dnscache: preserve hostname case in localName property

[Copilot]

Summary (non-technical, complete)

Fixes test failures on systems with mixed-case hostnames (e.g., build32U10b32b1b199). The DNS cache was incorrectly lowercasing hostnames when they should preserve the original case from DNS resolution.

References

Refs: https://github.com/rsyslog/rsyslog/issues/PLACEHOLDER (issue describing parsertest-parse1-udp.sh failure on cloud hosts)

Notes

Root cause: runtime/dnscache.c:setLocalHostName() was using fqdnLowerCase instead of fqdn when creating the localName property.

What changed:

• Extract hostname from case-preserved fqdn property (not fqdnLowerCase)
• Create new property when extracting short hostname from FQDN
• Preserves behavior: fqdnLowerCase still available for case-insensitive matching

Before/After:

// Before: always lowercased
etry->localName = etry->fqdnLowerCase;  // "myhost.example.com" → "myhost"

// After: case preserved
fqdnStr = propGetSzStr(etry->fqdn);     // "MyHost.example.com" → "MyHost"
prop.CreateStringProp(&etry->localName, hostbuf, i);

Impact: UDP messages without hostnames now preserve case from reverse DNS. Affects:

• parsertest-parse1-udp.sh
• parsertest-parse-nodate-udp.sh
• Any UDP-based test relying on source hostname

Most existing deployments unaffected (hostnames typically lowercase by convention).

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Original prompt

使用一台云主机编译rsyslog的时候，rsyslog tests 用例parsertest-parse1-udp.sh失败，日志报错信息如下，请帮助分析原因，并解决问题。 tr: write error: Broken pipe
testbench: TZ env var not set, setting it to UTC

01:55:00[0] Test: ./parsertest-parse1-udp.sh

Obtaining HOSTNAME (prerequisite, not actual test)

config rstb_607389_d1146e46d42O_.conf is:
1 module(load="../plugins/imdiag/.libs/imdiag")
2 global(inputs.timeout.shutdown="60000"
3 default.action.queue.timeoutshutdown="20000"
4 default.action.queue.timeoutEnqueue="20000")
5 # use legacy-style for the following settings so that we can override if needed
6 $MainmsgQueueTimeoutEnqueue 20000
7 $MainmsgQueueTimeoutShutdown 10000
8 $IMDiagListenPortFileName rstb_607389_d1146e46d42O.imdiag.port
9 $IMDiagServerRun 0
10 $IMDiagAbortTimeout 580
11
12 :syslogtag, contains, "rsyslogd" ./rstb_607389_d1146e46d42O.started
13 ###### end of testbench instrumentation part, test conf follows:
14 module(load="../plugins/imtcp/.libs/imtcp")
15 input(type="imtcp" port="0" listenPortFileName="rstb_607389_d1146e46d42O.tcpflood_port")
16
17 $template hostname,"%hostname%"
18 local0.* ./rstb_607389_d1146e46d42O.HOSTNAME;hostname
rsyslogd: NOTE: RSYSLOG_DEBUG_TIMEOUTS_TO_STDERR activated
main Q:Reg: worker start requested, num workers currently 0
main Q:Reg: wrkr start initiated with state 0, num workers now 1
rsyslog debug: main Q:Reg: worker 0xaaaeb2314660 started
rsyslog debug: main Q:Reg: started with state 3, num workers now 1
01:55:00[0] rstb_607389_d1146e46d42O:.pid found, pid 2477558
01:55:00[0] rsyslogd startup msg seen, pid 2477558
waiting for file rstb_607389_d1146e46d42O.imdiag.port
imdiag port: 43797
waiting for file rstb_607389_d1146e46d42O.tcpflood_port
TCPFLOOD_PORT now: 36821
starting run 1
Sending 1 messages.

00000001 messages sent
runtime: 0.000
End of tcpflood Run
Shutting down instance 1
imdiag: wait q_empty: qsize 0 nempty 1
imdiag[43797]: mainqueue empty
rsyslogd debug: info: trying to cooperatively stop input ../plugins/imdiag/.libs/imdiag, timeout 60000 ms
rsyslogd debug: info: trying to cooperatively stop input imtcp, timeout 60000 ms
rsyslog debug: main Q:Reg/w0: enter WrkrExecCleanup
rsyslog debug: 0xaaaeb23147f0: worker exiting
rsyslog debug: main Q:Reg/w0: thread joined
01:55:01[1] wait on shutdown of 2477558
HOSTNAME is: build32U10b32b1b199
mkdir: cannot create directory 'rstb_607389_d1146e46d42O.spool': File exists
config rstb_607389_d1146e46d42O_.conf is:
1 module(load="../plugins/imdiag/.libs/imdiag")
2 global(inputs.timeout.shutdown="60000"
3 default.action.queue.timeoutshutdown="20000"
4 default.action.queue.timeoutEnqueue="20000")
5 # use legacy-style for the following settings so that we can override if needed
6 $MainmsgQueueTimeoutEnqueue 20000
7 $MainmsgQueueTimeoutShutdown 10000
8 $IMDiagListenPortFileName rstb_607389_d1146e46d42O.imdiag.port
9 $IMDiagServerRun 0
10 $IMDiagAbortTimeout 580
11
12 :syslogtag, contains, "rsyslogd" ./rstb_607389_d1146e46d42O.started
13 ###### end of testbench instrumentation part, test conf follows:
14
15 module(load="../plugins/imudp/.libs/imudp")
16 input(type="imudp" port="54403" ruleset="ruleset1")
17
18 global(localHostname="localhost")
19
20 template(name="outfmt" type="string" string="%PRI%,%syslogfacility-text%,%syslogseverity-text%,%timestamp%,%hostname%,%programname%,%syslogtag%,%msg%\n")
21
22 ruleset(name="ruleset1") {
23 action(type="omfile" file=echo $RSYSLOG_OUT_LOG
24 template="outfmt")
25 }
26
rsyslogd: NOTE: RSYSLOG_DEBUG_TIMEOUTS_TO_STDERR activated
main Q:Reg: worker start requested, num workers currently 0
main Q:Reg: wrkr start initiated with state 0, num workers now 1
rsyslog debug: main Q:Reg: worker 0xaaacd7cc5540 started
rsyslog debug: main Q:Reg: started with state 3, num workers now 1
01:55:01[1] rstb_607389_d1146e46d42O:.pid found, pid 2477609
01:55:01[1] rsyslogd startup msg seen, pid 2477609
waiting for file rstb_607389_d1146e46d42O.imdiag.port
imdiag port: 40363
starting run 1
Sending 1 messages.

00000001 messages sent
runtime: 0.000
End of tcpflood Run
starting run 1
Sending 1 messages.

00000001 messages sent
runtime: 0.000
End of tcpflood Run
starting run 1
Sending 1 messages.

00000001 messages sent
runtime: 0.000
End of tcpflood Run
starting run 1
Sending 1 messages.

00000001 messages sent
runtime: 0.000
End of tcpflood Run
starting run 1
Sending 1 messages.

00000001 messages sent
runtime: 0.000
End of tcpflood Run
starting run 1
Sending 1 messages.

00000001 messages sent
runtime: 0.000
End of tcpflood Run
starting run 1
Sending 1 messages.

00000001 messages sent
runtime: 0.000
End of tcpflood ...

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