Rehome some logic from server.c -> serve.c

1 files changed, 128 insertions, 0 deletions

diff --git a/src/serve.c b/src/serve.c
new file mode 100644
index 0000000..00d51b5
--- /dev/null
+++ b/src/serve.c
@@ -0,0 +1,128 @@
+#include <assert.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <stdlib.h>
+#include <string.h>
+#include "config.h"
+#include "gemini.h"
+#include "log.h"
+#include "mime.h"
+#include "server.h"
+#include "url.h"
+
+void
+client_submit_response(struct gmnisrv_client *client,
+	enum gemini_status status, const char *meta, int bodyfd)
+{
+	client->status = status;
+	client->meta = strdup(meta);
+	client->bodyfd = bodyfd;
+	client->pollfd->events = POLLOUT;
+}
+
+void
+client_oom(struct gmnisrv_client *client)
+{
+	const char *error = "Out of memory";
+	client_submit_response(client,
+		GEMINI_STATUS_TEMPORARY_FAILURE, error, -1);
+}
+
+void
+serve_request(struct gmnisrv_client *client)
+{
+	struct gmnisrv_host *host = client->host;
+	assert(host);
+	assert(host->root); // TODO: reverse proxy support
+
+	char path[PATH_MAX + 1];
+	int n = snprintf(path, sizeof(path), "%s%s", host->root, client->path);
+	if ((size_t)n >= sizeof(path)) {
+		client_submit_response(client, GEMINI_STATUS_PERMANENT_FAILURE,
+			"Request path exceeds PATH_MAX", -1);
+		return;
+	}
+
+	if (path[strlen(path) - 1] == '/') {
+		// TODO: Let user configure index file name?
+		strncat(path, "index.gmi", sizeof(path) - 1);
+	}
+
+	int fd = open(path, O_RDONLY);
+	if (fd == -1) {
+		if (errno == ENOENT) {
+			client_submit_response(client, GEMINI_STATUS_NOT_FOUND,
+				"Not found", -1);
+			return;
+		} else {
+			client_error(&client->addr, "error opening %s: %s",
+					path, strerror(errno));
+			client_submit_response(client, GEMINI_STATUS_PERMANENT_FAILURE,
+				"Internal server error", -1);
+			return;
+		}
+	}
+
+	const char *meta = gmnisrv_mimetype_for_path(path);
+	client_submit_response(client, GEMINI_STATUS_SUCCESS, meta, fd);
+}
+
+bool
+request_validate(struct gmnisrv_client *client, char **path)
+{
+	struct Curl_URL *url = curl_url();
+	if (!url) {
+		client_oom(client);
+		return false;
+	}
+	if (curl_url_set(url, CURLUPART_URL, client->buf, 0) != CURLUE_OK) {
+		const char *error = "Protocol error: invalid URL";
+		client_submit_response(client,
+			GEMINI_STATUS_BAD_REQUEST, error, -1);
+		goto exit;
+	}
+
+	char *part;
+	if (curl_url_get(url, CURLUPART_SCHEME, &part, 0) != CURLUE_OK) {
+		const char *error = "Protocol error: invalid URL (expected scheme)";
+		client_submit_response(client,
+			GEMINI_STATUS_BAD_REQUEST, error, -1);
+		goto exit;
+	} else if (strcmp(part, "gemini") != 0) {
+		free(part);
+		const char *error = "Refusing proxy to non-gemini URL";
+		client_submit_response(client,
+			GEMINI_STATUS_PROXY_REQUEST_REFUSED, error, -1);
+		goto exit;
+	}
+	free(part);
+
+	if (curl_url_get(url, CURLUPART_HOST, &part, 0) != CURLUE_OK) {
+		const char *error = "Protocol error: invalid URL (expected host)";
+		client_submit_response(client,
+			GEMINI_STATUS_BAD_REQUEST, error, -1);
+		goto exit;
+	} else if (strcmp(part, client->host->hostname) != 0) {
+		free(part);
+		const char *error = "Protocol error: hostname does not match SNI";
+		client_submit_response(client,
+			GEMINI_STATUS_BAD_REQUEST, error, -1);
+		goto exit;
+	}
+	free(part);
+
+	if (curl_url_get(url, CURLUPART_PATH, &part, 0) != CURLUE_OK) {
+		const char *error = "Protocol error: invalid URL (expected path)";
+		client_submit_response(client,
+			GEMINI_STATUS_BAD_REQUEST, error, -1);
+		goto exit;
+	}
+	// NOTE: curl_url_set(..., CURLUPART_URL, ..., 0) will consoldate .. and
+	// . to prevent directory traversal without additional code.
+	*path = part;
+
+exit:
+	curl_url_cleanup(url);
+	return true;
+}