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 +1,128 @@
+---
+c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
+SPDX-License-Identifier: curl
+Title: CURLOPT_PREREQFUNCTION
+Section: 3
+Source: libcurl
+See-also:
+  - CURLINFO_PRIMARY_IP (3)
+  - CURLINFO_PRIMARY_PORT (3)
+  - CURLOPT_PREREQDATA (3)
+Protocol:
+  - All
+Added-in: 7.80.0
+---
+
+# NAME
+
+CURLOPT_PREREQFUNCTION - user callback called when a connection has been
+established, but before a request has been made.
+
+# SYNOPSIS
+
+~~~c
+#include <curl/curl.h>
+
+/* These are the return codes for the pre-request callback. */
+#define CURL_PREREQFUNC_OK 0
+#define CURL_PREREQFUNC_ABORT 1 /* fail the entire transfer */
+
+int prereq_callback(void *clientp,
+                    char *conn_primary_ip,
+                    char *conn_local_ip,
+                    int conn_primary_port,
+                    int conn_local_port);
+
+CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PREREQFUNCTION, prereq_callback);
+~~~
+
+# DESCRIPTION
+
+Pass a pointer to your callback function, which should match the prototype
+shown above.
+
+This function gets called by libcurl after a connection has been established
+or a connection has been reused (including any SSL handshaking), but before any
+request is actually made on the connection. For example, for HTTP, this
+callback is called once a connection has been established to the server, but
+before a GET/HEAD/POST/etc request has been sent.
+
+This function may be called multiple times if redirections are enabled and are
+being followed (see CURLOPT_FOLLOWLOCATION(3)).
+
+The callback function must return *CURL_PREREQFUNC_OK* on success, or
+*CURL_PREREQFUNC_ABORT* to cause the transfer to fail with result
+*CURLE_ABORTED_BY_CALLBACK*.
+
+This function is passed the following arguments:
+
+## `conn_primary_ip`
+
+A pointer to a null-terminated C string containing the primary IP of the
+remote server established with this connection. For FTP, this is the IP for
+the control connection. IPv6 addresses are represented without surrounding
+brackets.
+
+## `conn_local_ip`
+
+A pointer to a null-terminated C string containing the originating IP for this
+connection. IPv6 addresses are represented without surrounding brackets.
+
+## `conn_primary_port`
+
+The primary port number on the remote server established with this connection.
+For FTP, this is the port for the control connection. This can be a TCP or a
+UDP port number depending on the protocol.
+
+## `conn_local_port`
+
+The originating port number for this connection. This can be a TCP or a UDP
+port number depending on the protocol.
+
+## `clientp`
+
+The pointer you set with CURLOPT_PREREQDATA(3).
+
+# DEFAULT
+
+NULL
+
+# %PROTOCOLS%
+
+# EXAMPLE
+
+~~~c
+struct priv {
+  void *custom;
+};
+
+static int prereq_callback(void *clientp,
+                           char *conn_primary_ip,
+                           char *conn_local_ip,
+                           int conn_primary_port,
+                           int conn_local_port)
+{
+  printf("Connection made to %s:%d\n", conn_primary_ip, conn_primary_port);
+  return CURL_PREREQFUNC_OK;
+}
+
+int main(void)
+{
+  struct priv prereq_data;
+  CURL *curl = curl_easy_init();
+  if(curl) {
+    curl_easy_setopt(curl, CURLOPT_PREREQFUNCTION, prereq_callback);
+    curl_easy_setopt(curl, CURLOPT_PREREQDATA, &prereq_data);
+    curl_easy_perform(curl);
+  }
+}
+~~~
+
+# %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).