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source: rtems-tools/linkers/elftoolchain/libelf/libelf_ar_util.c @ ec24a37

4.104.115

Last change on this file since ec24a37 was ec24a37, checked in by Chris Johns <chrisj@…>, on 05/06/12 at 22:47:11
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1	/*-
2	* Copyright (c) 2006,2009,2010 Joseph Koshy
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	*
14	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS `AS IS' AND
15	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17	* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24	* SUCH DAMAGE.
25	*/
26
27	#include <sys/cdefs.h>
28
29	#include <assert.h>
30	#include <libelf.h>
31	#include <stdlib.h>
32	#include <string.h>
33
34	#include "_libelf.h"
35	#include "_libelf_ar.h"
36
37	LIBELF_VCSID("$Id: libelf_ar_util.c 2066 2011-10-26 15:40:28Z jkoshy $");
38
39	/*
40	* Convert a string bounded by `start' and `start+sz' (exclusive) to a
41	* number in the specified base.
42	*/
43	int
44	_libelf_ar_get_number(const char s, size_t sz, int base, size_t ret)
45	{
46	int c, v;
47	size_t r;
48	const char *e;
49
50	assert(base <= 10);
51
52	e = s + sz;
53
54	/* skip leading blanks */
55	for (;s < e && (c = *s) == ' '; s++)
56	;
57
58	r = 0L;
59	for (;s < e; s++) {
60	if ((c = *s) == ' ')
61	break;
62	if (c < '0' \|\| c > '9')
63	return (0);
64	v = c - '0';
65	if (v >= base) /* Illegal digit. */
66	break;
67	r *= base;
68	r += v;
69	}
70
71	*ret = r;
72
73	return (1);
74	}
75
76	/*
77	* Return the translated name for an archive member.
78	*/
79	char *
80	_libelf_ar_get_translated_name(const struct ar_hdr arh, Elf ar)
81	{
82	char c, *s;
83	size_t len, offset;
84	const char buf, p, q, r;
85	const size_t bufsize = sizeof(arh->ar_name);
86
87	assert(arh != NULL);
88	assert(ar->e_kind == ELF_K_AR);
89	assert((const char *) arh >= ar->e_rawfile &&
90	(const char *) arh < ar->e_rawfile + ar->e_rawsize);
91
92	buf = arh->ar_name;
93
94	/*
95	* Check for extended naming.
96	*
97	* If the name matches the pattern "^/[0-9]+", it is an
98	* SVR4-style extended name. If the name matches the pattern
99	* "#1/[0-9]+", the entry uses BSD style extended naming.
100	*/
101	if (buf[0] == '/' && (c = buf[1]) >= '0' && c <= '9') {
102	/*
103	* The value in field ar_name is a decimal offset into
104	* the archive string table where the actual name
105	* resides.
106	*/
107	if (_libelf_ar_get_number(buf + 1, bufsize - 1, 10,
108	&offset) == 0) {
109	LIBELF_SET_ERROR(ARCHIVE, 0);
110	return (NULL);
111	}
112
113	if (offset > ar->e_u.e_ar.e_rawstrtabsz) {
114	LIBELF_SET_ERROR(ARCHIVE, 0);
115	return (NULL);
116	}
117
118	p = q = ar->e_u.e_ar.e_rawstrtab + offset;
119	r = ar->e_u.e_ar.e_rawstrtab + ar->e_u.e_ar.e_rawstrtabsz;
120
121	for (; p < r && *p != '/'; p++)
122	;
123	len = p - q + 1; /* space for the trailing NUL */
124
125	if ((s = malloc(len)) == NULL) {
126	LIBELF_SET_ERROR(RESOURCE, 0);
127	return (NULL);
128	}
129
130	(void) strncpy(s, q, len - 1);
131	s[len - 1] = '\0';
132
133	return (s);
134	} else if (IS_EXTENDED_BSD_NAME(buf)) {
135	r = buf + LIBELF_AR_BSD_EXTENDED_NAME_PREFIX_SIZE;
136
137	if (_libelf_ar_get_number(r, bufsize -
138	LIBELF_AR_BSD_EXTENDED_NAME_PREFIX_SIZE, 10,
139	&len) == 0) {
140	LIBELF_SET_ERROR(ARCHIVE, 0);
141	return (NULL);
142	}
143
144	/*
145	* Allocate space for the file name plus a
146	* trailing NUL.
147	*/
148	if ((s = malloc(len + 1)) == NULL) {
149	LIBELF_SET_ERROR(RESOURCE, 0);
150	return (NULL);
151	}
152
153	/*
154	* The file name follows the archive header.
155	*/
156	q = (const char *) (arh + 1);
157
158	(void) strncpy(s, q, len);
159	s[len] = '\0';
160
161	return (s);
162	}
163
164	/*
165	* A 'normal' name.
166	*
167	* Skip back over trailing blanks from the end of the field.
168	* In the SVR4 format, a '/' is used as a terminator for
169	* non-special names.
170	*/
171	for (q = buf + bufsize - 1; q >= buf && *q == ' '; --q)
172	;
173
174	if (q >= buf) {
175	if (*q == '/') {
176	/*
177	* SVR4 style names: ignore the trailing
178	* character '/', but only if the name is not
179	* one of the special names "/" and "//".
180	*/
181	if (q > buf + 1 \|\|
182	(q == (buf + 1) && *buf != '/'))
183	q--;
184	}
185
186	len = q - buf + 2; /* Add space for a trailing NUL. */
187	} else {
188	/* The buffer only had blanks. */
189	buf = "";
190	len = 1;
191	}
192
193	if ((s = malloc(len)) == NULL) {
194	LIBELF_SET_ERROR(RESOURCE, 0);
195	return (NULL);
196	}
197
198	(void) strncpy(s, buf, len - 1);
199	s[len - 1] = '\0';
200
201	return (s);
202	}
203
204	/*
205	* Return the raw name for an archive member, inclusive of any
206	* formatting characters.
207	*/
208	char *
209	_libelf_ar_get_raw_name(const struct ar_hdr *arh)
210	{
211	char *rawname;
212	const size_t namesz = sizeof(arh->ar_name);
213
214	if ((rawname = malloc(namesz + 1)) == NULL) {
215	LIBELF_SET_ERROR(RESOURCE, 0);
216	return (NULL);
217	}
218
219	(void) strncpy(rawname, arh->ar_name, namesz);
220	rawname[namesz] = '\0';
221	return (rawname);
222	}
223
224	/*
225	* Open an 'ar' archive.
226	*/
227	Elf *
228	_libelf_ar_open(Elf *e)
229	{
230	int scanahead;
231	char s, end;
232	size_t sz;
233	struct ar_hdr arh;
234
235	e->e_kind = ELF_K_AR;
236	e->e_u.e_ar.e_nchildren = 0;
237	e->e_u.e_ar.e_next = (off_t) -1;
238
239	/*
240	* Look for special members.
241	*/
242
243	s = e->e_rawfile + SARMAG;
244	end = e->e_rawfile + e->e_rawsize;
245
246	assert(e->e_rawsize > 0);
247
248	/*
249	* We use heuristics to determine the flavor of the archive we
250	* are examining.
251	*
252	* SVR4 flavor archives use the name "/ " and "// " for
253	* special members.
254	*
255	* In BSD flavor archives the symbol table, if present, is the
256	* first archive with name "__.SYMDEF".
257	*/
258
259	#define READ_AR_HEADER(S, ARH, SZ, END) \
260	do { \
261	if ((S) + sizeof((ARH)) > (END)) \
262	goto error; \
263	(void) memcpy(&(ARH), (S), sizeof((ARH))); \
264	if ((ARH).ar_fmag[0] != '`' \|\| (ARH).ar_fmag[1] != '\n') \
265	goto error; \
266	if (_libelf_ar_get_number((ARH).ar_size, \
267	sizeof((ARH).ar_size), 10, &(SZ)) == 0) \
268	goto error; \
269	} while (0)
270
271	READ_AR_HEADER(s, arh, sz, end);
272
273	/*
274	* Handle special archive members for the SVR4 format.
275	*/
276	if (arh.ar_name[0] == '/') {
277
278	assert(sz > 0);
279
280	e->e_flags \|= LIBELF_F_AR_VARIANT_SVR4;
281
282	scanahead = 0;
283
284	/*
285	* The symbol table (file name "/ ") always comes before the
286	* string table (file name "// ").
287	*/
288	if (arh.ar_name[1] == ' ') {
289	/* "/ " => symbol table. */
290	scanahead = 1; /* The string table to follow. */
291
292	s += sizeof(arh);
293	e->e_u.e_ar.e_rawsymtab = s;
294	e->e_u.e_ar.e_rawsymtabsz = sz;
295
296	sz = LIBELF_ADJUST_AR_SIZE(sz);
297	s += sz;
298
299	} else if (arh.ar_name[1] == '/' && arh.ar_name[2] == ' ') {
300	/* "// " => string table for long file names. */
301	s += sizeof(arh);
302	e->e_u.e_ar.e_rawstrtab = s;
303	e->e_u.e_ar.e_rawstrtabsz = sz;
304
305	sz = LIBELF_ADJUST_AR_SIZE(sz);
306	s += sz;
307	}
308
309	/*
310	* If the string table hasn't been seen yet, look for
311	* it in the next member.
312	*/
313	if (scanahead) {
314	READ_AR_HEADER(s, arh, sz, end);
315
316	/* "// " => string table for long file names. */
317	if (arh.ar_name[0] == '/' && arh.ar_name[1] == '/' &&
318	arh.ar_name[2] == ' ') {
319
320	s += sizeof(arh);
321
322	e->e_u.e_ar.e_rawstrtab = s;
323	e->e_u.e_ar.e_rawstrtabsz = sz;
324
325	sz = LIBELF_ADJUST_AR_SIZE(sz);
326	s += sz;
327	}
328	}
329	} else if (strncmp(arh.ar_name, LIBELF_AR_BSD_SYMTAB_NAME,
330	sizeof(LIBELF_AR_BSD_SYMTAB_NAME) - 1) == 0) {
331	/*
332	* BSD style archive symbol table.
333	*/
334	s += sizeof(arh);
335	e->e_u.e_ar.e_rawsymtab = s;
336	e->e_u.e_ar.e_rawsymtabsz = sz;
337
338	sz = LIBELF_ADJUST_AR_SIZE(sz);
339	s += sz;
340	}
341
342	/*
343	* Update the 'next' offset, so that a subsequent elf_begin()
344	* works as expected.
345	*/
346	e->e_u.e_ar.e_next = (off_t) (s - e->e_rawfile);
347
348	return (e);
349
350	error:
351	LIBELF_SET_ERROR(ARCHIVE, 0);
352	return (NULL);
353
354	}

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