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37 * Author: Archie Cobbs <archie@freebsd.org>
39 * $FreeBSD: src/sys/netgraph/ng_tty.c,v 1.7.2.3 2002/02/13 00:43:12 dillon Exp $
40 * $DragonFly: src/sys/netgraph/tty/ng_tty.c,v 1.9 2005/02/17 14:00:00 joerg Exp $
41 * $Whistle: ng_tty.c,v 1.21 1999/11/01 09:24:52 julian Exp $
45 * This file implements a terminal line discipline that is also a
46 * netgraph node. Installing this line discipline on a terminal device
47 * instantiates a new netgraph node of this type, which allows access
48 * to the device via the "hook" hook of the node.
50 * Once the line discipline is installed, you can find out the name
51 * of the corresponding netgraph node via a NGIOCGINFO ioctl().
53 * Incoming characters are delievered to the hook one at a time, each
54 * in its own mbuf. You may optionally define a ``hotchar,'' which causes
55 * incoming characters to be buffered up until either the hotchar is
56 * seen or the mbuf is full (MHLEN bytes). Then all buffered characters
57 * are immediately delivered.
59 * NOTE: This node operates at spltty().
62 #include <sys/param.h>
63 #include <sys/systm.h>
64 #include <sys/kernel.h>
68 #include <sys/malloc.h>
69 #include <sys/fcntl.h>
71 #include <sys/ttycom.h>
72 #include <sys/syslog.h>
73 #include <sys/errno.h>
74 #include <sys/ioccom.h>
76 #include <netgraph/ng_message.h>
77 #include <netgraph/netgraph.h>
80 #ifdef __i386__ /* fiddle with the spl locking */
81 #include <machine/ipl.h>
82 #include <i386/isa/intr_machdep.h>
86 #define MAX_MBUFQ 3 /* Max number of queued mbufs */
87 #define NGT_HIWATER 400 /* High water mark on output */
89 /* Per-node private info */
91 struct tty *tp; /* Terminal device */
92 node_p node; /* Netgraph node */
93 hook_p hook; /* Netgraph hook */
94 struct mbuf *m; /* Incoming data buffer */
95 struct mbuf *qhead, **qtail; /* Queue of outgoing mbuf's */
96 short qlen; /* Length of queue */
97 short hotchar; /* Hotchar, or -1 if none */
98 u_int flags; /* Flags */
99 struct callout ctimeout; /* See man timeout(9) */
101 typedef struct ngt_sc *sc_p;
104 #define FLG_TIMEOUT 0x0001 /* A timeout is pending */
105 #define FLG_DEBUG 0x0002
109 #define QUEUECHECK(sc) \
114 for (k = 0, mp = &sc->qhead; \
115 k <= MAX_MBUFQ && *mp; \
116 k++, mp = &(*mp)->m_nextpkt); \
117 if (k != sc->qlen || k > MAX_MBUFQ || *mp || mp != sc->qtail) \
118 panic("%s: queue", __func__); \
121 #define QUEUECHECK(sc) do {} while (0)
124 /* Line discipline methods */
125 static int ngt_open(dev_t dev, struct tty *tp);
126 static int ngt_close(struct tty *tp, int flag);
127 static int ngt_read(struct tty *tp, struct uio *uio, int flag);
128 static int ngt_write(struct tty *tp, struct uio *uio, int flag);
129 static int ngt_tioctl(struct tty *tp,
130 u_long cmd, caddr_t data, int flag, d_thread_t *td);
131 static int ngt_input(int c, struct tty *tp);
132 static int ngt_start(struct tty *tp);
134 /* Netgraph methods */
135 static ng_constructor_t ngt_constructor;
136 static ng_rcvmsg_t ngt_rcvmsg;
137 static ng_shutdown_t ngt_shutdown;
138 static ng_newhook_t ngt_newhook;
139 static ng_rcvdata_t ngt_rcvdata;
140 static ng_disconnect_t ngt_disconnect;
141 static int ngt_mod_event(module_t mod, int event, void *data);
144 static void ngt_timeout(void *arg);
146 #define ERROUT(x) do { error = (x); goto done; } while (0)
148 /* Line discipline descriptor */
149 static struct linesw ngt_disc = {
158 NG_TTY_DFL_HOTCHAR /* XXX can't change this in serial driver */
161 /* Netgraph node type descriptor */
162 static struct ng_type typestruct = {
177 NETGRAPH_INIT(tty, &typestruct);
180 static int ngt_nodeop_ok; /* OK to create/remove node */
181 static int ngt_ldisc;
183 /******************************************************************
184 LINE DISCIPLINE METHODS
185 ******************************************************************/
188 * Set our line discipline on the tty.
189 * Called from device open routine or ttioctl() at >= splsofttty()
192 ngt_open(dev_t dev, struct tty *tp)
194 struct thread *td = curthread; /* XXX */
195 char name[sizeof(NG_TTY_NODE_TYPE) + 8];
199 /* Super-user only */
200 if ((error = suser(td)))
203 (void) spltty(); /* XXX is this necessary? */
205 /* Already installed? */
206 if (tp->t_line == NETGRAPHDISC) {
207 sc = (sc_p) tp->t_sc;
208 if (sc != NULL && sc->tp == tp)
212 /* Initialize private struct */
213 MALLOC(sc, sc_p, sizeof(*sc), M_NETGRAPH, M_WAITOK);
218 bzero(sc, sizeof(*sc));
220 sc->hotchar = NG_TTY_DFL_HOTCHAR;
221 sc->qtail = &sc->qhead;
223 callout_init(&sc->ctimeout);
225 /* Setup netgraph node */
227 error = ng_make_node_common(&typestruct, &sc->node);
230 FREE(sc, M_NETGRAPH);
233 snprintf(name, sizeof(name), "%s%d", typestruct.name, ngt_unit++);
235 /* Set back pointers */
236 sc->node->private = sc;
237 tp->t_sc = (caddr_t) sc;
239 /* Assign node its name */
240 if ((error = ng_name_node(sc->node, name))) {
241 log(LOG_ERR, "%s: node name exists?\n", name);
249 * Pre-allocate cblocks to the an appropriate amount.
250 * I'm not sure what is appropriate.
252 ttyflush(tp, FREAD | FWRITE);
253 clist_alloc_cblocks(&tp->t_canq, 0, 0);
254 clist_alloc_cblocks(&tp->t_rawq, 0, 0);
255 clist_alloc_cblocks(&tp->t_outq,
256 MLEN + NGT_HIWATER, MLEN + NGT_HIWATER);
265 * Line specific close routine, called from device close routine
266 * and from ttioctl at >= splsofttty(). This causes the node to
267 * be destroyed as well.
270 ngt_close(struct tty *tp, int flag)
272 const sc_p sc = (sc_p) tp->t_sc;
276 ttyflush(tp, FREAD | FWRITE);
277 clist_free_cblocks(&tp->t_outq);
280 if (sc->flags & FLG_TIMEOUT) {
281 callout_stop(&sc->ctimeout);
282 sc->flags &= ~FLG_TIMEOUT;
294 * Once the device has been turned into a node, we don't allow reading.
297 ngt_read(struct tty *tp, struct uio *uio, int flag)
303 * Once the device has been turned into a node, we don't allow writing.
306 ngt_write(struct tty *tp, struct uio *uio, int flag)
312 * We implement the NGIOCGINFO ioctl() defined in ng_message.h.
315 ngt_tioctl(struct tty *tp, u_long cmd, caddr_t data, int flag, d_thread_t *td)
317 const sc_p sc = (sc_p) tp->t_sc;
324 struct nodeinfo *const ni = (struct nodeinfo *) data;
325 const node_p node = sc->node;
327 bzero(ni, sizeof(*ni));
329 strncpy(ni->name, node->name, sizeof(ni->name) - 1);
330 strncpy(ni->type, node->type->name, sizeof(ni->type) - 1);
331 ni->id = (u_int32_t) node;
332 ni->hooks = node->numhooks;
344 * Receive data coming from the device. We get one character at
345 * a time, which is kindof silly.
346 * Only guaranteed to be at splsofttty() or spltty().
349 ngt_input(int c, struct tty *tp)
351 const sc_p sc = (sc_p) tp->t_sc;
352 const node_p node = sc->node;
356 if (!sc || tp != sc->tp)
362 /* Check for error conditions */
363 if ((tp->t_state & TS_CONNECTED) == 0) {
364 if (sc->flags & FLG_DEBUG)
365 log(LOG_DEBUG, "%s: no carrier\n", node->name);
368 if (c & TTY_ERRORMASK) {
369 /* framing error or overrun on this char */
370 if (sc->flags & FLG_DEBUG)
371 log(LOG_DEBUG, "%s: line error %x\n",
372 node->name, c & TTY_ERRORMASK);
377 /* Get a new header mbuf if we need one */
379 MGETHDR(m, MB_DONTWAIT, MT_DATA);
381 if (sc->flags & FLG_DEBUG)
383 "%s: can't get mbuf\n", node->name);
386 m->m_len = m->m_pkthdr.len = 0;
387 m->m_pkthdr.rcvif = NULL;
391 /* Add char to mbuf */
392 *mtod(m, u_char *) = c;
397 /* Ship off mbuf if it's time */
398 if (sc->hotchar == -1 || c == sc->hotchar || m->m_len >= MHLEN) {
399 m->m_data = m->m_pktdat;
400 error = ng_queue_data(sc->hook, m, NULL);
409 * This is called when the device driver is ready for more output.
410 * Called from tty system at splsofttty() or spltty().
411 * Also call from ngt_rcv_data() when a new mbuf is available for output.
414 ngt_start(struct tty *tp)
416 const sc_p sc = (sc_p) tp->t_sc;
420 while (tp->t_outq.c_cc < NGT_HIWATER) { /* XXX 2.2 specific ? */
421 struct mbuf *m = sc->qhead;
423 /* Remove first mbuf from queue */
426 if ((sc->qhead = m->m_nextpkt) == NULL)
427 sc->qtail = &sc->qhead;
431 /* Send as much of it as possible */
436 - b_to_q(mtod(m, u_char *), m->m_len, &tp->t_outq);
440 break; /* device can't take no more */
444 /* Put remainder of mbuf chain (if any) back on queue */
446 m->m_nextpkt = sc->qhead;
448 if (sc->qtail == &sc->qhead)
449 sc->qtail = &m->m_nextpkt;
456 /* Call output process whether or not there is any output. We are
457 * being called in lieu of ttstart and must do what it would. */
458 if (tp->t_oproc != NULL)
461 /* This timeout is needed for operation on a pseudo-tty, because the
462 * pty code doesn't call pppstart after it has drained the t_outq. */
463 if (sc->qhead && (sc->flags & FLG_TIMEOUT) == 0) {
464 callout_reset(&sc->ctimeout, 1, ngt_timeout, sc);
465 sc->flags |= FLG_TIMEOUT;
472 * We still have data to output to the device, so try sending more.
475 ngt_timeout(void *arg)
477 const sc_p sc = (sc_p) arg;
481 sc->flags &= ~FLG_TIMEOUT;
486 /******************************************************************
487 NETGRAPH NODE METHODS
488 ******************************************************************/
491 * Initialize a new node of this type.
493 * We only allow nodes to be created as a result of setting
494 * the line discipline on a tty, so always return an error if not.
497 ngt_constructor(node_p *nodep)
501 return (ng_make_node_common(&typestruct, nodep));
505 * Add a new hook. There can only be one.
508 ngt_newhook(node_p node, hook_p hook, const char *name)
510 const sc_p sc = node->private;
513 if (strcmp(name, NG_TTY_HOOK))
525 * Disconnect the hook
528 ngt_disconnect(hook_p hook)
530 const sc_p sc = hook->node->private;
534 if (hook != sc->hook)
544 * Remove this node. The does the netgraph portion of the shutdown.
545 * This should only be called indirectly from ngt_close().
548 ngt_shutdown(node_p node)
550 const sc_p sc = node->private;
556 node->private = NULL;
560 bzero(sc, sizeof(*sc));
561 FREE(sc, M_NETGRAPH);
566 * Receive incoming data from netgraph system. Put it on our
567 * output queue and start output if necessary.
570 ngt_rcvdata(hook_p hook, struct mbuf *m, meta_p meta)
572 const sc_p sc = hook->node->private;
575 if (hook != sc->hook)
579 if (sc->qlen >= MAX_MBUFQ)
583 sc->qtail = &m->m_nextpkt;
597 * Receive control message
600 ngt_rcvmsg(node_p node, struct ng_mesg *msg, const char *retaddr,
601 struct ng_mesg **rptr)
603 const sc_p sc = (sc_p) node->private;
604 struct ng_mesg *resp = NULL;
607 switch (msg->header.typecookie) {
609 switch (msg->header.cmd) {
610 case NGM_TTY_SET_HOTCHAR:
614 if (msg->header.arglen != sizeof(int))
616 hotchar = *((int *) msg->data);
617 if (hotchar != (u_char) hotchar && hotchar != -1)
619 sc->hotchar = hotchar; /* race condition is OK */
622 case NGM_TTY_GET_HOTCHAR:
623 NG_MKRESPONSE(resp, msg, sizeof(int), M_NOWAIT);
626 /* Race condition here is OK */
627 *((int *) resp->data) = sc->hotchar;
639 FREE(resp, M_NETGRAPH);
642 FREE(msg, M_NETGRAPH);
646 /******************************************************************
648 ******************************************************************/
651 * Handle loading and unloading for this node type
654 ngt_mod_event(module_t mod, int event, void *data)
656 /* struct ng_type *const type = data;*/
662 /* Insure the soft net "engine" can't run during spltty code */
664 tty_imask |= softnet_imask; /* spltty() block spl[soft]net() */
665 net_imask |= softtty_imask; /* splimp() block splsofttty() */
666 net_imask |= tty_imask; /* splimp() block spltty() */
671 log(LOG_DEBUG, "new masks: bio %x, tty %x, net %x\n",
672 bio_imask, tty_imask, net_imask);
675 /* Register line discipline */
677 if ((ngt_ldisc = ldisc_register(NETGRAPHDISC, &ngt_disc)) < 0) {
679 log(LOG_ERR, "%s: can't register line discipline",
688 /* Unregister line discipline */
690 ldisc_deregister(ngt_ldisc);