Add sub-second packet timestamp checks for invalid micro/nano

Now prints e.g.:
    2  17:16:10.1000000 (invalid ms) IP [...]
    3  17:16:10.2147483648 (invalid ms) IP [...]
or
    2  17:16:10.1000000000 (invalid ns) IP [...]
    3  17:16:10.2147483648 (invalid ns) IP [...]

Add two test files.

Author: fxlb

tests/TESTLIST

@@ -38,6 +38,10 @@ tcp-handshake-nano-ttt tcp-handshake-nano.pcap tcp-handshake-nano-ttt.out -ttt -
 tcp-handshake-nano-tttt tcp-handshake-nano.pcap tcp-handshake-nano-tttt.out -tttt -q --nano SPECIAL_t
 tcp-handshake-nano-ttttt tcp-handshake-nano.pcap tcp-handshake-nano-ttttt.out -ttttt -q --nano SPECIAL_t
 
+# Invalid timestamps, micro and nano precision
+timestamp_invalid_micro timestamp_invalid_micro.pcap timestamp_invalid_micro.out -q SPECIAL_t
+timestamp_invalid_nano timestamp_invalid_nano.pcap timestamp_invalid_nano.out -q --nano SPECIAL_t
+
 # TCP with data in the RST segment
 tcp_rst_data tcp_rst_data.pcap tcp_rst_data-v.out -v
 tcp_rst_data tcp_rst_data.pcap tcp_rst_data.out

tests/timestamp_invalid_micro.out

@@ -0,0 +1,3 @@
+    1  17:16:09.999999 IP 131.155.215.69.46656 > 137.116.81.94.80: tcp 0
+    2  17:16:10.1000000 (invalid ms) IP 137.116.81.94.80 > 131.155.215.69.46656: tcp 0
+    3  17:16:10.2147483648 (invalid ms) IP 131.155.215.69.46656 > 137.116.81.94.80: tcp 0

tests/timestamp_invalid_micro.pcap

@@ -0,0 +1,3 @@
+    1  17:16:09.999999999 IP 131.155.215.69.46656 > 137.116.81.94.80: tcp 0
+    2  17:16:10.1000000000 (invalid ns) IP 137.116.81.94.80 > 131.155.215.69.46656: tcp 0
+    3  17:16:10.2147483648 (invalid ns) IP 131.155.215.69.46656 > 137.116.81.94.80: tcp 0

tests/timestamp_invalid_nano.out

@@ -216,10 +216,14 @@ ts_frac_print(netdissect_options *ndo, const struct timeval *tv)
 
 	case PCAP_TSTAMP_PRECISION_MICRO:
 		ND_PRINT(".%06u", (unsigned)tv->tv_usec);
+		if ((unsigned)tv->tv_usec > ND_MICRO_PER_SEC - 1)
+			ND_PRINT(" (invalid ms)");
 		break;
 
 	case PCAP_TSTAMP_PRECISION_NANO:
 		ND_PRINT(".%09u", (unsigned)tv->tv_usec);
+		if ((unsigned)tv->tv_usec > ND_NANO_PER_SEC - 1)
+			ND_PRINT(" (invalid ns)");
 		break;
 
 	default:
@@ -228,6 +232,8 @@ ts_frac_print(netdissect_options *ndo, const struct timeval *tv)
 	}
 #else
 	ND_PRINT(".%06u", (unsigned)tv->tv_usec);
+	if ((unsigned)tv->tv_usec > ND_MICRO_PER_SEC - 1)
+		ND_PRINT(" (invalid ms)");
 #endif
 }