DnsFuzzer: Added fuzzer test for exercising lwip/dns receiving DNS responses

components/lwip/test_afl_host/test_dhcp_server.c

@@ -0,0 +1,64 @@
+#include "no_warn_host.h"
+#include "lwip/pbuf.h"
+#include "lwip/udp.h"
+#include "tcpip_adapter.h"
+#include <string.h>
+#include <stdio.h>
+
+const ip_addr_t ip_addr_any;
+ip4_addr_t server_ip;
+struct netif mynetif;
+
+// Dependency injected static function to pass the packet into parser
+void dhcp_test_handle_dhcp(void *arg, struct udp_pcb *pcb, struct pbuf *p, const ip_addr_t *addr, u16_t port);
+void dhcp_test_init_di();
+
+//
+// Test starts here
+//
+int main(int argc, char** argv)
+{
+    uint8_t *buf;
+    struct pbuf *p;
+    FILE *file;
+    size_t len = 1460;
+
+    dhcp_test_init_di();
+
+    IP4_ADDR(&server_ip, 192,168,4,1);
+    dhcps_start(&mynetif, server_ip);
+
+#ifdef INSTR_IS_OFF
+    p = pbuf_alloc(PBUF_RAW, len, PBUF_POOL);
+    buf = p->payload;
+    memset(buf, 0, 1460);
+    if (argc != 2)
+    {
+        printf("Non-instrumentation mode: please supply a file name created by AFL to reproduce crash\n");
+        return 1;
+    }
+    //
+    // Note: parameter1 is a file (mangled packet) which caused the crash
+    file = fopen(argv[1], "r");
+    if (file) {
+    len = fread(buf, 1, 1460, file);
+    }
+    fclose(file);
+
+    int i;
+    for (i=0; i<1; i++) {
+#else
+    while (__AFL_LOOP(1000)) {
+        p = pbuf_alloc(PBUF_RAW, len, PBUF_POOL);
+        buf = p->payload;
+        memset(buf, 0, 1460);
+        size_t len = read(0, buf, 1460);
+#endif
+        p->len = len;
+        p->tot_len = len;
+        p->next = NULL;
+
+        dhcp_test_handle_dhcp(NULL, NULL, p, &ip_addr_any, 0);
+    }
+    return 0;
+}