Bind raw socket linux
I have recently been investigating raw socket programming bind raw socket linux C for linux and I decided to provide a collection of routines I have prepared. The intention here is to be able to arbitrarily set the various parameters within a packet. Rather than use command-line arguments, each example has hard-coded values, so you need to modify each example to suit your preferences.
Three combinations of the DomainTypeand Protocol arguments are shown here. There are other possible combinations you could try. The packet parameters that can be modified are determined by which combination you choose. In the Table 2 examples, we fill out all values, including the layer 2 data link information source and next-hop MAC addresses.
In the Table 3 examples, we fill out all values, but only including the destination i. This is called a "cooked packet.
I have included an example which sends an ARP request ethernet frame as well as an example that receives an ARP reply ethernet frame.
Additionally, I have included some router solicitation and advertisement routines. Table 5 below provides some examples of packet fragmentation. The first file, called "data", contains a list of numbers. The following three routines use bind raw socket linux as data for the upper layer protocols. Feel free to provide to the routines your own data in any manner you prefer. Without doing something special using neighbor discoverywe can only change the hop limit and traffic class to arbitrary values.
Before we try some neighbor discovery, let's take a quick look at a couple of examples where we don't use neighbor discovery, and thus can only change the hop limit and traffic bind raw socket linux values in the IPv6 header. Note that changes made to the properties of the socket with setsockopt will remain in effect for all packets sent through the socket, whereas ancillary data is associated with a particular packet.
In either case, the supplied source address must actually be assigned to the interface or else the sendto call will fail and the packet won't be sent.
If we wish to have the ability to change any parameter in the IPv6 header, we need to have the source and destination MAC addresses available more explanation. In this case we have the same sort of options available to us as we did in Tables 2 and 3 above for IPv4. To recap, these are:. The neighbor discovery process is used to obtain the MAC address of a bind raw socket linux node's interface card could be the MAC address of a link-local router or host's interface the frames will be routed through.
First we send a neighbor solicitation with our MAC address to the target node, and then it replies with a neighbor advertisement that contains its MAC address. The neighbor solicitation is sent to the target node's solicited-node multicast address.
Some router discovery routines are also included. Router solicitations are issued by a host looking for local routers, and router advertisements are issued by routers announcing their presence on the LAN. Now that we have used neighbor discovery to determine the MAC address of a link-local router or host, we can go ahead and modify all parameters within the ethernet frame. As in the IPv4 examples of Table 3, in Table 10 below we fill out all values, but only including the destination i.
Table 11 presents some 6to4 examples. The following table provides some examples of packet fragmentation. In IPv6, fragmentation requires the introduction of a fragment extension header.
The first file, called "data", contains a list bind raw socket linux numbers, and the following routines use it as data for the upper layer protocols. Table 14 provides an example of sending a TCP packet with a hop-by-hop extension header and enough TCP data to require bind raw socket linux. The hop-by-hop header contains two options: For demonstration purposes here, the router alert option provides a value which is currently unassigned by IANA see Section 2.
The following few tables give examples of the authentication extension header AH and the encapsulating security payload extension header ESP header. The AH provides data origin and integrity authentication. The ESP header provides confidentiality, data origin and integrity authentication, an anti-replay service, and limited traffic flow confidentiality. The respective RFCs given below explain the encryption requirements; no encryption is done here in the examples.
Table 15 provides an example of sending a TCP packet bind raw socket linux a hop-by-hop extension header, authentication extension header, and enough TCP data to require fragmentation. Here, the authentication header carries a random bogus integrity check value ICV for bind raw socket linux normally, bind raw socket linux is computed as per Section bind raw socket linux of RFC Since the bind raw socket linux header can be used in transport or tunnel mode, an example is given of bind raw socket linux.
Table 16 provides an example of sending a TCP packet with a hop-by-hop extension header, ecapsulating security payload ESP extension header, and enough TCP data to require fragmentation. The hop-by-hop header is the same as in Table The authentication data portion bind raw socket linux the ESP header is the same as the authentication data used in Table Similar to the authentication header, the ESP header can be used in transport or tunnel mode, so an example is given of each.
Table 17 provides an example of sending a TCP packet with a hop-by-hop extension header with a router alert option, destination extension header last with an Identifier-Locator Network Protocol ILNP nonce option, and enough TCP data to require fragmentation.
Here "last" means a destination header that is to be processed only by the final destination node. This is relevent in terms of where in the packet the destination header is placed. A destination header can also be placed bind raw socket linux that it is processed by devices specified within a routing header. If you examine the code, you'll see that when multiple extension headers are introduced, a more generalized approach to chaining the headers via Next Header fields is going to be necessary, bind raw socket linux than bind raw socket linux and awkward lists of "if" statments, as I have here.
Table 18 gives an example of a routing header. There are several possible types of routing header, specified in the Routing Type field of the header itself. Here we use a type 3 routing header, which is a Source Routing Header for the routing protocol for bind raw socket linux and lossy networks RPL. We provide layer 2 data link information. Change hop limit and specify source interface using ancillary data. Source IP address set using bind. Change hop limit, specify source interface, and source IP address using ancillary data.
Send a neighbor advertisement this example doesn't detect and respond to a solicitation. Receive a neighbor advertisement and extract lots of info including MAC address.
Send a router advertisement this example doesn't detect and respond to a solicitation. Receive a router bind raw socket linux and extract lots of info including MAC address. Hop-by-Hop Extension Header - Section 4. Send TCP packet with a hop-by-hop extension header with router alert option and enough data to require fragmentation.
Send TCP packet with a hop-by-hop extension header with router alert option, authentication extension header in transport modeand enough data to require fragmentation. Send TCP packet with a hop-by-hop extension header with router alert option, authentication extension header in tunnel modeand enough data to require fragmentation.
Send TCP packet with a hop-by-hop extension header with router alert option, ESP extension header in transport modeand enough data to require fragmentation. Send TCP packet with a hop-by-hop extension header with router alert option, ESP extension header in tunnel modeand enough data to require fragmentation.
Send TCP packet with a hop-by-hop extension header, destination extension header lastand enough data to require fragmentation. Send TCP packet with a hop-by-hop extension header, type 3 routing extension header, and enough data to require fragmentation.
A raw socket is a type of socket that allows access to the underlying transport provider. This topic focuses only on raw sockets and the IPv4 and IPv6 protocols. This is because most other protocols with the exception of ATM do not support raw sockets. To use raw sockets, an application needs to have detailed information on the underlying protocol bind raw socket linux used.
The following command run from a CMD window will display data from the Winsock catalog on the console:. Raw sockets offer the capability to manipulate the underlying transport, so they can be used for malicious purposes that pose a security threat.
An application must have a mechanism to recognize the datagrams of interest and to ignore all others. One common use of raw sockets bind raw socket linux troubleshooting applications that need to examine IP packets and headers in detail. For example, all applications listening for a specific protocol will receive all packets received for this protocol. This may not be what is desired for multiple applications using a protocol.
This is also not suitable for high-performance bind raw socket linux. To get around these issues, it may be required to write a Windows network protocol driver bind raw socket linux driver for the specific network protocol. The network protocol would then be added to the Winsock catalog as a supported protocol. This allows multiple applications to open sockets for this specific protocol and the device driver can keep track of which socket receives specific packets and errors.
In earlier versions of Windows, access for raw sockets is enforced during other socket operations. Other Winsock providers may not support the use of raw sockets. Is this page helpful? Bind raw socket linux appreciate your feedback.
Here, I will argue various topics from program fragments, programming techniques, and modules, and so on. If you find an error, please let me know it. I will fix it. Every time I write a program in C, I am quire tired. I thought it was easier to write one by Python. So I wrote a demo program of raw socket communication. It was not so easy as I expected, but the following program sends and receives an Ethernet packet almost every second.
Whole this article is licensed by Creative Commons, but the program is in public domain; that is, it can be bind raw socket linux without any restriction. It is easy to specify "raw socket", but I actually wanted to write a program that can communicate by promiscuous mode. However, I found it was quite difficult to communicate by promiscuous mode in Python in a normative method. So MAC addresses must be specified in this program.
Packets to be sent contains 0x88b5 as its Ethernet type, and 0x… as its contents. You can easily change them. The above code is for Python 2, but it can be used for Python 3 by modifying only "printPacket". The code for Python 2 is to be commented out and the bind raw socket linux for Python 3 is to be used.
When communicating by Ethernet, the interface name must be specified. This program specifies "eth1", but you can easily rewrite the value of variable "Interface". The usage is as follows.
The file name of the above program is assumed to be "term. Simple unicast communication sending and receiving can be done as follows. Here, the MAC address must be specified. If the bind raw socket linux address is omitted as follows, bind raw socket linux program broadcasts packets. The local address can be omitted too. The above program can be executed by two machines to send and to receive packets each other.
Otherwise, if one machine only receives packets and the other sends and receives packets, a one-way communication can be tested. Such one-way communication is useful for testing Ethernet switch functions. Created on August 5, 8: This page bind raw socket linux a single entry from the blog posted on August 5, 8: Many more can be found on the bind raw socket linux index page or by looking through the archives.
Post a comment Name: Search Search this blog: About This page contains a single entry from the blog posted on August 5, 8: Subscribe bind raw socket linux this blog's feed [ What is this? This weblog is licensed under a Creative Commons License.
Powered by Movable Type 3.