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
|
/* Copyright (C) 2020 C. McEnroe <june@causal.agency>
*
* 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/>.
*/
#include <err.h>
#include <fcntl.h>
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/capsicum.h>
#include <sys/types.h>
#include <sysexits.h>
#include <time.h>
#include <unistd.h>
#include <kcgi.h>
#include <kcgihtml.h>
static int cwd = -1;
static const struct kvalid Key = { NULL, "file" };
static enum kcgi_err head(struct kreq *req, enum khttp http, enum kmime mime) {
return khttp_head(req, kresps[KRESP_STATUS], "%s", khttps[http])
|| khttp_head(req, kresps[KRESP_CONTENT_TYPE], "%s", kmimetypes[mime]);
}
static enum kcgi_err fail(struct kreq *req, enum khttp http) {
return head(req, http, KMIME_TEXT_PLAIN)
|| khttp_body(req)
|| khttp_printf(req, "%s\n", khttps[http]);
}
static const char *upload(const char *ext, void *ptr, size_t len) {
static char name[256];
snprintf(
name, sizeof(name), "%jx%08x%s%s",
(intmax_t)time(NULL), arc4random(),
(ext && ext[0] != '.' ? "." : ""), (ext ? ext : "")
);
int fd = openat(cwd, name, O_CREAT | O_EXCL | O_WRONLY, 0644);
if (fd < 0) {
warn("%s", name);
return NULL;
}
ssize_t n = write(fd, ptr, len);
int error = close(fd);
if (n < 0 || error) {
warn("%s", name);
return NULL;
}
return name;
}
static enum kcgi_err handle(struct kreq *req) {
if (req->page) return fail(req, KHTTP_404);
if (req->method == KMETHOD_GET) {
struct khtmlreq html;
struct khtmlreq *h = &html;
return head(req, KHTTP_200, KMIME_TEXT_HTML)
|| khttp_body(req)
|| khtml_open(h, req, 0)
|| khtml_elem(h, KELEM_DOCTYPE)
|| khtml_elem(h, KELEM_TITLE)
|| khtml_puts(h, "Upload")
|| khtml_closeelem(h, 1)
|| khtml_attr(
h, KELEM_FORM,
KATTR_METHOD, "post",
KATTR_ACTION, "",
KATTR_ENCTYPE, "multipart/form-data",
KATTR__MAX
)
|| khtml_attr(
h, KELEM_INPUT,
KATTR_TYPE, "file",
KATTR_NAME, Key.name,
KATTR__MAX
)
|| khtml_attr(
h, KELEM_INPUT,
KATTR_TYPE, "submit",
KATTR_VALUE, "Upload",
KATTR__MAX
)
|| khtml_close(h);
} else if (req->method == KMETHOD_POST) {
struct kpair *field = req->fieldmap[0];
if (!field || !field->valsz) return fail(req, KHTTP_400);
const char *ext = strrchr(field->file, '.');
const char *name = upload(ext, field->val, field->valsz);
if (!name) return fail(req, KHTTP_507);
return head(req, KHTTP_303, KMIME_TEXT_PLAIN)
|| khttp_head(req, kresps[KRESP_LOCATION], "/%s", name)
|| khttp_body(req)
|| khttp_puts(req, name);
} else if (req->method == KMETHOD_PUT) {
struct kpair *field = req->fields;
if (!field || !field->valsz) return fail(req, KHTTP_400);
const char *ext = req->suffix;
if (!ext[0]) ext = strrchr(field->file, '.');
const char *name = upload(ext, field->val, field->valsz);
if (!name) return fail(req, KHTTP_507);
return head(req, KHTTP_200, KMIME_TEXT_PLAIN)
|| khttp_body(req)
|| khttp_printf(
req, "%s://%s/%s\n", kschemes[req->scheme], req->host, name
);
} else {
return fail(req, KHTTP_405);
}
}
static void sandbox(void) {
cwd = open(".", O_DIRECTORY);
if (cwd < 0) err(EX_CONFIG, ".");
int error = cap_enter();
if (error) err(EX_OSERR, "cap_enter");
cap_rights_t rights;
cap_rights_init(&rights, CAP_LOOKUP, CAP_CREATE, CAP_PWRITE);
error = cap_rights_limit(cwd, &rights);
if (error) err(EX_OSERR, "cap_rights_limit");
}
int main(void) {
const char *page = "up";
if (khttp_fcgi_test()) {
struct kfcgi *fcgi;
enum kcgi_err error = khttp_fcgi_init(&fcgi, &Key, 1, &page, 1, 0);
if (error) errx(EX_CONFIG, "khttp_fcgi_init: %s", kcgi_strerror(error));
sandbox();
for (
struct kreq req;
KCGI_OK == (error = khttp_fcgi_parse(fcgi, &req));
khttp_free(&req)
) {
error = handle(&req);
if (error && error != KCGI_HUP) break;
}
if (error != KCGI_EXIT) {
errx(EX_PROTOCOL, "khttp_fcgi_parse: %s", kcgi_strerror(error));
}
khttp_fcgi_free(fcgi);
} else {
struct kreq req;
enum kcgi_err error = khttp_parse(&req, &Key, 1, &page, 1, 0);
if (error) errx(EX_PROTOCOL, "khttp_parse: %s", kcgi_strerror(error));
sandbox();
error = handle(&req);
if (error) errx(EX_PROTOCOL, "%s", kcgi_strerror(error));
khttp_free(&req);
}
}
|