Decouple from Ethernet, introduce "l2"

src/net_builtin.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include "arch.h"
+#include "l2.h"
 #include "net.h"
 #include "queue.h"
 #include "str.h"
@@ -20,29 +21,32 @@ typedef void (*mg_tcpip_event_handler_t)(struct mg_tcpip_if *ifp, int ev,
                                          void *ev_data);
 
 enum {
-  MG_TCPIP_EV_ST_CHG,           // state change                   uint8_t * (&ifp->state)
-  MG_TCPIP_EV_DHCP_DNS,         // DHCP DNS assignment            uint32_t *ipaddr
-  MG_TCPIP_EV_DHCP_SNTP,        // DHCP SNTP assignment           uint32_t *ipaddr
-  MG_TCPIP_EV_ARP,              // Got ARP packet                 struct mg_str *
-  MG_TCPIP_EV_TIMER_1S,         // 1 second timer                 NULL
-  MG_TCPIP_EV_WIFI_SCAN_RESULT, // Wi-Fi scan results             struct mg_wifi_scan_bss_data *
-  MG_TCPIP_EV_WIFI_SCAN_END,    // Wi-Fi scan has finished        NULL
-  MG_TCPIP_EV_WIFI_CONNECT_ERR, // Wi-Fi connect has failed       driver and chip specific
-  MG_TCPIP_EV_DRIVER,           // Driver event                   driver specific
-  MG_TCPIP_EV_ST6_CHG,          // state6 change                  uint8_t * (&ifp->state6)
-  MG_TCPIP_EV_USER              // Starting ID for user events
+  MG_TCPIP_EV_ST_CHG,  // state change                   uint8_t * (&ifp->state)
+  MG_TCPIP_EV_DHCP_DNS,   // DHCP DNS assignment            uint32_t *ipaddr
+  MG_TCPIP_EV_DHCP_SNTP,  // DHCP SNTP assignment           uint32_t *ipaddr
+  MG_TCPIP_EV_ARP,        // Got ARP packet                 struct mg_str *
+  MG_TCPIP_EV_TIMER_1S,   // 1 second timer                 NULL
+  MG_TCPIP_EV_WIFI_SCAN_RESULT,  // Wi-Fi scan results             struct
+                                 // mg_wifi_scan_bss_data *
+  MG_TCPIP_EV_WIFI_SCAN_END,     // Wi-Fi scan has finished        NULL
+  MG_TCPIP_EV_WIFI_CONNECT_ERR,  // Wi-Fi connect has failed       driver and
+                                 // chip specific
+  MG_TCPIP_EV_DRIVER,   // Driver event                   driver specific
+  MG_TCPIP_EV_ST6_CHG,  // state6 change                  uint8_t *
+                        // (&ifp->state6)
+  MG_TCPIP_EV_USER      // Starting ID for user events
 };
 
 // Network interface
 struct mg_tcpip_if {
-  uint8_t mac[6];                  // MAC address. Must be set to a valid MAC
-  uint32_t ip, mask, gw;           // IP address, mask, default gateway
-  struct mg_str tx;                // Output (TX) buffer
-  bool enable_dhcp_client;         // Enable DCHP client
-  bool enable_dhcp_server;         // Enable DCHP server
-  bool enable_get_gateway;         // DCHP server sets client as gateway
-  bool enable_req_dns;             // DCHP client requests DNS server
-  bool enable_req_sntp;            // DCHP client requests SNTP server
+  uint8_t mac[sizeof(struct mg_l2addr)];  // hw address. Set to a valid addr
+  uint32_t ip, mask, gw;                  // IP address, mask, default gateway
+  struct mg_str tx;                       // Output (TX) buffer
+  bool enable_dhcp_client;                // Enable DCHP client
+  bool enable_dhcp_server;                // Enable DCHP server
+  bool enable_get_gateway;                // DCHP server sets client as gateway
+  bool enable_req_dns;                    // DCHP client requests DNS server
+  bool enable_req_sntp;                   // DCHP client requests SNTP server
   bool enable_crc32_check;         // Do a CRC check on RX frames and strip it
   bool enable_mac_check;           // Do a MAC check on RX frames
   bool update_mac_hash_table;      // Signal drivers to update MAC controller
@@ -53,21 +57,22 @@ struct mg_tcpip_if {
   struct mg_mgr *mgr;              // Mongoose event manager
   struct mg_queue recv_queue;      // Receive queue
   char dhcp_name[MG_TCPIP_DHCPNAME_SIZE];  // Name for DHCP, "mip" if unset
-  uint16_t mtu;                            // Interface MTU
-#define MG_TCPIP_MTU_DEFAULT 1500
+  uint16_t mtu;                            // Interface link payload
+  uint16_t framesize;                      // Interface frame max length
 #if MG_ENABLE_IPV6
-  uint64_t ip6ll[2], ip6[2];       // IPv6 link-local and global addresses
-  uint8_t prefix[8];               // IPv6 global address prefix
-  uint8_t prefix_len;              // Prefix length
-  uint64_t gw6[2];                 // Default gateway
-  bool enable_slaac;               // Enable IPv6 address autoconfiguration
-  bool enable_dhcp6_client;        // Enable DCHPv6 client
+  uint64_t ip6ll[2], ip6[2];  // IPv6 link-local and global addresses,
+  uint8_t prefix[8];          // prefix,
+  uint8_t prefix_len;         // prefix length,
+  uint64_t gw6[2];            // default gateway.
+  bool enable_slaac;          // Enable IPv6 address autoconfiguration
+  bool enable_dhcp6_client;   // Enable DCHPv6 client TODO()
 #endif
 
   // Internal state, user can use it but should not change it
-  uint8_t gwmac[6];             // Router's MAC
-  char *dns4_url;               // DNS server URL
-  uint64_t now;                 // Current time
+  uint8_t gwmac[sizeof(struct mg_l2addr)];  // Router's hw address
+  enum mg_l2type l2type;                    // Ethernet, PPP, etc.
+  char *dns4_url;                           // DNS server URL
+  uint64_t now;                             // Current time
   uint64_t timer_1000ms;        // 1000 ms timer: for DHCP and link state
   uint64_t lease_expire;        // Lease expiration time, in ms
   uint16_t eport;               // Next ephemeral port
@@ -83,11 +88,12 @@ struct mg_tcpip_if {
 #define MG_TCPIP_STATE_READY 4  // Interface has fully come up, ready to work
   bool gw_ready;                // We've got a hw address for the router
 #if MG_ENABLE_IPV6
-  uint8_t gw6mac[6];             // IPv6 Router's MAC
-  uint8_t state6;                // Current IPv6 state
-  bool gw6_ready;                // We've got a hw address for the IPv6 router
+  uint8_t gw6mac[sizeof(struct mg_l2addr)];  // IPV6 Router's hw address
+  uint8_t state6;                            // Current IPv6 state
+  bool gw6_ready;  // We've got a hw address for the IPv6 router
 #endif
 };
+
 void mg_tcpip_init(struct mg_mgr *, struct mg_tcpip_if *);
 void mg_tcpip_free(struct mg_tcpip_if *);
 void mg_tcpip_qwrite(void *buf, size_t len, struct mg_tcpip_if *ifp);
@@ -119,39 +125,38 @@ struct mg_tcpip_spi {
   uint8_t (*txn)(void *, uint8_t);  // SPI transaction: write 1 byte, read reply
 };
 
-
 // Alignment and memory section requirements
 #ifndef MG_8BYTE_ALIGNED
 #if defined(__GNUC__)
 #define MG_8BYTE_ALIGNED __attribute__((aligned((8U))))
 #else
 #define MG_8BYTE_ALIGNED
-#endif // compiler
-#endif // 8BYTE_ALIGNED
+#endif  // compiler
+#endif  // 8BYTE_ALIGNED
 
 #ifndef MG_16BYTE_ALIGNED
 #if defined(__GNUC__)
 #define MG_16BYTE_ALIGNED __attribute__((aligned((16U))))
 #else
 #define MG_16BYTE_ALIGNED
-#endif // compiler
-#endif // 16BYTE_ALIGNED
+#endif  // compiler
+#endif  // 16BYTE_ALIGNED
 
 #ifndef MG_32BYTE_ALIGNED
 #if defined(__GNUC__)
 #define MG_32BYTE_ALIGNED __attribute__((aligned((32U))))
 #else
 #define MG_32BYTE_ALIGNED
-#endif // compiler
-#endif // 32BYTE_ALIGNED
+#endif  // compiler
+#endif  // 32BYTE_ALIGNED
 
 #ifndef MG_64BYTE_ALIGNED
 #if defined(__GNUC__)
 #define MG_64BYTE_ALIGNED __attribute__((aligned((64U))))
 #else
 #define MG_64BYTE_ALIGNED
-#endif // compiler
-#endif // 64BYTE_ALIGNED
+#endif  // compiler
+#endif  // 64BYTE_ALIGNED
 
 #ifndef MG_ETH_RAM
 #define MG_ETH_RAM