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38 * Author: Archie Cobbs <archie@freebsd.org>
41 * $Whistle: ng_async.c,v 1.17 1999/11/01 09:24:51 julian Exp $
45 * This node type implements a PPP style sync <-> async converter.
46 * See RFC 1661 for details of how asynchronous encoding works.
49 #include <sys/param.h>
50 #include <sys/systm.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_async.h>
59 #include <netgraph/ng_parse.h>
61 #include <net/ppp_defs.h>
63 #ifdef NG_SEPARATE_MALLOC
64 static MALLOC_DEFINE(M_NETGRAPH_ASYNC, "netgraph_async", "netgraph async node");
66 #define M_NETGRAPH_ASYNC M_NETGRAPH
69 /* Async decode state */
74 /* Private data structure */
75 struct ng_async_private {
76 node_p node; /* Our node */
77 hook_p async; /* Asynchronous side */
78 hook_p sync; /* Synchronous side */
79 u_char amode; /* Async hunt/esape mode */
80 u_int16_t fcs; /* Decoded async FCS (so far) */
81 u_char *abuf; /* Buffer to encode sync into */
82 u_char *sbuf; /* Buffer to decode async into */
83 u_int slen; /* Length of data in sbuf */
84 long lasttime; /* Time of last async packet sent */
85 struct ng_async_cfg cfg; /* Configuration */
86 struct ng_async_stat stats; /* Statistics */
88 typedef struct ng_async_private *sc_p;
91 #define ASYNC_BUF_SIZE(smru) (2 * (smru) + 10)
92 #define SYNC_BUF_SIZE(amru) ((amru) + 10)
93 #define ERROUT(x) do { error = (x); goto done; } while (0)
95 /* Netgraph methods */
96 static ng_constructor_t nga_constructor;
97 static ng_rcvdata_t nga_rcvdata;
98 static ng_rcvmsg_t nga_rcvmsg;
99 static ng_shutdown_t nga_shutdown;
100 static ng_newhook_t nga_newhook;
101 static ng_disconnect_t nga_disconnect;
104 static int nga_rcv_sync(const sc_p sc, item_p item);
105 static int nga_rcv_async(const sc_p sc, item_p item);
107 /* Parse type for struct ng_async_cfg */
108 static const struct ng_parse_struct_field nga_config_type_fields[]
109 = NG_ASYNC_CONFIG_TYPE_INFO;
110 static const struct ng_parse_type nga_config_type = {
111 &ng_parse_struct_type,
112 &nga_config_type_fields
115 /* Parse type for struct ng_async_stat */
116 static const struct ng_parse_struct_field nga_stats_type_fields[]
117 = NG_ASYNC_STATS_TYPE_INFO;
118 static const struct ng_parse_type nga_stats_type = {
119 &ng_parse_struct_type,
120 &nga_stats_type_fields
123 /* List of commands and how to convert arguments to/from ASCII */
124 static const struct ng_cmdlist nga_cmdlist[] = {
127 NGM_ASYNC_CMD_SET_CONFIG,
134 NGM_ASYNC_CMD_GET_CONFIG,
141 NGM_ASYNC_CMD_GET_STATS,
148 NGM_ASYNC_CMD_CLR_STATS,
156 /* Define the netgraph node type */
157 static struct ng_type typestruct = {
158 .version = NG_ABI_VERSION,
159 .name = NG_ASYNC_NODE_TYPE,
160 .constructor = nga_constructor,
161 .rcvmsg = nga_rcvmsg,
162 .shutdown = nga_shutdown,
163 .newhook = nga_newhook,
164 .rcvdata = nga_rcvdata,
165 .disconnect = nga_disconnect,
166 .cmdlist = nga_cmdlist
168 NETGRAPH_INIT(async, &typestruct);
171 static const u_int16_t fcstab[];
173 /******************************************************************
174 NETGRAPH NODE METHODS
175 ******************************************************************/
178 * Initialize a new node
181 nga_constructor(node_p node)
185 sc = malloc(sizeof(*sc), M_NETGRAPH_ASYNC, M_WAITOK | M_ZERO);
186 sc->amode = MODE_HUNT;
188 sc->cfg.amru = NG_ASYNC_DEFAULT_MRU;
189 sc->cfg.smru = NG_ASYNC_DEFAULT_MRU;
190 sc->abuf = malloc(ASYNC_BUF_SIZE(sc->cfg.smru),
191 M_NETGRAPH_ASYNC, M_WAITOK);
192 sc->sbuf = malloc(SYNC_BUF_SIZE(sc->cfg.amru),
193 M_NETGRAPH_ASYNC, M_WAITOK);
194 NG_NODE_SET_PRIVATE(node, sc);
200 * Reserve a hook for a pending connection
203 nga_newhook(node_p node, hook_p hook, const char *name)
205 const sc_p sc = NG_NODE_PRIVATE(node);
208 if (!strcmp(name, NG_ASYNC_HOOK_ASYNC)) {
210 * We use a static buffer here so only one packet
211 * at a time can be allowed to travel in this direction.
212 * Force Writer semantics.
214 NG_HOOK_FORCE_WRITER(hook);
216 } else if (!strcmp(name, NG_ASYNC_HOOK_SYNC)) {
218 * We use a static state here so only one packet
219 * at a time can be allowed to travel in this direction.
220 * Force Writer semantics.
221 * Since we set this for both directions
222 * we might as well set it for the whole node
223 * bit I haven;t done that (yet).
225 NG_HOOK_FORCE_WRITER(hook);
230 if (*hookp) /* actually can't happen I think [JRE] */
237 * Receive incoming data
240 nga_rcvdata(hook_p hook, item_p item)
242 const sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
244 if (hook == sc->sync)
245 return (nga_rcv_sync(sc, item));
246 if (hook == sc->async)
247 return (nga_rcv_async(sc, item));
248 panic("%s", __func__);
252 * Receive incoming control message
255 nga_rcvmsg(node_p node, item_p item, hook_p lasthook)
257 const sc_p sc = NG_NODE_PRIVATE(node);
258 struct ng_mesg *resp = NULL;
262 NGI_GET_MSG(item, msg);
263 switch (msg->header.typecookie) {
264 case NGM_ASYNC_COOKIE:
265 switch (msg->header.cmd) {
266 case NGM_ASYNC_CMD_GET_STATS:
267 NG_MKRESPONSE(resp, msg, sizeof(sc->stats), M_NOWAIT);
270 *((struct ng_async_stat *) resp->data) = sc->stats;
272 case NGM_ASYNC_CMD_CLR_STATS:
273 bzero(&sc->stats, sizeof(sc->stats));
275 case NGM_ASYNC_CMD_SET_CONFIG:
277 struct ng_async_cfg *const cfg =
278 (struct ng_async_cfg *) msg->data;
281 if (msg->header.arglen != sizeof(*cfg))
283 if (cfg->amru < NG_ASYNC_MIN_MRU
284 || cfg->amru > NG_ASYNC_MAX_MRU
285 || cfg->smru < NG_ASYNC_MIN_MRU
286 || cfg->smru > NG_ASYNC_MAX_MRU)
288 cfg->enabled = !!cfg->enabled; /* normalize */
289 if (cfg->smru > sc->cfg.smru) { /* reallocate buffer */
290 buf = malloc(ASYNC_BUF_SIZE(cfg->smru),
291 M_NETGRAPH_ASYNC, M_NOWAIT);
294 free(sc->abuf, M_NETGRAPH_ASYNC);
297 if (cfg->amru > sc->cfg.amru) { /* reallocate buffer */
298 buf = malloc(SYNC_BUF_SIZE(cfg->amru),
299 M_NETGRAPH_ASYNC, M_NOWAIT);
302 free(sc->sbuf, M_NETGRAPH_ASYNC);
304 sc->amode = MODE_HUNT;
308 sc->amode = MODE_HUNT;
314 case NGM_ASYNC_CMD_GET_CONFIG:
315 NG_MKRESPONSE(resp, msg, sizeof(sc->cfg), M_NOWAIT);
318 *((struct ng_async_cfg *) resp->data) = sc->cfg;
328 NG_RESPOND_MSG(error, node, item, resp);
337 nga_shutdown(node_p node)
339 const sc_p sc = NG_NODE_PRIVATE(node);
341 free(sc->abuf, M_NETGRAPH_ASYNC);
342 free(sc->sbuf, M_NETGRAPH_ASYNC);
343 bzero(sc, sizeof(*sc));
344 free(sc, M_NETGRAPH_ASYNC);
345 NG_NODE_SET_PRIVATE(node, NULL);
351 * Lose a hook. When both hooks go away, we disappear.
354 nga_disconnect(hook_p hook)
356 const sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
359 if (hook == sc->async)
361 else if (hook == sc->sync)
364 panic("%s", __func__);
366 panic("%s 2", __func__);
368 bzero(&sc->stats, sizeof(sc->stats));
370 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
371 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook))))
372 ng_rmnode_self(NG_HOOK_NODE(hook));
376 /******************************************************************
377 INTERNAL HELPER STUFF
378 ******************************************************************/
381 * Encode a byte into the async buffer
384 nga_async_add(const sc_p sc, u_int16_t *fcs, u_int32_t accm, int *len, u_char x)
386 *fcs = PPP_FCS(*fcs, x);
387 if ((x < 32 && ((1 << x) & accm))
389 || (x == PPP_FLAG)) {
390 sc->abuf[(*len)++] = PPP_ESCAPE;
393 sc->abuf[(*len)++] = x;
397 * Receive incoming synchronous data.
400 nga_rcv_sync(const sc_p sc, item_p item)
409 #define ADD_BYTE(x) nga_async_add(sc, &fcs, accm, &alen, (x))
411 /* Check for bypass mode */
412 if (!sc->cfg.enabled) {
413 NG_FWD_ITEM_HOOK(error, item, sc->async );
418 rcvif = m->m_pkthdr.rcvif;
420 /* Get ACCM; special case LCP frames, which use full ACCM */
422 if (m->m_pkthdr.len >= 4) {
423 static const u_char lcphdr[4] = {
426 (u_char)(PPP_LCP >> 8),
427 (u_char)(PPP_LCP & 0xff)
431 m_copydata(m, 0, 4, (caddr_t)buf);
432 if (bcmp(buf, &lcphdr, 4) == 0)
436 /* Check for overflow */
437 if (m->m_pkthdr.len > sc->cfg.smru) {
438 sc->stats.syncOverflows++;
445 sc->stats.syncFrames++;
446 sc->stats.syncOctets += m->m_pkthdr.len;
448 /* Initialize async encoded version of input mbuf */
452 /* Add beginning sync flag if it's been long enough to need one */
454 if (time.tv_sec >= sc->lasttime + 1) {
455 sc->abuf[alen++] = PPP_FLAG;
456 sc->lasttime = time.tv_sec;
459 /* Add packet payload */
461 while (m->m_len > 0) {
462 ADD_BYTE(*mtod(m, u_char *));
469 /* Add checksum and final sync flag */
471 ADD_BYTE(~fcs0 & 0xff);
472 ADD_BYTE(~fcs0 >> 8);
473 sc->abuf[alen++] = PPP_FLAG;
475 /* Put frame in an mbuf and ship it off */
476 if (!(m = m_devget(sc->abuf, alen, 0, rcvif, NULL))) {
480 NG_FWD_NEW_DATA(error, item, sc->async, m);
486 * Receive incoming asynchronous data
487 * XXX Technically, we should strip out incoming characters
488 * that are in our ACCM. Not sure if this is good or not.
491 nga_rcv_async(const sc_p sc, item_p item)
497 if (!sc->cfg.enabled) {
498 NG_FWD_ITEM_HOOK(error, item, sc->sync);
502 rcvif = m->m_pkthdr.rcvif;
506 for (; m->m_len > 0; m->m_data++, m->m_len--) {
507 u_char ch = *mtod(m, u_char *);
509 sc->stats.asyncOctets++;
510 if (ch == PPP_FLAG) { /* Flag overrides everything */
513 /* Check for runts */
516 sc->stats.asyncRunts++;
521 if (sc->fcs != PPP_GOODFCS) {
522 sc->stats.asyncBadCheckSums++;
527 /* Strip address and control fields */
529 && sc->sbuf[0] == PPP_ALLSTATIONS
530 && sc->sbuf[1] == PPP_UI)
533 /* Check for frame too big */
534 if (sc->slen - skip > sc->cfg.amru) {
535 sc->stats.asyncOverflows++;
539 /* OK, ship it out */
540 if ((n = m_devget(sc->sbuf + skip,
541 sc->slen - skip, 0, rcvif, NULL))) {
542 if (item) { /* sets NULL -> item */
543 NG_FWD_NEW_DATA(error, item,
546 NG_SEND_DATA_ONLY(error,
550 sc->stats.asyncFrames++;
552 sc->amode = MODE_NORMAL;
553 sc->fcs = PPP_INITFCS;
559 if (ch == PPP_ESCAPE) {
560 sc->amode = MODE_ESC;
566 sc->amode = MODE_NORMAL;
573 /* Add byte to frame */
574 if (sc->slen >= SYNC_BUF_SIZE(sc->cfg.amru)) {
575 sc->stats.asyncOverflows++;
576 sc->amode = MODE_HUNT;
579 sc->sbuf[sc->slen++] = ch;
580 sc->fcs = PPP_FCS(sc->fcs, ch);
593 * Taken from RFC 1171 Appendix B
595 static const u_int16_t fcstab[256] = {
596 0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
597 0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
598 0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
599 0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
600 0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
601 0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
602 0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
603 0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
604 0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
605 0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
606 0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
607 0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
608 0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
609 0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
610 0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
611 0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
612 0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
613 0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
614 0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
615 0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
616 0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
617 0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
618 0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
619 0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
620 0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
621 0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
622 0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
623 0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
624 0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
625 0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
626 0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
627 0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78