Fast and extensible multi-platform HTTP/1-2-3 web server with automatic HTTPS
Mirrored from https://github.com/Slazee/caddy.git
Synced Nov 11, 02:15 UTC
| 1 | // Copyright 2015 Matthew Holt and The Caddy Authors |
| 2 | // |
| 3 | // Licensed under the Apache License, Version 2.0 (the "License"); |
| 4 | // you may not use this file except in compliance with the License. |
| 5 | // You may obtain a copy of the License at |
| 6 | // |
| 7 | // http://www.apache.org/licenses/LICENSE-2.0 |
| 8 | // |
| 9 | // Unless required by applicable law or agreed to in writing, software |
| 10 | // distributed under the License is distributed on an "AS IS" BASIS, |
| 11 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 12 | // See the License for the specific language governing permissions and |
| 13 | // limitations under the License. |
| 14 | |
| 15 | package fastcgi |
| 16 | |
| 17 | import ( |
| 18 | "bytes" |
| 19 | "encoding/binary" |
| 20 | ) |
| 21 | |
| 22 | // streamWriter abstracts out the separation of a stream into discrete records. |
| 23 | // It only writes maxWrite bytes at a time. |
| 24 | type streamWriter struct { |
| 25 | c *client |
| 26 | h header |
| 27 | buf *bytes.Buffer |
| 28 | recType uint8 |
| 29 | } |
| 30 | |
| 31 | func (w *streamWriter) writeRecord(recType uint8, content []byte) (err error) { |
| 32 | w.h.init(recType, w.c.reqID, len(content)) |
| 33 | w.buf.Write(pad[:8]) |
| 34 | w.writeHeader() |
| 35 | w.buf.Write(content) |
| 36 | w.buf.Write(pad[:w.h.PaddingLength]) |
| 37 | _, err = w.buf.WriteTo(w.c.rwc) |
| 38 | return err |
| 39 | } |
| 40 | |
| 41 | func (w *streamWriter) writeBeginRequest(role uint16, flags uint8) error { |
| 42 | b := [8]byte{byte(role >> 8), byte(role), flags} |
| 43 | return w.writeRecord(BeginRequest, b[:]) |
| 44 | } |
| 45 | |
| 46 | func (w *streamWriter) Write(p []byte) (int, error) { |
| 47 | // init header |
| 48 | if w.buf.Len() < 8 { |
| 49 | w.buf.Write(pad[:8]) |
| 50 | } |
| 51 | |
| 52 | nn := 0 |
| 53 | for len(p) > 0 { |
| 54 | n := len(p) |
| 55 | nl := maxWrite + 8 - w.buf.Len() |
| 56 | if n > nl { |
| 57 | n = nl |
| 58 | w.buf.Write(p[:n]) |
| 59 | if err := w.Flush(); err != nil { |
| 60 | return nn, err |
| 61 | } |
| 62 | // reset headers |
| 63 | w.buf.Write(pad[:8]) |
| 64 | } else { |
| 65 | w.buf.Write(p[:n]) |
| 66 | } |
| 67 | nn += n |
| 68 | p = p[n:] |
| 69 | } |
| 70 | return nn, nil |
| 71 | } |
| 72 | |
| 73 | func (w *streamWriter) endStream() error { |
| 74 | // send empty record to close the stream |
| 75 | return w.writeRecord(w.recType, nil) |
| 76 | } |
| 77 | |
| 78 | func (w *streamWriter) writePairs(pairs map[string]string) error { |
| 79 | b := make([]byte, 8) |
| 80 | nn := 0 |
| 81 | // init headers |
| 82 | w.buf.Write(b) |
| 83 | for k, v := range pairs { |
| 84 | m := 8 + len(k) + len(v) |
| 85 | if m > maxWrite { |
| 86 | // param data size exceed 65535 bytes" |
| 87 | vl := maxWrite - 8 - len(k) |
| 88 | v = v[:vl] |
| 89 | } |
| 90 | n := encodeSize(b, uint32(len(k))) |
| 91 | n += encodeSize(b[n:], uint32(len(v))) |
| 92 | m = n + len(k) + len(v) |
| 93 | if (nn + m) > maxWrite { |
| 94 | if err := w.Flush(); err != nil { |
| 95 | return err |
| 96 | } |
| 97 | // reset headers |
| 98 | w.buf.Write(b) |
| 99 | nn = 0 |
| 100 | } |
| 101 | nn += m |
| 102 | w.buf.Write(b[:n]) |
| 103 | w.buf.WriteString(k) |
| 104 | w.buf.WriteString(v) |
| 105 | } |
| 106 | return w.FlushStream() |
| 107 | } |
| 108 | |
| 109 | func encodeSize(b []byte, size uint32) int { |
| 110 | if size > 127 { |
| 111 | size |= 1 << 31 |
| 112 | binary.BigEndian.PutUint32(b, size) |
| 113 | return 4 |
| 114 | } |
| 115 | b[0] = byte(size) //nolint:gosec // false positive; b is made 8 bytes long, then this function is always called with b being at least 4 or 1 byte long |
| 116 | return 1 |
| 117 | } |
| 118 | |
| 119 | // writeHeader populate header wire data in buf, it abuses buffer.Bytes() modification |
| 120 | func (w *streamWriter) writeHeader() { |
| 121 | h := w.buf.Bytes()[:8] |
| 122 | h[0] = w.h.Version |
| 123 | h[1] = w.h.Type |
| 124 | binary.BigEndian.PutUint16(h[2:4], w.h.ID) |
| 125 | binary.BigEndian.PutUint16(h[4:6], w.h.ContentLength) |
| 126 | h[6] = w.h.PaddingLength |
| 127 | h[7] = w.h.Reserved |
| 128 | } |
| 129 | |
| 130 | // Flush write buffer data to the underlying connection, it assumes header data is the first 8 bytes of buf |
| 131 | func (w *streamWriter) Flush() error { |
| 132 | w.h.init(w.recType, w.c.reqID, w.buf.Len()-8) |
| 133 | w.writeHeader() |
| 134 | w.buf.Write(pad[:w.h.PaddingLength]) |
| 135 | _, err := w.buf.WriteTo(w.c.rwc) |
| 136 | return err |
| 137 | } |
| 138 | |
| 139 | // FlushStream flush data then end current stream |
| 140 | func (w *streamWriter) FlushStream() error { |
| 141 | if err := w.Flush(); err != nil { |
| 142 | return err |
| 143 | } |
| 144 | return w.endStream() |
| 145 | } |