Commit 298970c8 authored by John Fastabend's avatar John Fastabend Committed by Daniel Borkmann
Browse files

bpf, sockmap: Build helper to create connected socket pair 



A common operation for testing is to spin up a pair of sockets that are
connected. Then we can use these to run specific tests that need to
send data, check BPF programs and so on.

The sockmap_listen programs already have this logic lets move it into
the new sockmap_helpers header file for general use.

Signed-off-by: default avatarJohn Fastabend <john.fastabend@gmail.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Reviewed-by: default avatarJakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/20230523025618.113937-11-john.fastabend@gmail.com
parent 4e02588d

tools/testing/selftests/bpf/prog_tests/sockmap_helpers.h

+118 −0
Original line number Diff line number Diff line
@@ -269,4 +269,122 @@ static inline struct sockaddr *sockaddr(struct sockaddr_storage *ss) 
	return (struct sockaddr *)ss;

}



static inline int add_to_sockmap(int sock_mapfd, int fd1, int fd2)

{

	u64 value;

	u32 key;

	int err;



	key = 0;

	value = fd1;

	err = xbpf_map_update_elem(sock_mapfd, &key, &value, BPF_NOEXIST);

	if (err)

		return err;



	key = 1;

	value = fd2;

	return xbpf_map_update_elem(sock_mapfd, &key, &value, BPF_NOEXIST);

}



static inline int create_pair(int s, int family, int sotype, int *c, int *p)

{

	struct sockaddr_storage addr;

	socklen_t len;

	int err = 0;



	len = sizeof(addr);

	err = xgetsockname(s, sockaddr(&addr), &len);

	if (err)

		return err;



	*c = xsocket(family, sotype, 0);

	if (*c < 0)

		return errno;

	err = xconnect(*c, sockaddr(&addr), len);

	if (err) {

		err = errno;

		goto close_cli0;

	}



	*p = xaccept_nonblock(s, NULL, NULL);

	if (*p < 0) {

		err = errno;

		goto close_cli0;

	}

	return err;

close_cli0:

	close(*c);

	return err;

}



static inline int create_socket_pairs(int s, int family, int sotype,

				      int *c0, int *c1, int *p0, int *p1)

{

	int err;



	err = create_pair(s, family, sotype, c0, p0);

	if (err)

		return err;



	err = create_pair(s, family, sotype, c1, p1);

	if (err) {

		close(*c0);

		close(*p0);

	}

	return err;

}



static inline int enable_reuseport(int s, int progfd)

{

	int err, one = 1;



	err = xsetsockopt(s, SOL_SOCKET, SO_REUSEPORT, &one, sizeof(one));

	if (err)

		return -1;

	err = xsetsockopt(s, SOL_SOCKET, SO_ATTACH_REUSEPORT_EBPF, &progfd,

			  sizeof(progfd));

	if (err)

		return -1;



	return 0;

}



static inline int socket_loopback_reuseport(int family, int sotype, int progfd)

{

	struct sockaddr_storage addr;

	socklen_t len;

	int err, s;



	init_addr_loopback(family, &addr, &len);



	s = xsocket(family, sotype, 0);

	if (s == -1)

		return -1;



	if (progfd >= 0)

		enable_reuseport(s, progfd);



	err = xbind(s, sockaddr(&addr), len);

	if (err)

		goto close;



	if (sotype & SOCK_DGRAM)

		return s;



	err = xlisten(s, SOMAXCONN);

	if (err)

		goto close;



	return s;

close:

	xclose(s);

	return -1;

}



static inline int socket_loopback(int family, int sotype)

{

	return socket_loopback_reuseport(family, sotype, -1);

}





#endif // __SOCKMAP_HELPERS__

tools/testing/selftests/bpf/prog_tests/sockmap_listen.c

+5 −102
Original line number Diff line number Diff line
@@ -29,58 +29,6 @@ 


#include "sockmap_helpers.h"



static int enable_reuseport(int s, int progfd)

{

	int err, one = 1;



	err = xsetsockopt(s, SOL_SOCKET, SO_REUSEPORT, &one, sizeof(one));

	if (err)

		return -1;

	err = xsetsockopt(s, SOL_SOCKET, SO_ATTACH_REUSEPORT_EBPF, &progfd,

			  sizeof(progfd));

	if (err)

		return -1;



	return 0;

}



static int socket_loopback_reuseport(int family, int sotype, int progfd)

{

	struct sockaddr_storage addr;

	socklen_t len;

	int err, s;



	init_addr_loopback(family, &addr, &len);



	s = xsocket(family, sotype, 0);

	if (s == -1)

		return -1;



	if (progfd >= 0)

		enable_reuseport(s, progfd);



	err = xbind(s, sockaddr(&addr), len);

	if (err)

		goto close;



	if (sotype & SOCK_DGRAM)

		return s;



	err = xlisten(s, SOMAXCONN);

	if (err)

		goto close;



	return s;

close:

	xclose(s);

	return -1;

}



static int socket_loopback(int family, int sotype)

{

	return socket_loopback_reuseport(family, sotype, -1);

}



static void test_insert_invalid(struct test_sockmap_listen *skel __always_unused,

				int family, int sotype, int mapfd)

{
@@ -723,31 +671,12 @@ static const char *redir_mode_str(enum redir_mode mode) 
	}

}



static int add_to_sockmap(int sock_mapfd, int fd1, int fd2)

{

	u64 value;

	u32 key;

	int err;



	key = 0;

	value = fd1;

	err = xbpf_map_update_elem(sock_mapfd, &key, &value, BPF_NOEXIST);

	if (err)

		return err;



	key = 1;

	value = fd2;

	return xbpf_map_update_elem(sock_mapfd, &key, &value, BPF_NOEXIST);

}



static void redir_to_connected(int family, int sotype, int sock_mapfd,

			       int verd_mapfd, enum redir_mode mode)

{

	const char *log_prefix = redir_mode_str(mode);

	struct sockaddr_storage addr;

	int s, c0, c1, p0, p1;

	unsigned int pass;

	socklen_t len;

	int err, n;

	u32 key;

	char b;
@@ -758,36 +687,13 @@ static void redir_to_connected(int family, int sotype, int sock_mapfd, 
	if (s < 0)

		return;



	len = sizeof(addr);

	err = xgetsockname(s, sockaddr(&addr), &len);

	err = create_socket_pairs(s, family, sotype, &c0, &c1, &p0, &p1);

	if (err)

		goto close_srv;



	c0 = xsocket(family, sotype, 0);

	if (c0 < 0)

		goto close_srv;

	err = xconnect(c0, sockaddr(&addr), len);

	if (err)

		goto close_cli0;



	p0 = xaccept_nonblock(s, NULL, NULL);

	if (p0 < 0)

		goto close_cli0;



	c1 = xsocket(family, sotype, 0);

	if (c1 < 0)

		goto close_peer0;

	err = xconnect(c1, sockaddr(&addr), len);

	if (err)

		goto close_cli1;



	p1 = xaccept_nonblock(s, NULL, NULL);

	if (p1 < 0)

		goto close_cli1;



	err = add_to_sockmap(sock_mapfd, p0, p1);

	if (err)

		goto close_peer1;

		goto close;



	n = write(mode == REDIR_INGRESS ? c1 : p1, "a", 1);

	if (n < 0)
@@ -795,12 +701,12 @@ static void redir_to_connected(int family, int sotype, int sock_mapfd, 
	if (n == 0)

		FAIL("%s: incomplete write", log_prefix);

	if (n < 1)

		goto close_peer1;

		goto close;



	key = SK_PASS;

	err = xbpf_map_lookup_elem(verd_mapfd, &key, &pass);

	if (err)

		goto close_peer1;

		goto close;

	if (pass != 1)

		FAIL("%s: want pass count 1, have %d", log_prefix, pass);

	n = recv_timeout(c0, &b, 1, 0, IO_TIMEOUT_SEC);
@@ -809,13 +715,10 @@ static void redir_to_connected(int family, int sotype, int sock_mapfd, 
	if (n == 0)

		FAIL("%s: incomplete recv", log_prefix);



close_peer1:

close:

	xclose(p1);

close_cli1:

	xclose(c1);

close_peer0:

	xclose(p0);

close_cli0:

	xclose(c0);

close_srv:

	xclose(s);