# 2.11BSD#431 - /usr/src/libexec/talkd/table.c

##### Functions

    delete            X
    delete_invite     X
    find_match        X
    find_request      X
    insert_table      X
    new_id            X

##### Variables

    table             X
    tp                X
    txp               X

##### Macros

    MAX_ID            X
    NIL               X

##### struct's

    table_entry       X

##### typedef's

    TABLE_ENTRY       X

       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: #if defined(DOSCCS) && !defined(lint)
       8: static char sccsid[] = "@(#)table.c	5.2.1 (2.11BSD GTE) 1/1/94";
       9: #endif
      10:
      11: /*
      12:  * Routines to handle insertion, deletion, etc on the table
      13:  * of requests kept by the daemon. Nothing fancy here, linear
      14:  * search on a double-linked list. A time is kept with each
      15:  * entry so that overly old invitations can be eliminated.
      16:  *
      17:  * Consider this a mis-guided attempt at modularity
      18:  */
      19: #include <stdio.h>
      20: #include <sys/time.h>
      21: #include <syslog.h>
      22: #include <sys/types.h>
      23: #include <netinet/in.h>
      24:
      25: #include <protocols/talkd.h>
      26:
      27: #define MAX_ID 16000    /* << 2^15 so I don't have sign troubles */
      28:
      29: #define NIL ((TABLE_ENTRY *)0)
      30:
      31: extern  int debug;
      32: struct  timeval tp;
      33: struct  timezone *txp;
      34:
      35: typedef struct table_entry TABLE_ENTRY;
      36:
      37: struct table_entry {
      38:     CTL_MSG request;
      39:     long    time;
      40:     TABLE_ENTRY *next;
      41:     TABLE_ENTRY *last;
      42: };
      43:
      44: TABLE_ENTRY *table = NIL;
      45: CTL_MSG *find_request();
      46: CTL_MSG *find_match();
      47: char    *malloc();
      48:
      49: /*
      50:  * Look in the table for an invitation that matches the current
      51:  * request looking for an invitation
      52:  */
      53: CTL_MSG *
      54: find_match(request)
      55:     register CTL_MSG *request;
      56: {
      57:     register TABLE_ENTRY *ptr;
      58:     long current_time;
      59:
      60:     gettimeofday(&tp, &txp);
      61:     current_time = tp.tv_sec;
      62:     if (debug)
      63:         print_request("find_match", request);
      64:     for (ptr = table; ptr != NIL; ptr = ptr->next) {
      65:         if ((ptr->time - current_time) > MAX_LIFE) {
      66:             /* the entry is too old */
      67:             if (debug)
      68:                 print_request("deleting expired entry",
      69:                     &ptr->request);
      70:             delete(ptr);
      71:             continue;
      72:         }
      73:         if (debug)
      74:             print_request("", &ptr->request);
      75:         if (strcmp(request->l_name, ptr->request.r_name) == 0 &&
      76:             strcmp(request->r_name, ptr->request.l_name) == 0 &&
      77:              ptr->request.type == LEAVE_INVITE)
      78:             return (&ptr->request);
      79:     }
      80:     return ((CTL_MSG *)0);
      81: }
      82:
      83: /*
      84:  * Look for an identical request, as opposed to a complimentary
      85:  * one as find_match does
      86:  */
      87: CTL_MSG *
      88: find_request(request)
      89:     register CTL_MSG *request;
      90: {
      91:     register TABLE_ENTRY *ptr;
      92:     long current_time;
      93:
      94:     gettimeofday(&tp, &txp);
      95:     current_time = tp.tv_sec;
      96:     /*
      97: 	 * See if this is a repeated message, and check for
      98: 	 * out of date entries in the table while we are it.
      99: 	 */
     100:     if (debug)
     101:         print_request("find_request", request);
     102:     for (ptr = table; ptr != NIL; ptr = ptr->next) {
     103:         if ((ptr->time - current_time) > MAX_LIFE) {
     104:             /* the entry is too old */
     105:             if (debug)
     106:                 print_request("deleting expired entry",
     107:                     &ptr->request);
     108:             delete(ptr);
     109:             continue;
     110:         }
     111:         if (debug)
     112:             print_request("", &ptr->request);
     113:         if (strcmp(request->r_name, ptr->request.r_name) == 0 &&
     114:             strcmp(request->l_name, ptr->request.l_name) == 0 &&
     115:             request->type == ptr->request.type &&
     116:             request->pid == ptr->request.pid) {
     117:             /* update the time if we 'touch' it */
     118:             ptr->time = current_time;
     119:             return (&ptr->request);
     120:         }
     121:     }
     122:     return ((CTL_MSG *)0);
     123: }
     124:
     125: insert_table(request, response)
     126:     CTL_MSG *request;
     127:     CTL_RESPONSE *response;
     128: {
     129:     register TABLE_ENTRY *ptr;
     130:     long current_time;
     131:
     132:     gettimeofday(&tp, &txp);
     133:     current_time = tp.tv_sec;
     134:     request->id_num = new_id();
     135:     response->id_num = htonl(request->id_num);
     136:     /* insert a new entry into the top of the list */
     137:     ptr = (TABLE_ENTRY *)malloc(sizeof(TABLE_ENTRY));
     138:     if (ptr == NIL) {
     139:         syslog(LOG_ERR, "insert_table: Out of memory");
     140:         _exit(1);
     141:     }
     142:     ptr->time = current_time;
     143:     ptr->request = *request;
     144:     ptr->next = table;
     145:     if (ptr->next != NIL)
     146:         ptr->next->last = ptr;
     147:     ptr->last = NIL;
     148:     table = ptr;
     149: }
     150:
     151: /*
     152:  * Generate a unique non-zero sequence number
     153:  */
     154: new_id()
     155: {
     156:     static int current_id = 0;
     157:
     158:     current_id = (current_id + 1) % MAX_ID;
     159:     /* 0 is reserved, helps to pick up bugs */
     160:     if (current_id == 0)
     161:         current_id = 1;
     162:     return (current_id);
     163: }
     164:
     165: /*
     166:  * Delete the invitation with id 'id_num'
     167:  */
     168: delete_invite(id_num)
     169:     long id_num;
     170: {
     171:     register TABLE_ENTRY *ptr;
     172:
     173:     ptr = table;
     174:     if (debug)
     175:         syslog(LOG_DEBUG, "delete_invite(%ld)", id_num);
     176:     for (ptr = table; ptr != NIL; ptr = ptr->next) {
     177:         if (ptr->request.id_num == id_num)
     178:             break;
     179:         if (debug)
     180:             print_request("", &ptr->request);
     181:     }
     182:     if (ptr != NIL) {
     183:         delete(ptr);
     184:         return (SUCCESS);
     185:     }
     186:     return (NOT_HERE);
     187: }
     188:
     189: /*
     190:  * Classic delete from a double-linked list
     191:  */
     192: delete(ptr)
     193:     register TABLE_ENTRY *ptr;
     194: {
     195:
     196:     if (debug)
     197:         print_request("delete", &ptr->request);
     198:     if (table == ptr)
     199:         table = ptr->next;
     200:     else if (ptr->last != NIL)
     201:         ptr->last->next = ptr->next;
     202:     if (ptr->next != NIL)
     203:         ptr->next->last = ptr->last;
     204:     free((char *)ptr);
     205: }

#### Defined functions

delete defined in line 192; used 3 times

- in line 70, 108, 183

delete_invite defined in line 168; used 1 times

- in /usr/src/libexec/talkd/process.c line 92

find_match defined in line 53; used 3 times

- in line 46
- in /usr/src/libexec/talkd/process.c line 30, 81

find_request defined in line 87; used 4 times

- in line 45
- in /usr/src/libexec/talkd/process.c line 29, 72, 124

insert_table defined in line 125; used 2 times

- in /usr/src/libexec/talkd/process.c line 77, 126

new_id defined in line 154; used 2 times

- in line 134
- in /usr/src/libexec/talkd/process.c line 135

#### Defined variables

sccsid defined in line 8; never used
table defined in line 44; used 8 times

- in line 64, 102, 144-148(2), 173-176(2), 198-199(2)

tp defined in line 32; used 6 times

- in line 60-61(2), 94-95(2), 132-133(2)

txp defined in line 33; used 3 times

- in line 60, 94, 132

#### Defined struct's

table_entry defined in line 37; used 1 times

- in line 35

#### Defined typedef's

TABLE_ENTRY defined in line 35; used 11 times

- in line 44, 193-29(2), 40-41(2), 57, 91, 129, 137(2), 171

#### Defined macros

MAX_ID defined in line 27; used 1 times

- in line 158

NIL defined in line 29; used 10 times

- in line 44, 64, 102, 138, 145-147(2), 176, 182, 200-202(2)

Last modified: 1994-01-11 Generated: 2016-12-26 | Generated by src2html V0.67 page hit count: 1460 |