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BSD 4_3 development
[unix-history] / usr / contrib / enet / net / enet.c
/* enet.c Stanford 25 April 1983 */
/*
* Ethernet packet filter layer,
* formerly: Ethernet interface driver
*
**********************************************************************
* HISTORY
* 7 October 1985 Jeff Mogul Stanford
* Removed ENMAXOPENS limitation; available minors are now
* dynamically allocated to interfaces, out of pool of NENETFILTER
* minors.
* Certain arrays formerly in the enState structure are now global.
* Depends on modified openi() function so that enetopen() need
* only be called once.
* Remove support for "kernel access", it won't ever be used again.
* Added EIOCMFREE ioctl.
*
* 17 October 1984 Jeff Mogul Stanford
* More performance improvements:
* Added ENF_CAND, ENF_COR, ENF_CNAND, and ENF_CNOR, short-circuit
* operators, to make filters run faster.
* All evaluate "(*sp++ == *sp++)":
* ENF_CAND: returns false immediately if result is false, otherwise
* continue
* ENF_COR: returns true immediately if result is true, otherwise
* continue
* ENF_CNAND: returns true immediately if result is false, otherwise
* continue
* ENF_CNOR: returns false immediately if result is true, otherwise
* continue
* Also added ENF_NEQ to complement ENF_EQ
* - Maintain count of received packets per filter, dynamically
* re-organize filter queue to keep highly active filters in
* front of queue (but maintaining priority order), if they are
* "high priority" filters.
*
* 2 October 1984 Jeff Mogul Stanford
* Made a few changes to enDoFilter() to speed it up, since profiling
* shows it to be rather popular:
* - precompute maximum word in packet and address of end of
* filters (thereby moving this code out of "inner loop").
* - minor re-arrangement to avoid re-evaluating a
* common subexpression.
* - changed #ifdef DEBUG in a few routines to #ifdef INNERDEBUG,
* so that code in inner loops isn't always testing the enDebug
* flag; this not only costs directly, but also breaks up some
* basic blocks that the optimizer could play with.
* - added enOneCopy flag; if true, then never deliver more than
* one copy of a packet. This is equivalent to giving everyone
* a "high priority" device, and cuts down the number of superfluous
* calls to enDoFilter(). [Temporary hack, will remove this!]
*
* 24 August 1984 Jeff Mogul Stanford
* YA bug with sleeping in enetwrite(); straightened out handling
* of counts in enKludgeSleep so that they indicate the number
* of sleeps in progress. Maybe I've got this right, now?
* Also, don't sleep forever (since the net might be down).
*
* 17 July 1984 Jeff Mogul Stanford
* Bug fix: in enetwrite(), several problems with sleeping on
* IF_QFULL:
* - don't do it for kernel mode writes.
* - count # of procs sleeping, to avoid lost wakeups. Old
* scheme would only wake up the first sleeper.
* - using sleeper-count, avoid using more than one timeout
* table entry per device; old scheme caused timeout table panics
* - trap interupted sleeps using setjmp, so that we can deallocate
* packet header and mbufs; otherwise we lost them and panicked.
*
* 5 July 1984 Jeff Mogul Stanford
* Bug fix: in enetwrite() make sure enP_RefCount is zero before
* deallocating "packet". Otherwise, "packets" get lost, and
* take mbufs (and ultimately, the system) with them.
*
* 8 December 1983 Jeffrey Mogul Stanford
* Fixed bug in enetwrite() that eventually caused allocator
* to run out of packets and panic. If enetwrite() returns
* an error it should first deallocate any packets it has allocated.
*
* 10 November 1983 Jeffrey Mogul Stanford
* Slight restructuring for support of 10mb ethers;
* - added the EIOCDEVP ioctl
* - removed the EIOCMTU ioctl (subsumed by EIOCDEVP)
* This requires an additional parameter to the enetattach
* call so that the device driver can specify things.
*
* Also, cleaned up the enDebug scheme by adding symbolic
* definitions for the bits.
*
* 25-Apr-83 Jeffrey Mogul Stanford
* Began conversion to 4.2BSD. This involves removing all
* references to the actual hardware.
* Changed read/write interface to use uio scheme.
* Changed ioctl interface to "new style"; this places a hard
* limit on the size of a filter (about 128 bytes).
* "Packets" now point to mbufs, not private buffers.
* Filter can only access data in first mbuf (about 50 words worst case);
* this is long enough for all Pup purposes.
* Added EIOCMTU ioctl to get MTU (max packet size).
* Added an enetselect() routine and other select() support.
* Other stuff is (more or less) left intact.
* Most previous history comments removed.
* Changed some names from enXXXX to enetXXXX to avoid confusion(?)
*
* 10-Aug-82 Mike Accetta (mja) at Carnegie-Mellon University
* Added new EIOCMBIS and EIOCMBIC ioctl calls to set and clear
* bits in mode word; added mode bit ENHOLDSIG which suppresses
* the resetting of an enabled signal after it is sent (to be
* used inconjunction with the SIGHOLD mechanism); changed
* EIOCGETP to zero pad word for future compatibility; changed enwrite()
* to enforce correct source host address on output packets (V3.05e).
* (Stanford already uses long timeout value and has no pad word - JCM)
* [Last change before 4.2BSD conversion starts.]
*
* 01-Dec-81 Mike Accetta (mja) at Carnegie-Mellon University
* Fixed bug in timeout handling caused by missing "break" in the
* "switch" state check within enetread(). This caused all reads
* to be preceeded by a bogus timeout. In addition, fixed another
* bug in signal processing by also recording process ID of
* process to signal when an input packet is available. This is
* necessary because it is possible for a process with an enabled
* signal to fork and exit with no guarantee that the child will
* reenable the signal. Thus under appropriately bizarre race
* conditions, an incoming packet to the child can cause a signal
* to be sent to the unsuspecting process which inherited the
* process slot of the parent. Of course, if the PID's wrap around
* AND the inheriting process has the same PID, well ... (V3.03d).
*
* 22-Feb-80 Rick Rashid (rfr) at Carnegie-Mellon University
* Rewritten to provide multiple user access via user settable
* filters (V1.05).
*
* 18-Jan-80 Mike Accetta (mja) at Carnegie-Mellon University
* Created (V1.00).
*
**********************************************************************
*/
#include "en.h"
#include "ec.h"
#include "il.h"
#include "de.h"
#include "enetfilter.h"
/* number of potential units */
#define NENET (NEC + NEN + NIL + NDE)
#if (NENETFILTER > 0)
#define SUN_OPENI
#include "param.h"
#include "systm.h"
#include "mbuf.h"
#include "buf.h"
#include "dir.h"
#include "user.h"
#include "ioctl.h"
#include "map.h"
#include "proc.h"
#include "inode.h"
#include "file.h"
#include "tty.h"
#include "uio.h"
#include "protosw.h"
#include "socket.h"
#include "../net/if.h"
#undef queue
#undef dequeue
#include "../net/enet.h"
#include "../net/enetdefs.h"
#if (NENETFILTER < 32)
#undef NENETFILTER
#define NENETFILTER 32
#endif
#if (NENETFILTER > 256)
#undef NENETFILTER
#define NENETFILTER 256 /* maximum number of minor devices */
#endif
#define DEBUG 1
/* #define INNERDEBUG 1 */ /* define only when debugging enDoFilter()
or enInputDone() */
#define enprintf(flags) if (enDebug&(flags)) printf
/*
* Symbolic definitions for enDebug flag bits
* ENDBG_TRACE should be 1 because it is the most common
* use in the code, and the compiler generates faster code
* for testing the low bit in a word.
*/
#define ENDBG_TRACE 1 /* trace most operations */
#define ENDBG_DESQ 2 /* trace descriptor queues */
#define ENDBG_INIT 4 /* initialization info */
#define ENDBG_SCAV 8 /* scavenger operation */
#define ENDBG_ABNORM 16 /* abnormal events */
#define min(a,b) ( ((a)<=(b)) ? (a) : (b) )
#define splenet splimp /* used to be spl6 but I'm paranoid */
#define PRINET 26 /* interruptible */
\f
/*
* 'enQueueElts' is the pool of packet headers used by the driver.
* 'enPackets' is the pool of packets used by the driver (these should
* be allocated dynamically when this becomes possible).
* 'enFreeq' is the queue of available packets
* 'enState' is the driver state table per logical unit number
* 'enUnit' is the physical unit number table per logical unit number;
* the first "attach"ed ethernet is logical unit 0, etc.
* 'enUnitMap' maps minor device numbers onto interface unit #s
* 'enAllocMap' indicates if minor device is allocated or free
* 'enAllDescriptors' stores OpenDescriptors, indexed by minor device #
* 'enFreeqMin' is the minimum number of packets ever in the free queue
* (for statistics purposes)
* 'enScavenges' is the number of scavenges of the active input queues
* (for statustics purposes)
* 'enDebug' is a collection of debugging bits which enable trace and/or
* diagnostic output as defined above (ENDBG_*)
* 'enUnits' is the number of attached units
* 'enOneCopy' if true, then no packet is delivered to more than one minor
* device
*/
struct enPacket enQueueElts[ENPACKETS];
struct enQueue enFreeq;
struct enState enState[NENET];
char enUnitMap[NENETFILTER];
char enAllocMap[NENETFILTER];
struct enOpenDescriptor
enAllDescriptors[NENETFILTER];
int enFreeqMin = ENPACKETS;
int enScavenges = 0;
int enDebug = ENDBG_ABNORM;
int enUnits = 0;
int enOneCopy = 0;
int enMaxMinors = NENETFILTER;
/*
* Forward declarations for subroutines which return other
* than integer types.
*/
extern boolean enDoFilter();
/*
* Linkages to if_en.c
*/
struct enet_info {
struct ifnet *ifp; /* which ifp for output */
} enet_info[NENET];
struct sockaddr enetaf = { AF_IMPLINK };
\f
/****************************************************************
* *
* Various Macros & Routines *
* *
****************************************************************/
/*
* forAllOpenDescriptors(p) -- a macro for iterating
* over all currently open devices. Use it in place of
* "for ( ...; ... ; ... )"
* and supply your own loop body. The loop variable is the
* parameter p which is set to point to the descriptor for
* each open device in turn.
*/
#define forAllOpenDescriptors(p) \
for ((p) = (struct enOpenDescriptor *)enDesq.enQ_F; \
(struct Queue *)(&enDesq) != &((p)->enOD_Link); \
(p) = (struct enOpenDescriptor *)(p)->enOD_Link.F)
/*
* enEnqueue - add an element to a queue
*/
#define enEnqueue(q, elt) \
{ \
enqueue((struct Queue *)(q), (struct Queue *)(elt)); \
(q)->enQ_NumQueued++; \
}
/*
* enFlushQueue - release all packets from queue, freeing any
* whose reference counts drop to 0. Assumes caller
* is at high IPL so that queue will not be modified while
* it is being flushed.
*/
enFlushQueue(q)
register struct enQueue *q;
{
register struct enPacket *qelt;
while((qelt=(struct enPacket *)dequeue((struct Queue *)q)) != NULL)
{
if (0 == --(qelt->enP_RefCount))
{
enEnqueue(&enFreeq, qelt);
}
}
q->enQ_NumQueued = 0;
}
/*
* enInitWaitQueue - initialize an empty packet wait queue
*/
enInitWaitQueue(wq)
register struct enWaitQueue *wq;
{
wq->enWQ_Head = 0;
wq->enWQ_Tail = 0;
wq->enWQ_NumQueued = 0;
wq->enWQ_MaxWaiting = ENDEFWAITING;
}
/*
* enEnWaitQueue - add a packet to a wait queue
*/
enEnWaitQueue(wq, p)
register struct enWaitQueue *wq;
struct enPacket *p;
{
wq->enWQ_Packets[wq->enWQ_Tail] = p;
wq->enWQ_NumQueued++;
enNextWaitQueueIndex(wq->enWQ_Tail);
}
/*
* enDeWaitQueue - remove a packet from a wait queue
*/
struct enPacket *
enDeWaitQueue(wq)
register struct enWaitQueue *wq;
{
struct enPacket *p;
wq->enWQ_NumQueued--;
if (wq->enWQ_NumQueued < 0)
panic("enDeWaitQueue");
p = wq->enWQ_Packets[wq->enWQ_Head];
enNextWaitQueueIndex(wq->enWQ_Head);
return(p);
}
/*
* enTrimWaitQueue - cut a wait queue back to size
*/
enTrimWaitQueue(wq, threshold)
register struct enWaitQueue *wq;
{
register int Counter = (wq->enWQ_NumQueued - threshold);
register struct enPacket *p;
#ifdef DEBUG
enprintf(ENDBG_SCAV)
("enTrimWaitQueue(%x, %d): %d\n", wq, threshold, Counter);
#endif
while (Counter-- > 0)
{
wq->enWQ_NumQueued--;
enPrevWaitQueueIndex(wq->enWQ_Tail);
p = wq->enWQ_Packets[wq->enWQ_Tail];
if (0 == --(p->enP_RefCount))
{
m_freem(p->enP_mbuf);
enEnqueue(&enFreeq, p);
}
}
}
/*
* enFlushWaitQueue - remove all packets from wait queue
*/
#define enFlushWaitQueue(wq) enTrimWaitQueue(wq, 0)
/*
* scavenging thresholds:
*
* index by number of active files; for N open files, each queue may retain
* up to 1/Nth of the packets not guaranteed to be freed on scavenge. The
* total number of available packets is computed less one for sending.
*
* (assumes high IPL)
*/
char enScavLevel[NENETFILTER+1];
/*
* enInitScavenge -- set up ScavLevel table
*/
enInitScavenge()
{
register int PoolSize = (ENPACKETS-ENMINSCAVENGE);
register int i = sizeof(enScavLevel);
PoolSize--; /* leave one for transmitter */
while (--i>0)
enScavLevel[i] = (PoolSize / i);
}
/*
* enScavenge -- scan all OpenDescriptors for all ethernets, releasing
* any queued buffers beyond the prescribed limit and freeing any whose
* refcounts drop to 0.
* Assumes caller is at high IPL so that it is safe to modify the queues.
*/
enScavenge()
{
register struct enOpenDescriptor *d;
register int threshold = 0;
register struct enState *enStatep;
for (enStatep=enState; enStatep < &enState[NENET]; enStatep++)
threshold += enCurOpens;
threshold = enScavLevel[threshold];
/* recalculate thresholds based on current allocations */
enInitScavenge();
enScavenges++;
#ifdef DEBUG
enprintf(ENDBG_SCAV)("enScavenge: %d\n", threshold);
#endif
for (enStatep=enState; enStatep < &enState[NENET]; enStatep++)
{
if (enDesq.enQ_F == 0)
continue; /* never initialized */
forAllOpenDescriptors(d)
{
enTrimWaitQueue(&(d->enOD_Waiting), threshold);
}
}
}
/*
* enAllocatePacket - allocate the next packet from the free list
*
* Assumes IPL is at high priority so that it is safe to touch the
* packet queue. If the queue is currently empty, scavenge for
* more packets.
*/
struct enPacket *
enAllocatePacket()
{
register struct enPacket *p;
if (0 == enFreeq.enQ_NumQueued)
enScavenge();
p = (struct enPacket *)dequeue((struct Queue *)&enFreeq);
if (p == NULL)
panic("enAllocatePacket");
if (enFreeqMin > --enFreeq.enQ_NumQueued)
enFreeqMin = enFreeq.enQ_NumQueued;
p->enP_RefCount = 0; /* just in case */
return(p);
}
/*
* enDeallocatePacket - place the packet back on the free packet queue
*
* (High IPL assumed).
*/
#define enDeallocatePacket(p) \
{ \
if (p->enP_RefCount) panic("enDeallocatePacket: refcount != 0");\
enqueue((struct Queue *)&enFreeq, (struct Queue *)(p)); \
enFreeq.enQ_NumQueued++; \
}
\f
/****************************************************************
* *
* Routines to move uio data to/from mbufs *
* *
****************************************************************/
/*
* These two routines were inspired by/stolen from ../sys/uipc_socket.c
* Both return error code (or 0 if success).
*/
/*
* read: return contents of mbufs to user. DO NOT free them, since
* there may be multiple claims on the packet!
*/
enrmove(m, uio, count)
register struct mbuf *m;
register struct uio *uio;
register int count;
{
register int len;
register int error = 0;
count = min(count, uio->uio_resid); /* # of bytes to return */
while ((count > 0) && m && (error == 0)) {
len = min(count, m->m_len); /* length of this transfer */
count -= len;
error = uiomove(mtod(m, caddr_t), (int)len, UIO_READ, uio);
m = m->m_next;
}
return(error);
}
enwmove(uio, mbufp)
register struct uio *uio;
register struct mbuf **mbufp; /* top mbuf is returned by reference */
{
struct mbuf *mtop = 0;
register struct mbuf *m;
register struct mbuf **mp = &mtop;
register struct iovec *iov;
register int len;
int error = 0;
while ((uio->uio_resid > 0) && (error == 0)) {
iov = uio->uio_iov;
if (iov->iov_len == 0) {
uio->uio_iov++;
uio->uio_iovcnt--;
if (uio->uio_iovcnt < 0)
panic("enwmove: uio_iovcnt < 0 while uio_resid > 0");
}
MGET(m, M_WAIT, MT_DATA);
if (m == NULL) {
error = ENOBUFS;
break;
}
if (iov->iov_len >= CLBYTES) { /* big enough to use a page */
register struct mbuf *p;
MCLGET(p, 1);
if (p == 0)
goto nopages;
m->m_off = (int)p - (int)m;
len = CLBYTES;
}
else {
nopages:
len = MIN(MLEN, iov->iov_len);
}
error = uiomove(mtod(m, caddr_t), len, UIO_WRITE, uio);
m->m_len = len;
*mp = m;
mp = &(m->m_next);
}
if (error) { /* probably uiomove fouled up */
if (mtop)
m_freem(mtop);
}
else {
*mbufp = mtop; /* return ptr to top mbuf */
}
return(error);
}
/*
* enetopen - open ether net device
*
* Errors: ENXIO - illegal minor device number
* EBUSY - minor device already in use
*/
/* ARGSUSED */
enetopen(dev, flag, newmin)
dev_t dev;
int flag;
int *newmin;
{
register int md;
register int unit = minor(dev);
register struct enState *enStatep;
#ifndef SUN_OPENI
register int error;
#endif SUN_OPENI
/*
* Each open enet file has a different minor device number.
* When a user tries to open any of them, we actually open
* any available minor device and associate it with the
* corresponding unit.
*
* This is not elegant, but UNIX will call
* open for each new open file using the same inode but calls
* close only when the last open file referring to the inode
* is released. This means that we cannot know inside the
* driver code when the resources associated with a particular
* open of the same inode should be deallocated. Thus, we have
* to make up a temporary inode to represent each simultaneous
* open of the ethernet. Each inode has a different minor device number.
*/
#ifdef DEBUG
enprintf(ENDBG_TRACE)("enetopen(%o, %x):\n", unit, flag);
#endif
/* check for illegal minor dev */
if ( (unit >= enUnits) /* bad unit */
|| (enet_info[unit].ifp == 0) /* ifp not known */
|| ((enet_info[unit].ifp->if_flags & IFF_UP) == 0) )
/* or if down */
{
return(ENXIO);
}
md = enFindMinor();
#ifdef DEBUG
enprintf(ENDBG_TRACE)("enetopen: md = %d\n", md);
#endif
if (md < 0)
{
return(EBUSY);
}
enUnitMap[md] = unit;
enAllocMap[md] = TRUE;
#ifdef SUN_OPENI
*newmin = md;
#else
error = mkpseudo(makedev(major(dev), md)));
if (error) {
enAllocMap[md] = FALSE;
return(error);
}
#endif SUN_OPENI
enStatep = &enState[unit];
enprintf(ENDBG_DESQ)
("enetopen: Desq: %x, %x\n", enDesq.enQ_F, enDesq.enQ_B);
enInitDescriptor(&enAllDescriptors[md], flag);
enInsertDescriptor(&(enDesq), &enAllDescriptors[md]);
return(0);
}
/*
* enFindMinor - find a free logical device on specified unit
*/
enFindMinor()
{
register int md;
for (md = 0; md < enMaxMinors; md++) {
if (enAllocMap[md] == FALSE)
return(md);
}
return(-1);
}
/*
* enInit - intialize ethernet unit (called by enetattach)
*/
enInit(enStatep, unit)
register struct enState *enStatep;
register int unit;
{
#ifdef DEBUG
enprintf(ENDBG_INIT)("enInit(%x %d):\n", enStatep, unit);
#endif
/* initialize free queue if not already done */
if (enFreeq.enQ_F == 0)
{
register int i;
initqueue((struct Queue *)&enFreeq);
for (i=0; i<ENPACKETS; i++)
{
register struct enPacket *p;
p = &enQueueElts[i];
p->enP_RefCount = 0;
enDeallocatePacket(p);
}
/* also a good time to init enAllocMap */
for (i = 0; i < enMaxMinors; i++)
enAllocMap[i] = FALSE;
}
initqueue((struct Queue *)&enDesq); /* init descriptor queue */
}
\f
/*
* enetclose - ether net device close routine
*/
/* ARGSUSED */
enetclose(dev, flag)
{
register int md = ENINDEX(dev);
register struct enState *enStatep = &enState[ENUNIT(dev)];
register struct enOpenDescriptor *d = &enAllDescriptors[md];
int ipl;
enAllocMap[md] = FALSE;
#ifdef DEBUG
enprintf(ENDBG_TRACE)("enetclose(%d, %x):\n", md, flag);
#endif
/*
* insure that receiver doesn't try to queue something
* for the device as we are decommissioning it.
* (I don't think this is necessary, but I'm a coward.)
*/
ipl = splenet();
dequeue((struct Queue *)d->enOD_Link.B);
enCurOpens--;
enprintf(ENDBG_DESQ)
("enetclose: Desq: %x, %x\n", enDesq.enQ_F, enDesq.enQ_B);
enFlushWaitQueue(&(d->enOD_Waiting));
splx(ipl);
}
\f
/*
* enetread - read next packet from net
*/
/* VARARGS */
enetread(dev, uio)
dev_t dev;
register struct uio *uio;
{
register struct enOpenDescriptor *d = &enAllDescriptors[ENINDEX(dev)];
register struct enPacket *p;
int ipl;
int error;
extern enTimeout();
#if DEBUG
enprintf(ENDBG_TRACE)("enetread(%x):", dev);
#endif
ipl = splenet();
/*
* If nothing is on the queue of packets waiting for
* this open enet file, then set timer and sleep until
* either the timeout has occurred or a packet has
* arrived.
*/
while (0 == d->enOD_Waiting.enWQ_NumQueued)
{
if (d->enOD_Timeout < 0)
{
splx(ipl);
return(0);
}
if (d->enOD_Timeout)
{
/*
* If there was a previous timeout pending for this file,
* cancel it before setting another. This is necessary since
* a cancel after the sleep might never happen if the read is
* interrupted by a signal.
*/
if (d->enOD_RecvState == ENRECVTIMING)
untimeout(enTimeout, (caddr_t)d);
timeout(enTimeout, (caddr_t)d, (int)(d->enOD_Timeout));
d->enOD_RecvState = ENRECVTIMING;
}
else
d->enOD_RecvState = ENRECVIDLE;
sleep((caddr_t)d, PRINET);
switch (d->enOD_RecvState)
{
case ENRECVTIMING:
{
untimeout(enTimeout, (caddr_t)d);
d->enOD_RecvState = ENRECVIDLE;
break;
}
case ENRECVTIMEDOUT:
{
splx(ipl);
return(0);
}
}
}
p = enDeWaitQueue(&(d->enOD_Waiting));
splx(ipl);
/*
* Move data from packet into user space.
*/
error = enrmove(p->enP_mbuf, uio, p->enP_ByteCount);
ipl = splenet();
if (0 == --(p->enP_RefCount)) /* if no more claims on this packet */
{
m_freem(p->enP_mbuf); /* release mbuf */
enDeallocatePacket(p); /* and packet */
}
splx(ipl);
return(error);
}
/*
* enTimeout - process ethernet read timeout
*/
enTimeout(d)
register struct enOpenDescriptor * d;
{
register int ipl;
#ifdef DEBUG
enprintf(ENDBG_TRACE)("enTimeout(%x):\n", d);
#endif
ipl = splenet();
d->enOD_RecvState = ENRECVTIMEDOUT;
wakeup((caddr_t)d);
enetwakeup(d);
splx(ipl);
}
\f
/*
* enetwrite - write next packet to net
*/
int enKludgeSleep[NENET]; /* Are we sleeping on IF_QFULL? */
/* really, # of procs sleeping on IF_QFULL */
/* VARARGS */
enetwrite(dev, uio)
dev_t dev;
register struct uio *uio;
{
register int unit = ENUNIT(dev);
register struct enState *enStatep = &enState[unit];
struct mbuf *mp;
register struct ifnet *ifp = enet_info[unit].ifp;
int ipl;
int error;
int sleepcount;
int enKludgeTime();
#if DEBUG
enprintf(ENDBG_TRACE)("enetwrite(%x):\n", dev);
#endif
if (uio->uio_resid == 0)
return(0);
if (uio->uio_resid > ifp->if_mtu) /* too large */
return(EMSGSIZE);
/*
* Copy user data into mbufs
*/
if (error = enwmove(uio, &mp)) {
return(error);
}
ipl = splenet();
/*
* if the queue is full,
* hang around until there's room or until process is interrupted
*/
sleepcount = 0;
while (IF_QFULL(&(ifp->if_snd))) {
extern int hz;
if (sleepcount++ > 2) { /* don't sleep too long */
splx(ipl);
return(ETIMEDOUT);
}
/* if nobody else has a timeout pending for this unit, set one */
if (enKludgeSleep[unit] == 0)
timeout(enKludgeTime, (caddr_t)unit, 2 * hz);
enKludgeSleep[unit]++; /* record that we are sleeping */
if (setjmp(&u.u_qsave)) {
/* sleep (following) was interrupted, clean up */
#if DEBUG
enprintf(ENDBG_ABNORM)
("enetwrite(%x): enet%d sleep %d interrupted\n", dev,
unit, enKludgeSleep[unit]);
#endif DEBUG
enKludgeSleep[unit]--; /* we're no longer sleeping */
m_freem(mp);
splx(ipl);
return(EINTR);
}
sleep((caddr_t)&(enKludgeSleep[unit]), PRINET);
enKludgeSleep[unit]--; /* we are no longer sleeping */
}
/* place mbuf chain on outgoing queue & start if necessary */
error = (*ifp->if_output)(ifp, mp, &enetaf);
/* this always frees the mbuf chain */
enXcnt++;
splx(ipl);
return(error);
}
enKludgeTime(unit)
int unit;
{
/* XXX perhaps we should always wakeup? */
if (enKludgeSleep[unit]) {
wakeup((caddr_t)&(enKludgeSleep[unit]));
/* XXX should we restart transmitter? */
}
}
\f
/*
* enetioctl - ether net control
*
* EIOCGETP - get ethernet parameters
* EIOCSETP - set ethernet read timeout
* EIOCSETF - set ethernet read filter
* EIOCENBS - enable signal when read packet available
* EIOCINHS - inhibit signal when read packet available
* FIONREAD - check for read packet available
* EIOCSETW - set maximum read packet waiting queue length
* EIOCFLUSH - flush read packet waiting queue
* EIOCMBIS - set mode bits
* EIOCMBIC - clear mode bits
* EICODEVP - get device parameters
* EIOCMFREE - number of free minors
*/
/* ARGSUSED */
enetioctl(dev, cmd, addr, flag)
caddr_t addr;
dev_t flag;
{
register struct enState *enStatep = &enState[ENUNIT(dev)];
register struct enOpenDescriptor * d = &enAllDescriptors[ENINDEX(dev)];
int ipl;
#if DEBUG
enprintf(ENDBG_TRACE)
("enetioctl(%x, %x, %x, %x):\n", dev, cmd, addr, flag);
#endif
switch (cmd)
{
case EIOCGETP:
{
struct eniocb t;
t.en_maxwaiting = ENMAXWAITING;
t.en_maxpriority = ENMAXPRI;
t.en_rtout = d->enOD_Timeout;
t.en_addr = -1;
t.en_maxfilters = ENMAXFILTERS;
bcopy((caddr_t)&t, addr, sizeof t);
}
endcase
case EIOCSETP:
{
struct eniocb t;
bcopy(addr, (caddr_t)&t, sizeof t);
d->enOD_Timeout = t.en_rtout;
}
endcase
case EIOCSETF:
{
struct enfilter f;
unsigned short *fp;
bcopy(addr, (caddr_t)&f, sizeof f);
if (f.enf_FilterLen > ENMAXFILTERS)
{
return(EINVAL);
}
/* insure that filter is installed indivisibly */
ipl = splenet();
bcopy((caddr_t)&f, (caddr_t)&(d->enOD_OpenFilter), sizeof f);
/* pre-compute length of filter */
fp = &(d->enOD_OpenFilter.enf_Filter[0]);
d->enOD_FiltEnd = &(fp[d->enOD_OpenFilter.enf_FilterLen]);
d->enOD_RecvCount = 0; /* reset count when filter changes */
dequeue((struct Queue *)d->enOD_Link.B);
enDesq.enQ_NumQueued--;
enInsertDescriptor(&(enDesq), d);
splx(ipl);
}
endcase
/*
* Enable signal n on input packet
*/
case EIOCENBS:
{
int snum;
bcopy(addr, (caddr_t)&snum, sizeof snum);
if (snum < NSIG) {
d->enOD_SigProc = u.u_procp;
d->enOD_SigPid = u.u_procp->p_pid;
d->enOD_SigNumb = snum; /* This must be set last */
} else {
goto bad;
}
}
endcase
/*
* Disable signal on input packet
*/
case EIOCINHS:
{
d->enOD_SigNumb = 0;
}
endcase
/*
* Check for packet waiting
*/
case FIONREAD:
{
int n;
register struct enWaitQueue *wq;
ipl = splenet();
if ((wq = &(d->enOD_Waiting))->enWQ_NumQueued)
n = wq->enWQ_Packets[wq->enWQ_Head]->enP_ByteCount;
else
n = 0;
splx(ipl);
bcopy((caddr_t)&n, addr, sizeof n);
}
endcase
/*
* Set maximum recv queue length for a device
*/
case EIOCSETW:
{
unsigned un;
bcopy(addr, (caddr_t)&un, sizeof un);
/*
* unsigned un MaxQueued
* ---------------- ------------
* 0 -> DEFWAITING
* 1..MAXWAITING -> un
* MAXWAITING..-1 -> MAXWAITING
*/
d->enOD_Waiting.enWQ_MaxWaiting = (un) ? min(un, ENMAXWAITING)
: ENDEFWAITING;
}
endcase
/*
* Flush all packets queued for a device
*/
case EIOCFLUSH:
{
ipl = splenet();
enFlushWaitQueue(&(d->enOD_Waiting));
splx(ipl);
}
endcase
/*
* Set mode bits
*/
case EIOCMBIS:
{
u_short mode;
bcopy(addr, (caddr_t)&mode, sizeof mode);
if (mode&ENPRIVMODES)
return(EINVAL);
else
d->enOD_Flag |= mode;
}
endcase
/*
* Clear mode bits
*/
case EIOCMBIC:
{
u_short mode;
bcopy(addr, (caddr_t)&mode, sizeof mode);
if (mode&ENPRIVMODES)
return(EINVAL);
else
d->enOD_Flag &= ~mode;
}
endcase
/*
* Return hardware-specific device parameters.
*/
case EIOCDEVP:
{
bcopy((caddr_t)&(enDevParams), addr, sizeof(struct endevp));
}
endcase;
/*
* Return # of free minor devices.
*/
case EIOCMFREE:
{
register int md;
register int sum = 0;
for (md = 0; md < enMaxMinors; md++)
if (enAllocMap[md] == FALSE)
sum++;
*(int *)addr = sum;
}
endcase;
default:
{
bad:
return(EINVAL);
}
}
return(0);
}
\f
/****************************************************************
* *
* Support for select() system call *
* *
* Other hooks in: *
* enInitDescriptor() *
* enInputDone() *
* enTimeout() *
****************************************************************/
/*
* inspired by the code in tty.c for the same purpose.
*/
/*
* enetselect - returns true iff the specific operation
* will not block indefinitely. Otherwise, return
* false but make a note that a selwakeup() must be done.
*/
enetselect(dev, rw)
register dev_t dev;
int rw;
{
register struct enOpenDescriptor *d;
register struct enWaitQueue *wq;
register int ipl;
register int avail;
switch (rw) {
case FREAD:
/*
* an imitation of the FIONREAD ioctl code
*/
d = &(enAllDescriptors[ENINDEX(dev)]);
ipl = splenet();
wq = &(d->enOD_Waiting);
if (wq->enWQ_NumQueued)
avail = 1; /* at least one packet queued */
else {
avail = 0; /* sorry, nothing queued now */
/*
* If there's already a select() waiting on this
* minor device then this is a collision.
* [This shouldn't happen because enet minors
* really should not be shared, but if a process
* forks while one of these is open, it is possible
* that both processes could select() us.]
*/
if (d->enOD_SelProc
&& d->enOD_SelProc->p_wchan == (caddr_t)&selwait)
d->enOD_SelColl = 1;
else
d->enOD_SelProc = u.u_procp;
}
splx(ipl);
return(avail);
case FWRITE:
/*
* since the queueing for output is shared not just with
* the other enet devices but also with the IP system,
* we can't predict what would happen on a subsequent
* write. However, since we presume that all writes
* complete eventually, and probably fairly fast, we
* pretend that select() is true.
*/
return(1);
default: /* hmmm. */
return(1); /* don't block in select() */
}
}
enetwakeup(d)
register struct enOpenDescriptor *d;
{
if (d->enOD_SelProc) {
selwakeup(d->enOD_SelProc, d->enOD_SelColl);
d->enOD_SelColl = 0;
d->enOD_SelProc = 0;
}
}
\f
/*
* enetFilter - incoming linkage from ../vaxif/if_en.c
*/
enetFilter(en, m, count)
register int en;
register struct mbuf *m;
register int count;
{
register struct enState *enStatep = &enState[en];
register struct enPacket *p;
register int pullcount; /* bytes, not words */
int s = splenet();
#if DEBUG
enprintf(ENDBG_TRACE)("enetFilter(%d):\n", en);
#endif
p = enAllocatePacket(); /* panics if not possible */
p->enP_ByteCount = count;
pullcount = min(MLEN, count); /* largest possible first mbuf */
if (m->m_len < pullcount) {
/* first mbuf not as full as it could be - fix this */
if ((m = m_pullup(m, pullcount)) == 0) {
/* evidently no resources; bloody m_pullup discarded mbuf */
enDeallocatePacket(p);
enRdrops++;
goto out;
}
}
p->enP_mbuf = m;
p->enP_Data = mtod(m, u_short *);
enInputDone(enStatep, p);
out:
splx(s);
}
\f
/*
* enInputDone - process correctly received packet
*/
enInputDone(enStatep, p)
register struct enState *enStatep;
register struct enPacket *p;
{
register struct enOpenDescriptor *d;
int queued = 0;
register int maxword;
register unsigned long rcount;
register struct enOpenDescriptor *prevd;
#if INNERDEBUG
enprintf(ENDBG_TRACE)("enInputDone(%x): %x\n", enStatep, p);
#endif
/* precompute highest possible word offset */
/* can't address beyond end of packet or end of first mbuf */
maxword = (min(p->enP_ByteCount, p->enP_mbuf->m_len)>>1);
forAllOpenDescriptors(d)
{
if (enDoFilter(p, d, maxword))
{
if (d->enOD_Waiting.enWQ_NumQueued < d->enOD_Waiting.enWQ_MaxWaiting)
{
enEnWaitQueue(&(d->enOD_Waiting), p);
p->enP_RefCount++;
queued++;
wakeup((caddr_t)d);
enetwakeup(d);
#if INNERDEBUG
enprintf(ENDBG_TRACE)("enInputDone: queued\n");
#endif
}
/* send notification when input packet received */
if (d->enOD_SigNumb) {
if (d->enOD_SigProc->p_pid == d->enOD_SigPid)
psignal(d->enOD_SigProc, d->enOD_SigNumb);
if ((d->enOD_Flag & ENHOLDSIG) == 0)
d->enOD_SigNumb = 0; /* disable signal */
}
rcount = ++(d->enOD_RecvCount);
/* see if ordering of filters is wrong */
if (d->enOD_OpenFilter.enf_Priority >= ENHIPRI) {
prevd = (struct enOpenDescriptor *)d->enOD_Link.B;
/*
* If d is not the first element on the queue, and
* the previous element is at equal priority but has
* a lower count, then promote d to be in front of prevd.
*/
if (((struct Queue *)prevd != &(enDesq.enQ_Head)) &&
(d->enOD_OpenFilter.enf_Priority ==
prevd->enOD_OpenFilter.enf_Priority)) {
/* threshold difference to avoid thrashing */
if ((100 + prevd->enOD_RecvCount) < rcount) {
enReorderQueue(&(prevd->enOD_Link), &(d->enOD_Link));
}
}
break; /* high-priority filter => no more deliveries */
}
else if (enOneCopy)
break;
}
}
if (queued == 0) /* this buffer no longer in use */
{
m_freem(p->enP_mbuf); /* free mbuf */
enDeallocatePacket(p); /* and packet */
enRdrops++;
}
else
enRcnt++;
}
\f
#define opx(i) (i>>ENF_NBPA)
boolean
enDoFilter(p, d, maxword)
struct enPacket *p;
struct enOpenDescriptor *d;
register int maxword;
{
register unsigned short *sp;
register unsigned short *fp;
register unsigned short *fpe;
register unsigned op;
register unsigned arg;
unsigned short stack[ENMAXFILTERS+1];
struct fw {unsigned arg:ENF_NBPA, op:ENF_NBPO;};
#ifdef INNERDEBUG
enprintf(ENDBG_TRACE)("enDoFilter(%x,%x):\n", p, d);
#endif
sp = &stack[ENMAXFILTERS];
fp = &d->enOD_OpenFilter.enf_Filter[0];
fpe = d->enOD_FiltEnd;
/* ^ is really: fpe = &fp[d->enOD_OpenFilter.enf_FilterLen]; */
*sp = TRUE;
for (; fp < fpe; )
{
op = ((struct fw *)fp)->op;
arg = ((struct fw *)fp)->arg;
fp++;
switch (arg)
{
default:
arg -= ENF_PUSHWORD;
#ifndef lint
/*
* This next test is a little bogus; since arg
* is unsigned, it is always >= 0 (the compiler
* knows this and emits no code). If arg were
* less than ENF_PUSHWORD before the subtract,
* it is certaintly going to be more than maxword
* afterward, so the code does work "right"
*/
if ((arg >= 0) && (arg < maxword))
#else
if (arg < maxword)
#endif lint
*--sp = p->enP_Data[arg];
else
{
#ifdef INNERDEBUG
enprintf(ENDBG_TRACE)("=>0(len)\n");
#endif
return(false);
}
break;
case ENF_PUSHLIT:
*--sp = *fp++;
break;
case ENF_PUSHZERO:
*--sp = 0;
case ENF_NOPUSH:
break;
}
if (sp < &stack[2]) /* check stack overflow: small yellow zone */
{
enprintf(ENDBG_TRACE)("=>0(--sp)\n");
return(false);
}
if (op == ENF_NOP)
continue;
/*
* all non-NOP operators binary, must have at least two operands
* on stack to evaluate.
*/
if (sp > &stack[ENMAXFILTERS-2])
{
enprintf(ENDBG_TRACE)("=>0(sp++)\n");
return(false);
}
arg = *sp++;
switch (op)
{
default:
#ifdef INNERDEBUG
enprintf(ENDBG_TRACE)("=>0(def)\n");
#endif
return(false);
case opx(ENF_AND):
*sp &= arg;
break;
case opx(ENF_OR):
*sp |= arg;
break;
case opx(ENF_XOR):
*sp ^= arg;
break;
case opx(ENF_EQ):
*sp = (*sp == arg);
break;
case opx(ENF_NEQ):
*sp = (*sp != arg);
break;
case opx(ENF_LT):
*sp = (*sp < arg);
break;
case opx(ENF_LE):
*sp = (*sp <= arg);
break;
case opx(ENF_GT):
*sp = (*sp > arg);
break;
case opx(ENF_GE):
*sp = (*sp >= arg);
break;
/* short-circuit operators */
case opx(ENF_COR):
if (*sp++ == arg) {
#ifdef INNERDEBUG
enprintf(ENDBG_TRACE)("=>COR %x\n", *sp);
#endif
return(true);
}
break;
case opx(ENF_CAND):
if (*sp++ != arg) {
#ifdef INNERDEBUG
enprintf(ENDBG_TRACE)("=>CAND %x\n", *sp);
#endif
return(false);
}
break;
case opx(ENF_CNOR):
if (*sp++ == arg) {
#ifdef INNERDEBUG
enprintf(ENDBG_TRACE)("=>COR %x\n", *sp);
#endif
return(false);
}
break;
case opx(ENF_CNAND):
if (*sp++ != arg) {
#ifdef INNERDEBUG
enprintf(ENDBG_TRACE)("=>CAND %x\n", *sp);
#endif
return(true);
}
break;
}
}
#ifdef INNERDEBUG
enprintf(ENDBG_TRACE)("=>%x\n", *sp);
#endif
return((boolean)*sp);
}
\f
enInitDescriptor(d, flag)
register struct enOpenDescriptor *d;
{
#if DEBUG
enprintf(ENDBG_TRACE)("enInitDescriptor(%x):\n", d);
#endif
d->enOD_RecvState = ENRECVIDLE;
d->enOD_OpenFilter.enf_FilterLen = 0;
d->enOD_OpenFilter.enf_Priority = 0;
d->enOD_FiltEnd = &(d->enOD_OpenFilter.enf_Filter[0]);
d->enOD_RecvCount = 0;
d->enOD_Timeout = 0;
d->enOD_SigNumb = 0;
d->enOD_Flag = flag;
d->enOD_SelColl = 0;
d->enOD_SelProc = 0; /* probably unnecessary */
/*
* Remember the PID that opened us, at least until some process
* sets a signal for this minor device
*/
d->enOD_SigPid = u.u_procp->p_pid;
enInitWaitQueue(&(d->enOD_Waiting));
#if DEBUG
enprintf(ENDBG_TRACE)("=>eninitdescriptor\n");
#endif
}
/*
* enInsertDescriptor - insert open descriptor in queue ordered by priority
*/
enInsertDescriptor(q, d)
register struct enQueue *q;
register struct enOpenDescriptor *d;
{
struct enOpenDescriptor * nxt;
register int ipl;
ipl = splenet();
nxt = (struct enOpenDescriptor *)q->enQ_F;
while ((struct Queue *)q != &(nxt->enOD_Link))
{
if (d->enOD_OpenFilter.enf_Priority > nxt->enOD_OpenFilter.enf_Priority)
break;
nxt = (struct enOpenDescriptor *)nxt->enOD_Link.F;
}
enqueue((struct Queue *)&(nxt->enOD_Link),(struct Queue *)&(d->enOD_Link));
enprintf(ENDBG_DESQ)("enID: Desq: %x, %x\n", q->enQ_F, q->enQ_B);
q->enQ_NumQueued++;
splx(ipl);
}
int enReorderCount = 0; /* for external monitoring */
/*
* enReorderQueue - swap order of two elements in queue
* assumed to be called at splenet
*/
enReorderQueue(first, last)
register struct Queue *first;
register struct Queue *last;
{
register struct Queue *prev;
register struct Queue *next;
enprintf(ENDBG_DESQ)("enReorderQ: %x, %x\n", first, last);
enReorderCount++;
/* get pointers to other queue elements */
prev = first->B;
next = last->F;
/*
* no more reading from queue elements; this ensures that
* the code works even if there are fewer than 4 elements
* in the queue.
*/
prev->F = last;
next->B = first;
last->B = prev;
last->F = first;
first->F = next;
first->B = last;
}
enetattach(ifp, devp)
struct ifnet *ifp;
struct endevp *devp;
{
register struct enState *enStatep = &enState[enUnits];
#ifdef DEBUG
enprintf(ENDBG_INIT) ("enetattach: type %d, addr ", devp->end_dev_type);
if (enDebug&ENDBG_INIT) {
register int i;
for (i = 0; i < devp->end_addr_len; i++)
printf("%o ", devp->end_addr[i]);
printf("\n");
}
#endif DEBUG
enet_info[enUnits].ifp = ifp;
bcopy((caddr_t)devp, (caddr_t)&(enDevParams), sizeof(struct endevp));
enInit(enStatep, enUnits);
return(enUnits++);
}
#endif (NENETFILTER > 0)
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.