sys/netgraph7/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: src/sys/netgraph/ng_rfc1490.c,v 1.24 2005/01/07 01:45:39 imp Exp $
  41  * $DragonFly: src/sys/netgraph7/ng_rfc1490.c,v 1.2 2008/06/26 23:05:35 dillon Exp $
  42  * $Whistle: ng_rfc1490.c,v 1.22 1999/11/01 09:24:52 julian Exp $
  43  */
  44
  45 /*
  46  * This node does RFC 1490 multiplexing.
  47  *
  48  * NOTE: RFC 1490 is updated by RFC 2427.
  49  */
  50
  51 #include <sys/param.h>
  52 #include <sys/systm.h>
  53 #include <sys/errno.h>
  54 #include <sys/kernel.h>
  55 #include <sys/malloc.h>
  56 #include <sys/mbuf.h>
  57 #include <sys/errno.h>
  58 #include <sys/socket.h>
  59
  60 #include <net/if.h>
  61 #include <netinet/in.h>
  62 #include <netinet/if_ether.h>
  63
  64 #include "ng_message.h"
  65 #include "netgraph.h"
  66 #include "ng_parse.h"
  67 #include "ng_rfc1490.h"
  68
  69 /*
  70  * DEFINITIONS
  71  */
  72
  73 /* Q.922 stuff -- see RFC 1490 */
  74 #define HDLC_UI         0x03
  75
  76 #define NLPID_IP        0xCC
  77 #define NLPID_PPP       0xCF
  78 #define NLPID_SNAP      0x80
  79 #define NLPID_Q933      0x08
  80 #define NLPID_CLNP      0x81
  81 #define NLPID_ESIS      0x82
  82 #define NLPID_ISIS      0x83
  83
  84 #define ERROUT(x)       do { error = (x); goto done; } while (0)
  85
  86 /* Encapsulation methods we understand */
  87 enum {
  88         NG_RFC1490_ENCAP_IETF_IP = 1,   /* see RFC2427, chapter 7, table 1 */
  89         NG_RFC1490_ENCAP_IETF_SNAP,     /* see RFC2427, chapter 7, table 2 */
  90         NG_RFC1490_ENCAP_CISCO,         /* Cisco's proprietary encapsulation */
  91 };
  92
  93 struct ng_rfc1490_encap_t {
  94         u_int8_t        method;
  95         const char      *name;
  96 };
  97
  98 static const struct ng_rfc1490_encap_t ng_rfc1490_encaps[] = {
  99         { NG_RFC1490_ENCAP_IETF_IP,     "ietf-ip" },
 100         { NG_RFC1490_ENCAP_IETF_SNAP,   "ietf-snap" },
 101         { NG_RFC1490_ENCAP_CISCO,       "cisco" },
 102         { 0, NULL},
 103 };
 104
 105 /* Node private data */
 106 struct ng_rfc1490_private {
 107         hook_p  downlink;
 108         hook_p  ppp;
 109         hook_p  inet;
 110         hook_p  ethernet;
 111         const struct ng_rfc1490_encap_t *enc;
 112 };
 113 typedef struct ng_rfc1490_private *priv_p;
 114
 115 /* Netgraph node methods */
 116 static ng_constructor_t ng_rfc1490_constructor;
 117 static ng_rcvmsg_t      ng_rfc1490_rcvmsg;
 118 static ng_shutdown_t    ng_rfc1490_shutdown;
 119 static ng_newhook_t     ng_rfc1490_newhook;
 120 static ng_rcvdata_t     ng_rfc1490_rcvdata;
 121 static ng_disconnect_t  ng_rfc1490_disconnect;
 122
 123 /* List of commands and how to convert arguments to/from ASCII */
 124 static const struct ng_cmdlist ng_rfc1490_cmds[] = {
 125         {
 126           NGM_RFC1490_COOKIE,
 127           NGM_RFC1490_SET_ENCAP,
 128           "setencap",
 129           &ng_parse_string_type,
 130           NULL
 131         },
 132         {
 133           NGM_RFC1490_COOKIE,
 134           NGM_RFC1490_GET_ENCAP,
 135           "getencap",
 136           NULL,
 137           &ng_parse_string_type
 138         },
 139         { 0 }
 140 };
 141
 142 /* Node type descriptor */
 143 static struct ng_type typestruct = {
 144         .version =      NG_ABI_VERSION,
 145         .name =         NG_RFC1490_NODE_TYPE,
 146         .constructor =  ng_rfc1490_constructor,
 147         .rcvmsg =       ng_rfc1490_rcvmsg,
 148         .shutdown =     ng_rfc1490_shutdown,
 149         .newhook =      ng_rfc1490_newhook,
 150         .rcvdata =      ng_rfc1490_rcvdata,
 151         .disconnect =   ng_rfc1490_disconnect,
 152         .cmdlist =      ng_rfc1490_cmds,
 153 };
 154 NETGRAPH_INIT(rfc1490, &typestruct);
 155
 156 /************************************************************************
 157                         NETGRAPH NODE STUFF
 158  ************************************************************************/
 159
 160 /*
 161  * Node constructor
 162  */
 163 static int
 164 ng_rfc1490_constructor(node_p node)
 165 {
 166         priv_p priv;
 167
 168         /* Allocate private structure */
 169         MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_WAITOK | M_NULLOK | M_ZERO);
 170         if (priv == NULL)
 171                 return (ENOMEM);
 172
 173         /* Initialize to default encapsulation method - ietf-ip */
 174         priv->enc = ng_rfc1490_encaps;
 175
 176         NG_NODE_SET_PRIVATE(node, priv);
 177
 178         /* Done */
 179         return (0);
 180 }
 181
 182 /*
 183  * Give our ok for a hook to be added
 184  */
 185 static int
 186 ng_rfc1490_newhook(node_p node, hook_p hook, const char *name)
 187 {
 188         const priv_p priv = NG_NODE_PRIVATE(node);
 189
 190         if (!strcmp(name, NG_RFC1490_HOOK_DOWNSTREAM)) {
 191                 if (priv->downlink)
 192                         return (EISCONN);
 193                 priv->downlink = hook;
 194         } else if (!strcmp(name, NG_RFC1490_HOOK_PPP)) {
 195                 if (priv->ppp)
 196                         return (EISCONN);
 197                 priv->ppp = hook;
 198         } else if (!strcmp(name, NG_RFC1490_HOOK_INET)) {
 199                 if (priv->inet)
 200                         return (EISCONN);
 201                 priv->inet = hook;
 202         } else if (!strcmp(name, NG_RFC1490_HOOK_ETHERNET)) {
 203                 if (priv->ethernet)
 204                         return (EISCONN);
 205                 priv->ethernet = hook;
 206         } else
 207                 return (EINVAL);
 208         return (0);
 209 }
 210
 211 /*
 212  * Receive a control message.
 213  */
 214 static int
 215 ng_rfc1490_rcvmsg(node_p node, item_p item, hook_p lasthook)
 216 {
 217         const priv_p priv = NG_NODE_PRIVATE(node);
 218         struct ng_mesg *msg;
 219         struct ng_mesg *resp = NULL;
 220         int error = 0;
 221
 222         NGI_GET_MSG(item, msg);
 223
 224         if (msg->header.typecookie == NGM_RFC1490_COOKIE) {
 225                 switch (msg->header.cmd) {
 226                 case NGM_RFC1490_SET_ENCAP:
 227                 {
 228                         const struct ng_rfc1490_encap_t *enc;
 229                         char *s;
 230                         size_t len;
 231
 232                         if (msg->header.arglen == 0)
 233                                 ERROUT(EINVAL);
 234
 235                         s = (char *)msg->data;
 236                         len = msg->header.arglen - 1;
 237
 238                         /* Search for matching encapsulation method */
 239                         for (enc = ng_rfc1490_encaps; enc->method != 0; enc++ )
 240                                 if ((strlen(enc->name) == len) &&
 241                                     !strncmp(enc->name, s, len))
 242                                         break;  /* found */
 243
 244                         if (enc->method != 0)
 245                                 priv->enc = enc;
 246                         else
 247                                 error = EINVAL;
 248                         break;
 249                 }
 250                 case NGM_RFC1490_GET_ENCAP:
 251
 252                         NG_MKRESPONSE(resp, msg, strlen(priv->enc->name) + 1, M_WAITOK | M_NULLOK);
 253                         if (resp == NULL)
 254                                 ERROUT(ENOMEM);
 255
 256                         strlcpy((char *)resp->data, priv->enc->name,
 257                             strlen(priv->enc->name) + 1);
 258                         break;
 259
 260                 default:
 261                         error = EINVAL;
 262                         break;
 263                 }
 264         } else
 265                 error = EINVAL;
 266
 267 done:
 268         NG_RESPOND_MSG(error, node, item, resp);
 269         NG_FREE_MSG(msg);
 270         return (error);
 271 }
 272
 273 /*
 274  * Receive data on a hook and encapsulate according to RFC 1490.
 275  * Only those nodes marked (*) are supported by this routine so far.
 276  *
 277  *                            Q.922 control
 278  *                                 |
 279  *                                 |
 280  *            ---------------------------------------------------------------------
 281  *            | 0x03                                     |                        |
 282  *           UI                                       I Frame                   Cisco
 283  *            |                                          |                  Encapsulation
 284  *      ---------------------------------         --------------                  |
 285  *      | 0x08  | 0x81  |0xCC   |0xCF   | 0x00    |..01....    |..10....   --------------
 286  *      |       |       |       |       | 0x80    |            |           |0x800       |
 287  *     Q.933   CLNP    IP(*)   PPP(*)  SNAP     ISO 8208    ISO 8208       |            |
 288  *      |                    (rfc1973)  |       Modulo 8    Modulo 128     IP(*)     Others
 289  *      |                               |
 290  *      --------------------           OUI
 291  *      |                  |            |
 292  *     L2 ID              L3 ID      -------------------------
 293  *      |               User         |00-80-C2               |00-00-00
 294  *      |               specified    |                       |
 295  *      |               0x70        PID                     Ethertype
 296  *      |                            |                       |
 297  *      -------------------        -----------------...     ----------
 298  *      |0x51 |0x4E |     |0x4C    |0x7      |0xB  |        |0x806   |
 299  *      |     |     |     |        |         |     |        |        |
 300  *     7776  Q.922 Others 802.2   802.3(*)  802.6 Others    IP(*)   Others
 301  *
 302  *
 303  */
 304
 305 #define MAX_ENCAPS_HDR  8
 306 #define OUICMP(P,A,B,C) ((P)[0]==(A) && (P)[1]==(B) && (P)[2]==(C))
 307
 308 static int
 309 ng_rfc1490_rcvdata(hook_p hook, item_p item)
 310 {
 311         const node_p node = NG_HOOK_NODE(hook);
 312         const priv_p priv = NG_NODE_PRIVATE(node);
 313         int error = 0;
 314         struct mbuf *m;
 315
 316         NGI_GET_M(item, m);
 317         if (hook == priv->downlink) {
 318                 const u_char *start;
 319                 const u_char *ptr;
 320
 321                 if (m->m_len < MAX_ENCAPS_HDR
 322                     && !(m = m_pullup(m, MAX_ENCAPS_HDR)))
 323                         ERROUT(ENOBUFS);
 324                 ptr = start = mtod(m, const u_char *);
 325
 326                 if (priv->enc->method == NG_RFC1490_ENCAP_CISCO)
 327                         goto switch_on_etype;
 328
 329                 /* Must be UI frame */
 330                 if (*ptr++ != HDLC_UI)
 331                         ERROUT(0);
 332
 333                 /* Eat optional zero pad byte */
 334                 if (*ptr == 0x00)
 335                         ptr++;
 336
 337                 /* Multiplex on NLPID */
 338                 switch (*ptr++) {
 339                 case NLPID_SNAP:
 340                         if (OUICMP(ptr, 0, 0, 0)) {     /* It's an ethertype */
 341                                 u_int16_t etype;
 342
 343                                 ptr += 3;
 344 switch_on_etype:                etype = ntohs(*((const u_int16_t *)ptr));
 345                                 ptr += 2;
 346                                 m_adj(m, ptr - start);
 347                                 switch (etype) {
 348                                 case ETHERTYPE_IP:
 349                                         NG_FWD_NEW_DATA(error, item,
 350                                             priv->inet, m);
 351                                         break;
 352                                 case ETHERTYPE_ARP:
 353                                 case ETHERTYPE_REVARP:
 354                                 default:
 355                                         ERROUT(0);
 356                                 }
 357                         } else if (OUICMP(ptr, 0x00, 0x80, 0xc2)) {
 358                                 /* 802.1 bridging */
 359                                 ptr += 3;
 360                                 if (*ptr++ != 0x00)
 361                                         ERROUT(0);      /* unknown PID octet 0 */
 362                                 if (*ptr++ != 0x07)
 363                                         ERROUT(0);      /* not FCS-less 802.3 */
 364                                 m_adj(m, ptr - start);
 365                                 NG_FWD_NEW_DATA(error, item, priv->ethernet, m);
 366                         } else  /* Other weird stuff... */
 367                                 ERROUT(0);
 368                         break;
 369                 case NLPID_IP:
 370                         m_adj(m, ptr - start);
 371                         NG_FWD_NEW_DATA(error, item, priv->inet, m);
 372                         break;
 373                 case NLPID_PPP:
 374                         m_adj(m, ptr - start);
 375                         NG_FWD_NEW_DATA(error, item, priv->ppp, m);
 376                         break;
 377                 case NLPID_Q933:
 378                 case NLPID_CLNP:
 379                 case NLPID_ESIS:
 380                 case NLPID_ISIS:
 381                         ERROUT(0);
 382                 default:        /* Try PPP (see RFC 1973) */
 383                         ptr--;  /* NLPID becomes PPP proto */
 384                         if ((*ptr & 0x01) == 0x01)
 385                                 ERROUT(0);
 386                         m_adj(m, ptr - start);
 387                         NG_FWD_NEW_DATA(error, item, priv->ppp, m);
 388                         break;
 389                 }
 390         } else if (hook == priv->ppp) {
 391                 M_PREPEND(m, 2, MB_DONTWAIT);   /* Prepend PPP NLPID */
 392                 if (!m)
 393                         ERROUT(ENOBUFS);
 394                 mtod(m, u_char *)[0] = HDLC_UI;
 395                 mtod(m, u_char *)[1] = NLPID_PPP;
 396                 NG_FWD_NEW_DATA(error, item, priv->downlink, m);
 397         } else if (hook == priv->inet) {
 398                 switch (priv->enc->method) {
 399                 case NG_RFC1490_ENCAP_IETF_IP:
 400                         M_PREPEND(m, 2, MB_DONTWAIT);   /* Prepend IP NLPID */
 401                         if (!m)
 402                                 ERROUT(ENOBUFS);
 403                         mtod(m, u_char *)[0] = HDLC_UI;
 404                         mtod(m, u_char *)[1] = NLPID_IP;
 405                         break;
 406                 case NG_RFC1490_ENCAP_IETF_SNAP:
 407                         /*
 408                          *  According to RFC2427 frame should begin with
 409                          *  HDLC_UI  PAD  NLIPID  OUI      PID
 410                          *  03      00   80      00 00 00  08 00
 411                          */
 412                         M_PREPEND(m, 8, MB_DONTWAIT);
 413                         if (!m)
 414                                 ERROUT(ENOBUFS);
 415                         mtod(m, u_char *)[0] = HDLC_UI;
 416                         mtod(m, u_char *)[1] = 0x00;                    /* PAD */
 417                         mtod(m, u_char *)[2] = NLPID_SNAP;
 418                         bzero((char *)(mtod(m, u_char *) + 3), 3);      /* OUI 0-0-0 */
 419                         *((u_int16_t *)mtod(m, u_int16_t *) + 6/sizeof(u_int16_t))
 420                             = htons(ETHERTYPE_IP);  /* PID */
 421                         break;
 422                 case NG_RFC1490_ENCAP_CISCO:
 423                         M_PREPEND(m, 2, MB_DONTWAIT);   /* Prepend IP ethertype */
 424                         if (!m)
 425                                 ERROUT(ENOBUFS);
 426                         *((u_int16_t *)mtod(m, u_int16_t *)) = htons(ETHERTYPE_IP);
 427                         break;
 428                 }
 429                 NG_FWD_NEW_DATA(error, item, priv->downlink, m);
 430         } else if (hook == priv->ethernet) {
 431                 M_PREPEND(m, 8, MB_DONTWAIT);   /* Prepend NLPID, OUI, PID */
 432                 if (!m)
 433                         ERROUT(ENOBUFS);
 434                 mtod(m, u_char *)[0] = HDLC_UI;
 435                 mtod(m, u_char *)[1] = 0x00;            /* pad */
 436                 mtod(m, u_char *)[2] = NLPID_SNAP;
 437                 mtod(m, u_char *)[3] = 0x00;            /* OUI */
 438                 mtod(m, u_char *)[4] = 0x80;
 439                 mtod(m, u_char *)[5] = 0xc2;
 440                 mtod(m, u_char *)[6] = 0x00;            /* PID */
 441                 mtod(m, u_char *)[7] = 0x07;
 442                 NG_FWD_NEW_DATA(error, item, priv->downlink, m);
 443         } else
 444                 panic(__func__);
 445
 446 done:
 447         if (item)
 448                 NG_FREE_ITEM(item);
 449         NG_FREE_M(m);
 450         return (error);
 451 }
 452
 453 /*
 454  * Nuke node
 455  */
 456 static int
 457 ng_rfc1490_shutdown(node_p node)
 458 {
 459         const priv_p priv = NG_NODE_PRIVATE(node);
 460
 461         /* Take down netgraph node */
 462         bzero(priv, sizeof(*priv));
 463         FREE(priv, M_NETGRAPH);
 464         NG_NODE_SET_PRIVATE(node, NULL);
 465         NG_NODE_UNREF(node);            /* let the node escape */
 466         return (0);
 467 }
 468
 469 /*
 470  * Hook disconnection
 471  */
 472 static int
 473 ng_rfc1490_disconnect(hook_p hook)
 474 {
 475         const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
 476
 477         if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
 478         && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook))))
 479                 ng_rmnode_self(NG_HOOK_NODE(hook));
 480         else if (hook == priv->downlink)
 481                 priv->downlink = NULL;
 482         else if (hook == priv->inet)
 483                 priv->inet = NULL;
 484         else if (hook == priv->ppp)
 485                 priv->ppp = NULL;
 486         else if (hook == priv->ethernet)
 487                 priv->ethernet = NULL;
 488         else
 489                 panic(__func__);
 490         return (0);
 491 }
 492