35 lines
1021 B
Go
35 lines
1021 B
Go
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package xt
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import (
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"bytes"
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"fmt"
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)
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// CommentSize is the fixed size of a comment info xt blob, see:
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// https://elixir.bootlin.com/linux/v6.8.7/source/include/uapi/linux/netfilter/xt_comment.h#L5
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const CommentSize = 256
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// Comment gets marshalled and unmarshalled as a fixed-sized char array, filled
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// with zeros as necessary, see:
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// https://elixir.bootlin.com/linux/v6.8.7/source/include/uapi/linux/netfilter/xt_comment.h#L7
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type Comment string
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func (c *Comment) marshal(fam TableFamily, rev uint32) ([]byte, error) {
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if len(*c) >= CommentSize {
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return nil, fmt.Errorf("comment must be less than %d bytes, got %d bytes",
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CommentSize, len(*c))
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}
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data := make([]byte, CommentSize)
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copy(data, []byte(*c))
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return data, nil
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}
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func (c *Comment) unmarshal(fam TableFamily, rev uint32, data []byte) error {
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if len(data) != CommentSize {
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return fmt.Errorf("malformed comment: got %d bytes, expected exactly %d bytes",
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len(data), CommentSize)
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}
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*c = Comment(bytes.TrimRight(data, "\x00"))
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return nil
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}
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