feat: add NTP; fix networking bugs/regressions

kernel/src/Api/Net.hpp

@@ -12,6 +12,7 @@
 #include <Timekeeping/ApicTimer.hpp>
 #include <Net/Icmp.hpp>
 #include <Net/Dns.hpp>
+#include <Net/Ipv4.hpp>
 #include <Net/Socket.hpp>
 #include <Net/NetConfig.hpp>
 #include <Drivers/Net/E1000.hpp>
@@ -82,6 +83,10 @@ namespace montauk::abi {
 
     static int Sys_RecvFrom(int fd, uint8_t* buf, uint32_t maxLen,
                             uint32_t* srcIp, uint16_t* srcPort) {
+        // A preceding UDP send may be queued while ARP resolves the next hop.
+        // Drive the pending IPv4 queue on each non-blocking receive so a lost
+        // initial ARP request is retried without unrelated network traffic.
+        Net::Ipv4::FlushPending();
         return Net::Socket::RecvFrom(fd, buf, maxLen, srcIp, srcPort, Sched::GetCurrentPid());
     }