22 lines
407 B
Go
22 lines
407 B
Go
package protocol
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// ValidHostLabel returns if the label is a valid RFC 1123 Section 2.1 domain
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// host label name.
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func ValidHostLabel(label string) bool {
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if l := len(label); l == 0 || l > 63 {
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return false
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}
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for _, r := range label {
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switch {
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case r >= '0' && r <= '9':
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case r >= 'A' && r <= 'Z':
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case r >= 'a' && r <= 'z':
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case r == '-':
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default:
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return false
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}
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}
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return true
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}
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