tc/f_flow.c

   1 /*
   2  * f_flow.c             Flow filter
   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:     Patrick McHardy <kaber@trash.net>
  10  */
  11 #include <stdio.h>
  12 #include <stdlib.h>
  13 #include <unistd.h>
  14 #include <string.h>
  15 #include <errno.h>
  16
  17 #include "utils.h"
  18 #include "tc_util.h"
  19 #include "m_ematch.h"
  20
  21 static void explain(void)
  22 {
  23         fprintf(stderr,
  24 "Usage: ... flow ...\n"
  25 "\n"
  26 " [mapping mode]: map key KEY [ OPS ] ...\n"
  27 " [hashing mode]: hash keys KEY-LIST ...\n"
  28 "\n"
  29 "                 [ divisor NUM ] [ baseclass ID ] [ match EMATCH_TREE ]\n"
  30 "                 [ police POLICE_SPEC ] [ action ACTION_SPEC ]\n"
  31 "\n"
  32 "KEY-LIST := [ KEY-LIST , ] KEY\n"
  33 "KEY      := [ src | dst | proto | proto-src | proto-dst | iif | priority | \n"
  34 "              mark | nfct | nfct-src | nfct-dst | nfct-proto-src | \n"
  35 "              nfct-proto-dst | rt-classid | sk-uid | sk-gid ]\n"
  36 "OPS      := [ or NUM | and NUM | xor NUM | rshift NUM | addend NUM ]\n"
  37 "ID       := X:Y\n"
  38         );
  39 }
  40
  41 static const char *flow_keys[FLOW_KEY_MAX+1] = {
  42         [FLOW_KEY_SRC]                  = "src",
  43         [FLOW_KEY_DST]                  = "dst",
  44         [FLOW_KEY_PROTO]                = "proto",
  45         [FLOW_KEY_PROTO_SRC]            = "proto-src",
  46         [FLOW_KEY_PROTO_DST]            = "proto-dst",
  47         [FLOW_KEY_IIF]                  = "iif",
  48         [FLOW_KEY_PRIORITY]             = "priority",
  49         [FLOW_KEY_MARK]                 = "mark",
  50         [FLOW_KEY_NFCT]                 = "nfct",
  51         [FLOW_KEY_NFCT_SRC]             = "nfct-src",
  52         [FLOW_KEY_NFCT_DST]             = "nfct-dst",
  53         [FLOW_KEY_NFCT_PROTO_SRC]       = "nfct-proto-src",
  54         [FLOW_KEY_NFCT_PROTO_DST]       = "nfct-proto-dst",
  55         [FLOW_KEY_RTCLASSID]            = "rt-classid",
  56         [FLOW_KEY_SKUID]                = "sk-uid",
  57         [FLOW_KEY_SKGID]                = "sk-gid",
  58 };
  59
  60 static int flow_parse_keys(__u32 *keys, __u32 *nkeys, char *argv)
  61 {
  62         char *s, *sep;
  63         unsigned int i;
  64
  65         *keys = 0;
  66         *nkeys = 0;
  67         s = argv;
  68         while (s != NULL) {
  69                 sep = strchr(s, ',');
  70                 if (sep)
  71                         *sep = '\0';
  72
  73                 for (i = 0; i <= FLOW_KEY_MAX; i++) {
  74                         if (matches(s, flow_keys[i]) == 0) {
  75                                 *keys |= 1 << i;
  76                                 (*nkeys)++;
  77                                 break;
  78                         }
  79                 }
  80                 if (i > FLOW_KEY_MAX) {
  81                         fprintf(stderr, "Unknown flow key \"%s\"\n", s);
  82                         return -1;
  83                 }
  84                 s = sep ? sep + 1 : NULL;
  85         }
  86         return 0;
  87 }
  88
  89 static void transfer_bitop(__u32 *mask, __u32 *xor, __u32 m, __u32 x)
  90 {
  91         *xor = x ^ (*xor & m);
  92         *mask &= m;
  93 }
  94
  95 static int get_addend(__u32 *addend, char *argv, __u32 keys)
  96 {
  97         inet_prefix addr;
  98         int sign = 0;
  99         __u32 tmp;
 100
 101         if (*argv == '-') {
 102                 sign = 1;
 103                 argv++;
 104         }
 105
 106         if (get_u32(&tmp, argv, 0) == 0)
 107                 goto out;
 108
 109         if (keys & (FLOW_KEY_SRC | FLOW_KEY_DST |
 110                     FLOW_KEY_NFCT_SRC | FLOW_KEY_NFCT_DST) &&
 111             get_addr(&addr, argv, AF_UNSPEC) == 0) {
 112                 switch (addr.family) {
 113                 case AF_INET:
 114                         tmp = ntohl(addr.data[0]);
 115                         goto out;
 116                 case AF_INET6:
 117                         tmp = ntohl(addr.data[3]);
 118                         goto out;
 119                 }
 120         }
 121
 122         return -1;
 123 out:
 124         if (sign)
 125                 tmp = -tmp;
 126         *addend = tmp;
 127         return 0;
 128 }
 129
 130 static int flow_parse_opt(struct filter_util *fu, char *handle,
 131                           int argc, char **argv, struct nlmsghdr *n)
 132 {
 133         struct tc_police tp;
 134         struct tcmsg *t = NLMSG_DATA(n);
 135         struct rtattr *tail;
 136         __u32 mask = ~0U, xor = 0;
 137         __u32 keys = 0, nkeys = 0;
 138         __u32 mode = FLOW_MODE_MAP;
 139         __u32 tmp;
 140
 141         memset(&tp, 0, sizeof(tp));
 142
 143         if (handle) {
 144                 if (get_u32(&t->tcm_handle, handle, 0)) {
 145                         fprintf(stderr, "Illegal \"handle\"\n");
 146                         return -1;
 147                 }
 148         }
 149
 150         tail = NLMSG_TAIL(n);
 151         addattr_l(n, 4096, TCA_OPTIONS, NULL, 0);
 152
 153         while (argc > 0) {
 154                 if (matches(*argv, "map") == 0) {
 155                         mode = FLOW_MODE_MAP;
 156                 } else if (matches(*argv, "hash") == 0) {
 157                         mode = FLOW_MODE_HASH;
 158                 } else if (matches(*argv, "keys") == 0) {
 159                         NEXT_ARG();
 160                         if (flow_parse_keys(&keys, &nkeys, *argv))
 161                                 return -1;
 162                         addattr32(n, 4096, TCA_FLOW_KEYS, keys);
 163                 } else if (matches(*argv, "and") == 0) {
 164                         NEXT_ARG();
 165                         if (get_u32(&tmp, *argv, 0)) {
 166                                 fprintf(stderr, "Illegal \"mask\"\n");
 167                                 return -1;
 168                         }
 169                         transfer_bitop(&mask, &xor, tmp, 0);
 170                 } else if (matches(*argv, "or") == 0) {
 171                         NEXT_ARG();
 172                         if (get_u32(&tmp, *argv, 0)) {
 173                                 fprintf(stderr, "Illegal \"or\"\n");
 174                                 return -1;
 175                         }
 176                         transfer_bitop(&mask, &xor, ~tmp, tmp);
 177                 } else if (matches(*argv, "xor") == 0) {
 178                         NEXT_ARG();
 179                         if (get_u32(&tmp, *argv, 0)) {
 180                                 fprintf(stderr, "Illegal \"xor\"\n");
 181                                 return -1;
 182                         }
 183                         transfer_bitop(&mask, &xor, ~0, tmp);
 184                 } else if (matches(*argv, "rshift") == 0) {
 185                         NEXT_ARG();
 186                         if (get_u32(&tmp, *argv, 0)) {
 187                                 fprintf(stderr, "Illegal \"rshift\"\n");
 188                                 return -1;
 189                         }
 190                         addattr32(n, 4096, TCA_FLOW_RSHIFT, tmp);
 191                 } else if (matches(*argv, "addend") == 0) {
 192                         NEXT_ARG();
 193                         if (get_addend(&tmp, *argv, keys)) {
 194                                 fprintf(stderr, "Illegal \"addend\"\n");
 195                                 return -1;
 196                         }
 197                         addattr32(n, 4096, TCA_FLOW_ADDEND, tmp);
 198                 } else if (matches(*argv, "divisor") == 0) {
 199                         NEXT_ARG();
 200                         if (get_u32(&tmp, *argv, 0)) {
 201                                 fprintf(stderr, "Illegal \"divisor\"\n");
 202                                 return -1;
 203                         }
 204                         addattr32(n, 4096, TCA_FLOW_DIVISOR, tmp);
 205                 } else if (matches(*argv, "baseclass") == 0) {
 206                         NEXT_ARG();
 207                         if (get_tc_classid(&tmp, *argv) || TC_H_MIN(tmp) == 0) {
 208                                 fprintf(stderr, "Illegal \"baseclass\"\n");
 209                                 return -1;
 210                         }
 211                         addattr32(n, 4096, TCA_FLOW_BASECLASS, tmp);
 212                 } else if (matches(*argv, "police") == 0) {
 213                         NEXT_ARG();
 214                         if (parse_police(&argc, &argv, TCA_FLOW_POLICE, n)) {
 215                                 fprintf(stderr, "Illegal \"police\"\n");
 216                                 return -1;
 217                         }
 218                         continue;
 219                 } else if (matches(*argv, "action") == 0) {
 220                         NEXT_ARG();
 221                         if (parse_action(&argc, &argv, TCA_FLOW_ACT, n)) {
 222                                 fprintf(stderr, "Illegal \"action\"\n");
 223                                 return -1;
 224                         }
 225                         continue;
 226                 } else if (matches(*argv, "match") == 0) {
 227                         NEXT_ARG();
 228                         if (parse_ematch(&argc, &argv, TCA_FLOW_EMATCHES, n)) {
 229                                 fprintf(stderr, "Illegal \"ematch\"\n");
 230                                 return -1;
 231                         }
 232                         continue;
 233                 } else if (matches(*argv, "help") == 0) {
 234                         explain();
 235                         return -1;
 236                 } else {
 237                         fprintf(stderr, "What is \"%s\"?\n", *argv);
 238                         explain();
 239                         return -1;
 240                 }
 241                 argv++, argc--;
 242         }
 243
 244         if (nkeys > 1 && mode != FLOW_MODE_HASH) {
 245                 fprintf(stderr, "Invalid mode \"map\" for multiple keys\n");
 246                 return -1;
 247         }
 248         addattr32(n, 4096, TCA_FLOW_MODE, mode);
 249
 250         if (mask != ~0 || xor != 0) {
 251                 addattr32(n, 4096, TCA_FLOW_MASK, mask);
 252                 addattr32(n, 4096, TCA_FLOW_XOR, xor);
 253         }
 254
 255         tail->rta_len = (void *)NLMSG_TAIL(n) - (void *)tail;
 256         return 0;
 257 }
 258
 259 static int flow_print_opt(struct filter_util *fu, FILE *f, struct rtattr *opt,
 260                           __u32 handle)
 261 {
 262         struct rtattr *tb[TCA_FLOW_MAX+1];
 263         SPRINT_BUF(b1);
 264         unsigned int i;
 265         __u32 mask = ~0, val = 0;
 266
 267         if (opt == NULL)
 268                 return -EINVAL;
 269
 270         parse_rtattr_nested(tb, TCA_FLOW_MAX, opt);
 271
 272         fprintf(f, "handle 0x%x ", handle);
 273
 274         if (tb[TCA_FLOW_MODE]) {
 275                 __u32 mode = *(__u32 *)RTA_DATA(tb[TCA_FLOW_MODE]);
 276
 277                 switch (mode) {
 278                 case FLOW_MODE_MAP:
 279                         fprintf(f, "map ");
 280                         break;
 281                 case FLOW_MODE_HASH:
 282                         fprintf(f, "hash ");
 283                         break;
 284                 }
 285         }
 286
 287         if (tb[TCA_FLOW_KEYS]) {
 288                 __u32 keymask = *(__u32 *)RTA_DATA(tb[TCA_FLOW_KEYS]);
 289                 char *sep = "";
 290
 291                 fprintf(f, "keys ");
 292                 for (i = 0; i <= FLOW_KEY_MAX; i++) {
 293                         if (keymask & (1 << i)) {
 294                                 fprintf(f, "%s%s", sep, flow_keys[i]);
 295                                 sep = ",";
 296                         }
 297                 }
 298                 fprintf(f, " ");
 299         }
 300
 301         if (tb[TCA_FLOW_MASK])
 302                 mask = *(__u32 *)RTA_DATA(tb[TCA_FLOW_MASK]);
 303         if (tb[TCA_FLOW_XOR])
 304                 val = *(__u32 *)RTA_DATA(tb[TCA_FLOW_XOR]);
 305
 306         if (mask != ~0 || val != 0) {
 307                 __u32 or = (mask & val) ^ val;
 308                 __u32 xor = mask & val;
 309
 310                 if (mask != ~0)
 311                         fprintf(f, "and 0x%.8x ", mask);
 312                 if (xor != 0)
 313                         fprintf(f, "xor 0x%.8x ", xor);
 314                 if (or != 0)
 315                         fprintf(f, "or 0x%.8x ", or);
 316         }
 317
 318         if (tb[TCA_FLOW_RSHIFT])
 319                 fprintf(f, "rshift %u ",
 320                         *(__u32 *)RTA_DATA(tb[TCA_FLOW_RSHIFT]));
 321         if (tb[TCA_FLOW_ADDEND])
 322                 fprintf(f, "addend 0x%x ",
 323                         *(__u32 *)RTA_DATA(tb[TCA_FLOW_ADDEND]));
 324
 325         if (tb[TCA_FLOW_DIVISOR])
 326                 fprintf(f, "divisor %u ",
 327                         *(__u32 *)RTA_DATA(tb[TCA_FLOW_DIVISOR]));
 328         if (tb[TCA_FLOW_BASECLASS])
 329                 fprintf(f, "baseclass %s ",
 330                         sprint_tc_classid(*(__u32 *)RTA_DATA(tb[TCA_FLOW_BASECLASS]), b1));
 331
 332         if (tb[TCA_FLOW_EMATCHES])
 333                 print_ematch(f, tb[TCA_FLOW_EMATCHES]);
 334         if (tb[TCA_FLOW_POLICE])
 335                 tc_print_police(f, tb[TCA_FLOW_POLICE]);
 336         if (tb[TCA_FLOW_ACT]) {
 337                 fprintf(f, "\n");
 338                 tc_print_action(f, tb[TCA_FLOW_ACT]);
 339         }
 340         return 0;
 341 }
 342
 343 struct filter_util flow_filter_util = {
 344         .id             = "flow",
 345         .parse_fopt     = flow_parse_opt,
 346         .print_fopt     = flow_print_opt,
 347 };