selftests/bpf: Migrate sendmsg6 v4 mapped address tests

Migrate test case from bpf/test_sock_addr.c ensuring that sendmsg
returns -ENOTSUPP when sending to an IPv4-mapped IPv6 address to
prog_tests/sock_addr.c.

Signed-off-by: Jordan Rife <jrife@google.com>
Link: https://lore.kernel.org/r/20240510190246.3247730-9-jrife@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

Author: jrife

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

@@ -447,6 +447,7 @@ BPF_SKEL_FUNCS(sendmsg4_prog, sendmsg_v4_deny_prog);
 BPF_SKEL_FUNCS(sendmsg6_prog, sendmsg_v6_prog);
 BPF_SKEL_FUNCS(sendmsg6_prog, sendmsg_v6_deny_prog);
 BPF_SKEL_FUNCS(sendmsg6_prog, sendmsg_v6_preserve_dst_prog);
+BPF_SKEL_FUNCS(sendmsg6_prog, sendmsg_v6_v4mapped_prog);
 BPF_SKEL_FUNCS(sendmsg_unix_prog, sendmsg_unix_prog);
 BPF_SKEL_FUNCS(recvmsg4_prog, recvmsg4_prog);
 BPF_SKEL_FUNCS(recvmsg6_prog, recvmsg6_prog);
@@ -832,6 +833,22 @@ static struct sock_addr_test tests[] = {
 		SRC6_REWRITE_IP,
 		SYSCALL_EPERM,
 	},
+	{
+		SOCK_ADDR_TEST_SENDMSG,
+		"sendmsg6: sendmsg IPv4-mapped IPv6 (dgram)",
+		sendmsg_v6_v4mapped_prog_load,
+		sendmsg_v6_v4mapped_prog_destroy,
+		BPF_CGROUP_UDP6_SENDMSG,
+		&user_ops,
+		AF_INET6,
+		SOCK_DGRAM,
+		SERV6_IP,
+		SERV6_PORT,
+		SERV6_REWRITE_IP,
+		SERV6_REWRITE_PORT,
+		SRC6_REWRITE_IP,
+		SYSCALL_ENOTSUPP,
+	},
 	{
 		SOCK_ADDR_TEST_SENDMSG,
 		"sendmsg_unix: sendmsg (dgram)",

tools/testing/selftests/bpf/progs/sendmsg6_prog.c

@@ -20,6 +20,11 @@
 #define DST_REWRITE_IP6_2	0
 #define DST_REWRITE_IP6_3	1
 
+#define DST_REWRITE_IP6_V4_MAPPED_0	0
+#define DST_REWRITE_IP6_V4_MAPPED_1	0
+#define DST_REWRITE_IP6_V4_MAPPED_2	0x0000FFFF
+#define DST_REWRITE_IP6_V4_MAPPED_3	0xc0a80004 // 192.168.0.4
+
 #define DST_REWRITE_PORT6	6666
 
 SEC("cgroup/sendmsg6")
@@ -59,6 +64,26 @@ int sendmsg_v6_prog(struct bpf_sock_addr *ctx)
 	return 1;
 }
 
+SEC("cgroup/sendmsg6")
+int sendmsg_v6_v4mapped_prog(struct bpf_sock_addr *ctx)
+{
+	/* Rewrite source. */
+	ctx->msg_src_ip6[0] = bpf_htonl(SRC_REWRITE_IP6_0);
+	ctx->msg_src_ip6[1] = bpf_htonl(SRC_REWRITE_IP6_1);
+	ctx->msg_src_ip6[2] = bpf_htonl(SRC_REWRITE_IP6_2);
+	ctx->msg_src_ip6[3] = bpf_htonl(SRC_REWRITE_IP6_3);
+
+	/* Rewrite destination. */
+	ctx->user_ip6[0] = bpf_htonl(DST_REWRITE_IP6_V4_MAPPED_0);
+	ctx->user_ip6[1] = bpf_htonl(DST_REWRITE_IP6_V4_MAPPED_1);
+	ctx->user_ip6[2] = bpf_htonl(DST_REWRITE_IP6_V4_MAPPED_2);
+	ctx->user_ip6[3] = bpf_htonl(DST_REWRITE_IP6_V4_MAPPED_3);
+
+	ctx->user_port = bpf_htons(DST_REWRITE_PORT6);
+
+	return 1;
+}
+
 SEC("cgroup/sendmsg6")
 int sendmsg_v6_preserve_dst_prog(struct bpf_sock_addr *ctx)
 {

tools/testing/selftests/bpf/test_sock_addr.c

@@ -94,7 +94,6 @@ static int connect4_prog_load(const struct sock_addr_test *test);
 static int connect6_prog_load(const struct sock_addr_test *test);
 static int sendmsg4_rw_asm_prog_load(const struct sock_addr_test *test);
 static int sendmsg6_rw_asm_prog_load(const struct sock_addr_test *test);
-static int sendmsg6_rw_v4mapped_prog_load(const struct sock_addr_test *test);
 static int sendmsg6_rw_wildcard_prog_load(const struct sock_addr_test *test);
 
 static struct sock_addr_test tests[] = {
@@ -299,20 +298,6 @@ static struct sock_addr_test tests[] = {
 		SRC6_REWRITE_IP,
 		SUCCESS,
 	},
-	{
-		"sendmsg6: IPv4-mapped IPv6",
-		sendmsg6_rw_v4mapped_prog_load,
-		BPF_CGROUP_UDP6_SENDMSG,
-		BPF_CGROUP_UDP6_SENDMSG,
-		AF_INET6,
-		SOCK_DGRAM,
-		SERV6_IP,
-		SERV6_PORT,
-		SERV6_REWRITE_IP,
-		SERV6_REWRITE_PORT,
-		SRC6_REWRITE_IP,
-		SYSCALL_ENOTSUPP,
-	},
 	{
 		"sendmsg6: set dst IP = [::] (BSD'ism)",
 		sendmsg6_rw_wildcard_prog_load,
@@ -512,11 +497,6 @@ static int sendmsg6_rw_asm_prog_load(const struct sock_addr_test *test)
 	return sendmsg6_rw_dst_asm_prog_load(test, SERV6_REWRITE_IP);
 }
 
-static int sendmsg6_rw_v4mapped_prog_load(const struct sock_addr_test *test)
-{
-	return sendmsg6_rw_dst_asm_prog_load(test, SERV6_V4MAPPED_IP);
-}
-
 static int sendmsg6_rw_wildcard_prog_load(const struct sock_addr_test *test)
 {
 	return sendmsg6_rw_dst_asm_prog_load(test, WILDCARD6_IP);