6 * Copyright (c) 1996-1999 Whistle Communications, Inc.
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.
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
38 * Author: Archie Cobbs <archie@freebsd.org>
40 * $FreeBSD: src/sys/netgraph/ng_tty.c,v 1.37 2006/11/06 13:42:03 rwatson Exp $
41 * $DragonFly: src/sys/netgraph7/ng_tty.c,v 1.2 2008/06/26 23:05:35 dillon Exp $
42 * $Whistle: ng_tty.c,v 1.21 1999/11/01 09:24:52 julian Exp $
46 * This file implements a terminal line discipline that is also a
47 * netgraph node. Installing this line discipline on a terminal device
48 * instantiates a new netgraph node of this type, which allows access
49 * to the device via the "hook" hook of the node.
51 * Once the line discipline is installed, you can find out the name
52 * of the corresponding netgraph node via a NGIOCGINFO ioctl().
54 * Incoming characters are delievered to the hook one at a time, each
55 * in its own mbuf. You may optionally define a ``hotchar,'' which causes
56 * incoming characters to be buffered up until either the hotchar is
57 * seen or the mbuf is full (MHLEN bytes). Then all buffered characters
58 * are immediately delivered.
61 #include <sys/param.h>
62 #include <sys/systm.h>
64 #include <sys/errno.h>
65 #include <sys/fcntl.h>
66 #include <sys/ioccom.h>
67 #include <sys/kernel.h>
68 #include <sys/malloc.h>
71 #include <sys/socket.h>
72 #include <sys/syslog.h>
74 #include <sys/ttycom.h>
77 #include <net/if_var.h>
79 #include "ng_message.h"
84 #define MAX_MBUFQ 3 /* Max number of queued mbufs */
85 #define NGT_HIWATER 400 /* High water mark on output */
87 /* Per-node private info */
89 struct tty
*tp
; /* Terminal device */
90 node_p node
; /* Netgraph node */
91 hook_p hook
; /* Netgraph hook */
92 struct ifqueue outq
; /* Queue of outgoing data */
93 struct mbuf
*m
; /* Incoming data buffer */
94 short hotchar
; /* Hotchar, or -1 if none */
95 u_int flags
; /* Flags */
96 struct callout chand
; /* See man timeout(9) */
98 typedef struct ngt_sc
*sc_p
;
101 #define FLG_DEBUG 0x0002
102 #define FLG_DIE 0x0004
104 /* Line discipline methods */
105 static int ngt_open(struct cdev
*dev
, struct tty
*tp
);
106 static int ngt_close(struct tty
*tp
, int flag
);
107 static int ngt_read(struct tty
*tp
, struct uio
*uio
, int flag
);
108 static int ngt_write(struct tty
*tp
, struct uio
*uio
, int flag
);
109 static int ngt_tioctl(struct tty
*tp
,
110 u_long cmd
, caddr_t data
, int flag
, struct thread
*);
111 static int ngt_input(int c
, struct tty
*tp
);
112 static int ngt_start(struct tty
*tp
);
114 /* Netgraph methods */
115 static ng_constructor_t ngt_constructor
;
116 static ng_rcvmsg_t ngt_rcvmsg
;
117 static ng_shutdown_t ngt_shutdown
;
118 static ng_newhook_t ngt_newhook
;
119 static ng_connect_t ngt_connect
;
120 static ng_rcvdata_t ngt_rcvdata
;
121 static ng_disconnect_t ngt_disconnect
;
122 static int ngt_mod_event(module_t mod
, int event
, void *data
);
125 static void ngt_timeout(node_p node
, hook_p hook
, void *arg1
, int arg2
);
127 #define ERROUT(x) do { error = (x); goto done; } while (0)
129 /* Line discipline descriptor */
130 static struct linesw ngt_disc
= {
132 .l_close
= ngt_close
,
134 .l_write
= ngt_write
,
135 .l_ioctl
= ngt_tioctl
,
137 .l_start
= ngt_start
,
141 /* Netgraph node type descriptor */
142 static struct ng_type typestruct
= {
143 .version
= NG_ABI_VERSION
,
144 .name
= NG_TTY_NODE_TYPE
,
145 .mod_event
= ngt_mod_event
,
146 .constructor
= ngt_constructor
,
147 .rcvmsg
= ngt_rcvmsg
,
148 .shutdown
= ngt_shutdown
,
149 .newhook
= ngt_newhook
,
150 .connect
= ngt_connect
,
151 .rcvdata
= ngt_rcvdata
,
152 .disconnect
= ngt_disconnect
,
154 NETGRAPH_INIT(tty
, &typestruct
);
159 * - node private data and tp->t_lsc is protected by mutex in struct
160 * ifqueue, locking is done using IF_XXX() macros.
161 * - in all tty methods we should acquire node ifqueue mutex, when accessing
163 * - in _rcvdata() we should use locked versions of IF_{EN,DE}QUEUE() since
164 * we may have multiple _rcvdata() threads.
165 * - when calling any of tty methods from netgraph methods, we should
166 * acquire tty locking (now Giant).
168 * - ngt_unit is incremented atomically.
171 #define NGTLOCK(sc) IF_LOCK(&sc->outq)
172 #define NGTUNLOCK(sc) IF_UNLOCK(&sc->outq)
175 static int ngt_ldisc
;
177 /******************************************************************
178 LINE DISCIPLINE METHODS
179 ******************************************************************/
182 * Set our line discipline on the tty.
183 * Called from device open routine or ttioctl()
186 ngt_open(struct cdev
*dev
, struct tty
*tp
)
188 struct thread
*const td
= curthread
; /* XXX */
189 char name
[sizeof(NG_TTY_NODE_TYPE
) + 8];
193 /* Super-user only */
194 error
= priv_check(td
, PRIV_NETGRAPH_TTY
);
198 /* Initialize private struct */
199 MALLOC(sc
, sc_p
, sizeof(*sc
), M_NETGRAPH
, M_WAITOK
| M_ZERO
);
204 sc
->hotchar
= tp
->t_hotchar
= NG_TTY_DFL_HOTCHAR
;
205 mtx_init(&sc
->outq
.ifq_mtx
, "ng_tty node+queue", NULL
, MTX_DEF
);
206 IFQ_SET_MAXLEN(&sc
->outq
, MAX_MBUFQ
);
210 /* Setup netgraph node */
211 error
= ng_make_node_common(&typestruct
, &sc
->node
);
214 FREE(sc
, M_NETGRAPH
);
218 atomic_add_int(&ngt_unit
, 1);
219 snprintf(name
, sizeof(name
), "%s%d", typestruct
.name
, ngt_unit
);
221 /* Assign node its name */
222 if ((error
= ng_name_node(sc
->node
, name
))) {
223 sc
->flags
|= FLG_DIE
;
225 NG_NODE_UNREF(sc
->node
);
226 log(LOG_ERR
, "%s: node name exists?\n", name
);
230 /* Set back pointers */
231 NG_NODE_SET_PRIVATE(sc
->node
, sc
);
234 ng_callout_init(&sc
->chand
);
237 * Pre-allocate cblocks to the an appropriate amount.
238 * I'm not sure what is appropriate.
240 ttyflush(tp
, FREAD
| FWRITE
);
241 clist_alloc_cblocks(&tp
->t_canq
, 0, 0);
242 clist_alloc_cblocks(&tp
->t_rawq
, 0, 0);
243 clist_alloc_cblocks(&tp
->t_outq
,
244 MLEN
+ NGT_HIWATER
, MLEN
+ NGT_HIWATER
);
252 * Line specific close routine, called from device close routine
253 * and from ttioctl. This causes the node to be destroyed as well.
256 ngt_close(struct tty
*tp
, int flag
)
258 const sc_p sc
= (sc_p
) tp
->t_lsc
;
260 ttyflush(tp
, FREAD
| FWRITE
);
261 clist_free_cblocks(&tp
->t_outq
);
264 if (callout_pending(&sc
->chand
))
265 ng_uncallout(&sc
->chand
, sc
->node
);
267 sc
->flags
|= FLG_DIE
;
269 ng_rmnode_self(sc
->node
);
275 * Once the device has been turned into a node, we don't allow reading.
278 ngt_read(struct tty
*tp
, struct uio
*uio
, int flag
)
284 * Once the device has been turned into a node, we don't allow writing.
287 ngt_write(struct tty
*tp
, struct uio
*uio
, int flag
)
293 * We implement the NGIOCGINFO ioctl() defined in ng_message.h.
296 ngt_tioctl(struct tty
*tp
, u_long cmd
, caddr_t data
, int flag
, struct thread
*td
)
298 const sc_p sc
= (sc_p
) tp
->t_lsc
;
301 /* No node attached */
307 struct nodeinfo
*const ni
= (struct nodeinfo
*) data
;
308 const node_p node
= sc
->node
;
310 bzero(ni
, sizeof(*ni
));
312 if (NG_NODE_HAS_NAME(node
))
313 strncpy(ni
->name
, NG_NODE_NAME(node
), sizeof(ni
->name
) - 1);
314 strncpy(ni
->type
, node
->nd_type
->name
, sizeof(ni
->type
) - 1);
315 ni
->id
= (u_int32_t
) ng_node2ID(node
);
316 ni
->hooks
= NG_NODE_NUMHOOKS(node
);
328 * Receive data coming from the device. We get one character at
329 * a time, which is kindof silly.
331 * Full locking of softc is not required, since we are the only
335 ngt_input(int c
, struct tty
*tp
)
342 sc
= (sc_p
) tp
->t_lsc
;
344 /* No node attached */
352 /* Check for error conditions */
353 if ((tp
->t_state
& TS_CONNECTED
) == 0) {
354 if (sc
->flags
& FLG_DEBUG
)
355 log(LOG_DEBUG
, "%s: no carrier\n", NG_NODE_NAME(node
));
358 if (c
& TTY_ERRORMASK
) {
359 /* framing error or overrun on this char */
360 if (sc
->flags
& FLG_DEBUG
)
361 log(LOG_DEBUG
, "%s: line error %x\n",
362 NG_NODE_NAME(node
), c
& TTY_ERRORMASK
);
367 /* Get a new header mbuf if we need one */
369 MGETHDR(m
, MB_DONTWAIT
, MT_DATA
);
371 if (sc
->flags
& FLG_DEBUG
)
373 "%s: can't get mbuf\n", NG_NODE_NAME(node
));
376 m
->m_len
= m
->m_pkthdr
.len
= 0;
377 m
->m_pkthdr
.rcvif
= NULL
;
381 /* Add char to mbuf */
382 *mtod(m
, u_char
*) = c
;
387 /* Ship off mbuf if it's time */
388 if (sc
->hotchar
== -1 || c
== sc
->hotchar
|| m
->m_len
>= MHLEN
) {
389 m
->m_data
= m
->m_pktdat
;
393 * We have built our mbuf without checking that we actually
394 * have a hook to send it. This was done to avoid
395 * acquiring mutex on each character. Check now.
400 if (sc
->hook
== NULL
) {
403 return (0); /* XXX: original behavior */
405 NG_SEND_DATA_ONLY(error
, sc
->hook
, m
); /* Will queue */
413 * This is called when the device driver is ready for more output.
414 * Also called from ngt_rcv_data() when a new mbuf is available for output.
417 ngt_start(struct tty
*tp
)
419 const sc_p sc
= (sc_p
) tp
->t_lsc
;
421 while (tp
->t_outq
.c_cc
< NGT_HIWATER
) { /* XXX 2.2 specific ? */
424 /* Remove first mbuf from queue */
425 IF_DEQUEUE(&sc
->outq
, m
);
429 /* Send as much of it as possible */
434 - b_to_q(mtod(m
, u_char
*), m
->m_len
, &tp
->t_outq
);
438 break; /* device can't take no more */
442 /* Put remainder of mbuf chain (if any) back on queue */
444 IF_PREPEND(&sc
->outq
, m
);
449 /* Call output process whether or not there is any output. We are
450 * being called in lieu of ttstart and must do what it would. */
453 /* This timeout is needed for operation on a pseudo-tty, because the
454 * pty code doesn't call pppstart after it has drained the t_outq. */
455 /* XXX: outq not locked */
456 if (!IFQ_IS_EMPTY(&sc
->outq
) && !callout_pending(&sc
->chand
))
457 ng_callout(&sc
->chand
, sc
->node
, NULL
, 1, ngt_timeout
, NULL
, 0);
463 * We still have data to output to the device, so try sending more.
466 ngt_timeout(node_p node
, hook_p hook
, void *arg1
, int arg2
)
468 const sc_p sc
= NG_NODE_PRIVATE(node
);
475 /******************************************************************
476 NETGRAPH NODE METHODS
477 ******************************************************************/
480 * Initialize a new node of this type.
482 * We only allow nodes to be created as a result of setting
483 * the line discipline on a tty, so always return an error if not.
486 ngt_constructor(node_p node
)
492 * Add a new hook. There can only be one.
495 ngt_newhook(node_p node
, hook_p hook
, const char *name
)
497 const sc_p sc
= NG_NODE_PRIVATE(node
);
499 if (strcmp(name
, NG_TTY_HOOK
))
513 * Set the hook into queueing mode (for outgoing packets),
514 * so that we wont deliver mbuf thru the whole graph holding
518 ngt_connect(hook_p hook
)
520 NG_HOOK_FORCE_QUEUE(NG_HOOK_PEER(hook
));
522 * XXX: While ngt_start() is Giant-locked, queue incoming
523 * packets, too. Otherwise we acquire Giant holding some
524 * IP stack locks, e.g. divinp, and this makes WITNESS scream.
526 NG_HOOK_FORCE_QUEUE(hook
);
531 * Disconnect the hook
534 ngt_disconnect(hook_p hook
)
536 const sc_p sc
= NG_NODE_PRIVATE(NG_HOOK_NODE(hook
));
538 if (hook
!= sc
->hook
)
549 * Remove this node. The does the netgraph portion of the shutdown.
550 * This should only be called indirectly from ngt_close().
552 * tp->t_lsc is already NULL, so we should be protected from
556 ngt_shutdown(node_p node
)
558 const sc_p sc
= NG_NODE_PRIVATE(node
);
561 if (!(sc
->flags
& FLG_DIE
)) {
568 _IF_DRAIN(&sc
->outq
);
569 mtx_destroy(&(sc
)->outq
.ifq_mtx
);
571 NG_NODE_UNREF(sc
->node
);
572 FREE(sc
, M_NETGRAPH
);
578 * Receive incoming data from netgraph system. Put it on our
579 * output queue and start output if necessary.
582 ngt_rcvdata(hook_p hook
, item_p item
)
584 const sc_p sc
= NG_NODE_PRIVATE(NG_HOOK_NODE(hook
));
588 if (hook
!= sc
->hook
)
595 if (_IF_QFULL(&sc
->outq
)) {
597 IF_UNLOCK(&sc
->outq
);
602 _IF_ENQUEUE(&sc
->outq
, m
);
603 qlen
= sc
->outq
.ifq_len
;
604 IF_UNLOCK(&sc
->outq
);
607 * If qlen > 1, then we should already have a scheduled callout.
619 * Receive control message
622 ngt_rcvmsg(node_p node
, item_p item
, hook_p lasthook
)
624 const sc_p sc
= NG_NODE_PRIVATE(node
);
625 struct ng_mesg
*msg
, *resp
= NULL
;
628 NGI_GET_MSG(item
, msg
);
629 switch (msg
->header
.typecookie
) {
631 switch (msg
->header
.cmd
) {
632 case NGM_TTY_SET_HOTCHAR
:
636 if (msg
->header
.arglen
!= sizeof(int))
638 hotchar
= *((int *) msg
->data
);
639 if (hotchar
!= (u_char
) hotchar
&& hotchar
!= -1)
641 sc
->hotchar
= hotchar
; /* race condition is OK */
644 case NGM_TTY_GET_HOTCHAR
:
645 NG_MKRESPONSE(resp
, msg
, sizeof(int), M_WAITOK
| M_NULLOK
);
648 /* Race condition here is OK */
649 *((int *) resp
->data
) = sc
->hotchar
;
659 NG_RESPOND_MSG(error
, node
, item
, resp
);
664 /******************************************************************
666 ******************************************************************/
669 * Handle loading and unloading for this node type
672 ngt_mod_event(module_t mod
, int event
, void *data
)
679 /* Register line discipline */
681 if ((ngt_ldisc
= ldisc_register(NETGRAPHDISC
, &ngt_disc
)) < 0) {
683 log(LOG_ERR
, "%s: can't register line discipline",
692 /* Unregister line discipline */
694 ldisc_deregister(ngt_ldisc
);