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From: vandys@cisco.com (Andrew Valencia)
Newsgroups: comp.os.386bsd.development
Subject: if_ne support for BPF
Date: 4 Nov 93 00:45:46 GMT
Organization: cisco Systems
Lines: 337
Message-ID: <vandys.752373946@cisco.com>
NNTP-Posting-Host: glare.cisco.com
I needed to do some tcpdump'ing off my 386BSD machine and found that
the if_ne driver for my NE2000 didn't have BPF support. I stole
from the if_we.c and if_loop.c drivers, and the result seems to work
pretty well. I didn't have any technical docs for the NE2000, so if
I got the promiscuous part wrong, please let me know. It *does*
seem to work--your mileage may vary.
These patches are a derivative work of the named sources, and I provide
them as-is. My system is at patch level 0.2.3; if this has been done in
a later patch level please ignore it.
Andy Valencia
vandys@cisco.com
*** /tmp/,RCSt1000079 Wed Nov 3 17:31:44 1993
--- if_ne.c Wed Nov 3 17:07:41 1993
***************
*** 71,76 ****
--- 71,81 ----
#include "netns/ns_if.h"
#endif
+ #include "bpfilter.h"
+ #if NBPFILTER > 0
+ #include "net/bpf.h"
+ #include "net/bpfdesc.h"
+ #endif
#include "i386/isa/isa_device.h"
#include "i386/isa/if_nereg.h"
#include "i386/isa/icu.h"
***************
*** 82,89 ****
neprobe, neattach, "ne",
};
- struct mbuf *neget();
-
#define ETHER_MIN_LEN 64
#define ETHER_MAX_LEN 1536
--- 87,92 ----
***************
*** 100,105 ****
--- 103,111 ----
#define ns_addr ns_ac.ac_enaddr /* hardware Ethernet address */
int ns_flags;
#define DSF_LOCK 1 /* block re-entering enstart */
+ #if NBPFILTER > 0
+ #define DSF_ATTACHED 0x80
+ #endif
int ns_oactive ;
int ns_mask ;
int ns_ba; /* byte addr in buffer ram of inc pkt */
***************
*** 112,122 ****
--- 118,130 ----
short ns_rxbndry; /* recevier buffer boundary */
short ns_port; /* i/o port base */
short ns_mode; /* word/byte mode */
+ caddr_t ns_bpf; /* Magic Cookie for BPF */
} ne_softc[NNE] ;
#define ENBUFSIZE (sizeof(struct ether_header) + ETHERMTU + 2 + ETHER_MIN_LEN)
#define PAT(n) (0xa55a + 37*(n))
+ static struct mbuf *neget(caddr_t, int, int, struct ne_softc *);
u_short boarddata[16];
neprobe(dvp)
***************
*** 342,347 ****
--- 350,371 ----
ifp->if_reset = nereset;
ifp->if_watchdog = 0;
if_attach(ifp);
+ ns->ns_flags &= ~DSF_ATTACHED; /* Make sure BPF attach flag clear */
+ }
+
+ /*
+ * set_rcr()
+ * Apply appropriate bits to receive control register
+ */
+ static inline void
+ set_rcr(struct ne_softc *ns)
+ {
+ #if NBPFILTER > 0
+ if (ns->ns_if.if_flags & IFF_PROMISC) {
+ outb(ns->ns_port + ds0_rcr, DSRC_AB|DSRC_PRO);
+ } else
+ #endif
+ outb(ns->ns_port + ds0_rcr, DSRC_AB);
}
/*
***************
*** 357,362 ****
--- 381,393 ----
int i; char *cp;
register nec = ns->ns_port;
+ #if NBPFILTER > 0
+ if ((ns->ns_flags & DSF_ATTACHED) == 0) {
+ bpfattach(&ns->ns_bpf, ifp, DLT_EN10MB,
+ sizeof(struct ether_header));
+ ns->ns_flags |= DSF_ATTACHED;
+ }
+ #endif
if (ifp->if_addrlist == (struct ifaddr *)0) return;
if (ifp->if_flags & IFF_RUNNING) return;
***************
*** 389,395 ****
outb(nec+ds1_curr, (ns->ns_txstart+PKTSZ)/DS_PGSIZE);
ns->ns_cur = (ns->ns_txstart+PKTSZ)/DS_PGSIZE;
outb (nec+ds_cmd, DSCM_NODMA|DSCM_PG0|DSCM_START);
! outb (nec+ds0_rcr, DSRC_AB);
outb(nec+ds0_dcr, ns->ns_mode);
outb (nec+ds0_imr, 0xff);
--- 420,427 ----
outb(nec+ds1_curr, (ns->ns_txstart+PKTSZ)/DS_PGSIZE);
ns->ns_cur = (ns->ns_txstart+PKTSZ)/DS_PGSIZE;
outb (nec+ds_cmd, DSCM_NODMA|DSCM_PG0|DSCM_START);
! set_rcr(ns);
!
outb(nec+ds0_dcr, ns->ns_mode);
outb (nec+ds0_imr, 0xff);
***************
*** 444,451 ****
t = 0;
for (m0 = m; m != 0; m = m->m_next)
t += m->m_len;
-
m = m0;
total = t;
for (m0 = m; m != 0; ) {
--- 476,530 ----
t = 0;
for (m0 = m; m != 0; m = m->m_next)
t += m->m_len;
m = m0;
+ #if NBPFILTER > 0
+ if (ns->ns_bpf) {
+ u_short etype;
+ int off, datasize, resid;
+ struct ether_header *eh;
+ struct trailer_header {
+ u_short ether_type;
+ u_short ether_residual;
+ } trailer_header;
+ char ether_packet[ETHERMTU+100];
+ char *ep;
+
+ ep = ether_packet;
+
+ /* copy ether header */
+ m_copydata(m, 0, sizeof(struct ether_header), ep);
+ eh = (struct ether_header *) ep;
+ ep += sizeof(struct ether_header);
+ etype = ntohs(eh->ether_type);
+ if (etype >= ETHERTYPE_TRAIL &&
+ etype < ETHERTYPE_TRAIL+ETHERTYPE_NTRAILER) {
+ datasize = ((etype - ETHERTYPE_TRAIL) << 9);
+ off = datasize + sizeof(struct ether_header);
+
+ /* copy trailer_header into a data structure */
+ m_copydata(m, off, sizeof(struct trailer_header),
+ &trailer_header.ether_type);
+
+ /* copy residual data */
+ m_copydata(m, off+sizeof(struct trailer_header),
+ resid = ntohs(trailer_header.ether_residual) -
+ sizeof(struct trailer_header), ep);
+ ep += resid;
+
+ /* copy data */
+ m_copydata(m, sizeof(struct ether_header), datasize, ep);
+ ep += datasize;
+
+ /* restore original ether packet type */
+ eh->ether_type = trailer_header.ether_type;
+
+ bpf_tap(ns->ns_bpf, ether_packet, ep - ether_packet);
+ } else {
+ bpf_mtap(ns->ns_bpf, m);
+ }
+ }
+ #endif
+
total = t;
for (m0 = m; m != 0; ) {
***************
*** 660,665 ****
--- 739,745 ----
struct mbuf *m;
int off, resid;
register struct ifqueue *inq;
+ u_short etype;
/*
* Deal with trailer protocol: if type is trailer type
***************
*** 667,679 ****
* Remember that type was trailer by setting off.
*/
eh = (struct ether_header *)buf;
! eh->ether_type = ntohs((u_short)eh->ether_type);
#define nedataaddr(eh, off, type) ((type)(((caddr_t)((eh)+1)+(off))))
! if (eh->ether_type >= ETHERTYPE_TRAIL &&
! eh->ether_type < ETHERTYPE_TRAIL+ETHERTYPE_NTRAILER) {
! off = (eh->ether_type - ETHERTYPE_TRAIL) * 512;
if (off >= ETHERMTU) return; /* sanity */
! eh->ether_type = ntohs(*nedataaddr(eh, off, u_short *));
resid = ntohs(*(nedataaddr(eh, off+2, u_short *)));
if (off + resid > len) return; /* sanity */
len = off + resid;
--- 747,759 ----
* Remember that type was trailer by setting off.
*/
eh = (struct ether_header *)buf;
! etype = ntohs((u_short)eh->ether_type);
#define nedataaddr(eh, off, type) ((type)(((caddr_t)((eh)+1)+(off))))
! if (etype >= ETHERTYPE_TRAIL &&
! etype < ETHERTYPE_TRAIL+ETHERTYPE_NTRAILER) {
! off = (etype - ETHERTYPE_TRAIL) << 9;
if (off >= ETHERMTU) return; /* sanity */
! etype = ntohs(*nedataaddr(eh, off, u_short *));
resid = ntohs(*(nedataaddr(eh, off+2, u_short *)));
if (off + resid > len) return; /* sanity */
len = off + resid;
***************
*** 687,695 ****
* 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 = neget(buf, len, off, &ns->ns_if);
if (m == 0) return;
ether_input(&ns->ns_if, eh, m);
}
--- 767,813 ----
* 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 = neget(buf, len, off, ns);
if (m == 0) return;
+ #if NBPFILTER > 0
+ /*
+ * Check if there's a bpf filter listening on this interface.
+ * If so, hand off the raw packet to bpf.
+ */
+ if (ns->ns_bpf) {
+ struct mbuf m0;
+
+ /*
+ * BPF wants to see the ether header at the front of the
+ * packet. neget() doesn't do that, so we create * a
+ * pseudo-mbuf just long enough to fool bpf_mtap().
+ */
+ m0.m_next = m;
+ m0.m_len = sizeof(struct ether_header);
+ m0.m_data = buf;
+ bpf_mtap(ns->ns_bpf, &m0);
+ }
+
+ /*
+ * If in promiscuous, dump packets which aren't for our protocol
+ * stack.
+ */
+ #define ESZ sizeof(eh->ether_dhost)
+ if ((ns->ns_if.if_flags & IFF_PROMISC) &&
+ bcmp(eh->ether_dhost, ns->ns_addr, ESZ) &&
+ bcmp(eh->ether_dhost, etherbroadcastaddr, ESZ)) {
+ m_freem(m);
+ return;
+ }
+ #undef ESZ
+ #endif
+ /*
+ * Now map ether_type into host-format true ether type. BPF
+ * wants net format, so we kept it in a local variable until
+ * he was done.
+ */
+ eh->ether_type = etype;
ether_input(&ns->ns_if, eh, m);
}
***************
*** 706,721 ****
* data into mbufs. When full cluster sized units are present
* we copy into clusters.
*/
! struct mbuf *
! neget(buf, totlen, off0, ifp)
! caddr_t buf;
! int totlen, off0;
! struct ifnet *ifp;
{
struct mbuf *top, **mp, *m, *p;
int off = off0, len;
! register caddr_t cp = buf;
char *epkt;
buf += sizeof(struct ether_header);
cp = buf;
--- 824,837 ----
* data into mbufs. When full cluster sized units are present
* we copy into clusters.
*/
! static struct mbuf *
! neget(caddr_t buf, int totlen, int off0, struct ne_softc *ns)
{
struct mbuf *top, **mp, *m, *p;
int off = off0, len;
! caddr_t cp = buf;
char *epkt;
+ struct ifnet *ifp = &ns->ns_if;
buf += sizeof(struct ether_header);
cp = buf;
***************
*** 837,842 ****
--- 953,961 ----
} else if (ifp->if_flags & IFF_UP &&
(ifp->if_flags & IFF_RUNNING) == 0)
neinit(ifp->if_unit);
+ #if NBPFILTER > 0
+ set_rcr(ns);
+ #endif
break;
#ifdef notdef