selftests/bpf: Add wait send memory test for sockmap redirect

Add one test for wait redirect sock's send memory test for sockmap.
Signed-off-by: Liu Jian <liujian56@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20220823133755.314697-3-liujian56@huawei.com

tools/testing/selftests/bpf/test_sockmap.c

@@ -138,6 +138,7 @@ struct sockmap_options {
 	bool data_test;
 	bool drop_expected;
 	bool check_recved_len;
+	bool tx_wait_mem;
 	int iov_count;
 	int iov_length;
 	int rate;
@@ -578,6 +579,10 @@ static int msg_loop(int fd, int iov_count, int iov_length, int cnt,
 			sent = sendmsg(fd, &msg, flags);
 
 			if (!drop && sent < 0) {
+				if (opt->tx_wait_mem && errno == EACCES) {
+					errno = 0;
+					goto out_errno;
+				}
 				perror("sendmsg loop error");
 				goto out_errno;
 			} else if (drop && sent >= 0) {
@@ -644,6 +649,15 @@ static int msg_loop(int fd, int iov_count, int iov_length, int cnt,
 				goto out_errno;
 			}
 
+			if (opt->tx_wait_mem) {
+				FD_ZERO(&w);
+				FD_SET(fd, &w);
+				slct = select(max_fd + 1, NULL, NULL, &w, &timeout);
+				errno = 0;
+				close(fd);
+				goto out_errno;
+			}
+
 			errno = 0;
 			if (peek_flag) {
 				flags |= MSG_PEEK;
@@ -752,6 +766,22 @@ static int sendmsg_test(struct sockmap_options *opt)
 			return err;
 	}
 
+	if (opt->tx_wait_mem) {
+		struct timeval timeout;
+		int rxtx_buf_len = 1024;
+
+		timeout.tv_sec = 3;
+		timeout.tv_usec = 0;
+
+		err = setsockopt(c2, SOL_SOCKET, SO_SNDTIMEO, &timeout, sizeof(struct timeval));
+		err |= setsockopt(c2, SOL_SOCKET, SO_SNDBUFFORCE, &rxtx_buf_len, sizeof(int));
+		err |= setsockopt(p2, SOL_SOCKET, SO_RCVBUFFORCE, &rxtx_buf_len, sizeof(int));
+		if (err) {
+			perror("setsockopt failed()");
+			return errno;
+		}
+	}
+
 	rxpid = fork();
 	if (rxpid == 0) {
 		if (txmsg_pop || txmsg_start_pop)
@@ -788,6 +818,9 @@ static int sendmsg_test(struct sockmap_options *opt)
 		return errno;
 	}
 
+	if (opt->tx_wait_mem)
+		close(c2);
+
 	txpid = fork();
 	if (txpid == 0) {
 		if (opt->sendpage)
@@ -1452,6 +1485,14 @@ static void test_txmsg_redir(int cgrp, struct sockmap_options *opt)
 	test_send(opt, cgrp);
 }
 
+static void test_txmsg_redir_wait_sndmem(int cgrp, struct sockmap_options *opt)
+{
+	txmsg_redir = 1;
+	opt->tx_wait_mem = true;
+	test_send_large(opt, cgrp);
+	opt->tx_wait_mem = false;
+}
+
 static void test_txmsg_drop(int cgrp, struct sockmap_options *opt)
 {
 	txmsg_drop = 1;
@@ -1800,6 +1841,7 @@ static int populate_progs(char *bpf_file)
 struct _test test[] = {
 	{"txmsg test passthrough", test_txmsg_pass},
 	{"txmsg test redirect", test_txmsg_redir},
+	{"txmsg test redirect wait send mem", test_txmsg_redir_wait_sndmem},
 	{"txmsg test drop", test_txmsg_drop},
 	{"txmsg test ingress redirect", test_txmsg_ingress_redir},
 	{"txmsg test skb", test_txmsg_skb},