diff options
Diffstat (limited to 'vendor/github.com/miekg/dns/labels.go')
-rw-r--r-- | vendor/github.com/miekg/dns/labels.go | 212 |
1 files changed, 0 insertions, 212 deletions
diff --git a/vendor/github.com/miekg/dns/labels.go b/vendor/github.com/miekg/dns/labels.go deleted file mode 100644 index cd498d2e9..000000000 --- a/vendor/github.com/miekg/dns/labels.go +++ /dev/null @@ -1,212 +0,0 @@ -package dns - -// Holds a bunch of helper functions for dealing with labels. - -// SplitDomainName splits a name string into it's labels. -// www.miek.nl. returns []string{"www", "miek", "nl"} -// .www.miek.nl. returns []string{"", "www", "miek", "nl"}, -// The root label (.) returns nil. Note that using -// strings.Split(s) will work in most cases, but does not handle -// escaped dots (\.) for instance. -// s must be a syntactically valid domain name, see IsDomainName. -func SplitDomainName(s string) (labels []string) { - if s == "" { - return nil - } - fqdnEnd := 0 // offset of the final '.' or the length of the name - idx := Split(s) - begin := 0 - if IsFqdn(s) { - fqdnEnd = len(s) - 1 - } else { - fqdnEnd = len(s) - } - - switch len(idx) { - case 0: - return nil - case 1: - // no-op - default: - for _, end := range idx[1:] { - labels = append(labels, s[begin:end-1]) - begin = end - } - } - - return append(labels, s[begin:fqdnEnd]) -} - -// CompareDomainName compares the names s1 and s2 and -// returns how many labels they have in common starting from the *right*. -// The comparison stops at the first inequality. The names are downcased -// before the comparison. -// -// www.miek.nl. and miek.nl. have two labels in common: miek and nl -// www.miek.nl. and www.bla.nl. have one label in common: nl -// -// s1 and s2 must be syntactically valid domain names. -func CompareDomainName(s1, s2 string) (n int) { - // the first check: root label - if s1 == "." || s2 == "." { - return 0 - } - - l1 := Split(s1) - l2 := Split(s2) - - j1 := len(l1) - 1 // end - i1 := len(l1) - 2 // start - j2 := len(l2) - 1 - i2 := len(l2) - 2 - // the second check can be done here: last/only label - // before we fall through into the for-loop below - if equal(s1[l1[j1]:], s2[l2[j2]:]) { - n++ - } else { - return - } - for { - if i1 < 0 || i2 < 0 { - break - } - if equal(s1[l1[i1]:l1[j1]], s2[l2[i2]:l2[j2]]) { - n++ - } else { - break - } - j1-- - i1-- - j2-- - i2-- - } - return -} - -// CountLabel counts the number of labels in the string s. -// s must be a syntactically valid domain name. -func CountLabel(s string) (labels int) { - if s == "." { - return - } - off := 0 - end := false - for { - off, end = NextLabel(s, off) - labels++ - if end { - return - } - } -} - -// Split splits a name s into its label indexes. -// www.miek.nl. returns []int{0, 4, 9}, www.miek.nl also returns []int{0, 4, 9}. -// The root name (.) returns nil. Also see SplitDomainName. -// s must be a syntactically valid domain name. -func Split(s string) []int { - if s == "." { - return nil - } - idx := make([]int, 1, 3) - off := 0 - end := false - - for { - off, end = NextLabel(s, off) - if end { - return idx - } - idx = append(idx, off) - } -} - -// NextLabel returns the index of the start of the next label in the -// string s starting at offset. A negative offset will cause a panic. -// The bool end is true when the end of the string has been reached. -// Also see PrevLabel. -func NextLabel(s string, offset int) (i int, end bool) { - if s == "" { - return 0, true - } - for i = offset; i < len(s)-1; i++ { - if s[i] != '.' { - continue - } - j := i - 1 - for j >= 0 && s[j] == '\\' { - j-- - } - - if (j-i)%2 == 0 { - continue - } - - return i + 1, false - } - return i + 1, true -} - -// PrevLabel returns the index of the label when starting from the right and -// jumping n labels to the left. -// The bool start is true when the start of the string has been overshot. -// Also see NextLabel. -func PrevLabel(s string, n int) (i int, start bool) { - if s == "" { - return 0, true - } - if n == 0 { - return len(s), false - } - - l := len(s) - 1 - if s[l] == '.' { - l-- - } - - for ; l >= 0 && n > 0; l-- { - if s[l] != '.' { - continue - } - j := l - 1 - for j >= 0 && s[j] == '\\' { - j-- - } - - if (j-l)%2 == 0 { - continue - } - - n-- - if n == 0 { - return l + 1, false - } - } - - return 0, n > 1 -} - -// equal compares a and b while ignoring case. It returns true when equal otherwise false. -func equal(a, b string) bool { - // might be lifted into API function. - la := len(a) - lb := len(b) - if la != lb { - return false - } - - for i := la - 1; i >= 0; i-- { - ai := a[i] - bi := b[i] - if ai >= 'A' && ai <= 'Z' { - ai |= 'a' - 'A' - } - if bi >= 'A' && bi <= 'Z' { - bi |= 'a' - 'A' - } - if ai != bi { - return false - } - } - return true -} |