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  * $Whistle: ng_rfc1490.c,v 1.22 1999/11/01 09:24:52 julian Exp $
  41  */
  42
  43 /*
  44  * This node does RFC 1490 multiplexing.
  45  *
  46  * NOTE: RFC 1490 is updated by RFC 2427.
  47  */
  48
  49 #include <sys/param.h>
  50 #include <sys/systm.h>
  51 #include <sys/errno.h>
  52 #include <sys/kernel.h>
  53 #include <sys/malloc.h>
  54 #include <sys/mbuf.h>
  55 #include <sys/errno.h>
  56 #include <sys/socket.h>
  57
  58 #include <net/if.h>
  59 #include <netinet/in.h>
  60 #include <netinet/if_ether.h>
  61
  62 #include <netgraph/ng_message.h>
  63 #include <netgraph/netgraph.h>
  64 #include "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 /* Node private data */
  82 struct ng_rfc1490_private {
  83         hook_p  downlink;
  84         hook_p  ppp;
  85         hook_p  inet;
  86 };
  87 typedef struct ng_rfc1490_private *priv_p;
  88
  89 /* Netgraph node methods */
  90 static ng_constructor_t ng_rfc1490_constructor;
  91 static ng_rcvmsg_t      ng_rfc1490_rcvmsg;
  92 static ng_shutdown_t    ng_rfc1490_rmnode;
  93 static ng_newhook_t     ng_rfc1490_newhook;
  94 static ng_rcvdata_t     ng_rfc1490_rcvdata;
  95 static ng_disconnect_t  ng_rfc1490_disconnect;
  96
  97 /* Node type descriptor */
  98 static struct ng_type typestruct = {
  99         NG_VERSION,
 100         NG_RFC1490_NODE_TYPE,
 101         NULL,
 102         ng_rfc1490_constructor,
 103         ng_rfc1490_rcvmsg,
 104         ng_rfc1490_rmnode,
 105         ng_rfc1490_newhook,
 106         NULL,
 107         NULL,
 108         ng_rfc1490_rcvdata,
 109         ng_rfc1490_rcvdata,
 110         ng_rfc1490_disconnect,
 111         NULL
 112 };
 113 NETGRAPH_INIT(rfc1490, &typestruct);
 114
 115 /************************************************************************
 116                         NETGRAPH NODE STUFF
 117  ************************************************************************/
 118
 119 /*
 120  * Node constructor
 121  */
 122 static int
 123 ng_rfc1490_constructor(node_p *nodep)
 124 {
 125         priv_p priv;
 126         int error;
 127
 128         /* Allocate private structure */
 129         priv = kmalloc(sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO);
 130         if (priv == NULL)
 131                 return (ENOMEM);
 132
 133         /* Call generic node constructor */
 134         if ((error = ng_make_node_common(&typestruct, nodep))) {
 135                 kfree(priv, M_NETGRAPH);
 136                 return (error);
 137         }
 138         (*nodep)->private = priv;
 139
 140         /* Done */
 141         return (0);
 142 }
 143
 144 /*
 145  * Give our ok for a hook to be added
 146  */
 147 static int
 148 ng_rfc1490_newhook(node_p node, hook_p hook, const char *name)
 149 {
 150         const priv_p priv = node->private;
 151
 152         if (!strcmp(name, NG_RFC1490_HOOK_DOWNSTREAM)) {
 153                 if (priv->downlink)
 154                         return (EISCONN);
 155                 priv->downlink = hook;
 156         } else if (!strcmp(name, NG_RFC1490_HOOK_PPP)) {
 157                 if (priv->ppp)
 158                         return (EISCONN);
 159                 priv->ppp = hook;
 160         } else if (!strcmp(name, NG_RFC1490_HOOK_INET)) {
 161                 if (priv->inet)
 162                         return (EISCONN);
 163                 priv->inet = hook;
 164         } else
 165                 return (EINVAL);
 166         return (0);
 167 }
 168
 169 /*
 170  * Receive a control message. We don't support any special ones.
 171  */
 172 static int
 173 ng_rfc1490_rcvmsg(node_p node, struct ng_mesg *msg,
 174                   const char *raddr, struct ng_mesg **rp)
 175 {
 176         kfree(msg, M_NETGRAPH);
 177         return (EINVAL);
 178 }
 179
 180 /*
 181  * Receive data on a hook and encapsulate according to RFC 1490.
 182  * Only those nodes marked (*) are supported by this routine so far.
 183  *
 184  *                            Q.922 control
 185  *                                 |
 186  *                                 |
 187  *            --------------------------------------------
 188  *            | 0x03                                     |
 189  *           UI                                       I Frame
 190  *            |                                          |
 191  *      ---------------------------------         --------------
 192  *      | 0x08  | 0x81  |0xCC   |0xCF   | 0x00    |..01....    |..10....
 193  *      |       |       |       |       | 0x80    |            |
 194  *     Q.933   CLNP    IP(*)   PPP(*)  SNAP     ISO 8208    ISO 8208
 195  *      |                    (rfc1973)  |       Modulo 8    Modulo 128
 196  *      |                               |
 197  *      --------------------           OUI
 198  *      |                  |            |
 199  *     L2 ID              L3 ID      -------------------------
 200  *      |               User         |00-80-C2               |00-00-00
 201  *      |               specified    |                       |
 202  *      |               0x70        PID                     Ethertype
 203  *      |                            |                       |
 204  *      -------------------        --------------...        ----------
 205  *      |0x51 |0x4E |     |0x4C    |0x1   |0xB  |           |0x806   |
 206  *      |     |     |     |        |      |     |           |        |
 207  *     7776  Q.922 Others 802.2   802.3  802.6 Others       ARP(*)  Others
 208  *
 209  *
 210  */
 211
 212 #define MAX_ENCAPS_HDR  8
 213 #define ERROUT(x)       do { error = (x); goto done; } while (0)
 214 #define OUICMP(P,A,B,C) ((P)[0]==(A) && (P)[1]==(B) && (P)[2]==(C))
 215
 216 static int
 217 ng_rfc1490_rcvdata(hook_p hook, struct mbuf *m, meta_p meta)
 218 {
 219         const node_p node = hook->node;
 220         const priv_p priv = node->private;
 221         int error = 0;
 222
 223         if (hook == priv->downlink) {
 224                 const u_char *start;
 225                 const u_char *ptr;
 226
 227                 if (!m || (m->m_len < MAX_ENCAPS_HDR
 228                     && !(m = m_pullup(m, MAX_ENCAPS_HDR))))
 229                         ERROUT(ENOBUFS);
 230                 ptr = start = mtod(m, const u_char *);
 231
 232                 /* Must be UI frame */
 233                 if (*ptr++ != HDLC_UI)
 234                         ERROUT(0);
 235
 236                 /* Eat optional zero pad byte */
 237                 if (*ptr == 0x00)
 238                         ptr++;
 239
 240                 /* Multiplex on NLPID */
 241                 switch (*ptr++) {
 242                 case NLPID_SNAP:
 243                         if (OUICMP(ptr, 0, 0, 0)) {     /* It's an ethertype */
 244                                 u_int16_t etype;
 245
 246                                 ptr += 3;
 247                                 etype = ntohs(*((const u_int16_t *)ptr));
 248                                 ptr += 2;
 249                                 m_adj(m, ptr - start);
 250                                 switch (etype) {
 251                                 case ETHERTYPE_IP:
 252                                         NG_SEND_DATA(error,
 253                                             priv->inet, m, meta);
 254                                         break;
 255                                 case ETHERTYPE_ARP:
 256                                 case ETHERTYPE_REVARP:
 257                                 default:
 258                                         ERROUT(0);
 259                                 }
 260                         } else if (OUICMP(ptr, 0x00, 0x80, 0xc2))       /* 802.1 bridging */
 261                                 ERROUT(0);
 262                         else    /* Other weird stuff... */
 263                                 ERROUT(0);
 264                         break;
 265                 case NLPID_IP:
 266                         m_adj(m, ptr - start);
 267                         NG_SEND_DATA(error, priv->inet, m, meta);
 268                         break;
 269                 case NLPID_PPP:
 270                         m_adj(m, ptr - start);
 271                         NG_SEND_DATA(error, priv->ppp, m, meta);
 272                         break;
 273                 case NLPID_Q933:
 274                 case NLPID_CLNP:
 275                 case NLPID_ESIS:
 276                 case NLPID_ISIS:
 277                         ERROUT(0);
 278                 default:        /* Try PPP (see RFC 1973) */
 279                         ptr--;  /* NLPID becomes PPP proto */
 280                         if ((*ptr & 0x01) == 0x01)
 281                                 ERROUT(0);
 282                         m_adj(m, ptr - start);
 283                         NG_SEND_DATA(error, priv->ppp, m, meta);
 284                         break;
 285                 }
 286         } else if (hook == priv->ppp) {
 287                 M_PREPEND(m, 2, MB_DONTWAIT);   /* Prepend PPP NLPID */
 288                 if (!m)
 289                         ERROUT(ENOBUFS);
 290                 mtod(m, u_char *)[0] = HDLC_UI;
 291                 mtod(m, u_char *)[1] = NLPID_PPP;
 292                 NG_SEND_DATA(error, priv->downlink, m, meta);
 293         } else if (hook == priv->inet) {
 294                 M_PREPEND(m, 2, MB_DONTWAIT);   /* Prepend IP NLPID */
 295                 if (!m)
 296                         ERROUT(ENOBUFS);
 297                 mtod(m, u_char *)[0] = HDLC_UI;
 298                 mtod(m, u_char *)[1] = NLPID_IP;
 299                 NG_SEND_DATA(error, priv->downlink, m, meta);
 300         } else
 301                 panic(__func__);
 302
 303 done:
 304         NG_FREE_DATA(m, meta);
 305         return (error);
 306 }
 307
 308 /*
 309  * Nuke node
 310  */
 311 static int
 312 ng_rfc1490_rmnode(node_p node)
 313 {
 314         const priv_p priv = node->private;
 315
 316         /* Take down netgraph node */
 317         node->flags |= NG_INVALID;
 318         ng_cutlinks(node);
 319         ng_unname(node);
 320         bzero(priv, sizeof(*priv));
 321         node->private = NULL;
 322         kfree(priv, M_NETGRAPH);
 323         ng_unref(node);         /* let the node escape */
 324         return (0);
 325 }
 326
 327 /*
 328  * Hook disconnection
 329  */
 330 static int
 331 ng_rfc1490_disconnect(hook_p hook)
 332 {
 333         const priv_p priv = hook->node->private;
 334
 335         if (hook->node->numhooks == 0)
 336                 ng_rmnode(hook->node);
 337         else if (hook == priv->downlink)
 338                 priv->downlink = NULL;
 339         else if (hook == priv->inet)
 340                 priv->inet = NULL;
 341         else if (hook == priv->ppp)
 342                 priv->ppp = NULL;
 343         else
 344                 panic(__func__);
 345         return (0);
 346 }
 347