/* * * Copyright (C) 1988, 1989 by the Massachusetts Institute of Technology * Developed by the MIT Student Information Processing Board (SIPB). * For copying information, see the file mit-copyright.h in this release. * */ /* * * $Source: /afs/sipb.mit.edu/project/discuss/.cvsroot/discuss/source/libds/res_module.c,v $ * $Header: /afs/sipb.mit.edu/project/discuss/.cvsroot/discuss/source/libds/res_module.c,v 1.16 1995/03/18 07:24:27 srz Exp $ * * resolve_module () -- * Can you say "Put all the configuration into one file?" Can you * say "Concentrated kludgery?" I knew you could. This procedure * resolves a module name into port number, hostname, service; it * is allowed to use any trick in the book -- it can depend on hostnames, * have hard coded constants (hopefully recorded in config files, etc.). * Note that if service name contains a '/' as the first character, then * the remote function is executed as a subprocess. * * $Log: res_module.c,v $ * Revision 1.16 1995/03/18 07:24:27 srz * Remove extraneous <<<<<<<<< stuff. Add in check for to deal * with htons(). * * Revision 1.15 1994/09/24 04:07:40 srz * Changed source tree to use configure instead of Imake. Added WEAK_REALM * authentication. Fixed up includes, etc, for new configure... still needs * more testing. * * Revision 1.14 1994/09/19 03:44:17 raeburn * make sure MAX_HSTNM gets defined; use htons on SERVICE_PORT * * Revision 1.13 1992/06/26 02:18:41 raeburn * getting in sync with current source tree * * Revision 1.12 92/02/22 00:10:14 srz * Use SERVICE_PORT if SERVICE_NAME is not found. * * Revision 1.11 91/08/08 00:35:35 eichin * revert 1.10... since meetings are stored in host-byte-order, we * can't do the hack after all without rewriting lots of things. * * Revision 1.10 90/12/01 22:40:09 eichin * added SERVER_LOCAL usage if hostname is "" * * Revision 1.9 90/06/03 16:44:03 raeburn * jtkohl's patches to DTRT wrt Kerberos realm determination * * Revision 1.8 89/06/03 00:21:31 srz * Added standard copyright notice. * * Revision 1.7 89/05/19 18:12:21 srz * krb name changes, etc. * * Revision 1.6 89/05/19 17:05:18 raeburn * *** empty log message *** * */ #ifndef lint static char rcsid_res_module_c[] = "$Header: /afs/sipb.mit.edu/project/discuss/.cvsroot/discuss/source/libds/res_module.c,v 1.16 1995/03/18 07:24:27 srz Exp $"; #endif lint #include "rpc_et.h" #include "config.h" #include "ansi.h" #include #include #include #include #include #include #if HAVE_NETINET_IN_H #include #endif /* HAVE_NETINET_IN_H */ #ifdef KERBEROS #include "krb.h" #ifndef MAX_K_NAME_SZ /* @#$%^$ last minute changes by jtkohl */ #define krb_get_lrealm get_krbrlm #endif static void ExpandHost (); #endif /* KERBEROS */ #ifndef SNAME_SZ #define SNAME_SZ 30 #define REALM_SZ 30 #endif /* SNAME_SZ */ #ifndef MAX_HSTNM #define MAX_HSTNM 60 #endif #ifndef NULL #define NULL 0 #endif char *local_host_name (); const char *local_realm (); static int service_port = 0; void resolve_module (modname, port, hostp, servp, result) char *modname; /* name to translate */ int *port; /* resultant port number */ char **hostp; /* ptr to hostname (static) */ char **servp; /* service_id */ int *result; /* std error code */ { static char service_id [SNAME_SZ+REALM_SZ]; static char hostname [MAX_HSTNM]; char realm [REALM_SZ]; char *myhnamep = NULL; const char *realmp = NULL; struct servent *sp; struct hostent *hp; *hostp = NULL; *servp = NULL; *port = 0; *result = 0; /* The module name could be of the form "discuss@hostname", where * hostname is the host to contact. If the hostname is omitted, * the current host is assumed */ if (!strncmp (modname, "discuss", 7)) { if (modname [7] == '@') { /* got hostname */ myhnamep = &modname [8]; hp = gethostbyname (myhnamep); /* make it primary */ if (!hp) { extern int h_errno; int h = h_errno; switch (h) { case HOST_NOT_FOUND: *result = RPC_HOST_UNKNOWN; break; case TRY_AGAIN: *result = RPC_NS_TIMEOUT; break; case NO_RECOVERY: *result = RPC_NS_ERROR; break; case NO_ADDRESS: *result = RPC_NO_ADDR; break; default: *result = RPC_NS_ERROR; } return; } strcpy (hostname, hp -> h_name); myhnamep = hostname; } else if (modname [7] == '\0') { /* Just discuss - use current host */ myhnamep = local_host_name (); } else { *result = RPC_MOD_UNKNOWN; return; } } #if 0 /* or... the module could be of the form of disname@realm, where realm * is a kerberos realm. If realm is not given, then the current realm * is assumed. */ else if (!strncmp (modname, "disname", 7)) { if (modname [7] == '@') { /* got realm */ realmp = &modname [8]; } else if (modname [7] == '\0') { /* Just disname - use current realm */ realmp = local_realm (); } else { *result = RPC_MOD_UNKNOWN; return; } /* got realm -- use our static lookup. */ if (!strcmp (realmp, "LCS.MIT.EDU")) myhnamep = "GRAPE-NEHI.LCS.MIT.EDU"; else if (!strcmp (realmp, "ATHENA.MIT.EDU")) myhnamep = "CHARON.MIT.EDU"; else { *result = RPC_REALM_UNKNOWN; return; } } #endif else { *result = RPC_MOD_UNKNOWN; return; } /* Now we have the host name, and all we have to do is create the * service id & port number. If this is local, we use the subprocess, * for better authentication */ if (!namcmp (myhnamep, local_host_name ())) { *port = 0; *servp = SERVER; *hostp = myhnamep; *result = 0; return; } /* otherwise, we have to generate the port number */ if (service_port == 0) { sp = getservbyname (SERVICE_NAME, 0); if (!sp) { service_port = htons (SERVICE_PORT); } else { service_port = sp -> s_port; } } *port = service_port; /* generate the service name, but concatenating "discuss.instance@realm" * desired realm. */ #ifndef KERBEROS strcpy (service_id, "discuss@"); strcpy (&service_id[8], REALM); #else strcpy (service_id, "discuss."); ExpandHost (myhnamep, &service_id[8], realm); strcat(service_id, "@"); if (realmp) strcat (service_id, realmp); else strcat (service_id, realm); #endif KERBEROS *hostp = myhnamep; *servp = service_id; *result = 0; } #ifdef KERBEROS /* * * ExpandHost -- takes a user string alias for a host, and converts it * to the official Kerberos principal name, plus the realm * that it lies in. * * Warning: There are some heuristics here. * */ static void ExpandHost (primary_name, krb_host, krb_realm ) char *primary_name,*krb_realm; char *krb_host; { char *p,*sp=primary_name,*dp=krb_host; /* * The convention established by the Kerberos-authenticated * rcmd services (rlogin, rsh, rcp) is that the principal host * name is all lower case characters. Therefore, we can get * this name from an alias by taking the official, fully * qualified hostname, stripping off the domain info (ie, take * everything up to but excluding the '.') and translating it * to lower case. For example, if "menel" is an alias for * host officially named "menelaus" (in /etc/hosts), for the * host whose official name is "MENELAUS.MIT.EDU", the user * could give the command "menel echo foo" and we will resolve * it to "menelaus". */ #ifdef OLD_KERBEROS *krb_realm = '\0'; /* null for now */ p = index( sp, '.' ); if (p) { char *p1; strncpy(krb_realm,p+1,REALM_SZ); /* Realm after '.' */ krb_realm[REALM_SZ-1] = NULL; p1 = krb_realm; /* Upper case this */ do { if (islower(*p1)) *p1=toupper(*p1); } while (*p1++); } #else (void) strcpy(krb_realm, (char *) krb_realmofhost(primary_name)); #endif /* OLD_KERBEROS */ /* lower case Kerberos host name */ do { if (isupper(*sp)) *dp=tolower(*sp); else *dp = *sp; } while (dp++,*sp && (*sp++ != '.')); *(--dp) = NULL; /* heuristics */ if (*krb_realm == '\0') strcpy (krb_realm, local_realm()); #ifdef notdef if (!strcmp(krb_realm,"MIT.EDU")) strcpy(krb_realm,"ATHENA.MIT.EDU"); #endif return; } #endif const char *local_realm () { #ifdef KERBEROS static char realm [REALM_SZ] = ""; if (realm [0] == '\0') krb_get_lrealm (realm, 1); return (realm); #else KERBEROS return (REALM); #endif KERBEROS }