usr.sbin/lpr/lpc/lpc.c

   1 /*      $NetBSD: lpc.c,v 1.24 2008/07/21 13:36:58 lukem Exp $   */
   2
   3 /*
   4  * Copyright (c) 1983, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the name of the University nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 #include <sys/cdefs.h>
  34 #ifndef lint
  35 __COPYRIGHT("@(#) Copyright (c) 1983, 1993\
  36  The Regents of the University of California.  All rights reserved.");
  37 #if 0
  38 static char sccsid[] = "@(#)lpc.c       8.3 (Berkeley) 4/28/95";
  39 #else
  40 __RCSID("$NetBSD: lpc.c,v 1.24 2008/07/21 13:36:58 lukem Exp $");
  41 #endif
  42 #endif /* not lint */
  43
  44 #include <sys/param.h>
  45
  46 #include <dirent.h>
  47 #include <signal.h>
  48 #include <setjmp.h>
  49 #include <syslog.h>
  50 #include <histedit.h>
  51 #include <unistd.h>
  52 #include <stdlib.h>
  53 #include <stdio.h>
  54 #include <ctype.h>
  55 #include <string.h>
  56 #include <grp.h>
  57 #include <err.h>
  58 #include "lp.h"
  59 #include "lpc.h"
  60 #include "extern.h"
  61
  62 #ifndef LPR_OPER
  63 #define LPR_OPER        "operator"      /* group name of lpr operators */
  64 #endif
  65
  66 /*
  67  * lpc -- line printer control program
  68  */
  69
  70 #define MAX_MARGV       20
  71 int     fromatty;
  72
  73 char    *cmdline;
  74 int     margc;
  75 char    *margv[MAX_MARGV];
  76 int     top;
  77 uid_t   uid, euid;
  78
  79 jmp_buf toplevel;
  80
  81 History *hist;
  82 HistEvent he;
  83 EditLine *elptr;
  84
  85 static void              cmdscanner(int);
  86 static struct cmd       *getcmd(const char *);
  87 static void              intr(int);
  88 static void              makeargv(void);
  89 static int               ingroup(const char *);
  90 int                      main(int, char *p[]);
  91 const char              *prompt(void);
  92 static int               parse(char *, char *p[], int);
  93
  94 int
  95 main(int argc, char *argv[])
  96 {
  97         euid = geteuid();
  98         uid = getuid();
  99         seteuid(uid);
 100         setprogname(argv[0]);
 101         openlog("lpd", 0, LOG_LPR);
 102
 103         if (--argc > 0) {
 104                 argv++;
 105                 exit(!parse(*argv, argv, argc));
 106         }
 107         fromatty = isatty(fileno(stdin));
 108         top = setjmp(toplevel) == 0;
 109         if (top)
 110                 signal(SIGINT, intr);
 111         for (;;) {
 112                 cmdscanner(top);
 113                 top = 1;
 114         }
 115 }
 116
 117 static int
 118 parse(char *arg, char **pargv, int pargc)
 119 {
 120         struct cmd *c;
 121
 122         c = getcmd(arg);
 123         if (c == (struct cmd *)-1) {
 124                 printf("?Ambiguous command\n");
 125                 return(0);
 126         }
 127         if (c == 0) {
 128                 printf("?Invalid command\n");
 129                 return(0);
 130         }
 131         if (c->c_priv && getuid() && ingroup(LPR_OPER) == 0) {
 132                 printf("?Privileged command\n");
 133                 return(0);
 134         }
 135         (*c->c_handler)(pargc, pargv);
 136         return(1);
 137 }
 138
 139 static void
 140 intr(int signo)
 141 {
 142         el_end(elptr);
 143         history_end(hist);
 144         if (!fromatty)
 145                 exit(0);
 146         longjmp(toplevel, 1);
 147 }
 148
 149 const char *
 150 prompt(void)
 151 {
 152         return ("lpc> ");
 153 }
 154
 155 /*
 156  * Command parser.
 157  */
 158 static void
 159 cmdscanner(int tp)
 160 {
 161         int scratch;
 162         const char *elline;
 163
 164         if (!tp)
 165                 putchar('\n');
 166         hist = history_init();
 167         history(hist, &he, H_SETSIZE, 100);     /* 100 elt history buffer */
 168
 169         elptr = el_init(getprogname(), stdin, stdout, stderr);
 170         el_set(elptr, EL_EDITOR, "emacs");
 171         el_set(elptr, EL_PROMPT, prompt);
 172         el_set(elptr, EL_HIST, history, hist);
 173         el_source(elptr, NULL);
 174
 175         for (;;) {
 176                 cmdline = NULL;
 177                 do {
 178                         if (((elline = el_gets(elptr, &scratch)) != NULL)
 179                             && (scratch != 0)) {
 180                                 history(hist, &he, H_ENTER, elline);
 181                                 cmdline = strdup(elline);
 182                                 makeargv();
 183                         } else {
 184                                 margc = 0;
 185                                 break;
 186                         }
 187                 } while (margc == 0);
 188                 if (margc == 0)
 189                         quit(0, NULL);
 190                 if (!parse(cmdline, margv, margc)) {
 191                         if (cmdline != NULL)
 192                                 free(cmdline);
 193                         continue;
 194                 }
 195                 fflush(stdout);
 196                 if (cmdline != NULL)
 197                         free(cmdline);
 198         }
 199         longjmp(toplevel, 0);
 200 }
 201
 202 static struct cmd *
 203 getcmd(const char *name)
 204 {
 205         const char *p, *q;
 206         struct cmd *c, *found;
 207         int nmatches, longest;
 208
 209         longest = 0;
 210         nmatches = 0;
 211         found = 0;
 212         for (c = cmdtab; (p = c->c_name) != NULL; c++) {
 213                 for (q = name; *q == *p++; q++)
 214                         if (*q == 0)            /* exact match? */
 215                                 return(c);
 216                 if (!*q) {                      /* the name was a prefix */
 217                         if (q - name > longest) {
 218                                 longest = q - name;
 219                                 nmatches = 1;
 220                                 found = c;
 221                         } else if (q - name == longest)
 222                                 nmatches++;
 223                 }
 224         }
 225         if (nmatches > 1)
 226                 return((struct cmd *)-1);
 227         return(found);
 228 }
 229
 230 /*
 231  * Slice a string up into argc/argv.
 232  */
 233 static void
 234 makeargv(void)
 235 {
 236         char *cp;
 237         char **argp = margv;
 238         int n = 0;
 239         size_t s;
 240
 241         s = strlen(cmdline) + 1;
 242         margc = 0;
 243         for (cp = cmdline; *cp && (size_t)(cp - cmdline) < s && n < MAX_MARGV; n++) {
 244                 while (isspace((unsigned char)*cp))
 245                         cp++;
 246                 if (*cp == '\0')
 247                         break;
 248                 *argp++ = cp;
 249                 margc += 1;
 250                 while (*cp != '\0' && !isspace((unsigned char)*cp))
 251                         cp++;
 252                 if (*cp == '\0')
 253                         break;
 254                 *cp++ = '\0';
 255         }
 256         *argp++ = 0;
 257 }
 258
 259 #define HELPINDENT (sizeof ("directory"))
 260
 261 /*
 262  * Help command.
 263  */
 264 void
 265 help(int argc, char *argv[])
 266 {
 267         struct cmd *c;
 268
 269         if (argc == 1) {
 270                 size_t i, j, w;
 271                 size_t columns, width = 0, lines;
 272
 273                 printf("Commands may be abbreviated.  Commands are:\n\n");
 274                 for (c = cmdtab; c->c_name; c++) {
 275                         size_t len = strlen(c->c_name);
 276
 277                         if (len > width)
 278                                 width = len;
 279                 }
 280                 width = (width + 8) &~ 7;
 281                 columns = 80 / width;
 282                 if (columns == 0)
 283                         columns = 1;
 284                 lines = (NCMDS + columns - 1) / columns;
 285                 for (i = 0; i < lines; i++) {
 286                         for (j = 0; j < columns; j++) {
 287                                 c = cmdtab + j * lines + i;
 288                                 printf("%s", c->c_name);
 289                                 if (c + lines >= &cmdtab[NCMDS - 1]) {
 290                                         printf("\n");
 291                                         break;
 292                                 }
 293                                 w = strlen(c->c_name);
 294                                 while (w < width) {
 295                                         w = (w + 8) &~ 7;
 296                                         putchar('\t');
 297                                 }
 298                         }
 299                 }
 300                 return;
 301         }
 302         while (--argc > 0) {
 303                 char *arg;
 304                 arg = *++argv;
 305                 c = getcmd(arg);
 306                 if (c == (struct cmd *)-1)
 307                         printf("?Ambiguous help command %s\n", arg);
 308                 else if (c == (struct cmd *)0)
 309                         printf("?Invalid help command %s\n", arg);
 310                 else
 311                         printf("%-*s\t%s\n", (int)HELPINDENT,
 312                                 c->c_name, c->c_help);
 313         }
 314 }
 315
 316 /*
 317  * return non-zero if the user is a member of the given group
 318  */
 319 static int
 320 ingroup(const char *grname)
 321 {
 322         static struct group *gptr = NULL;
 323         static gid_t groups[NGROUPS];
 324         static int ngroups;
 325         gid_t gid;
 326         int i;
 327
 328         if (gptr == NULL) {
 329                 if ((gptr = getgrnam(grname)) == NULL) {
 330                         warnx("Warning: unknown group `%s'",
 331                                 grname);
 332                         return(0);
 333                 }
 334                 ngroups = getgroups(NGROUPS, groups);
 335                 if (ngroups < 0)
 336                         err(1, "getgroups");
 337         }
 338         gid = gptr->gr_gid;
 339         for (i = 0; i < ngroups; i++)
 340                 if (gid == groups[i])
 341                         return(1);
 342         return(0);
 343 }