freebsd-dev/usr.sbin/rwhod/rwhod.c
Ed Schouten b3608ae18f Replace index() and rindex() calls with strchr() and strrchr().
The index() and rindex() functions were marked LEGACY in the 2001
revision of POSIX and were subsequently removed from the 2008 revision.
The strchr() and strrchr() functions are part of the C standard.

This makes the source code a lot more consistent, as most of these C
files also call into other str*() routines. In fact, about a dozen
already perform strchr() calls.
2012-01-03 18:51:58 +00:00

711 lines
19 KiB
C

/*
* Copyright (c) 1983, 1993
* 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 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.
* 4. 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.
*/
#ifndef lint
static const char copyright[] =
"@(#) Copyright (c) 1983, 1993\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#if 0
#ifndef lint
static char sccsid[] = "@(#)rwhod.c 8.1 (Berkeley) 6/6/93";
#endif /* not lint */
#endif
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/signal.h>
#include <sys/ioctl.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/if_dl.h>
#include <net/route.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <protocols/rwhod.h>
#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <netdb.h>
#include <paths.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <timeconv.h>
#include <unistd.h>
#include <utmpx.h>
#include <pwd.h>
#include <grp.h>
/*
* This version of Berkeley's rwhod has been modified to use IP multicast
* datagrams, under control of a new command-line option:
*
* rwhod -m causes rwhod to use IP multicast (instead of
* broadcast or unicast) on all interfaces that have
* the IFF_MULTICAST flag set in their "ifnet" structs
* (excluding the loopback interface). The multicast
* reports are sent with a time-to-live of 1, to prevent
* forwarding beyond the directly-connected subnet(s).
*
* rwhod -m <ttl> causes rwhod to send IP multicast datagrams with a
* time-to-live of <ttl>, via a SINGLE interface rather
* than all interfaces. <ttl> must be between 0 and
* MAX_MULTICAST_SCOPE, defined below. Note that "-m 1"
* is different than "-m", in that "-m 1" specifies
* transmission on one interface only.
*
* When "-m" is used without a <ttl> argument, the program accepts multicast
* rwhod reports from all multicast-capable interfaces. If a <ttl> argument
* is given, it accepts multicast reports from only one interface, the one
* on which reports are sent (which may be controlled via the host's routing
* table). Regardless of the "-m" option, the program accepts broadcast or
* unicast reports from all interfaces. Thus, this program will hear the
* reports of old, non-multicasting rwhods, but, if multicasting is used,
* those old rwhods won't hear the reports generated by this program.
*
* -- Steve Deering, Stanford University, February 1989
*/
#define UNPRIV_USER "daemon"
#define UNPRIV_GROUP "daemon"
#define NO_MULTICAST 0 /* multicast modes */
#define PER_INTERFACE_MULTICAST 1
#define SCOPED_MULTICAST 2
#define MAX_MULTICAST_SCOPE 32 /* "site-wide", by convention */
#define INADDR_WHOD_GROUP (u_long)0xe0000103 /* 224.0.1.3 */
/* (belongs in protocols/rwhod.h) */
int insecure_mode;
int quiet_mode;
int iff_flag = IFF_POINTOPOINT;
int multicast_mode = NO_MULTICAST;
int multicast_scope;
struct sockaddr_in multicast_addr =
{ sizeof multicast_addr, AF_INET, 0, { 0 }, { 0 } };
/*
* Alarm interval. Don't forget to change the down time check in ruptime
* if this is changed.
*/
#define AL_INTERVAL (3 * 60)
char myname[MAXHOSTNAMELEN];
/*
* We communicate with each neighbor in a list constructed at the time we're
* started up. Neighbors are currently directly connected via a hardware
* interface.
*/
struct neighbor {
struct neighbor *n_next;
char *n_name; /* interface name */
struct sockaddr *n_addr; /* who to send to */
int n_addrlen; /* size of address */
int n_flags; /* should forward?, interface flags */
};
struct neighbor *neighbors;
struct whod mywd;
struct servent *sp;
int s;
#define WHDRSIZE (int)(sizeof(mywd) - sizeof(mywd.wd_we))
void run_as(uid_t *, gid_t *);
int configure(int);
void getboottime(int);
void onalrm(int);
void quit(const char *);
void rt_xaddrs(caddr_t, caddr_t, struct rt_addrinfo *);
int verify(char *, int);
static void usage(void);
#ifdef DEBUG
char *interval(int, char *);
void Sendto(int, const void *, size_t, int, const struct sockaddr *, int);
#define sendto Sendto
#endif
int
main(int argc, char *argv[])
{
struct sockaddr_in from;
struct stat st;
char path[64];
int on = 1;
char *cp;
struct sockaddr_in soin;
uid_t unpriv_uid;
gid_t unpriv_gid;
if (getuid())
errx(1, "not super user");
run_as(&unpriv_uid, &unpriv_gid);
argv++; argc--;
while (argc > 0 && *argv[0] == '-') {
if (strcmp(*argv, "-m") == 0) {
if (argc > 1 && isdigit(*(argv + 1)[0])) {
argv++, argc--;
multicast_mode = SCOPED_MULTICAST;
multicast_scope = atoi(*argv);
if (multicast_scope > MAX_MULTICAST_SCOPE)
errx(1, "ttl must not exceed %u",
MAX_MULTICAST_SCOPE);
}
else multicast_mode = PER_INTERFACE_MULTICAST;
}
else if (strcmp(*argv, "-i") == 0)
insecure_mode = 1;
else if (strcmp(*argv, "-l") == 0)
quiet_mode = 1;
else if (strcmp(*argv, "-p") == 0)
iff_flag = 0;
else
usage();
argv++, argc--;
}
if (argc > 0)
usage();
#ifndef DEBUG
daemon(1, 0);
#endif
(void) signal(SIGHUP, getboottime);
openlog("rwhod", LOG_PID, LOG_DAEMON);
sp = getservbyname("who", "udp");
if (sp == NULL) {
syslog(LOG_ERR, "who/udp: unknown service");
exit(1);
}
if (chdir(_PATH_RWHODIR) < 0) {
syslog(LOG_ERR, "%s: %m", _PATH_RWHODIR);
exit(1);
}
/*
* Establish host name as returned by system.
*/
if (gethostname(myname, sizeof(myname) - 1) < 0) {
syslog(LOG_ERR, "gethostname: %m");
exit(1);
}
if ((cp = strchr(myname, '.')) != NULL)
*cp = '\0';
strncpy(mywd.wd_hostname, myname, sizeof(mywd.wd_hostname) - 1);
mywd.wd_hostname[sizeof(mywd.wd_hostname) - 1] = '\0';
getboottime(0);
if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
syslog(LOG_ERR, "socket: %m");
exit(1);
}
if (setsockopt(s, SOL_SOCKET, SO_BROADCAST, &on, sizeof(on)) < 0) {
syslog(LOG_ERR, "setsockopt SO_BROADCAST: %m");
exit(1);
}
memset(&soin, 0, sizeof(soin));
soin.sin_len = sizeof(soin);
soin.sin_family = AF_INET;
soin.sin_port = sp->s_port;
if (bind(s, (struct sockaddr *)&soin, sizeof(soin)) < 0) {
syslog(LOG_ERR, "bind: %m");
exit(1);
}
if (setgid(unpriv_gid) != 0) {
syslog(LOG_ERR, "setgid: %m");
exit(1);
}
if (setgroups(1, &unpriv_gid) != 0) { /* XXX BOGUS groups[0] = egid */
syslog(LOG_ERR, "setgroups: %m");
exit(1);
}
if (setuid(unpriv_uid) != 0) {
syslog(LOG_ERR, "setuid: %m");
exit(1);
}
if (!configure(s))
exit(1);
if (!quiet_mode) {
signal(SIGALRM, onalrm);
onalrm(0);
}
for (;;) {
struct whod wd;
socklen_t len = sizeof(from);
int cc, whod;
time_t t;
cc = recvfrom(s, (char *)&wd, sizeof(struct whod), 0,
(struct sockaddr *)&from, &len);
if (cc <= 0) {
if (cc < 0 && errno != EINTR)
syslog(LOG_WARNING, "recv: %m");
continue;
}
if (from.sin_port != sp->s_port && !insecure_mode) {
syslog(LOG_WARNING, "%d: bad source port from %s",
ntohs(from.sin_port), inet_ntoa(from.sin_addr));
continue;
}
if (cc < WHDRSIZE) {
syslog(LOG_WARNING, "short packet from %s",
inet_ntoa(from.sin_addr));
continue;
}
if (wd.wd_vers != WHODVERSION)
continue;
if (wd.wd_type != WHODTYPE_STATUS)
continue;
if (!verify(wd.wd_hostname, sizeof wd.wd_hostname)) {
syslog(LOG_WARNING, "malformed host name from %s",
inet_ntoa(from.sin_addr));
continue;
}
(void) snprintf(path, sizeof path, "whod.%s", wd.wd_hostname);
/*
* Rather than truncating and growing the file each time,
* use ftruncate if size is less than previous size.
*/
whod = open(path, O_WRONLY | O_CREAT, 0644);
if (whod < 0) {
syslog(LOG_WARNING, "%s: %m", path);
continue;
}
#if ENDIAN != BIG_ENDIAN
{
int i, n = (cc - WHDRSIZE)/sizeof(struct whoent);
struct whoent *we;
/* undo header byte swapping before writing to file */
wd.wd_sendtime = ntohl(wd.wd_sendtime);
for (i = 0; i < 3; i++)
wd.wd_loadav[i] = ntohl(wd.wd_loadav[i]);
wd.wd_boottime = ntohl(wd.wd_boottime);
we = wd.wd_we;
for (i = 0; i < n; i++) {
we->we_idle = ntohl(we->we_idle);
we->we_utmp.out_time =
ntohl(we->we_utmp.out_time);
we++;
}
}
#endif
(void) time(&t);
wd.wd_recvtime = _time_to_int(t);
(void) write(whod, (char *)&wd, cc);
if (fstat(whod, &st) < 0 || st.st_size > cc)
ftruncate(whod, cc);
(void) close(whod);
}
}
static void
usage()
{
fprintf(stderr, "usage: rwhod [-i] [-p] [-l] [-m [ttl]]\n");
exit(1);
}
void
run_as(uid, gid)
uid_t *uid;
gid_t *gid;
{
struct passwd *pw;
struct group *gr;
pw = getpwnam(UNPRIV_USER);
if (!pw) {
syslog(LOG_ERR, "getpwnam(%s): %m", UNPRIV_USER);
exit(1);
}
*uid = pw->pw_uid;
gr = getgrnam(UNPRIV_GROUP);
if (!gr) {
syslog(LOG_ERR, "getgrnam(%s): %m", UNPRIV_GROUP);
exit(1);
}
*gid = gr->gr_gid;
}
/*
* Check out host name for unprintables
* and other funnies before allowing a file
* to be created. Sorry, but blanks aren't allowed.
*/
int
verify(name, maxlen)
register char *name;
register int maxlen;
{
register int size = 0;
while (*name && size < maxlen - 1) {
if (!isascii(*name) || !(isalnum(*name) || ispunct(*name)))
return (0);
name++, size++;
}
*name = '\0';
return (size > 0);
}
void
onalrm(int signo __unused)
{
struct neighbor *np;
struct whoent *we = mywd.wd_we, *wend;
struct stat stb;
struct utmpx *ut;
static int alarmcount = 0;
double avenrun[3];
time_t now;
int i, cc;
now = time(NULL);
if (alarmcount % 10 == 0)
getboottime(0);
alarmcount++;
wend = &mywd.wd_we[1024 / sizeof(struct whoent)];
setutxent();
while ((ut = getutxent()) != NULL && we < wend) {
if (ut->ut_type != USER_PROCESS)
continue;
strncpy(we->we_utmp.out_line, ut->ut_line,
sizeof(we->we_utmp.out_line));
strncpy(we->we_utmp.out_name, ut->ut_user,
sizeof(we->we_utmp.out_name));
we->we_utmp.out_time =
htonl(_time_to_time32(ut->ut_tv.tv_sec));
we++;
}
endutxent();
if (chdir(_PATH_DEV)) {
syslog(LOG_ERR, "chdir(%s): %m", _PATH_DEV);
exit(1);
}
wend = we;
for (we = mywd.wd_we; we < wend; we++) {
if (stat(we->we_utmp.out_line, &stb) >= 0)
we->we_idle = htonl(now - stb.st_atime);
we++;
}
(void)getloadavg(avenrun, sizeof(avenrun)/sizeof(avenrun[0]));
for (i = 0; i < 3; i++)
mywd.wd_loadav[i] = htonl((u_long)(avenrun[i] * 100));
cc = (char *)wend - (char *)&mywd;
mywd.wd_sendtime = htonl(_time_to_time32(time(NULL)));
mywd.wd_vers = WHODVERSION;
mywd.wd_type = WHODTYPE_STATUS;
if (multicast_mode == SCOPED_MULTICAST) {
(void) sendto(s, (char *)&mywd, cc, 0,
(struct sockaddr *)&multicast_addr,
sizeof(multicast_addr));
}
else for (np = neighbors; np != NULL; np = np->n_next) {
if (multicast_mode == PER_INTERFACE_MULTICAST &&
np->n_flags & IFF_MULTICAST) {
/*
* Select the outgoing interface for the multicast.
*/
if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_IF,
&(((struct sockaddr_in *)np->n_addr)->sin_addr),
sizeof(struct in_addr)) < 0) {
syslog(LOG_ERR,
"setsockopt IP_MULTICAST_IF: %m");
exit(1);
}
(void) sendto(s, (char *)&mywd, cc, 0,
(struct sockaddr *)&multicast_addr,
sizeof(multicast_addr));
} else (void) sendto(s, (char *)&mywd, cc, 0,
np->n_addr, np->n_addrlen);
}
if (chdir(_PATH_RWHODIR)) {
syslog(LOG_ERR, "chdir(%s): %m", _PATH_RWHODIR);
exit(1);
}
(void) alarm(AL_INTERVAL);
}
void
getboottime(signo)
int signo __unused;
{
int mib[2];
size_t size;
struct timeval tm;
mib[0] = CTL_KERN;
mib[1] = KERN_BOOTTIME;
size = sizeof(tm);
if (sysctl(mib, 2, &tm, &size, NULL, 0) == -1) {
syslog(LOG_ERR, "cannot get boottime: %m");
exit(1);
}
mywd.wd_boottime = htonl(_time_to_time32(tm.tv_sec));
}
void
quit(msg)
const char *msg;
{
syslog(LOG_ERR, "%s", msg);
exit(1);
}
void
rt_xaddrs(cp, cplim, rtinfo)
register caddr_t cp, cplim;
register struct rt_addrinfo *rtinfo;
{
register struct sockaddr *sa;
register int i;
memset(rtinfo->rti_info, 0, sizeof(rtinfo->rti_info));
for (i = 0; (i < RTAX_MAX) && (cp < cplim); i++) {
if ((rtinfo->rti_addrs & (1 << i)) == 0)
continue;
rtinfo->rti_info[i] = sa = (struct sockaddr *)cp;
cp += SA_SIZE(sa);
}
}
/*
* Figure out device configuration and select
* networks which deserve status information.
*/
int
configure(so)
int so;
{
register struct neighbor *np;
register struct if_msghdr *ifm;
register struct ifa_msghdr *ifam;
struct sockaddr_dl *sdl;
size_t needed;
int mib[6], flags = 0, len;
char *buf, *lim, *next;
struct rt_addrinfo info;
if (multicast_mode != NO_MULTICAST) {
multicast_addr.sin_addr.s_addr = htonl(INADDR_WHOD_GROUP);
multicast_addr.sin_port = sp->s_port;
}
if (multicast_mode == SCOPED_MULTICAST) {
struct ip_mreq mreq;
unsigned char ttl;
mreq.imr_multiaddr.s_addr = htonl(INADDR_WHOD_GROUP);
mreq.imr_interface.s_addr = htonl(INADDR_ANY);
if (setsockopt(so, IPPROTO_IP, IP_ADD_MEMBERSHIP,
&mreq, sizeof(mreq)) < 0) {
syslog(LOG_ERR,
"setsockopt IP_ADD_MEMBERSHIP: %m");
return(0);
}
ttl = multicast_scope;
if (setsockopt(so, IPPROTO_IP, IP_MULTICAST_TTL,
&ttl, sizeof(ttl)) < 0) {
syslog(LOG_ERR,
"setsockopt IP_MULTICAST_TTL: %m");
return(0);
}
return(1);
}
mib[0] = CTL_NET;
mib[1] = PF_ROUTE;
mib[2] = 0;
mib[3] = AF_INET;
mib[4] = NET_RT_IFLIST;
mib[5] = 0;
if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
quit("route-sysctl-estimate");
if ((buf = malloc(needed)) == NULL)
quit("malloc");
if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0)
quit("actual retrieval of interface table");
lim = buf + needed;
sdl = NULL; /* XXX just to keep gcc -Wall happy */
for (next = buf; next < lim; next += ifm->ifm_msglen) {
ifm = (struct if_msghdr *)next;
if (ifm->ifm_type == RTM_IFINFO) {
sdl = (struct sockaddr_dl *)(ifm + 1);
flags = ifm->ifm_flags;
continue;
}
if ((flags & IFF_UP) == 0 ||
(flags & (((multicast_mode == PER_INTERFACE_MULTICAST) ?
IFF_MULTICAST : 0) |
IFF_BROADCAST|iff_flag)) == 0)
continue;
if (ifm->ifm_type != RTM_NEWADDR)
quit("out of sync parsing NET_RT_IFLIST");
ifam = (struct ifa_msghdr *)ifm;
info.rti_addrs = ifam->ifam_addrs;
rt_xaddrs((char *)(ifam + 1), ifam->ifam_msglen + (char *)ifam,
&info);
/* gag, wish we could get rid of Internet dependencies */
#define dstaddr info.rti_info[RTAX_BRD]
#define ifaddr info.rti_info[RTAX_IFA]
#define IPADDR_SA(x) ((struct sockaddr_in *)(x))->sin_addr.s_addr
#define PORT_SA(x) ((struct sockaddr_in *)(x))->sin_port
if (dstaddr == 0 || dstaddr->sa_family != AF_INET)
continue;
PORT_SA(dstaddr) = sp->s_port;
for (np = neighbors; np != NULL; np = np->n_next)
if (memcmp(sdl->sdl_data, np->n_name,
sdl->sdl_nlen) == 0 &&
IPADDR_SA(np->n_addr) == IPADDR_SA(dstaddr))
break;
if (np != NULL)
continue;
len = sizeof(*np) + dstaddr->sa_len + sdl->sdl_nlen + 1;
np = (struct neighbor *)malloc(len);
if (np == NULL)
quit("malloc of neighbor structure");
memset(np, 0, len);
np->n_flags = flags;
np->n_addr = (struct sockaddr *)(np + 1);
np->n_addrlen = dstaddr->sa_len;
np->n_name = np->n_addrlen + (char *)np->n_addr;
memcpy((char *)np->n_addr, (char *)dstaddr, np->n_addrlen);
memcpy(np->n_name, sdl->sdl_data, sdl->sdl_nlen);
if (multicast_mode == PER_INTERFACE_MULTICAST &&
(flags & IFF_MULTICAST) &&
!(flags & IFF_LOOPBACK)) {
struct ip_mreq mreq;
memcpy((char *)np->n_addr, (char *)ifaddr,
np->n_addrlen);
mreq.imr_multiaddr.s_addr = htonl(INADDR_WHOD_GROUP);
mreq.imr_interface.s_addr =
((struct sockaddr_in *)np->n_addr)->sin_addr.s_addr;
if (setsockopt(s, IPPROTO_IP, IP_ADD_MEMBERSHIP,
&mreq, sizeof(mreq)) < 0) {
syslog(LOG_ERR,
"setsockopt IP_ADD_MEMBERSHIP: %m");
#if 0
/* Fall back to broadcast on this if. */
np->n_flags &= ~IFF_MULTICAST;
#else
free((char *)np);
continue;
#endif
}
}
np->n_next = neighbors;
neighbors = np;
}
free(buf);
return (1);
}
#ifdef DEBUG
void
Sendto(s, buf, cc, flags, to, tolen)
int s;
const void *buf;
size_t cc;
int flags;
const struct sockaddr *to;
int tolen;
{
register struct whod *w = (struct whod *)buf;
register struct whoent *we;
struct sockaddr_in *sin = (struct sockaddr_in *)to;
printf("sendto %x.%d\n", ntohl(sin->sin_addr.s_addr),
ntohs(sin->sin_port));
printf("hostname %s %s\n", w->wd_hostname,
interval(ntohl(w->wd_sendtime) - ntohl(w->wd_boottime), " up"));
printf("load %4.2f, %4.2f, %4.2f\n",
ntohl(w->wd_loadav[0]) / 100.0, ntohl(w->wd_loadav[1]) / 100.0,
ntohl(w->wd_loadav[2]) / 100.0);
cc -= WHDRSIZE;
for (we = w->wd_we, cc /= sizeof(struct whoent); cc > 0; cc--, we++) {
time_t t = _time32_to_time(ntohl(we->we_utmp.out_time));
printf("%-8.8s %s:%s %.12s",
we->we_utmp.out_name,
w->wd_hostname, we->we_utmp.out_line,
ctime(&t)+4);
we->we_idle = ntohl(we->we_idle) / 60;
if (we->we_idle) {
if (we->we_idle >= 100*60)
we->we_idle = 100*60 - 1;
if (we->we_idle >= 60)
printf(" %2d", we->we_idle / 60);
else
printf(" ");
printf(":%02d", we->we_idle % 60);
}
printf("\n");
}
}
char *
interval(time, updown)
int time;
char *updown;
{
static char resbuf[32];
int days, hours, minutes;
if (time < 0 || time > 3*30*24*60*60) {
(void) sprintf(resbuf, " %s ??:??", updown);
return (resbuf);
}
minutes = (time + 59) / 60; /* round to minutes */
hours = minutes / 60; minutes %= 60;
days = hours / 24; hours %= 24;
if (days)
(void) sprintf(resbuf, "%s %2d+%02d:%02d",
updown, days, hours, minutes);
else
(void) sprintf(resbuf, "%s %2d:%02d",
updown, hours, minutes);
return (resbuf);
}
#endif