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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /tools/testing/selftests/bpf/progs/test_tc_edt.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tools/testing/selftests/bpf/progs/test_tc_edt.c')
-rw-r--r-- | tools/testing/selftests/bpf/progs/test_tc_edt.c | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/test_tc_edt.c b/tools/testing/selftests/bpf/progs/test_tc_edt.c new file mode 100644 index 000000000..bf28814bf --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_tc_edt.c @@ -0,0 +1,110 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <stdint.h> +#include <linux/bpf.h> +#include <linux/if_ether.h> +#include <linux/stddef.h> +#include <linux/in.h> +#include <linux/ip.h> +#include <linux/pkt_cls.h> +#include <linux/tcp.h> +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_endian.h> + +/* the maximum delay we are willing to add (drop packets beyond that) */ +#define TIME_HORIZON_NS (2000 * 1000 * 1000) +#define NS_PER_SEC 1000000000 +#define ECN_HORIZON_NS 5000000 +#define THROTTLE_RATE_BPS (5 * 1000 * 1000) + +/* flow_key => last_tstamp timestamp used */ +struct bpf_map_def SEC("maps") flow_map = { + .type = BPF_MAP_TYPE_HASH, + .key_size = sizeof(uint32_t), + .value_size = sizeof(uint64_t), + .max_entries = 1, +}; + +static inline int throttle_flow(struct __sk_buff *skb) +{ + int key = 0; + uint64_t *last_tstamp = bpf_map_lookup_elem(&flow_map, &key); + uint64_t delay_ns = ((uint64_t)skb->len) * NS_PER_SEC / + THROTTLE_RATE_BPS; + uint64_t now = bpf_ktime_get_ns(); + uint64_t tstamp, next_tstamp = 0; + + if (last_tstamp) + next_tstamp = *last_tstamp + delay_ns; + + tstamp = skb->tstamp; + if (tstamp < now) + tstamp = now; + + /* should we throttle? */ + if (next_tstamp <= tstamp) { + if (bpf_map_update_elem(&flow_map, &key, &tstamp, BPF_ANY)) + return TC_ACT_SHOT; + return TC_ACT_OK; + } + + /* do not queue past the time horizon */ + if (next_tstamp - now >= TIME_HORIZON_NS) + return TC_ACT_SHOT; + + /* set ecn bit, if needed */ + if (next_tstamp - now >= ECN_HORIZON_NS) + bpf_skb_ecn_set_ce(skb); + + if (bpf_map_update_elem(&flow_map, &key, &next_tstamp, BPF_EXIST)) + return TC_ACT_SHOT; + skb->tstamp = next_tstamp; + + return TC_ACT_OK; +} + +static inline int handle_tcp(struct __sk_buff *skb, struct tcphdr *tcp) +{ + void *data_end = (void *)(long)skb->data_end; + + /* drop malformed packets */ + if ((void *)(tcp + 1) > data_end) + return TC_ACT_SHOT; + + if (tcp->dest == bpf_htons(9000)) + return throttle_flow(skb); + + return TC_ACT_OK; +} + +static inline int handle_ipv4(struct __sk_buff *skb) +{ + void *data_end = (void *)(long)skb->data_end; + void *data = (void *)(long)skb->data; + struct iphdr *iph; + uint32_t ihl; + + /* drop malformed packets */ + if (data + sizeof(struct ethhdr) > data_end) + return TC_ACT_SHOT; + iph = (struct iphdr *)(data + sizeof(struct ethhdr)); + if ((void *)(iph + 1) > data_end) + return TC_ACT_SHOT; + ihl = iph->ihl * 4; + if (((void *)iph) + ihl > data_end) + return TC_ACT_SHOT; + + if (iph->protocol == IPPROTO_TCP) + return handle_tcp(skb, (struct tcphdr *)(((void *)iph) + ihl)); + + return TC_ACT_OK; +} + +SEC("cls_test") int tc_prog(struct __sk_buff *skb) +{ + if (skb->protocol == bpf_htons(ETH_P_IP)) + return handle_ipv4(skb); + + return TC_ACT_OK; +} + +char __license[] SEC("license") = "GPL"; |