mirror of
https://github.com/xdp-project/bpf-examples.git
synced 2024-05-06 15:54:53 +00:00
397b44cff7
Remove the saddr and daddr parmeters from parse_packet_identifier, and use the is_egress parmeter to perform the saddr/daddr swap inside the function. Also, minor style fixes. Signed-off-by: Simon Sundberg <simon.sundberg@kau.se>
61 lines
1.7 KiB
C
61 lines
1.7 KiB
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
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#include <linux/bpf.h>
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#include <bpf/bpf_helpers.h>
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#include "pping.h"
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#include "pping_helpers.h"
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char _license[] SEC("license") = "GPL";
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struct {
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__uint(type, BPF_MAP_TYPE_HASH);
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__uint(key_size, sizeof(struct packet_id));
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__uint(value_size, sizeof(struct packet_timestamp));
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__uint(max_entries, 16384);
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__uint(pinning, LIBBPF_PIN_BY_NAME);
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} ts_start SEC(".maps");
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struct {
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__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
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__uint(key_size, sizeof(__u32));
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__uint(value_size, sizeof(__u32));
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} rtt_events SEC(".maps");
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// XDP program for parsing identifier in ingress traffic and check for match in map
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SEC(XDP_PROG_SEC)
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int xdp_prog_ingress(struct xdp_md *ctx)
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{
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struct packet_id p_id = { 0 };
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struct packet_timestamp *p_ts;
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struct rtt_event event = { 0 };
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void *data = (void *)(long)ctx->data;
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void *data_end = (void *)(long)ctx->data_end;
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if (parse_packet_identifier(data, data_end, false, &p_id) < 0)
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goto end;
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p_ts = bpf_map_lookup_elem(&ts_start, &p_id);
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// Only calculate RTT for first packet with matching identifer
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if (p_ts && p_ts->used == 0) {
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/*
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* As used is not set atomically with the lookup, could
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* potentially have multiple "first" packets (on different
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* CPUs), but all those should then also have very similar RTT,
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* so don't consider it a significant issue
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*/
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p_ts->used = 1;
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// TODO - Optional delete of entry (if identifier is garantued unique)
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__builtin_memcpy(&event.flow, &p_id.flow,
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sizeof(struct network_tuple));
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event.rtt = bpf_ktime_get_ns() - p_ts->timestamp;
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bpf_perf_event_output(ctx, &rtt_events, BPF_F_CURRENT_CPU,
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&event, sizeof(event));
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}
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end:
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return XDP_PASS;
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}
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