/*
 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
 *
 * SPDX-License-Identifier: MPL-2.0
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, you can obtain one at https://mozilla.org/MPL/2.0/.
 *
 * See the COPYRIGHT file distributed with this work for additional
 * information regarding copyright ownership.
 */

#include <inttypes.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include <isc/attributes.h>
#include <isc/base64.h>
#include <isc/getaddresses.h>
#include <isc/hash.h>
#include <isc/hex.h>
#include <isc/lib.h>
#include <isc/log.h>
#include <isc/loop.h>
#include <isc/managers.h>
#include <isc/mem.h>
#include <isc/net.h>
#include <isc/netmgr.h>
#include <isc/nonce.h>
#include <isc/parseint.h>
#include <isc/portset.h>
#include <isc/random.h>
#include <isc/result.h>
#include <isc/sockaddr.h>
#include <isc/string.h>
#include <isc/time.h>
#include <isc/util.h>

#include <dns/byaddr.h>
#include <dns/dispatch.h>
#include <dns/fixedname.h>
#include <dns/lib.h>
#include <dns/message.h>
#include <dns/name.h>
#include <dns/rdata.h>
#include <dns/rdataclass.h>
#include <dns/rdataset.h>
#include <dns/rdatatype.h>
#include <dns/request.h>
#include <dns/types.h>
#include <dns/view.h>

#define CHECKM(str, x)                                                      \
	{                                                                   \
		if ((x) != ISC_R_SUCCESS) {                                 \
			fprintf(stderr, "mdig: %s failed with %s\n", (str), \
				isc_result_totext(x));                      \
			exit(EXIT_FAILURE);                                 \
		}                                                           \
	}

#define RUNCHECK(x) RUNTIME_CHECK((x) == ISC_R_SUCCESS)

#define ADD_STRING(b, s)                                        \
	{                                                       \
		if (strlen(s) >= isc_buffer_availablelength(b)) \
			return ((ISC_R_NOSPACE));               \
		else                                            \
			isc_buffer_putstr(b, s);                \
	}

#define MXNAME	   (DNS_NAME_MAXTEXT + 1)
#define COMMSIZE   0xffff
#define OUTPUTBUF  32767
#define MAXPORT	   0xffff
#define PORT	   53
#define MAXTIMEOUT 0xffff
#define TCPTIMEOUT 10
#define UDPTIMEOUT 5
#define MAXTRIES   0xffffffff

static dns_requestmgr_t *requestmgr = NULL;
static const char *batchname = NULL;
static FILE *batchfp = NULL;
static bool burst = false;
static bool have_ipv4 = false;
static bool have_ipv6 = false;
static bool have_src = false;
static bool tcp_mode = false;
static bool besteffort = true;
static bool display_short_form = false;
static bool display_headers = true;
static bool display_comments = true;
static int display_rrcomments = 0;
static bool display_ttlunits = true;
static bool display_ttl = true;
static bool display_class = true;
static bool display_crypto = true;
static bool display_multiline = false;
static bool display_question = true;
static bool display_answer = true;
static bool display_authority = true;
static bool display_additional = true;
static bool display_unknown_format = false;
static bool yaml = false;
static bool continue_on_error = false;
static uint32_t display_splitwidth = 0xffffffff;
static isc_sockaddr_t srcaddr;
static char *server = NULL;
static isc_sockaddr_t dstaddr;
static in_port_t port = 53;
static unsigned char cookie_secret[33];
static int onfly = 0;
static char hexcookie[81];

static isc_sockaddr_t bind_any;
static dns_dispatchmgr_t *dispatchmgr = NULL;
static dns_dispatch_t *dispatchvx = NULL;
static dns_view_t *view = NULL;

struct query {
	char textname[MXNAME]; /*% Name we're going to be
				* looking up */
	bool recurse;
	bool have_aaonly;
	bool have_adflag;
	bool have_cdflag;
	bool have_zflag;
	bool dnssec;
	bool expire;
	bool send_cookie;
	char *cookie;
	bool nsid;
	dns_rdatatype_t rdtype;
	dns_rdataclass_t rdclass;
	uint16_t udpsize;
	int16_t edns;
	dns_ednsopt_t *ednsopts;
	unsigned int ednsoptscnt;
	unsigned int ednsflags;
	isc_sockaddr_t *ecs_addr;
	unsigned int timeout;
	unsigned int udptimeout;
	unsigned int udpretries;
	ISC_LINK(struct query) link;
};
static struct query default_query;
static ISC_LIST(struct query) queries;

#define EDNSOPTS 100U
/*% opcode text */
static const char *const opcodetext[] = {
	"QUERY",      "IQUERY",	    "STATUS",	  "RESERVED3",
	"NOTIFY",     "UPDATE",	    "RESERVED6",  "RESERVED7",
	"RESERVED8",  "RESERVED9",  "RESERVED10", "RESERVED11",
	"RESERVED12", "RESERVED13", "RESERVED14", "RESERVED15"
};

/*% return code text */
static const char *const rcodetext[] = {
	"NOERROR",    "FORMERR",    "SERVFAIL",	  "NXDOMAIN",	"NOTIMP",
	"REFUSED",    "YXDOMAIN",   "YXRRSET",	  "NXRRSET",	"NOTAUTH",
	"NOTZONE",    "RESERVED11", "RESERVED12", "RESERVED13", "RESERVED14",
	"RESERVED15", "BADVERS"
};

/*% safe rcodetext[] */
static char *
rcode_totext(dns_rcode_t rcode) {
	static char buf[sizeof("?65535")];
	union {
		const char *consttext;
		char *deconsttext;
	} totext;

	if (rcode >= (sizeof(rcodetext) / sizeof(rcodetext[0]))) {
		snprintf(buf, sizeof(buf), "?%u", rcode);
		totext.deconsttext = buf;
	} else {
		totext.consttext = rcodetext[rcode];
	}
	return totext.deconsttext;
}

static void
recvresponse(void *arg) {
	dns_request_t *request = (dns_request_t *)arg;
	isc_result_t result;
	dns_message_t *query = NULL, *response = NULL;
	unsigned int parseflags = 0;
	isc_buffer_t *msgbuf = NULL, *buf = NULL;
	unsigned int len = OUTPUTBUF;
	dns_master_style_t *style = NULL;
	unsigned int styleflags = 0;
	dns_messagetextflag_t flags;

	query = dns_request_getarg(request);

	result = dns_request_getresult(request);
	if (result != ISC_R_SUCCESS) {
		fprintf(stderr, "response failed with %s\n",
			isc_result_totext(result));
		if (continue_on_error) {
			goto cleanup;
		} else {
			exit(EXIT_FAILURE);
		}
	}

	dns_message_create(isc_g_mctx, NULL, NULL, DNS_MESSAGE_INTENTPARSE,
			   &response);

	parseflags |= DNS_MESSAGEPARSE_PRESERVEORDER;
	if (besteffort) {
		parseflags |= DNS_MESSAGEPARSE_BESTEFFORT;
		parseflags |= DNS_MESSAGEPARSE_IGNORETRUNCATION;
	}

	msgbuf = dns_request_getanswer(request);
	result = dns_request_getresponse(request, response, parseflags);
	CHECKM("dns_request_getresponse", result);

	styleflags |= DNS_STYLEFLAG_REL_OWNER;
	if (yaml) {
		styleflags |= DNS_STYLEFLAG_YAML;
		response->indent.string = "  ";
		response->indent.count = 3;
	} else {
		if (display_comments) {
			styleflags |= DNS_STYLEFLAG_COMMENT;
		}
		if (display_unknown_format) {
			styleflags |= DNS_STYLEFLAG_UNKNOWNFORMAT;
		}
		if (display_rrcomments > 0) {
			styleflags |= DNS_STYLEFLAG_RRCOMMENT;
		}
		if (display_ttlunits) {
			styleflags |= DNS_STYLEFLAG_TTL_UNITS;
		}
		if (!display_ttl) {
			styleflags |= DNS_STYLEFLAG_NO_TTL;
		}
		if (!display_class) {
			styleflags |= DNS_STYLEFLAG_NO_CLASS;
		}
		if (!display_crypto) {
			styleflags |= DNS_STYLEFLAG_NOCRYPTO;
		}
		if (display_multiline) {
			styleflags |= DNS_STYLEFLAG_OMIT_OWNER;
			styleflags |= DNS_STYLEFLAG_OMIT_CLASS;
			styleflags |= DNS_STYLEFLAG_REL_DATA;
			styleflags |= DNS_STYLEFLAG_OMIT_TTL;
			styleflags |= DNS_STYLEFLAG_TTL;
			styleflags |= DNS_STYLEFLAG_MULTILINE;
			styleflags |= DNS_STYLEFLAG_COMMENT;
			/* Turn on rrcomments unless explicitly disabled */
			if (display_rrcomments >= 0) {
				styleflags |= DNS_STYLEFLAG_RRCOMMENT;
			}
		}
	}
	if (display_multiline || (!display_ttl && !display_class)) {
		result = dns_master_stylecreate(&style, styleflags, 24, 24, 24,
						32, 80, 8, display_splitwidth,
						isc_g_mctx);
	} else if (!display_ttl || !display_class) {
		result = dns_master_stylecreate(&style, styleflags, 24, 24, 32,
						40, 80, 8, display_splitwidth,
						isc_g_mctx);
	} else {
		result = dns_master_stylecreate(&style, styleflags, 24, 32, 40,
						48, 80, 8, display_splitwidth,
						isc_g_mctx);
	}
	CHECKM("dns_master_stylecreate2", result);

	flags = 0;
	if (!display_headers) {
		flags |= DNS_MESSAGETEXTFLAG_NOHEADERS;
		flags |= DNS_MESSAGETEXTFLAG_NOCOMMENTS;
	}
	if (!display_comments) {
		flags |= DNS_MESSAGETEXTFLAG_NOCOMMENTS;
	}

	isc_buffer_allocate(isc_g_mctx, &buf, len);

	if (yaml) {
		char sockstr[ISC_SOCKADDR_FORMATSIZE];
		uint16_t sport;
		char *hash;
		int pf;

		printf("- type: MESSAGE\n");
		printf("  message:\n");

		if (((response->flags & DNS_MESSAGEFLAG_RD) != 0) &&
		    ((response->flags & DNS_MESSAGEFLAG_RA) != 0))
		{
			printf("    type: RECURSIVE_RESPONSE\n");
		} else {
			printf("    type: AUTH_RESPONSE\n");
		}

		printf("    message_size: %ub\n",
		       isc_buffer_usedlength(msgbuf));

		pf = isc_sockaddr_pf(&dstaddr);
		if (pf == PF_INET || pf == PF_INET6) {
			printf("    socket_family: %s\n",
			       pf == PF_INET ? "INET" : "INET6");

			printf("    socket_protocol: %s\n",
			       tcp_mode ? "TCP" : "UDP");

			sport = isc_sockaddr_getport(&dstaddr);
			isc_sockaddr_format(&dstaddr, sockstr, sizeof(sockstr));
			hash = strchr(sockstr, '#');
			if (hash != NULL) {
				*hash = '\0';
			}
			printf("    response_address: \"%s\"\n", sockstr);
			printf("    response_port: %u\n", sport);
		}

		if (have_src) {
			sport = isc_sockaddr_getport(&srcaddr);
			isc_sockaddr_format(&srcaddr, sockstr, sizeof(sockstr));
			hash = strchr(sockstr, '#');
			if (hash != NULL) {
				*hash = '\0';
			}
			printf("    query_address: \"%s\"\n", sockstr);
			printf("    query_port: %u\n", sport);
		}

		printf("    %s:\n", "response_message_data");
		result = dns_message_headertotext(response, style, flags, buf);
		CHECKM("dns_message_headertotext", result);
	} else if (display_comments && !display_short_form) {
		printf(";; Got answer:\n");

		if (display_headers) {
			printf(";; ->>HEADER<<- opcode: %s, status: %s, "
			       "id: %u\n",
			       opcodetext[response->opcode],
			       rcode_totext(response->rcode), response->id);
			printf(";; flags:");
			if ((response->flags & DNS_MESSAGEFLAG_QR) != 0) {
				printf(" qr");
			}
			if ((response->flags & DNS_MESSAGEFLAG_AA) != 0) {
				printf(" aa");
			}
			if ((response->flags & DNS_MESSAGEFLAG_TC) != 0) {
				printf(" tc");
			}
			if ((response->flags & DNS_MESSAGEFLAG_RD) != 0) {
				printf(" rd");
			}
			if ((response->flags & DNS_MESSAGEFLAG_RA) != 0) {
				printf(" ra");
			}
			if ((response->flags & DNS_MESSAGEFLAG_AD) != 0) {
				printf(" ad");
			}
			if ((response->flags & DNS_MESSAGEFLAG_CD) != 0) {
				printf(" cd");
			}
			if ((response->flags & 0x0040U) != 0) {
				printf("; MBZ: 0x4");
			}

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

			if ((response->flags & DNS_MESSAGEFLAG_RD) != 0 &&
			    (response->flags & DNS_MESSAGEFLAG_RA) == 0)
			{
				printf(";; WARNING: recursion requested "
				       "but not available\n");
			}
		}
	}

repopulate_buffer:

	if (display_comments && display_headers && !display_short_form) {
		result = dns_message_pseudosectiontotext(
			response, DNS_PSEUDOSECTION_OPT, style, flags, buf);
		if (result == ISC_R_NOSPACE) {
		buftoosmall:
			len += OUTPUTBUF;
			isc_buffer_free(&buf);
			isc_buffer_allocate(isc_g_mctx, &buf, len);
			goto repopulate_buffer;
		}
		CHECKM("dns_message_pseudosectiontotext", result);
	}

	if (display_question && display_headers && !display_short_form) {
		result = dns_message_sectiontotext(
			response, DNS_SECTION_QUESTION, style, flags, buf);
		if (result == ISC_R_NOSPACE) {
			goto buftoosmall;
		}
		CHECKM("dns_message_sectiontotext", result);
	}

	if (display_answer && !display_short_form) {
		result = dns_message_sectiontotext(response, DNS_SECTION_ANSWER,
						   style, flags, buf);
		if (result == ISC_R_NOSPACE) {
			goto buftoosmall;
		}
		CHECKM("dns_message_sectiontotext", result);
	} else if (display_answer) {
		dns_name_t empty_name;
		unsigned int answerstyleflags = 0;

		if (!display_crypto) {
			answerstyleflags |= DNS_STYLEFLAG_NOCRYPTO;
		}
		if (display_unknown_format) {
			answerstyleflags |= DNS_STYLEFLAG_UNKNOWNFORMAT;
		}

		dns_name_init(&empty_name);

		MSG_SECTION_FOREACH(response, DNS_SECTION_ANSWER, name) {
			ISC_LIST_FOREACH(name->list, rdataset, link) {
				DNS_RDATASET_FOREACH(rdataset) {
					dns_rdata_t rdata = DNS_RDATA_INIT;
					dns_rdataset_current(rdataset, &rdata);
					result = dns_rdata_tofmttext(
						&rdata, NULL, answerstyleflags,
						0, 60, " ", buf);
					if (result == ISC_R_NOSPACE) {
						goto buftoosmall;
					}
					CHECKM("dns_rdata_tofmttext", result);
					if (strlen("\n") >=
					    isc_buffer_availablelength(buf))
					{
						goto buftoosmall;
					}
					isc_buffer_putstr(buf, "\n");
				}
			}
		}
	}

	if (display_authority && !display_short_form) {
		result = dns_message_sectiontotext(
			response, DNS_SECTION_AUTHORITY, style, flags, buf);
		if (result == ISC_R_NOSPACE) {
			goto buftoosmall;
		}
		CHECKM("dns_message_sectiontotext", result);
	}

	if (display_additional && !display_short_form) {
		result = dns_message_sectiontotext(
			response, DNS_SECTION_ADDITIONAL, style, flags, buf);
		if (result == ISC_R_NOSPACE) {
			goto buftoosmall;
		}
		CHECKM("dns_message_sectiontotext", result);
	}

	if (display_additional && !display_short_form && display_headers) {
		/*
		 * Only print the signature on the first record.
		 */
		result = dns_message_pseudosectiontotext(
			response, DNS_PSEUDOSECTION_TSIG, style, flags, buf);
		if (result == ISC_R_NOSPACE) {
			goto buftoosmall;
		}
		CHECKM("dns_message_pseudosectiontotext", result);
		result = dns_message_pseudosectiontotext(
			response, DNS_PSEUDOSECTION_SIG0, style, flags, buf);
		if (result == ISC_R_NOSPACE) {
			goto buftoosmall;
		}
		CHECKM("dns_message_pseudosectiontotext", result);
	}

	if (display_headers && display_comments && !display_short_form && !yaml)
	{
		printf("\n");
	}

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

cleanup:
	fflush(stdout);
	if (style != NULL) {
		dns_master_styledestroy(&style, isc_g_mctx);
	}
	if (query != NULL) {
		dns_message_detach(&query);
	}
	if (response != NULL) {
		dns_message_detach(&response);
	}
	dns_request_destroy(&request);

	if (--onfly == 0) {
		isc_loopmgr_shutdown();
	}
	return;
}

static void
compute_cookie(unsigned char *cookie, size_t len) {
	/* XXXMPA need to fix, should be per server. */
	INSIST(len >= 8U);
	memmove(cookie, cookie_secret, 8);
}

static isc_result_t
sendquery(struct query *query) {
	dns_request_t *request = NULL;
	dns_message_t *message = NULL;
	dns_name_t *qname = NULL;
	dns_rdataset_t *qrdataset = NULL;
	isc_result_t result;
	dns_fixedname_t queryname;
	isc_buffer_t buf;
	unsigned int options = 0;

	onfly++;

	dns_fixedname_init(&queryname);
	isc_buffer_init(&buf, query->textname, strlen(query->textname));
	isc_buffer_add(&buf, strlen(query->textname));
	result = dns_name_fromtext(dns_fixedname_name(&queryname), &buf,
				   dns_rootname, 0);
	CHECKM("dns_name_fromtext", result);

	dns_message_create(isc_g_mctx, NULL, NULL, DNS_MESSAGE_INTENTRENDER,
			   &message);

	message->opcode = dns_opcode_query;
	if (query->recurse) {
		message->flags |= DNS_MESSAGEFLAG_RD;
	}
	if (query->have_aaonly) {
		message->flags |= DNS_MESSAGEFLAG_AA;
	}
	if (query->have_adflag) {
		message->flags |= DNS_MESSAGEFLAG_AD;
	}
	if (query->have_cdflag) {
		message->flags |= DNS_MESSAGEFLAG_CD;
	}
	if (query->have_zflag) {
		message->flags |= 0x0040U;
	}
	message->rdclass = query->rdclass;
	message->id = (unsigned short)(random() & 0xFFFF);

	dns_message_gettempname(message, &qname);

	dns_message_gettemprdataset(message, &qrdataset);

	dns_name_clone(dns_fixedname_name(&queryname), qname);
	dns_rdataset_makequestion(qrdataset, query->rdclass, query->rdtype);
	ISC_LIST_APPEND(qname->list, qrdataset, link);
	dns_message_addname(message, qname, DNS_SECTION_QUESTION);

	if (query->udpsize > 0 || query->dnssec || query->edns > -1 ||
	    query->ecs_addr != NULL)
	{
		unsigned int flags;
		char ecsbuf[20];
		unsigned char cookie[40];

		flags = query->ednsflags;
		flags &= ~DNS_MESSAGEEXTFLAG_DO;
		if (query->dnssec) {
			flags |= DNS_MESSAGEEXTFLAG_DO;
		}

		if (query->udpsize == 0) {
			query->udpsize = 1232;
		}
		if (query->edns < 0) {
			query->edns = 0;
		}

		dns_message_ednsinit(message, query->edns, query->udpsize,
				     flags, 0);

		if (query->nsid) {
			dns_ednsopt_t option = { .code = DNS_OPT_NSID };
			result = dns_message_ednsaddopt(message, &option);
			CHECKM("dns_message_ednsaddopt", result);
		}

		if (query->ecs_addr != NULL) {
			uint8_t addr[16], family;
			uint32_t plen;
			struct sockaddr *sa;
			struct sockaddr_in *sin;
			struct sockaddr_in6 *sin6;
			size_t addrl;
			isc_buffer_t b;

			sa = &query->ecs_addr->type.sa;
			plen = query->ecs_addr->length;

			/* Round up prefix len to a multiple of 8 */
			addrl = (plen + 7) / 8;

			isc_buffer_init(&b, ecsbuf, sizeof(ecsbuf));
			if (sa->sa_family == AF_INET) {
				family = 1;
				sin = (struct sockaddr_in *)sa;
				memmove(addr, &sin->sin_addr, 4);
				if ((plen % 8) != 0) {
					addr[addrl - 1] &= ~0U
							   << (8 - (plen % 8));
				}
			} else {
				family = 2;
				sin6 = (struct sockaddr_in6 *)sa;
				memmove(addr, &sin6->sin6_addr, 16);
			}

			/* Mask off last address byte */
			if (addrl > 0 && (plen % 8) != 0) {
				addr[addrl - 1] &= ~0U << (8 - (plen % 8));
			}

			/* family */
			isc_buffer_putuint16(&b, family);
			/* source prefix-length */
			isc_buffer_putuint8(&b, plen);
			/* scope prefix-length */
			isc_buffer_putuint8(&b, 0);
			/* address */
			if (addrl > 0) {
				isc_buffer_putmem(&b, addr,
						  (unsigned int)addrl);
			}

			dns_ednsopt_t option = { .code = DNS_OPT_CLIENT_SUBNET,
						 .value = (uint8_t *)ecsbuf,
						 .length = (uint16_t)addrl +
							   4 };
			result = dns_message_ednsaddopt(message, &option);
			CHECKM("dns_message_ednsaddopt", result);
		}

		if (query->send_cookie) {
			dns_ednsopt_t option = { .code = DNS_OPT_COOKIE };
			if (query->cookie != NULL) {
				isc_buffer_t b;

				isc_buffer_init(&b, cookie, sizeof(cookie));
				result = isc_hex_decodestring(query->cookie,
							      &b);
				CHECKM("isc_hex_decodestring", result);
				option.value = isc_buffer_base(&b);
				option.length = isc_buffer_usedlength(&b);
			} else {
				compute_cookie(cookie, 8);
				option.length = 8;
				option.value = cookie;
			}

			result = dns_message_ednsaddopt(message, &option);
			CHECKM("dns_message_ednsaddopt", result);
		}

		if (query->expire) {
			dns_ednsopt_t option = { .code = DNS_OPT_EXPIRE };
			result = dns_message_ednsaddopt(message, &option);
			CHECKM("dns_message_ednsaddopt", result);
		}

		if (query->ednsoptscnt != 0) {
			for (size_t i = 0; i < query->ednsoptscnt; i++) {
				result = dns_message_ednsaddopt(
					message, &query->ednsopts[i]);
				CHECKM("dns_message_ednsaddopt", result);
			}
		}

		result = dns_message_setopt(message);
		CHECKM("dns_message_setopt", result);
	}

	if (tcp_mode) {
		options |= DNS_REQUESTOPT_TCP;
	}

	result = dns_request_create(
		requestmgr, message, have_src ? &srcaddr : NULL, &dstaddr, NULL,
		NULL, options, NULL, query->timeout, query->timeout,
		query->udptimeout, query->udpretries, isc_loop_main(),
		recvresponse, message, &request);
	CHECKM("dns_request_create", result);

	return ISC_R_SUCCESS;
}

static void
sendqueries(void *arg) {
	struct query *query = (struct query *)arg;

	while (query != NULL) {
		struct query *next = ISC_LIST_NEXT(query, link);

		sendquery(query);
		query = next;
	}

	if (onfly == 0) {
		isc_loopmgr_shutdown();
	}
}

ISC_NORETURN static void
usage(void);

static void
usage(void) {
	fprintf(stderr, "Usage: mdig @server {global-opt} host\n"
			"           {local-opt} [ host {local-opt} [...]]\n"
			"\nUse \"mdig -h\" (or \"mdig -h | more\") "
			"for complete list of options\n");
	exit(EXIT_FAILURE);
}

/*% help */
static void
help(void) {
	printf("Usage: mdig @server {global-opt} host\n"
	       "           {local-opt} [ host {local-opt} [...]]\n"
	       "Where:\n"
	       " anywhere opt    is one of:\n"
	       "                 -f filename         (batch mode)\n"
	       "                 -h                  (print help and exit)\n"
	       "                 -v                  (print version and exit)\n"
	       " global opt      is one of:\n"
	       "                 -4                  (use IPv4 query transport "
	       "only)\n"
	       "                 -6                  (use IPv6 query transport "
	       "only)\n"
	       "                 -b address[#port]   (bind to source "
	       "address/port)\n"
	       "                 -p port             (specify port number)\n"
	       "                 -m                  (enable memory usage "
	       "debugging)\n"
	       "                 +[no]vc             (TCP mode)\n"
	       "                 +[no]tcp            (TCP mode, alternate "
	       "syntax)\n"
	       "                 +[no]besteffort     (Try to parse even "
	       "illegal "
	       "messages)\n"
	       "                 +[no]cl             (Control display of class "
	       "in records)\n"
	       "                 +[no]comments       (Control display of "
	       "comment lines)\n"
	       "                 +[no]rrcomments     (Control display of "
	       "per-record "
	       "comments)\n"
	       "                 +[no]crypto         (Control display of "
	       "cryptographic "
	       "fields in records)\n"
	       "                 +[no]question       (Control display of "
	       "question)\n"
	       "                 +[no]answer         (Control display of "
	       "answer)\n"
	       "                 +[no]authority      (Control display of "
	       "authority)\n"
	       "                 +[no]additional     (Control display of "
	       "additional)\n"
	       "                 +[no]short          (Disable everything "
	       "except "
	       "short\n"
	       "                                      form of answer)\n"
	       "                 +[no]ttlid          (Control display of ttls "
	       "in records)\n"
	       "                 +[no]ttlunits       (Display TTLs in "
	       "human-readable units)\n"
	       "                 +[no]unknownformat  (Print RDATA in RFC 3597 "
	       "\"unknown\" format)\n"
	       "                 +[no]all            (Set or clear all display "
	       "flags)\n"
	       "                 +[no]multiline      (Print records in an "
	       "expanded format)\n"
	       "                 +[no]split=##       (Split hex/base64 fields "
	       "into chunks)\n"
	       " local opt       is one of:\n"
	       "                 -c class            (specify query class)\n"
	       "                 -t type             (specify query type)\n"
	       "                 -x dot-notation     (shortcut for reverse "
	       "lookups)\n"
	       "                 +timeout=###        (Set query timeout) "
	       "[UDP=5,TCP=10]\n"
	       "                 +udptimeout=###     (Set timeout before UDP "
	       "retry)\n"
	       "                 +tries=###          (Set number of UDP "
	       "attempts) [3]\n"
	       "                 +retry=###          (Set number of UDP "
	       "retries) [2]\n"
	       "                 +bufsize=###        (Set EDNS0 Max UDP packet "
	       "size)\n"
	       "                 +subnet=addr        (Set edns-client-subnet "
	       "option)\n"
	       "                 +[no]edns[=###]     (Set EDNS version) [0]\n"
	       "                 +ednsflags=###      (Set EDNS flag bits)\n"
	       "                 +ednsopt=###[:value] (Send specified EDNS "
	       "option)\n"
	       "                 +noednsopt          (Clear list of +ednsopt "
	       "options)\n"
	       "                 +[no]recurse        (Recursive mode)\n"
	       "                 +[no]aaonly         (Set AA flag in query "
	       "(+[no]aaflag))\n"
	       "                 +[no]adflag         (Set AD flag in query)\n"
	       "                 +[no]cdflag         (Set CD flag in query)\n"
	       "                 +[no]zflag          (Set Z flag in query)\n"
	       "                 +[no]dnssec         (Request DNSSEC records)\n"
	       "                 +[no]expire         (Request time to expire)\n"
	       "                 +[no]cookie[=###]   (Send a COOKIE option)\n"
	       "                 +[no]nsid           (Request Name "
	       "Server ID)\n");
}

ISC_NORETURN static void
fatal(const char *format, ...) ISC_FORMAT_PRINTF(1, 2);

static void
fatal(const char *format, ...) {
	va_list args;

	fflush(stdout);
	fprintf(stderr, "mdig: ");
	va_start(args, format);
	vfprintf(stderr, format, args);
	va_end(args);
	fprintf(stderr, "\n");
	_exit(EXIT_FAILURE);
}

static isc_result_t
parse_uint_helper(uint32_t *uip, const char *value, uint32_t max,
		  const char *desc, int base) {
	uint32_t n;
	isc_result_t result = isc_parse_uint32(&n, value, base);
	if (result == ISC_R_SUCCESS && n > max) {
		result = ISC_R_RANGE;
	}
	if (result != ISC_R_SUCCESS) {
		printf("invalid %s '%s': %s\n", desc, value,
		       isc_result_totext(result));
		return result;
	}
	*uip = n;
	return ISC_R_SUCCESS;
}

static isc_result_t
parse_uint(uint32_t *uip, const char *value, uint32_t max, const char *desc) {
	return parse_uint_helper(uip, value, max, desc, 10);
}

static isc_result_t
parse_xint(uint32_t *uip, const char *value, uint32_t max, const char *desc) {
	return parse_uint_helper(uip, value, max, desc, 0);
}

static void
newopts(struct query *query) {
	size_t len = sizeof(query->ednsopts[0]) * EDNSOPTS;
	size_t i;

	query->ednsopts = isc_mem_allocate(isc_g_mctx, len);

	for (i = 0; i < EDNSOPTS; i++) {
		query->ednsopts[i].code = 0;
		query->ednsopts[i].length = 0;
		query->ednsopts[i].value = NULL;
	}
}

static void
save_opt(struct query *query, char *code, char *value) {
	uint32_t num;
	isc_buffer_t b;
	isc_result_t result;

	if (query->ednsopts == NULL) {
		newopts(query);
	}

	if (query->ednsoptscnt == EDNSOPTS) {
		fatal("too many ednsopts");
	}

	result = parse_uint(&num, code, 65535, "ednsopt");
	if (result != ISC_R_SUCCESS) {
		fatal("bad edns code point: %s", code);
	}

	query->ednsopts[query->ednsoptscnt].code = num;
	query->ednsopts[query->ednsoptscnt].length = 0;
	query->ednsopts[query->ednsoptscnt].value = NULL;

	if (value != NULL) {
		char *buf;
		buf = isc_mem_allocate(isc_g_mctx, strlen(value) / 2 + 1);
		isc_buffer_init(&b, buf, strlen(value) / 2 + 1);
		result = isc_hex_decodestring(value, &b);
		CHECKM("isc_hex_decodestring", result);
		query->ednsopts[query->ednsoptscnt].value = isc_buffer_base(&b);
		query->ednsopts[query->ednsoptscnt].length =
			isc_buffer_usedlength(&b);
	}

	query->ednsoptscnt++;
}

static isc_result_t
parse_netprefix(isc_sockaddr_t **sap, const char *value) {
	isc_sockaddr_t *sa = NULL;
	struct in_addr in4;
	struct in6_addr in6;
	uint32_t netmask = 0xffffffff;
	char *slash = NULL;
	bool parsed = false;
	char buf[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:XXX.XXX.XXX.XXX/128")];

	if (strlcpy(buf, value, sizeof(buf)) >= sizeof(buf)) {
		fatal("invalid prefix '%s'\n", value);
	}

	slash = strchr(buf, '/');
	if (slash != NULL) {
		isc_result_t result;
		*slash = '\0';
		result = isc_parse_uint32(&netmask, slash + 1, 10);
		if (result != ISC_R_SUCCESS) {
			fatal("invalid prefix length in '%s': %s\n", value,
			      isc_result_totext(result));
		}
	} else if (strcmp(value, "0") == 0) {
		netmask = 0;
	}

	sa = isc_mem_allocate(isc_g_mctx, sizeof(*sa));
	if (inet_pton(AF_INET6, buf, &in6) == 1) {
		parsed = true;
		isc_sockaddr_fromin6(sa, &in6, 0);
		if (netmask > 128) {
			netmask = 128;
		}
	} else if (inet_pton(AF_INET, buf, &in4) == 1) {
		parsed = true;
		isc_sockaddr_fromin(sa, &in4, 0);
		if (netmask > 32) {
			netmask = 32;
		}
	} else if (netmask != 0xffffffff) {
		int i;

		for (i = 0; i < 3 && strlen(buf) < sizeof(buf) - 2; i++) {
			strlcat(buf, ".0", sizeof(buf));
			if (inet_pton(AF_INET, buf, &in4) == 1) {
				parsed = true;
				isc_sockaddr_fromin(sa, &in4, 0);
				break;
			}
		}

		if (netmask > 32) {
			netmask = 32;
		}
	}

	if (!parsed) {
		fatal("invalid address '%s'", value);
	}

	sa->length = netmask;
	*sap = sa;

	return ISC_R_SUCCESS;
}

/*%
 * Append 'len' bytes of 'text' at '*p', failing with
 * ISC_R_NOSPACE if that would advance p past 'end'.
 */
static isc_result_t
append(const char *text, int len, char **p, char *end) {
	if (len > end - *p) {
		return ISC_R_NOSPACE;
	}
	memmove(*p, text, len);
	*p += len;
	return ISC_R_SUCCESS;
}

static isc_result_t
reverse_octets(const char *in, char **p, char *end) {
	const char *dot = strchr(in, '.');
	int len;
	if (dot != NULL) {
		isc_result_t result;
		result = reverse_octets(dot + 1, p, end);
		CHECKM("reverse_octets", result);
		result = append(".", 1, p, end);
		CHECKM("append", result);
		len = (int)(dot - in);
	} else {
		len = strlen(in);
	}
	return append(in, len, p, end);
}

static void
get_reverse(char *reverse, size_t len, const char *value) {
	int r;
	isc_result_t result;
	isc_netaddr_t addr;

	addr.family = AF_INET6;
	r = inet_pton(AF_INET6, value, &addr.type.in6);
	if (r > 0) {
		/* This is a valid IPv6 address. */
		dns_fixedname_t fname;
		dns_name_t *name;

		name = dns_fixedname_initname(&fname);
		result = dns_byaddr_createptrname(&addr, name);
		CHECKM("dns_byaddr_createptrname", result);
		dns_name_format(name, reverse, (unsigned int)len);
		return;
	} else {
		/*
		 * Not a valid IPv6 address.  Assume IPv4.
		 * Construct the in-addr.arpa name by blindly
		 * reversing octets whether or not they look like
		 * integers, so that this can be used for RFC2317
		 * names and such.
		 */
		char *p = reverse;
		char *end = reverse + len;
		result = reverse_octets(value, &p, end);
		CHECKM("reverse_octets", result);
		/* Append .in-addr.arpa. and a terminating NUL. */
		result = append(".in-addr.arpa.", 15, &p, end);
		CHECKM("append", result);
		return;
	}
}

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

static void
plus_option(char *option, struct query *query, bool global) {
	isc_result_t result;
	char *cmd, *value, *last = NULL, *code;
	uint32_t num;
	bool state = true;
	size_t n;

	INSIST(option != NULL);

	if ((cmd = strtok_r(option, "=", &last)) == NULL) {
		printf(";; Invalid option %s\n", option);
		return;
	}
	if (strncasecmp(cmd, "no", 2) == 0) {
		cmd += 2;
		state = false;
	}
	/* parse the rest of the string */
	value = strtok_r(NULL, "", &last);

#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)
#define GLOBAL()                            \
	do {                                \
		if (!global)                \
			goto global_option; \
	} while (0)

	switch (cmd[0]) {
	case 'a':
		switch (cmd[1]) {
		case 'a': /* aaonly / aaflag */
			FULLCHECK2("aaonly", "aaflag");
			query->have_aaonly = state;
			break;
		case 'd':
			switch (cmd[2]) {
			case 'd': /* additional */
				FULLCHECK("additional");
				display_additional = state;
				break;
			case 'f':  /* adflag */
			case '\0': /* +ad is a synonym for +adflag */
				FULLCHECK("adflag");
				query->have_adflag = state;
				break;
			default:
				goto invalid_option;
			}
			break;
		case 'l': /* all */
			FULLCHECK("all");
			GLOBAL();
			display_question = state;
			display_answer = state;
			display_authority = state;
			display_additional = state;
			display_comments = state;
			display_rrcomments = state ? 1 : -1;
			break;
		case 'n': /* answer */
			FULLCHECK("answer");
			GLOBAL();
			display_answer = state;
			break;
		case 'u': /* authority */
			FULLCHECK("authority");
			GLOBAL();
			display_authority = state;
			break;
		default:
			goto invalid_option;
		}
		break;
	case 'b':
		switch (cmd[1]) {
		case 'e': /* besteffort */
			FULLCHECK("besteffort");
			GLOBAL();
			besteffort = state;
			break;
		case 'u':
			switch (cmd[2]) {
			case 'f': /* bufsize */
				FULLCHECK("bufsize");
				if (value == NULL) {
					goto need_value;
				}
				if (!state) {
					goto invalid_option;
				}
				result = parse_uint(&num, value, COMMSIZE,
						    "buffer size");
				CHECKM("parse_uint(buffer size)", result);
				query->udpsize = num;
				break;
			case 'r': /* burst */
				FULLCHECK("burst");
				GLOBAL();
				burst = state;
				break;
			default:
				goto invalid_option;
			}
			break;
		default:
			goto invalid_option;
		}
		break;
	case 'c':
		switch (cmd[1]) {
		case 'd': /* cdflag */
			switch (cmd[2]) {
			case 'f':  /* cdflag */
			case '\0': /* +cd is a synonym for +cdflag */
				FULLCHECK("cdflag");
				query->have_cdflag = state;
				break;
			default:
				goto invalid_option;
			}
			break;
		case 'l': /* cl */
			FULLCHECK("cl");
			GLOBAL();
			display_class = state;
			break;
		case 'o': /* comments */
			switch (cmd[2]) {
			case 'm':
				FULLCHECK("comments");
				GLOBAL();
				display_comments = state;
				break;
			case 'n':
				FULLCHECK("continue");
				GLOBAL();
				continue_on_error = state;
				break;
			case 'o':
				FULLCHECK("cookie");
				if (state && query->edns == -1) {
					query->edns = 0;
				}
				query->send_cookie = state;
				if (value != NULL) {
					n = strlcpy(hexcookie, value,
						    sizeof(hexcookie));
					if (n >= sizeof(hexcookie)) {
						fatal("COOKIE data too large");
					}
					query->cookie = hexcookie;
				} else {
					query->cookie = NULL;
				}
				break;
			default:
				goto invalid_option;
			}
			break;
		case 'r':
			FULLCHECK("crypto");
			GLOBAL();
			display_crypto = state;
			break;
		default:
			goto invalid_option;
		}
		break;
	case 'd':
		switch (cmd[1]) {
		case 'n': /* dnssec */
			FULLCHECK("dnssec");
			if (state && query->edns == -1) {
				query->edns = 0;
			}
			query->dnssec = state;
			break;
		default:
			goto invalid_option;
		}
		break;
	case 'e':
		switch (cmd[1]) {
		case 'd':
			switch (cmd[2]) {
			case 'n':
				switch (cmd[3]) {
				case 's':
					switch (cmd[4]) {
					case 0:
						FULLCHECK("edns");
						if (!state) {
							query->edns = -1;
							break;
						}
						if (value == NULL) {
							query->edns = 0;
							break;
						}
						result = parse_uint(&num, value,
								    255,
								    "edns");
						CHECKM("parse_uint(edns)",
						       result);
						query->edns = num;
						break;
					case 'f':
						FULLCHECK("ednsflags");
						if (!state) {
							query->ednsflags = 0;
							break;
						}
						if (value == NULL) {
							query->ednsflags = 0;
							break;
						}
						result = parse_xint(
							&num, value, 0xffff,
							"ednsflags");
						CHECKM("parse_xint(ednsflags)",
						       result);
						if (query->edns == -1) {
							query->edns = 1;
						}
						query->ednsflags = num;
						break;
					case 'o':
						FULLCHECK("ednsopt");
						if (!state) {
							query->ednsoptscnt = 0;
							break;
						}
						code = NULL;
						if (value != NULL) {
							code = strtok_r(value,
									":",
									&last);
						}
						if (code == NULL) {
							fatal("ednsopt no "
							      "code point "
							      "specified");
						}
						value = strtok_r(NULL, "\0",
								 &last);
						save_opt(query, code, value);
						break;
					default:
						goto invalid_option;
					}
					break;
				default:
					goto invalid_option;
				}
				break;
			default:
				goto invalid_option;
			}
			break;
		case 'x':
			FULLCHECK("expire");
			query->expire = state;
			break;
		default:
			goto invalid_option;
		}
		break;
	case 'm': /* multiline */
		FULLCHECK("multiline");
		GLOBAL();
		display_multiline = state;
		break;
	case 'n':
		FULLCHECK("nsid");
		if (state && query->edns == -1) {
			query->edns = 0;
		}
		query->nsid = state;
		break;
	case 'q':
		FULLCHECK("question");
		GLOBAL();
		display_question = state;
		break;
	case 'r':
		switch (cmd[1]) {
		case 'e':
			switch (cmd[2]) {
			case 'c': /* recurse */
				FULLCHECK("recurse");
				query->recurse = state;
				break;
			case 't': /* retry / retries */
				FULLCHECK2("retry", "retries");
				if (value == NULL) {
					goto need_value;
				}
				if (!state) {
					goto invalid_option;
				}
				result = parse_uint(&query->udpretries, value,
						    MAXTRIES - 1, "udpretries");
				CHECKM("parse_uint(udpretries)", result);
				break;
			default:
				goto invalid_option;
			}
			break;
		case 'r':
			FULLCHECK("rrcomments");
			GLOBAL();
			display_rrcomments = state ? 1 : -1;
			break;
		default:
			goto invalid_option;
		}
		break;
	case 's':
		switch (cmd[1]) {
		case 'h':
			FULLCHECK("short");
			GLOBAL();
			display_short_form = state;
			if (state) {
				display_question = false;
				display_answer = true;
				display_authority = false;
				display_additional = false;
				display_comments = false;
				display_rrcomments = -1;
			}
			break;
		case 'p': /* split */
			FULLCHECK("split");
			GLOBAL();
			if (value != NULL && !state) {
				goto invalid_option;
			}
			if (!state) {
				display_splitwidth = 0;
				break;
			} else if (value == NULL) {
				break;
			}

			result = parse_uint(&display_splitwidth, value, 1023,
					    "split");
			if ((display_splitwidth % 4) != 0) {
				display_splitwidth =
					((display_splitwidth + 3) / 4) * 4;
				fprintf(stderr,
					";; Warning, split must be "
					"a multiple of 4; adjusting "
					"to %u\n",
					display_splitwidth);
			}
			/*
			 * There is an adjustment done in the
			 * totext_<rrtype>() functions which causes
			 * splitwidth to shrink.  This is okay when we're
			 * using the default width but incorrect in this
			 * case, so we correct for it
			 */
			if (display_splitwidth) {
				display_splitwidth += 3;
			}
			CHECKM("parse_uint(split)", result);
			break;
		case 'u': /* subnet */
			FULLCHECK("subnet");
			if (state && value == NULL) {
				goto need_value;
			}
			if (!state) {
				if (query->ecs_addr != NULL) {
					isc_mem_free(isc_g_mctx,
						     query->ecs_addr);
				}
				break;
			}
			if (query->edns == -1) {
				query->edns = 0;
			}
			result = parse_netprefix(&query->ecs_addr, value);
			CHECKM("parse_netprefix", result);
			break;
		default:
			goto invalid_option;
		}
		break;
	case 't':
		switch (cmd[1]) {
		case 'c': /* tcp */
			FULLCHECK("tcp");
			GLOBAL();
			tcp_mode = state;
			break;
		case 'i': /* timeout */
			FULLCHECK("timeout");
			if (value == NULL) {
				goto need_value;
			}
			if (!state) {
				goto invalid_option;
			}
			result = parse_uint(&query->timeout, value, MAXTIMEOUT,
					    "timeout");
			CHECKM("parse_uint(timeout)", result);
			if (query->timeout == 0) {
				query->timeout = 1;
			}
			break;
		case 'r':
			FULLCHECK("tries");
			if (value == NULL) {
				goto need_value;
			}
			if (!state) {
				goto invalid_option;
			}
			result = parse_uint(&query->udpretries, value, MAXTRIES,
					    "udpretries");
			CHECKM("parse_uint(udpretries)", result);
			if (query->udpretries > 0) {
				query->udpretries -= 1;
			}
			break;
		case 't':
			switch (cmd[2]) {
			case 'l':
				switch (cmd[3]) {
				case 0:
				case 'i': /* ttlid */
					FULLCHECK2("ttl", "ttlid");
					GLOBAL();
					display_ttl = state;
					break;
				case 'u': /* ttlunits */
					FULLCHECK("ttlunits");
					GLOBAL();
					display_ttl = true;
					display_ttlunits = state;
					break;
				default:
					goto invalid_option;
				}
				break;
			default:
				goto invalid_option;
			}
			break;
		default:
			goto invalid_option;
		}
		break;
	case 'u':
		switch (cmd[1]) {
		case 'd':
			FULLCHECK("udptimeout");
			if (value == NULL) {
				goto need_value;
			}
			if (!state) {
				goto invalid_option;
			}
			result = parse_uint(&query->udptimeout, value,
					    MAXTIMEOUT, "udptimeout");
			CHECKM("parse_uint(udptimeout)", result);
			break;
		case 'n':
			FULLCHECK("unknownformat");
			display_unknown_format = state;
			break;
		default:
			goto invalid_option;
		}
		break;
	case 'v':
		FULLCHECK("vc");
		GLOBAL();
		tcp_mode = state;
		break;
	case 'y': /* yaml */
		FULLCHECK("yaml");
		yaml = state;
		if (state) {
			display_rrcomments = 1;
		}
		break;
	case 'z': /* zflag */
		FULLCHECK("zflag");
		query->have_zflag = state;
		break;
	global_option:
		fprintf(stderr, "Ignored late global option: +%s\n", option);
		break;
	default:
	invalid_option:
	need_value:
		fprintf(stderr, "Invalid option: +%s\n", option);
		usage();
	}
	return;
}

/*%
 * #true returned if value was used
 */
static const char *single_dash_opts = "46himv";
static const char *dash_opts = "46bcfhiptvx";
static bool
dash_option(const char *option, char *next, struct query *query, bool global,
	    bool *setname) {
	char opt;
	const char *value;
	isc_result_t result;
	bool value_from_next;
	isc_consttextregion_t tr;
	dns_rdatatype_t rdtype;
	dns_rdataclass_t rdclass;
	char textname[MXNAME];
	struct in_addr in4;
	struct in6_addr in6;
	in_port_t srcport;
	char *hash;
	uint32_t num;

	while (strpbrk(option, single_dash_opts) == &option[0]) {
		/*
		 * Since the -[46hiv] options do not take an argument,
		 * account for them (in any number and/or combination)
		 * if they appear as the first character(s) of an opt.
		 */
		opt = option[0];
		switch (opt) {
		case '4':
			GLOBAL();
			if (have_ipv4) {
				isc_net_disableipv6();
				have_ipv6 = false;
			} else {
				fatal("can't find IPv4 networking");
				UNREACHABLE();
				return false;
			}
			break;
		case '6':
			GLOBAL();
			if (have_ipv6) {
				isc_net_disableipv4();
				have_ipv4 = false;
			} else {
				fatal("can't find IPv6 networking");
				UNREACHABLE();
				return false;
			}
			break;
		case 'h':
			help();
			exit(EXIT_SUCCESS);
			break;
		case 'i':
			fatal("-%c removed", opt);
		case 'm':
			/*
			 * handled by preparse_args()
			 */
			break;
		case 'v':
			printf("mDiG %s\n", PACKAGE_VERSION);
			exit(EXIT_SUCCESS);
			break;
		}
		if (strlen(option) > 1U) {
			option = &option[1];
		} else {
			return false;
		}
	}
	opt = option[0];
	if (strlen(option) > 1U) {
		value_from_next = false;
		value = &option[1];
	} else {
		value_from_next = true;
		value = next;
	}
	if (value == NULL) {
		goto invalid_option;
	}
	switch (opt) {
	case 'b':
		GLOBAL();
		hash = strchr(value, '#');
		if (hash != NULL) {
			result = parse_uint(&num, hash + 1, MAXPORT,
					    "port number");
			CHECKM("parse_uint(srcport)", result);
			srcport = num;
			*hash = '\0';
		} else {
			srcport = 0;
		}
		if (have_ipv6 && inet_pton(AF_INET6, value, &in6) == 1) {
			isc_sockaddr_fromin6(&srcaddr, &in6, srcport);
			isc_net_disableipv4();
		} else if (have_ipv4 && inet_pton(AF_INET, value, &in4) == 1) {
			isc_sockaddr_fromin(&srcaddr, &in4, srcport);
			isc_net_disableipv6();
		} else {
			if (hash != NULL) {
				*hash = '#';
			}
			fatal("invalid address %s", value);
		}
		if (hash != NULL) {
			*hash = '#';
		}
		have_src = true;
		return value_from_next;
	case 'c':
		tr.base = value;
		tr.length = strlen(value);
		result = dns_rdataclass_fromtext(&rdclass,
						 (isc_textregion_t *)&tr);
		CHECKM("dns_rdataclass_fromtext", result);
		query->rdclass = rdclass;
		return value_from_next;
	case 'f':
		batchname = value;
		return value_from_next;
	case 'p':
		GLOBAL();
		result = parse_uint(&num, value, MAXPORT, "port number");
		CHECKM("parse_uint(port)", result);
		port = num;
		return value_from_next;
	case 't':
		tr.base = value;
		tr.length = strlen(value);
		result = dns_rdatatype_fromtext(&rdtype,
						(isc_textregion_t *)&tr);
		CHECKM("dns_rdatatype_fromtext", result);
		query->rdtype = rdtype;
		return value_from_next;
	case 'x':
		get_reverse(textname, sizeof(textname), value);
		strlcpy(query->textname, textname, sizeof(query->textname));
		query->rdtype = dns_rdatatype_ptr;
		query->rdclass = dns_rdataclass_in;
		*setname = true;
		return value_from_next;
	global_option:
		fprintf(stderr, "Ignored late global option: -%s\n", option);
		usage();
	default:
	invalid_option:
		fprintf(stderr, "Invalid option: -%s\n", option);
		usage();
	}
	UNREACHABLE();
	return false;
}

static struct query *
clone_default_query(void) {
	struct query *query;

	query = isc_mem_allocate(isc_g_mctx, sizeof(struct query));
	memmove(query, &default_query, sizeof(struct query));
	if (default_query.ecs_addr != NULL) {
		size_t len = sizeof(isc_sockaddr_t);

		query->ecs_addr = isc_mem_allocate(isc_g_mctx, len);
		memmove(query->ecs_addr, default_query.ecs_addr, len);
	}

	if (query->timeout == 0) {
		query->timeout = tcp_mode ? TCPTIMEOUT : UDPTIMEOUT;
	}

	return query;
}

/*%
 * Because we may be trying to do memory allocation recording, we're going
 * to need to parse the arguments for the -m *before* we start the main
 * argument parsing routine.
 *
 * I'd prefer not to have to do this, but I am not quite sure how else to
 * fix the problem.  Argument parsing in mdig involves memory allocation
 * by its nature, so it can't be done in the main argument parser.
 */
static void
preparse_args(int argc, char **argv) {
	int rc;
	char **rv;
	char *option;
	bool ipv4only = false, ipv6only = false;

	rc = argc;
	rv = argv;
	for (rc--, rv++; rc > 0; rc--, rv++) {
		if (rv[0][0] != '-') {
			continue;
		}
		option = &rv[0][1];
		while (strpbrk(option, single_dash_opts) == &option[0]) {
			switch (option[0]) {
			case 'm':
				isc_mem_debugon(ISC_MEM_DEBUGTRACE |
						ISC_MEM_DEBUGRECORD);
				break;
			case '4':
				if (ipv6only) {
					fatal("only one of -4 and -6 allowed");
				}
				ipv4only = true;
				break;
			case '6':
				if (ipv4only) {
					fatal("only one of -4 and -6 allowed");
				}
				ipv6only = true;
				break;
			}
			option = &option[1];
		}
		if (strlen(option) == 0U) {
			continue;
		}
		/* Look for dash value option. */
		if (strpbrk(option, dash_opts) != &option[0] ||
		    strlen(option) > 1U)
		{
			/* Error or value in option. */
			continue;
		}
		/* Dash value is next argument so we need to skip it. */
		rc--, rv++;
		/* Handle missing argument */
		if (rc == 0) {
			break;
		}
	}
}

static void
parse_args(bool is_batchfile, int argc, char **argv) {
	struct query *query = NULL;
	char batchline[MXNAME];
	int bargc;
	char *bargv[64];
	int rc;
	char **rv;
	bool global = true;
	char *last;

	/*
	 * The semantics for parsing the args is a bit complex; if
	 * we don't have a host yet, make the arg apply globally,
	 * otherwise make it apply to the latest host.  This is
	 * a bit different than the previous versions, but should
	 * form a consistent user interface.
	 *
	 * First, create a "default query" which won't actually be used
	 * anywhere, except for cloning into new queries
	 */

	if (!is_batchfile) {
		default_query.textname[0] = 0;
		default_query.recurse = true;
		default_query.have_aaonly = false;
		default_query.have_adflag = true; /*XXX*/
		default_query.have_cdflag = false;
		default_query.have_zflag = false;
		default_query.dnssec = false;
		default_query.expire = false;
		default_query.send_cookie = false;
		default_query.cookie = NULL;
		default_query.nsid = false;
		default_query.rdtype = dns_rdatatype_a;
		default_query.rdclass = dns_rdataclass_in;
		default_query.udpsize = 0;
		default_query.edns = 0; /*XXX*/
		default_query.ednsopts = NULL;
		default_query.ednsoptscnt = 0;
		default_query.ednsflags = 0;
		default_query.ecs_addr = NULL;
		default_query.timeout = 0;
		default_query.udptimeout = 0;
		default_query.udpretries = 2;
		ISC_LINK_INIT(&default_query, link);
	}

	if (is_batchfile) {
		/* Processing '-f batchfile'. */
		query = clone_default_query();
		global = false;
	} else {
		query = &default_query;
	}

	rc = argc;
	rv = argv;
	for (rc--, rv++; rc > 0; rc--, rv++) {
		if (strncmp(rv[0], "%", 1) == 0) {
			break;
		}
		if (rv[0][0] == '@') {
			if (server != NULL) {
				fatal("server already set to @%s", server);
			}
			server = &rv[0][1];
		} else if (rv[0][0] == '+') {
			plus_option(&rv[0][1], query, global);
		} else if (rv[0][0] == '-') {
			bool setname = false;

			if (rc <= 1) {
				if (dash_option(&rv[0][1], NULL, query, global,
						&setname))
				{
					rc--;
					rv++;
				}
			} else {
				if (dash_option(&rv[0][1], rv[1], query, global,
						&setname))
				{
					rc--;
					rv++;
				}
			}
			if (setname) {
				if (query == &default_query) {
					query = clone_default_query();
				}
				ISC_LIST_APPEND(queries, query, link);

				default_query.textname[0] = 0;
				query = clone_default_query();
				global = false;
			}
		} else {
			/*
			 * Anything which isn't an option
			 */
			if (query == &default_query) {
				query = clone_default_query();
			}
			strlcpy(query->textname, rv[0],
				sizeof(query->textname));
			ISC_LIST_APPEND(queries, query, link);

			query = clone_default_query();
			global = false;
			/* XXX Error message */
		}
	}

	/*
	 * If we have a batchfile, read the query list from it.
	 */
	if ((batchname != NULL) && !is_batchfile) {
		if (strcmp(batchname, "-") == 0) {
			batchfp = stdin;
		} else {
			batchfp = fopen(batchname, "r");
		}
		if (batchfp == NULL) {
			perror(batchname);
			fatal("couldn't open batch file '%s'", batchname);
		}
		while (fgets(batchline, sizeof(batchline), batchfp) != 0) {
			if (batchline[0] == '\r' || batchline[0] == '\n' ||
			    batchline[0] == '#' || batchline[0] == ';')
			{
				continue;
			}
			for (bargc = 1, bargv[bargc] = strtok_r(
						batchline, " \t\r\n", &last);
			     (bargc < 14) && bargv[bargc]; bargc++,
			    bargv[bargc] = strtok_r(NULL, " \t\r\n", &last))
			{
				/* empty body */
			}

			bargv[0] = argv[0];
			parse_args(true, bargc, (char **)bargv);
		}
		if (batchfp != stdin) {
			fclose(batchfp);
		}
	}
	if (query != &default_query) {
		if (query->ecs_addr != NULL) {
			isc_mem_free(isc_g_mctx, query->ecs_addr);
		}
		isc_mem_free(isc_g_mctx, query);
	}
}

/*
 * Try honoring the operating system's preferred ephemeral port range.
 */
static void
set_source_ports(dns_dispatchmgr_t *manager) {
	isc_portset_t *v4portset = NULL, *v6portset = NULL;
	in_port_t udpport_low, udpport_high;
	isc_result_t result;

	isc_portset_create(isc_g_mctx, &v4portset);
	result = isc_net_getudpportrange(AF_INET, &udpport_low, &udpport_high);
	if (result != ISC_R_SUCCESS) {
		fatal("isc_net_getudpportrange (v4) failed");
	}

	isc_portset_addrange(v4portset, udpport_low, udpport_high);

	isc_portset_create(isc_g_mctx, &v6portset);
	result = isc_net_getudpportrange(AF_INET6, &udpport_low, &udpport_high);
	if (result != ISC_R_SUCCESS) {
		fatal("isc_net_getudpportrange (v6) failed");
	}

	isc_portset_addrange(v6portset, udpport_low, udpport_high);

	result = dns_dispatchmgr_setavailports(manager, v4portset, v6portset);
	if (result != ISC_R_SUCCESS) {
		fatal("dns_dispatchmgr_setavailports failed");
	}

	isc_portset_destroy(isc_g_mctx, &v4portset);
	isc_portset_destroy(isc_g_mctx, &v6portset);
}

static void
teardown(void *arg ISC_ATTR_UNUSED) {
	dns_view_detach(&view);
	dns_requestmgr_shutdown(requestmgr);
	dns_requestmgr_detach(&requestmgr);
	dns_dispatch_detach(&dispatchvx);
	dns_dispatchmgr_detach(&dispatchmgr);
}

static void
setup(void *arg ISC_ATTR_UNUSED) {
	RUNCHECK(dns_dispatchmgr_create(isc_g_mctx, &dispatchmgr));

	set_source_ports(dispatchmgr);

	if (have_ipv4) {
		isc_sockaddr_any(&bind_any);
	} else {
		isc_sockaddr_any6(&bind_any);
	}
	RUNCHECK(dns_dispatch_createudp(
		dispatchmgr, have_src ? &srcaddr : &bind_any, &dispatchvx));

	RUNCHECK(dns_requestmgr_create(
		isc_g_mctx, dispatchmgr, have_ipv4 ? dispatchvx : NULL,
		have_ipv6 ? dispatchvx : NULL, &requestmgr));

	dns_view_create(isc_g_mctx, NULL, 0, "_mdig", &view);
}

/*% Main processing routine for mdig */
int
main(int argc, char *argv[]) {
	isc_result_t result;
	unsigned int i;
	int ns;

	if (isc_net_probeipv4() == ISC_R_SUCCESS) {
		have_ipv4 = true;
	}
	if (isc_net_probeipv6() == ISC_R_SUCCESS) {
		have_ipv6 = true;
	}
	if (!have_ipv4 && !have_ipv6) {
		fatal("could not find either IPv4 or IPv6");
	}

	preparse_args(argc, argv);

	isc_managers_create(1);

	isc_nonce_buf(cookie_secret, sizeof(cookie_secret));

	ISC_LIST_INIT(queries);
	parse_args(false, argc, argv);
	if (server == NULL) {
		fatal("a server '@xxx' is required");
	}

	ns = 0;
	result = isc_getaddresses(server, port, &dstaddr, 1, &ns);
	if (result != ISC_R_SUCCESS) {
		fatal("couldn't get address for '%s': %s", server,
		      isc_result_totext(result));
	}

	if (isc_sockaddr_pf(&dstaddr) == PF_INET && have_ipv6) {
		isc_net_disableipv6();
		have_ipv6 = false;
	} else if (isc_sockaddr_pf(&dstaddr) == PF_INET6 && have_ipv4) {
		isc_net_disableipv4();
		have_ipv4 = false;
	}
	if (have_ipv4 && have_ipv6) {
		fatal("can't choose between IPv4 and IPv6");
	}

	isc_loopmgr_setup(setup, NULL);
	isc_loopmgr_setup(sendqueries, ISC_LIST_HEAD(queries));
	isc_loopmgr_teardown(teardown, NULL);

	/*
	 * Stall to the start of a new second.
	 */
	if (burst) {
		isc_time_t start, now;
		start = isc_time_now();
		/*
		 * Sleep to 1ms of the end of the second then run a busy loop
		 * until the second changes.
		 */
		do {
			now = isc_time_now();
			if (isc_time_seconds(&start) == isc_time_seconds(&now))
			{
				unsigned int us = US_PER_SEC -
						  (isc_time_nanoseconds(&now) /
						   NS_PER_US);
				if (us > US_PER_MS) {
					usleep(us - US_PER_MS);
				}
			} else {
				break;
			}
		} while (1);
	}

	isc_loopmgr_run();

	ISC_LIST_FOREACH(queries, query, link) {
		if (query->ednsopts != NULL) {
			for (i = 0; i < EDNSOPTS; i++) {
				if (query->ednsopts[i].value != NULL) {
					isc_mem_free(isc_g_mctx,
						     query->ednsopts[i].value);
				}
			}
			isc_mem_free(isc_g_mctx, query->ednsopts);
		}
		if (query->ecs_addr != NULL) {
			isc_mem_free(isc_g_mctx, query->ecs_addr);
		}
		isc_mem_free(isc_g_mctx, query);
	}

	if (default_query.ecs_addr != NULL) {
		isc_mem_free(isc_g_mctx, default_query.ecs_addr);
	}

	isc_managers_destroy();
	return 0;
}
