selftests/net: reap zerocopy completions passed up as ancillary data.

PF_RDS sockets pass up cookies for zerocopy completion as ancillary
data. Update msg_zerocopy to reap this information.
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

tools/testing/selftests/net/msg_zerocopy.c

@@ -344,7 +344,53 @@ static int do_setup_tx(int domain, int type, int protocol)
 	return fd;
 }
 
-static bool do_recv_completion(int fd)
+static uint32_t do_process_zerocopy_cookies(struct rds_zcopy_cookies *ck)
+{
+	int i;
+
+	if (ck->num > RDS_MAX_ZCOOKIES)
+		error(1, 0, "Returned %d cookies, max expected %d\n",
+		      ck->num, RDS_MAX_ZCOOKIES);
+	for (i = 0; i < ck->num; i++)
+		if (cfg_verbose >= 2)
+			fprintf(stderr, "%d\n", ck->cookies[i]);
+	return ck->num;
+}
+
+static bool do_recvmsg_completion(int fd)
+{
+	char cmsgbuf[CMSG_SPACE(sizeof(struct rds_zcopy_cookies))];
+	struct rds_zcopy_cookies *ck;
+	struct cmsghdr *cmsg;
+	struct msghdr msg;
+	bool ret = false;
+
+	memset(&msg, 0, sizeof(msg));
+	msg.msg_control = cmsgbuf;
+	msg.msg_controllen = sizeof(cmsgbuf);
+
+	if (recvmsg(fd, &msg, MSG_DONTWAIT))
+		return ret;
+
+	if (msg.msg_flags & MSG_CTRUNC)
+		error(1, errno, "recvmsg notification: truncated");
+
+	for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
+		if (cmsg->cmsg_level == SOL_RDS &&
+		    cmsg->cmsg_type == RDS_CMSG_ZCOPY_COMPLETION) {
+
+			ck = (struct rds_zcopy_cookies *)CMSG_DATA(cmsg);
+			completions += do_process_zerocopy_cookies(ck);
+			ret = true;
+			break;
+		}
+		error(0, 0, "ignoring cmsg at level %d type %d\n",
+			    cmsg->cmsg_level, cmsg->cmsg_type);
+	}
+	return ret;
+}
+
+static bool do_recv_completion(int fd, int domain)
 {
 	struct sock_extended_err *serr;
 	struct msghdr msg = {};
@@ -353,6 +399,9 @@ static bool do_recv_completion(int fd)
 	int ret, zerocopy;
 	char control[100];
 
+	if (domain == PF_RDS)
+		return do_recvmsg_completion(fd);
+
 	msg.msg_control = control;
 	msg.msg_controllen = sizeof(control);
 
@@ -409,20 +458,20 @@ static bool do_recv_completion(int fd)
 }
 
 /* Read all outstanding messages on the errqueue */
-static void do_recv_completions(int fd)
+static void do_recv_completions(int fd, int domain)
 {
-	while (do_recv_completion(fd)) {}
+	while (do_recv_completion(fd, domain)) {}
 }
 
 /* Wait for all remaining completions on the errqueue */
-static void do_recv_remaining_completions(int fd)
+static void do_recv_remaining_completions(int fd, int domain)
 {
 	int64_t tstop = gettimeofday_ms() + cfg_waittime_ms;
 
 	while (completions < expected_completions &&
 	       gettimeofday_ms() < tstop) {
-		if (do_poll(fd, POLLERR))
-			do_recv_completions(fd);
+		if (do_poll(fd, domain == PF_RDS ? POLLIN : POLLERR))
+			do_recv_completions(fd, domain);
 	}
 
 	if (completions < expected_completions)
@@ -503,13 +552,13 @@ static void do_tx(int domain, int type, int protocol)
 
 		while (!do_poll(fd, POLLOUT)) {
 			if (cfg_zerocopy)
-				do_recv_completions(fd);
+				do_recv_completions(fd, domain);
 		}
 
 	} while (gettimeofday_ms() < tstop);
 
 	if (cfg_zerocopy)
-		do_recv_remaining_completions(fd);
+		do_recv_remaining_completions(fd, domain);
 
 	if (close(fd))
 		error(1, errno, "close");