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| author | Phil Sutter <phil@nwl.cc> | 2023-10-12 17:54:53 +0200 |
|---|---|---|
| committer | Phil Sutter <phil@nwl.cc> | 2023-10-12 18:07:28 +0200 |
| commit | 920ece2b392fb83bd26416e0e6f8f6a847aacbaa (patch) | |
| tree | 1bd235383c2e0c6f157734c6aa96cf0334ca0f7e | |
| parent | e2d7ee9c49b582f399ad4ba2da2ee1b3e1f89620 (diff) | |
extensions: string: Clarify description of --to
String match indeed returns a match as long as the given pattern starts
in the range of --from and --to, update the text accordingly.
Also add a note regarding fragment boundaries.
Closes: https://bugzilla.netfilter.org/show_bug.cgi?id=1707
| -rw-r--r-- | extensions/libxt_string.man | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/extensions/libxt_string.man b/extensions/libxt_string.man index 2a470ece..efdda492 100644 --- a/extensions/libxt_string.man +++ b/extensions/libxt_string.man @@ -7,9 +7,13 @@ Select the pattern matching strategy. (bm = Boyer-Moore, kmp = Knuth-Pratt-Morri Set the offset from which it starts looking for any matching. If not passed, default is 0. .TP \fB\-\-to\fP \fIoffset\fP -Set the offset up to which should be scanned. That is, byte \fIoffset\fP-1 -(counting from 0) is the last one that is scanned. +Set the offset up to which should be scanned. If the pattern does not start +within this offset, it is not considered a match. If not passed, default is the packet size. +A second function of this parameter is instructing the kernel how much data +from the packet should be provided. With non-linear skbuffs (e.g. due to +fragmentation), a pattern extending past this offset may not be found. Also see +the related note below about Boyer-Moore algorithm in these cases. .TP [\fB!\fP] \fB\-\-string\fP \fIpattern\fP Matches the given pattern. |