Update networking layer w/ CURL and emscripten impl

2025-11-08 01:50:36 +11:00
parent a17925904d
commit f6874dc55a
4105 changed files with 694617 additions and 179 deletions
@@ -0,0 +1,106 @@
+---
+c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
+SPDX-License-Identifier: curl
+Title: CURLOPT_ALTSVC_CTRL
+Section: 3
+Source: libcurl
+See-also:
+  - CURLOPT_ALTSVC (3)
+  - CURLOPT_CONNECT_TO (3)
+  - CURLOPT_RESOLVE (3)
+Protocol:
+  - HTTP
+Added-in: 7.64.1
+---
+
+# NAME
+
+CURLOPT_ALTSVC_CTRL - control alt-svc behavior
+
+# SYNOPSIS
+
+~~~c
+#include <curl/curl.h>
+
+#define CURLALTSVC_READONLYFILE (1L<<2)
+#define CURLALTSVC_H1           (1L<<3)
+#define CURLALTSVC_H2           (1L<<4)
+#define CURLALTSVC_H3           (1L<<5)
+
+CURLcode curl_easy_setopt(CURL *handle, CURLOPT_ALTSVC_CTRL, long bitmask);
+~~~
+
+# DESCRIPTION
+
+Populate the long *bitmask* with the correct set of features to instruct
+libcurl how to handle Alt-Svc for the transfers using this handle.
+
+libcurl only accepts Alt-Svc headers over HTTPS. It also only completes a
+request to an alternative origin if that origin is properly hosted over HTTPS.
+These requirements are there to make sure both the source and the destination
+are legitimate.
+
+Alternative services are only used when setting up new connections. If there
+exists an existing connection to the host in the connection pool, then that is
+preferred.
+
+If CURLOPT_ALTSVC(3) is set, CURLOPT_ALTSVC_CTRL(3) gets a default value
+corresponding to CURLALTSVC_H1 | CURLALTSVC_H2 | CURLALTSVC_H3 - the HTTP/2
+and HTTP/3 bits are only set if libcurl was built with support for those
+versions.
+
+Setting any bit enables the alt-svc engine.
+
+## CURLALTSVC_READONLYFILE
+
+Do not write the alt-svc cache back to the file specified with
+CURLOPT_ALTSVC(3) even if it gets updated. By default a file specified
+with that option is read and written to as deemed necessary.
+
+## CURLALTSVC_H1
+
+Accept alternative services offered over HTTP/1.1.
+
+## CURLALTSVC_H2
+
+Accept alternative services offered over HTTP/2. This is only used if libcurl
+was also built to actually support HTTP/2, otherwise this bit is ignored.
+
+## CURLALTSVC_H3
+
+Accept alternative services offered over HTTP/3. This is only used if libcurl
+was also built to actually support HTTP/3, otherwise this bit is ignored.
+
+# DEFAULT
+
+0 - Alt-Svc handling is disabled
+
+# %PROTOCOLS%
+
+# EXAMPLE
+
+~~~c
+int main(void)
+{
+  CURL *curl = curl_easy_init();
+  if(curl) {
+    curl_easy_setopt(curl, CURLOPT_ALTSVC_CTRL, CURLALTSVC_H1);
+    curl_easy_setopt(curl, CURLOPT_ALTSVC, "altsvc-cache.txt");
+    curl_easy_perform(curl);
+  }
+}
+~~~
+
+# HISTORY
+
+**CURLALTSVC_*** macros became `long` types in 8.16.0, prior to this version
+a `long` cast was necessary when passed to curl_easy_setopt(3).
+
+# %AVAILABILITY%
+
+# RETURN VALUE
+
+curl_easy_setopt(3) returns a CURLcode indicating success or error.
+
+CURLE_OK (0) means everything was OK, non-zero means an error occurred, see
+libcurl-errors(3).