135 lines
2.7 KiB
Go
135 lines
2.7 KiB
Go
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package request
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import (
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"fmt"
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"bytes"
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"regexp"
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)
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// httpMethod represents available http methods
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type httpMethod byte
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const (
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OPTIONS httpMethod = iota
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GET
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HEAD
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POST
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PUT
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DELETE
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)
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// RequestLine 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 RequestLine struct {
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method httpMethod
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uri string
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version byte
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}
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// parseRequestLine parses the first HTTP request line
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func (r *RequestLine) 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 RequestLine) 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 *RequestLine) 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": 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 *RequestLine) extractURI(b []byte) error {
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/* (1) Check format */
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checker := regexp.MustCompile("^(?:/[^/]+)*/?$")
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if !checker.Match(b) {
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return fmt.Errorf("invalid URI, expected an absolute path, got '%s'", b)
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}
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/* (2) Store */
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r.uri = string(b)
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return nil
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}
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// extractHttpVersion extracts the version and checks for errors
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// allowed format: [1-9] or [1.9].[0-9]
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func (r *RequestLine) extractHttpVersion(b []byte) error {
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/* (1) Extract version parts */
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extractor := regexp.MustCompile(`^HTTP/([1-9])(?:\.([0-9]))?$`);
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if !extractor.Match(b) {
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return fmt.Errorf("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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