On Jan 5, 8:37*pm, John John - MVP wrote:
karthikbalaguru wrote:
On Jan 5, 4:54 pm, Andrew McLaren wrote:
karthikbalaguru wrote:
I am eager to know the reasons for the raw socket
support in the Winsock interface during the initial
Windows XP release ?
http://msdn.microsoft.com/en-us/libr...48(VS.85).aspx

Thx for the link !

As per the link, the ability to send traffic over raw sockets
has been restricted in several ways in new Windows
releases after 'Windows XP with SP2' .

The reasons for the below changes w.r.t Raw Sockets
are not clearly mentioned in that link . Any ideas ?
1) TCP data cannot be sent over raw sockets.
But why ?

2) A call to the bind function with a raw socket is not allowed.
But why ? Any ideas ?

But, the below reason w.r.t raw socket & UDP datagram
support is clear -
3) UDP datagrams with an invalid source address cannot be sent
over raw sockets. The IP source address for any outgoing UDP
datagram must exist on a network interface or the datagram is
dropped. This change was made to limit the ability of malicious
code to create distributed denial-of-service attacks and limits the
ability to send spoofed packets (TCP/IP packets with a forged
source IP address).

It's all to do with security.


Okay. Agreed !!
But, why is this change not present in the
versions earlier to 'Windows XP with SP2' ?

The below link seems to convey that these restrictions
do not apply to Windows Server 2008 , Windows Server
2003, or to versions of the operating system earlier
than Windows XP with SP2 . But, Why ?
http://msdn.microsoft.com/en-us/libr...8(VS.85).aspx#

[quote]

Restricted traffic over raw sockets

Detailed description

A very small number of Windows applications make use of raw IP sockets,
which provide an industry-standard way for applications to create TCP/IP
packets with fewer integrity and security checks by the TCP/IP stack.
The Windows implementation of TCP/IP still supports receiving traffic on
raw IP sockets. However, the ability to send traffic over raw sockets
has been restricted in two ways:

* *TCP data cannot be sent over raw sockets.

* *UDP datagrams with invalid source addresses cannot be sent over raw
sockets. The IP source address for any outgoing UDP datagram must exist
on a network interface or the datagram is dropped.

Why is this change important? What threats does it help mitigate?

This change limits the ability of malicious code to create distributed
denial-of-service attacks and limits the ability to send spoofed
packets, which are TCP/IP packets with a forged source IP address.

[end quote]

http://technet.microsoft.com/en-us/l.../bb457156.aspx


Thx for the link !

The above link conveys that this change helps to limit the
speed at which malicious programs, such as viruses and
worms, spread to uninfected computers as Malicious
programs often attempt to reach uninfected computers
by opening simultaneous connections to random IP
addresses.

Thx in advans,
Karthik Balaguru