feat: set response header (#31)

Author: spacewander

proxy_wasm_abi.md

@@ -174,6 +174,21 @@ configuration separately because proxy-wasm-rust-sdk still uses it.
   - `i32 (proxy_result_t) call_result`
 
 
+### `proxy_add_map_value`
+
+* params:
+  - `i32 (proxy_map_type_t) map_type`
+  - `i32 (const char*) key_data`
+  - `i32 (size_t) key_size`
+  - `i32 (const char*) value_data`
+  - `i32 (size_t) value_size`
+* returns:
+  - `i32 (proxy_result_t) call_result`
+
+Add key (`key_data`, `key_size`) with the value (`value_data`, `value_size`) to a given map
+(`map_type`).
+
+
 ## HTTP (L7) extensions
 
 ### `proxy_send_http_response`

src/http/ngx_http_wasm_api.c

@@ -7,11 +7,18 @@
 #include "ngx_http_wasm_map.h"
 
 
+#define FFI_NO_REQ_CTX  -100
+#define FFI_BAD_CONTEXT -101
+
+
 static int (*set_resp_header) (ngx_http_request_t *r,
     const char *key_data, size_t key_len, int is_nil,
     const char *sval, size_t sval_len, ngx_str_t *mvals,
     size_t mvals_len, int override, char **errmsg);
 
+static char *err_bad_ctx = "API disabled in the current context";
+static char *err_no_req_ctx = "no request ctx found";
+
 
 wasm_functype_t *
 ngx_http_wasm_host_api_func(const ngx_wasm_host_api_t *api)
@@ -107,6 +114,37 @@ ngx_http_wasm_copy_to_wasm(ngx_log_t *log, const u_char *data, int32_t len,
 }
 
 
+static ngx_int_t
+ngx_http_wasm_set_resp_header(ngx_http_request_t *r,
+    const char *key, size_t key_len, int is_nil,
+    const char *val, size_t val_len,
+    int override)
+{
+    char               *errmsg = NULL;
+    ngx_int_t           rc;
+
+    rc = set_resp_header(r, key, key_len, is_nil, val, val_len, NULL, 0,
+                         override, &errmsg);
+    if (rc != NGX_OK && rc != NGX_DECLINED) {
+        if (rc == FFI_BAD_CONTEXT) {
+            errmsg = err_bad_ctx;
+        } else if (rc == FFI_NO_REQ_CTX) {
+            errmsg = err_no_req_ctx;
+        }
+
+        if (errmsg != NULL) {
+            ngx_log_error(NGX_LOG_ERR, r->connection->log, 0,
+                          "faied to set header %*s to %*s: %s",
+                          key_len, key, val_len, val, errmsg);
+        }
+
+        return NGX_ERROR;
+    }
+
+    return NGX_OK;
+}
+
+
 int32_t
 proxy_get_property(int32_t path_data, int32_t path_size,
                    int32_t res_data, int32_t res_size)
@@ -249,7 +287,6 @@ proxy_send_http_response(int32_t res_code,
     wmcf->body.len = body_size;
 
     if (headers_size > 0) {
-        char               *errmsg = NULL;
         char               *key, *val;
         int32_t             key_len, val_len;
         ngx_int_t           rc;
@@ -262,15 +299,8 @@ proxy_send_http_response(int32_t res_code,
 
         ngx_http_wasm_map_init_iter(&it, p);
         while (ngx_http_wasm_map_next(&it, &key, &key_len, &val, &val_len)) {
-            rc = set_resp_header(r, key, key_len, 0, val, val_len, NULL, 0,
-                                 0, &errmsg);
-            if (rc != NGX_OK && rc != NGX_DECLINED) {
-                if (errmsg != NULL) {
-                    ngx_log_error(NGX_LOG_ERR, log, 0,
-                                  "faied to set header %*s to %*s: %s",
-                                  key_len, key, val_len, val, errmsg);
-                }
-
+            rc = ngx_http_wasm_set_resp_header(r, key, key_len, 0, val, val_len, 0);
+            if (rc != NGX_OK) {
                 return PROXY_RESULT_BAD_ARGUMENT;
             }
         }
@@ -366,6 +396,34 @@ int32_t
 proxy_add_header_map_value(int32_t type, int32_t key_data, int32_t key_size,
                            int32_t data, int32_t size)
 {
+    ngx_int_t                   rc;
+    ngx_log_t                  *log;
+    ngx_http_request_t         *r;
+    char                       *key, *val;
+
+    log = ngx_http_wasm_get_log();
+    r = ngx_http_wasm_get_req();
+    if (r == NULL) {
+        return PROXY_RESULT_BAD_ARGUMENT;
+    }
+
+    key = (char *) ngx_wasm_vm.get_memory(log, key_data, key_size);
+    if (key == NULL) {
+        return PROXY_RESULT_INVALID_MEMORY_ACCESS;
+    }
+
+    val = (char *) ngx_wasm_vm.get_memory(log, data, size);
+    if (val == NULL) {
+        return PROXY_RESULT_INVALID_MEMORY_ACCESS;
+    }
+
+    if (type == PROXY_MAP_TYPE_HTTP_RESPONSE_HEADERS) {
+        rc = ngx_http_wasm_set_resp_header(r, key, key_size, 0, val, size, 0);
+        if (rc != NGX_OK) {
+            return PROXY_RESULT_BAD_ARGUMENT;
+        }
+    }
+
     return PROXY_RESULT_OK;
 }
 

src/http/ngx_http_wasm_map.h

@@ -4,6 +4,16 @@
 #include <ngx_core.h>
 
 
+typedef enum {
+  PROXY_MAP_TYPE_HTTP_REQUEST_HEADERS = 0,
+  PROXY_MAP_TYPE_HTTP_REQUEST_TRAILERS = 1,
+  PROXY_MAP_TYPE_HTTP_RESPONSE_HEADERS = 2,
+  PROXY_MAP_TYPE_HTTP_RESPONSE_TRAILERS = 3,
+  PROXY_MAP_TYPE_HTTP_CALL_RESPONSE_HEADERS = 6,
+  PROXY_MAP_TYPE_HTTP_CALL_RESPONSE_TRAILERS = 7,
+} proxy_map_type_t;
+
+
 typedef struct {
     int32_t  idx;
     int32_t  len;

t/http_header.t

@@ -0,0 +1,19 @@
+use t::WASM 'no_plan';
+
+run_tests();
+
+__DATA__
+
+=== TEST 1: response header add
+--- config
+location /t {
+    return 200;
+    header_filter_by_lua_block {
+        local wasm = require("resty.proxy-wasm")
+        local plugin = assert(wasm.load("plugin", "t/testdata/http_header/main.go.wasm"))
+        local ctx = assert(wasm.on_configure(plugin, 'resp_hdr_add'))
+        assert(wasm.on_http_response_headers(ctx))
+    }
+}
+--- response_headers
+add: foo, bar

t/testdata/http_header/main.go

@@ -0,0 +1,48 @@
+package main
+
+import (
+	"github.com/tetratelabs/proxy-wasm-go-sdk/proxywasm"
+	"github.com/tetratelabs/proxy-wasm-go-sdk/proxywasm/types"
+)
+
+func main() {
+	proxywasm.SetVMContext(&vmContext{})
+}
+
+type vmContext struct {
+	types.DefaultVMContext
+}
+
+func (*vmContext) NewPluginContext(contextID uint32) types.PluginContext {
+	return &pluginContext{}
+}
+
+type pluginContext struct {
+	types.DefaultPluginContext
+}
+
+func (*pluginContext) NewHttpContext(contextID uint32) types.HttpContext {
+	return &httpContext{contextID: contextID}
+}
+
+type httpContext struct {
+	types.DefaultHttpContext
+	contextID uint32
+}
+
+func (ctx *httpContext) OnHttpResponseHeaders(numHeaders int, endOfStream bool) types.Action {
+	data, err := proxywasm.GetPluginConfiguration()
+	if err != nil {
+		proxywasm.LogCriticalf("error reading plugin configuration: %v", err)
+		return types.ActionContinue
+	}
+
+	action := string(data)
+	proxywasm.AddHttpResponseHeader("add", "foo")
+
+	if action == "resp_hdr_add" {
+		proxywasm.AddHttpResponseHeader("add", "bar")
+	}
+
+	return types.ActionContinue
+}