xref: /freebsd/usr.sbin/pkg/config.c (revision 2f02600abfddfc4e9f20dd384a2e729b451e16bd)
1 /*-
2  * Copyright (c) 2013 Baptiste Daroussin <bapt@FreeBSD.org>
3  * Copyright (c) 2013 Bryan Drewery <bdrewery@FreeBSD.org>
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25  * SUCH DAMAGE.
26  */
27 
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
30 
31 #include <sys/param.h>
32 #include <sys/sbuf.h>
33 #include <sys/elf_common.h>
34 #include <sys/endian.h>
35 
36 #include <assert.h>
37 #include <yaml.h>
38 #include <ctype.h>
39 #include <err.h>
40 #include <errno.h>
41 #include <fcntl.h>
42 #include <gelf.h>
43 #include <inttypes.h>
44 #include <paths.h>
45 #include <stdbool.h>
46 #include <string.h>
47 #include <unistd.h>
48 
49 #include "elf_tables.h"
50 #include "config.h"
51 
52 #define roundup2(x, y)	(((x)+((y)-1))&(~((y)-1))) /* if y is powers of two */
53 
54 struct config_entry {
55 	uint8_t type;
56 	const char *key;
57 	const char *val;
58 	char *value;
59 	bool envset;
60 };
61 
62 static struct config_entry c[] = {
63 	[PACKAGESITE] = {
64 		PKG_CONFIG_STRING,
65 		"PACKAGESITE",
66 		URL_SCHEME_PREFIX "http://pkg.FreeBSD.org/${ABI}/latest",
67 		NULL,
68 		false,
69 	},
70 	[ABI] = {
71 		PKG_CONFIG_STRING,
72 		"ABI",
73 		NULL,
74 		NULL,
75 		false,
76 	},
77 	[MIRROR_TYPE] = {
78 		PKG_CONFIG_STRING,
79 		"MIRROR_TYPE",
80 		"SRV",
81 		NULL,
82 		false,
83 	},
84 	[ASSUME_ALWAYS_YES] = {
85 		PKG_CONFIG_BOOL,
86 		"ASSUME_ALWAYS_YES",
87 		"NO",
88 		NULL,
89 		false,
90 	},
91 	[SIGNATURE_TYPE] = {
92 		PKG_CONFIG_STRING,
93 		"SIGNATURE_TYPE",
94 		NULL,
95 		NULL,
96 		false,
97 	},
98 	[FINGERPRINTS] = {
99 		PKG_CONFIG_STRING,
100 		"FINGERPRINTS",
101 		NULL,
102 		NULL,
103 		false,
104 	},
105 };
106 
107 static const char *
108 elf_corres_to_string(struct _elf_corres *m, int e)
109 {
110 	int i;
111 
112 	for (i = 0; m[i].string != NULL; i++)
113 		if (m[i].elf_nb == e)
114 			return (m[i].string);
115 
116 	return ("unknown");
117 }
118 
119 static const char *
120 aeabi_parse_arm_attributes(void *data, size_t length)
121 {
122 	uint32_t sect_len;
123 	uint8_t *section = data;
124 
125 #define	MOVE(len) do {            \
126 	assert(length >= (len));  \
127 	section += (len);         \
128 	length -= (len);          \
129 } while (0)
130 
131 	if (length == 0 || *section != 'A')
132 		return (NULL);
133 
134 	MOVE(1);
135 
136 	/* Read the section length */
137 	if (length < sizeof(sect_len))
138 		return (NULL);
139 
140 	memcpy(&sect_len, section, sizeof(sect_len));
141 
142 	/*
143 	 * The section length should be no longer than the section it is within
144 	 */
145 	if (sect_len > length)
146 		return (NULL);
147 
148 	MOVE(sizeof(sect_len));
149 
150 	/* Skip the vendor name */
151 	while (length != 0) {
152 		if (*section == '\0')
153 			break;
154 		MOVE(1);
155 	}
156 	if (length == 0)
157 		return (NULL);
158 	MOVE(1);
159 
160 	while (length != 0) {
161 		uint32_t tag_length;
162 
163 	switch(*section) {
164 	case 1: /* Tag_File */
165 		MOVE(1);
166 		if (length < sizeof(tag_length))
167 			return (NULL);
168 		memcpy(&tag_length, section, sizeof(tag_length));
169 		break;
170 	case 2: /* Tag_Section */
171 	case 3: /* Tag_Symbol */
172 	default:
173 		return (NULL);
174 	}
175 	/* At least space for the tag and size */
176 	if (tag_length <= 5)
177 		return (NULL);
178 	tag_length--;
179 	/* Check the tag fits */
180 	if (tag_length > length)
181 		return (NULL);
182 
183 #define  MOVE_TAG(len) do {           \
184 	assert(tag_length >= (len));  \
185 	MOVE(len);                    \
186 	tag_length -= (len);          \
187 } while(0)
188 
189 		MOVE(sizeof(tag_length));
190 		tag_length -= sizeof(tag_length);
191 
192 		while (tag_length != 0) {
193 			uint8_t tag;
194 
195 			assert(tag_length >= length);
196 
197 			tag = *section;
198 			MOVE_TAG(1);
199 
200 			/*
201 			 * These tag values come from:
202 			 *
203 			 * Addenda to, and Errata in, the ABI for the
204 			 * ARM Architecture. Release 2.08, section 2.3.
205 			 */
206 			if (tag == 6) { /* == Tag_CPU_arch */
207 				uint8_t val;
208 
209 				val = *section;
210 				/*
211 				 * We don't support values that require
212 				 * more than one byte.
213 				 */
214 				if (val & (1 << 7))
215 					return (NULL);
216 
217 				/* We have an ARMv4 or ARMv5 */
218 				if (val <= 5)
219 					return ("arm");
220 				else /* We have an ARMv6+ */
221 					return ("armv6");
222 			} else if (tag == 4 || tag == 5 || tag == 32 ||
223 			    tag == 65 || tag == 67) {
224 				while (*section != '\0' && length != 0)
225 					MOVE_TAG(1);
226 				if (tag_length == 0)
227 					return (NULL);
228 				/* Skip the last byte */
229 				MOVE_TAG(1);
230 			} else if ((tag >= 7 && tag <= 31) || tag == 34 ||
231 			    tag == 36 || tag == 38 || tag == 42 || tag == 44 ||
232 			    tag == 64 || tag == 66 || tag == 68 || tag == 70) {
233 				/* Skip the uleb128 data */
234 				while (*section & (1 << 7) && length != 0)
235 					MOVE_TAG(1);
236 				if (tag_length == 0)
237 					return (NULL);
238 				/* Skip the last byte */
239 				MOVE_TAG(1);
240 			} else
241 				return (NULL);
242 #undef MOVE_TAG
243 		}
244 
245 		break;
246 	}
247 	return (NULL);
248 #undef MOVE
249 }
250 
251 static int
252 pkg_get_myabi(char *dest, size_t sz)
253 {
254 	Elf *elf;
255 	Elf_Data *data;
256 	Elf_Note note;
257 	Elf_Scn *scn;
258 	char *src, *osname;
259 	const char *arch, *abi, *fpu, *endian_corres_str;
260 	const char *wordsize_corres_str;
261 	GElf_Ehdr elfhdr;
262 	GElf_Shdr shdr;
263 	int fd, i, ret;
264 	uint32_t version;
265 
266 	version = 0;
267 	ret = -1;
268 	scn = NULL;
269 	abi = NULL;
270 
271 	if (elf_version(EV_CURRENT) == EV_NONE) {
272 		warnx("ELF library initialization failed: %s",
273 		    elf_errmsg(-1));
274 		return (-1);
275 	}
276 
277 	if ((fd = open(_PATH_BSHELL, O_RDONLY)) < 0) {
278 		warn("open()");
279 		return (-1);
280 	}
281 
282 	if ((elf = elf_begin(fd, ELF_C_READ, NULL)) == NULL) {
283 		ret = -1;
284 		warnx("elf_begin() failed: %s.", elf_errmsg(-1));
285 		goto cleanup;
286 	}
287 
288 	if (gelf_getehdr(elf, &elfhdr) == NULL) {
289 		ret = -1;
290 		warn("getehdr() failed: %s.", elf_errmsg(-1));
291 		goto cleanup;
292 	}
293 	while ((scn = elf_nextscn(elf, scn)) != NULL) {
294 		if (gelf_getshdr(scn, &shdr) != &shdr) {
295 			ret = -1;
296 			warn("getshdr() failed: %s.", elf_errmsg(-1));
297 			goto cleanup;
298 		}
299 
300 		if (shdr.sh_type == SHT_NOTE)
301 			break;
302 	}
303 
304 	if (scn == NULL) {
305 		ret = -1;
306 		warn("failed to get the note section");
307 		goto cleanup;
308 	}
309 
310 	data = elf_getdata(scn, NULL);
311 	src = data->d_buf;
312 	for (;;) {
313 		memcpy(&note, src, sizeof(Elf_Note));
314 		src += sizeof(Elf_Note);
315 		if (note.n_type == NT_VERSION)
316 			break;
317 		src += note.n_namesz + note.n_descsz;
318 	}
319 	osname = src;
320 	src += roundup2(note.n_namesz, 4);
321 	if (elfhdr.e_ident[EI_DATA] == ELFDATA2MSB)
322 		version = be32dec(src);
323 	else
324 		version = le32dec(src);
325 
326 	for (i = 0; osname[i] != '\0'; i++)
327 		osname[i] = (char)tolower(osname[i]);
328 
329 	wordsize_corres_str = elf_corres_to_string(wordsize_corres,
330 	    (int)elfhdr.e_ident[EI_CLASS]);
331 
332 	arch = elf_corres_to_string(mach_corres, (int) elfhdr.e_machine);
333 
334 	snprintf(dest, sz, "%s:%d",
335 	    osname, version / 100000);
336 
337 	ret = 0;
338 
339 	switch (elfhdr.e_machine) {
340 	case EM_ARM:
341 		endian_corres_str = elf_corres_to_string(endian_corres,
342 		    (int)elfhdr.e_ident[EI_DATA]);
343 
344 		/* FreeBSD doesn't support the hard-float ABI yet */
345 		fpu = "softfp";
346 		if ((elfhdr.e_flags & 0xFF000000) != 0) {
347 			const char *sh_name = NULL;
348 			size_t shstrndx;
349 
350 			/* This is an EABI file, the conformance level is set */
351 			abi = "eabi";
352 			/* Find which TARGET_ARCH we are building for. */
353 			elf_getshdrstrndx(elf, &shstrndx);
354 			while ((scn = elf_nextscn(elf, scn)) != NULL) {
355 				sh_name = NULL;
356 				if (gelf_getshdr(scn, &shdr) != &shdr) {
357 					scn = NULL;
358 					break;
359 				}
360 
361 				sh_name = elf_strptr(elf, shstrndx,
362 				    shdr.sh_name);
363 				if (sh_name == NULL)
364 					continue;
365 				if (strcmp(".ARM.attributes", sh_name) == 0)
366 					break;
367 			}
368 			if (scn != NULL && sh_name != NULL) {
369 				data = elf_getdata(scn, NULL);
370 				/*
371 				 * Prior to FreeBSD 10.0 libelf would return
372 				 * NULL from elf_getdata on the .ARM.attributes
373 				 * section. As this was the first release to
374 				 * get armv6 support assume a NULL value means
375 				 * arm.
376 				 *
377 				 * This assumption can be removed when 9.x
378 				 * is unsupported.
379 				 */
380 				if (data != NULL) {
381 					arch = aeabi_parse_arm_attributes(
382 					    data->d_buf, data->d_size);
383 					if (arch == NULL) {
384 						ret = 1;
385 						warn("unknown ARM ARCH");
386 						goto cleanup;
387 					}
388 				}
389 			} else {
390 				ret = 1;
391 				warn("Unable to find the .ARM.attributes "
392 				    "section");
393 				goto cleanup;
394 			}
395 		} else if (elfhdr.e_ident[EI_OSABI] != ELFOSABI_NONE) {
396 			/*
397 			 * EABI executables all have this field set to
398 			 * ELFOSABI_NONE, therefore it must be an oabi file.
399 			 */
400 			abi = "oabi";
401 		} else {
402 			ret = 1;
403 			warn("unknown ARM ABI");
404 			goto cleanup;
405 		}
406 		snprintf(dest + strlen(dest), sz - strlen(dest),
407 		    ":%s:%s:%s:%s:%s", arch, wordsize_corres_str,
408 		    endian_corres_str, abi, fpu);
409 		break;
410 	case EM_MIPS:
411 		/*
412 		 * this is taken from binutils sources:
413 		 * include/elf/mips.h
414 		 * mapping is figured out from binutils:
415 		 * gas/config/tc-mips.c
416 		 */
417 		switch (elfhdr.e_flags & EF_MIPS_ABI) {
418 		case E_MIPS_ABI_O32:
419 			abi = "o32";
420 			break;
421 		case E_MIPS_ABI_N32:
422 			abi = "n32";
423 			break;
424 		default:
425 			if (elfhdr.e_ident[EI_DATA] ==
426 			    ELFCLASS32)
427 				abi = "o32";
428 			else if (elfhdr.e_ident[EI_DATA] ==
429 			    ELFCLASS64)
430 				abi = "n64";
431 			break;
432 		}
433 		endian_corres_str = elf_corres_to_string(endian_corres,
434 		    (int)elfhdr.e_ident[EI_DATA]);
435 
436 		snprintf(dest + strlen(dest), sz - strlen(dest), ":%s:%s:%s:%s",
437 		    arch, wordsize_corres_str, endian_corres_str, abi);
438 		break;
439 	default:
440 		snprintf(dest + strlen(dest), sz - strlen(dest), ":%s:%s",
441 		    arch, wordsize_corres_str);
442 	}
443 
444 cleanup:
445 	if (elf != NULL)
446 		elf_end(elf);
447 
448 	close(fd);
449 	return (ret);
450 }
451 
452 static void
453 subst_packagesite(const char *abi)
454 {
455 	struct sbuf *newval;
456 	const char *variable_string;
457 	const char *oldval;
458 
459 	if (c[PACKAGESITE].value != NULL)
460 		oldval = c[PACKAGESITE].value;
461 	else
462 		oldval = c[PACKAGESITE].val;
463 
464 	if ((variable_string = strstr(oldval, "${ABI}")) == NULL)
465 		return;
466 
467 	newval = sbuf_new_auto();
468 	sbuf_bcat(newval, oldval, variable_string - oldval);
469 	sbuf_cat(newval, abi);
470 	sbuf_cat(newval, variable_string + strlen("${ABI}"));
471 	sbuf_finish(newval);
472 
473 	free(c[PACKAGESITE].value);
474 	c[PACKAGESITE].value = strdup(sbuf_data(newval));
475 }
476 
477 static void
478 config_parse(yaml_document_t *doc, yaml_node_t *node, pkg_conf_file_t conftype)
479 {
480 	yaml_node_pair_t *pair;
481 	yaml_node_t *key, *val;
482 	struct sbuf *buf = sbuf_new_auto();
483 	int i;
484 	size_t j;
485 
486 	pair = node->data.mapping.pairs.start;
487 
488 	while (pair < node->data.mapping.pairs.top) {
489 		key = yaml_document_get_node(doc, pair->key);
490 		val = yaml_document_get_node(doc, pair->value);
491 
492 		/*
493 		 * ignoring silently empty keys can be empty lines
494 		 * or user mistakes
495 		 */
496 		if (key->data.scalar.length <= 0) {
497 			++pair;
498 			continue;
499 		}
500 
501 		/*
502 		 * silently skip on purpose to allow user to leave
503 		 * empty lines without complaining
504 		 */
505 		if (val->type == YAML_NO_NODE ||
506 		    (val->type == YAML_SCALAR_NODE &&
507 		     val->data.scalar.length <= 0)) {
508 			++pair;
509 			continue;
510 		}
511 
512 		sbuf_clear(buf);
513 
514 		if (conftype == CONFFILE_PKG) {
515 			for (j = 0; j < strlen(key->data.scalar.value); ++j)
516 				sbuf_putc(buf,
517 				    toupper(key->data.scalar.value[j]));
518 			sbuf_finish(buf);
519 		} else if (conftype == CONFFILE_REPO) {
520 			/* The CONFFILE_REPO type is more restrictive. Only
521 			   parse known elements. */
522 			if (strcasecmp(key->data.scalar.value, "url") == 0)
523 				sbuf_cpy(buf, "PACKAGESITE");
524 			else if (strcasecmp(key->data.scalar.value,
525 			    "mirror_type") == 0)
526 				sbuf_cpy(buf, "MIRROR_TYPE");
527 			else if (strcasecmp(key->data.scalar.value,
528 			    "signature_type") == 0)
529 				sbuf_cpy(buf, "SIGNATURE_TYPE");
530 			else if (strcasecmp(key->data.scalar.value,
531 			    "fingerprints") == 0)
532 				sbuf_cpy(buf, "FINGERPRINTS");
533 			else { /* Skip unknown entries for future use. */
534 				++pair;
535 				continue;
536 			}
537 			sbuf_finish(buf);
538 		}
539 
540 		for (i = 0; i < CONFIG_SIZE; i++) {
541 			if (strcmp(sbuf_data(buf), c[i].key) == 0)
542 				break;
543 		}
544 
545 		/* Silently skip unknown keys to be future compatible. */
546 		if (i == CONFIG_SIZE) {
547 			++pair;
548 			continue;
549 		}
550 
551 		/* env has priority over config file */
552 		if (c[i].envset) {
553 			++pair;
554 			continue;
555 		}
556 
557 		c[i].value = strdup(val->data.scalar.value);
558 		++pair;
559 	}
560 
561 	sbuf_delete(buf);
562 }
563 
564 /*-
565  * Parse new repo style configs in style:
566  * Name:
567  *   URL:
568  *   MIRROR_TYPE:
569  * etc...
570  */
571 static void
572 parse_repo_file(yaml_document_t *doc, yaml_node_t *node)
573 {
574 	yaml_node_pair_t *pair;
575 
576 	pair = node->data.mapping.pairs.start;
577 	while (pair < node->data.mapping.pairs.top) {
578 		yaml_node_t *key = yaml_document_get_node(doc, pair->key);
579 		yaml_node_t *val = yaml_document_get_node(doc, pair->value);
580 
581 		if (key->data.scalar.length <= 0) {
582 			++pair;
583 			continue;
584 		}
585 
586 		if (val->type != YAML_MAPPING_NODE) {
587 			++pair;
588 			continue;
589 		}
590 
591 		config_parse(doc, val, CONFFILE_REPO);
592 		++pair;
593 	}
594 }
595 
596 
597 static int
598 read_conf_file(const char *confpath, pkg_conf_file_t conftype)
599 {
600 	FILE *fp;
601 	yaml_parser_t parser;
602 	yaml_document_t doc;
603 	yaml_node_t *node;
604 
605 	if ((fp = fopen(confpath, "r")) == NULL) {
606 		if (errno != ENOENT)
607 			err(EXIT_FAILURE, "Unable to open configuration "
608 			    "file %s", confpath);
609 		/* no configuration present */
610 		return (1);
611 	}
612 
613 	yaml_parser_initialize(&parser);
614 	yaml_parser_set_input_file(&parser, fp);
615 	yaml_parser_load(&parser, &doc);
616 
617 	node = yaml_document_get_root_node(&doc);
618 
619 	if (node == NULL || node->type != YAML_MAPPING_NODE)
620 		warnx("Invalid configuration format, ignoring the "
621 		    "configuration file %s", confpath);
622 	else {
623 		if (conftype == CONFFILE_PKG)
624 			config_parse(&doc, node, conftype);
625 		else if (conftype == CONFFILE_REPO)
626 			parse_repo_file(&doc, node);
627 	}
628 
629 	yaml_document_delete(&doc);
630 	yaml_parser_delete(&parser);
631 
632 	return (0);
633 }
634 
635 int
636 config_init(void)
637 {
638 	const char *val;
639 	int i;
640 	const char *localbase;
641 	char confpath[MAXPATHLEN];
642 	char abi[BUFSIZ];
643 
644 	for (i = 0; i < CONFIG_SIZE; i++) {
645 		val = getenv(c[i].key);
646 		if (val != NULL) {
647 			c[i].val = val;
648 			c[i].envset = true;
649 		}
650 	}
651 
652 	localbase = getenv("LOCALBASE") ? getenv("LOCALBASE") : _LOCALBASE;
653 	snprintf(confpath, sizeof(confpath), "%s/etc/pkg.conf",
654 	    localbase);
655 
656 	if (access(confpath, F_OK) == 0 && read_conf_file(confpath,
657 	    CONFFILE_PKG))
658 		goto finalize;
659 
660 	snprintf(confpath, sizeof(confpath), "/etc/pkg/FreeBSD.conf");
661 	if (access(confpath, F_OK) == 0 && read_conf_file(confpath,
662 	    CONFFILE_REPO))
663 		goto finalize;
664 
665 finalize:
666 	if (c[ABI].val == NULL && c[ABI].value == NULL) {
667 		if (pkg_get_myabi(abi, BUFSIZ) != 0)
668 			errx(EXIT_FAILURE, "Failed to determine the system "
669 			    "ABI");
670 		c[ABI].val = abi;
671 	}
672 
673 	subst_packagesite(c[ABI].value != NULL ? c[ABI].value : c[ABI].val);
674 
675 	return (0);
676 }
677 
678 int
679 config_string(pkg_config_key k, const char **val)
680 {
681 	if (c[k].type != PKG_CONFIG_STRING)
682 		return (-1);
683 
684 	if (c[k].value != NULL)
685 		*val = c[k].value;
686 	else
687 		*val = c[k].val;
688 
689 	return (0);
690 }
691 
692 int
693 config_bool(pkg_config_key k, bool *val)
694 {
695 	const char *value;
696 
697 	if (c[k].type != PKG_CONFIG_BOOL)
698 		return (-1);
699 
700 	*val = false;
701 
702 	if (c[k].value != NULL)
703 		value = c[k].value;
704 	else
705 		value = c[k].val;
706 
707 	if (strcasecmp(value, "true") == 0 ||
708 	    strcasecmp(value, "yes") == 0 ||
709 	    strcasecmp(value, "on") == 0 ||
710 	    *value == '1')
711 		*val = true;
712 
713 	return (0);
714 }
715 
716 void
717 config_finish(void) {
718 	int i;
719 
720 	for (i = 0; i < CONFIG_SIZE; i++)
721 		free(c[i].value);
722 }
723