[PATCH v1 3/4] selftests/bpf: Add netpoll kfunc IPv6 variant test

[Mahe Tardy <mahe.tardy@gmail.com>]

Add a selftest that exercises the bpf_netpoll kfuncs end-to-end with
IPv6, reusing the code that was added for IPv4.

Signed-off-by: Mahe Tardy <mahe.tardy@gmail.com>
---
 .../selftests/bpf/prog_tests/netpoll.c        | 42 +++++++++++++++----
 .../selftests/bpf/progs/netpoll_sanity.c      | 33 +++++++++++----
 2 files changed, 58 insertions(+), 17 deletions(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/netpoll.c b/tools/testing/selftests/bpf/prog_tests/netpoll.c
index 1cfac4b13e7d..eac0378c426a 100644
--- a/tools/testing/selftests/bpf/prog_tests/netpoll.c
+++ b/tools/testing/selftests/bpf/prog_tests/netpoll.c
@@ -9,15 +9,20 @@
 #include "netpoll_sanity.skel.h"

 #define NS_TEST "netpoll_sanity_ns"
+#define NS_TEST_V6 "netpoll_sanity_ns_v6"
 #define DUMMY_DEV "dummy0"
 #define DUMMY_IP "10.0.0.1"
 #define REMOTE_IP "10.0.0.2"
+#define DUMMY_IP6 "fd00::1"
+#define REMOTE_IP6 "fd00::2"

-void test_netpoll_sanity(void)
+static void run_netpoll_test(const char *ns_name, const char *local_ip,
+			      const char *remote_ip, bool ipv6)
 {
 	LIBBPF_OPTS(bpf_test_run_opts, opts);
 	struct nstoken *nstoken = NULL;
 	struct netpoll_sanity *skel;
+	struct in6_addr addr6;
 	int err, pfd, fd;

 	skel = netpoll_sanity__open_and_load();
@@ -25,18 +30,28 @@ void test_netpoll_sanity(void)
 		return;

 	/* Create a network namespace with a dummy device */
-	SYS(fail, "ip netns add %s", NS_TEST);
-	SYS(fail, "ip -net %s link add %s type dummy", NS_TEST, DUMMY_DEV);
-	SYS(fail, "ip -net %s addr add %s/24 dev %s", NS_TEST, DUMMY_IP, DUMMY_DEV);
-	SYS(fail, "ip -net %s link set %s up", NS_TEST, DUMMY_DEV);
-
-	nstoken = open_netns(NS_TEST);
+	SYS(fail, "ip netns add %s", ns_name);
+	SYS(fail, "ip -net %s link add %s type dummy", ns_name, DUMMY_DEV);
+	if (ipv6)
+		SYS(fail, "ip -net %s addr add %s/64 dev %s", ns_name, local_ip, DUMMY_DEV);
+	else
+		SYS(fail, "ip -net %s addr add %s/24 dev %s", ns_name, local_ip, DUMMY_DEV);
+	SYS(fail, "ip -net %s link set %s up", ns_name, DUMMY_DEV);
+
+	nstoken = open_netns(ns_name);
 	if (!ASSERT_OK_PTR(nstoken, "open_netns"))
 		goto fail;

 	/* Configure the BPF program globals */
 	snprintf(skel->bss->dev_name, sizeof(skel->bss->dev_name), "%s", DUMMY_DEV);
-	skel->bss->remote_ip = inet_addr(REMOTE_IP);
+	if (ipv6) {
+		if (inet_pton(AF_INET6, remote_ip, &addr6) != 1)
+			goto fail;
+		__builtin_memcpy(&skel->bss->remote_ip6, &addr6, sizeof(addr6));
+		skel->bss->ipv6 = 1;
+	} else {
+		skel->bss->remote_ip = inet_addr(remote_ip);
+	}
 	skel->bss->local_port = 5555;
 	skel->bss->remote_port = 6666;
 	skel->bss->remote_mac[0] = 0xaa;
@@ -87,6 +102,15 @@ void test_netpoll_sanity(void)
 fail:
 	if (nstoken)
 		close_netns(nstoken);
-	SYS_NOFAIL("ip netns del " NS_TEST " &> /dev/null");
+	SYS_NOFAIL("ip netns del %s &> /dev/null", ns_name);
 	netpoll_sanity__destroy(skel);
 }
+
+void test_netpoll_sanity(void)
+{
+	if (test__start_subtest("ipv4"))
+		run_netpoll_test(NS_TEST, DUMMY_IP, REMOTE_IP, false);
+
+	if (test__start_subtest("ipv6"))
+		run_netpoll_test(NS_TEST_V6, DUMMY_IP6, REMOTE_IP6, true);
+}
diff --git a/tools/testing/selftests/bpf/progs/netpoll_sanity.c b/tools/testing/selftests/bpf/progs/netpoll_sanity.c
index 9e1e595eff2c..26303632ebde 100644
--- a/tools/testing/selftests/bpf/progs/netpoll_sanity.c
+++ b/tools/testing/selftests/bpf/progs/netpoll_sanity.c
@@ -12,9 +12,11 @@
 /* Globals for passing config from userspace */
 char dev_name[16] = {};
 __be32 remote_ip;
+struct in6_addr remote_ip6;
 __u16 local_port;
 __u16 remote_port;
 __u8 remote_mac[6] = {};
+int ipv6;

 /* Results */
 int status;
@@ -35,10 +37,14 @@ int netpoll_setup_test(void *ctx)
 	status = 0;

 	__builtin_memcpy(opts.dev_name, dev_name, 16);
-	opts.remote_ip = remote_ip;
+	if (ipv6)
+		__builtin_memcpy(&opts.remote_ip6, &remote_ip6, sizeof(remote_ip6));
+	else
+		opts.remote_ip = remote_ip;
 	opts.local_port = local_port;
 	opts.remote_port = remote_port;
 	__builtin_memcpy(opts.remote_mac, remote_mac, 6);
+	opts.ipv6 = ipv6;

 	bnp = bpf_netpoll_create(&opts, sizeof(opts), &err);
 	if (!bnp) {
@@ -88,7 +94,9 @@ int BPF_PROG(netpoll_dummy_xmit, struct sk_buff *skb, struct net_device *dev)
 	unsigned char *data;
 	struct ethhdr eth;
 	struct iphdr ip;
+	struct ipv6hdr ip6;
 	struct udphdr udp;
+	unsigned int offset;

 	if (bpf_probe_read_kernel(&data, sizeof(data), &skb->data) < 0)
 		return 0;
@@ -97,19 +105,28 @@ int BPF_PROG(netpoll_dummy_xmit, struct sk_buff *skb, struct net_device *dev)

 	if (bpf_probe_read_kernel(&eth, sizeof(eth), data) < 0)
 		return 0;
-	if (eth.h_proto != bpf_htons(ETH_P_IP))
-		return 0;

-	if (bpf_probe_read_kernel(&ip, sizeof(ip), data + sizeof(struct ethhdr)) < 0)
-		return 0;
-	if (ip.protocol != IPPROTO_UDP)
+	if (eth.h_proto == bpf_htons(ETH_P_IP)) {
+		if (bpf_probe_read_kernel(&ip, sizeof(ip), data + sizeof(struct ethhdr)) < 0)
+			return 0;
+		if (ip.protocol != IPPROTO_UDP)
+			return 0;
+		offset = sizeof(struct ethhdr) + (ip.ihl * 4);
+	} else if (eth.h_proto == bpf_htons(ETH_P_IPV6)) {
+		if (bpf_probe_read_kernel(&ip6, sizeof(ip6), data + sizeof(struct ethhdr)) < 0)
+			return 0;
+		if (ip6.nexthdr != IPPROTO_UDP)
+			return 0;
+		offset = sizeof(struct ethhdr) + sizeof(struct ipv6hdr);
+	} else {
 		return 0;
+	}

-	if (bpf_probe_read_kernel(&udp, sizeof(udp), data + sizeof(struct ethhdr) + (ip.ihl * 4)) < 0)
+	if (bpf_probe_read_kernel(&udp, sizeof(udp), data + offset) < 0)
 		return 0;
 	if (udp.dest != bpf_htons(remote_port))
 		return 0;
-	if (bpf_probe_read_kernel(&driver_xmit, sizeof(driver_xmit), data + sizeof(struct ethhdr) + (ip.ihl * 4) + sizeof(struct udphdr)) < 0)
+	if (bpf_probe_read_kernel(&driver_xmit, sizeof(driver_xmit), data + offset + sizeof(struct udphdr)) < 0)
 		return 0;

 	return 0;
--
2.34.1