_fanout_open(PACKET_FANOUT_CPU, first_group_id)) {

		fprintf(stderr, "ERROR: joined group with wrong type.\n");

		exit(1);

	}



	fds[1] = sock_fanout_open(PACKET_FANOUT_HASH, first_group_id);

	if (fds[1] == -1) {

		fprintf(stderr,

			"ERROR: failed to join previously created group.\n");

		exit(1);

	}



	fds[2] = sock_fanout_open(PACKET_FANOUT_HASH |

				  PACKET_FANOUT_FLAG_UNIQUEID, 0);

	if (fds[2] == -1) {

		fprintf(stderr,

			"ERROR: failed to create a second unique id group.\n");

		exit(1);

	}



	sock_fanout_getopts(fds[2], &typeflags, &second_group_id);

	if (sock_fanout_open(PACKET_FANOUT_HASH | PACKET_FANOUT_FLAG_UNIQUEID,

			     second_group_id) != -1) {

		fprintf(stderr,

			"ERROR: specified a group id when requesting unique id\n");

		exit(1);

	}



	if (close(fds[0]) || close(fds[1]) || close(fds[2])) {

		fprintf(stderr, "ERROR: closing sockets\n");

		exit(1);

	}

}



static int test_datapath(uint16_t typeflags, int port_off,

			 const int expect1[], const int expect2[])

{
@@ -281,8 +349,8 @@ static int test_datapath(uint16_t typeflags, int port_off, 


	fprintf(stderr, "test: datapath 0x%hx\n", typeflags);



	fds[0] = sock_fanout_open(typeflags, 20);

	fds[1] = sock_fanout_open(typeflags, 20);

	fds[0] = sock_fanout_open(typeflags, 0);

	fds[1] = sock_fanout_open(typeflags, 0);

	if (fds[0] == -1 || fds[1] == -1) {

		fprintf(stderr, "ERROR: failed open\n");

		exit(1);
@@ -349,10 +417,12 @@ int main(int argc, char **argv) 
	const int expect_cpu0[2][2]	= { { 20, 0 },  { 20, 0 } };

	const int expect_cpu1[2][2]	= { { 0, 20 },  { 0, 20 } };

	const int expect_bpf[2][2]	= { { 15, 5 },  { 15, 20 } };

	const int expect_uniqueid[2][2] = { { 20, 20},  { 20, 20 } };

	int port_off = 2, tries = 5, ret;



	test_control_single();

	test_control_group();

	test_unique_fanout_group_ids();



	/* find a set of ports that do not collide onto the same socket */

	ret = test_datapath(PACKET_FANOUT_HASH, port_off,
@@ -383,6 +453,9 @@ int main(int argc, char **argv) 
		ret |= test_datapath(PACKET_FANOUT_CPU, port_off,

				     expect_cpu1[0], expect_cpu1[1]);



	ret |= test_datapath(PACKET_FANOUT_FLAG_UNIQUEID, port_off,

			     expect_uniqueid[0], expect_uniqueid[1]);



	if (ret)

		return 1;

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