1*f8fb3368SJohn Marino /*-
2*f8fb3368SJohn Marino * Copyright (c) 2006,2009,2010 Joseph Koshy
3*f8fb3368SJohn Marino * All rights reserved.
4*f8fb3368SJohn Marino *
5*f8fb3368SJohn Marino * Redistribution and use in source and binary forms, with or without
6*f8fb3368SJohn Marino * modification, are permitted provided that the following conditions
7*f8fb3368SJohn Marino * are met:
8*f8fb3368SJohn Marino * 1. Redistributions of source code must retain the above copyright
9*f8fb3368SJohn Marino * notice, this list of conditions and the following disclaimer.
10*f8fb3368SJohn Marino * 2. Redistributions in binary form must reproduce the above copyright
11*f8fb3368SJohn Marino * notice, this list of conditions and the following disclaimer in the
12*f8fb3368SJohn Marino * documentation and/or other materials provided with the distribution.
13*f8fb3368SJohn Marino *
14*f8fb3368SJohn Marino * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS `AS IS' AND
15*f8fb3368SJohn Marino * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16*f8fb3368SJohn Marino * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17*f8fb3368SJohn Marino * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18*f8fb3368SJohn Marino * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19*f8fb3368SJohn Marino * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20*f8fb3368SJohn Marino * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21*f8fb3368SJohn Marino * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22*f8fb3368SJohn Marino * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23*f8fb3368SJohn Marino * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24*f8fb3368SJohn Marino * SUCH DAMAGE.
25*f8fb3368SJohn Marino */
26*f8fb3368SJohn Marino
27*f8fb3368SJohn Marino #include <assert.h>
28*f8fb3368SJohn Marino #include <libelf.h>
29*f8fb3368SJohn Marino #include <stdlib.h>
30*f8fb3368SJohn Marino #include <string.h>
31*f8fb3368SJohn Marino
32*f8fb3368SJohn Marino #include "_libelf.h"
33*f8fb3368SJohn Marino #include "_libelf_ar.h"
34*f8fb3368SJohn Marino
35*f8fb3368SJohn Marino ELFTC_VCSID("$Id: libelf_ar_util.c 3174 2015-03-27 17:13:41Z emaste $");
36*f8fb3368SJohn Marino
37*f8fb3368SJohn Marino /*
38*f8fb3368SJohn Marino * Convert a string bounded by `start' and `start+sz' (exclusive) to a
39*f8fb3368SJohn Marino * number in the specified base.
40*f8fb3368SJohn Marino */
41*f8fb3368SJohn Marino int
_libelf_ar_get_number(const char * src,size_t sz,unsigned int base,size_t * ret)42*f8fb3368SJohn Marino _libelf_ar_get_number(const char *src, size_t sz, unsigned int base,
43*f8fb3368SJohn Marino size_t *ret)
44*f8fb3368SJohn Marino {
45*f8fb3368SJohn Marino size_t r;
46*f8fb3368SJohn Marino unsigned int c, v;
47*f8fb3368SJohn Marino const unsigned char *e, *s;
48*f8fb3368SJohn Marino
49*f8fb3368SJohn Marino assert(base <= 10);
50*f8fb3368SJohn Marino
51*f8fb3368SJohn Marino s = (const unsigned char *) src;
52*f8fb3368SJohn Marino e = s + sz;
53*f8fb3368SJohn Marino
54*f8fb3368SJohn Marino /* skip leading blanks */
55*f8fb3368SJohn Marino for (;s < e && (c = *s) == ' '; s++)
56*f8fb3368SJohn Marino ;
57*f8fb3368SJohn Marino
58*f8fb3368SJohn Marino r = 0L;
59*f8fb3368SJohn Marino for (;s < e; s++) {
60*f8fb3368SJohn Marino if ((c = *s) == ' ')
61*f8fb3368SJohn Marino break;
62*f8fb3368SJohn Marino if (c < '0' || c > '9')
63*f8fb3368SJohn Marino return (0);
64*f8fb3368SJohn Marino v = c - '0';
65*f8fb3368SJohn Marino if (v >= base) /* Illegal digit. */
66*f8fb3368SJohn Marino break;
67*f8fb3368SJohn Marino r *= base;
68*f8fb3368SJohn Marino r += v;
69*f8fb3368SJohn Marino }
70*f8fb3368SJohn Marino
71*f8fb3368SJohn Marino *ret = r;
72*f8fb3368SJohn Marino
73*f8fb3368SJohn Marino return (1);
74*f8fb3368SJohn Marino }
75*f8fb3368SJohn Marino
76*f8fb3368SJohn Marino /*
77*f8fb3368SJohn Marino * Return the translated name for an archive member.
78*f8fb3368SJohn Marino */
79*f8fb3368SJohn Marino char *
_libelf_ar_get_translated_name(const struct ar_hdr * arh,Elf * ar)80*f8fb3368SJohn Marino _libelf_ar_get_translated_name(const struct ar_hdr *arh, Elf *ar)
81*f8fb3368SJohn Marino {
82*f8fb3368SJohn Marino char *s;
83*f8fb3368SJohn Marino unsigned char c;
84*f8fb3368SJohn Marino size_t len, offset;
85*f8fb3368SJohn Marino const unsigned char *buf, *p, *q, *r;
86*f8fb3368SJohn Marino const size_t bufsize = sizeof(arh->ar_name);
87*f8fb3368SJohn Marino
88*f8fb3368SJohn Marino assert(arh != NULL);
89*f8fb3368SJohn Marino assert(ar->e_kind == ELF_K_AR);
90*f8fb3368SJohn Marino assert((const unsigned char *) arh >= ar->e_rawfile &&
91*f8fb3368SJohn Marino (const unsigned char *) arh < ar->e_rawfile + ar->e_rawsize);
92*f8fb3368SJohn Marino
93*f8fb3368SJohn Marino buf = (const unsigned char *) arh->ar_name;
94*f8fb3368SJohn Marino
95*f8fb3368SJohn Marino /*
96*f8fb3368SJohn Marino * Check for extended naming.
97*f8fb3368SJohn Marino *
98*f8fb3368SJohn Marino * If the name matches the pattern "^/[0-9]+", it is an
99*f8fb3368SJohn Marino * SVR4-style extended name. If the name matches the pattern
100*f8fb3368SJohn Marino * "#1/[0-9]+", the entry uses BSD style extended naming.
101*f8fb3368SJohn Marino */
102*f8fb3368SJohn Marino if (buf[0] == '/' && (c = buf[1]) >= '0' && c <= '9') {
103*f8fb3368SJohn Marino /*
104*f8fb3368SJohn Marino * The value in field ar_name is a decimal offset into
105*f8fb3368SJohn Marino * the archive string table where the actual name
106*f8fb3368SJohn Marino * resides.
107*f8fb3368SJohn Marino */
108*f8fb3368SJohn Marino if (_libelf_ar_get_number((const char *) (buf + 1),
109*f8fb3368SJohn Marino bufsize - 1, 10, &offset) == 0) {
110*f8fb3368SJohn Marino LIBELF_SET_ERROR(ARCHIVE, 0);
111*f8fb3368SJohn Marino return (NULL);
112*f8fb3368SJohn Marino }
113*f8fb3368SJohn Marino
114*f8fb3368SJohn Marino if (offset > ar->e_u.e_ar.e_rawstrtabsz) {
115*f8fb3368SJohn Marino LIBELF_SET_ERROR(ARCHIVE, 0);
116*f8fb3368SJohn Marino return (NULL);
117*f8fb3368SJohn Marino }
118*f8fb3368SJohn Marino
119*f8fb3368SJohn Marino p = q = ar->e_u.e_ar.e_rawstrtab + offset;
120*f8fb3368SJohn Marino r = ar->e_u.e_ar.e_rawstrtab + ar->e_u.e_ar.e_rawstrtabsz;
121*f8fb3368SJohn Marino
122*f8fb3368SJohn Marino for (; p < r && *p != '/'; p++)
123*f8fb3368SJohn Marino ;
124*f8fb3368SJohn Marino len = (size_t) (p - q + 1); /* space for the trailing NUL */
125*f8fb3368SJohn Marino
126*f8fb3368SJohn Marino if ((s = malloc(len)) == NULL) {
127*f8fb3368SJohn Marino LIBELF_SET_ERROR(RESOURCE, 0);
128*f8fb3368SJohn Marino return (NULL);
129*f8fb3368SJohn Marino }
130*f8fb3368SJohn Marino
131*f8fb3368SJohn Marino (void) strncpy(s, (const char *) q, len - 1);
132*f8fb3368SJohn Marino s[len - 1] = '\0';
133*f8fb3368SJohn Marino
134*f8fb3368SJohn Marino return (s);
135*f8fb3368SJohn Marino } else if (IS_EXTENDED_BSD_NAME(buf)) {
136*f8fb3368SJohn Marino r = buf + LIBELF_AR_BSD_EXTENDED_NAME_PREFIX_SIZE;
137*f8fb3368SJohn Marino
138*f8fb3368SJohn Marino if (_libelf_ar_get_number((const char *) r, bufsize -
139*f8fb3368SJohn Marino LIBELF_AR_BSD_EXTENDED_NAME_PREFIX_SIZE, 10,
140*f8fb3368SJohn Marino &len) == 0) {
141*f8fb3368SJohn Marino LIBELF_SET_ERROR(ARCHIVE, 0);
142*f8fb3368SJohn Marino return (NULL);
143*f8fb3368SJohn Marino }
144*f8fb3368SJohn Marino
145*f8fb3368SJohn Marino /*
146*f8fb3368SJohn Marino * Allocate space for the file name plus a
147*f8fb3368SJohn Marino * trailing NUL.
148*f8fb3368SJohn Marino */
149*f8fb3368SJohn Marino if ((s = malloc(len + 1)) == NULL) {
150*f8fb3368SJohn Marino LIBELF_SET_ERROR(RESOURCE, 0);
151*f8fb3368SJohn Marino return (NULL);
152*f8fb3368SJohn Marino }
153*f8fb3368SJohn Marino
154*f8fb3368SJohn Marino /*
155*f8fb3368SJohn Marino * The file name follows the archive header.
156*f8fb3368SJohn Marino */
157*f8fb3368SJohn Marino q = (const unsigned char *) (arh + 1);
158*f8fb3368SJohn Marino
159*f8fb3368SJohn Marino (void) strncpy(s, (const char *) q, len);
160*f8fb3368SJohn Marino s[len] = '\0';
161*f8fb3368SJohn Marino
162*f8fb3368SJohn Marino return (s);
163*f8fb3368SJohn Marino }
164*f8fb3368SJohn Marino
165*f8fb3368SJohn Marino /*
166*f8fb3368SJohn Marino * A 'normal' name.
167*f8fb3368SJohn Marino *
168*f8fb3368SJohn Marino * Skip back over trailing blanks from the end of the field.
169*f8fb3368SJohn Marino * In the SVR4 format, a '/' is used as a terminator for
170*f8fb3368SJohn Marino * non-special names.
171*f8fb3368SJohn Marino */
172*f8fb3368SJohn Marino for (q = buf + bufsize - 1; q >= buf && *q == ' '; --q)
173*f8fb3368SJohn Marino ;
174*f8fb3368SJohn Marino
175*f8fb3368SJohn Marino if (q >= buf) {
176*f8fb3368SJohn Marino if (*q == '/') {
177*f8fb3368SJohn Marino /*
178*f8fb3368SJohn Marino * SVR4 style names: ignore the trailing
179*f8fb3368SJohn Marino * character '/', but only if the name is not
180*f8fb3368SJohn Marino * one of the special names "/" and "//".
181*f8fb3368SJohn Marino */
182*f8fb3368SJohn Marino if (q > buf + 1 ||
183*f8fb3368SJohn Marino (q == (buf + 1) && *buf != '/'))
184*f8fb3368SJohn Marino q--;
185*f8fb3368SJohn Marino }
186*f8fb3368SJohn Marino
187*f8fb3368SJohn Marino len = (size_t) (q - buf + 2); /* Space for a trailing NUL. */
188*f8fb3368SJohn Marino } else {
189*f8fb3368SJohn Marino /* The buffer only had blanks. */
190*f8fb3368SJohn Marino buf = (const unsigned char *) "";
191*f8fb3368SJohn Marino len = 1;
192*f8fb3368SJohn Marino }
193*f8fb3368SJohn Marino
194*f8fb3368SJohn Marino if ((s = malloc(len)) == NULL) {
195*f8fb3368SJohn Marino LIBELF_SET_ERROR(RESOURCE, 0);
196*f8fb3368SJohn Marino return (NULL);
197*f8fb3368SJohn Marino }
198*f8fb3368SJohn Marino
199*f8fb3368SJohn Marino (void) strncpy(s, (const char *) buf, len - 1);
200*f8fb3368SJohn Marino s[len - 1] = '\0';
201*f8fb3368SJohn Marino
202*f8fb3368SJohn Marino return (s);
203*f8fb3368SJohn Marino }
204*f8fb3368SJohn Marino
205*f8fb3368SJohn Marino /*
206*f8fb3368SJohn Marino * Return the raw name for an archive member, inclusive of any
207*f8fb3368SJohn Marino * formatting characters.
208*f8fb3368SJohn Marino */
209*f8fb3368SJohn Marino char *
_libelf_ar_get_raw_name(const struct ar_hdr * arh)210*f8fb3368SJohn Marino _libelf_ar_get_raw_name(const struct ar_hdr *arh)
211*f8fb3368SJohn Marino {
212*f8fb3368SJohn Marino char *rawname;
213*f8fb3368SJohn Marino const size_t namesz = sizeof(arh->ar_name);
214*f8fb3368SJohn Marino
215*f8fb3368SJohn Marino if ((rawname = malloc(namesz + 1)) == NULL) {
216*f8fb3368SJohn Marino LIBELF_SET_ERROR(RESOURCE, 0);
217*f8fb3368SJohn Marino return (NULL);
218*f8fb3368SJohn Marino }
219*f8fb3368SJohn Marino
220*f8fb3368SJohn Marino (void) strncpy(rawname, arh->ar_name, namesz);
221*f8fb3368SJohn Marino rawname[namesz] = '\0';
222*f8fb3368SJohn Marino return (rawname);
223*f8fb3368SJohn Marino }
224*f8fb3368SJohn Marino
225*f8fb3368SJohn Marino /*
226*f8fb3368SJohn Marino * Open an 'ar' archive.
227*f8fb3368SJohn Marino */
228*f8fb3368SJohn Marino Elf *
_libelf_ar_open(Elf * e,int reporterror)229*f8fb3368SJohn Marino _libelf_ar_open(Elf *e, int reporterror)
230*f8fb3368SJohn Marino {
231*f8fb3368SJohn Marino size_t sz;
232*f8fb3368SJohn Marino int scanahead;
233*f8fb3368SJohn Marino struct ar_hdr arh;
234*f8fb3368SJohn Marino unsigned char *s, *end;
235*f8fb3368SJohn Marino
236*f8fb3368SJohn Marino _libelf_init_elf(e, ELF_K_AR);
237*f8fb3368SJohn Marino
238*f8fb3368SJohn Marino e->e_u.e_ar.e_nchildren = 0;
239*f8fb3368SJohn Marino e->e_u.e_ar.e_next = (off_t) -1;
240*f8fb3368SJohn Marino
241*f8fb3368SJohn Marino /*
242*f8fb3368SJohn Marino * Look for special members.
243*f8fb3368SJohn Marino */
244*f8fb3368SJohn Marino
245*f8fb3368SJohn Marino s = e->e_rawfile + SARMAG;
246*f8fb3368SJohn Marino end = e->e_rawfile + e->e_rawsize;
247*f8fb3368SJohn Marino
248*f8fb3368SJohn Marino assert(e->e_rawsize > 0);
249*f8fb3368SJohn Marino
250*f8fb3368SJohn Marino /*
251*f8fb3368SJohn Marino * We use heuristics to determine the flavor of the archive we
252*f8fb3368SJohn Marino * are examining.
253*f8fb3368SJohn Marino *
254*f8fb3368SJohn Marino * SVR4 flavor archives use the name "/ " and "// " for
255*f8fb3368SJohn Marino * special members.
256*f8fb3368SJohn Marino *
257*f8fb3368SJohn Marino * In BSD flavor archives the symbol table, if present, is the
258*f8fb3368SJohn Marino * first archive with name "__.SYMDEF".
259*f8fb3368SJohn Marino */
260*f8fb3368SJohn Marino
261*f8fb3368SJohn Marino #define READ_AR_HEADER(S, ARH, SZ, END) \
262*f8fb3368SJohn Marino do { \
263*f8fb3368SJohn Marino if ((S) + sizeof((ARH)) > (END)) \
264*f8fb3368SJohn Marino goto error; \
265*f8fb3368SJohn Marino (void) memcpy(&(ARH), (S), sizeof((ARH))); \
266*f8fb3368SJohn Marino if ((ARH).ar_fmag[0] != '`' || (ARH).ar_fmag[1] != '\n') \
267*f8fb3368SJohn Marino goto error; \
268*f8fb3368SJohn Marino if (_libelf_ar_get_number((char *) (ARH).ar_size, \
269*f8fb3368SJohn Marino sizeof((ARH).ar_size), 10, &(SZ)) == 0) \
270*f8fb3368SJohn Marino goto error; \
271*f8fb3368SJohn Marino } while (0)
272*f8fb3368SJohn Marino
273*f8fb3368SJohn Marino READ_AR_HEADER(s, arh, sz, end);
274*f8fb3368SJohn Marino
275*f8fb3368SJohn Marino /*
276*f8fb3368SJohn Marino * Handle special archive members for the SVR4 format.
277*f8fb3368SJohn Marino */
278*f8fb3368SJohn Marino if (arh.ar_name[0] == '/') {
279*f8fb3368SJohn Marino if (sz == 0)
280*f8fb3368SJohn Marino goto error;
281*f8fb3368SJohn Marino
282*f8fb3368SJohn Marino e->e_flags |= LIBELF_F_AR_VARIANT_SVR4;
283*f8fb3368SJohn Marino
284*f8fb3368SJohn Marino scanahead = 0;
285*f8fb3368SJohn Marino
286*f8fb3368SJohn Marino /*
287*f8fb3368SJohn Marino * The symbol table (file name "/ ") always comes before the
288*f8fb3368SJohn Marino * string table (file name "// ").
289*f8fb3368SJohn Marino */
290*f8fb3368SJohn Marino if (arh.ar_name[1] == ' ') {
291*f8fb3368SJohn Marino /* "/ " => symbol table. */
292*f8fb3368SJohn Marino scanahead = 1; /* The string table to follow. */
293*f8fb3368SJohn Marino
294*f8fb3368SJohn Marino s += sizeof(arh);
295*f8fb3368SJohn Marino e->e_u.e_ar.e_rawsymtab = s;
296*f8fb3368SJohn Marino e->e_u.e_ar.e_rawsymtabsz = sz;
297*f8fb3368SJohn Marino
298*f8fb3368SJohn Marino sz = LIBELF_ADJUST_AR_SIZE(sz);
299*f8fb3368SJohn Marino s += sz;
300*f8fb3368SJohn Marino
301*f8fb3368SJohn Marino } else if (arh.ar_name[1] == '/' && arh.ar_name[2] == ' ') {
302*f8fb3368SJohn Marino /* "// " => string table for long file names. */
303*f8fb3368SJohn Marino s += sizeof(arh);
304*f8fb3368SJohn Marino e->e_u.e_ar.e_rawstrtab = s;
305*f8fb3368SJohn Marino e->e_u.e_ar.e_rawstrtabsz = sz;
306*f8fb3368SJohn Marino
307*f8fb3368SJohn Marino sz = LIBELF_ADJUST_AR_SIZE(sz);
308*f8fb3368SJohn Marino s += sz;
309*f8fb3368SJohn Marino }
310*f8fb3368SJohn Marino
311*f8fb3368SJohn Marino /*
312*f8fb3368SJohn Marino * If the string table hasn't been seen yet, look for
313*f8fb3368SJohn Marino * it in the next member.
314*f8fb3368SJohn Marino */
315*f8fb3368SJohn Marino if (scanahead) {
316*f8fb3368SJohn Marino READ_AR_HEADER(s, arh, sz, end);
317*f8fb3368SJohn Marino
318*f8fb3368SJohn Marino /* "// " => string table for long file names. */
319*f8fb3368SJohn Marino if (arh.ar_name[0] == '/' && arh.ar_name[1] == '/' &&
320*f8fb3368SJohn Marino arh.ar_name[2] == ' ') {
321*f8fb3368SJohn Marino
322*f8fb3368SJohn Marino s += sizeof(arh);
323*f8fb3368SJohn Marino
324*f8fb3368SJohn Marino e->e_u.e_ar.e_rawstrtab = s;
325*f8fb3368SJohn Marino e->e_u.e_ar.e_rawstrtabsz = sz;
326*f8fb3368SJohn Marino
327*f8fb3368SJohn Marino sz = LIBELF_ADJUST_AR_SIZE(sz);
328*f8fb3368SJohn Marino s += sz;
329*f8fb3368SJohn Marino }
330*f8fb3368SJohn Marino }
331*f8fb3368SJohn Marino } else if (strncmp(arh.ar_name, LIBELF_AR_BSD_SYMTAB_NAME,
332*f8fb3368SJohn Marino sizeof(LIBELF_AR_BSD_SYMTAB_NAME) - 1) == 0) {
333*f8fb3368SJohn Marino /*
334*f8fb3368SJohn Marino * BSD style archive symbol table.
335*f8fb3368SJohn Marino */
336*f8fb3368SJohn Marino s += sizeof(arh);
337*f8fb3368SJohn Marino e->e_u.e_ar.e_rawsymtab = s;
338*f8fb3368SJohn Marino e->e_u.e_ar.e_rawsymtabsz = sz;
339*f8fb3368SJohn Marino
340*f8fb3368SJohn Marino sz = LIBELF_ADJUST_AR_SIZE(sz);
341*f8fb3368SJohn Marino s += sz;
342*f8fb3368SJohn Marino }
343*f8fb3368SJohn Marino
344*f8fb3368SJohn Marino /*
345*f8fb3368SJohn Marino * Update the 'next' offset, so that a subsequent elf_begin()
346*f8fb3368SJohn Marino * works as expected.
347*f8fb3368SJohn Marino */
348*f8fb3368SJohn Marino e->e_u.e_ar.e_next = (off_t) (s - e->e_rawfile);
349*f8fb3368SJohn Marino
350*f8fb3368SJohn Marino return (e);
351*f8fb3368SJohn Marino
352*f8fb3368SJohn Marino error:
353*f8fb3368SJohn Marino if (!reporterror) {
354*f8fb3368SJohn Marino e->e_kind = ELF_K_NONE;
355*f8fb3368SJohn Marino return (e);
356*f8fb3368SJohn Marino }
357*f8fb3368SJohn Marino
358*f8fb3368SJohn Marino LIBELF_SET_ERROR(ARCHIVE, 0);
359*f8fb3368SJohn Marino return (NULL);
360*f8fb3368SJohn Marino }
361