xref: /freebsd/usr.sbin/pkg/config.c (revision ce3adf4362fcca6a43e500b2531f0038adbfbd21)
1 /*-
2  * Copyright (c) 2013 Baptiste Daroussin <bapt@FreeBSD.org>
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 __FBSDID("$FreeBSD$");
29 
30 #include <sys/param.h>
31 #include <sys/sbuf.h>
32 #include <sys/elf_common.h>
33 #include <sys/endian.h>
34 
35 #include <assert.h>
36 #include <bsdyml.h>
37 #include <ctype.h>
38 #include <err.h>
39 #include <errno.h>
40 #include <fcntl.h>
41 #include <gelf.h>
42 #include <inttypes.h>
43 #include <paths.h>
44 #include <stdbool.h>
45 #include <string.h>
46 #include <unistd.h>
47 
48 #include "elf_tables.h"
49 #include "config.h"
50 
51 #define roundup2(x, y)	(((x)+((y)-1))&(~((y)-1))) /* if y is powers of two */
52 
53 struct config_entry {
54 	uint8_t type;
55 	const char *key;
56 	const char *val;
57 	char *value;
58 	bool envset;
59 };
60 
61 static struct config_entry c[] = {
62 	[PACKAGESITE] = {
63 		PKG_CONFIG_STRING,
64 		"PACKAGESITE",
65 		"http://pkg.FreeBSD.org/${ABI}/latest",
66 		NULL,
67 		false,
68 	},
69 	[ABI] = {
70 		PKG_CONFIG_STRING,
71 		"ABI",
72 		NULL,
73 		NULL,
74 		false,
75 	},
76 	[MIRROR_TYPE] = {
77 		PKG_CONFIG_STRING,
78 		"MIRROR_TYPE",
79 		"SRV",
80 		NULL,
81 		false,
82 	},
83 	[ASSUME_ALWAYS_YES] = {
84 		PKG_CONFIG_BOOL,
85 		"ASSUME_ALWAYS_YES",
86 		"NO",
87 		NULL,
88 		false,
89 	}
90 };
91 
92 static const char *
93 elf_corres_to_string(struct _elf_corres *m, int e)
94 {
95 	int i;
96 
97 	for (i = 0; m[i].string != NULL; i++)
98 		if (m[i].elf_nb == e)
99 			return (m[i].string);
100 
101 	return ("unknown");
102 }
103 
104 static const char *
105 aeabi_parse_arm_attributes(void *data, size_t length)
106 {
107 	uint32_t sect_len;
108 	uint8_t *section = data;
109 
110 #define	MOVE(len) do {            \
111 	assert(length >= (len));  \
112 	section += (len);         \
113 	length -= (len);          \
114 } while (0)
115 
116 	if (length == 0 || *section != 'A')
117 		return (NULL);
118 
119 	MOVE(1);
120 
121 	/* Read the section length */
122 	if (length < sizeof(sect_len))
123 		return (NULL);
124 
125 	memcpy(&sect_len, section, sizeof(sect_len));
126 
127 	/*
128 	 * The section length should be no longer than the section it is within
129 	 */
130 	if (sect_len > length)
131 		return (NULL);
132 
133 	MOVE(sizeof(sect_len));
134 
135 	/* Skip the vendor name */
136 	while (length != 0) {
137 		if (*section == '\0')
138 			break;
139 		MOVE(1);
140 	}
141 	if (length == 0)
142 		return (NULL);
143 	MOVE(1);
144 
145 	while (length != 0) {
146 		uint32_t tag_length;
147 
148 	switch(*section) {
149 	case 1: /* Tag_File */
150 		MOVE(1);
151 		if (length < sizeof(tag_length))
152 			return (NULL);
153 		memcpy(&tag_length, section, sizeof(tag_length));
154 		break;
155 	case 2: /* Tag_Section */
156 	case 3: /* Tag_Symbol */
157 	default:
158 		return (NULL);
159 	}
160 	/* At least space for the tag and size */
161 	if (tag_length <= 5)
162 		return (NULL);
163 	tag_length--;
164 	/* Check the tag fits */
165 	if (tag_length > length)
166 		return (NULL);
167 
168 #define  MOVE_TAG(len) do {           \
169 	assert(tag_length >= (len));  \
170 	MOVE(len);                    \
171 	tag_length -= (len);          \
172 } while(0)
173 
174 		MOVE(sizeof(tag_length));
175 		tag_length -= sizeof(tag_length);
176 
177 		while (tag_length != 0) {
178 			uint8_t tag;
179 
180 			assert(tag_length >= length);
181 
182 			tag = *section;
183 			MOVE_TAG(1);
184 
185 			/*
186 			 * These tag values come from:
187 			 *
188 			 * Addenda to, and Errata in, the ABI for the
189 			 * ARM Architecture. Release 2.08, section 2.3.
190 			 */
191 			if (tag == 6) { /* == Tag_CPU_arch */
192 				uint8_t val;
193 
194 				val = *section;
195 				/*
196 				 * We don't support values that require
197 				 * more than one byte.
198 				 */
199 				if (val & (1 << 7))
200 					return (NULL);
201 
202 				/* We have an ARMv4 or ARMv5 */
203 				if (val <= 5)
204 					return ("arm");
205 				else /* We have an ARMv6+ */
206 					return ("armv6");
207 			} else if (tag == 4 || tag == 5 || tag == 32 ||
208 			    tag == 65 || tag == 67) {
209 				while (*section != '\0' && length != 0)
210 					MOVE_TAG(1);
211 				if (tag_length == 0)
212 					return (NULL);
213 				/* Skip the last byte */
214 				MOVE_TAG(1);
215 			} else if ((tag >= 7 && tag <= 31) || tag == 34 ||
216 			    tag == 36 || tag == 38 || tag == 42 || tag == 44 ||
217 			    tag == 64 || tag == 66 || tag == 68 || tag == 70) {
218 				/* Skip the uleb128 data */
219 				while (*section & (1 << 7) && length != 0)
220 					MOVE_TAG(1);
221 				if (tag_length == 0)
222 					return (NULL);
223 				/* Skip the last byte */
224 				MOVE_TAG(1);
225 			} else
226 				return (NULL);
227 #undef MOVE_TAG
228 		}
229 
230 		break;
231 	}
232 	return (NULL);
233 #undef MOVE
234 }
235 
236 static int
237 pkg_get_myabi(char *dest, size_t sz)
238 {
239 	Elf *elf;
240 	Elf_Data *data;
241 	Elf_Note note;
242 	Elf_Scn *scn;
243 	char *src, *osname;
244 	const char *arch, *abi, *fpu, *endian_corres_str;
245 	const char *wordsize_corres_str;
246 	GElf_Ehdr elfhdr;
247 	GElf_Shdr shdr;
248 	int fd, i, ret;
249 	uint32_t version;
250 
251 	version = 0;
252 	ret = -1;
253 	scn = NULL;
254 	abi = NULL;
255 
256 	if (elf_version(EV_CURRENT) == EV_NONE) {
257 		warnx("ELF library initialization failed: %s",
258 		    elf_errmsg(-1));
259 		return (-1);
260 	}
261 
262 	if ((fd = open(_PATH_BSHELL, O_RDONLY)) < 0) {
263 		warn("open()");
264 		return (-1);
265 	}
266 
267 	if ((elf = elf_begin(fd, ELF_C_READ, NULL)) == NULL) {
268 		ret = -1;
269 		warnx("elf_begin() failed: %s.", elf_errmsg(-1));
270 		goto cleanup;
271 	}
272 
273 	if (gelf_getehdr(elf, &elfhdr) == NULL) {
274 		ret = -1;
275 		warn("getehdr() failed: %s.", elf_errmsg(-1));
276 		goto cleanup;
277 	}
278 	while ((scn = elf_nextscn(elf, scn)) != NULL) {
279 		if (gelf_getshdr(scn, &shdr) != &shdr) {
280 			ret = -1;
281 			warn("getshdr() failed: %s.", elf_errmsg(-1));
282 			goto cleanup;
283 		}
284 
285 		if (shdr.sh_type == SHT_NOTE)
286 			break;
287 	}
288 
289 	if (scn == NULL) {
290 		ret = -1;
291 		warn("failed to get the note section");
292 		goto cleanup;
293 	}
294 
295 	data = elf_getdata(scn, NULL);
296 	src = data->d_buf;
297 	for (;;) {
298 		memcpy(&note, src, sizeof(Elf_Note));
299 		src += sizeof(Elf_Note);
300 		if (note.n_type == NT_VERSION)
301 			break;
302 		src += note.n_namesz + note.n_descsz;
303 	}
304 	osname = src;
305 	src += roundup2(note.n_namesz, 4);
306 	if (elfhdr.e_ident[EI_DATA] == ELFDATA2MSB)
307 		version = be32dec(src);
308 	else
309 		version = le32dec(src);
310 
311 	for (i = 0; osname[i] != '\0'; i++)
312 		osname[i] = (char)tolower(osname[i]);
313 
314 	wordsize_corres_str = elf_corres_to_string(wordsize_corres,
315 	    (int)elfhdr.e_ident[EI_CLASS]);
316 
317 	arch = elf_corres_to_string(mach_corres, (int) elfhdr.e_machine);
318 
319 	snprintf(dest, sz, "%s:%d",
320 	    osname, version / 100000);
321 
322 	ret = 0;
323 
324 	switch (elfhdr.e_machine) {
325 	case EM_ARM:
326 		endian_corres_str = elf_corres_to_string(endian_corres,
327 		    (int)elfhdr.e_ident[EI_DATA]);
328 
329 		/* FreeBSD doesn't support the hard-float ABI yet */
330 		fpu = "softfp";
331 		if ((elfhdr.e_flags & 0xFF000000) != 0) {
332 			const char *sh_name = NULL;
333 			size_t shstrndx;
334 
335 			/* This is an EABI file, the conformance level is set */
336 			abi = "eabi";
337 			/* Find which TARGET_ARCH we are building for. */
338 			elf_getshdrstrndx(elf, &shstrndx);
339 			while ((scn = elf_nextscn(elf, scn)) != NULL) {
340 				sh_name = NULL;
341 				if (gelf_getshdr(scn, &shdr) != &shdr) {
342 					scn = NULL;
343 					break;
344 				}
345 
346 				sh_name = elf_strptr(elf, shstrndx,
347 				    shdr.sh_name);
348 				if (sh_name == NULL)
349 					continue;
350 				if (strcmp(".ARM.attributes", sh_name) == 0)
351 					break;
352 			}
353 			if (scn != NULL && sh_name != NULL) {
354 				data = elf_getdata(scn, NULL);
355 				/*
356 				 * Prior to FreeBSD 10.0 libelf would return
357 				 * NULL from elf_getdata on the .ARM.attributes
358 				 * section. As this was the first release to
359 				 * get armv6 support assume a NULL value means
360 				 * arm.
361 				 *
362 				 * This assumption can be removed when 9.x
363 				 * is unsupported.
364 				 */
365 				if (data != NULL) {
366 					arch = aeabi_parse_arm_attributes(
367 					    data->d_buf, data->d_size);
368 					if (arch == NULL) {
369 						ret = 1;
370 						warn("unknown ARM ARCH");
371 						goto cleanup;
372 					}
373 				}
374 			} else {
375 				ret = 1;
376 				warn("Unable to find the .ARM.attributes "
377 				    "section");
378 				goto cleanup;
379 			}
380 		} else if (elfhdr.e_ident[EI_OSABI] != ELFOSABI_NONE) {
381 			/*
382 			 * EABI executables all have this field set to
383 			 * ELFOSABI_NONE, therefore it must be an oabi file.
384 			 */
385 			abi = "oabi";
386 		} else {
387 			ret = 1;
388 			warn("unknown ARM ABI");
389 			goto cleanup;
390 		}
391 		snprintf(dest + strlen(dest), sz - strlen(dest),
392 		    ":%s:%s:%s:%s:%s", arch, wordsize_corres_str,
393 		    endian_corres_str, abi, fpu);
394 		break;
395 	case EM_MIPS:
396 		/*
397 		 * this is taken from binutils sources:
398 		 * include/elf/mips.h
399 		 * mapping is figured out from binutils:
400 		 * gas/config/tc-mips.c
401 		 */
402 		switch (elfhdr.e_flags & EF_MIPS_ABI) {
403 		case E_MIPS_ABI_O32:
404 			abi = "o32";
405 			break;
406 		case E_MIPS_ABI_N32:
407 			abi = "n32";
408 			break;
409 		default:
410 			if (elfhdr.e_ident[EI_DATA] ==
411 			    ELFCLASS32)
412 				abi = "o32";
413 			else if (elfhdr.e_ident[EI_DATA] ==
414 			    ELFCLASS64)
415 				abi = "n64";
416 			break;
417 		}
418 		endian_corres_str = elf_corres_to_string(endian_corres,
419 		    (int)elfhdr.e_ident[EI_DATA]);
420 
421 		snprintf(dest + strlen(dest), sz - strlen(dest), ":%s:%s:%s:%s",
422 		    arch, wordsize_corres_str, endian_corres_str, abi);
423 		break;
424 	default:
425 		snprintf(dest + strlen(dest), sz - strlen(dest), ":%s:%s",
426 		    arch, wordsize_corres_str);
427 	}
428 
429 cleanup:
430 	if (elf != NULL)
431 		elf_end(elf);
432 
433 	close(fd);
434 	return (ret);
435 }
436 
437 static void
438 subst_packagesite(const char *abi)
439 {
440 	struct sbuf *newval;
441 	const char *variable_string;
442 	const char *oldval;
443 
444 	if (c[PACKAGESITE].value != NULL)
445 		oldval = c[PACKAGESITE].value;
446 	else
447 		oldval = c[PACKAGESITE].val;
448 
449 	if ((variable_string = strstr(oldval, "${ABI}")) == NULL)
450 		return;
451 
452 	newval = sbuf_new_auto();
453 	sbuf_bcat(newval, oldval, variable_string - oldval);
454 	sbuf_cat(newval, abi);
455 	sbuf_cat(newval, variable_string + strlen("${ABI}"));
456 	sbuf_finish(newval);
457 
458 	free(c[PACKAGESITE].value);
459 	c[PACKAGESITE].value = strdup(sbuf_data(newval));
460 }
461 
462 static void
463 config_parse(yaml_document_t *doc, yaml_node_t *node)
464 {
465 	yaml_node_pair_t *pair;
466 	yaml_node_t *key, *val;
467 	struct sbuf *buf = sbuf_new_auto();
468 	int i;
469 	size_t j;
470 
471 	pair = node->data.mapping.pairs.start;
472 
473 	while (pair < node->data.mapping.pairs.top) {
474 		key = yaml_document_get_node(doc, pair->key);
475 		val = yaml_document_get_node(doc, pair->value);
476 
477 		/*
478 		 * ignoring silently empty keys can be empty lines
479 		 * or user mistakes
480 		 */
481 		if (key->data.scalar.length <= 0) {
482 			++pair;
483 			continue;
484 		}
485 
486 		/*
487 		 * silently skip on purpose to allow user to leave
488 		 * empty lines without complaining
489 		 */
490 		if (val->type == YAML_NO_NODE ||
491 		    (val->type == YAML_SCALAR_NODE &&
492 		     val->data.scalar.length <= 0)) {
493 			++pair;
494 			continue;
495 		}
496 
497 		sbuf_clear(buf);
498 		for (j = 0; j < strlen(key->data.scalar.value); ++j)
499 			sbuf_putc(buf, toupper(key->data.scalar.value[j]));
500 
501 		sbuf_finish(buf);
502 		for (i = 0; i < CONFIG_SIZE; i++) {
503 			if (strcmp(sbuf_data(buf), c[i].key) == 0)
504 				break;
505 		}
506 
507 		if (i == CONFIG_SIZE) {
508 			++pair;
509 			continue;
510 		}
511 
512 		/* env has priority over config file */
513 		if (c[i].envset) {
514 			++pair;
515 			continue;
516 		}
517 
518 		c[i].value = strdup(val->data.scalar.value);
519 		++pair;
520 	}
521 
522 	sbuf_delete(buf);
523 }
524 
525 int
526 config_init(void)
527 {
528 	FILE *fp;
529 	yaml_parser_t parser;
530 	yaml_document_t doc;
531 	yaml_node_t *node;
532 	const char *val;
533 	int i;
534 	const char *localbase;
535 	char confpath[MAXPATHLEN];
536 	char abi[BUFSIZ];
537 
538 	for (i = 0; i < CONFIG_SIZE; i++) {
539 		val = getenv(c[i].key);
540 		if (val != NULL) {
541 			c[i].val = val;
542 			c[i].envset = true;
543 		}
544 	}
545 
546 	localbase = getenv("LOCALBASE") ? getenv("LOCALBASE") : _LOCALBASE;
547 	snprintf(confpath, sizeof(confpath), "%s/etc/pkg.conf", localbase);
548 
549 	if ((fp = fopen(confpath, "r")) == NULL) {
550 		if (errno != ENOENT)
551 			err(EXIT_FAILURE, "Unable to open configuration file %s", confpath);
552 		/* no configuration present */
553 		goto finalize;
554 	}
555 
556 	yaml_parser_initialize(&parser);
557 	yaml_parser_set_input_file(&parser, fp);
558 	yaml_parser_load(&parser, &doc);
559 
560 	node = yaml_document_get_root_node(&doc);
561 
562 	if (node != NULL) {
563 		if (node->type != YAML_MAPPING_NODE)
564 			warnx("Invalid configuration format, ignoring the configuration file");
565 		else
566 			config_parse(&doc, node);
567 	} else {
568 		warnx("Invalid configuration format, ignoring the configuration file");
569 	}
570 
571 	yaml_document_delete(&doc);
572 	yaml_parser_delete(&parser);
573 
574 finalize:
575 	if (c[ABI].val == NULL && c[ABI].value == NULL) {
576 		if (pkg_get_myabi(abi, BUFSIZ) != 0)
577 			errx(EXIT_FAILURE, "Failed to determine the system ABI");
578 		c[ABI].val = abi;
579 	}
580 
581 	subst_packagesite(c[ABI].value != NULL ? c[ABI].value : c[ABI].val);
582 
583 	return (0);
584 }
585 
586 int
587 config_string(pkg_config_key k, const char **val)
588 {
589 	if (c[k].type != PKG_CONFIG_STRING)
590 		return (-1);
591 
592 	if (c[k].value != NULL)
593 		*val = c[k].value;
594 	else
595 		*val = c[k].val;
596 
597 	return (0);
598 }
599 
600 int
601 config_bool(pkg_config_key k, bool *val)
602 {
603 	const char *value;
604 
605 	if (c[k].type != PKG_CONFIG_BOOL)
606 		return (-1);
607 
608 	*val = false;
609 
610 	if (c[k].value != NULL)
611 		value = c[k].value;
612 	else
613 		value = c[k].val;
614 
615 	if (strcasecmp(value, "true") == 0 ||
616 	    strcasecmp(value, "yes") == 0 ||
617 	    strcasecmp(value, "on") == 0 ||
618 	    *value == '1')
619 		*val = true;
620 
621 	return (0);
622 }
623 
624 void
625 config_finish(void) {
626 	int i;
627 
628 	for (i = 0; i < CONFIG_SIZE; i++)
629 		free(c[i].value);
630 }
631