package api import ( "bytes" "encoding/json" "fmt" "io" "net/http" "net/textproto" "net/url" "strconv" "strings" "github.com/prometheus/client_golang/prometheus" "github.com/prometheus/client_golang/prometheus/promauto" "gitlab.com/gitlab-org/gitaly/proto/go/gitalypb" "gitlab.com/gitlab-org/gitlab-workhorse/internal/config" "gitlab.com/gitlab-org/gitlab-workhorse/internal/gitaly" "gitlab.com/gitlab-org/gitlab-workhorse/internal/helper" "gitlab.com/gitlab-org/gitlab-workhorse/internal/log" "gitlab.com/gitlab-org/gitlab-workhorse/internal/secret" ) const ( // Custom content type for API responses, to catch routing / programming mistakes ResponseContentType = "application/vnd.gitlab-workhorse+json" failureResponseLimit = 32768 ) type API struct { Client *http.Client URL *url.URL Version string } var ( requestsCounter = promauto.NewCounterVec( prometheus.CounterOpts{ Name: "gitlab_workhorse_internal_api_requests", Help: "How many internal API requests have been completed by gitlab-workhorse, partitioned by status code and HTTP method.", }, []string{"code", "method"}, ) bytesTotal = promauto.NewCounter( prometheus.CounterOpts{ Name: "gitlab_workhorse_internal_api_failure_response_bytes", Help: "How many bytes have been returned by upstream GitLab in API failure/rejection response bodies.", }, ) ) func NewAPI(myURL *url.URL, version string, roundTripper http.RoundTripper) *API { return &API{ Client: &http.Client{Transport: roundTripper}, URL: myURL, Version: version, } } type HandleFunc func(http.ResponseWriter, *http.Request, *Response) type MultipartUploadParams struct { // PartSize is the exact size of each uploaded part. Only the last one can be smaller PartSize int64 // PartURLs contains the presigned URLs for each part PartURLs []string // CompleteURL is a presigned URL for CompleteMulipartUpload CompleteURL string // AbortURL is a presigned URL for AbortMultipartUpload AbortURL string } type ObjectStorageParams struct { Provider string S3Config config.S3Config GoCloudConfig config.GoCloudConfig } type RemoteObject struct { // GetURL is an S3 GetObject URL GetURL string // DeleteURL is a presigned S3 RemoveObject URL DeleteURL string // StoreURL is the temporary presigned S3 PutObject URL to which upload the first found file StoreURL string // Boolean to indicate whether to use headers included in PutHeaders CustomPutHeaders bool // PutHeaders are HTTP headers (e.g. Content-Type) to be sent with StoreURL PutHeaders map[string]string // Whether to ignore Rails pre-signed URLs and have Workhorse directly access object storage provider UseWorkhorseClient bool // Remote, temporary object name where Rails will move to the final destination RemoteTempObjectID string // ID is a unique identifier of object storage upload ID string // Timeout is a number that represents timeout in seconds for sending data to StoreURL Timeout int // MultipartUpload contains presigned URLs for S3 MultipartUpload MultipartUpload *MultipartUploadParams // Object storage config for Workhorse client ObjectStorage *ObjectStorageParams } type Response struct { // GL_ID is an environment variable used by gitlab-shell hooks during 'git // push' and 'git pull' GL_ID string // GL_USERNAME holds gitlab username of the user who is taking the action causing hooks to be invoked GL_USERNAME string // GL_REPOSITORY is an environment variable used by gitlab-shell hooks during // 'git push' and 'git pull' GL_REPOSITORY string // GitConfigOptions holds the custom options that we want to pass to the git command GitConfigOptions []string // StoreLFSPath is provided by the GitLab Rails application to mark where the tmp file should be placed. // This field is deprecated. GitLab will use TempPath instead StoreLFSPath string // LFS object id LfsOid string // LFS object size LfsSize int64 // TmpPath is the path where we should store temporary files // This is set by authorization middleware TempPath string // RemoteObject is provided by the GitLab Rails application // and defines a way to store object on remote storage RemoteObject RemoteObject // Archive is the path where the artifacts archive is stored Archive string `json:"archive"` // Entry is a filename inside the archive point to file that needs to be extracted Entry string `json:"entry"` // Used to communicate channel session details Channel *ChannelSettings // GitalyServer specifies an address and authentication token for a gitaly server we should connect to. GitalyServer gitaly.Server // Repository object for making gRPC requests to Gitaly. Repository gitalypb.Repository // For git-http, does the requestor have the right to view all refs? ShowAllRefs bool // Detects whether an artifact is used for code intelligence ProcessLsif bool // Detects whether LSIF artifact will be parsed with references ProcessLsifReferences bool // The maximum accepted size in bytes of the upload MaximumSize int64 // Feature flag used to determine whether to strip the multipart filename of any directories FeatureFlagExtractBase bool } // singleJoiningSlash is taken from reverseproxy.go:singleJoiningSlash func singleJoiningSlash(a, b string) string { aslash := strings.HasSuffix(a, "/") bslash := strings.HasPrefix(b, "/") switch { case aslash && bslash: return a + b[1:] case !aslash && !bslash: return a + "/" + b } return a + b } // joinURLPath is taken from reverseproxy.go:joinURLPath func joinURLPath(a *url.URL, b string) (path string, rawpath string) { if a.RawPath == "" && b == "" { return singleJoiningSlash(a.Path, b), "" } // Same as singleJoiningSlash, but uses EscapedPath to determine // whether a slash should be added apath := a.EscapedPath() bpath := b aslash := strings.HasSuffix(apath, "/") bslash := strings.HasPrefix(bpath, "/") switch { case aslash && bslash: return a.Path + bpath[1:], apath + bpath[1:] case !aslash && !bslash: return a.Path + "/" + bpath, apath + "/" + bpath } return a.Path + bpath, apath + bpath } // rebaseUrl is taken from reverseproxy.go:NewSingleHostReverseProxy func rebaseUrl(url *url.URL, onto *url.URL, suffix string) *url.URL { newUrl := *url newUrl.Scheme = onto.Scheme newUrl.Host = onto.Host newUrl.Path, newUrl.RawPath = joinURLPath(url, suffix) if onto.RawQuery == "" || newUrl.RawQuery == "" { newUrl.RawQuery = onto.RawQuery + newUrl.RawQuery } else { newUrl.RawQuery = onto.RawQuery + "&" + newUrl.RawQuery } return &newUrl } func (api *API) newRequest(r *http.Request, suffix string) (*http.Request, error) { authReq := &http.Request{ Method: r.Method, URL: rebaseUrl(r.URL, api.URL, suffix), Header: helper.HeaderClone(r.Header), } authReq = authReq.WithContext(r.Context()) removeConnectionHeaders(authReq.Header) // Clean some headers when issuing a new request without body authReq.Header.Del("Content-Type") authReq.Header.Del("Content-Encoding") authReq.Header.Del("Content-Length") authReq.Header.Del("Content-Disposition") authReq.Header.Del("Accept-Encoding") // Hop-by-hop headers. These are removed when sent to the backend. // http://www.w3.org/Protocols/rfc2616/rfc2616-sec13.html authReq.Header.Del("Transfer-Encoding") authReq.Header.Del("Connection") authReq.Header.Del("Keep-Alive") authReq.Header.Del("Proxy-Authenticate") authReq.Header.Del("Proxy-Authorization") authReq.Header.Del("Te") // "Trailer", not "Trailers" as per rfc2616; See errata https://www.rfc-editor.org/errata_search.php?eid=4522 // See https://httpwg.org/http-core/draft-ietf-httpbis-semantics-latest.html#field.connection authReq.Header.Del("Trailer") authReq.Header.Del("Upgrade") // Also forward the Host header, which is excluded from the Header map by the http library. // This allows the Host header received by the backend to be consistent with other // requests not going through gitlab-workhorse. authReq.Host = r.Host return authReq, nil } // PreAuthorize performs a pre-authorization check against the API for the given HTTP request // // If `outErr` is set, the other fields will be nil and it should be treated as // a 500 error. // // If httpResponse is present, the caller is responsible for closing its body // // authResponse will only be present if the authorization check was successful func (api *API) PreAuthorize(suffix string, r *http.Request) (httpResponse *http.Response, authResponse *Response, outErr error) { authReq, err := api.newRequest(r, suffix) if err != nil { return nil, nil, fmt.Errorf("preAuthorizeHandler newUpstreamRequest: %v", err) } httpResponse, err = api.doRequestWithoutRedirects(authReq) if err != nil { return nil, nil, fmt.Errorf("preAuthorizeHandler: do request: %v", err) } defer func() { if outErr != nil { httpResponse.Body.Close() httpResponse = nil } }() requestsCounter.WithLabelValues(strconv.Itoa(httpResponse.StatusCode), authReq.Method).Inc() // This may be a false positive, e.g. for .../info/refs, rather than a // failure, so pass the response back if httpResponse.StatusCode != http.StatusOK || !validResponseContentType(httpResponse) { return httpResponse, nil, nil } authResponse = &Response{} // The auth backend validated the client request and told us additional // request metadata. We must extract this information from the auth // response body. if err := json.NewDecoder(httpResponse.Body).Decode(authResponse); err != nil { return httpResponse, nil, fmt.Errorf("preAuthorizeHandler: decode authorization response: %v", err) } return httpResponse, authResponse, nil } func (api *API) PreAuthorizeHandler(next HandleFunc, suffix string) http.Handler { return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { httpResponse, authResponse, err := api.PreAuthorize(suffix, r) if httpResponse != nil { defer httpResponse.Body.Close() } if err != nil { helper.Fail500(w, r, err) return } // The response couldn't be interpreted as a valid auth response, so // pass it back (mostly) unmodified if httpResponse != nil && authResponse == nil { passResponseBack(httpResponse, w, r) return } httpResponse.Body.Close() // Free up the Unicorn worker copyAuthHeader(httpResponse, w) next(w, r, authResponse) }) } func (api *API) doRequestWithoutRedirects(authReq *http.Request) (*http.Response, error) { signingTripper := secret.NewRoundTripper(api.Client.Transport, api.Version) return signingTripper.RoundTrip(authReq) } // removeConnectionHeaders removes hop-by-hop headers listed in the "Connection" header of h. // See https://tools.ietf.org/html/rfc7230#section-6.1 func removeConnectionHeaders(h http.Header) { for _, f := range h["Connection"] { for _, sf := range strings.Split(f, ",") { if sf = textproto.TrimString(sf); sf != "" { h.Del(sf) } } } } func copyAuthHeader(httpResponse *http.Response, w http.ResponseWriter) { // Negotiate authentication (Kerberos) may need to return a WWW-Authenticate // header to the client even in case of success as per RFC4559. for k, v := range httpResponse.Header { // Case-insensitive comparison as per RFC7230 if strings.EqualFold(k, "WWW-Authenticate") { w.Header()[k] = v } } } func passResponseBack(httpResponse *http.Response, w http.ResponseWriter, r *http.Request) { // NGINX response buffering is disabled on this path (with // X-Accel-Buffering: no) but we still want to free up the Unicorn worker // that generated httpResponse as fast as possible. To do this we buffer // the entire response body in memory before sending it on. responseBody, err := bufferResponse(httpResponse.Body) if err != nil { helper.Fail500(w, r, err) return } httpResponse.Body.Close() // Free up the Unicorn worker bytesTotal.Add(float64(responseBody.Len())) for k, v := range httpResponse.Header { // Accommodate broken clients that do case-sensitive header lookup if k == "Www-Authenticate" { w.Header()["WWW-Authenticate"] = v } else { w.Header()[k] = v } } w.WriteHeader(httpResponse.StatusCode) if _, err := io.Copy(w, responseBody); err != nil { log.WithRequest(r).WithError(err).Error() } } func bufferResponse(r io.Reader) (*bytes.Buffer, error) { responseBody := &bytes.Buffer{} n, err := io.Copy(responseBody, io.LimitReader(r, failureResponseLimit)) if err != nil { return nil, err } if n == failureResponseLimit { return nil, fmt.Errorf("response body exceeded maximum buffer size (%d bytes)", failureResponseLimit) } return responseBody, nil } func validResponseContentType(resp *http.Response) bool { return helper.IsContentType(ResponseContentType, resp.Header.Get("Content-Type")) }