usr.bin/login/common.c

   1 /*      $NetBSD: common.c,v 1.3 2009/12/29 20:15:15 christos Exp $      */
   2
   3 /*-
   4  * Copyright (c) 1980, 1987, 1988, 1991, 1993, 1994
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31 #include <sys/cdefs.h>
  32 __RCSID("$NetBSD: common.c,v 1.3 2009/12/29 20:15:15 christos Exp $");
  33
  34 #include <sys/types.h>
  35 #include <sys/param.h>
  36 #include <sys/socket.h>
  37 #include <stdio.h>
  38 #include <string.h>
  39 #include <unistd.h>
  40 #include <stdlib.h>
  41 #include <syslog.h>
  42 #include <fcntl.h>
  43 #include <ttyent.h>
  44 #include <setjmp.h>
  45 #include <time.h>
  46 #include <pwd.h>
  47 #include <err.h>
  48 #include <vis.h>
  49 #include <util.h>
  50
  51 #include "pathnames.h"
  52 #include "common.h"
  53
  54 #if defined(KERBEROS5)
  55 #define NBUFSIZ         (MAXLOGNAME + 1 + 5)    /* .root suffix */
  56 #else
  57 #define NBUFSIZ         (MAXLOGNAME + 1)
  58 #endif
  59
  60 #ifdef SUPPORT_UTMP
  61 #include <utmp.h>
  62 static void      doutmp(void);
  63 static void      dolastlog(int);
  64 #endif
  65 #ifdef SUPPORT_UTMPX
  66 #include <utmpx.h>
  67 static void      doutmpx(void);
  68 static void      dolastlogx(int);
  69 #endif
  70
  71 /*
  72  * This bounds the time given to login.  Not a define so it can
  73  * be patched on machines where it's too small.
  74  */
  75 u_int   timeout = 300;
  76
  77 void     decode_ss(const char *);
  78 struct  passwd *pwd;
  79 int     failures, have_ss;
  80 char    term[64], *envinit[1], *hostname, *username, *tty, *nested;
  81 struct timeval now;
  82 struct sockaddr_storage ss;
  83
  84 void
  85 getloginname(void)
  86 {
  87         int ch;
  88         char *p;
  89         static char nbuf[NBUFSIZ];
  90
  91         for (;;) {
  92                 (void)printf("login: ");
  93                 for (p = nbuf; (ch = getchar()) != '\n'; ) {
  94                         if (ch == EOF) {
  95                                 badlogin(username);
  96                                 exit(EXIT_FAILURE);
  97                         }
  98                         if (p < nbuf + (NBUFSIZ - 1))
  99                                 *p++ = ch;
 100                 }
 101                 if (p > nbuf) {
 102                         if (nbuf[0] == '-')
 103                                 (void)fprintf(stderr,
 104                                     "login names may not start with '-'.\n");
 105                         else {
 106                                 *p = '\0';
 107                                 username = nbuf;
 108                                 break;
 109                         }
 110                 }
 111         }
 112 }
 113
 114 int
 115 rootterm(char *ttyn)
 116 {
 117         struct ttyent *t;
 118
 119         return ((t = getttynam(ttyn)) && t->ty_status & TTY_SECURE);
 120 }
 121
 122 static jmp_buf motdinterrupt;
 123
 124 void
 125 motd(char *fname)
 126 {
 127         int fd, nchars;
 128         sig_t oldint;
 129         char tbuf[8192];
 130
 131         if ((fd = open(fname ? fname : _PATH_MOTDFILE, O_RDONLY, 0)) < 0)
 132                 return;
 133         oldint = signal(SIGINT, sigint);
 134         if (setjmp(motdinterrupt) == 0)
 135                 while ((nchars = read(fd, tbuf, sizeof(tbuf))) > 0)
 136                         (void)write(fileno(stdout), tbuf, nchars);
 137         (void)signal(SIGINT, oldint);
 138         (void)close(fd);
 139 }
 140
 141 /* ARGSUSED */
 142 void
 143 sigint(int signo)
 144 {
 145
 146         longjmp(motdinterrupt, 1);
 147 }
 148
 149 /* ARGSUSED */
 150 void
 151 timedout(int signo)
 152 {
 153
 154         (void)fprintf(stderr, "Login timed out after %d seconds\n", timeout);
 155         exit(EXIT_FAILURE);
 156 }
 157
 158 void
 159 update_db(int quietlog, int rootlogin, int fflag)
 160 {
 161         struct sockaddr_storage ass;
 162         char assbuf[1024];
 163         socklen_t alen;
 164         const char *hname;
 165         int remote;
 166
 167         hname = (hostname == NULL) ? "?" : hostname;
 168         if (getpeername(STDIN_FILENO, (struct sockaddr *)&ass, &alen) != -1) {
 169                 (void)sockaddr_snprintf(assbuf,
 170                     sizeof(assbuf), "%A (%a)", (void *)&ass);
 171                 if (have_ss) {
 172                         char ssbuf[1024];
 173                         (void)sockaddr_snprintf(ssbuf,
 174                             sizeof(ssbuf), "%A(%a)", (void *)&ss);
 175                          if (memcmp(&ass, &ss, alen) != 0)
 176                                 syslog(LOG_NOTICE,
 177                                     "login %s on tty %s address mismatch "
 178                                     "passed %s != actual %s", username, tty,
 179                                     ssbuf, assbuf);
 180                 } else
 181                         ss = ass;
 182                 remote = 1;
 183         } else if (have_ss) {
 184                 (void)sockaddr_snprintf(assbuf,
 185                     sizeof(assbuf), "%A(%a)", (void *)&ss);
 186                 remote = 1;
 187         } else if (hostname) {
 188                 (void)snprintf(assbuf, sizeof(assbuf), "? ?");
 189                 remote = 1;
 190         } else
 191                 remote = 0;
 192
 193         /* If fflag is on, assume caller/authenticator has logged root login. */
 194         if (rootlogin && fflag == 0) {
 195                 if (remote)
 196                         syslog(LOG_NOTICE, "ROOT LOGIN (%s) on tty %s from %s /"
 197                             " %s", username, tty, hname, assbuf);
 198                 else
 199                         syslog(LOG_NOTICE, "ROOT LOGIN (%s) on tty %s",
 200                             username, tty);
 201         } else if (nested != NULL) {
 202                 if (remote)
 203                         syslog(LOG_NOTICE, "%s to %s on tty %s from %s / "
 204                             "%s", nested, pwd->pw_name, tty, hname, assbuf);
 205                 else
 206                         syslog(LOG_NOTICE, "%s to %s on tty %s", nested,
 207                             pwd->pw_name, tty);
 208         } else {
 209                 if (remote)
 210                         syslog(LOG_NOTICE, "%s on tty %s from %s / %s",
 211                             pwd->pw_name, tty, hname, assbuf);
 212                 else
 213                         syslog(LOG_NOTICE, "%s on tty %s",
 214                             pwd->pw_name, tty);
 215         }
 216         (void)gettimeofday(&now, NULL);
 217 #ifdef SUPPORT_UTMPX
 218         doutmpx();
 219         dolastlogx(quietlog);
 220         quietlog = 1;
 221 #endif
 222 #ifdef SUPPORT_UTMP
 223         doutmp();
 224         dolastlog(quietlog);
 225 #endif
 226 }
 227
 228 #ifdef SUPPORT_UTMPX
 229 static void
 230 doutmpx(void)
 231 {
 232         struct utmpx utmpx;
 233         char *t;
 234
 235         memset((void *)&utmpx, 0, sizeof(utmpx));
 236         utmpx.ut_tv = now;
 237         (void)strncpy(utmpx.ut_name, username, sizeof(utmpx.ut_name));
 238         if (hostname) {
 239                 (void)strncpy(utmpx.ut_host, hostname, sizeof(utmpx.ut_host));
 240                 utmpx.ut_ss = ss;
 241         }
 242         (void)strncpy(utmpx.ut_line, tty, sizeof(utmpx.ut_line));
 243         utmpx.ut_type = USER_PROCESS;
 244         utmpx.ut_pid = getpid();
 245         t = tty + strlen(tty);
 246         if (t - tty >= sizeof(utmpx.ut_id)) {
 247             (void)strncpy(utmpx.ut_id, t - sizeof(utmpx.ut_id),
 248                 sizeof(utmpx.ut_id));
 249         } else {
 250             (void)strncpy(utmpx.ut_id, tty, sizeof(utmpx.ut_id));
 251         }
 252         if (pututxline(&utmpx) == NULL)
 253                 syslog(LOG_NOTICE, "Cannot update utmpx: %m");
 254         endutxent();
 255         if (updwtmpx(_PATH_WTMPX, &utmpx) != 0)
 256                 syslog(LOG_NOTICE, "Cannot update wtmpx: %m");
 257 }
 258
 259 static void
 260 dolastlogx(int quiet)
 261 {
 262         struct lastlogx ll;
 263         if (!quiet && getlastlogx(_PATH_LASTLOGX, pwd->pw_uid, &ll) != NULL) {
 264                 time_t t = (time_t)ll.ll_tv.tv_sec;
 265                 (void)printf("Last login: %.24s ", ctime(&t));
 266                 if (*ll.ll_host != '\0')
 267                         (void)printf("from %.*s ",
 268                             (int)sizeof(ll.ll_host),
 269                             ll.ll_host);
 270                 (void)printf("on %.*s\n",
 271                     (int)sizeof(ll.ll_line),
 272                     ll.ll_line);
 273         }
 274         ll.ll_tv = now;
 275         (void)strncpy(ll.ll_line, tty, sizeof(ll.ll_line));
 276         if (hostname)
 277                 (void)strncpy(ll.ll_host, hostname, sizeof(ll.ll_host));
 278         else
 279                 (void)memset(ll.ll_host, '\0', sizeof(ll.ll_host));
 280         if (have_ss)
 281                 ll.ll_ss = ss;
 282         else
 283                 (void)memset(&ll.ll_ss, 0, sizeof(ll.ll_ss));
 284         if (updlastlogx(_PATH_LASTLOGX, pwd->pw_uid, &ll) != 0)
 285                 syslog(LOG_NOTICE, "Cannot update lastlogx: %m");
 286 }
 287 #endif
 288
 289 #ifdef SUPPORT_UTMP
 290 static void
 291 doutmp(void)
 292 {
 293         struct utmp utmp;
 294
 295         (void)memset((void *)&utmp, 0, sizeof(utmp));
 296         utmp.ut_time = now.tv_sec;
 297         (void)strncpy(utmp.ut_name, username, sizeof(utmp.ut_name));
 298         if (hostname)
 299                 (void)strncpy(utmp.ut_host, hostname, sizeof(utmp.ut_host));
 300         (void)strncpy(utmp.ut_line, tty, sizeof(utmp.ut_line));
 301         login(&utmp);
 302 }
 303
 304 static void
 305 dolastlog(int quiet)
 306 {
 307         struct lastlog ll;
 308         int fd;
 309
 310         if ((fd = open(_PATH_LASTLOG, O_RDWR, 0)) >= 0) {
 311                 (void)lseek(fd, (off_t)(pwd->pw_uid * sizeof(ll)), SEEK_SET);
 312                 if (!quiet) {
 313                         if (read(fd, (char *)&ll, sizeof(ll)) == sizeof(ll) &&
 314                             ll.ll_time != 0) {
 315                                 (void)printf("Last login: %.24s ",
 316                                     ctime(&ll.ll_time));
 317                                 if (*ll.ll_host != '\0')
 318                                         (void)printf("from %.*s ",
 319                                             (int)sizeof(ll.ll_host),
 320                                             ll.ll_host);
 321                                 (void)printf("on %.*s\n",
 322                                     (int)sizeof(ll.ll_line), ll.ll_line);
 323                         }
 324                         (void)lseek(fd, (off_t)(pwd->pw_uid * sizeof(ll)),
 325                             SEEK_SET);
 326                 }
 327                 memset((void *)&ll, 0, sizeof(ll));
 328                 ll.ll_time = now.tv_sec;
 329                 (void)strncpy(ll.ll_line, tty, sizeof(ll.ll_line));
 330                 if (hostname)
 331                         (void)strncpy(ll.ll_host, hostname, sizeof(ll.ll_host));
 332                 (void)write(fd, (char *)&ll, sizeof(ll));
 333                 (void)close(fd);
 334         }
 335 }
 336 #endif
 337
 338 void
 339 badlogin(const char *name)
 340 {
 341
 342         if (failures == 0)
 343                 return;
 344         if (hostname) {
 345                 syslog(LOG_NOTICE, "%d LOGIN FAILURE%s FROM %s",
 346                     failures, failures > 1 ? "S" : "", hostname);
 347                 syslog(LOG_AUTHPRIV|LOG_NOTICE,
 348                     "%d LOGIN FAILURE%s FROM %s, %s",
 349                     failures, failures > 1 ? "S" : "", hostname, name);
 350         } else {
 351                 syslog(LOG_NOTICE, "%d LOGIN FAILURE%s ON %s",
 352                     failures, failures > 1 ? "S" : "", tty);
 353                 syslog(LOG_AUTHPRIV|LOG_NOTICE,
 354                     "%d LOGIN FAILURE%s ON %s, %s",
 355                     failures, failures > 1 ? "S" : "", tty, name);
 356         }
 357 }
 358
 359 const char *
 360 stypeof(const char *ttyid)
 361 {
 362         struct ttyent *t;
 363
 364         return (ttyid && (t = getttynam(ttyid)) ? t->ty_type : NULL);
 365 }
 366
 367 void
 368 sleepexit(int eval)
 369 {
 370
 371         (void)sleep(5);
 372         exit(eval);
 373 }
 374
 375 void
 376 decode_ss(const char *arg)
 377 {
 378         struct sockaddr_storage *ssp;
 379         size_t len = strlen(arg);
 380
 381         if (len > sizeof(*ssp) * 4 + 1 || len < sizeof(*ssp))
 382                 errx(EXIT_FAILURE, "Bad argument");
 383
 384         if ((ssp = malloc(len)) == NULL)
 385                 err(EXIT_FAILURE, NULL);
 386
 387         if (strunvis((char *)ssp, arg) != sizeof(*ssp))
 388                 errx(EXIT_FAILURE, "Decoding error");
 389
 390         (void)memcpy(&ss, ssp, sizeof(ss));
 391         free(ssp);
 392         have_ss = 1;
 393 }