feat: support headers in proxy_send_http_response (#29)

Author: spacewander

config

@@ -4,6 +4,7 @@ ngx_module_srcs=" \
     $ngx_addon_dir/src/http/ngx_http_wasm_module.c \
     $ngx_addon_dir/src/http/ngx_http_wasm_api.c \
     $ngx_addon_dir/src/http/ngx_http_wasm_state.c \
+    $ngx_addon_dir/src/http/ngx_http_wasm_map.c \
     $ngx_addon_dir/src/vm/wasmtime.c \
     $ngx_addon_dir/src/vm/vm.c \
 "

src/http/ngx_http_wasm_api.c

@@ -1,7 +1,16 @@
+#define _GNU_SOURCE /* for RTLD_DEFAULT */
+#include <dlfcn.h>
 #include "vm/vm.h"
 #include "ngx_http_wasm_api.h"
 #include "ngx_http_wasm_module.h"
 #include "ngx_http_wasm_state.h"
+#include "ngx_http_wasm_map.h"
+
+
+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);
 
 
 wasm_functype_t *
@@ -33,6 +42,25 @@ ngx_http_wasm_host_api_func(const ngx_wasm_host_api_t *api)
 }
 
 
+ngx_int_t
+ngx_http_wasm_resolve_symbol(void)
+{
+    char        *err;
+
+    dlerror();    /* Clear any existing error */
+
+    set_resp_header = dlsym(RTLD_DEFAULT, "ngx_http_lua_ffi_set_resp_header");
+    err = dlerror();
+    if (err != NULL) {
+        ngx_log_error(NGX_LOG_ERR, ngx_cycle->log, 0,
+                      "failed to resolve symbol: %s", err);
+        return NGX_ERROR;
+    }
+
+    return NGX_OK;
+}
+
+
 int32_t
 proxy_set_effective_context(int32_t id)
 {
@@ -217,10 +245,37 @@ proxy_send_http_response(int32_t res_code,
     log = r->connection->log;
 
     wmcf = ngx_http_get_module_main_conf(r, ngx_http_wasm_module);
-    /* TODO handle other args */
     wmcf->code = 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;
+        proxy_wasm_map_iter it;
+
+        p = ngx_wasm_vm.get_memory(log, headers, headers_size);
+        if (p == NULL) {
+            return PROXY_RESULT_INVALID_MEMORY_ACCESS;
+        }
+
+        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);
+                }
+
+                return PROXY_RESULT_BAD_ARGUMENT;
+            }
+        }
+    }
+
     if (body_size > 0) {
         p = ngx_wasm_vm.get_memory(log, body, body_size);
         if (p == NULL) {

src/http/ngx_http_wasm_api.h

@@ -336,6 +336,7 @@ static ngx_wasm_host_api_t host_apis[] = {
 
 
 wasm_functype_t *ngx_http_wasm_host_api_func(const ngx_wasm_host_api_t *api);
+ngx_int_t ngx_http_wasm_resolve_symbol(void);
 
 
 #endif // NGX_HTTP_WASM_API_H

src/http/ngx_http_wasm_map.c

@@ -0,0 +1,42 @@
+#include "ngx_http_wasm_map.h"
+
+
+/**
+ * the format of proxy_map_t is:
+ * number of items (4 bytes) +
+ * len of key1 + len of val1 + len of key2 + ... (4 bytes for each len)
+ * data of key1 + \0 + data of val1 + data of key2 + ...
+ */
+
+
+void
+ngx_http_wasm_map_init_iter(proxy_wasm_map_iter *it, const u_char *map_data)
+{
+    it->idx = 0;
+    it->len = *(int32_t *) map_data;
+    it->size_ptr = (int32_t *) (map_data) + 1;
+    it->data_ptr = (char *) (it->size_ptr + 2 * it->len);
+}
+
+
+bool
+ngx_http_wasm_map_next(proxy_wasm_map_iter *it, char **key, int32_t *key_len,
+                       char **val, int32_t *val_len)
+{
+    if (it->idx == it->len) {
+        return false;
+    }
+
+    *key_len = *it->size_ptr;
+    it->size_ptr++;
+    *val_len = *it->size_ptr;
+    it->size_ptr++;
+
+    *key = it->data_ptr;
+    it->data_ptr += *key_len + 1;
+    *val = it->data_ptr;
+    it->data_ptr += *val_len + 1;
+
+    it->idx++;
+    return true;
+}

src/http/ngx_http_wasm_map.h

@@ -0,0 +1,20 @@
+#ifndef NGX_HTTP_WASM_MAP_H
+#define NGX_HTTP_WASM_MAP_H
+#include <stdbool.h>
+#include <ngx_core.h>
+
+
+typedef struct {
+    int32_t  idx;
+    int32_t  len;
+    int32_t *size_ptr;
+    char    *data_ptr;
+} proxy_wasm_map_iter;
+
+
+void ngx_http_wasm_map_init_iter(proxy_wasm_map_iter *it, const u_char *map_data);
+bool ngx_http_wasm_map_next(proxy_wasm_map_iter *it, char **key, int32_t *key_len,
+                            char **val, int32_t *val_len);
+
+
+#endif // NGX_HTTP_WASM_MAP_H

src/http/ngx_http_wasm_module.c

@@ -1,6 +1,7 @@
 #include <ngx_config.h>
 #include <ngx_core.h>
 #include <ngx_http.h>
+#include "ngx_http_wasm_api.h"
 #include "ngx_http_wasm_module.h"
 #include "ngx_http_wasm_state.h"
 #include "ngx_http_wasm_ctx.h"
@@ -141,6 +142,11 @@ ngx_http_wasm_init(ngx_conf_t *cf)
         return NGX_OK;
     }
 
+    rc = ngx_http_wasm_resolve_symbol();
+    if (rc != NGX_OK) {
+        return rc;
+    }
+
     wmcf = ngx_http_conf_get_module_main_conf(cf, ngx_http_wasm_module);
     if (wmcf->vm.len == 0) {
         return NGX_OK;

t/http_send_response.t

@@ -17,6 +17,8 @@ location /t {
 --- error_code: 403
 --- response_body chomp
 should not pass
+--- response_headers
+powered-by: proxy-wasm-go-sdk!!
 
 
 
@@ -36,3 +38,20 @@ location /t {
 --- error_code: 502
 --- response_body_like eval
 qr/<title>502 Bad Gateway<\/title>/
+
+
+
+=== TEST 3: multi headers
+--- config
+location /t {
+    content_by_lua_block {
+        local wasm = require("resty.proxy-wasm")
+        local plugin = assert(wasm.load("plugin", "t/testdata/http_send_response/main.go.wasm"))
+        local ctx = assert(wasm.on_configure(plugin, 'multi_hdrs'))
+        assert(wasm.on_http_request_headers(ctx))
+    }
+}
+--- error_code: 401
+--- response_headers
+hi: spacewander
+hello: spacewander, world

t/testdata/http_send_response/main.go

@@ -55,6 +55,12 @@ func (ctx *httpContext) OnHttpRequestHeaders(numHeaders int, endOfStream bool) t
 		}, []byte(body), -1)
 	} else if action == "502" {
 		err = proxywasm.SendHttpResponse(502, nil, nil, -1)
+	} else if action == "multi_hdrs" {
+		err = proxywasm.SendHttpResponse(401, [][2]string{
+			{"hello", "spacewander"},
+			{"hi", "spacewander"},
+			{"hello", "world"},
+		}, nil, -1)
 	}
 
 	if err != nil {