08c855ad4eec180554cfcd7a511e6ccabf0d93e5
[dragonfly.git] / sys / netgraph / vjc / 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@freebsd.org>
38  *
39  * $FreeBSD: src/sys/netgraph/ng_vjc.c,v 1.9.2.5 2002/07/02 23:44:03 archie Exp $
40  * $DragonFly: src/sys/netgraph/vjc/ng_vjc.c,v 1.7 2007/05/13 18:33:58 swildner Exp $
41  * $Whistle: ng_vjc.c,v 1.17 1999/11/01 09:24:52 julian Exp $
42  */
43
44 /*
45  * This node performs Van Jacobson IP header (de)compression.
46  * You must have included net/slcompress.c in your kernel compilation.
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/mbuf.h>
54 #include <sys/malloc.h>
55 #include <sys/errno.h>
56
57 #include <netgraph/ng_message.h>
58 #include <netgraph/netgraph.h>
59 #include <netgraph/ng_parse.h>
60 #include "ng_vjc.h"
61
62 #include <netinet/in.h>
63 #include <netinet/in_systm.h>
64 #include <netinet/ip.h>
65 #include <netinet/tcp.h>
66
67 #include <net/slcompress.h>
68
69 /* Check agreement with slcompress.c */
70 #if MAX_STATES != NG_VJC_MAX_CHANNELS
71 #error NG_VJC_MAX_CHANNELS must be the same as MAX_STATES
72 #endif
73
74 /* Maximum length of a compressed TCP VJ header */
75 #define MAX_VJHEADER            19
76
77 /* Node private data */
78 struct ng_vjc_private {
79         struct  ngm_vjc_config conf;
80         struct  slcompress slc;
81         hook_p  ip;
82         hook_p  vjcomp;
83         hook_p  vjuncomp;
84         hook_p  vjip;
85 };
86 typedef struct ng_vjc_private *priv_p;
87
88 #define ERROUT(x)       do { error = (x); goto done; } while (0)
89
90 /* Netgraph node methods */
91 static ng_constructor_t ng_vjc_constructor;
92 static ng_rcvmsg_t      ng_vjc_rcvmsg;
93 static ng_shutdown_t    ng_vjc_rmnode;
94 static ng_newhook_t     ng_vjc_newhook;
95 static ng_rcvdata_t     ng_vjc_rcvdata;
96 static ng_disconnect_t  ng_vjc_disconnect;
97
98 /* Helper stuff */
99 static struct mbuf *ng_vjc_pulluphdrs(struct mbuf *m, int knownTCP);
100
101 /* Parse type for struct ngm_vjc_config */
102 static const struct ng_parse_struct_field ng_vjc_config_type_fields[]
103         = NG_VJC_CONFIG_TYPE_INFO;
104 static const struct ng_parse_type ng_vjc_config_type = {
105         &ng_parse_struct_type,
106         &ng_vjc_config_type_fields
107 };
108
109 /* Parse type for the 'last_cs' and 'cs_next' fields in struct slcompress,
110    which are pointers converted to integer indices, so parse them that way. */
111 #if _MACHINE_ARCH == i386
112 #define NG_VJC_TSTATE_PTR_TYPE  &ng_parse_uint32_type
113 #else
114 #error Unsupported _MACHINE_ARCH
115 #endif
116
117 /* Parse type for the 'cs_hdr' field in a struct cstate. Ideally we would
118    like to use a 'struct ip' type instead of a simple array of bytes. */
119 static const struct ng_parse_fixedarray_info ng_vjc_cs_hdr_type_info = {
120         &ng_parse_hint8_type,
121         MAX_HDR
122 };
123 static const struct ng_parse_type ng_vjc_cs_hdr_type = {
124         &ng_parse_fixedarray_type,
125         &ng_vjc_cs_hdr_type_info
126 };
127
128 /* Parse type for a struct cstate */
129 static const struct ng_parse_struct_field ng_vjc_cstate_type_fields[] = {
130         { "cs_next",            NG_VJC_TSTATE_PTR_TYPE          },
131         { "cs_hlen",            &ng_parse_uint16_type           },
132         { "cs_id",              &ng_parse_uint8_type            },
133         { "cs_filler",          &ng_parse_uint8_type            },
134         { "cs_hdr",             &ng_vjc_cs_hdr_type             },
135         { NULL }
136 };
137 static const struct ng_parse_type ng_vjc_cstate_type = {
138         &ng_parse_struct_type,
139         &ng_vjc_cstate_type_fields
140 };
141
142 /* Parse type for an array of MAX_STATES struct cstate's, ie, tstate & rstate */
143 static const struct ng_parse_fixedarray_info ng_vjc_cstatearray_type_info = {
144         &ng_vjc_cstate_type,
145         MAX_STATES
146 };
147 static const struct ng_parse_type ng_vjc_cstatearray_type = {
148         &ng_parse_fixedarray_type,
149         &ng_vjc_cstatearray_type_info
150 };
151
152 /* Parse type for struct slcompress. Keep this in sync with the
153    definition of struct slcompress defined in <net/slcompress.h> */
154 static const struct ng_parse_struct_field ng_vjc_slcompress_type_fields[] = {
155         { "last_cs",            NG_VJC_TSTATE_PTR_TYPE          },
156         { "last_recv",          &ng_parse_uint8_type            },
157         { "last_xmit",          &ng_parse_uint8_type            },
158         { "flags",              &ng_parse_hint16_type           },
159 #ifndef SL_NO_STATS
160         { "sls_packets",        &ng_parse_uint32_type           },
161         { "sls_compressed",     &ng_parse_uint32_type           },
162         { "sls_searches",       &ng_parse_uint32_type           },
163         { "sls_misses",         &ng_parse_uint32_type           },
164         { "sls_uncompressedin", &ng_parse_uint32_type           },
165         { "sls_compressedin",   &ng_parse_uint32_type           },
166         { "sls_errorin",        &ng_parse_uint32_type           },
167         { "sls_tossed",         &ng_parse_uint32_type           },
168 #endif
169         { "tstate",             &ng_vjc_cstatearray_type        },
170         { "rstate",             &ng_vjc_cstatearray_type        },
171         { NULL }
172 };
173 static const struct ng_parse_type ng_vjc_slcompress_type = {
174         &ng_parse_struct_type,
175         &ng_vjc_slcompress_type_fields
176 };
177
178 /* List of commands and how to convert arguments to/from ASCII */
179 static const struct ng_cmdlist ng_vjc_cmds[] = {
180         {
181           NGM_VJC_COOKIE,
182           NGM_VJC_SET_CONFIG,
183           "setconfig",
184           &ng_vjc_config_type,
185           NULL
186         },
187         {
188           NGM_VJC_COOKIE,
189           NGM_VJC_GET_CONFIG,
190           "getconfig",
191           NULL,
192           &ng_vjc_config_type,
193         },
194         {
195           NGM_VJC_COOKIE,
196           NGM_VJC_GET_STATE,
197           "getstate",
198           NULL,
199           &ng_vjc_slcompress_type,
200         },
201         {
202           NGM_VJC_COOKIE,
203           NGM_VJC_CLR_STATS,
204           "clrstats",
205           NULL,
206           NULL,
207         },
208         {
209           NGM_VJC_COOKIE,
210           NGM_VJC_RECV_ERROR,
211           "recverror",
212           NULL,
213           NULL,
214         },
215         { 0 }
216 };
217
218 /* Node type descriptor */
219 static struct ng_type ng_vjc_typestruct = {
220         NG_VERSION,
221         NG_VJC_NODE_TYPE,
222         NULL,
223         ng_vjc_constructor,
224         ng_vjc_rcvmsg,
225         ng_vjc_rmnode,
226         ng_vjc_newhook,
227         NULL,
228         NULL,
229         ng_vjc_rcvdata,
230         ng_vjc_rcvdata,
231         ng_vjc_disconnect,
232         ng_vjc_cmds
233 };
234 NETGRAPH_INIT(vjc, &ng_vjc_typestruct);
235
236 /************************************************************************
237                         NETGRAPH NODE METHODS
238  ************************************************************************/
239
240 /*
241  * Create a new node
242  */
243 static int
244 ng_vjc_constructor(node_p *nodep)
245 {
246         priv_p priv;
247         int error;
248
249         /* Allocate private structure */
250         MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT);
251         if (priv == NULL)
252                 return (ENOMEM);
253         bzero(priv, sizeof(*priv));
254
255         /* Call generic node constructor */
256         if ((error = ng_make_node_common(&ng_vjc_typestruct, nodep))) {
257                 FREE(priv, M_NETGRAPH);
258                 return (error);
259         }
260         (*nodep)->private = priv;
261
262         /* Done */
263         return (0);
264 }
265
266 /*
267  * Add a new hook
268  */
269 static int
270 ng_vjc_newhook(node_p node, hook_p hook, const char *name)
271 {
272         const priv_p priv = (priv_p) node->private;
273         hook_p *hookp;
274
275         /* Get hook */
276         if (strcmp(name, NG_VJC_HOOK_IP) == 0)
277                 hookp = &priv->ip;
278         else if (strcmp(name, NG_VJC_HOOK_VJCOMP) == 0)
279                 hookp = &priv->vjcomp;
280         else if (strcmp(name, NG_VJC_HOOK_VJUNCOMP) == 0)
281                 hookp = &priv->vjuncomp;
282         else if (strcmp(name, NG_VJC_HOOK_VJIP) == 0)
283                 hookp = &priv->vjip;
284         else
285                 return (EINVAL);
286
287         /* See if already connected */
288         if (*hookp)
289                 return (EISCONN);
290
291         /* OK */
292         *hookp = hook;
293         return (0);
294 }
295
296 /*
297  * Receive a control message
298  */
299 static int
300 ng_vjc_rcvmsg(node_p node, struct ng_mesg *msg,
301               const char *raddr, struct ng_mesg **rptr)
302 {
303         const priv_p priv = (priv_p) node->private;
304         struct ng_mesg *resp = NULL;
305         int error = 0;
306
307         /* Check type cookie */
308         switch (msg->header.typecookie) {
309         case NGM_VJC_COOKIE:
310                 switch (msg->header.cmd) {
311                 case NGM_VJC_SET_CONFIG:
312                     {
313                         struct ngm_vjc_config *const c =
314                                 (struct ngm_vjc_config *) msg->data;
315
316                         if (msg->header.arglen != sizeof(*c))
317                                 ERROUT(EINVAL);
318                         if ((priv->conf.enableComp || priv->conf.enableDecomp)
319                             && (c->enableComp || c->enableDecomp))
320                                 ERROUT(EALREADY);
321                         if (c->enableComp) {
322                                 if (c->maxChannel > NG_VJC_MAX_CHANNELS - 1
323                                     || c->maxChannel < NG_VJC_MIN_CHANNELS - 1)
324                                         ERROUT(EINVAL);
325                         } else
326                                 c->maxChannel = NG_VJC_MAX_CHANNELS - 1;
327                         if (c->enableComp != 0 || c->enableDecomp != 0) {
328                                 bzero(&priv->slc, sizeof(priv->slc));
329                                 sl_compress_init(&priv->slc, c->maxChannel);
330                         }
331                         priv->conf = *c;
332                         break;
333                     }
334                 case NGM_VJC_GET_CONFIG:
335                     {
336                         struct ngm_vjc_config *conf;
337
338                         NG_MKRESPONSE(resp, msg, sizeof(*conf), M_NOWAIT);
339                         if (resp == NULL)
340                                 ERROUT(ENOMEM);
341                         conf = (struct ngm_vjc_config *)resp->data;
342                         *conf = priv->conf;
343                         break;
344                     }
345                 case NGM_VJC_GET_STATE:
346                     {
347                         const struct slcompress *const sl0 = &priv->slc;
348                         struct slcompress *sl;
349                         u_int16_t index;
350                         int i;
351
352                         /* Get response structure */
353                         NG_MKRESPONSE(resp, msg, sizeof(*sl), M_NOWAIT);
354                         if (resp == NULL)
355                                 ERROUT(ENOMEM);
356                         sl = (struct slcompress *)resp->data;
357                         *sl = *sl0;
358
359                         /* Replace pointers with integer indicies */
360                         if (sl->last_cs != NULL) {
361                                 index = sl0->last_cs - sl0->tstate;
362                                 bzero(&sl->last_cs, sizeof(sl->last_cs));
363                                 *((u_int16_t *)&sl->last_cs) = index;
364                         }
365                         for (i = 0; i < MAX_STATES; i++) {
366                                 struct cstate *const cs = &sl->tstate[i];
367
368                                 index = sl0->tstate[i].cs_next - sl0->tstate;
369                                 bzero(&cs->cs_next, sizeof(cs->cs_next));
370                                 *((u_int16_t *)&cs->cs_next) = index;
371                         }
372                         break;
373                     }
374                 case NGM_VJC_CLR_STATS:
375                         priv->slc.sls_packets = 0;
376                         priv->slc.sls_compressed = 0;
377                         priv->slc.sls_searches = 0;
378                         priv->slc.sls_misses = 0;
379                         priv->slc.sls_uncompressedin = 0;
380                         priv->slc.sls_compressedin = 0;
381                         priv->slc.sls_errorin = 0;
382                         priv->slc.sls_tossed = 0;
383                         break;
384                 case NGM_VJC_RECV_ERROR:
385                         sl_uncompress_tcp(NULL, 0, TYPE_ERROR, &priv->slc);
386                         break;
387                 default:
388                         error = EINVAL;
389                         break;
390                 }
391                 break;
392         default:
393                 error = EINVAL;
394                 break;
395         }
396         if (rptr)
397                 *rptr = resp;
398         else if (resp)
399                 FREE(resp, M_NETGRAPH);
400
401 done:
402         FREE(msg, M_NETGRAPH);
403         return (error);
404 }
405
406 /*
407  * Receive data
408  */
409 static int
410 ng_vjc_rcvdata(hook_p hook, struct mbuf *m, meta_p meta)
411 {
412         const node_p node = hook->node;
413         const priv_p priv = (priv_p) node->private;
414         int error = 0;
415
416         if (hook == priv->ip) {                 /* outgoing packet */
417                 u_int type = TYPE_IP;
418
419                 /* Compress packet if enabled and proto is TCP */
420                 if (priv->conf.enableComp) {
421                         struct ip *ip;
422
423                         if ((m = ng_vjc_pulluphdrs(m, 0)) == NULL) {
424                                 NG_FREE_META(meta);
425                                 return (ENOBUFS);
426                         }
427                         ip = mtod(m, struct ip *);
428                         if (ip->ip_p == IPPROTO_TCP) {
429                                 const int origLen = m->m_len;
430
431                                 type = sl_compress_tcp(m, ip,
432                                     &priv->slc, priv->conf.compressCID);
433                                 m->m_pkthdr.len += m->m_len - origLen;
434                         }
435                 }
436
437                 /* Dispatch to the appropriate outgoing hook */
438                 switch (type) {
439                 case TYPE_IP:
440                         hook = priv->vjip;
441                         break;
442                 case TYPE_UNCOMPRESSED_TCP:
443                         hook = priv->vjuncomp;
444                         break;
445                 case TYPE_COMPRESSED_TCP:
446                         hook = priv->vjcomp;
447                         break;
448                 default:
449                         panic("%s: type=%d", __func__, type);
450                 }
451         } else if (hook == priv->vjcomp) {      /* incoming compressed packet */
452                 int vjlen, need2pullup;
453                 struct mbuf *hm;
454                 u_char *hdr;
455                 u_int hlen;
456
457                 /* Are we decompressing? */
458                 if (!priv->conf.enableDecomp) {
459                         NG_FREE_DATA(m, meta);
460                         return (ENXIO);
461                 }
462
463                 /* Pull up the necessary amount from the mbuf */
464                 need2pullup = MAX_VJHEADER;
465                 if (need2pullup > m->m_pkthdr.len)
466                         need2pullup = m->m_pkthdr.len;
467                 if (m->m_len < need2pullup
468                     && (m = m_pullup(m, need2pullup)) == NULL) {
469                         priv->slc.sls_errorin++;
470                         NG_FREE_META(meta);
471                         return (ENOBUFS);
472                 }
473
474                 /* Uncompress packet to reconstruct TCP/IP header */
475                 vjlen = sl_uncompress_tcp_core(mtod(m, u_char *),
476                     m->m_len, m->m_pkthdr.len, TYPE_COMPRESSED_TCP,
477                     &priv->slc, &hdr, &hlen);
478                 if (vjlen <= 0) {
479                         NG_FREE_DATA(m, meta);
480                         return (EINVAL);
481                 }
482                 m_adj(m, vjlen);
483
484                 /* Copy the reconstructed TCP/IP headers into a new mbuf */
485                 MGETHDR(hm, MB_DONTWAIT, MT_DATA);
486                 if (hm == NULL) {
487                         priv->slc.sls_errorin++;
488                         NG_FREE_DATA(m, meta);
489                         return (ENOBUFS);
490                 }
491                 hm->m_len = 0;
492                 hm->m_pkthdr.rcvif = NULL;
493                 if (hlen > MHLEN) {             /* unlikely, but can happen */
494                         MCLGET(hm, MB_DONTWAIT);
495                         if ((hm->m_flags & M_EXT) == 0) {
496                                 m_freem(hm);
497                                 priv->slc.sls_errorin++;
498                                 NG_FREE_DATA(m, meta);
499                                 return (ENOBUFS);
500                         }
501                 }
502                 bcopy(hdr, mtod(hm, u_char *), hlen);
503                 hm->m_len = hlen;
504
505                 /* Glue TCP/IP headers and rest of packet together */
506                 hm->m_next = m;
507                 hm->m_pkthdr.len = hlen + m->m_pkthdr.len;
508                 m = hm;
509                 hook = priv->ip;
510         } else if (hook == priv->vjuncomp) {    /* incoming uncompressed pkt */
511                 u_char *hdr;
512                 u_int hlen;
513
514                 /* Are we decompressing? */
515                 if (!priv->conf.enableDecomp) {
516                         NG_FREE_DATA(m, meta);
517                         return (ENXIO);
518                 }
519
520                 /* Pull up IP+TCP headers */
521                 if ((m = ng_vjc_pulluphdrs(m, 1)) == NULL) {
522                         NG_FREE_META(meta);
523                         return (ENOBUFS);
524                 }
525
526                 /* Run packet through uncompressor */
527                 if (sl_uncompress_tcp_core(mtod(m, u_char *),
528                     m->m_len, m->m_pkthdr.len, TYPE_UNCOMPRESSED_TCP,
529                     &priv->slc, &hdr, &hlen) < 0) {
530                         NG_FREE_DATA(m, meta);
531                         return (EINVAL);
532                 }
533                 hook = priv->ip;
534         } else if (hook == priv->vjip)  /* incoming regular packet (bypass) */
535                 hook = priv->ip;
536         else
537                 panic("%s: unknown hook", __func__);
538
539         /* Send result back out */
540         NG_SEND_DATA(error, hook, m, meta);
541         return (error);
542 }
543
544 /*
545  * Shutdown node
546  */
547 static int
548 ng_vjc_rmnode(node_p node)
549 {
550         const priv_p priv = (priv_p) node->private;
551
552         node->flags |= NG_INVALID;
553         ng_cutlinks(node);
554         ng_unname(node);
555         bzero(priv, sizeof(*priv));
556         FREE(priv, M_NETGRAPH);
557         node->private = NULL;
558         ng_unref(node);
559         return (0);
560 }
561
562 /*
563  * Hook disconnection
564  */
565 static int
566 ng_vjc_disconnect(hook_p hook)
567 {
568         const node_p node = hook->node;
569         const priv_p priv = node->private;
570
571         /* Zero out hook pointer */
572         if (hook == priv->ip)
573                 priv->ip = NULL;
574         else if (hook == priv->vjcomp)
575                 priv->vjcomp = NULL;
576         else if (hook == priv->vjuncomp)
577                 priv->vjuncomp = NULL;
578         else if (hook == priv->vjip)
579                 priv->vjip = NULL;
580         else
581                 panic("%s: unknown hook", __func__);
582
583         /* Go away if no hooks left */
584         if (node->numhooks == 0)
585                 ng_rmnode(node);
586         return (0);
587 }
588
589 /************************************************************************
590                         HELPER STUFF
591  ************************************************************************/
592
593 /*
594  * Pull up the full IP and TCP headers of a packet. If packet is not
595  * a TCP packet, just pull up the IP header.
596  */
597 static struct mbuf *
598 ng_vjc_pulluphdrs(struct mbuf *m, int knownTCP)
599 {
600         struct ip *ip;
601         struct tcphdr *tcp;
602         int ihlen, thlen;
603
604         if (m->m_len < sizeof(*ip) && (m = m_pullup(m, sizeof(*ip))) == NULL)
605                 return (NULL);
606         ip = mtod(m, struct ip *);
607         if (!knownTCP && ip->ip_p != IPPROTO_TCP)
608                 return (m);
609         ihlen = ip->ip_hl << 2;
610         if (m->m_len < ihlen + sizeof(*tcp)) {
611                 if ((m = m_pullup(m, ihlen + sizeof(*tcp))) == NULL)
612                         return (NULL);
613                 ip = mtod(m, struct ip *);
614         }
615         tcp = (struct tcphdr *)((u_char *)ip + ihlen);
616         thlen = tcp->th_off << 2;
617         if (m->m_len < ihlen + thlen)
618                 m = m_pullup(m, ihlen + thlen);
619         return (m);
620 }
621