Simple NTP implementation, time translation, and RTC updating.

README

@@ -75,6 +75,11 @@ Setup and Installation for Windows:
 - Update PATH:
   - Add QEMU and /usr/local/cross/bin to the PATH variable in .bash_profile
 
+-------------------------------------------------------------------------------
+Configuration:
+
+- tz_local in time.c
+
 -------------------------------------------------------------------------------
 What to expect:
 

REFERENCES

@@ -61,6 +61,11 @@ DHCP:
 - RFC 2131: Dynamic Host Configuration Protocol
 - RFC 2132: DHCP Options and BOOTP Vendor Extensions
 
+NTP:
+
+- RFC 5905: Network Time Protocol Version 4: Protocol and Algorithms Specification (NTP)
+
+
 Registries:
 
 - http://www.iana.org/numbers.html

kernel/console_cmd.c

@@ -8,27 +8,20 @@
 #include "icmp.h"
 #include "io.h"
 #include "ipv4.h"
+#include "ntp.h"
 #include "pit.h"
 #include "rtc.h"
 
 // ------------------------------------------------------------------------------------------------
 static void cmd_datetime(uint argc, const char** argv)
 {
-    static const char* week_days[] =
-    {
-        "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
-    };
-
-    static const char* months[] =
-    {
-        "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
-    };
+    char buf[TIME_STRING_SIZE];
 
-    RTC_Time t;
-    rtc_get_time(&t);
+    DateTime dt;
+    rtc_get_time(&dt);
+    format_time(buf, sizeof(buf), &dt);
 
-    console_print("%s, %02d %s %d %02d:%02d:%02d",
-        week_days[t.week_day], t.day, months[t.month - 1], t.year, t.hour, t.min, t.sec);
+    console_print("%s\n", buf);
 }
 
 // ------------------------------------------------------------------------------------------------
@@ -97,6 +90,25 @@ static void cmd_ping(uint argc, const char** argv)
     icmp_echo_request(&dst_addr, 1, 2, 0, 0);
 }
 
+// ------------------------------------------------------------------------------------------------
+static void cmd_synctime(uint argc, const char** argv)
+{
+    if (argc != 2)
+    {
+        console_print("Usage: synctime <dest ipv4 address>\n");
+        return;
+    }
+
+    IPv4_Addr dst_addr;
+    if (!str_to_ipv4_addr(&dst_addr, argv[1]))
+    {
+        console_print("Failed to parse destination address\n");
+        return;
+    }
+
+    ntp_tx(&dst_addr);
+}
+
 // ------------------------------------------------------------------------------------------------
 static void cmd_reboot(uint argc, const char** argv)
 {
@@ -120,6 +132,7 @@ ConsoleCmd console_cmd_table[] =
     { "lsroute", cmd_lsroute },
     { "ping", cmd_ping },
     { "reboot", cmd_reboot },
+    { "synctime", cmd_synctime },
     { "ticks", cmd_ticks },
     { 0, 0 },
 };

kernel/dns.c

@@ -91,7 +91,7 @@ void dns_query_host(const char* host, uint id)
 
     uint len = q - pkt;
 
-    uint src_port = 3141;   // TODO - bind to random port
+    uint src_port = PORT_EPHEMERAL;
 
     dns_print(pkt, len);
 

kernel/module.mk

@@ -28,12 +28,14 @@ KERNEL_SOURCES := \
 	kernel/net_addr.c \
 	kernel/net_intf.c \
 	kernel/net_port.c \
+	kernel/ntp.c \
 	kernel/pci.c \
 	kernel/pci_classify.c \
 	kernel/pci_driver.c \
 	kernel/pic.c \
 	kernel/pit.c \
 	kernel/rtc.c \
+	kernel/time.c \
 	kernel/smp.c \
 	kernel/string.c \
 	kernel/udp.c \

kernel/net.h

@@ -18,19 +18,31 @@
 // ------------------------------------------------------------------------------------------------
 // Byte Order translation
 
-static inline u16 net_swap16(uint n)
+static inline u16 net_swap16(u16 n)
 {
     return ((n & 0x00ff) << 8) | ((n & 0xff00) >> 8);
 }
 
-static inline u32 net_swap32(uint n)
+static inline u32 net_swap32(u32 n)
 {
     return ((n & 0x000000ff) << 24) |
            ((n & 0x0000ff00) << 8) |
            ((n & 0x00ff0000) >> 8) |
            ((n & 0xff000000) >> 24);
 }
 
+static inline u64 net_swap64(u64 n)
+{
+    return ((n & 0x00000000000000ff) << 56) |
+           ((n & 0x000000000000ff00) << 40) |
+           ((n & 0x0000000000ff0000) << 24) |
+           ((n & 0x00000000ff000000) << 8) |
+           ((n & 0x000000ff00000000) >> 8) |
+           ((n & 0x0000ff0000000000) >> 24) |
+           ((n & 0x00ff000000000000) >> 40) |
+           ((n & 0xff00000000000000) >> 56);
+}
+
 // ------------------------------------------------------------------------------------------------
 // Globals
 

kernel/net_port.h

@@ -12,3 +12,6 @@
 #define PORT_DNS                        53
 #define PORT_BOOTP_SERVER               67
 #define PORT_BOOTP_CLIENT               68
+#define PORT_NTP                        123
+
+#define PORT_EPHEMERAL                  3141    // TODO - add proper ephemeral port management

kernel/ntp.c

@@ -0,0 +1,120 @@
+// ------------------------------------------------------------------------------------------------
+// ntp.c
+// ------------------------------------------------------------------------------------------------
+
+#include "ntp.h"
+#include "console.h"
+#include "net.h"
+#include "net_port.h"
+#include "rtc.h"
+#include "time.h"
+#include "udp.h"
+
+// ------------------------------------------------------------------------------------------------
+// NTP Constants
+
+#define NTP_VERSION                     4
+#define UNIX_EPOCH                      0x83aa7e80
+
+// ------------------------------------------------------------------------------------------------
+// NTP Packet
+
+typedef struct NTP_Header
+{
+    u8 mode;
+    u8 stratum;
+    u8 poll;
+    i8 precision;
+    u32 root_delay;
+    u32 root_dispersion;
+    u32 ref_id;
+    u64 ref_timestamp;
+    u64 orig_timestamp;
+    u64 rx_timestamp;
+    u64 tx_timestamp;
+} PACKED NTP_Header;
+
+// ------------------------------------------------------------------------------------------------
+// NTP Modes
+
+#define MODE_CLIENT                     3
+#define MODE_SERVER                     4
+
+// ------------------------------------------------------------------------------------------------
+void ntp_rx(Net_Intf* intf, const u8* pkt, uint len)
+{
+    ntp_print(pkt, len);
+
+    if (len < sizeof(NTP_Header))
+    {
+        return;
+    }
+
+    NTP_Header* hdr = (NTP_Header*)pkt;
+
+    time_t t = (net_swap64(hdr->tx_timestamp) >> 32) - UNIX_EPOCH;
+    DateTime dt;
+    split_time(&dt, t, tz_local);
+
+    char str[TIME_STRING_SIZE];
+    format_time(str, sizeof(str), &dt);
+    console_print("Setting time to %s\n", str);
+
+    rtc_set_time(&dt);
+}
+
+// ------------------------------------------------------------------------------------------------
+void ntp_tx(const IPv4_Addr* dst_addr)
+{
+    u8 buf[MAX_PACKET_SIZE];
+    u8* pkt = buf + MAX_PACKET_HEADER;
+
+    NTP_Header* hdr = (NTP_Header*)pkt;
+    hdr->mode = (NTP_VERSION << 3) | MODE_CLIENT;
+    hdr->stratum = 0;
+    hdr->poll = 4;
+    hdr->precision = -6;
+    hdr->root_delay = net_swap32(1 << 16);
+    hdr->root_dispersion = net_swap32(1 << 16);
+    hdr->ref_id = net_swap32(0);
+    hdr->ref_timestamp = net_swap64(0);
+    hdr->orig_timestamp = net_swap64(0);
+    hdr->rx_timestamp = net_swap64(0);
+    hdr->tx_timestamp = net_swap64(0);
+
+    uint len = sizeof(NTP_Header);
+    uint src_port = PORT_EPHEMERAL;
+
+    ntp_print(pkt, len);
+    udp_tx(dst_addr, PORT_NTP, src_port, pkt, len);
+}
+
+// ------------------------------------------------------------------------------------------------
+void ntp_print(const u8* pkt, uint len)
+{
+    if (!net_trace)
+    {
+        return;
+    }
+
+    if (len < sizeof(NTP_Header))
+    {
+        return;
+    }
+
+    NTP_Header* hdr = (NTP_Header*)pkt;
+
+    time_t t = (net_swap64(hdr->tx_timestamp) >> 32) - UNIX_EPOCH;
+
+    console_print("   NTP: mode=%02x stratum=%d poll=%d precision=%d\n",
+        hdr->mode, hdr->stratum, hdr->poll, hdr->precision);
+    console_print("   NTP: root_delay=%08x root_dispersion=%08x ref_id=%08x\n",
+        net_swap32(hdr->root_delay), net_swap32(hdr->root_dispersion), net_swap32(hdr->ref_id));
+    console_print("   NTP: ref_timestamp=%016x orig_timestamp=%016x\n",
+        net_swap64(hdr->ref_timestamp), net_swap64(hdr->orig_timestamp));
+    console_print("   NTP: rx_timestamp=%016x tx_timestamp=%016x\n",
+        net_swap64(hdr->rx_timestamp), net_swap64(hdr->tx_timestamp));
+    console_print("   NTP: unix_epoch=%u\n",
+        t);
+}
+

kernel/ntp.h

@@ -0,0 +1,13 @@
+// ------------------------------------------------------------------------------------------------
+// ntp.h
+// ------------------------------------------------------------------------------------------------
+
+#pragma once
+
+#include "net_intf.h"
+
+// ------------------------------------------------------------------------------------------------
+void ntp_rx(Net_Intf* intf, const u8* pkt, uint len);
+void ntp_tx(const IPv4_Addr* dst_addr);
+
+void ntp_print(const u8* pkt, uint len);