freebsd-src/libexec/rbootd/bpf.c
Pedro F. Giffuni 8a16b7a18f General further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
2017-11-20 19:49:47 +00:00

409 lines
10 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 1988, 1992 The University of Utah and the Center
* for Software Science (CSS).
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* the Center for Software Science of the University of Utah Computer
* Science Department. CSS requests users of this software to return
* to css-dist@cs.utah.edu any improvements that they make and grant
* CSS redistribution rights.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. 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 BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from: @(#)bpf.c 8.1 (Berkeley) 6/4/93
*
* From: Utah Hdr: bpf.c 3.1 92/07/06
* Author: Jeff Forys, University of Utah CSS
*/
#ifndef lint
#if 0
static const char sccsid[] = "@(#)bpf.c 8.1 (Berkeley) 6/4/93";
#endif
static const char rcsid[] =
"$FreeBSD$";
#endif /* not lint */
#include <sys/param.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <net/if.h>
#include <net/bpf.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>
#include "defs.h"
#include "pathnames.h"
static int BpfFd = -1;
static unsigned BpfLen = 0;
static u_int8_t *BpfPkt = NULL;
/*
** BpfOpen -- Open and initialize a BPF device.
**
** Parameters:
** None.
**
** Returns:
** File descriptor of opened BPF device (for select() etc).
**
** Side Effects:
** If an error is encountered, the program terminates here.
*/
int
BpfOpen(void)
{
struct ifreq ifr;
char bpfdev[32];
int n = 0;
/*
* Open the first available BPF device.
*/
do {
(void) sprintf(bpfdev, _PATH_BPF, n++);
BpfFd = open(bpfdev, O_RDWR);
} while (BpfFd < 0 && (errno == EBUSY || errno == EPERM));
if (BpfFd < 0) {
syslog(LOG_ERR, "bpf: no available devices: %m");
Exit(0);
}
/*
* Set interface name for bpf device, get data link layer
* type and make sure it's type Ethernet.
*/
(void) strncpy(ifr.ifr_name, IntfName, sizeof(ifr.ifr_name));
if (ioctl(BpfFd, BIOCSETIF, (caddr_t)&ifr) < 0) {
syslog(LOG_ERR, "bpf: ioctl(BIOCSETIF,%s): %m", IntfName);
Exit(0);
}
/*
* Make sure we are dealing with an Ethernet device.
*/
if (ioctl(BpfFd, BIOCGDLT, (caddr_t)&n) < 0) {
syslog(LOG_ERR, "bpf: ioctl(BIOCGDLT): %m");
Exit(0);
}
if (n != DLT_EN10MB) {
syslog(LOG_ERR,"bpf: %s: data-link type %d unsupported",
IntfName, n);
Exit(0);
}
/*
* On read(), return packets immediately (do not buffer them).
*/
n = 1;
if (ioctl(BpfFd, BIOCIMMEDIATE, (caddr_t)&n) < 0) {
syslog(LOG_ERR, "bpf: ioctl(BIOCIMMEDIATE): %m");
Exit(0);
}
/*
* Try to enable the chip/driver's multicast address filter to
* grab our RMP address. If this fails, try promiscuous mode.
* If this fails, there's no way we are going to get any RMP
* packets so just exit here.
*/
#ifdef MSG_EOR
ifr.ifr_addr.sa_len = RMP_ADDRLEN + 2;
#endif
ifr.ifr_addr.sa_family = AF_UNSPEC;
memmove((char *)&ifr.ifr_addr.sa_data[0], &RmpMcastAddr[0], RMP_ADDRLEN);
if (ioctl(BpfFd, BIOCPROMISC, (caddr_t)0) < 0) {
syslog(LOG_ERR, "bpf: can't set promiscuous mode: %m");
Exit(0);
}
/*
* Ask BPF how much buffer space it requires and allocate one.
*/
if (ioctl(BpfFd, BIOCGBLEN, (caddr_t)&BpfLen) < 0) {
syslog(LOG_ERR, "bpf: ioctl(BIOCGBLEN): %m");
Exit(0);
}
if (BpfPkt == NULL)
BpfPkt = (u_int8_t *)malloc(BpfLen);
if (BpfPkt == NULL) {
syslog(LOG_ERR, "bpf: out of memory (%u bytes for bpfpkt)",
BpfLen);
Exit(0);
}
/*
* Write a little program to snarf RMP Boot packets and stuff
* it down BPF's throat (i.e. set up the packet filter).
*/
{
#define RMP ((struct rmp_packet *)0)
static struct bpf_insn bpf_insn[] = {
{ BPF_LD|BPF_B|BPF_ABS, 0, 0, (long)&RMP->hp_llc.dsap },
{ BPF_JMP|BPF_JEQ|BPF_K, 0, 5, IEEE_DSAP_HP },
{ BPF_LD|BPF_H|BPF_ABS, 0, 0, (long)&RMP->hp_llc.cntrl },
{ BPF_JMP|BPF_JEQ|BPF_K, 0, 3, IEEE_CNTL_HP },
{ BPF_LD|BPF_H|BPF_ABS, 0, 0, (long)&RMP->hp_llc.dxsap },
{ BPF_JMP|BPF_JEQ|BPF_K, 0, 1, HPEXT_DXSAP },
{ BPF_RET|BPF_K, 0, 0, RMP_MAX_PACKET },
{ BPF_RET|BPF_K, 0, 0, 0x0 }
};
#undef RMP
static struct bpf_program bpf_pgm = {
sizeof(bpf_insn)/sizeof(bpf_insn[0]), bpf_insn
};
if (ioctl(BpfFd, BIOCSETF, (caddr_t)&bpf_pgm) < 0) {
syslog(LOG_ERR, "bpf: ioctl(BIOCSETF): %m");
Exit(0);
}
}
return(BpfFd);
}
/*
** BPF GetIntfName -- Return the name of a network interface attached to
** the system, or 0 if none can be found. The interface
** must be configured up; the lowest unit number is
** preferred; loopback is ignored.
**
** Parameters:
** errmsg - if no network interface found, *errmsg explains why.
**
** Returns:
** A (static) pointer to interface name, or NULL on error.
**
** Side Effects:
** None.
*/
char *
BpfGetIntfName(char **errmsg)
{
struct ifreq ibuf[8], *ifrp, *ifend, *mp;
struct ifconf ifc;
int fd;
int minunit, n;
char *cp;
static char device[sizeof(ifrp->ifr_name)];
static char errbuf[128] = "No Error!";
if (errmsg != NULL)
*errmsg = errbuf;
if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
(void) strcpy(errbuf, "bpf: socket: %m");
return(NULL);
}
ifc.ifc_len = sizeof ibuf;
ifc.ifc_buf = (caddr_t)ibuf;
if (ioctl(fd, SIOCGIFCONF, (char *)&ifc) < 0 ||
ifc.ifc_len < sizeof(struct ifreq)) {
(void) strcpy(errbuf, "bpf: ioctl(SIOCGIFCONF): %m");
return(NULL);
}
ifrp = ibuf;
ifend = (struct ifreq *)((char *)ibuf + ifc.ifc_len);
mp = NULL;
minunit = 666;
for (; ifrp < ifend; ++ifrp) {
if (ioctl(fd, SIOCGIFFLAGS, (char *)ifrp) < 0) {
(void) strcpy(errbuf, "bpf: ioctl(SIOCGIFFLAGS): %m");
return(NULL);
}
/*
* If interface is down or this is the loopback interface,
* ignore it.
*/
if ((ifrp->ifr_flags & IFF_UP) == 0 ||
#ifdef IFF_LOOPBACK
(ifrp->ifr_flags & IFF_LOOPBACK))
#else
(strcmp(ifrp->ifr_name, "lo0") == 0))
#endif
continue;
for (cp = ifrp->ifr_name; !isdigit(*cp); ++cp)
;
n = atoi(cp);
if (n < minunit) {
minunit = n;
mp = ifrp;
}
}
(void) close(fd);
if (mp == NULL) {
(void) strcpy(errbuf, "bpf: no interfaces found");
return(NULL);
}
(void) strcpy(device, mp->ifr_name);
return(device);
}
/*
** BpfRead -- Read packets from a BPF device and fill in `rconn'.
**
** Parameters:
** rconn - filled in with next packet.
** doread - is True if we can issue a read() syscall.
**
** Returns:
** True if `rconn' contains a new packet, False otherwise.
**
** Side Effects:
** None.
*/
int
BpfRead(RMPCONN *rconn, int doread)
{
int datlen, caplen, hdrlen;
static u_int8_t *bp = NULL, *ep = NULL;
int cc;
/*
* The read() may block, or it may return one or more packets.
* We let the caller decide whether or not we can issue a read().
*/
if (doread) {
if ((cc = read(BpfFd, (char *)BpfPkt, (int)BpfLen)) < 0) {
syslog(LOG_ERR, "bpf: read: %m");
return(0);
} else {
bp = BpfPkt;
ep = BpfPkt + cc;
}
}
#define bhp ((struct bpf_hdr *)bp)
/*
* If there is a new packet in the buffer, stuff it into `rconn'
* and return a success indication.
*/
if (bp < ep) {
datlen = bhp->bh_datalen;
caplen = bhp->bh_caplen;
hdrlen = bhp->bh_hdrlen;
if (caplen != datlen)
syslog(LOG_ERR,
"bpf: short packet dropped (%d of %d bytes)",
caplen, datlen);
else if (caplen > sizeof(struct rmp_packet))
syslog(LOG_ERR, "bpf: large packet dropped (%d bytes)",
caplen);
else {
rconn->rmplen = caplen;
memmove((char *)&rconn->tstamp, (char *)&bhp->bh_tstamp,
sizeof(struct timeval));
memmove((char *)&rconn->rmp, (char *)bp + hdrlen, caplen);
}
bp += BPF_WORDALIGN(caplen + hdrlen);
return(1);
}
#undef bhp
return(0);
}
/*
** BpfWrite -- Write packet to BPF device.
**
** Parameters:
** rconn - packet to send.
**
** Returns:
** True if write succeeded, False otherwise.
**
** Side Effects:
** None.
*/
int
BpfWrite(RMPCONN *rconn)
{
if (write(BpfFd, (char *)&rconn->rmp, rconn->rmplen) < 0) {
syslog(LOG_ERR, "write: %s: %m", EnetStr(rconn));
return(0);
}
return(1);
}
/*
** BpfClose -- Close a BPF device.
**
** Parameters:
** None.
**
** Returns:
** Nothing.
**
** Side Effects:
** None.
*/
void
BpfClose(void)
{
struct ifreq ifr;
if (BpfPkt != NULL) {
free((char *)BpfPkt);
BpfPkt = NULL;
}
if (BpfFd == -1)
return;
#ifdef MSG_EOR
ifr.ifr_addr.sa_len = RMP_ADDRLEN + 2;
#endif
ifr.ifr_addr.sa_family = AF_UNSPEC;
memmove((char *)&ifr.ifr_addr.sa_data[0], &RmpMcastAddr[0], RMP_ADDRLEN);
if (ioctl(BpfFd, SIOCDELMULTI, (caddr_t)&ifr) < 0)
(void) ioctl(BpfFd, BIOCPROMISC, (caddr_t)0);
(void) close(BpfFd);
BpfFd = -1;
}