xref: /freebsd/usr.sbin/kldxref/kldxref.c (revision 2e5b60079b7d8c3ca68f1390cd90f305e651f8d3)
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