tc/em_meta.c

   1 /*
   2  * em_meta.c            Metadata Ematch
   3  *
   4  *              This program is free software; you can distribute 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:     Thomas Graf <tgraf@suug.ch>
  10  */
  11
  12 #include <stdio.h>
  13 #include <stdlib.h>
  14 #include <unistd.h>
  15 #include <syslog.h>
  16 #include <fcntl.h>
  17 #include <sys/socket.h>
  18 #include <netinet/in.h>
  19 #include <arpa/inet.h>
  20 #include <string.h>
  21 #include <dlfcn.h>
  22 #include <errno.h>
  23
  24 #include "m_ematch.h"
  25 #include <linux/tc_ematch/tc_em_meta.h>
  26
  27 extern struct ematch_util meta_ematch_util;
  28
  29 static void meta_print_usage(FILE *fd)
  30 {
  31         fprintf(fd,
  32             "Usage: meta(OBJECT { eq | lt | gt } OBJECT)\n" \
  33             "where: OBJECT  := { META_ID | VALUE }\n" \
  34             "       META_ID := id [ shift SHIFT ] [ mask MASK ]\n" \
  35             "\n" \
  36             "Example: meta(nfmark gt 24)\n" \
  37             "         meta(indev shift 1 eq \"ppp\"\n" \
  38             "         meta(tcindex mask 0xf0 eq 0xf0)\n" \
  39             "         meta(dev eq indev)\n" \
  40             "\n" \
  41             "For a list of meta identifiers, use meta(list).\n");
  42 }
  43
  44 struct meta_entry {
  45         int             id;
  46         char *          kind;
  47         char *          mask;
  48         char *          desc;
  49 } meta_table[] = {
  50 #define TCF_META_ID_SECTION 0
  51 #define __A(id, name, mask, desc) { TCF_META_ID_##id, name, mask, desc }
  52         __A(SECTION,            "Generic", "", ""),
  53         __A(RANDOM,             "random",       "i",
  54                                 "Random value (32 bit)"),
  55         __A(LOADAVG_0,          "loadavg_1",    "i",
  56                                 "Load average in last minute"),
  57         __A(LOADAVG_1,          "loadavg_5",    "i",
  58                                 "Load average in last 5 minutes"),
  59         __A(LOADAVG_2,          "loadavg_15",   "i",
  60                                 "Load average in last 15 minutes"),
  61
  62         __A(SECTION,            "Interfaces", "", ""),
  63         __A(DEV,                "dev",          "iv",
  64                                 "Device the packet is on"),
  65         __A(SECTION,            "Packet attributes", "", ""),
  66         __A(PRIORITY,           "priority",     "i",
  67                                 "Priority of packet"),
  68         __A(PROTOCOL,           "protocol",     "i",
  69                                 "Link layer protocol"),
  70         __A(PKTTYPE,            "pkt_type",     "i",
  71                                 "Packet type (uni|multi|broad|...)cast"),
  72         __A(PKTLEN,             "pkt_len",      "i",
  73                                 "Length of packet"),
  74         __A(DATALEN,            "data_len",     "i",
  75                                 "Length of data in packet"),
  76         __A(MACLEN,             "mac_len",      "i",
  77                                 "Length of link layer header"),
  78
  79         __A(SECTION,            "Netfilter", "", ""),
  80         __A(NFMARK,             "nf_mark",      "i",
  81                                 "Netfilter mark"),
  82         __A(NFMARK,             "fwmark",       "i",
  83                                 "Alias for nf_mark"),
  84
  85         __A(SECTION,            "Traffic Control", "", ""),
  86         __A(TCINDEX,            "tc_index",     "i",    "TC Index"),
  87         __A(SECTION,            "Routing", "", ""),
  88         __A(RTCLASSID,          "rt_classid",   "i",
  89                                 "Routing ClassID (cls_route)"),
  90         __A(RTIIF,              "rt_iif",       "i",
  91                                 "Incoming interface index"),
  92
  93         __A(SECTION,            "Sockets", "", ""),
  94         __A(SK_FAMILY,          "sk_family",    "i",    "Address family"),
  95         __A(SK_STATE,           "sk_state",     "i",    "State"),
  96         __A(SK_REUSE,           "sk_reuse",     "i",    "Reuse Flag"),
  97         __A(SK_BOUND_IF,        "sk_bind_if",   "iv",   "Bound interface"),
  98         __A(SK_REFCNT,          "sk_refcnt",    "i",    "Reference counter"),
  99         __A(SK_SHUTDOWN,        "sk_shutdown",  "i",    "Shutdown mask"),
 100         __A(SK_PROTO,           "sk_proto",     "i",    "Protocol"),
 101         __A(SK_TYPE,            "sk_type",      "i",    "Type"),
 102         __A(SK_RCVBUF,          "sk_rcvbuf",    "i",    "Receive buffer size"),
 103         __A(SK_RMEM_ALLOC,      "sk_rmem",      "i",    "RMEM"),
 104         __A(SK_WMEM_ALLOC,      "sk_wmem",      "i",    "WMEM"),
 105         __A(SK_OMEM_ALLOC,      "sk_omem",      "i",    "OMEM"),
 106         __A(SK_WMEM_QUEUED,     "sk_wmem_queue","i",    "WMEM queue"),
 107         __A(SK_SND_QLEN,        "sk_snd_queue", "i",    "Send queue length"),
 108         __A(SK_RCV_QLEN,        "sk_rcv_queue", "i",    "Receive queue length"),
 109         __A(SK_ERR_QLEN,        "sk_err_queue", "i",    "Error queue length"),
 110         __A(SK_FORWARD_ALLOCS,  "sk_fwd_alloc", "i",    "Forward allocations"),
 111         __A(SK_SNDBUF,          "sk_sndbuf",    "i",    "Send buffer size"),
 112 #undef __A
 113 };
 114
 115 static inline int map_type(char k)
 116 {
 117         switch (k) {
 118                 case 'i': return TCF_META_TYPE_INT;
 119                 case 'v': return TCF_META_TYPE_VAR;
 120         }
 121
 122         fprintf(stderr, "BUG: Unknown map character '%c'\n", k);
 123         return INT_MAX;
 124 }
 125
 126 static struct meta_entry * lookup_meta_entry(struct bstr *kind)
 127 {
 128         int i;
 129
 130         for (i = 0; i < (sizeof(meta_table)/sizeof(meta_table[0])); i++)
 131                 if (!bstrcmp(kind, meta_table[i].kind) &&
 132                     meta_table[i].id != 0)
 133                         return &meta_table[i];
 134
 135         return NULL;
 136 }
 137
 138 static struct meta_entry * lookup_meta_entry_byid(int id)
 139 {
 140         int i;
 141
 142         for (i = 0; i < (sizeof(meta_table)/sizeof(meta_table[0])); i++)
 143                 if (meta_table[i].id == id)
 144                         return &meta_table[i];
 145
 146         return NULL;
 147 }
 148
 149 static inline void dump_value(struct nlmsghdr *n, int tlv, unsigned long val,
 150                               struct tcf_meta_val *hdr)
 151 {
 152         __u32 t;
 153
 154         switch (TCF_META_TYPE(hdr->kind)) {
 155                 case TCF_META_TYPE_INT:
 156                         t = val;
 157                         addattr_l(n, MAX_MSG, tlv, &t, sizeof(t));
 158                         break;
 159
 160                 case TCF_META_TYPE_VAR:
 161                         if (TCF_META_ID(hdr->kind) == TCF_META_ID_VALUE) {
 162                                 struct bstr *a = (struct bstr *) val;
 163                                 addattr_l(n, MAX_MSG, tlv, a->data, a->len);
 164                         }
 165                         break;
 166         }
 167 }
 168
 169 static inline int is_compatible(struct tcf_meta_val *what,
 170                                 struct tcf_meta_val *needed)
 171 {
 172         char *p;
 173         struct meta_entry *entry;
 174
 175         entry = lookup_meta_entry_byid(TCF_META_ID(what->kind));
 176
 177         if (entry == NULL)
 178                 return 0;
 179
 180         for (p = entry->mask; p; p++)
 181                 if (map_type(*p) == TCF_META_TYPE(needed->kind))
 182                         return 1;
 183
 184         return 0;
 185 }
 186
 187 static void list_meta_ids(FILE *fd)
 188 {
 189         int i;
 190
 191         fprintf(fd,
 192             "--------------------------------------------------------\n" \
 193             "  ID               Type       Description\n" \
 194             "--------------------------------------------------------");
 195
 196         for (i = 0; i < (sizeof(meta_table)/sizeof(meta_table[0])); i++) {
 197                 if (meta_table[i].id == TCF_META_ID_SECTION) {
 198                         fprintf(fd, "\n%s:\n", meta_table[i].kind);
 199                 } else {
 200                         char *p = meta_table[i].mask;
 201                         char buf[64] = {0};
 202
 203                         fprintf(fd, "  %-16s ", meta_table[i].kind);
 204
 205                         while (*p) {
 206                                 int type = map_type(*p);
 207
 208                                 switch (type) {
 209                                         case TCF_META_TYPE_INT:
 210                                                 strcat(buf, "INT");
 211                                                 break;
 212
 213                                         case TCF_META_TYPE_VAR:
 214                                                 strcat(buf, "VAR");
 215                                                 break;
 216                                 }
 217
 218                                 if (*(++p))
 219                                         strcat(buf, ",");
 220                         }
 221
 222                         fprintf(fd, "%-10s %s\n", buf, meta_table[i].desc);
 223                 }
 224         }
 225
 226         fprintf(fd,
 227             "--------------------------------------------------------\n");
 228 }
 229
 230 #undef TCF_META_ID_SECTION
 231
 232 #define PARSE_FAILURE ((void *) (-1))
 233
 234 #define PARSE_ERR(CARG, FMT, ARGS...) \
 235         em_parse_error(EINVAL, args, CARG, &meta_ematch_util, FMT ,##ARGS)
 236
 237 static inline int can_adopt(struct tcf_meta_val *val)
 238 {
 239         return !!TCF_META_ID(val->kind);
 240 }
 241
 242 static inline int overwrite_type(struct tcf_meta_val *src,
 243                                  struct tcf_meta_val *dst)
 244 {
 245         return (TCF_META_TYPE(dst->kind) << 12) | TCF_META_ID(src->kind);
 246 }
 247
 248
 249 static inline struct bstr *
 250 parse_object(struct bstr *args, struct bstr *arg, struct tcf_meta_val *obj,
 251              unsigned long *dst, struct tcf_meta_val *left)
 252 {
 253         struct meta_entry *entry;
 254         unsigned long num;
 255         struct bstr *a;
 256
 257         if (arg->quoted) {
 258                 obj->kind = TCF_META_TYPE_VAR << 12;
 259                 obj->kind |= TCF_META_ID_VALUE;
 260                 *dst = (unsigned long) arg;
 261                 return bstr_next(arg);
 262         }
 263
 264         num = bstrtoul(arg);
 265         if (num != LONG_MAX) {
 266                 obj->kind = TCF_META_TYPE_INT << 12;
 267                 obj->kind |= TCF_META_ID_VALUE;
 268                 *dst = (unsigned long) num;
 269                 return bstr_next(arg);
 270         }
 271
 272         entry = lookup_meta_entry(arg);
 273
 274         if (entry == NULL) {
 275                 PARSE_ERR(arg, "meta: unknown meta id\n");
 276                 return PARSE_FAILURE;
 277         }
 278
 279         obj->kind = entry->id | (map_type(entry->mask[0]) << 12);
 280
 281         if (left) {
 282                 struct tcf_meta_val *right = obj;
 283
 284                 if (TCF_META_TYPE(right->kind) == TCF_META_TYPE(left->kind))
 285                         goto compatible;
 286
 287                 if (can_adopt(left) && !can_adopt(right)) {
 288                         if (is_compatible(left, right))
 289                                 left->kind = overwrite_type(left, right);
 290                         else
 291                                 goto not_compatible;
 292                 } else if (can_adopt(right) && !can_adopt(left)) {
 293                         if (is_compatible(right, left))
 294                                 right->kind = overwrite_type(right, left);
 295                         else
 296                                 goto not_compatible;
 297                 } else if (can_adopt(left) && can_adopt(right)) {
 298                         if (is_compatible(left, right))
 299                                 left->kind = overwrite_type(left, right);
 300                         else if (is_compatible(right, left))
 301                                 right->kind = overwrite_type(right, left);
 302                         else
 303                                 goto not_compatible;
 304                 } else
 305                         goto not_compatible;
 306         }
 307
 308 compatible:
 309
 310         a = bstr_next(arg);
 311
 312         while(a) {
 313                 if (!bstrcmp(a, "shift")) {
 314                         unsigned long shift;
 315
 316                         if (a->next == NULL) {
 317                                 PARSE_ERR(a, "meta: missing argument");
 318                                 return PARSE_FAILURE;
 319                         }
 320                         a = bstr_next(a);
 321
 322                         shift = bstrtoul(a);
 323                         if (shift == LONG_MAX) {
 324                                 PARSE_ERR(a, "meta: invalid shift, must " \
 325                                     "be numeric");
 326                                 return PARSE_FAILURE;
 327                         }
 328
 329                         obj->shift = (__u8) shift;
 330                         a = bstr_next(a);
 331                 } else if (!bstrcmp(a, "mask")) {
 332                         unsigned long mask;
 333
 334                         if (a->next == NULL) {
 335                                 PARSE_ERR(a, "meta: missing argument");
 336                                 return PARSE_FAILURE;
 337                         }
 338                         a = bstr_next(a);
 339
 340                         mask = bstrtoul(a);
 341                         if (mask == LONG_MAX) {
 342                                 PARSE_ERR(a, "meta: invalid mask, must be " \
 343                                     "numeric");
 344                                 return PARSE_FAILURE;
 345                         }
 346                         *dst = (unsigned long) mask;
 347                         a = bstr_next(a);
 348                 } else
 349                         break;
 350         }
 351
 352         return a;
 353
 354 not_compatible:
 355         PARSE_ERR(arg, "lvalue and rvalue are not compatible.");
 356         return PARSE_FAILURE;
 357 }
 358
 359 static int meta_parse_eopt(struct nlmsghdr *n, struct tcf_ematch_hdr *hdr,
 360                            struct bstr *args)
 361 {
 362         int opnd;
 363         struct bstr *a;
 364         struct tcf_meta_hdr meta_hdr;
 365         unsigned long lvalue = 0, rvalue = 0;
 366
 367         memset(&meta_hdr, 0, sizeof(meta_hdr));
 368
 369         if (args == NULL)
 370                 return PARSE_ERR(args, "meta: missing arguments");
 371
 372         if (!bstrcmp(args, "list")) {
 373                 list_meta_ids(stderr);
 374                 return -1;
 375         }
 376
 377         a = parse_object(args, args, &meta_hdr.left, &lvalue, NULL);
 378         if (a == PARSE_FAILURE)
 379                 return -1;
 380         else if (a == NULL)
 381                 return PARSE_ERR(args, "meta: missing operand");
 382
 383         if (!bstrcmp(a, "eq"))
 384                 opnd = TCF_EM_OPND_EQ;
 385         else if (!bstrcmp(a, "gt"))
 386                 opnd = TCF_EM_OPND_GT;
 387         else if (!bstrcmp(a, "lt"))
 388                 opnd = TCF_EM_OPND_LT;
 389         else
 390                 return PARSE_ERR(a, "meta: invalid operand");
 391
 392         meta_hdr.left.op = (__u8) opnd;
 393
 394         if (a->next == NULL)
 395                 return PARSE_ERR(args, "meta: missing rvalue");
 396         a = bstr_next(a);
 397
 398         a = parse_object(args, a, &meta_hdr.right, &rvalue, &meta_hdr.left);
 399         if (a == PARSE_FAILURE)
 400                 return -1;
 401         else if (a != NULL)
 402                 return PARSE_ERR(a, "meta: unexpected trailer");
 403
 404
 405         addraw_l(n, MAX_MSG, hdr, sizeof(*hdr));
 406
 407         addattr_l(n, MAX_MSG, TCA_EM_META_HDR, &meta_hdr, sizeof(meta_hdr));
 408
 409         dump_value(n, TCA_EM_META_LVALUE, lvalue, &meta_hdr.left);
 410         dump_value(n, TCA_EM_META_RVALUE, rvalue, &meta_hdr.right);
 411
 412         return 0;
 413 }
 414 #undef PARSE_ERR
 415
 416 static inline void print_binary(FILE *fd, unsigned char *str, int len)
 417 {
 418         int i;
 419
 420         for (i = 0; i < len; i++)
 421                 if (!isprint(str[i]))
 422                         goto binary;
 423
 424         for (i = 0; i < len; i++)
 425                 fprintf(fd, "%c", str[i]);
 426         return;
 427
 428 binary:
 429         for (i = 0; i < len; i++)
 430                 fprintf(fd, "%02x ", str[i]);
 431
 432         fprintf(fd, "\"");
 433         for (i = 0; i < len; i++)
 434                 fprintf(fd, "%c", isprint(str[i]) ? str[i] : '.');
 435         fprintf(fd, "\"");
 436 }
 437
 438 static inline int print_value(FILE *fd, int type, struct rtattr *rta)
 439 {
 440         if (rta == NULL) {
 441                 fprintf(stderr, "Missing value TLV\n");
 442                 return -1;
 443         }
 444
 445         switch(type) {
 446                 case TCF_META_TYPE_INT:
 447                         if (RTA_PAYLOAD(rta) < sizeof(__u32)) {
 448                                 fprintf(stderr, "meta int type value TLV " \
 449                                     "size mismatch.\n");
 450                                 return -1;
 451                         }
 452                         fprintf(fd, "%d", *(__u32 *) RTA_DATA(rta));
 453                         break;
 454
 455                 case TCF_META_TYPE_VAR:
 456                         print_binary(fd, RTA_DATA(rta), RTA_PAYLOAD(rta));
 457                         break;
 458         }
 459
 460         return 0;
 461 }
 462
 463 static int print_object(FILE *fd, struct tcf_meta_val *obj, struct rtattr *rta)
 464 {
 465         int id = TCF_META_ID(obj->kind);
 466         int type = TCF_META_TYPE(obj->kind);
 467         struct meta_entry *entry;
 468
 469         if (id == TCF_META_ID_VALUE)
 470                 return print_value(fd, type, rta);
 471
 472         entry = lookup_meta_entry_byid(id);
 473
 474         if (entry == NULL)
 475                 fprintf(fd, "[unknown meta id %d]", id);
 476         else
 477                 fprintf(fd, "%s", entry->kind);
 478
 479         if (obj->shift)
 480                 fprintf(fd, " shift %d", obj->shift);
 481
 482         switch (type) {
 483                 case TCF_META_TYPE_INT:
 484                         if (rta) {
 485                                 if (RTA_PAYLOAD(rta) < sizeof(__u32))
 486                                         goto size_mismatch;
 487
 488                                 fprintf(fd, " mask 0x%08x",
 489                                     *(__u32*) RTA_DATA(rta));
 490                         }
 491                         break;
 492         }
 493
 494         return 0;
 495
 496 size_mismatch:
 497         fprintf(stderr, "meta int type mask TLV size mismatch\n");
 498         return -1;
 499 }
 500
 501
 502 static int meta_print_eopt(FILE *fd, struct tcf_ematch_hdr *hdr, void *data,
 503                            int data_len)
 504 {
 505         struct rtattr *tb[TCA_EM_META_MAX+1];
 506         struct tcf_meta_hdr *meta_hdr;
 507
 508         if (parse_rtattr(tb, TCA_EM_META_MAX, data, data_len) < 0)
 509                 return -1;
 510
 511         if (tb[TCA_EM_META_HDR] == NULL) {
 512                 fprintf(stderr, "Missing meta header\n");
 513                 return -1;
 514         }
 515
 516         if (RTA_PAYLOAD(tb[TCA_EM_META_HDR]) < sizeof(*meta_hdr)) {
 517                 fprintf(stderr, "Meta header size mismatch\n");
 518                 return -1;
 519         }
 520
 521         meta_hdr = RTA_DATA(tb[TCA_EM_META_HDR]);
 522
 523         if (print_object(fd, &meta_hdr->left, tb[TCA_EM_META_LVALUE]) < 0)
 524                 return -1;
 525
 526         switch (meta_hdr->left.op) {
 527                 case TCF_EM_OPND_EQ:
 528                         fprintf(fd, " eq ");
 529                         break;
 530                 case TCF_EM_OPND_LT:
 531                         fprintf(fd, " lt ");
 532                         break;
 533                 case TCF_EM_OPND_GT:
 534                         fprintf(fd, " gt ");
 535                         break;
 536         }
 537
 538         return print_object(fd, &meta_hdr->right, tb[TCA_EM_META_RVALUE]);
 539 }
 540
 541 struct ematch_util meta_ematch_util = {
 542         .kind = "meta",
 543         .kind_num = TCF_EM_META,
 544         .parse_eopt = meta_parse_eopt,
 545         .print_eopt = meta_print_eopt,
 546         .print_usage = meta_print_usage
 547 };