DhcpFuzzer: Added AFL test for dhcpserver with sample packets

components/lwip/test_afl_host/network_mock.c

@@ -0,0 +1,74 @@
+#include <stdio.h>
+#include "lwip/opt.h"
+#include "lwip/def.h"
+#include "lwip/pbuf.h"
+#include "lwip/udp.h"
+#include "tcpip_adapter.h"
+#include <string.h>
+
+u16_t lwip_htons(u16_t n)
+{
+    return 0;
+}
+
+u32_t lwip_htonl(u32_t n)
+{
+    return 0;
+}
+
+esp_err_t tcpip_adapter_get_ip_info(tcpip_adapter_if_t tcpip_if, tcpip_adapter_ip_info_t *ip_info)
+{
+ return ESP_OK;
+}
+
+struct pbuf * pbuf_alloc(pbuf_layer layer, u16_t length, pbuf_type type)
+{
+    struct pbuf * p;
+    p = (struct pbuf *)malloc(MEMP_PBUF_POOL);
+    p->tot_len = length;
+    p->next = NULL;
+    p->type = PBUF_POOL;
+    p->len = length;
+    p->payload = malloc(length);
+    return p;
+}
+
+u8_t pbuf_free(struct pbuf *p)
+{
+    if (p) {
+        if (p->payload) {
+            free(p->payload);
+            p->payload = NULL;
+        }
+        free (p);
+        p = NULL;
+    }
+    return 1;
+}
+
+err_t udp_sendto(struct udp_pcb *pcb, struct pbuf *p, const ip_addr_t *dst_ip, u16_t dst_port)
+{
+    return ESP_OK;
+}
+
+void udp_remove(struct udp_pcb *pcb)
+{
+}
+
+struct udp_pcb *udp_new(void)
+{
+    return NULL;
+}
+
+err_t udp_bind(struct udp_pcb *pcb, const ip_addr_t *ipaddr, u16_t port)
+{
+    return ESP_OK;
+}
+
+void udp_recv(struct udp_pcb *pcb, udp_recv_fn recv, void *recv_arg)
+{
+}
+
+void udp_disconnect(struct udp_pcb *pcb)
+{
+}