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37 * Author: Archie Cobbs <archie@freebsd.org>
40 * $Whistle: ng_vjc.c,v 1.17 1999/11/01 09:24:52 julian Exp $
44 * This node performs Van Jacobson IP header (de)compression.
45 * You must have included net/slcompress.c in your kernel compilation.
48 #include <sys/param.h>
49 #include <sys/systm.h>
50 #include <sys/errno.h>
51 #include <sys/kernel.h>
53 #include <sys/malloc.h>
54 #include <sys/errno.h>
56 #include <netgraph/ng_message.h>
57 #include <netgraph/netgraph.h>
58 #include <netgraph/ng_parse.h>
59 #include <netgraph/ng_vjc.h>
61 #include <netinet/in.h>
62 #include <netinet/in_systm.h>
63 #include <netinet/ip.h>
64 #include <netinet/tcp.h>
66 #include <net/slcompress.h>
68 /* Check agreement with slcompress.c */
69 #if MAX_STATES != NG_VJC_MAX_CHANNELS
70 #error NG_VJC_MAX_CHANNELS must be the same as MAX_STATES
73 /* Maximum length of a compressed TCP VJ header */
74 #define MAX_VJHEADER 19
76 /* Node private data */
77 struct ng_vjc_private {
78 struct ngm_vjc_config conf;
79 struct slcompress slc;
85 typedef struct ng_vjc_private *priv_p;
87 #define ERROUT(x) do { error = (x); goto done; } while (0)
89 /* Netgraph node methods */
90 static ng_constructor_t ng_vjc_constructor;
91 static ng_rcvmsg_t ng_vjc_rcvmsg;
92 static ng_shutdown_t ng_vjc_shutdown;
93 static ng_newhook_t ng_vjc_newhook;
94 static ng_rcvdata_t ng_vjc_rcvdata;
95 static ng_disconnect_t ng_vjc_disconnect;
98 static struct mbuf *ng_vjc_pulluphdrs(struct mbuf *m, int knownTCP);
100 /* Parse type for struct ngm_vjc_config */
101 static const struct ng_parse_struct_field ng_vjc_config_type_fields[]
102 = NG_VJC_CONFIG_TYPE_INFO;
103 static const struct ng_parse_type ng_vjc_config_type = {
104 &ng_parse_struct_type,
105 &ng_vjc_config_type_fields
108 /* Parse type for the 'last_cs' and 'cs_next' fields in struct slcompress,
109 which are pointers converted to integer indices, so parse them that way. */
110 #if _MACHINE_ARCH == i386
111 #define NG_VJC_TSTATE_PTR_TYPE &ng_parse_uint32_type
112 #elif _MACHINE_ARCH == alpha
113 #define NG_VJC_TSTATE_PTR_TYPE &ng_parse_uint64_type
115 #error Unspported _MACHINE_ARCH
118 /* Parse type for the 'cs_hdr' field in a struct cstate. Ideally we would
119 like to use a 'struct ip' type instead of a simple array of bytes. */
120 static const struct ng_parse_fixedarray_info ng_vjc_cs_hdr_type_info = {
121 &ng_parse_hint8_type,
124 static const struct ng_parse_type ng_vjc_cs_hdr_type = {
125 &ng_parse_fixedarray_type,
126 &ng_vjc_cs_hdr_type_info
129 /* Parse type for a struct cstate */
130 static const struct ng_parse_struct_field ng_vjc_cstate_type_fields[] = {
131 { "cs_next", NG_VJC_TSTATE_PTR_TYPE },
132 { "cs_hlen", &ng_parse_uint16_type },
133 { "cs_id", &ng_parse_uint8_type },
134 { "cs_filler", &ng_parse_uint8_type },
135 { "cs_hdr", &ng_vjc_cs_hdr_type },
138 static const struct ng_parse_type ng_vjc_cstate_type = {
139 &ng_parse_struct_type,
140 &ng_vjc_cstate_type_fields
143 /* Parse type for an array of MAX_STATES struct cstate's, ie, tstate & rstate */
144 static const struct ng_parse_fixedarray_info ng_vjc_cstatearray_type_info = {
148 static const struct ng_parse_type ng_vjc_cstatearray_type = {
149 &ng_parse_fixedarray_type,
150 &ng_vjc_cstatearray_type_info
153 /* Parse type for struct slcompress. Keep this in sync with the
154 definition of struct slcompress defined in <net/slcompress.h> */
155 static const struct ng_parse_struct_field ng_vjc_slcompress_type_fields[] = {
156 { "last_cs", NG_VJC_TSTATE_PTR_TYPE },
157 { "last_recv", &ng_parse_uint8_type },
158 { "last_xmit", &ng_parse_uint8_type },
159 { "flags", &ng_parse_hint16_type },
161 { "sls_packets", &ng_parse_uint32_type },
162 { "sls_compressed", &ng_parse_uint32_type },
163 { "sls_searches", &ng_parse_uint32_type },
164 { "sls_misses", &ng_parse_uint32_type },
165 { "sls_uncompressedin", &ng_parse_uint32_type },
166 { "sls_compressedin", &ng_parse_uint32_type },
167 { "sls_errorin", &ng_parse_uint32_type },
168 { "sls_tossed", &ng_parse_uint32_type },
170 { "tstate", &ng_vjc_cstatearray_type },
171 { "rstate", &ng_vjc_cstatearray_type },
174 static const struct ng_parse_type ng_vjc_slcompress_type = {
175 &ng_parse_struct_type,
176 &ng_vjc_slcompress_type_fields
179 /* List of commands and how to convert arguments to/from ASCII */
180 static const struct ng_cmdlist ng_vjc_cmds[] = {
200 &ng_vjc_slcompress_type,
219 /* Node type descriptor */
220 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 node)
248 /* Allocate private structure */
249 MALLOC(priv, priv_p, sizeof(*priv), M_NETGRAPH, M_NOWAIT | M_ZERO);
253 NG_NODE_SET_PRIVATE(node, priv);
263 ng_vjc_newhook(node_p node, hook_p hook, const char *name)
265 const priv_p priv = NG_NODE_PRIVATE(node);
269 if (strcmp(name, NG_VJC_HOOK_IP) == 0)
271 else if (strcmp(name, NG_VJC_HOOK_VJCOMP) == 0)
272 hookp = &priv->vjcomp;
273 else if (strcmp(name, NG_VJC_HOOK_VJUNCOMP) == 0)
274 hookp = &priv->vjuncomp;
275 else if (strcmp(name, NG_VJC_HOOK_VJIP) == 0)
280 /* See if already connected */
290 * Receive a control message
293 ng_vjc_rcvmsg(node_p node, item_p item, hook_p lasthook)
295 const priv_p priv = NG_NODE_PRIVATE(node);
296 struct ng_mesg *resp = NULL;
300 NGI_GET_MSG(item, msg);
301 /* Check type cookie */
302 switch (msg->header.typecookie) {
304 switch (msg->header.cmd) {
305 case NGM_VJC_SET_CONFIG:
307 struct ngm_vjc_config *const c =
308 (struct ngm_vjc_config *) msg->data;
310 if (msg->header.arglen != sizeof(*c))
312 if ((priv->conf.enableComp || priv->conf.enableDecomp)
313 && (c->enableComp || c->enableDecomp))
316 if (c->maxChannel > NG_VJC_MAX_CHANNELS - 1
317 || c->maxChannel < NG_VJC_MIN_CHANNELS - 1)
320 c->maxChannel = NG_VJC_MAX_CHANNELS - 1;
321 if (c->enableComp != 0 || c->enableDecomp != 0) {
322 bzero(&priv->slc, sizeof(priv->slc));
323 sl_compress_init(&priv->slc, c->maxChannel);
328 case NGM_VJC_GET_CONFIG:
330 struct ngm_vjc_config *conf;
332 NG_MKRESPONSE(resp, msg, sizeof(*conf), M_NOWAIT);
335 conf = (struct ngm_vjc_config *)resp->data;
339 case NGM_VJC_GET_STATE:
341 const struct slcompress *const sl0 = &priv->slc;
342 struct slcompress *sl;
346 /* Get response structure */
347 NG_MKRESPONSE(resp, msg, sizeof(*sl), M_NOWAIT);
350 sl = (struct slcompress *)resp->data;
353 /* Replace pointers with integer indicies */
354 if (sl->last_cs != NULL) {
355 index = sl0->last_cs - sl0->tstate;
356 bzero(&sl->last_cs, sizeof(sl->last_cs));
357 *((u_int16_t *)&sl->last_cs) = index;
359 for (i = 0; i < MAX_STATES; i++) {
360 struct cstate *const cs = &sl->tstate[i];
362 index = sl0->tstate[i].cs_next - sl0->tstate;
363 bzero(&cs->cs_next, sizeof(cs->cs_next));
364 *((u_int16_t *)&cs->cs_next) = index;
368 case NGM_VJC_CLR_STATS:
369 priv->slc.sls_packets = 0;
370 priv->slc.sls_compressed = 0;
371 priv->slc.sls_searches = 0;
372 priv->slc.sls_misses = 0;
373 priv->slc.sls_uncompressedin = 0;
374 priv->slc.sls_compressedin = 0;
375 priv->slc.sls_errorin = 0;
376 priv->slc.sls_tossed = 0;
378 case NGM_VJC_RECV_ERROR:
379 sl_uncompress_tcp(NULL, 0, TYPE_ERROR, &priv->slc);
391 NG_RESPOND_MSG(error, node, item, resp);
400 ng_vjc_rcvdata(hook_p hook, item_p item)
402 const node_p node = NG_HOOK_NODE(hook);
403 const priv_p priv = NG_NODE_PRIVATE(node);
408 if (hook == priv->ip) { /* outgoing packet */
409 u_int type = TYPE_IP;
411 /* Compress packet if enabled and proto is TCP */
412 if (priv->conf.enableComp) {
415 if ((m = ng_vjc_pulluphdrs(m, 0)) == NULL) {
419 ip = mtod(m, struct ip *);
420 if (ip->ip_p == IPPROTO_TCP) {
421 const int origLen = m->m_len;
423 type = sl_compress_tcp(m, ip,
424 &priv->slc, priv->conf.compressCID);
425 m->m_pkthdr.len += m->m_len - origLen;
429 /* Dispatch to the appropriate outgoing hook */
434 case TYPE_UNCOMPRESSED_TCP:
435 hook = priv->vjuncomp;
437 case TYPE_COMPRESSED_TCP:
441 panic("%s: type=%d", __func__, type);
443 } else if (hook == priv->vjcomp) { /* incoming compressed packet */
444 int vjlen, need2pullup;
449 /* Are we decompressing? */
450 if (!priv->conf.enableDecomp) {
456 /* Pull up the necessary amount from the mbuf */
457 need2pullup = MAX_VJHEADER;
458 if (need2pullup > m->m_pkthdr.len)
459 need2pullup = m->m_pkthdr.len;
460 if (m->m_len < need2pullup
461 && (m = m_pullup(m, need2pullup)) == NULL) {
462 priv->slc.sls_errorin++;
467 /* Uncompress packet to reconstruct TCP/IP header */
468 vjlen = sl_uncompress_tcp_core(mtod(m, u_char *),
469 m->m_len, m->m_pkthdr.len, TYPE_COMPRESSED_TCP,
470 &priv->slc, &hdr, &hlen);
478 /* Copy the reconstructed TCP/IP headers into a new mbuf */
479 MGETHDR(hm, M_DONTWAIT, MT_DATA);
481 priv->slc.sls_errorin++;
487 hm->m_pkthdr.rcvif = NULL;
488 if (hlen > MHLEN) { /* unlikely, but can happen */
489 MCLGET(hm, M_DONTWAIT);
490 if ((hm->m_flags & M_EXT) == 0) {
492 priv->slc.sls_errorin++;
498 bcopy(hdr, mtod(hm, u_char *), hlen);
501 /* Glue TCP/IP headers and rest of packet together */
503 hm->m_pkthdr.len = hlen + m->m_pkthdr.len;
506 } else if (hook == priv->vjuncomp) { /* incoming uncompressed pkt */
510 /* Are we decompressing? */
511 if (!priv->conf.enableDecomp) {
517 /* Pull up IP+TCP headers */
518 if ((m = ng_vjc_pulluphdrs(m, 1)) == NULL) {
523 /* Run packet through uncompressor */
524 if (sl_uncompress_tcp_core(mtod(m, u_char *),
525 m->m_len, m->m_pkthdr.len, TYPE_UNCOMPRESSED_TCP,
526 &priv->slc, &hdr, &hlen) < 0) {
532 } else if (hook == priv->vjip) /* incoming regular packet (bypass) */
535 panic("%s: unknown hook", __func__);
537 /* Send result back out */
538 NG_FWD_NEW_DATA(error, item, hook, m);
546 ng_vjc_shutdown(node_p node)
548 const priv_p priv = NG_NODE_PRIVATE(node);
550 bzero(priv, sizeof(*priv));
551 FREE(priv, M_NETGRAPH);
552 NG_NODE_SET_PRIVATE(node, NULL);
561 ng_vjc_disconnect(hook_p hook)
563 const node_p node = NG_HOOK_NODE(hook);
564 const priv_p priv = NG_NODE_PRIVATE(node);
566 /* Zero out hook pointer */
567 if (hook == priv->ip)
569 else if (hook == priv->vjcomp)
571 else if (hook == priv->vjuncomp)
572 priv->vjuncomp = NULL;
573 else if (hook == priv->vjip)
576 panic("%s: unknown hook", __func__);
578 /* Go away if no hooks left */
579 if ((NG_NODE_NUMHOOKS(node) == 0)
580 && (NG_NODE_IS_VALID(node)))
581 ng_rmnode_self(node);
585 /************************************************************************
587 ************************************************************************/
590 * Pull up the full IP and TCP headers of a packet. If packet is not
591 * a TCP packet, just pull up the IP header.
594 ng_vjc_pulluphdrs(struct mbuf *m, int knownTCP)
600 if (m->m_len < sizeof(*ip) && (m = m_pullup(m, sizeof(*ip))) == NULL)
602 ip = mtod(m, struct ip *);
603 if (!knownTCP && ip->ip_p != IPPROTO_TCP)
605 ihlen = ip->ip_hl << 2;
606 if (m->m_len < ihlen + sizeof(*tcp)) {
607 if ((m = m_pullup(m, ihlen + sizeof(*tcp))) == NULL)
609 ip = mtod(m, struct ip *);
611 tcp = (struct tcphdr *)((u_char *)ip + ihlen);
612 thlen = tcp->th_off << 2;
613 if (m->m_len < ihlen + thlen)
614 m = m_pullup(m, ihlen + thlen);