1 /*
2 * m_bpf.c BPF based action module
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
8 *
9 * Authors: Jiri Pirko <jiri@resnulli.us>
10 * Daniel Borkmann <daniel@iogearbox.net>
11 */
12
13 #include <stdio.h>
14 #include <stdlib.h>
15
16 #include <linux/bpf.h>
17 #include <linux/tc_act/tc_bpf.h>
18
19 #include "utils.h"
20 #include "tc_util.h"
21 #include "tc_bpf.h"
22
23 static const enum bpf_prog_type bpf_type = BPF_PROG_TYPE_SCHED_ACT;
24
25 static const int nla_tbl[BPF_NLA_MAX] = {
26 [BPF_NLA_OPS_LEN] = TCA_ACT_BPF_OPS_LEN,
27 [BPF_NLA_OPS] = TCA_ACT_BPF_OPS,
28 [BPF_NLA_FD] = TCA_ACT_BPF_FD,
29 [BPF_NLA_NAME] = TCA_ACT_BPF_NAME,
30 };
31
explain(void)32 static void explain(void)
33 {
34 fprintf(stderr, "Usage: ... bpf ... [ index INDEX ]\n");
35 fprintf(stderr, "\n");
36 fprintf(stderr, "BPF use case:\n");
37 fprintf(stderr, " bytecode BPF_BYTECODE\n");
38 fprintf(stderr, " bytecode-file FILE\n");
39 fprintf(stderr, "\n");
40 fprintf(stderr, "eBPF use case:\n");
41 fprintf(stderr, " object-file FILE [ section ACT_NAME ] [ export UDS_FILE ]");
42 fprintf(stderr, " [ verbose ]\n");
43 fprintf(stderr, " object-pinned FILE\n");
44 fprintf(stderr, "\n");
45 fprintf(stderr, "Where BPF_BYTECODE := \'s,c t f k,c t f k,c t f k,...\'\n");
46 fprintf(stderr, "c,t,f,k and s are decimals; s denotes number of 4-tuples\n");
47 fprintf(stderr, "\n");
48 fprintf(stderr, "Where FILE points to a file containing the BPF_BYTECODE string,\n");
49 fprintf(stderr, "an ELF file containing eBPF map definitions and bytecode, or a\n");
50 fprintf(stderr, "pinned eBPF program.\n");
51 fprintf(stderr, "\n");
52 fprintf(stderr, "Where ACT_NAME refers to the section name containing the\n");
53 fprintf(stderr, "action (default \'%s\').\n", bpf_default_section(bpf_type));
54 fprintf(stderr, "\n");
55 fprintf(stderr, "Where UDS_FILE points to a unix domain socket file in order\n");
56 fprintf(stderr, "to hand off control of all created eBPF maps to an agent.\n");
57 fprintf(stderr, "\n");
58 fprintf(stderr, "Where optionally INDEX points to an existing action, or\n");
59 fprintf(stderr, "explicitly specifies an action index upon creation.\n");
60 }
61
bpf_parse_opt(struct action_util * a,int * ptr_argc,char *** ptr_argv,int tca_id,struct nlmsghdr * n)62 static int bpf_parse_opt(struct action_util *a, int *ptr_argc, char ***ptr_argv,
63 int tca_id, struct nlmsghdr *n)
64 {
65 const char *bpf_obj = NULL, *bpf_uds_name = NULL;
66 struct tc_act_bpf parm;
67 bool seen_run = false;
68 struct rtattr *tail;
69 int argc, ret = 0;
70 char **argv;
71
72 argv = *ptr_argv;
73 argc = *ptr_argc;
74
75 if (matches(*argv, "bpf") != 0)
76 return -1;
77
78 NEXT_ARG();
79
80 tail = NLMSG_TAIL(n);
81 addattr_l(n, MAX_MSG, tca_id, NULL, 0);
82
83 while (argc > 0) {
84 if (matches(*argv, "run") == 0) {
85 NEXT_ARG();
86 opt_bpf:
87 seen_run = true;
88 if (bpf_parse_common(&argc, &argv, nla_tbl, bpf_type,
89 &bpf_obj, &bpf_uds_name, n)) {
90 fprintf(stderr, "Failed to retrieve (e)BPF data!\n");
91 return -1;
92 }
93 } else if (matches(*argv, "help") == 0) {
94 explain();
95 return -1;
96 } else if (matches(*argv, "index") == 0) {
97 break;
98 } else {
99 if (!seen_run)
100 goto opt_bpf;
101 break;
102 }
103
104 NEXT_ARG_FWD();
105 }
106
107 memset(&parm, 0, sizeof(parm));
108 parm.action = TC_ACT_PIPE;
109
110 if (argc) {
111 if (matches(*argv, "reclassify") == 0) {
112 parm.action = TC_ACT_RECLASSIFY;
113 NEXT_ARG_FWD();
114 } else if (matches(*argv, "pipe") == 0) {
115 parm.action = TC_ACT_PIPE;
116 NEXT_ARG_FWD();
117 } else if (matches(*argv, "drop") == 0 ||
118 matches(*argv, "shot") == 0) {
119 parm.action = TC_ACT_SHOT;
120 NEXT_ARG_FWD();
121 } else if (matches(*argv, "continue") == 0) {
122 parm.action = TC_ACT_UNSPEC;
123 NEXT_ARG_FWD();
124 } else if (matches(*argv, "pass") == 0 ||
125 matches(*argv, "ok") == 0) {
126 parm.action = TC_ACT_OK;
127 NEXT_ARG_FWD();
128 }
129 }
130
131 if (argc) {
132 if (matches(*argv, "index") == 0) {
133 NEXT_ARG();
134 if (get_u32(&parm.index, *argv, 10)) {
135 fprintf(stderr, "bpf: Illegal \"index\"\n");
136 return -1;
137 }
138
139 NEXT_ARG_FWD();
140 }
141 }
142
143 addattr_l(n, MAX_MSG, TCA_ACT_BPF_PARMS, &parm, sizeof(parm));
144 tail->rta_len = (char *)NLMSG_TAIL(n) - (char *)tail;
145
146 if (bpf_uds_name)
147 ret = bpf_send_map_fds(bpf_uds_name, bpf_obj);
148
149 *ptr_argc = argc;
150 *ptr_argv = argv;
151
152 return ret;
153 }
154
bpf_print_opt(struct action_util * au,FILE * f,struct rtattr * arg)155 static int bpf_print_opt(struct action_util *au, FILE *f, struct rtattr *arg)
156 {
157 struct rtattr *tb[TCA_ACT_BPF_MAX + 1];
158 struct tc_act_bpf *parm;
159 SPRINT_BUF(action_buf);
160
161 if (arg == NULL)
162 return -1;
163
164 parse_rtattr_nested(tb, TCA_ACT_BPF_MAX, arg);
165
166 if (!tb[TCA_ACT_BPF_PARMS]) {
167 fprintf(f, "[NULL bpf parameters]");
168 return -1;
169 }
170
171 parm = RTA_DATA(tb[TCA_ACT_BPF_PARMS]);
172 fprintf(f, "bpf ");
173
174 if (tb[TCA_ACT_BPF_NAME])
175 fprintf(f, "%s ", rta_getattr_str(tb[TCA_ACT_BPF_NAME]));
176 else if (tb[TCA_ACT_BPF_FD])
177 fprintf(f, "pfd %u ", rta_getattr_u32(tb[TCA_ACT_BPF_FD]));
178
179 if (tb[TCA_ACT_BPF_OPS] && tb[TCA_ACT_BPF_OPS_LEN]) {
180 bpf_print_ops(f, tb[TCA_ACT_BPF_OPS],
181 rta_getattr_u16(tb[TCA_ACT_BPF_OPS_LEN]));
182 fprintf(f, " ");
183 }
184
185 fprintf(f, "default-action %s\n", action_n2a(parm->action, action_buf,
186 sizeof(action_buf)));
187 fprintf(f, "\tindex %d ref %d bind %d", parm->index, parm->refcnt,
188 parm->bindcnt);
189
190 if (show_stats) {
191 if (tb[TCA_ACT_BPF_TM]) {
192 struct tcf_t *tm = RTA_DATA(tb[TCA_ACT_BPF_TM]);
193 print_tm(f, tm);
194 }
195 }
196
197 fprintf(f, "\n ");
198 return 0;
199 }
200
201 struct action_util bpf_action_util = {
202 .id = "bpf",
203 .parse_aopt = bpf_parse_opt,
204 .print_aopt = bpf_print_opt,
205 };
206