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