499 lines
13 KiB
C
499 lines
13 KiB
C
/* $NetBSD: llc_input.c,v 1.11 2001/11/13 00:12:57 lukem Exp $ */
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/*
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* Copyright (c) 1990, 1991, 1992
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* Dirk Husemann, Computer Science Department IV,
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* University of Erlangen-Nuremberg, Germany.
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* Copyright (c) 1992, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* Dirk Husemann and the Computer Science Department (IV) of
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* the University of Erlangen-Nuremberg, Germany.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)llc_input.c 8.1 (Berkeley) 6/10/93
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*/
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#include <sys/cdefs.h>
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__KERNEL_RCSID(0, "$NetBSD: llc_input.c,v 1.11 2001/11/13 00:12:57 lukem Exp $");
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/mbuf.h>
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#include <sys/domain.h>
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#include <sys/socket.h>
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#include <sys/protosw.h>
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#include <sys/errno.h>
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#include <sys/time.h>
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#include <sys/kernel.h>
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#include <net/if.h>
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#include <net/if_dl.h>
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#include <net/if_llc.h>
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#include <net/route.h>
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#include <netccitt/dll.h>
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#include <netccitt/llc_var.h>
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#include <machine/stdarg.h>
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struct ifqueue llcintrq;
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/*
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* This module implements LLC as specified by ISO 8802-2.
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*/
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/*
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* llcintr() handles all LLC frames (except ISO CLNS ones for the time being)
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* and tries to pass them on to the appropriate network layer entity.
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*/
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void
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llcintr()
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{
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struct mbuf *m;
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int i;
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int frame_kind;
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u_char cmdrsp;
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struct llc_linkcb *linkp;
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struct npaidbentry *sapinfo = NULL;
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struct sdl_hdr *sdlhdr;
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struct llc *frame;
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long expected_len;
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struct ifnet *ifp;
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struct rtentry *llrt;
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struct rtentry *nlrt;
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for (;;) {
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i = splnet();
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IF_DEQUEUE(&llcintrq, m);
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splx(i);
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if (m == 0)
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break;
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#ifdef DIAGNOSTIC
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if ((m->m_flags & M_PKTHDR) == 0)
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panic("llcintr no HDR");
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#endif
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/*
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* Get ifp this packet was received on
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*/
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ifp = m->m_pkthdr.rcvif;
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sdlhdr = mtod(m, struct sdl_hdr *);
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/*
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* [Copied from net/ip_input.c]
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*
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* Check that the amount of data in the buffers is
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* at least as much as the LLC header tells us.
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* Trim mbufs if longer than expected.
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* Drop packets if shorter than we think they are.
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*
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* Layout of mbuf chain at this point:
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*
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* +-------------------------------+----+ -\
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* | sockaddr_dl src - sdlhdr_src | 20 | \
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* +-------------------------------+----+ |
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* | sockaddr_dl dst - sdlhdr_dst | 20 | > sizeof(struct sdl_hdr) == 44
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* +-------------------------------+----+ |
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* | LLC frame len - sdlhdr_len | 04 | /
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* +-------------------------------+----+ -/
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* /
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* | m_next
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* \
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* +----------------------------+----+ -\
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* | llc DSAP | 01 | \
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* +----------------------------+----+ |
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* | llc SSAP | 01 | |
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* +----------------------------+----+ > sdlhdr_len
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* | llc control | 01 | |
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* +----------------------------+----+ |
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* | ... | | /
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* -/
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*
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* Thus the we expect to have exactly
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* (sdlhdr->sdlhdr_len+sizeof(struct sdl_hdr)) in the mbuf chain
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*/
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expected_len = sdlhdr->sdlhdr_len + sizeof(struct sdl_hdr);
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if (m->m_pkthdr.len < expected_len) {
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m_freem(m);
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continue;
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}
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if (m->m_pkthdr.len > expected_len) {
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if (m->m_len == m->m_pkthdr.len) {
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m->m_len = expected_len;
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m->m_pkthdr.len = expected_len;
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} else
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m_adj(m, expected_len - m->m_pkthdr.len);
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}
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/*
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* Get llc header
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*/
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if (m->m_len > sizeof(struct sdl_hdr))
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frame = mtod((struct mbuf *)((struct sdl_hdr*)(m+1)),
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struct llc *);
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else frame = mtod(m->m_next, struct llc *);
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if (frame == (struct llc *) NULL)
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panic("llcintr no llc header");
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/*
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* Now check for bogus I/S frame, i.e. those with a control
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* field telling us they're an I/S frame yet their length
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* is less than the established I/S frame length (DSAP + SSAP +
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* control + N(R)&P/F = 4) --- we drop those suckers
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*/
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if (((frame->llc_control & 0x03) != 0x03)
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&& ((expected_len - sizeof(struct sdl_hdr)) < LLC_ISFRAMELEN)) {
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m_freem(m);
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printf("llc: hurz error\n");
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continue;
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}
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/*
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* Get link control block for the addressed link connection.
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* If there is none we take care of it later on.
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*/
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cmdrsp = (frame->llc_ssap & 0x01);
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frame->llc_ssap &= ~0x01;
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llrt = rtalloc1((struct sockaddr *)&sdlhdr->sdlhdr_src, 0);
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if (llrt)
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llrt->rt_refcnt--;
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#ifdef notyet
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else
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llrt = npaidb_enter(&sdlhdr->sdlhdr_src, 0, 0, 0);
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#endif /* notyet */
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else {
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/*
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* We cannot do anything currently here as we
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* don't `know' this link --- drop it
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*/
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m_freem(m);
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continue;
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}
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linkp = ((struct npaidbentry *)(llrt->rt_llinfo))->np_link;
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nlrt = ((struct npaidbentry *)(llrt->rt_llinfo))->np_rt;
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/*
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* If the link is not existing right now, we can try and look up
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* the SAP info block.
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*/
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if ((linkp == 0) && frame->llc_ssap)
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sapinfo = llc_getsapinfo(frame->llc_dsap, ifp);
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/*
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* Handle XID and TEST frames
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* XID: if DLSAP == 0, return type-of-services
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* window-0
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* DLSAP-0
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* format-identifier-?
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* if DLSAP != 0, locate sapcb and return
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* type-of-services
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* SAP-window
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* format-identifier-?
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* TEST: swap (snpah_dst, snpah_src) and return frame
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*
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* Also toggle the CMD/RESP bit
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*
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* Is this behaviour correct? Check ISO 8802-2 (90)!
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*/
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frame_kind = llc_decode(frame, (struct llc_linkcb *)0);
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switch(frame_kind) {
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case LLCFT_XID:
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if (linkp || sapinfo) {
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if (linkp)
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frame->llc_window = linkp->llcl_window;
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else frame->llc_window = sapinfo->si_window;
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frame->llc_fid = 9; /* XXX */
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frame->llc_class = sapinfo->si_class;
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frame->llc_ssap = frame->llc_dsap;
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} else {
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frame->llc_window = 0;
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frame->llc_fid = 9;
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frame->llc_class = 1;
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frame->llc_dsap = frame->llc_ssap = 0;
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}
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/* fall thru to */
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case LLCFT_TEST:
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sdl_swapaddr(&(mtod(m, struct sdl_hdr *)->sdlhdr_dst),
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&(mtod(m, struct sdl_hdr *)->sdlhdr_src));
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/* Now set the CMD/RESP bit */
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frame->llc_ssap |= (cmdrsp == 0x0 ? 0x1 : 0x0);
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/* Ship it out again */
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(*ifp->if_output)(ifp, m,
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(struct sockaddr *) &(mtod(m, struct sdl_hdr *)->sdlhdr_dst),
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(struct rtentry *) 0);
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continue;
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}
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/*
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* Create link control block in case it is not existing
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*/
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if (linkp == 0 && sapinfo) {
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if ((linkp = llc_newlink(&sdlhdr->sdlhdr_src, ifp, nlrt,
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(nlrt == 0) ? 0 : nlrt->rt_llinfo,
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llrt)) == 0) {
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printf("llcintr: couldn't create new link\n");
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m_freem(m);
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continue;
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}
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((struct npaidbentry *)llrt->rt_llinfo)->np_link = linkp;
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} else if (linkp == 0) {
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/* The link is not known to us, drop the frame and continue */
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m_freem(m);
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continue;
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}
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/*
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* Drop SNPA header and get rid of empty mbuf at the
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* front of the mbuf chain (I don't like 'em)
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*/
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m_adj(m, sizeof(struct sdl_hdr));
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/*
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* LLC_UFRAMELEN is sufficient, m_pullup() will pull up
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* the min(m->m_len, maxprotohdr_len [=40]) thus doing
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* the trick ...
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*/
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if ((m = m_pullup(m, LLC_UFRAMELEN)))
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/*
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* Pass it on thru the elements of procedure
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*/
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llc_input(m, linkp, cmdrsp);
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}
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return;
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}
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/*
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* llc_input() --- We deal with the various incoming frames here.
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* Basically we (indirectly) call the appropriate
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* state handler function that's pointed to by
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* llcl_statehandler.
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*
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* The statehandler returns an action code ---
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* further actions like
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* o notify network layer
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* o block further sending
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* o deblock link
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* o ...
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* are then enacted accordingly.
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*/
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int
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#if __STDC__
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llc_input(struct mbuf *m, ...)
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#else
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llc_input(m, va_alist)
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struct mbuf *m;
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va_dcl
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#endif
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{
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int frame_kind;
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int pollfinal;
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int action = 0;
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struct llc *frame;
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struct llc_linkcb *linkp;
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u_int cmdrsp;
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va_list ap;
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va_start(ap, m);
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linkp = va_arg(ap, struct llc_linkcb *);
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cmdrsp = va_arg(ap, u_int);
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va_end(ap);
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if ((frame = mtod(m, struct llc *)) == (struct llc *) 0) {
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m_freem(m);
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return 0;
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}
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pollfinal = ((frame->llc_control & 0x03) == 0x03) ?
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LLCGBITS(frame->llc_control, u_pf) :
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LLCGBITS(frame->llc_control_ext, s_pf);
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/*
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* first decode the frame
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*/
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frame_kind = llc_decode(frame, linkp);
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switch (action = llc_statehandler(linkp, frame, frame_kind, cmdrsp,
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pollfinal)) {
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case LLC_DATA_INDICATION:
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m_adj(m, LLC_ISFRAMELEN);
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if ((m = m_pullup(m, NLHDRSIZEGUESS)) != NULL) {
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m->m_pkthdr.rcvif = (struct ifnet *)linkp->llcl_nlnext;
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(*linkp->llcl_sapinfo->si_input)(m, NULL, NULL, NULL);
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}
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break;
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}
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/* release mbuf if not an info frame */
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if (action != LLC_DATA_INDICATION && m)
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m_freem(m);
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/* try to get frames out ... */
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llc_start(linkp);
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return 0;
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}
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/*
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* This routine is called by configuration setup. It sets up a station control
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* block and notifies all registered upper level protocols.
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*/
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void *
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llc_ctlinput(prc, addr, info)
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int prc;
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struct sockaddr *addr;
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void *info;
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{
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struct ifnet *ifp = NULL;
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struct ifaddr *ifa;
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struct dll_ctlinfo *ctlinfo = (struct dll_ctlinfo *)info;
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u_char sap;
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struct dllconfig *config;
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caddr_t pcb;
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struct rtentry *nlrt;
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struct rtentry *llrt = NULL;
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struct llc_linkcb *linkp = NULL;
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int i;
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/* info must point to something valid at all times */
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if (info == 0)
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return 0;
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if (prc == PRC_IFUP || prc == PRC_IFDOWN) {
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/* we use either this set ... */
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ifa = ifa_ifwithaddr(addr);
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if (ifa == NULL)
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return (0);
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ifp = ifa->ifa_ifp;
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if (ifp == NULL)
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return (0);
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sap = ctlinfo->dlcti_lsap;
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config = ctlinfo->dlcti_cfg;
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pcb = (caddr_t) 0;
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nlrt = (struct rtentry *) 0;
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} else {
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/* or this one */
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sap = 0;
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config = (struct dllconfig *) 0;
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pcb = ctlinfo->dlcti_pcb;
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nlrt = ctlinfo->dlcti_rt;
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if ((llrt = rtalloc1(nlrt->rt_gateway, 0)))
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llrt->rt_refcnt--;
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else return 0;
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linkp = ((struct npaidbentry *)llrt->rt_llinfo)->np_link;
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}
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switch (prc) {
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case PRC_IFUP:
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(void) llc_setsapinfo(ifp, addr->sa_family, sap, config);
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return 0;
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case PRC_IFDOWN: {
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struct llc_linkcb *linkp;
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struct llc_linkcb *nlinkp;
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int i;
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/*
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* All links are accessible over the doubly linked list llccb_q
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*/
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if (!LQEMPTY) {
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/*
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* A for-loop is not that great an idea as the linkp
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* will get deleted by llc_timer()
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*/
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linkp = LQFIRST;
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while (LQVALID(linkp)) {
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nlinkp = LQNEXT(linkp);
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if ((linkp->llcl_if = ifp) != NULL) {
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i = splnet();
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(void)llc_statehandler(linkp, (struct llc *)0,
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NL_DISCONNECT_REQUEST,
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0, 1);
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splx(i);
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}
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linkp = nlinkp;
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}
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}
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}
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case PRC_CONNECT_REQUEST:
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if (linkp == 0) {
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if ((linkp = llc_newlink((struct sockaddr_dl *) nlrt->rt_gateway,
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nlrt->rt_ifp, nlrt,
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pcb, llrt)) == 0)
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return (0);
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((struct npaidbentry *)llrt->rt_llinfo)->np_link = linkp;
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i = splnet();
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(void)llc_statehandler(linkp, (struct llc *) 0,
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NL_CONNECT_REQUEST, 0, 1);
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splx(i);
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}
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return ((caddr_t)linkp);
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case PRC_DISCONNECT_REQUEST:
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if (linkp == 0)
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panic("no link control block!");
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i = splnet();
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(void)llc_statehandler(linkp, (struct llc *) 0,
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NL_DISCONNECT_REQUEST, 0, 1);
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splx(i);
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/*
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* The actual removal of the link control block is done by the
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* cleaning neutrum (i.e. llc_timer()).
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*/
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break;
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case PRC_RESET_REQUEST:
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if (linkp == 0)
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panic("no link control block!");
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i = splnet();
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(void)llc_statehandler(linkp, (struct llc *) 0,
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NL_RESET_REQUEST, 0, 1);
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splx(i);
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break;
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}
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return 0;
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}
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