/*
   3APA3A simplest proxy server
   (c) 2002-2026 by Vladimir Dubrovin <vlad@3proxy.org>

   please read License Agreement
*/

#include "proxy.h"

int socksend(struct clientparam *param, SOCKET sock, unsigned char * buf, int bufsize, int to){
 int sent = 0;
 int res;
 struct pollfd fds;

 fds.fd = sock;
 fds.events = POLLOUT;
 do {
	if(conf.timetoexit) return 0;
	/* try to send first; poll only when the socket would block */
	res = param?param->srv->so._send(param->sostate, sock, (char *)buf + sent, bufsize - sent, 0) : so._send(so.state, sock, (char *)buf + sent, bufsize - sent, 0);
	if(res > 0) {
		sent += res;
		continue;
	}
	if(res < 0 && errno != EAGAIN && errno != EINTR) break;
	res = param?param->srv->so._poll(param->sostate, &fds, 1, to*1000):so._poll(so.state, &fds, 1, to*1000);
	if(res < 0 && (errno == EAGAIN || errno == EINTR)) continue;
	if(res < 1) break;
 } while (sent < bufsize);
 return sent;
}


int socksendto(struct clientparam *param, SOCKET sock, struct sockaddr * sin, unsigned char * buf, int bufsize, int to){
 int sent = 0;
 int res;
 struct pollfd fds;

 fds.fd = sock;
 do {
	if(conf.timetoexit) return 0;
	fds.events = POLLOUT;
	res = param?param->srv->so._poll(param->sostate, &fds, 1, to):so._poll(so.state, &fds, 1, to);
	if(res < 0 && (errno == EAGAIN || errno == EINTR)) continue;
	if(res < 1) break;
	res = param?param->srv->so._sendto(param->sostate, sock, (char *)buf + sent, bufsize - sent, 0, sin, SASIZE(sin)):so._sendto(so.state, sock, (char *)buf + sent, bufsize - sent, 0, sin, SASIZE(sin)); 
	if(res < 0) {
		if(errno !=  EAGAIN && errno != EINTR) break;
		continue;
	}
	sent += res;
 } while (sent < bufsize);
 return sent;
}

int sockrecvfrom(struct clientparam *param, SOCKET sock, struct sockaddr * sin, unsigned char * buf, int bufsize, int to){
	struct pollfd fds;
	SASIZETYPE sasize;
	int res;

	fds.fd = sock;
	fds.events = POLLIN;
	if(conf.timetoexit) return EOF;
	res = param?param->srv->so._poll(param->sostate, &fds, 1, to):so._poll(so.state, &fds, 1, to);
	if (res<1) return 0;
	sasize = SASIZE(sin);
	do {
		res = param?param->srv->so._recvfrom(param->sostate, sock, (char *)buf, bufsize, 0, (struct sockaddr *)sin, &sasize):so._recvfrom(so.state, sock, (char *)buf, bufsize, 0, (struct sockaddr *)sin, &sasize);
	} while (res < 0 && (errno == EAGAIN || errno == EINTR));
	return res;
}

int sockgetcharcli(struct clientparam * param, int timeosec, int timeousec){
	int len;

	if(!param->clibuf){
		if(!(param->clibuf = malloc(SRVBUFSIZE))) return 0;
		param->clibufsize = SRVBUFSIZE;
		param->clioffset = param->cliinbuf = 0;
	}
	if(param->cliinbuf && param->clioffset < param->cliinbuf){
		return (int)param->clibuf[param->clioffset++];
	}
	param->clioffset = param->cliinbuf = 0;
	if ((len = sockrecvfrom(param, param->clisock, (struct sockaddr *)&param->sincr, param->clibuf, param->clibufsize, timeosec*1000 + timeousec))<=0) return EOF;
	param->cliinbuf = len;
	param->clioffset = 1;
	return (int)*param->clibuf;
}

unsigned long sockfillbuffcli(struct clientparam * param, unsigned long size, int timeosec){
	int len;

	if(!param->clibuf) return 0;
	if(param->cliinbuf == param->clioffset){
		param->cliinbuf = param->clioffset = 0;
	}
	else if(param->clioffset){
		memmove(param->clibuf, param->clibuf + param->clioffset, param->cliinbuf - param->clioffset);
		param->cliinbuf -= param->clioffset;
		param->clioffset = 0;
	}
	if(size <= param->cliinbuf) return size;
	size -= param->cliinbuf;
	if((len = sockrecvfrom(param, param->clisock, (struct sockaddr *)&param->sincr, param->clibuf + param->cliinbuf, (param->clibufsize - param->cliinbuf) < size? param->clibufsize - param->cliinbuf:size, timeosec*1000)) > 0){
		param->cliinbuf += len;
	}
	return param->cliinbuf;
}

unsigned long sockfillbuffsrv(struct clientparam * param, unsigned long size, int timeosec){
	int len;

	if(!param->srvbuf) return 0;
	if(param->srvinbuf == param->srvoffset){
		param->srvinbuf = param->srvoffset = 0;
	}
	else if(param->srvoffset){
		memmove(param->srvbuf, param->srvbuf + param->srvoffset, param->srvinbuf - param->srvoffset);
		param->srvinbuf -= param->srvoffset;
		param->srvoffset = 0;
	}
	if(size <= param->srvinbuf) return size;
	size -= param->srvinbuf;
	if((len = sockrecvfrom(param, param->remsock, (struct sockaddr *)&param->sinsr, param->srvbuf + param->srvinbuf, (param->srvbufsize - param->srvinbuf) < size? param->srvbufsize - param->srvinbuf:size, timeosec*1000)) > 0){
		param->srvinbuf += len;
		param->nreads++;
		param->statssrv64 += len;
	}
	return param->srvinbuf;
}


int sockgetcharsrv(struct clientparam * param, int timeosec, int timeousec){
	int len;
	int bufsize;

	if(!param->srvbuf){
		bufsize = SRVBUFSIZE;
		if(param->ndatfilterssrv > 0 && bufsize < 32768) bufsize = 32768;
		if(!(param->srvbuf = malloc(bufsize))) return 0;
		param->srvbufsize = bufsize;
		param->srvoffset = param->srvinbuf = 0;
		
	}
	if(param->srvinbuf && param->srvoffset < param->srvinbuf){
		return (int)param->srvbuf[param->srvoffset++];
	}
	param->srvoffset = param->srvinbuf = 0;
	if ((len = sockrecvfrom(param, param->remsock, (struct sockaddr *)&param->sinsr, param->srvbuf, param->srvbufsize, timeosec*1000 + timeousec))<=0) return EOF;
	param->srvinbuf = len;
	param->srvoffset = 1;
	param->nreads++;
	param->statssrv64 += len;
	return (int)*param->srvbuf;
}

int sockgetlinebuf(struct clientparam * param, DIRECTION which, unsigned char * buf, int bufsize, int delim, int to){
 int c;
 int i=0;

 for(;;){
	unsigned char *base = which? param->srvbuf : param->clibuf;
	unsigned *offp = which? &param->srvoffset : &param->clioffset;
	unsigned *inp  = which? &param->srvinbuf  : &param->cliinbuf;

	/* drain already-buffered bytes in bulk instead of one call per byte */
	if(base && *offp < *inp && i < bufsize){
		int avail = (int)(*inp - *offp);
		int n = (bufsize - i < avail)? bufsize - i : avail;
		if(delim != EOF){
			unsigned char *d = (unsigned char *)memchr(base + *offp, delim, n);
			if(d) n = (int)(d - (base + *offp)) + 1;
			/* caller may use param->srvbuf / param->clibuf as buf */
			memmove(buf + i, base + *offp, n);
			i += n; *offp += n;
			if(d || i >= bufsize) return i;
		}
		else {
			memmove(buf + i, base + *offp, n);
			i += n; *offp += n;
			if(i >= bufsize) return i;
		}
	}
	if(i >= bufsize) return i;
	/* buffer empty: one call forces a refill (with poll + accounting), then bulk-drain the rest */
	if((c = which? sockgetcharsrv(param, to, 0) : sockgetcharcli(param, to, 0)) == EOF) return i;
	buf[i++] = c;
	if((delim != EOF && c == delim) || i >= bufsize) return i;
 }
}