Add support for changing the hostname.

lib/system/system.toit

@@ -3,6 +3,12 @@
 // found in the lib/LICENSE file.
 
 import system.trace show send-trace-message
+import system.storage
+
+// Use lazy initialization to delay opening the storage bucket
+// until we need it the first time. From that point forward,
+// we keep it around forever.
+bucket_/storage.Bucket ::= storage.Bucket.open --flash "toitlang.org/system"
 
 /** The number of bits per byte. */
 BITS-PER-BYTE ::= 8
@@ -247,3 +253,28 @@ If the program is run as an executable, this is the fully resolved path to the
 */
 program-path -> string?:
   #primitive.core.program-path
+
+/**
+The hostname of the machine running the program.
+*/
+hostname -> string:
+  if platform == PLATFORM-FREERTOS:
+    config-name := bucket_.get "hostname"
+    if config-name: return config-name
+  return hostname_
+
+/**
+Sets the hostname of the machine running the program.
+
+This operation is not supported on all platforms.
+
+Only new network connections will use the new hostname. Also, some
+  routers may cache the old hostname for a while.
+*/
+hostname= hostname/string -> none:
+  if platform != PLATFORM-FREERTOS:
+    throw "Setting hostname is not supported on this platform"
+  bucket_["hostname"] = hostname
+
+hostname_ -> string:
+  #primitive.core.hostname

src/compiler/propagation/type_primitive_core.cc

@@ -290,6 +290,8 @@ TYPE_PRIMITIVE_ANY(firmware_mapping_at)
 TYPE_PRIMITIVE_ANY(firmware_mapping_copy)
 TYPE_PRIMITIVE_BYTE_ARRAY(rtc_user_bytes)
 
+TYPE_PRIMITIVE_STRING(hostname)
+
 bool TypePrimitive::uses_entry_task(unsigned module, unsigned index) {
   return module == INDEX_core && index == CoreIndexes::task_new;
 }

src/compiler/propagation/type_primitive_ethernet.cc

@@ -27,6 +27,7 @@ TYPE_PRIMITIVE_ANY(connect)
 TYPE_PRIMITIVE_ANY(setup_ip)
 TYPE_PRIMITIVE_ANY(disconnect)
 TYPE_PRIMITIVE_ANY(get_ip)
+TYPE_PRIMITIVE_ANY(set_hostname)
 
 }  // namespace toit::compiler
 }  // namespace toit

src/compiler/propagation/type_primitive_wifi.cc

@@ -31,6 +31,7 @@ TYPE_PRIMITIVE_ANY(get_ip)
 TYPE_PRIMITIVE_ANY(init_scan)
 TYPE_PRIMITIVE_ANY(start_scan)
 TYPE_PRIMITIVE_ANY(read_scan)
+TYPE_PRIMITIVE_ANY(set_hostname)
 TYPE_PRIMITIVE_ARRAY(ap_info)
 
 }  // namespace toit::compiler

src/primitive.h

@@ -256,6 +256,7 @@ namespace toit {
   PRIMITIVE(firmware_mapping_at, 2)          \
   PRIMITIVE(firmware_mapping_copy, 5)        \
   PRIMITIVE(rtc_user_bytes, 0)               \
+  PRIMITIVE(hostname, 0)                     \
 
 #define MODULE_TIMER(PRIMITIVE)              \
   PRIMITIVE(init, 0)                         \
@@ -324,6 +325,7 @@ namespace toit {
   PRIMITIVE(init_scan, 1)                    \
   PRIMITIVE(start_scan, 4)                   \
   PRIMITIVE(read_scan, 1)                    \
+  PRIMITIVE(set_hostname, 2)                 \
   PRIMITIVE(ap_info, 1)                      \
 
 #define MODULE_ETHERNET(PRIMITIVE)           \
@@ -334,6 +336,7 @@ namespace toit {
   PRIMITIVE(setup_ip, 1)                     \
   PRIMITIVE(disconnect, 2)                   \
   PRIMITIVE(get_ip, 1)                       \
+  PRIMITIVE(set_hostname, 2)                 \
 
 #define MODULE_BLE(PRIMITIVE)                \
   PRIMITIVE(init, 0)                         \

src/primitive_core.cc

@@ -2571,4 +2571,19 @@ PRIMITIVE(rtc_user_bytes) {
 }
 #endif
 
+PRIMITIVE(hostname) {
+  const char* name;
+#ifdef TOIT_ESP32
+  name = CONFIG_LWIP_LOCAL_HOSTNAME;
+#else
+  char buffer[HOST_NAME_MAX + 1];
+  int result = gethostname(buffer, sizeof(buffer));
+  if (result != 0) {
+    return Primitive::os_error(errno, process);
+  }
+  name = buffer;
+#endif
+  return process->allocate_string_or_error(name);
+}
+
 } // namespace toit

src/resources/ethernet_esp32.cc

@@ -91,6 +91,10 @@ class EthernetResourceGroup : public ResourceGroup {
 
   uint32_t on_event(Resource* resource, word data, uint32_t state);
 
+  esp_err_t set_hostname(const char* hostname) {
+    return esp_netif_set_hostname(netif_, hostname);
+  }
+
  private:
   int id_;
   esp_eth_mac_t* mac_;
@@ -449,6 +453,16 @@ PRIMITIVE(get_ip) {
   return result;
 }
 
+PRIMITIVE(set_hostname) {
+  ARGS(EthernetResourceGroup, group, cstring, hostname);
+
+  if (strlen(hostname) > 32) FAIL(INVALID_ARGUMENT);
+
+  esp_err_t err = group->set_hostname(hostname);
+  if (err != ESP_OK) return Primitive::os_error(err, process);
+
+  return process->null_object();
+}
 
 } // namespace toit
 

src/resources/wifi_esp32.cc

@@ -82,6 +82,10 @@ class WifiResourceGroup : public ResourceGroup {
 
   esp_err_t start_scan(bool passive, int channel, uint32_t period_ms);
 
+  esp_err_t set_hostname(const char* hostname) {
+    return esp_netif_set_hostname(netif_, hostname);
+  }
+
   ~WifiResourceGroup() {
     esp_err_t err = ESP_OK;
     for (int i = 0; i < DEINIT_ATTEMPTS; i++) {
@@ -464,7 +468,6 @@ esp_err_t WifiResourceGroup::start_scan(bool passive, int channel, uint32_t peri
   return esp_wifi_scan_start(&config, false);
 }
 
-
 MODULE_IMPLEMENTATION(wifi, MODULE_WIFI)
 
 PRIMITIVE(init) {
@@ -763,6 +766,17 @@ PRIMITIVE(read_scan) {
   return ap_array;
 }
 
+PRIMITIVE(set_hostname) {
+  ARGS(WifiResourceGroup, group, cstring, hostname);
+
+  if (strlen(hostname) > 32) FAIL(INVALID_ARGUMENT);
+
+  esp_err_t err = group->set_hostname(hostname);
+  if (err != ESP_OK) return Primitive::os_error(err, process);
+
+  return process->null_object();
+}
+
 PRIMITIVE(ap_info) {
   ARGS(WifiResourceGroup, group);
 

system/extensions/esp32/wifi.toit

@@ -23,6 +23,7 @@ import net.udp
 import net.wifi
 
 import encoding.tison
+import system
 import system.assets
 import system.firmware
 import system.storage
@@ -226,6 +227,7 @@ class WifiModule implements NetworkModule:
     return address_
 
   connect -> none:
+    wifi-set-hostname_ resource-group_ system.hostname
     with-timeout WIFI-CONNECT-TIMEOUT_: wait-for-connected_
     if ap:
       wait-for-static-ip-address_
@@ -357,6 +359,9 @@ class WifiModule implements NetworkModule:
 wifi-init_ ap:
   #primitive.wifi.init
 
+wifi-set-hostname_ resource-group hostname:
+  #primitive.wifi.set-hostname
+
 wifi-close_ resource-group:
   #primitive.wifi.close
 

tests/hostname-test.toit

@@ -0,0 +1,19 @@
+// Copyright (C) 2024 Toitware ApS.
+// Use of this source code is governed by a Zero-Clause BSD license that can
+// be found in the tests/LICENSE file.
+
+import expect show *
+import host.pipe
+import system
+
+main:
+  expected-hostname/string := ?
+  if system.platform == system.PLATFORM-WINDOWS:
+    expected-hostname = pipe.backticks "hostname"
+  else if system.platform == system.PLATFORM-LINUX:
+    expected-hostname = pipe.backticks "hostnamectl" "hostname"
+  else:
+    expected-hostname = pipe.backticks "hostname" "-s"
+  expected-hostname = expected-hostname.trim
+
+  expect-equals expected-hostname system.hostname