From 26a2ccb8368a9968b6ec16068ad68dd0edb40641 Mon Sep 17 00:00:00 2001 From: user Date: Fri, 17 Jul 2026 12:54:43 +0200 Subject: net: UDP sockets in the kernel + a DNS resolver (real hostname lookups) Adds UDP to the kernel socket layer on top of the ICMP core: - net_sum() (raw folded sum) split out of net_cksum() so a UDP pseudo-header (src/dst IP + proto + length) can seed the segment checksum. - udp_send: builds IP+UDP with the pseudo-header checksum; NET_BIND sets the local/source port; net_connect sets the peer. - udp_in: demuxes inbound UDP by destination port to the bound socket (net_find_udp), delivers the payload + source addr. Also fixes a real recv bug: net_pump clobbers BC/DE/HL, so the old recv timeout counted in registers and was effectively random. recv now counts in WRAM. New `nslookup HOST` (PROG_NSLOOKUP=28, bank 30): builds a DNS A query and parses the answer (with 0xC0 name-compression) entirely in userland over a UDP socket - the kernel never sees DNS, just UDP. Verified through the bridge NAT: /# nslookup example.com -> example.com -> 172.66.147.243 This gives us name resolution for the TCP/HTTP demo next. --- include/gbos.inc | 1 + 1 file changed, 1 insertion(+) (limited to 'include/gbos.inc') diff --git a/include/gbos.inc b/include/gbos.inc index a4c9d52..74eee8e 100644 --- a/include/gbos.inc +++ b/include/gbos.inc @@ -249,5 +249,6 @@ DEF PROG_WGET EQU 24 DEF PROG_CHAT EQU 25 DEF PROG_NETD EQU 26 DEF PROG_PING EQU 27 +DEF PROG_NSLOOKUP EQU 28 ENDC -- cgit v1.3.1-sl0p