extmod/modnetwork: Implement IPv6 API to set and get NIC configuration.

This commit implements a new <AbstractNIC>.ipconfig() function for the NIC
classes that use lwIP, to set and retrieve network configuration for a NIC.
Currently this method supports:
- ipconfig("addr4"): obtain a tuple (addr, netmask) of the currently
  configured ipv4 address
- ipconfig("addr6"): obtain a list of tuples (addr, state,
  prefered_lifetime, valid_lifetime) of all currently active ipv6
  addresses; this includes static, slaac and link-local addresses
- ipconfig("has_dhcp4"): whether ipv4 dhcp has supplied an address
- ipconfig("has_autoconf6"): if there is a valid, non-static ipv6 address
- ipconfig(addr4="1.2.3.4/24"): to set the ipv4 address and netmask
- ipconfig(addr6="2a01::2"): to set a static ipv6 address; note that this
  does not configure an interface route, as this does not seem supported by
  lwIP
- ipconfig(autoconf6=True): to enable ipv6 network configuration with slaac
- ipconfig(gw4="1.2.3.1"): to set the ipv4 gateway
- ipconfig(dhcp4=True): enable ipv4 dhcp; this sets ipv4 address, netmask,
  gateway and a dns server
- ipconfig(dhcp4=False): stops dhcp, releases the ip, and clears the
  configured ipv4 address.
- ipconfig(dhcp6=True): enable stateless dhcpv6 to obtain a dns server

There is also a new global configuration function network.ipconfig() that
supports the following:
- network.ipconfig(dns="2a01::2"): set the primary dns server (can be a
  ipv4 or ipv6 address)
- network.ipconfig(prefer=6): to prefer ipv6 addresses to be returned as
  dns responses (falling back to ipv4 if the host does not have an ipv6
  address); note that this does not flush the dns cache, so if a host is
  already in the dns cache with its v4 address, subsequent lookups will
  return that address even if prefer=6 is set

This interface replaces NIC.ifconfig() completely, and ifconfig() should be
marked as deprecated and removed in a future version.

Signed-off-by: Felix Dörre <felix@dogcraft.de>

1 files changed, 296 insertions, 0 deletions

diff --git a/extmod/network_lwip.c b/extmod/network_lwip.c
index caa30f6fff..97cb43902d 100644
--- a/extmod/network_lwip.c
+++ b/extmod/network_lwip.c
@@ -26,6 +26,7 @@
 
 #include "py/runtime.h"
 #include "py/mphal.h"
+#include "py/parsenum.h"
 
 #if MICROPY_PY_NETWORK && MICROPY_PY_LWIP
 
@@ -40,9 +41,19 @@
 #include "lwip/timeouts.h"
 #include "lwip/dns.h"
 #include "lwip/dhcp.h"
+#include "lwip/nd6.h"
+#include "lwip/dhcp6.h"
+#include "lwip/prot/dhcp.h"
+#include "lwip/prot/dhcp6.h"
+#include <string.h>
+#include <stdlib.h>
+
+int mp_mod_network_prefer_dns_use_ip_version = 4;
 
 // Implementations of network methods that can be used by any interface.
 
+// This function provides the implementation of nic.ifconfig, is deprecated and will be removed.
+// Use network.ipconfig and nic.ipconfig instead.
 mp_obj_t mod_network_nic_ifconfig(struct netif *netif, size_t n_args, const mp_obj_t *args) {
     if (n_args == 0) {
         // Get IP addresses
@@ -90,6 +101,291 @@ mp_obj_t mod_network_nic_ifconfig(struct netif *netif, size_t n_args, const mp_o
     }
 }
 
+// This function provides the common implementation of network.ipconfig
+mp_obj_t mod_network_ipconfig(size_t n_args, const mp_obj_t *args, mp_map_t *kwargs) {
+    if (kwargs->used == 0) {
+        // Get config value
+        if (n_args != 1) {
+            mp_raise_TypeError(MP_ERROR_TEXT("must query one param"));
+        }
+
+        switch (mp_obj_str_get_qstr(args[0])) {
+            case MP_QSTR_dns: {
+                char addr_str[IPADDR_STRLEN_MAX];
+                ipaddr_ntoa_r(dns_getserver(0), addr_str, sizeof(addr_str));
+                return mp_obj_new_str(addr_str, strlen(addr_str));
+            }
+            case MP_QSTR_prefer: {
+                return MP_OBJ_NEW_SMALL_INT(mp_mod_network_prefer_dns_use_ip_version);
+            }
+            default: {
+                mp_raise_ValueError(MP_ERROR_TEXT("unexpected key"));
+                break;
+            }
+        }
+    } else {
+        // Set config value(s)
+        if (n_args != 0) {
+            mp_raise_TypeError(MP_ERROR_TEXT("can't specify pos and kw args"));
+        }
+
+        for (size_t i = 0; i < kwargs->alloc; ++i) {
+            if (MP_MAP_SLOT_IS_FILLED(kwargs, i)) {
+                mp_map_elem_t *e = &kwargs->table[i];
+                switch (mp_obj_str_get_qstr(e->key)) {
+                    case MP_QSTR_dns: {
+                        ip_addr_t dns;
+                        size_t addr_len;
+                        const char *addr_str = mp_obj_str_get_data(e->value, &addr_len);
+                        if (!ipaddr_aton(addr_str, &dns)) {
+                            mp_raise_ValueError(MP_ERROR_TEXT("invalid arguments as dns server"));
+                        }
+                        dns_setserver(0, &dns);
+                        break;
+                    }
+                    case MP_QSTR_prefer: {
+                        int value = mp_obj_get_int(e->value);
+                        if (value != 4 && value != 6) {
+                            mp_raise_ValueError(MP_ERROR_TEXT("invalid prefer argument"));
+                        }
+                        mp_mod_network_prefer_dns_use_ip_version = value;
+                        break;
+                    }
+                    default: {
+                        mp_raise_ValueError(MP_ERROR_TEXT("unexpected key"));
+                        break;
+                    }
+                }
+            }
+        }
+    }
+    return mp_const_none;
+}
+
+mp_obj_t mod_network_nic_ipconfig(struct netif *netif, size_t n_args, const mp_obj_t *args, mp_map_t *kwargs) {
+
+    if (kwargs->used == 0) {
+        // Get config value
+        if (n_args != 1) {
+            mp_raise_TypeError(MP_ERROR_TEXT("must query one param"));
+        }
+
+        switch (mp_obj_str_get_qstr(args[0])) {
+            case MP_QSTR_dhcp4: {
+                struct dhcp *dhcp = netif_dhcp_data(netif);
+                return mp_obj_new_bool(dhcp != NULL && dhcp->state != DHCP_STATE_OFF);
+            }
+            case MP_QSTR_has_dhcp4: {
+                return mp_obj_new_bool(dhcp_supplied_address(netif));
+            }
+            #if LWIP_IPV6_DHCP6
+            case MP_QSTR_dhcp6: {
+                struct dhcp6 *dhcp = netif_dhcp6_data(netif);
+                return mp_obj_new_bool(dhcp != NULL && dhcp->state != DHCP6_STATE_OFF);
+            }
+            #endif
+            #if LWIP_IPV6_AUTOCONFIG
+            case MP_QSTR_autoconf6: {
+                return netif->ip6_autoconfig_enabled ?  mp_const_true : mp_const_false;
+            }
+            case MP_QSTR_has_autoconf6: {
+                int found = 0;
+                for (int i = 1; i < LWIP_IPV6_NUM_ADDRESSES; i++) {
+                    if (ip6_addr_isvalid(netif_ip6_addr_state(netif, i)) &&
+                        !netif_ip6_addr_isstatic(netif, i)) {
+                        found = 1;
+                        break;
+                    }
+                }
+                if (found) {
+                    break;
+                }
+                return mp_obj_new_bool(found);
+            }
+            #endif
+            case MP_QSTR_addr4: {
+                mp_obj_t tuple[2] = {
+                    netutils_format_ipv4_addr((uint8_t *)&netif->ip_addr, NETUTILS_BIG),
+                    netutils_format_ipv4_addr((uint8_t *)&netif->netmask, NETUTILS_BIG),
+                };
+                return mp_obj_new_tuple(2, tuple);
+            }
+            #if LWIP_IPV6
+            case MP_QSTR_addr6: {
+                mp_obj_t addrs[LWIP_IPV6_NUM_ADDRESSES];
+                size_t n_addrs = 0;
+                for (int i = 0; i < LWIP_IPV6_NUM_ADDRESSES; i++) {
+                    if (ip6_addr_isvalid(netif_ip6_addr_state(netif, i))) {
+                        char addr_str[IPADDR_STRLEN_MAX];
+                        ipaddr_ntoa_r(netif_ip_addr6(netif, i), addr_str, sizeof(addr_str));
+                        mp_obj_t tuple[4] = {
+                            mp_obj_new_str(addr_str, strlen(addr_str)),
+                            MP_OBJ_NEW_SMALL_INT(netif_ip6_addr_state(netif, i)),
+                            MP_OBJ_NEW_SMALL_INT(netif_ip6_addr_pref_life(netif, i)), // preferred
+                            MP_OBJ_NEW_SMALL_INT(netif_ip6_addr_valid_life(netif, i))
+                        };
+                        addrs[n_addrs++] = mp_obj_new_tuple(4, tuple);
+                    }
+                }
+                return mp_obj_new_list(n_addrs, addrs);
+            }
+            #endif
+            case MP_QSTR_gw4: {
+                return netutils_format_ipv4_addr((uint8_t *)&netif->gw, NETUTILS_BIG);
+            }
+            default: {
+                mp_raise_ValueError(MP_ERROR_TEXT("unexpected key"));
+                break;
+            }
+        }
+        return mp_const_none;
+    } else {
+        // Set config value(s)
+        if (n_args != 0) {
+            mp_raise_TypeError(MP_ERROR_TEXT("can't specify pos and kw args"));
+        }
+
+        for (size_t i = 0; i < kwargs->alloc; ++i) {
+            if (MP_MAP_SLOT_IS_FILLED(kwargs, i)) {
+                mp_map_elem_t *e = &kwargs->table[i];
+                switch (mp_obj_str_get_qstr(e->key)) {
+                    case MP_QSTR_dhcp4: {
+                        if (mp_obj_is_true(e->value)) {
+                            if (dhcp_supplied_address(netif)) {
+                                dhcp_renew(netif);
+                            } else {
+                                dhcp_release_and_stop(netif);
+                                dhcp_start(netif);
+                            }
+                        } else {
+                            dhcp_release_and_stop(netif);
+                        }
+                        break;
+                    }
+                    #if LWIP_IPV6_DHCP6
+                    case MP_QSTR_dhcp6: {
+                        dhcp6_disable(netif);
+                        dhcp6_enable_stateless(netif);
+                        break;
+                    }
+                    #endif
+                    #if LWIP_IPV6_AUTOCONFIG
+                    case MP_QSTR_autoconf6: {
+                        netif_set_ip6_autoconfig_enabled(netif, mp_obj_is_true(e->value));
+                        if (mp_obj_is_true(e->value)) {
+                            nd6_restart_netif(netif);
+                        } else {
+                            // Clear out any non-static addresses, skip link-local address in slot 0
+                            for (i = 1; i < LWIP_IPV6_NUM_ADDRESSES; i++) {
+                                if (ip6_addr_isvalid(netif_ip6_addr_state(netif, i)) &&
+                                    !netif_ip6_addr_isstatic(netif, i)) {
+                                    netif_ip6_addr_set_state(netif, i, IP6_ADDR_INVALID);
+                                }
+                            }
+                        }
+                        break;
+                    }
+                    #endif
+                    case MP_QSTR_addr4:
+                    case MP_QSTR_addr6: {
+                        ip_addr_t ip_addr;
+                        ip_addr_t netmask;
+                        int prefix_bits = 32;
+                        if (e->value != mp_const_none && mp_obj_is_str(e->value)) {
+                            size_t addr_len;
+                            const char *input_str = mp_obj_str_get_data(e->value, &addr_len);
+                            char plain_ip[IPADDR_STRLEN_MAX];
+                            char *split = strchr(input_str, '/');
+                            const char *addr_str = input_str;
+                            if (split) {
+                                int to_copy = sizeof(plain_ip) - 1;
+                                if (split - addr_str < to_copy) {
+                                    to_copy = split - addr_str;
+                                }
+                                memcpy(plain_ip, addr_str, to_copy);
+                                mp_obj_t prefix_obj = mp_parse_num_integer(split + 1, strlen(split + 1), 10, NULL);
+                                prefix_bits = mp_obj_get_int(prefix_obj);
+                            }
+                            if (mp_obj_str_get_qstr(args[0]) == MP_QSTR_addr4) {
+                                uint32_t mask = -(1u << (32 - prefix_bits));
+                                ip_addr_set_ip4_u32_val(netmask, ((mask & 0xFF) << 24) | ((mask & 0xFF00) << 8) | ((mask >> 8) & 0xFF00) | ((mask >> 24) & 0xFF));
+                            }
+                            if (!ipaddr_aton(addr_str, &ip_addr)) {
+                                mp_raise_ValueError(MP_ERROR_TEXT("invalid arguments"));
+                            }
+                            if ((mp_obj_str_get_qstr(args[0]) == MP_QSTR_addr6) != IP_IS_V6(&ip_addr)
+                                || (mp_obj_str_get_qstr(args[0]) == MP_QSTR_addr4) != IP_IS_V4(&ip_addr)) {
+                                mp_raise_ValueError(MP_ERROR_TEXT("invalid address type"));
+                            }
+                        } else if (e->value != mp_const_none) {
+                            mp_obj_t *items;
+                            mp_obj_get_array_fixed_n(e->value, 2, &items);
+                            size_t addr_len;
+                            const char *ip_addr_str = mp_obj_str_get_data(items[0], &addr_len);
+                            const char *netmask_str = mp_obj_str_get_data(items[1], &addr_len);
+                            if (!ipaddr_aton(ip_addr_str, &ip_addr)) {
+                                mp_raise_ValueError(MP_ERROR_TEXT("invalid arguments"));
+                            }
+                            if (!ipaddr_aton(netmask_str, &netmask)) {
+                                mp_raise_ValueError(MP_ERROR_TEXT("invalid arguments"));
+                            }
+                            if (!IP_IS_V4(&ip_addr) || !IP_IS_V4(&netmask)) {
+                                mp_raise_ValueError(MP_ERROR_TEXT("invalid address type"));
+                            }
+                        }
+                        if (mp_obj_str_get_qstr(args[0]) == MP_QSTR_addr4) {
+                            if (e->value != mp_const_none) {
+                                netif->ip_addr = ip_addr;
+                                netif->netmask = netmask;
+                            } else {
+                                ip4_addr_set_any(ip_2_ip4(&netif->ip_addr));
+                                ip4_addr_set_any(ip_2_ip4(&netif->netmask));
+                            }
+                        #if LWIP_IPV6
+                        } else if (mp_obj_str_get_qstr(args[0]) == MP_QSTR_addr6) {
+                            // Clear out any existing static addresses. Address 0 comes from autoconf.
+                            for (i = 1; i < LWIP_IPV6_NUM_ADDRESSES; i++) {
+                                if (ip6_addr_isvalid(netif_ip6_addr_state(netif, i)) &&
+                                    netif_ip6_addr_isstatic(netif, i)) {
+                                    netif_ip6_addr_set_state(netif, i, IP6_ADDR_INVALID);
+                                }
+                            }
+                            if (e->value != mp_const_none) {
+                                s8_t free_idx;
+                                netif_add_ip6_address(netif, ip_2_ip6(&ip_addr), &free_idx);
+                                netif_ip6_addr_set_valid_life(netif, free_idx, IP6_ADDR_LIFE_STATIC);
+                                netif_ip6_addr_set_pref_life(netif, free_idx, IP6_ADDR_LIFE_STATIC);
+                                netif_ip6_addr_set_state(netif, free_idx, IP6_ADDR_PREFERRED);
+                            }
+                        #endif
+                        }
+                        break;
+                    }
+                    case MP_QSTR_gw4: {
+                        ip_addr_t ip_addr;
+                        size_t addr_len;
+                        const char *addr_str = mp_obj_str_get_data(e->value, &addr_len);
+                        if (!ipaddr_aton(addr_str, &ip_addr)) {
+                            mp_raise_ValueError(MP_ERROR_TEXT("invalid arguments"));
+                        }
+                        if (IP_IS_V4(&ip_addr)) {
+                            netif->gw = ip_addr;
+                        } else {
+                            mp_raise_ValueError(MP_ERROR_TEXT("invalid address type"));
+                        }
+                        break;
+                    }
+                    default: {
+                        mp_raise_ValueError(MP_ERROR_TEXT("unexpected key"));
+                        break;
+                    }
+                }
+            }
+        }
+    }
+    return mp_const_none;
+}
+
 #endif // LWIP_VERSION_MAJOR >= 2
 
 #endif  // MICROPY_PY_NETWORK && MICROPY_PY_LWIP