sys/netgraph/rfc1490/ng_rfc1490.c

   1
   2 /*
   3  * ng_rfc1490.c
   4  *
   5  * Copyright (c) 1996-1999 Whistle Communications, Inc.
   6  * All rights reserved.
   7  *
   8  * Subject to the following obligations and disclaimer of warranty, use and
   9  * redistribution of this software, in source or object code forms, with or
  10  * without modifications are expressly permitted by Whistle Communications;
  11  * provided, however, that:
  12  * 1. Any and all reproductions of the source or object code must include the
  13  *    copyright notice above and the following disclaimer of warranties; and
  14  * 2. No rights are granted, in any manner or form, to use Whistle
  15  *    Communications, Inc. trademarks, including the mark "WHISTLE
  16  *    COMMUNICATIONS" on advertising, endorsements, or otherwise except as
  17  *    such appears in the above copyright notice or in the software.
  18  *
  19  * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND
  20  * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO
  21  * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE,
  22  * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF
  23  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT.
  24  * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY
  25  * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS
  26  * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE.
  27  * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES
  28  * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING
  29  * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
  30  * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR
  31  * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY
  32  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  33  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  34  * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY
  35  * OF SUCH DAMAGE.
  36  *
  37  * Author: Julian Elischer <julian@freebsd.org>
  38  *
  39  * $FreeBSD: src/sys/netgraph/ng_rfc1490.c,v 1.6.2.4 2002/07/02 22:17:18 archie Exp $
  40  * $DragonFly: src/sys/netgraph/rfc1490/ng_rfc1490.c,v 1.5 2005/02/17 14:00:00 joerg Exp $
  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 "ng_rfc1490.h"
  66
  67 /*
  68  * DEFINITIONS
  69  */
  70
  71 /* Q.922 stuff -- see RFC 1490 */
  72 #define HDLC_UI         0x03
  73
  74 #define NLPID_IP        0xCC
  75 #define NLPID_PPP       0xCF
  76 #define NLPID_SNAP      0x80
  77 #define NLPID_Q933      0x08
  78 #define NLPID_CLNP      0x81
  79 #define NLPID_ESIS      0x82
  80 #define NLPID_ISIS      0x83
  81
  82 /* Node private data */
  83 struct ng_rfc1490_private {
  84         hook_p  downlink;
  85         hook_p  ppp;
  86         hook_p  inet;
  87 };
  88 typedef struct ng_rfc1490_private *priv_p;
  89
  90 /* Netgraph node methods */
  91 static ng_constructor_t ng_rfc1490_constructor;
  92 static ng_rcvmsg_t      ng_rfc1490_rcvmsg;
  93 static ng_shutdown_t    ng_rfc1490_rmnode;
  94 static ng_newhook_t     ng_rfc1490_newhook;
  95 static ng_rcvdata_t     ng_rfc1490_rcvdata;
  96 static ng_disconnect_t  ng_rfc1490_disconnect;
  97
  98 /* Node type descriptor */
  99 static struct ng_type typestruct = {
 100         NG_VERSION,
 101         NG_RFC1490_NODE_TYPE,
 102         NULL,
 103         ng_rfc1490_constructor,
 104         ng_rfc1490_rcvmsg,
 105         ng_rfc1490_rmnode,
 106         ng_rfc1490_newhook,
 107         NULL,
 108         NULL,
 109         ng_rfc1490_rcvdata,
 110         ng_rfc1490_rcvdata,
 111         ng_rfc1490_disconnect,
 112         NULL
 113 };
 114 NETGRAPH_INIT(rfc1490, &typestruct);
 115
 116 /************************************************************************
 117                         NETGRAPH NODE STUFF
 118  ************************************************************************/
 119
 120 /*
 121  * Node constructor
 122  */
 123 static int
 124 ng_rfc1490_constructor(node_p *nodep)
 125 {
 126         priv_p priv;
 127         int error;
 128
 129         /* Allocate private structure */
 130         MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT);
 131         if (priv == NULL)
 132                 return (ENOMEM);
 133         bzero(priv, sizeof(*priv));
 134
 135         /* Call generic node constructor */
 136         if ((error = ng_make_node_common(&typestruct, nodep))) {
 137                 FREE(priv, M_NETGRAPH);
 138                 return (error);
 139         }
 140         (*nodep)->private = priv;
 141
 142         /* Done */
 143         return (0);
 144 }
 145
 146 /*
 147  * Give our ok for a hook to be added
 148  */
 149 static int
 150 ng_rfc1490_newhook(node_p node, hook_p hook, const char *name)
 151 {
 152         const priv_p priv = node->private;
 153
 154         if (!strcmp(name, NG_RFC1490_HOOK_DOWNSTREAM)) {
 155                 if (priv->downlink)
 156                         return (EISCONN);
 157                 priv->downlink = hook;
 158         } else if (!strcmp(name, NG_RFC1490_HOOK_PPP)) {
 159                 if (priv->ppp)
 160                         return (EISCONN);
 161                 priv->ppp = hook;
 162         } else if (!strcmp(name, NG_RFC1490_HOOK_INET)) {
 163                 if (priv->inet)
 164                         return (EISCONN);
 165                 priv->inet = hook;
 166         } else
 167                 return (EINVAL);
 168         return (0);
 169 }
 170
 171 /*
 172  * Receive a control message. We don't support any special ones.
 173  */
 174 static int
 175 ng_rfc1490_rcvmsg(node_p node, struct ng_mesg *msg,
 176                   const char *raddr, struct ng_mesg **rp)
 177 {
 178         FREE(msg, M_NETGRAPH);
 179         return (EINVAL);
 180 }
 181
 182 /*
 183  * Receive data on a hook and encapsulate according to RFC 1490.
 184  * Only those nodes marked (*) are supported by this routine so far.
 185  *
 186  *                            Q.922 control
 187  *                                 |
 188  *                                 |
 189  *            --------------------------------------------
 190  *            | 0x03                                     |
 191  *           UI                                       I Frame
 192  *            |                                          |
 193  *      ---------------------------------         --------------
 194  *      | 0x08  | 0x81  |0xCC   |0xCF   | 0x00    |..01....    |..10....
 195  *      |       |       |       |       | 0x80    |            |
 196  *     Q.933   CLNP    IP(*)   PPP(*)  SNAP     ISO 8208    ISO 8208
 197  *      |                    (rfc1973)  |       Modulo 8    Modulo 128
 198  *      |                               |
 199  *      --------------------           OUI
 200  *      |                  |            |
 201  *     L2 ID              L3 ID      -------------------------
 202  *      |               User         |00-80-C2               |00-00-00
 203  *      |               specified    |                       |
 204  *      |               0x70        PID                     Ethertype
 205  *      |                            |                       |
 206  *      -------------------        --------------...        ----------
 207  *      |0x51 |0x4E |     |0x4C    |0x1   |0xB  |           |0x806   |
 208  *      |     |     |     |        |      |     |           |        |
 209  *     7776  Q.922 Others 802.2   802.3  802.6 Others       ARP(*)  Others
 210  *
 211  *
 212  */
 213
 214 #define MAX_ENCAPS_HDR  8
 215 #define ERROUT(x)       do { error = (x); goto done; } while (0)
 216 #define OUICMP(P,A,B,C) ((P)[0]==(A) && (P)[1]==(B) && (P)[2]==(C))
 217
 218 static int
 219 ng_rfc1490_rcvdata(hook_p hook, struct mbuf *m, meta_p meta)
 220 {
 221         const node_p node = hook->node;
 222         const priv_p priv = node->private;
 223         int error = 0;
 224
 225         if (hook == priv->downlink) {
 226                 const u_char *start;
 227                 const u_char *ptr;
 228
 229                 if (!m || (m->m_len < MAX_ENCAPS_HDR
 230                     && !(m = m_pullup(m, MAX_ENCAPS_HDR))))
 231                         ERROUT(ENOBUFS);
 232                 ptr = start = mtod(m, const u_char *);
 233
 234                 /* Must be UI frame */
 235                 if (*ptr++ != HDLC_UI)
 236                         ERROUT(0);
 237
 238                 /* Eat optional zero pad byte */
 239                 if (*ptr == 0x00)
 240                         ptr++;
 241
 242                 /* Multiplex on NLPID */
 243                 switch (*ptr++) {
 244                 case NLPID_SNAP:
 245                         if (OUICMP(ptr, 0, 0, 0)) {     /* It's an ethertype */
 246                                 u_int16_t etype;
 247
 248                                 ptr += 3;
 249                                 etype = ntohs(*((const u_int16_t *)ptr));
 250                                 ptr += 2;
 251                                 m_adj(m, ptr - start);
 252                                 switch (etype) {
 253                                 case ETHERTYPE_IP:
 254                                         NG_SEND_DATA(error,
 255                                             priv->inet, m, meta);
 256                                         break;
 257                                 case ETHERTYPE_ARP:
 258                                 case ETHERTYPE_REVARP:
 259                                 default:
 260                                         ERROUT(0);
 261                                 }
 262                         } else if (OUICMP(ptr, 0x00, 0x80, 0xc2))       /* 802.1 bridging */
 263                                 ERROUT(0);
 264                         else    /* Other weird stuff... */
 265                                 ERROUT(0);
 266                         break;
 267                 case NLPID_IP:
 268                         m_adj(m, ptr - start);
 269                         NG_SEND_DATA(error, priv->inet, m, meta);
 270                         break;
 271                 case NLPID_PPP:
 272                         m_adj(m, ptr - start);
 273                         NG_SEND_DATA(error, priv->ppp, m, meta);
 274                         break;
 275                 case NLPID_Q933:
 276                 case NLPID_CLNP:
 277                 case NLPID_ESIS:
 278                 case NLPID_ISIS:
 279                         ERROUT(0);
 280                 default:        /* Try PPP (see RFC 1973) */
 281                         ptr--;  /* NLPID becomes PPP proto */
 282                         if ((*ptr & 0x01) == 0x01)
 283                                 ERROUT(0);
 284                         m_adj(m, ptr - start);
 285                         NG_SEND_DATA(error, priv->ppp, m, meta);
 286                         break;
 287                 }
 288         } else if (hook == priv->ppp) {
 289                 M_PREPEND(m, 2, MB_DONTWAIT);   /* Prepend PPP NLPID */
 290                 if (!m)
 291                         ERROUT(ENOBUFS);
 292                 mtod(m, u_char *)[0] = HDLC_UI;
 293                 mtod(m, u_char *)[1] = NLPID_PPP;
 294                 NG_SEND_DATA(error, priv->downlink, m, meta);
 295         } else if (hook == priv->inet) {
 296                 M_PREPEND(m, 2, MB_DONTWAIT);   /* Prepend IP NLPID */
 297                 if (!m)
 298                         ERROUT(ENOBUFS);
 299                 mtod(m, u_char *)[0] = HDLC_UI;
 300                 mtod(m, u_char *)[1] = NLPID_IP;
 301                 NG_SEND_DATA(error, priv->downlink, m, meta);
 302         } else
 303                 panic(__func__);
 304
 305 done:
 306         NG_FREE_DATA(m, meta);
 307         return (error);
 308 }
 309
 310 /*
 311  * Nuke node
 312  */
 313 static int
 314 ng_rfc1490_rmnode(node_p node)
 315 {
 316         const priv_p priv = node->private;
 317
 318         /* Take down netgraph node */
 319         node->flags |= NG_INVALID;
 320         ng_cutlinks(node);
 321         ng_unname(node);
 322         bzero(priv, sizeof(*priv));
 323         node->private = NULL;
 324         FREE(priv, M_NETGRAPH);
 325         ng_unref(node);         /* let the node escape */
 326         return (0);
 327 }
 328
 329 /*
 330  * Hook disconnection
 331  */
 332 static int
 333 ng_rfc1490_disconnect(hook_p hook)
 334 {
 335         const priv_p priv = hook->node->private;
 336
 337         if (hook->node->numhooks == 0)
 338                 ng_rmnode(hook->node);
 339         else if (hook == priv->downlink)
 340                 priv->downlink = NULL;
 341         else if (hook == priv->inet)
 342                 priv->inet = NULL;
 343         else if (hook == priv->ppp)
 344                 priv->ppp = NULL;
 345         else
 346                 panic(__func__);
 347         return (0);
 348 }
 349