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6 * modification, are permitted provided that the following conditions
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29 * @(#)table.c 8.1 (Berkeley) 6/4/93
30 * $FreeBSD: src/libexec/talkd/table.c,v 1.7 1999/08/28 00:10:17 peter Exp $
34 * Routines to handle insertion, deletion, etc on the table
35 * of requests kept by the daemon. Nothing fancy here, linear
36 * search on a double-linked list. A time is kept with each
37 * entry so that overly old invitations can be eliminated.
39 * Consider this a mis-guided attempt at modularity
41 #include <sys/param.h>
43 #include <sys/socket.h>
44 #include <protocols/talkd.h>
53 #define MAX_ID 16000 /* << 2^15 so I don't have sign troubles */
58 typedef struct table_entry TABLE_ENTRY
;
67 static void delete(TABLE_ENTRY
*);
69 TABLE_ENTRY
*table
= NULL
;
72 * Look in the table for an invitation that matches the current
73 * request looking for an invitation
76 find_match(CTL_MSG
*request
)
81 gettimeofday(&tp
, NULL
);
82 current_time
= tp
.tv_sec
;
84 print_request("find_match", request
);
85 for (ptr
= table
; ptr
!= NULL
; ptr
= ptr
->next
) {
86 if ((ptr
->time
- current_time
) > MAX_LIFE
) {
87 /* the entry is too old */
89 print_request("deleting expired entry",
95 print_request("", &ptr
->request
);
96 if (strcmp(request
->l_name
, ptr
->request
.r_name
) == 0 &&
97 strcmp(request
->r_name
, ptr
->request
.l_name
) == 0 &&
98 ptr
->request
.type
== LEAVE_INVITE
)
99 return (&ptr
->request
);
105 * Look for an identical request, as opposed to a complimentary
106 * one as find_match does
109 find_request(CTL_MSG
*request
)
114 gettimeofday(&tp
, NULL
);
115 current_time
= tp
.tv_sec
;
117 * See if this is a repeated message, and check for
118 * out of date entries in the table while we are it.
121 print_request("find_request", request
);
122 for (ptr
= table
; ptr
!= NULL
; ptr
= ptr
->next
) {
123 if ((ptr
->time
- current_time
) > MAX_LIFE
) {
124 /* the entry is too old */
126 print_request("deleting expired entry",
132 print_request("", &ptr
->request
);
133 if (strcmp(request
->r_name
, ptr
->request
.r_name
) == 0 &&
134 strcmp(request
->l_name
, ptr
->request
.l_name
) == 0 &&
135 request
->type
== ptr
->request
.type
&&
136 request
->pid
== ptr
->request
.pid
) {
137 /* update the time if we 'touch' it */
138 ptr
->time
= current_time
;
139 return (&ptr
->request
);
146 insert_table(CTL_MSG
*request
, CTL_RESPONSE
*response
)
151 gettimeofday(&tp
, NULL
);
152 current_time
= tp
.tv_sec
;
153 request
->id_num
= new_id();
154 response
->id_num
= htonl(request
->id_num
);
155 /* insert a new entry into the top of the list */
156 ptr
= (TABLE_ENTRY
*)malloc(sizeof(TABLE_ENTRY
));
158 syslog(LOG_ERR
, "insert_table: Out of memory");
161 ptr
->time
= current_time
;
162 ptr
->request
= *request
;
164 if (ptr
->next
!= NULL
)
165 ptr
->next
->last
= ptr
;
171 * Generate a unique non-zero sequence number
176 static int current_id
= 0;
178 current_id
= (current_id
+ 1) % MAX_ID
;
179 /* 0 is reserved, helps to pick up bugs */
186 * Delete the invitation with id 'id_num'
189 delete_invite(unsigned int id_num
)
195 syslog(LOG_DEBUG
, "delete_invite(%d)", id_num
);
196 for (ptr
= table
; ptr
!= NULL
; ptr
= ptr
->next
) {
197 if (ptr
->request
.id_num
== id_num
)
200 print_request("", &ptr
->request
);
210 * Classic delete from a double-linked list
213 delete(TABLE_ENTRY
*ptr
)
217 print_request("delete", &ptr
->request
);
220 else if (ptr
->last
!= NULL
)
221 ptr
->last
->next
= ptr
->next
;
222 if (ptr
->next
!= NULL
)
223 ptr
->next
->last
= ptr
->last
;