sys/netgraph/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  * $FreeBSD$
  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 <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 /* 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_shutdown;
  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_ABI_VERSION,
 100         NG_RFC1490_NODE_TYPE,
 101         NULL,
 102         ng_rfc1490_constructor,
 103         ng_rfc1490_rcvmsg,
 104         ng_rfc1490_shutdown,
 105         ng_rfc1490_newhook,
 106         NULL,
 107         NULL,
 108         ng_rfc1490_rcvdata,
 109         ng_rfc1490_disconnect,
 110         NULL
 111 };
 112 NETGRAPH_INIT(rfc1490, &typestruct);
 113
 114 /************************************************************************
 115                         NETGRAPH NODE STUFF
 116  ************************************************************************/
 117
 118 /*
 119  * Node constructor
 120  */
 121 static int
 122 ng_rfc1490_constructor(node_p node)
 123 {
 124         priv_p priv;
 125
 126         /* Allocate private structure */
 127         MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO);
 128         if (priv == NULL)
 129                 return (ENOMEM);
 130
 131         NG_NODE_SET_PRIVATE(node, priv);
 132
 133         /* Done */
 134         return (0);
 135 }
 136
 137 /*
 138  * Give our ok for a hook to be added
 139  */
 140 static int
 141 ng_rfc1490_newhook(node_p node, hook_p hook, const char *name)
 142 {
 143         const priv_p priv = NG_NODE_PRIVATE(node);
 144
 145         if (!strcmp(name, NG_RFC1490_HOOK_DOWNSTREAM)) {
 146                 if (priv->downlink)
 147                         return (EISCONN);
 148                 priv->downlink = hook;
 149         } else if (!strcmp(name, NG_RFC1490_HOOK_PPP)) {
 150                 if (priv->ppp)
 151                         return (EISCONN);
 152                 priv->ppp = hook;
 153         } else if (!strcmp(name, NG_RFC1490_HOOK_INET)) {
 154                 if (priv->inet)
 155                         return (EISCONN);
 156                 priv->inet = hook;
 157         } else
 158                 return (EINVAL);
 159         return (0);
 160 }
 161
 162 /*
 163  * Receive a control message. We don't support any special ones.
 164  */
 165 static int
 166 ng_rfc1490_rcvmsg(node_p node, item_p item, hook_p lasthook)
 167 {
 168         NG_FREE_ITEM(item);
 169         return (EINVAL);
 170 }
 171
 172 /*
 173  * Receive data on a hook and encapsulate according to RFC 1490.
 174  * Only those nodes marked (*) are supported by this routine so far.
 175  *
 176  *                            Q.922 control
 177  *                                 |
 178  *                                 |
 179  *            --------------------------------------------
 180  *            | 0x03                                     |
 181  *           UI                                       I Frame
 182  *            |                                          |
 183  *      ---------------------------------         --------------
 184  *      | 0x08  | 0x81  |0xCC   |0xCF   | 0x00    |..01....    |..10....
 185  *      |       |       |       |       | 0x80    |            |
 186  *     Q.933   CLNP    IP(*)   PPP(*)  SNAP     ISO 8208    ISO 8208
 187  *      |                    (rfc1973)  |       Modulo 8    Modulo 128
 188  *      |                               |
 189  *      --------------------           OUI
 190  *      |                  |            |
 191  *     L2 ID              L3 ID      -------------------------
 192  *      |               User         |00-80-C2               |00-00-00
 193  *      |               specified    |                       |
 194  *      |               0x70        PID                     Ethertype
 195  *      |                            |                       |
 196  *      -------------------        --------------...        ----------
 197  *      |0x51 |0x4E |     |0x4C    |0x1   |0xB  |           |0x806   |
 198  *      |     |     |     |        |      |     |           |        |
 199  *     7776  Q.922 Others 802.2   802.3  802.6 Others       ARP(*)  Others
 200  *
 201  *
 202  */
 203
 204 #define MAX_ENCAPS_HDR  8
 205 #define ERROUT(x)       do { error = (x); goto done; } while (0)
 206 #define OUICMP(P,A,B,C) ((P)[0]==(A) && (P)[1]==(B) && (P)[2]==(C))
 207
 208 static int
 209 ng_rfc1490_rcvdata(hook_p hook, item_p item)
 210 {
 211         const node_p node = NG_HOOK_NODE(hook);
 212         const priv_p priv = NG_NODE_PRIVATE(node);
 213         int error = 0;
 214         struct mbuf *m;
 215
 216         NGI_GET_M(item, m);
 217         if (hook == priv->downlink) {
 218                 const u_char *start;
 219                 const u_char *ptr;
 220
 221                 if (!m || (m->m_len < MAX_ENCAPS_HDR
 222                     && !(m = m_pullup(m, MAX_ENCAPS_HDR))))
 223                         ERROUT(ENOBUFS);
 224                 ptr = start = mtod(m, const u_char *);
 225
 226                 /* Must be UI frame */
 227                 if (*ptr++ != HDLC_UI)
 228                         ERROUT(0);
 229
 230                 /* Eat optional zero pad byte */
 231                 if (*ptr == 0x00)
 232                         ptr++;
 233
 234                 /* Multiplex on NLPID */
 235                 switch (*ptr++) {
 236                 case NLPID_SNAP:
 237                         if (OUICMP(ptr, 0, 0, 0)) {     /* It's an ethertype */
 238                                 u_int16_t etype;
 239
 240                                 ptr += 3;
 241                                 etype = ntohs(*((const u_int16_t *)ptr));
 242                                 ptr += 2;
 243                                 m_adj(m, ptr - start);
 244                                 switch (etype) {
 245                                 case ETHERTYPE_IP:
 246                                         NG_FWD_NEW_DATA(error, item,
 247                                             priv->inet, m);
 248                                         break;
 249                                 case ETHERTYPE_ARP:
 250                                 case ETHERTYPE_REVARP:
 251                                 default:
 252                                         ERROUT(0);
 253                                 }
 254                         } else if (OUICMP(ptr, 0x00, 0x80, 0xc2))       /* 802.1 bridging */
 255                                 ERROUT(0);
 256                         else    /* Other weird stuff... */
 257                                 ERROUT(0);
 258                         break;
 259                 case NLPID_IP:
 260                         m_adj(m, ptr - start);
 261                         NG_FWD_NEW_DATA(error, item, priv->inet, m);
 262                         break;
 263                 case NLPID_PPP:
 264                         m_adj(m, ptr - start);
 265                         NG_FWD_NEW_DATA(error, item, priv->ppp, m);
 266                         break;
 267                 case NLPID_Q933:
 268                 case NLPID_CLNP:
 269                 case NLPID_ESIS:
 270                 case NLPID_ISIS:
 271                         ERROUT(0);
 272                 default:        /* Try PPP (see RFC 1973) */
 273                         ptr--;  /* NLPID becomes PPP proto */
 274                         if ((*ptr & 0x01) == 0x01)
 275                                 ERROUT(0);
 276                         m_adj(m, ptr - start);
 277                         NG_FWD_NEW_DATA(error, item, priv->ppp, m);
 278                         break;
 279                 }
 280         } else if (hook == priv->ppp) {
 281                 M_PREPEND(m, 2, M_DONTWAIT);    /* Prepend PPP NLPID */
 282                 if (!m)
 283                         ERROUT(ENOBUFS);
 284                 mtod(m, u_char *)[0] = HDLC_UI;
 285                 mtod(m, u_char *)[1] = NLPID_PPP;
 286                 NG_FWD_NEW_DATA(error, item, priv->downlink, m);
 287         } else if (hook == priv->inet) {
 288                 M_PREPEND(m, 2, M_DONTWAIT);    /* Prepend IP NLPID */
 289                 if (!m)
 290                         ERROUT(ENOBUFS);
 291                 mtod(m, u_char *)[0] = HDLC_UI;
 292                 mtod(m, u_char *)[1] = NLPID_IP;
 293                 NG_FWD_NEW_DATA(error, item, priv->downlink, m);
 294         } else
 295                 panic(__func__);
 296
 297 done:
 298         if (item)
 299                 NG_FREE_ITEM(item);
 300         NG_FREE_M(m);
 301         return (error);
 302 }
 303
 304 /*
 305  * Nuke node
 306  */
 307 static int
 308 ng_rfc1490_shutdown(node_p node)
 309 {
 310         const priv_p priv = NG_NODE_PRIVATE(node);
 311
 312         /* Take down netgraph node */
 313         bzero(priv, sizeof(*priv));
 314         FREE(priv, M_NETGRAPH);
 315         NG_NODE_SET_PRIVATE(node, NULL);
 316         NG_NODE_UNREF(node);            /* let the node escape */
 317         return (0);
 318 }
 319
 320 /*
 321  * Hook disconnection
 322  */
 323 static int
 324 ng_rfc1490_disconnect(hook_p hook)
 325 {
 326         const priv_p priv = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
 327
 328         if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
 329         && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook))))
 330                 ng_rmnode_self(NG_HOOK_NODE(hook));
 331         else if (hook == priv->downlink)
 332                 priv->downlink = NULL;
 333         else if (hook == priv->inet)
 334                 priv->inet = NULL;
 335         else if (hook == priv->ppp)
 336                 priv->ppp = NULL;
 337         else
 338                 panic(__func__);
 339         return (0);
 340 }
 341