Implement DNS resolution

```
>>> s = socketpool.SocketPool(wifi.radio)
>>> s.getaddrinfo("google.com", 80)
[(0, 0, 0, '', ('142.250.81.206', 80))]
```

ports/raspberrypi/Makefile

@@ -79,6 +79,7 @@ SRC_SDK_CYW43 := \
 	src/rp2_common/pico_lwip/random.c \
 
 SRC_LWIP := \
+	shared/netutils/netutils.c \
 	$(wildcard sdk/lib/lwip/src/core/*.c) \
 	$(wildcard sdk/lib/lwip/src/core/ipv4/*.c) \
 	sdk/lib/lwip/src/netif/ethernet.c \

ports/raspberrypi/boards/raspberry_pi_pico_w/mpconfigboard.mk

@@ -15,7 +15,7 @@ CIRCUITPY_SSL = 0
 CIRCUITPY_HASHLIB = 0
 CIRCUITPY_WEB_WORKFLOW = 0
 CIRCUITPY_MDNS = 0
-CIRCUITPY_SOCKETPOOL = 0
+CIRCUITPY_SOCKETPOOL = 1
 CIRCUITPY_WIFI = 1
 
 CFLAGS += -DCYW43_PIN_WL_HOST_WAKE=24 -DCYW43_PIN_WL_REG_ON=23 -DCYW43_WL_GPIO_COUNT=3 -DCYW43_WL_GPIO_LED_PIN=0

ports/raspberrypi/common-hal/socketpool/Socket.c

@@ -0,0 +1,165 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2020 Lucian Copeland for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "shared-bindings/socketpool/Socket.h"
+
+#include "shared/runtime/interrupt_char.h"
+#include "py/mperrno.h"
+#include "py/runtime.h"
+#include "shared-bindings/socketpool/SocketPool.h"
+#include "supervisor/port.h"
+#include "supervisor/shared/tick.h"
+#include "supervisor/workflow.h"
+
+#include "lwip/err.h"
+#include "lwip/sys.h"
+#include "lwip/netdb.h"
+
+#define MAX_SOCKETS (8)
+
+STATIC mp_obj_t open_socket_objs[MAX_SOCKETS];
+STATIC bool user_socket[MAX_SOCKETS];
+
+void socket_user_reset(void) {
+    for (size_t i = 0; i < MP_ARRAY_SIZE(open_socket_objs); i++) {
+        if (open_socket_objs[i] && user_socket[i]) {
+            // shut 'er down
+        }
+    }
+}
+
+// The writes below send an event to the socket select task so that it redoes the
+// select with the new open socket set.
+
+STATIC bool register_open_socket(mp_obj_t obj) {
+    for (size_t i = 0; i < MP_ARRAY_SIZE(open_socket_objs); i++) {
+        if (!open_socket_objs[i]) {
+            open_socket_objs[i] = obj;
+            user_socket[i] = false;
+            return true;
+        }
+    }
+    return false;
+}
+
+STATIC void unregister_open_socket(mp_obj_t obj) {
+    for (size_t i = 0; i < MP_ARRAY_SIZE(open_socket_objs); i++) {
+        if (open_socket_objs[i] == obj) {
+            open_socket_objs[i] = NULL;
+            user_socket[i] = false;
+        }
+    }
+}
+
+STATIC void mark_user_socket(mp_obj_t obj) {
+    for (size_t i = 0; i < MP_ARRAY_SIZE(open_socket_objs); i++) {
+        if (open_socket_objs[i] == obj) {
+            user_socket[i] = true;
+            return;
+        }
+    }
+}
+
+bool socketpool_socket(socketpool_socketpool_obj_t *self,
+    socketpool_socketpool_addressfamily_t family, socketpool_socketpool_sock_t type,
+    socketpool_socket_obj_t *sock) {
+    mp_raise_NotImplementedError(NULL);
+}
+
+socketpool_socket_obj_t *common_hal_socketpool_socket(socketpool_socketpool_obj_t *self,
+    socketpool_socketpool_addressfamily_t family, socketpool_socketpool_sock_t type) {
+    mp_raise_NotImplementedError(NULL);
+}
+
+int socketpool_socket_accept(socketpool_socket_obj_t *self, uint8_t *ip, uint32_t *port) {
+    mp_raise_NotImplementedError(NULL);
+}
+
+socketpool_socket_obj_t *common_hal_socketpool_socket_accept(socketpool_socket_obj_t *self,
+    uint8_t *ip, uint32_t *port) {
+    mp_raise_NotImplementedError(NULL);
+}
+
+bool common_hal_socketpool_socket_bind(socketpool_socket_obj_t *self,
+    const char *host, size_t hostlen, uint32_t port) {
+    mp_raise_NotImplementedError(NULL);
+}
+
+void socketpool_socket_close(socketpool_socket_obj_t *self) {
+    mp_raise_NotImplementedError(NULL);
+}
+
+void common_hal_socketpool_socket_close(socketpool_socket_obj_t *self) {
+    mp_raise_NotImplementedError(NULL);
+}
+
+void common_hal_socketpool_socket_connect(socketpool_socket_obj_t *self,
+    const char *host, size_t hostlen, uint32_t port) {
+    mp_raise_NotImplementedError(NULL);
+}
+
+bool common_hal_socketpool_socket_get_closed(socketpool_socket_obj_t *self) {
+    mp_raise_NotImplementedError(NULL);
+}
+
+bool common_hal_socketpool_socket_get_connected(socketpool_socket_obj_t *self) {
+    mp_raise_NotImplementedError(NULL);
+}
+
+bool common_hal_socketpool_socket_listen(socketpool_socket_obj_t *self, int backlog) {
+    mp_raise_NotImplementedError(NULL);
+}
+
+mp_uint_t common_hal_socketpool_socket_recvfrom_into(socketpool_socket_obj_t *self,
+    uint8_t *buf, uint32_t len, uint8_t *ip, uint32_t *port) {
+    mp_raise_NotImplementedError(NULL);
+}
+
+int socketpool_socket_recv_into(socketpool_socket_obj_t *self,
+    const uint8_t *buf, uint32_t len) {
+    mp_raise_NotImplementedError(NULL);
+}
+
+mp_uint_t common_hal_socketpool_socket_recv_into(socketpool_socket_obj_t *self, const uint8_t *buf, uint32_t len) {
+    mp_raise_NotImplementedError(NULL);
+}
+
+int socketpool_socket_send(socketpool_socket_obj_t *self, const uint8_t *buf, uint32_t len) {
+    mp_raise_NotImplementedError(NULL);
+}
+
+mp_uint_t common_hal_socketpool_socket_send(socketpool_socket_obj_t *self, const uint8_t *buf, uint32_t len) {
+    mp_raise_NotImplementedError(NULL);
+}
+
+mp_uint_t common_hal_socketpool_socket_sendto(socketpool_socket_obj_t *self,
+    const char *host, size_t hostlen, uint32_t port, const uint8_t *buf, uint32_t len) {
+    mp_raise_NotImplementedError(NULL);
+}
+
+void common_hal_socketpool_socket_settimeout(socketpool_socket_obj_t *self, uint32_t timeout_ms) {
+    mp_raise_NotImplementedError(NULL);
+}

ports/raspberrypi/common-hal/socketpool/Socket.h

@@ -0,0 +1,77 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2013-2019 Damien P. George
+ * Copyright (c) 2015 Galen Hazelwood
+ * Copyright (c) 2015-2017 Paul Sokolovsky
+ * Copyright (c) 2022 Jeff Epler for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#pragma once
+
+#include "py/obj.h"
+
+#include "common-hal/socketpool/SocketPool.h"
+
+typedef struct _lwip_socket_obj_t {
+    mp_obj_base_t base;
+
+    volatile union {
+        struct tcp_pcb *tcp;
+        struct udp_pcb *udp;
+        struct raw_pcb *raw;
+    } pcb;
+    volatile union {
+        struct pbuf *pbuf;
+        struct {
+            uint8_t alloc;
+            uint8_t iget;
+            uint8_t iput;
+            union {
+                struct tcp_pcb *item; // if alloc == 0
+                struct tcp_pcb **array; // if alloc != 0
+            } tcp;
+        } connection;
+    } incoming;
+    mp_obj_t callback;
+    byte peer[4];
+    mp_uint_t peer_port;
+    mp_uint_t timeout;
+    uint16_t recv_offset;
+
+    uint8_t domain;
+    uint8_t type;
+
+    #define STATE_NEW 0
+    #define STATE_LISTENING 1
+    #define STATE_CONNECTING 2
+    #define STATE_CONNECTED 3
+    #define STATE_PEER_CLOSED 4
+    #define STATE_ACTIVE_UDP 5
+    // Negative value is lwIP error
+    int8_t state;
+
+    socketpool_socketpool_obj_t *pool;
+} socketpool_socket_obj_t;
+
+void socket_user_reset(void);

ports/raspberrypi/common-hal/socketpool/SocketPool.c

@@ -0,0 +1,97 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2020 Scott Shawcroft for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "shared-bindings/socketpool/SocketPool.h"
+#include "common-hal/socketpool/Socket.h"
+#include "shared/runtime/interrupt_char.h"
+#include "py/runtime.h"
+#include "shared-bindings/wifi/__init__.h"
+
+#include "lwip/dns.h"
+#include "lwip/inet.h"
+
+void common_hal_socketpool_socketpool_construct(socketpool_socketpool_obj_t *self, mp_obj_t radio) {
+    if (radio != MP_OBJ_FROM_PTR(&common_hal_wifi_radio_obj)) {
+        mp_raise_ValueError(translate("SocketPool can only be used with wifi.radio"));
+    }
+}
+
+// common_hal_socketpool_socket is in socketpool/Socket.c to centralize open socket tracking.
+
+typedef struct _getaddrinfo_state_t {
+    volatile int status;
+    volatile ip_addr_t ipaddr;
+} getaddrinfo_state_t;
+
+STATIC void lwip_getaddrinfo_cb(const char *name, const ip_addr_t *ipaddr, void *arg) {
+    getaddrinfo_state_t *state = arg;
+    if (ipaddr != NULL) {
+        state->status = 1;
+        state->ipaddr = *ipaddr;
+    } else {
+        // error
+        state->status = -2;
+    }
+}
+
+mp_obj_t common_hal_socketpool_socketpool_gethostbyname(socketpool_socketpool_obj_t *self,
+    const char *host) {
+
+    getaddrinfo_state_t state;
+    state.status = 0;
+
+    MICROPY_PY_LWIP_ENTER
+    err_t ret = dns_gethostbyname(host, (ip_addr_t *)&state.ipaddr, lwip_getaddrinfo_cb, &state);
+    MICROPY_PY_LWIP_EXIT
+
+    switch (ret) {
+        case ERR_OK:
+            // cached
+            state.status = 1;
+            break;
+        case ERR_INPROGRESS:
+            while (state.status == 0) {
+                RUN_BACKGROUND_TASKS;
+                if (mp_hal_is_interrupted()) {
+                    break;
+                }
+            }
+            break;
+        default:
+            state.status = ret;
+    }
+
+    if (state.status < 0) {
+        // TODO: CPython raises gaierror, we raise with native lwIP negative error
+        // values, to differentiate from normal errno's at least in such way.
+        mp_raise_OSError(state.status);
+    }
+
+    char ip_str[IP4ADDR_STRLEN_MAX];
+    inet_ntoa_r(state.ipaddr, ip_str, IP4ADDR_STRLEN_MAX);
+    mp_obj_t ip_obj = mp_obj_new_str(ip_str, strlen(ip_str));
+    return ip_obj;
+}

ports/raspberrypi/common-hal/socketpool/SocketPool.h

@@ -0,0 +1,33 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2020 Scott Shawcroft for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#pragma once
+
+#include "py/obj.h"
+
+typedef struct {
+    mp_obj_base_t base;
+} socketpool_socketpool_obj_t;

ports/raspberrypi/common-hal/socketpool/__init__.c

@@ -0,0 +1,33 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2020 Scott Shawcroft for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "shared-bindings/socketpool/__init__.h"
+
+#include "common-hal/socketpool/Socket.h"
+
+void socketpool_user_reset(void) {
+    socket_user_reset();
+}

ports/raspberrypi/common-hal/socketpool/__init__.h

@@ -0,0 +1,27 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2020 Scott Shawcroft for Adafruit Industries
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#pragma once

ports/raspberrypi/common-hal/wifi/Radio.c

@@ -271,17 +271,17 @@ mp_int_t common_hal_wifi_radio_ping(wifi_radio_obj_t *self, mp_obj_t ip_address,
     ipaddress_ipaddress_to_lwip(ip_address, &ping_addr);
 
     struct raw_pcb *ping_pcb;
-    MICROPY_PY_LWIP_ENTER();
-    ping_pcb = raw_new(IP_PROTO_ICMP);
+    MICROPY_PY_LWIP_ENTER
+        ping_pcb = raw_new(IP_PROTO_ICMP);
     if (!ping_pcb) {
-        MICROPY_PY_LWIP_EXIT();
+        MICROPY_PY_LWIP_EXIT
         return -1;
     }
     raw_recv(ping_pcb, ping_recv, NULL);
     raw_bind(ping_pcb, IP_ADDR_ANY);
-    MICROPY_PY_LWIP_EXIT();
+    MICROPY_PY_LWIP_EXIT
 
-    ping_received = false;
+        ping_received = false;
     ping_send(ping_pcb, &ping_addr);
     size_t timeout_ms = (size_t)MICROPY_FLOAT_C_FUN(ceil)(timeout * 1000);
     uint64_t start = port_get_raw_ticks(NULL);
@@ -298,9 +298,9 @@ mp_int_t common_hal_wifi_radio_ping(wifi_radio_obj_t *self, mp_obj_t ip_address,
         result = now - start;
     }
 
-    MICROPY_PY_LWIP_ENTER();
+    MICROPY_PY_LWIP_ENTER;
     raw_remove(ping_pcb);
-    MICROPY_PY_LWIP_EXIT();
+    MICROPY_PY_LWIP_EXIT;
 
     return result;
 }

ports/raspberrypi/lwip_inc/lwipopts.h

@@ -89,4 +89,6 @@
 
 #define LWIP_TIMEVAL_PRIVATE 0
 
+#define LWIP_NO_CTYPE_H 1
+
 #endif /* __LWIPOPTS_H__ */

ports/raspberrypi/mpconfigport.h

@@ -51,10 +51,9 @@
 
 #if CIRCUITPY_CYW43
 #include "pico/cyw43_arch.h"
-#undef _L // interferes with ulab, indirectly defined in ctype.h, is ulab bug to use identifier _L
-#define MICROPY_PY_LWIP_ENTER   cyw43_arch_lwip_begin
+#define MICROPY_PY_LWIP_ENTER   cyw43_arch_lwip_begin();
 #define MICROPY_PY_LWIP_REENTER MICROPY_PY_LWIP_ENTER
-#define MICROPY_PY_LWIP_EXIT    cyw43_arch_lwip_end
+#define MICROPY_PY_LWIP_EXIT    cyw43_arch_lwip_end();
 #endif
 
 #endif  // __INCLUDED_MPCONFIGPORT_H

shared-bindings/socketpool/Socket.c

@@ -184,7 +184,7 @@ STATIC mp_obj_t socketpool_socket_recvfrom_into(mp_obj_t self_in, mp_obj_t data_
     mp_get_buffer_raise(data_in, &bufinfo, MP_BUFFER_WRITE);
 
     byte ip[4];
-    mp_uint_t port;
+    uint32_t port;
     mp_int_t ret = common_hal_socketpool_socket_recvfrom_into(self,
         (byte *)bufinfo.buf, bufinfo.len, ip, &port);
     mp_obj_t tuple_contents[2];