xref: /freebsd/usr.sbin/kldxref/kldxref.c (revision ca9aa9026b7a5f1b9baee68021ad651a389da2f9)
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	1024
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  	default:
176  		warnx("unknown metadata record %d in file %s", md->md_type, kldname);
177  	}
178  	if (!error)
179  		record_end();
180  	return error;
181  }
182  
183  static int
184  read_kld(char *filename, char *kldname)
185  {
186  	struct mod_metadata md;
187  	struct elf_file ef;
188  	void **p, **orgp;
189  	int error, eftype, nmlen;
190  	long start, finish, entries;
191  	char kldmodname[MAXMODNAME + 1], cval[MAXMODNAME + 1], *cp;
192  
193  	if (verbose || dflag)
194  		printf("%s\n", filename);
195  	error = ef_open(filename, &ef, verbose);
196  	if (error) {
197  		error = ef_obj_open(filename, &ef, verbose);
198  		if (error) {
199  			if (verbose)
200  				warnc(error, "elf_open(%s)", filename);
201  			return error;
202  		}
203  	}
204  	eftype = EF_GET_TYPE(&ef);
205  	if (eftype != EFT_KLD && eftype != EFT_KERNEL)  {
206  		EF_CLOSE(&ef);
207  		return 0;
208  	}
209  	if (!dflag) {
210  		cp = strrchr(kldname, '.');
211  		nmlen = (cp != NULL) ? cp - kldname : (int)strlen(kldname);
212  		if (nmlen > MAXMODNAME)
213  			nmlen = MAXMODNAME;
214  		strlcpy(kldmodname, kldname, nmlen);
215  /*		fprintf(fxref, "%s:%s:%d\n", kldmodname, kldname, 0);*/
216  	}
217  	do {
218  		check(EF_LOOKUP_SET(&ef, MDT_SETNAME, &start, &finish,
219  		    &entries));
220  		check(EF_SEG_READ_ENTRY_REL(&ef, start, sizeof(*p) * entries,
221  		    (void *)&p));
222  		orgp = p;
223  		while(entries--) {
224  			check(EF_SEG_READ_REL(&ef, (Elf_Off)*p, sizeof(md),
225  			    &md));
226  			p++;
227  			check(EF_SEG_READ(&ef, (Elf_Off)md.md_cval,
228  			    sizeof(cval), cval));
229  			cval[MAXMODNAME] = '\0';
230  			parse_entry(&md, cval, &ef, kldname);
231  		}
232  		if (error)
233  			warnc(error, "error while reading %s", filename);
234  		free(orgp);
235  	} while(0);
236  	EF_CLOSE(&ef);
237  	return error;
238  }
239  
240  /*
241   * Create a temp file in directory root, make sure we don't
242   * overflow the buffer for the destination name
243   */
244  static FILE *
245  maketempfile(char *dest, const char *root)
246  {
247  	char *p;
248  	int n, fd;
249  
250  	p = strrchr(root, '/');
251  	n = p != NULL ? p - root + 1 : 0;
252  	if (snprintf(dest, MAXPATHLEN, "%.*slhint.XXXXXX", n, root) >=
253  	    MAXPATHLEN) {
254  		errno = ENAMETOOLONG;
255  		return NULL;
256  	}
257  
258  	fd = mkstemp(dest);
259  	if (fd < 0)
260  		return NULL;
261  	fchmod(fd, 0644);	/* nothing secret in the file */
262  	return fdopen(fd, "w+");
263  }
264  
265  static char xrefname[MAXPATHLEN], tempname[MAXPATHLEN];
266  
267  static void
268  usage(void)
269  {
270  
271  	fprintf(stderr, "%s\n",
272  	    "usage: kldxref [-Rdv] [-f hintsfile] path ..."
273  	);
274  	exit(1);
275  }
276  
277  static int
278  compare(const FTSENT *const *a, const FTSENT *const *b)
279  {
280  	if ((*a)->fts_info == FTS_D && (*b)->fts_info != FTS_D)
281  		return 1;
282  	if ((*a)->fts_info != FTS_D && (*b)->fts_info == FTS_D)
283  		return -1;
284  	return strcmp((*a)->fts_name, (*b)->fts_name);
285  }
286  
287  int
288  main(int argc, char *argv[])
289  {
290  	FTS *ftsp;
291  	FTSENT *p;
292  	int opt, fts_options, ival;
293  	struct stat sb;
294  
295  	fts_options = FTS_PHYSICAL;
296  
297  	while ((opt = getopt(argc, argv, "Rdf:v")) != -1) {
298  		switch (opt) {
299  		case 'd':	/* no hint file, only print on stdout */
300  			dflag = 1;
301  			break;
302  		case 'f':	/* use this name instead of linker.hints */
303  			xref_file = optarg;
304  			break;
305  		case 'v':
306  			verbose++;
307  			break;
308  		case 'R':	/* recurse on directories */
309  			fts_options |= FTS_COMFOLLOW;
310  			break;
311  		default:
312  			usage();
313  			/* NOTREACHED */
314  		}
315  	}
316  	if (argc - optind < 1)
317  		usage();
318  	argc -= optind;
319  	argv += optind;
320  
321  	if (stat(argv[0], &sb) != 0)
322  		err(1, "%s", argv[0]);
323  	if ((sb.st_mode & S_IFDIR) == 0) {
324  		errno = ENOTDIR;
325  		err(1, "%s", argv[0]);
326  	}
327  
328  	ftsp = fts_open(argv, fts_options, compare);
329  	if (ftsp == NULL)
330  		exit(1);
331  
332  	for (;;) {
333  		p = fts_read(ftsp);
334  		if ((p == NULL || p->fts_info == FTS_D) && fxref) {
335  			/* close and rename the current hint file */
336  			fclose(fxref);
337  			fxref = NULL;
338  			if (reccnt) {
339  				rename(tempname, xrefname);
340  			} else {
341  				/* didn't find any entry, ignore this file */
342  				unlink(tempname);
343  				unlink(xrefname);
344  			}
345  		}
346  		if (p == NULL)
347  			break;
348  		if (p->fts_info == FTS_D && !dflag) {
349  			/* visiting a new directory, create a new hint file */
350  			snprintf(xrefname, sizeof(xrefname), "%s/%s",
351  			    ftsp->fts_path, xref_file);
352  			fxref = maketempfile(tempname, ftsp->fts_path);
353  			if (fxref == NULL)
354  				err(1, "can't create %s", tempname);
355  			ival = 1;
356  			fwrite(&ival, sizeof(ival), 1, fxref);
357  			reccnt = 0;
358  		}
359  		/* skip non-files or .symbols entries */
360  		if (p->fts_info != FTS_F)
361  			continue;
362  		if (p->fts_namelen >= 8 &&
363  		    strcmp(p->fts_name + p->fts_namelen - 8, ".symbols") == 0)
364  			continue;
365  		read_kld(p->fts_path, p->fts_name);
366  	}
367  	fts_close(ftsp);
368  	return 0;
369  }
370