tc/m_mpls.c

   1 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
   2 /* Copyright (C) 2019 Netronome Systems, Inc. */
   3
   4 #include <linux/if_ether.h>
   5 #include <linux/tc_act/tc_mpls.h>
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #include <string.h>
   9 #include <unistd.h>
  10
  11 #include "utils.h"
  12 #include "rt_names.h"
  13 #include "tc_util.h"
  14
  15 static const char * const action_names[] = {
  16         [TCA_MPLS_ACT_POP] = "pop",
  17         [TCA_MPLS_ACT_PUSH] = "push",
  18         [TCA_MPLS_ACT_MODIFY] = "modify",
  19         [TCA_MPLS_ACT_DEC_TTL] = "dec_ttl",
  20 };
  21
  22 static void explain(void)
  23 {
  24         fprintf(stderr,
  25                 "Usage: mpls pop [ protocol MPLS_PROTO ]\n"
  26                 "       mpls push [ protocol MPLS_PROTO ] [ label MPLS_LABEL ] [ tc MPLS_TC ]\n"
  27                 "                 [ ttl MPLS_TTL ] [ bos MPLS_BOS ] [CONTROL]\n"
  28                 "       mpls modify [ label MPLS_LABEL ] [ tc MPLS_TC ] [ ttl MPLS_TTL ] [CONTROL]\n"
  29                 "           for pop MPLS_PROTO is next header of packet - e.g. ip or mpls_uc\n"
  30                 "           for push MPLS_PROTO is one of mpls_uc or mpls_mc\n"
  31                 "               with default: mpls_uc\n"
  32                 "       CONTROL := reclassify | pipe | drop | continue | pass |\n"
  33                 "                  goto chain <CHAIN_INDEX>\n");
  34 }
  35
  36 static void usage(void)
  37 {
  38         explain();
  39         exit(-1);
  40 }
  41
  42 static bool can_modify_mpls_fields(unsigned int action)
  43 {
  44         return action == TCA_MPLS_ACT_PUSH || action == TCA_MPLS_ACT_MODIFY;
  45 }
  46
  47 static bool can_modify_ethtype(unsigned int action)
  48 {
  49         return action == TCA_MPLS_ACT_PUSH || action == TCA_MPLS_ACT_POP;
  50 }
  51
  52 static bool is_valid_label(__u32 label)
  53 {
  54         return label <= 0xfffff;
  55 }
  56
  57 static bool check_double_action(unsigned int action, const char *arg)
  58 {
  59         if (!action)
  60                 return false;
  61
  62         fprintf(stderr,
  63                 "Error: got \"%s\" but action already set to \"%s\"\n",
  64                 arg, action_names[action]);
  65         explain();
  66         return true;
  67 }
  68
  69 static int parse_mpls(struct action_util *a, int *argc_p, char ***argv_p,
  70                       int tca_id, struct nlmsghdr *n)
  71 {
  72         struct tc_mpls parm = {};
  73         __u32 label = 0xffffffff;
  74         unsigned int action = 0;
  75         char **argv = *argv_p;
  76         struct rtattr *tail;
  77         int argc = *argc_p;
  78         __u16 proto = 0;
  79         __u8 bos = 0xff;
  80         __u8 tc = 0xff;
  81         __u8 ttl = 0;
  82
  83         if (matches(*argv, "mpls") != 0)
  84                 return -1;
  85
  86         NEXT_ARG();
  87
  88         while (argc > 0) {
  89                 if (matches(*argv, "pop") == 0) {
  90                         if (check_double_action(action, *argv))
  91                                 return -1;
  92                         action = TCA_MPLS_ACT_POP;
  93                 } else if (matches(*argv, "push") == 0) {
  94                         if (check_double_action(action, *argv))
  95                                 return -1;
  96                         action = TCA_MPLS_ACT_PUSH;
  97                 } else if (matches(*argv, "modify") == 0) {
  98                         if (check_double_action(action, *argv))
  99                                 return -1;
 100                         action = TCA_MPLS_ACT_MODIFY;
 101                 } else if (matches(*argv, "dec_ttl") == 0) {
 102                         if (check_double_action(action, *argv))
 103                                 return -1;
 104                         action = TCA_MPLS_ACT_DEC_TTL;
 105                 } else if (matches(*argv, "label") == 0) {
 106                         if (!can_modify_mpls_fields(action))
 107                                 invarg("only valid for push/modify", *argv);
 108                         NEXT_ARG();
 109                         if (get_u32(&label, *argv, 0) || !is_valid_label(label))
 110                                 invarg("label must be <=0xFFFFF", *argv);
 111                 } else if (matches(*argv, "tc") == 0) {
 112                         if (!can_modify_mpls_fields(action))
 113                                 invarg("only valid for push/modify", *argv);
 114                         NEXT_ARG();
 115                         if (get_u8(&tc, *argv, 0) || (tc & ~0x7))
 116                                 invarg("tc field is 3 bits max", *argv);
 117                 } else if (matches(*argv, "ttl") == 0) {
 118                         if (!can_modify_mpls_fields(action))
 119                                 invarg("only valid for push/modify", *argv);
 120                         NEXT_ARG();
 121                         if (get_u8(&ttl, *argv, 0) || !ttl)
 122                                 invarg("ttl must be >0 and <=255", *argv);
 123                 } else if (matches(*argv, "bos") == 0) {
 124                         if (!can_modify_mpls_fields(action))
 125                                 invarg("only valid for push/modify", *argv);
 126                         NEXT_ARG();
 127                         if (get_u8(&bos, *argv, 0) || (bos & ~0x1))
 128                                 invarg("bos must be 0 or 1", *argv);
 129                 } else if (matches(*argv, "protocol") == 0) {
 130                         if (!can_modify_ethtype(action))
 131                                 invarg("only valid for push/pop", *argv);
 132                         NEXT_ARG();
 133                         if (ll_proto_a2n(&proto, *argv))
 134                                 invarg("protocol is invalid", *argv);
 135                 } else if (matches(*argv, "help") == 0) {
 136                         usage();
 137                 } else {
 138                         break;
 139                 }
 140
 141                 NEXT_ARG_FWD();
 142         }
 143
 144         if (!action)
 145                 incomplete_command();
 146
 147         parse_action_control_dflt(&argc, &argv, &parm.action,
 148                                   false, TC_ACT_PIPE);
 149
 150         if (argc) {
 151                 if (matches(*argv, "index") == 0) {
 152                         NEXT_ARG();
 153                         if (get_u32(&parm.index, *argv, 10))
 154                                 invarg("illegal index", *argv);
 155                         NEXT_ARG_FWD();
 156                 }
 157         }
 158
 159         if (action == TCA_MPLS_ACT_PUSH && !label)
 160                 missarg("label");
 161
 162         if (action == TCA_MPLS_ACT_PUSH && proto &&
 163             proto != htons(ETH_P_MPLS_UC) && proto != htons(ETH_P_MPLS_MC)) {
 164                 fprintf(stderr,
 165                         "invalid push protocol \"0x%04x\" - use mpls_(uc|mc)\n",
 166                         ntohs(proto));
 167                 return -1;
 168         }
 169
 170         if (action == TCA_MPLS_ACT_POP && !proto)
 171                 missarg("protocol");
 172
 173         parm.m_action = action;
 174         tail = addattr_nest(n, MAX_MSG, tca_id | NLA_F_NESTED);
 175         addattr_l(n, MAX_MSG, TCA_MPLS_PARMS, &parm, sizeof(parm));
 176         if (label != 0xffffffff)
 177                 addattr_l(n, MAX_MSG, TCA_MPLS_LABEL, &label, sizeof(label));
 178         if (proto)
 179                 addattr_l(n, MAX_MSG, TCA_MPLS_PROTO, &proto, sizeof(proto));
 180         if (tc != 0xff)
 181                 addattr8(n, MAX_MSG, TCA_MPLS_TC, tc);
 182         if (ttl)
 183                 addattr8(n, MAX_MSG, TCA_MPLS_TTL, ttl);
 184         if (bos != 0xff)
 185                 addattr8(n, MAX_MSG, TCA_MPLS_BOS, bos);
 186         addattr_nest_end(n, tail);
 187
 188         *argc_p = argc;
 189         *argv_p = argv;
 190         return 0;
 191 }
 192
 193 static int print_mpls(struct action_util *au, FILE *f, struct rtattr *arg)
 194 {
 195         struct rtattr *tb[TCA_MPLS_MAX + 1];
 196         struct tc_mpls *parm;
 197         SPRINT_BUF(b1);
 198         __u32 val;
 199
 200         if (!arg)
 201                 return -1;
 202
 203         parse_rtattr_nested(tb, TCA_MPLS_MAX, arg);
 204
 205         if (!tb[TCA_MPLS_PARMS]) {
 206                 fprintf(stderr, "[NULL mpls parameters]\n");
 207                 return -1;
 208         }
 209         parm = RTA_DATA(tb[TCA_MPLS_PARMS]);
 210
 211         print_string(PRINT_ANY, "kind", "%s ", "mpls");
 212         print_string(PRINT_ANY, "mpls_action", " %s",
 213                      action_names[parm->m_action]);
 214
 215         switch (parm->m_action) {
 216         case TCA_MPLS_ACT_POP:
 217                 if (tb[TCA_MPLS_PROTO]) {
 218                         __u16 proto;
 219
 220                         proto = rta_getattr_u16(tb[TCA_MPLS_PROTO]);
 221                         print_string(PRINT_ANY, "protocol", " protocol %s",
 222                                      ll_proto_n2a(proto, b1, sizeof(b1)));
 223                 }
 224                 break;
 225         case TCA_MPLS_ACT_PUSH:
 226                 if (tb[TCA_MPLS_PROTO]) {
 227                         __u16 proto;
 228
 229                         proto = rta_getattr_u16(tb[TCA_MPLS_PROTO]);
 230                         print_string(PRINT_ANY, "protocol", " protocol %s",
 231                                      ll_proto_n2a(proto, b1, sizeof(b1)));
 232                 }
 233                 /* Fallthrough */
 234         case TCA_MPLS_ACT_MODIFY:
 235                 if (tb[TCA_MPLS_LABEL]) {
 236                         val = rta_getattr_u32(tb[TCA_MPLS_LABEL]);
 237                         print_uint(PRINT_ANY, "label", " label %u", val);
 238                 }
 239                 if (tb[TCA_MPLS_TC]) {
 240                         val = rta_getattr_u8(tb[TCA_MPLS_TC]);
 241                         print_uint(PRINT_ANY, "tc", " tc %u", val);
 242                 }
 243                 if (tb[TCA_MPLS_BOS]) {
 244                         val = rta_getattr_u8(tb[TCA_MPLS_BOS]);
 245                         print_uint(PRINT_ANY, "bos", " bos %u", val);
 246                 }
 247                 if (tb[TCA_MPLS_TTL]) {
 248                         val = rta_getattr_u8(tb[TCA_MPLS_TTL]);
 249                         print_uint(PRINT_ANY, "ttl", " ttl %u", val);
 250                 }
 251                 break;
 252         }
 253         print_action_control(f, " ", parm->action, "");
 254
 255         print_uint(PRINT_ANY, "index", "\n\t index %u", parm->index);
 256         print_int(PRINT_ANY, "ref", " ref %d", parm->refcnt);
 257         print_int(PRINT_ANY, "bind", " bind %d", parm->bindcnt);
 258
 259         if (show_stats) {
 260                 if (tb[TCA_MPLS_TM]) {
 261                         struct tcf_t *tm = RTA_DATA(tb[TCA_MPLS_TM]);
 262
 263                         print_tm(f, tm);
 264                 }
 265         }
 266
 267         print_string(PRINT_FP, NULL, "%s", _SL_);
 268
 269         return 0;
 270 }
 271
 272 struct action_util mpls_action_util = {
 273         .id = "mpls",
 274         .parse_aopt = parse_mpls,
 275         .print_aopt = print_mpls,
 276 };