selftests/bpf: Parametrize AF_UNIX redir functions to accept send() flags

Extend pairs_redir_to_connected() and unix_inet_redir_to_connected() with a
send_flags parameter. Replace write() with send() allowing packets to be
sent as MSG_OOB.
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Jakub Sitnicki <jakub@cloudflare.com>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/20240713200218.2140950-4-mhal@rbox.co

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

@@ -29,6 +29,8 @@
 
 #include "sockmap_helpers.h"
 
+#define NO_FLAGS 0
+
 static void test_insert_invalid(struct test_sockmap_listen *skel __always_unused,
 				int family, int sotype, int mapfd)
 {
@@ -1376,7 +1378,8 @@ static void test_redir(struct test_sockmap_listen *skel, struct bpf_map *map,
 
 static void pairs_redir_to_connected(int cli0, int peer0, int cli1, int peer1,
 				     int sock_mapfd, int nop_mapfd,
-				     int verd_mapfd, enum redir_mode mode)
+				     int verd_mapfd, enum redir_mode mode,
+				     int send_flags)
 {
 	const char *log_prefix = redir_mode_str(mode);
 	unsigned int pass;
@@ -1396,11 +1399,9 @@ static void pairs_redir_to_connected(int cli0, int peer0, int cli1, int peer1,
 			return;
 	}
 
-	n = write(cli1, "a", 1);
-	if (n < 0)
-		FAIL_ERRNO("%s: write", log_prefix);
+	n = xsend(cli1, "a", 1, send_flags);
 	if (n == 0)
-		FAIL("%s: incomplete write", log_prefix);
+		FAIL("%s: incomplete send", log_prefix);
 	if (n < 1)
 		return;
 
@@ -1432,7 +1433,8 @@ static void unix_redir_to_connected(int sotype, int sock_mapfd,
 		goto close0;
 	c1 = sfd[0], p1 = sfd[1];
 
-	pairs_redir_to_connected(c0, p0, c1, p1, sock_mapfd, -1, verd_mapfd, mode);
+	pairs_redir_to_connected(c0, p0, c1, p1, sock_mapfd, -1, verd_mapfd,
+				 mode, NO_FLAGS);
 
 	xclose(c1);
 	xclose(p1);
@@ -1722,7 +1724,8 @@ static void udp_redir_to_connected(int family, int sock_mapfd, int verd_mapfd,
 	if (err)
 		goto close_cli0;
 
-	pairs_redir_to_connected(c0, p0, c1, p1, sock_mapfd, -1, verd_mapfd, mode);
+	pairs_redir_to_connected(c0, p0, c1, p1, sock_mapfd, -1, verd_mapfd,
+				 mode, NO_FLAGS);
 
 	xclose(c1);
 	xclose(p1);
@@ -1780,7 +1783,8 @@ static void inet_unix_redir_to_connected(int family, int type, int sock_mapfd,
 	if (err)
 		goto close;
 
-	pairs_redir_to_connected(c0, p0, c1, p1, sock_mapfd, -1, verd_mapfd, mode);
+	pairs_redir_to_connected(c0, p0, c1, p1, sock_mapfd, -1, verd_mapfd,
+				 mode, NO_FLAGS);
 
 	xclose(c1);
 	xclose(p1);
@@ -1815,10 +1819,9 @@ static void inet_unix_skb_redir_to_connected(struct test_sockmap_listen *skel,
 	xbpf_prog_detach2(verdict, sock_map, BPF_SK_SKB_VERDICT);
 }
 
-static void unix_inet_redir_to_connected(int family, int type,
-					int sock_mapfd, int nop_mapfd,
-					int verd_mapfd,
-					enum redir_mode mode)
+static void unix_inet_redir_to_connected(int family, int type, int sock_mapfd,
+					 int nop_mapfd, int verd_mapfd,
+					 enum redir_mode mode, int send_flags)
 {
 	int c0, c1, p0, p1;
 	int sfd[2];
@@ -1832,8 +1835,8 @@ static void unix_inet_redir_to_connected(int family, int type,
 		goto close_cli0;
 	c1 = sfd[0], p1 = sfd[1];
 
-	pairs_redir_to_connected(c0, p0, c1, p1,
-				 sock_mapfd, nop_mapfd, verd_mapfd, mode);
+	pairs_redir_to_connected(c0, p0, c1, p1, sock_mapfd, nop_mapfd,
+				 verd_mapfd, mode, send_flags);
 
 	xclose(c1);
 	xclose(p1);
@@ -1858,31 +1861,32 @@ static void unix_inet_skb_redir_to_connected(struct test_sockmap_listen *skel,
 	skel->bss->test_ingress = false;
 	unix_inet_redir_to_connected(family, SOCK_DGRAM,
 				     sock_map, -1, verdict_map,
-				     REDIR_EGRESS);
+				     REDIR_EGRESS, NO_FLAGS);
 	unix_inet_redir_to_connected(family, SOCK_DGRAM,
 				     sock_map, -1, verdict_map,
-				     REDIR_EGRESS);
+				     REDIR_EGRESS, NO_FLAGS);
 
 	unix_inet_redir_to_connected(family, SOCK_DGRAM,
 				     sock_map, nop_map, verdict_map,
-				     REDIR_EGRESS);
+				     REDIR_EGRESS, NO_FLAGS);
 	unix_inet_redir_to_connected(family, SOCK_STREAM,
 				     sock_map, nop_map, verdict_map,
-				     REDIR_EGRESS);
+				     REDIR_EGRESS, NO_FLAGS);
+
 	skel->bss->test_ingress = true;
 	unix_inet_redir_to_connected(family, SOCK_DGRAM,
 				     sock_map, -1, verdict_map,
-				     REDIR_INGRESS);
+				     REDIR_INGRESS, NO_FLAGS);
 	unix_inet_redir_to_connected(family, SOCK_STREAM,
 				     sock_map, -1, verdict_map,
-				     REDIR_INGRESS);
+				     REDIR_INGRESS, NO_FLAGS);
 
 	unix_inet_redir_to_connected(family, SOCK_DGRAM,
 				     sock_map, nop_map, verdict_map,
-				     REDIR_INGRESS);
+				     REDIR_INGRESS, NO_FLAGS);
 	unix_inet_redir_to_connected(family, SOCK_STREAM,
 				     sock_map, nop_map, verdict_map,
-				     REDIR_INGRESS);
+				     REDIR_INGRESS, NO_FLAGS);
 
 	xbpf_prog_detach2(verdict, sock_map, BPF_SK_SKB_VERDICT);
 }