/*
  * $Id$

  *
  * Copyright (C) 2001-2003 Fhg Fokus
  *
  * This file is part of ser, a free SIP server.
  *
  * ser is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version
  *
  * For a license to use the ser software under conditions
  * other than those described here, or to purchase support for this
  * software, please contact iptel.org by e-mail at the following addresses:
  *    info@iptel.org
  *
  * ser is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License 
  * along with this program; if not, write to the Free Software 
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

  *
  * History
  * --------

  *  2003-01-28  packet zero-termination moved to receive_msg (jiri)
  *  2003-02-10  undoed the above changes (andrei)
  *  2003-03-19  replaced all the mallocs/frees w/ pkg_malloc/pkg_free (andrei)

  *  2003-04-14  set sockopts to TOS low delay (andrei)

  */
 

 #include <stdlib.h>
 #include <string.h>

 #include <sys/types.h>
 #include <sys/socket.h>
 #include <netinet/in.h>

 #include <netinet/in_systm.h>

 #include <netinet/ip.h>

 #include <errno.h>

 #include <arpa/inet.h>

 #ifdef __linux__
 	#include <linux/types.h>
 	#include <linux/errqueue.h>
 #endif

 
 
 #include "udp_server.h"

 #include "globals.h"

 #include "config.h"
 #include "dprint.h"

 #include "receive.h"

 #include "mem/mem.h"

 #include "ip_addr.h"

 #ifdef DBG_MSG_QA
 /* message quality assurance -- frequently, bugs in ser have
    been indicated by zero characters or long whitespaces
    in generated messages; this debugging option aborts if
    any such message is sighted
 */
 static int dbg_msg_qa(char *buf, int len)
 {
 #define _DBG_WS_LEN 3
 #define _DBG_WS "   "
 
 	char *scan;
 	int my_len;
 	int space_cnt;
 	enum { QA_ANY, QA_SPACE, QA_EOL1 } state;
 
 
 	/* is there a zero character inthere ? */	
 	if (memchr(buf, 0, len)) {

 		LOG(L_CRIT, "BUG: message with 0 in it\n");

 		return 0;
 	}
 
 	my_len=len;
 	scan=buf;
 	state=QA_ANY;
 	space_cnt=0;
 
 	while(my_len) {
 		switch(*scan) {
 			case ' ':	if (state==QA_SPACE) {
 							space_cnt++;
 							if (space_cnt==4) {
 								LOG(L_CRIT, "BUG(propably): DBG_MSG_QA: "
 									"too many spaces\n");
 								return 0;
 							}
 						} else space_cnt=0;
 						state=QA_SPACE; 
 						break;
 
 			case '\r':	/* ignore */
 						space_cnt=0;
 						break;
 
 			case '\n': /* don't proceed to body on EoH */
 						if (state==QA_EOL1) goto qa_passed;
 						space_cnt=0;
 						state=QA_EOL1;
 						break;
 
 			default:	space_cnt=0;
 						state=QA_ANY;
 						break;
 		}
 		scan++;
 		my_len--;
 	}
 
 
 qa_passed:
 	return 1;
 }
 
 #endif
 

 int probe_max_receive_buffer( int udp_sock )

 {

 	int optval;

 	int ioptval;
 	unsigned int ioptvallen;
 	int foptval;
 	unsigned int foptvallen;
 	int voptval;
 	unsigned int voptvallen;

 	int phase=0;
 
 	/* jku: try to increase buffer size as much as we can */
 	ioptvallen=sizeof(ioptval);
 	if (getsockopt( udp_sock, SOL_SOCKET, SO_RCVBUF, (void*) &ioptval,
 		    &ioptvallen) == -1 )
 	{
 		LOG(L_ERR, "ERROR: udp_init: getsockopt: %s\n", strerror(errno));

 		return -1;

 	}
 	if ( ioptval==0 ) 
 	{
 		LOG(L_DBG, "DEBUG: udp_init: SO_RCVBUF initialy set to 0; resetting to %d\n",
 			BUFFER_INCREMENT );
 		ioptval=BUFFER_INCREMENT;
 	} else LOG(L_INFO, "INFO: udp_init: SO_RCVBUF is initially %d\n", ioptval );

 	for (optval=ioptval; ;  ) {

 		/* increase size; double in initial phase, add linearly later */
 		if (phase==0) optval <<= 1; else optval+=BUFFER_INCREMENT;

 		if (optval > maxbuffer){
 			if (phase==1) break; 

 			else { phase=1; optval >>=1; continue; }
 		}

 		LOG(L_DBG, "DEBUG: udp_init: trying SO_RCVBUF: %d\n", optval );

 		if (setsockopt( udp_sock, SOL_SOCKET, SO_RCVBUF,
 			(void*)&optval, sizeof(optval)) ==-1){

 			/* Solaris returns -1 if asked size too big; Linux ignores */

 			LOG(L_DBG, "DEBUG: udp_init: SOL_SOCKET failed"
 					" for %d, phase %d: %s\n", optval, phase, strerror(errno));

 			/* if setting buffer size failed and still in the aggressive
 			   phase, try less agressively; otherwise give up 
 			*/
 			if (phase==0) { phase=1; optval >>=1 ; continue; } 
 			else break;

 		} 

 		/* verify if change has taken effect */

 		/* Linux note -- otherwise I would never know that; funny thing: Linux
 		   doubles size for which we asked in setsockopt
 		*/

 		voptvallen=sizeof(voptval);
 		if (getsockopt( udp_sock, SOL_SOCKET, SO_RCVBUF, (void*) &voptval,
 		    &voptvallen) == -1 )
 		{
 			LOG(L_ERR, "ERROR: udp_init: getsockopt: %s\n", strerror(errno));

 			return -1;

 		} else {
 			LOG(L_DBG, "DEBUG: setting SO_RCVBUF; set=%d,verify=%d\n", 
 				optval, voptval);
 			if (voptval<optval) {
 				LOG(L_DBG, "DEBUG: setting SO_RCVBUF has no effect\n");
 				/* if setting buffer size failed and still in the aggressive

 				phase, try less agressively; otherwise give up 

 				*/

 				if (phase==0) { phase=1; optval >>=1 ; continue; } 
 				else break;

 			} 

 		}

 	} /* for ... */
 	foptvallen=sizeof(foptval);
 	if (getsockopt( udp_sock, SOL_SOCKET, SO_RCVBUF, (void*) &foptval,
 		    &foptvallen) == -1 )
 	{
 		LOG(L_ERR, "ERROR: udp_init: getsockopt: %s\n", strerror(errno));

 		return -1;

 	}

 	LOG(L_INFO, "INFO: udp_init: SO_RCVBUF is finally %d\n", foptval );

 	return 0;

 
 	/* EoJKU */

 }
 

 int udp_init(struct socket_info* sock_info)

 {

 	union sockaddr_union* addr;

 	int optval;

 	addr=&sock_info->su;
 /*

 	addr=(union sockaddr_union*)pkg_malloc(sizeof(union sockaddr_union));

 	if (addr==0){
 		LOG(L_ERR, "ERROR: udp_init: out of memory\n");
 		goto error;
 	}

 */

 	sock_info->proto=PROTO_UDP;

 	if (init_su(addr, &sock_info->address, sock_info->port_no)<0){

 		LOG(L_ERR, "ERROR: udp_init: could not init sockaddr_union\n");
 		goto error;
 	}

 	sock_info->socket = socket(AF2PF(addr->s.sa_family), SOCK_DGRAM, 0);
 	if (sock_info->socket==-1){

 		LOG(L_ERR, "ERROR: udp_init: socket: %s\n", strerror(errno));
 		goto error;
 	}
 	/* set sock opts? */
 	optval=1;

 	if (setsockopt(sock_info->socket, SOL_SOCKET, SO_REUSEADDR ,

 					(void*)&optval, sizeof(optval)) ==-1){
 		LOG(L_ERR, "ERROR: udp_init: setsockopt: %s\n", strerror(errno));
 		goto error;
 	}

 	/* tos */
 	optval=IPTOS_LOWDELAY;
 	if (setsockopt(sock_info->socket, IPPROTO_IP, IP_TOS, (void*)&optval, 
 			sizeof(optval)) ==-1){
 		LOG(L_WARN, "WARNING: udp_init: setsockopt tos: %s\n", strerror(errno));
 		/* continue since this is not critical */
 	}

 #if defined (__linux__) && defined(UDP_ERRORS)

 	optval=1;
 	/* enable error receiving on unconnected sockets */
 	if(setsockopt(sock_info->socket, SOL_IP, IP_RECVERR,
 					(void*)&optval, sizeof(optval)) ==-1){

 		LOG(L_ERR, "ERROR: udp_init: setsockopt: %s\n", strerror(errno));
 		goto error;
 	}

 #endif
 

 	if ( probe_max_receive_buffer(sock_info->socket)==-1) goto error;

 	if (bind(sock_info->socket,  &addr->s, sockaddru_len(*addr))==-1){

 		LOG(L_ERR, "ERROR: udp_init: bind(%x, %p, %d) on %s: %s\n",
 				sock_info->socket, &addr->s, 

 				sockaddru_len(*addr),

 				sock_info->address_str.s,
 				strerror(errno));
 	#ifdef USE_IPV6
 		if (addr->s.sa_family==AF_INET6)
 			LOG(L_ERR, "ERROR: udp_init: might be caused by using a link "
 					" local address, try site local or global\n");
 	#endif

 		goto error;
 	}
 

 /*	pkg_free(addr);*/

 	return 0;
 
 error:

 /*	if (addr) pkg_free(addr);*/

 	return -1;
 }
 
 
 
 int udp_rcv_loop()
 {

 	unsigned len;

 #ifdef DYN_BUF

 	char* buf;

 #else

 	static char buf [BUF_SIZE+1];

 #endif
 

 	union sockaddr_union* from;

 	unsigned int fromlen;

 	struct receive_info ri;

 	from=(union sockaddr_union*) pkg_malloc(sizeof(union sockaddr_union));

 	if (from==0){

 		LOG(L_ERR, "ERROR: udp_rcv_loop: out of memory\n");

 		goto error;
 	}

 	memset(from, 0 , sizeof(union sockaddr_union));

 	ri.bind_address=bind_address; /* this will not change, we do it only once*/
 	ri.dst_port=bind_address->port_no;
 	ri.dst_ip=bind_address->address;
 	ri.proto=PROTO_UDP;
 	ri.proto_reserved1=ri.proto_reserved2=0;

 	for(;;){

 #ifdef DYN_BUF

 		buf=pkg_malloc(BUF_SIZE+1);
 		if (buf==0){
 			LOG(L_ERR, "ERROR: udp_rcv_loop: could not allocate receive"
 					 " buffer\n");
 			goto error;
 		}

 #endif

 		fromlen=sockaddru_len(bind_address->su);

 		len=recvfrom(bind_address->socket, buf, BUF_SIZE, 0, &from->s,
 											&fromlen);

 		if (len==-1){

 			LOG(L_ERR, "ERROR: udp_rcv_loop:recvfrom:[%d] %s\n",
 						errno, strerror(errno));

 			if ((errno==EINTR)||(errno==EAGAIN)||(errno==EWOULDBLOCK)||
 					(errno==ECONNREFUSED))

 				continue; /* goto skip;*/

 			else goto error;
 		}

 		/* we must 0-term the messages, receive_msg expects it */

 		buf[len]=0; /* no need to save the previous char */

 
 #ifndef NO_ZERO_CHECKS

 		if (len<5) {
 			DBG("DEBUG: probing packet received\n");

 			continue;
 		}
 		if (buf[len-1]==0) {
 			LOG(L_WARN, "WARNING: upstream bug - 0-terminated packet\n");
 			len--;
 		}
 #endif

 #ifdef DBG_MSG_QA
 		if (!dbg_msg_qa(buf, len)) {

 			LOG(L_WARN, "WARNING: an incoming message didn't pass test,"
 						"  drop it: %.*s\n", len, buf );

 			continue;
 		}
 #endif

 		ri.src_su=*from;
 		su2ip_addr(&ri.src_ip, from);
 		ri.src_port=su_getport(from);
 		

 		
 		/* receive_msg must free buf too!*/

 		receive_msg(buf, len, &ri);

 	/* skip: do other stuff */

 		
 	}

 	/*

 	if (from) pkg_free(from);

 	return 0;

 	*/

 	
 error:

 	if (from) pkg_free(from);

 	return -1;
 }
 
 
 

 /* which socket to use? main socket or new one? */

 int udp_send(struct socket_info *source, char *buf, unsigned len,
 										union sockaddr_union*  to)

 {
 
 	int n;

 	int tolen;

 
 #ifdef DBG_MSG_QA
 	/* aborts on error, does nothing otherwise */

 	if (!dbg_msg_qa( buf, len )) {
 		LOG(L_ERR, "ERROR: udp_send: dbg_msg_qa failed\n");
 		abort();
 	}

 #endif
 

 	tolen=sockaddru_len(*to);

 again:

 	n=sendto(source->socket, buf, len, 0, &to->s, tolen);

 #ifdef XL_DEBUG
 	LOG(L_INFO, "INFO: send status: %d\n", n);
 #endif

 	if (n==-1){

 		LOG(L_ERR, "ERROR: udp_send: sendto(sock,%p,%d,0,%p,%d): %s(%d)\n",

 				buf,len,to,tolen,
 				strerror(errno),errno);

 		if (errno==EINTR) goto again;

 		if (errno==EINVAL) {
 			LOG(L_CRIT,"CRITICAL: invalid sendtoparameters\n"

 			"one possible reason is the server is bound to localhost and\n"
 			"attempts to send to the net\n");

 		}

 	}
 	return n;
 }