usr.sbin/timed/timedc/timedc.c

   1 /*      $NetBSD: timedc.c,v 1.20 2008/02/16 07:31:13 matt Exp $ */
   2
   3 /*-
   4  * Copyright (c) 1985, 1993 The Regents of the University of California.
   5  * 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
  32 #include <sys/cdefs.h>
  33 #ifndef lint
  34 __COPYRIGHT("@(#) Copyright (c) 1985, 1993\
  35  The Regents of the University of California.  All rights reserved.");
  36 #endif /* not lint */
  37
  38 #ifndef lint
  39 #if 0
  40 static char sccsid[] = "@(#)timedc.c    8.1 (Berkeley) 6/6/93";
  41 #else
  42 __RCSID("$NetBSD: timedc.c,v 1.20 2008/02/16 07:31:13 matt Exp $");
  43 #endif
  44 #endif /* not lint */
  45
  46 #include "timedc.h"
  47 #include <ctype.h>
  48 #include <setjmp.h>
  49 #include <signal.h>
  50 #include <stdlib.h>
  51 #include <string.h>
  52 #include <syslog.h>
  53 #include <unistd.h>
  54 #include <fcntl.h>
  55 #include <pwd.h>
  56 #include <err.h>
  57
  58 int trace = 0;
  59 FILE *fd = 0;
  60 int     margc;
  61 int     fromatty;
  62 #define MAX_MARGV       20
  63 char    *margv[MAX_MARGV];
  64 char    cmdline[200];
  65 jmp_buf toplevel;
  66 static const struct cmd *getcmd(char *);
  67 static int drop_privileges(void);
  68
  69 int
  70 main(int argc, char *argv[])
  71 {
  72         const struct cmd *c;
  73
  74         fcntl(3, F_CLOSEM);
  75         openlog("timedc", 0, LOG_AUTH);
  76
  77         /*
  78          * security dictates!
  79          */
  80         if (priv_resources() < 0)
  81                 errx(EXIT_FAILURE, "Could not get privileged resources");
  82         if (drop_privileges() < 0)
  83                 errx(EXIT_FAILURE, "Could not drop privileges");
  84
  85         if (--argc > 0) {
  86                 c = getcmd(*++argv);
  87                 if (c == (struct cmd *)-1) {
  88                         printf("?Ambiguous command\n");
  89                         exit(EXIT_FAILURE);
  90                 }
  91                 if (c == 0) {
  92                         printf("?Invalid command\n");
  93                         exit(EXIT_FAILURE);
  94                 }
  95                 (*c->c_handler)(argc, argv);
  96                 exit(EXIT_SUCCESS);
  97         }
  98
  99         fromatty = isatty(fileno(stdin));
 100         if (setjmp(toplevel))
 101                 putchar('\n');
 102         (void) signal(SIGINT, intr);
 103         for (;;) {
 104                 if (fromatty) {
 105                         printf("timedc> ");
 106                         (void) fflush(stdout);
 107                 }
 108                 if (fgets(cmdline, sizeof(cmdline), stdin) == 0)
 109                         quit(0, NULL);
 110                 if (cmdline[0] == 0)
 111                         break;
 112                 if (makeargv()) {
 113                         printf("?Too many arguments\n");
 114                         continue;
 115                 }
 116                 if (margv[0] == 0)
 117                         continue;
 118                 c = getcmd(margv[0]);
 119                 if (c == (struct cmd *)-1) {
 120                         printf("?Ambiguous command\n");
 121                         continue;
 122                 }
 123                 if (c == 0) {
 124                         printf("?Invalid command\n");
 125                         continue;
 126                 }
 127                 (*c->c_handler)(margc, margv);
 128         }
 129         return 0;
 130 }
 131
 132 void
 133 intr(int signo)
 134 {
 135         (void) signo;
 136         if (!fromatty)
 137                 exit(EXIT_SUCCESS);
 138         longjmp(toplevel, 1);
 139 }
 140
 141
 142 static const struct cmd *
 143 getcmd(char *name)
 144 {
 145         const char *p;
 146         char *q;
 147         const struct cmd *c, *found;
 148         int nmatches, longest;
 149         extern const struct cmd cmdtab[];
 150         extern int NCMDS;
 151
 152         longest = 0;
 153         nmatches = 0;
 154         found = 0;
 155         for (c = cmdtab; c < &cmdtab[NCMDS]; c++) {
 156                 p = c->c_name;
 157                 for (q = name; *q == *p++; q++)
 158                         if (*q == 0)            /* exact match? */
 159                                 return(c);
 160                 if (!*q) {                      /* the name was a prefix */
 161                         if (q - name > longest) {
 162                                 longest = q - name;
 163                                 nmatches = 1;
 164                                 found = c;
 165                         } else if (q - name == longest)
 166                                 nmatches++;
 167                 }
 168         }
 169         if (nmatches > 1)
 170                 return((struct cmd *)-1);
 171         return(found);
 172 }
 173
 174 /*
 175  * Slice a string up into argc/argv.
 176  */
 177 int
 178 makeargv(void)
 179 {
 180         char *cp;
 181         char **argp = margv;
 182
 183         margc = 0;
 184         for (cp = cmdline; argp < &margv[MAX_MARGV - 1] && *cp;) {
 185                 while (isspace((unsigned char)*cp))
 186                         cp++;
 187                 if (*cp == '\0')
 188                         break;
 189                 *argp++ = cp;
 190                 margc += 1;
 191                 while (*cp != '\0' && !isspace((unsigned char)*cp))
 192                         cp++;
 193                 if (*cp == '\0')
 194                         break;
 195                 *cp++ = '\0';
 196         }
 197         if (margc == MAX_MARGV - 1)
 198                 return 1;
 199         *argp++ = 0;
 200         return 0;
 201 }
 202
 203 #define HELPINDENT (sizeof ("directory"))
 204
 205 /*
 206  * Help command.
 207  */
 208 void
 209 help(int argc, char *argv[])
 210 {
 211         const struct cmd *c;
 212         extern const struct cmd cmdtab[];
 213
 214         if (argc == 1) {
 215                 int i, j, w;
 216                 int columns, width = 0, lines;
 217                 extern int NCMDS;
 218
 219                 printf("Commands may be abbreviated.  Commands are:\n\n");
 220                 for (c = cmdtab; c < &cmdtab[NCMDS]; c++) {
 221                         int len = strlen(c->c_name);
 222
 223                         if (len > width)
 224                                 width = len;
 225                 }
 226                 width = (width + 8) &~ 7;
 227                 columns = 80 / width;
 228                 if (columns == 0)
 229                         columns = 1;
 230                 lines = (NCMDS + columns - 1) / columns;
 231                 for (i = 0; i < lines; i++) {
 232                         for (j = 0; j < columns; j++) {
 233                                 c = cmdtab + j * lines + i;
 234                                 printf("%s", c->c_name);
 235                                 if (c + lines >= &cmdtab[NCMDS]) {
 236                                         printf("\n");
 237                                         break;
 238                                 }
 239                                 w = strlen(c->c_name);
 240                                 while (w < width) {
 241                                         w = (w + 8) &~ 7;
 242                                         putchar('\t');
 243                                 }
 244                         }
 245                 }
 246                 return;
 247         }
 248         while (--argc > 0) {
 249                 char *arg;
 250                 arg = *++argv;
 251                 c = getcmd(arg);
 252                 if (c == (struct cmd *)-1)
 253                         printf("?Ambiguous help command %s\n", arg);
 254                 else if (c == (struct cmd *)0)
 255                         printf("?Invalid help command %s\n", arg);
 256                 else
 257                         printf("%-*s\t%s\n", (int)HELPINDENT,
 258                                 c->c_name, c->c_help);
 259         }
 260 }
 261
 262 static int
 263 drop_privileges(void)
 264 {
 265         static const char user[] = "_timedc";
 266         const struct passwd *pw;
 267         uid_t uid;
 268         gid_t gid;
 269
 270         if ((pw = getpwnam(user)) == NULL) {
 271                 warnx("getpwnam(\"%s\") failed", user);
 272                 return -1;
 273         }
 274         uid = pw->pw_uid;
 275         gid = pw->pw_gid;
 276         if (setgroups(1, &gid)) {
 277                 warn("setgroups");
 278                 return -1;
 279         }
 280         if (setgid(gid)) {
 281                 warn("setgid");
 282                 return -1;
 283         }
 284         if (setuid(uid)) {
 285                 warn("setuid");
 286                 return -1;
 287         }
 288         return 0;
 289 }