xref: /freebsd/usr.sbin/kldxref/kldxref.c (revision 57736250480e254798e7869eb82a8268bca03a0d)
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   * $FreeBSD$
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  
59  static int dflag;	/* do not create a hint file, only write on stdout */
60  static int verbose;
61  
62  static FILE *fxref;	/* current hints file */
63  
64  static const char *xref_file = "linker.hints";
65  
66  /*
67   * A record is stored in the static buffer recbuf before going to disk.
68   */
69  static char recbuf[MAXRECSIZE];
70  static int recpos;	/* current write position */
71  static int reccnt;	/* total record written to this file so far */
72  
73  static void
74  intalign(void)
75  {
76  	recpos = (recpos + sizeof(int) - 1) & ~(sizeof(int) - 1);
77  }
78  
79  static void
80  record_start(void)
81  {
82  	recpos = 0;
83  	memset(recbuf, 0, MAXRECSIZE);
84  }
85  
86  static int
87  record_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  
97  static int
98  record_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   */
110  static int
111  record_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   */
120  static int
121  record_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  
137  static int
138  parse_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  
187  static int
188  read_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   */
248  static FILE *
249  maketempfile(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  
269  static char xrefname[MAXPATHLEN], tempname[MAXPATHLEN];
270  
271  static void
272  usage(void)
273  {
274  
275  	fprintf(stderr, "%s\n",
276  	    "usage: kldxref [-Rdv] [-f hintsfile] path ..."
277  	);
278  	exit(1);
279  }
280  
281  static int
282  compare(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  
291  int
292  main(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