4.3BSD - /usr/src/old/talk/process.c

   1: /*
   2:  * Copyright (c) 1983 Regents of the University of California.
   3:  * All rights reserved.  The Berkeley software License Agreement
   4:  * specifies the terms and conditions for redistribution.
   5:  */
   6: 
   7: #ifndef lint
   8: static char sccsid[] = "@(#)process.c	5.2 (Berkeley) 6/8/85";
   9: #endif not lint
  10: 
  11: /*
  12:  * process.c handles the requests, which can be of three types:
  13:  *	ANNOUNCE - announce to a user that a talk is wanted
  14:  *	LEAVE_INVITE - insert the request into the table
  15:  *	LOOK_UP - look up to see if a request is waiting in
  16:  *		  in the table for the local user
  17:  *	DELETE - delete invitation
  18:  */
  19: #include "ctl.h"
  20: #include <sys/stat.h>
  21: #include <stdio.h>
  22: 
  23: char *strcpy();
  24: CTL_MSG *find_request();
  25: CTL_MSG *find_match();
  26: 
  27: process_request(request, response)
  28:     CTL_MSG *request;
  29:     CTL_RESPONSE *response;
  30: {
  31:     CTL_MSG *ptr;
  32: 
  33:     response->type = request->type;
  34:     response->id_num = 0;
  35: 
  36:     switch (request->type) {
  37: 
  38:     case ANNOUNCE :
  39:         do_announce(request, response);
  40:         break;
  41: 
  42:     case LEAVE_INVITE :
  43:         ptr = find_request(request);
  44:         if (ptr != (CTL_MSG *) 0) {
  45:             response->id_num = ptr->id_num;
  46:             response->answer = SUCCESS;
  47:         } else
  48:             insert_table(request, response);
  49:         break;
  50: 
  51:     case LOOK_UP :
  52:         ptr = find_match(request);
  53:         if (ptr != (CTL_MSG *) 0) {
  54:             response->id_num = ptr->id_num;
  55:             response->addr = ptr->addr;
  56:             response->answer = SUCCESS;
  57:         } else
  58:             response->answer = NOT_HERE;
  59:         break;
  60: 
  61:     case DELETE :
  62:         response->answer = delete_invite(request->id_num);
  63:         break;
  64: 
  65:     default :
  66:         response->answer = UNKNOWN_REQUEST;
  67:         break;
  68:     }
  69: }
  70: 
  71: struct hostent *gethostbyaddr();
  72: 
  73: do_announce(request, response)
  74:     CTL_MSG *request;
  75:     CTL_RESPONSE *response;
  76: {
  77:     struct hostent *hp;
  78:     CTL_MSG *ptr;
  79:     int result;
  80: 
  81:     /* see if the user is logged */
  82:     result = find_user(request->r_name, request->r_tty);
  83:     if (result != SUCCESS) {
  84:         response->answer = result;
  85:         return;
  86:     }
  87:     hp = gethostbyaddr(&request->ctl_addr.sin_addr,
  88:         sizeof(struct in_addr), AF_INET);
  89:     if (hp == (struct hostent *)0) {
  90:         response->answer = MACHINE_UNKNOWN;
  91:         return;
  92:     }
  93:     ptr = find_request(request);
  94:     if (ptr == (CTL_MSG *) 0) {
  95:         insert_table(request,response);
  96:         response->answer = announce(request, hp->h_name);
  97:         return;
  98:     }
  99:     if (request->id_num > ptr->id_num) {
 100:         /*
 101: 		 * this is an explicit re-announce, so update the id_num
 102: 		 * field to avoid duplicates and re-announce the talk
 103: 		 */
 104:         ptr->id_num = response->id_num = new_id();
 105:         response->answer = announce(request, hp->h_name);
 106:         return;
 107:     }
 108:     /* a duplicated request, so ignore it */
 109:     response->id_num = ptr->id_num;
 110:     response->answer = SUCCESS;
 111: }
 112: 
 113: #include <utmp.h>
 114: 
 115: /*
 116:  * Search utmp for the local user
 117:  */
 118: find_user(name, tty)
 119:     char *name;
 120:     char *tty;
 121: {
 122:     struct utmp ubuf;
 123:     int status;
 124:     FILE *fd;
 125:     struct stat statb;
 126:     char ftty[20];
 127: 
 128:     if ((fd = fopen("/etc/utmp", "r")) == NULL) {
 129:         perror("Can't open /etc/utmp");
 130:         return (FAILED);
 131:     }
 132: #define SCMPN(a, b) strncmp(a, b, sizeof (a))
 133:     status = NOT_HERE;
 134:     (void) strcpy(ftty, "/dev/");
 135:     while (fread((char *) &ubuf, sizeof ubuf, 1, fd) == 1)
 136:         if (SCMPN(ubuf.ut_name, name) == 0) {
 137:             if (*tty == '\0') {
 138:                 status = PERMISSION_DENIED;
 139:                 /* no particular tty was requested */
 140:                 (void) strcpy(ftty+5, ubuf.ut_line);
 141:                 if (stat(ftty,&statb) == 0) {
 142:                     if (!(statb.st_mode & 020))
 143:                         continue;
 144:                     (void) strcpy(tty, ubuf.ut_line);
 145:                     status = SUCCESS;
 146:                     break;
 147:                 }
 148:             }
 149:             if (strcmp(ubuf.ut_line, tty) == 0) {
 150:                 status = SUCCESS;
 151:                 break;
 152:             }
 153:         }
 154:     fclose(fd);
 155:     return (status);
 156: }

Defined functions

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Defined macros