2.9BSD/usr/net/sys/net/if_en.c
/* if_en.c 4.67 82/06/20 */
#include "en.h"
/*
* Xerox prototype (3 Mb) Ethernet interface driver.
*/
#include "param.h"
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/buf.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/ubavar.h>
#include <sys/enreg.h>
#include "../net/in.h"
#include "../net/in_systm.h"
#include "../net/if.h"
#include "../net/if_en.h"
#include "../net/if_uba.h"
#include "../net/ip.h"
#include "../net/ip_var.h"
#include "../net/pup.h"
#include "../net/route.h"
#include <errno.h>
#define ENMTU (1024+512)
#define ENMRU (1024+512+16) /* 16 is enough to receive trailer */
int enprobe(), enattach(), enrint(), enxint(), encollide();
struct uba_device *eninfo[NEN];
u_short enstd[] = { 0 };
struct uba_driver endriver =
{ enprobe, 0, enattach, 0, enstd, "en", eninfo };
#define ENUNIT(x) minor(x)
int eninit(),enoutput(),enreset();
/*
* Ethernet software status per interface.
*
* Each interface is referenced by a network interface structure,
* es_if, which the routing code uses to locate the interface.
* This structure contains the output queue for the interface, its address, ...
* We also have, for each interface, a UBA interface structure, which
* contains information about the UNIBUS resources held by the interface:
* map registers, buffered data paths, etc. Information is cached in this
* structure for use by the if_uba.c routines in running the interface
* efficiently.
*/
struct en_softc {
struct ifnet es_if; /* network-visible interface */
struct ifuba es_ifuba; /* UNIBUS resources */
short es_delay; /* current output delay */
short es_mask; /* mask for current output delay */
short es_lastx; /* host last transmitted to */
short es_oactive; /* is output active? */
short es_olen; /* length of last output */
} en_softc[NEN];
/*
* Do output DMA to determine interface presence and
* interrupt vector. DMA is too short to disturb other hosts.
*/
enprobe(reg)
caddr_t reg;
{
register int br, cvec; /* r11, r10 value-result */
register struct endevice *addr = (struct endevice *)reg;
#ifdef lint
br = 0; cvec = br; br = cvec;
enrint(0); enxint(0); encollide(0);
#endif
addr->en_istat = 0;
addr->en_owc = -1;
addr->en_oba = 0;
addr->en_ostat = EN_IEN|EN_GO;
DELAY(100000);
addr->en_ostat = 0;
#ifdef ECHACK
br = 0x16;
#endif
return (1);
}
/*
* Interface exists: make available by filling in network interface
* record. System will initialize the interface when it is ready
* to accept packets.
*/
enattach(ui)
struct uba_device *ui;
{
register struct en_softc *es = &en_softc[ui->ui_unit];
register struct sockaddr_in *sin;
es->es_if.if_unit = ui->ui_unit;
es->es_if.if_name = "en";
es->es_if.if_mtu = ENMTU;
es->es_if.if_net = ui->ui_flags;
es->es_if.if_host[0] =
(~(((struct endevice *)eninfo[ui->ui_unit]->ui_addr)->en_addr)) & 0xff;
sin = (struct sockaddr_in *)&es->es_if.if_addr;
sin->sin_family = AF_INET;
sin->sin_addr = if_makeaddr(es->es_if.if_net, es->es_if.if_host[0]);
sin = (struct sockaddr_in *)&es->es_if.if_broadaddr;
sin->sin_family = AF_INET;
sin->sin_addr = if_makeaddr(es->es_if.if_net, 0);
es->es_if.if_flags = IFF_BROADCAST;
es->es_if.if_init = eninit;
es->es_if.if_output = enoutput;
es->es_if.if_ubareset = enreset;
es->es_ifuba.ifu_flags = UBA_NEEDBDP | UBA_NEED16 | UBA_CANTWAIT;
if_attach(&es->es_if);
}
/*
* Reset of interface after UNIBUS reset.
* If interface is on specified uba, reset its state.
*/
enreset(unit, uban)
int unit, uban;
{
register struct uba_device *ui;
if (unit >= NEN || (ui = eninfo[unit]) == 0 || ui->ui_alive == 0 ||
ui->ui_ubanum != uban)
return;
printf(" en%d", unit);
eninit(unit);
}
/*
* Initialization of interface; clear recorded pending
* operations, and reinitialize UNIBUS usage.
*/
eninit(unit)
int unit;
{
register struct en_softc *es = &en_softc[unit];
register struct uba_device *ui = eninfo[unit];
register struct endevice *addr;
int s;
if (if_ubainit(&es->es_ifuba, ui->ui_ubanum,
sizeof (struct en_header), (int)btoc(ENMRU)) == 0) {
printf("en%d: can't initialize\n", unit);
es->es_if.if_flags &= ~IFF_UP;
return;
}
addr = (struct endevice *)ui->ui_addr;
addr->en_istat = addr->en_ostat = 0;
/*
* Hang a receive and start any
* pending writes by faking a transmit complete.
*/
s = splimp();
addr->en_iba = es->es_ifuba.ifu_r.ifrw_info;
addr->en_iwc = -(sizeof (struct en_header) + ENMRU) >> 1;
addr->en_istat = EN_IEN|EN_GO;
es->es_oactive = 1;
es->es_if.if_flags |= IFF_UP;
enxint(unit);
splx(s);
if_rtinit(&es->es_if, RTF_UP);
}
int enalldelay = 0;
int enlastdel = 50;
int enlastmask = (~0) << 5;
/*
* Start or restart output on interface.
* If interface is already active, then this is a retransmit
* after a collision, and just restuff registers and delay.
* If interface is not already active, get another datagram
* to send off of the interface queue, and map it to the interface
* before starting the output.
*/
enstart(dev)
dev_t dev;
{
int unit = ENUNIT(dev);
struct uba_device *ui = eninfo[unit];
register struct en_softc *es = &en_softc[unit];
register struct endevice *addr;
struct mbuf *m;
int dest;
if (es->es_oactive)
goto restart;
/*
* Not already active: dequeue another request
* and map it to the UNIBUS. If no more requests,
* just return.
*/
IF_DEQUEUE(&es->es_if.if_snd, m);
if (m == 0) {
es->es_oactive = 0;
return;
}
dest = mtod(m, struct en_header *)->en_dhost;
es->es_olen = if_wubaput(&es->es_ifuba, m);
/*
* Ethernet cannot take back-to-back packets (no
* buffering in interface. To help avoid overrunning
* receivers, enforce a small delay (about 1ms) in interface:
* * between all packets when enalldelay
* * whenever last packet was broadcast
* * whenever this packet is to same host as last packet
*/
if (enalldelay || es->es_lastx == 0 || es->es_lastx == dest) {
es->es_delay = enlastdel;
es->es_mask = enlastmask;
}
es->es_lastx = dest;
restart:
/*
* Have request mapped to UNIBUS for transmission.
* Purge any stale data from this BDP, and start the otput.
*/
if (es->es_ifuba.ifu_flags & UBA_NEEDBDP)
UBAPURGE(es->es_ifuba.ifu_uba, es->es_ifuba.ifu_w.ifrw_bdp);
addr = (struct endevice *)ui->ui_addr;
addr->en_oba = (int)es->es_ifuba.ifu_w.ifrw_info;
addr->en_odelay = es->es_delay;
addr->en_owc = -((es->es_olen + 1) >> 1);
addr->en_ostat = EN_IEN|EN_GO;
es->es_oactive = 1;
}
/*
* Ethernet interface transmitter interrupt.
* Start another output if more data to send.
*/
enxint(unit)
int unit;
{
register struct uba_device *ui = eninfo[unit];
register struct en_softc *es = &en_softc[unit];
register struct endevice *addr = (struct endevice *)ui->ui_addr;
if (es->es_oactive == 0)
return;
if (es->es_mask && (addr->en_ostat&EN_OERROR)) {
es->es_if.if_oerrors++;
endocoll(unit);
return;
}
es->es_if.if_opackets++;
es->es_oactive = 0;
es->es_delay = 0;
es->es_mask = ~0;
if (es->es_ifuba.ifu_xtofree) {
m_freem(es->es_ifuba.ifu_xtofree);
es->es_ifuba.ifu_xtofree = 0;
}
if (es->es_if.if_snd.ifq_head == 0) {
es->es_lastx = 256; /* putatively illegal */
return;
}
enstart(unit);
}
/*
* Collision on ethernet interface. Do exponential
* backoff, and retransmit. If have backed off all
* the way print warning diagnostic, and drop packet.
*/
encollide(unit)
int unit;
{
struct en_softc *es = &en_softc[unit];
es->es_if.if_collisions++;
if (es->es_oactive == 0)
return;
endocoll(unit);
}
endocoll(unit)
int unit;
{
register struct en_softc *es = &en_softc[unit];
/*
* Es_mask is a 16 bit number with n low zero bits, with
* n the number of backoffs. When es_mask is 0 we have
* backed off 16 times, and give up.
*/
if (es->es_mask == 0) {
printf("en%d: send error\n", unit);
enxint(unit);
return;
}
/*
* Another backoff. Restart with delay based on n low bits
* of the interval timer.
*/
es->es_mask <<= 1;
es->es_delay = mfpr(ICR) &~ es->es_mask;
enstart(unit);
}
struct sockaddr_pup pupsrc = { AF_PUP };
struct sockaddr_pup pupdst = { AF_PUP };
struct sockproto pupproto = { PF_PUP };
/*
* Ethernet interface receiver interrupt.
* If input error just drop packet.
* Otherwise purge input buffered data path and examine
* packet to determine type. If can't determine length
* from type, then have to drop packet. Othewise decapsulate
* packet based on type and pass to type specific higher-level
* input routine.
*/
enrint(unit)
int unit;
{
register struct en_softc *es = &en_softc[unit];
struct endevice *addr = (struct endevice *)eninfo[unit]->ui_addr;
register struct en_header *en;
struct mbuf *m;
int len, plen; short resid;
register struct ifqueue *inq;
int off;
es->es_if.if_ipackets++;
/*
* Purge BDP; drop if input error indicated.
*/
if (es->es_ifuba.ifu_flags & UBA_NEEDBDP)
UBAPURGE(es->es_ifuba.ifu_uba, es->es_ifuba.ifu_r.ifrw_bdp);
if (addr->en_istat&EN_IERROR) {
es->es_if.if_ierrors++;
goto setup;
}
/*
* Calculate input data length.
* Get pointer to ethernet header (in input buffer).
* Deal with trailer protocol: if type is PUP trailer
* get true type from first 16-bit word past data.
* Remember that type was trailer by setting off.
*/
resid = addr->en_iwc;
if (resid)
resid |= 0176000;
len = (((sizeof (struct en_header) + ENMRU) >> 1) + resid) << 1;
len -= sizeof (struct en_header);
if (len > ENMRU)
goto setup; /* sanity */
en = (struct en_header *)(es->es_ifuba.ifu_r.ifrw_addr);
#define endataaddr(en, off, type) ((type)(((caddr_t)((en)+1)+(off))))
if (en->en_type >= ENPUP_TRAIL &&
en->en_type < ENPUP_TRAIL+ENPUP_NTRAILER) {
off = (en->en_type - ENPUP_TRAIL) * 512;
if (off > ENMTU)
goto setup; /* sanity */
en->en_type = *endataaddr(en, off, u_short *);
resid = *(endataaddr(en, off+2, u_short *));
if (off + resid > len)
goto setup; /* sanity */
len = off + resid;
} else
off = 0;
if (len == 0)
goto setup;
/*
* Pull packet off interface. Off is nonzero if packet
* has trailing header; if_rubaget will then force this header
* information to be at the front, but we still have to drop
* the type and length which are at the front of any trailer data.
*/
m = if_rubaget(&es->es_ifuba, len, off);
if (m == 0)
goto setup;
if (off) {
m->m_off += 2 * sizeof (u_short);
m->m_len -= 2 * sizeof (u_short);
}
switch (en->en_type) {
#ifdef INET
case ENPUP_IPTYPE:
schednetisr(NETISR_IP);
inq = &ipintrq;
break;
#endif
#ifdef PUP
case ENPUP_PUPTYPE: {
struct pup_header *pup = mtod(m, struct pup_header *);
pupproto.sp_protocol = pup->pup_type;
pupdst.spup_addr = pup->pup_dport;
pupsrc.spup_addr = pup->pup_sport;
raw_input(m, &pupproto, (struct sockaddr *)&pupsrc,
(struct sockaddr *)&pupdst);
goto setup;
}
#endif
default:
m_freem(m);
goto setup;
}
if (IF_QFULL(inq)) {
IF_DROP(inq);
m_freem(m);
} else
IF_ENQUEUE(inq, m);
setup:
/*
* Reset for next packet.
*/
addr->en_iba = es->es_ifuba.ifu_r.ifrw_info;
addr->en_iwc = -(sizeof (struct en_header) + ENMRU) >> 1;
addr->en_istat = EN_IEN|EN_GO;
}
/*
* Ethernet output routine.
* Encapsulate a packet of type family for the local net.
* Use trailer local net encapsulation if enough data in first
* packet leaves a multiple of 512 bytes of data in remainder.
*/
enoutput(ifp, m0, dst)
struct ifnet *ifp;
struct mbuf *m0;
struct sockaddr *dst;
{
int type, dest, s, error;
register struct mbuf *m = m0;
register struct en_header *en;
register int off;
switch (dst->sa_family) {
#ifdef INET
case AF_INET:
dest = ((struct sockaddr_in *)dst)->sin_addr.s_addr;
if (dest & 0x00ffff00) {
error = EPERM; /* ??? */
goto bad;
}
dest = (dest >> 24) & 0xff;
off = ntohs((u_short)mtod(m, struct ip *)->ip_len) - m->m_len;
if (off > 0 && (off & 0x1ff) == 0 &&
m->m_off >= MMINOFF + 2 * sizeof (u_short)) {
type = ENPUP_TRAIL + (off>>9);
m->m_off -= 2 * sizeof (u_short);
m->m_len += 2 * sizeof (u_short);
*mtod(m, u_short *) = ENPUP_IPTYPE;
*(mtod(m, u_short *) + 1) = m->m_len;
goto gottrailertype;
}
type = ENPUP_IPTYPE;
off = 0;
goto gottype;
#endif
#ifdef PUP
case AF_PUP:
dest = ((struct sockaddr_pup *)dst)->spup_addr.pp_host;
type = ENPUP_PUPTYPE;
off = 0;
goto gottype;
#endif
default:
printf("en%d: can't handle af%d\n", ifp->if_unit,
dst->sa_family);
error = EAFNOSUPPORT;
goto bad;
}
gottrailertype:
/*
* Packet to be sent as trailer: move first packet
* (control information) to end of chain.
*/
while (m->m_next)
m = m->m_next;
m->m_next = m0;
m = m0->m_next;
m0->m_next = 0;
m0 = m;
gottype:
/*
* Add local net header. If no space in first mbuf,
* allocate another.
*/
if (m->m_off > MMAXOFF ||
MMINOFF + sizeof (struct en_header) > m->m_off) {
m = m_get(M_DONTWAIT);
if (m == 0) {
error = ENOBUFS;
goto bad;
}
m->m_next = m0;
m->m_off = MMINOFF;
m->m_len = sizeof (struct en_header);
} else {
m->m_off -= sizeof (struct en_header);
m->m_len += sizeof (struct en_header);
}
en = mtod(m, struct en_header *);
en->en_shost = ifp->if_host[0];
en->en_dhost = dest;
en->en_type = type;
/*
* Queue message on interface, and start output if interface
* not yet active.
*/
s = splimp();
if (IF_QFULL(&ifp->if_snd)) {
IF_DROP(&ifp->if_snd);
error = ENOBUFS;
goto qfull;
}
IF_ENQUEUE(&ifp->if_snd, m);
if (en_softc[ifp->if_unit].es_oactive == 0)
enstart(ifp->if_unit);
splx(s);
return (0);
qfull:
m0 = m;
splx(s);
bad:
m_freem(m0);
return (error);
}