mirror/freebsd
1
0
Fork 0
mirror of https://git.FreeBSD.org/src.git synced 2024-12-18 10:35:55 +00:00
Code Issues Releases Activity
07049f23e9
freebsd/sys/netccitt/llc_input.c
David Greenman 3c4dd3568f Added $Id$
1994-08-02 07:55:43 +00:00

470 lines
13 KiB
C
Raw Blame History

/*
* 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. 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_input.c 8.1 (Berkeley) 6/10/93
* $Id$
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/domain.h>
#include <sys/socket.h>
#include <sys/protosw.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <net/if.h>
#include <net/if_dl.h>
#include <net/if_llc.h>
#include <net/route.h>
#include <netccitt/dll.h>
#include <netccitt/llc_var.h>
/*
* This module implements LLC as specified by ISO 8802-2.
*/
/*
* llcintr() handles all LLC frames (except ISO CLNS ones for the time being)
* and tries to pass them on to the appropriate network layer entity.
*/
void
llcintr()
{
register struct mbuf *m;
register int i;
register int frame_kind;
register u_char cmdrsp;
struct llc_linkcb *linkp;
struct rtentry *sirt;
struct npaidbentry *sapinfo;
struct sdl_hdr *sdlhdr;
struct llc *frame;
char *c;
long expected_len;
struct ifnet *ifp;
struct rtentry *llrt;
struct rtentry *nlrt;
for (;;) {
i = splimp();
IF_DEQUEUE(&llcintrq, m);
splx(i);
if (m == 0)
break;
#ifdef DIAGNOSTIC
if ((m->m_flags & M_PKTHDR) == 0)
panic("llcintr no HDR");
#endif
/*
* Get ifp this packet was received on
*/
ifp = m->m_pkthdr.rcvif;
sdlhdr = mtod(m, struct sdl_hdr *);
/*
* [Copied from net/ip_input.c]
*
* Check that the amount of data in the buffers is
* at least as much as the LLC header tells us.
* Trim mbufs if longer than expected.
* Drop packets if shorter than we think they are.
*
* Layout of mbuf chain at this point:
*
* +-------------------------------+----+ -\
* | sockaddr_dl src - sdlhdr_src | 20 | \
* +-------------------------------+----+ |
* | sockaddr_dl dst - sdlhdr_dst | 20 | > sizeof(struct sdl_hdr) == 44
* +-------------------------------+----+ |
* | LLC frame len - sdlhdr_len | 04 | /
* +-------------------------------+----+ -/
* /
* | m_next
* \
* +----------------------------+----+ -\
* | llc DSAP | 01 | \
* +----------------------------+----+ |
* | llc SSAP | 01 | |
* +----------------------------+----+ > sdlhdr_len
* | llc control | 01 | |
* +----------------------------+----+ |
* | ... | | /
* -/
*
* Thus the we expect to have exactly
* (sdlhdr->sdlhdr_len+sizeof(struct sdl_hdr)) in the mbuf chain
*/
expected_len = sdlhdr->sdlhdr_len + sizeof(struct sdl_hdr);
if (m->m_pkthdr.len < expected_len) {
m_freem(m);
continue;
}
if (m->m_pkthdr.len > expected_len) {
if (m->m_len == m->m_pkthdr.len) {
m->m_len = expected_len;
m->m_pkthdr.len = expected_len;
} else
m_adj(m, expected_len - m->m_pkthdr.len);
}
/*
* Get llc header
*/
if (m->m_len > sizeof(struct sdl_hdr))
frame = mtod((struct mbuf *)((struct sdl_hdr*)(m+1)),
struct llc *);
else frame = mtod(m->m_next, struct llc *);
if (frame == (struct llc *) NULL)
panic("llcintr no llc header");
/*
* Now check for bogus I/S frame, i.e. those with a control
* field telling us they're an I/S frame yet their length
* is less than the established I/S frame length (DSAP + SSAP +
* control + N(R)&P/F = 4) --- we drop those suckers
*/
if (((frame->llc_control & 0x03) != 0x03)
&& ((expected_len - sizeof(struct sdl_hdr)) < LLC_ISFRAMELEN)) {
m_freem(m);
printf("llc: hurz error\n");
continue;
}
/*
* Get link control block for the addressed link connection.
* If there is none we take care of it later on.
*/
cmdrsp = (frame->llc_ssap & 0x01);
frame->llc_ssap &= ~0x01;
if (llrt = rtalloc1((struct sockaddr *)&sdlhdr->sdlhdr_src, 0))
llrt->rt_refcnt--;
#ifdef notyet
else llrt = npaidb_enter(&sdlhdr->sdlhdr_src, 0, 0, 0);
#endif /* notyet */
else {
/*
* We cannot do anything currently here as we
* don't `know' this link --- drop it
*/
m_freem(m);
continue;
}
linkp = ((struct npaidbentry *)(llrt->rt_llinfo))->np_link;
nlrt = ((struct npaidbentry *)(llrt->rt_llinfo))->np_rt;
/*
* If the link is not existing right now, we can try and look up
* the SAP info block.
*/
if ((linkp == 0) && frame->llc_ssap)
sapinfo = llc_getsapinfo(frame->llc_dsap, ifp);
/*
* Handle XID and TEST frames
* XID: if DLSAP == 0, return type-of-services
* window-0
* DLSAP-0
* format-identifier-?
* if DLSAP != 0, locate sapcb and return
* type-of-services
* SAP-window
* format-identifier-?
* TEST: swap (snpah_dst, snpah_src) and return frame
*
* Also toggle the CMD/RESP bit
*
* Is this behaviour correct? Check ISO 8802-2 (90)!
*/
frame_kind = llc_decode(frame, (struct llc_linkcb *)0);
switch(frame_kind) {
case LLCFT_XID:
if (linkp || sapinfo) {
if (linkp)
frame->llc_window = linkp->llcl_window;
else frame->llc_window = sapinfo->si_window;
frame->llc_fid = 9; /* XXX */
frame->llc_class = sapinfo->si_class;
frame->llc_ssap = frame->llc_dsap;
} else {
frame->llc_window = 0;
frame->llc_fid = 9;
frame->llc_class = 1;
frame->llc_dsap = frame->llc_ssap = 0;
}
/* fall thru to */
case LLCFT_TEST:
sdl_swapaddr(&(mtod(m, struct sdl_hdr *)->sdlhdr_dst),
&(mtod(m, struct sdl_hdr *)->sdlhdr_src));
/* Now set the CMD/RESP bit */
frame->llc_ssap |= (cmdrsp == 0x0 ? 0x1 : 0x0);
/* Ship it out again */
(*ifp->if_output)(ifp, m,
(struct sockaddr *) &(mtod(m, struct sdl_hdr *)->sdlhdr_dst),
(struct rtentry *) 0);
continue;
}
/*
* Create link control block in case it is not existing
*/
if (linkp == 0 && sapinfo) {
if ((linkp = llc_newlink(&sdlhdr->sdlhdr_src, ifp, nlrt,
(nlrt == 0) ? 0 : nlrt->rt_llinfo,
llrt)) == 0) {
printf("llcintr: couldn't create new link\n");
m_freem(m);
continue;
}
((struct npaidbentry *)llrt->rt_llinfo)->np_link = linkp;
} else if (linkp == 0) {
/* The link is not known to us, drop the frame and continue */
m_freem(m);
continue;
}
/*
* Drop SNPA header and get rid of empty mbuf at the
* front of the mbuf chain (I don't like 'em)
*/
m_adj(m, sizeof(struct sdl_hdr));
/*
* LLC_UFRAMELEN is sufficient, m_pullup() will pull up
* the min(m->m_len, maxprotohdr_len [=40]) thus doing
* the trick ...
*/
if ((m = m_pullup(m, LLC_UFRAMELEN)))
/*
* Pass it on thru the elements of procedure
*/
llc_input(linkp, m, cmdrsp);
}
return;
}
/*
* llc_input() --- We deal with the various incoming frames here.
* Basically we (indirectly) call the appropriate
* state handler function that's pointed to by
* llcl_statehandler.
*
* The statehandler returns an action code ---
* further actions like
* o notify network layer
* o block further sending
* o deblock link
* o ...
* are then enacted accordingly.
*/
llc_input(struct llc_linkcb *linkp, struct mbuf *m, u_char cmdrsp)
{
int frame_kind;
int pollfinal;
int action = 0;
struct llc *frame;
struct ifnet *ifp = linkp->llcl_if;
if ((frame = mtod(m, struct llc *)) == (struct llc *) 0) {
m_freem(m);
return 0;
}
pollfinal = ((frame->llc_control & 0x03) == 0x03) ?
LLCGBITS(frame->llc_control, u_pf) :
LLCGBITS(frame->llc_control_ext, s_pf);
/*
* first decode the frame
*/
frame_kind = llc_decode(frame, linkp);
switch (action = llc_statehandler(linkp, frame, frame_kind, cmdrsp,
pollfinal)) {
case LLC_DATA_INDICATION:
m_adj(m, LLC_ISFRAMELEN);
if (m = m_pullup(m, NLHDRSIZEGUESS)) {
m->m_pkthdr.rcvif = (struct ifnet *)linkp->llcl_nlnext;
(*linkp->llcl_sapinfo->si_input)(m);
}
break;
}
/* release mbuf if not an info frame */
if (action != LLC_DATA_INDICATION && m)
m_freem(m);
/* try to get frames out ... */
llc_start(linkp);
return 0;
}
/*
* This routine is called by configuration setup. It sets up a station control
* block and notifies all registered upper level protocols.
*/
caddr_t
llc_ctlinput(int prc, struct sockaddr *addr, caddr_t info)
{
struct ifnet *ifp;
struct ifaddr *ifa;
struct dll_ctlinfo *ctlinfo = (struct dll_ctlinfo *)info;
u_char sap;
struct dllconfig *config;
caddr_t pcb;
struct rtentry *nlrt;
struct rtentry *llrt;
struct llc_linkcb *linkp;
register int i;
/* info must point to something valid at all times */
if (info == 0)
return 0;
if (prc == PRC_IFUP || prc == PRC_IFDOWN) {
/* we use either this set ... */
ifa = ifa_ifwithaddr(addr);
ifp = ifa ? ifa->ifa_ifp : 0;
if (ifp == 0)
return 0;
sap = ctlinfo->dlcti_lsap;
config = ctlinfo->dlcti_cfg;
pcb = (caddr_t) 0;
nlrt = (struct rtentry *) 0;
} else {
/* or this one */
sap = 0;
config = (struct dllconfig *) 0;
pcb = ctlinfo->dlcti_pcb;
nlrt = ctlinfo->dlcti_rt;
if ((llrt = rtalloc1(nlrt->rt_gateway, 0)))
llrt->rt_refcnt--;
else return 0;
linkp = ((struct npaidbentry *)llrt->rt_llinfo)->np_link;
}
switch (prc) {
case PRC_IFUP:
(void) llc_setsapinfo(ifp, addr->sa_family, sap, config);
return 0;
case PRC_IFDOWN: {
register struct llc_linkcb *linkp;
register struct llc_linkcb *nlinkp;
register int i;
/*
* All links are accessible over the doubly linked list llccb_q
*/
if (!LQEMPTY) {
/*
* A for-loop is not that great an idea as the linkp
* will get deleted by llc_timer()
*/
linkp = LQFIRST;
while (LQVALID(linkp)) {
nlinkp = LQNEXT(linkp);
if (linkp->llcl_if = ifp) {
i = splimp();
(void)llc_statehandler(linkp, (struct llc *)0,
NL_DISCONNECT_REQUEST,
0, 1);
splx(i);
}
linkp = nlinkp;
}
}
}
case PRC_CONNECT_REQUEST:
if (linkp == 0) {
if ((linkp = llc_newlink((struct sockaddr_dl *) nlrt->rt_gateway,
nlrt->rt_ifp, nlrt,
pcb, llrt)) == 0)
return (0);
((struct npaidbentry *)llrt->rt_llinfo)->np_link = linkp;
i = splimp();
(void)llc_statehandler(linkp, (struct llc *) 0,
NL_CONNECT_REQUEST, 0, 1);
splx(i);
}
return ((caddr_t)linkp);
case PRC_DISCONNECT_REQUEST:
if (linkp == 0)
panic("no link control block!");
i = splimp();
(void)llc_statehandler(linkp, (struct llc *) 0,
NL_DISCONNECT_REQUEST, 0, 1);
splx(i);
/*
* The actual removal of the link control block is done by the
* cleaning neutrum (i.e. llc_timer()).
*/
break;
case PRC_RESET_REQUEST:
if (linkp == 0)
panic("no link control block!");
i = splimp();
(void)llc_statehandler(linkp, (struct llc *) 0,
NL_RESET_REQUEST, 0, 1);
splx(i);
break;
}
return 0;
}
Reference in New Issue View Git Blame Copy Permalink