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ID8fde29bcf3ee352d63c09a2097b588eab738fdbd
AuthorRunxi Yu<me@runxiyu.org>
Author dateWed, 19 Feb 2025 09:03:03 +0800
CommitterRunxi Yu<me@runxiyu.org>
Committer dateWed, 19 Feb 2025 09:03:03 +0800
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*.go: Use lowercase error values
package main

import (
	"bufio"
	"context"
	"errors"
	"os"

	"github.com/jackc/pgx/v5/pgxpool"
	"go.lindenii.runxiyu.org/lindenii-common/scfg"
)

var database *pgxpool.Pool

var err_unsupported_database_type = errors.New("Unsupported database type")
var err_unsupported_database_type = errors.New("unsupported database type")

var config struct {
	HTTP struct {
		Net          string `scfg:"net"`
		Addr         string `scfg:"addr"`
		CookieExpiry int    `scfg:"cookie_expiry"`
		Root         string `scfg:"root"`
	} `scfg:"http"`
	Hooks struct {
		Socket string `scfg:"socket"`
		Execs  string `scfg:"execs"`
	} `scfg:"hooks"`
	SSH struct {
		Net  string `scfg:"net"`
		Addr string `scfg:"addr"`
		Key  string `scfg:"key"`
		Root string `scfg:"root"`
	} `scfg:"ssh"`
	General struct {
		Title string `scfg:"title"`
	} `scfg:"general"`
	DB struct {
		Type string `scfg:"type"`
		Conn string `scfg:"conn"`
	} `scfg:"db"`
}

func load_config(path string) (err error) {
	config_file, err := os.Open(path)
	if err != nil {
		return err
	}
	defer config_file.Close()

	decoder := scfg.NewDecoder(bufio.NewReader(config_file))
	err = decoder.Decode(&config)
	if err != nil {
		return err
	}

	if config.DB.Type != "postgres" {
		return err_unsupported_database_type
	}
	database, err = pgxpool.New(context.Background(), config.DB.Conn)
	if err != nil {
		return err
	}

	global_data["forge_title"] = config.General.Title

	return nil
}
package main

import (
	"bytes"
	"encoding/binary"
	"errors"
	"fmt"
	"io"
	"net"
	"os"
	"path/filepath"
	"strings"
	"syscall"
)

var (
	err_get_fd    = errors.New("Unable to get file descriptor")
	err_get_ucred = errors.New("Failed getsockopt")
	err_get_fd    = errors.New("unable to get file descriptor")
	err_get_ucred = errors.New("failed getsockopt")
)

// hooks_handle_connection handles a connection from git_hooks_client via the
// unix socket.
func hooks_handle_connection(conn net.Conn) {
	defer conn.Close()

	// There aren't reasonable cases where someone would run this as
	// another user.
	ucred, err := get_ucred(conn)
	if err != nil {
		if _, err := conn.Write([]byte{1}); err != nil {
			return
		}
		fmt.Fprintln(conn, "Unable to get peer credentials:", err.Error())
		return
	}
	if ucred.Uid != uint32(os.Getuid()) {
		if _, err := conn.Write([]byte{1}); err != nil {
			return
		}
		fmt.Fprintln(conn, "UID mismatch")
		return
	}

	cookie := make([]byte, 64)
	_, err = conn.Read(cookie)
	if err != nil {
		if _, err := conn.Write([]byte{1}); err != nil {
			return
		}
		fmt.Fprintln(conn, "Failed to read cookie:", err.Error())
		return
	}

	pack_to_hook, ok := pack_to_hook_by_cookie.Load(string(cookie))
	if !ok {
		if _, err := conn.Write([]byte{1}); err != nil {
			return
		}
		fmt.Fprintln(conn, "Invalid handler cookie")
		return
	}

	var argc64 uint64
	err = binary.Read(conn, binary.NativeEndian, &argc64)
	if err != nil {
		if _, err := conn.Write([]byte{1}); err != nil {
			return
		}
		fmt.Fprintln(conn, "Failed to read argc:", err.Error())
		return
	}
	var args []string
	for i := uint64(0); i < argc64; i++ {
		var arg bytes.Buffer
		for {
			b := make([]byte, 1)
			n, err := conn.Read(b)
			if err != nil || n != 1 {
				if _, err := conn.Write([]byte{1}); err != nil {
					return
				}
				fmt.Fprintln(conn, "Failed to read arg:", err.Error())
				return
			}
			if b[0] == 0 {
				break
			}
			arg.WriteByte(b[0])
		}
		args = append(args, arg.String())
	}

	var stdin bytes.Buffer
	_, err = io.Copy(&stdin, conn)
	if err != nil {
		fmt.Fprintln(conn, "Failed to read to the stdin buffer:", err.Error())
	}

	switch filepath.Base(args[0]) {
	case "pre-receive":
		if pack_to_hook.direct_access {
			if _, err := conn.Write([]byte{0}); err != nil {
				return
			}
		} else {
			ref_ok := make(map[string]uint8)
			// 0 for ok
			// 1 for rejection due to not a contrib branch
			// 2 for rejection due to not being a new branch

			for {
				line, err := stdin.ReadString('\n')
				if errors.Is(err, io.EOF) {
					break
				}
				line = line[:len(line)-1]

				old_oid, rest, found := strings.Cut(line, " ")
				if !found {
					if _, err := conn.Write([]byte{1}); err != nil {
						return
					}
					fmt.Fprintln(conn, "Invalid pre-receive line:", line)
					break
				}

				new_oid, ref_name, found := strings.Cut(rest, " ")
				if !found {
					if _, err := conn.Write([]byte{1}); err != nil {
						return
					}
					fmt.Fprintln(conn, "Invalid pre-receive line:", line)
					break
				}

				_ = new_oid

				if strings.HasPrefix(ref_name, "refs/heads/contrib/") {
					if all_zero_num_string(old_oid) {
						ref_ok[ref_name] = 0
					} else {
						ref_ok[ref_name] = 2
					}
				} else {
					ref_ok[ref_name] = 1
				}
			}

			if or_all_in_map(ref_ok) == 0 {
				if _, err := conn.Write([]byte{0}); err != nil {
					return
				}
				fmt.Fprintln(conn, "Stuff")
			} else {
				if _, err := conn.Write([]byte{1}); err != nil {
					return
				}
				for ref, status := range ref_ok {
					switch status {
					case 0:
						fmt.Fprintln(conn, "Acceptable", ref)
					case 1:
						fmt.Fprintln(conn, "Not in the contrib/ namespace", ref)
					case 2:
						fmt.Fprintln(conn, "Branch already exists", ref)
					default:
						panic("Invalid branch status")
					}
				}
			}
		}
	default:
		if _, err := conn.Write([]byte{1}); err != nil {
			return
		}
		fmt.Fprintln(conn, "Invalid hook:", args[0])
	}
}

func serve_git_hooks(listener net.Listener) error {
	for {
		conn, err := listener.Accept()
		if err != nil {
			return err
		}
		go hooks_handle_connection(conn)
	}
}

func get_ucred(conn net.Conn) (*syscall.Ucred, error) {
	unix_conn := conn.(*net.UnixConn)
	fd, err := unix_conn.File()
	if err != nil {
		return nil, err_get_fd
	}
	defer fd.Close()

	ucred, err := syscall.GetsockoptUcred(int(fd.Fd()), syscall.SOL_SOCKET, syscall.SO_PEERCRED)
	if err != nil {
		return nil, err_get_ucred
	}
	return ucred, nil
}

func all_zero_num_string(s string) bool {
	for _, r := range s {
		if r != '0' {
			return false
		}
	}
	return true
}

func or_all_in_map[K comparable, V uint8 | uint16 | uint32 | uint64](m map[K]V) (result V) {
	for _, value := range m {
		result |= value
	}
	return
}
package main

import (
	"context"
	"errors"
	"io"
	"strings"

	"github.com/go-git/go-git/v5"
	"github.com/go-git/go-git/v5/plumbing"
	"github.com/go-git/go-git/v5/plumbing/object"
	"go.lindenii.runxiyu.org/lindenii-common/misc"
)

var (
	err_getting_commit_tree          = errors.New("Error getting commit tree")
	err_getting_patch_of_commit      = errors.New("Error getting patch of commit")
	err_getting_parent_commit_object = errors.New("Error getting parent commit object")
	err_getting_commit_tree          = errors.New("error getting commit tree")
	err_getting_patch_of_commit      = errors.New("error getting patch of commit")
	err_getting_parent_commit_object = errors.New("error getting parent commit object")
)

// open_git_repo opens a git repository by group and repo name.
func open_git_repo(ctx context.Context, group_name, repo_name string) (repo *git.Repository, description string, repo_id int, err error) {
	var fs_path string
	err = database.QueryRow(ctx, "SELECT r.filesystem_path, COALESCE(r.description, ''), r.id FROM repos r JOIN groups g ON r.group_id = g.id WHERE g.name = $1 AND r.name = $2;", group_name, repo_name).Scan(&fs_path, &description, &repo_id)
	if err != nil {
		return
	}
	repo, err = git.PlainOpen(fs_path)
	return
}

// go-git's tree entries are not friendly for use in HTML templates.
type display_git_tree_entry_t struct {
	Name       string
	Mode       string
	Size       int64
	Is_file    bool
	Is_subtree bool
}

func build_display_git_tree(tree *object.Tree) []display_git_tree_entry_t {
	display_git_tree := make([]display_git_tree_entry_t, 0)
	for _, entry := range tree.Entries {
		display_git_tree_entry := display_git_tree_entry_t{}
		os_mode, err := entry.Mode.ToOSFileMode()
		if err != nil {
			display_git_tree_entry.Mode = "x---------"
		} else {
			display_git_tree_entry.Mode = os_mode.String()
		}
		display_git_tree_entry.Is_file = entry.Mode.IsFile()
		display_git_tree_entry.Size, err = tree.Size(entry.Name)
		if err != nil {
			display_git_tree_entry.Size = 0
		}
		display_git_tree_entry.Name = strings.TrimPrefix(entry.Name, "/")
		display_git_tree = append(display_git_tree, display_git_tree_entry)
	}
	return display_git_tree
}

var err_get_recent_commits = errors.New("Error getting recent commits")
var err_get_recent_commits = errors.New("error getting recent commits")

func get_recent_commits(repo *git.Repository, head_hash plumbing.Hash, number_of_commits int) (recent_commits []*object.Commit, err error) {
	commit_iter, err := repo.Log(&git.LogOptions{From: head_hash})
	if err != nil {
		err = misc.Wrap_one_error(err_get_recent_commits, err)
		return nil, err
	}
	recent_commits = make([]*object.Commit, 0)
	defer commit_iter.Close()
	if number_of_commits < 0 {
		for {
			this_recent_commit, err := commit_iter.Next()
			if errors.Is(err, io.EOF) {
				return recent_commits, nil
			} else if err != nil {
				err = misc.Wrap_one_error(err_get_recent_commits, err)
				return nil, err
			}
			recent_commits = append(recent_commits, this_recent_commit)
		}
	} else {
		for range number_of_commits {
			this_recent_commit, err := commit_iter.Next()
			if errors.Is(err, io.EOF) {
				return recent_commits, nil
			} else if err != nil {
				err = misc.Wrap_one_error(err_get_recent_commits, err)
				return nil, err
			}
			recent_commits = append(recent_commits, this_recent_commit)
		}
	}
	return recent_commits, err
}

func get_patch_from_commit(commit_object *object.Commit) (parent_commit_hash plumbing.Hash, patch *object.Patch, ret_err error) {
	parent_commit_object, err := commit_object.Parent(0)
	if errors.Is(err, object.ErrParentNotFound) {
		commit_tree, err := commit_object.Tree()
		if err != nil {
			ret_err = misc.Wrap_one_error(err_getting_commit_tree, err)
			return
		}
		patch, err = (&object.Tree{}).Patch(commit_tree)
		if err != nil {
			ret_err = misc.Wrap_one_error(err_getting_patch_of_commit, err)
			return
		}
	} else if err != nil {
		ret_err = misc.Wrap_one_error(err_getting_parent_commit_object, err)
		return
	} else {
		parent_commit_hash = parent_commit_object.Hash
		patch, err = parent_commit_object.Patch(commit_object)
		if err != nil {
			ret_err = misc.Wrap_one_error(err_getting_patch_of_commit, err)
			return
		}
	}
	return
}
package main

import (
	"errors"

	"github.com/go-git/go-git/v5"
	"github.com/go-git/go-git/v5/plumbing"
	"go.lindenii.runxiyu.org/lindenii-common/misc"
)

var (
	err_getting_tag_reference    = errors.New("Error getting tag reference")
	err_getting_branch_reference = errors.New("Error getting branch reference")
	err_getting_head             = errors.New("Error getting HEAD")
	err_getting_tag_reference    = errors.New("error getting tag reference")
	err_getting_branch_reference = errors.New("error getting branch reference")
	err_getting_head             = errors.New("error getting HEAD")
)

// get_ref_hash_from_type_and_name returns the hash of a reference given its
// type and name as supplied in URL queries.
func get_ref_hash_from_type_and_name(repo *git.Repository, ref_type, ref_name string) (ref_hash plumbing.Hash, ret_err error) {
	switch ref_type {
	case "":
		head, err := repo.Head()
		if err != nil {
			ret_err = misc.Wrap_one_error(err_getting_head, err)
			return
		}
		ref_hash = head.Hash()
	case "commit":
		ref_hash = plumbing.NewHash(ref_name)
	case "branch":
		ref, err := repo.Reference(plumbing.NewBranchReferenceName(ref_name), true)
		if err != nil {
			ret_err = misc.Wrap_one_error(err_getting_branch_reference, err)
			return
		}
		ref_hash = ref.Hash()
	case "tag":
		ref, err := repo.Reference(plumbing.NewTagReferenceName(ref_name), true)
		if err != nil {
			ret_err = misc.Wrap_one_error(err_getting_tag_reference, err)
			return
		}
		ref_hash = ref.Hash()
	default:
		panic("Invalid ref type " + ref_type)
	}
	return
}
package main

import (
	"errors"
	"fmt"
	"net/http"
	"strconv"
	"strings"

	"github.com/jackc/pgx/v5"
	"go.lindenii.runxiyu.org/lindenii-common/clog"
)

type http_router_t struct{}

func (router *http_router_t) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	clog.Info("Incoming HTTP: " + r.RemoteAddr + " " + r.Method + " " + r.RequestURI)

	segments, _, err := parse_request_uri(r.RequestURI)
	if err != nil {
		http.Error(w, err.Error(), http.StatusBadRequest)
		return
	}
	non_empty_last_segments_len := len(segments)
	if segments[len(segments)-1] == "" {
		non_empty_last_segments_len--
	}

	if segments[0] == ":" {
		if len(segments) < 2 {
			http.Error(w, "Blank system endpoint", http.StatusNotFound)
			return
		} else if len(segments) == 2 && redirect_with_slash(w, r) {
			return
		}

		switch segments[1] {
		case "static":
			static_handler.ServeHTTP(w, r)
			return
		case "source":
			source_handler.ServeHTTP(w, r)
			return
		}
	}

	params := make(map[string]any)
	params["url_segments"] = segments
	params["global"] = global_data
	var _user_id int // 0 for none
	_user_id, params["username"], err = get_user_info_from_request(r)
	if errors.Is(err, http.ErrNoCookie) {
	} else if errors.Is(err, pgx.ErrNoRows) {
	} else if err != nil {
		http.Error(w, "Error getting user info from request: "+err.Error(), http.StatusInternalServerError)
		return
	}

	if _user_id == 0 {
		params["user_id"] = ""
	} else {
		params["user_id"] = strconv.Itoa(_user_id)
	}

	if segments[0] == ":" {
		switch segments[1] {
		case "login":
			handle_login(w, r, params)
			return
		case "users":
			handle_users(w, r, params)
			return
		default:
			http.Error(w, fmt.Sprintf("Unknown system module type: %s", segments[1]), http.StatusNotFound)
			return
		}
	}

	separator_index := -1
	for i, part := range segments {
		if part == ":" {
			separator_index = i
			break
		}
	}

	params["separator_index"] = separator_index

	// TODO
	if separator_index > 1 {
		http.Error(w, "Subgroups haven't been implemented yet", http.StatusNotImplemented)
		return
	}

	switch {
	case non_empty_last_segments_len == 0:
		handle_index(w, r, params)
	case separator_index == -1:
		http.Error(w, "Group indexing hasn't been implemented yet", http.StatusNotImplemented)
	case non_empty_last_segments_len == separator_index+1:
		http.Error(w, "Group root hasn't been implemented yet", http.StatusNotImplemented)
	case non_empty_last_segments_len == separator_index+2:
		if redirect_with_slash(w, r) {
			return
		}
		module_type := segments[separator_index+1]
		params["group_name"] = segments[0]
		switch module_type {
		case "repos":
			handle_group_repos(w, r, params)
		default:
			http.Error(w, fmt.Sprintf("Unknown module type: %s", module_type), http.StatusNotFound)
		}
	default:
		module_type := segments[separator_index+1]
		module_name := segments[separator_index+2]
		group_name := segments[0]
		params["group_name"] = group_name
		switch module_type {
		case "repos":
			params["repo_name"] = module_name

			if non_empty_last_segments_len > separator_index+3 {
				switch segments[separator_index+3] {
				case "info":
					err = handle_repo_info(w, r, params)
					if err != nil {
						http.Error(w, err.Error(), http.StatusInternalServerError)
					}
					return
				case "git-upload-pack":
					err = handle_upload_pack(w, r, params)
					if err != nil {
						http.Error(w, err.Error(), http.StatusInternalServerError)
					}
					return
				}
			}

			params["ref_type"], params["ref_name"], err = get_param_ref_and_type(r)
			if err != nil {
				if errors.Is(err, err_no_ref_spec) {
					params["ref_type"] = ""
				} else {
					http.Error(w, "Error querying ref type: "+err.Error(), http.StatusInternalServerError)
					return
				}
			}

			// TODO: subgroups

			params["repo"], params["repo_description"], params["repo_id"], err = open_git_repo(r.Context(), group_name, module_name)
			if err != nil {
				http.Error(w, "Error opening repo: "+err.Error(), http.StatusInternalServerError)
				return
			}

			if non_empty_last_segments_len == separator_index+3 {
				if redirect_with_slash(w, r) {
					return
				}
				handle_repo_index(w, r, params)
				return
			}

			repo_feature := segments[separator_index+3]
			switch repo_feature {
			case "tree":
				params["rest"] = strings.Join(segments[separator_index+4:], "/")
				if len(segments) < separator_index+5 && redirect_with_slash(w, r) {
					return
				}
				handle_repo_tree(w, r, params)
			case "raw":
				params["rest"] = strings.Join(segments[separator_index+4:], "/")
				if len(segments) < separator_index+5 && redirect_with_slash(w, r) {
					return
				}
				handle_repo_raw(w, r, params)
			case "log":
				if non_empty_last_segments_len > separator_index+4 {
					http.Error(w, "Too many parameters", http.StatusBadRequest)
					return
				}
				if redirect_with_slash(w, r) {
					return
				}
				handle_repo_log(w, r, params)
			case "commit":
				if redirect_without_slash(w, r) {
					return
				}
				params["commit_id"] = segments[separator_index+4]
				handle_repo_commit(w, r, params)
			case "contrib":
				if redirect_with_slash(w, r) {
					return
				}
				switch non_empty_last_segments_len {
				case separator_index+4:
					handle_repo_contrib_index(w, r, params)
				case separator_index+5:
					params["mr_id"] = segments[separator_index+4]
					handle_repo_contrib_one(w, r, params)
				default:
					http.Error(w, "Too many parameters", http.StatusBadRequest)
				}
			default:
				http.Error(w, fmt.Sprintf("Unknown repo feature: %s", repo_feature), http.StatusNotFound)
			}
		default:
			http.Error(w, fmt.Sprintf("Unknown module type: %s", module_type), http.StatusNotFound)
		}
	}
}

var err_bad_request = errors.New("Bad Request")
var err_bad_request = errors.New("bad request")
package main

import (
	"errors"
	"fmt"
	"os"
	"os/exec"

	glider_ssh "github.com/gliderlabs/ssh"
	"go.lindenii.runxiyu.org/lindenii-common/cmap"
)

var err_unauthorized_push = errors.New("You are not authorized to push to this repository")
var err_unauthorized_push = errors.New("you are not authorized to push to this repository")

type pack_to_hook_t struct {
	session       *glider_ssh.Session
	pubkey        string
	direct_access bool
	repo_path     string
}

var pack_to_hook_by_cookie = cmap.Map[string, pack_to_hook_t]{}

// ssh_handle_receive_pack handles attempts to push to repos.
func ssh_handle_receive_pack(session glider_ssh.Session, pubkey string, repo_identifier string) (err error) {
	// Here "access" means direct maintainer access. access=false doesn't
	// necessarily mean the push is declined. This decision is delegated to
	// the pre-receive hook, which is then handled by git_hooks_handle.go
	// while being aware of the refs to be updated.
	repo_path, access, err := get_repo_path_perms_from_ssh_path_pubkey(session.Context(), repo_identifier, pubkey)
	if err != nil {
		return err
	}

	cookie, err := random_urlsafe_string(16)
	if err != nil {
		fmt.Fprintln(session.Stderr(), "Error while generating cookie:", err)
	}

	pack_to_hook_by_cookie.Store(cookie, pack_to_hook_t{
		session:       &session,
		pubkey:        pubkey,
		direct_access: access,
		repo_path:     repo_path,
	})
	defer pack_to_hook_by_cookie.Delete(cookie)
	// The Delete won't execute until proc.Wait returns unless something
	// horribly wrong such as a panic occurs.

	proc := exec.CommandContext(session.Context(), "git-receive-pack", repo_path)
	proc.Env = append(os.Environ(),
		"LINDENII_FORGE_HOOKS_SOCKET_PATH="+config.Hooks.Socket,
		"LINDENII_FORGE_HOOKS_COOKIE="+cookie,
	)
	proc.Stdin = session
	proc.Stdout = session
	proc.Stderr = session.Stderr()

	err = proc.Start()
	if err != nil {
		fmt.Fprintln(session.Stderr(), "Error while starting process:", err)
		return err
	}

	err = proc.Wait()
	if exitError, ok := err.(*exec.ExitError); ok {
		fmt.Fprintln(session.Stderr(), "Process exited with error", exitError.ExitCode())
	} else if err != nil {
		fmt.Fprintln(session.Stderr(), "Error while waiting for process:", err)
	}

	return err
}
package main

import (
	"context"
	"errors"
	"net/url"
	"strings"
)

var err_ssh_illegal_endpoint = errors.New("Illegal endpoint during SSH access")
var err_ssh_illegal_endpoint = errors.New("illegal endpoint during SSH access")

func get_repo_path_perms_from_ssh_path_pubkey(ctx context.Context, ssh_path string, ssh_pubkey string) (repo_path string, direct_access bool, err error) {
	segments := strings.Split(strings.TrimPrefix(ssh_path, "/"), "/")

	for i, segment := range segments {
		var err error
		segments[i], err = url.PathUnescape(segment)
		if err != nil {
			return "", false, err
		}
	}

	if segments[0] == ":" {
		return "", false, err_ssh_illegal_endpoint
	}

	separator_index := -1
	for i, part := range segments {
		if part == ":" {
			separator_index = i
			break
		}
	}
	if segments[len(segments)-1] == "" {
		segments = segments[:len(segments)-1]
	}

	switch {
	case separator_index == -1:
		return "", false, err_ssh_illegal_endpoint
	case len(segments) <= separator_index+2:
		return "", false, err_ssh_illegal_endpoint
	}

	group_name := segments[0]
	module_type := segments[separator_index+1]
	module_name := segments[separator_index+2]
	switch module_type {
	case "repos":
		return get_path_perm_by_group_repo_key(ctx, group_name, module_name, ssh_pubkey)
	default:
		return "", false, err_ssh_illegal_endpoint
	}
}
package main

import (
	"errors"
	"net/http"
	"net/url"
	"strings"

	"go.lindenii.runxiyu.org/lindenii-common/misc"
)

var (
	err_duplicate_ref_spec = errors.New("Duplicate ref spec")
	err_no_ref_spec        = errors.New("No ref spec")
	err_duplicate_ref_spec = errors.New("duplicate ref spec")
	err_no_ref_spec        = errors.New("no ref spec")
)

func get_param_ref_and_type(r *http.Request) (ref_type, ref string, err error) {
	qr := r.URL.RawQuery
	q, err := url.ParseQuery(qr)
	if err != nil {
		return
	}
	done := false
	for _, _ref_type := range []string{"commit", "branch", "tag"} {
		_ref, ok := q[_ref_type]
		if ok {
			if done {
				err = err_duplicate_ref_spec
				return
			} else {
				done = true
				if len(_ref) != 1 {
					err = err_duplicate_ref_spec
					return
				}
				ref = _ref[0]
				ref_type = _ref_type
			}
		}
	}
	if !done {
		err = err_no_ref_spec
	}
	return
}

func parse_request_uri(request_uri string) (segments []string, params url.Values, err error) {
	path, params_string, _ := strings.Cut(request_uri, "?")

	segments = strings.Split(strings.TrimPrefix(path, "/"), "/")

	for i, segment := range segments {
		segments[i], err = url.PathUnescape(segment)
		if err != nil {
			return nil, nil, misc.Wrap_one_error(err_bad_request, err)
		}
	}

	params, err = url.ParseQuery(params_string)
	if err != nil {
		return nil, nil, misc.Wrap_one_error(err_bad_request, err)
	}

	return
}

func redirect_with_slash(w http.ResponseWriter, r *http.Request) bool {
	request_uri := r.RequestURI

	path_end := strings.IndexAny(request_uri, "?#")
	var path, rest string
	if path_end == -1 {
		path = request_uri
	} else {
		path = request_uri[:path_end]
		rest = request_uri[path_end:]
	}

	if !strings.HasSuffix(path, "/") {
		http.Redirect(w, r, path+"/"+rest, http.StatusSeeOther)
		return true
	}
	return false
}

func redirect_without_slash(w http.ResponseWriter, r *http.Request) bool {
	request_uri := r.RequestURI

	path_end := strings.IndexAny(request_uri, "?#")
	var path, rest string
	if path_end == -1 {
		path = request_uri
	} else {
		path = request_uri[:path_end]
		rest = request_uri[path_end:]
	}

	if strings.HasSuffix(path, "/") {
		http.Redirect(w, r, strings.TrimSuffix(path, "/")+rest, http.StatusSeeOther)
		return true
	}
	return false
}