archie/tcl-dp/generic/dpSock.c
2024-05-27 16:13:40 +02:00

125 lines
3.0 KiB
C
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/*
* generic/dpSock.c --
*
* This file implements the socket code for various channel drivers.
* In other words, platforms that support Berkeley sockets can use routines
* in this module as part of their platform specific driver.
* This code is supported by the routines in the file dpSock.c in the
* platform directories (i.e., win/dpSock.c, unix/dpSock.c, mac/dpSock.c)
* which handle platform-specific error translation and other non-portable
* functions.
*
* Copyright (c) 1995-1996 Cornell University.
*
* See the file "license.terms" for information on usage and redistribution
* of this file, and for a DISCLAIMER OF ALL WARRANTIES.
*
*/
#include "generic/dpInt.h"
#include "generic/dpPort.h"
/*
*--------------------------------------------------------------
*
* DpHostToIpAddr --
*
* Find the IP address corresponding to a hostname.
*
* Results:
* 1 on success, 0 if host is unknown
*
* Side effects:
* None
*
*--------------------------------------------------------------
*/
int
DpHostToIpAddr (host, ipAddrPtr)
char *host; /* (in) Hostname (human readable) */
int *ipAddrPtr; /* (out) IP address of host */
{
struct hostent *hostent;
if (strcmp (host, "localhost") == 0) {
*ipAddrPtr = 0x7F000001;
return 1;
}
/*
* Gotta watch this one -- on NT, gethostbyname on "" goes out
* to lunch
*/
if ((host == NULL) || (host[0] == 0)) {
return 0;
}
/*
* Try looking host up by address (i.e., host is something
* like "128.84.253.1"). Since the value is returned in
* network byte order, we change it to host byte order.
* We do this first because it's much faster (doesn't require
* a trip to the DNS).
*/
*ipAddrPtr = inet_addr(host);
if (*ipAddrPtr != DP_INADDR_NONE) {
*ipAddrPtr = ntohl(*ipAddrPtr);
return 1;
}
/*
* Looking up the host by address failed. Try looking it up by
* name. If successful, the IP address is in network byte order
* in hostent->h_addr_list[0]
*/
hostent = gethostbyname(host);
if (hostent != NULL) {
memcpy ((char *)ipAddrPtr,
(char *) hostent->h_addr_list[0],
(size_t) hostent->h_length);
*ipAddrPtr = ntohl(*ipAddrPtr);
return 1;
}
/*
* Total failure
*/
return 0;
}
/*
*--------------------------------------------------------------
*
* DpIpAddrToHost --
*
* Find the hostname corresponding to an IP address
*
* Results:
* 1 on success, 0 for failure
*
* Side effects:
* None
*
*--------------------------------------------------------------
*/
int
DpIpAddrToHost (ipAddr, hostPtr)
int ipAddr; /* (in) IP addr */
char *hostPtr; /* (out) Corresponding hostname */
{
struct hostent *hEnt;
if (ipAddr == 0x7F000001) {
strcpy(hostPtr, "localhost");
} else {
hEnt = gethostbyaddr((char *)&ipAddr, sizeof(int), AF_INET);
if (hEnt == NULL) {
return 0;
}
strcpy(hostPtr, hEnt->h_name);
}
return 1;
}