Merge pull request #22 from FireTail-io/enable-firetail-directive

Enable firetail directive

Author: rileyfiretail

README.md

@@ -29,13 +29,14 @@ To setup the Firetail NGINX Module, you will need to modify your `nginx.conf` to
 load_module modules/ngx_firetail_module.so;
 ```
 
-You can then configure it using the following directives, which all belong in the `http` block of your NGINX configuration:
-
-| Directive                         | Description                                                  | Example                                                      |
-| --------------------------------- | ------------------------------------------------------------ | ------------------------------------------------------------ |
-| `firetail_api_token`              | Your API token from the FireTail platform                    | `PS-02-xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx-xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx` |
-| `firetail_url`                    | The URL of the API endpoint the FireTail NGINX module will send logs to. | `https://api.logging.eu-west-1.prod.firetail.app/logs/bulk`  |
-| `firetail_allow_undefined_routes` | If set to `1`, `t`, `T`, `TRUE`, `true`, or `True`, requests to routes not defined in your OpenAPI specification will not be blocked. | `1`, `t`, `T`, `TRUE`, `true`, `True`, `0`, `f`, `F`, `FALSE`, `false`, `False` |
+You can then configure it using the following directives:
+
+| Directive                         | Valid in   | Description                                                  | Example Arguments                                            |
+| --------------------------------- | ---------- | ------------------------------------------------------------ | ------------------------------------------------------------ |
+| `firetail_api_token`              | `http`     | Your API token from the FireTail platform                    | `PS-02-xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx-xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx` |
+| `firetail_url`                    | `http`     | The URL of the API endpoint the FireTail NGINX module will send logs to. | `https://api.logging.eu-west-1.prod.firetail.app/logs/bulk`  |
+| `firetail_enable`                 | `location` | Use this in every location block for which you want FireTail to be enabled. | This directive takes no arguments.                           |
+| `firetail_allow_undefined_routes` | `http`     | If set to `1`, `t`, `T`, `TRUE`, `true`, or `True`, requests to routes not defined in your OpenAPI specification will not be blocked. | `1`, `t`, `T`, `TRUE`, `true`, `True`, `0`, `f`, `F`, `FALSE`, `false`, `False` |
 
 See [dev/nginx.conf](./dev/nginx.conf) for an example of these in use.
 

dev/nginx.conf

@@ -24,26 +24,32 @@ http {
     }
 
     location /health {
+      firetail_enable;
       return 200 '{"message":"I\'m healthy! 💖"}';
     }
 
     location /notfound {
+      firetail_enable;
       return 404 '{"message":"Not Found 🤷"}';
     }
 
     location /unhealthy {
+      firetail_enable;
       return 500 '{"message":"I\'m unhealthy! 🤒"}';
     }
 
     location /profile/alice {
+      firetail_enable;
       return 200 '{"username":"alice", "friends": 123456789}';
     }
 
     location /profile/bob {
+      firetail_enable;
       return 200 '{"username":"bob", "friends": 123456789, "address":"Oh dear, this shouldn\'t be public!"}';
     }
 
     location /profile/alice/comment {
+      firetail_enable;
       return 201 '{"message":"Success!"}';
     }
 

src/nginx_module/access_phase_handler.c

@@ -0,0 +1,245 @@
+#include <ngx_core.h>
+#include <ngx_http.h>
+#include "access_phase_handler.h"
+#include "filter_context.h"
+#include "firetail_config.h"
+#include "firetail_module.h"
+#include <json-c/json.h>
+
+static void FiretailClientBodyHandler(ngx_http_request_t *request);
+static ngx_int_t FiretailClientBodyHandlerInternal(ngx_http_request_t *request);
+static ngx_int_t FiretailReturnFailedValidationResult(ngx_http_request_t *request, ngx_buf_t *b,
+                                                      ngx_chain_t *chain_head, char *error);
+
+struct ValidateRequestBody_return {
+  int r0;
+  char *r1;
+};
+typedef struct ValidateRequestBody_return (*ValidateRequestBody)(void *, int, void *, int, void *, int, void *, int,
+                                                                 void *, int);
+
+typedef struct {
+  ngx_int_t status;
+} ngx_http_firetail_ctx_t;
+
+ngx_int_t FiretailAccessPhaseHandler(ngx_http_request_t *r) {
+  // Check if FireTail is enabled for this location; if not, skip this handler
+  FiretailConfig *location_config = ngx_http_get_module_loc_conf(r, ngx_firetail_module);
+  if (location_config->FiretailEnabled == 0) {
+    return NGX_DECLINED;
+  }
+
+  ngx_int_t rc;
+  ngx_http_firetail_ctx_t *ctx;
+
+  if (r != r->main) {
+    return NGX_DECLINED;
+  }
+
+  ctx = ngx_http_get_module_ctx(r, ngx_firetail_module);
+
+  if (ctx) {
+    return ctx->status;
+  }
+
+  ctx = ngx_pcalloc(r->pool, sizeof(ngx_http_firetail_ctx_t));
+  if (ctx == NULL) {
+    return NGX_ERROR;
+  }
+
+  ctx->status = NGX_DONE;
+
+  rc = ngx_http_read_client_request_body(r, FiretailClientBodyHandler);
+  if (rc >= NGX_HTTP_SPECIAL_RESPONSE) {
+    return rc;
+  }
+
+  ngx_http_finalize_request(r, NGX_DONE);
+  return NGX_DONE;
+}
+
+static void FiretailClientBodyHandler(ngx_http_request_t *request) {
+  FiretailClientBodyHandlerInternal(request);
+  request->preserve_body = 1;
+  request->write_event_handler = ngx_http_core_run_phases;
+  ngx_http_core_run_phases(request);
+}
+
+static ngx_int_t FiretailClientBodyHandlerInternal(ngx_http_request_t *request) {
+  ngx_log_debug(NGX_LOG_DEBUG, request->connection->log, 0, "✅️✅️✅️HANDLER INTERNAL✅️✅️✅️");
+
+  ngx_chain_t *chain_head;
+  chain_head = request->request_body->bufs;
+
+  // Get our context so we can store the request body data
+  FiretailFilterContext *ctx = GetFiretailFilterContext(request);
+  if (ctx == NULL) {
+    return NGX_ERROR;
+  }
+
+  // get the header values
+  ngx_list_part_t *part;
+  ngx_table_elt_t *h;
+  ngx_uint_t i;
+  part = &request->headers_in.headers.part;
+  h = part->elts;
+  json_object *log_root = json_object_new_object();
+  for (i = 0;; i++) {
+    if (i >= part->nelts) {
+      if (part->next == NULL) {
+        break;
+      }
+      part = part->next;
+      h = part->elts;
+      i = 0;
+    }
+    json_object *jobj = json_object_new_string((char *)h[i].value.data);
+    json_object *array = json_object_new_array();
+    json_object_array_add(array, jobj);
+    json_object_object_add(log_root, (char *)h[i].key.data, array);
+  }
+  ctx->request_headers_json = (u_char *)json_object_to_json_string(log_root);
+  ctx->request_headers_json_size = strlen((char *)ctx->request_headers_json);
+  ngx_log_debug(NGX_LOG_DEBUG, request->connection->log, 0, "json value %s", (char *)ctx->request_headers_json);
+
+  // Determine the length of the request body chain we've been given
+  long new_request_body_parts_size = 0;
+  for (ngx_chain_t *current_chain_link = chain_head; current_chain_link != NULL;
+       current_chain_link = current_chain_link->next) {
+    new_request_body_parts_size += current_chain_link->buf->last - current_chain_link->buf->pos;
+  }
+
+  // Take note of the request body size before and after adding the new chain
+  // & update it in our ctx
+  long old_request_body_size = ctx->request_body_size;
+  long new_request_body_size = old_request_body_size + new_request_body_parts_size;
+  ctx->request_body_size = new_request_body_size;
+
+  // Create a new updated body
+  u_char *updated_request_body = ngx_pcalloc(request->pool, new_request_body_size);
+
+  // Copy the body read so far into ctx into our new updated_request_body
+  u_char *updated_request_body_i = ngx_copy(updated_request_body, ctx->request_body, old_request_body_size);
+
+  // Iterate over the chain again and copy all of the buffers over to our new
+  // request body char*
+  for (ngx_chain_t *current_chain_link = chain_head; current_chain_link != NULL;
+       current_chain_link = current_chain_link->next) {
+    long buffer_length = current_chain_link->buf->last - current_chain_link->buf->pos;
+    updated_request_body_i = ngx_copy(updated_request_body_i, current_chain_link->buf->pos, buffer_length);
+  }
+
+  // Update the ctx with the new updated body
+  ctx->request_body = updated_request_body;
+
+  // Get the main config so we can check if we have 404s disabled from the middleware
+  FiretailConfig *main_config = ngx_http_get_module_main_conf(request, ngx_firetail_module);
+
+  // run the validation
+  void *validator_module = dlopen("/etc/nginx/modules/firetail-validator.so", RTLD_LAZY);
+  if (!validator_module) {
+    return NGX_ERROR;
+  }
+
+  ValidateRequestBody request_body_validator = (ValidateRequestBody)dlsym(validator_module, "ValidateRequestBody");
+  char *error;
+  if ((error = dlerror()) != NULL) {
+    ngx_log_debug(NGX_LOG_DEBUG, request->connection->log, 0, "Failed to load ValidateRequestBody: %s", error);
+    exit(1);
+  }
+  ngx_log_debug(NGX_LOG_DEBUG, request->connection->log, 0, "Validating request body...");
+
+  struct ValidateRequestBody_return validation_result = request_body_validator(
+      main_config->FiretailAllowUndefinedRoutes.data, main_config->FiretailAllowUndefinedRoutes.len, ctx->request_body,
+      ctx->request_body_size, request->unparsed_uri.data, request->unparsed_uri.len, request->method_name.data,
+      request->method_name.len, (char *)ctx->request_headers_json, ctx->request_headers_json_size);
+
+  ngx_log_debug(NGX_LOG_DEBUG, request->connection->log, 0, "Validation request result: %d", validation_result.r0);
+  ngx_log_debug(NGX_LOG_DEBUG, request->connection->log, 0, "Validating request body: %s", validation_result.r1);
+
+  // if validation is unsuccessful, return bad request
+  if (validation_result.r0 > 0)
+    return FiretailReturnFailedValidationResult(request, NULL, chain_head, validation_result.r1);
+
+  dlclose(validator_module);
+
+  return NGX_OK;  // can be NGX_DECLINED - see ngx_http_mirror_handler_internal
+                  // function in nginx mirror module
+}
+
+static ngx_int_t FiretailReturnFailedValidationResult(ngx_http_request_t *request, ngx_buf_t *b,
+                                                      ngx_chain_t *chain_head, char *error) {
+  ngx_chain_t out;
+  char *code;
+  struct json_object *jobj;
+  ngx_int_t rc;
+
+  FiretailFilterContext *ctx = GetFiretailFilterContext(request);
+
+  char empty_json[2] = "{}";
+  ngx_log_debug(NGX_LOG_DEBUG, request->connection->log, 0, "INCOMING Request Body: %s, json %s", ctx->request_body,
+                empty_json);
+
+  if (b == NULL) {
+    ngx_log_debug(NGX_LOG_DEBUG, request->connection->log, 0, "Buffer for REQUEST is null", NULL);
+
+    // bypass response validation because we no longer need
+    // to go through response validation
+    ctx->bypass_response = 0;
+    if (ctx->request_body || (char *)ctx->request_body != empty_json) {
+      ctx->bypass_response = 1;
+    }
+    ctx->request_result = (u_char *)error;
+
+    // response parse the middleware json response
+    jobj = json_tokener_parse(error);
+    // Get the string value in "code" json key
+    code = (char *)json_object_get_string(json_object_object_get(jobj, "code"));
+
+    // return and finalize request early since we are not going to send
+    // it to upstream server
+    ngx_str_t content_type = ngx_string("application/json");
+    request->headers_out.content_type = content_type;
+    // convert "code" which is string to integer (status), example: 200
+    request->headers_out.status = ngx_atoi((u_char *)code, strlen(code));
+    request->keepalive = 0;
+
+    rc = ngx_http_send_header(request);
+    if (rc == NGX_ERROR || rc > NGX_OK || request->header_only) {
+      ngx_http_finalize_request(request, rc);
+      return NGX_DONE;
+    }
+
+    // allocate buffer in pool
+    b = ngx_calloc_buf(request->pool);
+    // set the error as unsigned char
+    u_char *msg = (u_char *)error;
+    b->pos = msg;
+    b->last = msg + strlen((char *)msg);
+    b->memory = 1;
+
+    b->last_buf = 1;
+
+    out.buf = b;
+    out.next = NULL;
+
+    rc = ngx_http_output_filter(request, &out);
+
+    ngx_http_finalize_request(request, rc);
+  }
+
+  if (request == request->main) {
+    request->headers_out.content_length_n = b->last - b->pos;
+
+    if (request->headers_out.content_length) {
+      request->headers_out.content_length->hash = 0;
+      request->headers_out.content_length = NULL;
+    }
+  }
+
+  out.buf = b;
+  out.next = NULL;
+
+  ngx_log_debug(NGX_LOG_DEBUG, request->connection->log, 0, "Sending next REQUEST body", NULL);
+  return NGX_OK;
+}

src/nginx_module/access_phase_handler.h

@@ -0,0 +1,3 @@
+#include <ngx_http.h>
+
+ngx_int_t FiretailAccessPhaseHandler(ngx_http_request_t *r);

src/nginx_module/config

@@ -2,16 +2,20 @@ ngx_addon_name=ngx_firetail_module
 
 FIRETAIL_SRCS="                                                             \
         $ngx_addon_dir/firetail_module.c                                    \
+        $ngx_addon_dir/firetail_context.c                                   \
+        $ngx_addon_dir/firetail_directives.c                                \
         $ngx_addon_dir/filter_context.c                                     \
-        $ngx_addon_dir/filter_firetail_send.c                               \
+        $ngx_addon_dir/access_phase_handler.c                               \
         $ngx_addon_dir/filter_response_body.c                               \
         $ngx_addon_dir/filter_headers.c                                     \
         "
 
 FIRETAIL_DEPS="                                                             \
         $ngx_addon_dir/firetail_module.h                                    \
+        $ngx_addon_dir/firetail_context.h                                   \
+        $ngx_addon_dir/firetail_directives.h                                \
         $ngx_addon_dir/filter_context.h                                     \
-        $ngx_addon_dir/filter_firetail_send.h                               \
+        $ngx_addon_dir/access_phase_handler.h                               \
         $ngx_addon_dir/filter_response_body.h                               \
         $ngx_addon_dir/filter_headers.h                                     \
         "