master.c

非常好的dns解析软件

	ictx->origin_in_use = 0;
	ictx->origin = dns_fixedname_name(&ictx->fixed[ictx->origin_in_use]);
	ictx->in_use[ictx->origin_in_use] = ISC_TRUE;
	dns_name_toregion(origin, &r);
	dns_name_fromregion(ictx->origin, &r);

	ictx->glue = NULL;
	ictx->current = NULL;
	ictx->glue_in_use = -1;
	ictx->current_in_use = -1;
	ictx->parent = NULL;
	ictx->drop = ISC_FALSE;
	ictx->glue_line = 0;
	ictx->current_line = 0;

	*ictxp = ictx;
	return (ISC_R_SUCCESS);
}

static isc_result_t
loadctx_create(dns_masterformat_t format, isc_mem_t *mctx,
	       unsigned int options, dns_name_t *top,
	       dns_rdataclass_t zclass, dns_name_t *origin,
	       dns_rdatacallbacks_t *callbacks, isc_task_t *task,
	       dns_loaddonefunc_t done, void *done_arg, isc_lex_t *lex,
	       dns_loadctx_t **lctxp)
{
	dns_loadctx_t *lctx;
	isc_result_t result;
	isc_region_t r;
	isc_lexspecials_t specials;

	REQUIRE(lctxp != NULL && *lctxp == NULL);
	REQUIRE(callbacks != NULL);
	REQUIRE(callbacks->add != NULL);
	REQUIRE(callbacks->error != NULL);
	REQUIRE(callbacks->warn != NULL);
	REQUIRE(mctx != NULL);
	REQUIRE(dns_name_isabsolute(top));
	REQUIRE(dns_name_isabsolute(origin));
	REQUIRE((task == NULL && done == NULL) ||
		(task != NULL && done != NULL));

	lctx = isc_mem_get(mctx, sizeof(*lctx));
	if (lctx == NULL)
		return (ISC_R_NOMEMORY);
	result = isc_mutex_init(&lctx->lock);
	if (result != ISC_R_SUCCESS) {
		isc_mem_put(mctx, lctx, sizeof(*lctx));
		return (result);
	}

	lctx->inc = NULL;
	result = incctx_create(mctx, origin, &lctx->inc);
	if (result != ISC_R_SUCCESS) 
		goto cleanup_ctx;

	lctx->format = format;
	switch (format) {
	default:
		INSIST(0);
	case dns_masterformat_text:
		lctx->openfile = openfile_text;
		lctx->load = load_text;
		break;
	case dns_masterformat_raw:
		lctx->openfile = openfile_raw;
		lctx->load = load_raw;
		break;
	}

	if (lex != NULL) {
		lctx->lex = lex;
		lctx->keep_lex = ISC_TRUE;
	} else {
		lctx->lex = NULL;
		result = isc_lex_create(mctx, TOKENSIZ, &lctx->lex);
		if (result != ISC_R_SUCCESS)
			goto cleanup_inc;
		lctx->keep_lex = ISC_FALSE;
		memset(specials, 0, sizeof(specials));
		specials['('] = 1;
		specials[')'] = 1;
		specials['"'] = 1;
		isc_lex_setspecials(lctx->lex, specials);
		isc_lex_setcomments(lctx->lex, ISC_LEXCOMMENT_DNSMASTERFILE);
	}

	lctx->ttl_known = ISC_FALSE;
	lctx->ttl = 0;
	lctx->default_ttl_known = ISC_FALSE;
	lctx->default_ttl = 0;
	lctx->warn_1035 = ISC_TRUE;	/* XXX Argument? */
	lctx->warn_tcr = ISC_TRUE;	/* XXX Argument? */
	lctx->warn_sigexpired = ISC_TRUE;	/* XXX Argument? */
	lctx->options = options;
	lctx->seen_include = ISC_FALSE;
	lctx->zclass = zclass;
	lctx->result = ISC_R_SUCCESS;

	dns_fixedname_init(&lctx->fixed_top);
	lctx->top = dns_fixedname_name(&lctx->fixed_top);
	dns_name_toregion(top, &r);
	dns_name_fromregion(lctx->top, &r);

	lctx->f = NULL;
	lctx->first = ISC_TRUE;

	lctx->loop_cnt = (done != NULL) ? 100 : 0;
	lctx->callbacks = callbacks;
	lctx->task = NULL;
	if (task != NULL)
		isc_task_attach(task, &lctx->task);
	lctx->done = done;
	lctx->done_arg = done_arg;
	lctx->canceled = ISC_FALSE;
	lctx->mctx = NULL;
	isc_mem_attach(mctx, &lctx->mctx);
	lctx->references = 1;			/* Implicit attach. */
	lctx->magic = DNS_LCTX_MAGIC;
	*lctxp = lctx;
	return (ISC_R_SUCCESS);

 cleanup_inc:
	incctx_destroy(mctx, lctx->inc);
 cleanup_ctx:
	isc_mem_put(mctx, lctx, sizeof(*lctx));
	return (result);
}

static isc_result_t
genname(char *name, int it, char *buffer, size_t length) {
	char fmt[sizeof("%04000000000d")];
	char numbuf[128];
	char *cp;
	char mode[2];
	int delta = 0;
	isc_textregion_t r;
	unsigned int n;
	unsigned int width;

	r.base = buffer;
	r.length = length;

	while (*name != '\0') {
		if (*name == '$') {
			name++;
			if (*name == '$') {
				if (r.length == 0)
					return (ISC_R_NOSPACE);
				r.base[0] = *name++;
				isc_textregion_consume(&r, 1);
				continue;
			}
			strcpy(fmt, "%d");
			/* Get format specifier. */
			if (*name == '{' ) {
				n = sscanf(name, "{%d,%u,%1[doxX]}",
					   &delta, &width, mode);
				switch (n) {
				case 1:
					break;
				case 2:
					n = snprintf(fmt, sizeof(fmt),
						     "%%0%ud", width);
					break;
				case 3:
					n = snprintf(fmt, sizeof(fmt),
						     "%%0%u%c", width, mode[0]);
					break;
				default:
					return (DNS_R_SYNTAX);
				}
				if (n >= sizeof(fmt))
					return (ISC_R_NOSPACE);
				/* Skip past closing brace. */
				while (*name != '\0' && *name++ != '}')
					continue;
			}
			n = snprintf(numbuf, sizeof(numbuf), fmt, it + delta);
			if (n >= sizeof(numbuf))
				return (ISC_R_NOSPACE);
			cp = numbuf;
			while (*cp != '\0') {
				if (r.length == 0)
					return (ISC_R_NOSPACE);
				r.base[0] = *cp++;
				isc_textregion_consume(&r, 1);
			}
		} else if (*name == '\\') {
			if (r.length == 0)
				return (ISC_R_NOSPACE);
			r.base[0] = *name++;
			isc_textregion_consume(&r, 1);
			if (*name == '\0')
				continue;
			if (r.length == 0)
				return (ISC_R_NOSPACE);
			r.base[0] = *name++;
			isc_textregion_consume(&r, 1);
		} else {
			if (r.length == 0)
				return (ISC_R_NOSPACE);
			r.base[0] = *name++;
			isc_textregion_consume(&r, 1);
		}
	}
	if (r.length == 0)
		return (ISC_R_NOSPACE);
	r.base[0] = '\0';
	return (ISC_R_SUCCESS);
}

static isc_result_t
openfile_text(dns_loadctx_t *lctx, const char *master_file) {
	return (isc_lex_openfile(lctx->lex, master_file));
}

static isc_result_t
openfile_raw(dns_loadctx_t *lctx, const char *master_file) {
	isc_result_t result;

	result = isc_stdio_open(master_file, "r", &lctx->f);
	if (result != ISC_R_SUCCESS && result != ISC_R_FILENOTFOUND) {
		UNEXPECTED_ERROR(__FILE__, __LINE__,
				 "isc_stdio_open() failed: %s",
				 isc_result_totext(result));		
	}

	return (result);
}

static isc_result_t
generate(dns_loadctx_t *lctx, char *range, char *lhs, char *gtype, char *rhs,
	 const char *source, unsigned int line)
{
	char *target_mem = NULL;
	char *lhsbuf = NULL;
	char *rhsbuf = NULL;
	dns_fixedname_t ownerfixed;
	dns_name_t *owner;
	dns_rdata_t rdata = DNS_RDATA_INIT;
	dns_rdatacallbacks_t *callbacks;
	dns_rdatalist_t rdatalist;
	dns_rdatatype_t type;
	rdatalist_head_t head;
	int n;
	int target_size = MINTSIZ;	/* only one rdata at a time */
	isc_buffer_t buffer;
	isc_buffer_t target;
	isc_result_t result;
	isc_textregion_t r;
	unsigned int start, stop, step, i;
	dns_incctx_t *ictx;

	ictx = lctx->inc;
	callbacks = lctx->callbacks;
	dns_fixedname_init(&ownerfixed);
	owner = dns_fixedname_name(&ownerfixed);
	ISC_LIST_INIT(head);

	target_mem = isc_mem_get(lctx->mctx, target_size);
	rhsbuf = isc_mem_get(lctx->mctx, DNS_MASTER_BUFSZ);
	lhsbuf = isc_mem_get(lctx->mctx, DNS_MASTER_BUFSZ);
	if (target_mem == NULL || rhsbuf == NULL || lhsbuf == NULL) {
		result = ISC_R_NOMEMORY;
		goto error_cleanup;
	}
	isc_buffer_init(&target, target_mem, target_size);

	n = sscanf(range, "%u-%u/%u", &start, &stop, &step);
	if (n < 2 || stop < start) {
	       (*callbacks->error)(callbacks,
				  "%s: %s:%lu: invalid range '%s'",
				  "$GENERATE", source, line, range);
		result = DNS_R_SYNTAX;
		goto insist_cleanup;
	}
	if (n == 2)
		step = 1;

	/*
	 * Get type.
	 */
	r.base = gtype;
	r.length = strlen(gtype);
	result = dns_rdatatype_fromtext(&type, &r);
	if (result != ISC_R_SUCCESS) {
		(*callbacks->error)(callbacks,
				   "%s: %s:%lu: unknown RR type '%s'",
				   "$GENERATE", source, line, gtype);
		goto insist_cleanup;
	}

	switch (type) {
	case dns_rdatatype_ns:
	case dns_rdatatype_ptr:
	case dns_rdatatype_cname:
	case dns_rdatatype_dname:
		break;

	case dns_rdatatype_a:
	case dns_rdatatype_aaaa:
		if (lctx->zclass == dns_rdataclass_in ||
		    lctx->zclass == dns_rdataclass_ch ||
		    lctx->zclass == dns_rdataclass_hs)
			break;
		/* FALLTHROUGH */
	default:
	       (*callbacks->error)(callbacks,
				  "%s: %s:%lu: unsupported type '%s'",
				  "$GENERATE", source, line, gtype);
		result = ISC_R_NOTIMPLEMENTED;
		goto error_cleanup;
	}

	ISC_LIST_INIT(rdatalist.rdata);
	ISC_LINK_INIT(&rdatalist, link);
	for (i = start; i <= stop; i += step) {
		result = genname(lhs, i, lhsbuf, DNS_MASTER_BUFSZ);
		if (result != ISC_R_SUCCESS)
			goto error_cleanup;
		result = genname(rhs, i, rhsbuf, DNS_MASTER_BUFSZ);
		if (result != ISC_R_SUCCESS)
			goto error_cleanup;

		isc_buffer_init(&buffer, lhsbuf, strlen(lhsbuf));
		isc_buffer_add(&buffer, strlen(lhsbuf));
		isc_buffer_setactive(&buffer, strlen(lhsbuf));
		result = dns_name_fromtext(owner, &buffer, ictx->origin,
					   0, NULL);
		if (result != ISC_R_SUCCESS)
			goto error_cleanup;

		if ((lctx->options & DNS_MASTER_ZONE) != 0 &&
		    (lctx->options & DNS_MASTER_SLAVE) == 0 &&
		    !dns_name_issubdomain(owner, lctx->top))
		{
			char namebuf[DNS_NAME_FORMATSIZE];
			dns_name_format(owner, namebuf, sizeof(namebuf));
			/*
			 * Ignore out-of-zone data.
			 */
			(*callbacks->warn)(callbacks,
					   "%s:%lu: "
					   "ignoring out-of-zone data (%s)",
					   source, line, namebuf);
			continue;
		}

		isc_buffer_init(&buffer, rhsbuf, strlen(rhsbuf));
		isc_buffer_add(&buffer, strlen(rhsbuf));
		isc_buffer_setactive(&buffer, strlen(rhsbuf));

		result = isc_lex_openbuffer(lctx->lex, &buffer);
		if (result != ISC_R_SUCCESS)
			goto error_cleanup;

		isc_buffer_init(&target, target_mem, target_size);
		result = dns_rdata_fromtext(&rdata, lctx->zclass, type,
					    lctx->lex, ictx->origin, 0,
					    lctx->mctx, &target, callbacks);
		RUNTIME_CHECK(isc_lex_close(lctx->lex) == ISC_R_SUCCESS);
		if (result != ISC_R_SUCCESS)
			goto error_cleanup;

		rdatalist.type = type;
		rdatalist.covers = 0;
		rdatalist.rdclass = lctx->zclass;
		rdatalist.ttl = lctx->ttl;
		ISC_LIST_PREPEND(head, &rdatalist, link);
		ISC_LIST_APPEND(rdatalist.rdata, &rdata, link);
		result = commit(callbacks, lctx, &head, owner, source, line);
		ISC_LIST_UNLINK(rdatalist.rdata, &rdata, link);
		if (result != ISC_R_SUCCESS)
			goto error_cleanup;
		dns_rdata_reset(&rdata);
	}
	result = ISC_R_SUCCESS;
	goto cleanup;

 error_cleanup:
	if (result == ISC_R_NOMEMORY)
		(*callbacks->error)(callbacks, "$GENERATE: %s",
				    dns_result_totext(result));
	else
		(*callbacks->error)(callbacks, "$GENERATE: %s:%lu: %s",
				    source, line, dns_result_totext(result));

 insist_cleanup:
	INSIST(result != ISC_R_SUCCESS);

 cleanup:
	if (target_mem != NULL)
		isc_mem_put(lctx->mctx, target_mem, target_size);
	if (lhsbuf != NULL)
		isc_mem_put(lctx->mctx, lhsbuf, DNS_MASTER_BUFSZ);
	if (rhsbuf != NULL)
		isc_mem_put(lctx->mctx, rhsbuf, DNS_MASTER_BUFSZ);
	return (result);
}

static void
limit_ttl(dns_rdatacallbacks_t *callbacks, const char *source, unsigned int line,
	  isc_uint32_t *ttlp)
{
	if (*ttlp > 0x7fffffffUL) {
		(callbacks->warn)(callbacks,
				  "%s: %s:%lu: "
				  "$TTL %lu > MAXTTL, "
				  "setting $TTL to 0",
				  "dns_master_load",
				  source, line,
				  *ttlp);
		*ttlp = 0;
	}
}

static isc_result_t
check_ns(dns_loadctx_t *lctx, isc_token_t *token, const char *source,
	 unsigned long line)
{
	char *tmp = NULL;
	isc_result_t result = ISC_R_SUCCESS;
	void (*callback)(struct dns_rdatacallbacks *, const char *, ...);

	if ((lctx->options & DNS_MASTER_FATALNS) != 0)
		callback = lctx->callbacks->error;
	else
		callback = lctx->callbacks->warn;
		
	if (token->type == isc_tokentype_string) {
		struct in_addr addr;
		struct in6_addr addr6;

		tmp = isc_mem_strdup(lctx->mctx, DNS_AS_STR(*token));
		if (tmp == NULL)
			return (ISC_R_NOMEMORY);
		/*
		 * Catch both "1.2.3.4" and "1.2.3.4."
		 */
		if (tmp[strlen(tmp) - 1] == '.')
			tmp[strlen(tmp) - 1] = '\0';
		if (inet_aton(tmp, &addr) == 1 ||
		    inet_pton(AF_INET6, tmp, &addr6) == 1)
			result = DNS_R_NSISADDRESS;
	}
	if (result != ISC_R_SUCCESS)
		(*callback)(lctx->callbacks, "%s:%lu: NS record '%s' "
			    "appears to be an address",
			    source, line, DNS_AS_STR(*token));
	if (tmp != NULL)
		isc_mem_free(lctx->mctx, tmp);
	return (result);
}

static void
check_wildcard(dns_incctx_t *ictx, const char *source, unsigned long line,
	       dns_rdatacallbacks_t *callbacks)
{
	dns_name_t *name;

	name = (ictx->glue != NULL) ? ictx->glue : ictx->current;
	if (dns_name_internalwildcard(name)) {
		char namebuf[DNS_NAME_FORMATSIZE];

		dns_name_format(name, namebuf, sizeof(namebuf));
		(*callbacks->warn)(callbacks, "%s:%lu: warning: ownername "
				   "'%s' contains an non-terminal wildcard",
				   source, line, namebuf);
	}
}

static isc_result_t
load_text(dns_loadctx_t *lctx) {
	dns_rdataclass_t rdclass;
	dns_rdatatype_t type, covers;
	isc_uint32_t ttl_offset = 0;
	dns_name_t *new_name;
	isc_boolean_t current_has_delegation = ISC_FALSE;
	isc_boolean_t done = ISC_FALSE;