确保用curl精确地复制任何请求的细节?那不是curl的工作,而是socket_*的工作。我敢打赌有些人会说这不是PHP的工作,但是PHP确实能够以单线程的方式做到这一点。使用socket API接受来自服务器A的连接,读取请求,进行处理,按原样将请求转发到服务器B,读取来自服务器B的响应,并将该响应发送回服务器A。
示例(可以称之为ServerC.php):
<?php
declare(strict_types = 1);
if(php_sapi_name() !== 'cli'){die('this script must run in cli mode.');}
$port = 9999;
$targetIP = gethostbyname ( 'example.org' );
$targetPort = 80;
assert ( false !== filter_var ( $targetIP, FILTER_VALIDATE_IP ) );
var_dump ( $targetIP, $targetPort );
y ( ($listen = socket_create ( AF_INET, SOCK_STREAM, SOL_TCP )) );
register_shutdown_function ( function () use (&$listen) {
socket_close ( $listen );
} );
y ( socket_bind ( $listen, '0.0.0.0', $port ) );
y ( socket_listen ( $listen ) );
y ( socket_set_block ( $listen ) );
echo 'listening for connections... ', PHP_EOL;
while ( false !== ($newconn = socket_accept ( $listen )) ) {
echo 'new connection from ';
socket_getpeername ( $newconn, $peername, $peerport );
echo $peername . ':' . $peerport . PHP_EOL;
y ( socket_set_block ( $newconn ) );
$data = '';
echo 'reading request... ';
$data = socket_read_all ( $newconn, 2 );
var_dump ( $data );
echo 'done.' . PHP_EOL;
{
}
{
y ( ($targetSock = socket_create ( AF_INET, SOCK_STREAM, SOL_TCP )) );
y ( socket_set_block ( $targetSock ) );
y ( socket_connect ( $targetSock, $targetIP, $targetPort ) );
echo 'connected to target. forwarding request... ';
socket_write_all ( $targetSock, $data );
echo 'done.', PHP_EOL;
unset ( $data, $newdata );
$data = '';
echo 'reading response... ';
$data = socket_read_all ( $targetSock, 2 );
var_dump ( $data );
echo 'done.', PHP_EOL;
socket_close ( $targetSock );
}
echo 'sending response back to client... ';
socket_write_all ( $newconn, $data );
echo 'done.', PHP_EOL;
socket_close ( $newconn );
}
function y($in) {
if (! $in) {
$str = hhb_return_var_dump ( socket_last_error (), socket_strerror ( socket_last_error () ) );
throw new \Exception ( $str );
}
return $in;
}
function n($in) {
if (! ! $in) {
throw new \Exception ();
}
return $in;
}
function hhb_return_var_dump(): string // works like var_dump, but returns a string instead of printing it.
{
$args = func_get_args ();
ob_start ();
call_user_func_array ( 'var_dump', $args );
return ob_get_clean ();
}
function socket_write_all($sock, string $data) {
$len = strlen ( $data );
while ( $len > 0 ) {
$written = socket_write ( $sock, $data );
if ($written === false) {
throw new RuntimeException ( 'socket_write failed. errno: ' . socket_last_error ( $sock ) . '. error: ' . socket_strerror ( socket_last_error ( $sock ) ) );
}
$len -= $written;
$data = substr ( $data, $written );
}
return;
}
function socket_read_all($sock, int $sleep_sec = 2): string {
$ret = '';
while ( true ) {
sleep ( $sleep_sec );
$buf = '';
$read = socket_recv ( $sock, $buf, 9999, MSG_DONTWAIT );
if ($read === false || $read < 1) {
return $ret;
}
$ret .= $buf;
}
}
(这个脚本很慢,一次只能处理1个请求(尽管并发请求通过socket_accept被操作系统缓冲),而且是同步的。但是,如果值得优化,它可以通过socket_select&co进行优化和完全异步化)。