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/* @(#) implementation of network operations for udpxy
*
* Copyright 2008-2011 Pavel V. Cherenkov (pcherenkov@gmail.com)
*
* This file is part of udpxy.
*
* udpxy 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 3 of the License, or
* (at your option) any later version.
*
* udpxy 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 udpxy. If not, see <http://www.gnu.org/licenses/>.
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <assert.h>
#include <string.h>
#include <unistd.h>
#include <time.h>
#include <errno.h>
#include <stdio.h>
#include <fcntl.h>
#include "udpxy.h"
#include "netop.h"
#include "util.h"
#include "mtrace.h"
#include "osdef.h"
extern FILE* g_flog; /* application log */
/* set up (server) listening sockfd
*/
int
setup_listener( const char* ipaddr, int port, int* sockfd, int bklog )
{
#define LOWMARK 10 /* do not accept input of less than X octets */
int rc, lsock, wmark = LOWMARK;
struct sockaddr_in servaddr;
const int ON = 1;
extern const char IPv4_ALL[];
assert( (port > 0) && sockfd && ipaddr );
(void)IPv4_ALL;
TRACE( (void)tmfprintf( g_flog, "Setting up listener for [%s:%d]\n",
ipaddr[0] ? ipaddr : IPv4_ALL, port) );
rc = ERR_INTERNAL;
do {
lsock = socket( AF_INET, SOCK_STREAM, 0 );
if( -1 == lsock ) break;
(void) memset( &servaddr, 0, sizeof(servaddr) );
servaddr.sin_family = AF_INET;
servaddr.sin_port = htons( (short)port );
if( '\0' != ipaddr[0] ) {
if( 1 != inet_aton(ipaddr, &servaddr.sin_addr) ) {
TRACE( (void)tmfprintf( g_flog, "Invalid server IP: [%s]\n",
ipaddr) );
rc = ERR_PARAM;
break;
}
}
else {
servaddr.sin_addr.s_addr = htonl(INADDR_ANY);
}
rc = setsockopt( lsock, SOL_SOCKET, SO_REUSEADDR,
&ON, sizeof(ON) );
if( 0 != rc ) {
mperror(g_flog, errno, "%s: setsockopt SO_REUSEADDR",
__func__);
break;
}
#define NONBLOCK 1
rc = set_nblock (lsock, NONBLOCK);
if (0 != rc) break;
TRACE( (void)tmfprintf (g_flog, "Setting low watermark for "
"server socket [%d] to [%d]\n", lsock, wmark) );
rc = setsockopt (lsock, SOL_SOCKET, SO_RCVLOWAT,
(char*)&wmark, sizeof(wmark));
if (rc) {
mperror (g_flog, errno, "%s: setsockopt SO_RCVLOWAT",
__func__);
break;
}
rc = bind( lsock, (struct sockaddr*)&servaddr, sizeof(servaddr) );
if( 0 != rc ) break;
rc = listen (lsock, (bklog > 0 ? bklog : 1));
if( 0 != rc ) break;
rc = 0;
} while(0);
if( 0 != rc ) {
if(errno)
mperror(g_flog, errno, "%s: socket/bind/listen error",
__func__);
if( lsock ) {
(void) close( lsock );
}
}
else {
*sockfd = lsock;
TRACE( (void)tmfprintf( g_flog, "Created server socket=[%d], backlog=[%d]\n",
lsock, bklog) );
}
return rc;
}
/* add or drop membership in a multicast group
*/
int
set_multicast( int msockfd, const struct in_addr* mifaddr,
int opname )
{
struct sockaddr_in addr;
a_socklen_t len = sizeof(addr);
struct ip_mreq mreq;
int rc = 0;
const char *opstr =
((IP_DROP_MEMBERSHIP == opname) ? "DROP" :
((IP_ADD_MEMBERSHIP == opname) ? "ADD" : ""));
assert( opstr[0] );
assert( (msockfd > 0) && mifaddr );
(void) memset( &mreq, 0, sizeof(mreq) );
(void) memcpy( &mreq.imr_interface, mifaddr,
sizeof(struct in_addr) );
(void) memset( &addr, 0, sizeof(addr) );
rc = getsockname( msockfd, (struct sockaddr*)&addr, &len );
if( 0 != rc ) {
mperror( g_flog, errno, "%s: getsockname", __func__ );
return -1;
}
(void) memcpy( &mreq.imr_multiaddr, &addr.sin_addr,
sizeof(struct in_addr) );
rc = setsockopt( msockfd, IPPROTO_IP, opname,
&mreq, sizeof(mreq) );
if( 0 != rc ) {
mperror( g_flog, errno, "%s: setsockopt MCAST option: %s",
__func__, opstr );
return rc;
}
TRACE( (void)tmfprintf( g_flog, "multicast-group [%s]\n",
opstr ) );
return rc;
}
/* set up the socket to receive multicast data
*
*/
int
setup_mcast_listener( struct sockaddr_in* sa,
const struct in_addr* mifaddr,
int* mcastfd,
int sockbuflen )
{
int sockfd, rc;
int ON = 1;
int buflen = sockbuflen;
size_t rcvbuf_len = 0;
assert( sa && mifaddr && mcastfd && (sockbuflen >= 0) );
TRACE( (void)tmfprintf( g_flog, "Setting up multicast listener\n") );
rc = ERR_INTERNAL;
do {
sockfd = socket( AF_INET, SOCK_DGRAM, 0 );
if( -1 == sockfd ) {
mperror(g_flog, errno, "%s: socket", __func__);
break;
}
if (buflen != 0) {
rc = get_rcvbuf( sockfd, &rcvbuf_len );
if (0 != rc) break;
if ((size_t)buflen > rcvbuf_len) {
rc = set_rcvbuf( sockfd, buflen );
if (0 != rc) break;
}
}
else {
TRACE( (void)tmfprintf( g_flog, "Must not adjust buffer size "
"for mcast socket [%d]\n", sockfd ) );
}
rc = setsockopt( sockfd, SOL_SOCKET, SO_REUSEADDR,
&ON, sizeof(ON) );
if( 0 != rc ) {
mperror(g_flog, errno, "%s: setsockopt SO_REUSEADDR",
__func__);
break;
}
#ifdef SO_REUSEPORT
/* On some systems (such as FreeBSD) SO_REUSEADDR
just isn't enough to subscribe to N same channels for different clients.
*/
rc = setsockopt( sockfd, SOL_SOCKET, SO_REUSEPORT,
&ON, sizeof(ON) );
if( 0 != rc ) {
mperror(g_flog, errno, "%s: setsockopt SO_REUSEPORT",
__func__);
break;
}
#endif /* SO_REUSEPORT */
rc = bind( sockfd, (struct sockaddr*)sa, sizeof(*sa) );
if( 0 != rc ) {
mperror(g_flog, errno, "%s: bind", __func__);
break;
}
rc = set_multicast( sockfd, mifaddr, IP_ADD_MEMBERSHIP );
if( 0 != rc )
break;
} while(0);
if( 0 == rc ) {
*mcastfd = sockfd;
TRACE( (void)tmfprintf( g_flog, "Mcast listener socket=[%d] set up\n",
sockfd) );
}
else {
(void)close(sockfd);
}
return rc;
}
/* unsubscribe from multicast and close the reader socket
*/
void
close_mcast_listener( int msockfd, const struct in_addr* mifaddr )
{
assert( mifaddr );
if( msockfd <= 0 ) return;
(void) set_multicast( msockfd, mifaddr, IP_DROP_MEMBERSHIP );
(void) close( msockfd );
TRACE( (void)tmfprintf( g_flog, "Mcast listener socket=[%d] closed\n",
msockfd) );
return;
}
/* drop from and add into a multicast group
*/
int
renew_multicast( int msockfd, const struct in_addr* mifaddr )
{
int rc = 0;
rc = set_multicast( msockfd, mifaddr, IP_DROP_MEMBERSHIP );
if( 0 != rc ) return rc;
rc = set_multicast( msockfd, mifaddr, IP_ADD_MEMBERSHIP );
return rc;
}
/* set send/receive timeouts on socket(s)
*/
int
set_timeouts( int rsock, int ssock,
u_short rcv_tmout_sec, u_short rcv_tmout_usec,
u_short snd_tmout_sec, u_short snd_tmout_usec )
{
struct timeval rtv, stv;
int rc = 0;
if( rsock ) {
rtv.tv_sec = rcv_tmout_sec;
rtv.tv_usec = rcv_tmout_usec;
rc = setsockopt( rsock, SOL_SOCKET, SO_RCVTIMEO, &rtv, sizeof(rtv) );
if( -1 == rc ) {
mperror(g_flog, errno, "%s: setsockopt - SO_RCVTIMEO",
__func__);
return ERR_INTERNAL;
}
TRACE( (void)tmfprintf (g_flog, "socket %d: RCV timeout set to %ld sec, %ld usec\n",
rsock, rtv.tv_sec, rtv.tv_usec) );
}
if( ssock ) {
stv.tv_sec = snd_tmout_sec;
stv.tv_usec = snd_tmout_usec;
rc = setsockopt( ssock, SOL_SOCKET, SO_SNDTIMEO, &stv, sizeof(stv) );
if( -1 == rc ) {
mperror(g_flog, errno, "%s: setsockopt - SO_SNDTIMEO", __func__);
return ERR_INTERNAL;
}
TRACE( (void)tmfprintf (g_flog, "socket %d: SEND timeout set to %ld sec, %ld usec\n",
rsock, rtv.tv_sec, rtv.tv_usec) );
}
return rc;
}
/* set socket's send/receive buffer size
*/
static int
set_sockbuf_size( int sockfd, int option, const size_t len,
const char* bufname )
{
size_t data_len = len;
int rc = 0;
assert( bufname );
rc = setsockopt( sockfd, SOL_SOCKET, option,
&data_len, sizeof(data_len) );
if( 0 != rc ) {
mperror(g_flog, errno, "%s: setsockopt %s [%d]",
__func__, bufname, option);
return -1;
}
else {
TRACE( (void)tmfprintf( g_flog,
"%s buffer size set to [%u] bytes for socket [%d]\n",
bufname, data_len, sockfd ) );
}
return rc;
}
/* set socket's send buffer value
*/
int
set_sendbuf( int sockfd, const size_t len )
{
return set_sockbuf_size( sockfd, SO_SNDBUF, len, "send" );
}
/* set socket's send buffer value
*/
int
set_rcvbuf( int sockfd, const size_t len )
{
return set_sockbuf_size( sockfd, SO_RCVBUF, len, "receive" );
}
static int
get_sockbuf_size( int sockfd, int option, size_t* const len,
const char* bufname )
{
int rc = 0;
size_t buflen = 0;
socklen_t varsz = sizeof(buflen);
assert( sockfd && len && bufname );
rc = getsockopt( sockfd, SOL_SOCKET, option, &buflen, &varsz );
if (0 != rc) {
mperror( g_flog, errno, "%s: getsockopt (%s) [%d]", __func__,
bufname, option);
return -1;
}
else {
TRACE( (void)tmfprintf( g_flog,
"current %s buffer size is [%u] bytes for socket [%d]\n",
bufname, buflen, sockfd ) );
*len = buflen;
}
return rc;
}
/* get socket's send buffer size
*/
int
get_sendbuf( int sockfd, size_t* const len )
{
return get_sockbuf_size( sockfd, SO_SNDBUF, len, "send" );
}
/* get socket's receive buffer size
*/
int
get_rcvbuf( int sockfd, size_t* const len )
{
return get_sockbuf_size( sockfd, SO_RCVBUF, len, "receive" );
}
/* set/clear file/socket's mode as non-blocking
*/
int
set_nblock( int fd, int set )
{
int flags = 0;
flags = fcntl( fd, F_GETFL, 0 );
if( flags < 0 ) {
mperror( g_flog, errno, "%s: fcntl() getting flags on fd=[%d]",
__func__, fd );
return -1;
}
if( set )
flags |= O_NONBLOCK;
else
flags &= ~O_NONBLOCK;
if( fcntl( fd, F_SETFL, flags ) < 0 ) {
mperror( g_flog, errno, "%s: fcntl() %s non-blocking mode "
"on fd=[%d]", __func__, (set ? "setting" : "clearing"),
fd );
return -1;
}
return 0;
}
static int
sock_info (int peer, int sockfd, char* addr, size_t alen, int* port)
{
int rc = 0;
union {
struct sockaddr sa;
char data [sizeof(struct sockaddr_in6)];
} gsa;
socklen_t len;
const void* dst = NULL;
struct sockaddr_in6 *sa6 = NULL;
struct sockaddr_in *sa4 = NULL;
len = sizeof (gsa.data);
rc = peer ? getpeername (sockfd, (struct sockaddr*)gsa.data, &len):
getsockname (sockfd, (struct sockaddr*)gsa.data, &len);
if (0 != rc) {
rc = errno;
(void) fprintf (g_flog, "getsockname error [%d]: %s\n",
rc, strerror (rc));
return rc;
}
switch (gsa.sa.sa_family) {
case AF_INET:
sa4 = (struct sockaddr_in*)&gsa.sa;
if (addr) {
dst = inet_ntop (gsa.sa.sa_family, &(sa4->sin_addr),
addr, (socklen_t)alen);
}
if (port) *port = (int) ntohs (sa4->sin_port);
break;
case AF_INET6:
sa6 = (struct sockaddr_in6*)&gsa.sa;
if (addr) {
dst = inet_ntop (gsa.sa.sa_family, &(sa6->sin6_addr),
addr, (socklen_t)alen);
}
if (port) *port = (int) ntohs (sa6->sin6_port);
break;
default:
(void) tmfprintf (g_flog, "%s: unsupported socket family: %d\n",
__func__, (int)gsa.sa.sa_family);
return EAFNOSUPPORT;
}
if (addr && !dst) {
rc = errno;
(void) tmfprintf (g_flog, "%s: inet_pton error [%d]: %s\n",
__func__, rc, strerror (rc));
return rc;
}
return rc;
}
enum {e_host = 0, e_peer = 1};
int
get_sockinfo (int sockfd, char* addr, size_t alen, int* port)
{
return sock_info (e_host, sockfd, addr, alen, port);
}
int
get_peerinfo (int sockfd, char* addr, size_t alen, int* port)
{
return sock_info (e_peer, sockfd, addr, alen, port);
}
/* __EOF__ */