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
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
|
/*
* f_bpf.c BPF-based Classifier
*
* This program is free software; you can distribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* Authors: Daniel Borkmann <dborkman@redhat.com>
*/
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <syslog.h>
#include <fcntl.h>
#include <libgen.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <string.h>
#include <stdbool.h>
#include <errno.h>
#include <limits.h>
#include <linux/filter.h>
#include <linux/if.h>
#include "utils.h"
#include "tc_util.h"
#include "tc_bpf.h"
static const enum bpf_prog_type bpf_type = BPF_PROG_TYPE_SCHED_CLS;
static void explain(void)
{
fprintf(stderr, "Usage: ... bpf ...\n");
fprintf(stderr, "\n");
fprintf(stderr, "BPF use case:\n");
fprintf(stderr, " bytecode BPF_BYTECODE\n");
fprintf(stderr, " bytecode-file FILE\n");
fprintf(stderr, "\n");
fprintf(stderr, "eBPF use case:\n");
fprintf(stderr, " object-file FILE [ section CLS_NAME ] [ export UDS_FILE ]\n");
fprintf(stderr, "\n");
fprintf(stderr, "Common remaining options:\n");
fprintf(stderr, " [ action ACTION_SPEC ]\n");
fprintf(stderr, " [ classid CLASSID ]\n");
fprintf(stderr, "\n");
fprintf(stderr, "Where BPF_BYTECODE := \'s,c t f k,c t f k,c t f k,...\'\n");
fprintf(stderr, "c,t,f,k and s are decimals; s denotes number of 4-tuples\n");
fprintf(stderr, "\n");
fprintf(stderr, "Where FILE points to a file containing the BPF_BYTECODE string,\n");
fprintf(stderr, "an ELF file containing eBPF map definitions and bytecode.\n");
fprintf(stderr, "\n");
fprintf(stderr, "Where CLS_NAME refers to the section name containing the\n");
fprintf(stderr, "classifier (default \'%s\').\n", bpf_default_section(bpf_type));
fprintf(stderr, "\n");
fprintf(stderr, "Where UDS_FILE points to a unix domain socket file in order\n");
fprintf(stderr, "to hand off control of all created eBPF maps to an agent.\n");
fprintf(stderr, "\n");
fprintf(stderr, "ACTION_SPEC := ... look at individual actions\n");
fprintf(stderr, "NOTE: CLASSID is parsed as hexadecimal input.\n");
}
static int bpf_parse_opt(struct filter_util *qu, char *handle,
int argc, char **argv, struct nlmsghdr *n)
{
struct tcmsg *t = NLMSG_DATA(n);
const char *bpf_uds_name = NULL;
const char *bpf_sec_name = NULL;
char *bpf_obj = NULL;
struct rtattr *tail;
bool seen_run = false;
long h = 0;
int ret = 0;
if (argc == 0)
return 0;
if (handle) {
h = strtol(handle, NULL, 0);
if (h == LONG_MIN || h == LONG_MAX) {
fprintf(stderr, "Illegal handle \"%s\", must be "
"numeric.\n", handle);
return -1;
}
}
t->tcm_handle = h;
tail = (struct rtattr *)(((void *)n) + NLMSG_ALIGN(n->nlmsg_len));
addattr_l(n, MAX_MSG, TCA_OPTIONS, NULL, 0);
while (argc > 0) {
if (matches(*argv, "run") == 0) {
struct sock_filter bpf_ops[BPF_MAXINSNS];
bool from_file, ebpf;
int ret;
NEXT_ARG();
opt_bpf:
bpf_sec_name = bpf_default_section(bpf_type);
ebpf = false;
seen_run = true;
if (strcmp(*argv, "bytecode-file") == 0 ||
strcmp(*argv, "bcf") == 0) {
from_file = true;
} else if (strcmp(*argv, "bytecode") == 0 ||
strcmp(*argv, "bc") == 0) {
from_file = false;
} else if (strcmp(*argv, "object-file") == 0 ||
strcmp(*argv, "obj") == 0) {
ebpf = true;
} else {
fprintf(stderr, "What is \"%s\"?\n", *argv);
explain();
return -1;
}
NEXT_ARG();
if (ebpf) {
bpf_obj = *argv;
NEXT_ARG();
if (strcmp(*argv, "section") == 0 ||
strcmp(*argv, "sec") == 0) {
NEXT_ARG();
bpf_sec_name = *argv;
NEXT_ARG();
}
if (strcmp(*argv, "export") == 0 ||
strcmp(*argv, "exp") == 0) {
NEXT_ARG();
bpf_uds_name = *argv;
NEXT_ARG();
}
PREV_ARG();
}
ret = ebpf ? bpf_open_object(bpf_obj, bpf_type, bpf_sec_name) :
bpf_parse_ops(argc, argv, bpf_ops, from_file);
if (ret < 0) {
fprintf(stderr, "%s\n", ebpf ?
"Could not load object" :
"Illegal \"bytecode\"");
return -1;
}
if (ebpf) {
char bpf_name[256];
bpf_obj = basename(bpf_obj);
snprintf(bpf_name, sizeof(bpf_name), "%s:[%s]",
bpf_obj, bpf_sec_name);
addattr32(n, MAX_MSG, TCA_BPF_FD, ret);
addattrstrz(n, MAX_MSG, TCA_BPF_NAME, bpf_name);
} else {
addattr16(n, MAX_MSG, TCA_BPF_OPS_LEN, ret);
addattr_l(n, MAX_MSG, TCA_BPF_OPS, &bpf_ops,
ret * sizeof(struct sock_filter));
}
} else if (matches(*argv, "classid") == 0 ||
strcmp(*argv, "flowid") == 0) {
unsigned int handle;
NEXT_ARG();
if (get_tc_classid(&handle, *argv)) {
fprintf(stderr, "Illegal \"classid\"\n");
return -1;
}
addattr_l(n, MAX_MSG, TCA_BPF_CLASSID, &handle, 4);
} else if (matches(*argv, "action") == 0) {
NEXT_ARG();
if (parse_action(&argc, &argv, TCA_BPF_ACT, n)) {
fprintf(stderr, "Illegal \"action\"\n");
return -1;
}
continue;
} else if (matches(*argv, "police") == 0) {
NEXT_ARG();
if (parse_police(&argc, &argv, TCA_BPF_POLICE, n)) {
fprintf(stderr, "Illegal \"police\"\n");
return -1;
}
continue;
} else if (strcmp(*argv, "help") == 0) {
explain();
return -1;
} else {
if (!seen_run)
goto opt_bpf;
fprintf(stderr, "What is \"%s\"?\n", *argv);
explain();
return -1;
}
argc--;
argv++;
}
tail->rta_len = (((void *)n) + n->nlmsg_len) - (void *)tail;
if (bpf_uds_name)
ret = bpf_handoff_map_fds(bpf_uds_name, bpf_obj);
return ret;
}
static int bpf_print_opt(struct filter_util *qu, FILE *f,
struct rtattr *opt, __u32 handle)
{
struct rtattr *tb[TCA_BPF_MAX + 1];
if (opt == NULL)
return 0;
parse_rtattr_nested(tb, TCA_BPF_MAX, opt);
if (handle)
fprintf(f, "handle 0x%x ", handle);
if (tb[TCA_BPF_CLASSID]) {
SPRINT_BUF(b1);
fprintf(f, "flowid %s ",
sprint_tc_classid(rta_getattr_u32(tb[TCA_BPF_CLASSID]), b1));
}
if (tb[TCA_BPF_NAME])
fprintf(f, "%s ", rta_getattr_str(tb[TCA_BPF_NAME]));
else if (tb[TCA_BPF_FD])
fprintf(f, "pfd %u ", rta_getattr_u32(tb[TCA_BPF_FD]));
if (tb[TCA_BPF_OPS] && tb[TCA_BPF_OPS_LEN]) {
bpf_print_ops(f, tb[TCA_BPF_OPS],
rta_getattr_u16(tb[TCA_BPF_OPS_LEN]));
fprintf(f, "\n");
}
if (tb[TCA_BPF_POLICE]) {
fprintf(f, "\n");
tc_print_police(f, tb[TCA_BPF_POLICE]);
}
if (tb[TCA_BPF_ACT]) {
tc_print_action(f, tb[TCA_BPF_ACT]);
}
return 0;
}
struct filter_util bpf_filter_util = {
.id = "bpf",
.parse_fopt = bpf_parse_opt,
.print_fopt = bpf_print_opt,
};
|
