feat: add NTP; fix networking bugs/regressions

kernel/src/Api/BuildNo.hpp

@@ -12,4 +12,4 @@
 
 #pragma once
 
-#define MONTAUK_BUILD_NUMBER 8
+#define MONTAUK_BUILD_NUMBER 17

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());
     }
 

kernel/src/Api/Syscall.cpp

@@ -174,6 +174,8 @@ namespace montauk::abi {
                 if (!UserMemory::Writable<DateTime>(frame->arg1)) return -1;
                 Sys_GetTime((DateTime*)frame->arg1);
                 return 0;
+            case SYS_SETUNIXTIME:
+                return Sys_SetUnixTime((int64_t)frame->arg1);
             case SYS_SOCKET:
                 return (int64_t)Sys_Socket((int)frame->arg1);
             case SYS_CONNECT:
@@ -556,7 +558,7 @@ namespace montauk::abi {
         Hal::WriteMSR(Hal::IA32_FMASK, 0x200);
 
         Kt::KernelLogStream(Kt::OK, "Syscall") << "SYSCALL/SYSRET initialized (LSTAR="
-            << kcp::hex << (uint64_t)SyscallEntry << kcp::dec << ", 124 syscall slots)";
+            << kcp::hex << (uint64_t)SyscallEntry << kcp::dec << ", 154 syscall slots)";
     }
 
 }

kernel/src/Api/Syscall.hpp

@@ -287,6 +287,7 @@ namespace montauk::abi {
 
     // Path metadata (size, timestamps, mode). (const char* path, FileStat* out) -> 0, -1 on error/unsupported.
     static constexpr uint64_t SYS_STAT                = 152;
+    static constexpr uint64_t SYS_SETUNIXTIME         = 153;
 
     // Tunable parameters (for SYS_SDR_SETPARAM / SYS_SDR_GETPARAM).
     static constexpr int SDR_PARAM_FREQ        = 0;  // center frequency, Hz

kernel/src/Api/Time.hpp

@@ -38,4 +38,8 @@ namespace montauk::abi {
     static int64_t Sys_GetTZ() {
         return (int64_t)Timekeeping::GetTZOffset();
     }
-};
+
+    static int64_t Sys_SetUnixTime(int64_t unixSeconds) {
+        return Timekeeping::SetUnixTimestamp(unixSeconds) ? 0 : -1;
+    }
+};