From e3a6ad7173d8746af0fde87a1ead69c1c7d61bfa Mon Sep 17 00:00:00 2001
From: John-Mark Bell <jmb@netsurf-browser.org>
Date: Wed, 27 Dec 2023 19:12:07 +0000
Subject: Fetch/curl: expose socket open/close via fetch vtable

This allows frontends to customise the behaviour of sockets. The
default implementation simply maps to socket(2)/close(2).
---
 content/fetchers/curl.c | 20 ++++++++++++++++++++
 desktop/gui_factory.c   |  9 +++++++++
 include/netsurf/fetch.h | 17 +++++++++++++++++
 3 files changed, 46 insertions(+)

diff --git a/content/fetchers/curl.c b/content/fetchers/curl.c
index b1907448e..680e60456 100644
--- a/content/fetchers/curl.c
+++ b/content/fetchers/curl.c
@@ -1792,6 +1792,24 @@ fetch_curl_debug(CURL *handle,
 }
 
 
+static curl_socket_t fetch_curl_socket_open(void *clientp,
+		curlsocktype purpose, struct curl_sockaddr *address)
+{
+	(void) clientp;
+	(void) purpose;
+
+	return (curl_socket_t) guit->fetch->socket_open(
+			address->family, address->socktype,
+			address->protocol);
+}
+
+static int fetch_curl_socket_close(void *clientp, curl_socket_t item)
+{
+	(void) clientp;
+
+	return guit->fetch->socket_close((int) item);
+}
+
 /**
  * Callback function for cURL.
  */
@@ -2047,6 +2065,8 @@ nserror fetch_curl_register(void)
 	SETOPT(CURLOPT_LOW_SPEED_TIME, 180L);
 	SETOPT(CURLOPT_NOSIGNAL, 1L);
 	SETOPT(CURLOPT_CONNECTTIMEOUT, nsoption_uint(curl_fetch_timeout));
+	SETOPT(CURLOPT_OPENSOCKETFUNCTION, fetch_curl_socket_open);
+	SETOPT(CURLOPT_CLOSESOCKETFUNCTION, fetch_curl_socket_close);
 
 	if (nsoption_charp(ca_bundle) &&
 	    strcmp(nsoption_charp(ca_bundle), "")) {
diff --git a/desktop/gui_factory.c b/desktop/gui_factory.c
index 89f2e373f..c9dcd8b2b 100644
--- a/desktop/gui_factory.c
+++ b/desktop/gui_factory.c
@@ -20,6 +20,9 @@
 #include <stdint.h>
 #include <stdbool.h>
 #include <string.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/socket.h>
 
 #include "utils/config.h"
 #include "utils/errors.h"
@@ -498,6 +501,12 @@ static nserror verify_fetch_register(struct gui_fetch_table *gft)
 	if (gft->mimetype == NULL) {
 		gft->mimetype = gui_default_mimetype;
 	}
+	if (gft->socket_open == NULL) {
+		gft->socket_open = socket;
+	}
+	if (gft->socket_close == NULL) {
+		gft->socket_close = close;
+	}
 
 	return NSERROR_OK;
 }
diff --git a/include/netsurf/fetch.h b/include/netsurf/fetch.h
index 30b204868..156f4d1ef 100644
--- a/include/netsurf/fetch.h
+++ b/include/netsurf/fetch.h
@@ -99,6 +99,23 @@ struct gui_fetch_table {
 	 */
 	char *(*mimetype)(const char *ro_path);
 
+	/**
+	 * Open a socket
+	 *
+	 * \param domain Communication domain
+	 * \param type Socket type
+	 * \param protocol Protocol
+	 * \return Socket descriptor on success, -1 on error and errno set
+	 */
+	int (*socket_open)(int domain, int type, int protocol);
+
+	/**
+	 * Close a socket
+	 *
+	 * \param socket Socket descriptor
+	 * \return 0 on success, -1 on error and errno set
+	 */
+	int (*socket_close)(int socket);
 };
 
 #endif
-- 
cgit v1.2.3