tonyp7 · someone42 · Aug 14, 2021 · Aug 14, 2021 · Sep 25, 2021 · Sep 25, 2021
diff --git a/Kconfig b/Kconfig
@@ -12,17 +12,21 @@ config WIFI_MANAGER_RETRY_TIMER
 	help
 	Defines the time to wait before an attempt to re-connect to a saved wifi is made after connection is lost or another unsuccesful attempt is made.
 
+config WIFI_MANAGER_AUTOSTART_AP
+    bool "Automatically start the AP if the WiFi manager fails to connect to another AP"
+	default y
+
 config WIFI_MANAGER_MAX_RETRY_START_AP
-	int "Max Retry before starting the AP"
+	int "Max Retry before starting the AP" if WIFI_MANAGER_AUTOSTART_AP
     default 3
     help
-	Defines the maximum number of failed retries allowed before the WiFi manager starts its own access point.  
-	
+	Defines the maximum number of failed retries allowed before the WiFi manager starts its own access point.
+
 config WIFI_MANAGER_SHUTDOWN_AP_TIMER
 	int "Time (in ms) to wait before shutting down the AP"
 	default 60000
 	help
-	Defines the time (in ms) to wait after a succesful connection before shutting down the access point.
+	Defines the time (in ms) to wait after a succesful connection before shutting down the access point. Use a negative number to never shut down the access point.
 
 config WEBAPP_LOCATION
     string "Defines the URL where the wifi manager is located"
@@ -36,8 +40,18 @@ config DEFAULT_AP_SSID
     help
 	SSID (network name) the the esp32 will broadcast.
 
+config WIFI_MANAGER_APPEND_MAC
+    bool "Append MAC address to access point SSID"
+    default n
+    help
+    The last two octets of the device's MAC address will be appended (with a preceding space) to the configured access point SSID. For example, "esp32" -> "esp32 ad7e". This helps make the SSID unique if you might have multiple devices on at once.
+
+config USE_RANDOM_AP_PASSWORD
+	bool "Use a randomly-generated Access Point password"
+	default y
+
 config DEFAULT_AP_PASSWORD
-    string "Access Point Password"
+    string "Access Point Password" if !USE_RANDOM_AP_PASSWORD
     default "esp32pwd"
     help
 	Password used for the Access Point. Leave empty and set AUTH MODE to WIFI_AUTH_OPEN for no password.
@@ -78,4 +92,16 @@ config DEFAULT_AP_BEACON_INTERVAL
     help
 	100ms is the recommended default.
 
+config HARDCODED_SSID
+  	string "Hardcoded SSID"
+  	default "HardcodedSSID"
+  	help
+  	For factory configuration, the device will attempt to connect an an AP with this SSID if there are no user configured APs.
+
+config HARDCODED_PASSWORD
+  	string "Hardcoded password"
+  	default "HardcodedPassword"
+  	help
+  	For factory configuration, the device will attempt to connect an an AP with this password if there are no user configured APs.
+
 endmenu
diff --git a/src/code.js b/src/code.js
@@ -105,6 +105,30 @@ docReady(async function () {
     false
   );
 
+  gel("togglepwd").addEventListener(
+    "click",
+    (e) => {
+      if (gel("pwd").type == "password") {
+        gel("pwd").type = "text";
+      } else {
+        gel("pwd").type = "password";
+      }
+    },
+    false
+  );
+
+  gel("manual_togglepwd").addEventListener(
+    "click",
+    (e) => {
+      if (gel("manual_pwd").type == "password") {
+        gel("manual_pwd").type = "text";
+      } else {
+        gel("manual_pwd").type = "password";
+      }
+    },
+    false
+  );
+
   gel("ok-details").addEventListener(
     "click",
     () => {

diff --git a/src/dns_server.c b/src/dns_server.c
@@ -37,6 +37,7 @@ Contains the freeRTOS task for the DNS server that processes the requests.
 #include <freertos/FreeRTOS.h>
 #include <freertos/task.h>
 #include <freertos/event_groups.h>
+#include <freertos/semphr.h>
 #include <esp_system.h>
 #include <esp_wifi.h>
 #include <esp_event.h>
@@ -56,18 +57,29 @@ Contains the freeRTOS task for the DNS server that processes the requests.
 static const char TAG[] = "dns_server";
 static TaskHandle_t task_dns_server = NULL;
 int socket_fd;
+SemaphoreHandle_t socket_in_use_mutex = NULL;
 
 void dns_server_start() {
 	if(task_dns_server == NULL){
+		socket_in_use_mutex = xSemaphoreCreateMutex();
 		xTaskCreate(&dns_server, "dns_server", 3072, NULL, WIFI_MANAGER_TASK_PRIORITY-1, &task_dns_server);
 	}
 }
 
 void dns_server_stop(){
 	if(task_dns_server){
-		vTaskDelete(task_dns_server);
+		/* If the task is deleted while recvfrom() is waiting, the socket
+		 * will remain in use and will be in zombie state forever. Close the
+		 * socket to cause recvfrom() to abort. */
 		close(socket_fd);
+		/* Wait for recvfrom() to return, signified by the mutex being
+		 * released */
+		xSemaphoreTake(socket_in_use_mutex, pdMS_TO_TICKS(500));
+		/* Now it is safe to delete the task */
+		vTaskDelete(task_dns_server);
 		task_dns_server = NULL;
+		vSemaphoreDelete(socket_in_use_mutex);
+		socket_in_use_mutex = NULL;
 	}
 
 }
@@ -114,14 +126,18 @@ void dns_server(void *pvParameters) {
     char ip_address[INET_ADDRSTRLEN]; /* buffer to store IPs as text. This is only used for debug and serves no other purpose */
     char *domain; /* This is only used for debug and serves no other purpose */
     int err;
+    bool valid_request;
+    bool include_answer;
 
     ESP_LOGI(TAG, "DNS Server listening on 53/udp");
 
     /* Start loop to process DNS requests */
     for(;;) {
 
     	memset(data, 0x00,  sizeof(data)); /* reset buffer */
+		xSemaphoreTake(socket_in_use_mutex, portMAX_DELAY);
         length = recvfrom(socket_fd, data, sizeof(data), 0, (struct sockaddr *)&client, &client_len); /* read udp request */
+		xSemaphoreGive(socket_in_use_mutex);
 
         /*if the query is bigger than the buffer size we simply ignore it. This case should only happen in case of multiple
          * queries within the same DNS packet and is not supported by this simple DNS hijack. */
@@ -149,25 +165,58 @@ void dns_server(void *pvParameters) {
 
             /* extract domain name and request IP for debug */
             inet_ntop(AF_INET, &(client.sin_addr), ip_address, INET_ADDRSTRLEN);
-            domain = (char*) &data[sizeof(dns_header_t) + 1];
-            for(char* c=domain; *c != '\0'; c++){
-            	if(*c < ' ' || *c > 'z') *c = '.'; /* technically we should test if the first two bits are 00 (e.g. if( (*c & 0xC0) == 0x00) *c = '.') but this makes the code a lot more readable */
+            /* each label is preceded by a length octet, step over each label and replace
+             * the length octet with a '.' character to make the domain name easier to read */
+            valid_request = true;
+            include_answer = false;
+            uint8_t *current_octet = &(data[sizeof(dns_header_t)]);
+            uint8_t label_length = *current_octet;
+            while(label_length != 0){
+                current_octet += label_length + 1;
+                if((current_octet - data) >= length){
+                    /* uh oh, buffer overflow */
+                    valid_request = false;
+                    break;
+                }
+                label_length = *current_octet;
+                if(label_length != 0) *current_octet = '.';
+            }
+            domain = (char*)&data[sizeof(dns_header_t) + 1];
+
+            /* check type of request */
+            current_octet++;
+            if((current_octet - data + 4) <= length){
+                uint16_t query_type = ((uint16_t)current_octet[0] << 8UL) | current_octet[1];
+                current_octet += 2;
+                uint16_t query_class = ((uint16_t)current_octet[0] << 8UL) | current_octet[1];
+                if((query_type == DNS_ANSWER_TYPE_A) && (query_class == DNS_ANSWER_CLASS_IN)){
+                    /* only answer requests for A records */
+                    include_answer = true;
+                    ESP_LOGI(TAG, "Replying to DNS request for %s from %s", domain, ip_address);
+                }
+            }else{
+                valid_request = false;
             }
-            ESP_LOGI(TAG, "Replying to DNS request for %s from %s", domain, ip_address);
-
-
-            /* create DNS answer at the end of the query*/
-            dns_answer_t *dns_answer = (dns_answer_t*)&response[length];
-            dns_answer->NAME = __bswap_16(0xC00C); /* This is a pointer to the beginning of the question. As per DNS standard, first two bits must be set to 11 for some odd reason hence 0xC0 */
-            dns_answer->TYPE = __bswap_16(DNS_ANSWER_TYPE_A);
-            dns_answer->CLASS = __bswap_16(DNS_ANSWER_CLASS_IN);
-            dns_answer->TTL = (uint32_t)0x00000000; /* no caching. Avoids DNS poisoning since this is a DNS hijack */
-            dn
292D
s_answer->RDLENGTH = __bswap_16(0x0004); /* 4 byte => size of an ipv4 address */
-            dns_answer->RDATA = ip_resolved.addr;
 
-            err = sendto(socket_fd, response, length+sizeof(dns_answer_t), 0, (struct sockaddr *)&client, client_len);
-            if (err < 0) {
-            	ESP_LOGE(TAG, "UDP sendto failed: %d", err);
+            if(valid_request){
+                if(include_answer){
+                    /* create DNS answer at the end of the query*/
+                    dns_answer_t *dns_answer = (dns_answer_t*)&response[length];
+                    dns_answer->NAME = __bswap_16(0xC00C); /* This is a pointer to the beginning of the question. As per DNS standard, first two bits must be set to 11 for some odd reason hence 0xC0 */
+                    dns_answer->TYPE = __bswap_16(DNS_ANSWER_TYPE_A);
+                    dns_answer->CLASS = __bswap_16(DNS_ANSWER_CLASS_IN);
+                    dns_answer->TTL = __bswap_32(0x00000005); /* set TTL to something small but not 0 to placate windows */
+                    dns_answer->RDLENGTH = __bswap_16(0x0004); /* 4 byte => size of an ipv4 address */
+                    dns_answer->RDATA = ip_resolved.addr;
+
+                    err = sendto(socket_fd, response, length+sizeof(dns_answer_t), 0, (struct sockaddr *)&client, client_len);
+                }else{
+                    dns_header->ANCount = 0x0000;
+                    err = sendto(socket_fd, response, length, 0, (struct sockaddr *)&client, client_len);
+                }
+                if (err < 0) {
+                    ESP_LOGE(TAG, "UDP sendto failed: %d", err);
+                }
             }
         }
 

diff --git a/src/http_app.c b/src/http_app.c
@@ -166,13 +166,9 @@ static esp_err_t http_server_post_handler(httpd_req_t *req){
 			httpd_req_get_hdr_value_str(req, "X-Custom-ssid", ssid, ssid_len+1);
 			httpd_req_get_hdr_value_str(req, "X-Custom-pwd", password, password_len+1);
 
-			wifi_config_t* config = wifi_manager_get_wifi_sta_config();
-			memset(config, 0x00, sizeof(wifi_config_t));
-			memcpy(config->sta.ssid, ssid, ssid_len);
-			memcpy(config->sta.password, password, password_len);
 			ESP_LOGI(TAG, "ssid: %s, password: %s", ssid, password);
 			ESP_LOGD(TAG, "http_server_post_handler: wifi_manager_connect_async() call");
-			wifi_manager_connect_async();
+			wifi_manager_connect_async(true, ssid, password);
 
 			/* free memory */
 			free(ssid);
@@ -427,6 +423,7 @@ void http_app_start(bool lru_purge_enable){
 		 * We could register all URLs one by one, but this would not work while the fake DNS is active */
 		config.uri_match_fn = httpd_uri_match_wildcard;
 		config.lru_purge_enable = lru_purge_enable;
+		config.max_open_sockets = 2;
 
 		/* generate the URLs */
 		if(http_root_url == NULL){

diff --git a/src/index.html b/src/index.html
@@ -40,6 +40,7 @@ <h2>Manual Connection</span></h2>
 						<input id="manual_pwd" type="password" placeholder="Password" value="">
 					</section>
 					<div class="buttons">
+							<input id="manual_togglepwd" class="big-button" type="button" value="Show password" /><br>
 							<input id="manual_join" type="button" value="Join" data-connect="manual" />
 							<input id="manual_cancel" type="button" value="Cancel"/>
 					</div>
@@ -53,6 +54,7 @@ <h2>Password for <span id="ssid-pwd"></span></h2>
 						<input id="pwd" type="password" placeholder="Password" value="">
 					</section>
 					<div class="buttons">
+							<input id="togglepwd" class="big-button" type="button" value="Show password" /><br>
 							<input id="join" type="button" value="Join" />
 							<input id="cancel" type="button" value="Cancel"/>
 					</div>

diff --git a/src/style.css b/src/style.css
@@ -28,6 +28,11 @@ input[type="button"] {
     text-align: center;
     display: block;
 }
+input[type="button"].big-button {
+    width: 90%;
+    max-width: 300px;
+    margin: auto;
+}
 p {
     padding: 10px;
 }