Allow configurable max hostname length

Author: rechrtb

components/tcpip_adapter/Kconfig

@@ -21,4 +21,11 @@ config TCPIP_ADAPTER_GLOBAL_DATA_LINK_IRAM
     help
         Link TCPIP adapter global data(.bss .data COMMON) from DRAM to IRAM.
 
+config TCPIP_ADAPTER_HOSTNAME_MAX_LENGTH
+    int "Max hostname length"
+    range 1 253
+    default 32
+    help
+        Maximum number of characters in the local hostname
+
 endmenu

components/tcpip_adapter/include/tcpip_adapter.h

@@ -609,7 +609,6 @@ esp_interface_t tcpip_adapter_get_esp_if(void *dev);
  */
 esp_err_t tcpip_adapter_get_sta_list(wifi_sta_list_t *wifi_sta_list, tcpip_adapter_sta_list_t *tcpip_sta_list);
 
-#define TCPIP_HOSTNAME_MAX_SIZE    32
 /**
  * @brief  Set the hostname to the interface
  *

components/tcpip_adapter/tcpip_adapter_lwip.c

@@ -46,6 +46,8 @@
 #include "FreeRTOS.h"
 #include "timers.h"
 
+#include "sdkconfig.h"
+
 struct tcpip_adapter_pbuf {
     struct pbuf_custom  pbuf;
 
@@ -1217,13 +1219,13 @@ esp_err_t tcpip_adapter_set_hostname(tcpip_adapter_if_t tcpip_if, const char *ho
 {
 #if LWIP_NETIF_HOSTNAME
     struct netif *p_netif;
-    static char hostinfo[TCPIP_ADAPTER_IF_MAX][TCPIP_HOSTNAME_MAX_SIZE + 1];
+    static char hostinfo[TCPIP_ADAPTER_IF_MAX][CONFIG_TCPIP_ADAPTER_HOSTNAME_MAX_LENGTH + 1];
 
     if (tcpip_if >= TCPIP_ADAPTER_IF_MAX || hostname == NULL) {
         return ESP_ERR_TCPIP_ADAPTER_INVALID_PARAMS;
     }
 
-    if (strlen(hostname) > TCPIP_HOSTNAME_MAX_SIZE) {
+    if (strlen(hostname) > CONFIG_TCPIP_ADAPTER_HOSTNAME_MAX_LENGTH) {
         return ESP_ERR_TCPIP_ADAPTER_INVALID_PARAMS;
     }