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Merged
merged 1 commit into from
Jun 7, 2025
Merged

Set pico_w unique dhcp_hostname or configured hostname #1563

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4 changes: 4 additions & 0 deletions CHANGELOG.md
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Original file line number Diff line number Diff line change
Expand Up @@ -16,6 +16,7 @@ with nodejs and emscripten)
- Added `uart:read/2` with a timeout parameter.
- Missing `erlang:is_function/2` BIF
- Added `erlang:is_record/2`
- Added ability to set per-interface `dhcp_hostname` on Pico W if present in config.

### Fixed

Expand Down Expand Up @@ -67,6 +68,9 @@ memory error
- Fixed nif_atomvm_posix_read GC bug
- Fixed `erlang:is_number/1` function, now returns true also for floats
- Fixed unlink protocol and add support for `link/1` on ports
- Correctly set Pico-W unique dhcp hostname when using the default, previously all rp2040 devices
used the same "PicoW" dhcp hostname, causing collisions when multiple rp2040 are on the same
network. (See issue #1094)

### Changed

Expand Down
148 changes: 118 additions & 30 deletions src/platforms/rp2040/src/lib/networkdriver.c
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Original file line number Diff line number Diff line change
Expand Up @@ -35,16 +35,20 @@
#include <hardware/rtc.h>
#include <lwip/apps/sntp.h>
#include <pico/cyw43_arch.h>
#include <string.h>

#pragma GCC diagnostic pop

#define PORT_REPLY_SIZE (TUPLE_SIZE(2) + REF_SIZE)
#define DEFAULT_HOSTNAME_FMT "atomvm-%02x%02x%02x%02x%02x%02x"
#define DEFAULT_HOSTNAME_SIZE (strlen("atomvm-") + 12 + 1)

static const char *const ap_atom = ATOM_STR("\x2", "ap");
static const char *const ap_channel_atom = ATOM_STR("\xA", "ap_channel");
static const char *const ap_sta_connected_atom = ATOM_STR("\x10", "ap_sta_connected");
static const char *const ap_sta_disconnected_atom = ATOM_STR("\x13", "ap_sta_disconnected");
static const char *const ap_started_atom = ATOM_STR("\xA", "ap_started");
static const char *const dhcp_hostname_atom = ATOM_STR("\xD", "dhcp_hostname");
static const char *const host_atom = ATOM_STR("\x4", "host");
static const char *const psk_atom = ATOM_STR("\x3", "psk");
static const char *const sntp_atom = ATOM_STR("\x4", "sntp");
Expand Down Expand Up @@ -79,6 +83,8 @@ struct NetworkDriverData
int stas_count;
uint8_t *stas_mac;
struct dhcp_config *dhcp_config;
char *hostname;
char *ap_hostname;
queue_t queue;
};

Expand All @@ -100,6 +106,14 @@ struct NetworkDriverEvent
};
};

enum DriverErrorCodeType
{
DriverOK,
DriverBADARG,
DriverMACError,
DriverOOM
};

// Callbacks do not allow for user data
// netif->state is actually pointing to &cyw43_state
static struct NetworkDriverData *driver_data;
Expand All @@ -120,6 +134,26 @@ static term tuple_from_addr(Heap *heap, uint32_t addr)
return port_heap_create_tuple_n(heap, 4, terms);
}

static term error_code_to_term(int error, GlobalContext *global)
{
switch (error) {
case DriverOK:
return OK_ATOM;
break;
case DriverBADARG:
return BADARG_ATOM;
break;
case DriverMACError:
return globalcontext_make_atom(global, ATOM_STR("\x10", "device_mac_error"));
break;
case DriverOOM:
return OUT_OF_MEMORY_ATOM;
break;
default:
return BADARG_ATOM;
}
}

static void send_term(Heap *heap, term t)
{
term ref = term_from_ref_ticks(driver_data->ref_ticks, heap);
Expand Down Expand Up @@ -211,15 +245,60 @@ static void send_sntp_sync(struct timeval *tv)
END_WITH_STACK_HEAP(heap, driver_data->global);
}

static enum DriverErrorCodeType write_default_device_name(size_t size, char **out)
{
uint8_t mac[6];
// Device name is used for AP mode ssid (if undefined), and for the
// default dhcp_hostname on both interfaces. It seems the interface
// parameter is ignored and both interfaces have the same MAC address.
int err = cyw43_wifi_get_mac(&cyw43_state, CYW43_ITF_STA, mac);
if (UNLIKELY(err)) {
return DriverMACError;
}
*out = malloc(size);
if (IS_NULL_PTR(out)) {
return DriverOOM;
}
snprintf(*out, size,
DEFAULT_HOSTNAME_FMT, mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
return DriverOK;
}

static enum DriverErrorCodeType set_interface_dhcp_name(term dhcp_name, char **out)
{
if (term_is_invalid_term(dhcp_name)) {
enum DriverErrorCodeType ok_ret = write_default_device_name(DEFAULT_HOSTNAME_SIZE, out);
if (UNLIKELY(ok_ret != DriverOK)) {
free(out);
cyw43_arch_disable_sta_mode();
return ok_ret;
}
} else {
int ok = 0;
*out = interop_term_to_string(dhcp_name, &ok);
if (!ok || IS_NULL_PTR(out)) {
if (out != NULL) {
free(out);
cyw43_arch_disable_sta_mode();
return DriverBADARG;
}
cyw43_arch_disable_sta_mode();
return DriverOOM;
}
}
return DriverOK;
}

static term start_sta(term sta_config, GlobalContext *global)
{
term ssid_term = interop_kv_get_value(sta_config, ssid_atom, global);
term pass_term = interop_kv_get_value(sta_config, psk_atom, global);
term hostname_term = interop_kv_get_value(sta_config, dhcp_hostname_atom, global);

//
// Check parameters
//
if (term_is_invalid_term(ssid_term)) {
if (UNLIKELY(term_is_invalid_term(ssid_term))) {
return BADARG_ATOM;
}
int ok = 0;
Expand All @@ -230,13 +309,21 @@ static term start_sta(term sta_config, GlobalContext *global)
char *psk = NULL;
if (!term_is_invalid_term(pass_term)) {
psk = interop_term_to_string(pass_term, &ok);
if (!ok) {
if (UNLIKELY(!ok)) {
free(ssid);
return BADARG_ATOM;
}
}

cyw43_arch_enable_sta_mode();
enum DriverErrorCodeType ret = set_interface_dhcp_name(hostname_term, &driver_data->hostname);
if (UNLIKELY(ret != DriverOK)) {
free(ssid);
free(psk);
return error_code_to_term(ret, global);
}

netif_set_hostname(&cyw43_state.netif[CYW43_ITF_STA], driver_data->hostname);

uint32_t auth = (psk == NULL) ? CYW43_AUTH_OPEN : CYW43_AUTH_WPA2_MIXED_PSK;
int result = cyw43_arch_wifi_connect_async(ssid, psk, auth);
// We need to set the callback after calling connect async because it's
Expand All @@ -247,32 +334,14 @@ static term start_sta(term sta_config, GlobalContext *global)
free(ssid);
free(psk);
if (result != 0) {
free(driver_data->hostname);
cyw43_arch_disable_sta_mode();
return BADARG_ATOM;
}

return OK_ATOM;
}

static char *get_default_device_name()
{
uint8_t mac[6];
// Device name is used for AP mode. It seems the interface parameter is
// ignored and both interfaces have the same MAC address.
int err = cyw43_wifi_get_mac(&cyw43_state, CYW43_ITF_AP, mac);
if (err) {
return NULL;
}

size_t buf_size = strlen("atomvm-") + 12 + 1;
char *buf = malloc(buf_size);
if (IS_NULL_PTR(buf)) {
return NULL;
}
snprintf(buf, buf_size,
"atomvm-%02x%02x%02x%02x%02x%02x", mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
return buf;
}

static void network_driver_do_cyw43_assoc(GlobalContext *glb)
{
int max_stas;
Expand Down Expand Up @@ -384,13 +453,18 @@ static term start_ap(term ap_config, GlobalContext *global)
term ssid_term = interop_kv_get_value(ap_config, ssid_atom, global);
term pass_term = interop_kv_get_value(ap_config, psk_atom, global);
term channel_term = interop_kv_get_value(ap_config, ap_channel_atom, global);
term hostname_term = interop_kv_get_value(ap_config, dhcp_hostname_atom, global);

//
// Check parameters
//
char *ssid = NULL;
if (term_is_invalid_term(ssid_term)) {
ssid = get_default_device_name();
enum DriverErrorCodeType ret = write_default_device_name(DEFAULT_HOSTNAME_SIZE, &ssid);
if (UNLIKELY(ret != DriverOK)) {
free(ssid);
return error_code_to_term(ret, global);
}
} else {
int ok = 0;
ssid = interop_term_to_string(ssid_term, &ok);
Expand All @@ -402,11 +476,11 @@ static term start_ap(term ap_config, GlobalContext *global)
if (!term_is_invalid_term(pass_term)) {
int ok = 0;
psk = interop_term_to_string(pass_term, &ok);
if (strlen(psk) < 8) {
if (UNLIKELY(strlen(psk) < 8)) {
free(ssid);
return BADARG_ATOM;
}
if (!ok) {
if (UNLIKELY(!ok)) {
free(ssid);
return BADARG_ATOM;
}
Expand All @@ -419,9 +493,18 @@ static term start_ap(term ap_config, GlobalContext *global)
}
}

enum DriverErrorCodeType ret = set_interface_dhcp_name(hostname_term, &driver_data->ap_hostname);
if (UNLIKELY(ret != DriverOK)) {
free(ssid);
free(psk);
return error_code_to_term(ret, global);
}

uint32_t auth = (psk == NULL) ? CYW43_AUTH_OPEN : CYW43_AUTH_WPA2_AES_PSK;
cyw43_state.assoc_cb = network_driver_cyw43_assoc_cb;
cyw43_arch_enable_ap_mode(ssid, psk, auth);
// Set hostname after enabling AP mode otherwise hostname will revert to "PicoW"
netif_set_hostname(&cyw43_state.netif[CYW43_ITF_AP], driver_data->ap_hostname);
send_ap_started(global);
free(ssid);
free(psk);
Expand Down Expand Up @@ -574,17 +657,18 @@ static void start_network(Context *ctx, term pid, term ref, term config)
return;
}

// Always enable sta mode so the bus is initialized and we get a MAC
// address. This is done before configuring the interface because the
// MAC is added to the default hostname, and default ssid in ap mode.
// (i.e. atomvm-0123456789ab)
cyw43_arch_enable_sta_mode();
if (!term_is_invalid_term(sta_config)) {
term result_atom = start_sta(sta_config, ctx->global);
if (result_atom != OK_ATOM) {
term error = port_create_error_tuple(ctx, result_atom);
port_send_reply(ctx, pid, ref, error);
return;
}
} else {
// Always enable sta mode so the bus is initialized and we get a MAC
// address.
cyw43_arch_enable_sta_mode();
}

if (!term_is_invalid_term(ap_config)) {
Expand Down Expand Up @@ -705,6 +789,10 @@ void network_driver_init(GlobalContext *global)
void network_driver_destroy(GlobalContext *global)
{
if (driver_data) {
free(driver_data->hostname);
if (driver_data->ap_hostname) {
free(driver_data->ap_hostname);
}
free(driver_data->sntp_hostname);
free(driver_data->stas_mac);
if (driver_data->dhcp_config) {
Expand Down