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authorKumar Kartikeya Dwivedi <memxor@gmail.com>2021-08-21 03:19:58 +0300
committerAlexei Starovoitov <ast@kernel.org>2021-08-25 00:48:41 +0300
commit5f116212f4018fc9aa7a2a828b27aab540b8e5fa (patch)
treeef4db3627208ad4e9d9f81216c56ac8fa6b370fc
parentd771e217506adcfbfb08c693fb9332ee4859d61d (diff)
downloadlinux-5f116212f4018fc9aa7a2a828b27aab540b8e5fa.tar.xz
samples: bpf: Add BPF support for devmap_xmit tracepoint
This adds support for the devmap_xmit tracepoint, and its multi device variant that can be used to obtain streams for each individual net_device to net_device redirection. This is useful for decomposing total xmit stats in xdp_monitor. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210821002010.845777-11-memxor@gmail.com
-rw-r--r--samples/bpf/xdp_sample.bpf.c71
1 files changed, 71 insertions, 0 deletions
diff --git a/samples/bpf/xdp_sample.bpf.c b/samples/bpf/xdp_sample.bpf.c
index f01a5529751c..0eb7e1dcae22 100644
--- a/samples/bpf/xdp_sample.bpf.c
+++ b/samples/bpf/xdp_sample.bpf.c
@@ -11,6 +11,14 @@ array_map redir_err_cnt SEC(".maps");
array_map cpumap_enqueue_cnt SEC(".maps");
array_map cpumap_kthread_cnt SEC(".maps");
array_map exception_cnt SEC(".maps");
+array_map devmap_xmit_cnt SEC(".maps");
+
+struct {
+ __uint(type, BPF_MAP_TYPE_PERCPU_HASH);
+ __uint(max_entries, 32 * 32);
+ __type(key, u64);
+ __type(value, struct datarec);
+} devmap_xmit_cnt_multi SEC(".maps");
const volatile int nr_cpus = 0;
@@ -193,3 +201,66 @@ int BPF_PROG(tp_xdp_exception, const struct net_device *dev,
return 0;
}
+
+SEC("tp_btf/xdp_devmap_xmit")
+int BPF_PROG(tp_xdp_devmap_xmit, const struct net_device *from_dev,
+ const struct net_device *to_dev, int sent, int drops, int err)
+{
+ struct datarec *rec;
+ int idx_in, idx_out;
+ u32 cpu;
+
+ idx_in = from_dev->ifindex;
+ idx_out = to_dev->ifindex;
+
+ if (!IN_SET(from_match, idx_in))
+ return 0;
+ if (!IN_SET(to_match, idx_out))
+ return 0;
+
+ cpu = bpf_get_smp_processor_id();
+ rec = bpf_map_lookup_elem(&devmap_xmit_cnt, &cpu);
+ if (!rec)
+ return 0;
+ NO_TEAR_ADD(rec->processed, sent);
+ NO_TEAR_ADD(rec->dropped, drops);
+ /* Record bulk events, then userspace can calc average bulk size */
+ NO_TEAR_INC(rec->info);
+ /* Record error cases, where no frame were sent */
+ /* Catch API error of drv ndo_xdp_xmit sent more than count */
+ if (err || drops < 0)
+ NO_TEAR_INC(rec->issue);
+ return 0;
+}
+
+SEC("tp_btf/xdp_devmap_xmit")
+int BPF_PROG(tp_xdp_devmap_xmit_multi, const struct net_device *from_dev,
+ const struct net_device *to_dev, int sent, int drops, int err)
+{
+ struct datarec empty = {};
+ struct datarec *rec;
+ int idx_in, idx_out;
+ u64 idx;
+
+ idx_in = from_dev->ifindex;
+ idx_out = to_dev->ifindex;
+ idx = idx_in;
+ idx = idx << 32 | idx_out;
+
+ if (!IN_SET(from_match, idx_in))
+ return 0;
+ if (!IN_SET(to_match, idx_out))
+ return 0;
+
+ bpf_map_update_elem(&devmap_xmit_cnt_multi, &idx, &empty, BPF_NOEXIST);
+ rec = bpf_map_lookup_elem(&devmap_xmit_cnt_multi, &idx);
+ if (!rec)
+ return 0;
+
+ NO_TEAR_ADD(rec->processed, sent);
+ NO_TEAR_ADD(rec->dropped, drops);
+ NO_TEAR_INC(rec->info);
+ if (err || drops < 0)
+ NO_TEAR_INC(rec->issue);
+ return 0;
+}