#include <windows.h>
#include <winbase.h>
#include <winsock.h>
#include <stdio.h>
#include "wresolv.h"

#ifndef SD_SEND
#define SD_SEND 1
#endif

MXDATA     *
allocMX(int c)
{
	int         i;
	MXDATA     *mx;

	mx = (MXDATA *) malloc(c * sizeof(MXDATA));
	if (mx) {
		memset(mx, 0, c * sizeof(MXDATA));
		for (i = 0; i < c; i++)
			mx[i].cbMX = c;
	}

	return (mx);
}

MXDATA     *
freeMX(MXDATA * mx)
{
	free(mx);
	return ((MXDATA *) NULL);
}

void
sortMX(MXDATA * mx)
{
	int         i,
	            k,
	            done;
	MXDATA      t;

	k = mx->cbMX;

	if (k < 2)
		return;

	done = 0;
	while (!done) {
		done = 1;
		for (i = 0; i < k - 1; i++) {
			if (mx[i].priority > mx[i + 1].priority) {
				memcpy(&t, &mx[i], sizeof(MXDATA));
				memcpy(&mx[i], &mx[i + 1], sizeof(MXDATA));
				memcpy(&mx[i + 1], &t, sizeof(MXDATA));
				done = 0;
			}
		}
	}
}

int
isIPLocal(MXDATA * mx, MXDATA * lmx)
{
	return (strcmp(mx->hIP, lmx->hIP) == 0);
}

void
setMX(MXDATA * mx, unsigned short *pri, char *hname, char *hip)
{
	if (hname != NULL)
		strcpy(mx->hName, hname);
	if (hip != NULL)
		strcpy(mx->hIP, hip);
	if (pri != NULL)
		mx->priority = *pri;
}

/*
 * Since domain names CAN begin with a digit, I rolled this so that we can
 * see if we are looking at a dotted-quad IP address or a domain name. 
 */
int
isdotip(char *p)
{
	int         i = 0,
	            k,
	            ret = 1;

	k = strlen(p);
	for (i = 0; i < k; i++) {
		if ((p[i] != '.') && (isalpha(p[i]))) {
			ret = 0;
			break;
		}
	}
	return (ret);
}

void
GetQName(char *pszHostName, unsigned char *p, char *pOrigBuf)
{
	int         i,
	            j,
	            k;
	unsigned short comp;

	for (i = 0; i < BUFSIZE; i++) {
		j = *p;
		if (j == 0)
			break;
		if (j & 0xc0) {
			comp = *(p + 1);
			GetQName(pszHostName, pOrigBuf + comp, pOrigBuf);
			return;
		}
		for (k = 1; k <= j; k++) {
			*pszHostName++ = *(p + k);
		}
		if (*(p + j + 1)) {
			*pszHostName++ = '.';
		}
		p += j + 1;
	}
	*pszHostName = 0;
}

int
PutQName(char *pszHostName, char *pQName)
{
	int         i,
	            j = 0,
	            k = 0;
	char        c;

	for (i = 0; *(pszHostName + i); i++) {
		c = *(pszHostName + i);
		// printf("%c",c);
		if (c == '.') {
			*(pQName + j) = (unsigned char) k;
			// printf("%c", k+'0');
			k = 0;
			j = i + 1;
		} else {
			*(pQName + i + 1) = c;
			k++;
		}
	}
	*(pQName + j) = (unsigned char) k;
	// printf("%c", k+'0');
	*(pQName + i + 1) = 0;
	return (i + 1);
}

void
stopTCP(SOCKET s)
{
	int         b;
	char        buf[256];

	shutdown(s, SD_SEND);
	while ((b = recv(s, buf, 256, 0)) != 0)
		if (b == SOCKET_ERROR)
			break;
	closesocket(s);
}

int
getTCP(SOCKET s, char *buf, int *count)
{
	int         nRC;

	*buf = '\0';

	nRC = recv(s, buf, *count, 0);
	if (nRC == SOCKET_ERROR)
		nRC = WSAGetLastError();
	else {
		*count = nRC;
		buf[nRC] = 0;
		nRC = 0;
	}

	return (nRC);
}

int
sendTCP(SOCKET s, char *buf, int count)
{
	int         nRC = 0;

	while (count) {
		nRC = send(s, buf, 1, 0);
		if (nRC == SOCKET_ERROR) {
			nRC = WSAGetLastError();
			break;
		} else {
			count--;
			buf++;
			nRC = 0;
		}
	}

	return (nRC);
}

// waits for ack from receiver and returns status code..
int
AckSend(SOCKET s)
{
	char        buf[1024];
	int         nRC,
	            c = 1024;

	if ((nRC = getTCP(s, buf, &c)) != SOCKET_ERROR) {
		return (atoi(buf));
	} else
		return SOCKET_ERROR;
}

// sends a string to socket and waits for ack from receiver..
int
sendSMTP(SOCKET s, char *buf)
{
	int         nRC,
	            c = strlen(buf);

	nRC = sendTCP(s, buf, c);

	if (nRC != SOCKET_ERROR)
		return (AckSend(s));

	return (nRC);
}

MXDATA     *
fixMX(MXDATA * mx, char *tDomain)
{
	struct hostent *ph;
	struct in_addr addr;
	int         i;

	if (!mx) {					// no MX records, create one with default
								// domain
		mx = (MXDATA *) malloc(sizeof(MXDATA));
		if (mx) {
			memset(mx, 0, sizeof(MXDATA));
			mx->cbMX = 1;
			strcpy(mx->hName, tDomain);
			ph = gethostbyname(tDomain);
			memcpy(&addr, ph->h_addr_list[0], sizeof(struct in_addr));
			strcpy(mx->hIP, inet_ntoa(addr));
		}
	} else {					// else, make sure we have IPs for all MX
								// records
		for (i = 0; i < mx[0].cbMX; i++) {
			if (!strlen(mx[i].hIP)) {
				ph = gethostbyname(mx[i].hName);
				memcpy(&addr, ph->h_addr_list[0], sizeof(struct in_addr));
				strcpy(mx[i].hIP, inet_ntoa(addr));
			}
		}
	}
	return (mx);
}