veryroundbird.house
1package knotserver
2
3import (
4 "compress/gzip"
5 "fmt"
6 "io"
7 "net/http"
8 "path/filepath"
9 "strings"
10
11 securejoin "github.com/cyphar/filepath-securejoin"
12 "github.com/go-chi/chi/v5"
13 "tangled.sh/tangled.sh/core/knotserver/git/service"
14)
15
16func (d *Handle) InfoRefs(w http.ResponseWriter, r *http.Request) {
17 did := chi.URLParam(r, "did")
18 name := chi.URLParam(r, "name")
19 repoName, err := securejoin.SecureJoin(did, name)
20 if err != nil {
21 gitError(w, "repository not found", http.StatusNotFound)
22 d.l.Error("git: failed to secure join repo path", "handler", "InfoRefs", "error", err)
23 return
24 }
25
26 repoPath, err := securejoin.SecureJoin(d.c.Repo.ScanPath, repoName)
27 if err != nil {
28 gitError(w, "repository not found", http.StatusNotFound)
29 d.l.Error("git: failed to secure join repo path", "handler", "InfoRefs", "error", err)
30 return
31 }
32
33 cmd := service.ServiceCommand{
34 Dir: repoPath,
35 Stdout: w,
36 }
37
38 serviceName := r.URL.Query().Get("service")
39 switch serviceName {
40 case "git-upload-pack":
41 w.Header().Set("content-type", "application/x-git-upload-pack-advertisement")
42 w.WriteHeader(http.StatusOK)
43
44 if err := cmd.InfoRefs(); err != nil {
45 gitError(w, err.Error(), http.StatusInternalServerError)
46 d.l.Error("git: process failed", "handler", "InfoRefs", "service", serviceName, "error", err)
47 return
48 }
49 case "git-receive-pack":
50 d.RejectPush(w, r, name)
51 default:
52 gitError(w, fmt.Sprintf("service unsupported: '%s'", serviceName), http.StatusForbidden)
53 }
54}
55
56func (d *Handle) UploadPack(w http.ResponseWriter, r *http.Request) {
57 did := chi.URLParam(r, "did")
58 name := chi.URLParam(r, "name")
59 repo, err := securejoin.SecureJoin(d.c.Repo.ScanPath, filepath.Join(did, name))
60 if err != nil {
61 writeError(w, err.Error(), 500)
62 d.l.Error("git: failed to secure join repo path", "handler", "UploadPack", "error", err)
63 return
64 }
65
66 var bodyReader io.ReadCloser = r.Body
67 if r.Header.Get("Content-Encoding") == "gzip" {
68 gzipReader, err := gzip.NewReader(r.Body)
69 if err != nil {
70 writeError(w, err.Error(), 500)
71 d.l.Error("git: failed to create gzip reader", "handler", "UploadPack", "error", err)
72 return
73 }
74 defer gzipReader.Close()
75 bodyReader = gzipReader
76 }
77
78 w.Header().Set("Content-Type", "application/x-git-upload-pack-result")
79 w.Header().Set("Connection", "Keep-Alive")
80
81 d.l.Info("git: executing git-upload-pack", "handler", "UploadPack", "repo", repo)
82
83 cmd := service.ServiceCommand{
84 Dir: repo,
85 Stdout: w,
86 Stdin: bodyReader,
87 }
88
89 w.WriteHeader(http.StatusOK)
90
91 if err := cmd.UploadPack(); err != nil {
92 d.l.Error("git: failed to execute git-upload-pack", "handler", "UploadPack", "error", err)
93 return
94 }
95}
96
97func (d *Handle) ReceivePack(w http.ResponseWriter, r *http.Request) {
98 did := chi.URLParam(r, "did")
99 name := chi.URLParam(r, "name")
100 _, err := securejoin.SecureJoin(d.c.Repo.ScanPath, filepath.Join(did, name))
101 if err != nil {
102 gitError(w, err.Error(), http.StatusForbidden)
103 d.l.Error("git: failed to secure join repo path", "handler", "ReceivePack", "error", err)
104 return
105 }
106
107 d.RejectPush(w, r, name)
108}
109
110func (d *Handle) RejectPush(w http.ResponseWriter, r *http.Request, unqualifiedRepoName string) {
111 // A text/plain response will cause git to print each line of the body
112 // prefixed with "remote: ".
113 w.Header().Set("content-type", "text/plain; charset=UTF-8")
114 w.WriteHeader(http.StatusForbidden)
115
116 fmt.Fprintf(w, "Pushes are only supported over SSH.")
117
118 // If the appview gave us the repository owner's handle we can attempt to
119 // construct the correct ssh url.
120 ownerHandle := r.Header.Get("x-tangled-repo-owner-handle")
121 if ownerHandle != "" && !strings.ContainsAny(ownerHandle, ":") {
122 hostname := d.c.Server.Hostname
123 if strings.Contains(hostname, ":") {
124 hostname = strings.Split(hostname, ":")[0]
125 }
126
127 fmt.Fprintf(w, " Try:\ngit remote set-url --push origin git@%s:%s/%s\n\n... and push again.", hostname, ownerHandle, unqualifiedRepoName)
128 }
129 fmt.Fprintf(w, "\n\n")
130}
131
132func gitError(w http.ResponseWriter, msg string, status int) {
133 w.Header().Set("content-type", "text/plain; charset=UTF-8")
134 w.WriteHeader(status)
135 fmt.Fprintf(w, "%s\n", msg)
136}