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 (at) resnulli.us> 10 * Daniel Borkmann <daniel (at) 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 21 #include "tc_util.h" 22 #include "bpf_util.h" 23 24 static const enum bpf_prog_type bpf_type = BPF_PROG_TYPE_SCHED_ACT; 25 26 static void explain(void) 27 { 28 fprintf(stderr, "Usage: ... bpf ... [ index INDEX ]\n"); 29 fprintf(stderr, "\n"); 30 fprintf(stderr, "BPF use case:\n"); 31 fprintf(stderr, " bytecode BPF_BYTECODE\n"); 32 fprintf(stderr, " bytecode-file FILE\n"); 33 fprintf(stderr, "\n"); 34 fprintf(stderr, "eBPF use case:\n"); 35 fprintf(stderr, " object-file FILE [ section ACT_NAME ] [ export UDS_FILE ]"); 36 fprintf(stderr, " [ verbose ]\n"); 37 fprintf(stderr, " object-pinned FILE\n"); 38 fprintf(stderr, "\n"); 39 fprintf(stderr, "Where BPF_BYTECODE := \'s,c t f k,c t f k,c t f k,...\'\n"); 40 fprintf(stderr, "c,t,f,k and s are decimals; s denotes number of 4-tuples\n"); 41 fprintf(stderr, "\n"); 42 fprintf(stderr, "Where FILE points to a file containing the BPF_BYTECODE string,\n"); 43 fprintf(stderr, "an ELF file containing eBPF map definitions and bytecode, or a\n"); 44 fprintf(stderr, "pinned eBPF program.\n"); 45 fprintf(stderr, "\n"); 46 fprintf(stderr, "Where ACT_NAME refers to the section name containing the\n"); 47 fprintf(stderr, "action (default \'%s\').\n", bpf_prog_to_default_section(bpf_type)); 48 fprintf(stderr, "\n"); 49 fprintf(stderr, "Where UDS_FILE points to a unix domain socket file in order\n"); 50 fprintf(stderr, "to hand off control of all created eBPF maps to an agent.\n"); 51 fprintf(stderr, "\n"); 52 fprintf(stderr, "Where optionally INDEX points to an existing action, or\n"); 53 fprintf(stderr, "explicitly specifies an action index upon creation.\n"); 54 } 55 56 static void bpf_cbpf_cb(void *nl, const struct sock_filter *ops, int ops_len) 57 { 58 addattr16(nl, MAX_MSG, TCA_ACT_BPF_OPS_LEN, ops_len); 59 addattr_l(nl, MAX_MSG, TCA_ACT_BPF_OPS, ops, 60 ops_len * sizeof(struct sock_filter)); 61 } 62 63 static void bpf_ebpf_cb(void *nl, int fd, const char *annotation) 64 { 65 addattr32(nl, MAX_MSG, TCA_ACT_BPF_FD, fd); 66 addattrstrz(nl, MAX_MSG, TCA_ACT_BPF_NAME, annotation); 67 } 68 69 static const struct bpf_cfg_ops bpf_cb_ops = { 70 .cbpf_cb = bpf_cbpf_cb, 71 .ebpf_cb = bpf_ebpf_cb, 72 }; 73 74 static int bpf_parse_opt(struct action_util *a, int *ptr_argc, char ***ptr_argv, 75 int tca_id, struct nlmsghdr *n) 76 { 77 const char *bpf_obj = NULL, *bpf_uds_name = NULL; 78 struct tc_act_bpf parm = {}; 79 struct bpf_cfg_in cfg = {}; 80 bool seen_run = false; 81 struct rtattr *tail; 82 int argc, ret = 0; 83 char **argv; 84 85 argv = *ptr_argv; 86 argc = *ptr_argc; 87 88 if (matches(*argv, "bpf") != 0) 89 return -1; 90 91 NEXT_ARG(); 92 93 tail = NLMSG_TAIL(n); 94 addattr_l(n, MAX_MSG, tca_id, NULL, 0); 95 96 while (argc > 0) { 97 if (matches(*argv, "run") == 0) { 98 NEXT_ARG(); 99 opt_bpf: 100 seen_run = true; 101 cfg.argc = argc; 102 cfg.argv = argv; 103 104 if (bpf_parse_common(bpf_type, &cfg, &bpf_cb_ops, n)) 105 return -1; 106 107 argc = cfg.argc; 108 argv = cfg.argv; 109 110 bpf_obj = cfg.object; 111 bpf_uds_name = cfg.uds; 112 } else if (matches(*argv, "help") == 0) { 113 explain(); 114 return -1; 115 } else if (matches(*argv, "index") == 0) { 116 break; 117 } else { 118 if (!seen_run) 119 goto opt_bpf; 120 break; 121 } 122 123 NEXT_ARG_FWD(); 124 } 125 126 parse_action_control_dflt(&argc, &argv, &parm.action, 127 false, TC_ACT_PIPE); 128 129 if (argc) { 130 if (matches(*argv, "index") == 0) { 131 NEXT_ARG(); 132 if (get_u32(&parm.index, *argv, 10)) { 133 fprintf(stderr, "bpf: Illegal \"index\"\n"); 134 return -1; 135 } 136 137 NEXT_ARG_FWD(); 138 } 139 } 140 141 addattr_l(n, MAX_MSG, TCA_ACT_BPF_PARMS, &parm, sizeof(parm)); 142 tail->rta_len = (char *)NLMSG_TAIL(n) - (char *)tail; 143 144 if (bpf_uds_name) 145 ret = bpf_send_map_fds(bpf_uds_name, bpf_obj); 146 147 *ptr_argc = argc; 148 *ptr_argv = argv; 149 150 return ret; 151 } 152 153 static int bpf_print_opt(struct action_util *au, FILE *f, struct rtattr *arg) 154 { 155 struct rtattr *tb[TCA_ACT_BPF_MAX + 1]; 156 struct tc_act_bpf *parm; 157 int dump_ok = 0; 158 159 if (arg == NULL) 160 return -1; 161 162 parse_rtattr_nested(tb, TCA_ACT_BPF_MAX, arg); 163 164 if (!tb[TCA_ACT_BPF_PARMS]) { 165 fprintf(f, "[NULL bpf parameters]"); 166 return -1; 167 } 168 169 parm = RTA_DATA(tb[TCA_ACT_BPF_PARMS]); 170 fprintf(f, "bpf "); 171 172 if (tb[TCA_ACT_BPF_NAME]) 173 fprintf(f, "%s ", rta_getattr_str(tb[TCA_ACT_BPF_NAME])); 174 175 if (tb[TCA_ACT_BPF_OPS] && tb[TCA_ACT_BPF_OPS_LEN]) { 176 bpf_print_ops(f, tb[TCA_ACT_BPF_OPS], 177 rta_getattr_u16(tb[TCA_ACT_BPF_OPS_LEN])); 178 fprintf(f, " "); 179 } 180 181 if (tb[TCA_ACT_BPF_ID]) 182 dump_ok = bpf_dump_prog_info(f, rta_getattr_u32(tb[TCA_ACT_BPF_ID])); 183 if (!dump_ok && tb[TCA_ACT_BPF_TAG]) { 184 SPRINT_BUF(b); 185 186 fprintf(f, "tag %s ", 187 hexstring_n2a(RTA_DATA(tb[TCA_ACT_BPF_TAG]), 188 RTA_PAYLOAD(tb[TCA_ACT_BPF_TAG]), 189 b, sizeof(b))); 190 } 191 192 print_action_control(f, "default-action ", parm->action, "\n"); 193 fprintf(f, "\tindex %u ref %d bind %d", parm->index, parm->refcnt, 194 parm->bindcnt); 195 196 if (show_stats) { 197 if (tb[TCA_ACT_BPF_TM]) { 198 struct tcf_t *tm = RTA_DATA(tb[TCA_ACT_BPF_TM]); 199 200 print_tm(f, tm); 201 } 202 } 203 204 fprintf(f, "\n "); 205 return 0; 206 } 207 208 struct action_util bpf_action_util = { 209 .id = "bpf", 210 .parse_aopt = bpf_parse_opt, 211 .print_aopt = bpf_print_opt, 212 }; 213
