1198160Srrs/*	$NetBSD: timedc.c,v 1.21 2008/07/21 13:37:00 lukem Exp $	*/
2198160Srrs
3198160Srrs/*-
4198160Srrs * Copyright (c) 1985, 1993 The Regents of the University of California.
5198160Srrs * All rights reserved.
6198160Srrs *
7198160Srrs * Redistribution and use in source and binary forms, with or without
8198160Srrs * modification, are permitted provided that the following conditions
9198160Srrs * are met:
10198160Srrs * 1. Redistributions of source code must retain the above copyright
11198160Srrs *    notice, this list of conditions and the following disclaimer.
12198160Srrs * 2. Redistributions in binary form must reproduce the above copyright
13198160Srrs *    notice, this list of conditions and the following disclaimer in the
14198160Srrs *    documentation and/or other materials provided with the distribution.
15198160Srrs * 3. Neither the name of the University nor the names of its contributors
16198160Srrs *    may be used to endorse or promote products derived from this software
17198160Srrs *    without specific prior written permission.
18198160Srrs *
19198160Srrs * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20198160Srrs * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21198160Srrs * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22198160Srrs * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23198160Srrs * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24198160Srrs * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25198160Srrs * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26198160Srrs * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27198160Srrs * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28211994Sjchandra * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29211994Sjchandra * SUCH DAMAGE.
30211994Sjchandra */
31211994Sjchandra
32198160Srrs#include <sys/cdefs.h>
33198160Srrs#ifndef lint
34198160Srrs__COPYRIGHT("@(#) Copyright (c) 1985, 1993\
35198160Srrs The Regents of the University of California.  All rights reserved.");
36198160Srrs#endif /* not lint */
37208165Srrs
38208165Srrs#ifndef lint
39208165Srrs#if 0
40198160Srrsstatic char sccsid[] = "@(#)timedc.c	8.1 (Berkeley) 6/6/93";
41204130Srrs#else
42204130Srrs__RCSID("$NetBSD: timedc.c,v 1.21 2008/07/21 13:37:00 lukem Exp $");
43204130Srrs#endif
44204130Srrs#endif /* not lint */
45211893Sjchandra
46211893Sjchandra#include "timedc.h"
47211893Sjchandra#include <ctype.h>
48211893Sjchandra#include <setjmp.h>
49204130Srrs#include <signal.h>
50198625Srrs#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
58int trace = 0;
59FILE *fd = 0;
60int	margc;
61int	fromatty;
62#define MAX_MARGV	20
63char	*margv[MAX_MARGV];
64char	cmdline[200];
65jmp_buf	toplevel;
66static const struct cmd *getcmd(char *);
67static int drop_privileges(void);
68
69int
70main(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) == NULL)
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
132void
133intr(int signo)
134{
135	(void) signo;
136	if (!fromatty)
137		exit(EXIT_SUCCESS);
138	longjmp(toplevel, 1);
139}
140
141
142static const struct cmd *
143getcmd(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 */
177int
178makeargv(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 */
208void
209help(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
262static int
263drop_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}
290