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/* Released under GPLv2 with exception for the OpenSSL library. See license.txt */
#include <sys/types.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include "gen.h"
#include "io.h"
#include "tcp.h"
int connect_to(struct sockaddr *bind_to, struct addrinfo *ai, int timeout, char *tfo, char *msg, int msg_len, int *msg_accepted)
{
int fd;
int rc;
struct timeval to;
fd_set wfds;
/* create socket */
fd = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
if (fd == -1)
{
snprintf(last_error, sizeof last_error, "problem creating socket (%s)", strerror(errno));
return -1;
}
/* go through a specific interface? */
if (bind_to)
{
int set = 1;
/* set reuse flags */
if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &set, sizeof(set)) == -1)
{
close(fd);
snprintf(last_error, sizeof last_error, "error setting sockopt to interface (%s)", strerror(errno));
return -1;
}
if (bind(fd, bind_to, sizeof(*bind_to)) == -1)
{
close(fd);
snprintf(last_error, sizeof last_error, "error binding to interface (%s)", strerror(errno));
return -1;
}
}
/* make fd nonblocking */
if (set_fd_nonblocking(fd) == -1)
{
close(fd);
return -1;
}
/* wait for connection */
FD_ZERO(&wfds);
FD_SET(fd, &wfds);
to.tv_sec = timeout / 1000;
to.tv_usec = (timeout - (to.tv_sec * 1000)) * 1000;
/* connect to peer */
#ifdef TCP_TFO
if (*tfo)
{
rc = sendto(fd, msg, msg_len, MSG_FASTOPEN, ai -> ai_addr, ai -> ai_addrlen);
if(rc == msg_len)
*msg_accepted = 1;
if(errno == 0)
return fd;
if(errno == ENOTSUP)
{
printf("TCP TFO Not Supported. Please check if \"/proc/sys/net/ipv4/tcp_fastopen\" is 1. Disabling TFO for now.\n");
*tfo = 0;
}
}
else
#endif
{
int rc = connect(fd, ai -> ai_addr, ai -> ai_addrlen);
if (rc == 0)
{
/* connection made, return */
return fd;
}
if (rc == -1)
{
// problem connecting
if (errno != EINPROGRESS)
{
snprintf(last_error, sizeof last_error, "problem connecting to host: %s\n", strerror(errno));
close(fd);
return -1;
}
}
}
/* wait for connection */
rc = select(fd + 1, NULL, &wfds, NULL, &to);
if (rc == 0)
{
snprintf(last_error, sizeof last_error, "connect time out\n");
close(fd);
return RC_TIMEOUT; /* timeout */
}
else if (rc == -1)
{
close(fd);
if (errno == EINTR)
return RC_CTRLC;/* ^C pressed */
snprintf(last_error, sizeof last_error, "select() failed: %s\n", strerror(errno));
return -1; /* error */
}
else
{
int optval=0;
socklen_t optvallen=sizeof(optval);
/* see if the connect succeeded or failed */
if (getsockopt(fd, SOL_SOCKET, SO_ERROR, &optval, &optvallen) == -1)
{
snprintf(last_error, sizeof last_error, "getsockopt failed (%s)\n", strerror(errno));
close(fd);
return -1;
}
/* no error? */
if (optval == 0)
return fd;
/* don't ask */
errno = optval;
}
close(fd);
snprintf(last_error, sizeof last_error, "could not connect (%s)\n", strerror(errno));
return -1;
}
int set_tcp_low_latency(int sock)
{
int flag = 1;
if (setsockopt(sock, IPPROTO_TCP, TCP_NODELAY, (char *)&flag, sizeof(int)) < 0)
{
snprintf(last_error, sizeof last_error, "could not set TCP_NODELAY on socket (%s)\n", strerror(errno));
return -1;
}
return 0;
}
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