tcpdump mailing list archives
Re: TCP Header Flags
From: Denis Ovsienko <denis () ovsienko info>
Date: Sun, 26 Feb 2023 21:45:55 +0000
On Sun, 26 Feb 2023 15:46:56 +0100 Francois-Xavier Le Bail <devel.fx.lebail () orange fr> wrote: [...]
I wonder if there would be any other incurred future maintenance.The proposed patch is: diff --git a/pcap-filter.manmisc.in b/pcap-filter.manmisc.in index 10aeb42d..864cd238 100644 --- a/pcap-filter.manmisc.in +++ b/pcap-filter.manmisc.in @@ -1027,7 +1027,7 @@ The following ICMPv6 type field values are available: .BR \%icmp6-multicastrouterterm . .IP The following TCP flags field values are available: \fBtcp-fin\fP, -\fBtcp-syn\fP, \fBtcp-rst\fP, \fBtcp-push\fP, +\fBtcp-syn\fP, \fBtcp-rst\fP, \fBtcp-psh\fP (or \fBtcp-push\fP), \fBtcp-ack\fP, \fBtcp-urg\fP, \fBtcp-ece\fP, \fBtcp-cwr\fP. .LP diff --git a/scanner.l b/scanner.l index 85fe395a..7cc39f77 100644 --- a/scanner.l +++ b/scanner.l @@ -475,6 +475,7 @@ tcp-fin { yylval->h = 0x01; return NUM; } tcp-syn { yylval->h = 0x02; return NUM; } tcp-rst { yylval->h = 0x04; return NUM; } tcp-push { yylval->h = 0x08; return NUM; } +tcp-psh { yylval->h = 0x08; return NUM; } tcp-ack { yylval->h = 0x10; return NUM; } tcp-urg { yylval->h = 0x20; return NUM; } tcp-ece { yylval->h = 0x40; return NUM; } (the tcpdump man page will need an update too.)
Obviously, the change would be easy to make. But what comes to my mind is next 5 or 10 years of answering the same question: "Why tcp-psh is in the man page/my new book/stackoverflow/whatever and it works in my development environment, but some production servers reject the syntax? These are on a very expensive long term support contract, so everything is supposed just to work, right? Right?" You could argue that there would be a note in the "backward compatibility" section, but I could argue that only a fraction of users ever reads any documentation that comes directly with the software. It would be better to have some other problems solved before looking at this discrepancy again. Specifically, I wonder if it would be practicable to process all remaining longjmp() backlog in the next few months. The script reports 35 not yet converted files ranging from 110 to 2755 CLOC each. -- Denis Ovsienko _______________________________________________ tcpdump-workers mailing list -- tcpdump-workers () lists tcpdump org To unsubscribe send an email to tcpdump-workers-leave () lists tcpdump org %(web_page_url)slistinfo%(cgiext)s/%(_internal_name)s
Current thread:
- TCP Header Flags Francois-Xavier Le Bail (Feb 18)
- Re: TCP Header Flags Denis Ovsienko (Feb 18)
- Re: TCP Header Flags Francois-Xavier Le Bail (Feb 19)
- Re: TCP Header Flags Francois-Xavier Le Bail (Feb 26)
- Re: TCP Header Flags Denis Ovsienko (Feb 26)
- Re: TCP Header Flags Francois-Xavier Le Bail (Feb 26)
- Re: TCP Header Flags Denis Ovsienko (Feb 27)
- Re: TCP Header Flags Francois-Xavier Le Bail (Feb 19)
- Re: TCP Header Flags Denis Ovsienko (Feb 18)
- Re: TCP Header Flags Francois-Xavier Le Bail (Feb 26)