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 1.6 2008/01/05 14:02:40 swildner 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 | M_ZERO);
 131         if (priv == NULL)
 132                 return (ENOMEM);
 133
 134         /* Call generic node constructor */
 135         if ((error = ng_make_node_common(&typestruct, nodep))) {
 136                 FREE(priv, M_NETGRAPH);
 137                 return (error);
 138         }
 139         (*nodep)->private = priv;
 140
 141         /* Done */
 142         return (0);
 143 }
 144
 145 /*
 146  * Give our ok for a hook to be added
 147  */
 148 static int
 149 ng_rfc1490_newhook(node_p node, hook_p hook, const char *name)
 150 {
 151         const priv_p priv = node->private;
 152
 153         if (!strcmp(name, NG_RFC1490_HOOK_DOWNSTREAM)) {
 154                 if (priv->downlink)
 155                         return (EISCONN);
 156                 priv->downlink = hook;
 157         } else if (!strcmp(name, NG_RFC1490_HOOK_PPP)) {
 158                 if (priv->ppp)
 159                         return (EISCONN);
 160                 priv->ppp = hook;
 161         } else if (!strcmp(name, NG_RFC1490_HOOK_INET)) {
 162                 if (priv->inet)
 163                         return (EISCONN);
 164                 priv->inet = hook;
 165         } else
 166                 return (EINVAL);
 167         return (0);
 168 }
 169
 170 /*
 171  * Receive a control message. We don't support any special ones.
 172  */
 173 static int
 174 ng_rfc1490_rcvmsg(node_p node, struct ng_mesg *msg,
 175                   const char *raddr, struct ng_mesg **rp)
 176 {
 177         FREE(msg, M_NETGRAPH);
 178         return (EINVAL);
 179 }
 180
 181 /*
 182  * Receive data on a hook and encapsulate according to RFC 1490.
 183  * Only those nodes marked (*) are supported by this routine so far.
 184  *
 185  *                            Q.922 control
 186  *                                 |
 187  *                                 |
 188  *            --------------------------------------------
 189  *            | 0x03                                     |
 190  *           UI                                       I Frame
 191  *            |                                          |
 192  *      ---------------------------------         --------------
 193  *      | 0x08  | 0x81  |0xCC   |0xCF   | 0x00    |..01....    |..10....
 194  *      |       |       |       |       | 0x80    |            |
 195  *     Q.933   CLNP    IP(*)   PPP(*)  SNAP     ISO 8208    ISO 8208
 196  *      |                    (rfc1973)  |       Modulo 8    Modulo 128
 197  *      |                               |
 198  *      --------------------           OUI
 199  *      |                  |            |
 200  *     L2 ID              L3 ID      -------------------------
 201  *      |               User         |00-80-C2               |00-00-00
 202  *      |               specified    |                       |
 203  *      |               0x70        PID                     Ethertype
 204  *      |                            |                       |
 205  *      -------------------        --------------...        ----------
 206  *      |0x51 |0x4E |     |0x4C    |0x1   |0xB  |           |0x806   |
 207  *      |     |     |     |        |      |     |           |        |
 208  *     7776  Q.922 Others 802.2   802.3  802.6 Others       ARP(*)  Others
 209  *
 210  *
 211  */
 212
 213 #define MAX_ENCAPS_HDR  8
 214 #define ERROUT(x)       do { error = (x); goto done; } while (0)
 215 #define OUICMP(P,A,B,C) ((P)[0]==(A) && (P)[1]==(B) && (P)[2]==(C))
 216
 217 static int
 218 ng_rfc1490_rcvdata(hook_p hook, struct mbuf *m, meta_p meta)
 219 {
 220         const node_p node = hook->node;
 221         const priv_p priv = node->private;
 222         int error = 0;
 223
 224         if (hook == priv->downlink) {
 225                 const u_char *start;
 226                 const u_char *ptr;
 227
 228                 if (!m || (m->m_len < MAX_ENCAPS_HDR
 229                     && !(m = m_pullup(m, MAX_ENCAPS_HDR))))
 230                         ERROUT(ENOBUFS);
 231                 ptr = start = mtod(m, const u_char *);
 232
 233                 /* Must be UI frame */
 234                 if (*ptr++ != HDLC_UI)
 235                         ERROUT(0);
 236
 237                 /* Eat optional zero pad byte */
 238                 if (*ptr == 0x00)
 239                         ptr++;
 240
 241                 /* Multiplex on NLPID */
 242                 switch (*ptr++) {
 243                 case NLPID_SNAP:
 244                         if (OUICMP(ptr, 0, 0, 0)) {     /* It's an ethertype */
 245                                 u_int16_t etype;
 246
 247                                 ptr += 3;
 248                                 etype = ntohs(*((const u_int16_t *)ptr));
 249                                 ptr += 2;
 250                                 m_adj(m, ptr - start);
 251                                 switch (etype) {
 252                                 case ETHERTYPE_IP:
 253                                         NG_SEND_DATA(error,
 254                                             priv->inet, m, meta);
 255                                         break;
 256                                 case ETHERTYPE_ARP:
 257                                 case ETHERTYPE_REVARP:
 258                                 default:
 259                                         ERROUT(0);
 260                                 }
 261                         } else if (OUICMP(ptr, 0x00, 0x80, 0xc2))       /* 802.1 bridging */
 262                                 ERROUT(0);
 263                         else    /* Other weird stuff... */
 264                                 ERROUT(0);
 265                         break;
 266                 case NLPID_IP:
 267                         m_adj(m, ptr - start);
 268                         NG_SEND_DATA(error, priv->inet, m, meta);
 269                         break;
 270                 case NLPID_PPP:
 271                         m_adj(m, ptr - start);
 272                         NG_SEND_DATA(error, priv->ppp, m, meta);
 273                         break;
 274                 case NLPID_Q933:
 275                 case NLPID_CLNP:
 276                 case NLPID_ESIS:
 277                 case NLPID_ISIS:
 278                         ERROUT(0);
 279                 default:        /* Try PPP (see RFC 1973) */
 280                         ptr--;  /* NLPID becomes PPP proto */
 281                         if ((*ptr & 0x01) == 0x01)
 282                                 ERROUT(0);
 283                         m_adj(m, ptr - start);
 284                         NG_SEND_DATA(error, priv->ppp, m, meta);
 285                         break;
 286                 }
 287         } else if (hook == priv->ppp) {
 288                 M_PREPEND(m, 2, MB_DONTWAIT);   /* Prepend PPP NLPID */
 289                 if (!m)
 290                         ERROUT(ENOBUFS);
 291                 mtod(m, u_char *)[0] = HDLC_UI;
 292                 mtod(m, u_char *)[1] = NLPID_PPP;
 293                 NG_SEND_DATA(error, priv->downlink, m, meta);
 294         } else if (hook == priv->inet) {
 295                 M_PREPEND(m, 2, MB_DONTWAIT);   /* Prepend IP NLPID */
 296                 if (!m)
 297                         ERROUT(ENOBUFS);
 298                 mtod(m, u_char *)[0] = HDLC_UI;
 299                 mtod(m, u_char *)[1] = NLPID_IP;
 300                 NG_SEND_DATA(error, priv->downlink, m, meta);
 301         } else
 302                 panic(__func__);
 303
 304 done:
 305         NG_FREE_DATA(m, meta);
 306         return (error);
 307 }
 308
 309 /*
 310  * Nuke node
 311  */
 312 static int
 313 ng_rfc1490_rmnode(node_p node)
 314 {
 315         const priv_p priv = node->private;
 316
 317         /* Take down netgraph node */
 318         node->flags |= NG_INVALID;
 319         ng_cutlinks(node);
 320         ng_unname(node);
 321         bzero(priv, sizeof(*priv));
 322         node->private = NULL;
 323         FREE(priv, M_NETGRAPH);
 324         ng_unref(node);         /* let the node escape */
 325         return (0);
 326 }
 327
 328 /*
 329  * Hook disconnection
 330  */
 331 static int
 332 ng_rfc1490_disconnect(hook_p hook)
 333 {
 334         const priv_p priv = hook->node->private;
 335
 336         if (hook->node->numhooks == 0)
 337                 ng_rmnode(hook->node);
 338         else if (hook == priv->downlink)
 339                 priv->downlink = NULL;
 340         else if (hook == priv->inet)
 341                 priv->inet = NULL;
 342         else if (hook == priv->ppp)
 343                 priv->ppp = NULL;
 344         else
 345                 panic(__func__);
 346         return (0);
 347 }
 348