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 #include <sys/proc.h> 77 78 #include <net/if.h> 79 #include <net/if_var.h> 80 81 #include <netgraph/ng_message.h> 82 #include <netgraph/netgraph.h> 83 #include <netgraph/ng_tty.h> 84 85 /* Per-node private info */ 86 struct ngt_softc { 87 struct tty *tp; /* Terminal device */ 88 node_p node; /* Netgraph node */ 89 hook_p hook; /* Netgraph hook */ 90 struct ifqueue outq; /* Queue of outgoing data */ 91 size_t outqlen; /* Number of bytes in outq */ 92 struct mbuf *m; /* Incoming non-bypass data buffer */ 93 short hotchar; /* Hotchar, or -1 if none */ 94 u_int flags; /* Flags */ 95 }; 96 typedef struct ngt_softc *sc_p; 97 98 /* Flags */ 99 #define FLG_DEBUG 0x0002 100 101 /* Netgraph methods */ 102 static ng_constructor_t ngt_constructor; 103 static ng_rcvmsg_t ngt_rcvmsg; 104 static ng_shutdown_t ngt_shutdown; 105 static ng_newhook_t ngt_newhook; 106 static ng_connect_t ngt_connect; 107 static ng_rcvdata_t ngt_rcvdata; 108 static ng_disconnect_t ngt_disconnect; 109 110 #define ERROUT(x) do { error = (x); goto done; } while (0) 111 112 static th_getc_inject_t ngt_getc_inject; 113 static th_getc_poll_t ngt_getc_poll; 114 static th_rint_t ngt_rint; 115 static th_rint_bypass_t ngt_rint_bypass; 116 static th_rint_poll_t ngt_rint_poll; 117 118 static struct ttyhook ngt_hook = { 119 .th_getc_inject = ngt_getc_inject, 120 .th_getc_poll = ngt_getc_poll, 121 .th_rint = ngt_rint, 122 .th_rint_bypass = ngt_rint_bypass, 123 .th_rint_poll = ngt_rint_poll, 124 }; 125 126 /* Netgraph node type descriptor */ 127 static struct ng_type typestruct = { 128 .version = NG_ABI_VERSION, 129 .name = NG_TTY_NODE_TYPE, 130 .constructor = ngt_constructor, 131 .rcvmsg = ngt_rcvmsg, 132 .shutdown = ngt_shutdown, 133 .newhook = ngt_newhook, 134 .connect = ngt_connect, 135 .rcvdata = ngt_rcvdata, 136 .disconnect = ngt_disconnect, 137 }; 138 NETGRAPH_INIT(tty, &typestruct); 139 140 #define NGTLOCK(sc) IF_LOCK(&sc->outq) 141 #define NGTUNLOCK(sc) IF_UNLOCK(&sc->outq) 142 143 /****************************************************************** 144 NETGRAPH NODE METHODS 145 ******************************************************************/ 146 147 /* 148 * Initialize a new node of this type. 149 * 150 * We only allow nodes to be created as a result of setting 151 * the line discipline on a tty, so always return an error if not. 152 */ 153 static int 154 ngt_constructor(node_p node) 155 { 156 sc_p sc; 157 158 /* Allocate private structure */ 159 sc = malloc(sizeof(*sc), M_NETGRAPH, M_WAITOK | M_ZERO); 160 161 NG_NODE_SET_PRIVATE(node, sc); 162 sc->node = node; 163 164 mtx_init(&sc->outq.ifq_mtx, "ng_tty node+queue", NULL, MTX_DEF); 165 IFQ_SET_MAXLEN(&sc->outq, ifqmaxlen); 166 167 return (0); 168 } 169 170 /* 171 * Add a new hook. There can only be one. 172 */ 173 static int 174 ngt_newhook(node_p node, hook_p hook, const char *name) 175 { 176 const sc_p sc = NG_NODE_PRIVATE(node); 177 178 if (strcmp(name, NG_TTY_HOOK)) 179 return (EINVAL); 180 181 if (sc->hook) 182 return (EISCONN); 183 184 NGTLOCK(sc); 185 sc->hook = hook; 186 NGTUNLOCK(sc); 187 188 return (0); 189 } 190 191 /* 192 * Set the hook into queueing mode (for outgoing packets), 193 * so that we wont deliver mbuf thru the whole graph holding 194 * tty locks. 195 */ 196 static int 197 ngt_connect(hook_p hook) 198 { 199 NG_HOOK_FORCE_QUEUE(hook); 200 return (0); 201 } 202 203 /* 204 * Disconnect the hook 205 */ 206 static int 207 ngt_disconnect(hook_p hook) 208 { 209 const sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook)); 210 211 if (hook != sc->hook) 212 panic("%s", __func__); 213 214 NGTLOCK(sc); 215 sc->hook = NULL; 216 NGTUNLOCK(sc); 217 218 return (0); 219 } 220 221 /* 222 * Remove this node. The does the netgraph portion of the shutdown. 223 */ 224 static int 225 ngt_shutdown(node_p node) 226 { 227 const sc_p sc = NG_NODE_PRIVATE(node); 228 struct tty *tp; 229 230 tp = sc->tp; 231 if (tp != NULL) { 232 tty_lock(tp); 233 ttyhook_unregister(tp); 234 } 235 /* Free resources */ 236 IF_DRAIN(&sc->outq); 237 mtx_destroy(&(sc)->outq.ifq_mtx); 238 NG_NODE_UNREF(sc->node); 239 free(sc, M_NETGRAPH); 240 241 return (0); 242 } 243 244 /* 245 * Receive control message 246 */ 247 static int 248 ngt_rcvmsg(node_p node, item_p item, hook_p lasthook) 249 { 250 struct proc *p; 251 const sc_p sc = NG_NODE_PRIVATE(node); 252 struct ng_mesg *msg, *resp = NULL; 253 int error = 0; 254 255 NGI_GET_MSG(item, msg); 256 switch (msg->header.typecookie) { 257 case NGM_TTY_COOKIE: 258 switch (msg->header.cmd) { 259 case NGM_TTY_SET_TTY: 260 if (sc->tp != NULL) 261 return (EBUSY); 262 263 p = pfind(((int *)msg->data)[0]); 264 if (p == NULL || (p->p_flag & P_WEXIT)) 265 return (ESRCH); 266 _PHOLD(p); 267 PROC_UNLOCK(p); 268 error = ttyhook_register(&sc->tp, p, ((int *)msg->data)[1], 269 &ngt_hook, sc); 270 PRELE(p); 271 if (error != 0) 272 return (error); 273 break; 274 case NGM_TTY_SET_HOTCHAR: 275 { 276 int hotchar; 277 278 if (msg->header.arglen != sizeof(int)) 279 ERROUT(EINVAL); 280 hotchar = *((int *) msg->data); 281 if (hotchar != (u_char) hotchar && hotchar != -1) 282 ERROUT(EINVAL); 283 sc->hotchar = hotchar; /* race condition is OK */ 284 break; 285 } 286 case NGM_TTY_GET_HOTCHAR: 287 NG_MKRESPONSE(resp, msg, sizeof(int), M_NOWAIT); 288 if (!resp) 289 ERROUT(ENOMEM); 290 /* Race condition here is OK */ 291 *((int *) resp->data) = sc->hotchar; 292 break; 293 default: 294 ERROUT(EINVAL); 295 } 296 break; 297 default: 298 ERROUT(EINVAL); 299 } 300 done: 301 NG_RESPOND_MSG(error, node, item, resp); 302 NG_FREE_MSG(msg); 303 return (error); 304 } 305 306 /* 307 * Receive incoming data from netgraph system. Put it on our 308 * output queue and start output if necessary. 309 */ 310 static int 311 ngt_rcvdata(hook_p hook, item_p item) 312 { 313 const sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook)); 314 struct tty *tp = sc->tp; 315 struct mbuf *m; 316 317 if (hook != sc->hook) 318 panic("%s", __func__); 319 320 NGI_GET_M(item, m); 321 NG_FREE_ITEM(item); 322 323 if (tp == NULL) { 324 NG_FREE_M(m); 325 return (ENXIO); 326 } 327 328 IF_LOCK(&sc->outq); 329 if (_IF_QFULL(&sc->outq)) { 330 _IF_DROP(&sc->outq); 331 IF_UNLOCK(&sc->outq); 332 NG_FREE_M(m); 333 return (ENOBUFS); 334 } 335 336 _IF_ENQUEUE(&sc->outq, m); 337 sc->outqlen += m->m_pkthdr.len; 338 IF_UNLOCK(&sc->outq); 339 340 /* notify the TTY that data is ready */ 341 tty_lock(tp); 342 if (!tty_gone(tp)) 343 ttydevsw_outwakeup(tp); 344 tty_unlock(tp); 345 346 return (0); 347 } 348 349 static size_t 350 ngt_getc_inject(struct tty *tp, void *buf, size_t len) 351 { 352 sc_p sc = ttyhook_softc(tp); 353 size_t total = 0; 354 int length; 355 356 while (len) { 357 struct mbuf *m; 358 359 /* Remove first mbuf from queue */ 360 IF_DEQUEUE(&sc->outq, m); 361 if (m == NULL) 362 break; 363 364 /* Send as much of it as possible */ 365 while (m != NULL) { 366 length = min(m->m_len, len); 367 memcpy((char *)buf + total, mtod(m, char *), length); 368 369 m->m_data += length; 370 m->m_len -= length; 371 total += length; 372 len -= length; 373 374 if (m->m_len > 0) 375 break; /* device can't take any more */ 376 m = m_free(m); 377 } 378 379 /* Put remainder of mbuf chain (if any) back on queue */ 380 if (m != NULL) { 381 IF_PREPEND(&sc->outq, m); 382 break; 383 } 384 } 385 IF_LOCK(&sc->outq); 386 sc->outqlen -= total; 387 IF_UNLOCK(&sc->outq); 388 MPASS(sc->outqlen >= 0); 389 390 return (total); 391 } 392 393 static size_t 394 ngt_getc_poll(struct tty *tp) 395 { 396 sc_p sc = ttyhook_softc(tp); 397 398 return (sc->outqlen); 399 } 400 401 /* 402 * Optimised TTY input. 403 * 404 * We get a buffer pointer to hopefully a complete data frame. Do not check for 405 * the hotchar, just pass it on. 406 */ 407 static size_t 408 ngt_rint_bypass(struct tty *tp, const void *buf, size_t len) 409 { 410 sc_p sc = ttyhook_softc(tp); 411 node_p node = sc->node; 412 struct mbuf *m, *mb; 413 size_t total = 0; 414 int error = 0, length; 415 416 tty_lock_assert(tp, MA_OWNED); 417 418 if (sc->hook == NULL) 419 return (0); 420 421 m = m_getm2(NULL, len, M_NOWAIT, MT_DATA, M_PKTHDR); 422 if (m == NULL) { 423 if (sc->flags & FLG_DEBUG) 424 log(LOG_ERR, 425 "%s: can't get mbuf\n", NG_NODE_NAME(node)); 426 return (0); 427 } 428 m->m_pkthdr.rcvif = NULL; 429 430 for (mb = m; mb != NULL; mb = mb->m_next) { 431 length = min(M_TRAILINGSPACE(mb), len - total); 432 433 memcpy(mtod(m, char *), (const char *)buf + total, length); 434 mb->m_len = length; 435 total += length; 436 m->m_pkthdr.len += length; 437 } 438 if (sc->m != NULL) { 439 /* 440 * Odd, we have changed from non-bypass to bypass. It is 441 * unlikely but not impossible, flush the data first. 442 */ 443 sc->m->m_data = sc->m->m_pktdat; 444 NG_SEND_DATA_ONLY(error, sc->hook, sc->m); 445 sc->m = NULL; 446 } 447 NG_SEND_DATA_ONLY(error, sc->hook, m); 448 449 return (total); 450 } 451 452 /* 453 * Receive data coming from the device one char at a time, when it is not in 454 * bypass mode. 455 */ 456 static int 457 ngt_rint(struct tty *tp, char c, int flags) 458 { 459 sc_p sc = ttyhook_softc(tp); 460 node_p node = sc->node; 461 struct mbuf *m; 462 int error = 0; 463 464 tty_lock_assert(tp, MA_OWNED); 465 466 if (sc->hook == NULL) 467 return (0); 468 469 if (flags != 0) { 470 /* framing error or overrun on this char */ 471 if (sc->flags & FLG_DEBUG) 472 log(LOG_DEBUG, "%s: line error %x\n", 473 NG_NODE_NAME(node), flags); 474 return (0); 475 } 476 477 /* Get a new header mbuf if we need one */ 478 if (!(m = sc->m)) { 479 MGETHDR(m, M_NOWAIT, MT_DATA); 480 if (!m) { 481 if (sc->flags & FLG_DEBUG) 482 log(LOG_ERR, 483 "%s: can't get mbuf\n", NG_NODE_NAME(node)); 484 return (ENOBUFS); 485 } 486 m->m_len = m->m_pkthdr.len = 0; 487 m->m_pkthdr.rcvif = NULL; 488 sc->m = m; 489 } 490 491 /* Add char to mbuf */ 492 *mtod(m, u_char *) = c; 493 m->m_data++; 494 m->m_len++; 495 m->m_pkthdr.len++; 496 497 /* Ship off mbuf if it's time */ 498 if (sc->hotchar == -1 || c == sc->hotchar || m->m_len >= MHLEN) { 499 m->m_data = m->m_pktdat; 500 sc->m = NULL; 501 NG_SEND_DATA_ONLY(error, sc->hook, m); /* Will queue */ 502 } 503 504 return (error); 505 } 506 507 static size_t 508 ngt_rint_poll(struct tty *tp) 509 { 510 /* We can always accept input */ 511 return (1); 512 } 513 514