Added DHCP server. Robot succefully connected to controller !

program/CMakeLists.txt

@@ -19,6 +19,7 @@ add_executable(controller
   src/controller.c
   src/wifi/wifi_operator.c
   src/wifi/udp_server.c
+  src/wifi/dhcp_server.c
 )
 
 target_include_directories(controller PRIVATE

program/src/controller.c

@@ -18,14 +18,17 @@ void controller_init(void)
 
     cyw43_arch_gpio_put(CYW43_WL_GPIO_LED_PIN, true);
 
-    if(init_wifi_operator())
+    if(wifi_operator_init())
+        controller.is_running = false;
+
+    if(dhcp_server_init())
         controller.is_running = false;
 
     if(udp_server_init())
         controller.is_running = false;
 
     // Initialisation ended
-    for(uint i = 0, led_state = true; i < 5; i++)
+    for(uint8_t i = 0, led_state = true; i < 5; i++)
     {
         cyw43_arch_gpio_put(CYW43_WL_GPIO_LED_PIN, led_state);
 
@@ -62,6 +65,8 @@ void controller_handle_inputs_outputs(void)
 
     update_time();
 
+    udp_server_send();
+
     tight_loop_contents();
 }
 

program/src/headers/controller.h

@@ -2,8 +2,13 @@
 #define ROBOT_H
 
 #include <stdbool.h>
+#include "wifi/headers/dhcp_server.h"
+#include "wifi/headers/udp_server.h"
 
 typedef struct controller_t {
+    dhcp_server_t dhcp_server;
+    udp_server_t udp_server;
+
     bool is_running;
     float delta_time_ms;
 } controller_t;

program/src/wifi/dhcp_server.c

@@ -0,0 +1,290 @@
+#include "headers/dhcp_server.h"
+
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <cyw43_config.h>
+#include <lwip/udp.h>
+#include "headers/controller.h"
+
+#define DHCPDISCOVER    (1)
+#define DHCPOFFER       (2)
+#define DHCPREQUEST     (3)
+#define DHCPDECLINE     (4)
+#define DHCPACK         (5)
+#define DHCPNACK        (6)
+#define DHCPRELEASE     (7)
+#define DHCPINFORM      (8)
+
+#define DHCP_OPT_PAD                (0)
+#define DHCP_OPT_SUBNET_MASK        (1)
+#define DHCP_OPT_ROUTER             (3)
+#define DHCP_OPT_DNS                (6)
+#define DHCP_OPT_HOST_NAME          (12)
+#define DHCP_OPT_REQUESTED_IP       (50)
+#define DHCP_OPT_IP_LEASE_TIME      (51)
+#define DHCP_OPT_MSG_TYPE           (53)
+#define DHCP_OPT_SERVER_ID          (54)
+#define DHCP_OPT_PARAM_REQUEST_LIST (55)
+#define DHCP_OPT_MAX_MSG_SIZE       (57)
+#define DHCP_OPT_VENDOR_CLASS_ID    (60)
+#define DHCP_OPT_CLIENT_ID          (61)
+#define DHCP_OPT_END                (255)
+
+#define PORT_DHCP_SERVER (67)
+#define PORT_DHCP_CLIENT (68)
+
+#define DEFAULT_LEASE_TIME_S (24 * 60 * 60) // in seconds
+
+#define MAC_LEN (6)
+#define MAKE_IP4(a, b, c, d) ((a) << 24 | (b) << 16 | (c) << 8 | (d))
+
+#define DHCP_SERVER_IP   PP_HTONL(CYW43_DEFAULT_IP_AP_ADDRESS)
+#define DHCP_SERVER_MASK PP_HTONL(CYW43_DEFAULT_IP_MASK)
+
+typedef struct {
+    uint8_t op; // message opcode
+    uint8_t htype; // hardware address type
+    uint8_t hlen; // hardware address length
+    uint8_t hops;
+    uint32_t xid; // transaction id, chosen by client
+    uint16_t secs; // client seconds elapsed
+    uint16_t flags;
+    uint8_t ciaddr[4]; // client IP address
+    uint8_t yiaddr[4]; // your IP address
+    uint8_t siaddr[4]; // next server IP address
+    uint8_t giaddr[4]; // relay agent IP address
+    uint8_t chaddr[16]; // client hardware address
+    uint8_t sname[64]; // server host name
+    uint8_t file[128]; // boot file name
+    uint8_t options[312]; // optional parameters, variable, starts with magic
+} dhcp_msg_t;
+
+static int dhcp_socket_sendto(struct udp_pcb **pcb, struct netif *nif, const void *buf, size_t len, uint32_t ip, uint16_t port)
+{
+    if(len > 0xffff)
+    {
+        len = 0xffff;
+    }
+
+    struct pbuf *p = pbuf_alloc(PBUF_TRANSPORT, len, PBUF_RAM);
+    if(p == NULL)
+    {
+        return -ENOMEM;
+    }
+
+    memcpy(p->payload, buf, len);
+
+    ip_addr_t dest;
+    IP4_ADDR(ip_2_ip4(&dest), ip >> 24 & 0xff, ip >> 16 & 0xff, ip >> 8 & 0xff, ip & 0xff);
+
+    err_t err;
+
+    if(nif != NULL)
+    {
+        err = udp_sendto_if(*pcb, p, &dest, port, nif);
+    }
+    else
+    {
+        err = udp_sendto(*pcb, p, &dest, port);
+    }
+
+    pbuf_free(p);
+
+    if(err != ERR_OK)
+    {
+        return err;
+    }
+
+    return len;
+}
+
+static uint8_t *opt_find(uint8_t *opt, uint8_t cmd)
+{
+    for (int i = 0; i < 308 && opt[i] != DHCP_OPT_END;)
+    {
+        if (opt[i] == cmd)
+        {
+            return &opt[i];
+        }
+
+        i += 2 + opt[i + 1];
+    }
+
+    return NULL;
+}
+
+static void opt_write_n(uint8_t **opt, uint8_t cmd, size_t n, const void *data)
+{
+    uint8_t *o = *opt;
+    *o++ = cmd;
+    *o++ = n;
+    memcpy(o, data, n);
+    *opt = o + n;
+}
+
+static void opt_write_u8(uint8_t **opt, uint8_t cmd, uint8_t val)
+{
+    uint8_t *o = *opt;
+    *o++ = cmd;
+    *o++ = 1;
+    *o++ = val;
+    *opt = o;
+}
+
+static void opt_write_u32(uint8_t **opt, uint8_t cmd, uint32_t val)
+{
+    uint8_t *o = *opt;
+    *o++ = cmd;
+    *o++ = 4;
+    *o++ = val >> 24;
+    *o++ = val >> 16;
+    *o++ = val >> 8;
+    *o++ = val;
+    *opt = o;
+}
+
+static void dhcp_server_process(void *arg, struct udp_pcb *upcb __unused, struct pbuf *p, const ip_addr_t *src_addr __unused, u16_t src_port __unused)
+{
+    dhcp_server_t *d = arg;
+
+    // This is around 548 bytes
+    dhcp_msg_t dhcp_msg;
+
+    #define DHCP_MIN_SIZE (240 + 3)
+    if (p->tot_len < DHCP_MIN_SIZE) {
+        goto ignore_request;
+    }
+
+    size_t len = pbuf_copy_partial(p, &dhcp_msg, sizeof(dhcp_msg), 0);
+    if (len < DHCP_MIN_SIZE) {
+        goto ignore_request;
+    }
+
+    dhcp_msg.op = DHCPOFFER;
+    memcpy(&dhcp_msg.yiaddr, &ip4_addr_get_u32(ip_2_ip4(&d->ip)), 4);
+
+    uint8_t *opt = (uint8_t *)&dhcp_msg.options;
+    opt += 4; // assume magic cookie: 99, 130, 83, 99
+
+    uint8_t *msgtype = opt_find(opt, DHCP_OPT_MSG_TYPE);
+    if (msgtype == NULL) {
+        // A DHCP package without MSG_TYPE?
+        goto ignore_request;
+    }
+
+    switch (msgtype[2]) {
+        case DHCPDISCOVER: {
+            int yi = DHCPS_MAX_IP;
+            for (int i = 0; i < DHCPS_MAX_IP; ++i) {
+                if (memcmp(d->lease[i].mac, dhcp_msg.chaddr, MAC_LEN) == 0) {
+                    // MAC match, use this IP address
+                    yi = i;
+                    break;
+                }
+                if (yi == DHCPS_MAX_IP) {
+                    // Look for a free IP address
+                    if (memcmp(d->lease[i].mac, "\x00\x00\x00\x00\x00\x00", MAC_LEN) == 0) {
+                        // IP available
+                        yi = i;
+                    }
+                    uint32_t expiry = d->lease[i].expiry << 16 | 0xffff;
+                    if ((int32_t)(expiry - cyw43_hal_ticks_ms()) < 0) {
+                        // IP expired, reuse it
+                        memset(d->lease[i].mac, 0, MAC_LEN);
+                        yi = i;
+                    }
+                }
+            }
+            if (yi == DHCPS_MAX_IP) {
+                // No more IP addresses left
+                goto ignore_request;
+            }
+            dhcp_msg.yiaddr[3] = DHCPS_BASE_IP + yi;
+            opt_write_u8(&opt, DHCP_OPT_MSG_TYPE, DHCPOFFER);
+            break;
+        }
+
+        case DHCPREQUEST: {
+            uint8_t *o = opt_find(opt, DHCP_OPT_REQUESTED_IP);
+            if (o == NULL) {
+                // Should be NACK
+                goto ignore_request;
+            }
+            if (memcmp(o + 2, &ip4_addr_get_u32(ip_2_ip4(&d->ip)), 3) != 0) {
+                // Should be NACK
+                goto ignore_request;
+            }
+            uint8_t yi = o[5] - DHCPS_BASE_IP;
+            if (yi >= DHCPS_MAX_IP) {
+                // Should be NACK
+                goto ignore_request;
+            }
+            if (memcmp(d->lease[yi].mac, dhcp_msg.chaddr, MAC_LEN) == 0) {
+                // MAC match, ok to use this IP address
+            } else if (memcmp(d->lease[yi].mac, "\x00\x00\x00\x00\x00\x00", MAC_LEN) == 0) {
+                // IP unused, ok to use this IP address
+                memcpy(d->lease[yi].mac, dhcp_msg.chaddr, MAC_LEN);
+            } else {
+                // IP already in use
+                // Should be NACK
+                goto ignore_request;
+            }
+            d->lease[yi].expiry = (cyw43_hal_ticks_ms() + DEFAULT_LEASE_TIME_S * 1000) >> 16;
+            dhcp_msg.yiaddr[3] = DHCPS_BASE_IP + yi;
+            opt_write_u8(&opt, DHCP_OPT_MSG_TYPE, DHCPACK);
+            printf("DHCPS: client connected: MAC=%02x:%02x:%02x:%02x:%02x:%02x IP=%u.%u.%u.%u\n",
+                dhcp_msg.chaddr[0], dhcp_msg.chaddr[1], dhcp_msg.chaddr[2], dhcp_msg.chaddr[3], dhcp_msg.chaddr[4], dhcp_msg.chaddr[5],
+                dhcp_msg.yiaddr[0], dhcp_msg.yiaddr[1], dhcp_msg.yiaddr[2], dhcp_msg.yiaddr[3]);
+            break;
+        }
+
+        default:
+            goto ignore_request;
+    }
+
+    opt_write_n(&opt, DHCP_OPT_SERVER_ID, 4, &ip4_addr_get_u32(ip_2_ip4(&d->ip)));
+    opt_write_n(&opt, DHCP_OPT_SUBNET_MASK, 4, &ip4_addr_get_u32(ip_2_ip4(&d->nm)));
+    opt_write_n(&opt, DHCP_OPT_ROUTER, 4, &ip4_addr_get_u32(ip_2_ip4(&d->ip))); // aka gateway; can have multiple addresses
+    opt_write_n(&opt, DHCP_OPT_DNS, 4, &ip4_addr_get_u32(ip_2_ip4(&d->ip))); // this server is the dns
+    opt_write_u32(&opt, DHCP_OPT_IP_LEASE_TIME, DEFAULT_LEASE_TIME_S);
+    *opt++ = DHCP_OPT_END;
+    struct netif *nif = ip_current_input_netif();
+    dhcp_socket_sendto(&d->pcb, nif, &dhcp_msg, opt - (uint8_t *)&dhcp_msg, 0xffffffff, PORT_DHCP_CLIENT);
+
+ignore_request:
+    pbuf_free(p);
+}
+
+int dhcp_server_init(void)
+{
+    controller.dhcp_server.ip.addr = DHCP_SERVER_IP;
+    controller.dhcp_server.nm.addr = DHCP_SERVER_MASK;
+    memset(controller.dhcp_server.lease, 0, sizeof(controller.dhcp_server.lease));
+
+    controller.dhcp_server.pcb = udp_new();
+    if (controller.dhcp_server.pcb == NULL) {
+        return -ENOMEM;
+    }
+
+    // Register callback
+    udp_recv(controller.dhcp_server.pcb, dhcp_server_process, (void *)&controller.dhcp_server);
+
+    if(udp_bind(controller.dhcp_server.pcb, IP_ANY_TYPE, PORT_DHCP_SERVER))
+    {
+        return -1;
+    }
+
+    puts("DHCP server started");
+
+    return 0;
+}
+
+void dhcp_server_deinit(void)
+{
+    if (controller.dhcp_server.pcb != NULL)
+    {
+        udp_remove(controller.dhcp_server.pcb);
+        controller.dhcp_server.pcb = NULL;
+    }
+}

program/src/wifi/headers/dhcp_server.h

@@ -0,0 +1,24 @@
+#ifndef DHCP_SERVER_H
+#define DHCP_SERVER_H
+
+#include "lwip/ip_addr.h"
+
+#define DHCPS_BASE_IP (16)
+#define DHCPS_MAX_IP (8)
+
+typedef struct _dhcp_server_lease_t {
+    uint8_t mac[6];
+    uint16_t expiry;
+} dhcp_server_lease_t;
+
+typedef struct _dhcp_server_t {
+    ip_addr_t ip;
+    ip_addr_t nm;
+    dhcp_server_lease_t lease[DHCPS_MAX_IP];
+    struct udp_pcb *pcb;
+} dhcp_server_t;
+
+int dhcp_server_init(void);
+void dhcp_server_deinit(void);
+
+#endif // DHCP_SERVER_H

program/src/wifi/headers/udp_server.h

@@ -1,10 +1,11 @@
-#ifndef UDP_CLIENT_H
+#ifndef UDP_SERVER_H
-#define UDP_CLIENT_H
+#define UDP_SERVER_H
 
 #include <stdint.h>
 #include <lwip/udp.h>
 
 #define UDP_SERVER_PORT 4242
+#define UDP_CLIENT_PORT 4243
 
 typedef struct udp_server_t {
     struct udp_pcb *pcb;
@@ -17,4 +18,4 @@ void udp_server_send(void);
 // Exit udp client
 void udp_server_deinit(void);
 
-#endif // UDP_CLIENT_H
+#endif // UDP_SERVER_H

program/src/wifi/headers/wifi_operator.h

@@ -5,6 +5,6 @@
 #define WIFI_OPERATOR_PASSWORD "x4ptSLpPuJFcpzbLEhDoZ5J7dz"
 #define WIFI_OPERATOR_CHANNEL 3
 
-int init_wifi_operator(void);
+int wifi_operator_init(void);
 
 #endif // WIFI_OPERATOR_H

program/src/wifi/udp_server.c

@@ -1,39 +1,58 @@
 #include "headers/udp_server.h"
 
 #include <stdio.h>
+#include "headers/controller.h"
 
-udp_server_t udp_server;
+#define MSG_LEN 128
 
 int udp_server_init(void)
 {
-    udp_server.pcb = udp_new();
+    controller.udp_server.pcb = udp_new();
-    if(udp_server.pcb == NULL)
+    if(controller.udp_server.pcb == NULL)
     {
         puts("Error creating UDP server");
         return -1;
     }
 
-    if(udp_bind(udp_server.pcb, IP_ADDR_ANY, UDP_SERVER_PORT))
+    if(udp_bind(controller.udp_server.pcb, IP_ADDR_ANY, UDP_SERVER_PORT))
     {
         printf("Error bind UDP server");
         return -1;
     }
 
-    puts("UDP client started");
+    puts("UDP server started");
 
     return 0;
 }
 
 void udp_server_send(void)
 {
+    static float elapsed_time = 0.0f;
+    elapsed_time += controller.delta_time_ms;
 
+    static uint8_t counter = 0;
+
+    if(elapsed_time >= 1000.0f)
+    {
+        elapsed_time = 0.0f;
+
+        struct pbuf *p = pbuf_alloc(PBUF_TRANSPORT, MSG_LEN, PBUF_RAM);
+        uint8_t *payload = (uint8_t *)p->payload;
+        payload[0] = counter;
+
+        udp_sendto(controller.udp_server.pcb, p, IP_ADDR_ANY, UDP_CLIENT_PORT);
+
+        pbuf_free(p);
+
+        counter++;
+    }
 }
 
 void udp_server_deinit(void)
 {
-    if(udp_server.pcb)
+    if(controller.udp_server.pcb)
     {
-        udp_remove(udp_server.pcb);
+        udp_remove(controller.udp_server.pcb);
-        udp_server.pcb = NULL;
+        controller.udp_server.pcb = NULL;
     }
 }

program/src/wifi/wifi_operator.c

@@ -5,7 +5,7 @@
 #include <lwip/netif.h>
 #include <lwip/ip4_addr.h>
 
-int init_wifi_operator(void)
+int wifi_operator_init(void)
 {
     if(cyw43_wifi_pm(&cyw43_state, CYW43_NO_POWERSAVE_MODE))
     {