diff options
Diffstat (limited to 'vendor/github.com/grpc-ecosystem/grpc-gateway/v2/runtime/context.go')
| -rw-r--r-- | vendor/github.com/grpc-ecosystem/grpc-gateway/v2/runtime/context.go | 417 |
1 files changed, 417 insertions, 0 deletions
diff --git a/vendor/github.com/grpc-ecosystem/grpc-gateway/v2/runtime/context.go b/vendor/github.com/grpc-ecosystem/grpc-gateway/v2/runtime/context.go new file mode 100644 index 00000000..2f2b3424 --- /dev/null +++ b/vendor/github.com/grpc-ecosystem/grpc-gateway/v2/runtime/context.go @@ -0,0 +1,417 @@ +package runtime + +import ( + "context" + "encoding/base64" + "fmt" + "net" + "net/http" + "net/textproto" + "strconv" + "strings" + "sync" + "time" + + "google.golang.org/grpc/codes" + "google.golang.org/grpc/grpclog" + "google.golang.org/grpc/metadata" + "google.golang.org/grpc/status" +) + +// MetadataHeaderPrefix is the http prefix that represents custom metadata +// parameters to or from a gRPC call. +const MetadataHeaderPrefix = "Grpc-Metadata-" + +// MetadataPrefix is prepended to permanent HTTP header keys (as specified +// by the IANA) when added to the gRPC context. +const MetadataPrefix = "grpcgateway-" + +// MetadataTrailerPrefix is prepended to gRPC metadata as it is converted to +// HTTP headers in a response handled by grpc-gateway +const MetadataTrailerPrefix = "Grpc-Trailer-" + +const metadataGrpcTimeout = "Grpc-Timeout" +const metadataHeaderBinarySuffix = "-Bin" + +const xForwardedFor = "X-Forwarded-For" +const xForwardedHost = "X-Forwarded-Host" + +// DefaultContextTimeout is used for gRPC call context.WithTimeout whenever a Grpc-Timeout inbound +// header isn't present. If the value is 0 the sent `context` will not have a timeout. +var DefaultContextTimeout = 0 * time.Second + +// malformedHTTPHeaders lists the headers that the gRPC server may reject outright as malformed. +// See https://github.com/grpc/grpc-go/pull/4803#issuecomment-986093310 for more context. +var malformedHTTPHeaders = map[string]struct{}{ + "connection": {}, +} + +type ( + rpcMethodKey struct{} + httpPathPatternKey struct{} + httpPatternKey struct{} + + AnnotateContextOption func(ctx context.Context) context.Context +) + +func WithHTTPPathPattern(pattern string) AnnotateContextOption { + return func(ctx context.Context) context.Context { + return withHTTPPathPattern(ctx, pattern) + } +} + +func decodeBinHeader(v string) ([]byte, error) { + if len(v)%4 == 0 { + // Input was padded, or padding was not necessary. + return base64.StdEncoding.DecodeString(v) + } + return base64.RawStdEncoding.DecodeString(v) +} + +/* +AnnotateContext adds context information such as metadata from the request. + +At a minimum, the RemoteAddr is included in the fashion of "X-Forwarded-For", +except that the forwarded destination is not another HTTP service but rather +a gRPC service. +*/ +func AnnotateContext(ctx context.Context, mux *ServeMux, req *http.Request, rpcMethodName string, options ...AnnotateContextOption) (context.Context, error) { + ctx, md, err := annotateContext(ctx, mux, req, rpcMethodName, options...) + if err != nil { + return nil, err + } + if md == nil { + return ctx, nil + } + + return metadata.NewOutgoingContext(ctx, md), nil +} + +// AnnotateIncomingContext adds context information such as metadata from the request. +// Attach metadata as incoming context. +func AnnotateIncomingContext(ctx context.Context, mux *ServeMux, req *http.Request, rpcMethodName string, options ...AnnotateContextOption) (context.Context, error) { + ctx, md, err := annotateContext(ctx, mux, req, rpcMethodName, options...) + if err != nil { + return nil, err + } + if md == nil { + return ctx, nil + } + + return metadata.NewIncomingContext(ctx, md), nil +} + +func isValidGRPCMetadataKey(key string) bool { + // Must be a valid gRPC "Header-Name" as defined here: + // https://github.com/grpc/grpc/blob/4b05dc88b724214d0c725c8e7442cbc7a61b1374/doc/PROTOCOL-HTTP2.md + // This means 0-9 a-z _ - . + // Only lowercase letters are valid in the wire protocol, but the client library will normalize + // uppercase ASCII to lowercase, so uppercase ASCII is also acceptable. + bytes := []byte(key) // gRPC validates strings on the byte level, not Unicode. + for _, ch := range bytes { + validLowercaseLetter := ch >= 'a' && ch <= 'z' + validUppercaseLetter := ch >= 'A' && ch <= 'Z' + validDigit := ch >= '0' && ch <= '9' + validOther := ch == '.' || ch == '-' || ch == '_' + if !validLowercaseLetter && !validUppercaseLetter && !validDigit && !validOther { + return false + } + } + return true +} + +func isValidGRPCMetadataTextValue(textValue string) bool { + // Must be a valid gRPC "ASCII-Value" as defined here: + // https://github.com/grpc/grpc/blob/4b05dc88b724214d0c725c8e7442cbc7a61b1374/doc/PROTOCOL-HTTP2.md + // This means printable ASCII (including/plus spaces); 0x20 to 0x7E inclusive. + bytes := []byte(textValue) // gRPC validates strings on the byte level, not Unicode. + for _, ch := range bytes { + if ch < 0x20 || ch > 0x7E { + return false + } + } + return true +} + +func annotateContext(ctx context.Context, mux *ServeMux, req *http.Request, rpcMethodName string, options ...AnnotateContextOption) (context.Context, metadata.MD, error) { + ctx = withRPCMethod(ctx, rpcMethodName) + for _, o := range options { + ctx = o(ctx) + } + timeout := DefaultContextTimeout + if tm := req.Header.Get(metadataGrpcTimeout); tm != "" { + var err error + timeout, err = timeoutDecode(tm) + if err != nil { + return nil, nil, status.Errorf(codes.InvalidArgument, "invalid grpc-timeout: %s", tm) + } + } + var pairs []string + for key, vals := range req.Header { + key = textproto.CanonicalMIMEHeaderKey(key) + switch key { + case xForwardedFor, xForwardedHost: + // Handled separately below + continue + } + + for _, val := range vals { + // For backwards-compatibility, pass through 'authorization' header with no prefix. + if key == "Authorization" { + pairs = append(pairs, "authorization", val) + } + if h, ok := mux.incomingHeaderMatcher(key); ok { + if !isValidGRPCMetadataKey(h) { + grpclog.Errorf("HTTP header name %q is not valid as gRPC metadata key; skipping", h) + continue + } + // Handles "-bin" metadata in grpc, since grpc will do another base64 + // encode before sending to server, we need to decode it first. + if strings.HasSuffix(key, metadataHeaderBinarySuffix) { + b, err := decodeBinHeader(val) + if err != nil { + return nil, nil, status.Errorf(codes.InvalidArgument, "invalid binary header %s: %s", key, err) + } + + val = string(b) + } else if !isValidGRPCMetadataTextValue(val) { + grpclog.Errorf("Value of HTTP header %q contains non-ASCII value (not valid as gRPC metadata): skipping", h) + continue + } + pairs = append(pairs, h, val) + } + } + } + if host := req.Header.Get(xForwardedHost); host != "" { + pairs = append(pairs, strings.ToLower(xForwardedHost), host) + } else if req.Host != "" { + pairs = append(pairs, strings.ToLower(xForwardedHost), req.Host) + } + + xff := req.Header.Values(xForwardedFor) + if addr := req.RemoteAddr; addr != "" { + if remoteIP, _, err := net.SplitHostPort(addr); err == nil { + xff = append(xff, remoteIP) + } + } + if len(xff) > 0 { + pairs = append(pairs, strings.ToLower(xForwardedFor), strings.Join(xff, ", ")) + } + + if timeout != 0 { + ctx, _ = context.WithTimeout(ctx, timeout) + } + if len(pairs) == 0 { + return ctx, nil, nil + } + md := metadata.Pairs(pairs...) + for _, mda := range mux.metadataAnnotators { + md = metadata.Join(md, mda(ctx, req)) + } + return ctx, md, nil +} + +// ServerMetadata consists of metadata sent from gRPC server. +type ServerMetadata struct { + HeaderMD metadata.MD + TrailerMD metadata.MD +} + +type serverMetadataKey struct{} + +// NewServerMetadataContext creates a new context with ServerMetadata +func NewServerMetadataContext(ctx context.Context, md ServerMetadata) context.Context { + if ctx == nil { + ctx = context.Background() + } + return context.WithValue(ctx, serverMetadataKey{}, md) +} + +// ServerMetadataFromContext returns the ServerMetadata in ctx +func ServerMetadataFromContext(ctx context.Context) (md ServerMetadata, ok bool) { + if ctx == nil { + return md, false + } + md, ok = ctx.Value(serverMetadataKey{}).(ServerMetadata) + return +} + +// ServerTransportStream implements grpc.ServerTransportStream. +// It should only be used by the generated files to support grpc.SendHeader +// outside of gRPC server use. +type ServerTransportStream struct { + mu sync.Mutex + header metadata.MD + trailer metadata.MD +} + +// Method returns the method for the stream. +func (s *ServerTransportStream) Method() string { + return "" +} + +// Header returns the header metadata of the stream. +func (s *ServerTransportStream) Header() metadata.MD { + s.mu.Lock() + defer s.mu.Unlock() + return s.header.Copy() +} + +// SetHeader sets the header metadata. +func (s *ServerTransportStream) SetHeader(md metadata.MD) error { + if md.Len() == 0 { + return nil + } + + s.mu.Lock() + s.header = metadata.Join(s.header, md) + s.mu.Unlock() + return nil +} + +// SendHeader sets the header metadata. +func (s *ServerTransportStream) SendHeader(md metadata.MD) error { + return s.SetHeader(md) +} + +// Trailer returns the cached trailer metadata. +func (s *ServerTransportStream) Trailer() metadata.MD { + s.mu.Lock() + defer s.mu.Unlock() + return s.trailer.Copy() +} + +// SetTrailer sets the trailer metadata. +func (s *ServerTransportStream) SetTrailer(md metadata.MD) error { + if md.Len() == 0 { + return nil + } + + s.mu.Lock() + s.trailer = metadata.Join(s.trailer, md) + s.mu.Unlock() + return nil +} + +func timeoutDecode(s string) (time.Duration, error) { + size := len(s) + if size < 2 { + return 0, fmt.Errorf("timeout string is too short: %q", s) + } + d, ok := timeoutUnitToDuration(s[size-1]) + if !ok { + return 0, fmt.Errorf("timeout unit is not recognized: %q", s) + } + t, err := strconv.ParseInt(s[:size-1], 10, 64) + if err != nil { + return 0, err + } + return d * time.Duration(t), nil +} + +func timeoutUnitToDuration(u uint8) (d time.Duration, ok bool) { + switch u { + case 'H': + return time.Hour, true + case 'M': + return time.Minute, true + case 'S': + return time.Second, true + case 'm': + return time.Millisecond, true + case 'u': + return time.Microsecond, true + case 'n': + return time.Nanosecond, true + default: + return + } +} + +// isPermanentHTTPHeader checks whether hdr belongs to the list of +// permanent request headers maintained by IANA. +// http://www.iana.org/assignments/message-headers/message-headers.xml +func isPermanentHTTPHeader(hdr string) bool { + switch hdr { + case + "Accept", + "Accept-Charset", + "Accept-Language", + "Accept-Ranges", + "Authorization", + "Cache-Control", + "Content-Type", + "Cookie", + "Date", + "Expect", + "From", + "Host", + "If-Match", + "If-Modified-Since", + "If-None-Match", + "If-Schedule-Tag-Match", + "If-Unmodified-Since", + "Max-Forwards", + "Origin", + "Pragma", + "Referer", + "User-Agent", + "Via", + "Warning": + return true + } + return false +} + +// isMalformedHTTPHeader checks whether header belongs to the list of +// "malformed headers" and would be rejected by the gRPC server. +func isMalformedHTTPHeader(header string) bool { + _, isMalformed := malformedHTTPHeaders[strings.ToLower(header)] + return isMalformed +} + +// RPCMethod returns the method string for the server context. The returned +// string is in the format of "/package.service/method". +func RPCMethod(ctx context.Context) (string, bool) { + m := ctx.Value(rpcMethodKey{}) + if m == nil { + return "", false + } + ms, ok := m.(string) + if !ok { + return "", false + } + return ms, true +} + +func withRPCMethod(ctx context.Context, rpcMethodName string) context.Context { + return context.WithValue(ctx, rpcMethodKey{}, rpcMethodName) +} + +// HTTPPathPattern returns the HTTP path pattern string relating to the HTTP handler, if one exists. +// The format of the returned string is defined by the google.api.http path template type. +func HTTPPathPattern(ctx context.Context) (string, bool) { + m := ctx.Value(httpPathPatternKey{}) + if m == nil { + return "", false + } + ms, ok := m.(string) + if !ok { + return "", false + } + return ms, true +} + +func withHTTPPathPattern(ctx context.Context, httpPathPattern string) context.Context { + return context.WithValue(ctx, httpPathPatternKey{}, httpPathPattern) +} + +// HTTPPattern returns the HTTP path pattern struct relating to the HTTP handler, if one exists. +func HTTPPattern(ctx context.Context) (Pattern, bool) { + v, ok := ctx.Value(httpPatternKey{}).(Pattern) + return v, ok +} + +func withHTTPPattern(ctx context.Context, httpPattern Pattern) context.Context { + return context.WithValue(ctx, httpPatternKey{}, httpPattern) +} |
