1 /* 2 * ng_tty.c 3 */ 4 5 /*- 6 * Copyright (c) 1996-1999 Whistle Communications, Inc. 7 * All rights reserved. 8 * 9 * Subject to the following obligations and disclaimer of warranty, use and 10 * redistribution of this software, in source or object code forms, with or 11 * without modifications are expressly permitted by Whistle Communications; 12 * provided, however, that: 13 * 1. Any and all reproductions of the source or object code must include the 14 * copyright notice above and the following disclaimer of warranties; and 15 * 2. No rights are granted, in any manner or form, to use Whistle 16 * Communications, Inc. trademarks, including the mark "WHISTLE 17 * COMMUNICATIONS" on advertising, endorsements, or otherwise except as 18 * such appears in the above copyright notice or in the software. 19 * 20 * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND 21 * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO 22 * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE, 23 * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF 24 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. 25 * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY 26 * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS 27 * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE. 28 * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES 29 * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING 30 * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, 31 * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR 32 * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY 33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 35 * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY 36 * OF SUCH DAMAGE. 37 * 38 * Author: Archie Cobbs <archie@freebsd.org> 39 * 40 * Updated by Andrew Thompson <thompsa@FreeBSD.org> for MPSAFE TTY. 41 * 42 * $FreeBSD$ 43 * $Whistle: ng_tty.c,v 1.21 1999/11/01 09:24:52 julian Exp $ 44 */ 45 46 /* 47 * This file implements TTY hooks to link in to the netgraph system. The node 48 * is created and then passed the callers opened TTY file descriptor number to 49 * NGM_TTY_SET_TTY, this will hook the tty via ttyhook_register(). 50 * 51 * Incoming data is delivered directly to ng_tty via the TTY bypass hook as a 52 * buffer pointer and length, this is converted to a mbuf and passed to the 53 * peer. 54 * 55 * If the TTY device does not support bypass then incoming characters are 56 * delivered to the hook one at a time, each in its own mbuf. You may 57 * optionally define a ``hotchar,'' which causes incoming characters to be 58 * buffered up until either the hotchar is seen or the mbuf is full (MHLEN 59 * bytes). Then all buffered characters are immediately delivered. 60 */ 61 62 #include <sys/param.h> 63 #include <sys/systm.h> 64 #include <sys/conf.h> 65 #include <sys/errno.h> 66 #include <sys/fcntl.h> 67 #include <sys/ioccom.h> 68 #include <sys/kernel.h> 69 #include <sys/malloc.h> 70 #include <sys/mbuf.h> 71 #include <sys/priv.h> 72 #include <sys/socket.h> 73 #include <sys/syslog.h> 74 #include <sys/tty.h> 75 #include <sys/ttycom.h> 76 77 #include <net/if.h> 78 #include <net/if_var.h> 79 80 #include <netgraph/ng_message.h> 81 #include <netgraph/netgraph.h> 82 #include <netgraph/ng_tty.h> 83 84 /* Per-node private info */ 85 struct ngt_softc { 86 struct tty *tp; /* Terminal device */ 87 node_p node; /* Netgraph node */ 88 hook_p hook; /* Netgraph hook */ 89 struct ifqueue outq; /* Queue of outgoing data */ 90 size_t outqlen; /* Number of bytes in outq */ 91 struct mbuf *m; /* Incoming non-bypass data buffer */ 92 short hotchar; /* Hotchar, or -1 if none */ 93 u_int flags; /* Flags */ 94 }; 95 typedef struct ngt_softc *sc_p; 96 97 static int ngt_unit; 98 99 /* Flags */ 100 #define FLG_DEBUG 0x0002 101 102 /* Netgraph methods */ 103 static ng_constructor_t ngt_constructor; 104 static ng_rcvmsg_t ngt_rcvmsg; 105 static ng_shutdown_t ngt_shutdown; 106 static ng_newhook_t ngt_newhook; 107 static ng_connect_t ngt_connect; 108 static ng_rcvdata_t ngt_rcvdata; 109 static ng_disconnect_t ngt_disconnect; 110 111 #define ERROUT(x) do { error = (x); goto done; } while (0) 112 113 static th_getc_inject_t ngt_getc_inject; 114 static th_getc_poll_t ngt_getc_poll; 115 static th_rint_t ngt_rint; 116 static th_rint_bypass_t ngt_rint_bypass; 117 static th_rint_poll_t ngt_rint_poll; 118 static th_close_t ngt_close; 119 120 static struct ttyhook ngt_hook = { 121 .th_getc_inject = ngt_getc_inject, 122 .th_getc_poll = ngt_getc_poll, 123 .th_rint = ngt_rint, 124 .th_rint_bypass = ngt_rint_bypass, 125 .th_rint_poll = ngt_rint_poll, 126 .th_close = ngt_close, 127 }; 128 129 /* Netgraph node type descriptor */ 130 static struct ng_type typestruct = { 131 .version = NG_ABI_VERSION, 132 .name = NG_TTY_NODE_TYPE, 133 .constructor = ngt_constructor, 134 .rcvmsg = ngt_rcvmsg, 135 .shutdown = ngt_shutdown, 136 .newhook = ngt_newhook, 137 .connect = ngt_connect, 138 .rcvdata = ngt_rcvdata, 139 .disconnect = ngt_disconnect, 140 }; 141 NETGRAPH_INIT(tty, &typestruct); 142 143 #define NGTLOCK(sc) IF_LOCK(&sc->outq) 144 #define NGTUNLOCK(sc) IF_UNLOCK(&sc->outq) 145 146 /****************************************************************** 147 NETGRAPH NODE METHODS 148 ******************************************************************/ 149 150 /* 151 * Initialize a new node of this type. 152 * 153 * We only allow nodes to be created as a result of setting 154 * the line discipline on a tty, so always return an error if not. 155 */ 156 static int 157 ngt_constructor(node_p node) 158 { 159 sc_p sc; 160 char name[sizeof(NG_TTY_NODE_TYPE) + 8]; 161 162 /* Allocate private structure */ 163 MALLOC(sc, sc_p, sizeof(*sc), M_NETGRAPH, M_NOWAIT | M_ZERO); 164 if (sc == NULL) 165 return (ENOMEM); 166 167 NG_NODE_SET_PRIVATE(node, sc); 168 sc->node = node; 169 170 mtx_init(&sc->outq.ifq_mtx, "ng_tty node+queue", NULL, MTX_DEF); 171 IFQ_SET_MAXLEN(&sc->outq, IFQ_MAXLEN); 172 173 atomic_add_int(&ngt_unit, 1); 174 snprintf(name, sizeof(name), "%s%d", typestruct.name, ngt_unit); 175 176 /* Assign node its name */ 177 if (ng_name_node(node, name)) 178 log(LOG_WARNING, "%s: can't name node %s\n", 179 __func__, name); 180 /* Done */ 181 return (0); 182 } 183 184 /* 185 * Add a new hook. There can only be one. 186 */ 187 static int 188 ngt_newhook(node_p node, hook_p hook, const char *name) 189 { 190 const sc_p sc = NG_NODE_PRIVATE(node); 191 192 if (strcmp(name, NG_TTY_HOOK)) 193 return (EINVAL); 194 195 if (sc->hook) 196 return (EISCONN); 197 198 NGTLOCK(sc); 199 sc->hook = hook; 200 NGTUNLOCK(sc); 201 202 return (0); 203 } 204 205 /* 206 * Set the hook into queueing mode (for outgoing packets), 207 * so that we wont deliver mbuf thru the whole graph holding 208 * tty locks. 209 */ 210 static int 211 ngt_connect(hook_p hook) 212 { 213 NG_HOOK_FORCE_QUEUE(hook); 214 return (0); 215 } 216 217 /* 218 * Disconnect the hook 219 */ 220 static int 221 ngt_disconnect(hook_p hook) 222 { 223 const sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook)); 224 225 if (hook != sc->hook) 226 panic(__func__); 227 228 NGTLOCK(sc); 229 sc->hook = NULL; 230 NGTUNLOCK(sc); 231 232 return (0); 233 } 234 235 /* 236 * Remove this node. The does the netgraph portion of the shutdown. 237 */ 238 static int 239 ngt_shutdown(node_p node) 240 { 241 const sc_p sc = NG_NODE_PRIVATE(node); 242 struct tty *tp; 243 244 tp = sc->tp; 245 if (tp != NULL) { 246 tty_lock(tp); 247 ttyhook_unregister(tp); 248 } 249 /* Free resources */ 250 IF_DRAIN(&sc->outq); 251 mtx_destroy(&(sc)->outq.ifq_mtx); 252 NG_NODE_UNREF(sc->node); 253 FREE(sc, M_NETGRAPH); 254 255 return (0); 256 } 257 258 /* 259 * Receive control message 260 */ 261 static int 262 ngt_rcvmsg(node_p node, item_p item, hook_p lasthook) 263 { 264 struct thread *td = curthread; /* XXX */ 265 const sc_p sc = NG_NODE_PRIVATE(node); 266 struct ng_mesg *msg, *resp = NULL; 267 int error = 0; 268 269 NGI_GET_MSG(item, msg); 270 switch (msg->header.typecookie) { 271 case NGM_TTY_COOKIE: 272 switch (msg->header.cmd) { 273 case NGM_TTY_SET_TTY: 274 if (sc->tp != NULL) 275 return (EBUSY); 276 error = ttyhook_register(&sc->tp, td, *(int *)msg->data, 277 &ngt_hook, sc); 278 if (error != 0) 279 return (error); 280 break; 281 case NGM_TTY_SET_HOTCHAR: 282 { 283 int hotchar; 284 285 if (msg->header.arglen != sizeof(int)) 286 ERROUT(EINVAL); 287 hotchar = *((int *) msg->data); 288 if (hotchar != (u_char) hotchar && hotchar != -1) 289 ERROUT(EINVAL); 290 sc->hotchar = hotchar; /* race condition is OK */ 291 break; 292 } 293 case NGM_TTY_GET_HOTCHAR: 294 NG_MKRESPONSE(resp, msg, sizeof(int), M_NOWAIT); 295 if (!resp) 296 ERROUT(ENOMEM); 297 /* Race condition here is OK */ 298 *((int *) resp->data) = sc->hotchar; 299 break; 300 default: 301 ERROUT(EINVAL); 302 } 303 break; 304 default: 305 ERROUT(EINVAL); 306 } 307 done: 308 NG_RESPOND_MSG(error, node, item, resp); 309 NG_FREE_MSG(msg); 310 return (error); 311 } 312 313 /* 314 * Receive incoming data from netgraph system. Put it on our 315 * output queue and start output if necessary. 316 */ 317 static int 318 ngt_rcvdata(hook_p hook, item_p item) 319 { 320 const sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook)); 321 struct tty *tp = sc->tp; 322 struct mbuf *m; 323 324 if (hook != sc->hook) 325 panic(__func__); 326 327 NGI_GET_M(item, m); 328 NG_FREE_ITEM(item); 329 330 if (tp == NULL) { 331 NG_FREE_M(m); 332 return (ENXIO); 333 } 334 335 IF_LOCK(&sc->outq); 336 if (_IF_QFULL(&sc->outq)) { 337 _IF_DROP(&sc->outq); 338 IF_UNLOCK(&sc->outq); 339 NG_FREE_M(m); 340 return (ENOBUFS); 341 } 342 343 _IF_ENQUEUE(&sc->outq, m); 344 sc->outqlen += m->m_pkthdr.len; 345 IF_UNLOCK(&sc->outq); 346 347 /* notify the TTY that data is ready */ 348 tty_lock(tp); 349 if (!tty_gone(tp)) 350 ttydevsw_outwakeup(tp); 351 tty_unlock(tp); 352 353 return (0); 354 } 355 356 static size_t 357 ngt_getc_inject(struct tty *tp, void *buf, size_t len) 358 { 359 sc_p sc = ttyhook_softc(tp); 360 size_t total = 0; 361 int length; 362 363 while (len) { 364 struct mbuf *m; 365 366 /* Remove first mbuf from queue */ 367 IF_DEQUEUE(&sc->outq, m); 368 if (m == NULL) 369 break; 370 371 /* Send as much of it as possible */ 372 while (m != NULL) { 373 length = min(m->m_len, len); 374 memcpy((char *)buf + total, mtod(m, char *), length); 375 376 m->m_data += length; 377 m->m_len -= length; 378 total += length; 379 len -= length; 380 381 if (m->m_len > 0) 382 break; /* device can't take any more */ 383 m = m_free(m); 384 } 385 386 /* Put remainder of mbuf chain (if any) back on queue */ 387 if (m != NULL) { 388 IF_PREPEND(&sc->outq, m); 389 break; 390 } 391 } 392 IF_LOCK(&sc->outq); 393 sc->outqlen -= total; 394 IF_UNLOCK(&sc->outq); 395 MPASS(sc->outqlen >= 0); 396 397 return (total); 398 } 399 400 static size_t 401 ngt_getc_poll(struct tty *tp) 402 { 403 sc_p sc = ttyhook_softc(tp); 404 405 return (sc->outqlen); 406 } 407 408 /* 409 * Optimised TTY input. 410 * 411 * We get a buffer pointer to hopefully a complete data frame. Do not check for 412 * the hotchar, just pass it on. 413 */ 414 static size_t 415 ngt_rint_bypass(struct tty *tp, const void *buf, size_t len) 416 { 417 sc_p sc = ttyhook_softc(tp); 418 node_p node = sc->node; 419 struct mbuf *m, *mb; 420 size_t total = 0; 421 int error = 0, length; 422 423 tty_lock_assert(tp, MA_OWNED); 424 425 if (sc->hook == NULL) 426 return (0); 427 428 m = m_getm2(NULL, len, M_DONTWAIT, MT_DATA, M_PKTHDR); 429 if (m == NULL) { 430 if (sc->flags & FLG_DEBUG) 431 log(LOG_ERR, 432 "%s: can't get mbuf\n", NG_NODE_NAME(node)); 433 return (0); 434 } 435 m->m_pkthdr.rcvif = NULL; 436 437 for (mb = m; mb != NULL; mb = mb->m_next) { 438 length = min(M_TRAILINGSPACE(mb), len - total); 439 440 memcpy(mtod(m, char *), (const char *)buf + total, length); 441 mb->m_len = length; 442 total += length; 443 m->m_pkthdr.len += length; 444 } 445 if (sc->m != NULL) { 446 /* 447 * Odd, we have changed from non-bypass to bypass. It is 448 * unlikely but not impossible, flush the data first. 449 */ 450 sc->m->m_data = sc->m->m_pktdat; 451 NG_SEND_DATA_ONLY(error, sc->hook, sc->m); 452 sc->m = NULL; 453 } 454 NG_SEND_DATA_ONLY(error, sc->hook, m); 455 456 return (total); 457 } 458 459 /* 460 * Receive data coming from the device one char at a time, when it is not in 461 * bypass mode. 462 */ 463 static int 464 ngt_rint(struct tty *tp, char c, int flags) 465 { 466 sc_p sc = ttyhook_softc(tp); 467 node_p node = sc->node; 468 struct mbuf *m; 469 int error = 0; 470 471 tty_lock_assert(tp, MA_OWNED); 472 473 if (sc->hook == NULL) 474 return (0); 475 476 if (flags != 0) { 477 /* framing error or overrun on this char */ 478 if (sc->flags & FLG_DEBUG) 479 log(LOG_DEBUG, "%s: line error %x\n", 480 NG_NODE_NAME(node), flags); 481 return (0); 482 } 483 484 /* Get a new header mbuf if we need one */ 485 if (!(m = sc->m)) { 486 MGETHDR(m, M_DONTWAIT, MT_DATA); 487 if (!m) { 488 if (sc->flags & FLG_DEBUG) 489 log(LOG_ERR, 490 "%s: can't get mbuf\n", NG_NODE_NAME(node)); 491 return (ENOBUFS); 492 } 493 m->m_len = m->m_pkthdr.len = 0; 494 m->m_pkthdr.rcvif = NULL; 495 sc->m = m; 496 } 497 498 /* Add char to mbuf */ 499 *mtod(m, u_char *) = c; 500 m->m_data++; 501 m->m_len++; 502 m->m_pkthdr.len++; 503 504 /* Ship off mbuf if it's time */ 505 if (sc->hotchar == -1 || c == sc->hotchar || m->m_len >= MHLEN) { 506 m->m_data = m->m_pktdat; 507 sc->m = NULL; 508 NG_SEND_DATA_ONLY(error, sc->hook, m); /* Will queue */ 509 } 510 511 return (error); 512 } 513 514 static size_t 515 ngt_rint_poll(struct tty *tp) 516 { 517 /* We can always accept input */ 518 return (1); 519 } 520 521 static void 522 ngt_close(struct tty *tp) 523 { 524 sc_p sc = ttyhook_softc(tp); 525 526 /* Must be queued to drop the tty lock */ 527 ng_rmnode_flags(sc->node, NG_QUEUE); 528 } 529 530