FreeBSD-5.3/usr.sbin/lpr/common_source/net.c
/*
* Copyright (c) 1983, 1993
* The Regents of the University of California. All rights reserved.
* (c) UNIX System Laboratories, Inc.
* All or some portions of this file are derived from material licensed
* to the University of California by American Telephone and Telegraph
* Co. or Unix System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* From: @(#)common.c 8.5 (Berkeley) 4/28/95
*/
#include "lp.cdefs.h" /* A cross-platform version of <sys/cdefs.h> */
__FBSDID("$FreeBSD: src/usr.sbin/lpr/common_source/net.c,v 1.8 2003/07/14 05:15:21 gad Exp $");
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/uio.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <dirent.h> /* required for lp.h, not used here */
#include <errno.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "lp.h"
#include "lp.local.h"
#include "pathnames.h"
/*
* 'local_host' is always the hostname of the machine which is running
* lpr (lpd, whatever), while 'from_host' either points at 'local_host'
* or points at a different buffer when receiving a job from a remote
* machine (and that buffer has the hostname of that remote machine).
*/
char local_host[MAXHOSTNAMELEN]; /* host running lpd/lpr */
const char *from_host = local_host; /* client's machine name */
const char *from_ip = ""; /* client machine's IP address */
#ifdef INET6
u_char family = PF_UNSPEC;
#else
u_char family = PF_INET;
#endif
extern uid_t uid, euid;
/*
* Create a TCP connection to host "rhost" at port "rport".
* If rport == 0, then use the printer service port.
* Most of this code comes from rcmd.c.
*/
int
getport(const struct printer *pp, const char *rhost, int rport)
{
struct addrinfo hints, *res, *ai;
int s, timo = 1, lport = IPPORT_RESERVED - 1;
int err, refused = 0;
/*
* Get the host address and port number to connect to.
*/
if (rhost == NULL)
fatal(pp, "no remote host to connect to");
memset(&hints, 0, sizeof(hints));
hints.ai_family = family;
hints.ai_socktype = SOCK_STREAM;
hints.ai_protocol = 0;
err = getaddrinfo(rhost, (rport == 0 ? "printer" : NULL),
&hints, &res);
if (err)
fatal(pp, "%s\n", gai_strerror(err));
if (rport != 0)
((struct sockaddr_in *) res->ai_addr)->sin_port = htons(rport);
/*
* Try connecting to the server.
*/
ai = res;
retry:
seteuid(euid);
s = rresvport_af(&lport, ai->ai_family);
seteuid(uid);
if (s < 0) {
if (errno != EAGAIN) {
if (ai->ai_next) {
ai = ai->ai_next;
goto retry;
}
if (refused && timo <= 16) {
sleep(timo);
timo *= 2;
refused = 0;
ai = res;
goto retry;
}
}
freeaddrinfo(res);
return(-1);
}
if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0) {
err = errno;
(void) close(s);
errno = err;
/*
* This used to decrement lport, but the current semantics
* of rresvport do not provide such a function (in fact,
* rresvport should guarantee that the chosen port will
* never result in an EADDRINUSE).
*/
if (errno == EADDRINUSE) {
goto retry;
}
if (errno == ECONNREFUSED)
refused++;
if (ai->ai_next != NULL) {
ai = ai->ai_next;
goto retry;
}
if (refused && timo <= 16) {
sleep(timo);
timo *= 2;
refused = 0;
ai = res;
goto retry;
}
freeaddrinfo(res);
return(-1);
}
freeaddrinfo(res);
return(s);
}
/*
* Figure out whether the local machine is the same
* as the remote machine (RM) entry (if it exists).
* We do this by counting the intersection of our
* address list and theirs. This is better than the
* old method (comparing the canonical names), as it
* allows load-sharing between multiple print servers.
* The return value is an error message which must be
* free()d.
*/
char *
checkremote(struct printer *pp)
{
char lclhost[MAXHOSTNAMELEN];
struct addrinfo hints, *local_res, *remote_res, *lr, *rr;
char *err;
int ncommonaddrs, error;
char h1[NI_MAXHOST], h2[NI_MAXHOST];
if (!pp->rp_matches_local) { /* Remote printer doesn't match local */
pp->remote = 1;
return NULL;
}
pp->remote = 0; /* assume printer is local */
if (pp->remote_host == NULL)
return NULL;
/* get the addresses of the local host */
gethostname(lclhost, sizeof(lclhost));
lclhost[sizeof(lclhost) - 1] = '\0';
memset(&hints, 0, sizeof(hints));
hints.ai_family = family;
hints.ai_socktype = SOCK_STREAM;
hints.ai_flags = AI_PASSIVE;
if ((error = getaddrinfo(lclhost, NULL, &hints, &local_res)) != 0) {
asprintf(&err, "unable to get official name "
"for local machine %s: %s",
lclhost, gai_strerror(error));
return err;
}
/* get the official name of RM */
memset(&hints, 0, sizeof(hints));
hints.ai_family = family;
hints.ai_socktype = SOCK_STREAM;
hints.ai_flags = AI_PASSIVE;
if ((error = getaddrinfo(pp->remote_host, NULL,
&hints, &remote_res)) != 0) {
asprintf(&err, "unable to get address list for "
"remote machine %s: %s",
pp->remote_host, gai_strerror(error));
freeaddrinfo(local_res);
return err;
}
ncommonaddrs = 0;
for (lr = local_res; lr; lr = lr->ai_next) {
h1[0] = '\0';
if (getnameinfo(lr->ai_addr, lr->ai_addrlen, h1, sizeof(h1),
NULL, 0, NI_NUMERICHOST | NI_WITHSCOPEID) != 0)
continue;
for (rr = remote_res; rr; rr = rr->ai_next) {
h2[0] = '\0';
if (getnameinfo(rr->ai_addr, rr->ai_addrlen,
h2, sizeof(h2), NULL, 0,
NI_NUMERICHOST | NI_WITHSCOPEID) != 0)
continue;
if (strcmp(h1, h2) == 0)
ncommonaddrs++;
}
}
/*
* if the two hosts do not share at least one IP address
* then the printer must be remote.
*/
if (ncommonaddrs == 0)
pp->remote = 1;
freeaddrinfo(local_res);
freeaddrinfo(remote_res);
return NULL;
}
/*
* This isn't really network-related, but it's used here to write
* multi-part strings onto sockets without using stdio. Return
* values are as for writev(2).
*/
ssize_t
writel(int strm, ...)
{
va_list ap;
int i, n;
const char *cp;
#define NIOV 12
struct iovec iov[NIOV], *iovp = iov;
ssize_t retval;
/* first count them */
va_start(ap, strm);
n = 0;
do {
cp = va_arg(ap, char *);
n++;
} while (cp);
va_end(ap);
n--; /* correct for count of trailing null */
if (n > NIOV) {
iovp = malloc(n * sizeof *iovp);
if (iovp == 0)
return -1;
}
/* now make up iovec and send */
va_start(ap, strm);
for (i = 0; i < n; i++) {
iovp[i].iov_base = va_arg(ap, char *);
iovp[i].iov_len = strlen(iovp[i].iov_base);
}
va_end(ap);
retval = writev(strm, iovp, n);
if (iovp != iov)
free(iovp);
return retval;
}