119 lines
2.4 KiB
Go
119 lines
2.4 KiB
Go
package upgrade
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import (
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"bytes"
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"fmt"
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"regexp"
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)
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// Line represents the HTTP Request line
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// defined in rfc-2616 : https://tools.ietf.org/html/rfc2616#section-5.1
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type Line struct {
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method Method
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uri string
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version byte
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}
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// Parse parses the first HTTP request line
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func (r *Line) Parse(b []byte) error {
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// 1. Split by ' '
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parts := bytes.Split(b, []byte(" "))
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// 2. Fail when missing parts
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if len(parts) != 3 {
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return fmt.Errorf("expected 3 space-separated elements, got %d elements", len(parts))
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}
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// 3. Extract HTTP method
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err := r.extractHttpMethod(parts[0])
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if err != nil {
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return err
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}
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// 4. Extract URI
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err = r.extractURI(parts[1])
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if err != nil {
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return err
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}
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// 5. Extract version
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err = r.extractHttpVersion(parts[2])
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if err != nil {
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return err
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}
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return nil
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}
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// GetURI returns the actual URI
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func (r Line) GetURI() string {
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return r.uri
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}
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// extractHttpMethod extracts the HTTP method from a []byte
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// and checks for errors
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// allowed format: OPTIONS|GET|HEAD|POST|PUT|DELETE
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func (r *Line) extractHttpMethod(b []byte) error {
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switch string(b) {
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// case "OPTIONS": r.method = OPTIONS
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case "GET":
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r.method = Get
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// case "HEAD": r.method = HEAD
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// case "POST": r.method = POST
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// case "PUT": r.method = PUT
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// case "DELETE": r.method = DELETE
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default:
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return fmt.Errorf("invalid HTTP method '%s', expected 'GET'", b)
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}
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return nil
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}
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// extractURI extracts the URI from a []byte and checks for errors
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// allowed format: /([^/]/)*/?
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func (r *Line) extractURI(b []byte) error {
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// 1. Check format
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checker := regexp.MustCompile("^(?:/[^/]+)*/?$")
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if !checker.Match(b) {
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return fmt.Errorf("invalid URI, expected an absolute path, got '%s'", b)
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}
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// 2. Store
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r.uri = string(b)
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return nil
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}
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// extractHttpVersion extracts the version and checks for errors
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// allowed format: [1-9] or [1.9].[0-9]
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func (r *Line) extractHttpVersion(b []byte) error {
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// 1. Extract version parts
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extractor := regexp.MustCompile(`^HTTP/([1-9])(?:\.([0-9]))?$`)
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if !extractor.Match(b) {
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return fmt.Errorf("invalid HTTP version, expected INT or INT.INT, got '%s'", b)
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}
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// 2. Extract version number
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matches := extractor.FindSubmatch(b)
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var version byte = matches[1][0] - '0'
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// 3. Extract subversion (if exists)
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var subVersion byte = 0
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if len(matches[2]) > 0 {
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subVersion = matches[2][0] - '0'
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}
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// 4. Store version (x 10 to fit uint8)
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r.version = version*10 + subVersion
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return nil
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}
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