[PATCH net] selftests/net: report etf errors correctly

[Willem de Bruijn <willemdebruijn.kernel@gmail.com>]

From: Willem de Bruijn <willemb@google.com>

The ETF qdisc can queue skbs that it could not pace on the errqueue.

Address a few issues in the selftest

- recv buffer size was too small, and incorrectly calculated
- compared errno to ee_code instead of ee_errno
- missed error type invalid request

Fixes: ea6a547669b3 ("selftests/net: make so_txtime more robust to timer variance")
Signed-off-by: Willem de Bruijn <willemb@google.com>
---
 tools/testing/selftests/net/so_txtime.c | 33 +++++++++++++++++++------
 1 file changed, 26 insertions(+), 7 deletions(-)

diff --git a/tools/testing/selftests/net/so_txtime.c b/tools/testing/selftests/net/so_txtime.c
index 383bac05ac32..3400afff0c3c 100644
--- a/tools/testing/selftests/net/so_txtime.c
+++ b/tools/testing/selftests/net/so_txtime.c
@@ -15,8 +15,9 @@
 #include <inttypes.h>
 #include <linux/net_tstamp.h>
 #include <linux/errqueue.h>
+#include <linux/if_ether.h>
 #include <linux/ipv6.h>
-#include <linux/tcp.h>
+#include <linux/udp.h>
 #include <stdbool.h>
 #include <stdlib.h>
 #include <stdio.h>
@@ -140,8 +141,8 @@ static void do_recv_errqueue_timeout(int fdt)
 {
 	char control[CMSG_SPACE(sizeof(struct sock_extended_err)) +
 		     CMSG_SPACE(sizeof(struct sockaddr_in6))] = {0};
-	char data[sizeof(struct ipv6hdr) +
-		  sizeof(struct tcphdr) + 1];
+	char data[sizeof(struct ethhdr) + sizeof(struct ipv6hdr) +
+		  sizeof(struct udphdr) + 1];
 	struct sock_extended_err *err;
 	struct msghdr msg = {0};
 	struct iovec iov = {0};
@@ -159,6 +160,8 @@ static void do_recv_errqueue_timeout(int fdt)
 	msg.msg_controllen = sizeof(control);
 
 	while (1) {
+		const char *reason;
+
 		ret = recvmsg(fdt, &msg, MSG_ERRQUEUE);
 		if (ret == -1 && errno == EAGAIN)
 			break;
@@ -176,14 +179,30 @@ static void do_recv_errqueue_timeout(int fdt)
 		err = (struct sock_extended_err *)CMSG_DATA(cm);
 		if (err->ee_origin != SO_EE_ORIGIN_TXTIME)
 			error(1, 0, "errqueue: origin 0x%x\n", err->ee_origin);
-		if (err->ee_code != ECANCELED)
-			error(1, 0, "errqueue: code 0x%x\n", err->ee_code);
+
+		switch (err->ee_errno) {
+		case ECANCELED:
+			if (err->ee_code != SO_EE_CODE_TXTIME_MISSED)
+				error(1, 0, "errqueue: unknown ECANCELED %u\n",
+					    err->ee_code);
+			reason = "missed txtime";
+		break;
+		case EINVAL:
+			if (err->ee_code != SO_EE_CODE_TXTIME_INVALID_PARAM)
+				error(1, 0, "errqueue: unknown EINVAL %u\n",
+					    err->ee_code);
+			reason = "invalid txtime";
+		break;
+		default:
+			error(1, 0, "errqueue: errno %u code %u\n",
+			      err->ee_errno, err->ee_code);
+		};
 
 		tstamp = ((int64_t) err->ee_data) << 32 | err->ee_info;
 		tstamp -= (int64_t) glob_tstart;
 		tstamp /= 1000 * 1000;
-		fprintf(stderr, "send: pkt %c at %" PRId64 "ms dropped\n",
-				data[ret - 1], tstamp);
+		fprintf(stderr, "send: pkt %c at %" PRId64 "ms dropped: %s\n",
+				data[ret - 1], tstamp, reason);
 
 		msg.msg_flags = 0;
 		msg.msg_controllen = sizeof(control);
-- 
2.27.0.290.gba653c62da-goog