revarp.c revision c7e4935f5b755b4bbeaec416f1ad24337aeac7a4
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2007 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
#pragma ident "%Z%%M% %I% %E% SMI"
#include "defs.h"
#include "ifconfig.h"
#include <sys/types.h>
#include <libdlpi.h>
#include <sys/sysmacros.h>
#include <sys/time.h>
#include <deflt.h>
#define IPADDRL sizeof (struct in_addr)
#define RARPRETRIES 5
#define MSEC2NSEC(msec) ((msec) * 1000000)
#define NSEC2MSEC(nsec) ((nsec) / 1000000)
/*
* The following value (8) is determined to work reliably in switched 10/100MB
* ethernet environments. Use caution if you plan on decreasing it.
*/
#define RARPTIMEOUT 8
static char defaultfile[] = "/etc/inet/rarp";
static char retries_var[] = "RARP_RETRIES=";
static int rarp_timeout = RARPTIMEOUT;
static int rarp_retries = RARPRETRIES;
static dlpi_handle_t rarp_open(const char *, size_t *, uchar_t *, uchar_t *);
static int rarp_recv(dlpi_handle_t, struct arphdr *, size_t, size_t, int64_t);
int
doifrevarp(const char *linkname, struct sockaddr_in *laddr)
{
int s, retval;
struct arphdr *req, *ans;
struct in_addr from;
struct in_addr answer;
struct lifreq lifr;
int tries_left;
size_t physaddrlen, ifrarplen;
uchar_t my_macaddr[DLPI_PHYSADDR_MAX];
uchar_t my_broadcast[DLPI_PHYSADDR_MAX];
dlpi_handle_t dh;
if (linkname[0] == '\0') {
(void) fprintf(stderr, "ifconfig: doifrevarp: name not set\n");
exit(1);
}
if (debug)
(void) printf("doifrevarp interface %s\n", linkname);
if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
Perror0_exit("socket");
(void) strlcpy(lifr.lifr_name, linkname, sizeof (lifr.lifr_name));
if (ioctl(s, SIOCGLIFFLAGS, (char *)&lifr) < 0) {
(void) close(s);
Perror0_exit("SIOCGLIFFLAGS");
}
/* don't try to revarp if we know it won't work */
if ((lifr.lifr_flags & IFF_LOOPBACK) ||
(lifr.lifr_flags & IFF_NOARP) ||
(lifr.lifr_flags & IFF_POINTOPOINT)) {
(void) close(s);
return (0);
}
/* open rarp interface */
dh = rarp_open(linkname, &physaddrlen, my_macaddr, my_broadcast);
if (dh == NULL) {
(void) close(s);
return (0);
}
/*
* RARP looks at /etc/ethers and NIS, which only works
* with 6 byte addresses currently.
*/
if (physaddrlen != ETHERADDRL) {
dlpi_close(dh);
(void) close(s);
return (0);
}
ifrarplen = sizeof (struct arphdr) + (2 * IPADDRL) + (2 * physaddrlen);
/* look for adjustments to rarp_retries in the RARP defaults file */
if (defopen(defaultfile) == 0) {
char *cp;
if (cp = defread(retries_var)) {
int ntries;
ntries = atoi(cp);
if (ntries > 0)
rarp_retries = ntries;
}
(void) defopen(NULL); /* close default file */
}
/* allocate request and response buffers */
if (((req = malloc(ifrarplen)) == NULL) ||
((ans = malloc(ifrarplen)) == NULL)) {
dlpi_close(dh);
(void) close(s);
free(req);
return (0);
}
/* create rarp request */
(void) memset(req, 0, ifrarplen);
req->ar_hrd = htons(ARPHRD_ETHER);
req->ar_pro = htons(ETHERTYPE_IP);
req->ar_hln = physaddrlen;
req->ar_pln = IPADDRL;
req->ar_op = htons(REVARP_REQUEST);
(void) memcpy(&req[1], my_macaddr, physaddrlen);
(void) memcpy((uchar_t *)req + sizeof (struct arphdr) + IPADDRL +
physaddrlen, my_macaddr, physaddrlen);
for (tries_left = rarp_retries; tries_left > 0; --tries_left) {
/* send the request */
retval = dlpi_send(dh, my_broadcast, physaddrlen, req,
ifrarplen, NULL);
if (retval != DLPI_SUCCESS) {
Perrdlpi("doifrevarp: cannot send rarp request",
linkname, retval);
break;
}
if (debug)
(void) printf("rarp sent\n");
retval = rarp_recv(dh, ans, ifrarplen, physaddrlen,
rarp_timeout * MILLISEC);
if (retval != DLPI_ETIMEDOUT)
break;
if (debug)
(void) printf("rarp retry\n");
}
if (retval == DLPI_SUCCESS) {
(void) memcpy(&answer, (uchar_t *)ans +
sizeof (struct arphdr) + (2 * physaddrlen) + IPADDRL,
sizeof (answer));
(void) memcpy(&from, (uchar_t *)ans + physaddrlen +
sizeof (struct arphdr), sizeof (from));
if (debug) {
(void) printf("answer: %s", inet_ntoa(answer));
(void) printf(" [from %s]\n", inet_ntoa(from));
}
laddr->sin_addr = answer;
} else if (debug) {
Perrdlpi("doifrevarp: could not receive rarp reply",
linkname, retval);
}
dlpi_close(dh);
(void) close(s);
free(req);
free(ans);
return (retval == DLPI_SUCCESS);
}
/*
* Open the datalink provider device and bind to the REVARP type.
* Return the resulting DLPI handle.
*/
static dlpi_handle_t
rarp_open(const char *linkname, size_t *alen, uchar_t *myaddr, uchar_t *mybaddr)
{
int retval;
char *physaddr, *bcastaddr;
dlpi_info_t dlinfo;
dlpi_handle_t dh;
if (debug)
(void) printf("rarp_open %s\n", linkname);
if ((retval = dlpi_open(linkname, &dh, 0)) != DLPI_SUCCESS) {
Perrdlpi("rarp_open: dlpi_open failed", linkname, retval);
return (NULL);
}
if ((retval = dlpi_bind(dh, ETHERTYPE_REVARP, NULL)) != DLPI_SUCCESS) {
Perrdlpi("rarp_open: dlpi_bind failed", linkname, retval);
goto failed;
}
if ((retval = dlpi_info(dh, &dlinfo, 0)) != DLPI_SUCCESS) {
Perrdlpi("rarp_open: dlpi_info failed", linkname, retval);
goto failed;
}
if (dlinfo.di_bcastaddrlen == 0) {
(void) fprintf(stderr, "ifconfig: rarp_open: %s broadcast "
"not supported\n", linkname);
goto failed;
}
/* we assume the following are equal and fill in 'alen' */
assert(dlinfo.di_bcastaddrlen == dlinfo.di_physaddrlen);
(void) memcpy(mybaddr, dlinfo.di_bcastaddr, dlinfo.di_bcastaddrlen);
*alen = dlinfo.di_physaddrlen;
(void) memcpy(myaddr, dlinfo.di_physaddr, dlinfo.di_physaddrlen);
if (debug) {
bcastaddr = _link_ntoa(mybaddr, NULL, dlinfo.di_bcastaddrlen,
IFT_OTHER);
physaddr = _link_ntoa(myaddr, NULL, dlinfo.di_physaddrlen,
IFT_OTHER);
if (physaddr != NULL && bcastaddr != NULL) {
(void) printf("device %s: broadcast address %s, mac "
"address %s\n", linkname, bcastaddr, physaddr);
}
free(physaddr);
free(bcastaddr);
(void) printf("rarp_open: addr length = %d\n",
dlinfo.di_physaddrlen);
}
return (dh);
failed:
dlpi_close(dh);
return (NULL);
}
/*
* Read reply for RARP request. If a reply is received within waitms,
* validate the reply. If it is a correct RARP reply return DLPI_SUCCESS,
* otherwise return DLPI_ETIMEDOUT. If there is an error while reading retrun
* the error code.
*/
static int
rarp_recv(dlpi_handle_t dh, struct arphdr *ans, size_t msglen,
size_t physaddrlen, int64_t waitms)
{
int retval;
char *cause;
size_t anslen = msglen;
hrtime_t endtime = gethrtime() + MSEC2NSEC(waitms);
hrtime_t currtime;
while ((currtime = gethrtime()) < endtime) {
waitms = NSEC2MSEC(endtime - currtime);
retval = dlpi_recv(dh, NULL, NULL, ans, &anslen, waitms, NULL);
if (retval == DLPI_SUCCESS) {
cause = NULL;
if (anslen < msglen)
cause = "short packet";
else if (ans->ar_hrd != htons(ARPHRD_ETHER))
cause = "hardware type not Ethernet";
else if (ans->ar_pro != htons(ETHERTYPE_IP))
cause = "protocol type not IP";
else if (ans->ar_hln != physaddrlen)
cause = "unexpected hardware address length";
else if (ans->ar_pln != IPADDRL)
cause = "unexpected protocol address length";
if (cause != NULL) {
(void) fprintf(stderr, "RARP packet received "
"but discarded (%s)\n", cause);
continue;
}
switch (ntohs(ans->ar_op)) {
case REVARP_REQUEST:
if (debug)
(void) printf("Got a rarp request.\n");
break;
case REVARP_REPLY:
return (DLPI_SUCCESS);
default:
(void) fprintf(stderr, "ifconfig: unknown "
"RARP opcode 0x%x\n", ans->ar_op);
break;
}
} else if (retval != DLPI_ETIMEDOUT) {
Perrdlpi("doifrevarp: dlpi_recv failed",
dlpi_linkname(dh), retval);
return (retval);
}
}
return (DLPI_ETIMEDOUT);
}
int
dlpi_set_address(const char *linkname, uchar_t *physaddr, uint_t physaddrlen)
{
int retval;
dlpi_handle_t dh;
if ((retval = dlpi_open(linkname, &dh, 0)) != DLPI_SUCCESS) {
Perrdlpi("dlpi_open failed", linkname, retval);
return (-1);
}
if ((retval = dlpi_set_physaddr(dh, DL_CURR_PHYS_ADDR, physaddr,
physaddrlen)) != DLPI_SUCCESS) {
Perrdlpi("dlpi_set_physaddr failed", linkname, retval);
dlpi_close(dh);
return (-1);
}
dlpi_close(dh);
return (0);
}
void
dlpi_print_address(const char *linkname)
{
uint_t physaddrlen = DLPI_PHYSADDR_MAX;
uchar_t physaddr[DLPI_PHYSADDR_MAX];
char *str;
int retv;
dlpi_handle_t dh;
dlpi_info_t dlinfo;
if (dlpi_open(linkname, &dh, 0) != DLPI_SUCCESS) {
/* Do not report an error */
return;
}
retv = dlpi_get_physaddr(dh, DL_CURR_PHYS_ADDR, physaddr, &physaddrlen);
if (retv != DLPI_SUCCESS) {
Perrdlpi("dlpi_get_physaddr failed", linkname, retv);
dlpi_close(dh);
return;
}
retv = dlpi_info(dh, &dlinfo, 0);
if (retv != DLPI_SUCCESS) {
Perrdlpi("dlpi_info failed", linkname, retv);
dlpi_close(dh);
return;
}
dlpi_close(dh);
str = _link_ntoa(physaddr, NULL, physaddrlen, IFT_OTHER);
if (str != NULL) {
switch (dlinfo.di_mactype) {
case DL_IB:
(void) printf("\tipib %s \n", str);
break;
default:
(void) printf("\tether %s \n", str);
break;
}
free(str);
}
}