1 files changed, 208 insertions, 0 deletions
diff --git a/server.go b/server.go
new file mode 100644
index 0000000..6296574
--- /dev/null
+++ b/server.go
@@ -0,0 +1,208 @@
+/*
+Copyright 2022 Sam Anthony
+
+This file is part of samanthony.xyz.
+
+samanthony.xyz is free software: you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free Software
+Foundation, either version 3 of the License, or (at your option) any later
+version.
+
+samanthony.xyz 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 General Public License for more details.
+
+You should have received a copy of the GNU General Public License along with
+samanthony.xyz. If not, see <https://www.gnu.org/licenses/>.
+*/
+
+package main
+
+import (
+	"flag"
+	"fmt"
+	"golang.org/x/sys/unix"
+	"html/template"
+	"io/fs"
+	"log"
+	"net"
+	"net/http"
+	"os"
+	"path"
+	fp "path/filepath"
+	"strings"
+)
+
+// Flags
+var (
+	host   = "localhost"
+	port   = "80"
+	chroot = "/var/www/"
+	user   = "www"
+	group  = "www"
+	root   = "/htdocs/samanthony.xyz/"
+)
+
+func init() {
+	flag.StringVar(&host, "host", host, "")
+	flag.StringVar(&port, "port", port, "")
+	flag.StringVar(&chroot, "chroot", chroot, "")
+	flag.StringVar(&user, "user", user, "")
+	flag.StringVar(&group, "group", group, "")
+	flag.StringVar(&root, "root", root, "")
+
+	flag.Parse()
+}
+
+// Must lookup the hostname before entering the chroot.
+var addr = ""
+
+func init() {
+	// host is an ip address
+	if ip := net.ParseIP(host); ip != nil {
+		addr = ip.String()
+	} else { // host is a domain name
+		addrs, err := net.LookupHost(host)
+		if err != nil {
+			log.Fatal(err)
+		}
+		for _, a := range addrs {
+			if ip := net.ParseIP(a); ip != nil {
+				if v4 := ip.To4(); v4 != nil {
+					addr = v4.String()
+				}
+			}
+		}
+		if addr == "" {
+			log.Fatalf("No ipv4 address bound to %s", host)
+		}
+	}
+}
+
+var (
+	uid int
+	gid int
+)
+
+func init() {
+	var err error
+	uid, err = uidOf(user)
+	if err != nil {
+		log.Fatal(err)
+	}
+	gid, err = gidOf(group)
+	if err != nil {
+		log.Fatal(err)
+	}
+}
+
+// Enter chroot
+func init() {
+	if err := unix.Chroot(chroot); err != nil {
+		log.Fatalf("chroot: %s: %v", chroot, err)
+	}
+}
+
+// Build templates
+var tmpl = make(map[string]*template.Template)
+
+func init() {
+	err := fp.WalkDir(root, func(path string, d fs.DirEntry, err error) error {
+		if fp.Clean(path) == fp.Clean(root) ||
+			fp.Ext(path) != ".html" ||
+			path == fp.Join(root, "base.html") {
+			return nil
+		}
+		label := path[len(fp.Clean(root)):]
+		tmpl[label] = template.Must(template.ParseFiles(
+			fp.Join(root, "base.html"), path))
+		return nil
+	})
+	if err != nil {
+		log.Fatal(err)
+	}
+}
+
+// Template data
+type Page struct {
+	Nav Nav
+}
+
+type Nav struct {
+	ThisSection string
+	Links       []NavLink
+}
+
+type NavLink struct {
+	Href  string
+	Label string
+}
+
+var nav = Nav{
+	Links: []NavLink{
+		{"/", "samanthony.xyz"},
+		{"/software/", "software"},
+	},
+}
+
+func rootHandler(w http.ResponseWriter, r *http.Request) {
+	if err := dropPerms(uid, gid); err != nil {
+		log.Println(err)
+		code := http.StatusInternalServerError
+		http.Error(w, http.StatusText(code), code)
+		return
+	}
+
+	reqPath := r.URL.Path
+
+	// If request directory, serve index.html.
+	// ie. /software -> /software/index.html
+	if info, err := os.Stat(fp.Join(root, reqPath)); err == nil {
+		if info.IsDir() {
+			reqPath = path.Join(reqPath, "index.html")
+		}
+	} else if os.IsNotExist(err) {
+		http.NotFound(w, r)
+		return
+	} else {
+		log.Println(err)
+		code := http.StatusInternalServerError
+		http.Error(w, http.StatusText(code), code)
+		return
+	}
+
+	if t, ok := tmpl[reqPath]; ok {
+		thisSection := ""
+		for _, link := range nav.Links {
+			if strings.HasPrefix(reqPath, link.Href) {
+				thisSection = link.Href
+			}
+		}
+		nav := nav
+		nav.ThisSection = thisSection
+		page := Page{nav}
+
+		err := t.Execute(w, page)
+		if err != nil {
+			log.Println(err)
+			code := http.StatusInternalServerError
+			http.Error(w, http.StatusText(code), code)
+			return
+		}
+	} else {
+		http.ServeFile(w, r, fp.Join(root, reqPath))
+	}
+}
+
+func main() {
+	http.HandleFunc("/", rootHandler)
+	http.Handle("/.well-known/acme-challenge/",
+		http.StripPrefix(
+			"/.well-known/acme-challenge/",
+			http.FileServer(http.Dir("/acme/")),
+		),
+	)
+
+	log.Printf("Listening on %s:%s\n", addr, port)
+	log.Fatal(http.ListenAndServe(fmt.Sprintf("%s:%s", addr, port), nil))
+}