kldconfig.c revision 78982 
1/*
2 * Copyright (c) 2001 Peter Pentchev
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#ifndef lint
28static const char rcsid[] =
29  "$FreeBSD: head/sbin/kldconfig/kldconfig.c 78982 2001-06-29 19:46:29Z dd $";
30#endif /* not lint */
31
32#include <sys/param.h>
33#include <sys/types.h>
34#include <sys/queue.h>
35#include <sys/sysctl.h>
36
37#include <err.h>
38#include <errno.h>
39#include <limits.h>
40#include <stdio.h>
41#include <stdlib.h>
42#include <string.h>
43#include <unistd.h>
44
45#if defined(__FreeBSD_version)
46#if __FreeBSD_version < 500000
47#define NEED_SLASHTERM
48#endif /* < 500000 */
49#else  /* defined(__FreeBSD_version) */
50/* just in case.. */
51#define NEED_SLASHTERM
52#endif /* defined(__FreeBSD_version) */
53
54/* the default sysctl name */
55#define PATHCTL	"kern.module_path"
56
57/* queue structure for the module path broken down into components */
58TAILQ_HEAD(pathhead, pathentry);
59struct pathentry {
60	char			*path;
61	TAILQ_ENTRY(pathentry)	next;
62};
63
64/* the Management Information Base entries for the search path sysctl */
65static int	 mib[5];
66static size_t	 miblen;
67/* the sysctl name, defaults to PATHCTL */
68static char	*pathctl;
69/* the sysctl value - the current module search path */
70static char	*modpath;
71/* flag whether user actions require changing the sysctl value */
72static int	 changed;
73
74/* Top-level path management functions */
75static void	 addpath(struct pathhead *, char *, int, int);
76static void	 rempath(struct pathhead *, char *, int, int);
77static void	 showpath(struct pathhead *);
78
79/* Low-level path management functions */
80static char	*qstring(struct pathhead *);
81
82/* sysctl-related functions */
83static void	 getmib(void);
84static void	 getpath(void);
85static void	 parsepath(struct pathhead *, char *, int);
86static void	 setpath(struct pathhead *);
87
88static void	 usage(void);
89
90/* Get the MIB entry for our sysctl */
91static void
92getmib(void)
93{
94
95	/* have we already fetched it? */
96	if (miblen != 0)
97		return;
98
99	miblen = sizeof(mib) / sizeof(mib[0]);
100	if (sysctlnametomib(pathctl, mib, &miblen) != 0)
101		err(1, "sysctlnametomib(%s)", pathctl);
102}
103
104/* Get the current module search path */
105static void
106getpath(void)
107{
108	char *path;
109	size_t sz;
110
111	if (modpath != NULL) {
112		free(modpath);
113		modpath = NULL;
114	}
115
116	if (miblen == 0)
117		getmib();
118	if (sysctl(mib, miblen, NULL, &sz, NULL, NULL) == -1)
119		err(1, "getting path: sysctl(%s) - size only", pathctl);
120	if ((path = malloc(sz + 1)) == NULL) {
121		errno = ENOMEM;
122		err(1, "allocating %lu bytes for the path", (long)sz+1);
123	}
124	if (sysctl(mib, miblen, path, &sz, NULL, NULL) == -1)
125		err(1, "getting path: sysctl(%s)", pathctl);
126	modpath = path;
127}
128
129/* Set the module search path after changing it */
130static void
131setpath(struct pathhead *pathq)
132{
133	char *newpath;
134
135	if (miblen == 0)
136		getmib();
137	if ((newpath = qstring(pathq)) == NULL) {
138		errno = ENOMEM;
139		err(1, "building path string");
140	}
141	if (sysctl(mib, miblen, NULL, NULL, newpath, strlen(newpath)+1) == -1)
142		err(1, "setting path: sysctl(%s)", pathctl);
143
144	if (modpath)
145		free(modpath);
146	modpath = newpath;
147}
148
149/* Add/insert a new component to the module search path */
150static void
151addpath(struct pathhead *pathq, char *path, int force, int insert)
152{
153	struct pathentry *pe, *pskip;
154	char pathbuf[MAXPATHLEN+1];
155	size_t len;
156	static unsigned added = 0;
157	unsigned i;
158
159	/*
160	 * If the path exists, use it; otherwise, take the user-specified
161	 * path at face value - may be a removed directory.
162	 */
163	if (realpath(path, pathbuf) == NULL)
164		strlcpy(pathbuf, path, sizeof(pathbuf));
165
166	len = strlen(pathbuf);
167#ifdef NEED_SLASHTERM
168	/* slash-terminate, because the kernel linker said so. */
169	if ((len == 0) || (pathbuf[len-1] != '/')) {
170		if (len == sizeof(pathbuf) - 1)
171			errx(1, "path too long: %s", pathbuf);
172		pathbuf[len] = '/';
173	}
174#else  /* NEED_SLASHTERM */
175	/* remove a terminating slash if present */
176	if ((len > 0) && (pathbuf[len-1] == '/'))
177		pathbuf[--len] = '\0';
178#endif /* NEED_SLASHTERM */
179
180	/* is it already in there? */
181	TAILQ_FOREACH(pe, pathq, next)
182		if (!strcmp(pe->path, pathbuf))
183			break;
184	if (pe != NULL) {
185		if (force)
186			return;
187		errx(1, "already in the module search path: %s", pathbuf);
188	}
189
190	/* OK, allocate and add it. */
191	if (((pe = malloc(sizeof(*pe))) == NULL) ||
192	    ((pe->path = strdup(pathbuf)) == NULL)) {
193		errno = ENOMEM;
194		err(1, "allocating path component");
195	}
196	if (!insert) {
197		TAILQ_INSERT_TAIL(pathq, pe, next);
198	} else {
199		for (i = 0, pskip = TAILQ_FIRST(pathq); i < added; i++)
200			pskip = TAILQ_NEXT(pskip, next);
201		if (pskip != NULL)
202			TAILQ_INSERT_BEFORE(pskip, pe, next);
203		else
204			TAILQ_INSERT_TAIL(pathq, pe, next);
205		added++;
206	}
207	changed = 1;
208}
209
210/* Remove a path component from the module search path */
211static void
212rempath(struct pathhead *pathq, char *path, int force, int insert __unused)
213{
214	char pathbuf[MAXPATHLEN+1];
215	struct pathentry *pe;
216	size_t len;
217
218	/* same logic as in addpath() */
219	if (realpath(path, pathbuf) == NULL)
220		strlcpy(pathbuf, path, sizeof(pathbuf));
221
222	len = strlen(pathbuf);
223#ifdef NEED_SLASHTERM
224	/* slash-terminate, because the kernel linker said so. */
225	if ((len == 0) || (pathbuf[len-1] != '/')) {
226		if (len == sizeof(pathbuf) - 1)
227			errx(1, "path too long: %s", pathbuf);
228		pathbuf[len] = '/';
229	}
230#else  /* NEED_SLASHTERM */
231	/* remove a terminating slash if present */
232	if ((len > 0) && (pathbuf[len-1] == '/'))
233		pathbuf[--len] = '\0';
234#endif /* NEED_SLASHTERM */
235
236	/* Is it in there? */
237	TAILQ_FOREACH(pe, pathq, next)
238		if (!strcmp(pe->path, pathbuf))
239			break;
240	if (pe == NULL) {
241		if (force)
242			return;
243		errx(1, "not in module search path: %s", pathbuf);
244	}
245
246	/* OK, remove it now.. */
247	TAILQ_REMOVE(pathq, pe, next);
248	changed = 1;
249}
250
251/* Display the retrieved module search path */
252static void
253showpath(struct pathhead *pathq)
254{
255	char *s;
256
257	if ((s = qstring(pathq)) == NULL) {
258		errno = ENOMEM;
259		err(1, "building path string");
260	}
261	printf("%s\n", s);
262	free(s);
263}
264
265/* Break a string down into path components, store them into a queue */
266static void
267parsepath(struct pathhead *pathq, char *path, int uniq)
268{
269	char *p;
270	struct pathentry *pe;
271
272	while ((p = strsep(&path, ";")) != NULL)
273		if (!uniq) {
274			if (((pe = malloc(sizeof(pe))) == NULL) ||
275			    ((pe->path = strdup(p)) == NULL)) {
276				errno = ENOMEM;
277				err(1, "allocating path element");
278			}
279			TAILQ_INSERT_TAIL(pathq, pe, next);
280		} else {
281			addpath(pathq, p, 1, 0);
282		}
283}
284
285/* Recreate a path string from a components queue */
286static char *
287qstring(struct pathhead *pathq)
288{
289	char *s, *p;
290	struct pathentry *pe;
291
292	s = strdup("");
293	TAILQ_FOREACH(pe, pathq, next) {
294		asprintf(&p, "%s%s%s",
295		    s, pe->path, (TAILQ_NEXT(pe, next) != NULL? ";": ""));
296		free(s);
297		if (p == NULL)
298			return (NULL);
299		s = p;
300	}
301
302	return (s);
303}
304
305/* Usage message */
306static void
307usage(void)
308{
309
310	fprintf(stderr, "%s\n%s\n",
311	    "usage:\tkldconfig [-dfimnUv] [-S sysctlname] [path..]",
312	    "\tkldconfig -r");
313	exit(1);
314}
315
316/* Main function */
317int
318main(int argc, char *argv[])
319{
320	/* getopt() iterator */
321	int c;
322	/* iterator over argv[] path components */
323	int i;
324	/* Command-line flags: */
325	/* "-f" - no diagnostic messages */
326	int fflag;
327	/* "-i" - insert before the first element */
328	int iflag;
329	/* "-m" - merge into the existing path, do not replace it */
330	int mflag;
331	/* "-n" - do not actually set the new module path */
332	int nflag;
333	/* "-r" - print out the current search path */
334	int rflag;
335	/* "-U" - remove duplicate values from the path */
336	int uniqflag;
337	/* "-v" - verbose operation (currently a no-op) */
338	int vflag;
339	/* The higher-level function to call - add/remove */
340	void (*act)(struct pathhead *, char *, int, int);
341	/* The original path */
342	char *origpath;
343	/* The module search path broken down into components */
344	struct pathhead pathq;
345
346	fflag = iflag = mflag = nflag = rflag = uniqflag = vflag = 0;
347	act = addpath;
348	origpath = NULL;
349	if ((pathctl = strdup(PATHCTL)) == NULL) {
350		/* this is just too paranoid ;) */
351		errno = ENOMEM;
352		err(1, "initializing sysctl name %s", PATHCTL);
353	}
354
355	/* If no arguments and no options are specified, force '-m' */
356	if (argc == 1)
357		mflag = 1;
358
359	while ((c = getopt(argc, argv, "dfimnrS:Uv")) != -1)
360		switch (c) {
361			case 'd':
362				if (iflag || mflag)
363					usage();
364				act = rempath;
365				break;
366			case 'f':
367				fflag = 1;
368				break;
369			case 'i':
370				if (act != addpath)
371					usage();
372				iflag = 1;
373				break;
374			case 'm':
375				if (act != addpath)
376					usage();
377				mflag = 1;
378				break;
379			case 'n':
380				nflag = 1;
381				break;
382			case 'r':
383				rflag = 1;
384				break;
385			case 'S':
386				free(pathctl);
387				if ((pathctl = strdup(optarg)) == NULL) {
388					errno = ENOMEM;
389					err(1, "sysctl name %s", optarg);
390				}
391				break;
392			case 'U':
393				uniqflag = 1;
394				break;
395			case 'v':
396				vflag++;
397				break;
398			default:
399				usage();
400		}
401
402	argc -= optind;
403	argv += optind;
404
405	/* The '-r' flag cannot be used when paths are also specified */
406	if (rflag && (argc > 0))
407		usage();
408
409	TAILQ_INIT(&pathq);
410
411	/* Retrieve and store the path from the sysctl value */
412	getpath();
413	if ((origpath = strdup(modpath)) == NULL) {
414		errno = ENOMEM;
415		err(1, "saving the original search path");
416	}
417
418	/*
419	 * Break down the path into the components queue if:
420	 * - we are NOT adding paths, OR
421	 * - the 'merge' flag is specified, OR
422	 * - the 'print only' flag is specified, OR
423	 * - the 'unique' flag is specified.
424	 */
425	if ((act != addpath) || mflag || rflag || uniqflag)
426		parsepath(&pathq, modpath, uniqflag);
427	else if (modpath[0] != '\0')
428		changed = 1;
429
430	/* Process the path arguments */
431	for (i = 0; i < argc; i++)
432		act(&pathq, argv[i], fflag, iflag);
433
434	if (changed && !nflag)
435		setpath(&pathq);
436
437	if (rflag || (changed && vflag)) {
438		if (changed && (vflag > 1))
439			printf("%s -> ", origpath);
440		showpath(&pathq);
441	}
442
443	return (0);
444}
445