mastoGem/server.go

486 lines
12 KiB
Go

/*
MastoGem, A Mastodon proxy for Gemini
Copyright (C) 2021 Romain de Laage
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Affero General Public License for more details.
You should have received a copy of the GNU Affero General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
package main
import (
"crypto/tls"
"net/url"
"log"
"net"
"bufio"
"strconv"
"fmt"
"strings"
)
func listen(address, certFile, keyFile string) net.Listener {
cert, err := tls.LoadX509KeyPair(certFile, keyFile)
if err != nil {
log.Fatalln("loadkeys: %s", err)
}
config := &tls.Config{
ClientAuth: tls.RequestClientCert,
Certificates: []tls.Certificate{cert},
MinVersion: tls.VersionTLS12,
InsecureSkipVerify: true,
}
listener, err := tls.Listen("tcp", address, config)
if err != nil {
log.Fatalln("failed to listen on 0.0.0.0:1965: %s", err)
}
return listener
}
func serve(listener net.Listener, baseURL, title, home_message string, rateLimit int) {
for {
conn, err := listener.Accept()
if err != nil {
log.Println(err)
}
go handleConn(conn.(*tls.Conn), baseURL, title, home_message, rateLimit)
}
}
func getRawURL(conn *tls.Conn) (string, error) {
scanner := bufio.NewScanner(conn)
if ok := scanner.Scan(); !ok {
return "", scanner.Err()
}
rawURL := scanner.Text()
if strings.Contains(rawURL, "://") {
return rawURL, nil
}
return fmt.Sprintf("gemini://%s", rawURL), nil
}
func getPath(conn *tls.Conn) (string, string, error) {
rawURL, err := getRawURL(conn)
if err != nil {
return "", "", err
}
parsedURL, err := url.Parse(rawURL)
if err != nil {
return "", "", err
}
return parsedURL.Path, parsedURL.RawQuery, nil
}
func handleConn(conn *tls.Conn, baseURL, title, home_message string, rateLimit int) {
defer conn.Close()
if !rateIsOk(rateMap, strings.Split(conn.RemoteAddr().String(), ":")[0], rateLimit) {
log.Printf("Too many requests for %s\n", conn.RemoteAddr().String())
_, err := fmt.Fprintf(conn, "44 60\r\n")
if err != nil {
log.Println("send error: %s", err)
return
}
return
}
path, query, err := getPath(conn)
if err != nil {
log.Println("get url: %s", err)
_, err = fmt.Fprintf(conn, "59 Can't parse request\r\n")
if err != nil {
log.Println("send error: %s", err)
return
}
return
}
// home
if path == "" || path == "/" {
log.Println("Received request for home page")
_, err = fmt.Fprintf(conn, "20 text/gemini\r\n# %s\n\n%s\n\n=> /tag Search for a tag\n=> /about About MastoGem", title, home_message)
if err != nil {
log.Println("send error: %s", err)
return
}
return
}
// profile
if strings.HasPrefix(path, "/profile/") {
if strings.HasSuffix(path, "/reblog") {
// skip prefix and suffix
path = path[9:len(path)-len("/reblog")]
_, err = strconv.ParseUint(path, 10, 64)
if err != nil {
log.Println("invalid request: %s", err)
_, err = fmt.Fprintf(conn, "59 Can't parse request\r\n")
if err != nil {
log.Println("send error: %s", err)
return
}
return
}
log.Println("Received request for account with reblog " + path)
printProfileWithReblog(conn, baseURL, path)
} else {
// skip prefix
path = path[9:]
_, err = strconv.ParseUint(path, 10, 64)
if err != nil {
log.Println("invalid request: %s", err)
_, err = fmt.Fprintf(conn, "59 Can't parse request\r\n")
if err != nil {
log.Println("send error: %s", err)
return
}
return
}
log.Println("Received request for account " + path)
printProfile(conn, baseURL, path)
}
} /* thread */ else if strings.HasPrefix(path, "/thread/") {
// skip prefix
path = path[8:]
_, err = strconv.ParseUint(path, 10, 64)
if err != nil {
log.Println("invalid request: %s", err)
_, err = fmt.Fprintf(conn, "59 Can't parse request\r\n")
if err != nil {
log.Println("send error: %s", err)
return
}
return
}
log.Println("Received request for thread " + path)
printThread(conn, baseURL, path)
} /* about */ else if strings.HasPrefix(path, "/about") {
const page = `# About MastoGem
This capsule is running MastoGem, a free (as in free speech, not as in free beer) and open source software. It is released under AGPLv3 License (a copy a the license is available below). This software was written by Romain de Laage in 2021 during his free time. You can get a copy of the sources of this software here :
=> https://git.rdelaage.ovh/rdelaage/mastoGem Gitea repository (web)
Feel free to contribute, send feedback or share ideas.
# Mastodon instance
This capsule use %s Mastodon instance.
# AGPLv3 License
=> http://www.gnu.org/licenses/agpl-3.0.txt AGPLv3 License text`
log.Println("Received request for about page")
_, err = fmt.Fprintf(conn, "20 text/gemini\r\n" + page, baseURL)
if err != nil {
log.Println("send: %s", err)
return
}
} /* tag */ else if strings.HasPrefix(path, "/tag") {
if query == "" {
_, err = fmt.Fprintf(conn, "10 Enter a tag name\r\n")
if err != nil {
log.Println("send: %s", err)
return
}
return
}
log.Println("Received request for tag " + query)
printTag(conn, baseURL, query)
} /* toot */ else if strings.HasPrefix(path, "/toot/") {
path = path[6:]
_, err = strconv.ParseUint(path, 10, 64)
if err != nil {
log.Println("invalid request: %s", err)
_, err = fmt.Fprintf(conn, "59 Can't parse request\r\n")
if err != nil {
log.Println("send error: %s", err)
return
}
return
}
log.Println("Received request for toot " + path)
printToot(conn, baseURL, path)
} else {
_, err = fmt.Fprintf(conn, "59 Invalid request\r\n")
if err != nil {
log.Println("send: %s", err)
return
}
}
}
func printProfile(conn *tls.Conn, baseURL, profileID string) {
account, err := getAccount(baseURL, profileID)
if err != nil {
_, err = fmt.Fprintf(conn, "40 Remote mastodon instance failed\r\n")
if err != nil {
log.Println("handleConn: %s", err)
return
}
return
}
blogs, err := getBlog(baseURL, profileID)
if err != nil {
_, err = fmt.Fprintf(conn, "40 Remote mastodon instance failed\r\n")
if err != nil {
log.Println("handleConn: %s", err)
return
}
return
}
_, err = fmt.Fprintf(conn, "20 text/gemini\r\n# Toots for %s account\n", account.Name)
if err != nil {
log.Println("handleConn: %s", err)
return
}
for _, blog := range blogs {
_, err = fmt.Fprintf(conn, "\n%s\n=> /thread/%s View the thread\n", formatBlog(blog), blog.Id)
if err != nil {
log.Println("read blogs: %s", err)
return
}
}
_, err = fmt.Fprintf(conn, "\n=> /profile/%s/reblog This profile with reblog\n=> %s Go to %s account", account.Id, account.Url, account.Name)
if err != nil {
log.Println("add link: %s", err)
return
}
}
func printProfileWithReblog(conn *tls.Conn, baseURL, profileID string) {
account, err := getAccount(baseURL, profileID)
if err != nil {
_, err = fmt.Fprintf(conn, "40 Remote mastodon instance failed\r\n")
if err != nil {
log.Println("handleConn: %s", err)
return
}
return
}
blogs, err := getBlogAndReblog(baseURL, profileID)
if err != nil {
_, err = fmt.Fprintf(conn, "40 Remote mastodon instance failed\r\n")
if err != nil {
log.Println("handleConn: %s", err)
return
}
return
}
_, err = fmt.Fprintf(conn, "20 text/gemini\r\n# Toots for %s account\n", account.Name)
if err != nil {
log.Println("handleConn: %s", err)
return
}
for _, blog := range blogs {
_, err = fmt.Fprintf(conn, "\n%s\n=> /thread/%s View the thread\n", formatBlog(blog), blog.Id)
if err != nil {
log.Println("read blogs: %s", err)
return
}
}
_, err = fmt.Fprintf(conn, "\n=> /profile/%s This profile without reblog\n=> %s Go to %s account", account.Id, account.Url, account.Name)
if err != nil {
log.Println("add link: %s", err)
return
}
}
func printToot(conn *tls.Conn, baseURL, tootID string) {
toot, err := getToot(baseURL, tootID)
if err != nil {
_, err = fmt.Fprintf(conn, "40 Remote mastodon instance failed\r\n")
if err != nil {
log.Println("handleConn: %s", err)
return
}
return
}
// Print header
_, err = fmt.Fprintf(conn, "20 text/gemini\r\n")
if err != nil {
log.Println("handleConn: %s", err)
return
}
// Print toot
if toot.Reblog == nil {
_, err = fmt.Fprintf(conn, "# Toot\n\n%s\n=> /thread/%s View the thread\n=> /profile/%s More toots from %s\n", formatBlog(toot), toot.Id, toot.Author.Id, toot.Author.Name)
if err != nil {
log.Println("handleConn: %s", err)
return
}
} else {
_, err = fmt.Fprintf(conn, "# Toot\n\n%s\n=> /toot/%s Original toot\n=> /thread/%s View the thread\n=> /profile/%s More toots from %s\n=> /profile/%s More toots from %s\n", formatBlog(toot), toot.Reblog.Id, toot.Id, toot.Author.Id, toot.Author.Name, toot.Reblog.Author.Id, toot.Reblog.Author.Name)
if err != nil {
log.Println("handleConn: %s", err)
return
}
}
// print mentions
_, err = fmt.Fprintf(conn, "\n# Mentions\n")
if err != nil {
log.Println("handleConn: %s", err)
return
}
for _, mention := range toot.Mentions {
_, err = fmt.Fprintf(conn, "\n=> /profile/%s View %s profile", mention.Id, mention.Name)
if err != nil {
log.Println("handleConn: %s", err)
return
}
}
// print tags
_, err = fmt.Fprintf(conn, "\n\n# Tags\n")
if err != nil {
log.Println("handleConn: %s", err)
return
}
for _, tag := range toot.Tags {
_, err = fmt.Fprintf(conn, "\n=> /tag?%s View %s tag", url.QueryEscape(tag.Name), tag.Name)
if err != nil {
log.Println("handleConn: %s", err)
return
}
}
}
func printThread(conn *tls.Conn, baseURL, tootID string) {
originalToot, err := getToot(baseURL, tootID)
if err != nil {
_, err = fmt.Fprintf(conn, "40 Remote mastodon instance failed\r\n")
if err != nil {
log.Println("handleConn: %s", err)
return
}
return
}
thread, err := getThread(baseURL, tootID)
if err != nil {
_, err = fmt.Fprintf(conn, "40 Remote mastodon instance failed\r\n")
if err != nil {
log.Println("handleConn: %s", err)
return
}
return
}
// Print header
_, err = fmt.Fprintf(conn, "20 text/gemini\r\n# Ancestors\n")
if err != nil {
log.Println("handleConn: %s", err)
return
}
// Print each anscestor
for _, toot := range thread.Ancestors {
_, err = fmt.Fprintf(conn, "\n%s\n=> /profile/%s More toots from %s\n", formatBlog(toot), toot.Author.Id, toot.Author.Name)
if err != nil {
log.Println("handleConn: %s", err)
return
}
}
// Print original toot
_, err = fmt.Fprintf(conn, "\n# Toot\n\n%s\n=> /profile/%s More toots from %s\n", formatBlog(originalToot), originalToot.Author.Id, originalToot.Author.Name)
if err != nil {
log.Println("handleConn: %s", err)
return
}
// Print each descendant
_, err = fmt.Fprintf(conn, "\n# Descendants\n")
if err != nil {
log.Println("handleConn: %s", err)
return
}
for _, toot := range thread.Descendants {
_, err = fmt.Fprintf(conn, "\n%s\n=> /profile/%s More toots from %s\n", formatBlog(toot), toot.Author.Id, toot.Author.Name)
if err != nil {
log.Println("handleConn: %s", err)
return
}
}
}
func printTag(conn *tls.Conn, baseURL, tag string) {
toots, err := getTag(baseURL, tag)
if err != nil {
_, err = fmt.Fprintf(conn, "40 Remote mastodon instance failed\r\n")
if err != nil {
log.Println("handleConn: %s", err)
return
}
return
}
//decode tag (url encoded char like space)
tag, err = url.QueryUnescape(tag)
if err != nil {
_, err = fmt.Fprintf(conn, "59 Invalid url encoded tag\r\n")
if err != nil {
log.Println("handleConn: %s", err)
return
}
return
}
// Print header
_, err = fmt.Fprintf(conn, "20 text/gemini\r\n# Toots for %s\n", tag)
if err != nil {
log.Println("handleConn: %s", err)
return
}
// Print toots
for _, toot := range toots {
_, err = fmt.Fprintf(conn, "\n%s\n=> /profile/%s More toots from %s\n=> /thread/%s View the thread\n", formatBlog(toot), toot.Author.Id, toot.Author.Name, toot.Id)
if err != nil {
log.Println("handleConn: %s", err)
return
}
}
}