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37 * Author: Archie Cobbs <archie@freebsd.org>
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 $
45 * This node performs Van Jacobson IP header (de)compression.
46 * You must have included net/slcompress.c in your kernel compilation.
49 #include <sys/param.h>
50 #include <sys/systm.h>
51 #include <sys/errno.h>
52 #include <sys/kernel.h>
54 #include <sys/malloc.h>
55 #include <sys/errno.h>
57 #include <netgraph/ng_message.h>
58 #include <netgraph/netgraph.h>
59 #include <netgraph/ng_parse.h>
62 #include <netinet/in.h>
63 #include <netinet/in_systm.h>
64 #include <netinet/ip.h>
65 #include <netinet/tcp.h>
67 #include <net/slcompress.h>
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
74 /* Maximum length of a compressed TCP VJ header */
75 #define MAX_VJHEADER 19
77 /* Node private data */
78 struct ng_vjc_private {
79 struct ngm_vjc_config conf;
80 struct slcompress slc;
86 typedef struct ng_vjc_private *priv_p;
88 #define ERROUT(x) do { error = (x); goto done; } while (0)
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;
99 static struct mbuf *ng_vjc_pulluphdrs(struct mbuf *m, int knownTCP);
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
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
114 #error Unsupported _MACHINE_ARCH
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,
123 static const struct ng_parse_type ng_vjc_cs_hdr_type = {
124 &ng_parse_fixedarray_type,
125 &ng_vjc_cs_hdr_type_info
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 },
137 static const struct ng_parse_type ng_vjc_cstate_type = {
138 &ng_parse_struct_type,
139 &ng_vjc_cstate_type_fields
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 = {
147 static const struct ng_parse_type ng_vjc_cstatearray_type = {
148 &ng_parse_fixedarray_type,
149 &ng_vjc_cstatearray_type_info
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 },
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 },
169 { "tstate", &ng_vjc_cstatearray_type },
170 { "rstate", &ng_vjc_cstatearray_type },
173 static const struct ng_parse_type ng_vjc_slcompress_type = {
174 &ng_parse_struct_type,
175 &ng_vjc_slcompress_type_fields
178 /* List of commands and how to convert arguments to/from ASCII */
179 static const struct ng_cmdlist ng_vjc_cmds[] = {
199 &ng_vjc_slcompress_type,
218 /* Node type descriptor */
219 static struct ng_type ng_vjc_typestruct = {
234 NETGRAPH_INIT(vjc, &ng_vjc_typestruct);
236 /************************************************************************
237 NETGRAPH NODE METHODS
238 ************************************************************************/
244 ng_vjc_constructor(node_p *nodep)
249 /* Allocate private structure */
250 MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT);
253 bzero(priv, sizeof(*priv));
255 /* Call generic node constructor */
256 if ((error = ng_make_node_common(&ng_vjc_typestruct, nodep))) {
257 FREE(priv, M_NETGRAPH);
260 (*nodep)->private = priv;
270 ng_vjc_newhook(node_p node, hook_p hook, const char *name)
272 const priv_p priv = (priv_p) node->private;
276 if (strcmp(name, NG_VJC_HOOK_IP) == 0)
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)
287 /* See if already connected */
297 * Receive a control message
300 ng_vjc_rcvmsg(node_p node, struct ng_mesg *msg,
301 const char *raddr, struct ng_mesg **rptr)
303 const priv_p priv = (priv_p) node->private;
304 struct ng_mesg *resp = NULL;
307 /* Check type cookie */
308 switch (msg->header.typecookie) {
310 switch (msg->header.cmd) {
311 case NGM_VJC_SET_CONFIG:
313 struct ngm_vjc_config *const c =
314 (struct ngm_vjc_config *) msg->data;
316 if (msg->header.arglen != sizeof(*c))
318 if ((priv->conf.enableComp || priv->conf.enableDecomp)
319 && (c->enableComp || c->enableDecomp))
322 if (c->maxChannel > NG_VJC_MAX_CHANNELS - 1
323 || c->maxChannel < NG_VJC_MIN_CHANNELS - 1)
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);
334 case NGM_VJC_GET_CONFIG:
336 struct ngm_vjc_config *conf;
338 NG_MKRESPONSE(resp, msg, sizeof(*conf), M_NOWAIT);
341 conf = (struct ngm_vjc_config *)resp->data;
345 case NGM_VJC_GET_STATE:
347 const struct slcompress *const sl0 = &priv->slc;
348 struct slcompress *sl;
352 /* Get response structure */
353 NG_MKRESPONSE(resp, msg, sizeof(*sl), M_NOWAIT);
356 sl = (struct slcompress *)resp->data;
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;
365 for (i = 0; i < MAX_STATES; i++) {
366 struct cstate *const cs = &sl->tstate[i];
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;
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;
384 case NGM_VJC_RECV_ERROR:
385 sl_uncompress_tcp(NULL, 0, TYPE_ERROR, &priv->slc);
399 FREE(resp, M_NETGRAPH);
402 FREE(msg, M_NETGRAPH);
410 ng_vjc_rcvdata(hook_p hook, struct mbuf *m, meta_p meta)
412 const node_p node = hook->node;
413 const priv_p priv = (priv_p) node->private;
416 if (hook == priv->ip) { /* outgoing packet */
417 u_int type = TYPE_IP;
419 /* Compress packet if enabled and proto is TCP */
420 if (priv->conf.enableComp) {
423 if ((m = ng_vjc_pulluphdrs(m, 0)) == NULL) {
427 ip = mtod(m, struct ip *);
428 if (ip->ip_p == IPPROTO_TCP) {
429 const int origLen = m->m_len;
431 type = sl_compress_tcp(m, ip,
432 &priv->slc, priv->conf.compressCID);
433 m->m_pkthdr.len += m->m_len - origLen;
437 /* Dispatch to the appropriate outgoing hook */
442 case TYPE_UNCOMPRESSED_TCP:
443 hook = priv->vjuncomp;
445 case TYPE_COMPRESSED_TCP:
449 panic("%s: type=%d", __func__, type);
451 } else if (hook == priv->vjcomp) { /* incoming compressed packet */
452 int vjlen, need2pullup;
457 /* Are we decompressing? */
458 if (!priv->conf.enableDecomp) {
459 NG_FREE_DATA(m, meta);
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++;
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);
479 NG_FREE_DATA(m, meta);
484 /* Copy the reconstructed TCP/IP headers into a new mbuf */
485 MGETHDR(hm, MB_DONTWAIT, MT_DATA);
487 priv->slc.sls_errorin++;
488 NG_FREE_DATA(m, meta);
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) {
497 priv->slc.sls_errorin++;
498 NG_FREE_DATA(m, meta);
502 bcopy(hdr, mtod(hm, u_char *), hlen);
505 /* Glue TCP/IP headers and rest of packet together */
507 hm->m_pkthdr.len = hlen + m->m_pkthdr.len;
510 } else if (hook == priv->vjuncomp) { /* incoming uncompressed pkt */
514 /* Are we decompressing? */
515 if (!priv->conf.enableDecomp) {
516 NG_FREE_DATA(m, meta);
520 /* Pull up IP+TCP headers */
521 if ((m = ng_vjc_pulluphdrs(m, 1)) == NULL) {
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);
534 } else if (hook == priv->vjip) /* incoming regular packet (bypass) */
537 panic("%s: unknown hook", __func__);
539 /* Send result back out */
540 NG_SEND_DATA(error, hook, m, meta);
548 ng_vjc_rmnode(node_p node)
550 const priv_p priv = (priv_p) node->private;
552 node->flags |= NG_INVALID;
555 bzero(priv, sizeof(*priv));
556 FREE(priv, M_NETGRAPH);
557 node->private = NULL;
566 ng_vjc_disconnect(hook_p hook)
568 const node_p node = hook->node;
569 const priv_p priv = node->private;
571 /* Zero out hook pointer */
572 if (hook == priv->ip)
574 else if (hook == priv->vjcomp)
576 else if (hook == priv->vjuncomp)
577 priv->vjuncomp = NULL;
578 else if (hook == priv->vjip)
581 panic("%s: unknown hook", __func__);
583 /* Go away if no hooks left */
584 if (node->numhooks == 0)
589 /************************************************************************
591 ************************************************************************/
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.
598 ng_vjc_pulluphdrs(struct mbuf *m, int knownTCP)
604 if (m->m_len < sizeof(*ip) && (m = m_pullup(m, sizeof(*ip))) == NULL)
606 ip = mtod(m, struct ip *);
607 if (!knownTCP && ip->ip_p != IPPROTO_TCP)
609 ihlen = ip->ip_hl << 2;
610 if (m->m_len < ihlen + sizeof(*tcp)) {
611 if ((m = m_pullup(m, ihlen + sizeof(*tcp))) == NULL)
613 ip = mtod(m, struct ip *);
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);