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      1 /*	$NetBSD: lpc.c,v 1.27 2017/05/04 16:26:09 sevan 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 1.27 2017/05/04 16:26:09 sevan 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 __dead static void	 cmdscanner(int);
     86 static struct cmd	*getcmd(const char *);
     87 __dead static void	 intr(int);
     88 static void		 makeargv(void);
     89 static int		 ingroup(const char *);
     90 const char		*prompt(void);
     91 static int		 parse(char *, char *p[], int);
     92 
     93 int
     94 main(int argc, char *argv[])
     95 {
     96 	euid = geteuid();
     97 	uid = getuid();
     98 	seteuid(uid);
     99 	setprogname(argv[0]);
    100 	openlog("lpd", 0, LOG_LPR);
    101 
    102 	if (--argc > 0) {
    103 		argv++;
    104 		exit(!parse(*argv, argv, argc));
    105 	}
    106 	fromatty = isatty(fileno(stdin));
    107 	top = setjmp(toplevel) == 0;
    108 	if (top)
    109 		signal(SIGINT, intr);
    110 	for (;;) {
    111 		cmdscanner(top);
    112 		top = 1;
    113 	}
    114 }
    115 
    116 static int
    117 parse(char *arg, char **pargv, int pargc)
    118 {
    119 	struct cmd *c;
    120 
    121 	c = getcmd(arg);
    122 	if (c == (struct cmd *)-1) {
    123 		printf("?Ambiguous command\n");
    124 		return(0);
    125 	}
    126 	if (c == 0) {
    127 		printf("?Invalid command\n");
    128 		return(0);
    129 	}
    130 	if (c->c_priv && getuid() && ingroup(LPR_OPER) == 0) {
    131 		printf("?Privileged command\n");
    132 		return(0);
    133 	}
    134 	(*c->c_handler)(pargc, pargv);
    135 	return(1);
    136 }
    137 
    138 static void
    139 intr(int signo)
    140 {
    141 	el_end(elptr);
    142 	history_end(hist);
    143 	if (!fromatty)
    144 		exit(0);
    145 	longjmp(toplevel, 1);
    146 }
    147 
    148 const char *
    149 prompt(void)
    150 {
    151 	return ("lpc> ");
    152 }
    153 
    154 /*
    155  * Command parser.
    156  */
    157 static void
    158 cmdscanner(int tp)
    159 {
    160 	int scratch;
    161 	const char *elline;
    162 
    163 	if (!tp)
    164 		putchar('\n');
    165 	hist = history_init();
    166 	history(hist, &he, H_SETSIZE, 100);	/* 100 elt history buffer */
    167 
    168 	elptr = el_init(getprogname(), stdin, stdout, stderr);
    169 	el_set(elptr, EL_EDITOR, "emacs");
    170 	el_set(elptr, EL_PROMPT, prompt);
    171 	el_set(elptr, EL_HIST, history, hist);
    172 	el_source(elptr, NULL);
    173 
    174 	for (;;) {
    175 		cmdline = NULL;
    176 		do {
    177 			if (((elline = el_gets(elptr, &scratch)) != NULL)
    178 			    && (scratch != 0)) {
    179 				history(hist, &he, H_ENTER, elline);
    180 				cmdline = strdup(elline);
    181 				makeargv();
    182 			} else {
    183 				margc = 0;
    184 				break;
    185 			}
    186 		} while (margc == 0);
    187 		if (margc == 0)
    188 			quit(0, NULL);
    189 		if (!parse(cmdline, margv, margc)) {
    190 			if (cmdline != NULL)
    191 				free(cmdline);
    192 			continue;
    193 		}
    194 		fflush(stdout);
    195 		if (cmdline != NULL)
    196 			free(cmdline);
    197 	}
    198 	longjmp(toplevel, 0);
    199 }
    200 
    201 static struct cmd *
    202 getcmd(const char *name)
    203 {
    204 	const char *p, *q;
    205 	struct cmd *c, *found;
    206 	int nmatches, longest;
    207 
    208 	longest = 0;
    209 	nmatches = 0;
    210 	found = 0;
    211 	for (c = cmdtab; (p = c->c_name) != NULL; c++) {
    212 		for (q = name; *q == *p++; q++)
    213 			if (*q == 0)		/* exact match? */
    214 				return(c);
    215 		if (!*q) {			/* the name was a prefix */
    216 			if (q - name > longest) {
    217 				longest = q - name;
    218 				nmatches = 1;
    219 				found = c;
    220 			} else if (q - name == longest)
    221 				nmatches++;
    222 		}
    223 	}
    224 	if (nmatches > 1)
    225 		return((struct cmd *)-1);
    226 	return(found);
    227 }
    228 
    229 /*
    230  * Slice a string up into argc/argv.
    231  */
    232 static void
    233 makeargv(void)
    234 {
    235 	char *cp;
    236 	char **argp = margv;
    237 	int n = 0;
    238 	size_t s;
    239 
    240 	s = strlen(cmdline) + 1;
    241 	margc = 0;
    242 	for (cp = cmdline; *cp && (size_t)(cp - cmdline) < s && n < MAX_MARGV; n++) {
    243 		while (isspace((unsigned char)*cp))
    244 			cp++;
    245 		if (*cp == '\0')
    246 			break;
    247 		*argp++ = cp;
    248 		margc += 1;
    249 		while (*cp != '\0' && !isspace((unsigned char)*cp))
    250 			cp++;
    251 		if (*cp == '\0')
    252 			break;
    253 		*cp++ = '\0';
    254 	}
    255 	*argp++ = 0;
    256 }
    257 
    258 #define HELPINDENT (sizeof ("directory"))
    259 
    260 /*
    261  * Help command.
    262  */
    263 void
    264 help(int argc, char *argv[])
    265 {
    266 	struct cmd *c;
    267 
    268 	if (argc == 1) {
    269 		size_t i, j, w;
    270 		size_t columns, width = 0, lines;
    271 
    272 		printf("Commands may be abbreviated.  Commands are:\n\n");
    273 		for (c = cmdtab; c->c_name; c++) {
    274 			size_t len = strlen(c->c_name);
    275 
    276 			if (len > width)
    277 				width = len;
    278 		}
    279 		width = (width + 8) &~ 7;
    280 		columns = 80 / width;
    281 		if (columns == 0)
    282 			columns = 1;
    283 		lines = (NCMDS + columns - 1) / columns;
    284 		for (i = 0; i < lines; i++) {
    285 			for (j = 0; j < columns; j++) {
    286 				c = cmdtab + j * lines + i;
    287 				printf("%s", c->c_name);
    288 				if (c + lines >= &cmdtab[NCMDS - 1]) {
    289 					printf("\n");
    290 					break;
    291 				}
    292 				w = strlen(c->c_name);
    293 				while (w < width) {
    294 					w = (w + 8) &~ 7;
    295 					putchar('\t');
    296 				}
    297 			}
    298 		}
    299 		return;
    300 	}
    301 	while (--argc > 0) {
    302 		char *arg;
    303 		arg = *++argv;
    304 		c = getcmd(arg);
    305 		if (c == (struct cmd *)-1)
    306 			printf("?Ambiguous help command %s\n", arg);
    307 		else if (c == (struct cmd *)0)
    308 			printf("?Invalid help command %s\n", arg);
    309 		else
    310 			printf("%-*s\t%s\n", (int)HELPINDENT,
    311 				c->c_name, c->c_help);
    312 	}
    313 }
    314 
    315 /*
    316  * return non-zero if the user is a member of the given group
    317  */
    318 static int
    319 ingroup(const char *grname)
    320 {
    321 	static struct group *gptr = NULL;
    322 	static gid_t groups[NGROUPS];
    323 	static int ngroups;
    324 	gid_t gid;
    325 	int i;
    326 
    327 	if (gptr == NULL) {
    328 		if ((gptr = getgrnam(grname)) == NULL) {
    329 			warnx("Warning: unknown group `%s'",
    330 				grname);
    331 			return(0);
    332 		}
    333 		ngroups = getgroups(NGROUPS, groups);
    334 		if (ngroups < 0)
    335 			err(1, "getgroups");
    336 	}
    337 	gid = gptr->gr_gid;
    338 	for (i = 0; i < ngroups; i++)
    339 		if (gid == groups[i])
    340 			return(1);
    341 	return(0);
    342 }
    343