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 * $Whistle: ng_tty.c,v 1.21 1999/11/01 09:24:52 julian Exp $ 42 */ 43 44 /* 45 * This file implements TTY hooks to link in to the netgraph system. The node 46 * is created and then passed the callers opened TTY file descriptor number to 47 * NGM_TTY_SET_TTY, this will hook the tty via ttyhook_register(). 48 * 49 * Incoming data is delivered directly to ng_tty via the TTY bypass hook as a 50 * buffer pointer and length, this is converted to a mbuf and passed to the 51 * peer. 52 * 53 * If the TTY device does not support bypass then incoming characters are 54 * delivered to the hook one at a time, each in its own mbuf. You may 55 * optionally define a ``hotchar,'' which causes incoming characters to be 56 * buffered up until either the hotchar is seen or the mbuf is full (MHLEN 57 * bytes). Then all buffered characters are immediately delivered. 58 */ 59 60 #include <sys/param.h> 61 #include <sys/systm.h> 62 #include <sys/conf.h> 63 #include <sys/errno.h> 64 #include <sys/fcntl.h> 65 #include <sys/ioccom.h> 66 #include <sys/kernel.h> 67 #include <sys/malloc.h> 68 #include <sys/mbuf.h> 69 #include <sys/priv.h> 70 #include <sys/socket.h> 71 #include <sys/syslog.h> 72 #include <sys/tty.h> 73 #include <sys/ttycom.h> 74 #include <sys/proc.h> 75 76 #include <net/if.h> 77 #include <net/if_var.h> 78 79 #include <netgraph/ng_message.h> 80 #include <netgraph/netgraph.h> 81 #include <netgraph/ng_tty.h> 82 83 /* Per-node private info */ 84 struct ngt_softc { 85 struct tty *tp; /* Terminal device */ 86 node_p node; /* Netgraph node */ 87 hook_p hook; /* Netgraph hook */ 88 struct ifqueue outq; /* Queue of outgoing data */ 89 size_t outqlen; /* Number of bytes in outq */ 90 struct mbuf *m; /* Incoming non-bypass data buffer */ 91 short hotchar; /* Hotchar, or -1 if none */ 92 u_int flags; /* Flags */ 93 }; 94 typedef struct ngt_softc *sc_p; 95 96 /* Flags */ 97 #define FLG_DEBUG 0x0002 98 99 /* Netgraph methods */ 100 static ng_constructor_t ngt_constructor; 101 static ng_rcvmsg_t ngt_rcvmsg; 102 static ng_shutdown_t ngt_shutdown; 103 static ng_newhook_t ngt_newhook; 104 static ng_connect_t ngt_connect; 105 static ng_rcvdata_t ngt_rcvdata; 106 static ng_disconnect_t ngt_disconnect; 107 108 #define ERROUT(x) do { error = (x); goto done; } while (0) 109 110 static th_getc_inject_t ngt_getc_inject; 111 static th_getc_poll_t ngt_getc_poll; 112 static th_rint_t ngt_rint; 113 static th_rint_bypass_t ngt_rint_bypass; 114 static th_rint_poll_t ngt_rint_poll; 115 116 static struct ttyhook ngt_hook = { 117 .th_getc_inject = ngt_getc_inject, 118 .th_getc_poll = ngt_getc_poll, 119 .th_rint = ngt_rint, 120 .th_rint_bypass = ngt_rint_bypass, 121 .th_rint_poll = ngt_rint_poll, 122 }; 123 124 /* Netgraph node type descriptor */ 125 static struct ng_type typestruct = { 126 .version = NG_ABI_VERSION, 127 .name = NG_TTY_NODE_TYPE, 128 .constructor = ngt_constructor, 129 .rcvmsg = ngt_rcvmsg, 130 .shutdown = ngt_shutdown, 131 .newhook = ngt_newhook, 132 .connect = ngt_connect, 133 .rcvdata = ngt_rcvdata, 134 .disconnect = ngt_disconnect, 135 }; 136 NETGRAPH_INIT(tty, &typestruct); 137 138 #define NGTLOCK(sc) IF_LOCK(&sc->outq) 139 #define NGTUNLOCK(sc) IF_UNLOCK(&sc->outq) 140 141 /****************************************************************** 142 NETGRAPH NODE METHODS 143 ******************************************************************/ 144 145 /* 146 * Initialize a new node of this type. 147 * 148 * We only allow nodes to be created as a result of setting 149 * the line discipline on a tty, so always return an error if not. 150 */ 151 static int 152 ngt_constructor(node_p node) 153 { 154 sc_p sc; 155 156 /* Allocate private structure */ 157 sc = malloc(sizeof(*sc), M_NETGRAPH, M_WAITOK | M_ZERO); 158 159 NG_NODE_SET_PRIVATE(node, sc); 160 sc->node = node; 161 162 mtx_init(&sc->outq.ifq_mtx, "ng_tty node+queue", NULL, MTX_DEF); 163 IFQ_SET_MAXLEN(&sc->outq, ifqmaxlen); 164 165 return (0); 166 } 167 168 /* 169 * Add a new hook. There can only be one. 170 */ 171 static int 172 ngt_newhook(node_p node, hook_p hook, const char *name) 173 { 174 const sc_p sc = NG_NODE_PRIVATE(node); 175 176 if (strcmp(name, NG_TTY_HOOK)) 177 return (EINVAL); 178 179 if (sc->hook) 180 return (EISCONN); 181 182 NGTLOCK(sc); 183 sc->hook = hook; 184 NGTUNLOCK(sc); 185 186 return (0); 187 } 188 189 /* 190 * Set the hook into queueing mode (for outgoing packets), 191 * so that we wont deliver mbuf through the whole graph holding 192 * tty locks. 193 */ 194 static int 195 ngt_connect(hook_p hook) 196 { 197 NG_HOOK_FORCE_QUEUE(hook); 198 return (0); 199 } 200 201 /* 202 * Disconnect the hook 203 */ 204 static int 205 ngt_disconnect(hook_p hook) 206 { 207 const sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook)); 208 209 if (hook != sc->hook) 210 panic("%s", __func__); 211 212 NGTLOCK(sc); 213 sc->hook = NULL; 214 NGTUNLOCK(sc); 215 216 return (0); 217 } 218 219 /* 220 * Remove this node. The does the netgraph portion of the shutdown. 221 */ 222 static int 223 ngt_shutdown(node_p node) 224 { 225 const sc_p sc = NG_NODE_PRIVATE(node); 226 struct tty *tp; 227 228 tp = sc->tp; 229 if (tp != NULL) { 230 tty_lock(tp); 231 ttyhook_unregister(tp); 232 } 233 /* Free resources */ 234 IF_DRAIN(&sc->outq); 235 mtx_destroy(&(sc)->outq.ifq_mtx); 236 NG_NODE_UNREF(sc->node); 237 free(sc, M_NETGRAPH); 238 239 return (0); 240 } 241 242 /* 243 * Receive control message 244 */ 245 static int 246 ngt_rcvmsg(node_p node, item_p item, hook_p lasthook) 247 { 248 struct proc *p; 249 const sc_p sc = NG_NODE_PRIVATE(node); 250 struct ng_mesg *msg, *resp = NULL; 251 int error = 0; 252 253 NGI_GET_MSG(item, msg); 254 switch (msg->header.typecookie) { 255 case NGM_TTY_COOKIE: 256 switch (msg->header.cmd) { 257 case NGM_TTY_SET_TTY: 258 if (sc->tp != NULL) 259 return (EBUSY); 260 261 p = pfind(((int *)msg->data)[0]); 262 if (p == NULL || (p->p_flag & P_WEXIT)) 263 return (ESRCH); 264 _PHOLD(p); 265 PROC_UNLOCK(p); 266 error = ttyhook_register(&sc->tp, p, ((int *)msg->data)[1], 267 &ngt_hook, sc); 268 PRELE(p); 269 if (error != 0) 270 return (error); 271 break; 272 case NGM_TTY_SET_HOTCHAR: 273 { 274 int hotchar; 275 276 if (msg->header.arglen != sizeof(int)) 277 ERROUT(EINVAL); 278 hotchar = *((int *) msg->data); 279 if (hotchar != (u_char) hotchar && hotchar != -1) 280 ERROUT(EINVAL); 281 sc->hotchar = hotchar; /* race condition is OK */ 282 break; 283 } 284 case NGM_TTY_GET_HOTCHAR: 285 NG_MKRESPONSE(resp, msg, sizeof(int), M_NOWAIT); 286 if (!resp) 287 ERROUT(ENOMEM); 288 /* Race condition here is OK */ 289 *((int *) resp->data) = sc->hotchar; 290 break; 291 default: 292 ERROUT(EINVAL); 293 } 294 break; 295 default: 296 ERROUT(EINVAL); 297 } 298 done: 299 NG_RESPOND_MSG(error, node, item, resp); 300 NG_FREE_MSG(msg); 301 return (error); 302 } 303 304 /* 305 * Receive incoming data from netgraph system. Put it on our 306 * output queue and start output if necessary. 307 */ 308 static int 309 ngt_rcvdata(hook_p hook, item_p item) 310 { 311 const sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook)); 312 struct tty *tp = sc->tp; 313 struct mbuf *m; 314 315 if (hook != sc->hook) 316 panic("%s", __func__); 317 318 NGI_GET_M(item, m); 319 NG_FREE_ITEM(item); 320 321 if (tp == NULL) { 322 NG_FREE_M(m); 323 return (ENXIO); 324 } 325 326 IF_LOCK(&sc->outq); 327 if (_IF_QFULL(&sc->outq)) { 328 IF_UNLOCK(&sc->outq); 329 NG_FREE_M(m); 330 return (ENOBUFS); 331 } 332 333 _IF_ENQUEUE(&sc->outq, m); 334 sc->outqlen += m->m_pkthdr.len; 335 IF_UNLOCK(&sc->outq); 336 337 /* notify the TTY that data is ready */ 338 tty_lock(tp); 339 if (!tty_gone(tp)) 340 ttydevsw_outwakeup(tp); 341 tty_unlock(tp); 342 343 return (0); 344 } 345 346 static size_t 347 ngt_getc_inject(struct tty *tp, void *buf, size_t len) 348 { 349 sc_p sc = ttyhook_softc(tp); 350 size_t total = 0; 351 int length; 352 353 while (len) { 354 struct mbuf *m; 355 356 /* Remove first mbuf from queue */ 357 IF_DEQUEUE(&sc->outq, m); 358 if (m == NULL) 359 break; 360 361 /* Send as much of it as possible */ 362 while (m != NULL) { 363 length = min(m->m_len, len); 364 memcpy((char *)buf + total, mtod(m, char *), length); 365 366 m->m_data += length; 367 m->m_len -= length; 368 total += length; 369 len -= length; 370 371 if (m->m_len > 0) 372 break; /* device can't take any more */ 373 m = m_free(m); 374 } 375 376 /* Put remainder of mbuf chain (if any) back on queue */ 377 if (m != NULL) { 378 IF_PREPEND(&sc->outq, m); 379 break; 380 } 381 } 382 IF_LOCK(&sc->outq); 383 sc->outqlen -= total; 384 IF_UNLOCK(&sc->outq); 385 MPASS(sc->outqlen >= 0); 386 387 return (total); 388 } 389 390 static size_t 391 ngt_getc_poll(struct tty *tp) 392 { 393 sc_p sc = ttyhook_softc(tp); 394 395 return (sc->outqlen); 396 } 397 398 /* 399 * Optimised TTY input. 400 * 401 * We get a buffer pointer to hopefully a complete data frame. Do not check for 402 * the hotchar, just pass it on. 403 */ 404 static size_t 405 ngt_rint_bypass(struct tty *tp, const void *buf, size_t len) 406 { 407 sc_p sc = ttyhook_softc(tp); 408 node_p node = sc->node; 409 struct mbuf *m, *mb; 410 size_t total = 0; 411 int error = 0, length; 412 413 tty_assert_locked(tp); 414 415 if (sc->hook == NULL) 416 return (0); 417 418 m = m_getm2(NULL, len, M_NOWAIT, MT_DATA, M_PKTHDR); 419 if (m == NULL) { 420 if (sc->flags & FLG_DEBUG) 421 log(LOG_ERR, 422 "%s: can't get mbuf\n", NG_NODE_NAME(node)); 423 return (0); 424 } 425 m->m_pkthdr.rcvif = NULL; 426 427 for (mb = m; mb != NULL; mb = mb->m_next) { 428 length = min(M_TRAILINGSPACE(mb), len - total); 429 430 memcpy(mtod(m, char *), (const char *)buf + total, length); 431 mb->m_len = length; 432 total += length; 433 m->m_pkthdr.len += length; 434 } 435 if (sc->m != NULL) { 436 /* 437 * Odd, we have changed from non-bypass to bypass. It is 438 * unlikely but not impossible, flush the data first. 439 */ 440 NG_SEND_DATA_ONLY(error, sc->hook, sc->m); 441 sc->m = NULL; 442 } 443 NG_SEND_DATA_ONLY(error, sc->hook, m); 444 445 return (total); 446 } 447 448 /* 449 * Receive data coming from the device one char at a time, when it is not in 450 * bypass mode. 451 */ 452 static int 453 ngt_rint(struct tty *tp, char c, int flags) 454 { 455 sc_p sc = ttyhook_softc(tp); 456 node_p node = sc->node; 457 struct mbuf *m; 458 int error = 0; 459 460 tty_assert_locked(tp); 461 462 if (sc->hook == NULL) 463 return (0); 464 465 if (flags != 0) { 466 /* framing error or overrun on this char */ 467 if (sc->flags & FLG_DEBUG) 468 log(LOG_DEBUG, "%s: line error %x\n", 469 NG_NODE_NAME(node), flags); 470 return (0); 471 } 472 473 /* Get a new header mbuf if we need one */ 474 if (!(m = sc->m)) { 475 MGETHDR(m, M_NOWAIT, MT_DATA); 476 if (!m) { 477 if (sc->flags & FLG_DEBUG) 478 log(LOG_ERR, 479 "%s: can't get mbuf\n", NG_NODE_NAME(node)); 480 return (ENOBUFS); 481 } 482 m->m_len = m->m_pkthdr.len = 0; 483 m->m_pkthdr.rcvif = NULL; 484 sc->m = m; 485 } 486 487 /* Add char to mbuf */ 488 *mtod(m, u_char *) = c; 489 m->m_data++; 490 m->m_len++; 491 m->m_pkthdr.len++; 492 493 /* Ship off mbuf if it's time */ 494 if (sc->hotchar == -1 || c == sc->hotchar || m->m_len >= MHLEN) { 495 sc->m = NULL; 496 NG_SEND_DATA_ONLY(error, sc->hook, m); /* Will queue */ 497 } 498 499 return (error); 500 } 501 502 static size_t 503 ngt_rint_poll(struct tty *tp) 504 { 505 /* We can always accept input */ 506 return (1); 507 } 508