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BSD 4.3
/*
*******************************************************************************
*
* subr.c --
*
* Miscellaneous subroutines for the name server
* lookup program.
*
* Copyright (c) 1985
* Andrew Cherenson
* CS298-26 Fall 1985
*
* Copyright (c) 1985 Regents of the University of California.
* All rights reserved. The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*
*******************************************************************************
*/
#ifndef lint
static char sccsid[] = "@(#)subr.c 5.3 (Berkeley) 5/1/86";
#endif not lint
#include <stdio.h>
#include <strings.h>
#include <sys/types.h>
#include <netdb.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/nameser.h>
#include <signal.h>
#include <setjmp.h>
#include "res.h"
/*
*******************************************************************************
*
* IntrHandler --
*
* This routine is called whenever a control-C is typed.
* It performs three main functions:
* - close an open socket connection.
* - close an open output file (used by LookupHost, et al.)
* - jump back to the main read-eval loop.
*
* Since a user may type a ^C in the middle of a routine that
* is using a socket, the socket would never get closed by the
* routine. To prevent an overflow of the process's open file table,
* the socket and output file descriptors are closed by
* the interrupt handler.
*
* Side effects:
* If sockFD is valid, its socket is closed.
* If filePtr is valid, its file is closed.
* Flow of control returns to the main() routine.
*
*******************************************************************************
*/
int
IntrHandler()
{
extern jmp_buf env;
if (sockFD >= 0) {
close(sockFD);
sockFD = -1;
}
if (filePtr != NULL && filePtr != stdout) {
fclose(filePtr);
filePtr = NULL;
}
printf("\n");
longjmp(env, 1);
}
/*
*******************************************************************************
*
* Calloc --
*
* Calls the calloc library routine with the interrupt
* signal blocked. The interrupt signal blocking is done
* to prevent malloc from getting confused if a
* control-C arrives in the middle of its bookkeeping
* routines. We need to do this because a control-C
* causes a return to the main command loop instead
* causing the program to die.
*
* This method doesn't prevent the pointer returned
* by calloc from getting lost, so it is possible
* to get "core leaks".
*
* Results:
* (address) - address of new buffer.
* NULL - calloc failed.
*
*******************************************************************************
*/
char *
Calloc(num, size)
unsigned num, size;
{
char *ptr;
int saveMask;
extern char *calloc();
saveMask = sigblock(1 << (SIGINT-1));
ptr = calloc(num, size);
(void) sigsetmask(saveMask);
if (ptr == NULL) {
fflush(stdout);
fprintf(stderr, "Calloc failed\n");
fflush(stderr);
abort();
/*NOTREACHED*/
} else {
return(ptr);
}
}
/*
*******************************************************************************
*
* PrintHostInfo --
*
* Prints out the HostInfo structure for a host.
*
*******************************************************************************
*/
void
PrintHostInfo(file, title, hp)
FILE *file;
char *title;
register HostInfo *hp;
{
register char **cp;
register ServerInfo **sp;
char comma;
int i;
fprintf(file, "%-7s %s\n", title, hp->name);
if (hp->addrList != NULL) {
if (hp->addrList[1] != NULL) {
fprintf(file, "Addresses:");
} else {
fprintf(file, "Address:");
}
comma = ' ';
i = 0;
for (cp = hp->addrList; cp && *cp && **cp; cp++) {
i++;
if (i > 4) {
fprintf(file, "\n\t");
comma = ' ';
i = 0;
}
fprintf(file,"%c %s", comma, inet_ntoa(*(struct in_addr *)*cp));
comma = ',';
}
}
if (hp->aliases != NULL) {
fprintf(file, "\nAliases:");
comma = ' ';
i = 10;
for (cp = hp->aliases; cp && *cp && **cp; cp++) {
i += strlen(*cp) + 2;
if (i > 75) {
fprintf(file, "\n\t");
comma = ' ';
i = 10;
}
fprintf(file, "%c %s", comma, *cp);
comma = ',';
}
}
if (hp->servers != NULL) {
fprintf(file, "Served by:\n");
for (sp = hp->servers; *sp != NULL ; sp++) {
fprintf(file, "- %s\n\t", (*sp)->name);
comma = ' ';
i = 0;
for (cp = (*sp)->addrList; cp && *cp && **cp; cp++) {
i++;
if (i > 4) {
fprintf(file, "\n\t");
comma = ' ';
i = 0;
}
fprintf(file,
"%c %s", comma, inet_ntoa(*(struct in_addr *)*cp));
comma = ',';
}
fprintf(file, "\n\t");
comma = ' ';
i = 10;
for (cp = (*sp)->domains; cp && *cp && **cp; cp++) {
i += strlen(*cp) + 2;
if (i > 75) {
fprintf(file, "\n\t");
comma = ' ';
i = 10;
}
fprintf(file, "%c %s", comma, *cp);
comma = ',';
}
fprintf(file, "\n");
}
}
fprintf(file, "\n\n");
}
/*
*******************************************************************************
*
* OpenFile --
*
* Parses a command string for a file name and opens
* the file.
*
* Results:
* file pointer - the open was successful.
* NULL - there was an error opening the file or
* the input string was invalid.
*
*******************************************************************************
*/
FILE *
OpenFile(string, file)
char *string;
char *file;
{
char *redirect;
FILE *tmpPtr;
/*
* Open an output file if we see '>' or >>'.
* Check for overwrite (">") or concatenation (">>").
*/
redirect = index(string, '>');
if (redirect == NULL) {
return(NULL);
}
if (redirect[1] == '>') {
sscanf(redirect, ">> %s", file);
tmpPtr = fopen(file, "a+");
} else {
sscanf(redirect, "> %s", file);
tmpPtr = fopen(file, "w");
}
if (tmpPtr != NULL) {
redirect[0] = '\0';
}
return(tmpPtr);
}
/*
*******************************************************************************
*
* DecodeError --
*
* Converts an error code into a character string.
*
*******************************************************************************
*/
char *
DecodeError(result)
int result;
{
switch(result) {
case NOERROR: return("Success"); break;
case FORMERR: return("Format error"); break;
case SERVFAIL: return("Server failed"); break;
case NXDOMAIN: return("Non-existent domain"); break;
case NOTIMP: return("Not implemented"); break;
case REFUSED: return("Query refused"); break;
case NOCHANGE: return("No change"); break;
case NO_INFO: return("No information"); break;
case ERROR: return("Unspecified error"); break;
case TIME_OUT: return("Timed out"); break;
case NONAUTH: return("Non-authoritative answer"); break;
default: break;
}
return("BAD ERROR VALUE");
}
/*
*******************************************************************************
*
* StringToType --
*
* Converts a string form of a query type name to its
* corresponding integer value.
*
*******************************************************************************
*/
int
StringToType(type)
char *type;
{
if (strcmp(type, "A") == 0) {
return(T_A);
} else if (strcmp(type, "NS") == 0) {
return(T_NS); /* authoritative server */
} else if (strcmp(type, "MX") == 0) {
return(T_MX); /* mail exchanger */
} else if (strcmp(type, "CNAME") == 0) {
return(T_CNAME); /* canonical name */
} else if (strcmp(type, "SOA") == 0) {
return(T_SOA); /* start of authority zone */
} else if (strcmp(type, "MB") == 0) {
return(T_MB); /* mailbox domain name */
} else if (strcmp(type, "MG") == 0) {
return(T_MG); /* mail group member */
} else if (strcmp(type, "MR") == 0) {
return(T_MR); /* mail rename name */
} else if (strcmp(type, "WKS") == 0) {
return(T_WKS); /* well known service */
} else if (strcmp(type, "PTR") == 0) {
return(T_PTR); /* domain name pointer */
} else if (strcmp(type, "HINFO") == 0) {
return(T_HINFO); /* host information */
} else if (strcmp(type, "MINFO") == 0) {
return(T_MINFO); /* mailbox information */
} else if (strcmp(type, "AXFR") == 0) {
return(T_AXFR); /* zone transfer */
} else if (strcmp(type, "MAILB") == 0) {
return(T_MAILB); /* mail box */
} else if (strcmp(type, "ANY") == 0) {
return(T_ANY); /* matches any type */
} else if (strcmp(type, "UINFO") == 0) {
return(T_UINFO); /* user info */
} else if (strcmp(type, "UID") == 0) {
return(T_UID); /* user id */
} else if (strcmp(type, "GID") == 0) {
return(T_GID); /* group id */
} else {
return(T_A);
}
}
/*
*******************************************************************************
*
* DecodeType --
*
* Converts a query type to a descriptive name.
* (A more verbose form of p_type.)
*
*
*******************************************************************************
*/
static char nbuf[20];
extern char *sprintf();
char *
DecodeType(type)
int type;
{
switch (type) {
case T_A:
return("address");
case T_NS:
return("name server");
case T_MX:
return("mail exchanger");
case T_CNAME:
return("cannonical name");
case T_SOA:
return("start of authority zone");
case T_MB:
return("mailbox domain name");
case T_MG:
return("mail group member");
case T_MR:
return("mail rename name");
case T_NULL:
return("null resource record");
case T_WKS:
return("well known service");
case T_PTR:
return("domain name pointer");
case T_HINFO:
return("host");
case T_MINFO:
return("mailbox (MINFO)");
case T_AXFR:
return("zone transfer");
case T_MAILB:
return("mail box");
case T_ANY:
return("any type");
case T_UINFO:
return("user info");
case T_UID:
return("user id");
case T_GID:
return("group id");
default:
return (sprintf(nbuf, "%d", type));
}
}
printanswer(hp)
register struct hostent *hp;
{
register char **cp;
int i;
char comma;
extern char *inet_ntoa();
fprintf(stderr,"Name: %s\n", hp->h_name);
fprintf(stderr,"Address: %s\n",
inet_ntoa(*(struct in_addr *)hp->h_addr));
if (hp->h_aliases != NULL) {
fprintf(stderr, "Aliases:");
comma = ' ';
i = 10;
for (cp = hp->h_aliases; cp && *cp && **cp; cp++) {
i += strlen(*cp) + 2;
if (i > 75) {
fprintf(stderr, "\n\t");
comma = ' ';
i = 10;
}
fprintf(stderr, "%c %s", comma, *cp);
comma = ',';
}
}
fprintf(stderr,"\n\n");
}
hperror(errno)
int errno;
{
switch(errno) {
case HOST_NOT_FOUND:
fprintf(stderr,"Host not found.\n");
break;
case TRY_AGAIN:
fprintf(stderr,"Host not found, try again.\n");
break;
case NO_RECOVERY:
fprintf(stderr,"No recovery, Host not found.\n");
break;
case NO_ADDRESS:
fprintf(stderr,"No Address, look for MF record.\n");
break;
}
}
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