Lindenii Project Forge
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server

Lindenii Forge’s main backend daemon
Commit info
ID
20b4fe0c59357a433042732d46e38da9c3d14c3b
Author
Runxi Yu <me@runxiyu.org>
Author date
Sat, 05 Apr 2025 20:26:57 +0800
Committer
Runxi Yu <me@runxiyu.org>
Committer date
Sat, 05 Apr 2025 20:26:57 +0800
Actions
database shall no longer be a global variable
// SPDX-License-Identifier: AGPL-3.0-only
// SPDX-FileCopyrightText: Copyright (c) 2025 Runxi Yu <https://runxiyu.org>

package main

import (
	"context"

	"github.com/jackc/pgx/v5/pgtype"
)

// getRepoInfo returns the filesystem path and direct access permission for a
// given repo and a provided ssh public key.
//
// TODO: Revamp.
func (s *server) getRepoInfo(ctx context.Context, groupPath []string, repoName, sshPubkey string) (repoID int, fsPath string, access bool, contribReq, userType string, userID int, err error) {
	err = database.QueryRow(ctx, `
	err = s.database.QueryRow(ctx, `
WITH RECURSIVE group_path_cte AS (
	-- Start: match the first name in the path where parent_group IS NULL
	SELECT
		id,
		parent_group,
		name,
		1 AS depth
	FROM groups
	WHERE name = ($1::text[])[1]
		AND parent_group IS NULL

	UNION ALL

	-- Recurse: join next segment of the path
	SELECT
		g.id,
		g.parent_group,
		g.name,
		group_path_cte.depth + 1
	FROM groups g
	JOIN group_path_cte ON g.parent_group = group_path_cte.id
	WHERE g.name = ($1::text[])[group_path_cte.depth + 1]
		AND group_path_cte.depth + 1 <= cardinality($1::text[])
)
SELECT
	r.id,
	r.filesystem_path,
	CASE WHEN ugr.user_id IS NOT NULL THEN TRUE ELSE FALSE END AS has_role_in_group,
	r.contrib_requirements,
	COALESCE(u.type, ''),
	COALESCE(u.id, 0)
FROM group_path_cte g
JOIN repos r ON r.group_id = g.id
LEFT JOIN ssh_public_keys s ON s.key_string = $3
LEFT JOIN users u ON u.id = s.user_id
LEFT JOIN user_group_roles ugr ON ugr.group_id = g.id AND ugr.user_id = u.id
WHERE g.depth = cardinality($1::text[])
	AND r.name = $2
`, pgtype.FlatArray[string](groupPath), repoName, sshPubkey,
	).Scan(&repoID, &fsPath, &access, &contribReq, &userType, &userID)
	return
}
// SPDX-License-Identifier: AGPL-3.0-only
// SPDX-FileCopyrightText: Copyright (c) 2025 Runxi Yu <https://runxiyu.org>

package main

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

	"codeberg.org/emersion/go-scfg"
	"github.com/jackc/pgx/v5/pgxpool"
)

// config holds the global configuration used by this instance. There is
// currently no synchronization mechanism, so it must not be modified after
// request handlers are spawned.
type Config struct {
	HTTP struct {
		Net          string `scfg:"net"`
		Addr         string `scfg:"addr"`
		CookieExpiry int    `scfg:"cookie_expiry"`
		Root         string `scfg:"root"`
		ReadTimeout  uint32 `scfg:"read_timeout"`
		WriteTimeout uint32 `scfg:"write_timeout"`
		IdleTimeout  uint32 `scfg:"idle_timeout"`
		ReverseProxy bool   `scfg:"reverse_proxy"`
	} `scfg:"http"`
	Hooks struct {
		Socket string `scfg:"socket"`
		Execs  string `scfg:"execs"`
	} `scfg:"hooks"`
	LMTP struct {
		Socket       string `scfg:"socket"`
		Domain       string `scfg:"domain"`
		MaxSize      int64  `scfg:"max_size"`
		WriteTimeout uint32 `scfg:"write_timeout"`
		ReadTimeout  uint32 `scfg:"read_timeout"`
	} `scfg:"lmtp"`
	Git struct {
		RepoDir    string `scfg:"repo_dir"`
		Socket     string `scfg:"socket"`
		DaemonPath string `scfg:"daemon_path"`
	} `scfg:"git"`
	SSH struct {
		Net  string `scfg:"net"`
		Addr string `scfg:"addr"`
		Key  string `scfg:"key"`
		Root string `scfg:"root"`
	} `scfg:"ssh"`
	IRC struct {
		Net   string `scfg:"net"`
		Addr  string `scfg:"addr"`
		TLS   bool   `scfg:"tls"`
		SendQ uint   `scfg:"sendq"`
		Nick  string `scfg:"nick"`
		User  string `scfg:"user"`
		Gecos string `scfg:"gecos"`
	} `scfg:"irc"`
	General struct {
		Title string `scfg:"title"`
	} `scfg:"general"`
	DB struct {
		Type string `scfg:"type"`
		Conn string `scfg:"conn"`
	} `scfg:"db"`
}

// loadConfig loads a configuration file from the specified path and unmarshals
// it to the global [config] struct. This may race with concurrent reads from
// [config]; additional synchronization is necessary if the configuration is to
// be made reloadable.
//
// TODO: Currently, it returns an error when the user specifies any unknown
// configuration patterns, but silently ignores fields in the [config] struct
// that is not present in the user's configuration file. We would prefer the
// exact opposite behavior.
func (s *server) loadConfig(path string) (err error) {
	var configFile *os.File
	if configFile, err = os.Open(path); err != nil {
		return err
	}
	defer configFile.Close()

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

	if s.config.DB.Type != "postgres" {
		return errors.New("unsupported database type")
	}

	if database, err = pgxpool.New(context.Background(), s.config.DB.Conn); err != nil {
	if s.database, err = pgxpool.New(context.Background(), s.config.DB.Conn); err != nil {
		return err
	}

	globalData["forge_title"] = s.config.General.Title

	return nil
}
// SPDX-License-Identifier: AGPL-3.0-only
// SPDX-FileCopyrightText: Copyright (c) 2025 Runxi Yu <https://runxiyu.org>

package main

import (
	"context"

	"github.com/jackc/pgx/v5"
	"github.com/jackc/pgx/v5/pgxpool"
)

// TODO: All database handling logic in all request handlers must be revamped.
// We must ensure that each request has all logic in one transaction (subject
// to exceptions if appropriate) so they get a consistent view of the database
// at a single point. A failure to do so may cause things as serious as
// privilege escalation.

// database serves as the primary database handle for this entire application.
// Transactions or single reads may be used from it. A [pgxpool.Pool] is
// necessary to safely use pgx concurrently; pgx.Conn, etc. are insufficient.
var database *pgxpool.Pool

// queryNameDesc is a helper function that executes a query and returns a
// list of nameDesc results. The query must return two string arguments, i.e. a
// name and a description.
func (s *server) queryNameDesc(ctx context.Context, query string, args ...any) (result []nameDesc, err error) {
	var rows pgx.Rows

	if rows, err = database.Query(ctx, query, args...); err != nil {
	if rows, err = s.database.Query(ctx, query, args...); err != nil {
		return nil, err
	}
	defer rows.Close()

	for rows.Next() {
		var name, description string
		if err = rows.Scan(&name, &description); err != nil {
			return nil, err
		}
		result = append(result, nameDesc{name, description})
	}
	return result, rows.Err()
}

// nameDesc holds a name and a description.
type nameDesc struct {
	Name        string
	Description string
}
// SPDX-License-Identifier: AGPL-3.0-only
// SPDX-FileCopyrightText: Copyright (c) 2025 Runxi Yu <https://runxiyu.org>

package main

import (
	"bufio"
	"context"
	"errors"
	"io"
	"net/http"
	"net/url"
	"strings"

	"github.com/jackc/pgx/v5"
)

// fedauth checks whether a user's SSH public key matches the remote username
// they claim to have on the service. If so, the association is recorded.
func (s *server) fedauth(ctx context.Context, userID int, service, remoteUsername, pubkey string) (bool, error) {
	var err error

	matched := false
	usernameEscaped := url.PathEscape(remoteUsername)

	var req *http.Request
	switch service {
	// TODO: Services should be configurable by the instance administrator
	// and should not be hardcoded in the source code.
	case "sr.ht":
		req, err = http.NewRequestWithContext(ctx, http.MethodGet, "https://meta.sr.ht/~"+usernameEscaped+".keys", nil)
	case "github":
		req, err = http.NewRequestWithContext(ctx, http.MethodGet, "https://github.com/"+usernameEscaped+".keys", nil)
	case "codeberg":
		req, err = http.NewRequestWithContext(ctx, http.MethodGet, "https://codeberg.org/"+usernameEscaped+".keys", nil)
	case "tangled":
		req, err = http.NewRequestWithContext(ctx, http.MethodGet, "https://tangled.sh/keys/"+usernameEscaped, nil)
		// TODO: Don't rely on one webview
	default:
		return false, errors.New("unknown federated service")
	}
	if err != nil {
		return false, err
	}

	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		return false, err
	}
	defer func() {
		_ = resp.Body.Close()
	}()
	buf := bufio.NewReader(resp.Body)

	for {
		line, err := buf.ReadString('\n')
		if errors.Is(err, io.EOF) {
			break
		} else if err != nil {
			return false, err
		}

		lineSplit := strings.Split(line, " ")
		if len(lineSplit) < 2 {
			continue
		}
		line = strings.Join(lineSplit[:2], " ")

		if line == pubkey {
			matched = true
			break
		}
	}

	if !matched {
		return false, nil
	}

	var txn pgx.Tx
	if txn, err = database.Begin(ctx); err != nil {
	if txn, err = s.database.Begin(ctx); err != nil {
		return false, err
	}
	defer func() {
		_ = txn.Rollback(ctx)
	}()
	if _, err = txn.Exec(ctx, `UPDATE users SET type = 'federated' WHERE id = $1 AND type = 'pubkey_only'`, userID); err != nil {
		return false, err
	}
	if _, err = txn.Exec(ctx, `INSERT INTO federated_identities (user_id, service, remote_username) VALUES ($1, $2, $3)`, userID, service, remoteUsername); err != nil {
		return false, err
	}
	if err = txn.Commit(ctx); err != nil {
		return false, err
	}

	return true, nil
}
// SPDX-License-Identifier: AGPL-3.0-only
// SPDX-FileCopyrightText: Copyright (c) 2025 Runxi Yu <https://runxiyu.org>
//
//go:build linux

package main

import (
	"bytes"
	"context"
	"encoding/binary"
	"errors"
	"fmt"
	"io"
	"log/slog"
	"net"
	"os"
	"path/filepath"
	"strconv"
	"strings"
	"syscall"

	"github.com/go-git/go-git/v5/plumbing"
	"github.com/go-git/go-git/v5/plumbing/object"
	"github.com/jackc/pgx/v5"
	"go.lindenii.runxiyu.org/forge/ansiec"
	"go.lindenii.runxiyu.org/forge/misc"
)

var (
	errGetFD    = errors.New("unable to get file descriptor")
	errGetUcred = errors.New("failed getsockopt")
)

// hooksHandler handles a connection from hookc via the
// unix socket.
func (s *server) hooksHandler(conn net.Conn) {
	var ctx context.Context
	var cancel context.CancelFunc
	var ucred *syscall.Ucred
	var err error
	var cookie []byte
	var packPass packPass
	var sshStderr io.Writer
	var hookRet byte

	defer conn.Close()
	ctx, cancel = context.WithCancel(context.Background())
	defer cancel()

	// There aren't reasonable cases where someone would run this as
	// another user.
	if ucred, err = getUcred(conn); err != nil {
		if _, err = conn.Write([]byte{1}); err != nil {
			return
		}
		writeRedError(conn, "\nUnable to get peer credentials: %v", err)
		return
	}
	uint32uid := uint32(os.Getuid()) //#nosec G115
	if ucred.Uid != uint32uid {
		if _, err = conn.Write([]byte{1}); err != nil {
			return
		}
		writeRedError(conn, "\nUID mismatch")
		return
	}

	cookie = make([]byte, 64)
	if _, err = conn.Read(cookie); err != nil {
		if _, err = conn.Write([]byte{1}); err != nil {
			return
		}
		writeRedError(conn, "\nFailed to read cookie: %v", err)
		return
	}

	{
		var ok bool
		packPass, ok = packPasses.Load(misc.BytesToString(cookie))
		if !ok {
			if _, err = conn.Write([]byte{1}); err != nil {
				return
			}
			writeRedError(conn, "\nInvalid handler cookie")
			return
		}
	}

	sshStderr = packPass.session.Stderr()

	_, _ = sshStderr.Write([]byte{'\n'})

	hookRet = func() byte {
		var argc64 uint64
		if err = binary.Read(conn, binary.NativeEndian, &argc64); err != nil {
			writeRedError(sshStderr, "Failed to read argc: %v", err)
			return 1
		}
		var args []string
		for range argc64 {
			var arg bytes.Buffer
			for {
				nextByte := make([]byte, 1)
				n, err := conn.Read(nextByte)
				if err != nil || n != 1 {
					writeRedError(sshStderr, "Failed to read arg: %v", err)
					return 1
				}
				if nextByte[0] == 0 {
					break
				}
				arg.WriteByte(nextByte[0])
			}
			args = append(args, arg.String())
		}

		gitEnv := make(map[string]string)
		for {
			var envLine bytes.Buffer
			for {
				nextByte := make([]byte, 1)
				n, err := conn.Read(nextByte)
				if err != nil || n != 1 {
					writeRedError(sshStderr, "Failed to read environment variable: %v", err)
					return 1
				}
				if nextByte[0] == 0 {
					break
				}
				envLine.WriteByte(nextByte[0])
			}
			if envLine.Len() == 0 {
				break
			}
			kv := envLine.String()
			parts := strings.SplitN(kv, "=", 2)
			if len(parts) < 2 {
				writeRedError(sshStderr, "Invalid environment variable line: %v", kv)
				return 1
			}
			gitEnv[parts[0]] = parts[1]
		}

		var stdin bytes.Buffer
		if _, err = io.Copy(&stdin, conn); err != nil {
			writeRedError(conn, "Failed to read to the stdin buffer: %v", err)
		}

		switch filepath.Base(args[0]) {
		case "pre-receive":
			if packPass.directAccess {
				return 0
			}
			allOK := true
			for {
				var line, oldOID, rest, newIOID, refName string
				var found bool
				var oldHash, newHash plumbing.Hash
				var oldCommit, newCommit *object.Commit
				var pushOptCount int

				pushOptCount, err = strconv.Atoi(gitEnv["GIT_PUSH_OPTION_COUNT"])
				if err != nil {
					writeRedError(sshStderr, "Failed to parse GIT_PUSH_OPTION_COUNT: %v", err)
					return 1
				}

				// TODO: Allow existing users (even if they are already federated or registered) to add a federated user ID... though perhaps this should be in the normal SSH interface instead of the git push interface?
				// Also it'd be nice to be able to combine users or whatever
				if packPass.contribReq == "federated" && packPass.userType != "federated" && packPass.userType != "registered" {
					if pushOptCount == 0 {
						writeRedError(sshStderr, "This repo requires contributors to be either federated or registered users. You must supply your federated user ID as a push option. For example, git push -o fedid=sr.ht:runxiyu")
						return 1
					}
					for pushOptIndex := range pushOptCount {
						pushOpt, ok := gitEnv[fmt.Sprintf("GIT_PUSH_OPTION_%d", pushOptIndex)]
						if !ok {
							writeRedError(sshStderr, "Failed to get push option %d", pushOptIndex)
							return 1
						}
						if strings.HasPrefix(pushOpt, "fedid=") {
							fedUserID := strings.TrimPrefix(pushOpt, "fedid=")
							service, username, found := strings.Cut(fedUserID, ":")
							if !found {
								writeRedError(sshStderr, "Invalid federated user identifier %#v does not contain a colon", fedUserID)
								return 1
							}

							ok, err := s.fedauth(ctx, packPass.userID, service, username, packPass.pubkey)
							if err != nil {
								writeRedError(sshStderr, "Failed to verify federated user identifier %#v: %v", fedUserID, err)
								return 1
							}
							if !ok {
								writeRedError(sshStderr, "Failed to verify federated user identifier %#v: you don't seem to be on the list", fedUserID)
								return 1
							}

							break
						}
						if pushOptIndex == pushOptCount-1 {
							writeRedError(sshStderr, "This repo requires contributors to be either federated or registered users. You must supply your federated user ID as a push option. For example, git push -o fedid=sr.ht:runxiyu")
							return 1
						}
					}
				}

				line, err = stdin.ReadString('\n')
				if errors.Is(err, io.EOF) {
					break
				} else if err != nil {
					writeRedError(sshStderr, "Failed to read pre-receive line: %v", err)
					return 1
				}
				line = line[:len(line)-1]

				oldOID, rest, found = strings.Cut(line, " ")
				if !found {
					writeRedError(sshStderr, "Invalid pre-receive line: %v", line)
					return 1
				}

				newIOID, refName, found = strings.Cut(rest, " ")
				if !found {
					writeRedError(sshStderr, "Invalid pre-receive line: %v", line)
					return 1
				}

				if strings.HasPrefix(refName, "refs/heads/contrib/") {
					if allZero(oldOID) { // New branch
						fmt.Fprintln(sshStderr, ansiec.Blue+"POK"+ansiec.Reset, refName)
						var newMRLocalID int

						if packPass.userID != 0 {
							err = database.QueryRow(ctx,
							err = s.database.QueryRow(ctx,
								"INSERT INTO merge_requests (repo_id, creator, source_ref, status) VALUES ($1, $2, $3, 'open') RETURNING repo_local_id",
								packPass.repoID, packPass.userID, strings.TrimPrefix(refName, "refs/heads/"),
							).Scan(&newMRLocalID)
						} else {
							err = database.QueryRow(ctx,
							err = s.database.QueryRow(ctx,
								"INSERT INTO merge_requests (repo_id, source_ref, status) VALUES ($1, $2, 'open') RETURNING repo_local_id",
								packPass.repoID, strings.TrimPrefix(refName, "refs/heads/"),
							).Scan(&newMRLocalID)
						}
						if err != nil {
							writeRedError(sshStderr, "Error creating merge request: %v", err)
							return 1
						}
						mergeRequestWebURL := fmt.Sprintf("%s/contrib/%d/", s.genHTTPRemoteURL(packPass.groupPath, packPass.repoName), newMRLocalID)
						fmt.Fprintln(sshStderr, ansiec.Blue+"Created merge request at", mergeRequestWebURL+ansiec.Reset)

						select {
						case ircSendBuffered <- "PRIVMSG #chat :New merge request at " + mergeRequestWebURL:
						default:
							slog.Error("IRC SendQ exceeded")
						}
					} else { // Existing contrib branch
						var existingMRUser int
						var isAncestor bool

						err = database.QueryRow(ctx,
						err = s.database.QueryRow(ctx,
							"SELECT COALESCE(creator, 0) FROM merge_requests WHERE source_ref = $1 AND repo_id = $2",
							strings.TrimPrefix(refName, "refs/heads/"), packPass.repoID,
						).Scan(&existingMRUser)
						if err != nil {
							if errors.Is(err, pgx.ErrNoRows) {
								writeRedError(sshStderr, "No existing merge request for existing contrib branch: %v", err)
							} else {
								writeRedError(sshStderr, "Error querying for existing merge request: %v", err)
							}
							return 1
						}
						if existingMRUser == 0 {
							allOK = false
							fmt.Fprintln(sshStderr, ansiec.Red+"NAK"+ansiec.Reset, refName, "(branch belongs to unowned MR)")
							continue
						}

						if existingMRUser != packPass.userID {
							allOK = false
							fmt.Fprintln(sshStderr, ansiec.Red+"NAK"+ansiec.Reset, refName, "(branch belongs another user's MR)")
							continue
						}

						oldHash = plumbing.NewHash(oldOID)

						if oldCommit, err = packPass.repo.CommitObject(oldHash); err != nil {
							writeRedError(sshStderr, "Daemon failed to get old commit: %v", err)
							return 1
						}

						// Potential BUG: I'm not sure if new_commit is guaranteed to be
						// detectable as they haven't been merged into the main repo's
						// objects yet. But it seems to work, and I don't think there's
						// any reason for this to only work intermitently.
						newHash = plumbing.NewHash(newIOID)
						if newCommit, err = packPass.repo.CommitObject(newHash); err != nil {
							writeRedError(sshStderr, "Daemon failed to get new commit: %v", err)
							return 1
						}

						if isAncestor, err = oldCommit.IsAncestor(newCommit); err != nil {
							writeRedError(sshStderr, "Daemon failed to check if old commit is ancestor: %v", err)
							return 1
						}

						if !isAncestor {
							// TODO: Create MR snapshot ref instead
							allOK = false
							fmt.Fprintln(sshStderr, ansiec.Red+"NAK"+ansiec.Reset, refName, "(force pushes are not supported yet)")
							continue
						}

						fmt.Fprintln(sshStderr, ansiec.Blue+"POK"+ansiec.Reset, refName)
					}
				} else { // Non-contrib branch
					allOK = false
					fmt.Fprintln(sshStderr, ansiec.Red+"NAK"+ansiec.Reset, refName, "(you cannot push to branches outside of contrib/*)")
				}
			}

			fmt.Fprintln(sshStderr)
			if allOK {
				fmt.Fprintln(sshStderr, "Overall "+ansiec.Green+"ACK"+ansiec.Reset+" (all checks passed)")
				return 0
			}
			fmt.Fprintln(sshStderr, "Overall "+ansiec.Red+"NAK"+ansiec.Reset+" (one or more branches failed checks)")
			return 1
		default:
			fmt.Fprintln(sshStderr, ansiec.Red+"Invalid hook:", args[0]+ansiec.Reset)
			return 1
		}
	}()

	fmt.Fprintln(sshStderr)

	_, _ = conn.Write([]byte{hookRet})
}

// serveGitHooks handles connections on the specified network listener and
// treats incoming connections as those from git hook handlers by spawning
// sessions. The listener must be a SOCK_STREAM UNIX domain socket. The
// function itself blocks.
func (s *server) serveGitHooks(listener net.Listener) error {
	for {
		conn, err := listener.Accept()
		if err != nil {
			return err
		}
		go s.hooksHandler(conn)
	}
}

// getUcred fetches connection credentials as a [syscall.Ucred] from a given
// [net.Conn]. It panics when conn is not a [net.UnixConn].
func getUcred(conn net.Conn) (ucred *syscall.Ucred, err error) {
	unixConn := conn.(*net.UnixConn)
	var unixConnFD *os.File

	if unixConnFD, err = unixConn.File(); err != nil {
		return nil, errGetFD
	}
	defer unixConnFD.Close()

	if ucred, err = syscall.GetsockoptUcred(int(unixConnFD.Fd()), syscall.SOL_SOCKET, syscall.SO_PEERCRED); err != nil {
		return nil, errGetUcred
	}
	return ucred, nil
}

// allZero returns true if all runes in a given string are '0'. The comparison
// is not constant time and must not be used in contexts where time-based side
// channel attacks are a concern.
func allZero(s string) bool {
	for _, r := range s {
		if r != '0' {
			return false
		}
	}
	return true
}
// SPDX-License-Identifier: AGPL-3.0-only
// SPDX-FileCopyrightText: Copyright (c) 2025 Runxi Yu <https://runxiyu.org>
//
//go:build !linux

package main

import (
	"bytes"
	"context"
	"encoding/binary"
	"errors"
	"fmt"
	"io"
	"log/slog"
	"net"
	"path/filepath"
	"strconv"
	"strings"

	"github.com/go-git/go-git/v5/plumbing"
	"github.com/go-git/go-git/v5/plumbing/object"
	"github.com/jackc/pgx/v5"
	"go.lindenii.runxiyu.org/forge/ansiec"
	"go.lindenii.runxiyu.org/forge/misc"
)

var errGetFD = errors.New("unable to get file descriptor")

// hooksHandler handles a connection from hookc via the
// unix socket.
func (s *server) hooksHandler(conn net.Conn) {
	var ctx context.Context
	var cancel context.CancelFunc
	var err error
	var cookie []byte
	var packPass packPass
	var sshStderr io.Writer
	var hookRet byte

	defer conn.Close()
	ctx, cancel = context.WithCancel(context.Background())
	defer cancel()

	// TODO: Validate that the connection is from the right user.

	cookie = make([]byte, 64)
	if _, err = conn.Read(cookie); err != nil {
		if _, err = conn.Write([]byte{1}); err != nil {
			return
		}
		writeRedError(conn, "\nFailed to read cookie: %v", err)
		return
	}

	{
		var ok bool
		packPass, ok = packPasses.Load(misc.BytesToString(cookie))
		if !ok {
			if _, err = conn.Write([]byte{1}); err != nil {
				return
			}
			writeRedError(conn, "\nInvalid handler cookie")
			return
		}
	}

	sshStderr = packPass.session.Stderr()

	_, _ = sshStderr.Write([]byte{'\n'})

	hookRet = func() byte {
		var argc64 uint64
		if err = binary.Read(conn, binary.NativeEndian, &argc64); err != nil {
			writeRedError(sshStderr, "Failed to read argc: %v", err)
			return 1
		}
		var args []string
		for range argc64 {
			var arg bytes.Buffer
			for {
				nextByte := make([]byte, 1)
				n, err := conn.Read(nextByte)
				if err != nil || n != 1 {
					writeRedError(sshStderr, "Failed to read arg: %v", err)
					return 1
				}
				if nextByte[0] == 0 {
					break
				}
				arg.WriteByte(nextByte[0])
			}
			args = append(args, arg.String())
		}

		gitEnv := make(map[string]string)
		for {
			var envLine bytes.Buffer
			for {
				nextByte := make([]byte, 1)
				n, err := conn.Read(nextByte)
				if err != nil || n != 1 {
					writeRedError(sshStderr, "Failed to read environment variable: %v", err)
					return 1
				}
				if nextByte[0] == 0 {
					break
				}
				envLine.WriteByte(nextByte[0])
			}
			if envLine.Len() == 0 {
				break
			}
			kv := envLine.String()
			parts := strings.SplitN(kv, "=", 2)
			if len(parts) < 2 {
				writeRedError(sshStderr, "Invalid environment variable line: %v", kv)
				return 1
			}
			gitEnv[parts[0]] = parts[1]
		}

		var stdin bytes.Buffer
		if _, err = io.Copy(&stdin, conn); err != nil {
			writeRedError(conn, "Failed to read to the stdin buffer: %v", err)
		}

		switch filepath.Base(args[0]) {
		case "pre-receive":
			if packPass.directAccess {
				return 0
			}
			allOK := true
			for {
				var line, oldOID, rest, newIOID, refName string
				var found bool
				var oldHash, newHash plumbing.Hash
				var oldCommit, newCommit *object.Commit
				var pushOptCount int

				pushOptCount, err = strconv.Atoi(gitEnv["GIT_PUSH_OPTION_COUNT"])
				if err != nil {
					writeRedError(sshStderr, "Failed to parse GIT_PUSH_OPTION_COUNT: %v", err)
					return 1
				}

				// TODO: Allow existing users (even if they are already federated or registered) to add a federated user ID... though perhaps this should be in the normal SSH interface instead of the git push interface?
				// Also it'd be nice to be able to combine users or whatever
				if packPass.contribReq == "federated" && packPass.userType != "federated" && packPass.userType != "registered" {
					if pushOptCount == 0 {
						writeRedError(sshStderr, "This repo requires contributors to be either federated or registered users. You must supply your federated user ID as a push option. For example, git push -o fedid=sr.ht:runxiyu")
						return 1
					}
					for pushOptIndex := range pushOptCount {
						pushOpt, ok := gitEnv[fmt.Sprintf("GIT_PUSH_OPTION_%d", pushOptIndex)]
						if !ok {
							writeRedError(sshStderr, "Failed to get push option %d", pushOptIndex)
							return 1
						}
						if strings.HasPrefix(pushOpt, "fedid=") {
							fedUserID := strings.TrimPrefix(pushOpt, "fedid=")
							service, username, found := strings.Cut(fedUserID, ":")
							if !found {
								writeRedError(sshStderr, "Invalid federated user identifier %#v does not contain a colon", fedUserID)
								return 1
							}

							ok, err := s.fedauth(ctx, packPass.userID, service, username, packPass.pubkey)
							if err != nil {
								writeRedError(sshStderr, "Failed to verify federated user identifier %#v: %v", fedUserID, err)
								return 1
							}
							if !ok {
								writeRedError(sshStderr, "Failed to verify federated user identifier %#v: you don't seem to be on the list", fedUserID)
								return 1
							}

							break
						}
						if pushOptIndex == pushOptCount-1 {
							writeRedError(sshStderr, "This repo requires contributors to be either federated or registered users. You must supply your federated user ID as a push option. For example, git push -o fedid=sr.ht:runxiyu")
							return 1
						}
					}
				}

				line, err = stdin.ReadString('\n')
				if errors.Is(err, io.EOF) {
					break
				} else if err != nil {
					writeRedError(sshStderr, "Failed to read pre-receive line: %v", err)
					return 1
				}
				line = line[:len(line)-1]

				oldOID, rest, found = strings.Cut(line, " ")
				if !found {
					writeRedError(sshStderr, "Invalid pre-receive line: %v", line)
					return 1
				}

				newIOID, refName, found = strings.Cut(rest, " ")
				if !found {
					writeRedError(sshStderr, "Invalid pre-receive line: %v", line)
					return 1
				}

				if strings.HasPrefix(refName, "refs/heads/contrib/") {
					if allZero(oldOID) { // New branch
						fmt.Fprintln(sshStderr, ansiec.Blue+"POK"+ansiec.Reset, refName)
						var newMRLocalID int

						if packPass.userID != 0 {
							err = database.QueryRow(ctx,
							err = s.database.QueryRow(ctx,
								"INSERT INTO merge_requests (repo_id, creator, source_ref, status) VALUES ($1, $2, $3, 'open') RETURNING repo_local_id",
								packPass.repoID, packPass.userID, strings.TrimPrefix(refName, "refs/heads/"),
							).Scan(&newMRLocalID)
						} else {
							err = database.QueryRow(ctx,
							err = s.database.QueryRow(ctx,
								"INSERT INTO merge_requests (repo_id, source_ref, status) VALUES ($1, $2, 'open') RETURNING repo_local_id",
								packPass.repoID, strings.TrimPrefix(refName, "refs/heads/"),
							).Scan(&newMRLocalID)
						}
						if err != nil {
							writeRedError(sshStderr, "Error creating merge request: %v", err)
							return 1
						}
						mergeRequestWebURL := fmt.Sprintf("%s/contrib/%d/", s.genHTTPRemoteURL(packPass.groupPath, packPass.repoName), newMRLocalID)
						fmt.Fprintln(sshStderr, ansiec.Blue+"Created merge request at", mergeRequestWebURL+ansiec.Reset)

						select {
						case ircSendBuffered <- "PRIVMSG #chat :New merge request at " + mergeRequestWebURL:
						default:
							slog.Error("IRC SendQ exceeded")
						}
					} else { // Existing contrib branch
						var existingMRUser int
						var isAncestor bool

						err = database.QueryRow(ctx,
						err = s.database.QueryRow(ctx,
							"SELECT COALESCE(creator, 0) FROM merge_requests WHERE source_ref = $1 AND repo_id = $2",
							strings.TrimPrefix(refName, "refs/heads/"), packPass.repoID,
						).Scan(&existingMRUser)
						if err != nil {
							if errors.Is(err, pgx.ErrNoRows) {
								writeRedError(sshStderr, "No existing merge request for existing contrib branch: %v", err)
							} else {
								writeRedError(sshStderr, "Error querying for existing merge request: %v", err)
							}
							return 1
						}
						if existingMRUser == 0 {
							allOK = false
							fmt.Fprintln(sshStderr, ansiec.Red+"NAK"+ansiec.Reset, refName, "(branch belongs to unowned MR)")
							continue
						}

						if existingMRUser != packPass.userID {
							allOK = false
							fmt.Fprintln(sshStderr, ansiec.Red+"NAK"+ansiec.Reset, refName, "(branch belongs another user's MR)")
							continue
						}

						oldHash = plumbing.NewHash(oldOID)

						if oldCommit, err = packPass.repo.CommitObject(oldHash); err != nil {
							writeRedError(sshStderr, "Daemon failed to get old commit: %v", err)
							return 1
						}

						// Potential BUG: I'm not sure if new_commit is guaranteed to be
						// detectable as they haven't been merged into the main repo's
						// objects yet. But it seems to work, and I don't think there's
						// any reason for this to only work intermitently.
						newHash = plumbing.NewHash(newIOID)
						if newCommit, err = packPass.repo.CommitObject(newHash); err != nil {
							writeRedError(sshStderr, "Daemon failed to get new commit: %v", err)
							return 1
						}

						if isAncestor, err = oldCommit.IsAncestor(newCommit); err != nil {
							writeRedError(sshStderr, "Daemon failed to check if old commit is ancestor: %v", err)
							return 1
						}

						if !isAncestor {
							// TODO: Create MR snapshot ref instead
							allOK = false
							fmt.Fprintln(sshStderr, ansiec.Red+"NAK"+ansiec.Reset, refName, "(force pushes are not supported yet)")
							continue
						}

						fmt.Fprintln(sshStderr, ansiec.Blue+"POK"+ansiec.Reset, refName)
					}
				} else { // Non-contrib branch
					allOK = false
					fmt.Fprintln(sshStderr, ansiec.Red+"NAK"+ansiec.Reset, refName, "(you cannot push to branches outside of contrib/*)")
				}
			}

			fmt.Fprintln(sshStderr)
			if allOK {
				fmt.Fprintln(sshStderr, "Overall "+ansiec.Green+"ACK"+ansiec.Reset+" (all checks passed)")
				return 0
			}
			fmt.Fprintln(sshStderr, "Overall "+ansiec.Red+"NAK"+ansiec.Reset+" (one or more branches failed checks)")
			return 1
		default:
			fmt.Fprintln(sshStderr, ansiec.Red+"Invalid hook:", args[0]+ansiec.Reset)
			return 1
		}
	}()

	fmt.Fprintln(sshStderr)

	_, _ = conn.Write([]byte{hookRet})
}

// serveGitHooks handles connections on the specified network listener and
// treats incoming connections as those from git hook handlers by spawning
// sessions. The listener must be a SOCK_STREAM UNIX domain socket. The
// function itself blocks.
func (s *server) serveGitHooks(listener net.Listener) error {
	for {
		conn, err := listener.Accept()
		if err != nil {
			return err
		}
		go s.hooksHandler(conn)
	}
}

// allZero returns true if all runes in a given string are '0'. The comparison
// is not constant time and must not be used in contexts where time-based side
// channel attacks are a concern.
func allZero(s string) bool {
	for _, r := range s {
		if r != '0' {
			return false
		}
	}
	return true
}
// SPDX-License-Identifier: AGPL-3.0-only
// SPDX-FileCopyrightText: Copyright (c) 2025 Runxi Yu <https://runxiyu.org>

package main

import (
	"context"
	"errors"
	"io"
	"iter"
	"os"
	"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"
	"github.com/jackc/pgx/v5/pgtype"
)

// openRepo opens a git repository by group and repo name.
//
// TODO: This should be deprecated in favor of doing it in the relevant
// request/router context in the future, as it cannot cover the nuance of
// fields needed.
func openRepo(ctx context.Context, groupPath []string, repoName string) (repo *git.Repository, description string, repoID int, fsPath string, err error) {
	err = database.QueryRow(ctx, `
func (s *server) openRepo(ctx context.Context, groupPath []string, repoName string) (repo *git.Repository, description string, repoID int, fsPath string, err error) {
	err = s.database.QueryRow(ctx, `
WITH RECURSIVE group_path_cte AS (
	-- Start: match the first name in the path where parent_group IS NULL
	SELECT
		id,
		parent_group,
		name,
		1 AS depth
	FROM groups
	WHERE name = ($1::text[])[1]
		AND parent_group IS NULL

	UNION ALL

	-- Recurse: join next segment of the path
	SELECT
		g.id,
		g.parent_group,
		g.name,
		group_path_cte.depth + 1
	FROM groups g
	JOIN group_path_cte ON g.parent_group = group_path_cte.id
	WHERE g.name = ($1::text[])[group_path_cte.depth + 1]
		AND group_path_cte.depth + 1 <= cardinality($1::text[])
)
SELECT
	r.filesystem_path,
	COALESCE(r.description, ''),
	r.id
FROM group_path_cte g
JOIN repos r ON r.group_id = g.id
WHERE g.depth = cardinality($1::text[])
	AND r.name = $2
	`, pgtype.FlatArray[string](groupPath), repoName).Scan(&fsPath, &description, &repoID)
	if err != nil {
		return
	}

	repo, err = git.PlainOpen(fsPath)
	return
}

// go-git's tree entries are not friendly for use in HTML templates.
// This struct is a wrapper that is friendlier for use in templating.
type displayTreeEntry struct {
	Name      string
	Mode      string
	Size      uint64
	IsFile    bool
	IsSubtree bool
}

// makeDisplayTree takes git trees of form [object.Tree] and creates a slice of
// [displayTreeEntry] for easier templating.
func makeDisplayTree(tree *object.Tree) (displayTree []displayTreeEntry) {
	for _, entry := range tree.Entries {
		displayEntry := displayTreeEntry{} //exhaustruct:ignore
		var err error
		var osMode os.FileMode

		if osMode, err = entry.Mode.ToOSFileMode(); err != nil {
			displayEntry.Mode = "x---------"
		} else {
			displayEntry.Mode = osMode.String()
		}

		displayEntry.IsFile = entry.Mode.IsFile()

		size, _ := tree.Size(entry.Name)
		displayEntry.Size = uint64(size) //#nosec G115

		displayEntry.Name = strings.TrimPrefix(entry.Name, "/")

		displayTree = append(displayTree, displayEntry)
	}
	return displayTree
}

// commitIterSeqErr creates an [iter.Seq[*object.Commit]] from an
// [object.CommitIter], and additionally returns a pointer to error.
// The pointer to error is guaranteed to be populated with either nil or the
// error returned by the commit iterator after the returned iterator is
// finished.
func commitIterSeqErr(commitIter object.CommitIter) (iter.Seq[*object.Commit], *error) {
	var err error
	return func(yield func(*object.Commit) bool) {
		for {
			commit, err2 := commitIter.Next()
			if err2 != nil {
				if errors.Is(err2, io.EOF) {
					return
				}
				err = err2
				return
			}
			if !yield(commit) {
				return
			}
		}
	}, &err
}

// getRecentCommits fetches numCommits commits, starting from the headHash in a
// repo.
func getRecentCommits(repo *git.Repository, headHash plumbing.Hash, numCommits int) (recentCommits []*object.Commit, err error) {
	var commitIter object.CommitIter
	var thisCommit *object.Commit

	commitIter, err = repo.Log(&git.LogOptions{From: headHash}) //exhaustruct:ignore
	if err != nil {
		return nil, err
	}
	recentCommits = make([]*object.Commit, 0)
	defer commitIter.Close()
	if numCommits < 0 {
		for {
			thisCommit, err = commitIter.Next()
			if errors.Is(err, io.EOF) {
				return recentCommits, nil
			} else if err != nil {
				return nil, err
			}
			recentCommits = append(recentCommits, thisCommit)
		}
	} else {
		for range numCommits {
			thisCommit, err = commitIter.Next()
			if errors.Is(err, io.EOF) {
				return recentCommits, nil
			} else if err != nil {
				return nil, err
			}
			recentCommits = append(recentCommits, thisCommit)
		}
	}
	return recentCommits, err
}

// getRecentCommitsDisplay generates a slice of [commitDisplay] friendly for
// use in HTML templates, consisting of numCommits commits from headhash in the
// repo.
func getRecentCommitsDisplay(repo *git.Repository, headHash plumbing.Hash, numCommits int) (recentCommits []commitDisplayOld, err error) {
	var commitIter object.CommitIter
	var thisCommit *object.Commit

	commitIter, err = repo.Log(&git.LogOptions{From: headHash}) //exhaustruct:ignore
	if err != nil {
		return nil, err
	}
	recentCommits = make([]commitDisplayOld, 0)
	defer commitIter.Close()
	if numCommits < 0 {
		for {
			thisCommit, err = commitIter.Next()
			if errors.Is(err, io.EOF) {
				return recentCommits, nil
			} else if err != nil {
				return nil, err
			}
			recentCommits = append(recentCommits, commitDisplayOld{
				thisCommit.Hash,
				thisCommit.Author,
				thisCommit.Committer,
				thisCommit.Message,
				thisCommit.TreeHash,
			})
		}
	} else {
		for range numCommits {
			thisCommit, err = commitIter.Next()
			if errors.Is(err, io.EOF) {
				return recentCommits, nil
			} else if err != nil {
				return nil, err
			}
			recentCommits = append(recentCommits, commitDisplayOld{
				thisCommit.Hash,
				thisCommit.Author,
				thisCommit.Committer,
				thisCommit.Message,
				thisCommit.TreeHash,
			})
		}
	}
	return recentCommits, err
}

type commitDisplayOld struct {
	Hash      plumbing.Hash
	Author    object.Signature
	Committer object.Signature
	Message   string
	TreeHash  plumbing.Hash
}

// commitToPatch creates an [object.Patch] from the first parent of a given
// [object.Commit].
//
// TODO: This function should be deprecated as it only diffs with the first
// parent and does not correctly handle merge commits.
func commitToPatch(commit *object.Commit) (parentCommitHash plumbing.Hash, patch *object.Patch, err error) {
	var parentCommit *object.Commit
	var commitTree *object.Tree

	parentCommit, err = commit.Parent(0)
	switch {
	case errors.Is(err, object.ErrParentNotFound):
		if commitTree, err = commit.Tree(); err != nil {
			return
		}
		if patch, err = nullTree.Patch(commitTree); err != nil {
			return
		}
	case err != nil:
		return
	default:
		parentCommitHash = parentCommit.Hash
		if patch, err = parentCommit.Patch(commit); err != nil {
			return
		}
	}
	return
}

var nullTree object.Tree
// SPDX-License-Identifier: AGPL-3.0-only
// SPDX-FileCopyrightText: Copyright (c) 2025 Runxi Yu <https://runxiyu.org>

package main

import (
	"net/http"
)

// getUserFromRequest returns the user ID and username associated with the
// session cookie in a given [http.Request].
func getUserFromRequest(request *http.Request) (id int, username string, err error) {
func (s *server) getUserFromRequest(request *http.Request) (id int, username string, err error) {
	var sessionCookie *http.Cookie

	if sessionCookie, err = request.Cookie("session"); err != nil {
		return
	}

	err = database.QueryRow(
	err = s.database.QueryRow(
		request.Context(),
		"SELECT user_id, COALESCE(username, '') FROM users u JOIN sessions s ON u.id = s.user_id WHERE s.session_id = $1;",
		sessionCookie.Value,
	).Scan(&id, &username)

	return
}
// SPDX-License-Identifier: AGPL-3.0-only
// SPDX-FileCopyrightText: Copyright (c) 2025 Runxi Yu <https://runxiyu.org>

package main

import (
	"errors"
	"net/http"
	"path/filepath"
	"strconv"

	"github.com/jackc/pgx/v5"
	"github.com/jackc/pgx/v5/pgtype"
	"go.lindenii.runxiyu.org/forge/misc"
)

// httpHandleGroupIndex provides index pages for groups, which includes a list
// of its subgroups and repos, as well as a form for group maintainers to
// create repos.
func (s *server) httpHandleGroupIndex(writer http.ResponseWriter, request *http.Request, params map[string]any) {
	var groupPath []string
	var repos []nameDesc
	var subgroups []nameDesc
	var err error
	var groupID int
	var groupDesc string

	groupPath = params["group_path"].([]string)

	// The group itself
	err = database.QueryRow(request.Context(), `
	err = s.database.QueryRow(request.Context(), `
		WITH RECURSIVE group_path_cte AS (
			SELECT
				id,
				parent_group,
				name,
				1 AS depth
			FROM groups
			WHERE name = ($1::text[])[1]
				AND parent_group IS NULL

			UNION ALL

			SELECT
				g.id,
				g.parent_group,
				g.name,
				group_path_cte.depth + 1
			FROM groups g
			JOIN group_path_cte ON g.parent_group = group_path_cte.id
			WHERE g.name = ($1::text[])[group_path_cte.depth + 1]
				AND group_path_cte.depth + 1 <= cardinality($1::text[])
		)
		SELECT c.id, COALESCE(g.description, '')
		FROM group_path_cte c
		JOIN groups g ON g.id = c.id
		WHERE c.depth = cardinality($1::text[])
	`,
		pgtype.FlatArray[string](groupPath),
	).Scan(&groupID, &groupDesc)

	if errors.Is(err, pgx.ErrNoRows) {
		errorPage404(writer, params)
		return
	} else if err != nil {
		errorPage500(writer, params, "Error getting group: "+err.Error())
		return
	}

	// ACL
	var count int
	err = database.QueryRow(request.Context(), `
	err = s.database.QueryRow(request.Context(), `
		SELECT COUNT(*)
		FROM user_group_roles
		WHERE user_id = $1
			AND group_id = $2
	`, params["user_id"].(int), groupID).Scan(&count)
	if err != nil {
		errorPage500(writer, params, "Error checking access: "+err.Error())
		return
	}
	directAccess := (count > 0)

	if request.Method == http.MethodPost {
		if !directAccess {
			errorPage403(writer, params, "You do not have direct access to this group")
			return
		}

		repoName := request.FormValue("repo_name")
		repoDesc := request.FormValue("repo_desc")
		contribReq := request.FormValue("repo_contrib")
		if repoName == "" {
			errorPage400(writer, params, "Repo name is required")
			return
		}

		var newRepoID int
		err := database.QueryRow(
		err := s.database.QueryRow(
			request.Context(),
			`INSERT INTO repos (name, description, group_id, contrib_requirements)
	 VALUES ($1, $2, $3, $4)
	 RETURNING id`,
			repoName,
			repoDesc,
			groupID,
			contribReq,
		).Scan(&newRepoID)
		if err != nil {
			errorPage500(writer, params, "Error creating repo: "+err.Error())
			return
		}

		filePath := filepath.Join(s.config.Git.RepoDir, strconv.Itoa(newRepoID)+".git")

		_, err = database.Exec(
		_, err = s.database.Exec(
			request.Context(),
			`UPDATE repos
	 SET filesystem_path = $1
	 WHERE id = $2`,
			filePath,
			newRepoID,
		)
		if err != nil {
			errorPage500(writer, params, "Error updating repo path: "+err.Error())
			return
		}

		if err = s.gitInit(filePath); err != nil {
			errorPage500(writer, params, "Error initializing repo: "+err.Error())
			return
		}

		misc.RedirectUnconditionally(writer, request)
		return
	}

	// Repos
	var rows pgx.Rows
	rows, err = database.Query(request.Context(), `
	rows, err = s.database.Query(request.Context(), `
		SELECT name, COALESCE(description, '')
		FROM repos
		WHERE group_id = $1
	`, groupID)
	if err != nil {
		errorPage500(writer, params, "Error getting repos: "+err.Error())
		return
	}
	defer rows.Close()

	for rows.Next() {
		var name, description string
		if err = rows.Scan(&name, &description); err != nil {
			errorPage500(writer, params, "Error getting repos: "+err.Error())
			return
		}
		repos = append(repos, nameDesc{name, description})
	}
	if err = rows.Err(); err != nil {
		errorPage500(writer, params, "Error getting repos: "+err.Error())
		return
	}

	// Subgroups
	rows, err = database.Query(request.Context(), `
	rows, err = s.database.Query(request.Context(), `
		SELECT name, COALESCE(description, '')
		FROM groups
		WHERE parent_group = $1
	`, groupID)
	if err != nil {
		errorPage500(writer, params, "Error getting subgroups: "+err.Error())
		return
	}
	defer rows.Close()

	for rows.Next() {
		var name, description string
		if err = rows.Scan(&name, &description); err != nil {
			errorPage500(writer, params, "Error getting subgroups: "+err.Error())
			return
		}
		subgroups = append(subgroups, nameDesc{name, description})
	}
	if err = rows.Err(); err != nil {
		errorPage500(writer, params, "Error getting subgroups: "+err.Error())
		return
	}

	params["repos"] = repos
	params["subgroups"] = subgroups
	params["description"] = groupDesc
	params["direct_access"] = directAccess

	renderTemplate(writer, "group", params)
}
// SPDX-License-Identifier: AGPL-3.0-only
// SPDX-FileCopyrightText: Copyright (c) 2025 Runxi Yu <https://runxiyu.org>

package main

import (
	"crypto/rand"
	"encoding/base64"
	"errors"
	"fmt"
	"net/http"
	"time"

	"github.com/alexedwards/argon2id"
	"github.com/jackc/pgx/v5"
)

// httpHandleLogin provides the login page for local users.
func (s *server) httpHandleLogin(writer http.ResponseWriter, request *http.Request, params map[string]any) {
	var username, password string
	var userID int
	var passwordHash string
	var err error
	var passwordMatches bool
	var cookieValue string
	var now time.Time
	var expiry time.Time
	var cookie http.Cookie

	if request.Method != http.MethodPost {
		renderTemplate(writer, "login", params)
		return
	}

	username = request.PostFormValue("username")
	password = request.PostFormValue("password")

	err = database.QueryRow(request.Context(),
	err = s.database.QueryRow(request.Context(),
		"SELECT id, COALESCE(password, '') FROM users WHERE username = $1",
		username,
	).Scan(&userID, &passwordHash)
	if err != nil {
		if errors.Is(err, pgx.ErrNoRows) {
			params["login_error"] = "Unknown username"
			renderTemplate(writer, "login", params)
			return
		}
		errorPage500(writer, params, "Error querying user information: "+err.Error())
		return
	}
	if passwordHash == "" {
		params["login_error"] = "User has no password"
		renderTemplate(writer, "login", params)
		return
	}

	if passwordMatches, err = argon2id.ComparePasswordAndHash(password, passwordHash); err != nil {
		errorPage500(writer, params, "Error comparing password and hash: "+err.Error())
		return
	}

	if !passwordMatches {
		params["login_error"] = "Invalid password"
		renderTemplate(writer, "login", params)
		return
	}

	if cookieValue, err = randomUrlsafeStr(16); err != nil {
		errorPage500(writer, params, "Error getting random string: "+err.Error())
		return
	}

	now = time.Now()
	expiry = now.Add(time.Duration(s.config.HTTP.CookieExpiry) * time.Second)

	cookie = http.Cookie{
		Name:     "session",
		Value:    cookieValue,
		SameSite: http.SameSiteLaxMode,
		HttpOnly: true,
		Secure:   false, // TODO
		Expires:  expiry,
		Path:     "/",
	} //exhaustruct:ignore

	http.SetCookie(writer, &cookie)

	_, err = database.Exec(request.Context(), "INSERT INTO sessions (user_id, session_id) VALUES ($1, $2)", userID, cookieValue)
	_, err = s.database.Exec(request.Context(), "INSERT INTO sessions (user_id, session_id) VALUES ($1, $2)", userID, cookieValue)
	if err != nil {
		errorPage500(writer, params, "Error inserting session: "+err.Error())
		return
	}

	http.Redirect(writer, request, "/", http.StatusSeeOther)
}

// randomUrlsafeStr generates a random string of the given entropic size
// using the URL-safe base64 encoding. The actual size of the string returned
// will be 4*sz.
func randomUrlsafeStr(sz int) (string, error) {
	r := make([]byte, 3*sz)
	_, err := rand.Read(r)
	if err != nil {
		return "", fmt.Errorf("error generating random string: %w", err)
	}
	return base64.RawURLEncoding.EncodeToString(r), nil
}
// SPDX-License-Identifier: AGPL-3.0-only
// SPDX-FileCopyrightText: Copyright (c) 2025 Runxi Yu <https://runxiyu.org>

package main

import (
	"net/http"

	"github.com/jackc/pgx/v5"
)

// idTitleStatus describes properties of a merge request that needs to be
// present in MR listings.
type idTitleStatus struct {
	ID     int
	Title  string
	Status string
}

// httpHandleRepoContribIndex provides an index to merge requests of a repo.
func httpHandleRepoContribIndex(writer http.ResponseWriter, request *http.Request, params map[string]any) {
func (s *server) httpHandleRepoContribIndex(writer http.ResponseWriter, request *http.Request, params map[string]any) {
	var rows pgx.Rows
	var result []idTitleStatus
	var err error

	if rows, err = database.Query(request.Context(),
	if rows, err = s.database.Query(request.Context(),
		"SELECT repo_local_id, COALESCE(title, 'Untitled'), status FROM merge_requests WHERE repo_id = $1",
		params["repo_id"],
	); err != nil {
		errorPage500(writer, params, "Error querying merge requests: "+err.Error())
		return
	}
	defer rows.Close()

	for rows.Next() {
		var mrID int
		var mrTitle, mrStatus string
		if err = rows.Scan(&mrID, &mrTitle, &mrStatus); err != nil {
			errorPage500(writer, params, "Error scanning merge request: "+err.Error())
			return
		}
		result = append(result, idTitleStatus{mrID, mrTitle, mrStatus})
	}
	if err = rows.Err(); err != nil {
		errorPage500(writer, params, "Error ranging over merge requests: "+err.Error())
		return
	}
	params["merge_requests"] = result

	renderTemplate(writer, "repo_contrib_index", params)
}
// SPDX-License-Identifier: AGPL-3.0-only
// SPDX-FileCopyrightText: Copyright (c) 2025 Runxi Yu <https://runxiyu.org>

package main

import (
	"net/http"
	"strconv"

	"github.com/go-git/go-git/v5"
	"github.com/go-git/go-git/v5/plumbing"
	"github.com/go-git/go-git/v5/plumbing/object"
)

// httpHandleRepoContribOne provides an interface to each merge request of a
// repo.
func httpHandleRepoContribOne(writer http.ResponseWriter, request *http.Request, params map[string]any) {
func (s *server) httpHandleRepoContribOne(writer http.ResponseWriter, request *http.Request, params map[string]any) {
	var mrIDStr string
	var mrIDInt int
	var err error
	var title, status, srcRefStr, dstBranchStr string
	var repo *git.Repository
	var srcRefHash plumbing.Hash
	var dstBranchHash plumbing.Hash
	var srcCommit, dstCommit, mergeBaseCommit *object.Commit
	var mergeBases []*object.Commit

	mrIDStr = params["mr_id"].(string)
	mrIDInt64, err := strconv.ParseInt(mrIDStr, 10, strconv.IntSize)
	if err != nil {
		errorPage400(writer, params, "Merge request ID not an integer")
		return
	}
	mrIDInt = int(mrIDInt64)

	if err = database.QueryRow(request.Context(),
	if err = s.database.QueryRow(request.Context(),
		"SELECT COALESCE(title, ''), status, source_ref, COALESCE(destination_branch, '') FROM merge_requests WHERE repo_id = $1 AND repo_local_id = $2",
		params["repo_id"], mrIDInt,
	).Scan(&title, &status, &srcRefStr, &dstBranchStr); err != nil {
		errorPage500(writer, params, "Error querying merge request: "+err.Error())
		return
	}

	repo = params["repo"].(*git.Repository)

	if srcRefHash, err = getRefHash(repo, "branch", srcRefStr); err != nil {
		errorPage500(writer, params, "Error getting source ref hash: "+err.Error())
		return
	}
	if srcCommit, err = repo.CommitObject(srcRefHash); err != nil {
		errorPage500(writer, params, "Error getting source commit: "+err.Error())
		return
	}
	params["source_commit"] = srcCommit

	if dstBranchStr == "" {
		dstBranchStr = "HEAD"
		dstBranchHash, err = getRefHash(repo, "", "")
	} else {
		dstBranchHash, err = getRefHash(repo, "branch", dstBranchStr)
	}
	if err != nil {
		errorPage500(writer, params, "Error getting destination branch hash: "+err.Error())
		return
	}

	if dstCommit, err = repo.CommitObject(dstBranchHash); err != nil {
		errorPage500(writer, params, "Error getting destination commit: "+err.Error())
		return
	}
	params["destination_commit"] = dstCommit

	if mergeBases, err = srcCommit.MergeBase(dstCommit); err != nil {
		errorPage500(writer, params, "Error getting merge base: "+err.Error())
		return
	}

	if len(mergeBases) < 1 {
		errorPage500(writer, params, "No merge base found for this merge request; these two branches do not share any common history")
		// TODO
		return
	}

	mergeBaseCommit = mergeBases[0]
	params["merge_base"] = mergeBaseCommit

	patch, err := mergeBaseCommit.Patch(srcCommit)
	if err != nil {
		errorPage500(writer, params, "Error getting patch: "+err.Error())
		return
	}
	params["file_patches"] = makeUsableFilePatches(patch)

	params["mr_title"], params["mr_status"], params["mr_source_ref"], params["mr_destination_branch"] = title, status, srcRefStr, dstBranchStr

	renderTemplate(writer, "repo_contrib_one", params)
}
// SPDX-License-Identifier: AGPL-3.0-only
// SPDX-FileCopyrightText: Copyright (c) 2025 Runxi Yu <https://runxiyu.org>

package main

import (
	"fmt"
	"io"
	"net/http"
	"os/exec"

	"github.com/jackc/pgx/v5/pgtype"
)

// httpHandleRepoInfo provides advertised refs of a repo for use in Git's Smart
// HTTP protocol.
//
// TODO: Reject access from web browsers.
func httpHandleRepoInfo(writer http.ResponseWriter, request *http.Request, params map[string]any) (err error) {
func (s *server) httpHandleRepoInfo(writer http.ResponseWriter, request *http.Request, params map[string]any) (err error) {
	groupPath := params["group_path"].([]string)
	repoName := params["repo_name"].(string)
	var repoPath string

	if err := database.QueryRow(request.Context(), `
	if err := s.database.QueryRow(request.Context(), `
	WITH RECURSIVE group_path_cte AS (
		-- Start: match the first name in the path where parent_group IS NULL
		SELECT
			id,
			parent_group,
			name,
			1 AS depth
		FROM groups
		WHERE name = ($1::text[])[1]
			AND parent_group IS NULL
	
		UNION ALL
	
		-- Recurse: jion next segment of the path
		SELECT
			g.id,
			g.parent_group,
			g.name,
			group_path_cte.depth + 1
		FROM groups g
		JOIN group_path_cte ON g.parent_group = group_path_cte.id
		WHERE g.name = ($1::text[])[group_path_cte.depth + 1]
			AND group_path_cte.depth + 1 <= cardinality($1::text[])
	)
	SELECT r.filesystem_path
	FROM group_path_cte c
	JOIN repos r ON r.group_id = c.id
	WHERE c.depth = cardinality($1::text[])
		AND r.name = $2
	`,
		pgtype.FlatArray[string](groupPath),
		repoName,
	).Scan(&repoPath); err != nil {
		return err
	}

	writer.Header().Set("Content-Type", "application/x-git-upload-pack-advertisement")
	writer.WriteHeader(http.StatusOK)

	cmd := exec.Command("git", "upload-pack", "--stateless-rpc", "--advertise-refs", repoPath)
	stdout, err := cmd.StdoutPipe()
	if err != nil {
		return err
	}
	defer func() {
		_ = stdout.Close()
	}()
	cmd.Stderr = cmd.Stdout

	if err = cmd.Start(); err != nil {
		return err
	}

	if err = packLine(writer, "# service=git-upload-pack\n"); err != nil {
		return err
	}

	if err = packFlush(writer); err != nil {
		return
	}

	if _, err = io.Copy(writer, stdout); err != nil {
		return err
	}

	if err = cmd.Wait(); err != nil {
		return err
	}

	return nil
}

// Taken from https://github.com/icyphox/legit, MIT license.
func packLine(w io.Writer, s string) error {
	_, err := fmt.Fprintf(w, "%04x%s", len(s)+4, s)
	return err
}

// Taken from https://github.com/icyphox/legit, MIT license.
func packFlush(w io.Writer) error {
	_, err := fmt.Fprint(w, "0000")
	return err
}
// SPDX-License-Identifier: AGPL-3.0-only
// SPDX-FileCopyrightText: Copyright (c) 2025 Runxi Yu <https://runxiyu.org>

package main

import (
	"io"
	"net/http"
	"os"
	"os/exec"

	"github.com/jackc/pgx/v5/pgtype"
)

// httpHandleUploadPack handles incoming Git fetch/pull/clone's over the Smart
// HTTP protocol.
func (s *server) httpHandleUploadPack(writer http.ResponseWriter, request *http.Request, params map[string]any) (err error) {
	var groupPath []string
	var repoName string
	var repoPath string
	var stdout io.ReadCloser
	var stdin io.WriteCloser
	var cmd *exec.Cmd

	groupPath, repoName = params["group_path"].([]string), params["repo_name"].(string)

	if err := database.QueryRow(request.Context(), `
	if err := s.database.QueryRow(request.Context(), `
	WITH RECURSIVE group_path_cte AS (
		-- Start: match the first name in the path where parent_group IS NULL
		SELECT
			id,
			parent_group,
			name,
			1 AS depth
		FROM groups
		WHERE name = ($1::text[])[1]
			AND parent_group IS NULL
	
		UNION ALL
	
		-- Recurse: jion next segment of the path
		SELECT
			g.id,
			g.parent_group,
			g.name,
			group_path_cte.depth + 1
		FROM groups g
		JOIN group_path_cte ON g.parent_group = group_path_cte.id
		WHERE g.name = ($1::text[])[group_path_cte.depth + 1]
			AND group_path_cte.depth + 1 <= cardinality($1::text[])
	)
	SELECT r.filesystem_path
	FROM group_path_cte c
	JOIN repos r ON r.group_id = c.id
	WHERE c.depth = cardinality($1::text[])
		AND r.name = $2
	`,
		pgtype.FlatArray[string](groupPath),
		repoName,
	).Scan(&repoPath); err != nil {
		return err
	}

	writer.Header().Set("Content-Type", "application/x-git-upload-pack-result")
	writer.Header().Set("Connection", "Keep-Alive")
	writer.Header().Set("Transfer-Encoding", "chunked")
	writer.WriteHeader(http.StatusOK)

	cmd = exec.Command("git", "upload-pack", "--stateless-rpc", repoPath)
	cmd.Env = append(os.Environ(), "LINDENII_FORGE_HOOKS_SOCKET_PATH="+s.config.Hooks.Socket)
	if stdout, err = cmd.StdoutPipe(); err != nil {
		return err
	}
	cmd.Stderr = cmd.Stdout
	defer func() {
		_ = stdout.Close()
	}()

	if stdin, err = cmd.StdinPipe(); err != nil {
		return err
	}
	defer func() {
		_ = stdin.Close()
	}()

	if err = cmd.Start(); err != nil {
		return err
	}

	if _, err = io.Copy(stdin, request.Body); err != nil {
		return err
	}

	if err = stdin.Close(); err != nil {
		return err
	}

	if _, err = io.Copy(writer, stdout); err != nil {
		return err
	}

	if err = cmd.Wait(); err != nil {
		return err
	}

	return nil
}
// SPDX-License-Identifier: AGPL-3.0-only
// SPDX-FileCopyrightText: Copyright (c) 2025 Runxi Yu <https://runxiyu.org>

package main

import (
	"errors"
	"log/slog"
	"net/http"
	"net/url"
	"strconv"
	"strings"

	"github.com/jackc/pgx/v5"
	"go.lindenii.runxiyu.org/forge/misc"
)

// ServeHTTP handles all incoming HTTP requests and routes them to the correct
// location.
//
// TODO: This function is way too large.
func (s *server) ServeHTTP(writer http.ResponseWriter, request *http.Request) {
	var remoteAddr string
	if s.config.HTTP.ReverseProxy {
		remoteAddrs, ok := request.Header["X-Forwarded-For"]
		if ok && len(remoteAddrs) == 1 {
			remoteAddr = remoteAddrs[0]
		} else {
			remoteAddr = request.RemoteAddr
		}
	} else {
		remoteAddr = request.RemoteAddr
	}
	slog.Info("incoming http", "addr", remoteAddr, "method", request.Method, "uri", request.RequestURI)

	var segments []string
	var err error
	var sepIndex int
	params := make(map[string]any)

	if segments, _, err = misc.ParseReqURI(request.RequestURI); err != nil {
		errorPage400(writer, params, "Error parsing request URI: "+err.Error())
		return
	}
	dirMode := false
	if segments[len(segments)-1] == "" {
		dirMode = true
		segments = segments[:len(segments)-1]
	}

	params["url_segments"] = segments
	params["dir_mode"] = dirMode
	params["global"] = globalData
	var userID int // 0 for none
	userID, params["username"], err = getUserFromRequest(request)
	userID, params["username"], err = s.getUserFromRequest(request)
	params["user_id"] = userID
	if err != nil && !errors.Is(err, http.ErrNoCookie) && !errors.Is(err, pgx.ErrNoRows) {
		errorPage500(writer, params, "Error getting user info from request: "+err.Error())
		return
	}

	if userID == 0 {
		params["user_id_string"] = ""
	} else {
		params["user_id_string"] = strconv.Itoa(userID)
	}

	for _, v := range segments {
		if strings.Contains(v, ":") {
			errorPage400Colon(writer, params)
			return
		}
	}

	if len(segments) == 0 {
		s.httpHandleIndex(writer, request, params)
		return
	}

	if segments[0] == "-" {
		if len(segments) < 2 {
			errorPage404(writer, params)
			return
		} else if len(segments) == 2 && misc.RedirectDir(writer, request) {
			return
		}

		switch segments[1] {
		case "static":
			staticHandler.ServeHTTP(writer, request)
			return
		case "source":
			sourceHandler.ServeHTTP(writer, request)
			return
		}
	}

	if segments[0] == "-" {
		switch segments[1] {
		case "login":
			s.httpHandleLogin(writer, request, params)
			return
		case "users":
			httpHandleUsers(writer, request, params)
			return
		default:
			errorPage404(writer, params)
			return
		}
	}

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

	params["separator_index"] = sepIndex

	var groupPath []string
	var moduleType string
	var moduleName string

	if sepIndex > 0 {
		groupPath = segments[:sepIndex]
	} else {
		groupPath = segments
	}
	params["group_path"] = groupPath

	switch {
	case sepIndex == -1:
		if misc.RedirectDir(writer, request) {
			return
		}
		s.httpHandleGroupIndex(writer, request, params)
	case len(segments) == sepIndex+1:
		errorPage404(writer, params)
		return
	case len(segments) == sepIndex+2:
		errorPage404(writer, params)
		return
	default:
		moduleType = segments[sepIndex+1]
		moduleName = segments[sepIndex+2]
		switch moduleType {
		case "repos":
			params["repo_name"] = moduleName

			if len(segments) > sepIndex+3 {
				switch segments[sepIndex+3] {
				case "info":
					if err = httpHandleRepoInfo(writer, request, params); err != nil {
					if err = s.httpHandleRepoInfo(writer, request, params); err != nil {
						errorPage500(writer, params, err.Error())
					}
					return
				case "git-upload-pack":
					if err = s.httpHandleUploadPack(writer, request, params); err != nil {
						errorPage500(writer, params, err.Error())
					}
					return
				}
			}

			if params["ref_type"], params["ref_name"], err = misc.GetParamRefTypeName(request); err != nil {
				if errors.Is(err, misc.ErrNoRefSpec) {
					params["ref_type"] = ""
				} else {
					errorPage400(writer, params, "Error querying ref type: "+err.Error())
					return
				}
			}

			if params["repo"], params["repo_description"], params["repo_id"], _, err = openRepo(request.Context(), groupPath, moduleName); err != nil {
			if params["repo"], params["repo_description"], params["repo_id"], _, err = s.openRepo(request.Context(), groupPath, moduleName); err != nil {
				errorPage500(writer, params, "Error opening repo: "+err.Error())
				return
			}

			repoURLRoot := "/"
			for _, part := range segments[:sepIndex+3] {
				repoURLRoot = repoURLRoot + url.PathEscape(part) + "/"
			}
			params["repo_url_root"] = repoURLRoot
			params["repo_patch_mailing_list"] = repoURLRoot[1:len(repoURLRoot)-1] + "@" + s.config.LMTP.Domain
			params["http_clone_url"] = s.genHTTPRemoteURL(groupPath, moduleName)
			params["ssh_clone_url"] = s.genSSHRemoteURL(groupPath, moduleName)

			if len(segments) == sepIndex+3 {
				if misc.RedirectDir(writer, request) {
					return
				}
				s.httpHandleRepoIndex(writer, request, params)
				return
			}

			repoFeature := segments[sepIndex+3]
			switch repoFeature {
			case "tree":
				if misc.AnyContain(segments[sepIndex+4:], "/") {
					errorPage400(writer, params, "Repo tree paths may not contain slashes in any segments")
					return
				}
				if dirMode {
					params["rest"] = strings.Join(segments[sepIndex+4:], "/") + "/"
				} else {
					params["rest"] = strings.Join(segments[sepIndex+4:], "/")
				}
				if len(segments) < sepIndex+5 && misc.RedirectDir(writer, request) {
					return
				}
				s.httpHandleRepoTree(writer, request, params)
			case "branches":
				if misc.RedirectDir(writer, request) {
					return
				}
				s.httpHandleRepoBranches(writer, request, params)
				return
			case "raw":
				if misc.AnyContain(segments[sepIndex+4:], "/") {
					errorPage400(writer, params, "Repo tree paths may not contain slashes in any segments")
					return
				}
				if dirMode {
					params["rest"] = strings.Join(segments[sepIndex+4:], "/") + "/"
				} else {
					params["rest"] = strings.Join(segments[sepIndex+4:], "/")
				}
				if len(segments) < sepIndex+5 && misc.RedirectDir(writer, request) {
					return
				}
				s.httpHandleRepoRaw(writer, request, params)
			case "log":
				if len(segments) > sepIndex+4 {
					errorPage400(writer, params, "Too many parameters")
					return
				}
				if misc.RedirectDir(writer, request) {
					return
				}
				httpHandleRepoLog(writer, request, params)
			case "commit":
				if len(segments) != sepIndex+5 {
					errorPage400(writer, params, "Incorrect number of parameters")
					return
				}
				if misc.RedirectNoDir(writer, request) {
					return
				}
				params["commit_id"] = segments[sepIndex+4]
				httpHandleRepoCommit(writer, request, params)
			case "contrib":
				if misc.RedirectDir(writer, request) {
					return
				}
				switch len(segments) {
				case sepIndex + 4:
					httpHandleRepoContribIndex(writer, request, params)
					s.httpHandleRepoContribIndex(writer, request, params)
				case sepIndex + 5:
					params["mr_id"] = segments[sepIndex+4]
					httpHandleRepoContribOne(writer, request, params)
					s.httpHandleRepoContribOne(writer, request, params)
				default:
					errorPage400(writer, params, "Too many parameters")
				}
			default:
				errorPage404(writer, params)
				return
			}
		default:
			errorPage404(writer, params)
			return
		}
	}
}
// SPDX-License-Identifier: AGPL-3.0-only
// SPDX-FileCopyrightText: Copyright (c) 2025 Runxi Yu <https://runxiyu.org>

package main

import (
	"bytes"
	"crypto/rand"
	"encoding/hex"
	"fmt"
	"io"
	"os"
	"os/exec"
	"strings"
	"time"

	"github.com/bluekeyes/go-gitdiff/gitdiff"
	"github.com/go-git/go-git/v5"
	"go.lindenii.runxiyu.org/forge/misc"
)

func lmtpHandlePatch(session *lmtpSession, groupPath []string, repoName string, mbox io.Reader) (err error) {
func (s *server) lmtpHandlePatch(session *lmtpSession, groupPath []string, repoName string, mbox io.Reader) (err error) {
	var diffFiles []*gitdiff.File
	var preamble string
	if diffFiles, preamble, err = gitdiff.Parse(mbox); err != nil {
		return fmt.Errorf("failed to parse patch: %w", err)
	}

	var header *gitdiff.PatchHeader
	if header, err = gitdiff.ParsePatchHeader(preamble); err != nil {
		return fmt.Errorf("failed to parse patch headers: %w", err)
	}

	var repo *git.Repository
	var fsPath string
	repo, _, _, fsPath, err = openRepo(session.ctx, groupPath, repoName)
	repo, _, _, fsPath, err = s.openRepo(session.ctx, groupPath, repoName)
	if err != nil {
		return fmt.Errorf("failed to open repo: %w", err)
	}

	headRef, err := repo.Head()
	if err != nil {
		return fmt.Errorf("failed to get repo head hash: %w", err)
	}
	headCommit, err := repo.CommitObject(headRef.Hash())
	if err != nil {
		return fmt.Errorf("failed to get repo head commit: %w", err)
	}
	headTree, err := headCommit.Tree()
	if err != nil {
		return fmt.Errorf("failed to get repo head tree: %w", err)
	}

	headTreeHash := headTree.Hash.String()

	blobUpdates := make(map[string][]byte)
	for _, diffFile := range diffFiles {
		sourceFile, err := headTree.File(diffFile.OldName)
		if err != nil {
			return fmt.Errorf("failed to get file at old name %#v: %w", diffFile.OldName, err)
		}
		sourceString, err := sourceFile.Contents()
		if err != nil {
			return fmt.Errorf("failed to get contents: %w", err)
		}

		sourceBuf := bytes.NewReader(misc.StringToBytes(sourceString))
		var patchedBuf bytes.Buffer
		if err := gitdiff.Apply(&patchedBuf, sourceBuf, diffFile); err != nil {
			return fmt.Errorf("failed to apply patch: %w", err)
		}

		var hashBuf bytes.Buffer

		// It's really difficult to do this via go-git so we're just
		// going to use upstream git for now.
		// TODO
		cmd := exec.CommandContext(session.ctx, "git", "hash-object", "-w", "-t", "blob", "--stdin")
		cmd.Env = append(os.Environ(), "GIT_DIR="+fsPath)
		cmd.Stdout = &hashBuf
		cmd.Stdin = &patchedBuf
		if err := cmd.Run(); err != nil {
			return fmt.Errorf("failed to run git hash-object: %w", err)
		}

		newHashStr := strings.TrimSpace(hashBuf.String())
		newHash, err := hex.DecodeString(newHashStr)
		if err != nil {
			return fmt.Errorf("failed to decode hex string from git: %w", err)
		}

		blobUpdates[diffFile.NewName] = newHash
		if diffFile.NewName != diffFile.OldName {
			blobUpdates[diffFile.OldName] = nil // Mark for deletion.
		}
	}

	newTreeSha, err := buildTreeRecursive(session.ctx, fsPath, headTreeHash, blobUpdates)
	if err != nil {
		return fmt.Errorf("failed to recursively build a tree: %w", err)
	}

	commitMsg := header.Title
	if header.Body != "" {
		commitMsg += "\n\n" + header.Body
	}

	env := append(os.Environ(),
		"GIT_DIR="+fsPath,
		"GIT_AUTHOR_NAME="+header.Author.Name,
		"GIT_AUTHOR_EMAIL="+header.Author.Email,
		"GIT_AUTHOR_DATE="+header.AuthorDate.Format(time.RFC3339),
	)
	commitCmd := exec.CommandContext(session.ctx, "git", "commit-tree", newTreeSha, "-p", headCommit.Hash.String(), "-m", commitMsg)
	commitCmd.Env = env

	var commitOut bytes.Buffer
	commitCmd.Stdout = &commitOut
	if err := commitCmd.Run(); err != nil {
		return fmt.Errorf("failed to commit tree: %w", err)
	}
	newCommitSha := strings.TrimSpace(commitOut.String())

	newBranchName := rand.Text()

	refCmd := exec.CommandContext(session.ctx, "git", "update-ref", "refs/heads/contrib/"+newBranchName, newCommitSha) //#nosec G204
	refCmd.Env = append(os.Environ(), "GIT_DIR="+fsPath)
	if err := refCmd.Run(); err != nil {
		return fmt.Errorf("failed to update ref: %w", err)
	}

	return nil
}
// SPDX-License-Identifier: AGPL-3.0-only
// SPDX-FileCopyrightText: Copyright (c) 2025 Runxi Yu <https://runxiyu.org>
// SPDX-FileCopyrightText: Copyright (c) 2024 Robin Jarry <robin@jarry.cc>

package main

import (
	"bytes"
	"context"
	"errors"
	"fmt"
	"io"
	"log/slog"
	"net"
	"strings"
	"time"

	"github.com/emersion/go-message"
	"github.com/emersion/go-smtp"
	"go.lindenii.runxiyu.org/forge/misc"
)

type lmtpHandler struct{}

type lmtpSession struct {
	from   string
	to     []string
	ctx    context.Context
	cancel context.CancelFunc
	s      server
}

func (session *lmtpSession) Reset() {
	session.from = ""
	session.to = nil
}

func (session *lmtpSession) Logout() error {
	session.cancel()
	return nil
}

func (session *lmtpSession) AuthPlain(_, _ string) error {
	return nil
}

func (session *lmtpSession) Mail(from string, _ *smtp.MailOptions) error {
	session.from = from
	return nil
}

func (session *lmtpSession) Rcpt(to string, _ *smtp.RcptOptions) error {
	session.to = append(session.to, to)
	return nil
}

func (*lmtpHandler) NewSession(_ *smtp.Conn) (smtp.Session, error) {
	ctx, cancel := context.WithCancel(context.Background())
	session := &lmtpSession{
		ctx:    ctx,
		cancel: cancel,
	}
	return session, nil
}

func (s *server) serveLMTP(listener net.Listener) error {
	smtpServer := smtp.NewServer(&lmtpHandler{})
	smtpServer.LMTP = true
	smtpServer.Domain = s.config.LMTP.Domain
	smtpServer.Addr = s.config.LMTP.Socket
	smtpServer.WriteTimeout = time.Duration(s.config.LMTP.WriteTimeout) * time.Second
	smtpServer.ReadTimeout = time.Duration(s.config.LMTP.ReadTimeout) * time.Second
	smtpServer.EnableSMTPUTF8 = true
	return smtpServer.Serve(listener)
}

func (session *lmtpSession) Data(r io.Reader) error {
	var (
		email *message.Entity
		from  string
		to    []string
		err   error
		buf   bytes.Buffer
		data  []byte
		n     int64
	)

	n, err = io.CopyN(&buf, r, session.s.config.LMTP.MaxSize)
	switch {
	case n == session.s.config.LMTP.MaxSize:
		err = errors.New("Message too big.")
		// drain whatever is left in the pipe
		_, _ = io.Copy(io.Discard, r)
		goto end
	case errors.Is(err, io.EOF):
		// message was smaller than max size
		break
	case err != nil:
		goto end
	}

	data = buf.Bytes()

	email, err = message.Read(bytes.NewReader(data))
	if err != nil && message.IsUnknownCharset(err) {
		goto end
	}

	switch strings.ToLower(email.Header.Get("Auto-Submitted")) {
	case "auto-generated", "auto-replied":
		// Disregard automatic emails like OOO repliesession.s.
		slog.Info("ignoring automatic message",
			"from", session.from,
			"to", strings.Join(session.to, ","),
			"message-id", email.Header.Get("Message-Id"),
			"subject", email.Header.Get("Subject"),
		)
		goto end
	}

	slog.Info("message received",
		"from", session.from,
		"to", strings.Join(session.to, ","),
		"message-id", email.Header.Get("Message-Id"),
		"subject", email.Header.Get("Subject"),
	)

	// Make local copies of the values before to ensure the references will
	// still be valid when the task is run.
	from = session.from
	to = session.to

	_ = from

	for _, to := range to {
		if !strings.HasSuffix(to, "@"+session.s.config.LMTP.Domain) {
			continue
		}
		localPart := to[:len(to)-len("@"+session.s.config.LMTP.Domain)]
		var segments []string
		segments, err = misc.PathToSegments(localPart)
		if err != nil {
			// TODO: Should the entire email fail or should we just
			// notify them out of band?
			err = fmt.Errorf("cannot parse path: %w", err)
			goto end
		}
		sepIndex := -1
		for i, part := range segments {
			if part == "-" {
				sepIndex = i
				break
			}
		}
		if segments[len(segments)-1] == "" {
			segments = segments[:len(segments)-1] // We don't care about dir or not.
		}
		if sepIndex == -1 || len(segments) <= sepIndex+2 {
			err = errors.New("illegal path")
			goto end
		}

		mbox := bytes.Buffer{}
		if _, err = fmt.Fprint(&mbox, "From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001\r\n"); err != nil {
			slog.Error("error handling patch... malloc???", "error", err)
			goto end
		}
		data = bytes.ReplaceAll(data, []byte("\r\n"), []byte("\n"))
		if _, err = mbox.Write(data); err != nil {
			slog.Error("error handling patch... malloc???", "error", err)
			goto end
		}
		// TODO: Is mbox's From escaping necessary here?

		groupPath := segments[:sepIndex]
		moduleType := segments[sepIndex+1]
		moduleName := segments[sepIndex+2]
		switch moduleType {
		case "repos":
			err = lmtpHandlePatch(session, groupPath, moduleName, &mbox)
			err = session.s.lmtpHandlePatch(session, groupPath, moduleName, &mbox)
			if err != nil {
				slog.Error("error handling patch", "error", err)
				goto end
			}
		default:
			err = errors.New("Emailing any endpoint other than repositories, is not supported yet.") // TODO
			goto end
		}
	}

end:
	session.to = nil
	session.from = ""
	switch err {
	case nil:
		return nil
	default:
		return &smtp.SMTPError{
			Code:         550,
			Message:      "Permanent failure: " + err.Error(),
			EnhancedCode: [3]int{5, 7, 1},
		}
	}
}
package main

import "github.com/jackc/pgx/v5/pgxpool"

type server struct {
	config Config

	// database serves as the primary database handle for this entire application.
	// Transactions or single reads may be used from it. A [pgxpool.Pool] is
	// necessary to safely use pgx concurrently; pgx.Conn, etc. are insufficient.
	database *pgxpool.Pool
}
// SPDX-License-Identifier: AGPL-3.0-only
// SPDX-FileCopyrightText: Copyright (c) 2025 Runxi Yu <https://runxiyu.org>

package main

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

	gliderSSH "github.com/gliderlabs/ssh"
	"github.com/go-git/go-git/v5"
	"go.lindenii.runxiyu.org/lindenii-common/cmap"
)

// packPass contains information known when handling incoming SSH connections
// that then needs to be used in hook socket connection handlers. See hookc(1).
type packPass struct {
	session      gliderSSH.Session
	repo         *git.Repository
	pubkey       string
	directAccess bool
	repoPath     string
	userID       int
	userType     string
	repoID       int
	groupPath    []string
	repoName     string
	contribReq   string
}

// packPasses contains hook cookies mapped to their packPass.
var packPasses = cmap.Map[string, packPass]{}

// sshHandleRecvPack handles attempts to push to repos.
func (s *server) sshHandleRecvPack(session gliderSSH.Session, pubkey, repoIdentifier string) (err error) {
	groupPath, repoName, repoID, repoPath, directAccess, contribReq, userType, userID, err := s.getRepoInfo2(session.Context(), repoIdentifier, pubkey)
	if err != nil {
		return err
	}
	repo, err := git.PlainOpen(repoPath)
	if err != nil {
		return err
	}

	repoConf, err := repo.Config()
	if err != nil {
		return err
	}

	repoConfCore := repoConf.Raw.Section("core")
	if repoConfCore == nil {
		return errors.New("repository has no core section in config")
	}

	hooksPath := repoConfCore.OptionAll("hooksPath")
	if len(hooksPath) != 1 || hooksPath[0] != s.config.Hooks.Execs {
		return errors.New("repository has hooksPath set to an unexpected value")
	}

	if !directAccess {
		switch contribReq {
		case "closed":
			if !directAccess {
				return errors.New("you need direct access to push to this repo")
			}
		case "registered_user":
			if userType != "registered" {
				return errors.New("you need to be a registered user to push to this repo")
			}
		case "ssh_pubkey":
			fallthrough
		case "federated":
			if pubkey == "" {
				return errors.New("you need to have an SSH public key to push to this repo")
			}
			if userType == "" {
				userID, err = addUserSSH(session.Context(), pubkey)
				userID, err = s.addUserSSH(session.Context(), pubkey)
				if err != nil {
					return err
				}
				fmt.Fprintln(session.Stderr(), "you are now registered as user ID", userID)
				userType = "pubkey_only"
			}

		case "public":
		default:
			panic("unknown contrib_requirements value " + contribReq)
		}
	}

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

	packPasses.Store(cookie, packPass{
		session:      session,
		pubkey:       pubkey,
		directAccess: directAccess,
		repoPath:     repoPath,
		userID:       userID,
		repoID:       repoID,
		groupPath:    groupPath,
		repoName:     repoName,
		repo:         repo,
		contribReq:   contribReq,
		userType:     userType,
	})
	defer packPasses.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", repoPath)
	proc.Env = append(os.Environ(),
		"LINDENII_FORGE_HOOKS_SOCKET_PATH="+s.config.Hooks.Socket,
		"LINDENII_FORGE_HOOKS_COOKIE="+cookie,
	)
	proc.Stdin = session
	proc.Stdout = session
	proc.Stderr = session.Stderr()

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

	err = proc.Wait()
	if err != nil {
		fmt.Fprintln(session.Stderr(), "Error while waiting for process:", err)
	}

	return err
}
// SPDX-License-Identifier: AGPL-3.0-only
// SPDX-FileCopyrightText: Copyright (c) 2025 Runxi Yu <https://runxiyu.org>

package main

import (
	"context"

	"github.com/jackc/pgx/v5"
)

// addUserSSH adds a new user solely based on their SSH public key.
//
// TODO: Audit all users of this function.
func addUserSSH(ctx context.Context, pubkey string) (userID int, err error) {
func (s *server) addUserSSH(ctx context.Context, pubkey string) (userID int, err error) {
	var txn pgx.Tx

	if txn, err = database.Begin(ctx); err != nil {
	if txn, err = s.database.Begin(ctx); err != nil {
		return
	}
	defer func() {
		_ = txn.Rollback(ctx)
	}()

	if err = txn.QueryRow(ctx, `INSERT INTO users (type) VALUES ('pubkey_only') RETURNING id`).Scan(&userID); err != nil {
		return
	}

	if _, err = txn.Exec(ctx, `INSERT INTO ssh_public_keys (key_string, user_id) VALUES ($1, $2)`, pubkey, userID); err != nil {
		return
	}

	err = txn.Commit(ctx)
	return
}