ng_rfc1490.c revision 67506
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: head/sys/netgraph/ng_rfc1490.c 67506 2000-10-24 17:32:45Z julian $ 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 */ 82struct ng_rfc1490_private { 83 hook_p downlink; 84 hook_p ppp; 85 hook_p inet; 86}; 87typedef struct ng_rfc1490_private *priv_p; 88 89/* Netgraph node methods */ 90static ng_constructor_t ng_rfc1490_constructor; 91static ng_rcvmsg_t ng_rfc1490_rcvmsg; 92static ng_shutdown_t ng_rfc1490_rmnode; 93static ng_newhook_t ng_rfc1490_newhook; 94static ng_rcvdata_t ng_rfc1490_rcvdata; 95static ng_disconnect_t ng_rfc1490_disconnect; 96 97/* Node type descriptor */ 98static 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}; 113NETGRAPH_INIT(rfc1490, &typestruct); 114 115/************************************************************************ 116 NETGRAPH NODE STUFF 117 ************************************************************************/ 118 119/* 120 * Node constructor 121 */ 122static int 123ng_rfc1490_constructor(node_p *nodep) 124{ 125 priv_p priv; 126 int error; 127 128 /* Allocate private structure */ 129 MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT); 130 if (priv == NULL) 131 return (ENOMEM); 132 bzero(priv, sizeof(*priv)); 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 */ 148static int 149ng_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 */ 173static int 174ng_rfc1490_rcvmsg(node_p node, struct ng_mesg *msg, 175 const char *raddr, struct ng_mesg **rp, hook_p lasthook) 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 217static int 218ng_rfc1490_rcvdata(hook_p hook, struct mbuf *m, meta_p meta, 219 struct mbuf **ret_m, meta_p *ret_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 u_char *start, *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, 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(*((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, M_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, M_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(__FUNCTION__); 303 304done: 305 NG_FREE_DATA(m, meta); 306 return (error); 307} 308 309/* 310 * Nuke node 311 */ 312static int 313ng_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 ng_unref(node); /* let the node escape */ 324 return (0); 325} 326 327/* 328 * Hook disconnection 329 */ 330static int 331ng_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(__FUNCTION__); 345 return (0); 346} 347 348