1/*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License, Version 1.0 only
6 * (the "License"). You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22/*
23 * Copyright 2003 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27#pragma ident "%Z%%M% %I% %E% SMI"
28
29#if HAVE_NBTOOL_CONFIG_H
30# include "nbtool_config.h"
31#endif
32
33#include <sys/types.h>
34#include <sys/stat.h>
35#include <sys/mman.h>
36#include <sys/zmod.h>
37#include <ctf_impl.h>
38#include <unistd.h>
39#include <fcntl.h>
40#include <errno.h>
41#ifdef illumos
42#include <dlfcn.h>
43#else
44#include <zlib.h>
45#endif
46#include <gelf.h>
47
48#ifdef illumos
49#ifdef _LP64
50static const char *_libctf_zlib = "/usr/lib/64/libz.so";
51#else
52static const char *_libctf_zlib = "/usr/lib/libz.so";
53#endif
54#endif
55
56static struct {
57 int (*z_uncompress)(uchar_t *, ulong_t *, const uchar_t *, ulong_t);
58 const char *(*z_error)(int);
59 void *z_dlp;
60} zlib;
61
62static size_t _PAGESIZE;
63static size_t _PAGEMASK;
64
65#ifdef illumos
66#pragma init(_libctf_init)
67#else
68void _libctf_init(void) __attribute__ ((constructor));
69#endif
70void
71_libctf_init(void)
72{
73#ifdef illumos
74 const char *p = getenv("LIBCTF_DECOMPRESSOR");
75
76 if (p != NULL)
77 _libctf_zlib = p; /* use alternate decompression library */
78#endif
79
80 _libctf_debug = getenv("LIBCTF_DEBUG") != NULL;
81
82 _PAGESIZE = getpagesize();
83 _PAGEMASK = ~(_PAGESIZE - 1);
84}
85
86/*
87 * Attempt to dlopen the decompression library and locate the symbols of
88 * interest that we will need to call. This information in cached so
89 * that multiple calls to ctf_bufopen() do not need to reopen the library.
90 */
91void *
92ctf_zopen(int *errp)
93{
94#ifdef illumos
95 ctf_dprintf("decompressing CTF data using %s\n", _libctf_zlib);
96
97 if (zlib.z_dlp != NULL)
98 return (zlib.z_dlp); /* library is already loaded */
99
100 if (access(_libctf_zlib, R_OK) == -1)
101 return (ctf_set_open_errno(errp, ECTF_ZMISSING));
102
103 if ((zlib.z_dlp = dlopen(_libctf_zlib, RTLD_LAZY | RTLD_LOCAL)) == NULL)
104 return (ctf_set_open_errno(errp, ECTF_ZINIT));
105
106 zlib.z_uncompress = (int (*)(uchar_t *, ulong_t *, const uchar_t *, ulong_t)) dlsym(zlib.z_dlp, "uncompress");
107 zlib.z_error = (const char *(*)(int)) dlsym(zlib.z_dlp, "zError");
108
109 if (zlib.z_uncompress == NULL || zlib.z_error == NULL) {
110 (void) dlclose(zlib.z_dlp);
111 bzero(&zlib, sizeof (zlib));
112 return (ctf_set_open_errno(errp, ECTF_ZINIT));
113 }
114#else
115 zlib.z_uncompress = uncompress;
116 zlib.z_error = zError;
117
118 /* Dummy return variable as 'no error' */
119 zlib.z_dlp = (void *) (uintptr_t) 1;
120#endif
121
122 return (zlib.z_dlp);
123}
124
125/*
126 * The ctf_bufopen() routine calls these subroutines, defined by <sys/zmod.h>,
127 * which we then patch through to the functions in the decompression library.
128 */
129int
130z_uncompress(void *dst, size_t *dstlen, const void *src, size_t srclen)
131{
132 return (zlib.z_uncompress(dst, (ulong_t *)dstlen, src, srclen));
133}
134
135const char *
136z_strerror(int err)
137{
138 return (zlib.z_error(err));
139}
140
141/*
142 * Convert a 32-bit ELF file header into GElf.
143 */
144static void
145ehdr_to_gelf(const Elf32_Ehdr *src, GElf_Ehdr *dst)
146{
147 bcopy(src->e_ident, dst->e_ident, EI_NIDENT);
148 dst->e_type = src->e_type;
149 dst->e_machine = src->e_machine;
150 dst->e_version = src->e_version;
151 dst->e_entry = (Elf64_Addr)src->e_entry;
152 dst->e_phoff = (Elf64_Off)src->e_phoff;
153 dst->e_shoff = (Elf64_Off)src->e_shoff;
154 dst->e_flags = src->e_flags;
155 dst->e_ehsize = src->e_ehsize;
156 dst->e_phentsize = src->e_phentsize;
157 dst->e_phnum = src->e_phnum;
158 dst->e_shentsize = src->e_shentsize;
159 dst->e_shnum = src->e_shnum;
160 dst->e_shstrndx = src->e_shstrndx;
161}
162
163/*
164 * Convert a 32-bit ELF section header into GElf.
165 */
166static void
167shdr_to_gelf(const Elf32_Shdr *src, GElf_Shdr *dst)
168{
169 dst->sh_name = src->sh_name;
170 dst->sh_type = src->sh_type;
171 dst->sh_flags = src->sh_flags;
172 dst->sh_addr = src->sh_addr;
173 dst->sh_offset = src->sh_offset;
174 dst->sh_size = src->sh_size;
175 dst->sh_link = src->sh_link;
176 dst->sh_info = src->sh_info;
177 dst->sh_addralign = src->sh_addralign;
178 dst->sh_entsize = src->sh_entsize;
179}
180
181/*
182 * In order to mmap a section from the ELF file, we must round down sh_offset
183 * to the previous page boundary, and mmap the surrounding page. We store
184 * the pointer to the start of the actual section data back into sp->cts_data.
185 */
186const void *
187ctf_sect_mmap(ctf_sect_t *sp, int fd)
188{
189 size_t pageoff = sp->cts_offset & ~_PAGEMASK;
190
191 caddr_t base = mmap64(NULL, sp->cts_size + pageoff, PROT_READ,
192 MAP_PRIVATE, fd, sp->cts_offset & _PAGEMASK);
193
194 if (base != MAP_FAILED)
195 sp->cts_data = base + pageoff;
196
197 return (base);
198}
199
200/*
201 * Since sp->cts_data has the adjusted offset, we have to again round down
202 * to get the actual mmap address and round up to get the size.
203 */
204void
205ctf_sect_munmap(const ctf_sect_t *sp)
206{
207 uintptr_t addr = (uintptr_t)sp->cts_data;
208 uintptr_t pageoff = addr & ~_PAGEMASK;
209
210 (void) munmap((void *)(addr - pageoff), sp->cts_size + pageoff);
211}
212
213/*
214 * Open the specified file descriptor and return a pointer to a CTF container.
215 * The file can be either an ELF file or raw CTF file. The caller is
216 * responsible for closing the file descriptor when it is no longer needed.
217 */
218ctf_file_t *
219ctf_fdopen(int fd, int *errp)
220{
221 ctf_sect_t ctfsect, symsect, strsect;
222 ctf_file_t *fp = NULL;
223 size_t shstrndx, shnum;
224
225 struct stat64 st;
226 ssize_t nbytes;
227
228 union {
229 ctf_preamble_t ctf;
230 Elf32_Ehdr e32;
231 GElf_Ehdr e64;
232 } hdr;
233
234 bzero(&ctfsect, sizeof (ctf_sect_t));
235 bzero(&symsect, sizeof (ctf_sect_t));
236 bzero(&strsect, sizeof (ctf_sect_t));
237 bzero(&hdr.ctf, sizeof (hdr));
238
239 if (fstat64(fd, &st) == -1)
240 return (ctf_set_open_errno(errp, errno));
241
242 if ((nbytes = pread64(fd, &hdr.ctf, sizeof (hdr), 0)) <= 0)
243 return (ctf_set_open_errno(errp, nbytes < 0? errno : ECTF_FMT));
244
245 /*
246 * If we have read enough bytes to form a CTF header and the magic
247 * string matches, attempt to interpret the file as raw CTF.
248 */
249 if (nbytes >= (ssize_t) sizeof (ctf_preamble_t) &&
250 hdr.ctf.ctp_magic == CTF_MAGIC) {
251 if (hdr.ctf.ctp_version > CTF_VERSION)
252 return (ctf_set_open_errno(errp, ECTF_CTFVERS));
253
254 ctfsect.cts_data = mmap64(NULL, st.st_size, PROT_READ,
255 MAP_PRIVATE, fd, 0);
256
257 if (ctfsect.cts_data == MAP_FAILED)
258 return (ctf_set_open_errno(errp, errno));
259
260 ctfsect.cts_name = _CTF_SECTION;
261 ctfsect.cts_type = SHT_PROGBITS;
262 ctfsect.cts_flags = SHF_ALLOC;
263 ctfsect.cts_size = (size_t)st.st_size;
264 ctfsect.cts_entsize = 1;
265 ctfsect.cts_offset = 0;
266
267 if ((fp = ctf_bufopen(&ctfsect, NULL, NULL, errp)) == NULL)
268 ctf_sect_munmap(&ctfsect);
269
270 return (fp);
271 }
272
273 /*
274 * If we have read enough bytes to form an ELF header and the magic
275 * string matches, attempt to interpret the file as an ELF file. We
276 * do our own largefile ELF processing, and convert everything to
277 * GElf structures so that clients can operate on any data model.
278 */
279 if (nbytes >= (ssize_t) sizeof (Elf32_Ehdr) &&
280 bcmp(&hdr.e32.e_ident[EI_MAG0], ELFMAG, SELFMAG) == 0) {
281#if BYTE_ORDER == _BIG_ENDIAN
282 uchar_t order = ELFDATA2MSB;
283#else
284 uchar_t order = ELFDATA2LSB;
285#endif
286 GElf_Shdr *sp;
287
288 void *strs_map;
289 size_t strs_mapsz, i;
290 char *strs;
291
292 if (hdr.e32.e_ident[EI_DATA] != order)
293 return (ctf_set_open_errno(errp, ECTF_ENDIAN));
294 if (hdr.e32.e_version != EV_CURRENT)
295 return (ctf_set_open_errno(errp, ECTF_ELFVERS));
296
297 if (hdr.e32.e_ident[EI_CLASS] == ELFCLASS64) {
298 if (nbytes < (ssize_t) sizeof (GElf_Ehdr))
299 return (ctf_set_open_errno(errp, ECTF_FMT));
300 } else {
301 Elf32_Ehdr e32 = hdr.e32;
302 ehdr_to_gelf(&e32, &hdr.e64);
303 }
304
305 shnum = hdr.e64.e_shnum;
306 shstrndx = hdr.e64.e_shstrndx;
307
308 /* Extended ELF sections */
309 if ((shstrndx == SHN_XINDEX) || (shnum == 0)) {
310 if (hdr.e32.e_ident[EI_CLASS] == ELFCLASS32) {
311 Elf32_Shdr x32;
312
313 if (pread64(fd, &x32, sizeof (x32),
314 hdr.e64.e_shoff) != sizeof (x32))
315 return (ctf_set_open_errno(errp,
316 errno));
317
318 shnum = x32.sh_size;
319 shstrndx = x32.sh_link;
320 } else {
321 Elf64_Shdr x64;
322
323 if (pread64(fd, &x64, sizeof (x64),
324 hdr.e64.e_shoff) != sizeof (x64))
325 return (ctf_set_open_errno(errp,
326 errno));
327
328 shnum = x64.sh_size;
329 shstrndx = x64.sh_link;
330 }
331 }
332
333 if (shstrndx >= shnum)
334 return (ctf_set_open_errno(errp, ECTF_CORRUPT));
335
336 nbytes = sizeof (GElf_Shdr) * shnum;
337
338 if ((sp = malloc(nbytes)) == NULL)
339 return (ctf_set_open_errno(errp, errno));
340
341 /*
342 * Read in and convert to GElf the array of Shdr structures
343 * from e_shoff so we can locate sections of interest.
344 */
345 if (hdr.e32.e_ident[EI_CLASS] == ELFCLASS32) {
346 Elf32_Shdr *sp32;
347
348 nbytes = sizeof (Elf32_Shdr) * shnum;
349
350 if ((sp32 = malloc(nbytes)) == NULL || pread64(fd,
351 sp32, nbytes, hdr.e64.e_shoff) != nbytes) {
352 free(sp);
353 free(sp32);
354 return (ctf_set_open_errno(errp, errno));
355 }
356
357 for (i = 0; i < shnum; i++)
358 shdr_to_gelf(&sp32[i], &sp[i]);
359
360 free(sp32);
361
362 } else if (pread64(fd, sp, nbytes, hdr.e64.e_shoff) != nbytes) {
363 free(sp);
364 return (ctf_set_open_errno(errp, errno));
365 }
366
367 /*
368 * Now mmap the section header strings section so that we can
369 * perform string comparison on the section names.
370 */
371 strs_mapsz = sp[shstrndx].sh_size +
372 (sp[shstrndx].sh_offset & ~_PAGEMASK);
373
374 strs_map = mmap64(NULL, strs_mapsz, PROT_READ, MAP_PRIVATE,
375 fd, sp[shstrndx].sh_offset & _PAGEMASK);
376
377 strs = (char *)strs_map +
378 (sp[shstrndx].sh_offset & ~_PAGEMASK);
379
380 if (strs_map == MAP_FAILED) {
381 free(sp);
382 return (ctf_set_open_errno(errp, ECTF_MMAP));
383 }
384
385 /*
386 * Iterate over the section header array looking for the CTF
387 * section and symbol table. The strtab is linked to symtab.
388 */
389 for (i = 0; i < shnum; i++) {
390 const GElf_Shdr *shp = &sp[i];
391 const GElf_Shdr *lhp = &sp[shp->sh_link];
392
393 if (shp->sh_link >= shnum)
394 continue; /* corrupt sh_link field */
395
396 if (shp->sh_name >= sp[shstrndx].sh_size ||
397 lhp->sh_name >= sp[shstrndx].sh_size)
398 continue; /* corrupt sh_name field */
399
400 if (shp->sh_type == SHT_PROGBITS &&
401 strcmp(strs + shp->sh_name, _CTF_SECTION) == 0) {
402 ctfsect.cts_name = strs + shp->sh_name;
403 ctfsect.cts_type = shp->sh_type;
404 ctfsect.cts_flags = shp->sh_flags;
405 ctfsect.cts_size = shp->sh_size;
406 ctfsect.cts_entsize = shp->sh_entsize;
407 ctfsect.cts_offset = (off64_t)shp->sh_offset;
408
409 } else if (shp->sh_type == SHT_SYMTAB) {
410 symsect.cts_name = strs + shp->sh_name;
411 symsect.cts_type = shp->sh_type;
412 symsect.cts_flags = shp->sh_flags;
413 symsect.cts_size = shp->sh_size;
414 symsect.cts_entsize = shp->sh_entsize;
415 symsect.cts_offset = (off64_t)shp->sh_offset;
416
417 strsect.cts_name = strs + lhp->sh_name;
418 strsect.cts_type = lhp->sh_type;
419 strsect.cts_flags = lhp->sh_flags;
420 strsect.cts_size = lhp->sh_size;
421 strsect.cts_entsize = lhp->sh_entsize;
422 strsect.cts_offset = (off64_t)lhp->sh_offset;
423 }
424 }
425
426 free(sp); /* free section header array */
427
428 if (ctfsect.cts_type == SHT_NULL) {
429 (void) munmap(strs_map, strs_mapsz);
430 return (ctf_set_open_errno(errp, ECTF_NOCTFDATA));
431 }
432
433 /*
434 * Now mmap the CTF data, symtab, and strtab sections and
435 * call ctf_bufopen() to do the rest of the work.
436 */
437 if (ctf_sect_mmap(&ctfsect, fd) == MAP_FAILED) {
438 (void) munmap(strs_map, strs_mapsz);
439 return (ctf_set_open_errno(errp, ECTF_MMAP));
440 }
441
442 if (symsect.cts_type != SHT_NULL &&
443 strsect.cts_type != SHT_NULL) {
444 if (ctf_sect_mmap(&symsect, fd) == MAP_FAILED ||
445 ctf_sect_mmap(&strsect, fd) == MAP_FAILED) {
446 (void) ctf_set_open_errno(errp, ECTF_MMAP);
447 goto bad; /* unmap all and abort */
448 }
449 fp = ctf_bufopen(&ctfsect, &symsect, &strsect, errp);
450 } else
451 fp = ctf_bufopen(&ctfsect, NULL, NULL, errp);
452bad:
453 if (fp == NULL) {
454 ctf_sect_munmap(&ctfsect);
455 ctf_sect_munmap(&symsect);
456 ctf_sect_munmap(&strsect);
457 } else
458 fp->ctf_flags |= LCTF_MMAP;
459
460 (void) munmap(strs_map, strs_mapsz);
461 return (fp);
462 }
463
464 return (ctf_set_open_errno(errp, ECTF_FMT));
465}
466
467/*
468 * Open the specified file and return a pointer to a CTF container. The file
469 * can be either an ELF file or raw CTF file. This is just a convenient
470 * wrapper around ctf_fdopen() for callers.
471 */
472ctf_file_t *
473ctf_open(const char *filename, int *errp)
474{
475 ctf_file_t *fp;
476 int fd;
477
478 if ((fd = open64(filename, O_RDONLY)) == -1) {
479 if (errp != NULL)
480 *errp = errno;
481 return (NULL);
482 }
483
484 fp = ctf_fdopen(fd, errp);
485 (void) close(fd);
486 return (fp);
487}
488
489/*
490 * Write the uncompressed CTF data stream to the specified file descriptor.
491 * This is useful for saving the results of dynamic CTF containers.
492 */
493int
494ctf_write(ctf_file_t *fp, int fd)
495{
496 const uchar_t *buf = fp->ctf_base;
497 ssize_t resid = fp->ctf_size;
498 ssize_t len;
499
500 while (resid != 0) {
501 if ((len = write(fd, buf, resid)) <= 0)
502 return (ctf_set_errno(fp, errno));
503 resid -= len;
504 buf += len;
505 }
506
507 return (0);
508}
509
510/*
511 * Set the CTF library client version to the specified version. If version is
512 * zero, we just return the default library version number.
513 */
514int
515ctf_version(int version)
516{
517 if (version < 0) {
518 errno = EINVAL;
519 return (-1);
520 }
521
522 if (version > 0) {
523 if (version > CTF_VERSION) {
524 errno = ENOTSUP;
525 return (-1);
526 }
527 ctf_dprintf("ctf_version: client using version %d\n", version);
528 _libctf_version = version;
529 }
530
531 return (_libctf_version);
532}
533