/* $OpenBSD: llc_output.c,v 1.6 2003/12/10 07:22:42 itojun Exp $ */ /* $NetBSD: llc_output.c,v 1.3 1996/02/13 22:04:47 christos Exp $ */ /* * Copyright (C) Dirk Husemann, Computer Science Department IV, * University of Erlangen-Nuremberg, Germany, 1990, 1991, 1992 * Copyright (c) 1992, 1993 * The Regents of the University of California. All rights reserved. * * This code is derived from software contributed to Berkeley by * Dirk Husemann and the Computer Science Department (IV) of * the University of Erlangen-Nuremberg, Germany. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON 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 ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)llc_output.c 8.1 (Berkeley) 6/10/93 */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * llc_output() --- called by an upper layer (network layer) entity whenever * there is an INFO frame to be transmitted. We enqueue the * info frame and call llc_start() to do the actual sending. */ int llc_output(struct mbuf *m, ...) { struct llc_linkcb *linkp; int i = splimp(); va_list ap; va_start(ap, m); linkp = va_arg(ap, struct llc_linkcb *); va_end(ap); LLC_ENQUEUE(linkp, m); llc_start(linkp); splx(i); return 0; } /* * llc_start() --- We try to subsequently dequeue all the frames available and * send them out. */ void llc_start(linkp) struct llc_linkcb *linkp; { struct mbuf *m; while ((LLC_STATEEQ(linkp,NORMAL) || LLC_STATEEQ(linkp,BUSY) || LLC_STATEEQ(linkp,REJECT)) && (linkp->llcl_slotsfree > 0) && (LLC_GETFLAG(linkp,REMOTE_BUSY) == 0)) { LLC_DEQUEUE(linkp,m); if (m == NULL) break; LLC_SETFRAME(linkp, m); (void) llc_statehandler(linkp, NULL, NL_DATA_REQUEST, 0, 0); } } /* * llc_send() --- Handles single frames. If dealing with INFO frames we need to * prepend the LLC header, otherwise we just allocate an mbuf. * In both cases the actual send is done by llc_rawsend(). */ void llc_send(linkp, frame_kind, cmdrsp, pollfinal) struct llc_linkcb *linkp; int frame_kind; int cmdrsp; int pollfinal; { struct mbuf *m = (struct mbuf *) 0; struct llc *frame; if (frame_kind == LLCFT_INFO) m = linkp->llcl_output_buffers[llc_seq2slot(linkp, linkp->llcl_vs)]; LLC_GETHDR(frame, m); /* pass it on to llc_rawsend() */ llc_rawsend(linkp, m, frame, frame_kind, linkp->llcl_vs, cmdrsp, pollfinal); if (frame_kind == LLCFT_INFO) LLC_INC(linkp->llcl_vs); } /* * llc_resend() --- llc_resend() retransmits all unacknowledged INFO frames. */ void llc_resend(linkp, cmdrsp, pollfinal) struct llc_linkcb *linkp; int cmdrsp; int pollfinal; { struct llc *frame; struct mbuf *m; int slot; if (linkp->llcl_slotsfree < linkp->llcl_window) /* assert lock between nr_received & V(S) */ if (linkp->llcl_nr_received != linkp->llcl_vs) panic("llc: V(S) != N(R) received"); for (slot = llc_seq2slot(linkp, linkp->llcl_vs); slot != linkp->llcl_freeslot; LLC_INC(linkp->llcl_vs), slot = llc_seq2slot(linkp, linkp->llcl_vs)) { m = linkp->llcl_output_buffers[slot]; LLC_GETHDR(frame, m); llc_rawsend(linkp, m, frame, LLCFT_INFO, linkp->llcl_vs, cmdrsp, pollfinal); pollfinal = 0; } } /* * llc_rawsend() --- constructs an LLC frame and sends it out via the * associated interface of the link control block. * * We need to make sure that outgoing frames have the correct length, * in particular the 4 byte ones (RR, RNR, REJ) as LLC_GETHDR() will * set the mbuf len to 3 as default len for non INFO frames ... * * Frame kind Length (w/o MAC header, {D,S}SAP incl.) * -------------------------------------------------------------- * DISC, SABME, UA, DM 3 bytes ({D,S}SAP + CONTROL) * RR, RNR, REJ 4 bytes ({D,S}SAP + CONTROL0 + CONTROL1) * XID 6 bytes ({D,S}SAP + CONTROL0 + FI,CLASS,WINDOW) * FRMR 7 bytes ({D,S}SAP + CONTROL0 + REJ CONTROL,V(S),V(R),CAUSE) * INFO 4 -- MTU * UI, TEST 3 -- MTU * */ #define LLC_SETLEN(m, l) (m)->m_pkthdr.len = (m)->m_len = (l) void llc_rawsend(linkp, m, frame, frame_kind, vs, cmdrsp, pollfinal) struct llc_linkcb *linkp; struct mbuf *m; struct llc *frame; int frame_kind; int vs; int cmdrsp; int pollfinal; { short adjust = LLC_UFRAMELEN; struct ifnet *ifp; switch (frame_kind) { /* supervisory and information frames */ case LLCFT_INFO: frame->llc_control = LLC_INFO; LLCSBITS(frame->llc_control, i_ns, vs); LLCSBITS(frame->llc_control_ext, i_nr, linkp->llcl_vr); adjust = LLC_ISFRAMELEN; break; case LLCFT_RR: frame->llc_control = LLC_RR; LLC_SETLEN(m, LLC_ISFRAMELEN); LLCSBITS(frame->llc_control_ext, s_nr, linkp->llcl_vr); adjust = LLC_ISFRAMELEN; break; case LLCFT_RNR: frame->llc_control = LLC_RNR; LLC_SETLEN(m, LLC_ISFRAMELEN); LLCSBITS(frame->llc_control_ext, s_nr, linkp->llcl_vr); adjust = LLC_ISFRAMELEN; break; case LLCFT_REJ: frame->llc_control = LLC_REJ; LLC_SETLEN(m, LLC_ISFRAMELEN); LLCSBITS(frame->llc_control_ext, s_nr, linkp->llcl_vr); adjust = LLC_ISFRAMELEN; break; /* unnumbered frames */ case LLCFT_DM: frame->llc_control = LLC_DM; break; case LLCFT_SABME: frame->llc_control = LLC_SABME; break; case LLCFT_DISC: frame->llc_control = LLC_DISC; break; case LLCFT_UA: frame->llc_control = LLC_UA; break; case LLCFT_UI: frame->llc_control = LLC_UI; break; case LLCFT_FRMR: frame->llc_control = LLC_FRMR; /* get more space --- FRMR frame are longer then usual */ LLC_SETLEN(m, LLC_FRMRLEN); bcopy((caddr_t) & linkp->llcl_frmrinfo, (caddr_t) & frame->llc_frmrinfo, sizeof(struct frmrinfo)); break; default: /* * We don't send {XID, TEST} frames */ if (m) m_freem(m); return; } /* * Fill in DSAP/SSAP */ frame->llc_dsap = frame->llc_ssap = LLSAPADDR(&linkp->llcl_addr); frame->llc_ssap |= cmdrsp; /* * Check for delayed action pending. ISO 8802-2, 7.9.2 (5) * and ISO 8802-2, 7.9.2.3 (32), (34), (36) pertain to this * piece of code --- hopefully we got it right here (i.e. * in the spirit of (32), (34), and (36) ... */ switch (frame_kind) { case LLCFT_RR: case LLCFT_RNR: case LLCFT_REJ: case LLCFT_INFO: switch (LLC_GETFLAG(linkp,DACTION)) { case LLC_DACKCMD: case LLC_DACKRSP: LLC_STOPTIMER(linkp,DACTION); break; case LLC_DACKCMDPOLL: if (cmdrsp == LLC_CMD) { pollfinal = 1; LLC_STOPTIMER(linkp,DACTION); } break; case LLC_DACKRSPFINAL: if (cmdrsp == LLC_RSP) { pollfinal = 1; LLC_STOPTIMER(linkp,DACTION); } break; } break; } if (adjust == LLC_UFRAMELEN) LLCSBITS(frame->llc_control,u_pf,pollfinal); else LLCSBITS(frame->llc_control_ext,s_pf,pollfinal); /* * Get interface to send frame onto */ ifp = linkp->llcl_if; if (frame_kind == LLCFT_INFO) { /* * send out a copy of the frame, retain the original */ (*ifp->if_output) (ifp, m_copy(m, 0, (int) M_COPYALL), rt_key(linkp->llcl_nlrt), linkp->llcl_nlrt); /* * Account for the LLC header and let it ``disappear'' * as the raw info frame payload is what we hold in * the output_buffers of the link. */ m_adj(m, LLC_ISFRAMELEN); } else (*ifp->if_output) (ifp, m, rt_key(linkp->llcl_nlrt), linkp->llcl_nlrt); }