xref: /openbmc/qemu/net/can/can_core.c (revision 09a274d8)
1 /*
2  * CAN common CAN bus emulation support
3  *
4  * Copyright (c) 2013-2014 Jin Yang
5  * Copyright (c) 2014-2018 Pavel Pisa
6  *
7  * Initial development supported by Google GSoC 2013 from RTEMS project slot
8  *
9  * Permission is hereby granted, free of charge, to any person obtaining a copy
10  * of this software and associated documentation files (the "Software"), to deal
11  * in the Software without restriction, including without limitation the rights
12  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
13  * copies of the Software, and to permit persons to whom the Software is
14  * furnished to do so, subject to the following conditions:
15  *
16  * The above copyright notice and this permission notice shall be included in
17  * all copies or substantial portions of the Software.
18  *
19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
22  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
23  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
24  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
25  * THE SOFTWARE.
26  */
27 #include "qemu/osdep.h"
28 #include "chardev/char.h"
29 #include "qemu/sockets.h"
30 #include "qapi/error.h"
31 #include "net/can_emu.h"
32 #include "qom/object_interfaces.h"
33 
34 struct CanBusState {
35     Object object;
36 
37     QTAILQ_HEAD(, CanBusClientState) clients;
38 };
39 
40 static void can_bus_instance_init(Object *object)
41 {
42     CanBusState *bus = (CanBusState *)object;
43 
44     QTAILQ_INIT(&bus->clients);
45 }
46 
47 int can_bus_insert_client(CanBusState *bus, CanBusClientState *client)
48 {
49     client->bus = bus;
50     QTAILQ_INSERT_TAIL(&bus->clients, client, next);
51     return 0;
52 }
53 
54 int can_bus_remove_client(CanBusClientState *client)
55 {
56     CanBusState *bus = client->bus;
57     if (bus == NULL) {
58         return 0;
59     }
60 
61     QTAILQ_REMOVE(&bus->clients, client, next);
62     client->bus = NULL;
63     return 1;
64 }
65 
66 ssize_t can_bus_client_send(CanBusClientState *client,
67              const struct qemu_can_frame *frames, size_t frames_cnt)
68 {
69     int ret = 0;
70     CanBusState *bus = client->bus;
71     CanBusClientState *peer;
72     if (bus == NULL) {
73         return -1;
74     }
75 
76     QTAILQ_FOREACH(peer, &bus->clients, next) {
77         if (peer->info->can_receive(peer)) {
78             if (peer == client) {
79                 /* No loopback support for now */
80                 continue;
81             }
82             if (peer->info->receive(peer, frames, frames_cnt) > 0) {
83                 ret = 1;
84             }
85         }
86     }
87 
88     return ret;
89 }
90 
91 int can_bus_filter_match(struct qemu_can_filter *filter, qemu_canid_t can_id)
92 {
93     int m;
94     if (((can_id | filter->can_mask) & QEMU_CAN_ERR_FLAG)) {
95         return (filter->can_mask & QEMU_CAN_ERR_FLAG) != 0;
96     }
97     m = (can_id & filter->can_mask) == (filter->can_id & filter->can_mask);
98     return filter->can_id & QEMU_CAN_INV_FILTER ? !m : m;
99 }
100 
101 int can_bus_client_set_filters(CanBusClientState *client,
102              const struct qemu_can_filter *filters, size_t filters_cnt)
103 {
104     return 0;
105 }
106 
107 
108 static bool can_bus_can_be_deleted(UserCreatable *uc)
109 {
110     return false;
111 }
112 
113 static void can_bus_class_init(ObjectClass *klass,
114                                 void *class_data G_GNUC_UNUSED)
115 {
116     UserCreatableClass *uc_klass = USER_CREATABLE_CLASS(klass);
117 
118     uc_klass->can_be_deleted = can_bus_can_be_deleted;
119 }
120 
121 static const TypeInfo can_bus_info = {
122     .parent = TYPE_OBJECT,
123     .name = TYPE_CAN_BUS,
124     .instance_size = sizeof(CanBusState),
125     .instance_init = can_bus_instance_init,
126     .class_init = can_bus_class_init,
127     .interfaces = (InterfaceInfo[]) {
128         { TYPE_USER_CREATABLE },
129         { }
130     }
131 };
132 
133 static void can_bus_register_types(void)
134 {
135     type_register_static(&can_bus_info);
136 }
137 
138 type_init(can_bus_register_types);
139