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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
70 /* Async decode state */
75 /* Private data structure */
76 struct ng_async_private {
77 node_p node; /* Our node */
78 hook_p async; /* Asynchronous side */
79 hook_p sync; /* Synchronous side */
80 u_char amode; /* Async hunt/esape mode */
81 u_int16_t fcs; /* Decoded async FCS (so far) */
82 u_char *abuf; /* Buffer to encode sync into */
83 u_char *sbuf; /* Buffer to decode async into */
84 u_int slen; /* Length of data in sbuf */
85 long lasttime; /* Time of last async packet sent */
86 struct ng_async_cfg cfg; /* Configuration */
87 struct ng_async_stat stats; /* Statistics */
89 typedef struct ng_async_private *sc_p;
92 #define ASYNC_BUF_SIZE(smru) (2 * (smru) + 10)
93 #define SYNC_BUF_SIZE(amru) ((amru) + 10)
94 #define ERROUT(x) do { error = (x); goto done; } while (0)
96 /* Netgraph methods */
97 static ng_constructor_t nga_constructor;
98 static ng_rcvdata_t nga_rcvdata;
99 static ng_rcvmsg_t nga_rcvmsg;
100 static ng_shutdown_t nga_shutdown;
101 static ng_newhook_t nga_newhook;
102 static ng_disconnect_t nga_disconnect;
105 static int nga_rcv_sync(const sc_p sc, item_p item);
106 static int nga_rcv_async(const sc_p sc, item_p item);
108 /* Parse type for struct ng_async_cfg */
109 static const struct ng_parse_struct_field nga_config_type_fields[]
110 = NG_ASYNC_CONFIG_TYPE_INFO;
111 static const struct ng_parse_type nga_config_type = {
112 &ng_parse_struct_type,
113 &nga_config_type_fields
116 /* Parse type for struct ng_async_stat */
117 static const struct ng_parse_struct_field nga_stats_type_fields[]
118 = NG_ASYNC_STATS_TYPE_INFO;
119 static const struct ng_parse_type nga_stats_type = {
120 &ng_parse_struct_type,
121 &nga_stats_type_fields
124 /* List of commands and how to convert arguments to/from ASCII */
125 static const struct ng_cmdlist nga_cmdlist[] = {
128 NGM_ASYNC_CMD_SET_CONFIG,
135 NGM_ASYNC_CMD_GET_CONFIG,
142 NGM_ASYNC_CMD_GET_STATS,
149 NGM_ASYNC_CMD_CLR_STATS,
157 /* Define the netgraph node type */
158 static struct ng_type typestruct = {
159 .version = NG_ABI_VERSION,
160 .name = NG_ASYNC_NODE_TYPE,
161 .constructor = nga_constructor,
162 .rcvmsg = nga_rcvmsg,
163 .shutdown = nga_shutdown,
164 .newhook = nga_newhook,
165 .rcvdata = nga_rcvdata,
166 .disconnect = nga_disconnect,
167 .cmdlist = nga_cmdlist
169 NETGRAPH_INIT(async, &typestruct);
172 static const u_int16_t fcstab[];
174 /******************************************************************
175 NETGRAPH NODE METHODS
176 ******************************************************************/
179 * Initialize a new node
182 nga_constructor(node_p node)
186 sc = malloc(sizeof(*sc), M_NETGRAPH_ASYNC, M_WAITOK | M_ZERO);
187 sc->amode = MODE_HUNT;
189 sc->cfg.amru = NG_ASYNC_DEFAULT_MRU;
190 sc->cfg.smru = NG_ASYNC_DEFAULT_MRU;
191 sc->abuf = malloc(ASYNC_BUF_SIZE(sc->cfg.smru),
192 M_NETGRAPH_ASYNC, M_WAITOK);
193 sc->sbuf = malloc(SYNC_BUF_SIZE(sc->cfg.amru),
194 M_NETGRAPH_ASYNC, M_WAITOK);
195 NG_NODE_SET_PRIVATE(node, sc);
201 * Reserve a hook for a pending connection
204 nga_newhook(node_p node, hook_p hook, const char *name)
206 const sc_p sc = NG_NODE_PRIVATE(node);
209 if (!strcmp(name, NG_ASYNC_HOOK_ASYNC)) {
211 * We use a static buffer here so only one packet
212 * at a time can be allowed to travel in this direction.
213 * Force Writer semantics.
215 NG_HOOK_FORCE_WRITER(hook);
217 } else if (!strcmp(name, NG_ASYNC_HOOK_SYNC)) {
219 * We use a static state here so only one packet
220 * at a time can be allowed to travel in this direction.
221 * Force Writer semantics.
222 * Since we set this for both directions
223 * we might as well set it for the whole node
224 * bit I haven;t done that (yet).
226 NG_HOOK_FORCE_WRITER(hook);
231 if (*hookp) /* actually can't happen I think [JRE] */
238 * Receive incoming data
241 nga_rcvdata(hook_p hook, item_p item)
243 const sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
245 if (hook == sc->sync)
246 return (nga_rcv_sync(sc, item));
247 if (hook == sc->async)
248 return (nga_rcv_async(sc, item));
249 panic("%s", __func__);
253 * Receive incoming control message
256 nga_rcvmsg(node_p node, item_p item, hook_p lasthook)
258 const sc_p sc = NG_NODE_PRIVATE(node);
259 struct ng_mesg *resp = NULL;
263 NGI_GET_MSG(item, msg);
264 switch (msg->header.typecookie) {
265 case NGM_ASYNC_COOKIE:
266 switch (msg->header.cmd) {
267 case NGM_ASYNC_CMD_GET_STATS:
268 NG_MKRESPONSE(resp, msg, sizeof(sc->stats), M_NOWAIT);
271 *((struct ng_async_stat *) resp->data) = sc->stats;
273 case NGM_ASYNC_CMD_CLR_STATS:
274 bzero(&sc->stats, sizeof(sc->stats));
276 case NGM_ASYNC_CMD_SET_CONFIG:
278 struct ng_async_cfg *const cfg =
279 (struct ng_async_cfg *) msg->data;
282 if (msg->header.arglen != sizeof(*cfg))
284 if (cfg->amru < NG_ASYNC_MIN_MRU
285 || cfg->amru > NG_ASYNC_MAX_MRU
286 || cfg->smru < NG_ASYNC_MIN_MRU
287 || cfg->smru > NG_ASYNC_MAX_MRU)
289 cfg->enabled = !!cfg->enabled; /* normalize */
290 if (cfg->smru > sc->cfg.smru) { /* reallocate buffer */
291 buf = malloc(ASYNC_BUF_SIZE(cfg->smru),
292 M_NETGRAPH_ASYNC, M_NOWAIT);
295 free(sc->abuf, M_NETGRAPH_ASYNC);
298 if (cfg->amru > sc->cfg.amru) { /* reallocate buffer */
299 buf = malloc(SYNC_BUF_SIZE(cfg->amru),
300 M_NETGRAPH_ASYNC, M_NOWAIT);
303 free(sc->sbuf, M_NETGRAPH_ASYNC);
305 sc->amode = MODE_HUNT;
309 sc->amode = MODE_HUNT;
315 case NGM_ASYNC_CMD_GET_CONFIG:
316 NG_MKRESPONSE(resp, msg, sizeof(sc->cfg), M_NOWAIT);
319 *((struct ng_async_cfg *) resp->data) = sc->cfg;
329 NG_RESPOND_MSG(error, node, item, resp);
338 nga_shutdown(node_p node)
340 const sc_p sc = NG_NODE_PRIVATE(node);
342 free(sc->abuf, M_NETGRAPH_ASYNC);
343 free(sc->sbuf, M_NETGRAPH_ASYNC);
344 bzero(sc, sizeof(*sc));
345 free(sc, M_NETGRAPH_ASYNC);
346 NG_NODE_SET_PRIVATE(node, NULL);
352 * Lose a hook. When both hooks go away, we disappear.
355 nga_disconnect(hook_p hook)
357 const sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
360 if (hook == sc->async)
362 else if (hook == sc->sync)
365 panic("%s", __func__);
367 panic("%s 2", __func__);
369 bzero(&sc->stats, sizeof(sc->stats));
371 if ((NG_NODE_NUMHOOKS(NG_HOOK_NODE(hook)) == 0)
372 && (NG_NODE_IS_VALID(NG_HOOK_NODE(hook))))
373 ng_rmnode_self(NG_HOOK_NODE(hook));
377 /******************************************************************
378 INTERNAL HELPER STUFF
379 ******************************************************************/
382 * Encode a byte into the async buffer
385 nga_async_add(const sc_p sc, u_int16_t *fcs, u_int32_t accm, int *len, u_char x)
387 *fcs = PPP_FCS(*fcs, x);
388 if ((x < 32 && ((1 << x) & accm))
390 || (x == PPP_FLAG)) {
391 sc->abuf[(*len)++] = PPP_ESCAPE;
394 sc->abuf[(*len)++] = x;
398 * Receive incoming synchronous data.
401 nga_rcv_sync(const sc_p sc, item_p item)
411 #define ADD_BYTE(x) nga_async_add(sc, &fcs, accm, &alen, (x))
413 /* Check for bypass mode */
414 if (!sc->cfg.enabled) {
415 NG_FWD_ITEM_HOOK(error, item, sc->async );
420 rcvif = m->m_pkthdr.rcvif;
422 /* Get ACCM; special case LCP frames, which use full ACCM */
424 if (m->m_pkthdr.len >= 4) {
425 static const u_char lcphdr[4] = {
428 (u_char)(PPP_LCP >> 8),
429 (u_char)(PPP_LCP & 0xff)
433 m_copydata(m, 0, 4, (caddr_t)buf);
434 if (bcmp(buf, &lcphdr, 4) == 0)
438 /* Check for overflow */
439 if (m->m_pkthdr.len > sc->cfg.smru) {
440 sc->stats.syncOverflows++;
447 sc->stats.syncFrames++;
448 sc->stats.syncOctets += m->m_pkthdr.len;
450 /* Initialize async encoded version of input mbuf */
454 /* Add beginning sync flag if it's been long enough to need one */
456 if (time.tv_sec >= sc->lasttime + 1) {
457 sc->abuf[alen++] = PPP_FLAG;
458 sc->lasttime = time.tv_sec;
461 /* Add packet payload */
463 while (m->m_len > 0) {
464 ADD_BYTE(*mtod(m, u_char *));
471 /* Add checksum and final sync flag */
473 ADD_BYTE(~fcs0 & 0xff);
474 ADD_BYTE(~fcs0 >> 8);
475 sc->abuf[alen++] = PPP_FLAG;
477 /* Put frame in an mbuf and ship it off */
478 if (!(m = m_devget(sc->abuf, alen, 0, rcvif, NULL))) {
482 NG_FWD_NEW_DATA(error, item, sc->async, m);
488 * Receive incoming asynchronous data
489 * XXX Technically, we should strip out incoming characters
490 * that are in our ACCM. Not sure if this is good or not.
493 nga_rcv_async(const sc_p sc, item_p item)
499 if (!sc->cfg.enabled) {
500 NG_FWD_ITEM_HOOK(error, item, sc->sync);
504 rcvif = m->m_pkthdr.rcvif;
508 for (; m->m_len > 0; m->m_data++, m->m_len--) {
509 u_char ch = *mtod(m, u_char *);
511 sc->stats.asyncOctets++;
512 if (ch == PPP_FLAG) { /* Flag overrides everything */
515 /* Check for runts */
518 sc->stats.asyncRunts++;
523 if (sc->fcs != PPP_GOODFCS) {
524 sc->stats.asyncBadCheckSums++;
529 /* Strip address and control fields */
531 && sc->sbuf[0] == PPP_ALLSTATIONS
532 && sc->sbuf[1] == PPP_UI)
535 /* Check for frame too big */
536 if (sc->slen - skip > sc->cfg.amru) {
537 sc->stats.asyncOverflows++;
541 /* OK, ship it out */
542 if ((n = m_devget(sc->sbuf + skip,
543 sc->slen - skip, 0, rcvif, NULL))) {
544 if (item) { /* sets NULL -> item */
545 NG_FWD_NEW_DATA(error, item,
548 NG_SEND_DATA_ONLY(error,
552 sc->stats.asyncFrames++;
554 sc->amode = MODE_NORMAL;
555 sc->fcs = PPP_INITFCS;
561 if (ch == PPP_ESCAPE) {
562 sc->amode = MODE_ESC;
568 sc->amode = MODE_NORMAL;
575 /* Add byte to frame */
576 if (sc->slen >= SYNC_BUF_SIZE(sc->cfg.amru)) {
577 sc->stats.asyncOverflows++;
578 sc->amode = MODE_HUNT;
581 sc->sbuf[sc->slen++] = ch;
582 sc->fcs = PPP_FCS(sc->fcs, ch);
595 * Taken from RFC 1171 Appendix B
597 static const u_int16_t fcstab[256] = {
598 0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
599 0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
600 0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
601 0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
602 0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
603 0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
604 0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
605 0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
606 0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
607 0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
608 0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
609 0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
610 0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
611 0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
612 0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
613 0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
614 0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
615 0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
616 0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
617 0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
618 0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
619 0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
620 0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
621 0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
622 0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
623 0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
624 0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
625 0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
626 0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
627 0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
628 0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
629 0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78