-
Notifications
You must be signed in to change notification settings - Fork 7.2k
/
l2tap_main.c
265 lines (233 loc) · 9.24 KB
/
l2tap_main.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
/*
* SPDX-FileCopyrightText: 2022-2023 Espressif Systems (Shanghai) CO LTD
*
* SPDX-License-Identifier: Unlicense OR CC0-1.0
*/
#include <stdio.h>
#include <string.h>
#include <unistd.h> // read/write
#include <sys/fcntl.h>
#include <sys/ioctl.h>
#include <errno.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_event.h"
#include "esp_err.h"
#include "esp_eth.h"
#include "esp_log.h"
#include "nvs_flash.h"
#include "sdkconfig.h"
#include "esp_vfs_l2tap.h"
#include "lwip/prot/ethernet.h" // Ethernet header
#include "arpa/inet.h" // ntohs, etc.
#include "protocol_examples_common.h"
#if !defined(CONFIG_EXAMPLE_CONNECT_ETHERNET)
#error Ethernet interface is not configured to connect.
#endif
#define ETH_INTERFACE "ETH_DEF"
#define ETH_TYPE_FILTER_BLOCK 0x2220
#define ETH_TYPE_FILTER_NOBLOCK 0x2221
#define ETH_TYPE_FILTER_TX 0x2223
#define INVALID_FD -1
typedef struct {
struct eth_hdr header;
char payload[44];
} test_vfs_eth_tap_msg_t;
static const char *TAG = "l2tap_example";
/** Opens and configures L2 TAP file descriptor */
static int init_l2tap_fd(int flags, uint16_t eth_type_filter)
{
int fd = open("/dev/net/tap", flags);
if (fd < 0) {
ESP_LOGE(TAG, "Unable to open L2 TAP interface: errno %d", errno);
goto error;
}
ESP_LOGI(TAG, "/dev/net/tap fd %d successfully opened", fd);
// Check fd block status (just for demonstration purpose)
flags = 0;
flags = fcntl(fd, F_GETFL);
if (flags == -1) {
ESP_LOGE(TAG, "Unable to get L2 TAP fd %d status flag: errno %d", fd, errno);
goto error;
}
if (flags & O_NONBLOCK) {
ESP_LOGI(TAG, "L2 TAP fd %d configured in non-blocking mode", fd);
} else {
ESP_LOGI(TAG, "L2 TAP fd %d configured in blocking mode", fd);
}
// Configure Ethernet interface on which to get raw frames
int ret;
if ((ret = ioctl(fd, L2TAP_S_INTF_DEVICE, ETH_INTERFACE)) == -1) {
ESP_LOGE(TAG, "Unable to bound L2 TAP fd %d with Ethernet device: errno %d", fd, errno);
goto error;
}
ESP_LOGI(TAG, "L2 TAP fd %d successfully bound to `%s`", fd, ETH_INTERFACE);
// Configure Ethernet frames we want to filter out
if ((ret = ioctl(fd, L2TAP_S_RCV_FILTER, ð_type_filter)) == -1) {
ESP_LOGE(TAG, "Unable to configure fd %d Ethernet type receive filter: errno %d", fd, errno);
goto error;
}
ESP_LOGI(TAG, "L2 TAP fd %d Ethernet type filter configured to 0x%x", fd, eth_type_filter);
return fd;
error:
if (fd != INVALID_FD) {
close(fd);
}
return INVALID_FD;
}
/** Creates "echo" message from received frame */
static void create_echo_frame(test_vfs_eth_tap_msg_t *in_frame, test_vfs_eth_tap_msg_t *out_frame, int len)
{
// Set source address equal to our MAC address
esp_eth_handle_t eth_hndl = get_example_eth_handle();
uint8_t mac_addr[ETH_ADDR_LEN];
esp_eth_ioctl(eth_hndl, ETH_CMD_G_MAC_ADDR, mac_addr);
memcpy(out_frame->header.src.addr, mac_addr, ETH_ADDR_LEN);
// Set destination address equal to source address from where the frame was received
memcpy(out_frame->header.dest.addr, in_frame->header.src.addr, ETH_ADDR_LEN);
// Set Ethernet type
memcpy(&out_frame->header.type, &in_frame->header.type, sizeof(uint16_t));
// Copy the payload
memcpy(out_frame->payload, in_frame->payload, len - ETH_HEADER_LEN);
}
/** Demonstrates usage of L2 TAP in blocking mode */
static void echo_l2tap_task(void *pvParameters)
{
uint8_t rx_buffer[128];
int eth_tap_fd;
// Open and configure L2 TAP File descriptor
if ((eth_tap_fd = init_l2tap_fd(0, ETH_TYPE_FILTER_BLOCK)) == INVALID_FD) {
goto error;
}
while (1) {
ssize_t len = read(eth_tap_fd, rx_buffer, sizeof(rx_buffer));
if (len > 0) {
test_vfs_eth_tap_msg_t *recv_msg = (test_vfs_eth_tap_msg_t *)rx_buffer;
ESP_LOGI(TAG, "fd %d received %d bytes from %.2x:%.2x:%.2x:%.2x:%.2x:%.2x", eth_tap_fd,
len, recv_msg->header.src.addr[0], recv_msg->header.src.addr[1], recv_msg->header.src.addr[2],
recv_msg->header.src.addr[3], recv_msg->header.src.addr[4], recv_msg->header.src.addr[5]);
// Construct echo frame
test_vfs_eth_tap_msg_t echo_msg;
create_echo_frame(recv_msg, &echo_msg, len);
// Send the echo message
ssize_t ret = write(eth_tap_fd, &echo_msg, len);
if (ret == -1) {
ESP_LOGE(TAG, "L2 TAP fd %d write error: errno: %d", eth_tap_fd, errno);
break;
}
} else {
ESP_LOGE(TAG, "L2 TAP fd %d read error: errno %d", eth_tap_fd, errno);
break;
}
}
close(eth_tap_fd);
error:
vTaskDelete(NULL);
}
/** Demonstrates usage of L2 TAP non-blocking mode with select */
static void nonblock_l2tap_echo_task(void *pvParameters)
{
uint8_t rx_buffer[128];
int eth_tap_fd;
// Open and configure L2 TAP File descriptor
if ((eth_tap_fd = init_l2tap_fd(O_NONBLOCK, ETH_TYPE_FILTER_NOBLOCK)) == INVALID_FD) {
goto error;
}
while (1) {
struct timeval tv;
tv.tv_sec = 5;
tv.tv_usec = 0;
fd_set rfds;
FD_ZERO(&rfds);
FD_SET(eth_tap_fd, &rfds);
int ret_sel = select(eth_tap_fd + 1, &rfds, NULL, NULL, &tv);
if (ret_sel > 0) {
ssize_t len = read(eth_tap_fd, rx_buffer, sizeof(rx_buffer));
if (len > 0) {
test_vfs_eth_tap_msg_t *recv_msg = (test_vfs_eth_tap_msg_t *)rx_buffer;
ESP_LOGI(TAG, "fd %d received %d bytes from %.2x:%.2x:%.2x:%.2x:%.2x:%.2x", eth_tap_fd,
len, recv_msg->header.src.addr[0], recv_msg->header.src.addr[1], recv_msg->header.src.addr[2],
recv_msg->header.src.addr[3], recv_msg->header.src.addr[4], recv_msg->header.src.addr[5]);
// Construct echo frame
test_vfs_eth_tap_msg_t echo_msg;
create_echo_frame(recv_msg, &echo_msg, len);
// Send the echo message
ssize_t ret = write(eth_tap_fd, &echo_msg, len);
if (ret == -1) {
ESP_LOGE(TAG, "L2 TAP fd %d write error: errno: %d", eth_tap_fd, errno);
break;
}
} else {
ESP_LOGE(TAG, "L2 TAP fd %d read error: errno %d", eth_tap_fd, errno);
break;
}
} else if (ret_sel == 0) {
ESP_LOGD(TAG, "L2 TAP select timeout");
} else {
ESP_LOGE(TAG, "L2 TAP select error: errno %d", errno);
break;
}
}
close(eth_tap_fd);
error:
vTaskDelete(NULL);
}
/** Demonstrates of how to construct Ethernet frame for transmit via L2 TAP */
static void hello_tx_l2tap_task(void *pvParameters)
{
uint16_t eth_type_filter = ETH_TYPE_FILTER_TX;
int eth_tap_fd;
// Open and configure L2 TAP File descriptor
if ((eth_tap_fd = init_l2tap_fd(0, eth_type_filter)) == INVALID_FD) {
goto error;
}
// Construct "Hello" frame
test_vfs_eth_tap_msg_t hello_msg = {
.header = {
.src.addr = {0},
.dest.addr = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff}, // broadcast address
.type = htons(eth_type_filter) // convert to big endian (network) byte order
},
.payload = "ESP32 hello to everybody!"
};
esp_eth_handle_t eth_hndl = get_example_eth_handle();
esp_eth_ioctl(eth_hndl, ETH_CMD_G_MAC_ADDR, hello_msg.header.src.addr);
while (1) {
// Send the Hello frame
ssize_t ret = write(eth_tap_fd, &hello_msg, ETH_HEADER_LEN + strlen(hello_msg.payload));
if (ret == -1) {
ESP_LOGE(TAG, "L2 TAP fd %d write error: errno: %d", eth_tap_fd, errno);
break;
}
vTaskDelay(pdMS_TO_TICKS(3000));
}
close(eth_tap_fd);
error:
vTaskDelete(NULL);
}
void app_main(void)
{
// Initialize L2 TAP VFS interface
ESP_ERROR_CHECK(esp_vfs_l2tap_intf_register(NULL));
// Initialize NVS Flash
ESP_ERROR_CHECK(nvs_flash_init());
// Initialize TCP/IP network interface (should be called only once in application)
ESP_ERROR_CHECK(esp_netif_init());
ESP_ERROR_CHECK(esp_event_loop_create_default());
/* This helper function configures Wi-Fi or Ethernet, as selected in menuconfig.
* Read "Establishing Wi-Fi or Ethernet Connection" section in
* examples/protocols/README.md for more information about this function.
*/
ESP_ERROR_CHECK(example_connect());
esp_eth_handle_t eth_hndl = get_example_eth_handle();
uint8_t mac_addr[ETH_ADDR_LEN];
esp_eth_ioctl(eth_hndl, ETH_CMD_G_MAC_ADDR, mac_addr);
ESP_LOGI(TAG, "Ethernet HW Addr %02x:%02x:%02x:%02x:%02x:%02x",
mac_addr[0], mac_addr[1], mac_addr[2], mac_addr[3], mac_addr[4], mac_addr[5]);
// Echo received message back to sender (blocks indefinitely)
xTaskCreate(echo_l2tap_task, "echo", 4096, NULL, 6, NULL);
// Echo received message back to sender (blocks with timeout)
xTaskCreate(nonblock_l2tap_echo_task, "echo_no-block", 4096, NULL, 5, NULL);
// Periodically broadcast "Hello message"
xTaskCreate(hello_tx_l2tap_task, "hello_tx", 4096, NULL, 4, NULL);
}