查看Laravel API：
Request::ip();
在内部，它使用Symfony Request对象中的
getClientIps方法：
public function getClientIps(){ $clientIps = array(); $ip = $this->server->get('REMOTE_ADDR'); if (!$this->isFromTrustedProxy()) { return array($ip); } if (self::$trustedHeaders[self::HEADER_FORWARDED] && $this->headers->has(self::$trustedHeaders[self::HEADER_FORWARDED])) { $forwardedHeader = $this->headers->get(self::$trustedHeaders[self::HEADER_FORWARDED]); preg_match_all('{(for)=("?[?)([a-z0-9.:_-/]*)}', $forwardedHeader, $matches); $clientIps = $matches[3]; } elseif (self::$trustedHeaders[self::HEADER_CLIENT_IP] && $this->headers->has(self::$trustedHeaders[self::HEADER_CLIENT_IP])) { $clientIps = array_map('trim', explode(',', $this->headers->get(self::$trustedHeaders[self::HEADER_CLIENT_IP]))); } $clientIps[] = $ip; // Complete the IP chain with the IP the request actually came from $ip = $clientIps[0]; // Fallback to this when the client IP falls into the range of trusted proxies foreach ($clientIps as $key => $clientIp) { // Remove port (unfortunately, it does happen) if (preg_match('{((?:d+.){3}d+):d+}', $clientIp, $match)) { $clientIps[$key] = $clientIp = $match[1]; } if (IpUtils::checkIp($clientIp, self::$trustedProxies)) { unset($clientIps[$key]); } } // Now the IP chain contains only untrusted proxies and the client IP return $clientIps ? array_reverse($clientIps) : array($ip);}
