Add CGI upload program for temp.causal.agency

3 files changed, 173 insertions, 0 deletions

diff --git a/www/temp.causal.agency/.gitignore b/www/temp.causal.agency/.gitignore
new file mode 100644
index 00000000..e31ee94e
--- /dev/null
+++ b/www/temp.causal.agency/.gitignore
@@ -0,0 +1 @@
+up
diff --git a/www/temp.causal.agency/Makefile b/www/temp.causal.agency/Makefile
new file mode 100644
index 00000000..3f608286
--- /dev/null
+++ b/www/temp.causal.agency/Makefile
@@ -0,0 +1,16 @@
+WEBROOT = /usr/local/www/temp.causal.agency
+
+CFLAGS += -std=c11 -Wall -Wextra -Wpedantic -I/usr/local/include
+LDFLAGS += -static -L/usr/local/lib
+LDLIBS = -lkcgihtml -lkcgi -lz -lmd
+
+up:
+
+clean:
+	rm -f up
+
+install: up
+	install up ${WEBROOT}/up
+
+uninstall:
+	rm -f ${WEBROOT}/up
diff --git a/www/temp.causal.agency/up.c b/www/temp.causal.agency/up.c
new file mode 100644
index 00000000..b004abd3
--- /dev/null
+++ b/www/temp.causal.agency/up.c
@@ -0,0 +1,156 @@
+/* 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) 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);
+	}
+}