coap: coap server using libcoap. also scrapped.

Signed-off-by: HeshamTB <hishaminv@gmail.com>

coap/coap-server1/common.c

@@ -0,0 +1,48 @@
+/* minimal CoAP functions
+ *
+ * Copyright (C) 2018-2021 Olaf Bergmann <bergmann@tzi.org>
+ */
+
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netdb.h>
+
+#include "common.h"
+
+int
+resolve_address(const char *host, const char *service, coap_address_t *dst) {
+
+  struct addrinfo *res, *ainfo;
+  struct addrinfo hints;
+  int error, len=-1;
+
+  memset(&hints, 0, sizeof(hints));
+  memset(dst, 0, sizeof(*dst));
+  hints.ai_socktype = SOCK_DGRAM;
+  hints.ai_family = AF_UNSPEC;
+
+  error = getaddrinfo(host, service, &hints, &res);
+
+  if (error != 0) {
+    fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(error));
+    return error;
+  }
+
+  for (ainfo = res; ainfo != NULL; ainfo = ainfo->ai_next) {
+    switch (ainfo->ai_family) {
+    case AF_INET6:
+    case AF_INET:
+      len = dst->size = ainfo->ai_addrlen;
+      memcpy(&dst->addr.sin6, ainfo->ai_addr, dst->size);
+      goto finish;
+    default:
+      ;
+    }
+  }
+
+ finish:
+  freeaddrinfo(res);
+  return len;
+}
+

coap/coap-server1/common.h

@@ -0,0 +1,8 @@
+/* minimal CoAP functions
+ *
+ * Copyright (C) 2018-2021 Olaf Bergmann <bergmann@tzi.org>
+ */
+
+#include <coap3/coap.h>
+
+int resolve_address(const char *host, const char *service, coap_address_t *dst);

coap/coap-server1/handlers.c

@@ -0,0 +1,15 @@
+#include "handlers.h"
+#include <coap3/resource.h>
+
+void hnd_get_hello(coap_resource_t *resource,
+    coap_session_t *session,
+    const coap_pdu_t *request,
+    const coap_string_t *query_string,
+    coap_pdu_t *response)
+{
+    coap_show_pdu(LOG_WARNING, request);
+    coap_pdu_set_code(response, COAP_RESPONSE_CODE_CONTENT);
+    coap_add_data(response, 5, (const uint8_t *)"world");
+    coap_show_pdu(LOG_WARNING, response);
+    return;
+}

coap/coap-server1/handlers.h

@@ -0,0 +1,12 @@
+
+#include <coap3/coap.h>
+#include <coap3/coap_forward_decls.h>
+#include <coap3/resource.h>
+#include <coap3/str.h>
+
+void hnd_get_hello(
+    coap_resource_t *resource,
+    coap_session_t *session,
+    const coap_pdu_t *resquest,
+    const coap_string_t *query_string,
+    coap_pdu_t* response);

coap/coap-server1/libcoap

@@ -0,0 +1 @@
+Subproject commit 1da37b9abbe871675d5939395b498324ccc8ecfe

coap/coap-server1/main.c

@@ -0,0 +1,77 @@
+/* minimal CoAP server
+ *
+ * Copyright (C) 2018-2021 Olaf Bergmann <bergmann@tzi.org>
+ * Edited by Hesham T. Banafa Mar 8, 2022 for ibs
+ */
+
+#include <gsl/gsl_matrix_uint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <sys/socket.h>
+
+#include <gsl/gsl_matrix.h>
+#include <coap3/coap.h>
+#include "common.h"
+#include "handlers.h"
+
+int main(void) {
+  coap_context_t  *ctx = NULL;
+  coap_address_t dst;
+  coap_resource_t *resource = NULL;
+  coap_endpoint_t *endpoint = NULL;
+  int result = EXIT_FAILURE;;
+  coap_str_const_t *ruri = coap_make_str_const("hello");
+  coap_startup();
+
+  /* resolve destination address where server should be sent */
+  
+  if (resolve_address("localhost", "5683", &dst) < 0) {
+    coap_log(LOG_CRIT, "failed to resolve address\n");
+    goto finish;
+  }
+
+  /* create CoAP context and a client session */
+  ctx = coap_new_context(NULL);
+
+  if (!ctx || !(endpoint = coap_new_endpoint(ctx, &dst, COAP_PROTO_UDP))) {
+    coap_log(LOG_EMERG, "cannot initialize context\n");
+    goto finish;
+  }
+
+  resource = coap_resource_init(ruri, 0);
+  // coap_register_handler(resource, COAP_REQUEST_GET,
+  //                       [](auto, auto,
+  //                          const coap_pdu_t *request,
+  //                          auto,
+  //                          coap_pdu_t *response) {
+  //                         coap_show_pdu(LOG_WARNING, request);
+  //                         coap_pdu_set_code(response, COAP_RESPONSE_CODE_CONTENT);
+  //                         coap_add_data(response, 5,
+  //                                       (const uint8_t *)"world");
+  //                         coap_show_pdu(LOG_WARNING, response);
+  //                       });
+  
+  /* From what I understand, we need to implement the coap_method_handler_t
+      a supply a fucntion ptr to a function that takes args defined in
+      coap_method_handler_t typedef.
+      Holy crap this different. 
+      This kind of typedef is similar to a java abstract class or interface..
+      (somefunkystudd.txt)
+      Mar 8, 2022 - H.B. */
+  
+  //coap_method_handler_t  hnd = &hnd_get_hello;
+  coap_register_handler(resource, COAP_REQUEST_GET, &hnd_get_hello);
+  coap_add_resource(ctx, resource);
+
+  while (true) { coap_io_process(ctx, COAP_IO_WAIT); }
+
+  result = EXIT_SUCCESS;
+ finish:
+
+  coap_free_context(ctx);
+  coap_cleanup();
+
+  return result;
+}

coap/coap-server1/somefunckystuff.txt

@@ -0,0 +1,2 @@
+https://stackoverflow.com/questions/840501/how-do-function-pointers-in-c-work
+https://stackoverflow.com/questions/3674200/what-does-a-typedef-with-parenthesis-like-typedef-int-fvoid-mean-is-it-a