/* * ng_tty.c */ /*- * Copyright (c) 1996-1999 Whistle Communications, Inc. * All rights reserved. * * Subject to the following obligations and disclaimer of warranty, use and * redistribution of this software, in source or object code forms, with or * without modifications are expressly permitted by Whistle Communications; * provided, however, that: * 1. Any and all reproductions of the source or object code must include the * copyright notice above and the following disclaimer of warranties; and * 2. No rights are granted, in any manner or form, to use Whistle * Communications, Inc. trademarks, including the mark "WHISTLE * COMMUNICATIONS" on advertising, endorsements, or otherwise except as * such appears in the above copyright notice or in the software. * * THIS SOFTWARE IS BEING PROVIDED BY WHISTLE COMMUNICATIONS "AS IS", AND * TO THE MAXIMUM EXTENT PERMITTED BY LAW, WHISTLE COMMUNICATIONS MAKES NO * REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, REGARDING THIS SOFTWARE, * INCLUDING WITHOUT LIMITATION, ANY AND ALL IMPLIED WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. * WHISTLE COMMUNICATIONS DOES NOT WARRANT, GUARANTEE, OR MAKE ANY * REPRESENTATIONS REGARDING THE USE OF, OR THE RESULTS OF THE USE OF THIS * SOFTWARE IN TERMS OF ITS CORRECTNESS, ACCURACY, RELIABILITY OR OTHERWISE. * IN NO EVENT SHALL WHISTLE COMMUNICATIONS BE LIABLE FOR ANY DAMAGES * RESULTING FROM OR ARISING OUT OF ANY USE OF THIS SOFTWARE, INCLUDING * WITHOUT LIMITATION, ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, * PUNITIVE, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR * SERVICES, LOSS OF USE, DATA OR PROFITS, HOWEVER CAUSED AND UNDER ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF WHISTLE COMMUNICATIONS IS ADVISED OF THE POSSIBILITY * OF SUCH DAMAGE. * * Author: Archie Cobbs * * Updated by Andrew Thompson for MPSAFE TTY. * * $FreeBSD$ * $Whistle: ng_tty.c,v 1.21 1999/11/01 09:24:52 julian Exp $ */ /* * This file implements TTY hooks to link in to the netgraph system. The node * is created and then passed the callers opened TTY file descriptor number to * NGM_TTY_SET_TTY, this will hook the tty via ttyhook_register(). * * Incoming data is delivered directly to ng_tty via the TTY bypass hook as a * buffer pointer and length, this is converted to a mbuf and passed to the * peer. * * If the TTY device does not support bypass then incoming characters are * delivered to the hook one at a time, each in its own mbuf. You may * optionally define a ``hotchar,'' which causes incoming characters to be * buffered up until either the hotchar is seen or the mbuf is full (MHLEN * bytes). Then all buffered characters are immediately delivered. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* Per-node private info */ struct ngt_softc { struct tty *tp; /* Terminal device */ node_p node; /* Netgraph node */ hook_p hook; /* Netgraph hook */ struct ifqueue outq; /* Queue of outgoing data */ size_t outqlen; /* Number of bytes in outq */ struct mbuf *m; /* Incoming non-bypass data buffer */ short hotchar; /* Hotchar, or -1 if none */ u_int flags; /* Flags */ }; typedef struct ngt_softc *sc_p; /* Flags */ #define FLG_DEBUG 0x0002 /* Netgraph methods */ static ng_constructor_t ngt_constructor; static ng_rcvmsg_t ngt_rcvmsg; static ng_shutdown_t ngt_shutdown; static ng_newhook_t ngt_newhook; static ng_connect_t ngt_connect; static ng_rcvdata_t ngt_rcvdata; static ng_disconnect_t ngt_disconnect; #define ERROUT(x) do { error = (x); goto done; } while (0) static th_getc_inject_t ngt_getc_inject; static th_getc_poll_t ngt_getc_poll; static th_rint_t ngt_rint; static th_rint_bypass_t ngt_rint_bypass; static th_rint_poll_t ngt_rint_poll; static struct ttyhook ngt_hook = { .th_getc_inject = ngt_getc_inject, .th_getc_poll = ngt_getc_poll, .th_rint = ngt_rint, .th_rint_bypass = ngt_rint_bypass, .th_rint_poll = ngt_rint_poll, }; /* Netgraph node type descriptor */ static struct ng_type typestruct = { .version = NG_ABI_VERSION, .name = NG_TTY_NODE_TYPE, .constructor = ngt_constructor, .rcvmsg = ngt_rcvmsg, .shutdown = ngt_shutdown, .newhook = ngt_newhook, .connect = ngt_connect, .rcvdata = ngt_rcvdata, .disconnect = ngt_disconnect, }; NETGRAPH_INIT(tty, &typestruct); #define NGTLOCK(sc) IF_LOCK(&sc->outq) #define NGTUNLOCK(sc) IF_UNLOCK(&sc->outq) /****************************************************************** NETGRAPH NODE METHODS ******************************************************************/ /* * Initialize a new node of this type. * * We only allow nodes to be created as a result of setting * the line discipline on a tty, so always return an error if not. */ static int ngt_constructor(node_p node) { sc_p sc; /* Allocate private structure */ sc = malloc(sizeof(*sc), M_NETGRAPH, M_WAITOK | M_ZERO); NG_NODE_SET_PRIVATE(node, sc); sc->node = node; mtx_init(&sc->outq.ifq_mtx, "ng_tty node+queue", NULL, MTX_DEF); IFQ_SET_MAXLEN(&sc->outq, ifqmaxlen); return (0); } /* * Add a new hook. There can only be one. */ static int ngt_newhook(node_p node, hook_p hook, const char *name) { const sc_p sc = NG_NODE_PRIVATE(node); if (strcmp(name, NG_TTY_HOOK)) return (EINVAL); if (sc->hook) return (EISCONN); NGTLOCK(sc); sc->hook = hook; NGTUNLOCK(sc); return (0); } /* * Set the hook into queueing mode (for outgoing packets), * so that we wont deliver mbuf thru the whole graph holding * tty locks. */ static int ngt_connect(hook_p hook) { NG_HOOK_FORCE_QUEUE(hook); return (0); } /* * Disconnect the hook */ static int ngt_disconnect(hook_p hook) { const sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook)); if (hook != sc->hook) panic("%s", __func__); NGTLOCK(sc); sc->hook = NULL; NGTUNLOCK(sc); return (0); } /* * Remove this node. The does the netgraph portion of the shutdown. */ static int ngt_shutdown(node_p node) { const sc_p sc = NG_NODE_PRIVATE(node); struct tty *tp; tp = sc->tp; if (tp != NULL) { tty_lock(tp); ttyhook_unregister(tp); } /* Free resources */ IF_DRAIN(&sc->outq); mtx_destroy(&(sc)->outq.ifq_mtx); NG_NODE_UNREF(sc->node); free(sc, M_NETGRAPH); return (0); } /* * Receive control message */ static int ngt_rcvmsg(node_p node, item_p item, hook_p lasthook) { struct proc *p; const sc_p sc = NG_NODE_PRIVATE(node); struct ng_mesg *msg, *resp = NULL; int error = 0; NGI_GET_MSG(item, msg); switch (msg->header.typecookie) { case NGM_TTY_COOKIE: switch (msg->header.cmd) { case NGM_TTY_SET_TTY: if (sc->tp != NULL) return (EBUSY); p = pfind(((int *)msg->data)[0]); if (p == NULL || (p->p_flag & P_WEXIT)) return (ESRCH); _PHOLD(p); PROC_UNLOCK(p); error = ttyhook_register(&sc->tp, p, ((int *)msg->data)[1], &ngt_hook, sc); PRELE(p); if (error != 0) return (error); break; case NGM_TTY_SET_HOTCHAR: { int hotchar; if (msg->header.arglen != sizeof(int)) ERROUT(EINVAL); hotchar = *((int *) msg->data); if (hotchar != (u_char) hotchar && hotchar != -1) ERROUT(EINVAL); sc->hotchar = hotchar; /* race condition is OK */ break; } case NGM_TTY_GET_HOTCHAR: NG_MKRESPONSE(resp, msg, sizeof(int), M_NOWAIT); if (!resp) ERROUT(ENOMEM); /* Race condition here is OK */ *((int *) resp->data) = sc->hotchar; break; default: ERROUT(EINVAL); } break; default: ERROUT(EINVAL); } done: NG_RESPOND_MSG(error, node, item, resp); NG_FREE_MSG(msg); return (error); } /* * Receive incoming data from netgraph system. Put it on our * output queue and start output if necessary. */ static int ngt_rcvdata(hook_p hook, item_p item) { const sc_p sc = NG_NODE_PRIVATE(NG_HOOK_NODE(hook)); struct tty *tp = sc->tp; struct mbuf *m; if (hook != sc->hook) panic("%s", __func__); NGI_GET_M(item, m); NG_FREE_ITEM(item); if (tp == NULL) { NG_FREE_M(m); return (ENXIO); } IF_LOCK(&sc->outq); if (_IF_QFULL(&sc->outq)) { _IF_DROP(&sc->outq); IF_UNLOCK(&sc->outq); NG_FREE_M(m); return (ENOBUFS); } _IF_ENQUEUE(&sc->outq, m); sc->outqlen += m->m_pkthdr.len; IF_UNLOCK(&sc->outq); /* notify the TTY that data is ready */ tty_lock(tp); if (!tty_gone(tp)) ttydevsw_outwakeup(tp); tty_unlock(tp); return (0); } static size_t ngt_getc_inject(struct tty *tp, void *buf, size_t len) { sc_p sc = ttyhook_softc(tp); size_t total = 0; int length; while (len) { struct mbuf *m; /* Remove first mbuf from queue */ IF_DEQUEUE(&sc->outq, m); if (m == NULL) break; /* Send as much of it as possible */ while (m != NULL) { length = min(m->m_len, len); memcpy((char *)buf + total, mtod(m, char *), length); m->m_data += length; m->m_len -= length; total += length; len -= length; if (m->m_len > 0) break; /* device can't take any more */ m = m_free(m); } /* Put remainder of mbuf chain (if any) back on queue */ if (m != NULL) { IF_PREPEND(&sc->outq, m); break; } } IF_LOCK(&sc->outq); sc->outqlen -= total; IF_UNLOCK(&sc->outq); MPASS(sc->outqlen >= 0); return (total); } static size_t ngt_getc_poll(struct tty *tp) { sc_p sc = ttyhook_softc(tp); return (sc->outqlen); } /* * Optimised TTY input. * * We get a buffer pointer to hopefully a complete data frame. Do not check for * the hotchar, just pass it on. */ static size_t ngt_rint_bypass(struct tty *tp, const void *buf, size_t len) { sc_p sc = ttyhook_softc(tp); node_p node = sc->node; struct mbuf *m, *mb; size_t total = 0; int error = 0, length; tty_lock_assert(tp, MA_OWNED); if (sc->hook == NULL) return (0); m = m_getm2(NULL, len, M_NOWAIT, MT_DATA, M_PKTHDR); if (m == NULL) { if (sc->flags & FLG_DEBUG) log(LOG_ERR, "%s: can't get mbuf\n", NG_NODE_NAME(node)); return (0); } m->m_pkthdr.rcvif = NULL; for (mb = m; mb != NULL; mb = mb->m_next) { length = min(M_TRAILINGSPACE(mb), len - total); memcpy(mtod(m, char *), (const char *)buf + total, length); mb->m_len = length; total += length; m->m_pkthdr.len += length; } if (sc->m != NULL) { /* * Odd, we have changed from non-bypass to bypass. It is * unlikely but not impossible, flush the data first. */ sc->m->m_data = sc->m->m_pktdat; NG_SEND_DATA_ONLY(error, sc->hook, sc->m); sc->m = NULL; } NG_SEND_DATA_ONLY(error, sc->hook, m); return (total); } /* * Receive data coming from the device one char at a time, when it is not in * bypass mode. */ static int ngt_rint(struct tty *tp, char c, int flags) { sc_p sc = ttyhook_softc(tp); node_p node = sc->node; struct mbuf *m; int error = 0; tty_lock_assert(tp, MA_OWNED); if (sc->hook == NULL) return (0); if (flags != 0) { /* framing error or overrun on this char */ if (sc->flags & FLG_DEBUG) log(LOG_DEBUG, "%s: line error %x\n", NG_NODE_NAME(node), flags); return (0); } /* Get a new header mbuf if we need one */ if (!(m = sc->m)) { MGETHDR(m, M_NOWAIT, MT_DATA); if (!m) { if (sc->flags & FLG_DEBUG) log(LOG_ERR, "%s: can't get mbuf\n", NG_NODE_NAME(node)); return (ENOBUFS); } m->m_len = m->m_pkthdr.len = 0; m->m_pkthdr.rcvif = NULL; sc->m = m; } /* Add char to mbuf */ *mtod(m, u_char *) = c; m->m_data++; m->m_len++; m->m_pkthdr.len++; /* Ship off mbuf if it's time */ if (sc->hotchar == -1 || c == sc->hotchar || m->m_len >= MHLEN) { m->m_data = m->m_pktdat; sc->m = NULL; NG_SEND_DATA_ONLY(error, sc->hook, m); /* Will queue */ } return (error); } static size_t ngt_rint_poll(struct tty *tp) { /* We can always accept input */ return (1); }