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/*++
/* NAME
/* inet_listen 3
/* SUMMARY
/* start TCP listener
/* SYNOPSIS
/* #include <listen.h>
/*
/* int inet_windowsize;
/*
/* int inet_listen(addr, backlog, block_mode)
/* const char *addr;
/* int backlog;
/* int block_mode;
/*
/* int inet_accept(fd)
/* int fd;
/* DESCRIPTION
/* The \fBinet_listen\fR routine starts a TCP listener
/* on the specified address, with the specified backlog, and returns
/* the resulting file descriptor.
/*
/* inet_accept() accepts a connection and sanitizes error results.
/*
/* Specify an inet_windowsize value > 0 to override the TCP
/* window size that the server advertises to the client.
/*
/* Arguments:
/* .IP addr
/* The communication endpoint to listen on. The syntax is "host:port".
/* Host and port may be specified in symbolic form or numerically.
/* A null host field means listen on all network interfaces.
/* .IP backlog
/* This argument is passed on to the \fIlisten(2)\fR routine.
/* .IP block_mode
/* Either NON_BLOCKING for a non-blocking socket, or BLOCKING for
/* blocking mode.
/* .IP fd
/* File descriptor returned by inet_listen().
/* DIAGNOSTICS
/* Fatal errors: inet_listen() aborts upon any system call failure.
/* inet_accept() leaves all error handling up to the caller.
/* 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
/*--*/
/* System libraries. */
#include <sys_defs.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#ifndef MAXHOSTNAMELEN
#include <sys/param.h>
#endif
#include <errno.h>
#include <string.h>
#include <unistd.h>
/* Utility library. */
#include "mymalloc.h"
#include "msg.h"
#include "host_port.h"
#include "iostuff.h"
#include "listen.h"
#include "sane_accept.h"
#include "myaddrinfo.h"
#include "sock_addr.h"
#include "inet_proto.h"
/* inet_listen - create TCP listener */
int inet_listen(const char *addr, int backlog, int block_mode)
{
struct addrinfo *res;
struct addrinfo *res0;
int aierr;
int sock;
int on = 1;
char *buf;
char *host;
char *port;
const char *parse_err;
MAI_HOSTADDR_STR hostaddr;
MAI_SERVPORT_STR portnum;
INET_PROTO_INFO *proto_info;
/*
* Translate address information to internal form.
*/
buf = mystrdup(addr);
if ((parse_err = host_port(buf, &host, "", &port, (char *) 0)) != 0)
msg_fatal("%s: %s", addr, parse_err);
if (*host == 0)
host = 0;
if ((aierr = hostname_to_sockaddr(host, port, SOCK_STREAM, &res0)) != 0)
msg_fatal("%s: %s", addr, MAI_STRERROR(aierr));
myfree(buf);
/* No early returns or res0 leaks. */
proto_info = inet_proto_info();
for (res = res0; /* see below */ ; res = res->ai_next) {
/*
* No usable address found.
*/
if (res == 0)
msg_fatal("%s: host found but no usable address", addr);
/*
* Safety net.
*/
if (strchr((char *) proto_info->sa_family_list, res->ai_family) != 0)
break;
msg_info("skipping address family %d for %s", res->ai_family, addr);
}
/*
* Show what address we're trying.
*/
if (msg_verbose) {
SOCKADDR_TO_HOSTADDR(res->ai_addr, res->ai_addrlen,
&hostaddr, &portnum, 0);
msg_info("trying... [%s]:%s", hostaddr.buf, portnum.buf);
}
/*
* Create a listener socket.
*/
if ((sock = socket(res->ai_family, res->ai_socktype, 0)) < 0)
msg_fatal("socket: %m");
#ifdef HAS_IPV6
#if defined(IPV6_V6ONLY) && !defined(BROKEN_AI_PASSIVE_NULL_HOST)
if (res->ai_family == AF_INET6
&& setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY,
(void *) &on, sizeof(on)) < 0)
msg_fatal("setsockopt(IPV6_V6ONLY): %m");
#endif
#endif
if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
(void *) &on, sizeof(on)) < 0)
msg_fatal("setsockopt(SO_REUSEADDR): %m");
if (bind(sock, res->ai_addr, res->ai_addrlen) < 0) {
SOCKADDR_TO_HOSTADDR(res->ai_addr, res->ai_addrlen,
&hostaddr, &portnum, 0);
msg_fatal("bind %s port %s: %m", hostaddr.buf, portnum.buf);
}
freeaddrinfo(res0);
non_blocking(sock, block_mode);
if (inet_windowsize > 0)
set_inet_windowsize(sock, inet_windowsize);
if (listen(sock, backlog) < 0)
msg_fatal("listen: %m");
return (sock);
}
/* inet_accept - accept connection */
int inet_accept(int fd)
{
struct sockaddr_storage ss;
SOCKADDR_SIZE ss_len = sizeof(ss);
return (sane_accept(fd, (struct sockaddr *) &ss, &ss_len));
}
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