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, 01:00 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 caddyfile |
| 16 | |
| 17 | import ( |
| 18 | "fmt" |
| 19 | "io" |
| 20 | "os" |
| 21 | "path/filepath" |
| 22 | |
| 23 | "github.com/caddyserver/caddy/v2" |
| 24 | ) |
| 25 | |
| 26 | type importedFile struct { |
| 27 | path string |
| 28 | content []byte |
| 29 | info os.FileInfo |
| 30 | } |
| 31 | |
| 32 | // discoverImportedFileContents returns files reached by imports which the parser |
| 33 | // actually executes, in discovery order and excluding rootFile. Driving the real |
| 34 | // parser is important here: import behavior depends on declaration order, snippet |
| 35 | // expansion, import arguments, block substitutions, environment expansion, and |
| 36 | // whether an import appears in active configuration. Reimplementing those rules |
| 37 | // in a separate token scanner caused FormatImports to disagree with adaptation. |
| 38 | // |
| 39 | // The parser calls importObserver after opening and reading each imported file, |
| 40 | // but before inserting its tokens. The observer retains those exact bytes for |
| 41 | // formatting so the file is not reopened later. Each physical file is retained |
| 42 | // once, but repeated imports still expand with their own arguments. Only imports |
| 43 | // of an active physical ancestor are skipped, preventing symlink cycles. |
| 44 | // os.FileInfo values are retained to verify that each canonical pathname still |
| 45 | // identifies the file whose contents were parsed. |
| 46 | func discoverImportedFileContents(rootFile string, rootInput []byte, rootInfo os.FileInfo) ([]importedFile, error) { |
| 47 | // Compare file identity rather than path spelling: lexical paths do not catch |
| 48 | // imports such as dir/link/dir/link/Caddyfile through a symlink cycle. |
| 49 | seen := []os.FileInfo{rootInfo} |
| 50 | var files []importedFile |
| 51 | |
| 52 | // allTokens performs environment replacement in-place, so preserve the bytes |
| 53 | // which FormatImports will subsequently pass to the formatter. |
| 54 | inputCopy := append([]byte(nil), rootInput...) |
| 55 | tokens, err := allTokens(rootFile, inputCopy) |
| 56 | if err != nil { |
| 57 | return nil, err |
| 58 | } |
| 59 | rootAncestry := &importAncestor{info: rootInfo} |
| 60 | for i := range tokens { |
| 61 | tokens[i].importAncestry = rootAncestry |
| 62 | } |
| 63 | // Construct the parser exactly as parse() does. The import graph remains |
| 64 | // responsible for logical snippet/import cycles; the observer below adds |
| 65 | // physical-file identity handling for symlink aliases. |
| 66 | p := parser{ |
| 67 | Dispenser: NewDispenser(tokens), |
| 68 | importGraph: importGraph{ |
| 69 | nodes: make(map[string]struct{}), |
| 70 | edges: make(adjacency), |
| 71 | }, |
| 72 | } |
| 73 | p.importObserver = func(path string, info os.FileInfo, content []byte, ancestry *importAncestor) (bool, error) { |
| 74 | for ancestor := ancestry; ancestor != nil; ancestor = ancestor.parent { |
| 75 | if os.SameFile(ancestor.info, info) { |
| 76 | return true, nil |
| 77 | } |
| 78 | } |
| 79 | // Deduplicate output without suppressing argument-dependent descendants |
| 80 | // or imports resolved relative to a different lexical alias. |
| 81 | for _, previous := range seen { |
| 82 | if os.SameFile(previous, info) { |
| 83 | return false, nil |
| 84 | } |
| 85 | } |
| 86 | |
| 87 | // Store one stable, absolute spelling for callers, but verify it still |
| 88 | // resolves to the descriptor which supplied content before retaining it. |
| 89 | canonical, err := canonicalPath(path) |
| 90 | if err != nil { |
| 91 | return false, err |
| 92 | } |
| 93 | currentInfo, err := os.Stat(canonical) |
| 94 | if err != nil { |
| 95 | return false, err |
| 96 | } |
| 97 | if !os.SameFile(info, currentInfo) { |
| 98 | return false, fmt.Errorf("imported file changed while being read") |
| 99 | } |
| 100 | |
| 101 | seen = append(seen, info) |
| 102 | files = append(files, importedFile{ |
| 103 | path: canonical, |
| 104 | // The parser owns its read buffer; keep an independent copy for the |
| 105 | // formatting pass and avoid a second pathname-based read. |
| 106 | content: append([]byte(nil), content...), |
| 107 | info: info, |
| 108 | }) |
| 109 | return false, nil |
| 110 | } |
| 111 | |
| 112 | if _, err := p.parseAll(); err != nil { |
| 113 | return nil, err |
| 114 | } |
| 115 | return files, nil |
| 116 | } |
| 117 | |
| 118 | // canonicalPath returns an absolute path with symlinks resolved. Canonical paths |
| 119 | // make the FormattedFile API consistent for the root and every imported file; |
| 120 | // physical deduplication still uses os.SameFile because spelling alone is not a |
| 121 | // portable file-identity test. |
| 122 | func canonicalPath(path string) (string, error) { |
| 123 | abs, err := caddy.FastAbs(path) |
| 124 | if err != nil { |
| 125 | return "", err |
| 126 | } |
| 127 | return filepath.EvalSymlinks(abs) |
| 128 | } |
| 129 | |
| 130 | // FormattedFile is a file path paired with its formatted contents. |
| 131 | type FormattedFile struct { |
| 132 | Path string |
| 133 | Content []byte |
| 134 | } |
| 135 | |
| 136 | // FormatImports reads filename, formats it (honoring opts), then discovers all |
| 137 | // files reached by active import directives and formats each one independently |
| 138 | // at nesting-0 baseline. WrapUnbracedSite is always disabled for imported files |
| 139 | // because they are fragments, not standalone Caddyfiles. |
| 140 | // |
| 141 | // All returned paths are absolute, symlink-resolved paths. The root file is |
| 142 | // always first, followed by imported files in parser discovery order. |
| 143 | func FormatImports(filename string, opts FormatOptions) ([]FormattedFile, error) { |
| 144 | // Keep the lexical absolute path for parser-relative import resolution, while |
| 145 | // using the canonical path for opening and returning the root file. This |
| 146 | // matches adaptation when the supplied Caddyfile itself is reached by symlink. |
| 147 | rootLexicalPath, err := caddy.FastAbs(filename) |
| 148 | if err != nil { |
| 149 | return nil, err |
| 150 | } |
| 151 | rootPath, err := canonicalPath(filename) |
| 152 | if err != nil { |
| 153 | return nil, err |
| 154 | } |
| 155 | // Reading and statting one open descriptor binds rootBytes and rootInfo to the |
| 156 | // same physical file. Separate ReadFile and Stat calls would permit a pathname |
| 157 | // replacement between the two operations. |
| 158 | root, err := os.Open(rootPath) |
| 159 | if err != nil { |
| 160 | return nil, err |
| 161 | } |
| 162 | rootInfo, err := root.Stat() |
| 163 | if err != nil { |
| 164 | root.Close() |
| 165 | return nil, err |
| 166 | } |
| 167 | rootBytes, err := io.ReadAll(root) |
| 168 | closeErr := root.Close() |
| 169 | if err != nil { |
| 170 | return nil, err |
| 171 | } |
| 172 | if closeErr != nil { |
| 173 | return nil, closeErr |
| 174 | } |
| 175 | |
| 176 | discovered, err := discoverImportedFileContents(rootLexicalPath, rootBytes, rootInfo) |
| 177 | if err != nil { |
| 178 | return nil, err |
| 179 | } |
| 180 | |
| 181 | results := make([]FormattedFile, 0, 1+len(discovered)) |
| 182 | results = append(results, FormattedFile{Path: rootPath, Content: FormatWithOptions(rootBytes, opts)}) |
| 183 | for _, file := range discovered { |
| 184 | results = append(results, FormattedFile{ |
| 185 | Path: file.path, |
| 186 | Content: FormatWithOptions(file.content, FormatOptions{}), |
| 187 | }) |
| 188 | } |
| 189 | |
| 190 | // Formatting can take long enough for a pathname to be replaced. Before |
| 191 | // returning writable paths to the caller, ensure every one still identifies |
| 192 | // the physical file whose bytes were parsed and formatted. The command layer |
| 193 | // performs another check immediately before atomic replacement. |
| 194 | for i, result := range results { |
| 195 | currentInfo, err := os.Stat(result.Path) |
| 196 | if err != nil { |
| 197 | return nil, err |
| 198 | } |
| 199 | originalInfo := rootInfo |
| 200 | if i > 0 { |
| 201 | originalInfo = discovered[i-1].info |
| 202 | } |
| 203 | if !os.SameFile(originalInfo, currentInfo) { |
| 204 | return nil, fmt.Errorf("file changed while formatting: %s", result.Path) |
| 205 | } |
| 206 | } |
| 207 | |
| 208 | return results, nil |
| 209 | } |