[PATCH net-next 4/6] selftests: drv-net: add primary RX redirect support to NetDrvContEnv

@@ -1,4 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0-only
 iou-zcrx
 ncdevmem
+nk_primary_rx_redirect
 toeplitz

@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/bpf.h>
+#include <linux/if_ether.h>
+#include <linux/ipv6.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+
+#define TC_ACT_OK 0
+#define ETH_P_IPV6 0x86DD
+#define IPPROTO_ICMPV6 58
+
+#define ctx_ptr(field)		((void *)(long)(field))
+
+volatile __u32 phys_ifindex;
+
+SEC("tc/ingress")
+int nk_primary_rx_redirect(struct __sk_buff *skb)
+{
+	void *data_end = ctx_ptr(skb->data_end);
+	void *data = ctx_ptr(skb->data);
+	struct ethhdr *eth;
+	struct ipv6hdr *ip6h;
+
+	eth = data;
+	if ((void *)(eth + 1) > data_end)
+		return TC_ACT_OK;
+
+	if (eth->h_proto != bpf_htons(ETH_P_IPV6))
+		return TC_ACT_OK;
+
+	ip6h = data + sizeof(struct ethhdr);
+	if ((void *)(ip6h + 1) > data_end)
+		return TC_ACT_OK;
+
+	if (ip6h->nexthdr == IPPROTO_ICMPV6)
+		return TC_ACT_OK;
+
+	return bpf_redirect_neigh(phys_ifindex, NULL, 0, 0);
+}
+
+char __license[] SEC("license") = "GPL";

@@ -327,12 +327,13 @@ class NetDrvContEnv(NetDrvEpEnv):
               +---------------+
     """
 
-    def __init__(self, src_path, rxqueues=1, **kwargs):
+    def __init__(self, src_path, rxqueues=1, primary_rx_redirect=False, **kwargs):
         self.netns = None
         self._nk_host_ifname = None
         self._nk_guest_ifname = None
         self._tc_clsact_added = False
         self._tc_attached = False
+        self._primary_rx_redirect_attached = False
         self._bpf_prog_pref = None
         self._bpf_prog_id = None
         self._init_ns_attached = False

@@ -387,8 +388,14 @@ class NetDrvContEnv(NetDrvEpEnv):
 
         self._setup_ns()
         self._attach_bpf()
+        if primary_rx_redirect:
+            self._attach_primary_rx_redirect_bpf()
 
     def __del__(self):
+        if self._primary_rx_redirect_attached:
+            cmd(f"tc qdisc del dev {self._nk_host_ifname} clsact", fail=False)
+            self._primary_rx_redirect_attached = False
+
         if self._tc_attached:
             cmd(f"tc filter del dev {self.ifname} ingress pref {self._bpf_prog_pref}")
             self._tc_attached = False

@@ -450,6 +457,8 @@ class NetDrvContEnv(NetDrvEpEnv):
         ip(f"-6 addr add {self.nk_guest_ipv6}/64 dev {self._nk_guest_ifname} nodad", ns=self.netns)
         ip(f"-6 route add default via fe80::1 dev {self._nk_guest_ifname}", ns=self.netns)
 
+        ip(f"-6 route add {self.nk_guest_ipv6}/128 via {self.addr_v['6']}", host=self.remote)
+
     def _tc_ensure_clsact(self):
         qdisc = json.loads(cmd(f"tc -j qdisc show dev {self.ifname}").stdout)
         for q in qdisc:

@@ -495,3 +504,31 @@ class NetDrvContEnv(NetDrvEpEnv):
         value = ipv6_bytes + ifindex_bytes
         value_hex = ' '.join(f'{b:02x}' for b in value)
         bpftool(f"map update id {bss_map_id} key hex 00 00 00 00 value hex {value_hex}")
+
+    def _attach_primary_rx_redirect_bpf(self):
+        """Attach BPF redirect program on the primary netkit ingress."""
+        bpf_obj = self.test_dir / "nk_primary_rx_redirect.bpf.o"
+        if not bpf_obj.exists():
+            raise KsftSkipEx("Primary RX redirect BPF prog not found")
+
+        cmd(f"tc qdisc add dev {self._nk_host_ifname} clsact")
+        cmd(f"tc filter add dev {self._nk_host_ifname} ingress"
+            f" bpf obj {bpf_obj} sec tc/ingress direct-action")
+        self._primary_rx_redirect_attached = True
+
+        filters = json.loads(
+            cmd(f"tc -j filter show dev {self._nk_host_ifname} ingress").stdout)
+        redirect_prog_id = None
+        for bpf in filters:
+            if 'options' not in bpf:
+                continue
+            if bpf['options']['bpf_name'].startswith('nk_primary_rx_redirect'):
+                redirect_prog_id = bpf['options']['prog']['id']
+                break
+        if redirect_prog_id is None:
+            raise Exception("Failed to get primary RX redirect BPF prog ID")
+
+        bss_map_id = self._find_bss_map_id(redirect_prog_id)
+        phys_ifindex_bytes = self.ifindex.to_bytes(4, byteorder='little')
+        value_hex = ' '.join(f'{b:02x}' for b in phys_ifindex_bytes)
+        bpftool(f"map update id {bss_map_id} key hex 00 00 00 00 value hex {value_hex}")