1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
|
package port
import (
"bytes"
"fmt"
"html/template"
"io"
"log"
"net"
"net/http"
"net/url"
"strings"
"git.vulpes.one/Feuerfuchs/port/pkg/libgopher"
"github.com/davidbyttow/govips/pkg/vips"
"github.com/temoto/robotstxt"
)
type gopherTemplateVariables struct {
Title string
URL string
Assets AssetList
Lines []GopherItem
Nav []GopherNavItem
IsPlain bool
}
type GopherNavItem struct {
Label string
URL string
Current bool
}
type GopherItem struct {
Link template.URL
Type string
Text string
}
func trimLeftChars(s string, n int) string {
m := 0
for i := range s {
if m >= n {
return s[i:]
}
m++
}
return s[:0]
}
func urlToGopherNav(url string) (items []GopherNavItem) {
partialURL := "/gopher"
parts := strings.Split(url, "/")
if len(parts) != 0 && parts[len(parts)-1] == "" {
parts = parts[:len(parts)-1]
}
for i, part := range parts {
if i == 1 {
partialURL = partialURL + "/1"
part = trimLeftChars(part, 1)
if part == "" {
continue
}
} else {
partialURL = partialURL + "/" + part
}
current := false
if i == len(parts)-1 || (len(parts) == 2 && i == 0) {
current = true
}
items = append(items, GopherNavItem{
Label: part,
URL: partialURL,
Current: current,
})
}
return
}
func renderGopherDirectory(w http.ResponseWriter, tpl *template.Template, assetList AssetList, uri string, hostport string, d libgopher.Directory) error {
var title string
out := make([]GopherItem, len(d.Items))
for i, x := range d.Items {
if x.Type == libgopher.INFO && x.Selector == "TITLE" {
title = x.Description
continue
}
tr := GopherItem{
Text: x.Description,
Type: x.Type.String(),
}
if x.Type == libgopher.INFO {
out[i] = tr
continue
}
if strings.HasPrefix(x.Selector, "URL:") || strings.HasPrefix(x.Selector, "/URL:") {
link := strings.TrimPrefix(strings.TrimPrefix(x.Selector, "/"), "URL:")
if strings.HasPrefix(link, "gemini://") {
link = fmt.Sprintf(
"/gemini/%s",
strings.TrimPrefix(link, "gemini://"),
)
} else if strings.HasPrefix(link, "gopher://") {
link = fmt.Sprintf(
"/gopher/%s",
strings.TrimPrefix(link, "gopher://"),
)
}
tr.Link = template.URL(link)
} else {
var linkHostport string
if x.Port != "70" {
linkHostport = net.JoinHostPort(x.Host, x.Port)
} else {
linkHostport = x.Host
}
path := url.PathEscape(x.Selector)
path = strings.Replace(path, "%2F", "/", -1)
tr.Link = template.URL(
fmt.Sprintf(
"/gopher/%s/%s%s",
linkHostport,
string(byte(x.Type)),
path,
),
)
}
out[i] = tr
}
if title == "" {
if uri != "" {
title = fmt.Sprintf("%s/%s", hostport, uri)
} else {
title = hostport
}
}
return tpl.Execute(w, gopherTemplateVariables{
Title: title,
URL: fmt.Sprintf("%s/%s", hostport, uri),
Assets: assetList,
Lines: out,
Nav: urlToGopherNav(fmt.Sprintf("%s/%s", hostport, uri)),
})
}
// GopherHandler returns a Handler that proxies requests
// to the specified Gopher server as denoated by the first argument
// to the request path and renders the content using the provided template.
// The optional robots parameters points to a robotstxt.RobotsData struct
// to test user agents against a configurable robotst.txt file.
func GopherHandler(tpl *template.Template, robotsdata *robotstxt.RobotsData, assetList AssetList, robotsdebug bool) http.HandlerFunc {
return func(w http.ResponseWriter, req *http.Request) {
agent := req.UserAgent()
path := strings.TrimPrefix(req.URL.Path, "/gopher/")
if robotsdata != nil && robotsdebug && !robotsdata.TestAgent(path, agent) {
log.Printf("UserAgent %s ignored robots.txt", agent)
}
parts := strings.Split(path, "/")
hostport := parts[0]
if len(hostport) == 0 {
http.Redirect(w, req, "/", http.StatusFound)
return
}
title := hostport
var qs string
if req.URL.RawQuery != "" {
qs = fmt.Sprintf("?%s", url.QueryEscape(req.URL.RawQuery))
}
uri, err := url.QueryUnescape(strings.Join(parts[1:], "/"))
if err != nil {
if e := tpl.Execute(w, gopherTemplateVariables{
Title: title,
URL: hostport,
Assets: assetList,
Lines: []GopherItem{{
Text: fmt.Sprintf("Error: %s", err),
}},
Nav: urlToGopherNav(hostport),
IsPlain: true,
}); e != nil {
log.Println("Template error: " + e.Error())
log.Println(err.Error())
}
return
}
if uri != "" {
title = fmt.Sprintf("%s/%s", hostport, uri)
}
res, err := libgopher.Get(
fmt.Sprintf(
"gopher://%s/%s%s",
hostport,
uri,
qs,
),
)
if err != nil {
if e := tpl.Execute(w, gopherTemplateVariables{
Title: title,
URL: fmt.Sprintf("%s/%s", hostport, uri),
Assets: assetList,
Lines: []GopherItem{{
Text: fmt.Sprintf("Error: %s", err),
}},
Nav: urlToGopherNav(fmt.Sprintf("%s/%s", hostport, uri)),
IsPlain: true,
}); e != nil {
log.Println("Template error: " + e.Error())
}
return
}
if res.Body != nil {
if len(parts) < 2 {
io.Copy(w, res.Body)
} else if strings.HasPrefix(parts[1], "0") && !strings.HasSuffix(uri, ".xml") && !strings.HasSuffix(uri, ".asc") {
buf := new(bytes.Buffer)
buf.ReadFrom(res.Body)
if err := tpl.Execute(w, gopherTemplateVariables{
Title: title,
URL: fmt.Sprintf("%s/%s", hostport, uri),
Assets: assetList,
Lines: []GopherItem{{
Text: buf.String(),
}},
Nav: urlToGopherNav(fmt.Sprintf("%s/%s", hostport, uri)),
IsPlain: true,
}); err != nil {
log.Println("Template error: " + err.Error())
}
} else if strings.HasPrefix(parts[1], "T") {
_, _, err = vips.NewTransform().
Load(res.Body).
ResizeStrategy(vips.ResizeStrategyAuto).
ResizeWidth(160).
Quality(75).
Output(w).
Apply()
} else {
io.Copy(w, res.Body)
}
} else {
if err := renderGopherDirectory(w, tpl, assetList, uri, hostport, res.Dir); err != nil {
if e := tpl.Execute(w, gopherTemplateVariables{
Title: title,
URL: fmt.Sprintf("%s/%s", hostport, uri),
Assets: assetList,
Lines: []GopherItem{{
Text: fmt.Sprintf("Error: %s", err),
}},
Nav: urlToGopherNav(fmt.Sprintf("%s/%s", hostport, uri)),
IsPlain: false,
}); e != nil {
log.Println("Template error: " + e.Error())
log.Println(e.Error())
}
}
}
}
}
|