From 7e493b7d703a09ed9c6be6bcb996c0c75d825a19 Mon Sep 17 00:00:00 2001 From: Ian Gulliver Date: Sun, 19 Apr 2026 08:26:57 -0700 Subject: [PATCH] Ethertype handler registry: arp/ipv4 self-register via __attribute__((constructor)), drop threaded mac/ip/subnet params --- firmware/include/arp.h | 3 +-- firmware/include/ipv4.h | 5 +++-- firmware/include/net.h | 3 +++ firmware/lib/arp.cpp | 17 +++++++++++------ firmware/lib/ipv4.cpp | 22 ++++++++++++++-------- firmware/lib/net.cpp | 30 ++++++++++++++++++------------ 6 files changed, 50 insertions(+), 30 deletions(-) diff --git a/firmware/include/arp.h b/firmware/include/arp.h index f073b01..0fff18c 100644 --- a/firmware/include/arp.h +++ b/firmware/include/arp.h @@ -19,7 +19,6 @@ struct __attribute__((packed)) header { }; static_assert(sizeof(header) == 28); -void handle(std::span frame, span_writer& tx, - eth::mac_addr our_mac, ipv4::ip4_addr our_ip); +void handle(std::span frame, span_writer& tx); } // namespace arp diff --git a/firmware/include/ipv4.h b/firmware/include/ipv4.h index 98626f7..eea75a8 100644 --- a/firmware/include/ipv4.h +++ b/firmware/include/ipv4.h @@ -36,6 +36,8 @@ static_assert(sizeof(header) == 20); uint16_t checksum(const void* data, size_t len); +static constexpr ip4_addr SUBNET_BROADCAST = {169, 254, 255, 255}; + template void prepend(Buf& buf, const eth::mac_addr& dst_mac, const eth::mac_addr& src_mac, ip4_addr src_ip, ip4_addr dst_ip, uint8_t protocol, @@ -55,7 +57,6 @@ void prepend(Buf& buf, const eth::mac_addr& dst_mac, const eth::mac_addr& src_ma eth::prepend(buf, dst_mac, src_mac, eth::ETH_IPV4); } -void handle(std::span frame, span_writer& tx, - eth::mac_addr our_mac, ip4_addr our_ip, ip4_addr subnet_broadcast); +void handle(std::span frame, span_writer& tx); } // namespace ipv4 diff --git a/firmware/include/net.h b/firmware/include/net.h index a369368..912fc2c 100644 --- a/firmware/include/net.h +++ b/firmware/include/net.h @@ -16,6 +16,8 @@ using net_frame_callback = bool (*)(std::span frame); using frame_cb_list = callback_list; using frame_cb_handle = frame_cb_list::node*; +using ethertype_handler = void (*)(std::span frame, span_writer& tx); + inline constexpr uint16_t PICOMAP_PORT_BE = __builtin_bswap16(28781); bool net_init(); @@ -24,3 +26,4 @@ frame_cb_handle net_add_frame_callback(net_frame_callback cb); void net_remove_frame_callback(frame_cb_handle h); void net_poll(std::span tx); void net_send_raw(std::span data); +void net_register_ethertype(uint16_t ethertype_be, ethertype_handler fn); diff --git a/firmware/lib/arp.cpp b/firmware/lib/arp.cpp index 02971b4..0fce56b 100644 --- a/firmware/lib/arp.cpp +++ b/firmware/lib/arp.cpp @@ -10,8 +10,8 @@ static constexpr uint16_t ARP_PTYPE_IPV4 = __builtin_bswap16(0x0800); static constexpr uint16_t ARP_OP_REQUEST = __builtin_bswap16(1); static constexpr uint16_t ARP_OP_REPLY = __builtin_bswap16(2); -void handle(std::span frame, span_writer& tx, - eth::mac_addr our_mac, ipv4::ip4_addr our_ip) { +void handle(std::span frame, span_writer& tx) { + const auto& ns = net_get_state(); parse_buffer pb(frame); pb.consume(); auto* arp_hdr = pb.consume
(); @@ -21,7 +21,7 @@ void handle(std::span frame, span_writer& tx, if (arp_hdr->ptype != ARP_PTYPE_IPV4) return; if (arp_hdr->hlen != 6 || arp_hdr->plen != 4) return; if (arp_hdr->oper != ARP_OP_REQUEST) return; - if (arp_hdr->tpa != our_ip) return; + if (arp_hdr->tpa != ns.ip) return; prepend_buffer<4096> buf; auto* reply = buf.template prepend
(); @@ -30,13 +30,18 @@ void handle(std::span frame, span_writer& tx, reply->hlen = 6; reply->plen = 4; reply->oper = ARP_OP_REPLY; - reply->sha = our_mac; - reply->spa = our_ip; + reply->sha = ns.mac; + reply->spa = ns.ip; reply->tha = arp_hdr->sha; reply->tpa = arp_hdr->spa; - eth::prepend(buf, arp_hdr->sha, our_mac, eth::ETH_ARP); + eth::prepend(buf, arp_hdr->sha, ns.mac, eth::ETH_ARP); net_send_raw(buf.span()); } +__attribute__((constructor)) +static void register_ethertype() { + net_register_ethertype(eth::ETH_ARP, handle); +} + } // namespace arp diff --git a/firmware/lib/ipv4.cpp b/firmware/lib/ipv4.cpp index e0fc52f..e42f1b9 100644 --- a/firmware/lib/ipv4.cpp +++ b/firmware/lib/ipv4.cpp @@ -1,6 +1,7 @@ #include "ipv4.h" #include "icmp.h" #include "igmp.h" +#include "net.h" #include "udp.h" #include "parse_buffer.h" @@ -20,12 +21,12 @@ uint16_t checksum(const void* data, size_t len) { return __builtin_bswap16(~sum); } -static bool ip_match(const ip4_addr& dst, const ip4_addr& our_ip, const ip4_addr& subnet_broadcast) { - return dst == our_ip || dst == IP_BROADCAST_ALL || dst == subnet_broadcast || igmp::is_member(dst); +static bool ip_match(const ip4_addr& dst, const ip4_addr& our_ip) { + return dst == our_ip || dst == IP_BROADCAST_ALL || dst == SUBNET_BROADCAST || igmp::is_member(dst); } -void handle(std::span frame, span_writer& tx, - eth::mac_addr our_mac, ip4_addr our_ip, ip4_addr subnet_broadcast) { +void handle(std::span frame, span_writer& tx) { + const auto& ns = net_get_state(); parse_buffer pb(frame); pb.consume(); auto* ip = pb.consume
(); @@ -37,19 +38,24 @@ void handle(std::span frame, span_writer& tx, switch (ip->protocol) { case 1: - if (!ip_match(ip->dst, our_ip, subnet_broadcast)) + if (!ip_match(ip->dst, ns.ip)) return; - icmp::handle(frame, tx, our_mac, our_ip); + icmp::handle(frame, tx, ns.mac, ns.ip); break; case 2: - igmp::handle(frame, tx, our_mac, our_ip); + igmp::handle(frame, tx, ns.mac, ns.ip); break; case 17: - if (!ip_match(ip->dst, our_ip, subnet_broadcast)) + if (!ip_match(ip->dst, ns.ip)) return; udp::handle(frame, tx); break; } } +__attribute__((constructor)) +static void register_ethertype() { + net_register_ethertype(eth::ETH_IPV4, handle); +} + } // namespace ipv4 diff --git a/firmware/lib/net.cpp b/firmware/lib/net.cpp index 9d65609..352871f 100644 --- a/firmware/lib/net.cpp +++ b/firmware/lib/net.cpp @@ -1,22 +1,30 @@ #include "net.h" +#include #include "pico/unique_id.h" #include "pico/time.h" #include "eth.h" -#include "arp.h" -#include "ipv4.h" -#include "udp.h" #include "igmp.h" #include "parse_buffer.h" #include "prepend_buffer.h" #include "w6300.h" #include "debug_log.h" -static constexpr ipv4::ip4_addr IP_BROADCAST_SUBNET = {169, 254, 255, 255}; - static net_state state; static w6300::socket_id raw_socket{0}; static frame_cb_list frame_callbacks; +struct ethertype_entry { + uint16_t ethertype_be; + ethertype_handler fn; +}; +static std::array eth_handlers; +static size_t eth_handler_count = 0; + +void net_register_ethertype(uint16_t ethertype_be, ethertype_handler fn) { + if (eth_handler_count < eth_handlers.size()) + eth_handlers[eth_handler_count++] = {ethertype_be, fn}; +} + void net_send_raw(std::span data) { dlog_if_slow("net_send_raw", 1000, [&]{ auto result = w6300::send(raw_socket, data); @@ -41,13 +49,11 @@ static void process_frame(std::span frame, span_writer& tx) { frame_callbacks.remove(n); }); - switch (eth_hdr.ethertype) { - case eth::ETH_ARP: - arp::handle(frame, tx, state.mac, state.ip); - break; - case eth::ETH_IPV4: - ipv4::handle(frame, tx, state.mac, state.ip, IP_BROADCAST_SUBNET); - break; + for (size_t i = 0; i < eth_handler_count; i++) { + if (eth_handlers[i].ethertype_be == eth_hdr.ethertype) { + eth_handlers[i].fn(frame, tx); + break; + } } }