selftests/bpf: Extend netkit tests to validate set {head,tail}room

Extend the netkit selftests to specify and validate the {head,tail}room
on the netdevice:

  # ./vmtest.sh -- ./test_progs -t netkit
  [...]
  ./test_progs -t netkit
  [    1.174147] bpf_testmod: loading out-of-tree module taints kernel.
  [    1.174585] bpf_testmod: module verification failed: signature and/or required key missing - tainting kernel
  [    1.422307] tsc: Refined TSC clocksource calibration: 3407.983 MHz
  [    1.424511] clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x311fc3e5084, max_idle_ns: 440795359833 ns
  [    1.428092] clocksource: Switched to clocksource tsc
  #363     tc_netkit_basic:OK
  #364     tc_netkit_device:OK
  #365     tc_netkit_multi_links:OK
  #366     tc_netkit_multi_opts:OK
  #367     tc_netkit_neigh_links:OK
  #368     tc_netkit_pkt_type:OK
  #369     tc_netkit_scrub:OK
  Summary: 7/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://lore.kernel.org/bpf/20241220234658.490686-3-daniel@iogearbox.net

diff --git a/tools/testing/selftests/bpf/prog_tests/tc_netkit.c b/tools/testing/selftests/bpf/prog_tests/tc_netkit.c
index 151a4210028f8ea4774e3ec1539ce0348d94c702..2461d183dee584297f68df19b3c28cb52118bc59 100644 (file)
--- a/tools/testing/selftests/bpf/prog_tests/tc_netkit.c
+++ b/tools/testing/selftests/bpf/prog_tests/tc_netkit.c
@@ -14,10 +14,16 @@
 #include "netlink_helpers.h"
 #include "tc_helpers.h"
 
+#define NETKIT_HEADROOM        32
+#define NETKIT_TAILROOM        8
+
 #define MARK           42
 #define PRIO           0xeb9f
 #define ICMP_ECHO      8
 
+#define FLAG_ADJUST_ROOM (1 << 0)
+#define FLAG_SAME_NETNS  (1 << 1)
+
 struct icmphdr {
        __u8            type;
        __u8            code;
@@ -35,7 +41,7 @@ struct iplink_req {
 };
 
 static int create_netkit(int mode, int policy, int peer_policy, int *ifindex,
-                        bool same_netns, int scrub, int peer_scrub)
+                        int scrub, int peer_scrub, __u32 flags)
 {
        struct rtnl_handle rth = { .fd = -1 };
        struct iplink_req req = {};
@@ -63,6 +69,10 @@ static int create_netkit(int mode, int policy, int peer_policy, int *ifindex,
        addattr32(&req.n, sizeof(req), IFLA_NETKIT_SCRUB, scrub);
        addattr32(&req.n, sizeof(req), IFLA_NETKIT_PEER_SCRUB, peer_scrub);
        addattr32(&req.n, sizeof(req), IFLA_NETKIT_MODE, mode);
+       if (flags & FLAG_ADJUST_ROOM) {
+               addattr16(&req.n, sizeof(req), IFLA_NETKIT_HEADROOM, NETKIT_HEADROOM);
+               addattr16(&req.n, sizeof(req), IFLA_NETKIT_TAILROOM, NETKIT_TAILROOM);
+       }
        addattr_nest_end(&req.n, data);
        addattr_nest_end(&req.n, linkinfo);
 
@@ -87,7 +97,7 @@ static int create_netkit(int mode, int policy, int peer_policy, int *ifindex,
                                 " addr ee:ff:bb:cc:aa:dd"),
                                 "set hwaddress");
        }
-       if (same_netns) {
+       if (flags & FLAG_SAME_NETNS) {
                ASSERT_OK(system("ip link set dev " netkit_peer " up"),
                                 "up peer");
                ASSERT_OK(system("ip addr add dev " netkit_peer " 10.0.0.2/24"),
@@ -184,8 +194,8 @@ void serial_test_tc_netkit_basic(void)
        int err, ifindex;
 
        err = create_netkit(NETKIT_L2, NETKIT_PASS, NETKIT_PASS,
-                           &ifindex, false, NETKIT_SCRUB_DEFAULT,
-                           NETKIT_SCRUB_DEFAULT);
+                           &ifindex, NETKIT_SCRUB_DEFAULT,
+                           NETKIT_SCRUB_DEFAULT, 0);
        if (err)
                return;
 
@@ -299,8 +309,8 @@ static void serial_test_tc_netkit_multi_links_target(int mode, int target)
        int err, ifindex;
 
        err = create_netkit(mode, NETKIT_PASS, NETKIT_PASS,
-                           &ifindex, false, NETKIT_SCRUB_DEFAULT,
-                           NETKIT_SCRUB_DEFAULT);
+                           &ifindex, NETKIT_SCRUB_DEFAULT,
+                           NETKIT_SCRUB_DEFAULT, 0);
        if (err)
                return;
 
@@ -428,8 +438,8 @@ static void serial_test_tc_netkit_multi_opts_target(int mode, int target)
        int err, ifindex;
 
        err = create_netkit(mode, NETKIT_PASS, NETKIT_PASS,
-                           &ifindex, false, NETKIT_SCRUB_DEFAULT,
-                           NETKIT_SCRUB_DEFAULT);
+                           &ifindex, NETKIT_SCRUB_DEFAULT,
+                           NETKIT_SCRUB_DEFAULT, 0);
        if (err)
                return;
 
@@ -543,8 +553,8 @@ void serial_test_tc_netkit_device(void)
        int err, ifindex, ifindex2;
 
        err = create_netkit(NETKIT_L3, NETKIT_PASS, NETKIT_PASS,
-                           &ifindex, true, NETKIT_SCRUB_DEFAULT,
-                           NETKIT_SCRUB_DEFAULT);
+                           &ifindex, NETKIT_SCRUB_DEFAULT,
+                           NETKIT_SCRUB_DEFAULT, FLAG_SAME_NETNS);
        if (err)
                return;
 
@@ -655,8 +665,8 @@ static void serial_test_tc_netkit_neigh_links_target(int mode, int target)
        int err, ifindex;
 
        err = create_netkit(mode, NETKIT_PASS, NETKIT_PASS,
-                           &ifindex, false, NETKIT_SCRUB_DEFAULT,
-                           NETKIT_SCRUB_DEFAULT);
+                           &ifindex, NETKIT_SCRUB_DEFAULT,
+                           NETKIT_SCRUB_DEFAULT, 0);
        if (err)
                return;
 
@@ -733,8 +743,8 @@ static void serial_test_tc_netkit_pkt_type_mode(int mode)
        struct bpf_link *link;
 
        err = create_netkit(mode, NETKIT_PASS, NETKIT_PASS,
-                           &ifindex, true, NETKIT_SCRUB_DEFAULT,
-                           NETKIT_SCRUB_DEFAULT);
+                           &ifindex, NETKIT_SCRUB_DEFAULT,
+                           NETKIT_SCRUB_DEFAULT, FLAG_SAME_NETNS);
        if (err)
                return;
 
@@ -799,7 +809,7 @@ void serial_test_tc_netkit_pkt_type(void)
        serial_test_tc_netkit_pkt_type_mode(NETKIT_L3);
 }
 
-static void serial_test_tc_netkit_scrub_type(int scrub)
+static void serial_test_tc_netkit_scrub_type(int scrub, bool room)
 {
        LIBBPF_OPTS(bpf_netkit_opts, optl);
        struct test_tc_link *skel;
@@ -807,7 +817,8 @@ static void serial_test_tc_netkit_scrub_type(int scrub)
        int err, ifindex;
 
        err = create_netkit(NETKIT_L2, NETKIT_PASS, NETKIT_PASS,
-                           &ifindex, false, scrub, scrub);
+                           &ifindex, scrub, scrub,
+                           room ? FLAG_ADJUST_ROOM : 0);
        if (err)
                return;
 
@@ -842,6 +853,8 @@ static void serial_test_tc_netkit_scrub_type(int scrub)
        ASSERT_EQ(skel->bss->seen_tc8, true, "seen_tc8");
        ASSERT_EQ(skel->bss->mark, scrub == NETKIT_SCRUB_NONE ? MARK : 0, "mark");
        ASSERT_EQ(skel->bss->prio, scrub == NETKIT_SCRUB_NONE ? PRIO : 0, "prio");
+       ASSERT_EQ(skel->bss->headroom, room ? NETKIT_HEADROOM : 0, "headroom");
+       ASSERT_EQ(skel->bss->tailroom, room ? NETKIT_TAILROOM : 0, "tailroom");
 cleanup:
        test_tc_link__destroy(skel);
 
@@ -852,6 +865,6 @@ cleanup:
 
 void serial_test_tc_netkit_scrub(void)
 {
-       serial_test_tc_netkit_scrub_type(NETKIT_SCRUB_DEFAULT);
-       serial_test_tc_netkit_scrub_type(NETKIT_SCRUB_NONE);
+       serial_test_tc_netkit_scrub_type(NETKIT_SCRUB_DEFAULT, false);
+       serial_test_tc_netkit_scrub_type(NETKIT_SCRUB_NONE, true);
 }

diff --git a/tools/testing/selftests/bpf/progs/test_tc_link.c b/tools/testing/selftests/bpf/progs/test_tc_link.c
index 10d8259284994d07b5b6c4c141f6388294bd98d4..630f12e51b075aeb8a2ff49507da0ce30c72309e 100644 (file)
--- a/tools/testing/selftests/bpf/progs/test_tc_link.c
+++ b/tools/testing/selftests/bpf/progs/test_tc_link.c
@@ -8,6 +8,7 @@
 #include <linux/if_packet.h>
 #include <bpf/bpf_endian.h>
 #include <bpf/bpf_helpers.h>
+#include <bpf/bpf_core_read.h>
 
 char LICENSE[] SEC("license") = "GPL";
 
@@ -27,6 +28,7 @@ bool seen_host;
 bool seen_mcast;
 
 int mark, prio;
+unsigned short headroom, tailroom;
 
 SEC("tc/ingress")
 int tc1(struct __sk_buff *skb)
@@ -104,11 +106,24 @@ out:
        return TCX_PASS;
 }
 
+struct sk_buff {
+       struct net_device *dev;
+};
+
+struct net_device {
+       unsigned short needed_headroom;
+       unsigned short needed_tailroom;
+};
+
 SEC("tc/egress")
 int tc8(struct __sk_buff *skb)
 {
+       struct net_device *dev = BPF_CORE_READ((struct sk_buff *)skb, dev);
+
        seen_tc8 = true;
        mark = skb->mark;
        prio = skb->priority;
+       headroom = BPF_CORE_READ(dev, needed_headroom);
+       tailroom = BPF_CORE_READ(dev, needed_tailroom);
        return TCX_PASS;
 }