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/* Copyright (C) 2020 June 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 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);
char name[256];
const char *ext = strrchr(field->file, '.');
if (!ext) ext = "";
snprintf(
name, sizeof(name), "%jx%08x%s",
(intmax_t)time(NULL), arc4random(), ext
);
int fd = openat(cwd, name, O_CREAT | O_EXCL | O_WRONLY, 0644);
if (fd < 0) {
warn("openat");
return fail(req, KHTTP_507);
}
ssize_t len = write(fd, field->val, field->valsz);
int error = close(fd);
if (len < 0 || error) {
warn("write");
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 {
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));
error = handle(&req);
if (error) errx(EX_PROTOCOL, "%s", kcgi_strerror(error));
khttp_free(&req);
}
}
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