Share the web workflow MDNS object with the user

ports/espressif/common-hal/mdns/Server.c

@@ -37,6 +37,7 @@ STATIC bool inited = false;
 
 void mdns_server_construct(mdns_server_obj_t *self, bool workflow) {
     if (inited) {
+        self->inited = false;
         return;
     }
     mdns_init();
@@ -46,6 +47,8 @@ void mdns_server_construct(mdns_server_obj_t *self, bool workflow) {
     snprintf(self->default_hostname, sizeof(self->default_hostname), "cpy-%02x%02x%02x", mac[3], mac[4], mac[5]);
     common_hal_mdns_server_set_hostname(self, self->default_hostname);
 
+    self->inited = true;
+
     if (workflow) {
         // Set a delegated entry to ourselves. This allows us to respond to "circuitpython.local"
         // queries as well.
@@ -67,21 +70,23 @@ void common_hal_mdns_server_construct(mdns_server_obj_t *self, mp_obj_t network_
         mp_raise_ValueError(translate("mDNS only works with built-in WiFi"));
         return;
     }
-    if (inited) {
+    mdns_server_construct(self, false);
+    if (common_hal_mdns_server_deinited(self)) {
         mp_raise_RuntimeError(translate("mDNS already initialized"));
     }
-    mdns_server_construct(self, false);
 }
 
 void common_hal_mdns_server_deinit(mdns_server_obj_t *self) {
+    if (common_hal_mdns_server_deinited(self)) {
+        return;
+    }
+    self->inited = false;
     inited = false;
     mdns_free();
 }
 
 bool common_hal_mdns_server_deinited(mdns_server_obj_t *self) {
-    // This returns INVALID_STATE when not initialized and INVALID_PARAM when it
-    // is.
-    return mdns_instance_name_set(NULL) == ESP_ERR_INVALID_STATE;
+    return !self->inited;
 }
 
 const char *common_hal_mdns_server_get_hostname(mdns_server_obj_t *self) {

ports/espressif/common-hal/mdns/Server.h

@@ -34,4 +34,5 @@ typedef struct {
     const char *instance_name;
     // "cpy-" "XXXXXX" "\0"
     char default_hostname[4 + 6 + 1];
+    bool inited;
 } mdns_server_obj_t;

ports/raspberrypi/common-hal/mdns/Server.c

@@ -36,18 +36,29 @@
 #include "lwip/apps/mdns.h"
 #include "lwip/prot/dns.h"
 
+// Track if we've inited the LWIP MDNS at all. It expects to only init once.
+// Subsequent times, we restart it.
 STATIC bool inited = false;
+// Track if we are globally inited. This essentially forces one inited MDNS
+// object at a time. (But ignores MDNS objects that are deinited.)
+STATIC bool object_inited = false;
 
 #define NETIF_STA (&cyw43_state.netif[CYW43_ITF_STA])
 #define NETIF_AP (&cyw43_state.netif[CYW43_ITF_AP])
 
 void mdns_server_construct(mdns_server_obj_t *self, bool workflow) {
-    if (inited) {
+    if (object_inited) {
+        self->inited = false;
         return;
     }
 
-    mdns_resp_init();
-    inited = true;
+    if (!inited) {
+        mdns_resp_init();
+        inited = true;
+    } else {
+        mdns_resp_restart(NETIF_STA);
+    }
+    self->inited = true;
 
     uint8_t mac[6];
     wifi_radio_get_mac_address(&common_hal_wifi_radio_obj, mac);
@@ -68,19 +79,23 @@ void common_hal_mdns_server_construct(mdns_server_obj_t *self, mp_obj_t network_
         mp_raise_ValueError(translate("mDNS only works with built-in WiFi"));
         return;
     }
-    if (inited) {
+    if (object_inited) {
         mp_raise_RuntimeError(translate("mDNS already initialized"));
     }
     mdns_server_construct(self, false);
 }
 
 void common_hal_mdns_server_deinit(mdns_server_obj_t *self) {
-    inited = false;
+    if (common_hal_mdns_server_deinited(self)) {
+        return;
+    }
+    self->inited = false;
+    object_inited = false;
     mdns_resp_remove_netif(NETIF_STA);
 }
 
 bool common_hal_mdns_server_deinited(mdns_server_obj_t *self) {
-    return !mdns_resp_netif_active(NETIF_STA);
+    return !self->inited;
 }
 
 const char *common_hal_mdns_server_get_hostname(mdns_server_obj_t *self) {
@@ -215,7 +230,6 @@ STATIC void alloc_search_result_cb(struct mdns_answer *answer, const char *varpa
     if ((flags & MDNS_SEARCH_RESULT_FIRST) != 0) {
         // first
         mdns_remoteservice_obj_t *service = gc_alloc(sizeof(mdns_remoteservice_obj_t), 0, false);
-        mp_printf(&mp_plat_print, "found service %p\n", service);
         if (service == NULL) {
             // alloc fails
             mdns_search_stop(state->request_id);

ports/raspberrypi/common-hal/mdns/Server.h

@@ -37,4 +37,5 @@ typedef struct {
     // "cpy-" "XXXXXX" "\0"
     char default_hostname[4 + 6 + 1];
     const char *service_type[MDNS_MAX_SERVICES];
+    bool inited;
 } mdns_server_obj_t;

shared-bindings/mdns/Server.c

@@ -33,6 +33,10 @@
 #include "shared-bindings/mdns/Server.h"
 #include "shared-bindings/util.h"
 
+#if CIRCUITPY_WEB_WORKFLOW
+#include "supervisor/shared/web_workflow/web_workflow.h"
+#endif
+
 //| class Server:
 //|     """The MDNS Server responds to queries for this device's information and allows for querying
 //|     other devices."""
@@ -53,7 +57,14 @@ STATIC mp_obj_t mdns_server_make_new(const mp_obj_type_t *type, size_t n_args, s
     mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
     mp_arg_parse_all_kw_array(n_args, n_kw, all_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
 
-    mdns_server_obj_t *self = m_new_obj(mdns_server_obj_t);
+    #if CIRCUITPY_WEB_WORKFLOW
+    mdns_server_obj_t *web_workflow_mdns = supervisor_web_workflow_mdns(args[ARG_network_interface].u_obj);
+    if (web_workflow_mdns != NULL) {
+        return web_workflow_mdns;
+    }
+    #endif
+
+    mdns_server_obj_t *self = m_new_obj_with_finaliser(mdns_server_obj_t);
     self->base.type = &mdns_server_type;
     common_hal_mdns_server_construct(self, args[ARG_network_interface].u_obj);
 
@@ -194,6 +205,7 @@ STATIC const mp_rom_map_elem_t mdns_server_locals_dict_table[] = {
     { MP_ROM_QSTR(MP_QSTR_find),              MP_ROM_PTR(&mdns_server_find_obj) },
     { MP_ROM_QSTR(MP_QSTR_advertise_service), MP_ROM_PTR(&mdns_server_advertise_service_obj) },
 
+    { MP_ROM_QSTR(MP_QSTR___del__),           MP_ROM_PTR(&mdns_server_deinit_obj) },
     { MP_ROM_QSTR(MP_QSTR_deinit),            MP_ROM_PTR(&mdns_server_deinit_obj) },
 };
 

supervisor/shared/web_workflow/web_workflow.c

@@ -200,6 +200,16 @@ STATIC void _update_encoded_ip(void) {
     }
 }
 
+mdns_server_obj_t *supervisor_web_workflow_mdns(mp_obj_t network_interface) {
+    #if CIRCUITPY_MDNS
+    if (network_interface == &common_hal_wifi_radio_obj &&
+        mdns.base.type == &mdns_server_type) {
+        return &mdns;
+    }
+    #endif
+    return NULL;
+}
+
 #if CIRCUITPY_STATUS_BAR
 bool supervisor_web_workflow_status_dirty(void) {
     return common_hal_wifi_radio_get_enabled(&common_hal_wifi_radio_obj) != _last_enabled ||
@@ -300,11 +310,6 @@ void supervisor_start_web_workflow(void) {
 
     if (first_start) {
         port_changed = false;
-        #if CIRCUITPY_MDNS
-        mdns_server_construct(&mdns, true);
-        mdns.base.type = &mdns_server_type;
-        common_hal_mdns_server_set_instance_name(&mdns, MICROPY_HW_BOARD_NAME);
-        #endif
         pool.base.type = &socketpool_socketpool_type;
         common_hal_socketpool_socketpool_construct(&pool, &common_hal_wifi_radio_obj);
 
@@ -313,13 +318,26 @@ void supervisor_start_web_workflow(void) {
 
         websocket_init();
     }
+    #if CIRCUITPY_MDNS
+    // Try to start MDNS if the user deinited it.
+    if (mdns.base.type != &mdns_server_type ||
+        common_hal_mdns_server_deinited(&mdns)) {
+        mdns_server_construct(&mdns, true);
+        mdns.base.type = &mdns_server_type;
+        if (!common_hal_mdns_server_deinited(&mdns)) {
+            common_hal_mdns_server_set_instance_name(&mdns, MICROPY_HW_BOARD_NAME);
+        }
+    }
+    #endif
     if (port_changed) {
         common_hal_socketpool_socket_close(&listening);
     }
     if (first_start || port_changed) {
         web_api_port = new_port;
         #if CIRCUITPY_MDNS
-        common_hal_mdns_server_advertise_service(&mdns, "_circuitpython", "_tcp", web_api_port);
+        if (!common_hal_mdns_server_deinited(&mdns)) {
+            common_hal_mdns_server_advertise_service(&mdns, "_circuitpython", "_tcp", web_api_port);
+        }
         #endif
         socketpool_socket(&pool, SOCKETPOOL_AF_INET, SOCKETPOOL_SOCK_STREAM, &listening);
         common_hal_socketpool_socket_settimeout(&listening, 0);
@@ -444,17 +462,18 @@ static bool _origin_ok(const char *origin) {
     }
     // These are prefix checks up to : so that any port works.
     // TODO: Support DHCP hostname in addition to MDNS.
+    const char *end;
     #if CIRCUITPY_MDNS
-    const char *local = ".local";
-    const char *hostname = common_hal_mdns_server_get_hostname(&mdns);
-    const char *end = origin + strlen(http) + strlen(hostname) + strlen(local);
-    if (strncmp(origin + strlen(http), hostname, strlen(hostname)) == 0 &&
-        strncmp(origin + strlen(http) + strlen(hostname), local, strlen(local)) == 0 &&
-        (end[0] == '\0' || end[0] == ':')) {
-        return true;
+    if (!common_hal_mdns_server_deinited(&mdns)) {
+        const char *local = ".local";
+        const char *hostname = common_hal_mdns_server_get_hostname(&mdns);
+        end = origin + strlen(http) + strlen(hostname) + strlen(local);
+        if (strncmp(origin + strlen(http), hostname, strlen(hostname)) == 0 &&
+            strncmp(origin + strlen(http) + strlen(hostname), local, strlen(local)) == 0 &&
+            (end[0] == '\0' || end[0] == ':')) {
+            return true;
+        }
     }
-    #else
-    const char *end;
     #endif
 
     _update_encoded_ip();
@@ -733,12 +752,13 @@ static void _reply_with_file(socketpool_socket_obj_t *socket, _request *request,
 }
 
 static void _reply_with_devices_json(socketpool_socket_obj_t *socket, _request *request) {
+    size_t total_results = 0;
     #if CIRCUITPY_MDNS
     mdns_remoteservice_obj_t found_devices[32];
-    size_t total_results = mdns_server_find(&mdns, "_circuitpython", "_tcp", 1, found_devices, MP_ARRAY_SIZE(found_devices));
+    if (!common_hal_mdns_server_deinited(&mdns)) {
+        total_results = mdns_server_find(&mdns, "_circuitpython", "_tcp", 1, found_devices, MP_ARRAY_SIZE(found_devices));
+    }
     size_t count = MIN(total_results, MP_ARRAY_SIZE(found_devices));
-    #else
-    size_t total_results = 0;
     #endif
     socketpool_socket_send(socket, (const uint8_t *)OK_JSON, strlen(OK_JSON));
     _cors_header(socket, request);
@@ -775,10 +795,11 @@ static void _reply_with_version_json(socketpool_socket_obj_t *socket, _request *
     _send_str(socket, "\r\n");
     mp_print_t _socket_print = {socket, _print_chunk};
 
-    #if CIRCUITPY_MDNS
-    const char *hostname = common_hal_mdns_server_get_hostname(&mdns);
-    #else
     const char *hostname = "";
+    #if CIRCUITPY_MDNS
+    if (!common_hal_mdns_server_deinited(&mdns)) {
+        hostname = common_hal_mdns_server_get_hostname(&mdns);
+    }
     #endif
     _update_encoded_ip();
     // Note: this leverages the fact that C concats consecutive string literals together.
@@ -1023,7 +1044,13 @@ static void _decode_percents(char *str) {
 static bool _reply(socketpool_socket_obj_t *socket, _request *request) {
     if (request->redirect) {
         #if CIRCUITPY_MDNS
-        _reply_redirect(socket, request, request->path);
+        if (!common_hal_mdns_server_deinited(&mdns)) {
+            _reply_redirect(socket, request, request->path);
+        } else {
+            _reply_missing(socket, request);
+        }
+        #else
+        _reply_missing(socket, request);
         #endif
     } else if (strlen(request->origin) > 0 && !_origin_ok(request->origin)) {
         _reply_forbidden(socket, request);

supervisor/shared/web_workflow/web_workflow.h

@@ -28,6 +28,7 @@
 
 #include <stdbool.h>
 
+#include "shared-bindings/mdns/Server.h"
 #include "shared-bindings/socketpool/Socket.h"
 
 // This background function should be called repeatedly. It cannot be done based
@@ -38,5 +39,8 @@ void supervisor_web_workflow_status(void);
 void supervisor_start_web_workflow(void);
 void supervisor_stop_web_workflow(void);
 
+// Share the MDNS object with user code.
+mdns_server_obj_t *supervisor_web_workflow_mdns(mp_obj_t network_interface);
+
 // To share with websocket.
 void web_workflow_send_raw(socketpool_socket_obj_t *socket, const uint8_t *buf, int len);