kldxref.c revision 298493 
1/*
2 * Copyright (c) 2000, Boris Popov
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 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *    This product includes software developed by Boris Popov.
16 * 4. Neither the name of the author nor the names of any co-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 AUTHOR 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 AUTHOR 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 * $FreeBSD: stable/10/usr.sbin/kldxref/kldxref.c 298493 2016-04-22 21:38:37Z emaste $
33 */
34
35#include <sys/types.h>
36#include <sys/param.h>
37#include <sys/exec.h>
38#include <sys/queue.h>
39#include <sys/kernel.h>
40#include <sys/reboot.h>
41#include <sys/linker.h>
42#include <sys/stat.h>
43#include <sys/module.h>
44#define FREEBSD_ELF
45#include <err.h>
46#include <fts.h>
47#include <string.h>
48#include <machine/elf.h>
49#include <stdio.h>
50#include <stdlib.h>
51#include <unistd.h>
52#include <errno.h>
53
54#include "ef.h"
55
56#define	MAXRECSIZE	8192
57#define check(val)	if ((error = (val)) != 0) break
58
59static int dflag;	/* do not create a hint file, only write on stdout */
60static int verbose;
61
62static FILE *fxref;	/* current hints file */
63
64static const char *xref_file = "linker.hints";
65
66/*
67 * A record is stored in the static buffer recbuf before going to disk.
68 */
69static char recbuf[MAXRECSIZE];
70static int recpos;	/* current write position */
71static int reccnt;	/* total record written to this file so far */
72
73static void
74intalign(void)
75{
76	recpos = (recpos + sizeof(int) - 1) & ~(sizeof(int) - 1);
77}
78
79static void
80record_start(void)
81{
82	recpos = 0;
83	memset(recbuf, 0, MAXRECSIZE);
84}
85
86static int
87record_end(void)
88{
89	if (recpos == 0)
90		return 0;
91	reccnt++;
92	intalign();
93	fwrite(&recpos, sizeof(recpos), 1, fxref);
94	return fwrite(recbuf, recpos, 1, fxref) != 1 ? errno : 0;
95}
96
97static int
98record_buf(const void *buf, int size)
99{
100	if (MAXRECSIZE - recpos < size)
101		errx(1, "record buffer overflow");
102	memcpy(recbuf + recpos, buf, size);
103	recpos += size;
104	return 0;
105}
106
107/*
108 * An int is stored in host order and aligned
109 */
110static int
111record_int(int val)
112{
113	intalign();
114	return record_buf(&val, sizeof(val));
115}
116
117/*
118 * A string is stored as 1-byte length plus data, no padding
119 */
120static int
121record_string(const char *str)
122{
123	int len, error;
124	u_char val;
125
126	if (dflag)
127		return 0;
128	val = len = strlen(str);
129	if (len > 255)
130		errx(1, "string %s too long", str);
131	error = record_buf(&val, sizeof(val));
132	if (error)
133		return error;
134	return record_buf(str, len);
135}
136
137static int
138parse_entry(struct mod_metadata *md, const char *cval,
139    struct elf_file *ef, const char *kldname)
140{
141	struct mod_depend mdp;
142	struct mod_version mdv;
143	Elf_Off data = (Elf_Off)md->md_data;
144	int error = 0;
145
146	record_start();
147	switch (md->md_type) {
148	case MDT_DEPEND:
149		if (!dflag)
150			break;
151		check(EF_SEG_READ(ef, data, sizeof(mdp), &mdp));
152		printf("  depends on %s.%d (%d,%d)\n", cval,
153		    mdp.md_ver_preferred, mdp.md_ver_minimum, mdp.md_ver_maximum);
154		break;
155	case MDT_VERSION:
156		check(EF_SEG_READ(ef, data, sizeof(mdv), &mdv));
157		if (dflag) {
158			printf("  interface %s.%d\n", cval, mdv.mv_version);
159		} else {
160			record_int(MDT_VERSION);
161			record_string(cval);
162			record_int(mdv.mv_version);
163			record_string(kldname);
164		}
165		break;
166	case MDT_MODULE:
167		if (dflag) {
168			printf("  module %s\n", cval);
169		} else {
170			record_int(MDT_MODULE);
171			record_string(cval);
172			record_string(kldname);
173		}
174		break;
175	case MDT_PNP_INFO:
176		if (dflag) {
177			printf("  pnp info for bus %s\n", cval);
178		}
179	default:
180		warnx("unknown metadata record %d in file %s", md->md_type, kldname);
181	}
182	if (!error)
183		record_end();
184	return error;
185}
186
187static int
188read_kld(char *filename, char *kldname)
189{
190	struct mod_metadata md;
191	struct elf_file ef;
192	void **p, **orgp;
193	int error, eftype, nmlen;
194	long start, finish, entries;
195	char kldmodname[MAXMODNAME + 1], cval[MAXMODNAME + 1], *cp;
196
197	if (verbose || dflag)
198		printf("%s\n", filename);
199	error = ef_open(filename, &ef, verbose);
200	if (error) {
201		error = ef_obj_open(filename, &ef, verbose);
202		if (error) {
203			if (verbose)
204				warnc(error, "elf_open(%s)", filename);
205			return error;
206		}
207	}
208	eftype = EF_GET_TYPE(&ef);
209	if (eftype != EFT_KLD && eftype != EFT_KERNEL)  {
210		EF_CLOSE(&ef);
211		return 0;
212	}
213	if (!dflag) {
214		cp = strrchr(kldname, '.');
215		nmlen = (cp != NULL) ? cp - kldname : (int)strlen(kldname);
216		if (nmlen > MAXMODNAME)
217			nmlen = MAXMODNAME;
218		strlcpy(kldmodname, kldname, nmlen);
219/*		fprintf(fxref, "%s:%s:%d\n", kldmodname, kldname, 0);*/
220	}
221	do {
222		check(EF_LOOKUP_SET(&ef, MDT_SETNAME, &start, &finish,
223		    &entries));
224		check(EF_SEG_READ_ENTRY_REL(&ef, start, sizeof(*p) * entries,
225		    (void *)&p));
226		orgp = p;
227		while(entries--) {
228			check(EF_SEG_READ_REL(&ef, (Elf_Off)*p, sizeof(md),
229			    &md));
230			p++;
231			check(EF_SEG_READ(&ef, (Elf_Off)md.md_cval,
232			    sizeof(cval), cval));
233			cval[MAXMODNAME] = '\0';
234			parse_entry(&md, cval, &ef, kldname);
235		}
236		if (error)
237			warnc(error, "error while reading %s", filename);
238		free(orgp);
239	} while(0);
240	EF_CLOSE(&ef);
241	return error;
242}
243
244/*
245 * Create a temp file in directory root, make sure we don't
246 * overflow the buffer for the destination name
247 */
248static FILE *
249maketempfile(char *dest, const char *root)
250{
251	char *p;
252	int n, fd;
253
254	p = strrchr(root, '/');
255	n = p != NULL ? p - root + 1 : 0;
256	if (snprintf(dest, MAXPATHLEN, "%.*slhint.XXXXXX", n, root) >=
257	    MAXPATHLEN) {
258		errno = ENAMETOOLONG;
259		return NULL;
260	}
261
262	fd = mkstemp(dest);
263	if (fd < 0)
264		return NULL;
265	fchmod(fd, 0644);	/* nothing secret in the file */
266	return fdopen(fd, "w+");
267}
268
269static char xrefname[MAXPATHLEN], tempname[MAXPATHLEN];
270
271static void
272usage(void)
273{
274
275	fprintf(stderr, "%s\n",
276	    "usage: kldxref [-Rdv] [-f hintsfile] path ..."
277	);
278	exit(1);
279}
280
281static int
282compare(const FTSENT *const *a, const FTSENT *const *b)
283{
284	if ((*a)->fts_info == FTS_D && (*b)->fts_info != FTS_D)
285		return 1;
286	if ((*a)->fts_info != FTS_D && (*b)->fts_info == FTS_D)
287		return -1;
288	return strcmp((*a)->fts_name, (*b)->fts_name);
289}
290
291int
292main(int argc, char *argv[])
293{
294	FTS *ftsp;
295	FTSENT *p;
296	int opt, fts_options, ival;
297	struct stat sb;
298
299	fts_options = FTS_PHYSICAL;
300
301	while ((opt = getopt(argc, argv, "Rdf:v")) != -1) {
302		switch (opt) {
303		case 'd':	/* no hint file, only print on stdout */
304			dflag = 1;
305			break;
306		case 'f':	/* use this name instead of linker.hints */
307			xref_file = optarg;
308			break;
309		case 'v':
310			verbose++;
311			break;
312		case 'R':	/* recurse on directories */
313			fts_options |= FTS_COMFOLLOW;
314			break;
315		default:
316			usage();
317			/* NOTREACHED */
318		}
319	}
320	if (argc - optind < 1)
321		usage();
322	argc -= optind;
323	argv += optind;
324
325	if (stat(argv[0], &sb) != 0)
326		err(1, "%s", argv[0]);
327	if ((sb.st_mode & S_IFDIR) == 0) {
328		errno = ENOTDIR;
329		err(1, "%s", argv[0]);
330	}
331
332	ftsp = fts_open(argv, fts_options, compare);
333	if (ftsp == NULL)
334		exit(1);
335
336	for (;;) {
337		p = fts_read(ftsp);
338		if ((p == NULL || p->fts_info == FTS_D) && fxref) {
339			/* close and rename the current hint file */
340			fclose(fxref);
341			fxref = NULL;
342			if (reccnt) {
343				rename(tempname, xrefname);
344			} else {
345				/* didn't find any entry, ignore this file */
346				unlink(tempname);
347				unlink(xrefname);
348			}
349		}
350		if (p == NULL)
351			break;
352		if (p->fts_info == FTS_D && !dflag) {
353			/* visiting a new directory, create a new hint file */
354			snprintf(xrefname, sizeof(xrefname), "%s/%s",
355			    ftsp->fts_path, xref_file);
356			fxref = maketempfile(tempname, ftsp->fts_path);
357			if (fxref == NULL)
358				err(1, "can't create %s", tempname);
359			ival = 1;
360			fwrite(&ival, sizeof(ival), 1, fxref);
361			reccnt = 0;
362		}
363		/* skip non-files or .symbols entries */
364		if (p->fts_info != FTS_F)
365			continue;
366		if (p->fts_namelen >= 8 &&
367		    strcmp(p->fts_name + p->fts_namelen - 8, ".symbols") == 0)
368			continue;
369		read_kld(p->fts_path, p->fts_name);
370	}
371	fts_close(ftsp);
372	return 0;
373}
374