hci_inject.cc revision 3e59b5b6f2ce1295e3e2711afcd2cdf0dd7e22b6 
1/******************************************************************************
2 *
3 *  Copyright (C) 2014 Google, Inc.
4 *
5 *  Licensed under the Apache License, Version 2.0 (the "License");
6 *  you may not use this file except in compliance with the License.
7 *  You may obtain a copy of the License at:
8 *
9 *  http://www.apache.org/licenses/LICENSE-2.0
10 *
11 *  Unless required by applicable law or agreed to in writing, software
12 *  distributed under the License is distributed on an "AS IS" BASIS,
13 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 *  See the License for the specific language governing permissions and
15 *  limitations under the License.
16 *
17 ******************************************************************************/
18
19#define LOG_TAG "bt_hci_inject"
20
21#include <assert.h>
22#include <errno.h>
23#include <string.h>
24
25#include "osi/include/allocator.h"
26#include "bt_types.h"
27#include "buffer_allocator.h"
28#include "hci_inject.h"
29#include "hci_layer.h"
30#include "osi/include/list.h"
31#include "osi/include/osi.h"
32#include "osi/include/log.h"
33#include "osi/include/socket.h"
34#include "osi/include/thread.h"
35
36typedef enum {
37  HCI_PACKET_COMMAND  = 1,
38  HCI_PACKET_ACL_DATA = 2,
39  HCI_PACKET_SCO_DATA = 3,
40  HCI_PACKET_EVENT    = 4,
41} hci_packet_t;
42
43typedef struct {
44  socket_t *socket;
45  uint8_t buffer[65536 + 3];  // 2 bytes length prefix, 1 byte type prefix.
46  size_t buffer_size;
47} client_t;
48
49static const port_t LISTEN_PORT = 8873;
50
51static const hci_inject_t interface;
52static const hci_t *hci;
53static const allocator_t *buffer_allocator;
54static socket_t *listen_socket;
55static thread_t *thread;
56static list_t *clients;
57
58static int hci_packet_to_event(hci_packet_t packet);
59static void accept_ready(socket_t *socket, void *context);
60static void read_ready(socket_t *socket, void *context);
61static void client_free(void *ptr);
62
63bool hci_inject_open(const hci_t *hci_interface) {
64  assert(listen_socket == NULL);
65  assert(thread == NULL);
66  assert(clients == NULL);
67  assert(hci_interface != NULL);
68
69  hci = hci_interface;
70
71  thread = thread_new("hci_inject");
72  if (!thread)
73    goto error;
74
75  clients = list_new(client_free);
76  if (!clients)
77    goto error;
78
79  listen_socket = socket_new();
80  if (!listen_socket)
81    goto error;
82
83  if (!socket_listen(listen_socket, LISTEN_PORT))
84    goto error;
85
86  socket_register(listen_socket, thread_get_reactor(thread), NULL, accept_ready, NULL);
87  return true;
88
89error:;
90  interface.close();
91  return false;
92}
93
94void hci_inject_close(void) {
95  socket_free(listen_socket);
96  list_free(clients);
97  thread_free(thread);
98
99  listen_socket = NULL;
100  thread = NULL;
101  clients = NULL;
102}
103
104static int hci_packet_to_event(hci_packet_t packet) {
105  switch (packet) {
106    case HCI_PACKET_COMMAND:
107      return MSG_STACK_TO_HC_HCI_CMD;
108    case HCI_PACKET_ACL_DATA:
109      return MSG_STACK_TO_HC_HCI_ACL;
110    case HCI_PACKET_SCO_DATA:
111      return MSG_STACK_TO_HC_HCI_SCO;
112    default:
113      LOG_ERROR("%s unsupported packet type: %d", __func__, packet);
114      return -1;
115  }
116}
117
118static void accept_ready(socket_t *socket, UNUSED_ATTR void *context) {
119  assert(socket != NULL);
120  assert(socket == listen_socket);
121
122  socket = socket_accept(socket);
123  if (!socket)
124    return;
125
126  client_t *client = (client_t *)osi_calloc(sizeof(client_t));
127  if (!client) {
128    LOG_ERROR("%s unable to allocate memory for client.", __func__);
129    socket_free(socket);
130    return;
131  }
132
133  client->socket = socket;
134
135  if (!list_append(clients, client)) {
136    LOG_ERROR("%s unable to add client to list.", __func__);
137    client_free(client);
138    return;
139  }
140
141  socket_register(socket, thread_get_reactor(thread), client, read_ready, NULL);
142}
143
144static void read_ready(UNUSED_ATTR socket_t *socket, void *context) {
145  assert(socket != NULL);
146  assert(context != NULL);
147
148  client_t *client = (client_t *)context;
149
150  ssize_t ret = socket_read(client->socket, client->buffer + client->buffer_size, sizeof(client->buffer) - client->buffer_size);
151  if (ret == 0 || (ret == -1 && ret != EWOULDBLOCK && ret != EAGAIN)) {
152    list_remove(clients, client);
153    return;
154  }
155  client->buffer_size += ret;
156
157  while (client->buffer_size > 3) {
158    uint8_t *buffer = client->buffer;
159    hci_packet_t packet_type = (hci_packet_t)buffer[0];
160    size_t packet_len = (buffer[2] << 8) | buffer[1];
161    size_t frame_len = 3 + packet_len;
162
163    if (client->buffer_size < frame_len)
164      break;
165
166    // TODO(sharvil): validate incoming HCI messages.
167    // TODO(sharvil): once we have an HCI parser, we can eliminate
168    //   the 2-byte size field since it will be contained in the packet.
169
170    BT_HDR *buf = (BT_HDR *)buffer_allocator->alloc(packet_len);
171    if (buf) {
172      buf->event = hci_packet_to_event(packet_type);
173      buf->offset = 0;
174      buf->layer_specific = 0;
175      buf->len = packet_len;
176      memcpy(buf->data, buffer + 3, packet_len);
177      hci->transmit_downward(buf->event, buf);
178    } else {
179      LOG_ERROR("%s dropping injected packet of length %zu", __func__, packet_len);
180    }
181
182    size_t remainder = client->buffer_size - frame_len;
183    memmove(buffer, buffer + frame_len, remainder);
184    client->buffer_size -= frame_len;
185  }
186}
187
188static void client_free(void *ptr) {
189  if (!ptr)
190    return;
191
192  client_t *client = (client_t *)ptr;
193  socket_free(client->socket);
194  osi_free(client);
195}
196
197static const hci_inject_t interface = {
198  hci_inject_open,
199  hci_inject_close
200};
201
202const hci_inject_t *hci_inject_get_interface() {
203  buffer_allocator = buffer_allocator_get_interface();
204  return &interface;
205}
206