xref: /freebsd/usr.sbin/kldxref/kldxref.c (revision 195ebc7e9e4b129de810833791a19dfb4349d6a9)
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 <link.h>
46 #include <err.h>
47 #include <fts.h>
48 #include <string.h>
49 #include <machine/elf.h>
50 #include <stdio.h>
51 #include <stdlib.h>
52 #include <unistd.h>
53 #include <errno.h>
54 
55 #include "ef.h"
56 
57 #define	MAXRECSIZE	1024
58 #define check(val)	if ((error = (val)) != 0) break
59 
60 static int dflag;	/* do not create a hint file, only write on stdout */
61 static int verbose;
62 
63 static FILE *fxref;	/* current hints file */
64 
65 static const char *xref_file = "linker.hints";
66 
67 /*
68  * A record is stored in the static buffer recbuf before going to disk.
69  */
70 static char recbuf[MAXRECSIZE];
71 static int recpos;	/* current write position */
72 static int reccnt;	/* total record written to this file so far */
73 
74 static void
75 intalign(void)
76 {
77 	recpos = (recpos + sizeof(int) - 1) & ~(sizeof(int) - 1);
78 }
79 
80 static void
81 record_start(void)
82 {
83 	recpos = 0;
84 	memset(recbuf, 0, MAXRECSIZE);
85 }
86 
87 static int
88 record_end(void)
89 {
90 	if (recpos == 0)
91 		return 0;
92 	reccnt++;
93 	intalign();
94 	fwrite(&recpos, sizeof(recpos), 1, fxref);
95 	return fwrite(recbuf, recpos, 1, fxref) != 1 ? errno : 0;
96 }
97 
98 static int
99 record_buf(const void *buf, int size)
100 {
101 	if (MAXRECSIZE - recpos < size)
102 		errx(1, "record buffer overflow");
103 	memcpy(recbuf + recpos, buf, size);
104 	recpos += size;
105 	return 0;
106 }
107 
108 /*
109  * An int is stored in host order and aligned
110  */
111 static int
112 record_int(int val)
113 {
114 	intalign();
115 	return record_buf(&val, sizeof(val));
116 }
117 
118 /*
119  * A string is stored as 1-byte length plus data, no padding
120  */
121 static int
122 record_string(const char *str)
123 {
124 	int len, error;
125 	u_char val;
126 
127 	if (dflag)
128 		return 0;
129 	val = len = strlen(str);
130 	if (len > 255)
131 		errx(1, "string %s too long", str);
132 	error = record_buf(&val, sizeof(val));
133 	if (error)
134 		return error;
135 	return record_buf(str, len);
136 }
137 
138 static int
139 parse_entry(struct mod_metadata *md, const char *cval,
140     struct elf_file *ef, const char *kldname)
141 {
142 	struct mod_depend mdp;
143 	struct mod_version mdv;
144 	Elf_Off data = (Elf_Off)md->md_data;
145 	int error = 0;
146 
147 	record_start();
148 	switch (md->md_type) {
149 	case MDT_DEPEND:
150 		if (!dflag)
151 			break;
152 		check(EF_SEG_READ(ef, data, sizeof(mdp), &mdp));
153 		printf("  depends on %s.%d (%d,%d)\n", cval,
154 		    mdp.md_ver_preferred, mdp.md_ver_minimum, mdp.md_ver_maximum);
155 		break;
156 	case MDT_VERSION:
157 		check(EF_SEG_READ(ef, data, sizeof(mdv), &mdv));
158 		if (dflag) {
159 			printf("  interface %s.%d\n", cval, mdv.mv_version);
160 		} else {
161 			record_int(MDT_VERSION);
162 			record_string(cval);
163 			record_int(mdv.mv_version);
164 			record_string(kldname);
165 		}
166 		break;
167 	case MDT_MODULE:
168 		if (dflag) {
169 			printf("  module %s\n", cval);
170 		} else {
171 			record_int(MDT_MODULE);
172 			record_string(cval);
173 			record_string(kldname);
174 		}
175 		break;
176 	default:
177 		warnx("unknown metadata record %d in file %s", md->md_type, kldname);
178 	}
179 	if (!error)
180 		record_end();
181 	return error;
182 }
183 
184 static int
185 read_kld(char *filename, char *kldname)
186 {
187 	struct mod_metadata md;
188 	struct elf_file ef;
189 	void **p, **orgp;
190 	int error, eftype, nmlen;
191 	long start, finish, entries;
192 	char kldmodname[MAXMODNAME + 1], cval[MAXMODNAME + 1], *cp;
193 
194 	if (verbose || dflag)
195 		printf("%s\n", filename);
196 	error = ef_open(filename, &ef, verbose);
197 	if (error) {
198 		error = ef_obj_open(filename, &ef, verbose);
199 		if (error) {
200 			if (verbose)
201 				warnc(error, "elf_open(%s)", filename);
202 			return error;
203 		}
204 	}
205 	eftype = EF_GET_TYPE(&ef);
206 	if (eftype != EFT_KLD && eftype != EFT_KERNEL)  {
207 		EF_CLOSE(&ef);
208 		return 0;
209 	}
210 	if (!dflag) {
211 		cp = strrchr(kldname, '.');
212 		nmlen = (cp != NULL) ? cp - kldname : (int)strlen(kldname);
213 		if (nmlen > MAXMODNAME)
214 			nmlen = MAXMODNAME;
215 		strlcpy(kldmodname, kldname, nmlen);
216 /*		fprintf(fxref, "%s:%s:%d\n", kldmodname, kldname, 0);*/
217 	}
218 	do {
219 		check(EF_LOOKUP_SET(&ef, MDT_SETNAME, &start, &finish,
220 		    &entries));
221 		check(EF_SEG_READ_ENTRY_REL(&ef, start, sizeof(*p) * entries,
222 		    (void *)&p));
223 		orgp = p;
224 		while(entries--) {
225 			check(EF_SEG_READ_REL(&ef, (Elf_Off)*p, sizeof(md),
226 			    &md));
227 			p++;
228 			check(EF_SEG_READ(&ef, (Elf_Off)md.md_cval,
229 			    sizeof(cval), cval));
230 			cval[MAXMODNAME] = '\0';
231 			parse_entry(&md, cval, &ef, kldname);
232 		}
233 		if (error)
234 			warnc(error, "error while reading %s", filename);
235 		free(orgp);
236 	} while(0);
237 	EF_CLOSE(&ef);
238 	return error;
239 }
240 
241 /*
242  * Create a temp file in directory root, make sure we don't
243  * overflow the buffer for the destination name
244  */
245 static FILE *
246 maketempfile(char *dest, const char *root)
247 {
248 	char *p;
249 	int n, fd;
250 
251 	p = strrchr(root, '/');
252 	n = p != NULL ? p - root + 1 : 0;
253 	if (snprintf(dest, MAXPATHLEN, "%.*slhint.XXXXXX", n, root) >=
254 	    MAXPATHLEN) {
255 		errno = ENAMETOOLONG;
256 		return NULL;
257 	}
258 
259 	fd = mkstemp(dest);
260 	if (fd < 0)
261 		return NULL;
262 	fchmod(fd, 0644);	/* nothing secret in the file */
263 	return fdopen(fd, "w+");
264 }
265 
266 static char xrefname[MAXPATHLEN], tempname[MAXPATHLEN];
267 
268 static void
269 usage(void)
270 {
271 
272 	fprintf(stderr, "%s\n",
273 	    "usage: kldxref [-Rdv] [-f hintsfile] path ..."
274 	);
275 	exit(1);
276 }
277 
278 int
279 main(int argc, char *argv[])
280 {
281 	FTS *ftsp;
282 	FTSENT *p;
283 	int opt, fts_options, ival;
284 	struct stat sb;
285 
286 	fts_options = FTS_PHYSICAL;
287 
288 	while ((opt = getopt(argc, argv, "Rdf:v")) != -1) {
289 		switch (opt) {
290 		case 'd':	/* no hint file, only print on stdout */
291 			dflag = 1;
292 			break;
293 		case 'f':	/* use this name instead of linker.hints */
294 			xref_file = optarg;
295 			break;
296 		case 'v':
297 			verbose++;
298 			break;
299 		case 'R':	/* recurse on directories */
300 			fts_options |= FTS_COMFOLLOW;
301 			break;
302 		default:
303 			usage();
304 			/* NOTREACHED */
305 		}
306 	}
307 	if (argc - optind < 1)
308 		usage();
309 	argc -= optind;
310 	argv += optind;
311 
312 	if (stat(argv[0], &sb) != 0)
313 		err(1, "%s", argv[0]);
314 	if ((sb.st_mode & S_IFDIR) == 0) {
315 		errno = ENOTDIR;
316 		err(1, "%s", argv[0]);
317 	}
318 
319 	ftsp = fts_open(argv, fts_options, 0);
320 	if (ftsp == NULL)
321 		exit(1);
322 
323 	for (;;) {
324 		p = fts_read(ftsp);
325 		if ((p == NULL || p->fts_info == FTS_D) && fxref) {
326 			/* close and rename the current hint file */
327 			fclose(fxref);
328 			fxref = NULL;
329 			if (reccnt) {
330 				rename(tempname, xrefname);
331 			} else {
332 				/* didn't find any entry, ignore this file */
333 				unlink(tempname);
334 				unlink(xrefname);
335 			}
336 		}
337 		if (p == NULL)
338 			break;
339 		if (p->fts_info == FTS_D && !dflag) {
340 			/* visiting a new directory, create a new hint file */
341 			snprintf(xrefname, sizeof(xrefname), "%s/%s",
342 			    ftsp->fts_path, xref_file);
343 			fxref = maketempfile(tempname, ftsp->fts_path);
344 			if (fxref == NULL)
345 				err(1, "can't create %s", tempname);
346 			ival = 1;
347 			fwrite(&ival, sizeof(ival), 1, fxref);
348 			reccnt = 0;
349 		}
350 		/* skip non-files or .symbols entries */
351 		if (p->fts_info != FTS_F)
352 			continue;
353 		if (p->fts_namelen >= 8 &&
354 		    strcmp(p->fts_name + p->fts_namelen - 8, ".symbols") == 0)
355 			continue;
356 		read_kld(p->fts_path, p->fts_name);
357 	}
358 	fts_close(ftsp);
359 	return 0;
360 }
361