X-Git-Url: https://git.subgeniuskitty.com/unix-history/.git/blobdiff_plain/8a13b73762073376faf12d2b8b2d763eeb7def70..5e35ed2481cff3093e5df1d23606e3f8ce318fba:/usr/src/sys/vax/if/if_en.c

diff --git a/usr/src/sys/vax/if/if_en.c b/usr/src/sys/vax/if/if_en.c
index 188a16fde9..6299fcb687 100644
--- a/usr/src/sys/vax/if/if_en.c
+++ b/usr/src/sys/vax/if/if_en.c
@@ -1,8 +1,9 @@
-/*	if_en.c	4.14	81/11/26	*/
+/*	if_en.c	4.71	82/10/24	*/
 
 #include "en.h"
+
 /*
- * Ethernet interface driver
+ * Xerox prototype (3 Mb) Ethernet interface driver.
  */
 
 #include "../h/param.h"
@@ -12,47 +13,70 @@
 #include "../h/buf.h"
 #include "../h/protosw.h"
 #include "../h/socket.h"
-#include "../h/ubareg.h"
-#include "../h/ubavar.h"
-#include "../h/enreg.h"
-#include "../h/cpu.h"
-#include "../h/mtpr.h"
 #include "../h/vmmac.h"
-#include "../net/in.h"
-#include "../net/in_systm.h"
+#include <errno.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/netisr.h"
+#include "../net/route.h"
+#include "../netinet/in.h"
+#include "../netinet/in_systm.h"
+#include "../netinet/ip.h"
+#include "../netinet/ip_var.h"
+#include "../netpup/pup.h"
+
+#include "../vax/cpu.h"
+#include "../vax/mtpr.h"
+#include "../vaxif/if_en.h"
+#include "../vaxif/if_enreg.h"
+#include "../vaxif/if_uba.h"
+#include "../vaxuba/ubareg.h"
+#include "../vaxuba/ubavar.h"
 
-#define	ENMTU	1024
+#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, "es", eninfo };
+	{ 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;
-	struct	ifuba *es_ifuba;
-	short	es_delay;
-	short	es_mask;
-	u_char	es_addr;
-	u_char	es_lastx;
-	short	es_oactive;
-	short	es_olen;
+	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;
+	register int br, cvec;		/* r11, r10 value-result */
 	register struct endevice *addr = (struct endevice *)reg;
 
-COUNT(ENPROBE);
 #ifdef lint
 	br = 0; cvec = br; br = cvec;
 	enrint(0); enxint(0); encollide(0);
@@ -63,250 +87,436 @@ COUNT(ENPROBE);
 	addr->en_ostat = EN_IEN|EN_GO;
 	DELAY(100000);
 	addr->en_ostat = 0;
+#ifdef ECHACK
+	br = 0x16;
+#endif
 	return (1);
 }
 
-/*ARGSUSED*/
+/*
+ * 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;
 
-COUNT(ENATTACH);
-	eninit(ui->ui_unit);
-	/* net initialization, based on ui->ui_flags?!? */
+	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 uba_device *ui;
+	register struct en_softc *es = &en_softc[unit];
+	register struct uba_device *ui = eninfo[unit];
 	register struct endevice *addr;
-	register struct en_softc *es;
+	int s;
 
-COUNT(ENINIT);
-	if (unit >= NEN || (ui = eninfo[unit]) == 0 || ui->ui_alive == 0) {
-		printf("es%d: not alive\n", unit);
-		return;
-	}
-	es = &en_softc[unit];
-	if (if_ubainit(es->es_ifuba, ui->ui_ubanum,
-	    sizeof (struct en_header), btop(ENMTU)) == 0) { 
-		printf("es%d: can't initialize\n", unit);
+	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;
-}
-
-enreset(uban)
-	int uban;
-{
-	register int unit;
-	struct uba_device *ui;
 
-COUNT(ENRESET);
-	for (unit = 0; unit < NEN; unit++) {
-		ui = eninfo[unit];
-		if (ui == 0 || ui->ui_ubanum != uban || ui->ui_alive == 0)
-			continue;
-		eninit(unit);
-		printf("es%d ", unit);
-	}
+	/*
+	 * 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	enlastdel = 25;
+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;
-	struct uba_device *ui;
+        int unit = ENUNIT(dev);
+	struct uba_device *ui = eninfo[unit];
+	register struct en_softc *es = &en_softc[unit];
 	register struct endevice *addr;
-	register struct en_softc *es;
-	register struct ifuba *ifu;
 	struct mbuf *m;
 	int dest;
-COUNT(ENSTART);
 
-	unit = ENUNIT(dev);
-	ui = eninfo[unit];
-	es = &en_softc[unit];
 	if (es->es_oactive)
 		goto restart;
-	IF_DEQUEUE(&es->es_if->if_snd, m);
+
+	/*
+	 * 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);
-	if (es->es_lastx && es->es_lastx == dest)
+
+	/*
+	 * 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;
-	else
-		es->es_lastx = dest;
+		es->es_mask = enlastmask;
+	}
+	es->es_lastx = dest;
+
 restart:
-	ifu = es->es_ifuba;
-	UBAPURGE(ifu->ifu_uba, ifu->ifu_w.ifrw_bdp);
+	/*
+	 * 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)ifu->ifu_w.ifrw_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 endevice *addr;
-	register struct uba_device *ui;
-	register struct en_softc *es;
-COUNT(ENXINT);
+	register struct uba_device *ui = eninfo[unit];
+	register struct en_softc *es = &en_softc[unit];
+	register struct endevice *addr = (struct endevice *)ui->ui_addr;
 
-	ui = eninfo[unit];
-	es = &en_softc[unit];
 	if (es->es_oactive == 0)
 		return;
-	addr = (struct endevice *)ui->ui_addr;
-	es = &en_softc[unit];
+	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 (addr->en_ostat&EN_OERROR)
-		printf("es%d: output error\n", unit);
-	if (es->es_if->if_snd.ifq_head == 0) {
-		es->es_lastx = 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;
 {
-	register struct en_softc *es;
-COUNT(ENCOLLIDE);
+	struct en_softc *es = &en_softc[unit];
 
-	es = &en_softc[unit];
-	es->es_if->if_collisions++;
+	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("es%d: send error\n", unit);
+		printf("en%d: send error\n", unit);
 		enxint(unit);
-	} else {
-		es->es_mask <<= 1;
-		es->es_delay = mfpr(ICR) &~ es->es_mask;
-		enstart(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;
 {
-	struct endevice *addr;
-	register struct en_softc *es;
-	register struct ifuba *ifu;
-	struct en_header *en;
+	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;
-	struct ifqueue *inq;
-	register int len;
+	int len; short resid;
+	register struct ifqueue *inq;
 	int off;
-COUNT(ENRINT);
 
-	addr = (struct endevice *)eninfo[unit]->ui_addr;
+	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++;
-		printf("es%d: input error\n", unit);
+		es->es_if.if_ierrors++;
 		goto setup;
 	}
-	ifu = en_softc[unit].es_ifuba;
-	UBAPURGE(ifu->ifu_uba, ifu->ifu_r.ifrw_bdp);
-	en = (struct en_header *)(ifu->ifu_r.ifrw_addr);
+
+	/*
+	 * 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 *);
-		off += 2;
+		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:
-		len = endataaddr(en, off, struct ip *)->ip_len;
-		setipintr();
+		schednetisr(NETISR_IP);
 		inq = &ipintrq;
 		break;
 #endif
+#ifdef PUP
+	case ENPUP_PUPTYPE: {
+		struct pup_header *pup = mtod(m, struct pup_header *);
 
-	default:
-		printf("en%d: unknow pkt type 0x%x\n", en->en_type);
+		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;
 	}
-	if (len == 0)
+#endif
+	default:
+		m_freem(m);
 		goto setup;
-	m = if_rubaget(&ifu->ifu_r, len, off);
-	IF_ENQUEUE(inq, m);
+	}
+
+	if (IF_QFULL(inq)) {
+		IF_DROP(inq);
+		m_freem(m);
+	} else
+		IF_ENQUEUE(inq, m);
+
 setup:
-	addr->en_iba = es->es_ifuba->ifu_r.ifrw_info;
-	addr->en_iwc = -(sizeof (struct en_header) + ENMTU) >> 1;
+	/*
+	 * 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, pf)
+enoutput(ifp, m0, dst)
 	struct ifnet *ifp;
 	struct mbuf *m0;
-	int pf;
+	struct sockaddr *dst;
 {
-	int type, dest;
-	register struct mbuf *m;
+	int type, dest, s, error;
+	register struct mbuf *m = m0;
 	register struct en_header *en;
-	int s;
+	register int off;
 
-	switch (pf) {
+	switch (dst->sa_family) {
 
 #ifdef INET
-	case PF_INET: {
-		register struct ip *ip = mtod(m0, struct ip *);
-		int off;
-
-		off = ip->ip_len - (ip->ip_hl << 2);
-		if (off && off % 512 == 0 && m0->m_off >= MMINOFF + 2) {
-			type = ENPUP_TRAIL + (off>>9);
-			m0->m_off -= 2;
-			m0->m_len += 2;
-			*mtod(m0, u_short *) = ENPUP_IPTYPE;
-		} else {
-			type = ENPUP_IPTYPE;
-			off = 0;
+	case AF_INET:
+		dest = ((struct sockaddr_in *)dst)->sin_addr.s_addr;
+		if (dest & 0x00ffff00) {
+			error = EPERM;		/* ??? */
+			goto bad;
 		}
-		dest = ip->ip_dst.s_addr >> 24;
+		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;
 		}
-		break;
+		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 encapsulate pf%d\n", ifp->if_unit, pf);
-		m_freem(m0);
-		return (0);
+		printf("en%d: can't handle af%d\n", ifp->if_unit,
+			dst->sa_family);
+		error = EAFNOSUPPORT;
+		goto bad;
 	}
-	if (MMINOFF + sizeof (struct en_header) > m0->m_off) {
-		m = m_get(0);
+
+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) {
-			m_freem(m0);
-			return (0);
+			error = ENOBUFS;
+			goto bad;
 		}
 		m->m_next = m0;
 		m->m_off = MMINOFF;
 		m->m_len = sizeof (struct en_header);
 	} else {
-		m = m0;
 		m->m_off -= sizeof (struct en_header);
 		m->m_len += sizeof (struct en_header);
 	}
@@ -314,9 +524,26 @@ enoutput(ifp, m0, pf)
 	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);
-	splx(s);
 	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);
 }