/* * Copyright (c) 1985 Regents of the University of California. * All rights reserved. * * Redistribution and use in source and binary forms are permitted * provided that this notice is preserved and that due credit is given * to the University of California at Berkeley. The name of the University * may not be used to endorse or promote products derived from this * software without specific prior written permission. This software * is provided ``as is'' without express or implied warranty. */ #ifndef lint static char sccsid[] = "@(#)subr.c 5.9 (Berkeley) 2/17/88"; #endif /* not lint */ /* ******************************************************************************* * * subr.c -- * * Miscellaneous subroutines for the name server * lookup program. * * Copyright (c) 1985 * Andrew Cherenson * CS298-26 Fall 1985 * ******************************************************************************* */ #include #include #include #include #include #include #include #include #include #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++) { 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"); } int StringToClass(class, dflt) char *class; int dflt; { if (strcasecmp(class, "IN") == 0) return(C_IN); if (strcasecmp(class, "CHAOS") == 0) return(C_CHAOS); if (strcasecmp(class, "ANY") == 0) return(C_ANY); fprintf(stderr, "unknown query class: %s\n", class); return(dflt); } /* ******************************************************************************* * * StringToType -- * * Converts a string form of a query type name to its * corresponding integer value. * ******************************************************************************* */ int StringToType(type, dflt) char *type; int dflt; { if (strcasecmp(type, "A") == 0) return(T_A); if (strcasecmp(type, "NS") == 0) return(T_NS); /* authoritative server */ if (strcasecmp(type, "MX") == 0) return(T_MX); /* mail exchanger */ if (strcasecmp(type, "CNAME") == 0) return(T_CNAME); /* canonical name */ if (strcasecmp(type, "SOA") == 0) return(T_SOA); /* start of authority zone */ if (strcasecmp(type, "MB") == 0) return(T_MB); /* mailbox domain name */ if (strcasecmp(type, "MG") == 0) return(T_MG); /* mail group member */ if (strcasecmp(type, "MR") == 0) return(T_MR); /* mail rename name */ if (strcasecmp(type, "WKS") == 0) return(T_WKS); /* well known service */ if (strcasecmp(type, "PTR") == 0) return(T_PTR); /* domain name pointer */ if (strcasecmp(type, "HINFO") == 0) return(T_HINFO); /* host information */ if (strcasecmp(type, "MINFO") == 0) return(T_MINFO); /* mailbox information */ if (strcasecmp(type, "AXFR") == 0) return(T_AXFR); /* zone transfer */ if (strcasecmp(type, "MAILB") == 0) return(T_MAILB); /* mail box */ if (strcasecmp(type, "ANY") == 0) return(T_ANY); /* matches any type */ if (strcasecmp(type, "UINFO") == 0) return(T_UINFO); /* user info */ if (strcasecmp(type, "UID") == 0) return(T_UID); /* user id */ if (strcasecmp(type, "GID") == 0) return(T_GID); /* group id */ fprintf(stderr, "unknown query type: %s\n", type); return(dflt); } /* ******************************************************************************* * * DecodeType -- * * Converts a query type to a descriptive name. * (A more verbose form of p_type.) * * ******************************************************************************* */ static char nbuf[20]; 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: (void) sprintf(nbuf, "%d", type); return (nbuf); } }