1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
|
// SPDX-License-Identifier: GPL-2.0
/* GPLv2, Copyright(c) 2017 Jesper Dangaard Brouer, Red Hat, Inc. */
#include "xdp_sample.bpf.h"
#include <bpf/bpf_tracing.h>
#include <bpf/bpf_core_read.h>
#include <bpf/bpf_helpers.h>
array_map rx_cnt SEC(".maps");
array_map redir_err_cnt SEC(".maps");
array_map exception_cnt SEC(".maps");
const volatile int nr_cpus = 0;
/* These can be set before loading so that redundant comparisons can be DCE'd by
* the verifier, and only actual matches are tried after loading tp_btf program.
* This allows sample to filter tracepoint stats based on net_device.
*/
const volatile int from_match[32] = {};
const volatile int to_match[32] = {};
/* Find if b is part of set a, but if a is empty set then evaluate to true */
#define IN_SET(a, b) \
({ \
bool __res = !(a)[0]; \
for (int i = 0; i < ARRAY_SIZE(a) && (a)[i]; i++) { \
__res = (a)[i] == (b); \
if (__res) \
break; \
} \
__res; \
})
static __always_inline __u32 xdp_get_err_key(int err)
{
switch (err) {
case 0:
return 0;
case -EINVAL:
return 2;
case -ENETDOWN:
return 3;
case -EMSGSIZE:
return 4;
case -EOPNOTSUPP:
return 5;
case -ENOSPC:
return 6;
default:
return 1;
}
}
static __always_inline int xdp_redirect_collect_stat(int from, int err)
{
u32 cpu = bpf_get_smp_processor_id();
u32 key = XDP_REDIRECT_ERROR;
struct datarec *rec;
u32 idx;
if (!IN_SET(from_match, from))
return 0;
key = xdp_get_err_key(err);
idx = key * nr_cpus + cpu;
rec = bpf_map_lookup_elem(&redir_err_cnt, &idx);
if (!rec)
return 0;
if (key)
NO_TEAR_INC(rec->dropped);
else
NO_TEAR_INC(rec->processed);
return 0; /* Indicate event was filtered (no further processing)*/
/*
* Returning 1 here would allow e.g. a perf-record tracepoint
* to see and record these events, but it doesn't work well
* in-practice as stopping perf-record also unload this
* bpf_prog. Plus, there is additional overhead of doing so.
*/
}
SEC("tp_btf/xdp_redirect_err")
int BPF_PROG(tp_xdp_redirect_err, const struct net_device *dev,
const struct bpf_prog *xdp, const void *tgt, int err,
const struct bpf_map *map, u32 index)
{
return xdp_redirect_collect_stat(dev->ifindex, err);
}
SEC("tp_btf/xdp_redirect_map_err")
int BPF_PROG(tp_xdp_redirect_map_err, const struct net_device *dev,
const struct bpf_prog *xdp, const void *tgt, int err,
const struct bpf_map *map, u32 index)
{
return xdp_redirect_collect_stat(dev->ifindex, err);
}
SEC("tp_btf/xdp_redirect")
int BPF_PROG(tp_xdp_redirect, const struct net_device *dev,
const struct bpf_prog *xdp, const void *tgt, int err,
const struct bpf_map *map, u32 index)
{
return xdp_redirect_collect_stat(dev->ifindex, err);
}
SEC("tp_btf/xdp_redirect_map")
int BPF_PROG(tp_xdp_redirect_map, const struct net_device *dev,
const struct bpf_prog *xdp, const void *tgt, int err,
const struct bpf_map *map, u32 index)
{
return xdp_redirect_collect_stat(dev->ifindex, err);
}
SEC("tp_btf/xdp_exception")
int BPF_PROG(tp_xdp_exception, const struct net_device *dev,
const struct bpf_prog *xdp, u32 act)
{
u32 cpu = bpf_get_smp_processor_id();
struct datarec *rec;
u32 key = act, idx;
if (!IN_SET(from_match, dev->ifindex))
return 0;
if (!IN_SET(to_match, dev->ifindex))
return 0;
if (key > XDP_REDIRECT)
key = XDP_REDIRECT + 1;
idx = key * nr_cpus + cpu;
rec = bpf_map_lookup_elem(&exception_cnt, &idx);
if (!rec)
return 0;
NO_TEAR_INC(rec->dropped);
return 0;
}
|
