Visit Our UNIX and Linux User Community

Top Forums Programming how to check port binding in pcap receiving program? Post 302343614 by pludi on Thursday 13th of August 2009 04:41:50 AM
Old 08-13-2009
Pcap is a library to capture traffic coming in on a device for any port, not just a single one. It will even capture traffic to a TCP/UDP port that's not even open. This means that it won't bind to any single port, but will watch the traffic at a very low level. If you want to transfer data between two machines, use the OS networking routines (socket/bind/connect/...) instead of Pcap.

9 More Discussions You Might Find Interesting

1. Filesystems, Disks and Memory

Receiving status code 39 when accessing files through program.

I'm working on a project to extract some information from archive file. I ran my program through MFCobol animator and I'm receiving a status code of 39(file not compatible) when opening the file for input. I have tried just about everything, rebuild, convert, etc. but I receive the same message.... (6 Replies)
Discussion started by: bigdawg
6 Replies

2. Shell Programming and Scripting

Check sendmail is not receiving any emails

Hi all, Need some advise again. I am new to sendmail service which is already configured by some other administrators. I would need to write a script to check whether sendmail service is enabled in Solaris and Linux. Using this command "ps -ef | grep sendmail | grep -v grep". Or is there... (6 Replies)
Discussion started by: Kinki
6 Replies

3. IP Networking

i want a UDP Client receiving program

Hi I want a UDP client receiving program. Here is the scenario. The client has to listen to the UDP server and has to acknowledge back on receiving data from the server. Can anyone help me out. regards, Nirmala (1 Reply)
Discussion started by: Nirmala
1 Replies

4. UNIX for Dummies Questions & Answers

How do you check whether a port currently being used?

Hi, Please help me out, how to check whether a port currently being used or not. is there any command which give the result? Thanks Rajesh (6 Replies)
Discussion started by: rajesh08
6 Replies

5. IP Networking

Binding the port number.

Hi all, Application A is using an port number 100 and is binded to an interface 1. Application B is using an port number 100 and is binded to an interface 2. can we bind the two applications on same port number based on interfaces. what i want to know is two... (3 Replies)
Discussion started by: vijaypdp2006
3 Replies

6. IP Networking

Binding the same port number on different interfaces

Hi, We can use the same port number for two applications based on protocols.(i.e one application is based on TCP and the other application based on UDP). But i don't know about interfaces, can anyone one help........ 1) Can we use same port number for different... (0 Replies)
Discussion started by: vijaypdp2006
0 Replies

7. UNIX for Advanced & Expert Users

how to check port already used in pcap pgm

hi, I am writing one packet receiving program using libpcap library. Now, I want to check port is already using or not. how to check in receiver program.. If normal program,using bind return value we can able to check the port is already using or not. but, in pcap program how can i... (1 Reply)
Discussion started by:
1 Replies

8. Shell Programming and Scripting

Program to listen a port

I need to launch a script as soon as a file comes via a specified port on my system from another system. Program should work as a dameon and should invoke only when port start/stop accepting file. Any idea how to program/script it... Please no suggestions for cron. Thanks in advance. (1 Reply)
Discussion started by: sumitwa
1 Replies

9. Solaris

Resolving port number to program name

I was just checking to see if anyone had a script that would allow me to go from port number to program name. I tried to create my own script but it looks like it only works for IPv4 sockets and it looks like daemons such as sshd return as AF_INET6 (in pfiles) for some reason. I can fix my script... (0 Replies)
Discussion started by: thmnetwork
0 Replies
PCAP-SAVEFILE(5)						File Formats Manual						  PCAP-SAVEFILE(5)

pcap-savefile - libpcap savefile format DESCRIPTION
NOTE: applications and libraries should, if possible, use libpcap to read savefiles, rather than having their own code to read savefiles. If, in the future, a new file format is supported by libpcap, applications and libraries using libpcap to read savefiles will be able to read the new format of savefiles, but applications and libraries using their own code to read savefiles will have to be changed to support the new file format. ``Savefiles'' read and written by libpcap and applications using libpcap start with a per-file header. The format of the per-file header is: +------------------------------+ | Magic number | +--------------+---------------+ |Major version | Minor version | +--------------+---------------+ | Time zone offset | +------------------------------+ | Time stamp accuracy | +------------------------------+ | Snapshot length | +------------------------------+ | Link-layer header type | +------------------------------+ All fields in the per-file header are in the byte order of the host writing the file. The first field in the per-file header is a 4-byte magic number, with the value 0xa1b2c3d4. The magic number, when read by a host with the same byte order as the host that wrote the file, will have the value 0xa1b2c3d4, and, when read by a host with the opposite byte order as the host that wrote the file, will have the value 0xd4c3b2a1. That allows software reading the file to determine whether the byte order of the host that wrote the file is the same as the byte order of the host on which the file is being read, and thus whether the values in the per-file and per-packet headers need to be byte- swapped. Following this are: A 2-byte file format major version number; the current version number is 2. A 2-byte file format minor version number; the current version number is 4. A 4-byte time zone offset; this is always 0. A 4-byte number giving the accuracy of time stamps in the file; this is always 0. A 4-byte number giving the "snapshot length" of the capture; packets longer than the snapshot length are truncated to the snapshot length, so that, if the snapshot length is N, only the first N bytes of a packet longer than N bytes will be saved in the capture. a 4-byte number giving the link-layer header type for packets in the capture; see pcap-linktype(7) for the LINKTYPE_ values that can appear in this field. Following the per-file header are zero or more packets; each packet begins with a per-packet header, which is immediately followed by the raw packet data. The format of the per-packet header is: +---------------------------------------+ | Time stamp, seconds value | +---------------------------------------+ | Time stamp, microseconds value | +---------------------------------------+ | Length of captured packet data | +---------------------------------------+ |Un-truncated length of the packet data | +---------------------------------------+ All fields in the per-packet header are in the byte order of the host writing the file. The per-packet header begins with a time stamp giving the approximate time the packet was captured; the time stamp consists of a 4-byte value, giving the time in seconds since January 1, 1970, 00:00:00 UTC, followed by a 4-byte value, giving the time in microseconds since that second. Following that are a 4-byte value giv- ing the number of bytes of captured data that follow the per-packet header and a 4-byte value giving the number of bytes that would have been present had the packet not been truncated by the snapshot length. The two lengths will be equal if the number of bytes of packet data are less than or equal to the snapshot length. SEE ALSO
pcap(3), pcap-linktype(7) 21 October 2008 PCAP-SAVEFILE(5)

Featured Tech Videos

All times are GMT -4. The time now is 01:56 AM.
Unix & Linux Forums Content Copyright 1993-2021. All Rights Reserved.
Privacy Policy