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/*++
/* NAME
/* inet_connect 3
/* SUMMARY
/* connect to TCP listener
/* SYNOPSIS
/* #include <connect.h>
/*
/* int inet_windowsize;
/*
/* int inet_connect(addr, block_mode, timeout)
/* const char *addr;
/* int block_mode;
/* int timeout;
/* DESCRIPTION
/* inet_connect connects to a TCP listener at
/* the specified address, and returns the resulting file descriptor.
/*
/* Specify an inet_windowsize value > 0 to override the TCP
/* window size that the client advertises to the server.
/*
/* Arguments:
/* .IP addr
/* The destination to connect to. The format is host:port. If no
/* host is specified, a port on the local host is assumed.
/* Host and port information may be given in numerical form
/* or as symbolical names.
/* .IP block_mode
/* Either NON_BLOCKING for a non-blocking socket, or BLOCKING for
/* blocking mode.
/* .IP timeout
/* Bounds the number of seconds that the operation may take. Specify
/* a value <= 0 to disable the time limit.
/* DIAGNOSTICS
/* The result is -1 when the connection could not be made.
/* The nature of the error is available via the global \fIerrno\fR
/* variable.
/* Fatal errors: other system call failures.
/* LICENSE
/* .ad
/* .fi
/* The Secure Mailer license must be distributed with this software.
/* AUTHOR(S)
/* Wietse Venema
/* IBM T.J. Watson Research
/* P.O. Box 704
/* Yorktown Heights, NY 10598, USA
/*
/* Wietse Venema
/* Google, Inc.
/* 111 8th Avenue
/* New York, NY 10011, USA
/*--*/
/* System interfaces. */
#include <sys_defs.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <netdb.h>
/* Utility library. */
#include "mymalloc.h"
#include "msg.h"
#include "iostuff.h"
#include "host_port.h"
#include "sane_connect.h"
#include "connect.h"
#include "timed_connect.h"
#include "myaddrinfo.h"
#include "sock_addr.h"
#include "inet_proto.h"
static int inet_connect_one(struct addrinfo *, int, int);
/* inet_connect - connect to TCP listener */
int inet_connect(const char *addr, int block_mode, int timeout)
{
char *buf;
char *host;
char *port;
const char *parse_err;
struct addrinfo *res;
struct addrinfo *res0;
int aierr;
int sock;
MAI_HOSTADDR_STR hostaddr;
const INET_PROTO_INFO *proto_info;
int found;
/*
* Translate address information to internal form. No host defaults to
* the local host.
*/
buf = mystrdup(addr);
if ((parse_err = host_port(buf, &host, "localhost", &port, (char *) 0)) != 0)
msg_fatal("%s: %s", addr, parse_err);
if ((aierr = hostname_to_sockaddr(host, port, SOCK_STREAM, &res0)) != 0)
msg_warn("host or service %s not found: %s",
addr, MAI_STRERROR(aierr));
myfree(buf);
if (aierr) {
errno = EADDRNOTAVAIL; /* for up-stream "%m" */
return (-1);
}
proto_info = inet_proto_info();
for (sock = -1, found = 0, res = res0; res != 0; res = res->ai_next) {
/*
* Safety net.
*/
if (strchr((char *) proto_info->sa_family_list, res->ai_family) == 0) {
msg_info("skipping address family %d for host %s",
res->ai_family, host);
continue;
}
found++;
/*
* In case of multiple addresses, show what address we're trying now.
*/
if (msg_verbose) {
SOCKADDR_TO_HOSTADDR(res->ai_addr, res->ai_addrlen,
&hostaddr, (MAI_SERVPORT_STR *) 0, 0);
msg_info("trying... [%s]", hostaddr.buf);
}
if ((sock = inet_connect_one(res, block_mode, timeout)) < 0) {
if (msg_verbose)
msg_info("%m");
} else
break;
}
if (found == 0)
msg_fatal("host not found: %s", addr);
freeaddrinfo(res0);
return (sock);
}
/* inet_connect_one - try to connect to one address */
static int inet_connect_one(struct addrinfo * res, int block_mode, int timeout)
{
int sock;
/*
* Create a client socket.
*/
sock = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
if (sock < 0)
return (-1);
/*
* Window scaling workaround.
*/
if (inet_windowsize > 0)
set_inet_windowsize(sock, inet_windowsize);
/*
* Timed connect.
*/
if (timeout > 0) {
non_blocking(sock, NON_BLOCKING);
if (timed_connect(sock, res->ai_addr, res->ai_addrlen, timeout) < 0) {
close(sock);
return (-1);
}
if (block_mode != NON_BLOCKING)
non_blocking(sock, block_mode);
return (sock);
}
/*
* Maybe block until connected.
*/
else {
non_blocking(sock, block_mode);
if (sane_connect(sock, res->ai_addr, res->ai_addrlen) < 0
&& errno != EINPROGRESS) {
close(sock);
return (-1);
}
return (sock);
}
}
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