Home | History | Annotate | Line # | Download | only in lpc
lpc.c revision 1.9 
      1 /*	$NetBSD: lpc.c,v 1.9 1997/10/05 16:45:44 mrg 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. All advertising materials mentioning features or use of this software
     17  *    must display the following acknowledgement:
     18  *	This product includes software developed by the University of
     19  *	California, Berkeley and its contributors.
     20  * 4. Neither the name of the University nor the names of its contributors
     21  *    may be used to endorse or promote products derived from this software
     22  *    without specific prior written permission.
     23  *
     24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     34  * SUCH DAMAGE.
     35  */
     36 
     37 #include <sys/cdefs.h>
     38 #ifndef lint
     39 __COPYRIGHT("@(#) Copyright (c) 1983, 1993\n\
     40 	The Regents of the University of California.  All rights reserved.\n");
     41 #if 0
     42 static char sccsid[] = "@(#)lpc.c	8.3 (Berkeley) 4/28/95";
     43 #else
     44 __RCSID("$NetBSD: lpc.c,v 1.9 1997/10/05 16:45:44 mrg Exp $");
     45 #endif
     46 #endif /* not lint */
     47 
     48 #include <sys/param.h>
     49 
     50 #include <dirent.h>
     51 #include <signal.h>
     52 #include <setjmp.h>
     53 #include <syslog.h>
     54 #include <unistd.h>
     55 #include <stdlib.h>
     56 #include <stdio.h>
     57 #include <ctype.h>
     58 #include <string.h>
     59 #include <grp.h>
     60 #include <err.h>
     61 #include "lp.h"
     62 #include "lpc.h"
     63 #include "extern.h"
     64 
     65 #ifndef LPR_OPER
     66 #define LPR_OPER	"operator"	/* group name of lpr operators */
     67 #endif
     68 
     69 /*
     70  * lpc -- line printer control program
     71  */
     72 
     73 #define MAX_CMDLINE	200
     74 #define MAX_MARGV	20
     75 int	fromatty;
     76 
     77 char	cmdline[MAX_CMDLINE];
     78 int	margc;
     79 char	*margv[MAX_MARGV];
     80 int	top;
     81 uid_t	uid, euid;
     82 
     83 jmp_buf	toplevel;
     84 
     85 static void		 cmdscanner __P((int));
     86 static struct cmd	*getcmd __P((char *));
     87 static void		 intr __P((int));
     88 static void		 makeargv __P((void));
     89 static int		 ingroup __P((char *));
     90 int			 main __P((int, char *p[]));
     91 
     92 int
     93 main(argc, argv)
     94 	int argc;
     95 	char *argv[];
     96 {
     97 	struct cmd *c;
     98 
     99 	euid = geteuid();
    100 	uid = getuid();
    101 	seteuid(uid);
    102 	name = argv[0];
    103 	openlog("lpd", 0, LOG_LPR);
    104 
    105 	if (--argc > 0) {
    106 		c = getcmd(*++argv);
    107 		if (c == (struct cmd *)-1) {
    108 			printf("?Ambiguous command\n");
    109 			exit(1);
    110 		}
    111 		if (c == 0) {
    112 			printf("?Invalid command\n");
    113 			exit(1);
    114 		}
    115 		if (c->c_priv && getuid() && ingroup(LPR_OPER) == 0) {
    116 			printf("?Privileged command\n");
    117 			exit(1);
    118 		}
    119 		(*c->c_handler)(argc, argv);
    120 		exit(0);
    121 	}
    122 	fromatty = isatty(fileno(stdin));
    123 	top = setjmp(toplevel) == 0;
    124 	if (top)
    125 		signal(SIGINT, intr);
    126 	for (;;) {
    127 		cmdscanner(top);
    128 		top = 1;
    129 	}
    130 }
    131 
    132 static void
    133 intr(signo)
    134 	int signo;
    135 {
    136 	if (!fromatty)
    137 		exit(0);
    138 	longjmp(toplevel, 1);
    139 }
    140 
    141 /*
    142  * Command parser.
    143  */
    144 static void
    145 cmdscanner(top)
    146 	int top;
    147 {
    148 	struct cmd *c;
    149 
    150 	if (!top)
    151 		putchar('\n');
    152 	for (;;) {
    153 		if (fromatty) {
    154 			printf("lpc> ");
    155 			fflush(stdout);
    156 		}
    157 		if (fgets(cmdline, MAX_CMDLINE, stdin) == 0)
    158 			quit(0, NULL);
    159 		if (cmdline[0] == 0 || cmdline[0] == '\n')
    160 			break;
    161 		makeargv();
    162 		c = getcmd(margv[0]);
    163 		if (c == (struct cmd *)-1) {
    164 			printf("?Ambiguous command\n");
    165 			continue;
    166 		}
    167 		if (c == 0) {
    168 			printf("?Invalid command\n");
    169 			continue;
    170 		}
    171 		if (c->c_priv && getuid() && ingroup(LPR_OPER) == 0) {
    172 			printf("?Privileged command\n");
    173 			continue;
    174 		}
    175 		(*c->c_handler)(margc, margv);
    176 	}
    177 	longjmp(toplevel, 0);
    178 }
    179 
    180 static struct cmd *
    181 getcmd(name)
    182 	char *name;
    183 {
    184 	char *p, *q;
    185 	struct cmd *c, *found;
    186 	int nmatches, longest;
    187 
    188 	longest = 0;
    189 	nmatches = 0;
    190 	found = 0;
    191 	for (c = cmdtab; (p = c->c_name) != NULL; c++) {
    192 		for (q = name; *q == *p++; q++)
    193 			if (*q == 0)		/* exact match? */
    194 				return(c);
    195 		if (!*q) {			/* the name was a prefix */
    196 			if (q - name > longest) {
    197 				longest = q - name;
    198 				nmatches = 1;
    199 				found = c;
    200 			} else if (q - name == longest)
    201 				nmatches++;
    202 		}
    203 	}
    204 	if (nmatches > 1)
    205 		return((struct cmd *)-1);
    206 	return(found);
    207 }
    208 
    209 /*
    210  * Slice a string up into argc/argv.
    211  */
    212 static void
    213 makeargv()
    214 {
    215 	char *cp;
    216 	char **argp = margv;
    217 	int n = 0;
    218 
    219 	margc = 0;
    220 	for (cp = cmdline; *cp && (cp - cmdline) < sizeof(cmdline) &&
    221 	    n < MAX_MARGV; n++) {
    222 		while (isspace(*cp))
    223 			cp++;
    224 		if (*cp == '\0')
    225 			break;
    226 		*argp++ = cp;
    227 		margc += 1;
    228 		while (*cp != '\0' && !isspace(*cp))
    229 			cp++;
    230 		if (*cp == '\0')
    231 			break;
    232 		*cp++ = '\0';
    233 	}
    234 	*argp++ = 0;
    235 }
    236 
    237 #define HELPINDENT (sizeof ("directory"))
    238 
    239 /*
    240  * Help command.
    241  */
    242 void
    243 help(argc, argv)
    244 	int argc;
    245 	char *argv[];
    246 {
    247 	struct cmd *c;
    248 
    249 	if (argc == 1) {
    250 		int i, j, w;
    251 		int columns, width = 0, lines;
    252 
    253 		printf("Commands may be abbreviated.  Commands are:\n\n");
    254 		for (c = cmdtab; c->c_name; c++) {
    255 			int len = strlen(c->c_name);
    256 
    257 			if (len > width)
    258 				width = len;
    259 		}
    260 		width = (width + 8) &~ 7;
    261 		columns = 80 / width;
    262 		if (columns == 0)
    263 			columns = 1;
    264 		lines = (NCMDS + columns - 1) / columns;
    265 		for (i = 0; i < lines; i++) {
    266 			for (j = 0; j < columns; j++) {
    267 				c = cmdtab + j * lines + i;
    268 				if (c->c_name)
    269 					printf("%s", c->c_name);
    270 				if (c + lines >= &cmdtab[NCMDS]) {
    271 					printf("\n");
    272 					break;
    273 				}
    274 				w = strlen(c->c_name);
    275 				while (w < width) {
    276 					w = (w + 8) &~ 7;
    277 					putchar('\t');
    278 				}
    279 			}
    280 		}
    281 		return;
    282 	}
    283 	while (--argc > 0) {
    284 		char *arg;
    285 		arg = *++argv;
    286 		c = getcmd(arg);
    287 		if (c == (struct cmd *)-1)
    288 			printf("?Ambiguous help command %s\n", arg);
    289 		else if (c == (struct cmd *)0)
    290 			printf("?Invalid help command %s\n", arg);
    291 		else
    292 			printf("%-*s\t%s\n", (int)HELPINDENT,
    293 				c->c_name, c->c_help);
    294 	}
    295 }
    296 
    297 /*
    298  * return non-zero if the user is a member of the given group
    299  */
    300 static int
    301 ingroup(grname)
    302 	char *grname;
    303 {
    304 	static struct group *gptr=NULL;
    305 	static gid_t groups[NGROUPS];
    306 	gid_t gid;
    307 	int i;
    308 
    309 	if (gptr == NULL) {
    310 		if ((gptr = getgrnam(grname)) == NULL) {
    311 			warnx("Warning: unknown group `%s'\n",
    312 				grname);
    313 			return(0);
    314 		}
    315 		if (getgroups(NGROUPS, groups) < 0)
    316 			err(1, "getgroups");
    317 	}
    318 	gid = gptr->gr_gid;
    319 	for (i = 0; i < NGROUPS; i++)
    320 		if (gid == groups[i])
    321 			return(1);
    322 	return(0);
    323 }
    324