sys/netgraph/ng_vjc.c

   1
   2 /*
   3  * ng_vjc.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: Archie Cobbs <archie@whistle.com>
  38  *
  39  * $FreeBSD$
  40  * $Whistle: ng_vjc.c,v 1.17 1999/11/01 09:24:52 julian Exp $
  41  */
  42
  43 /*
  44  * This node performs Van Jacobsen IP header (de)compression.
  45  * You must have included net/slcompress.c in your kernel compilation.
  46  */
  47
  48 #include <sys/param.h>
  49 #include <sys/systm.h>
  50 #include <sys/errno.h>
  51 #include <sys/kernel.h>
  52 #include <sys/mbuf.h>
  53 #include <sys/malloc.h>
  54 #include <sys/errno.h>
  55
  56 #include <netgraph/ng_message.h>
  57 #include <netgraph/netgraph.h>
  58 #include <netgraph/ng_vjc.h>
  59
  60 #include <netinet/in.h>
  61 #include <netinet/in_systm.h>
  62 #include <netinet/ip.h>
  63 #include <netinet/tcp.h>
  64
  65 #include <net/slcompress.h>
  66
  67 /* Check agreement with slcompress.c */
  68 #if MAX_STATES != NG_VJC_MAX_CHANNELS
  69 #error NG_VJC_MAX_CHANNELS must be the same as MAX_STATES
  70 #endif
  71
  72 /* Maximum length of a compressed TCP VJ header */
  73 #define MAX_VJHEADER            19
  74
  75 /* Node private data */
  76 struct ng_vjc_private {
  77         struct  ngm_vjc_config conf;
  78         struct  slcompress slc;
  79         hook_p  ip;
  80         hook_p  vjcomp;
  81         hook_p  vjuncomp;
  82         hook_p  vjip;
  83 };
  84 typedef struct ng_vjc_private *priv_p;
  85
  86 #define ERROUT(x)       do { error = (x); goto done; } while (0)
  87
  88 /* Netgraph node methods */
  89 static ng_constructor_t ng_vjc_constructor;
  90 static ng_rcvmsg_t      ng_vjc_rcvmsg;
  91 static ng_shutdown_t    ng_vjc_rmnode;
  92 static ng_newhook_t     ng_vjc_newhook;
  93 static ng_rcvdata_t     ng_vjc_rcvdata;
  94 static ng_disconnect_t  ng_vjc_disconnect;
  95
  96 /* Helper stuff */
  97 static struct mbuf *ng_vjc_pulluphdrs(struct mbuf *m, int knownTCP);
  98
  99 /* Node type descriptor */
 100 static struct ng_type typestruct = {
 101         NG_VERSION,
 102         NG_VJC_NODE_TYPE,
 103         NULL,
 104         ng_vjc_constructor,
 105         ng_vjc_rcvmsg,
 106         ng_vjc_rmnode,
 107         ng_vjc_newhook,
 108         NULL,
 109         NULL,
 110         ng_vjc_rcvdata,
 111         ng_vjc_rcvdata,
 112         ng_vjc_disconnect,
 113         NULL
 114 };
 115 NETGRAPH_INIT(vjc, &typestruct);
 116
 117 /************************************************************************
 118                         NETGRAPH NODE METHODS
 119  ************************************************************************/
 120
 121 /*
 122  * Create a new node
 123  */
 124 static int
 125 ng_vjc_constructor(node_p *nodep)
 126 {
 127         priv_p priv;
 128         int error;
 129
 130         /* Allocate private structure */
 131         MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_WAITOK);
 132         if (priv == NULL)
 133                 return (ENOMEM);
 134         bzero(priv, sizeof(*priv));
 135
 136         /* Call generic node constructor */
 137         if ((error = ng_make_node_common(&typestruct, nodep))) {
 138                 FREE(priv, M_NETGRAPH);
 139                 return (error);
 140         }
 141         (*nodep)->private = priv;
 142
 143         /* Done */
 144         return (0);
 145 }
 146
 147 /*
 148  * Add a new hook
 149  */
 150 static int
 151 ng_vjc_newhook(node_p node, hook_p hook, const char *name)
 152 {
 153         const priv_p priv = (priv_p) node->private;
 154         hook_p *hookp;
 155
 156         /* Get hook */
 157         if (strcmp(name, NG_VJC_HOOK_IP) == 0)
 158                 hookp = &priv->ip;
 159         else if (strcmp(name, NG_VJC_HOOK_VJCOMP) == 0)
 160                 hookp = &priv->vjcomp;
 161         else if (strcmp(name, NG_VJC_HOOK_VJUNCOMP) == 0)
 162                 hookp = &priv->vjuncomp;
 163         else if (strcmp(name, NG_VJC_HOOK_VJIP) == 0)
 164                 hookp = &priv->vjip;
 165         else
 166                 return (EINVAL);
 167
 168         /* See if already connected */
 169         if (*hookp)
 170                 return (EISCONN);
 171
 172         /* OK */
 173         *hookp = hook;
 174         return (0);
 175 }
 176
 177 /*
 178  * Receive a control message
 179  */
 180 static int
 181 ng_vjc_rcvmsg(node_p node, struct ng_mesg *msg,
 182               const char *raddr, struct ng_mesg **rptr, hook_p lasthook)
 183 {
 184         const priv_p priv = (priv_p) node->private;
 185         struct ng_mesg *resp = NULL;
 186         int error = 0;
 187
 188         /* Check type cookie */
 189         switch (msg->header.typecookie) {
 190         case NGM_VJC_COOKIE:
 191                 switch (msg->header.cmd) {
 192                 case NGM_VJC_SET_CONFIG:
 193                     {
 194                         struct ngm_vjc_config *const c =
 195                                 (struct ngm_vjc_config *) msg->data;
 196
 197                         if (msg->header.arglen != sizeof(*c))
 198                                 ERROUT(EINVAL);
 199                         if ((priv->conf.enableComp || priv->conf.enableDecomp)
 200                             && (c->enableComp || c->enableDecomp))
 201                                 ERROUT(EALREADY);
 202                         if (c->enableComp) {
 203                                 if (c->maxChannel > NG_VJC_MAX_CHANNELS - 1
 204                                     || c->maxChannel < NG_VJC_MIN_CHANNELS - 1)
 205                                         ERROUT(EINVAL);
 206                         } else
 207                                 c->maxChannel = NG_VJC_MAX_CHANNELS - 1;
 208                         if (c->enableComp != 0 || c->enableDecomp != 0) {
 209                                 bzero(&priv->slc, sizeof(priv->slc));
 210                                 sl_compress_init(&priv->slc, c->maxChannel);
 211                         }
 212                         priv->conf = *c;
 213                         break;
 214                     }
 215                 case NGM_VJC_GET_STATE:
 216                         NG_MKRESPONSE(resp, msg, sizeof(priv->slc), M_NOWAIT);
 217                         if (resp == NULL)
 218                                 ERROUT(ENOMEM);
 219                         *((struct slcompress *) resp->data) = priv->slc;
 220                         break;
 221                 case NGM_VJC_CLR_STATS:
 222                         priv->slc.sls_packets = 0;
 223                         priv->slc.sls_compressed = 0;
 224                         priv->slc.sls_searches = 0;
 225                         priv->slc.sls_misses = 0;
 226                         priv->slc.sls_uncompressedin = 0;
 227                         priv->slc.sls_compressedin = 0;
 228                         priv->slc.sls_errorin = 0;
 229                         priv->slc.sls_tossed = 0;
 230                         break;
 231                 case NGM_VJC_RECV_ERROR:
 232                         sl_uncompress_tcp(NULL, 0, TYPE_ERROR, &priv->slc);
 233                         break;
 234                 default:
 235                         error = EINVAL;
 236                         break;
 237                 }
 238                 break;
 239         default:
 240                 error = EINVAL;
 241                 break;
 242         }
 243         if (rptr)
 244                 *rptr = resp;
 245         else if (resp)
 246                 FREE(resp, M_NETGRAPH);
 247
 248 done:
 249         FREE(msg, M_NETGRAPH);
 250         return (error);
 251 }
 252
 253 /*
 254  * Receive data
 255  */
 256 static int
 257 ng_vjc_rcvdata(hook_p hook, struct mbuf *m, meta_p meta,
 258                 struct mbuf **ret_m, meta_p *ret_meta)
 259 {
 260         const node_p node = hook->node;
 261         const priv_p priv = (priv_p) node->private;
 262         int error = 0;
 263
 264         if (hook == priv->ip) {                 /* outgoing packet */
 265                 u_int type = TYPE_IP;
 266
 267                 /* Compress packet if enabled and proto is TCP */
 268                 if (priv->conf.enableComp) {
 269                         struct ip *ip;
 270
 271                         if ((m = ng_vjc_pulluphdrs(m, 0)) == NULL) {
 272                                 NG_FREE_META(meta);
 273                                 return (ENOBUFS);
 274                         }
 275                         ip = mtod(m, struct ip *);
 276                         if (ip->ip_p == IPPROTO_TCP) {
 277                                 const int origLen = m->m_len;
 278
 279                                 type = sl_compress_tcp(m, ip,
 280                                     &priv->slc, priv->conf.compressCID);
 281                                 m->m_pkthdr.len += m->m_len - origLen;
 282                         }
 283                 }
 284
 285                 /* Dispatch to the appropriate outgoing hook */
 286                 switch (type) {
 287                 case TYPE_IP:
 288                         hook = priv->vjip;
 289                         break;
 290                 case TYPE_UNCOMPRESSED_TCP:
 291                         hook = priv->vjuncomp;
 292                         break;
 293                 case TYPE_COMPRESSED_TCP:
 294                         hook = priv->vjcomp;
 295                         break;
 296                 default:
 297                         panic("%s: type=%d", __FUNCTION__, type);
 298                 }
 299         } else if (hook == priv->vjcomp) {      /* incoming compressed packet */
 300                 int vjlen, need2pullup;
 301                 struct mbuf *hm;
 302                 u_char *hdr;
 303                 u_int hlen;
 304
 305                 /* Are we decompressing? */
 306                 if (!priv->conf.enableDecomp) {
 307                         NG_FREE_DATA(m, meta);
 308                         return (ENXIO);
 309                 }
 310
 311                 /* Pull up the necessary amount from the mbuf */
 312                 need2pullup = MAX_VJHEADER;
 313                 if (need2pullup > m->m_pkthdr.len)
 314                         need2pullup = m->m_pkthdr.len;
 315                 if (m->m_len < need2pullup
 316                     && (m = m_pullup(m, need2pullup)) == NULL) {
 317                         priv->slc.sls_errorin++;
 318                         NG_FREE_META(meta);
 319                         return (ENOBUFS);
 320                 }
 321
 322                 /* Uncompress packet to reconstruct TCP/IP header */
 323                 vjlen = sl_uncompress_tcp_core(mtod(m, u_char *),
 324                     m->m_len, m->m_pkthdr.len, TYPE_COMPRESSED_TCP,
 325                     &priv->slc, &hdr, &hlen);
 326                 if (vjlen <= 0) {
 327                         NG_FREE_DATA(m, meta);
 328                         return (EINVAL);
 329                 }
 330                 m_adj(m, vjlen);
 331
 332                 /* Copy the reconstructed TCP/IP headers into a new mbuf */
 333                 MGETHDR(hm, M_DONTWAIT, MT_DATA);
 334                 if (hm == NULL) {
 335                         priv->slc.sls_errorin++;
 336                         NG_FREE_DATA(m, meta);
 337                         return (ENOBUFS);
 338                 }
 339                 hm->m_len = 0;
 340                 hm->m_pkthdr.rcvif = NULL;
 341                 if (hlen > MHLEN) {             /* unlikely, but can happen */
 342                         MCLGET(hm, M_DONTWAIT);
 343                         if ((hm->m_flags & M_EXT) == 0) {
 344                                 m_freem(hm);
 345                                 priv->slc.sls_errorin++;
 346                                 NG_FREE_DATA(m, meta);
 347                                 return (ENOBUFS);
 348                         }
 349                 }
 350                 bcopy(hdr, mtod(hm, u_char *), hlen);
 351                 hm->m_len = hlen;
 352
 353                 /* Glue TCP/IP headers and rest of packet together */
 354                 hm->m_next = m;
 355                 hm->m_pkthdr.len = hlen + m->m_pkthdr.len;
 356                 m = hm;
 357                 hook = priv->ip;
 358         } else if (hook == priv->vjuncomp) {    /* incoming uncompressed pkt */
 359                 u_char *hdr;
 360                 u_int hlen;
 361
 362                 /* Are we decompressing? */
 363                 if (!priv->conf.enableDecomp) {
 364                         NG_FREE_DATA(m, meta);
 365                         return (ENXIO);
 366                 }
 367
 368                 /* Pull up IP+TCP headers */
 369                 if ((m = ng_vjc_pulluphdrs(m, 1)) == NULL) {
 370                         NG_FREE_META(meta);
 371                         return (ENOBUFS);
 372                 }
 373
 374                 /* Run packet through uncompressor */
 375                 if (sl_uncompress_tcp_core(mtod(m, u_char *),
 376                     m->m_len, m->m_pkthdr.len, TYPE_UNCOMPRESSED_TCP,
 377                     &priv->slc, &hdr, &hlen) < 0) {
 378                         NG_FREE_DATA(m, meta);
 379                         return (EINVAL);
 380                 }
 381                 hook = priv->ip;
 382         } else if (hook == priv->vjip)  /* incoming regular packet (bypass) */
 383                 hook = priv->ip;
 384         else
 385                 panic("%s: unknown hook", __FUNCTION__);
 386
 387         /* Send result back out */
 388         NG_SEND_DATA(error, hook, m, meta);
 389         return (error);
 390 }
 391
 392 /*
 393  * Shutdown node
 394  */
 395 static int
 396 ng_vjc_rmnode(node_p node)
 397 {
 398         const priv_p priv = (priv_p) node->private;
 399
 400         node->flags |= NG_INVALID;
 401         ng_cutlinks(node);
 402         ng_unname(node);
 403         bzero(priv, sizeof(*priv));
 404         FREE(priv, M_NETGRAPH);
 405         node->private = NULL;
 406         ng_unref(node);
 407         return (0);
 408 }
 409
 410 /*
 411  * Hook disconnection
 412  */
 413 static int
 414 ng_vjc_disconnect(hook_p hook)
 415 {
 416         const node_p node = hook->node;
 417         const priv_p priv = node->private;
 418
 419         /* Zero out hook pointer */
 420         if (hook == priv->ip)
 421                 priv->ip = NULL;
 422         else if (hook == priv->vjcomp)
 423                 priv->vjcomp = NULL;
 424         else if (hook == priv->vjuncomp)
 425                 priv->vjuncomp = NULL;
 426         else if (hook == priv->vjip)
 427                 priv->vjip = NULL;
 428         else
 429                 panic("%s: unknown hook", __FUNCTION__);
 430
 431         /* Go away if no hooks left */
 432         if (node->numhooks == 0)
 433                 ng_rmnode(node);
 434         return (0);
 435 }
 436
 437 /************************************************************************
 438                         HELPER STUFF
 439  ************************************************************************/
 440
 441 /*
 442  * Pull up the full IP and TCP headers of a packet. If packet is not
 443  * a TCP packet, just pull up the IP header.
 444  */
 445 static struct mbuf *
 446 ng_vjc_pulluphdrs(struct mbuf *m, int knownTCP)
 447 {
 448         struct ip *ip;
 449         struct tcphdr *tcp;
 450         int ihlen, thlen;
 451
 452         if (m->m_len < sizeof(*ip) && (m = m_pullup(m, sizeof(*ip))) == NULL)
 453                 return (NULL);
 454         ip = mtod(m, struct ip *);
 455         if (!knownTCP && ip->ip_p != IPPROTO_TCP)
 456                 return (m);
 457         ihlen = ip->ip_hl << 2;
 458         if (m->m_len < ihlen + sizeof(*tcp)) {
 459                 if ((m = m_pullup(m, ihlen + sizeof(*tcp))) == NULL)
 460                         return (NULL);
 461                 ip = mtod(m, struct ip *);
 462         }
 463         tcp = (struct tcphdr *)((u_char *)ip + ihlen);
 464         thlen = tcp->th_off << 2;
 465         if (m->m_len < ihlen + thlen)
 466                 m = m_pullup(m, ihlen + thlen);
 467         return (m);
 468 }
 469