src/iperf_tcp.c - third_party/iperf - Git at Google

 /*
  * iperf, Copyright (c) 2014-2018, The Regents of the University of
  * California, through Lawrence Berkeley National Laboratory (subject
  * to receipt of any required approvals from the U.S. Dept. of
  * Energy).  All rights reserved.
  *
  * If you have questions about your rights to use or distribute this
  * software, please contact Berkeley Lab's Technology Transfer
  * Department at TTD@lbl.gov.
  *
  * NOTICE.  This software is owned by the U.S. Department of Energy.
  * As such, the U.S. Government has been granted for itself and others
  * acting on its behalf a paid-up, nonexclusive, irrevocable,
  * worldwide license in the Software to reproduce, prepare derivative
  * works, and perform publicly and display publicly.  Beginning five
  * (5) years after the date permission to assert copyright is obtained
  * from the U.S. Department of Energy, and subject to any subsequent
  * five (5) year renewals, the U.S. Government is granted for itself
  * and others acting on its behalf a paid-up, nonexclusive,
  * irrevocable, worldwide license in the Software to reproduce,
  * prepare derivative works, distribute copies to the public, perform
  * publicly and display publicly, and to permit others to do so.
  *
  * This code is distributed under a BSD style license, see the LICENSE
  * file for complete information.
  */
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <errno.h>
 #include <unistd.h>
 #include <sys/socket.h>
 #include <sys/types.h>
 #include <netinet/in.h>
 #include <netdb.h>
 #include <sys/time.h>
 #include <sys/select.h>

 #include "iperf.h"
 #include "iperf_api.h"
 #include "iperf_tcp.h"
 #include "net.h"
 #include "cjson.h"

 #if defined(HAVE_FLOWLABEL)
 #include "flowlabel.h"
 #endif /* HAVE_FLOWLABEL */

 /* iperf_tcp_recv
  *
  * receives the data for TCP
  */
 int
 iperf_tcp_recv(struct iperf_stream *sp)
 {
     int r;

     r = Nread(sp->socket, sp->buffer, sp->settings->blksize, Ptcp);

     if (r < 0)
         return r;

     sp->result->bytes_received += r;
     sp->result->bytes_received_this_interval += r;

     return r;
 }


 /* iperf_tcp_send
  *
  * sends the data for TCP
  */
 int
 iperf_tcp_send(struct iperf_stream *sp)
 {
     int r;

     if (sp->test->zerocopy)
 	r = Nsendfile(sp->buffer_fd, sp->socket, sp->buffer, sp->settings->blksize);
     else
 	r = Nwrite(sp->socket, sp->buffer, sp->settings->blksize, Ptcp);

     if (r < 0)
         return r;

     sp->result->bytes_sent += r;
     sp->result->bytes_sent_this_interval += r;

     if (sp->test->debug)
 	printf("sent %d bytes of %d, total %" PRIu64 "\n", r, sp->settings->blksize, sp->result->bytes_sent);

     return r;
 }


 /* iperf_tcp_accept
  *
  * accept a new TCP stream connection
  */
 int
 iperf_tcp_accept(struct iperf_test * test)
 {
     int     s;
     signed char rbuf = ACCESS_DENIED;
     char    cookie[COOKIE_SIZE];
     socklen_t len;
     struct sockaddr_storage addr;

     len = sizeof(addr);
     if ((s = accept(test->listener, (struct sockaddr *) &addr, &len)) < 0) {
         i_errno = IESTREAMCONNECT;
         return -1;
     }

     if (Nread(s, cookie, COOKIE_SIZE, Ptcp) < 0) {
         i_errno = IERECVCOOKIE;
         return -1;
     }

     if (strcmp(test->cookie, cookie) != 0) {
         if (Nwrite(s, (char*) &rbuf, sizeof(rbuf), Ptcp) < 0) {
             i_errno = IESENDMESSAGE;
             return -1;
         }
         close(s);
     }

     return s;
 }


 /* iperf_tcp_listen
  *
  * start up a listener for TCP stream connections
  */
 int
 iperf_tcp_listen(struct iperf_test *test)
 {
     int s, opt;
     socklen_t optlen;
     int saved_errno;
     int rcvbuf_actual, sndbuf_actual;

     s = test->listener;

     /*
      * If certain parameters are specified (such as socket buffer
      * size), then throw away the listening socket (the one for which
      * we just accepted the control connection) and recreate it with
      * those parameters.  That way, when new data connections are
      * set, they'll have all the correct parameters in place.
      *
      * It's not clear whether this is a requirement or a convenience.
      */
     if (test->no_delay || test->settings->mss || test->settings->socket_bufsize) {
 	struct addrinfo hints, *res;
 	char portstr[6];

         FD_CLR(s, &test->read_set);
         close(s);

         snprintf(portstr, 6, "%d", test->server_port);
         memset(&hints, 0, sizeof(hints));

 	/*
 	 * If binding to the wildcard address with no explicit address
 	 * family specified, then force us to get an AF_INET6 socket.
 	 * More details in the comments in netanounce().
 	 */
 	if (test->settings->domain == AF_UNSPEC && !test->bind_address) {
 	    hints.ai_family = AF_INET6;
 	}
 	else {
 	    hints.ai_family = test->settings->domain;
 	}
         hints.ai_socktype = SOCK_STREAM;
         hints.ai_flags = AI_PASSIVE;
         if (getaddrinfo(test->bind_address, portstr, &hints, &res) != 0) {
             i_errno = IESTREAMLISTEN;
             return -1;
         }

         if ((s = socket(res->ai_family, SOCK_STREAM, 0)) < 0) {
 	    freeaddrinfo(res);
             i_errno = IESTREAMLISTEN;
             return -1;
         }

         if (test->no_delay) {
             opt = 1;
             if (setsockopt(s, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof(opt)) < 0) {
 		saved_errno = errno;
 		close(s);
 		freeaddrinfo(res);
 		errno = saved_errno;
                 i_errno = IESETNODELAY;
                 return -1;
             }
         }
         // XXX: Setting MSS is very buggy!
         if ((opt = test->settings->mss)) {
             if (setsockopt(s, IPPROTO_TCP, TCP_MAXSEG, &opt, sizeof(opt)) < 0) {
 		saved_errno = errno;
 		close(s);
 		freeaddrinfo(res);
 		errno = saved_errno;
                 i_errno = IESETMSS;
                 return -1;
             }
         }
         if ((opt = test->settings->socket_bufsize)) {
             if (setsockopt(s, SOL_SOCKET, SO_RCVBUF, &opt, sizeof(opt)) < 0) {
 		saved_errno = errno;
 		close(s);
 		freeaddrinfo(res);
 		errno = saved_errno;
                 i_errno = IESETBUF;
                 return -1;
             }
             if (setsockopt(s, SOL_SOCKET, SO_SNDBUF, &opt, sizeof(opt)) < 0) {
 		saved_errno = errno;
 		close(s);
 		freeaddrinfo(res);
 		errno = saved_errno;
                 i_errno = IESETBUF;
                 return -1;
             }
         }
 #if defined(HAVE_SO_MAX_PACING_RATE)
     /* If fq socket pacing is specified, enable it. */
     if (test->settings->fqrate) {
 	/* Convert bits per second to bytes per second */
 	unsigned int fqrate = test->settings->fqrate / 8;
 	if (fqrate > 0) {
 	    if (test->debug) {
 		printf("Setting fair-queue socket pacing to %u\n", fqrate);
 	    }
 	    if (setsockopt(s, SOL_SOCKET, SO_MAX_PACING_RATE, &fqrate, sizeof(fqrate)) < 0) {
 		warning("Unable to set socket pacing");
 	    }
 	}
     }
 #endif /* HAVE_SO_MAX_PACING_RATE */
     {
 	unsigned int rate = test->settings->rate / 8;
 	if (rate > 0) {
 	    if (test->debug) {
 		printf("Setting application pacing to %u\n", rate);
 	    }
 	}
     }
         opt = 1;
         if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) < 0) {
 	    saved_errno = errno;
             close(s);
 	    freeaddrinfo(res);
 	    errno = saved_errno;
             i_errno = IEREUSEADDR;
             return -1;
         }

 	/*
 	 * If we got an IPv6 socket, figure out if it shoudl accept IPv4
 	 * connections as well.  See documentation in netannounce() for
 	 * more details.
 	 */
 #if defined(IPV6_V6ONLY) && !defined(__OpenBSD__)
 	if (res->ai_family == AF_INET6 && (test->settings->domain == AF_UNSPEC || test->settings->domain == AF_INET)) {
 	    if (test->settings->domain == AF_UNSPEC)
 		opt = 0;
 	    else
 		opt = 1;
 	    if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY,
 			   (char *) &opt, sizeof(opt)) < 0) {
 		saved_errno = errno;
 		close(s);
 		freeaddrinfo(res);
 		errno = saved_errno;
 		i_errno = IEV6ONLY;
 		return -1;
 	    }
 	}
 #endif /* IPV6_V6ONLY */

         if (bind(s, (struct sockaddr *) res->ai_addr, res->ai_addrlen) < 0) {
 	    saved_errno = errno;
             close(s);
 	    freeaddrinfo(res);
 	    errno = saved_errno;
             i_errno = IESTREAMLISTEN;
             return -1;
         }

         freeaddrinfo(res);

         if (listen(s, 5) < 0) {
             i_errno = IESTREAMLISTEN;
             return -1;
         }

         test->listener = s;
     }

     /* Read back and verify the sender socket buffer size */
     optlen = sizeof(sndbuf_actual);
     if (getsockopt(s, SOL_SOCKET, SO_SNDBUF, &sndbuf_actual, &optlen) < 0) {
 	saved_errno = errno;
 	close(s);
 	errno = saved_errno;
 	i_errno = IESETBUF;
 	return -1;
     }
     if (test->debug) {
 	printf("SNDBUF is %u, expecting %u\n", sndbuf_actual, test->settings->socket_bufsize);
     }
     if (test->settings->socket_bufsize && test->settings->socket_bufsize > sndbuf_actual) {
 	i_errno = IESETBUF2;
 	return -1;
     }

     /* Read back and verify the receiver socket buffer size */
     optlen = sizeof(rcvbuf_actual);
     if (getsockopt(s, SOL_SOCKET, SO_RCVBUF, &rcvbuf_actual, &optlen) < 0) {
 	saved_errno = errno;
 	close(s);
 	errno = saved_errno;
 	i_errno = IESETBUF;
 	return -1;
     }
     if (test->debug) {
 	printf("RCVBUF is %u, expecting %u\n", rcvbuf_actual, test->settings->socket_bufsize);
     }
     if (test->settings->socket_bufsize && test->settings->socket_bufsize > rcvbuf_actual) {
 	i_errno = IESETBUF2;
 	return -1;
     }

     if (test->json_output) {
 	cJSON_AddNumberToObject(test->json_start, "sock_bufsize", test->settings->socket_bufsize);
 	cJSON_AddNumberToObject(test->json_start, "sndbuf_actual", sndbuf_actual);
 	cJSON_AddNumberToObject(test->json_start, "rcvbuf_actual", rcvbuf_actual);
     }

     return s;
 }


 /* iperf_tcp_connect
  *
  * connect to a TCP stream listener
  * This function is roughly similar to netdial(), and may indeed have
  * been derived from it at some point, but it sets many TCP-specific
  * options between socket creation and connection.
  */
 int
 iperf_tcp_connect(struct iperf_test *test)
 {
     struct addrinfo hints, *local_res, *server_res;
     char portstr[6];
     int s, opt;
     socklen_t optlen;
     int saved_errno;
     int rcvbuf_actual, sndbuf_actual;

     if (test->bind_address) {
         memset(&hints, 0, sizeof(hints));
         hints.ai_family = test->settings->domain;
         hints.ai_socktype = SOCK_STREAM;
         if (getaddrinfo(test->bind_address, NULL, &hints, &local_res) != 0) {
             i_errno = IESTREAMCONNECT;
             return -1;
         }
     }

     memset(&hints, 0, sizeof(hints));
     hints.ai_family = test->settings->domain;
     hints.ai_socktype = SOCK_STREAM;
     snprintf(portstr, sizeof(portstr), "%d", test->server_port);
     if (getaddrinfo(test->server_hostname, portstr, &hints, &server_res) != 0) {
 	if (test->bind_address)
 	    freeaddrinfo(local_res);
         i_errno = IESTREAMCONNECT;
         return -1;
     }

     if ((s = socket(server_res->ai_family, SOCK_STREAM, 0)) < 0) {
 	if (test->bind_address)
 	    freeaddrinfo(local_res);
 	freeaddrinfo(server_res);
         i_errno = IESTREAMCONNECT;
         return -1;
     }

     /*
      * Various ways to bind the local end of the connection.
      * 1.  --bind (with or without --cport).
      */
     if (test->bind_address) {
         struct sockaddr_in *lcladdr;
         lcladdr = (struct sockaddr_in *)local_res->ai_addr;
         lcladdr->sin_port = htons(test->bind_port);

         if (bind(s, (struct sockaddr *) local_res->ai_addr, local_res->ai_addrlen) < 0) {
 	    saved_errno = errno;
 	    close(s);
 	    freeaddrinfo(local_res);
 	    freeaddrinfo(server_res);
 	    errno = saved_errno;
             i_errno = IESTREAMCONNECT;
             return -1;
         }
         freeaddrinfo(local_res);
     }
     /* --cport, no --bind */
     else if (test->bind_port) {
 	size_t addrlen;
 	struct sockaddr_storage lcl;

 	/* IPv4 */
 	if (server_res->ai_family == AF_INET) {
 	    struct sockaddr_in *lcladdr = (struct sockaddr_in *) &lcl;
 	    lcladdr->sin_family = AF_INET;
 	    lcladdr->sin_port = htons(test->bind_port);
 	    lcladdr->sin_addr.s_addr = INADDR_ANY;
 	    addrlen = sizeof(struct sockaddr_in);
 	}
 	/* IPv6 */
 	else if (server_res->ai_family == AF_INET6) {
 	    struct sockaddr_in6 *lcladdr = (struct sockaddr_in6 *) &lcl;
 	    lcladdr->sin6_family = AF_INET6;
 	    lcladdr->sin6_port = htons(test->bind_port);
 	    lcladdr->sin6_addr = in6addr_any;
 	    addrlen = sizeof(struct sockaddr_in6);
 	}
 	/* Unknown protocol */
 	else {
 	    saved_errno = errno;
 	    close(s);
 	    freeaddrinfo(server_res);
 	    errno = saved_errno;
             i_errno = IEPROTOCOL;
             return -1;
 	}

         if (bind(s, (struct sockaddr *) &lcl, addrlen) < 0) {
 	    saved_errno = errno;
 	    close(s);
 	    freeaddrinfo(server_res);
 	    errno = saved_errno;
             i_errno = IESTREAMCONNECT;
             return -1;
         }
     }

     /* Set socket options */
     if (test->no_delay) {
         opt = 1;
         if (setsockopt(s, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof(opt)) < 0) {
 	    saved_errno = errno;
 	    close(s);
 	    freeaddrinfo(server_res);
 	    errno = saved_errno;
             i_errno = IESETNODELAY;
             return -1;
         }
     }
     if ((opt = test->settings->mss)) {
         if (setsockopt(s, IPPROTO_TCP, TCP_MAXSEG, &opt, sizeof(opt)) < 0) {
 	    saved_errno = errno;
 	    close(s);
 	    freeaddrinfo(server_res);
 	    errno = saved_errno;
             i_errno = IESETMSS;
             return -1;
         }
     }
     if ((opt = test->settings->socket_bufsize)) {
         if (setsockopt(s, SOL_SOCKET, SO_RCVBUF, &opt, sizeof(opt)) < 0) {
 	    saved_errno = errno;
 	    close(s);
 	    freeaddrinfo(server_res);
 	    errno = saved_errno;
             i_errno = IESETBUF;
             return -1;
         }
         if (setsockopt(s, SOL_SOCKET, SO_SNDBUF, &opt, sizeof(opt)) < 0) {
 	    saved_errno = errno;
 	    close(s);
 	    freeaddrinfo(server_res);
 	    errno = saved_errno;
             i_errno = IESETBUF;
             return -1;
         }
     }

     /* Read back and verify the sender socket buffer size */
     optlen = sizeof(sndbuf_actual);
     if (getsockopt(s, SOL_SOCKET, SO_SNDBUF, &sndbuf_actual, &optlen) < 0) {
 	saved_errno = errno;
 	close(s);
 	freeaddrinfo(server_res);
 	errno = saved_errno;
 	i_errno = IESETBUF;
 	return -1;
     }
     if (test->debug) {
 	printf("SNDBUF is %u, expecting %u\n", sndbuf_actual, test->settings->socket_bufsize);
     }
     if (test->settings->socket_bufsize && test->settings->socket_bufsize > sndbuf_actual) {
 	i_errno = IESETBUF2;
 	return -1;
     }

     /* Read back and verify the receiver socket buffer size */
     optlen = sizeof(rcvbuf_actual);
     if (getsockopt(s, SOL_SOCKET, SO_RCVBUF, &rcvbuf_actual, &optlen) < 0) {
 	saved_errno = errno;
 	close(s);
 	freeaddrinfo(server_res);
 	errno = saved_errno;
 	i_errno = IESETBUF;
 	return -1;
     }
     if (test->debug) {
 	printf("RCVBUF is %u, expecting %u\n", rcvbuf_actual, test->settings->socket_bufsize);
     }
     if (test->settings->socket_bufsize && test->settings->socket_bufsize > rcvbuf_actual) {
 	i_errno = IESETBUF2;
 	return -1;
     }

     if (test->json_output) {
 	cJSON_AddNumberToObject(test->json_start, "sock_bufsize", test->settings->socket_bufsize);
 	cJSON_AddNumberToObject(test->json_start, "sndbuf_actual", sndbuf_actual);
 	cJSON_AddNumberToObject(test->json_start, "rcvbuf_actual", rcvbuf_actual);
     }

 #if defined(HAVE_FLOWLABEL)
     if (test->settings->flowlabel) {
         if (server_res->ai_addr->sa_family != AF_INET6) {
 	    saved_errno = errno;
 	    close(s);
 	    freeaddrinfo(server_res);
 	    errno = saved_errno;
             i_errno = IESETFLOW;
             return -1;
 	} else {
 	    struct sockaddr_in6* sa6P = (struct sockaddr_in6*) server_res->ai_addr;
             char freq_buf[sizeof(struct in6_flowlabel_req)];
             struct in6_flowlabel_req *freq = (struct in6_flowlabel_req *)freq_buf;
             int freq_len = sizeof(*freq);

             memset(freq, 0, sizeof(*freq));
             freq->flr_label = htonl(test->settings->flowlabel & IPV6_FLOWINFO_FLOWLABEL);
             freq->flr_action = IPV6_FL_A_GET;
             freq->flr_flags = IPV6_FL_F_CREATE;
             freq->flr_share = IPV6_FL_S_ANY;
             memcpy(&freq->flr_dst, &sa6P->sin6_addr, 16);

             if (setsockopt(s, IPPROTO_IPV6, IPV6_FLOWLABEL_MGR, freq, freq_len) < 0) {
 		saved_errno = errno;
                 close(s);
                 freeaddrinfo(server_res);
 		errno = saved_errno;
                 i_errno = IESETFLOW;
                 return -1;
             }
             sa6P->sin6_flowinfo = freq->flr_label;

             opt = 1;
             if (setsockopt(s, IPPROTO_IPV6, IPV6_FLOWINFO_SEND, &opt, sizeof(opt)) < 0) {
 		saved_errno = errno;
                 close(s);
                 freeaddrinfo(server_res);
 		errno = saved_errno;
                 i_errno = IESETFLOW;
                 return -1;
             }
 	}
     }
 #endif /* HAVE_FLOWLABEL */

 #if defined(HAVE_SO_MAX_PACING_RATE)
     /* If socket pacing is specified try to enable it. */
     if (test->settings->fqrate) {
 	/* Convert bits per second to bytes per second */
 	unsigned int fqrate = test->settings->fqrate / 8;
 	if (fqrate > 0) {
 	    if (test->debug) {
 		printf("Setting fair-queue socket pacing to %u\n", fqrate);
 	    }
 	    if (setsockopt(s, SOL_SOCKET, SO_MAX_PACING_RATE, &fqrate, sizeof(fqrate)) < 0) {
 		warning("Unable to set socket pacing");
 	    }
 	}
     }
 #endif /* HAVE_SO_MAX_PACING_RATE */
     {
 	unsigned int rate = test->settings->rate / 8;
 	if (rate > 0) {
 	    if (test->debug) {
 		printf("Setting application pacing to %u\n", rate);
 	    }
 	}
     }

     if (connect(s, (struct sockaddr *) server_res->ai_addr, server_res->ai_addrlen) < 0 && errno != EINPROGRESS) {
 	saved_errno = errno;
 	close(s);
 	freeaddrinfo(server_res);
 	errno = saved_errno;
         i_errno = IESTREAMCONNECT;
         return -1;
     }

     freeaddrinfo(server_res);

     /* Send cookie for verification */
     if (Nwrite(s, test->cookie, COOKIE_SIZE, Ptcp) < 0) {
 	saved_errno = errno;
 	close(s);
 	errno = saved_errno;
         i_errno = IESENDCOOKIE;
         return -1;
     }

     return s;
 }
	/*
	* iperf, Copyright (c) 2014-2018, The Regents of the University of
	* California, through Lawrence Berkeley National Laboratory (subject
	* to receipt of any required approvals from the U.S. Dept. of
	* Energy). All rights reserved.
	*
	* If you have questions about your rights to use or distribute this
	* software, please contact Berkeley Lab's Technology Transfer
	* Department at TTD@lbl.gov.
	*
	* NOTICE. This software is owned by the U.S. Department of Energy.
	* As such, the U.S. Government has been granted for itself and others
	* acting on its behalf a paid-up, nonexclusive, irrevocable,
	* worldwide license in the Software to reproduce, prepare derivative
	* works, and perform publicly and display publicly. Beginning five
	* (5) years after the date permission to assert copyright is obtained
	* from the U.S. Department of Energy, and subject to any subsequent
	* five (5) year renewals, the U.S. Government is granted for itself
	* and others acting on its behalf a paid-up, nonexclusive,
	* irrevocable, worldwide license in the Software to reproduce,
	* prepare derivative works, distribute copies to the public, perform
	* publicly and display publicly, and to permit others to do so.
	*
	* This code is distributed under a BSD style license, see the LICENSE
	* file for complete information.
	*/
	#include <stdio.h>
	#include <stdlib.h>
	#include <string.h>
	#include <errno.h>
	#include <unistd.h>
	#include <sys/socket.h>
	#include <sys/types.h>
	#include <netinet/in.h>
	#include <netdb.h>
	#include <sys/time.h>
	#include <sys/select.h>

	#include "iperf.h"
	#include "iperf_api.h"
	#include "iperf_tcp.h"
	#include "net.h"
	#include "cjson.h"

	#if defined(HAVE_FLOWLABEL)
	#include "flowlabel.h"
	#endif /* HAVE_FLOWLABEL */

	/* iperf_tcp_recv
	*
	* receives the data for TCP
	*/
	int
	iperf_tcp_recv(struct iperf_stream *sp)
	{
	int r;

	r = Nread(sp->socket, sp->buffer, sp->settings->blksize, Ptcp);

	if (r < 0)
	return r;

	sp->result->bytes_received += r;
	sp->result->bytes_received_this_interval += r;

	return r;
	}


	/* iperf_tcp_send
	*
	* sends the data for TCP
	*/
	int
	iperf_tcp_send(struct iperf_stream *sp)
	{
	int r;

	if (sp->test->zerocopy)
	r = Nsendfile(sp->buffer_fd, sp->socket, sp->buffer, sp->settings->blksize);
	else
	r = Nwrite(sp->socket, sp->buffer, sp->settings->blksize, Ptcp);

	if (r < 0)
	return r;

	sp->result->bytes_sent += r;
	sp->result->bytes_sent_this_interval += r;

	if (sp->test->debug)
	printf("sent %d bytes of %d, total %" PRIu64 "\n", r, sp->settings->blksize, sp->result->bytes_sent);

	return r;
	}


	/* iperf_tcp_accept
	*
	* accept a new TCP stream connection
	*/
	int
	iperf_tcp_accept(struct iperf_test * test)
	{
	int s;
	signed char rbuf = ACCESS_DENIED;
	char cookie[COOKIE_SIZE];
	socklen_t len;
	struct sockaddr_storage addr;

	len = sizeof(addr);
	if ((s = accept(test->listener, (struct sockaddr *) &addr, &len)) < 0) {
	i_errno = IESTREAMCONNECT;
	return -1;
	}

	if (Nread(s, cookie, COOKIE_SIZE, Ptcp) < 0) {
	i_errno = IERECVCOOKIE;
	return -1;
	}

	if (strcmp(test->cookie, cookie) != 0) {
	if (Nwrite(s, (char*) &rbuf, sizeof(rbuf), Ptcp) < 0) {
	i_errno = IESENDMESSAGE;
	return -1;
	}
	close(s);
	}

	return s;
	}


	/* iperf_tcp_listen
	*
	* start up a listener for TCP stream connections
	*/
	int
	iperf_tcp_listen(struct iperf_test *test)
	{
	int s, opt;
	socklen_t optlen;
	int saved_errno;
	int rcvbuf_actual, sndbuf_actual;

	s = test->listener;

	/*
	* If certain parameters are specified (such as socket buffer
	* size), then throw away the listening socket (the one for which
	* we just accepted the control connection) and recreate it with
	* those parameters. That way, when new data connections are
	* set, they'll have all the correct parameters in place.
	*
	* It's not clear whether this is a requirement or a convenience.
	*/
	if (test->no_delay \|\| test->settings->mss \|\| test->settings->socket_bufsize) {
	struct addrinfo hints, *res;
	char portstr[6];

	FD_CLR(s, &test->read_set);
	close(s);

	snprintf(portstr, 6, "%d", test->server_port);
	memset(&hints, 0, sizeof(hints));

	/*
	* If binding to the wildcard address with no explicit address
	* family specified, then force us to get an AF_INET6 socket.
	* More details in the comments in netanounce().
	*/
	if (test->settings->domain == AF_UNSPEC && !test->bind_address) {
	hints.ai_family = AF_INET6;
	}
	else {
	hints.ai_family = test->settings->domain;
	}
	hints.ai_socktype = SOCK_STREAM;
	hints.ai_flags = AI_PASSIVE;
	if (getaddrinfo(test->bind_address, portstr, &hints, &res) != 0) {
	i_errno = IESTREAMLISTEN;
	return -1;
	}

	if ((s = socket(res->ai_family, SOCK_STREAM, 0)) < 0) {
	freeaddrinfo(res);
	i_errno = IESTREAMLISTEN;
	return -1;
	}

	if (test->no_delay) {
	opt = 1;
	if (setsockopt(s, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof(opt)) < 0) {
	saved_errno = errno;
	close(s);
	freeaddrinfo(res);
	errno = saved_errno;
	i_errno = IESETNODELAY;
	return -1;
	}
	}
	// XXX: Setting MSS is very buggy!
	if ((opt = test->settings->mss)) {
	if (setsockopt(s, IPPROTO_TCP, TCP_MAXSEG, &opt, sizeof(opt)) < 0) {
	saved_errno = errno;
	close(s);
	freeaddrinfo(res);
	errno = saved_errno;
	i_errno = IESETMSS;
	return -1;
	}
	}
	if ((opt = test->settings->socket_bufsize)) {
	if (setsockopt(s, SOL_SOCKET, SO_RCVBUF, &opt, sizeof(opt)) < 0) {
	saved_errno = errno;
	close(s);
	freeaddrinfo(res);
	errno = saved_errno;
	i_errno = IESETBUF;
	return -1;
	}
	if (setsockopt(s, SOL_SOCKET, SO_SNDBUF, &opt, sizeof(opt)) < 0) {
	saved_errno = errno;
	close(s);
	freeaddrinfo(res);
	errno = saved_errno;
	i_errno = IESETBUF;
	return -1;
	}
	}
	#if defined(HAVE_SO_MAX_PACING_RATE)
	/* If fq socket pacing is specified, enable it. */
	if (test->settings->fqrate) {
	/* Convert bits per second to bytes per second */
	unsigned int fqrate = test->settings->fqrate / 8;
	if (fqrate > 0) {
	if (test->debug) {
	printf("Setting fair-queue socket pacing to %u\n", fqrate);
	}
	if (setsockopt(s, SOL_SOCKET, SO_MAX_PACING_RATE, &fqrate, sizeof(fqrate)) < 0) {
	warning("Unable to set socket pacing");
	}
	}
	}
	#endif /* HAVE_SO_MAX_PACING_RATE */
	{
	unsigned int rate = test->settings->rate / 8;
	if (rate > 0) {
	if (test->debug) {
	printf("Setting application pacing to %u\n", rate);
	}
	}
	}
	opt = 1;
	if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) < 0) {
	saved_errno = errno;
	close(s);
	freeaddrinfo(res);
	errno = saved_errno;
	i_errno = IEREUSEADDR;
	return -1;
	}

	/*
	* If we got an IPv6 socket, figure out if it shoudl accept IPv4
	* connections as well. See documentation in netannounce() for
	* more details.
	*/
	#if defined(IPV6_V6ONLY) && !defined(__OpenBSD__)
	if (res->ai_family == AF_INET6 && (test->settings->domain == AF_UNSPEC \|\| test->settings->domain == AF_INET)) {
	if (test->settings->domain == AF_UNSPEC)
	opt = 0;
	else
	opt = 1;
	if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY,
	(char *) &opt, sizeof(opt)) < 0) {
	saved_errno = errno;
	close(s);
	freeaddrinfo(res);
	errno = saved_errno;
	i_errno = IEV6ONLY;
	return -1;
	}
	}
	#endif /* IPV6_V6ONLY */

	if (bind(s, (struct sockaddr *) res->ai_addr, res->ai_addrlen) < 0) {
	saved_errno = errno;
	close(s);
	freeaddrinfo(res);
	errno = saved_errno;
	i_errno = IESTREAMLISTEN;
	return -1;
	}

	freeaddrinfo(res);

	if (listen(s, 5) < 0) {
	i_errno = IESTREAMLISTEN;
	return -1;
	}

	test->listener = s;
	}

	/* Read back and verify the sender socket buffer size */
	optlen = sizeof(sndbuf_actual);
	if (getsockopt(s, SOL_SOCKET, SO_SNDBUF, &sndbuf_actual, &optlen) < 0) {
	saved_errno = errno;
	close(s);
	errno = saved_errno;
	i_errno = IESETBUF;
	return -1;
	}
	if (test->debug) {
	printf("SNDBUF is %u, expecting %u\n", sndbuf_actual, test->settings->socket_bufsize);
	}
	if (test->settings->socket_bufsize && test->settings->socket_bufsize > sndbuf_actual) {
	i_errno = IESETBUF2;
	return -1;
	}

	/* Read back and verify the receiver socket buffer size */
	optlen = sizeof(rcvbuf_actual);
	if (getsockopt(s, SOL_SOCKET, SO_RCVBUF, &rcvbuf_actual, &optlen) < 0) {
	saved_errno = errno;
	close(s);
	errno = saved_errno;
	i_errno = IESETBUF;
	return -1;
	}
	if (test->debug) {
	printf("RCVBUF is %u, expecting %u\n", rcvbuf_actual, test->settings->socket_bufsize);
	}
	if (test->settings->socket_bufsize && test->settings->socket_bufsize > rcvbuf_actual) {
	i_errno = IESETBUF2;
	return -1;
	}

	if (test->json_output) {
	cJSON_AddNumberToObject(test->json_start, "sock_bufsize", test->settings->socket_bufsize);
	cJSON_AddNumberToObject(test->json_start, "sndbuf_actual", sndbuf_actual);
	cJSON_AddNumberToObject(test->json_start, "rcvbuf_actual", rcvbuf_actual);
	}

	return s;
	}


	/* iperf_tcp_connect
	*
	* connect to a TCP stream listener
	* This function is roughly similar to netdial(), and may indeed have
	* been derived from it at some point, but it sets many TCP-specific
	* options between socket creation and connection.
	*/
	int
	iperf_tcp_connect(struct iperf_test *test)
	{
	struct addrinfo hints, local_res, server_res;
	char portstr[6];
	int s, opt;
	socklen_t optlen;
	int saved_errno;
	int rcvbuf_actual, sndbuf_actual;

	if (test->bind_address) {
	memset(&hints, 0, sizeof(hints));
	hints.ai_family = test->settings->domain;
	hints.ai_socktype = SOCK_STREAM;
	if (getaddrinfo(test->bind_address, NULL, &hints, &local_res) != 0) {
	i_errno = IESTREAMCONNECT;
	return -1;
	}
	}

	memset(&hints, 0, sizeof(hints));
	hints.ai_family = test->settings->domain;
	hints.ai_socktype = SOCK_STREAM;
	snprintf(portstr, sizeof(portstr), "%d", test->server_port);
	if (getaddrinfo(test->server_hostname, portstr, &hints, &server_res) != 0) {
	if (test->bind_address)
	freeaddrinfo(local_res);
	i_errno = IESTREAMCONNECT;
	return -1;
	}

	if ((s = socket(server_res->ai_family, SOCK_STREAM, 0)) < 0) {
	if (test->bind_address)
	freeaddrinfo(local_res);
	freeaddrinfo(server_res);
	i_errno = IESTREAMCONNECT;
	return -1;
	}

	/*
	* Various ways to bind the local end of the connection.
	* 1. --bind (with or without --cport).
	*/
	if (test->bind_address) {
	struct sockaddr_in *lcladdr;
	lcladdr = (struct sockaddr_in *)local_res->ai_addr;
	lcladdr->sin_port = htons(test->bind_port);

	if (bind(s, (struct sockaddr *) local_res->ai_addr, local_res->ai_addrlen) < 0) {
	saved_errno = errno;
	close(s);
	freeaddrinfo(local_res);
	freeaddrinfo(server_res);
	errno = saved_errno;
	i_errno = IESTREAMCONNECT;
	return -1;
	}
	freeaddrinfo(local_res);
	}
	/* --cport, no --bind */
	else if (test->bind_port) {
	size_t addrlen;
	struct sockaddr_storage lcl;

	/* IPv4 */
	if (server_res->ai_family == AF_INET) {
	struct sockaddr_in lcladdr = (struct sockaddr_in ) &lcl;
	lcladdr->sin_family = AF_INET;
	lcladdr->sin_port = htons(test->bind_port);
	lcladdr->sin_addr.s_addr = INADDR_ANY;
	addrlen = sizeof(struct sockaddr_in);
	}
	/* IPv6 */
	else if (server_res->ai_family == AF_INET6) {
	struct sockaddr_in6 lcladdr = (struct sockaddr_in6 ) &lcl;
	lcladdr->sin6_family = AF_INET6;
	lcladdr->sin6_port = htons(test->bind_port);
	lcladdr->sin6_addr = in6addr_any;
	addrlen = sizeof(struct sockaddr_in6);
	}
	/* Unknown protocol */
	else {
	saved_errno = errno;
	close(s);
	freeaddrinfo(server_res);
	errno = saved_errno;
	i_errno = IEPROTOCOL;
	return -1;
	}

	if (bind(s, (struct sockaddr *) &lcl, addrlen) < 0) {
	saved_errno = errno;
	close(s);
	freeaddrinfo(server_res);
	errno = saved_errno;
	i_errno = IESTREAMCONNECT;
	return -1;
	}
	}

	/* Set socket options */
	if (test->no_delay) {
	opt = 1;
	if (setsockopt(s, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof(opt)) < 0) {
	saved_errno = errno;
	close(s);
	freeaddrinfo(server_res);
	errno = saved_errno;
	i_errno = IESETNODELAY;
	return -1;
	}
	}
	if ((opt = test->settings->mss)) {
	if (setsockopt(s, IPPROTO_TCP, TCP_MAXSEG, &opt, sizeof(opt)) < 0) {
	saved_errno = errno;
	close(s);
	freeaddrinfo(server_res);
	errno = saved_errno;
	i_errno = IESETMSS;
	return -1;
	}
	}
	if ((opt = test->settings->socket_bufsize)) {
	if (setsockopt(s, SOL_SOCKET, SO_RCVBUF, &opt, sizeof(opt)) < 0) {
	saved_errno = errno;
	close(s);
	freeaddrinfo(server_res);
	errno = saved_errno;
	i_errno = IESETBUF;
	return -1;
	}
	if (setsockopt(s, SOL_SOCKET, SO_SNDBUF, &opt, sizeof(opt)) < 0) {
	saved_errno = errno;
	close(s);
	freeaddrinfo(server_res);
	errno = saved_errno;
	i_errno = IESETBUF;
	return -1;
	}
	}

	/* Read back and verify the sender socket buffer size */
	optlen = sizeof(sndbuf_actual);
	if (getsockopt(s, SOL_SOCKET, SO_SNDBUF, &sndbuf_actual, &optlen) < 0) {
	saved_errno = errno;
	close(s);
	freeaddrinfo(server_res);
	errno = saved_errno;
	i_errno = IESETBUF;
	return -1;
	}
	if (test->debug) {
	printf("SNDBUF is %u, expecting %u\n", sndbuf_actual, test->settings->socket_bufsize);
	}
	if (test->settings->socket_bufsize && test->settings->socket_bufsize > sndbuf_actual) {
	i_errno = IESETBUF2;
	return -1;
	}

	/* Read back and verify the receiver socket buffer size */
	optlen = sizeof(rcvbuf_actual);
	if (getsockopt(s, SOL_SOCKET, SO_RCVBUF, &rcvbuf_actual, &optlen) < 0) {
	saved_errno = errno;
	close(s);
	freeaddrinfo(server_res);
	errno = saved_errno;
	i_errno = IESETBUF;
	return -1;
	}
	if (test->debug) {
	printf("RCVBUF is %u, expecting %u\n", rcvbuf_actual, test->settings->socket_bufsize);
	}
	if (test->settings->socket_bufsize && test->settings->socket_bufsize > rcvbuf_actual) {
	i_errno = IESETBUF2;
	return -1;
	}

	if (test->json_output) {
	cJSON_AddNumberToObject(test->json_start, "sock_bufsize", test->settings->socket_bufsize);
	cJSON_AddNumberToObject(test->json_start, "sndbuf_actual", sndbuf_actual);
	cJSON_AddNumberToObject(test->json_start, "rcvbuf_actual", rcvbuf_actual);
	}

	#if defined(HAVE_FLOWLABEL)
	if (test->settings->flowlabel) {
	if (server_res->ai_addr->sa_family != AF_INET6) {
	saved_errno = errno;
	close(s);
	freeaddrinfo(server_res);
	errno = saved_errno;
	i_errno = IESETFLOW;
	return -1;
	} else {
	struct sockaddr_in6* sa6P = (struct sockaddr_in6*) server_res->ai_addr;
	char freq_buf[sizeof(struct in6_flowlabel_req)];
	struct in6_flowlabel_req freq = (struct in6_flowlabel_req )freq_buf;
	int freq_len = sizeof(*freq);

	memset(freq, 0, sizeof(*freq));
	freq->flr_label = htonl(test->settings->flowlabel & IPV6_FLOWINFO_FLOWLABEL);
	freq->flr_action = IPV6_FL_A_GET;
	freq->flr_flags = IPV6_FL_F_CREATE;
	freq->flr_share = IPV6_FL_S_ANY;
	memcpy(&freq->flr_dst, &sa6P->sin6_addr, 16);

	if (setsockopt(s, IPPROTO_IPV6, IPV6_FLOWLABEL_MGR, freq, freq_len) < 0) {
	saved_errno = errno;
	close(s);
	freeaddrinfo(server_res);
	errno = saved_errno;
	i_errno = IESETFLOW;
	return -1;
	}
	sa6P->sin6_flowinfo = freq->flr_label;

	opt = 1;
	if (setsockopt(s, IPPROTO_IPV6, IPV6_FLOWINFO_SEND, &opt, sizeof(opt)) < 0) {
	saved_errno = errno;
	close(s);
	freeaddrinfo(server_res);
	errno = saved_errno;
	i_errno = IESETFLOW;
	return -1;
	}
	}
	}
	#endif /* HAVE_FLOWLABEL */

	#if defined(HAVE_SO_MAX_PACING_RATE)
	/* If socket pacing is specified try to enable it. */
	if (test->settings->fqrate) {
	/* Convert bits per second to bytes per second */
	unsigned int fqrate = test->settings->fqrate / 8;
	if (fqrate > 0) {
	if (test->debug) {
	printf("Setting fair-queue socket pacing to %u\n", fqrate);
	}
	if (setsockopt(s, SOL_SOCKET, SO_MAX_PACING_RATE, &fqrate, sizeof(fqrate)) < 0) {
	warning("Unable to set socket pacing");
	}
	}
	}
	#endif /* HAVE_SO_MAX_PACING_RATE */
	{
	unsigned int rate = test->settings->rate / 8;
	if (rate > 0) {
	if (test->debug) {
	printf("Setting application pacing to %u\n", rate);
	}
	}
	}

	if (connect(s, (struct sockaddr *) server_res->ai_addr, server_res->ai_addrlen) < 0 && errno != EINPROGRESS) {
	saved_errno = errno;
	close(s);
	freeaddrinfo(server_res);
	errno = saved_errno;
	i_errno = IESTREAMCONNECT;
	return -1;
	}

	freeaddrinfo(server_res);

	/* Send cookie for verification */
	if (Nwrite(s, test->cookie, COOKIE_SIZE, Ptcp) < 0) {
	saved_errno = errno;
	close(s);
	errno = saved_errno;
	i_errno = IESENDCOOKIE;
	return -1;
	}

	return s;
	}