[PATCH 3/3] Add utility to check proper scheduling of SI

From: Max <msuraev(a)sysmocom.de> There are several types of System Information messages with tricky scheduling rules described in 3GPP TS 05.02 § 6.3.1.3. This GNU Awk script takes in .csv file with sequence of scheduled SI messages (for example generated using tshark from GSMTAP capture - see usage note inside the script) and check the scheduling rules compliance. --- contrib/si_check.gawk | 91 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 91 insertions(+) create mode 100755 contrib/si_check.gawk diff --git a/contrib/si_check.gawk b/contrib/si_check.gawk new file mode 100755 index 0000000..0a54ed4 --- /dev/null +++ b/contrib/si_check.gawk @@ -0,0 +1,91 @@ +#!/usr/bin/gawk -f + +# Usage example: +# tshark -2 -t r -E 'header=n' -E 'separator=,' -E 'quote=n' -T fields -e gsmtap.frame_nr -e gsmtap.ts -e gsmtap.arfcn -e _ws.col.Info -Y 'gsmtap' -r test.pcapng.gz | grep Information | env ARFCN=878 ./si_check.gawk +# read summary on number of bis/ter messages and adjust BT_BOTH and BT_NONE environment variables accordingly + +BEGIN { + FS = "," + FAILED = 0 + IGNORE = 0 + BIS = 0 + TER = 0 + QUA = 0 + BT_BOTH = ENVIRON["BOTH"] + BT_NONE = ENVIRON["NONE"] + TC_INDEX = 0 + TC4[4] = 0 +} + +{ # expected .csv input as follows: gsmtap.frame_nr,gsmtap.ts,gsmtap.arfcn,_ws.col.Info + if ("ARFCN" in ENVIRON) { # ARFCN filtering is enabled + if (ENVIRON["ARFCN"] != $3) { # ignore other ARFCNs + IGNORE++ + next + } + } + type = get_si_type($4) + tc = get_tc($1) + result = "FAIL" + + if (1 == check_si_tc(tc, type)) { result = "OK" } + else { FAILED++ } + + if (4 == tc) { + TC4[TC_INDEX] = type + TC_INDEX = int((TC_INDEX + 1) % 4) + if (0 == check_tc4c(type) && "OK" == result) { + result = "FAIL" + FAILED++ + } + } + if (type == "2bis") { BIS++ } + if (type == "2ter") { TER++ } + if (type == "2quater") { QUA++ } + # for (i in TC4) print TC4[i] # debugging + printf "ARFCN=%d FN=%d TS=%d TC=%d TYPE=%s %s\n", $3, $1, $2, tc, type, result +} + +END { + printf "check completed: total %d, failed %d, ignored %d, ok %d\nSI2bis = %d, SI2ter = %d, SI2quater = %d\n", NR, FAILED, IGNORE, NR - FAILED - IGNORE, BIS, TER, QUA + if ((BIS > 0 || TER > 0) && BT_NONE) { printf "please re-run with correct environment: unset 'NONE' variable\n" } + if ((BIS > 0 && TER > 0) && !BT_BOTH) { printf "please re-run with correct environment: set 'BOTH' variable\n" } +} + +func get_si_type(s, x) { # we rely on format of Info column in wireshark output - if it's changed we're screwed + return x[split(s, x, " ")] +} + +func get_tc(f) { # N. B: all numbers in awk are float + return int(int(f / 51) % 8) +} + +func check_tc4c(si, count) { # check for "once in 4 consecutive occurrences" rule + count = 0 + if ("2quater" != si || "2ter" != si) { return 1 } # rules is not applicable to other types + if (BT_NONE && "2quater" == si) { return 0 } # should be on TC=5 instead + if (!BT_BOTH && "2ter" == si) { return 0 } # should be on TC=5 instead + if (0 in TC4 && 1 in TC4 && 2 in TC4 && 3 in TC4) { # only check if we have 4 consecutive occurrences already + if (si == TC4[0]) { count++ } + if (si == TC4[1]) { count++ } + if (si == TC4[2]) { count++ } + if (si == TC4[3]) { count++ } + if (0 == count) { return 0 } + } + return 1 +} + +func check_si_tc(tc, si) { # check that SI scheduling on BCCH Norm is matching rules from 3GPP TS 05.02 § 6.3.1.3 + switch (si) { + case "1": return (0 == tc) ? 1 : 0 + case "2": return (1 == tc) ? 1 : 0 + case "2bis": return (5 == tc) ? 1 : 0 + case "13": return (4 == tc) ? 1 : 0 + case "9": return (4 == tc) ? 1 : 0 + case "2ter": if (BT_BOTH) { return (4 == tc) ? 1 : 0 } else { return (5 == tc) ? 1 : 0 } + case "2quater": if (BT_NONE) { return (5 == tc) ? 1 : 0 } else { return (4 == tc) ? 1 : 0 } + case "3": return (2 == tc || 6 == tc) ? 1 : 0 + case "4": return (3 == tc || 7 == tc) ? 1 : 0 + } + return 0 +} -- 2.7.3