sys/netgraph/ng_rfc1490.c

   1 /*
   2  * ng_rfc1490.c
   3  */
   4
   5 /*-
   6  * Copyright (c) 1996-1999 Whistle Communications, Inc.
   7  * All rights reserved.
   8  *
   9  * Subject to the following obligations and disclaimer of warranty, use and
  10  * redistribution of this software, in source or object code forms, with or
  11  * without modifications are expressly permitted by Whistle Communications;
  12  * provided, however, that:
  13  * 1. Any and all reproductions of the source or object code must include the
  14  *    copyright notice above and the following disclaimer of warranties; and
  15  * 2. No rights are granted, in any manner or form, to use Whistle
  16  *    Communications, Inc. trademarks, including the mark "WHISTLE
  17  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
  18  *    such appears in the above copyright notice or in the software.
  19  *
  20  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
  21  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
  22  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
  23  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
  24  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
  25  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
  26  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
  27  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
  28  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
  29  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
  30  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
  31  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
  32  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
  33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  34  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  35  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
  36  * OF SUCH DAMAGE.
  37  *
  38  * Author: Julian Elischer <julian@freebsd.org>
  39  *
  40  * $FreeBSD$
  41  * $Whistle: ng_rfc1490.c,v 1.22 1999/11/01 09:24:52 julian Exp $
  42  */
  43
  44 /*
  45  * This node does RFC 1490 multiplexing.
  46  *
  47  * NOTE: RFC 1490 is updated by RFC 2427.
  48  */
  49
  50 #include <sys/param.h>
  51 #include <sys/systm.h>
  52 #include <sys/errno.h>
  53 #include <sys/kernel.h>
  54 #include <sys/malloc.h>
  55 #include <sys/mbuf.h>
  56 #include <sys/errno.h>
  57 #include <sys/socket.h>
  58
  59 #include <net/if.h>
  60 #include <netinet/in.h>
  61 #include <netinet/if_ether.h>
  62
  63 #include <netgraph/ng_message.h>
  64 #include <netgraph/netgraph.h>
  65 #include <netgraph/ng_parse.h>
  66 #include <netgraph/ng_rfc1490.h>
  67
  68 /*
  69  * DEFINITIONS
  70  */
  71
  72 /* Q.922 stuff -- see RFC 1490 */
  73 #define HDLC_UI         0x03
  74
  75 #define NLPID_IP        0xCC
  76 #define NLPID_PPP       0xCF
  77 #define NLPID_SNAP      0x80
  78 #define NLPID_Q933      0x08
  79 #define NLPID_CLNP      0x81
  80 #define NLPID_ESIS      0x82
  81 #define NLPID_ISIS      0x83
  82
  83 #define ERROUT(x)       do { error = (x); goto done; } while (0)
  84
  85 /* Encapsulation methods we understand */
  86 enum {
  87         NG_RFC1490_ENCAP_IETF_IP = 1,   /* see RFC2427, chapter 7, table 1 */
  88         NG_RFC1490_ENCAP_IETF_SNAP,     /* see RFC2427, chapter 7, table 2 */
  89         NG_RFC1490_ENCAP_CISCO,         /* Cisco's proprietary encapsulation */
  90 };
  91
  92 struct ng_rfc1490_encap_t {
  93         u_int8_t        method;
  94         const char      *name;
  95 };
  96
  97 static const struct ng_rfc1490_encap_t ng_rfc1490_encaps[] = {
  98         { NG_RFC1490_ENCAP_IETF_IP,     "ietf-ip" },
  99         { NG_RFC1490_ENCAP_IETF_SNAP,   "ietf-snap" },
 100         { NG_RFC1490_ENCAP_CISCO,       "cisco" },
 101         { 0, NULL},
 102 };
 103
 104 /* Node private data */
 105 struct ng_rfc1490_private {
 106         hook_p  downlink;
 107         hook_p  ppp;
 108         hook_p  inet;
 109         hook_p  ethernet;
 110         const struct ng_rfc1490_encap_t *enc;
 111 };
 112 typedef struct ng_rfc1490_private *priv_p;
 113
 114 /* Netgraph node methods */
 115 static ng_constructor_t ng_rfc1490_constructor;
 116 static ng_rcvmsg_t      ng_rfc1490_rcvmsg;
 117 static ng_shutdown_t    ng_rfc1490_shutdown;
 118 static ng_newhook_t     ng_rfc1490_newhook;
 119 static ng_rcvdata_t     ng_rfc1490_rcvdata;
 120 static ng_disconnect_t  ng_rfc1490_disconnect;
 121
 122 /* List of commands and how to convert arguments to/from ASCII */
 123 static const struct ng_cmdlist ng_rfc1490_cmds[] = {
 124         {
 125           NGM_RFC1490_COOKIE,
 126           NGM_RFC1490_SET_ENCAP,
 127           "setencap",
 128           &ng_parse_string_type,
 129           NULL
 130         },
 131         {
 132           NGM_RFC1490_COOKIE,
 133           NGM_RFC1490_GET_ENCAP,
 134           "getencap",
 135           NULL,
 136           &ng_parse_string_type
 137         },
 138         { 0 }
 139 };
 140
 141 /* Node type descriptor */
 142 static struct ng_type typestruct = {
 143         .version =      NG_ABI_VERSION,
 144         .name =         NG_RFC1490_NODE_TYPE,
 145         .constructor =  ng_rfc1490_constructor,
 146         .rcvmsg =       ng_rfc1490_rcvmsg,
 147         .shutdown =     ng_rfc1490_shutdown,
 148         .newhook =      ng_rfc1490_newhook,
 149         .rcvdata =      ng_rfc1490_rcvdata,
 150         .disconnect =   ng_rfc1490_disconnect,
 151         .cmdlist =      ng_rfc1490_cmds,
 152 };
 153 NETGRAPH_INIT(rfc1490, &typestruct);
 154
 155 /************************************************************************
 156                         NETGRAPH NODE STUFF
 157  ************************************************************************/
 158
 159 /*
 160  * Node constructor
 161  */
 162 static int
 163 ng_rfc1490_constructor(node_p node)
 164 {
 165         priv_p priv;
 166
 167         /* Allocate private structure */
 168         priv = malloc(sizeof(*priv), M_NETGRAPH, M_WAITOK | M_ZERO);
 169
 170         /* Initialize to default encapsulation method - ietf-ip */
 171         priv->enc = ng_rfc1490_encaps;
 172
 173         NG_NODE_SET_PRIVATE(node, priv);
 174
 175         /* Done */
 176         return (0);
 177 }
 178
 179 /*
 180  * Give our ok for a hook to be added
 181  */
 182 static int
 183 ng_rfc1490_newhook(node_p node, hook_p hook, const char *name)
 184 {
 185         const priv_p priv = NG_NODE_PRIVATE(node);
 186
 187         if (!strcmp(name, NG_RFC1490_HOOK_DOWNSTREAM)) {
 188                 if (priv->downlink)
 189                         return (EISCONN);
 190                 priv->downlink = hook;
 191         } else if (!strcmp(name, NG_RFC1490_HOOK_PPP)) {
 192                 if (priv->ppp)
 193                         return (EISCONN);
 194                 priv->ppp = hook;
 195         } else if (!strcmp(name, NG_RFC1490_HOOK_INET)) {
 196                 if (priv->inet)
 197                         return (EISCONN);
 198                 priv->inet = hook;
 199         } else if (!strcmp(name, NG_RFC1490_HOOK_ETHERNET)) {
 200                 if (priv->ethernet)
 201                         return (EISCONN);
 202                 priv->ethernet = hook;
 203         } else
 204                 return (EINVAL);
 205         return (0);
 206 }
 207
 208 /*
 209  * Receive a control message.
 210  */
 211 static int
 212 ng_rfc1490_rcvmsg(node_p node, item_p item, hook_p lasthook)
 213 {
 214         const priv_p priv = NG_NODE_PRIVATE(node);
 215         struct ng_mesg *msg;
 216         struct ng_mesg *resp = NULL;
 217         int error = 0;
 218
 219         NGI_GET_MSG(item, msg);
 220
 221         if (msg->header.typecookie == NGM_RFC1490_COOKIE) {
 222                 switch (msg->header.cmd) {
 223                 case NGM_RFC1490_SET_ENCAP:
 224                 {
 225                         const struct ng_rfc1490_encap_t *enc;
 226                         char *s;
 227                         size_t len;
 228
 229                         if (msg->header.arglen == 0)
 230                                 ERROUT(EINVAL);
 231
 232                         s = (char *)msg->data;
 233                         len = msg->header.arglen - 1;
 234
 235                         /* Search for matching encapsulation method */
 236                         for (enc = ng_rfc1490_encaps; enc->method != 0; enc++ )
 237                                 if ((strlen(enc->name) == len) &&
 238                                     !strncmp(enc->name, s, len))
 239                                         break;  /* found */
 240
 241                         if (enc->method != 0)
 242                                 priv->enc = enc;
 243                         else
 244                                 error = EINVAL;
 245                         break;
 246                 }
 247                 case NGM_RFC1490_GET_ENCAP:
 248
 249                         NG_MKRESPONSE(resp, msg, strlen(priv->enc->name) + 1, M_NOWAIT);
 250                         if (resp == NULL)
 251                                 ERROUT(ENOMEM);
 252
 253                         strlcpy((char *)resp->data, priv->enc->name,
 254                             strlen(priv->enc->name) + 1);
 255                         break;
 256
 257                 default:
 258                         error = EINVAL;
 259                         break;
 260                 }
 261         } else
 262                 error = EINVAL;
 263
 264 done:
 265         NG_RESPOND_MSG(error, node, item, resp);
 266         NG_FREE_MSG(msg);
 267         return (error);
 268 }
 269
 270 /*
 271  * Receive data on a hook and encapsulate according to RFC 1490.
 272  * Only those nodes marked (*) are supported by this routine so far.
 273  *
 274  *                            Q.922 control
 275  *                                 |
 276  *                                 |
 277  *            ---------------------------------------------------------------------
 278  *            | 0x03                                     |                        |
 279  *           UI                                       I Frame                   Cisco
 280  *            |                                          |                  Encapsulation
 281  *      ---------------------------------         --------------                  |
 282  *      | 0x08  | 0x81  |0xCC   |0xCF   | 0x00    |..01....    |..10....   --------------
 283  *      |       |       |       |       | 0x80    |            |           |0x800       |
 284  *     Q.933   CLNP    IP(*)   PPP(*)  SNAP     ISO 8208    ISO 8208       |            |
 285  *      |                    (rfc1973)  |       Modulo 8    Modulo 128     IP(*)     Others
 286  *      |                               |
 287  *      --------------------           OUI
 288  *      |                  |            |
 289  *     L2 ID              L3 ID      -------------------------
 290  *      |               User         |00-80-C2               |00-00-00
 291  *      |               specified    |                       |
 292  *      |               0x70        PID                     Ethertype
 293  *      |                            |                       |
 294  *      -------------------        -----------------...     ----------
 295  *      |0x51 |0x4E |     |0x4C    |0x7      |0xB  |        |0x806   |
 296  *      |     |     |     |        |         |     |        |        |
 297  *     7776  Q.922 Others 802.2   802.3(*)  802.6 Others    IP(*)   Others
 298  *
 299  *
 300  */
 301
 302 #define MAX_ENCAPS_HDR  8
 303 #define OUICMP(P,A,B,C) ((P)[0]==(A) && (P)[1]==(B) && (P)[2]==(C))
 304
 305 static int
 306 ng_rfc1490_rcvdata(hook_p hook, item_p item)
 307 {
 308         const node_p node = NG_HOOK_NODE(hook);
 309         const priv_p priv = NG_NODE_PRIVATE(node);
 310         int error = 0;
 311         struct mbuf *m;
 312
 313         NGI_GET_M(item, m);
 314         if (hook == priv->downlink) {
 315                 const u_char *start;
 316                 const u_char *ptr;
 317
 318                 if (m->m_len < MAX_ENCAPS_HDR
 319                     && !(m = m_pullup(m, MAX_ENCAPS_HDR)))
 320                         ERROUT(ENOBUFS);
 321                 ptr = start = mtod(m, const u_char *);
 322
 323                 if (priv->enc->method == NG_RFC1490_ENCAP_CISCO)
 324                         goto switch_on_etype;
 325
 326                 /* Must be UI frame */
 327                 if (*ptr++ != HDLC_UI)
 328                         ERROUT(0);
 329
 330                 /* Eat optional zero pad byte */
 331                 if (*ptr == 0x00)
 332                         ptr++;
 333
 334                 /* Multiplex on NLPID */
 335                 switch (*ptr++) {
 336                 case NLPID_SNAP:
 337                         if (OUICMP(ptr, 0, 0, 0)) {     /* It's an ethertype */
 338                                 u_int16_t etype;
 339
 340                                 ptr += 3;
 341 switch_on_etype:                etype = ntohs(*((const u_int16_t *)ptr));
 342                                 ptr += 2;
 343                                 m_adj(m, ptr - start);
 344                                 switch (etype) {
 345                                 case ETHERTYPE_IP:
 346                                         NG_FWD_NEW_DATA(error, item,
 347                                             priv->inet, m);
 348                                         break;
 349                                 case ETHERTYPE_ARP:
 350                                 case ETHERTYPE_REVARP:
 351                                 default:
 352                                         ERROUT(0);
 353                                 }
 354                         } else if (OUICMP(ptr, 0x00, 0x80, 0xc2)) {
 355                                 /* 802.1 bridging */
 356                                 ptr += 3;
 357                                 if (*ptr++ != 0x00)
 358                                         ERROUT(0);      /* unknown PID octet 0 */
 359                                 if (*ptr++ != 0x07)
 360                                         ERROUT(0);      /* not FCS-less 802.3 */
 361                                 m_adj(m, ptr - start);
 362                                 NG_FWD_NEW_DATA(error, item, priv->ethernet, m);
 363                         } else  /* Other weird stuff... */
 364                                 ERROUT(0);
 365                         break;
 366                 case NLPID_IP:
 367                         m_adj(m, ptr - start);
 368                         NG_FWD_NEW_DATA(error, item, priv->inet, m);
 369                         break;
 370                 case NLPID_PPP:
 371                         m_adj(m, ptr - start);
 372                         NG_FWD_NEW_DATA(error, item, priv->ppp, m);
 373                         break;
 374                 case NLPID_Q933:
 375                 case NLPID_CLNP:
 376                 case NLPID_ESIS:
 377                 case NLPID_ISIS:
 378                         ERROUT(0);
 379                 default:        /* Try PPP (see RFC 1973) */
 380                         ptr--;  /* NLPID becomes PPP proto */
 381                         if ((*ptr & 0x01) == 0x01)
 382                                 ERROUT(0);
 383                         m_adj(m, ptr - start);
 384                         NG_FWD_NEW_DATA(error, item, priv->ppp, m);
 385                         break;
 386                 }
 387         } else if (hook == priv->ppp) {
 388                 M_PREPEND(m, 2, M_NOWAIT);      /* Prepend PPP NLPID */
 389                 if (!m)
 390                         ERROUT(ENOBUFS);
 391                 mtod(m, u_char *)[0] = HDLC_UI;
 392                 mtod(m, u_char *)[1] = NLPID_PPP;
 393                 NG_FWD_NEW_DATA(error, item, priv->downlink, m);
 394         } else if (hook == priv->inet) {
 395                 switch (priv->enc->method) {
 396                 case NG_RFC1490_ENCAP_IETF_IP:
 397                         M_PREPEND(m, 2, M_NOWAIT);      /* Prepend IP NLPID */
 398                         if (!m)
 399                                 ERROUT(ENOBUFS);
 400                         mtod(m, u_char *)[0] = HDLC_UI;
 401                         mtod(m, u_char *)[1] = NLPID_IP;
 402                         break;
 403                 case NG_RFC1490_ENCAP_IETF_SNAP:
 404                         /*
 405                          *  According to RFC2427 frame should begin with
 406                          *  HDLC_UI  PAD  NLIPID  OUI      PID
 407                          *  03      00   80      00 00 00  08 00
 408                          */
 409                         M_PREPEND(m, 8, M_NOWAIT);
 410                         if (!m)
 411                                 ERROUT(ENOBUFS);
 412                         mtod(m, u_char *)[0] = HDLC_UI;
 413                         mtod(m, u_char *)[1] = 0x00;                    /* PAD */
 414                         mtod(m, u_char *)[2] = NLPID_SNAP;
 415                         bzero((char *)(mtod(m, u_char *) + 3), 3);      /* OUI 0-0-0 */
 416                         *((u_int16_t *)mtod(m, u_int16_t *) + 6/sizeof(u_int16_t))
 417                             = htons(ETHERTYPE_IP);  /* PID */
 418                         break;
 419                 case NG_RFC1490_ENCAP_CISCO:
 420                         M_PREPEND(m, 2, M_NOWAIT);      /* Prepend IP ethertype */
 421                         if (!m)
 422                                 ERROUT(ENOBUFS);
 423                         *((u_int16_t *)mtod(m, u_int16_t *)) = htons(ETHERTYPE_IP);
 424                         break;
 425                 }
 426                 NG_FWD_NEW_DATA(error, item, priv->downlink, m);
 427         } else if (hook == priv->ethernet) {
 428                 M_PREPEND(m, 8, M_NOWAIT);      /* Prepend NLPID, OUI, PID */
 429                 if (!m)
 430                         ERROUT(ENOBUFS);
 431                 mtod(m, u_char *)[0] = HDLC_UI;
 432                 mtod(m, u_char *)[1] = 0x00;            /* pad */
 433                 mtod(m, u_char *)[2] = NLPID_SNAP;
 434                 mtod(m, u_char *)[3] = 0x00;            /* OUI */
 435                 mtod(m, u_char *)[4] = 0x80;
 436                 mtod(m, u_char *)[5] = 0xc2;
 437                 mtod(m, u_char *)[6] = 0x00;            /* PID */
 438                 mtod(m, u_char *)[7] = 0x07;
 439                 NG_FWD_NEW_DATA(error, item, priv->downlink, m);
 440         } else
 441                 panic("%s", __func__);
 442
 443 done:
 444         if (item)
 445                 NG_FREE_ITEM(item);
 446         NG_FREE_M(m);
 447         return (error);
 448 }
 449
 450 /*
 451  * Nuke node
 452  */
 453 static int
 454 ng_rfc1490_shutdown(node_p node)
 455 {
 456         const priv_p priv = NG_NODE_PRIVATE(node);
 457
 458         /* Take down netgraph node */
 459         bzero(priv, sizeof(*priv));
 460         free(priv, M_NETGRAPH);
 461         NG_NODE_SET_PRIVATE(node, NULL);
 462         NG_NODE_UNREF(node);            /* let the node escape */
 463         return (0);
 464 }
 465
 466 /*
 467  * Hook disconnection
 468  */
 469 static int
 470 ng_rfc1490_disconnect(hook_p hook)
 471 {
 472         const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
 473
 474         if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
 475         && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook))))
 476                 ng_rmnode_self(NG_HOOK_NODE(hook));
 477         else if (hook == priv->downlink)
 478                 priv->downlink = NULL;
 479         else if (hook == priv->inet)
 480                 priv->inet = NULL;
 481         else if (hook == priv->ppp)
 482                 priv->ppp = NULL;
 483         else if (hook == priv->ethernet)
 484                 priv->ethernet = NULL;
 485         else
 486                 panic("%s", __func__);
 487         return (0);
 488 }
 489