dig.c

来自「非常好的dns解析软件」· C语言 代码 · 共 1,806 行 · 第 1/4 页

	result = ISC_R_SUCCESS;

	result = isc_buffer_allocate(mctx, &buf, len);
	check_result(result, "isc_buffer_allocate");

	if (query->lookup->comments && !short_form) {
		if (query->lookup->cmdline[0] != 0)
			printf("; %s\n", query->lookup->cmdline);
		if (msg == query->lookup->sendmsg)
			printf(";; Sending:\n");
		else
			printf(";; Got answer:\n");

		if (headers) {
			printf(";; ->>HEADER<<- opcode: %s, status: %s, "
			       "id: %u\n",
			       opcodetext[msg->opcode], rcodetext[msg->rcode],
			       msg->id);
			printf(";; flags:");
			if ((msg->flags & DNS_MESSAGEFLAG_QR) != 0)
				printf(" qr");
			if ((msg->flags & DNS_MESSAGEFLAG_AA) != 0)
				printf(" aa");
			if ((msg->flags & DNS_MESSAGEFLAG_TC) != 0)
				printf(" tc");
			if ((msg->flags & DNS_MESSAGEFLAG_RD) != 0)
				printf(" rd");
			if ((msg->flags & DNS_MESSAGEFLAG_RA) != 0)
				printf(" ra");
			if ((msg->flags & DNS_MESSAGEFLAG_AD) != 0)
				printf(" ad");
			if ((msg->flags & DNS_MESSAGEFLAG_CD) != 0)
				printf(" cd");

			printf("; QUERY: %u, ANSWER: %u, "
			       "AUTHORITY: %u, ADDITIONAL: %u\n",
			       msg->counts[DNS_SECTION_QUESTION],
			       msg->counts[DNS_SECTION_ANSWER],
			       msg->counts[DNS_SECTION_AUTHORITY],
			       msg->counts[DNS_SECTION_ADDITIONAL]);

			if (msg != query->lookup->sendmsg &&
			    (msg->flags & DNS_MESSAGEFLAG_RD) != 0 &&
			    (msg->flags & DNS_MESSAGEFLAG_RA) == 0)
				printf(";; WARNING: recursion requested "
				       "but not available\n");
		}
		if (msg != query->lookup->sendmsg && extrabytes != 0U)
			printf(";; WARNING: Messages has %u extra byte%s at "
			       "end\n", extrabytes, extrabytes != 0 ? "s" : "");
	}

repopulate_buffer:

	if (query->lookup->comments && headers && !short_form) {
		result = dns_message_pseudosectiontotext(msg,
			 DNS_PSEUDOSECTION_OPT,
			 style, flags, buf);
		if (result == ISC_R_NOSPACE) {
buftoosmall:
			len += OUTPUTBUF;
			isc_buffer_free(&buf);
			result = isc_buffer_allocate(mctx, &buf, len);
			if (result == ISC_R_SUCCESS)
				goto repopulate_buffer;
			else
				goto cleanup;
		}
		check_result(result,
		     "dns_message_pseudosectiontotext");
	}

	if (query->lookup->section_question && headers) {
		if (!short_form) {
			result = dns_message_sectiontotext(msg,
						       DNS_SECTION_QUESTION,
						       style, flags, buf);
			if (result == ISC_R_NOSPACE)
				goto buftoosmall;
			check_result(result, "dns_message_sectiontotext");
		}
	}
	if (query->lookup->section_answer) {
		if (!short_form) {
			result = dns_message_sectiontotext(msg,
						       DNS_SECTION_ANSWER,
						       style, flags, buf);
			if (result == ISC_R_NOSPACE)
				goto buftoosmall;
			check_result(result, "dns_message_sectiontotext");
		} else {
			result = short_answer(msg, flags, buf, query);
			if (result == ISC_R_NOSPACE)
				goto buftoosmall;
			check_result(result, "short_answer");
		}
	}
	if (query->lookup->section_authority) {
		if (!short_form) {
			result = dns_message_sectiontotext(msg,
						       DNS_SECTION_AUTHORITY,
						       style, flags, buf);
			if (result == ISC_R_NOSPACE)
				goto buftoosmall;
			check_result(result, "dns_message_sectiontotext");
		}
	}
	if (query->lookup->section_additional) {
		if (!short_form) {
			result = dns_message_sectiontotext(msg,
						      DNS_SECTION_ADDITIONAL,
						      style, flags, buf);
			if (result == ISC_R_NOSPACE)
				goto buftoosmall;
			check_result(result, "dns_message_sectiontotext");
			/*
			 * Only print the signature on the first record.
			 */
			if (headers) {
				result = dns_message_pseudosectiontotext(
						   msg,
						   DNS_PSEUDOSECTION_TSIG,
						   style, flags, buf);
				if (result == ISC_R_NOSPACE)
					goto buftoosmall;
				check_result(result,
					  "dns_message_pseudosectiontotext");
				result = dns_message_pseudosectiontotext(
						   msg,
						   DNS_PSEUDOSECTION_SIG0,
						   style, flags, buf);
				if (result == ISC_R_NOSPACE)
					goto buftoosmall;
				check_result(result,
					   "dns_message_pseudosectiontotext");
			}
		}
	}

	if (headers && query->lookup->comments && !short_form)
		printf("\n");

	printf("%.*s", (int)isc_buffer_usedlength(buf),
	       (char *)isc_buffer_base(buf));
	isc_buffer_free(&buf);

cleanup:
	if (style != NULL)
		dns_master_styledestroy(&style, mctx);
	return (result);
}

/*%
 * print the greeting message when the program first starts up.
 */
static void
printgreeting(int argc, char **argv, dig_lookup_t *lookup) {
	int i;
	int remaining;
	static isc_boolean_t first = ISC_TRUE;
	char append[MXNAME];

	if (printcmd) {
		lookup->cmdline[sizeof(lookup->cmdline) - 1] = 0;
		snprintf(lookup->cmdline, sizeof(lookup->cmdline),
			 "%s; <<>> DiG " VERSION " <<>>",
			 first?"\n":"");
		i = 1;
		while (i < argc) {
			snprintf(append, sizeof(append), " %s", argv[i++]);
			remaining = sizeof(lookup->cmdline) -
				    strlen(lookup->cmdline) - 1;
			strncat(lookup->cmdline, append, remaining);
		}
		remaining = sizeof(lookup->cmdline) -
			    strlen(lookup->cmdline) - 1;
		strncat(lookup->cmdline, "\n", remaining);
		if (first && addresscount != 0) {
			snprintf(append, sizeof(append),
				 "; (%d server%s found)\n",
				 addresscount,
				 addresscount > 1 ? "s" : "");
			remaining = sizeof(lookup->cmdline) -
				    strlen(lookup->cmdline) - 1;
			strncat(lookup->cmdline, append, remaining);
		}
		if (first) {
			snprintf(append, sizeof(append), 
				 ";; global options: %s %s\n",
			       short_form ? "short_form" : "",
			       printcmd ? "printcmd" : "");
			first = ISC_FALSE;
			remaining = sizeof(lookup->cmdline) -
				    strlen(lookup->cmdline) - 1;
			strncat(lookup->cmdline, append, remaining);
		}
	}
}

/*%
 * Reorder an argument list so that server names all come at the end.
 * This is a bit of a hack, to allow batch-mode processing to properly
 * handle the server options.
 */
static void
reorder_args(int argc, char *argv[]) {
	int i, j;
	char *ptr;
	int end;

	debug("reorder_args()");
	end = argc - 1;
	while (argv[end][0] == '@') {
		end--;
		if (end == 0)
			return;
	}
	debug("arg[end]=%s", argv[end]);
	for (i = 1; i < end - 1; i++) {
		if (argv[i][0] == '@') {
			debug("arg[%d]=%s", i, argv[i]);
			ptr = argv[i];
			for (j = i + 1; j < end; j++) {
				debug("Moving %s to %d", argv[j], j - 1);
				argv[j - 1] = argv[j];
			}
			debug("moving %s to end, %d", ptr, end - 1);
			argv[end - 1] = ptr;
			end--;
			if (end < 1)
				return;
		}
	}
}

static isc_uint32_t
parse_uint(char *arg, const char *desc, isc_uint32_t max) {
	isc_result_t result;
	isc_uint32_t tmp;

	result = isc_parse_uint32(&tmp, arg, 10);
	if (result == ISC_R_SUCCESS && tmp > max)
		result = ISC_R_RANGE;
	if (result != ISC_R_SUCCESS)
		fatal("%s '%s': %s", desc, arg, isc_result_totext(result));
	return (tmp);
}

/*%
 * We're not using isc_commandline_parse() here since the command line
 * syntax of dig is quite a bit different from that which can be described
 * by that routine.
 * XXX doc options
 */

static void
plus_option(char *option, isc_boolean_t is_batchfile,
	    dig_lookup_t *lookup)
{
	char option_store[256];
	char *cmd, *value, *ptr;
	isc_boolean_t state = ISC_TRUE;
#ifdef DIG_SIGCHASE
	size_t n;
#endif

	strncpy(option_store, option, sizeof(option_store));
	option_store[sizeof(option_store)-1]=0;
	ptr = option_store;
	cmd = next_token(&ptr,"=");
	if (cmd == NULL) {
		printf(";; Invalid option %s\n", option_store);
		return;
	}
	value = ptr;
	if (strncasecmp(cmd, "no", 2)==0) {
		cmd += 2;
		state = ISC_FALSE;
	}

#define FULLCHECK(A) \
	do { \
		size_t _l = strlen(cmd); \
		if (_l >= sizeof(A) || strncasecmp(cmd, A, _l) != 0) \
			goto invalid_option; \
	} while (0)
#define FULLCHECK2(A, B) \
	do { \
		size_t _l = strlen(cmd); \
		if ((_l >= sizeof(A) || strncasecmp(cmd, A, _l) != 0) && \
		    (_l >= sizeof(B) || strncasecmp(cmd, B, _l) != 0)) \
			goto invalid_option; \
	} while (0)

	switch (cmd[0]) {
	case 'a':
		switch (cmd[1]) {
		case 'a': /* aaonly / aaflag */
			FULLCHECK2("aaonly", "aaflag");
			lookup->aaonly = state;
			break;
		case 'd': 
			switch (cmd[2]) {
			case 'd': /* additional */
				FULLCHECK("additional");
				lookup->section_additional = state;
				break;
			case 'f': /* adflag */
				FULLCHECK("adflag");
				lookup->adflag = state;
				break;
			default:
				goto invalid_option;
			}
			break;
		case 'l': /* all */
			FULLCHECK("all");
			lookup->section_question = state;
			lookup->section_authority = state;
			lookup->section_answer = state;
			lookup->section_additional = state;
			lookup->comments = state;
			lookup->stats = state;
			printcmd = state;
			break;
		case 'n': /* answer */
			FULLCHECK("answer");
			lookup->section_answer = state;
			break;
		case 'u': /* authority */
			FULLCHECK("authority");
			lookup->section_authority = state;
			break;
		default:
			goto invalid_option;
		}
		break;
	case 'b':
		switch (cmd[1]) {
		case 'e':/* besteffort */
			FULLCHECK("besteffort");
			lookup->besteffort = state;
			break;
		case 'u':/* bufsize */
			FULLCHECK("bufsize");
			if (value == NULL)
				goto need_value;
			if (!state)
				goto invalid_option;
			lookup->udpsize = (isc_uint16_t) parse_uint(value,
						    "buffer size", COMMSIZE);
			break;
		default:
			goto invalid_option;
		}
		break;
	case 'c':
		switch (cmd[1]) {
		case 'd':/* cdflag */
			FULLCHECK("cdflag");
			lookup->cdflag = state;
			break;
		case 'l': /* cl */
			FULLCHECK("cl");
			noclass = ISC_TF(!state);
			break;
		case 'm': /* cmd */
			FULLCHECK("cmd");
			printcmd = state;
			break;
		case 'o': /* comments */
			FULLCHECK("comments");
			lookup->comments = state;
			if (lookup == default_lookup)
				pluscomm = state;
			break;
		default:
			goto invalid_option;
		}
		break;
	case 'd':
		switch (cmd[1]) {
		case 'e': /* defname */
			FULLCHECK("defname");
			usesearch = state;
			break;
		case 'n': /* dnssec */	
			FULLCHECK("dnssec");
			if (state && lookup->edns == -1)
				lookup->edns = 0;
			lookup->dnssec = state;
			break;
		case 'o': /* domain */	
			FULLCHECK("domain");
			if (value == NULL)
				goto need_value;
			if (!state)
				goto invalid_option;
			strncpy(domainopt, value, sizeof(domainopt));
			domainopt[sizeof(domainopt)-1] = '\0';
			break;
		default:
			goto invalid_option;
		}
		break;
	case 'e':
		FULLCHECK("edns");
		if (!state) {
			lookup->edns = -1;
			break;
		}
		if (value == NULL)
			goto need_value;
		lookup->edns = (isc_int16_t) parse_uint(value, "edns", 255);
		break;
	case 'f': /* fail */
		FULLCHECK("fail");
		lookup->servfail_stops = state;
		break;
	case 'i':
		switch (cmd[1]) {
		case 'd': /* identify */
			FULLCHECK("identify");
			lookup->identify = state;
			break;
		case 'g': /* ignore */
		default: /* Inherets default for compatibility */
			FULLCHECK("ignore");
			lookup->ignore = ISC_TRUE;
		}
		break;
	case 'm': /* multiline */
		FULLCHECK("multiline");
		multiline = state;
		break;
	case 'n':
		switch (cmd[1]) {
		case 'd': /* ndots */
			FULLCHECK("ndots");
			if (value == NULL)
				goto need_value;
			if (!state)
				goto invalid_option;
			ndots = parse_uint(value, "ndots", MAXNDOTS);
			break;
		case 's': /* nssearch */
			FULLCHECK("nssearch");
			lookup->ns_search_only = state;
			if (state) {
				lookup->trace_root = ISC_TRUE;
				lookup->recurse = ISC_TRUE;