1 /* 2 * Copyright (c) 1983, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #include <sys/cdefs.h> 35 #ifndef lint 36 __COPYRIGHT("@(#) Copyright (c) 1983, 1993\n\ 37 The Regents of the University of California. All rights reserved.\n"); 38 #endif /* not lint */ 39 40 #ifndef lint 41 #if 0 42 static char sccsid[] = "@(#)rwhod.c 8.1 (Berkeley) 6/6/93"; 43 #else 44 __RCSID("$NetBSD: rwhod.c,v 1.19 2002/08/02 02:38:15 christos Exp $"); 45 #endif 46 #endif /* not lint */ 47 48 #include <sys/param.h> 49 #include <sys/socket.h> 50 #include <sys/stat.h> 51 #include <sys/signal.h> 52 #include <sys/ioctl.h> 53 #include <sys/sysctl.h> 54 55 #include <net/if.h> 56 #include <net/if_dl.h> 57 #include <net/route.h> 58 #include <netinet/in.h> 59 #include <protocols/rwhod.h> 60 #include <arpa/inet.h> 61 62 #include <ctype.h> 63 #include <err.h> 64 #include <errno.h> 65 #include <fcntl.h> 66 #include <netdb.h> 67 #include <paths.h> 68 #include <stdio.h> 69 #include <stdlib.h> 70 #include <string.h> 71 #include <syslog.h> 72 #include <unistd.h> 73 #include <util.h> 74 75 #include "utmpentry.h" 76 /* 77 * Alarm interval. Don't forget to change the down time check in ruptime 78 * if this is changed. 79 */ 80 #define AL_INTERVAL (3 * 60) 81 82 char myname[MAXHOSTNAMELEN + 1]; 83 84 /* 85 * We communicate with each neighbor in a list constructed at the time we're 86 * started up. Neighbors are currently directly connected via a hardware 87 * interface. 88 */ 89 struct neighbor { 90 struct neighbor *n_next; 91 char *n_name; /* interface name */ 92 struct sockaddr *n_addr; /* who to send to */ 93 int n_addrlen; /* size of address */ 94 int n_flags; /* should forward?, interface flags */ 95 }; 96 97 struct neighbor *neighbors; 98 struct whod mywd; 99 struct servent *sp; 100 int s; 101 102 #define WHDRSIZE (sizeof(mywd) - sizeof(mywd.wd_we)) 103 104 int configure __P((int)); 105 void getboottime __P((int)); 106 int main __P((int, char **)); 107 void onalrm __P((int)); 108 void quit __P((char *)); 109 void rt_xaddrs __P((caddr_t, caddr_t, struct rt_addrinfo *)); 110 int verify __P((char *)); 111 #ifdef DEBUG 112 char *interval __P((int, char *)); 113 void Sendto __P((int, char *, int, int, char *, int)); 114 #define sendto Sendto 115 #endif 116 117 int 118 main(argc, argv) 119 int argc; 120 char *argv[]; 121 { 122 struct sockaddr_in from; 123 struct stat st; 124 char path[64]; 125 int on = 1; 126 char *cp; 127 struct sockaddr_in sin; 128 129 if (getuid()) 130 errx(1, "not super user"); 131 sp = getservbyname("who", "udp"); 132 if (sp == NULL) 133 errx(1, "udp/who: unknown service"); 134 #ifndef DEBUG 135 daemon(1, 0); 136 pidfile(NULL); 137 #endif 138 if (chdir(_PATH_RWHODIR) < 0) 139 err(1, "%s", _PATH_RWHODIR); 140 (void)signal(SIGHUP, getboottime); 141 openlog("rwhod", LOG_PID, LOG_DAEMON); 142 /* 143 * Establish host name as returned by system. 144 */ 145 if (gethostname(myname, sizeof(myname) - 1) < 0) { 146 syslog(LOG_ERR, "gethostname: %m"); 147 exit(1); 148 } 149 myname[sizeof(myname) - 1] = '\0'; 150 if ((cp = strchr(myname, '.')) != NULL) 151 *cp = '\0'; 152 strncpy(mywd.wd_hostname, myname, sizeof(mywd.wd_hostname) - 1); 153 getboottime(0); 154 if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0) { 155 syslog(LOG_ERR, "socket: %m"); 156 exit(1); 157 } 158 if (setsockopt(s, SOL_SOCKET, SO_BROADCAST, &on, sizeof(on)) < 0) { 159 syslog(LOG_ERR, "setsockopt SO_BROADCAST: %m"); 160 exit(1); 161 } 162 memset(&sin, 0, sizeof(sin)); 163 sin.sin_family = AF_INET; 164 sin.sin_port = sp->s_port; 165 if (bind(s, (struct sockaddr *)&sin, sizeof(sin)) < 0) { 166 syslog(LOG_ERR, "bind: %m"); 167 exit(1); 168 } 169 if (!configure(s)) 170 exit(1); 171 signal(SIGALRM, onalrm); 172 onalrm(0); 173 for (;;) { 174 struct whod wd; 175 int cc, whod, len = sizeof(from); 176 177 cc = recvfrom(s, (char *)&wd, sizeof(struct whod), 0, 178 (struct sockaddr *)&from, &len); 179 if (cc <= 0) { 180 if (cc < 0 && errno != EINTR) 181 syslog(LOG_WARNING, "recv: %m"); 182 continue; 183 } 184 if (from.sin_port != sp->s_port) { 185 syslog(LOG_WARNING, "%d: bad from port", 186 ntohs(from.sin_port)); 187 continue; 188 } 189 if (cc < WHDRSIZE) { 190 syslog(LOG_WARNING, "Short packet from %s", 191 inet_ntoa(from.sin_addr)); 192 continue; 193 } 194 195 if (wd.wd_vers != WHODVERSION) 196 continue; 197 if (wd.wd_type != WHODTYPE_STATUS) 198 continue; 199 /* 200 * Ensure null termination of the name within the packet. 201 * Otherwise we might overflow or read past the end. 202 */ 203 wd.wd_hostname[sizeof(wd.wd_hostname)-1] = 0; 204 if (!verify(wd.wd_hostname)) { 205 syslog(LOG_WARNING, "malformed host name from %s", 206 inet_ntoa(from.sin_addr)); 207 continue; 208 } 209 snprintf(path, sizeof(path), "whod.%s", wd.wd_hostname); 210 /* 211 * Rather than truncating and growing the file each time, 212 * use ftruncate if size is less than previous size. 213 */ 214 whod = open(path, O_WRONLY | O_CREAT, 0644); 215 if (whod < 0) { 216 syslog(LOG_WARNING, "%s: %m", path); 217 continue; 218 } 219 #if ENDIAN != BIG_ENDIAN 220 { 221 int i, n = (cc - WHDRSIZE)/sizeof(struct whoent); 222 struct whoent *we; 223 224 /* undo header byte swapping before writing to file */ 225 wd.wd_sendtime = ntohl(wd.wd_sendtime); 226 for (i = 0; i < 3; i++) 227 wd.wd_loadav[i] = ntohl(wd.wd_loadav[i]); 228 wd.wd_boottime = ntohl(wd.wd_boottime); 229 we = wd.wd_we; 230 for (i = 0; i < n; i++) { 231 we->we_idle = ntohl(we->we_idle); 232 we->we_utmp.out_time = 233 ntohl(we->we_utmp.out_time); 234 we++; 235 } 236 } 237 #endif 238 (void)time((time_t *)&wd.wd_recvtime); 239 (void)write(whod, (char *)&wd, cc); 240 if (fstat(whod, &st) < 0 || st.st_size > cc) 241 ftruncate(whod, cc); 242 (void)close(whod); 243 } 244 } 245 246 /* 247 * Check out host name for unprintables 248 * and other funnies before allowing a file 249 * to be created. Sorry, but blanks aren't allowed. 250 */ 251 int 252 verify(name) 253 char *name; 254 { 255 int size = 0; 256 257 while (*name) { 258 if (!isascii(*name) || !(isalnum(*name) || ispunct(*name))) 259 return (0); 260 name++, size++; 261 } 262 return (size > 0); 263 } 264 265 int alarmcount; 266 267 void 268 onalrm(signo) 269 int signo; 270 { 271 struct neighbor *np; 272 struct whoent *we = mywd.wd_we, *wlast; 273 int i; 274 struct stat stb; 275 double avenrun[3]; 276 time_t now; 277 int cc; 278 static struct utmpentry *ohead = NULL; 279 struct utmpentry *ep; 280 int utmpent = 0; 281 282 now = time(NULL); 283 if (alarmcount % 10 == 0) 284 getboottime(0); 285 alarmcount++; 286 287 (void)getutentries(NULL, &ep); 288 if (ep != ohead) { 289 freeutentries(ep); 290 wlast = &mywd.wd_we[1024 / sizeof(struct whoent) - 1]; 291 for (; ep; ep = ep->next) { 292 (void)strncpy(we->we_utmp.out_line, ep->line, 293 sizeof(we->we_utmp.out_line) - 1); 294 (void)strncpy(we->we_utmp.out_name, ep->name, 295 sizeof(we->we_utmp.out_name) - 1); 296 we->we_utmp.out_time = htonl(ep->tv.tv_sec); 297 if (we >= wlast) 298 break; 299 we++; 300 } 301 utmpent = we - mywd.wd_we; 302 } 303 304 /* 305 * The test on utmpent looks silly---after all, if no one is 306 * logged on, why worry about efficiency?---but is useful on 307 * (e.g.) compute servers. 308 */ 309 if (utmpent && chdir(_PATH_DEV)) { 310 syslog(LOG_ERR, "chdir(%s): %m", _PATH_DEV); 311 exit(1); 312 } 313 we = mywd.wd_we; 314 for (i = 0; i < utmpent; i++) { 315 if (stat(we->we_utmp.out_line, &stb) >= 0) 316 we->we_idle = htonl(now - stb.st_atime); 317 we++; 318 } 319 (void)getloadavg(avenrun, sizeof(avenrun)/sizeof(avenrun[0])); 320 for (i = 0; i < 3; i++) 321 mywd.wd_loadav[i] = htonl((u_long)(avenrun[i] * 100)); 322 cc = (char *)we - (char *)&mywd; 323 mywd.wd_sendtime = htonl(time(0)); 324 mywd.wd_vers = WHODVERSION; 325 mywd.wd_type = WHODTYPE_STATUS; 326 for (np = neighbors; np != NULL; np = np->n_next) 327 (void)sendto(s, (char *)&mywd, cc, 0, 328 np->n_addr, np->n_addrlen); 329 if (utmpent && chdir(_PATH_RWHODIR)) { 330 syslog(LOG_ERR, "chdir(%s): %m", _PATH_RWHODIR); 331 exit(1); 332 } 333 (void)alarm(AL_INTERVAL); 334 } 335 336 void 337 getboottime(signo) 338 int signo; 339 { 340 int mib[2]; 341 size_t size; 342 struct timeval tm; 343 344 mib[0] = CTL_KERN; 345 mib[1] = KERN_BOOTTIME; 346 size = sizeof(tm); 347 if (sysctl(mib, 2, &tm, &size, NULL, 0) == -1) { 348 syslog(LOG_ERR, "cannot get boottime: %m"); 349 exit(1); 350 } 351 mywd.wd_boottime = htonl(tm.tv_sec); 352 } 353 354 void 355 quit(msg) 356 char *msg; 357 { 358 syslog(LOG_ERR, "%s", msg); 359 exit(1); 360 } 361 362 #define ROUNDUP(a) \ 363 ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long)) 364 #define ADVANCE(x, n) (x += ROUNDUP((n)->sa_len)) 365 366 void 367 rt_xaddrs(cp, cplim, rtinfo) 368 caddr_t cp, cplim; 369 struct rt_addrinfo *rtinfo; 370 { 371 struct sockaddr *sa; 372 int i; 373 374 memset(rtinfo->rti_info, 0, sizeof(rtinfo->rti_info)); 375 for (i = 0; (i < RTAX_MAX) && (cp < cplim); i++) { 376 if ((rtinfo->rti_addrs & (1 << i)) == 0) 377 continue; 378 rtinfo->rti_info[i] = sa = (struct sockaddr *)cp; 379 ADVANCE(cp, sa); 380 } 381 } 382 383 /* 384 * Figure out device configuration and select 385 * networks which deserve status information. 386 */ 387 int 388 configure(s) 389 int s; 390 { 391 struct neighbor *np; 392 struct if_msghdr *ifm; 393 struct ifa_msghdr *ifam; 394 struct sockaddr_dl *sdl; 395 size_t needed; 396 int mib[6], flags = 0, len; 397 char *buf, *lim, *next; 398 struct rt_addrinfo info; 399 400 mib[0] = CTL_NET; 401 mib[1] = PF_ROUTE; 402 mib[2] = 0; 403 mib[3] = AF_INET; 404 mib[4] = NET_RT_IFLIST; 405 mib[5] = 0; 406 if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) 407 quit("route-sysctl-estimate"); 408 if ((buf = malloc(needed)) == NULL) 409 quit("malloc"); 410 if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) 411 quit("actual retrieval of interface table"); 412 lim = buf + needed; 413 414 sdl = NULL; /* XXX just to keep gcc -Wall happy */ 415 for (next = buf; next < lim; next += ifm->ifm_msglen) { 416 ifm = (struct if_msghdr *)next; 417 if (ifm->ifm_type == RTM_IFINFO) { 418 sdl = (struct sockaddr_dl *)(ifm + 1); 419 flags = ifm->ifm_flags; 420 continue; 421 } 422 if ((flags & IFF_UP) == 0 || 423 (flags & (IFF_BROADCAST|IFF_POINTOPOINT)) == 0) 424 continue; 425 if (ifm->ifm_type != RTM_NEWADDR) 426 quit("out of sync parsing NET_RT_IFLIST"); 427 ifam = (struct ifa_msghdr *)ifm; 428 info.rti_addrs = ifam->ifam_addrs; 429 rt_xaddrs((char *)(ifam + 1), ifam->ifam_msglen + (char *)ifam, 430 &info); 431 /* gag, wish we could get rid of Internet dependencies */ 432 #define dstaddr info.rti_info[RTAX_BRD] 433 #define IPADDR_SA(x) ((struct sockaddr_in *)(x))->sin_addr.s_addr 434 #define PORT_SA(x) ((struct sockaddr_in *)(x))->sin_port 435 if (dstaddr == 0 || dstaddr->sa_family != AF_INET) 436 continue; 437 PORT_SA(dstaddr) = sp->s_port; 438 for (np = neighbors; np != NULL; np = np->n_next) 439 if (memcmp(sdl->sdl_data, np->n_name, 440 sdl->sdl_nlen) == 0 && 441 IPADDR_SA(np->n_addr) == IPADDR_SA(dstaddr)) 442 break; 443 if (np != NULL) 444 continue; 445 len = sizeof(*np) + dstaddr->sa_len + sdl->sdl_nlen + 1; 446 np = (struct neighbor *)malloc(len); 447 if (np == NULL) 448 quit("malloc of neighbor structure"); 449 memset(np, 0, len); 450 np->n_flags = flags; 451 np->n_addr = (struct sockaddr *)(np + 1); 452 np->n_addrlen = dstaddr->sa_len; 453 np->n_name = np->n_addrlen + (char *)np->n_addr; 454 np->n_next = neighbors; 455 neighbors = np; 456 memcpy((char *)np->n_addr, (char *)dstaddr, np->n_addrlen); 457 memcpy(np->n_name, sdl->sdl_data, sdl->sdl_nlen); 458 } 459 free(buf); 460 return (1); 461 } 462 463 #ifdef DEBUG 464 void 465 Sendto(s, buf, cc, flags, to, tolen) 466 int s; 467 char *buf; 468 int cc, flags; 469 char *to; 470 int tolen; 471 { 472 struct whod *w = (struct whod *)buf; 473 struct whoent *we; 474 struct sockaddr_in *sin = (struct sockaddr_in *)to; 475 476 printf("sendto %x.%d\n", ntohl(sin->sin_addr), ntohs(sin->sin_port)); 477 printf("hostname %s %s\n", w->wd_hostname, 478 interval(ntohl(w->wd_sendtime) - ntohl(w->wd_boottime), " up")); 479 printf("load %4.2f, %4.2f, %4.2f\n", 480 ntohl(w->wd_loadav[0]) / 100.0, ntohl(w->wd_loadav[1]) / 100.0, 481 ntohl(w->wd_loadav[2]) / 100.0); 482 cc -= WHDRSIZE; 483 for (we = w->wd_we, cc /= sizeof(struct whoent); cc > 0; cc--, we++) { 484 time_t t = ntohl(we->we_utmp.out_time); 485 printf("%-8.8s %s:%s %.12s", 486 we->we_utmp.out_name, 487 w->wd_hostname, we->we_utmp.out_line, 488 ctime(&t)+4); 489 we->we_idle = ntohl(we->we_idle) / 60; 490 if (we->we_idle) { 491 if (we->we_idle >= 100*60) 492 we->we_idle = 100*60 - 1; 493 if (we->we_idle >= 60) 494 printf(" %2d", we->we_idle / 60); 495 else 496 printf(" "); 497 printf(":%02d", we->we_idle % 60); 498 } 499 printf("\n"); 500 } 501 } 502 503 char * 504 interval(time, updown) 505 int time; 506 char *updown; 507 { 508 static char resbuf[32]; 509 int days, hours, minutes; 510 511 if (time < 0 || time > 3*30*24*60*60) { 512 (void)sprintf(resbuf, " %s ??:??", updown); 513 return (resbuf); 514 } 515 minutes = (time + 59) / 60; /* round to minutes */ 516 hours = minutes / 60; minutes %= 60; 517 days = hours / 24; hours %= 24; 518 if (days) 519 (void)sprintf(resbuf, "%s %2d+%02d:%02d", 520 updown, days, hours, minutes); 521 else 522 (void)sprintf(resbuf, "%s %2d:%02d", 523 updown, hours, minutes); 524 return (resbuf); 525 } 526 #endif 527