1 /***
2   This file is part of avahi.
3 
4   avahi is free software; you can redistribute it and/or modify it
5   under the terms of the GNU Lesser General Public License as
6   published by the Free Software Foundation; either version 2.1 of the
7   License, or (at your option) any later version.
8 
9   avahi is distributed in the hope that it will be useful, but WITHOUT
10   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
11   or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
12   Public License for more details.
13 
14   You should have received a copy of the GNU Lesser General Public
15   License along with avahi; if not, write to the Free Software
16   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
17   USA.
18 ***/
19 
20 #ifdef HAVE_CONFIG_H
21 #include <config.h>
22 #endif
23 
24 #include <stdlib.h>
25 #include <assert.h>
26 
27 #include <avahi-common/llist.h>
28 #include "avahi-common/avahi-malloc.h"
29 
30 #include "rrlist.h"
31 #include "log.h"
32 
33 typedef struct AvahiRecordListItem AvahiRecordListItem;
34 
35 struct AvahiRecordListItem {
36     int read;
37     AvahiRecord *record;
38     int unicast_response;
39     int flush_cache;
40     int auxiliary;
41     AVAHI_LLIST_FIELDS(AvahiRecordListItem, items);
42 };
43 
44 struct AvahiRecordList {
45     AVAHI_LLIST_HEAD(AvahiRecordListItem, read);
46     AVAHI_LLIST_HEAD(AvahiRecordListItem, unread);
47 
48     int all_flush_cache;
49 };
50 
avahi_record_list_new(void)51 AvahiRecordList *avahi_record_list_new(void) {
52     AvahiRecordList *l;
53 
54     if (!(l = avahi_new(AvahiRecordList, 1))) {
55         avahi_log_error("avahi_new() failed.");
56         return NULL;
57     }
58 
59     AVAHI_LLIST_HEAD_INIT(AvahiRecordListItem, l->read);
60     AVAHI_LLIST_HEAD_INIT(AvahiRecordListItem, l->unread);
61 
62     l->all_flush_cache = 1;
63     return l;
64 }
65 
avahi_record_list_free(AvahiRecordList * l)66 void avahi_record_list_free(AvahiRecordList *l) {
67     assert(l);
68 
69     avahi_record_list_flush(l);
70     avahi_free(l);
71 }
72 
item_free(AvahiRecordList * l,AvahiRecordListItem * i)73 static void item_free(AvahiRecordList *l, AvahiRecordListItem *i) {
74     assert(l);
75     assert(i);
76 
77     if (i->read)
78         AVAHI_LLIST_REMOVE(AvahiRecordListItem, items, l->read, i);
79     else
80         AVAHI_LLIST_REMOVE(AvahiRecordListItem, items, l->unread, i);
81 
82     avahi_record_unref(i->record);
83     avahi_free(i);
84 }
85 
avahi_record_list_flush(AvahiRecordList * l)86 void avahi_record_list_flush(AvahiRecordList *l) {
87     assert(l);
88 
89     while (l->read)
90         item_free(l, l->read);
91     while (l->unread)
92         item_free(l, l->unread);
93 
94     l->all_flush_cache = 1;
95 }
96 
avahi_record_list_next(AvahiRecordList * l,int * ret_flush_cache,int * ret_unicast_response,int * ret_auxiliary)97 AvahiRecord* avahi_record_list_next(AvahiRecordList *l, int *ret_flush_cache, int *ret_unicast_response, int *ret_auxiliary) {
98     AvahiRecord *r;
99     AvahiRecordListItem *i;
100 
101     if (!(i = l->unread))
102         return NULL;
103 
104     assert(!i->read);
105 
106     r = avahi_record_ref(i->record);
107     if (ret_unicast_response)
108         *ret_unicast_response = i->unicast_response;
109     if (ret_flush_cache)
110         *ret_flush_cache = i->flush_cache;
111     if (ret_auxiliary)
112         *ret_auxiliary = i->auxiliary;
113 
114     AVAHI_LLIST_REMOVE(AvahiRecordListItem, items, l->unread, i);
115     AVAHI_LLIST_PREPEND(AvahiRecordListItem, items, l->read, i);
116 
117     i->read = 1;
118 
119     return r;
120 }
121 
get(AvahiRecordList * l,AvahiRecord * r)122 static AvahiRecordListItem *get(AvahiRecordList *l, AvahiRecord *r) {
123     AvahiRecordListItem *i;
124 
125     assert(l);
126     assert(r);
127 
128     for (i = l->read; i; i = i->items_next)
129         if (avahi_record_equal_no_ttl(i->record, r))
130             return i;
131 
132     for (i = l->unread; i; i = i->items_next)
133         if (avahi_record_equal_no_ttl(i->record, r))
134             return i;
135 
136     return NULL;
137 }
138 
avahi_record_list_push(AvahiRecordList * l,AvahiRecord * r,int flush_cache,int unicast_response,int auxiliary)139 void avahi_record_list_push(AvahiRecordList *l, AvahiRecord *r, int flush_cache, int unicast_response, int auxiliary) {
140     AvahiRecordListItem *i;
141 
142     assert(l);
143     assert(r);
144 
145     if (get(l, r))
146         return;
147 
148     if (!(i = avahi_new(AvahiRecordListItem, 1))) {
149         avahi_log_error("avahi_new() failed.");
150         return;
151     }
152 
153     i->unicast_response = unicast_response;
154     i->flush_cache = flush_cache;
155     i->auxiliary = auxiliary;
156     i->record = avahi_record_ref(r);
157     i->read = 0;
158 
159     l->all_flush_cache = l->all_flush_cache && flush_cache;
160 
161     AVAHI_LLIST_PREPEND(AvahiRecordListItem, items, l->unread, i);
162 }
163 
avahi_record_list_drop(AvahiRecordList * l,AvahiRecord * r)164 void avahi_record_list_drop(AvahiRecordList *l, AvahiRecord *r) {
165     AvahiRecordListItem *i;
166 
167     assert(l);
168     assert(r);
169 
170     if (!(i = get(l, r)))
171         return;
172 
173     item_free(l, i);
174 }
175 
avahi_record_list_is_empty(AvahiRecordList * l)176 int avahi_record_list_is_empty(AvahiRecordList *l) {
177     assert(l);
178 
179     return !l->unread && !l->read;
180 }
181 
avahi_record_list_all_flush_cache(AvahiRecordList * l)182 int avahi_record_list_all_flush_cache(AvahiRecordList *l) {
183     assert(l);
184 
185     /* Return TRUE if all entries in this list have flush_cache set */
186 
187     return l->all_flush_cache;
188 }
189