ng_rfc1490.c revision 69922
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 69922 2000-12-12 18:52:14Z 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_disconnect, 110 NULL 111}; 112NETGRAPH_INIT(rfc1490, &typestruct); 113 114/************************************************************************ 115 NETGRAPH NODE STUFF 116 ************************************************************************/ 117 118/* 119 * Node constructor 120 */ 121static int 122ng_rfc1490_constructor(node_p *nodep) 123{ 124 priv_p priv; 125 int error; 126 127 /* Allocate private structure */ 128 MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO); 129 if (priv == NULL) 130 return (ENOMEM); 131 132 /* Call generic node constructor */ 133 if ((error = ng_make_node_common(&typestruct, nodep))) { 134 FREE(priv, M_NETGRAPH); 135 return (error); 136 } 137 (*nodep)->private = priv; 138 139 /* Done */ 140 return (0); 141} 142 143/* 144 * Give our ok for a hook to be added 145 */ 146static int 147ng_rfc1490_newhook(node_p node, hook_p hook, const char *name) 148{ 149 const priv_p priv = node->private; 150 151 if (!strcmp(name, NG_RFC1490_HOOK_DOWNSTREAM)) { 152 if (priv->downlink) 153 return (EISCONN); 154 priv->downlink = hook; 155 } else if (!strcmp(name, NG_RFC1490_HOOK_PPP)) { 156 if (priv->ppp) 157 return (EISCONN); 158 priv->ppp = hook; 159 } else if (!strcmp(name, NG_RFC1490_HOOK_INET)) { 160 if (priv->inet) 161 return (EISCONN); 162 priv->inet = hook; 163 } else 164 return (EINVAL); 165 return (0); 166} 167 168/* 169 * Receive a control message. We don't support any special ones. 170 */ 171static int 172ng_rfc1490_rcvmsg(node_p node, struct ng_mesg *msg, 173 const char *raddr, struct ng_mesg **rp, hook_p lasthook) 174{ 175 FREE(msg, M_NETGRAPH); 176 return (EINVAL); 177} 178 179/* 180 * Receive data on a hook and encapsulate according to RFC 1490. 181 * Only those nodes marked (*) are supported by this routine so far. 182 * 183 * Q.922 control 184 * | 185 * | 186 * -------------------------------------------- 187 * | 0x03 | 188 * UI I Frame 189 * | | 190 * --------------------------------- -------------- 191 * | 0x08 | 0x81 |0xCC |0xCF | 0x00 |..01.... |..10.... 192 * | | | | | 0x80 | | 193 * Q.933 CLNP IP(*) PPP(*) SNAP ISO 8208 ISO 8208 194 * | (rfc1973) | Modulo 8 Modulo 128 195 * | | 196 * -------------------- OUI 197 * | | | 198 * L2 ID L3 ID ------------------------- 199 * | User |00-80-C2 |00-00-00 200 * | specified | | 201 * | 0x70 PID Ethertype 202 * | | | 203 * ------------------- --------------... ---------- 204 * |0x51 |0x4E | |0x4C |0x1 |0xB | |0x806 | 205 * | | | | | | | | | 206 * 7776 Q.922 Others 802.2 802.3 802.6 Others ARP(*) Others 207 * 208 * 209 */ 210 211#define MAX_ENCAPS_HDR 8 212#define ERROUT(x) do { error = (x); goto done; } while (0) 213#define OUICMP(P,A,B,C) ((P)[0]==(A) && (P)[1]==(B) && (P)[2]==(C)) 214 215static int 216ng_rfc1490_rcvdata(hook_p hook, struct mbuf *m, meta_p meta, 217 struct mbuf **ret_m, meta_p *ret_meta, struct ng_mesg **resp) 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 u_char *start, *ptr; 225 226 if (!m || (m->m_len < MAX_ENCAPS_HDR 227 && !(m = m_pullup(m, MAX_ENCAPS_HDR)))) 228 ERROUT(ENOBUFS); 229 ptr = start = mtod(m, u_char *); 230 231 /* Must be UI frame */ 232 if (*ptr++ != HDLC_UI) 233 ERROUT(0); 234 235 /* Eat optional zero pad byte */ 236 if (*ptr == 0x00) 237 ptr++; 238 239 /* Multiplex on NLPID */ 240 switch (*ptr++) { 241 case NLPID_SNAP: 242 if (OUICMP(ptr, 0, 0, 0)) { /* It's an ethertype */ 243 u_int16_t etype; 244 245 ptr += 3; 246 etype = ntohs(*((u_int16_t *) ptr)); 247 ptr += 2; 248 m_adj(m, ptr - start); 249 switch (etype) { 250 case ETHERTYPE_IP: 251 NG_SEND_DATA(error, 252 priv->inet, m, meta); 253 break; 254 case ETHERTYPE_ARP: 255 case ETHERTYPE_REVARP: 256 default: 257 ERROUT(0); 258 } 259 } else if (OUICMP(ptr, 0x00, 0x80, 0xc2)) /* 802.1 bridging */ 260 ERROUT(0); 261 else /* Other weird stuff... */ 262 ERROUT(0); 263 break; 264 case NLPID_IP: 265 m_adj(m, ptr - start); 266 NG_SEND_DATA(error, priv->inet, m, meta); 267 break; 268 case NLPID_PPP: 269 m_adj(m, ptr - start); 270 NG_SEND_DATA(error, priv->ppp, m, meta); 271 break; 272 case NLPID_Q933: 273 case NLPID_CLNP: 274 case NLPID_ESIS: 275 case NLPID_ISIS: 276 ERROUT(0); 277 default: /* Try PPP (see RFC 1973) */ 278 ptr--; /* NLPID becomes PPP proto */ 279 if ((*ptr & 0x01) == 0x01) 280 ERROUT(0); 281 m_adj(m, ptr - start); 282 NG_SEND_DATA(error, priv->ppp, m, meta); 283 break; 284 } 285 } else if (hook == priv->ppp) { 286 M_PREPEND(m, 2, M_DONTWAIT); /* Prepend PPP NLPID */ 287 if (!m) 288 ERROUT(ENOBUFS); 289 mtod(m, u_char *)[0] = HDLC_UI; 290 mtod(m, u_char *)[1] = NLPID_PPP; 291 NG_SEND_DATA(error, priv->downlink, m, meta); 292 } else if (hook == priv->inet) { 293 M_PREPEND(m, 2, M_DONTWAIT); /* Prepend IP NLPID */ 294 if (!m) 295 ERROUT(ENOBUFS); 296 mtod(m, u_char *)[0] = HDLC_UI; 297 mtod(m, u_char *)[1] = NLPID_IP; 298 NG_SEND_DATA(error, priv->downlink, m, meta); 299 } else 300 panic(__FUNCTION__); 301 302done: 303 NG_FREE_DATA(m, meta); 304 return (error); 305} 306 307/* 308 * Nuke node 309 */ 310static int 311ng_rfc1490_rmnode(node_p node) 312{ 313 const priv_p priv = node->private; 314 315 /* Take down netgraph node */ 316 node->flags |= NG_INVALID; 317 ng_cutlinks(node); 318 ng_unname(node); 319 bzero(priv, sizeof(*priv)); 320 node->private = NULL; 321 ng_unref(node); /* let the node escape */ 322 return (0); 323} 324 325/* 326 * Hook disconnection 327 */ 328static int 329ng_rfc1490_disconnect(hook_p hook) 330{ 331 const priv_p priv = hook->node->private; 332 333 if (hook->node->numhooks == 0) 334 ng_rmnode(hook->node); 335 else if (hook == priv->downlink) 336 priv->downlink = NULL; 337 else if (hook == priv->inet) 338 priv->inet = NULL; 339 else if (hook == priv->ppp) 340 priv->ppp = NULL; 341 else 342 panic(__FUNCTION__); 343 return (0); 344} 345 346