ext: use arguments and reply with them

diff --git a/lib/server-handshake.c b/lib/server-handshake.c
index 11279e9..85803b9 100644 (file)
--- a/lib/server-handshake.c
+++ b/lib/server-handshake.c
@@ -22,18 +22,20 @@
 #include "private-libwebsockets.h"
 
 #define LWS_CPYAPP(ptr, str) { strcpy(ptr, str); ptr += strlen(str); }
+
 #ifndef LWS_NO_EXTENSIONS
-LWS_VISIBLE int
-lws_extension_server_handshake(struct lws *wsi, char **p)
+static int
+lws_extension_server_handshake(struct lws *wsi, char **p, int budget)
 {
        struct lws_context *context = wsi->context;
        struct lws_context_per_thread *pt = &context->pt[(int)wsi->tsi];
+       char ext_name[64], *args, *end = (*p) + budget - 1;
+       const struct lws_ext_options *opts, *po;
        const struct lws_extension *ext;
-       char ext_name[128];
+       struct lws_ext_option_arg oa;
+       int n, m, more = 1;
        int ext_count = 0;
-       int more = 1;
        char ignore;
-       int n, m;
        char *c;
 
        /*
@@ -55,13 +57,29 @@ lws_extension_server_handshake(struct lws *wsi, char **p)
        c = (char *)pt->serv_buf;
        lwsl_parser("WSI_TOKEN_EXTENSIONS = '%s'\n", c);
        wsi->count_act_ext = 0;
-       n = 0;
        ignore = 0;
+       n = 0;
+       args = NULL;
+
+       /*
+        * We may get a simple request
+        *
+        * Sec-WebSocket-Extensions: permessage-deflate
+        *
+        * or an elaborated one with requested options
+        *
+        * Sec-WebSocket-Extensions: permessage-deflate; \
+        *                           server_no_context_takeover; \
+        *                           client_no_context_takeover
+        */
+
        while (more) {
 
                if (*c && (*c != ',' && *c != '\t')) {
-                       if (*c == ';')
+                       if (*c == ';') {
                                ignore = 1;
+                               args = c + 1;
+                       }
                        if (ignore || *c == ' ') {
                                c++;
                                continue;
@@ -82,6 +100,9 @@ lws_extension_server_handshake(struct lws *wsi, char **p)
                                continue;
                }
 
+               while (args && *args && *args == ' ')
+                       args++;
+
                /* check a client's extension against our support */
 
                ext = wsi->vhost->extensions;
@@ -92,17 +113,18 @@ lws_extension_server_handshake(struct lws *wsi, char **p)
                                ext++;
                                continue;
                        }
-#if 0
-                       m = ext->callback(lws_get_context(wsi), ext, wsi,
-                                         LWS_EXT_CB_ARGS_VALIDATE,
-                                         NULL, start + n, 0);
-                       if (m) {
-                               ext++;
-                               continue;
-                       }
-#endif
+
                        /*
                         * oh, we do support this one he asked for... but let's
+                        * confirm he only gave it once
+                        */
+                       for (m = 0; m < wsi->count_act_ext; m++)
+                               if (wsi->active_extensions[m] == ext) {
+                                       lwsl_info("extension mentioned twice\n");
+                                       return 1; /* shenanigans */
+                               }
+
+                       /*
                         * ask user code if it's OK to apply it on this
                         * particular connection + protocol
                         */
@@ -115,7 +137,6 @@ lws_extension_server_handshake(struct lws *wsi, char **p)
                         * the extension, it's what we get if the callback is
                         * unhandled
                         */
-
                        if (m) {
                                ext++;
                                continue;
@@ -132,28 +153,73 @@ lws_extension_server_handshake(struct lws *wsi, char **p)
                        /* allow him to construct his context */
 
                        if (ext->callback(lws_get_context(wsi), ext, wsi,
-                                     LWS_EXT_CB_CONSTRUCT,
-                                     (void *)&wsi->act_ext_user[wsi->count_act_ext],
-                                     NULL, 0)) {
-                               lwsl_notice("ext %s failed construction\n", ext_name);
+                                         LWS_EXT_CB_CONSTRUCT,
+                                         (void *)&wsi->act_ext_user[
+                                                           wsi->count_act_ext],
+                                         &opts, 0)) {
+                               lwsl_notice("ext %s failed construction\n",
+                                           ext_name);
                                ext_count--;
                                ext++;
+
                                continue;
                        }
 
                        if (ext_count > 1)
                                *(*p)++ = ',';
                        else
-                               LWS_CPYAPP(*p, "\x0d\x0aSec-WebSocket-Extensions: ");
-                       *p += sprintf(*p, "%s", ext_name);
+                               LWS_CPYAPP(*p,
+                                         "\x0d\x0aSec-WebSocket-Extensions: ");
+                       *p += lws_snprintf(*p, (end - *p), "%s", ext_name);
+
+                       /*
+                        *  go through the options trying to apply the
+                        * recognized ones
+                        */
+
+                       lwsl_debug("ext args %s", args);
+
+                       while (args && *args && *args != ',') {
+                               while (*args == ' ')
+                                       args++;
+                               po = opts;
+                               while (po->name) {
+                                       lwsl_debug("'%s' '%s'\n", po->name, args);
+                                       /* only support arg-less options... */
+                                       if (po->type == EXTARG_NONE &&
+                                           !strncmp(args, po->name,
+                                                           strlen(po->name))) {
+                                               oa.option_name = NULL;
+                                               oa.option_index = (po - opts) /
+                                                               sizeof(*po);
+                                               oa.start = NULL;
+                                               lwsl_debug("setting %s\n", po->name);
+                                               if (!ext->callback(
+                                                               lws_get_context(wsi), ext, wsi,
+                                                                 LWS_EXT_CB_OPTION_SET,
+                                                                 wsi->act_ext_user[
+                                                                        wsi->count_act_ext],
+                                                                 &oa, (end - *p))) {
+
+                                                       *p += lws_snprintf(*p, (end - *p), "; %s", po->name);
+                                                       lwsl_debug("adding option %s\n", po->name);
+                                               }
+                                       }
+                                       po++;
+                               }
+                               while (*args && *args != ',' && *args != ';')
+                                       args++;
+                       }
 
                        wsi->count_act_ext++;
-                       lwsl_parser("count_act_ext <- %d\n", wsi->count_act_ext);
+                       lwsl_parser("count_act_ext <- %d\n",
+                                   wsi->count_act_ext);
 
                        ext++;
                }
 
                n = 0;
+               args = NULL;
        }
 
        return 0;
@@ -190,8 +256,8 @@ handshake_0405(struct lws_context *context, struct lws *wsi)
 
        lws_SHA1(pt->serv_buf, n, hash);
 
-       accept_len = lws_b64_encode_string((char *)hash, 20, (char *)pt->serv_buf,
-                       context->pt_serv_buf_size);
+       accept_len = lws_b64_encode_string((char *)hash, 20,
+                       (char *)pt->serv_buf, context->pt_serv_buf_size);
        if (accept_len < 0) {
                lwsl_warn("Base64 encoded hash too long\n");
                goto bail;
@@ -227,9 +293,11 @@ handshake_0405(struct lws_context *context, struct lws *wsi)
 #ifndef LWS_NO_EXTENSIONS
        /*
         * Figure out which extensions the client has that we want to
-        * enable on this connection, and give him back the list
+        * enable on this connection, and give him back the list.
+        *
+        * Give him a limited write bugdet
         */
-       if (lws_extension_server_handshake(wsi, &p))
+       if (lws_extension_server_handshake(wsi, &p, 192))
                goto bail;
 #endif
 

diff --git a/test-server/test-client.c b/test-server/test-client.c
index 200e9e4..63d0d6d 100644 (file)
--- a/test-server/test-client.c
+++ b/test-server/test-client.c
@@ -357,7 +357,7 @@ static const struct lws_extension exts[] = {
        {
                "permessage-deflate",
                lws_extension_callback_pm_deflate,
-               "permessage-deflate; client_max_window_bits"
+               "permessage-deflate; client_no_context_takeover"
        },
        {
                "deflate-frame",