Self-registering IP-protocol and UDP-port dispatch; move picomap-specific constants out of generic net/dispatch layers

firmware/include/dispatch.h

@@ -9,6 +9,8 @@
 #include "prepend_buffer.h"
 #include "udp.h"
 
+uint16_t dispatch_listen_port_be();
+
 struct responder {
     uint32_t message_id;
     udp::address reply_to;
@@ -22,7 +24,7 @@ struct responder {
         if (!r) return;
         buf.append(*r);
         udp::prepend(buf, reply_to.mac, ns.mac, ns.ip, reply_to.ip,
-                     PICOMAP_PORT_BE, reply_to.port, *r);
+                     dispatch_listen_port_be(), reply_to.port, *r);
         net_send_raw(buf.span());
     }
 };
@@ -52,7 +54,7 @@ void typed_handler(const responder& resp, std::span<const uint8_t> payload) {
         resp.respond(*result);
 }
 
-void dispatch_init();
+void dispatch_init(uint16_t listen_port_be);
 timer_handle dispatch_schedule_ms(uint32_t ms, void (*fn)());
 bool dispatch_cancel_timer(timer_handle h);
 [[noreturn]] void dispatch_run(std::span<const handler_entry> handlers);

firmware/include/handlers.h

@@ -1,9 +1,14 @@
 #pragma once
+#include <cstdint>
 #include <optional>
 #include <string_view>
 #include "dispatch.h"
+#include "ipv4.h"
 #include "wire.h"
 
+inline constexpr uint16_t PICOMAP_PORT_BE = __builtin_bswap16(28781);
+inline constexpr ipv4::ip4_addr PICOMAP_DISCOVERY_GROUP = {239, 112, 77, 1};
+
 extern std::string_view firmware_name;
 
 void handlers_init();

firmware/include/icmp.h

@@ -16,8 +16,7 @@ struct __attribute__((packed)) echo {
 };
 static_assert(sizeof(echo) == 8);
 
-void handle(std::span<const uint8_t> frame, span_writer& tx,
-            eth::mac_addr our_mac, ipv4::ip4_addr our_ip);
+void handle(std::span<const uint8_t> frame, span_writer& tx);
 
 template <typename Buf>
 void prepend_echo_request(Buf& buf,

firmware/include/igmp.h

@@ -7,7 +7,6 @@
 
 namespace igmp {
 
-static constexpr ipv4::ip4_addr PICOMAP_DISCOVERY_GROUP = {239, 112, 77, 1};
 static constexpr ipv4::ip4_addr ALL_HOSTS = {224, 0, 0, 1};
 
 struct __attribute__((packed)) message {
@@ -22,13 +21,11 @@ eth::mac_addr mac_for_ip(const ipv4::ip4_addr& group);
 bool is_member(const ipv4::ip4_addr& ip);
 bool is_member_mac(const eth::mac_addr& mac);
 
-void join(const ipv4::ip4_addr& group,
-          eth::mac_addr our_mac, ipv4::ip4_addr our_ip);
+void join(const ipv4::ip4_addr& group);
 
-void send_all_reports(eth::mac_addr our_mac, ipv4::ip4_addr our_ip);
+void send_all_reports();
 
-void handle(std::span<const uint8_t> frame, span_writer& tx,
-            eth::mac_addr our_mac, ipv4::ip4_addr our_ip);
+void handle(std::span<const uint8_t> frame, span_writer& tx);
 
 template <typename Buf>
 void prepend_report(Buf& buf, const eth::mac_addr& src_mac, ipv4::ip4_addr src_ip,

firmware/include/ipv4.h

@@ -59,4 +59,9 @@ void prepend(Buf& buf, const eth::mac_addr& dst_mac, const eth::mac_addr& src_ma
 
 void handle(std::span<const uint8_t> frame, span_writer& tx);
 
+bool addressed_to_us(ip4_addr dst);
+
+using protocol_handler = void (*)(std::span<const uint8_t> frame, span_writer& tx);
+void register_protocol(uint8_t protocol, protocol_handler fn);
+
 } // namespace ipv4

firmware/include/net.h

@@ -18,8 +18,6 @@ using frame_cb_handle = frame_cb_list::node*;
 
 using ethertype_handler = void (*)(std::span<const uint8_t> frame, span_writer& tx);
 
-inline constexpr uint16_t PICOMAP_PORT_BE = __builtin_bswap16(28781);
-
 bool net_init();
 const net_state& net_get_state();
 frame_cb_handle net_add_frame_callback(net_frame_callback cb);

firmware/include/udp.h

@@ -39,10 +39,7 @@ void prepend(Buf& buf, const eth::mac_addr& dst_mac, const eth::mac_addr& src_ma
 
 void handle(std::span<const uint8_t> frame, span_writer& tx);
 
-namespace client {
-// Defined by the higher layer (dispatch) to receive decoded UDP payloads
-// addressed to PICOMAP_PORT_BE. Resolved at link time.
-void handler(std::span<const uint8_t> payload, const address& from);
-} // namespace client
+using port_handler = void (*)(std::span<const uint8_t> payload, const address& from);
+void register_port(uint16_t port_be, port_handler fn);
 
 } // namespace udp