Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Cross-merge networking fixes after downstream PR (net-6.13-rc6).

No conflicts.

Adjacent changes:

include/linux/if_vlan.h
  f91a5b808938 ("af_packet: fix vlan_get_protocol_dgram() vs MSG_PEEK")
  3f330db30638 ("net: reformat kdoc return statements")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>

4 files changed, 508 insertions, 384 deletions

diff --git a/tools/testing/selftests/bpf/prog_tests/socket_helpers.h b/tools/testing/selftests/bpf/prog_tests/socket_helpers.h
new file mode 100644
index 000000000000..1bdfb79ef009
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/socket_helpers.h
@@ -0,0 +1,394 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __SOCKET_HELPERS__
+#define __SOCKET_HELPERS__
+
+#include <linux/vm_sockets.h>
+
+/* include/linux/net.h */
+#define SOCK_TYPE_MASK 0xf
+
+#define IO_TIMEOUT_SEC 30
+#define MAX_STRERR_LEN 256
+
+/* workaround for older vm_sockets.h */
+#ifndef VMADDR_CID_LOCAL
+#define VMADDR_CID_LOCAL 1
+#endif
+
+/* include/linux/cleanup.h */
+#define __get_and_null(p, nullvalue)                                           \
+	({                                                                     \
+		__auto_type __ptr = &(p);                                      \
+		__auto_type __val = *__ptr;                                    \
+		*__ptr = nullvalue;                                            \
+		__val;                                                         \
+	})
+
+#define take_fd(fd) __get_and_null(fd, -EBADF)
+
+/* Wrappers that fail the test on error and report it. */
+
+#define _FAIL(errnum, fmt...)                                                  \
+	({                                                                     \
+		error_at_line(0, (errnum), __func__, __LINE__, fmt);           \
+		CHECK_FAIL(true);                                              \
+	})
+#define FAIL(fmt...) _FAIL(0, fmt)
+#define FAIL_ERRNO(fmt...) _FAIL(errno, fmt)
+#define FAIL_LIBBPF(err, msg)                                                  \
+	({                                                                     \
+		char __buf[MAX_STRERR_LEN];                                    \
+		libbpf_strerror((err), __buf, sizeof(__buf));                  \
+		FAIL("%s: %s", (msg), __buf);                                  \
+	})
+
+
+#define xaccept_nonblock(fd, addr, len)                                        \
+	({                                                                     \
+		int __ret =                                                    \
+			accept_timeout((fd), (addr), (len), IO_TIMEOUT_SEC);   \
+		if (__ret == -1)                                               \
+			FAIL_ERRNO("accept");                                  \
+		__ret;                                                         \
+	})
+
+#define xbind(fd, addr, len)                                                   \
+	({                                                                     \
+		int __ret = bind((fd), (addr), (len));                         \
+		if (__ret == -1)                                               \
+			FAIL_ERRNO("bind");                                    \
+		__ret;                                                         \
+	})
+
+#define xclose(fd)                                                             \
+	({                                                                     \
+		int __ret = close((fd));                                       \
+		if (__ret == -1)                                               \
+			FAIL_ERRNO("close");                                   \
+		__ret;                                                         \
+	})
+
+#define xconnect(fd, addr, len)                                                \
+	({                                                                     \
+		int __ret = connect((fd), (addr), (len));                      \
+		if (__ret == -1)                                               \
+			FAIL_ERRNO("connect");                                 \
+		__ret;                                                         \
+	})
+
+#define xgetsockname(fd, addr, len)                                            \
+	({                                                                     \
+		int __ret = getsockname((fd), (addr), (len));                  \
+		if (__ret == -1)                                               \
+			FAIL_ERRNO("getsockname");                             \
+		__ret;                                                         \
+	})
+
+#define xgetsockopt(fd, level, name, val, len)                                 \
+	({                                                                     \
+		int __ret = getsockopt((fd), (level), (name), (val), (len));   \
+		if (__ret == -1)                                               \
+			FAIL_ERRNO("getsockopt(" #name ")");                   \
+		__ret;                                                         \
+	})
+
+#define xlisten(fd, backlog)                                                   \
+	({                                                                     \
+		int __ret = listen((fd), (backlog));                           \
+		if (__ret == -1)                                               \
+			FAIL_ERRNO("listen");                                  \
+		__ret;                                                         \
+	})
+
+#define xsetsockopt(fd, level, name, val, len)                                 \
+	({                                                                     \
+		int __ret = setsockopt((fd), (level), (name), (val), (len));   \
+		if (__ret == -1)                                               \
+			FAIL_ERRNO("setsockopt(" #name ")");                   \
+		__ret;                                                         \
+	})
+
+#define xsend(fd, buf, len, flags)                                             \
+	({                                                                     \
+		ssize_t __ret = send((fd), (buf), (len), (flags));             \
+		if (__ret == -1)                                               \
+			FAIL_ERRNO("send");                                    \
+		__ret;                                                         \
+	})
+
+#define xrecv_nonblock(fd, buf, len, flags)                                    \
+	({                                                                     \
+		ssize_t __ret = recv_timeout((fd), (buf), (len), (flags),      \
+					     IO_TIMEOUT_SEC);                  \
+		if (__ret == -1)                                               \
+			FAIL_ERRNO("recv");                                    \
+		__ret;                                                         \
+	})
+
+#define xsocket(family, sotype, flags)                                         \
+	({                                                                     \
+		int __ret = socket(family, sotype, flags);                     \
+		if (__ret == -1)                                               \
+			FAIL_ERRNO("socket");                                  \
+		__ret;                                                         \
+	})
+
+static inline void close_fd(int *fd)
+{
+	if (*fd >= 0)
+		xclose(*fd);
+}
+
+#define __close_fd __attribute__((cleanup(close_fd)))
+
+static inline struct sockaddr *sockaddr(struct sockaddr_storage *ss)
+{
+	return (struct sockaddr *)ss;
+}
+
+static inline void init_addr_loopback4(struct sockaddr_storage *ss,
+				       socklen_t *len)
+{
+	struct sockaddr_in *addr4 = memset(ss, 0, sizeof(*ss));
+
+	addr4->sin_family = AF_INET;
+	addr4->sin_port = 0;
+	addr4->sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+	*len = sizeof(*addr4);
+}
+
+static inline void init_addr_loopback6(struct sockaddr_storage *ss,
+				       socklen_t *len)
+{
+	struct sockaddr_in6 *addr6 = memset(ss, 0, sizeof(*ss));
+
+	addr6->sin6_family = AF_INET6;
+	addr6->sin6_port = 0;
+	addr6->sin6_addr = in6addr_loopback;
+	*len = sizeof(*addr6);
+}
+
+static inline void init_addr_loopback_vsock(struct sockaddr_storage *ss,
+					    socklen_t *len)
+{
+	struct sockaddr_vm *addr = memset(ss, 0, sizeof(*ss));
+
+	addr->svm_family = AF_VSOCK;
+	addr->svm_port = VMADDR_PORT_ANY;
+	addr->svm_cid = VMADDR_CID_LOCAL;
+	*len = sizeof(*addr);
+}
+
+static inline void init_addr_loopback(int family, struct sockaddr_storage *ss,
+				      socklen_t *len)
+{
+	switch (family) {
+	case AF_INET:
+		init_addr_loopback4(ss, len);
+		return;
+	case AF_INET6:
+		init_addr_loopback6(ss, len);
+		return;
+	case AF_VSOCK:
+		init_addr_loopback_vsock(ss, len);
+		return;
+	default:
+		FAIL("unsupported address family %d", family);
+	}
+}
+
+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 = 0;
+	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);
+}
+
+static inline int poll_connect(int fd, unsigned int timeout_sec)
+{
+	struct timeval timeout = { .tv_sec = timeout_sec };
+	fd_set wfds;
+	int r, eval;
+	socklen_t esize = sizeof(eval);
+
+	FD_ZERO(&wfds);
+	FD_SET(fd, &wfds);
+
+	r = select(fd + 1, NULL, &wfds, NULL, &timeout);
+	if (r == 0)
+		errno = ETIME;
+	if (r != 1)
+		return -1;
+
+	if (getsockopt(fd, SOL_SOCKET, SO_ERROR, &eval, &esize) < 0)
+		return -1;
+	if (eval != 0) {
+		errno = eval;
+		return -1;
+	}
+
+	return 0;
+}
+
+static inline int poll_read(int fd, unsigned int timeout_sec)
+{
+	struct timeval timeout = { .tv_sec = timeout_sec };
+	fd_set rfds;
+	int r;
+
+	FD_ZERO(&rfds);
+	FD_SET(fd, &rfds);
+
+	r = select(fd + 1, &rfds, NULL, NULL, &timeout);
+	if (r == 0)
+		errno = ETIME;
+
+	return r == 1 ? 0 : -1;
+}
+
+static inline int accept_timeout(int fd, struct sockaddr *addr, socklen_t *len,
+				 unsigned int timeout_sec)
+{
+	if (poll_read(fd, timeout_sec))
+		return -1;
+
+	return accept(fd, addr, len);
+}
+
+static inline int recv_timeout(int fd, void *buf, size_t len, int flags,
+			       unsigned int timeout_sec)
+{
+	if (poll_read(fd, timeout_sec))
+		return -1;
+
+	return recv(fd, buf, len, flags);
+}
+
+
+static inline int create_pair(int family, int sotype, int *p0, int *p1)
+{
+	__close_fd int s, c = -1, p = -1;
+	struct sockaddr_storage addr;
+	socklen_t len = sizeof(addr);
+	int err;
+
+	s = socket_loopback(family, sotype);
+	if (s < 0)
+		return s;
+
+	err = xgetsockname(s, sockaddr(&addr), &len);
+	if (err)
+		return err;
+
+	c = xsocket(family, sotype, 0);
+	if (c < 0)
+		return c;
+
+	err = connect(c, sockaddr(&addr), len);
+	if (err) {
+		if (errno != EINPROGRESS) {
+			FAIL_ERRNO("connect");
+			return err;
+		}
+
+		err = poll_connect(c, IO_TIMEOUT_SEC);
+		if (err) {
+			FAIL_ERRNO("poll_connect");
+			return err;
+		}
+	}
+
+	switch (sotype & SOCK_TYPE_MASK) {
+	case SOCK_DGRAM:
+		err = xgetsockname(c, sockaddr(&addr), &len);
+		if (err)
+			return err;
+
+		err = xconnect(s, sockaddr(&addr), len);
+		if (err)
+			return err;
+
+		*p0 = take_fd(s);
+		break;
+	case SOCK_STREAM:
+	case SOCK_SEQPACKET:
+		p = xaccept_nonblock(s, NULL, NULL);
+		if (p < 0)
+			return p;
+
+		*p0 = take_fd(p);
+		break;
+	default:
+		FAIL("Unsupported socket type %#x", sotype);
+		return -EOPNOTSUPP;
+	}
+
+	*p1 = take_fd(c);
+	return 0;
+}
+
+static inline int create_socket_pairs(int family, int sotype, int *c0, int *c1,
+				      int *p0, int *p1)
+{
+	int err;
+
+	err = create_pair(family, sotype, c0, p0);
+	if (err)
+		return err;
+
+	err = create_pair(family, sotype, c1, p1);
+	if (err) {
+		close(*c0);
+		close(*p0);
+	}
+
+	return err;
+}
+
+#endif // __SOCKET_HELPERS__
diff --git a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c
index 248754296d97..884ad87783d5 100644
--- a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c
+++ b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c
@@ -12,6 +12,7 @@
 #include "test_sockmap_progs_query.skel.h"
 #include "test_sockmap_pass_prog.skel.h"
 #include "test_sockmap_drop_prog.skel.h"
+#include "test_sockmap_change_tail.skel.h"
 #include "bpf_iter_sockmap.skel.h"
 
 #include "sockmap_helpers.h"
@@ -643,6 +644,54 @@ out:
 		test_sockmap_drop_prog__destroy(drop);
 }
 
+static void test_sockmap_skb_verdict_change_tail(void)
+{
+	struct test_sockmap_change_tail *skel;
+	int err, map, verdict;
+	int c1, p1, sent, recvd;
+	int zero = 0;
+	char buf[2];
+
+	skel = test_sockmap_change_tail__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "open_and_load"))
+		return;
+	verdict = bpf_program__fd(skel->progs.prog_skb_verdict);
+	map = bpf_map__fd(skel->maps.sock_map_rx);
+
+	err = bpf_prog_attach(verdict, map, BPF_SK_SKB_STREAM_VERDICT, 0);
+	if (!ASSERT_OK(err, "bpf_prog_attach"))
+		goto out;
+	err = create_pair(AF_INET, SOCK_STREAM, &c1, &p1);
+	if (!ASSERT_OK(err, "create_pair()"))
+		goto out;
+	err = bpf_map_update_elem(map, &zero, &c1, BPF_NOEXIST);
+	if (!ASSERT_OK(err, "bpf_map_update_elem(c1)"))
+		goto out_close;
+	sent = xsend(p1, "Tr", 2, 0);
+	ASSERT_EQ(sent, 2, "xsend(p1)");
+	recvd = recv(c1, buf, 2, 0);
+	ASSERT_EQ(recvd, 1, "recv(c1)");
+	ASSERT_EQ(skel->data->change_tail_ret, 0, "change_tail_ret");
+
+	sent = xsend(p1, "G", 1, 0);
+	ASSERT_EQ(sent, 1, "xsend(p1)");
+	recvd = recv(c1, buf, 2, 0);
+	ASSERT_EQ(recvd, 2, "recv(c1)");
+	ASSERT_EQ(skel->data->change_tail_ret, 0, "change_tail_ret");
+
+	sent = xsend(p1, "E", 1, 0);
+	ASSERT_EQ(sent, 1, "xsend(p1)");
+	recvd = recv(c1, buf, 1, 0);
+	ASSERT_EQ(recvd, 1, "recv(c1)");
+	ASSERT_EQ(skel->data->change_tail_ret, -EINVAL, "change_tail_ret");
+
+out_close:
+	close(c1);
+	close(p1);
+out:
+	test_sockmap_change_tail__destroy(skel);
+}
+
 static void test_sockmap_skb_verdict_peek_helper(int map)
 {
 	int err, c1, p1, zero = 0, sent, recvd, avail;
@@ -1058,6 +1107,8 @@ void test_sockmap_basic(void)
 		test_sockmap_skb_verdict_fionread(true);
 	if (test__start_subtest("sockmap skb_verdict fionread on drop"))
 		test_sockmap_skb_verdict_fionread(false);
+	if (test__start_subtest("sockmap skb_verdict change tail"))
+		test_sockmap_skb_verdict_change_tail();
 	if (test__start_subtest("sockmap skb_verdict msg_f_peek"))
 		test_sockmap_skb_verdict_peek();
 	if (test__start_subtest("sockmap skb_verdict msg_f_peek with link"))
diff --git a/tools/testing/selftests/bpf/prog_tests/sockmap_helpers.h b/tools/testing/selftests/bpf/prog_tests/sockmap_helpers.h
index 38e35c72bdaa..3e5571dd578d 100644
--- a/tools/testing/selftests/bpf/prog_tests/sockmap_helpers.h
+++ b/tools/testing/selftests/bpf/prog_tests/sockmap_helpers.h
@@ -1,139 +1,12 @@
 #ifndef __SOCKMAP_HELPERS__
 #define __SOCKMAP_HELPERS__
 
-#include <linux/vm_sockets.h>
+#include "socket_helpers.h"
 
-/* include/linux/net.h */
-#define SOCK_TYPE_MASK 0xf
-
-#define IO_TIMEOUT_SEC 30
-#define MAX_STRERR_LEN 256
 #define MAX_TEST_NAME 80
 
-/* workaround for older vm_sockets.h */
-#ifndef VMADDR_CID_LOCAL
-#define VMADDR_CID_LOCAL 1
-#endif
-
 #define __always_unused	__attribute__((__unused__))
 
-/* include/linux/cleanup.h */
-#define __get_and_null(p, nullvalue)                                           \
-	({                                                                     \
-		__auto_type __ptr = &(p);                                      \
-		__auto_type __val = *__ptr;                                    \
-		*__ptr = nullvalue;                                            \
-		__val;                                                         \
-	})
-
-#define take_fd(fd) __get_and_null(fd, -EBADF)
-
-#define _FAIL(errnum, fmt...)                                                  \
-	({                                                                     \
-		error_at_line(0, (errnum), __func__, __LINE__, fmt);           \
-		CHECK_FAIL(true);                                              \
-	})
-#define FAIL(fmt...) _FAIL(0, fmt)
-#define FAIL_ERRNO(fmt...) _FAIL(errno, fmt)
-#define FAIL_LIBBPF(err, msg)                                                  \
-	({                                                                     \
-		char __buf[MAX_STRERR_LEN];                                    \
-		libbpf_strerror((err), __buf, sizeof(__buf));                  \
-		FAIL("%s: %s", (msg), __buf);                                  \
-	})
-
-/* Wrappers that fail the test on error and report it. */
-
-#define xaccept_nonblock(fd, addr, len)                                        \
-	({                                                                     \
-		int __ret =                                                    \
-			accept_timeout((fd), (addr), (len), IO_TIMEOUT_SEC);   \
-		if (__ret == -1)                                               \
-			FAIL_ERRNO("accept");                                  \
-		__ret;                                                         \
-	})
-
-#define xbind(fd, addr, len)                                                   \
-	({                                                                     \
-		int __ret = bind((fd), (addr), (len));                         \
-		if (__ret == -1)                                               \
-			FAIL_ERRNO("bind");                                    \
-		__ret;                                                         \
-	})
-
-#define xclose(fd)                                                             \
-	({                                                                     \
-		int __ret = close((fd));                                       \
-		if (__ret == -1)                                               \
-			FAIL_ERRNO("close");                                   \
-		__ret;                                                         \
-	})
-
-#define xconnect(fd, addr, len)                                                \
-	({                                                                     \
-		int __ret = connect((fd), (addr), (len));                      \
-		if (__ret == -1)                                               \
-			FAIL_ERRNO("connect");                                 \
-		__ret;                                                         \
-	})
-
-#define xgetsockname(fd, addr, len)                                            \
-	({                                                                     \
-		int __ret = getsockname((fd), (addr), (len));                  \
-		if (__ret == -1)                                               \
-			FAIL_ERRNO("getsockname");                             \
-		__ret;                                                         \
-	})
-
-#define xgetsockopt(fd, level, name, val, len)                                 \
-	({                                                                     \
-		int __ret = getsockopt((fd), (level), (name), (val), (len));   \
-		if (__ret == -1)                                               \
-			FAIL_ERRNO("getsockopt(" #name ")");                   \
-		__ret;                                                         \
-	})
-
-#define xlisten(fd, backlog)                                                   \
-	({                                                                     \
-		int __ret = listen((fd), (backlog));                           \
-		if (__ret == -1)                                               \
-			FAIL_ERRNO("listen");                                  \
-		__ret;                                                         \
-	})
-
-#define xsetsockopt(fd, level, name, val, len)                                 \
-	({                                                                     \
-		int __ret = setsockopt((fd), (level), (name), (val), (len));   \
-		if (__ret == -1)                                               \
-			FAIL_ERRNO("setsockopt(" #name ")");                   \
-		__ret;                                                         \
-	})
-
-#define xsend(fd, buf, len, flags)                                             \
-	({                                                                     \
-		ssize_t __ret = send((fd), (buf), (len), (flags));             \
-		if (__ret == -1)                                               \
-			FAIL_ERRNO("send");                                    \
-		__ret;                                                         \
-	})
-
-#define xrecv_nonblock(fd, buf, len, flags)                                    \
-	({                                                                     \
-		ssize_t __ret = recv_timeout((fd), (buf), (len), (flags),      \
-					     IO_TIMEOUT_SEC);                  \
-		if (__ret == -1)                                               \
-			FAIL_ERRNO("recv");                                    \
-		__ret;                                                         \
-	})
-
-#define xsocket(family, sotype, flags)                                         \
-	({                                                                     \
-		int __ret = socket(family, sotype, flags);                     \
-		if (__ret == -1)                                               \
-			FAIL_ERRNO("socket");                                  \
-		__ret;                                                         \
-	})
-
 #define xbpf_map_delete_elem(fd, key)                                          \
 	({                                                                     \
 		int __ret = bpf_map_delete_elem((fd), (key));                  \
@@ -193,130 +66,6 @@
 		__ret;                                                         \
 	})
 
-static inline void close_fd(int *fd)
-{
-	if (*fd >= 0)
-		xclose(*fd);
-}
-
-#define __close_fd __attribute__((cleanup(close_fd)))
-
-static inline int poll_connect(int fd, unsigned int timeout_sec)
-{
-	struct timeval timeout = { .tv_sec = timeout_sec };
-	fd_set wfds;
-	int r, eval;
-	socklen_t esize = sizeof(eval);
-
-	FD_ZERO(&wfds);
-	FD_SET(fd, &wfds);
-
-	r = select(fd + 1, NULL, &wfds, NULL, &timeout);
-	if (r == 0)
-		errno = ETIME;
-	if (r != 1)
-		return -1;
-
-	if (getsockopt(fd, SOL_SOCKET, SO_ERROR, &eval, &esize) < 0)
-		return -1;
-	if (eval != 0) {
-		errno = eval;
-		return -1;
-	}
-
-	return 0;
-}
-
-static inline int poll_read(int fd, unsigned int timeout_sec)
-{
-	struct timeval timeout = { .tv_sec = timeout_sec };
-	fd_set rfds;
-	int r;
-
-	FD_ZERO(&rfds);
-	FD_SET(fd, &rfds);
-
-	r = select(fd + 1, &rfds, NULL, NULL, &timeout);
-	if (r == 0)
-		errno = ETIME;
-
-	return r == 1 ? 0 : -1;
-}
-
-static inline int accept_timeout(int fd, struct sockaddr *addr, socklen_t *len,
-				 unsigned int timeout_sec)
-{
-	if (poll_read(fd, timeout_sec))
-		return -1;
-
-	return accept(fd, addr, len);
-}
-
-static inline int recv_timeout(int fd, void *buf, size_t len, int flags,
-			       unsigned int timeout_sec)
-{
-	if (poll_read(fd, timeout_sec))
-		return -1;
-
-	return recv(fd, buf, len, flags);
-}
-
-static inline void init_addr_loopback4(struct sockaddr_storage *ss,
-				       socklen_t *len)
-{
-	struct sockaddr_in *addr4 = memset(ss, 0, sizeof(*ss));
-
-	addr4->sin_family = AF_INET;
-	addr4->sin_port = 0;
-	addr4->sin_addr.s_addr = htonl(INADDR_LOOPBACK);
-	*len = sizeof(*addr4);
-}
-
-static inline void init_addr_loopback6(struct sockaddr_storage *ss,
-				       socklen_t *len)
-{
-	struct sockaddr_in6 *addr6 = memset(ss, 0, sizeof(*ss));
-
-	addr6->sin6_family = AF_INET6;
-	addr6->sin6_port = 0;
-	addr6->sin6_addr = in6addr_loopback;
-	*len = sizeof(*addr6);
-}
-
-static inline void init_addr_loopback_vsock(struct sockaddr_storage *ss,
-					    socklen_t *len)
-{
-	struct sockaddr_vm *addr = memset(ss, 0, sizeof(*ss));
-
-	addr->svm_family = AF_VSOCK;
-	addr->svm_port = VMADDR_PORT_ANY;
-	addr->svm_cid = VMADDR_CID_LOCAL;
-	*len = sizeof(*addr);
-}
-
-static inline void init_addr_loopback(int family, struct sockaddr_storage *ss,
-				      socklen_t *len)
-{
-	switch (family) {
-	case AF_INET:
-		init_addr_loopback4(ss, len);
-		return;
-	case AF_INET6:
-		init_addr_loopback6(ss, len);
-		return;
-	case AF_VSOCK:
-		init_addr_loopback_vsock(ss, len);
-		return;
-	default:
-		FAIL("unsupported address family %d", family);
-	}
-}
-
-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;
@@ -334,136 +83,4 @@ static inline int add_to_sockmap(int sock_mapfd, int fd1, int fd2)
 	return xbpf_map_update_elem(sock_mapfd, &key, &value, BPF_NOEXIST);
 }
 
-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 = 0;
-	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);
-}
-
-static inline int create_pair(int family, int sotype, int *p0, int *p1)
-{
-	__close_fd int s, c = -1, p = -1;
-	struct sockaddr_storage addr;
-	socklen_t len = sizeof(addr);
-	int err;
-
-	s = socket_loopback(family, sotype);
-	if (s < 0)
-		return s;
-
-	err = xgetsockname(s, sockaddr(&addr), &len);
-	if (err)
-		return err;
-
-	c = xsocket(family, sotype, 0);
-	if (c < 0)
-		return c;
-
-	err = connect(c, sockaddr(&addr), len);
-	if (err) {
-		if (errno != EINPROGRESS) {
-			FAIL_ERRNO("connect");
-			return err;
-		}
-
-		err = poll_connect(c, IO_TIMEOUT_SEC);
-		if (err) {
-			FAIL_ERRNO("poll_connect");
-			return err;
-		}
-	}
-
-	switch (sotype & SOCK_TYPE_MASK) {
-	case SOCK_DGRAM:
-		err = xgetsockname(c, sockaddr(&addr), &len);
-		if (err)
-			return err;
-
-		err = xconnect(s, sockaddr(&addr), len);
-		if (err)
-			return err;
-
-		*p0 = take_fd(s);
-		break;
-	case SOCK_STREAM:
-	case SOCK_SEQPACKET:
-		p = xaccept_nonblock(s, NULL, NULL);
-		if (p < 0)
-			return p;
-
-		*p0 = take_fd(p);
-		break;
-	default:
-		FAIL("Unsupported socket type %#x", sotype);
-		return -EOPNOTSUPP;
-	}
-
-	*p1 = take_fd(c);
-	return 0;
-}
-
-static inline int create_socket_pairs(int family, int sotype, int *c0, int *c1,
-				      int *p0, int *p1)
-{
-	int err;
-
-	err = create_pair(family, sotype, c0, p0);
-	if (err)
-		return err;
-
-	err = create_pair(family, sotype, c1, p1);
-	if (err) {
-		close(*c0);
-		close(*p0);
-	}
-
-	return err;
-}
-
 #endif // __SOCKMAP_HELPERS__
diff --git a/tools/testing/selftests/bpf/prog_tests/tc_change_tail.c b/tools/testing/selftests/bpf/prog_tests/tc_change_tail.c
new file mode 100644
index 000000000000..74752233e779
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/tc_change_tail.c
@@ -0,0 +1,62 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <error.h>
+#include <test_progs.h>
+#include <linux/pkt_cls.h>
+
+#include "test_tc_change_tail.skel.h"
+#include "socket_helpers.h"
+
+#define LO_IFINDEX 1
+
+void test_tc_change_tail(void)
+{
+	LIBBPF_OPTS(bpf_tcx_opts, tcx_opts);
+	struct test_tc_change_tail *skel = NULL;
+	struct bpf_link *link;
+	int c1, p1;
+	char buf[2];
+	int ret;
+
+	skel = test_tc_change_tail__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "test_tc_change_tail__open_and_load"))
+		return;
+
+	link = bpf_program__attach_tcx(skel->progs.change_tail, LO_IFINDEX,
+				     &tcx_opts);
+	if (!ASSERT_OK_PTR(link, "bpf_program__attach_tcx"))
+		goto destroy;
+
+	skel->links.change_tail = link;
+	ret = create_pair(AF_INET, SOCK_DGRAM, &c1, &p1);
+	if (!ASSERT_OK(ret, "create_pair"))
+		goto destroy;
+
+	ret = xsend(p1, "Tr", 2, 0);
+	ASSERT_EQ(ret, 2, "xsend(p1)");
+	ret = recv(c1, buf, 2, 0);
+	ASSERT_EQ(ret, 2, "recv(c1)");
+	ASSERT_EQ(skel->data->change_tail_ret, 0, "change_tail_ret");
+
+	ret = xsend(p1, "G", 1, 0);
+	ASSERT_EQ(ret, 1, "xsend(p1)");
+	ret = recv(c1, buf, 2, 0);
+	ASSERT_EQ(ret, 1, "recv(c1)");
+	ASSERT_EQ(skel->data->change_tail_ret, 0, "change_tail_ret");
+
+	ret = xsend(p1, "E", 1, 0);
+	ASSERT_EQ(ret, 1, "xsend(p1)");
+	ret = recv(c1, buf, 1, 0);
+	ASSERT_EQ(ret, 1, "recv(c1)");
+	ASSERT_EQ(skel->data->change_tail_ret, -EINVAL, "change_tail_ret");
+
+	ret = xsend(p1, "Z", 1, 0);
+	ASSERT_EQ(ret, 1, "xsend(p1)");
+	ret = recv(c1, buf, 1, 0);
+	ASSERT_EQ(ret, 1, "recv(c1)");
+	ASSERT_EQ(skel->data->change_tail_ret, -EINVAL, "change_tail_ret");
+
+	close(c1);
+	close(p1);
+destroy:
+	test_tc_change_tail__destroy(skel);
+}