1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
|
/* $OpenBSD: nlist.c,v 1.20 2001/01/25 05:40:28 art Exp $ */
/*-
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
#if 0
static char sccsid[] = "from: @(#)nlist.c 8.1 (Berkeley) 6/6/93";
#else
static char *rcsid = "$OpenBSD: nlist.c,v 1.20 2001/01/25 05:40:28 art Exp $";
#endif
#endif /* not lint */
#include <sys/param.h>
#include <a.out.h>
#include <db.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <kvm.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "extern.h"
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/file.h>
#include <sys/sysctl.h>
#ifdef _NLIST_DO_ELF
#include <elf_abi.h>
#endif
#ifdef _NLIST_DO_ECOFF
#include <sys/exec_ecoff.h>
#endif
typedef struct nlist NLIST;
#define _strx n_un.n_strx
#define _name n_un.n_name
static char *kfile;
static char *fmterr;
#if defined(_NLIST_DO_AOUT)
static u_long get_kerntext __P((char *kfn, u_int magic));
int
__aout_knlist(fd, db)
int fd;
DB *db;
{
register int nsyms;
struct exec ebuf;
FILE *fp;
NLIST nbuf;
DBT data, key;
int nr, strsize;
size_t len;
u_long kerntextoff;
size_t snamesize = 0;
char *strtab, buf[1024], *sname, *p;
/* Read in exec structure. */
nr = read(fd, &ebuf, sizeof(struct exec));
if (nr != sizeof(struct exec)) {
fmterr = "no exec header";
return (1);
}
/* Check magic number and symbol count. */
if (N_BADMAG(ebuf)) {
fmterr = "bad magic number";
return (1);
}
/* Must have a symbol table. */
if (!ebuf.a_syms) {
fmterr = "stripped";
return (-1);
}
/* Seek to string table. */
if (lseek(fd, N_STROFF(ebuf), SEEK_SET) == -1) {
fmterr = "corrupted string table";
return (-1);
}
/* Read in the size of the string table. */
nr = read(fd, (char *)&strsize, sizeof(strsize));
if (nr != sizeof(strsize)) {
fmterr = "no symbol table";
return (-1);
}
/* Read in the string table. */
strsize -= sizeof(strsize);
if (!(strtab = malloc(strsize)))
errx(1, "cannot allocate %d bytes for string table", strsize);
if ((nr = read(fd, strtab, strsize)) != strsize) {
fmterr = "corrupted symbol table";
return (-1);
}
/* Seek to symbol table. */
if (!(fp = fdopen(fd, "r")))
err(1, "%s", kfile);
if (fseek(fp, N_SYMOFF(ebuf), SEEK_SET) == -1) {
warn("fseek %s", kfile);
return (-1);
}
data.data = (u_char *)&nbuf;
data.size = sizeof(NLIST);
kerntextoff = get_kerntext(kfile, N_GETMAGIC(ebuf));
/* Read each symbol and enter it into the database. */
nsyms = ebuf.a_syms / sizeof(struct nlist);
sname = NULL;
while (nsyms--) {
if (fread((char *)&nbuf, sizeof (NLIST), 1, fp) != 1) {
if (feof(fp))
fmterr = "corrupted symbol table";
else
warn("%s", kfile);
return (-1);
}
if (!nbuf._strx || (nbuf.n_type & N_STAB))
continue;
/* If the symbol does not start with '_', add one */
p = strtab + nbuf._strx - sizeof(int);
if (*p != '_') {
len = strlen(p) + 1;
if (len >= snamesize)
sname = realloc(sname, len + 1024);
if (sname == NULL)
errx(1, "cannot allocate memory");
*sname = '_';
strcpy(sname+1, p);
key.data = (u_char *)sname;
key.size = len;
} else {
key.data = (u_char *)p;
key.size = strlen((char *)key.data);
}
if (db->put(db, &key, &data, 0))
err(1, "record enter");
if (strcmp((char *)key.data, VRS_SYM) == 0) {
long cur_off = -1;
if (ebuf.a_data && ebuf.a_text > __LDPGSZ) {
/*
* Calculate offset relative to a normal
* (non-kernel) a.out. Kerntextoff is where the
* kernel is really loaded; N_TXTADDR is where
* a normal file is loaded. From there, locate
* file offset in text or data.
*/
long voff;
voff = nbuf.n_value-kerntextoff+N_TXTADDR(ebuf);
if ((nbuf.n_type & N_TYPE) == N_TEXT)
voff += N_TXTOFF(ebuf)-N_TXTADDR(ebuf);
else
voff += N_DATOFF(ebuf)-N_DATADDR(ebuf);
cur_off = ftell(fp);
if (fseek(fp, voff, SEEK_SET) == -1) {
fmterr = "corrupted string table";
return (-1);
}
/*
* Read version string up to, and including
* newline. This code assumes that a newline
* terminates the version line.
*/
if (fgets(buf, sizeof(buf), fp) == NULL) {
fmterr = "corrupted string table";
return (-1);
}
} else {
/*
* No data segment and text is __LDPGSZ.
* This must be /dev/ksyms or a look alike.
* Use sysctl() to get version since we
* don't have real text or data.
*/
int mib[2];
mib[0] = CTL_KERN;
mib[1] = KERN_VERSION;
len = sizeof(buf);
if (sysctl(mib, 2, buf, &len, NULL, 0) == -1) {
err(1, "sysctl can't find kernel "
"version string");
}
if ((p = strchr(buf, '\n')) != NULL)
*(p+1) = '\0';
}
key.data = (u_char *)VRS_KEY;
key.size = sizeof(VRS_KEY) - 1;
data.data = (u_char *)buf;
data.size = strlen(buf);
if (db->put(db, &key, &data, 0))
err(1, "record enter");
/* Restore to original values. */
data.data = (u_char *)&nbuf;
data.size = sizeof(NLIST);
if (cur_off != -1 && fseek(fp, cur_off, SEEK_SET) == -1) {
fmterr = "corrupted string table";
return (-1);
}
}
}
(void)fclose(fp);
return (0);
}
/*
* XXX: Using this value from machine/param.h introduces a
* XXX: machine dependency on this program, so /usr can not
* XXX: be shared between (i.e.) several m68k machines.
* Instead of compiling in KERNTEXTOFF or KERNBASE, try to
* determine the text start address from a standard symbol.
* For backward compatibility, use the old compiled-in way
* when the standard symbol name is not found.
*/
#ifndef KERNTEXTOFF
#define KERNTEXTOFF KERNBASE
#endif
static u_long
get_kerntext(name, magic)
char *name;
u_int magic;
{
NLIST nl[2];
bzero((caddr_t)nl, sizeof(nl));
nl[0]._name = "_kernel_text";
if (nlist(name, nl) != 0)
return (KERNTEXTOFF);
return (nl[0].n_value);
}
#endif /* _NLIST_DO_AOUT */
#ifdef _NLIST_DO_ELF
int
__elf_knlist(fd, db)
int fd;
DB *db;
{
register caddr_t strtab;
register off_t symstroff, symoff;
register u_long symsize;
register u_long kernvma, kernoffs;
register int i;
Elf_Sym sbuf;
size_t symstrsize;
char *shstr, buf[1024];
Elf_Ehdr eh;
Elf_Shdr *sh = NULL;
DBT data, key;
NLIST nbuf;
FILE *fp;
if ((fp = fdopen(fd, "r")) < 0)
err(1, "%s", kfile);
if (fseek(fp, (off_t)0, SEEK_SET) == -1 ||
fread(&eh, sizeof(eh), 1, fp) != 1 ||
!IS_ELF(eh))
return (1);
sh = (Elf_Shdr *)malloc(sizeof(Elf_Shdr) * eh.e_shnum);
if (sh == NULL)
errx(1, "cannot allocate %d bytes for symbol header",
sizeof(Elf_Shdr) * eh.e_shnum);
if (fseek (fp, eh.e_shoff, SEEK_SET) < 0) {
fmterr = "no exec header";
return (-1);
}
if (fread(sh, sizeof(Elf_Shdr) * eh.e_shnum, 1, fp) != 1) {
fmterr = "no exec header";
return (-1);
}
shstr = (char *)malloc(sh[eh.e_shstrndx].sh_size);
if (shstr == NULL)
errx(1, "cannot allocate %d bytes for symbol string",
sh[eh.e_shstrndx].sh_size);
if (fseek (fp, sh[eh.e_shstrndx].sh_offset, SEEK_SET) < 0) {
fmterr = "corrupt file";
return (-1);
}
if (fread(shstr, sh[eh.e_shstrndx].sh_size, 1, fp) != 1) {
fmterr = "corrupt file";
return (-1);
}
for (i = 0; i < eh.e_shnum; i++) {
if (strcmp (shstr + sh[i].sh_name, ".strtab") == 0) {
symstroff = sh[i].sh_offset;
symstrsize = sh[i].sh_size;
}
else if (strcmp (shstr + sh[i].sh_name, ".symtab") == 0) {
symoff = sh[i].sh_offset;
symsize = sh[i].sh_size;
}
else if (strcmp (shstr + sh[i].sh_name, ".text") == 0) {
kernvma = sh[i].sh_addr;
kernoffs = sh[i].sh_offset;
}
}
/* Check for files too large to mmap. */
/* XXX is this really possible? */
if (symstrsize > SIZE_T_MAX) {
fmterr = "corrupt file";
return (-1);
}
/*
* Map string table into our address space. This gives us
* an easy way to randomly access all the strings, without
* making the memory allocation permanent as with malloc/free
* (i.e., munmap will return it to the system).
*/
strtab = mmap(NULL, (size_t)symstrsize, PROT_READ,
MAP_PRIVATE|MAP_FILE, fileno(fp), symstroff);
if (strtab == (char *)-1) {
fmterr = "corrupt file";
return (-1);
}
if (fseek(fp, symoff, SEEK_SET) == -1) {
fmterr = "corrupt file";
return (-1);
}
data.data = (u_char *)&nbuf;
data.size = sizeof(NLIST);
/* Read each symbol and enter it into the database. */
while (symsize > 0) {
symsize -= sizeof(Elf_Sym);
if (fread((char *)&sbuf, sizeof(sbuf), 1, fp) != 1) {
if (feof(fp))
fmterr = "corrupted symbol table";
else
warn("%s", kfile);
return (-1);
}
if (!sbuf.st_name)
continue;
nbuf.n_value = sbuf.st_value;
/*XXX type conversion is pretty rude... */
switch(ELF_ST_TYPE(sbuf.st_info)) {
case STT_NOTYPE:
nbuf.n_type = N_UNDF;
break;
case STT_FUNC:
nbuf.n_type = N_TEXT;
break;
case STT_OBJECT:
nbuf.n_type = N_DATA;
break;
}
if(ELF_ST_BIND(sbuf.st_info) == STB_LOCAL)
nbuf.n_type = N_EXT;
if(eh.e_machine == EM_MIPS) {
*buf = '_';
strcpy(buf+1,strtab + sbuf.st_name);
key.data = (u_char *)buf;
}
else {
key.data = (u_char *)(strtab + sbuf.st_name);
}
key.size = strlen((char *)key.data);
if (db->put(db, &key, &data, 0))
err(1, "record enter");
if (strcmp((char *)key.data, VRS_SYM) == 0) {
long cur_off, voff;
/*
* Calculate offset to the version string in the
* file. kernvma is where the kernel is really
* loaded; kernoffs is where in the file it starts.
*/
voff = nbuf.n_value - kernvma + kernoffs;
cur_off = ftell(fp);
if (fseek(fp, voff, SEEK_SET) == -1) {
fmterr = "corrupted string table";
return (-1);
}
/*
* Read version string up to, and including newline.
* This code assumes that a newline terminates the
* version line.
*/
if (fgets(buf, sizeof(buf), fp) == NULL) {
fmterr = "corrupted string table";
return (-1);
}
key.data = (u_char *)VRS_KEY;
key.size = sizeof(VRS_KEY) - 1;
data.data = (u_char *)buf;
data.size = strlen(buf);
if (db->put(db, &key, &data, 0))
err(1, "record enter");
/* Restore to original values. */
data.data = (u_char *)&nbuf;
data.size = sizeof(NLIST);
if (fseek(fp, cur_off, SEEK_SET) == -1) {
fmterr = "corrupted string table";
return (-1);
}
}
}
munmap(strtab, symstrsize);
(void)fclose(fp);
return (0);
}
#endif /* _NLIST_DO_ELF */
#ifdef _NLIST_DO_ECOFF
#define check(off, size) ((off < 0) || (off + size > mappedsize))
#define BAD do { rv = -1; goto out; } while (0)
#define BADUNMAP do { rv = -1; goto unmap; } while (0)
#define ECOFF_INTXT(p, e) ((p) > (e)->a.text_start && \
(p) < (e)->a.text_start + (e)->a.tsize)
#define ECOFF_INDAT(p, e) ((p) > (e)->a.data_start && \
(p) < (e)->a.data_start + (e)->a.dsize)
int
__ecoff_knlist(fd, db)
int fd;
DB *db;
{
struct ecoff_exechdr *exechdrp;
struct ecoff_symhdr *symhdrp;
struct ecoff_extsym *esyms;
struct stat st;
char *mappedfile, *cp;
size_t mappedsize;
u_long symhdroff, extstroff, off;
u_int symhdrsize;
int rv = 0;
long i, nesyms;
DBT data, key;
NLIST nbuf;
char *sname = NULL;
size_t len, snamesize = 0;
if (fstat(fd, &st) < 0)
err(1, "can't stat %s", kfile);
if (st.st_size > SIZE_T_MAX) {
fmterr = "file too large";
BAD;
}
mappedsize = st.st_size;
mappedfile = mmap(NULL, mappedsize, PROT_READ, MAP_COPY|MAP_FILE, fd, 0);
if (mappedfile == MAP_FAILED) {
fmterr = "unable to mmap";
BAD;
}
if (check(0, sizeof *exechdrp))
BADUNMAP;
exechdrp = (struct ecoff_exechdr *)&mappedfile[0];
if (ECOFF_BADMAG(exechdrp))
BADUNMAP;
symhdroff = exechdrp->f.f_symptr;
symhdrsize = exechdrp->f.f_nsyms;
if (symhdrsize == 0) {
fmterr = "stripped";
return (-1);
}
if (check(symhdroff, sizeof *symhdrp) ||
sizeof *symhdrp != symhdrsize)
BADUNMAP;
symhdrp = (struct ecoff_symhdr *)&mappedfile[symhdroff];
nesyms = symhdrp->esymMax;
if (check(symhdrp->cbExtOffset, nesyms * sizeof *esyms))
BADUNMAP;
esyms = (struct ecoff_extsym *)&mappedfile[symhdrp->cbExtOffset];
extstroff = symhdrp->cbSsExtOffset;
data.data = (u_char *)&nbuf;
data.size = sizeof(NLIST);
for (sname = NULL, i = 0; i < nesyms; i++) {
/* Need to prepend a '_' */
len = strlen(&mappedfile[extstroff + esyms[i].es_strindex]) + 1;
if (len >= snamesize)
sname = realloc(sname, len + 1024);
if (sname == NULL)
errx(1, "cannot allocate memory");
*sname = '_';
strcpy(sname+1, &mappedfile[extstroff + esyms[i].es_strindex]);
/* Fill in NLIST */
bzero(&nbuf, sizeof(nbuf));
nbuf.n_value = esyms[i].es_value;
nbuf.n_type = N_EXT; /* XXX */
/* Store entry in db */
key.data = (u_char *)sname;
key.size = strlen(sname);
if (db->put(db, &key, &data, 0))
err(1, "record enter");
if (strcmp(sname, VRS_SYM) == 0) {
key.data = (u_char *)VRS_KEY;
key.size = sizeof(VRS_KEY) - 1;
/* Version string may be in either text or data segs */
if (ECOFF_INTXT(nbuf.n_value, exechdrp))
off = nbuf.n_value - exechdrp->a.text_start +
ECOFF_TXTOFF(exechdrp);
else if (ECOFF_INDAT(nbuf.n_value, exechdrp))
off = nbuf.n_value - exechdrp->a.data_start +
ECOFF_DATOFF(exechdrp);
else
err(1, "unable to find version string");
/* Version string should end in newline but... */
data.data = &mappedfile[off];
if ((cp = strchr(data.data, '\n')) != NULL)
data.size = cp - (char *)data.data;
else
data.size = strlen((char *)data.data);
if (db->put(db, &key, &data, 0))
err(1, "record enter");
/* Restore to original values */
data.data = (u_char *)&nbuf;
data.size = sizeof(nbuf);
}
}
unmap:
munmap(mappedfile, mappedsize);
out:
return (rv);
}
#endif /* _NLIST_DO_ECOFF */
static struct knlist_handlers {
int (*fn) __P((int fd, DB *db));
} nlist_fn[] = {
#ifdef _NLIST_DO_AOUT
{ __aout_knlist },
#endif
#ifdef _NLIST_DO_ELF
{ __elf_knlist },
#endif
#ifdef _NLIST_DO_ECOFF
{ __ecoff_knlist },
#endif
};
int
create_knlist(name, fd, db)
char *name;
int fd;
DB *db;
{
int i, error;
for (i = 0; i < sizeof(nlist_fn)/sizeof(nlist_fn[0]); i++) {
fmterr = NULL;
kfile = name;
/* rval of 1 means wrong executable type */
if ((error = (nlist_fn[i].fn)(fd, db)) != 1)
break;
}
if (fmterr != NULL)
warnx("%s: %s: %s", kfile, fmterr, strerror(EFTYPE));
return(error);
}
|