Question

我正在尝试向此网址发送HEAD请求：

http://ubuntu-releases.mirror.net.in/releases/16.04.2/ubuntu-16.04.2-desktop-amd64.iso

并获取文件的大小。我目前的头部请求如下：

head_request = "HEAD " + file_path + " HTTP/1.0%s" % ('\r\n\r\n')
socket.socket(socket.AF_INET, socket.SOCK_STREAM).send(head_request)

其中file_path为"/releases/16.04.2/ubuntu-16.04.2-desktop-amd64.iso"。这很有效，但当我将1.0替换为1.1时，我得到400 HTTP Bad Request。

head_request = "HEAD " + file_path + " HTTP/1.1%s" % ('\r\n\r\n')

为什么会这样？

Answer 1

在HTTP / 1.1中，您必须提供Host:标题。

使用netcat（nc）实用程序进行演示：

$ nc ubuntu-releases.mirror.net.in 80 <<END
HEAD /releases/16.04.2/ubuntu-16.04.2-desktop-amd64.iso HTTP/1.0

END
HTTP/1.1 200 OK
Date: Sat, 04 Mar 2017 07:25:22 GMT
Server: Apache/2.4.18 (Ubuntu)
Last-Modified: Wed, 15 Feb 2017 21:44:24 GMT
ETag: "5ca30000-5489895805e00"
Accept-Ranges: bytes
Content-Length: 1554186240
Connection: close
Content-Type: application/x-iso9660-image

$ nc ubuntu-releases.mirror.net.in 80 <<END
HEAD /releases/16.04.2/ubuntu-16.04.2-desktop-amd64.iso HTTP/1.1

END

HTTP/1.1 400 Bad Request
Date: Sat, 04 Mar 2017 07:25:33 GMT
Server: Apache/2.4.18 (Ubuntu)
Connection: close
Content-Type: text/html; charset=iso-8859-1

$ nc ubuntu-releases.mirror.net.in 80 <<END
HEAD /releases/16.04.2/ubuntu-16.04.2-desktop-amd64.iso HTTP/1.1
Host: ubuntu-releases.mirror.net.in

END

HTTP/1.1 200 OK
Date: Sat, 04 Mar 2017 07:27:27 GMT
Server: Apache/2.4.18 (Ubuntu)
Last-Modified: Wed, 15 Feb 2017 21:44:24 GMT
ETag: "5ca30000-5489895805e00"
Accept-Ranges: bytes
Content-Length: 1554186240
Content-Type: application/x-iso9660-image

HTTP / 1.1中有400个错误请求但HTTP / 1.0中没有

1 个答案: