freebsd-src/contrib/libpcap/pcap-dlpi.c
2000-01-30 00:32:56 +00:00

849 lines
19 KiB
C

/*
* Copyright (c) 1993, 1994, 1995, 1996, 1997
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that: (1) source code distributions
* retain the above copyright notice and this paragraph in its entirety, (2)
* distributions including binary code include the above copyright notice and
* this paragraph in its entirety in the documentation or other materials
* provided with the distribution, and (3) all advertising materials mentioning
* features or use of this software display the following acknowledgement:
* ``This product includes software developed by the University of California,
* Lawrence Berkeley Laboratory and its contributors.'' 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 ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*
* This code contributed by Atanu Ghosh (atanu@cs.ucl.ac.uk),
* University College London.
*/
/*
* Packet capture routine for dlpi under SunOS 5
*
* Notes:
*
* - Apparently the DLIOCRAW ioctl() is specific to SunOS.
*
* - There is a bug in bufmod(7) such that setting the snapshot
* length results in data being left of the front of the packet.
*
* - It might be desirable to use pfmod(7) to filter packets in the
* kernel.
*/
#ifndef lint
static const char rcsid[] =
"@(#) $Header: /tcpdump/master/libpcap/pcap-dlpi.c,v 1.52.1.1 1999/10/07 23:46:40 mcr Exp $ (LBL)";
#endif
#include <sys/types.h>
#include <sys/time.h>
#ifdef HAVE_SYS_BUFMOD_H
#include <sys/bufmod.h>
#endif
#include <sys/dlpi.h>
#ifdef HAVE_SYS_DLPI_EXT_H
#include <sys/dlpi_ext.h>
#endif
#ifdef HAVE_HPUX9
#include <sys/socket.h>
#endif
#ifdef DL_HP_PPA_ACK_OBS
#include <sys/stat.h>
#endif
#include <sys/stream.h>
#if defined(HAVE_SOLARIS) && defined(HAVE_SYS_BUFMOD_H)
#include <sys/systeminfo.h>
#endif
#ifdef HAVE_HPUX9
#include <net/if.h>
#endif
#include <ctype.h>
#ifdef HAVE_HPUX9
#include <nlist.h>
#endif
#include <errno.h>
#include <fcntl.h>
#include <memory.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stropts.h>
#include <unistd.h>
#include "pcap-int.h"
#include "gnuc.h"
#ifdef HAVE_OS_PROTO_H
#include "os-proto.h"
#endif
#ifndef PCAP_DEV_PREFIX
#define PCAP_DEV_PREFIX "/dev"
#endif
#define MAXDLBUF 8192
/* Forwards */
static int dlattachreq(int, bpf_u_int32, char *);
static int dlbindack(int, char *, char *);
static int dlbindreq(int, bpf_u_int32, char *);
static int dlinfoack(int, char *, char *);
static int dlinforeq(int, char *);
static int dlokack(int, const char *, char *, char *);
static int recv_ack(int, int, const char *, char *, char *);
static int dlpromisconreq(int, bpf_u_int32, char *);
#if defined(HAVE_SOLARIS) && defined(HAVE_SYS_BUFMOD_H)
static char *get_release(bpf_u_int32 *, bpf_u_int32 *, bpf_u_int32 *);
#endif
static int send_request(int, char *, int, char *, char *);
#ifdef HAVE_SYS_BUFMOD_H
static int strioctl(int, int, int, char *);
#endif
#ifdef HAVE_HPUX9
static int dlpi_kread(int, off_t, void *, u_int, char *);
#endif
#ifdef HAVE_DEV_DLPI
static int get_dlpi_ppa(int, const char *, int, char *);
#endif
int
pcap_stats(pcap_t *p, struct pcap_stat *ps)
{
*ps = p->md.stat;
return (0);
}
/* XXX Needed by HP-UX (at least) */
static bpf_u_int32 ctlbuf[MAXDLBUF];
static struct strbuf ctl = {
MAXDLBUF,
0,
(char *)ctlbuf
};
int
pcap_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
{
register int cc, n, caplen, origlen;
register u_char *bp, *ep, *pk;
register struct bpf_insn *fcode;
#ifdef HAVE_SYS_BUFMOD_H
register struct sb_hdr *sbp;
#ifdef LBL_ALIGN
struct sb_hdr sbhdr;
#endif
#endif
int flags;
struct strbuf data;
struct pcap_pkthdr pkthdr;
flags = 0;
cc = p->cc;
if (cc == 0) {
data.buf = (char *)p->buffer + p->offset;
data.maxlen = MAXDLBUF;
data.len = 0;
do {
if (getmsg(p->fd, &ctl, &data, &flags) < 0) {
/* Don't choke when we get ptraced */
if (errno == EINTR) {
cc = 0;
continue;
}
strcpy(p->errbuf, pcap_strerror(errno));
return (-1);
}
cc = data.len;
} while (cc == 0);
bp = p->buffer + p->offset;
} else
bp = p->bp;
/* Loop through packets */
fcode = p->fcode.bf_insns;
ep = bp + cc;
n = 0;
#ifdef HAVE_SYS_BUFMOD_H
while (bp < ep) {
#ifdef LBL_ALIGN
if ((long)bp & 3) {
sbp = &sbhdr;
memcpy(sbp, bp, sizeof(*sbp));
} else
#endif
sbp = (struct sb_hdr *)bp;
p->md.stat.ps_drop += sbp->sbh_drops;
pk = bp + sizeof(*sbp);
bp += sbp->sbh_totlen;
origlen = sbp->sbh_origlen;
caplen = sbp->sbh_msglen;
#else
origlen = cc;
caplen = min(p->snapshot, cc);
pk = bp;
bp += caplen;
#endif
++p->md.stat.ps_recv;
if (bpf_filter(fcode, pk, origlen, caplen)) {
#ifdef HAVE_SYS_BUFMOD_H
pkthdr.ts = sbp->sbh_timestamp;
#else
(void)gettimeofday(&pkthdr.ts, NULL);
#endif
pkthdr.len = origlen;
pkthdr.caplen = caplen;
/* Insure caplen does not exceed snapshot */
if (pkthdr.caplen > p->snapshot)
pkthdr.caplen = p->snapshot;
(*callback)(user, &pkthdr, pk);
if (++n >= cnt && cnt >= 0) {
p->cc = ep - bp;
p->bp = bp;
return (n);
}
}
#ifdef HAVE_SYS_BUFMOD_H
}
#endif
p->cc = 0;
return (n);
}
pcap_t *
pcap_open_live(char *device, int snaplen, int promisc, int to_ms, char *ebuf)
{
register char *cp;
char *eos;
register pcap_t *p;
register int ppa;
register dl_info_ack_t *infop;
#ifdef HAVE_SYS_BUFMOD_H
bpf_u_int32 ss, flag;
#ifdef HAVE_SOLARIS
register char *release;
bpf_u_int32 osmajor, osminor, osmicro;
#endif
#endif
bpf_u_int32 buf[MAXDLBUF];
char dname[100];
#ifndef HAVE_DEV_DLPI
char dname2[100];
#endif
p = (pcap_t *)malloc(sizeof(*p));
if (p == NULL) {
strcpy(ebuf, pcap_strerror(errno));
return (NULL);
}
memset(p, 0, sizeof(*p));
/*
** Determine device and ppa
*/
cp = strpbrk(device, "0123456789");
if (cp == NULL) {
sprintf(ebuf, "%s missing unit number", device);
goto bad;
}
ppa = strtol(cp, &eos, 10);
if (*eos != '\0') {
sprintf(ebuf, "%s bad unit number", device);
goto bad;
}
if (*device == '/')
strcpy(dname, device);
else
sprintf(dname, "%s/%s", PCAP_DEV_PREFIX, device);
#ifdef HAVE_DEV_DLPI
/* Map network device to /dev/dlpi unit */
cp = "/dev/dlpi";
if ((p->fd = open(cp, O_RDWR)) < 0) {
sprintf(ebuf, "%s: %s", cp, pcap_strerror(errno));
goto bad;
}
/* Map network interface to /dev/dlpi unit */
ppa = get_dlpi_ppa(p->fd, dname, ppa, ebuf);
if (ppa < 0)
goto bad;
#else
/* Try device without unit number */
strcpy(dname2, dname);
cp = strchr(dname, *cp);
*cp = '\0';
if ((p->fd = open(dname, O_RDWR)) < 0) {
if (errno != ENOENT) {
sprintf(ebuf, "%s: %s", dname, pcap_strerror(errno));
goto bad;
}
/* Try again with unit number */
if ((p->fd = open(dname2, O_RDWR)) < 0) {
sprintf(ebuf, "%s: %s", dname2, pcap_strerror(errno));
goto bad;
}
/* XXX Assume unit zero */
ppa = 0;
}
#endif
p->snapshot = snaplen;
/*
** Attach if "style 2" provider
*/
if (dlinforeq(p->fd, ebuf) < 0 ||
dlinfoack(p->fd, (char *)buf, ebuf) < 0)
goto bad;
infop = &((union DL_primitives *)buf)->info_ack;
if (infop->dl_provider_style == DL_STYLE2 &&
(dlattachreq(p->fd, ppa, ebuf) < 0 ||
dlokack(p->fd, "attach", (char *)buf, ebuf) < 0))
goto bad;
/*
** Bind (defer if using HP-UX 9 or HP-UX 10.20, totally skip if
** using SINIX)
*/
#if !defined(HAVE_HPUX9) && !defined(HAVE_HPUX10_20) && !defined(sinix)
if (dlbindreq(p->fd, 0, ebuf) < 0 ||
dlbindack(p->fd, (char *)buf, ebuf) < 0)
goto bad;
#endif
if (promisc) {
/*
** Enable promiscuous
*/
if (dlpromisconreq(p->fd, DL_PROMISC_PHYS, ebuf) < 0 ||
dlokack(p->fd, "promisc_phys", (char *)buf, ebuf) < 0)
goto bad;
/*
** Try to enable multicast (you would have thought
** promiscuous would be sufficient). (Skip if using
** HP-UX or SINIX)
*/
#if !defined(__hpux) && !defined(sinix)
if (dlpromisconreq(p->fd, DL_PROMISC_MULTI, ebuf) < 0 ||
dlokack(p->fd, "promisc_multi", (char *)buf, ebuf) < 0)
fprintf(stderr,
"WARNING: DL_PROMISC_MULTI failed (%s)\n", ebuf);
#endif
}
/*
** Try to enable sap (when not in promiscuous mode when using
** using HP-UX and never under SINIX)
*/
#ifndef sinix
if (
#ifdef __hpux
!promisc &&
#endif
(dlpromisconreq(p->fd, DL_PROMISC_SAP, ebuf) < 0 ||
dlokack(p->fd, "promisc_sap", (char *)buf, ebuf) < 0)) {
/* Not fatal if promisc since the DL_PROMISC_PHYS worked */
if (promisc)
fprintf(stderr,
"WARNING: DL_PROMISC_SAP failed (%s)\n", ebuf);
else
goto bad;
}
#endif
/*
** HP-UX 9 and HP-UX 10.20 must bind after setting promiscuous
** options)
*/
#if defined(HAVE_HPUX9) || defined(HAVE_HPUX10_20)
if (dlbindreq(p->fd, 0, ebuf) < 0 ||
dlbindack(p->fd, (char *)buf, ebuf) < 0)
goto bad;
#endif
/*
** Determine link type
*/
if (dlinforeq(p->fd, ebuf) < 0 ||
dlinfoack(p->fd, (char *)buf, ebuf) < 0)
goto bad;
infop = &((union DL_primitives *)buf)->info_ack;
switch (infop->dl_mac_type) {
case DL_CSMACD:
case DL_ETHER:
p->linktype = DLT_EN10MB;
p->offset = 2;
break;
case DL_FDDI:
p->linktype = DLT_FDDI;
p->offset = 3;
break;
default:
sprintf(ebuf, "unknown mac type 0x%lu", infop->dl_mac_type);
goto bad;
}
#ifdef DLIOCRAW
/*
** This is a non standard SunOS hack to get the ethernet header.
*/
if (strioctl(p->fd, DLIOCRAW, 0, NULL) < 0) {
sprintf(ebuf, "DLIOCRAW: %s", pcap_strerror(errno));
goto bad;
}
#endif
#ifdef HAVE_SYS_BUFMOD_H
/*
** Another non standard call to get the data nicely buffered
*/
if (ioctl(p->fd, I_PUSH, "bufmod") != 0) {
sprintf(ebuf, "I_PUSH bufmod: %s", pcap_strerror(errno));
goto bad;
}
/*
** Now that the bufmod is pushed lets configure it.
**
** There is a bug in bufmod(7). When dealing with messages of
** less than snaplen size it strips data from the beginning not
** the end.
**
** This bug is supposed to be fixed in 5.3.2. Also, there is a
** patch available. Ask for bugid 1149065.
*/
ss = snaplen;
#ifdef HAVE_SOLARIS
release = get_release(&osmajor, &osminor, &osmicro);
if (osmajor == 5 && (osminor <= 2 || (osminor == 3 && osmicro < 2)) &&
getenv("BUFMOD_FIXED") == NULL) {
fprintf(stderr,
"WARNING: bufmod is broken in SunOS %s; ignoring snaplen.\n",
release);
ss = 0;
}
#endif
if (ss > 0 &&
strioctl(p->fd, SBIOCSSNAP, sizeof(ss), (char *)&ss) != 0) {
sprintf(ebuf, "SBIOCSSNAP: %s", pcap_strerror(errno));
goto bad;
}
/*
** Set up the bufmod flags
*/
if (strioctl(p->fd, SBIOCGFLAGS, sizeof(flag), (char *)&flag) < 0) {
sprintf(ebuf, "SBIOCGFLAGS: %s", pcap_strerror(errno));
goto bad;
}
flag |= SB_NO_DROPS;
if (strioctl(p->fd, SBIOCSFLAGS, sizeof(flag), (char *)&flag) != 0) {
sprintf(ebuf, "SBIOCSFLAGS: %s", pcap_strerror(errno));
goto bad;
}
/*
** Set up the bufmod timeout
*/
if (to_ms != 0) {
struct timeval to;
to.tv_sec = to_ms / 1000;
to.tv_usec = (to_ms * 1000) % 1000000;
if (strioctl(p->fd, SBIOCSTIME, sizeof(to), (char *)&to) != 0) {
sprintf(ebuf, "SBIOCSTIME: %s", pcap_strerror(errno));
goto bad;
}
}
#endif
/*
** As the last operation flush the read side.
*/
if (ioctl(p->fd, I_FLUSH, FLUSHR) != 0) {
sprintf(ebuf, "FLUSHR: %s", pcap_strerror(errno));
goto bad;
}
/* Allocate data buffer */
p->bufsize = MAXDLBUF * sizeof(bpf_u_int32);
p->buffer = (u_char *)malloc(p->bufsize + p->offset);
return (p);
bad:
free(p);
return (NULL);
}
int
pcap_setfilter(pcap_t *p, struct bpf_program *fp)
{
p->fcode = *fp;
return (0);
}
static int
send_request(int fd, char *ptr, int len, char *what, char *ebuf)
{
struct strbuf ctl;
int flags;
ctl.maxlen = 0;
ctl.len = len;
ctl.buf = ptr;
flags = 0;
if (putmsg(fd, &ctl, (struct strbuf *) NULL, flags) < 0) {
sprintf(ebuf, "send_request: putmsg \"%s\": %s",
what, pcap_strerror(errno));
return (-1);
}
return (0);
}
static int
recv_ack(int fd, int size, const char *what, char *bufp, char *ebuf)
{
union DL_primitives *dlp;
struct strbuf ctl;
int flags;
ctl.maxlen = MAXDLBUF;
ctl.len = 0;
ctl.buf = bufp;
flags = 0;
if (getmsg(fd, &ctl, (struct strbuf*)NULL, &flags) < 0) {
sprintf(ebuf, "recv_ack: %s getmsg: %s",
what, pcap_strerror(errno));
return (-1);
}
dlp = (union DL_primitives *) ctl.buf;
switch (dlp->dl_primitive) {
case DL_INFO_ACK:
case DL_BIND_ACK:
case DL_OK_ACK:
#ifdef DL_HP_PPA_ACK
case DL_HP_PPA_ACK:
#endif
/* These are OK */
break;
case DL_ERROR_ACK:
switch (dlp->error_ack.dl_errno) {
case DL_BADPPA:
sprintf(ebuf, "recv_ack: %s bad ppa (device unit)",
what);
break;
case DL_SYSERR:
sprintf(ebuf, "recv_ack: %s: %s",
what, pcap_strerror(dlp->error_ack.dl_unix_errno));
break;
case DL_UNSUPPORTED:
sprintf(ebuf,
"recv_ack: %s: Service not supplied by provider",
what);
break;
default:
sprintf(ebuf, "recv_ack: %s error 0x%x",
what, (bpf_u_int32)dlp->error_ack.dl_errno);
break;
}
return (-1);
default:
sprintf(ebuf, "recv_ack: %s unexpected primitive ack 0x%x ",
what, (bpf_u_int32)dlp->dl_primitive);
return (-1);
}
if (ctl.len < size) {
sprintf(ebuf, "recv_ack: %s ack too small (%d < %d)",
what, ctl.len, size);
return (-1);
}
return (ctl.len);
}
static int
dlattachreq(int fd, bpf_u_int32 ppa, char *ebuf)
{
dl_attach_req_t req;
req.dl_primitive = DL_ATTACH_REQ;
req.dl_ppa = ppa;
return (send_request(fd, (char *)&req, sizeof(req), "attach", ebuf));
}
static int
dlbindreq(int fd, bpf_u_int32 sap, char *ebuf)
{
dl_bind_req_t req;
memset((char *)&req, 0, sizeof(req));
req.dl_primitive = DL_BIND_REQ;
#ifdef DL_HP_RAWDLS
req.dl_max_conind = 1; /* XXX magic number */
/* 22 is INSAP as per the HP-UX DLPI Programmer's Guide */
req.dl_sap = 22;
req.dl_service_mode = DL_HP_RAWDLS;
#else
req.dl_sap = sap;
#ifdef DL_CLDLS
req.dl_service_mode = DL_CLDLS;
#endif
#endif
return (send_request(fd, (char *)&req, sizeof(req), "bind", ebuf));
}
static int
dlbindack(int fd, char *bufp, char *ebuf)
{
return (recv_ack(fd, DL_BIND_ACK_SIZE, "bind", bufp, ebuf));
}
static int
dlpromisconreq(int fd, bpf_u_int32 level, char *ebuf)
{
dl_promiscon_req_t req;
req.dl_primitive = DL_PROMISCON_REQ;
req.dl_level = level;
return (send_request(fd, (char *)&req, sizeof(req), "promiscon", ebuf));
}
static int
dlokack(int fd, const char *what, char *bufp, char *ebuf)
{
return (recv_ack(fd, DL_OK_ACK_SIZE, what, bufp, ebuf));
}
static int
dlinforeq(int fd, char *ebuf)
{
dl_info_req_t req;
req.dl_primitive = DL_INFO_REQ;
return (send_request(fd, (char *)&req, sizeof(req), "info", ebuf));
}
static int
dlinfoack(int fd, char *bufp, char *ebuf)
{
return (recv_ack(fd, DL_INFO_ACK_SIZE, "info", bufp, ebuf));
}
#ifdef HAVE_SYS_BUFMOD_H
static int
strioctl(int fd, int cmd, int len, char *dp)
{
struct strioctl str;
int rc;
str.ic_cmd = cmd;
str.ic_timout = -1;
str.ic_len = len;
str.ic_dp = dp;
rc = ioctl(fd, I_STR, &str);
if (rc < 0)
return (rc);
else
return (str.ic_len);
}
#endif
#if defined(HAVE_SOLARIS) && defined(HAVE_SYS_BUFMOD_H)
static char *
get_release(bpf_u_int32 *majorp, bpf_u_int32 *minorp, bpf_u_int32 *microp)
{
char *cp;
static char buf[32];
*majorp = 0;
*minorp = 0;
*microp = 0;
if (sysinfo(SI_RELEASE, buf, sizeof(buf)) < 0)
return ("?");
cp = buf;
if (!isdigit(*cp))
return (buf);
*majorp = strtol(cp, &cp, 10);
if (*cp++ != '.')
return (buf);
*minorp = strtol(cp, &cp, 10);
if (*cp++ != '.')
return (buf);
*microp = strtol(cp, &cp, 10);
return (buf);
}
#endif
#ifdef DL_HP_PPA_ACK_OBS
/*
* Under HP-UX 10, we can ask for the ppa
*/
/* Determine ppa number that specifies ifname */
static int
get_dlpi_ppa(register int fd, register const char *device, register int unit,
register char *ebuf)
{
register dl_hp_ppa_ack_t *ap;
register dl_hp_ppa_info_t *ip;
register int i;
register u_long majdev;
dl_hp_ppa_req_t req;
struct stat statbuf;
bpf_u_int32 buf[MAXDLBUF];
if (stat(device, &statbuf) < 0) {
sprintf(ebuf, "stat: %s: %s", device, pcap_strerror(errno));
return (-1);
}
majdev = major(statbuf.st_rdev);
memset((char *)&req, 0, sizeof(req));
req.dl_primitive = DL_HP_PPA_REQ;
memset((char *)buf, 0, sizeof(buf));
if (send_request(fd, (char *)&req, sizeof(req), "hpppa", ebuf) < 0 ||
recv_ack(fd, DL_HP_PPA_ACK_SIZE, "hpppa", (char *)buf, ebuf) < 0)
return (-1);
ap = (dl_hp_ppa_ack_t *)buf;
ip = (dl_hp_ppa_info_t *)((u_char *)ap + ap->dl_offset);
for(i = 0; i < ap->dl_count; i++) {
if (ip->dl_mjr_num == majdev && ip->dl_instance_num == unit)
break;
ip = (dl_hp_ppa_info_t *)((u_char *)ip + ip->dl_next_offset);
}
if (i == ap->dl_count) {
sprintf(ebuf, "can't find PPA for %s", device);
return (-1);
}
if (ip->dl_hdw_state == HDW_DEAD) {
sprintf(ebuf, "%s: hardware state: DOWN\n", device);
return (-1);
}
return ((int)ip->dl_ppa);
}
#endif
#ifdef HAVE_HPUX9
/*
* Under HP-UX 9, there is no good way to determine the ppa.
* So punt and read it from /dev/kmem.
*/
static struct nlist nl[] = {
#define NL_IFNET 0
{ "ifnet" },
{ "" }
};
static char path_vmunix[] = "/hp-ux";
/* Determine ppa number that specifies ifname */
static int
get_dlpi_ppa(register int fd, register const char *ifname, register int unit,
register char *ebuf)
{
register const char *cp;
register int kd;
void *addr;
struct ifnet ifnet;
char if_name[sizeof(ifnet.if_name)], tifname[32];
cp = strrchr(ifname, '/');
if (cp != NULL)
ifname = cp + 1;
if (nlist(path_vmunix, &nl) < 0) {
sprintf(ebuf, "nlist %s failed", path_vmunix);
return (-1);
}
if (nl[NL_IFNET].n_value == 0) {
sprintf(ebuf, "could't find %s kernel symbol",
nl[NL_IFNET].n_name);
return (-1);
}
kd = open("/dev/kmem", O_RDONLY);
if (kd < 0) {
sprintf(ebuf, "kmem open: %s", pcap_strerror(errno));
return (-1);
}
if (dlpi_kread(kd, nl[NL_IFNET].n_value,
&addr, sizeof(addr), ebuf) < 0) {
close(kd);
return (-1);
}
for (; addr != NULL; addr = ifnet.if_next) {
if (dlpi_kread(kd, (off_t)addr,
&ifnet, sizeof(ifnet), ebuf) < 0 ||
dlpi_kread(kd, (off_t)ifnet.if_name,
if_name, sizeof(if_name), ebuf) < 0) {
(void)close(kd);
return (-1);
}
sprintf(tifname, "%.*s%d",
(int)sizeof(if_name), if_name, ifnet.if_unit);
if (strcmp(tifname, ifname) == 0)
return (ifnet.if_index);
}
sprintf(ebuf, "Can't find %s", ifname);
return (-1);
}
static int
dlpi_kread(register int fd, register off_t addr,
register void *buf, register u_int len, register char *ebuf)
{
register int cc;
if (lseek(fd, addr, SEEK_SET) < 0) {
sprintf(ebuf, "lseek: %s", pcap_strerror(errno));
return (-1);
}
cc = read(fd, buf, len);
if (cc < 0) {
sprintf(ebuf, "read: %s", pcap_strerror(errno));
return (-1);
} else if (cc != len) {
sprintf(ebuf, "short read (%d != %d)", cc, len);
return (-1);
}
return (cc);
}
#endif