diff options
author | Joseph C. Sible <josephcsible@gmail.com> | 2018-09-02 14:09:15 -0400 |
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committer | Florian Westphal <fw@strlen.de> | 2018-09-10 15:25:16 +0200 |
commit | 15606f264c84f9cc01d2f60adb6eda6584ef2594 (patch) | |
tree | bfd813e4d1f1b965155298c5df0d3db54a0c56b6 /extensions/libxt_u32.man | |
parent | 7345037e08a385e078350de1006f5ee2299cd2ef (diff) |
doc: Improve layout of u32 instructions
Make it more clear where the instruction ends, and where
what it does begins.
Signed-off-by: Joseph C. Sible <josephcsible@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Diffstat (limited to 'extensions/libxt_u32.man')
-rw-r--r-- | extensions/libxt_u32.man | 25 |
1 files changed, 15 insertions, 10 deletions
diff --git a/extensions/libxt_u32.man b/extensions/libxt_u32.man index 7c8615d3..40a69f8e 100644 --- a/extensions/libxt_u32.man +++ b/extensions/libxt_u32.man @@ -40,18 +40,23 @@ A is of type \fBchar *\fP, initially the address of the IP header B and C are unsigned 32 bit integers, initially zero .PP The instructions are: -.IP -number B = number; +.TP +.B number +B = number; .IP C = (*(A+B)<<24) + (*(A+B+1)<<16) + (*(A+B+2)<<8) + *(A+B+3) -.IP -&number C = C & number -.IP -<< number C = C << number -.IP ->> number C = C >> number -.IP -@number A = A + C; then do the instruction number +.TP +.B &number +C = C & number +.TP +.B << number +C = C << number +.TP +.B >> number +C = C >> number +.TP +.B @number +A = A + C; then do the instruction number .PP Any access of memory outside [skb\->data,skb\->end] causes the match to fail. Otherwise the result of the computation is the final value of C. |