| 1 | package config |
| 2 | |
| 3 | import ( |
| 4 | "fmt" |
| 5 | "os" |
| 6 | "path/filepath" |
| 7 | "strings" |
| 8 | |
| 9 | "reasonix/internal/pathidentity" |
| 10 | ) |
| 11 | |
| 12 | // resolveConfigAccessPath resolves a config file symlink before any content is |
| 13 | // read or written. User config links are an explicit user choice and may target |
| 14 | // any valid file. Project links are repository-controlled, so their final target |
| 15 | // must stay within the project root (the directory containing reasonix.toml). |
| 16 | func resolveConfigAccessPath(path string, userConfig bool) (string, error) { |
| 17 | if resolved, ok := pinnedConfigEditPath(path); ok { |
| 18 | return resolved, nil |
| 19 | } |
| 20 | return resolveConfigAccessPathUnpinned(path, userConfig) |
| 21 | } |
| 22 | |
| 23 | func resolveConfigAccessPathUnpinned(path string, userConfig bool) (string, error) { |
| 24 | path = strings.TrimSpace(path) |
| 25 | if path == "" { |
| 26 | return "", fmt.Errorf("config path is empty") |
| 27 | } |
| 28 | logical, err := filepath.Abs(filepath.Clean(path)) |
| 29 | if err != nil { |
| 30 | return "", fmt.Errorf("resolve config path %q: %w", path, err) |
| 31 | } |
| 32 | resolved, err := evalSymlinksAllowMissing(logical) |
| 33 | if err != nil && plainConfigEntry(logical) { |
| 34 | return logical, nil |
| 35 | } |
| 36 | if err != nil { |
| 37 | scope := "project" |
| 38 | if userConfig { |
| 39 | scope = "user" |
| 40 | } |
| 41 | return "", fmt.Errorf("resolve %s config path %q: %w", scope, logical, err) |
| 42 | } |
| 43 | resolved = filepath.Clean(resolved) |
| 44 | if userConfig { |
| 45 | return resolved, nil |
| 46 | } |
| 47 | |
| 48 | root, err := evalSymlinksAllowMissing(filepath.Dir(logical)) |
| 49 | if err != nil { |
| 50 | return "", fmt.Errorf("resolve project root %q: %w", root, err) |
| 51 | } |
| 52 | root = filepath.Clean(root) |
| 53 | if !pathWithinRoot(root, resolved) { |
| 54 | return "", fmt.Errorf("project config path %q resolves outside project root %q: %q", logical, root, resolved) |
| 55 | } |
| 56 | return resolved, nil |
| 57 | } |
| 58 | |
| 59 | // plainConfigEntry reports whether path is absent or a non-link file. Such an |
| 60 | // entry lives in its own directory whatever its ancestors resolve to, so a |
| 61 | // cloud-drive mount that refuses canonicalization (Box Drive) need not |
| 62 | // block it; a link still has to resolve before it is trusted. |
| 63 | func plainConfigEntry(path string) bool { |
| 64 | info, err := os.Lstat(path) |
| 65 | if err != nil { |
| 66 | return os.IsNotExist(err) |
| 67 | } |
| 68 | return info.Mode()&os.ModeSymlink == 0 && !info.IsDir() |
| 69 | } |
| 70 | |
| 71 | var resolvePathIdentity = pathidentity.Resolve |
| 72 | |
| 73 | // evalSymlinksAllowMissing canonicalizes every existing path component while |
| 74 | // allowing a new file (and missing parent directories) to be created later. |
| 75 | // A broken link is not "missing": the shared resolver rejects it, preventing |
| 76 | // a write from replacing it. Windows junctions use the same native boundary. |
| 77 | func evalSymlinksAllowMissing(path string) (string, error) { |
| 78 | absolute, err := filepath.Abs(path) |
| 79 | if err != nil { |
| 80 | return "", err |
| 81 | } |
| 82 | identity, err := resolvePathIdentity(absolute, pathidentity.Options{FollowLeaf: true}) |
| 83 | return identity.PhysicalPath, err |
| 84 | } |
| 85 | |
| 86 | func resolveConfigReadPath(path string) (string, error) { |
| 87 | return resolveConfigAccessPath(path, isUserConfigPath(path)) |
| 88 | } |
| 89 | |
| 90 | func statConfigPath(path string) (resolved string, exists bool, err error) { |
| 91 | resolved, err = resolveConfigReadPath(path) |
| 92 | if err != nil { |
| 93 | return "", false, err |
| 94 | } |
| 95 | if _, err = os.Stat(resolved); err != nil { |
| 96 | if os.IsNotExist(err) { |
| 97 | return resolved, false, nil |
| 98 | } |
| 99 | return "", false, err |
| 100 | } |
| 101 | return resolved, true, nil |
| 102 | } |
| 103 | |
| 104 | func pathWithinRoot(root, path string) bool { |
| 105 | rel, err := filepath.Rel(root, path) |
| 106 | if err != nil || filepath.IsAbs(rel) { |
| 107 | return false |
| 108 | } |
| 109 | return rel == "." || (rel != ".." && !strings.HasPrefix(rel, ".."+string(os.PathSeparator))) |
| 110 | } |
| 111 |