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Diffstat (limited to 'src/cmd/go/internal/vcs/vcs.go')
| -rw-r--r-- | src/cmd/go/internal/vcs/vcs.go | 1363 |
1 files changed, 1363 insertions, 0 deletions
diff --git a/src/cmd/go/internal/vcs/vcs.go b/src/cmd/go/internal/vcs/vcs.go new file mode 100644 index 0000000..9feffe0 --- /dev/null +++ b/src/cmd/go/internal/vcs/vcs.go @@ -0,0 +1,1363 @@ +// Copyright 2012 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package vcs + +import ( + "encoding/json" + "errors" + "fmt" + exec "internal/execabs" + "internal/lazyregexp" + "internal/singleflight" + "io/fs" + "log" + urlpkg "net/url" + "os" + "path/filepath" + "regexp" + "strings" + "sync" + + "cmd/go/internal/base" + "cmd/go/internal/cfg" + "cmd/go/internal/search" + "cmd/go/internal/str" + "cmd/go/internal/web" + + "golang.org/x/mod/module" +) + +// A vcsCmd describes how to use a version control system +// like Mercurial, Git, or Subversion. +type Cmd struct { + Name string + Cmd string // name of binary to invoke command + + CreateCmd []string // commands to download a fresh copy of a repository + DownloadCmd []string // commands to download updates into an existing repository + + TagCmd []tagCmd // commands to list tags + TagLookupCmd []tagCmd // commands to lookup tags before running tagSyncCmd + TagSyncCmd []string // commands to sync to specific tag + TagSyncDefault []string // commands to sync to default tag + + Scheme []string + PingCmd string + + RemoteRepo func(v *Cmd, rootDir string) (remoteRepo string, err error) + ResolveRepo func(v *Cmd, rootDir, remoteRepo string) (realRepo string, err error) +} + +var defaultSecureScheme = map[string]bool{ + "https": true, + "git+ssh": true, + "bzr+ssh": true, + "svn+ssh": true, + "ssh": true, +} + +func (v *Cmd) IsSecure(repo string) bool { + u, err := urlpkg.Parse(repo) + if err != nil { + // If repo is not a URL, it's not secure. + return false + } + return v.isSecureScheme(u.Scheme) +} + +func (v *Cmd) isSecureScheme(scheme string) bool { + switch v.Cmd { + case "git": + // GIT_ALLOW_PROTOCOL is an environment variable defined by Git. It is a + // colon-separated list of schemes that are allowed to be used with git + // fetch/clone. Any scheme not mentioned will be considered insecure. + if allow := os.Getenv("GIT_ALLOW_PROTOCOL"); allow != "" { + for _, s := range strings.Split(allow, ":") { + if s == scheme { + return true + } + } + return false + } + } + return defaultSecureScheme[scheme] +} + +// A tagCmd describes a command to list available tags +// that can be passed to tagSyncCmd. +type tagCmd struct { + cmd string // command to list tags + pattern string // regexp to extract tags from list +} + +// vcsList lists the known version control systems +var vcsList = []*Cmd{ + vcsHg, + vcsGit, + vcsSvn, + vcsBzr, + vcsFossil, +} + +// vcsMod is a stub for the "mod" scheme. It's returned by +// repoRootForImportPathDynamic, but is otherwise not treated as a VCS command. +var vcsMod = &Cmd{Name: "mod"} + +// vcsByCmd returns the version control system for the given +// command name (hg, git, svn, bzr). +func vcsByCmd(cmd string) *Cmd { + for _, vcs := range vcsList { + if vcs.Cmd == cmd { + return vcs + } + } + return nil +} + +// vcsHg describes how to use Mercurial. +var vcsHg = &Cmd{ + Name: "Mercurial", + Cmd: "hg", + + CreateCmd: []string{"clone -U -- {repo} {dir}"}, + DownloadCmd: []string{"pull"}, + + // We allow both tag and branch names as 'tags' + // for selecting a version. This lets people have + // a go.release.r60 branch and a go1 branch + // and make changes in both, without constantly + // editing .hgtags. + TagCmd: []tagCmd{ + {"tags", `^(\S+)`}, + {"branches", `^(\S+)`}, + }, + TagSyncCmd: []string{"update -r {tag}"}, + TagSyncDefault: []string{"update default"}, + + Scheme: []string{"https", "http", "ssh"}, + PingCmd: "identify -- {scheme}://{repo}", + RemoteRepo: hgRemoteRepo, +} + +func hgRemoteRepo(vcsHg *Cmd, rootDir string) (remoteRepo string, err error) { + out, err := vcsHg.runOutput(rootDir, "paths default") + if err != nil { + return "", err + } + return strings.TrimSpace(string(out)), nil +} + +// vcsGit describes how to use Git. +var vcsGit = &Cmd{ + Name: "Git", + Cmd: "git", + + CreateCmd: []string{"clone -- {repo} {dir}", "-go-internal-cd {dir} submodule update --init --recursive"}, + DownloadCmd: []string{"pull --ff-only", "submodule update --init --recursive"}, + + TagCmd: []tagCmd{ + // tags/xxx matches a git tag named xxx + // origin/xxx matches a git branch named xxx on the default remote repository + {"show-ref", `(?:tags|origin)/(\S+)$`}, + }, + TagLookupCmd: []tagCmd{ + {"show-ref tags/{tag} origin/{tag}", `((?:tags|origin)/\S+)$`}, + }, + TagSyncCmd: []string{"checkout {tag}", "submodule update --init --recursive"}, + // both createCmd and downloadCmd update the working dir. + // No need to do more here. We used to 'checkout master' + // but that doesn't work if the default branch is not named master. + // DO NOT add 'checkout master' here. + // See golang.org/issue/9032. + TagSyncDefault: []string{"submodule update --init --recursive"}, + + Scheme: []string{"git", "https", "http", "git+ssh", "ssh"}, + + // Leave out the '--' separator in the ls-remote command: git 2.7.4 does not + // support such a separator for that command, and this use should be safe + // without it because the {scheme} value comes from the predefined list above. + // See golang.org/issue/33836. + PingCmd: "ls-remote {scheme}://{repo}", + + RemoteRepo: gitRemoteRepo, +} + +// scpSyntaxRe matches the SCP-like addresses used by Git to access +// repositories by SSH. +var scpSyntaxRe = lazyregexp.New(`^([a-zA-Z0-9_]+)@([a-zA-Z0-9._-]+):(.*)$`) + +func gitRemoteRepo(vcsGit *Cmd, rootDir string) (remoteRepo string, err error) { + cmd := "config remote.origin.url" + errParse := errors.New("unable to parse output of git " + cmd) + errRemoteOriginNotFound := errors.New("remote origin not found") + outb, err := vcsGit.run1(rootDir, cmd, nil, false) + if err != nil { + // if it doesn't output any message, it means the config argument is correct, + // but the config value itself doesn't exist + if outb != nil && len(outb) == 0 { + return "", errRemoteOriginNotFound + } + return "", err + } + out := strings.TrimSpace(string(outb)) + + var repoURL *urlpkg.URL + if m := scpSyntaxRe.FindStringSubmatch(out); m != nil { + // Match SCP-like syntax and convert it to a URL. + // Eg, "git@github.com:user/repo" becomes + // "ssh://git@github.com/user/repo". + repoURL = &urlpkg.URL{ + Scheme: "ssh", + User: urlpkg.User(m[1]), + Host: m[2], + Path: m[3], + } + } else { + repoURL, err = urlpkg.Parse(out) + if err != nil { + return "", err + } + } + + // Iterate over insecure schemes too, because this function simply + // reports the state of the repo. If we can't see insecure schemes then + // we can't report the actual repo URL. + for _, s := range vcsGit.Scheme { + if repoURL.Scheme == s { + return repoURL.String(), nil + } + } + return "", errParse +} + +// vcsBzr describes how to use Bazaar. +var vcsBzr = &Cmd{ + Name: "Bazaar", + Cmd: "bzr", + + CreateCmd: []string{"branch -- {repo} {dir}"}, + + // Without --overwrite bzr will not pull tags that changed. + // Replace by --overwrite-tags after http://pad.lv/681792 goes in. + DownloadCmd: []string{"pull --overwrite"}, + + TagCmd: []tagCmd{{"tags", `^(\S+)`}}, + TagSyncCmd: []string{"update -r {tag}"}, + TagSyncDefault: []string{"update -r revno:-1"}, + + Scheme: []string{"https", "http", "bzr", "bzr+ssh"}, + PingCmd: "info -- {scheme}://{repo}", + RemoteRepo: bzrRemoteRepo, + ResolveRepo: bzrResolveRepo, +} + +func bzrRemoteRepo(vcsBzr *Cmd, rootDir string) (remoteRepo string, err error) { + outb, err := vcsBzr.runOutput(rootDir, "config parent_location") + if err != nil { + return "", err + } + return strings.TrimSpace(string(outb)), nil +} + +func bzrResolveRepo(vcsBzr *Cmd, rootDir, remoteRepo string) (realRepo string, err error) { + outb, err := vcsBzr.runOutput(rootDir, "info "+remoteRepo) + if err != nil { + return "", err + } + out := string(outb) + + // Expect: + // ... + // (branch root|repository branch): <URL> + // ... + + found := false + for _, prefix := range []string{"\n branch root: ", "\n repository branch: "} { + i := strings.Index(out, prefix) + if i >= 0 { + out = out[i+len(prefix):] + found = true + break + } + } + if !found { + return "", fmt.Errorf("unable to parse output of bzr info") + } + + i := strings.Index(out, "\n") + if i < 0 { + return "", fmt.Errorf("unable to parse output of bzr info") + } + out = out[:i] + return strings.TrimSpace(out), nil +} + +// vcsSvn describes how to use Subversion. +var vcsSvn = &Cmd{ + Name: "Subversion", + Cmd: "svn", + + CreateCmd: []string{"checkout -- {repo} {dir}"}, + DownloadCmd: []string{"update"}, + + // There is no tag command in subversion. + // The branch information is all in the path names. + + Scheme: []string{"https", "http", "svn", "svn+ssh"}, + PingCmd: "info -- {scheme}://{repo}", + RemoteRepo: svnRemoteRepo, +} + +func svnRemoteRepo(vcsSvn *Cmd, rootDir string) (remoteRepo string, err error) { + outb, err := vcsSvn.runOutput(rootDir, "info") + if err != nil { + return "", err + } + out := string(outb) + + // Expect: + // + // ... + // URL: <URL> + // ... + // + // Note that we're not using the Repository Root line, + // because svn allows checking out subtrees. + // The URL will be the URL of the subtree (what we used with 'svn co') + // while the Repository Root may be a much higher parent. + i := strings.Index(out, "\nURL: ") + if i < 0 { + return "", fmt.Errorf("unable to parse output of svn info") + } + out = out[i+len("\nURL: "):] + i = strings.Index(out, "\n") + if i < 0 { + return "", fmt.Errorf("unable to parse output of svn info") + } + out = out[:i] + return strings.TrimSpace(out), nil +} + +// fossilRepoName is the name go get associates with a fossil repository. In the +// real world the file can be named anything. +const fossilRepoName = ".fossil" + +// vcsFossil describes how to use Fossil (fossil-scm.org) +var vcsFossil = &Cmd{ + Name: "Fossil", + Cmd: "fossil", + + CreateCmd: []string{"-go-internal-mkdir {dir} clone -- {repo} " + filepath.Join("{dir}", fossilRepoName), "-go-internal-cd {dir} open .fossil"}, + DownloadCmd: []string{"up"}, + + TagCmd: []tagCmd{{"tag ls", `(.*)`}}, + TagSyncCmd: []string{"up tag:{tag}"}, + TagSyncDefault: []string{"up trunk"}, + + Scheme: []string{"https", "http"}, + RemoteRepo: fossilRemoteRepo, +} + +func fossilRemoteRepo(vcsFossil *Cmd, rootDir string) (remoteRepo string, err error) { + out, err := vcsFossil.runOutput(rootDir, "remote-url") + if err != nil { + return "", err + } + return strings.TrimSpace(string(out)), nil +} + +func (v *Cmd) String() string { + return v.Name +} + +// run runs the command line cmd in the given directory. +// keyval is a list of key, value pairs. run expands +// instances of {key} in cmd into value, but only after +// splitting cmd into individual arguments. +// If an error occurs, run prints the command line and the +// command's combined stdout+stderr to standard error. +// Otherwise run discards the command's output. +func (v *Cmd) run(dir string, cmd string, keyval ...string) error { + _, err := v.run1(dir, cmd, keyval, true) + return err +} + +// runVerboseOnly is like run but only generates error output to standard error in verbose mode. +func (v *Cmd) runVerboseOnly(dir string, cmd string, keyval ...string) error { + _, err := v.run1(dir, cmd, keyval, false) + return err +} + +// runOutput is like run but returns the output of the command. +func (v *Cmd) runOutput(dir string, cmd string, keyval ...string) ([]byte, error) { + return v.run1(dir, cmd, keyval, true) +} + +// run1 is the generalized implementation of run and runOutput. +func (v *Cmd) run1(dir string, cmdline string, keyval []string, verbose bool) ([]byte, error) { + m := make(map[string]string) + for i := 0; i < len(keyval); i += 2 { + m[keyval[i]] = keyval[i+1] + } + args := strings.Fields(cmdline) + for i, arg := range args { + args[i] = expand(m, arg) + } + + if len(args) >= 2 && args[0] == "-go-internal-mkdir" { + var err error + if filepath.IsAbs(args[1]) { + err = os.Mkdir(args[1], fs.ModePerm) + } else { + err = os.Mkdir(filepath.Join(dir, args[1]), fs.ModePerm) + } + if err != nil { + return nil, err + } + args = args[2:] + } + + if len(args) >= 2 && args[0] == "-go-internal-cd" { + if filepath.IsAbs(args[1]) { + dir = args[1] + } else { + dir = filepath.Join(dir, args[1]) + } + args = args[2:] + } + + _, err := exec.LookPath(v.Cmd) + if err != nil { + fmt.Fprintf(os.Stderr, + "go: missing %s command. See https://golang.org/s/gogetcmd\n", + v.Name) + return nil, err + } + + cmd := exec.Command(v.Cmd, args...) + cmd.Dir = dir + cmd.Env = base.AppendPWD(os.Environ(), cmd.Dir) + if cfg.BuildX { + fmt.Fprintf(os.Stderr, "cd %s\n", dir) + fmt.Fprintf(os.Stderr, "%s %s\n", v.Cmd, strings.Join(args, " ")) + } + out, err := cmd.Output() + if err != nil { + if verbose || cfg.BuildV { + fmt.Fprintf(os.Stderr, "# cd %s; %s %s\n", dir, v.Cmd, strings.Join(args, " ")) + if ee, ok := err.(*exec.ExitError); ok && len(ee.Stderr) > 0 { + os.Stderr.Write(ee.Stderr) + } else { + fmt.Fprintf(os.Stderr, err.Error()) + } + } + } + return out, err +} + +// Ping pings to determine scheme to use. +func (v *Cmd) Ping(scheme, repo string) error { + return v.runVerboseOnly(".", v.PingCmd, "scheme", scheme, "repo", repo) +} + +// Create creates a new copy of repo in dir. +// The parent of dir must exist; dir must not. +func (v *Cmd) Create(dir, repo string) error { + for _, cmd := range v.CreateCmd { + if err := v.run(".", cmd, "dir", dir, "repo", repo); err != nil { + return err + } + } + return nil +} + +// Download downloads any new changes for the repo in dir. +func (v *Cmd) Download(dir string) error { + for _, cmd := range v.DownloadCmd { + if err := v.run(dir, cmd); err != nil { + return err + } + } + return nil +} + +// Tags returns the list of available tags for the repo in dir. +func (v *Cmd) Tags(dir string) ([]string, error) { + var tags []string + for _, tc := range v.TagCmd { + out, err := v.runOutput(dir, tc.cmd) + if err != nil { + return nil, err + } + re := regexp.MustCompile(`(?m-s)` + tc.pattern) + for _, m := range re.FindAllStringSubmatch(string(out), -1) { + tags = append(tags, m[1]) + } + } + return tags, nil +} + +// tagSync syncs the repo in dir to the named tag, +// which either is a tag returned by tags or is v.tagDefault. +func (v *Cmd) TagSync(dir, tag string) error { + if v.TagSyncCmd == nil { + return nil + } + if tag != "" { + for _, tc := range v.TagLookupCmd { + out, err := v.runOutput(dir, tc.cmd, "tag", tag) + if err != nil { + return err + } + re := regexp.MustCompile(`(?m-s)` + tc.pattern) + m := re.FindStringSubmatch(string(out)) + if len(m) > 1 { + tag = m[1] + break + } + } + } + + if tag == "" && v.TagSyncDefault != nil { + for _, cmd := range v.TagSyncDefault { + if err := v.run(dir, cmd); err != nil { + return err + } + } + return nil + } + + for _, cmd := range v.TagSyncCmd { + if err := v.run(dir, cmd, "tag", tag); err != nil { + return err + } + } + return nil +} + +// A vcsPath describes how to convert an import path into a +// version control system and repository name. +type vcsPath struct { + pathPrefix string // prefix this description applies to + regexp *lazyregexp.Regexp // compiled pattern for import path + repo string // repository to use (expand with match of re) + vcs string // version control system to use (expand with match of re) + check func(match map[string]string) error // additional checks + schemelessRepo bool // if true, the repo pattern lacks a scheme +} + +// FromDir inspects dir and its parents to determine the +// version control system and code repository to use. +// On return, root is the import path +// corresponding to the root of the repository. +func FromDir(dir, srcRoot string) (vcs *Cmd, root string, err error) { + // Clean and double-check that dir is in (a subdirectory of) srcRoot. + dir = filepath.Clean(dir) + srcRoot = filepath.Clean(srcRoot) + if len(dir) <= len(srcRoot) || dir[len(srcRoot)] != filepath.Separator { + return nil, "", fmt.Errorf("directory %q is outside source root %q", dir, srcRoot) + } + + var vcsRet *Cmd + var rootRet string + + origDir := dir + for len(dir) > len(srcRoot) { + for _, vcs := range vcsList { + if _, err := os.Stat(filepath.Join(dir, "."+vcs.Cmd)); err == nil { + root := filepath.ToSlash(dir[len(srcRoot)+1:]) + // Record first VCS we find, but keep looking, + // to detect mistakes like one kind of VCS inside another. + if vcsRet == nil { + vcsRet = vcs + rootRet = root + continue + } + // Allow .git inside .git, which can arise due to submodules. + if vcsRet == vcs && vcs.Cmd == "git" { + continue + } + // Otherwise, we have one VCS inside a different VCS. + return nil, "", fmt.Errorf("directory %q uses %s, but parent %q uses %s", + filepath.Join(srcRoot, rootRet), vcsRet.Cmd, filepath.Join(srcRoot, root), vcs.Cmd) + } + } + + // Move to parent. + ndir := filepath.Dir(dir) + if len(ndir) >= len(dir) { + // Shouldn't happen, but just in case, stop. + break + } + dir = ndir + } + + if vcsRet != nil { + if err := checkGOVCS(vcsRet, rootRet); err != nil { + return nil, "", err + } + return vcsRet, rootRet, nil + } + + return nil, "", fmt.Errorf("directory %q is not using a known version control system", origDir) +} + +// A govcsRule is a single GOVCS rule like private:hg|svn. +type govcsRule struct { + pattern string + allowed []string +} + +// A govcsConfig is a full GOVCS configuration. +type govcsConfig []govcsRule + +func parseGOVCS(s string) (govcsConfig, error) { + s = strings.TrimSpace(s) + if s == "" { + return nil, nil + } + var cfg govcsConfig + have := make(map[string]string) + for _, item := range strings.Split(s, ",") { + item = strings.TrimSpace(item) + if item == "" { + return nil, fmt.Errorf("empty entry in GOVCS") + } + i := strings.Index(item, ":") + if i < 0 { + return nil, fmt.Errorf("malformed entry in GOVCS (missing colon): %q", item) + } + pattern, list := strings.TrimSpace(item[:i]), strings.TrimSpace(item[i+1:]) + if pattern == "" { + return nil, fmt.Errorf("empty pattern in GOVCS: %q", item) + } + if list == "" { + return nil, fmt.Errorf("empty VCS list in GOVCS: %q", item) + } + if search.IsRelativePath(pattern) { + return nil, fmt.Errorf("relative pattern not allowed in GOVCS: %q", pattern) + } + if old := have[pattern]; old != "" { + return nil, fmt.Errorf("unreachable pattern in GOVCS: %q after %q", item, old) + } + have[pattern] = item + allowed := strings.Split(list, "|") + for i, a := range allowed { + a = strings.TrimSpace(a) + if a == "" { + return nil, fmt.Errorf("empty VCS name in GOVCS: %q", item) + } + allowed[i] = a + } + cfg = append(cfg, govcsRule{pattern, allowed}) + } + return cfg, nil +} + +func (c *govcsConfig) allow(path string, private bool, vcs string) bool { + for _, rule := range *c { + match := false + switch rule.pattern { + case "private": + match = private + case "public": + match = !private + default: + // Note: rule.pattern is known to be comma-free, + // so MatchPrefixPatterns is only matching a single pattern for us. + match = module.MatchPrefixPatterns(rule.pattern, path) + } + if !match { + continue + } + for _, allow := range rule.allowed { + if allow == vcs || allow == "all" { + return true + } + } + return false + } + + // By default, nothing is allowed. + return false +} + +var ( + govcs govcsConfig + govcsErr error + govcsOnce sync.Once +) + +// defaultGOVCS is the default setting for GOVCS. +// Setting GOVCS adds entries ahead of these but does not remove them. +// (They are appended to the parsed GOVCS setting.) +// +// The rationale behind allowing only Git and Mercurial is that +// these two systems have had the most attention to issues +// of being run as clients of untrusted servers. In contrast, +// Bazaar, Fossil, and Subversion have primarily been used +// in trusted, authenticated environments and are not as well +// scrutinized as attack surfaces. +// +// See golang.org/issue/41730 for details. +var defaultGOVCS = govcsConfig{ + {"private", []string{"all"}}, + {"public", []string{"git", "hg"}}, +} + +func checkGOVCS(vcs *Cmd, root string) error { + if vcs == vcsMod { + // Direct module (proxy protocol) fetches don't + // involve an external version control system + // and are always allowed. + return nil + } + + govcsOnce.Do(func() { + govcs, govcsErr = parseGOVCS(os.Getenv("GOVCS")) + govcs = append(govcs, defaultGOVCS...) + }) + if govcsErr != nil { + return govcsErr + } + + private := module.MatchPrefixPatterns(cfg.GOPRIVATE, root) + if !govcs.allow(root, private, vcs.Cmd) { + what := "public" + if private { + what = "private" + } + return fmt.Errorf("GOVCS disallows using %s for %s %s; see 'go help vcs'", vcs.Cmd, what, root) + } + + return nil +} + +// CheckNested checks for an incorrectly-nested VCS-inside-VCS +// situation for dir, checking parents up until srcRoot. +func CheckNested(vcs *Cmd, dir, srcRoot string) error { + if len(dir) <= len(srcRoot) || dir[len(srcRoot)] != filepath.Separator { + return fmt.Errorf("directory %q is outside source root %q", dir, srcRoot) + } + + otherDir := dir + for len(otherDir) > len(srcRoot) { + for _, otherVCS := range vcsList { + if _, err := os.Stat(filepath.Join(otherDir, "."+otherVCS.Cmd)); err == nil { + // Allow expected vcs in original dir. + if otherDir == dir && otherVCS == vcs { + continue + } + // Allow .git inside .git, which can arise due to submodules. + if otherVCS == vcs && vcs.Cmd == "git" { + continue + } + // Otherwise, we have one VCS inside a different VCS. + return fmt.Errorf("directory %q uses %s, but parent %q uses %s", dir, vcs.Cmd, otherDir, otherVCS.Cmd) + } + } + // Move to parent. + newDir := filepath.Dir(otherDir) + if len(newDir) >= len(otherDir) { + // Shouldn't happen, but just in case, stop. + break + } + otherDir = newDir + } + + return nil +} + +// RepoRoot describes the repository root for a tree of source code. +type RepoRoot struct { + Repo string // repository URL, including scheme + Root string // import path corresponding to root of repo + IsCustom bool // defined by served <meta> tags (as opposed to hard-coded pattern) + VCS *Cmd +} + +func httpPrefix(s string) string { + for _, prefix := range [...]string{"http:", "https:"} { + if strings.HasPrefix(s, prefix) { + return prefix + } + } + return "" +} + +// ModuleMode specifies whether to prefer modules when looking up code sources. +type ModuleMode int + +const ( + IgnoreMod ModuleMode = iota + PreferMod +) + +// RepoRootForImportPath analyzes importPath to determine the +// version control system, and code repository to use. +func RepoRootForImportPath(importPath string, mod ModuleMode, security web.SecurityMode) (*RepoRoot, error) { + rr, err := repoRootFromVCSPaths(importPath, security, vcsPaths) + if err == errUnknownSite { + rr, err = repoRootForImportDynamic(importPath, mod, security) + if err != nil { + err = importErrorf(importPath, "unrecognized import path %q: %v", importPath, err) + } + } + if err != nil { + rr1, err1 := repoRootFromVCSPaths(importPath, security, vcsPathsAfterDynamic) + if err1 == nil { + rr = rr1 + err = nil + } + } + + // Should have been taken care of above, but make sure. + if err == nil && strings.Contains(importPath, "...") && strings.Contains(rr.Root, "...") { + // Do not allow wildcards in the repo root. + rr = nil + err = importErrorf(importPath, "cannot expand ... in %q", importPath) + } + return rr, err +} + +var errUnknownSite = errors.New("dynamic lookup required to find mapping") + +// repoRootFromVCSPaths attempts to map importPath to a repoRoot +// using the mappings defined in vcsPaths. +func repoRootFromVCSPaths(importPath string, security web.SecurityMode, vcsPaths []*vcsPath) (*RepoRoot, error) { + if str.HasPathPrefix(importPath, "example.net") { + // TODO(rsc): This should not be necessary, but it's required to keep + // tests like ../../testdata/script/mod_get_extra.txt from using the network. + // That script has everything it needs in the replacement set, but it is still + // doing network calls. + return nil, fmt.Errorf("no modules on example.net") + } + if importPath == "rsc.io" { + // This special case allows tests like ../../testdata/script/govcs.txt + // to avoid making any network calls. The module lookup for a path + // like rsc.io/nonexist.svn/foo needs to not make a network call for + // a lookup on rsc.io. + return nil, fmt.Errorf("rsc.io is not a module") + } + // A common error is to use https://packagepath because that's what + // hg and git require. Diagnose this helpfully. + if prefix := httpPrefix(importPath); prefix != "" { + // The importPath has been cleaned, so has only one slash. The pattern + // ignores the slashes; the error message puts them back on the RHS at least. + return nil, fmt.Errorf("%q not allowed in import path", prefix+"//") + } + for _, srv := range vcsPaths { + if !str.HasPathPrefix(importPath, srv.pathPrefix) { + continue + } + m := srv.regexp.FindStringSubmatch(importPath) + if m == nil { + if srv.pathPrefix != "" { + return nil, importErrorf(importPath, "invalid %s import path %q", srv.pathPrefix, importPath) + } + continue + } + + // Build map of named subexpression matches for expand. + match := map[string]string{ + "prefix": srv.pathPrefix + "/", + "import": importPath, + } + for i, name := range srv.regexp.SubexpNames() { + if name != "" && match[name] == "" { + match[name] = m[i] + } + } + if srv.vcs != "" { + match["vcs"] = expand(match, srv.vcs) + } + if srv.repo != "" { + match["repo"] = expand(match, srv.repo) + } + if srv.check != nil { + if err := srv.check(match); err != nil { + return nil, err + } + } + vcs := vcsByCmd(match["vcs"]) + if vcs == nil { + return nil, fmt.Errorf("unknown version control system %q", match["vcs"]) + } + if err := checkGOVCS(vcs, match["root"]); err != nil { + return nil, err + } + var repoURL string + if !srv.schemelessRepo { + repoURL = match["repo"] + } else { + scheme := vcs.Scheme[0] // default to first scheme + repo := match["repo"] + if vcs.PingCmd != "" { + // If we know how to test schemes, scan to find one. + for _, s := range vcs.Scheme { + if security == web.SecureOnly && !vcs.isSecureScheme(s) { + continue + } + if vcs.Ping(s, repo) == nil { + scheme = s + break + } + } + } + repoURL = scheme + "://" + repo + } + rr := &RepoRoot{ + Repo: repoURL, + Root: match["root"], + VCS: vcs, + } + return rr, nil + } + return nil, errUnknownSite +} + +// urlForImportPath returns a partially-populated URL for the given Go import path. +// +// The URL leaves the Scheme field blank so that web.Get will try any scheme +// allowed by the selected security mode. +func urlForImportPath(importPath string) (*urlpkg.URL, error) { + slash := strings.Index(importPath, "/") + if slash < 0 { + slash = len(importPath) + } + host, path := importPath[:slash], importPath[slash:] + if !strings.Contains(host, ".") { + return nil, errors.New("import path does not begin with hostname") + } + if len(path) == 0 { + path = "/" + } + return &urlpkg.URL{Host: host, Path: path, RawQuery: "go-get=1"}, nil +} + +// repoRootForImportDynamic finds a *RepoRoot for a custom domain that's not +// statically known by repoRootForImportPathStatic. +// +// This handles custom import paths like "name.tld/pkg/foo" or just "name.tld". +func repoRootForImportDynamic(importPath string, mod ModuleMode, security web.SecurityMode) (*RepoRoot, error) { + url, err := urlForImportPath(importPath) + if err != nil { + return nil, err + } + resp, err := web.Get(security, url) + if err != nil { + msg := "https fetch: %v" + if security == web.Insecure { + msg = "http/" + msg + } + return nil, fmt.Errorf(msg, err) + } + body := resp.Body + defer body.Close() + imports, err := parseMetaGoImports(body, mod) + if len(imports) == 0 { + if respErr := resp.Err(); respErr != nil { + // If the server's status was not OK, prefer to report that instead of + // an XML parse error. + return nil, respErr + } + } + if err != nil { + return nil, fmt.Errorf("parsing %s: %v", importPath, err) + } + // Find the matched meta import. + mmi, err := matchGoImport(imports, importPath) + if err != nil { + if _, ok := err.(ImportMismatchError); !ok { + return nil, fmt.Errorf("parse %s: %v", url, err) + } + return nil, fmt.Errorf("parse %s: no go-import meta tags (%s)", resp.URL, err) + } + if cfg.BuildV { + log.Printf("get %q: found meta tag %#v at %s", importPath, mmi, url) + } + // If the import was "uni.edu/bob/project", which said the + // prefix was "uni.edu" and the RepoRoot was "evilroot.com", + // make sure we don't trust Bob and check out evilroot.com to + // "uni.edu" yet (possibly overwriting/preempting another + // non-evil student). Instead, first verify the root and see + // if it matches Bob's claim. + if mmi.Prefix != importPath { + if cfg.BuildV { + log.Printf("get %q: verifying non-authoritative meta tag", importPath) + } + var imports []metaImport + url, imports, err = metaImportsForPrefix(mmi.Prefix, mod, security) + if err != nil { + return nil, err + } + metaImport2, err := matchGoImport(imports, importPath) + if err != nil || mmi != metaImport2 { + return nil, fmt.Errorf("%s and %s disagree about go-import for %s", resp.URL, url, mmi.Prefix) + } + } + + if err := validateRepoRoot(mmi.RepoRoot); err != nil { + return nil, fmt.Errorf("%s: invalid repo root %q: %v", resp.URL, mmi.RepoRoot, err) + } + var vcs *Cmd + if mmi.VCS == "mod" { + vcs = vcsMod + } else { + vcs = vcsByCmd(mmi.VCS) + if vcs == nil { + return nil, fmt.Errorf("%s: unknown vcs %q", resp.URL, mmi.VCS) + } + } + + if err := checkGOVCS(vcs, mmi.Prefix); err != nil { + return nil, err + } + + rr := &RepoRoot{ + Repo: mmi.RepoRoot, + Root: mmi.Prefix, + IsCustom: true, + VCS: vcs, + } + return rr, nil +} + +// validateRepoRoot returns an error if repoRoot does not seem to be +// a valid URL with scheme. +func validateRepoRoot(repoRoot string) error { + url, err := urlpkg.Parse(repoRoot) + if err != nil { + return err + } + if url.Scheme == "" { + return errors.New("no scheme") + } + if url.Scheme == "file" { + return errors.New("file scheme disallowed") + } + return nil +} + +var fetchGroup singleflight.Group +var ( + fetchCacheMu sync.Mutex + fetchCache = map[string]fetchResult{} // key is metaImportsForPrefix's importPrefix +) + +// metaImportsForPrefix takes a package's root import path as declared in a <meta> tag +// and returns its HTML discovery URL and the parsed metaImport lines +// found on the page. +// +// The importPath is of the form "golang.org/x/tools". +// It is an error if no imports are found. +// url will still be valid if err != nil. +// The returned url will be of the form "https://golang.org/x/tools?go-get=1" +func metaImportsForPrefix(importPrefix string, mod ModuleMode, security web.SecurityMode) (*urlpkg.URL, []metaImport, error) { + setCache := func(res fetchResult) (fetchResult, error) { + fetchCacheMu.Lock() + defer fetchCacheMu.Unlock() + fetchCache[importPrefix] = res + return res, nil + } + + resi, _, _ := fetchGroup.Do(importPrefix, func() (resi interface{}, err error) { + fetchCacheMu.Lock() + if res, ok := fetchCache[importPrefix]; ok { + fetchCacheMu.Unlock() + return res, nil + } + fetchCacheMu.Unlock() + + url, err := urlForImportPath(importPrefix) + if err != nil { + return setCache(fetchResult{err: err}) + } + resp, err := web.Get(security, url) + if err != nil { + return setCache(fetchResult{url: url, err: fmt.Errorf("fetching %s: %v", importPrefix, err)}) + } + body := resp.Body + defer body.Close() + imports, err := parseMetaGoImports(body, mod) + if len(imports) == 0 { + if respErr := resp.Err(); respErr != nil { + // If the server's status was not OK, prefer to report that instead of + // an XML parse error. + return setCache(fetchResult{url: url, err: respErr}) + } + } + if err != nil { + return setCache(fetchResult{url: url, err: fmt.Errorf("parsing %s: %v", resp.URL, err)}) + } + if len(imports) == 0 { + err = fmt.Errorf("fetching %s: no go-import meta tag found in %s", importPrefix, resp.URL) + } + return setCache(fetchResult{url: url, imports: imports, err: err}) + }) + res := resi.(fetchResult) + return res.url, res.imports, res.err +} + +type fetchResult struct { + url *urlpkg.URL + imports []metaImport + err error +} + +// metaImport represents the parsed <meta name="go-import" +// content="prefix vcs reporoot" /> tags from HTML files. +type metaImport struct { + Prefix, VCS, RepoRoot string +} + +// A ImportMismatchError is returned where metaImport/s are present +// but none match our import path. +type ImportMismatchError struct { + importPath string + mismatches []string // the meta imports that were discarded for not matching our importPath +} + +func (m ImportMismatchError) Error() string { + formattedStrings := make([]string, len(m.mismatches)) + for i, pre := range m.mismatches { + formattedStrings[i] = fmt.Sprintf("meta tag %s did not match import path %s", pre, m.importPath) + } + return strings.Join(formattedStrings, ", ") +} + +// matchGoImport returns the metaImport from imports matching importPath. +// An error is returned if there are multiple matches. +// An ImportMismatchError is returned if none match. +func matchGoImport(imports []metaImport, importPath string) (metaImport, error) { + match := -1 + + errImportMismatch := ImportMismatchError{importPath: importPath} + for i, im := range imports { + if !str.HasPathPrefix(importPath, im.Prefix) { + errImportMismatch.mismatches = append(errImportMismatch.mismatches, im.Prefix) + continue + } + + if match >= 0 { + if imports[match].VCS == "mod" && im.VCS != "mod" { + // All the mod entries precede all the non-mod entries. + // We have a mod entry and don't care about the rest, + // matching or not. + break + } + return metaImport{}, fmt.Errorf("multiple meta tags match import path %q", importPath) + } + match = i + } + + if match == -1 { + return metaImport{}, errImportMismatch + } + return imports[match], nil +} + +// expand rewrites s to replace {k} with match[k] for each key k in match. +func expand(match map[string]string, s string) string { + // We want to replace each match exactly once, and the result of expansion + // must not depend on the iteration order through the map. + // A strings.Replacer has exactly the properties we're looking for. + oldNew := make([]string, 0, 2*len(match)) + for k, v := range match { + oldNew = append(oldNew, "{"+k+"}", v) + } + return strings.NewReplacer(oldNew...).Replace(s) +} + +// vcsPaths defines the meaning of import paths referring to +// commonly-used VCS hosting sites (github.com/user/dir) +// and import paths referring to a fully-qualified importPath +// containing a VCS type (foo.com/repo.git/dir) +var vcsPaths = []*vcsPath{ + // Github + { + pathPrefix: "github.com", + regexp: lazyregexp.New(`^(?P<root>github\.com/[A-Za-z0-9_.\-]+/[A-Za-z0-9_.\-]+)(/[A-Za-z0-9_.\-]+)*$`), + vcs: "git", + repo: "https://{root}", + check: noVCSSuffix, + }, + + // Bitbucket + { + pathPrefix: "bitbucket.org", + regexp: lazyregexp.New(`^(?P<root>bitbucket\.org/(?P<bitname>[A-Za-z0-9_.\-]+/[A-Za-z0-9_.\-]+))(/[A-Za-z0-9_.\-]+)*$`), + repo: "https://{root}", + check: bitbucketVCS, + }, + + // IBM DevOps Services (JazzHub) + { + pathPrefix: "hub.jazz.net/git", + regexp: lazyregexp.New(`^(?P<root>hub\.jazz\.net/git/[a-z0-9]+/[A-Za-z0-9_.\-]+)(/[A-Za-z0-9_.\-]+)*$`), + vcs: "git", + repo: "https://{root}", + check: noVCSSuffix, + }, + + // Git at Apache + { + pathPrefix: "git.apache.org", + regexp: lazyregexp.New(`^(?P<root>git\.apache\.org/[a-z0-9_.\-]+\.git)(/[A-Za-z0-9_.\-]+)*$`), + vcs: "git", + repo: "https://{root}", + }, + + // Git at OpenStack + { + pathPrefix: "git.openstack.org", + regexp: lazyregexp.New(`^(?P<root>git\.openstack\.org/[A-Za-z0-9_.\-]+/[A-Za-z0-9_.\-]+)(\.git)?(/[A-Za-z0-9_.\-]+)*$`), + vcs: "git", + repo: "https://{root}", + }, + + // chiselapp.com for fossil + { + pathPrefix: "chiselapp.com", + regexp: lazyregexp.New(`^(?P<root>chiselapp\.com/user/[A-Za-z0-9]+/repository/[A-Za-z0-9_.\-]+)$`), + vcs: "fossil", + repo: "https://{root}", + }, + + // General syntax for any server. + // Must be last. + { + regexp: lazyregexp.New(`(?P<root>(?P<repo>([a-z0-9.\-]+\.)+[a-z0-9.\-]+(:[0-9]+)?(/~?[A-Za-z0-9_.\-]+)+?)\.(?P<vcs>bzr|fossil|git|hg|svn))(/~?[A-Za-z0-9_.\-]+)*$`), + schemelessRepo: true, + }, +} + +// vcsPathsAfterDynamic gives additional vcsPaths entries +// to try after the dynamic HTML check. +// This gives those sites a chance to introduce <meta> tags +// as part of a graceful transition away from the hard-coded logic. +var vcsPathsAfterDynamic = []*vcsPath{ + // Launchpad. See golang.org/issue/11436. + { + pathPrefix: "launchpad.net", + regexp: lazyregexp.New(`^(?P<root>launchpad\.net/((?P<project>[A-Za-z0-9_.\-]+)(?P<series>/[A-Za-z0-9_.\-]+)?|~[A-Za-z0-9_.\-]+/(\+junk|[A-Za-z0-9_.\-]+)/[A-Za-z0-9_.\-]+))(/[A-Za-z0-9_.\-]+)*$`), + vcs: "bzr", + repo: "https://{root}", + check: launchpadVCS, + }, +} + +// noVCSSuffix checks that the repository name does not +// end in .foo for any version control system foo. +// The usual culprit is ".git". +func noVCSSuffix(match map[string]string) error { + repo := match["repo"] + for _, vcs := range vcsList { + if strings.HasSuffix(repo, "."+vcs.Cmd) { + return fmt.Errorf("invalid version control suffix in %s path", match["prefix"]) + } + } + return nil +} + +// bitbucketVCS determines the version control system for a +// Bitbucket repository, by using the Bitbucket API. +func bitbucketVCS(match map[string]string) error { + if err := noVCSSuffix(match); err != nil { + return err + } + + var resp struct { + SCM string `json:"scm"` + } + url := &urlpkg.URL{ + Scheme: "https", + Host: "api.bitbucket.org", + Path: expand(match, "/2.0/repositories/{bitname}"), + RawQuery: "fields=scm", + } + data, err := web.GetBytes(url) + if err != nil { + if httpErr, ok := err.(*web.HTTPError); ok && httpErr.StatusCode == 403 { + // this may be a private repository. If so, attempt to determine which + // VCS it uses. See issue 5375. + root := match["root"] + for _, vcs := range []string{"git", "hg"} { + if vcsByCmd(vcs).Ping("https", root) == nil { + resp.SCM = vcs + break + } + } + } + + if resp.SCM == "" { + return err + } + } else { + if err := json.Unmarshal(data, &resp); err != nil { + return fmt.Errorf("decoding %s: %v", url, err) + } + } + + if vcsByCmd(resp.SCM) != nil { + match["vcs"] = resp.SCM + if resp.SCM == "git" { + match["repo"] += ".git" + } + return nil + } + + return fmt.Errorf("unable to detect version control system for bitbucket.org/ path") +} + +// launchpadVCS solves the ambiguity for "lp.net/project/foo". In this case, +// "foo" could be a series name registered in Launchpad with its own branch, +// and it could also be the name of a directory within the main project +// branch one level up. +func launchpadVCS(match map[string]string) error { + if match["project"] == "" || match["series"] == "" { + return nil + } + url := &urlpkg.URL{ + Scheme: "https", + Host: "code.launchpad.net", + Path: expand(match, "/{project}{series}/.bzr/branch-format"), + } + _, err := web.GetBytes(url) + if err != nil { + match["root"] = expand(match, "launchpad.net/{project}") + match["repo"] = expand(match, "https://{root}") + } + return nil +} + +// importError is a copy of load.importError, made to avoid a dependency cycle +// on cmd/go/internal/load. It just needs to satisfy load.ImportPathError. +type importError struct { + importPath string + err error +} + +func importErrorf(path, format string, args ...interface{}) error { + err := &importError{importPath: path, err: fmt.Errorf(format, args...)} + if errStr := err.Error(); !strings.Contains(errStr, path) { + panic(fmt.Sprintf("path %q not in error %q", path, errStr)) + } + return err +} + +func (e *importError) Error() string { + return e.err.Error() +} + +func (e *importError) Unwrap() error { + // Don't return e.err directly, since we're only wrapping an error if %w + // was passed to ImportErrorf. + return errors.Unwrap(e.err) +} + +func (e *importError) ImportPath() string { + return e.importPath +} |