48 lines
832 B
Go
48 lines
832 B
Go
package smtp
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import (
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"errors"
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"io"
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)
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var ErrTooLongLine = errors.New("smtp: too longer line in input stream")
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// lineLimitReader reads from the underlying Reader but restricts
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// line length of lines in input stream to a certain length.
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//
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// If line length exceeds the limit - Read returns ErrTooLongLine
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type lineLimitReader struct {
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R io.Reader
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LineLimit int
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curLineLength int
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}
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func (r *lineLimitReader) Read(b []byte) (int, error) {
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if r.curLineLength > r.LineLimit && r.LineLimit > 0 {
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return 0, ErrTooLongLine
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}
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n, err := r.R.Read(b)
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if err != nil {
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return n, err
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}
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if r.LineLimit == 0 {
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return n, nil
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}
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for _, chr := range b[:n] {
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if chr == '\n' {
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r.curLineLength = 0
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}
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r.curLineLength++
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if r.curLineLength > r.LineLimit {
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return 0, ErrTooLongLine
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}
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}
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return n, nil
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}
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