Telemetry options constructor and component name size constraint (#1976)

sdk/inc/azure/core/internal/az_http_internal.h

@@ -8,6 +8,7 @@
 #include <azure/core/az_http.h>
 #include <azure/core/az_http_transport.h>
 #include <azure/core/az_result.h>
+#include <azure/core/internal/az_precondition_internal.h>
 
 #include <azure/core/_az_cfg_prefix.h>
 
@@ -65,12 +66,17 @@ typedef struct
 } _az_http_policy_telemetry_options;
 
 /**
- * @brief Initialize _az_http_policy_telemetry_options with default values
+ * @brief Creates _az_http_policy_telemetry_options with default values.
  *
+ * @param[in] component_name The name of the SDK component.
+ *
+ * @return Initialized telemetry options.
  */
-AZ_NODISCARD AZ_INLINE _az_http_policy_telemetry_options _az_http_policy_telemetry_options_default()
+AZ_NODISCARD AZ_INLINE _az_http_policy_telemetry_options
+_az_http_policy_telemetry_options_create(az_span component_name)
 {
-  return (_az_http_policy_telemetry_options){ 0 };
+  _az_PRECONDITION_VALID_SPAN(component_name, 1, false);
+  return (_az_http_policy_telemetry_options){ .component_name = component_name };
 }
 
 AZ_NODISCARD AZ_INLINE _az_http_policy_apiversion_options

sdk/src/azure/core/az_http_policy.c

@@ -46,6 +46,11 @@ AZ_NODISCARD az_result az_http_pipeline_policy_apiversion(
 // "-1" below is to account for the null terminator at the end of the string.
 #define _az_TELEMETRY_ID_PREFIX "azsdk-c-"
 #define _az_TELEMETRY_ID_PREFIX_LENGTH (sizeof(_az_TELEMETRY_ID_PREFIX) - 1)
+#define _az_TELEMETRY_COMPONENT_NAME_MAX_LENGTH 40
+#define _az_TELEMETRY_VERSION_MAX_LENGTH (sizeof("12.345.6789-preview.123") - 1)
+#define _az_TELEMETRY_ID_MAX_LENGTH                                                       \
+  (_az_TELEMETRY_ID_PREFIX_LENGTH + _az_TELEMETRY_COMPONENT_NAME_MAX_LENGTH + sizeof('/') \
+   + _az_TELEMETRY_VERSION_MAX_LENGTH)
 
 AZ_NODISCARD az_result az_http_pipeline_policy_telemetry(
     _az_http_policy* ref_policies,
@@ -56,14 +61,19 @@ AZ_NODISCARD az_result az_http_pipeline_policy_telemetry(
   _az_PRECONDITION_NOT_NULL(ref_options);
 
   // Format spec: https://azure.github.io/azure-sdk/general_azurecore.html#telemetry-policy
-  uint8_t telemetry_id_buffer[200] = _az_TELEMETRY_ID_PREFIX;
+  uint8_t telemetry_id_buffer[_az_TELEMETRY_ID_MAX_LENGTH] = _az_TELEMETRY_ID_PREFIX;
   az_span telemetry_id = AZ_SPAN_FROM_BUFFER(telemetry_id_buffer);
   {
     az_span remainder = az_span_slice_to_end(telemetry_id, _az_TELEMETRY_ID_PREFIX_LENGTH);
 
     _az_http_policy_telemetry_options* options = (_az_http_policy_telemetry_options*)(ref_options);
     az_span const component_name = options->component_name;
-    _az_PRECONDITION_VALID_SPAN(component_name, 1, false);
+#ifndef AZ_NO_PRECONDITION_CHECKING
+    {
+      int32_t const component_name_size = az_span_size(component_name);
+      _az_PRECONDITION_RANGE(1, component_name_size, _az_TELEMETRY_COMPONENT_NAME_MAX_LENGTH);
+    }
+#endif // AZ_NO_PRECONDITION_CHECKING
     remainder = az_span_copy(remainder, component_name);
 
     remainder = az_span_copy_u8(remainder, '/');
@@ -80,6 +90,9 @@ AZ_NODISCARD az_result az_http_pipeline_policy_telemetry(
 
 #undef _az_TELEMETRY_ID_PREFIX
 #undef _az_TELEMETRY_ID_PREFIX_LENGTH
+#undef _az_TELEMETRY_COMPONENT_NAME_MAX_LENGTH
+#undef _az_TELEMETRY_VERSION_MAX_LENGTH
+#undef _az_TELEMETRY_ID_MAX_LENGTH
 
 AZ_NODISCARD az_result az_http_pipeline_policy_credential(
     _az_http_policy* ref_policies,

sdk/tests/core/test_az_policy.c

@@ -68,16 +68,38 @@ az_result test_policy_transport(
   return AZ_OK;
 }
 
+static az_span telemetry_policy_expected_value;
+
+static az_result validate_telemetry_policy_value(
+    _az_http_policy* ref_policies,
+    void* ref_options,
+    az_http_request* ref_request,
+    az_http_response* ref_response)
+{
+  (void)ref_policies;
+  (void)ref_options;
+  (void)ref_response;
+
+  az_span header_name = { 0 };
+  az_span header_value = { 0 };
+
+  assert_return_code(
+      az_http_request_get_header(ref_request, 0, &header_name, &header_value), AZ_OK);
+
+  assert_true(az_span_is_content_equal(header_name, AZ_SPAN_FROM_STR("User-Agent")));
+  assert_true(az_span_is_content_equal(header_value, telemetry_policy_expected_value));
+
+  return AZ_OK;
+}
+
 void test_az_http_pipeline_policy_telemetry(void** state)
 {
   (void)state;
 
-  uint8_t buf[100];
-  uint8_t header_buf[(2 * sizeof(_az_http_request_header))];
-  memset(buf, 0, sizeof(buf));
-  memset(header_buf, 0, sizeof(header_buf));
+  uint8_t url_buf[100] = { 0 };
+  uint8_t header_buf[(2 * sizeof(_az_http_request_header))] = { 0 };
 
-  az_span url_span = AZ_SPAN_FROM_BUFFER(buf);
+  az_span url_span = AZ_SPAN_FROM_BUFFER(url_buf);
   az_span remainder = az_span_copy(url_span, AZ_SPAN_FROM_STR("url"));
   assert_int_equal(az_span_size(remainder), 97);
   az_span header_span = AZ_SPAN_FROM_BUFFER(header_buf);
@@ -95,36 +117,42 @@ void test_az_http_pipeline_policy_telemetry(void** state)
       AZ_OK);
 
   // Create policy options
-  _az_http_policy_telemetry_options telemetry = _az_http_policy_telemetry_options_default();
+  _az_http_policy_telemetry_options telemetry = _az_http_policy_telemetry_options_create(
+      AZ_SPAN_FROM_STR("a-fourty-character-component-id-for-test"));
+
+  telemetry_policy_expected_value
+      = AZ_SPAN_FROM_STR("azsdk-c-a-fourty-character-component-id-for-test/" AZ_SDK_VERSION_STRING);
 
   _az_http_policy policies[1] = {
             {
               ._internal = {
-                .process = test_policy_transport,
+                .process = validate_telemetry_policy_value,
                 .options = NULL,
               },
             },
         };
 
-  // Non-empty Component ID
-  telemetry.component_name = AZ_SPAN_FROM_STR("test");
-  {
-    assert_return_code(
-        az_http_pipeline_policy_telemetry(policies, &telemetry, &request, NULL), AZ_OK);
-
-    az_span header_name = { 0 };
-    az_span header_value = { 0 };
-    assert_return_code(az_http_request_get_header(&request, 0, &header_name, &header_value), AZ_OK);
-    assert_true(az_span_is_content_equal(header_name, AZ_SPAN_FROM_STR("User-Agent")));
-    assert_true(az_span_is_content_equal(
-        header_value, AZ_SPAN_FROM_STR("azsdk-c-test/" AZ_SDK_VERSION_STRING)));
-  }
+  // Valid Component ID
+  assert_return_code(
+      az_http_pipeline_policy_telemetry(policies, &telemetry, &request, NULL), AZ_OK);
 
 #ifndef AZ_NO_PRECONDITION_CHECKING
-  // Non-empty Component ID
+  policies[0] = (_az_http_policy){
+              ._internal = {
+                .process = test_policy_transport,
+                .options = NULL,
+              },
+            };
+
+  // Empty Component ID
   telemetry.component_name = AZ_SPAN_EMPTY;
   ASSERT_PRECONDITION_CHECKED(
       az_http_pipeline_policy_telemetry(policies, &telemetry, &request, NULL));
+
+  // Component ID too long
+  telemetry.component_name = AZ_SPAN_FROM_STR("a-fourty1-character-component-id-for-test");
+  ASSERT_PRECONDITION_CHECKED(
+      az_http_pipeline_policy_telemetry(policies, &telemetry, &request, NULL));
 #endif // AZ_NO_PRECONDITION_CHECKING
 }