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
|
/*
GoToSocial
Copyright (C) 2021-2023 GoToSocial Authors admin@gotosocial.org
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 <http://www.gnu.org/licenses/>.
*/
package fileserver
import (
"bytes"
"fmt"
"io"
"net/http"
"strconv"
"github.com/gin-gonic/gin"
apimodel "github.com/superseriousbusiness/gotosocial/internal/api/model"
apiutil "github.com/superseriousbusiness/gotosocial/internal/api/util"
"github.com/superseriousbusiness/gotosocial/internal/gtserror"
"github.com/superseriousbusiness/gotosocial/internal/iotools"
"github.com/superseriousbusiness/gotosocial/internal/log"
"github.com/superseriousbusiness/gotosocial/internal/oauth"
)
// ServeFile is for serving attachments, headers, and avatars to the requester from instance storage.
//
// Note: to mitigate scraping attempts, no information should be given out on a bad request except "404 page not found".
// Don't give away account ids or media ids or anything like that; callers shouldn't be able to infer anything.
func (m *Module) ServeFile(c *gin.Context) {
authed, err := oauth.Authed(c, false, false, false, false)
if err != nil {
apiutil.ErrorHandler(c, gtserror.NewErrorNotFound(err), m.processor.InstanceGetV1)
return
}
// We use request params to check what to pull out of the database/storage so check everything. A request URL should be formatted as follows:
// "https://example.org/fileserver/[ACCOUNT_ID]/[MEDIA_TYPE]/[MEDIA_SIZE]/[FILE_NAME]"
// "FILE_NAME" consists of two parts, the attachment's database id, a period, and the file extension.
accountID := c.Param(AccountIDKey)
if accountID == "" {
err := fmt.Errorf("missing %s from request", AccountIDKey)
apiutil.ErrorHandler(c, gtserror.NewErrorNotFound(err), m.processor.InstanceGetV1)
return
}
mediaType := c.Param(MediaTypeKey)
if mediaType == "" {
err := fmt.Errorf("missing %s from request", MediaTypeKey)
apiutil.ErrorHandler(c, gtserror.NewErrorNotFound(err), m.processor.InstanceGetV1)
return
}
mediaSize := c.Param(MediaSizeKey)
if mediaSize == "" {
err := fmt.Errorf("missing %s from request", MediaSizeKey)
apiutil.ErrorHandler(c, gtserror.NewErrorNotFound(err), m.processor.InstanceGetV1)
return
}
fileName := c.Param(FileNameKey)
if fileName == "" {
err := fmt.Errorf("missing %s from request", FileNameKey)
apiutil.ErrorHandler(c, gtserror.NewErrorNotFound(err), m.processor.InstanceGetV1)
return
}
content, errWithCode := m.processor.FileGet(c.Request.Context(), authed, &apimodel.GetContentRequestForm{
AccountID: accountID,
MediaType: mediaType,
MediaSize: mediaSize,
FileName: fileName,
})
if errWithCode != nil {
apiutil.ErrorHandler(c, errWithCode, m.processor.InstanceGetV1)
return
}
defer func() {
// close content when we're done
if content.Content != nil {
if err := content.Content.Close(); err != nil {
log.Errorf("ServeFile: error closing readcloser: %s", err)
}
}
}()
if content.URL != nil {
c.Redirect(http.StatusFound, content.URL.String())
return
}
// TODO: if the requester only accepts text/html we should try to serve them *something*.
// This is mostly needed because when sharing a link to a gts-hosted file on something like mastodon, the masto servers will
// attempt to look up the content to provide a preview of the link, and they ask for text/html.
format, err := apiutil.NegotiateAccept(c, apiutil.MIME(content.ContentType))
if err != nil {
apiutil.ErrorHandler(c, gtserror.NewErrorNotAcceptable(err, err.Error()), m.processor.InstanceGetV1)
return
}
// if this is a head request, just return info + throw the reader away
if c.Request.Method == http.MethodHead {
c.Header("Content-Type", format)
c.Header("Content-Length", strconv.FormatInt(content.ContentLength, 10))
c.Status(http.StatusOK)
return
}
// create a "slurp" buffer ;)
b := make([]byte, 64)
// Try read the first 64 bytes into memory, to try return a more useful "not found" error.
if _, err := io.ReadFull(content.Content, b); err != nil &&
(err != io.ErrUnexpectedEOF && err != io.EOF) {
err = fmt.Errorf("ServeFile: error reading from content: %w", err)
apiutil.ErrorHandler(c, gtserror.NewErrorNotFound(err, err.Error()), m.processor.InstanceGetV1)
return
}
// reconstruct the original content reader
r := io.MultiReader(bytes.NewReader(b), content.Content)
// Check the Range header: if this is a simple query for the whole file, we can return it now.
if c.GetHeader("Range") == "" && c.GetHeader("If-Range") == "" {
c.DataFromReader(http.StatusOK, content.ContentLength, format, r, nil)
return
}
// Range is set, so we need a ReadSeeker to pass to the ServeContent function.
tfs, err := iotools.TempFileSeeker(r)
if err != nil {
err = fmt.Errorf("ServeFile: error creating temp file seeker: %w", err)
apiutil.ErrorHandler(c, gtserror.NewErrorInternalError(err), m.processor.InstanceGetV1)
return
}
defer func() {
if err := tfs.Close(); err != nil {
log.Errorf("ServeFile: error closing temp file seeker: %s", err)
}
}()
// to avoid ServeContent wasting time seeking for the
// mime type, set this header already since we know it
c.Header("Content-Type", format)
// allow ServeContent to handle the rest of the request;
// it will handle Range as appropriate, and write correct
// response headers, http code, etc
http.ServeContent(c.Writer, c.Request, fileName, content.ContentUpdated, tfs)
}
|
