I'm sniffing network packets in ubuntu, I need to write these packets as raw bytes to memory but libpcap give packets in its special format. how can i save and recover packets in byte format?
View 2 Repliesi need to write a program in c that can sniff packets from Ethernet and distinguish RTP packets from Non-RTP packets, i have no idea what should i do
View 9 Replies View RelatedI am trying dump some packets using tcpdump and it does not seem to be working.
System is fedora12
TCPDUMP v4.1
Libpcap v1.0
I even rolled my own,
TCPDUMP v4.1.1
libpcap v1.1.1
As 2.17
I want to code this:
and byte[45],03
In words, AND the byte at memory location 45 with immediate value 03. As reports "Ambiguous operand size for and". How could I code the instruction such that as understands my intention?
john: .byte 45
and byte[john],03
gives the same error.
i play around with c for producing some io to a san-disk and struggle with basics here. :-(
if i'm using the write()-call to write 1 byte to a file on the disk iostat tells me i'm producing 3 writes. if i write 1 byte twice a second, it tells me i produce 6 writes (w/s).
I got across a peculiar problem with memcpy.History:writing a code which do flash/Read functionality for SPI Parts.
Implementation:
1.memory map the Flash chip registers to userspace. - fine
2.Issue block read command
3.Just print the data I got, using the memory mapped address - fine I got the correct data.
4.Copy the data to a local buffer from memory mapped address using memcpy - FAIL
UPDATE:
on SUSE 11.3 -32 bit the above code worked perfectly, but on SUSE 11.4 - 64bit , Ubantu, Fedora it failed.
I am using gcc compiler obviously. I am using i386/x86_64 OS. Processor: Intel core 2 duo, SNB after step 4 , when I dump the data from local buffer every thing is FF.But step 4, if i implement byte by byte copy using assignment operator, it worked.is there any known bug with memcpy? am I missing anything?
I am not a networking expert by any means (in fact I have never taken a networking course), but I have taken several security courses, and generally we wind up discussing replay attacks. For example, the Needham-Schroeder protocol (using symmetric-key cryptography anyway) is flawed because it allows for replay attacks, and I understand why.
I guess my question is actually how someone would perform a replay attack. I know I can sniff network traffic by downloading wireshark. I also have downloaded winpcap and npg on my WinXP virtual machine. I'm trying to use this guide to help me, but I'm quite lost:[URL]What I did was to post a "link" to my facebook profile and I sniffed the traffic using wireshark. What I would ultimately like to accomplish is to copy that packet out of the wireshark output, and then use a tool like npg to transfer the raw packet back to facebook, which should result in a second, redundant post. I just can't figure out how to do that.
I'm pretty sure this should be possible. Facebook only uses an SSL session for authentication during login. After that, the information is just sent in the clear, so I'm pretty sure this should be possible.Can anyone explain how to do such a thing? It would really help my research paper that I'm working on this semester if you can. As of right now the attack we are trying to demonstrate/defend against is using a Windows VM, which is why I'm using winpcap/npg. The attack is actually possible using just about any OS (depending on the exploit used), but our POC is Windows only at the moment
I'm using madwifi linux driver (ath1) in monitor mode to capture some wireless traffic. I can see that all wireless traffic is coming well through the wireless interface (checked using TCPDUMP). What I want to know is how I can forward the captured wireless packets to a different Ethernet interface (e.g. eth2) in the same machine to send those captured packet out to a different computer.
I set 1 for /proc/sys/net/ipv4/ip_forward
for iptables, I tried this rule: iptables -A FORWARD -i ath1 -o eth2 -j ACCEPT
However, I coudn't read any packet from eth2 via TCPDUMP.
I am running into trouble while trying to set-up a iptables routing policy. I have two machines on the same sub-network (xxx.xxx.153.0). One of the machines is used as a default gw for the other (xxx.xxx.153.250 is a gateway for xxx.xxx.153.142 and xxx.xxx.153.254 is a gw for xxx.xxx.153.250). There is no explanation for why the xxx.xxx.153.250 is in the middle -- xxx.xxx.153.142 can go straight to xxx.xxx.153.254, but is is like that for now.I am trying to find an iptable rule to be executed on the xxx.xxx.153.250 machine to route the packets.
View 3 Replies View RelatedHow do I write a script for my Linux that can show me total memory vs used memory and have it email me results if it's over 70 percent?
View 2 Replies View Relatedi have a linux server runnig oracle applications. i need to access this server from putty using ssh through internet. i did by registering my static ip with the dnydns.org and i am able to connect to the server. but now there is no security to authenticate any user as any one knowing the password can login to it.
i thought of configuring the firewall of linux server but the client ip`s are not static and they change continiously. so thought of keeping one more pc between the server and the router which will do the work of authenticating. but i am confuse as how to configure it to allow the packets coming from the internet after authenticating and to by pass the packets generated from internal LAN?
I am getting a new 4kb sector HDD for my laptop, WD scorpio black 750gb, I would like to image existing partitions on 512bytes sector HDD and move them to the new 4kb sector HDD, what's the best way to do this.
present config is as follows:
Disk /dev/sda: 80.0 GB, 80026361856 bytes
255 heads, 63 sectors/track, 9729 cylinders, total 156301488 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
[Code].....
I am planning to keep the same three partitions as the primary partitions on the new drive and add few more logical partitions. I would have liked to move to GPT but since I need Win 7, I am stuck with MBR partiotion table.
Now, I understand how to partition an Advanced format disk, what I want to know is how to move the existing partitions on the 80 Gb disk to the new disk?
I use Clonezilla to copy partitions but it is not compatible unless both the target and the source disks are already using 4096 sector size.
I can use Acronis True Image WD Edition to clone Win 7 but how do I clone Ubuntu?
Also my Laptop's chipset is limited to SATA 1.5, will it cause any issues, I know the bandwidth is not an issue.
I have a system running 11.04 and it is dropping packets on the hardwired ethernet interface to other systems on the LAN, only in the inbound direction. It drops packets every 5 seconds. I verified this with iperf. Outbound packets pass with no problems. The network card in this system is a Broadcom Corporation NetXtreme BCM5752
View 9 Replies View RelatedJust wanted input for this script i have cobbeled together. Its not done yet. I am trying to think of ways to close up my outgoing while maintaining full functionality of my laptop ( irc, web stuff, a torrent or two, etc.) . Anyways, I have done some myself; as well as, pulling bits and pieces from other stuff out on the web. I am starting to wonder why i have to write a specific rule to check for spoofed packets if my default input is set top drop. wouldnt it be caught?
Code:
#!/bin/bash
### Laptop + Desktop: No Forwarding firewall ip4 / ip6
### Distro > Debian / Ubuntu.
### oliverteasley@gmail.com
[Code]....
I am trying to format 4 GB sd memory using mkfs.vfat. I want to use the card both in linux and windows so I am formatting with Vfat filesystem. When I format the card from command line with "mkfs.vfat -F 32 /dev/mmcblk1" I am getting a warning message like "unable to get drive geometry, using default 255/63" but the data in the card is erased.
But when I mount the card and checks for the size using df -h its showing 1 GB instead of 4 GB. how to format the SD memory card or any other alternate way to format the card.
When I try to format my memory stick (using disk manager) , i get a error message saying "device busy", how can I stop the memory stick so I can format it?
View 5 Replies View RelatedI know this is going to sound stupid, but I have a few 2gb CompactFlash memory cards that I bought to use with my FujiS7000 digital camera. Only problem is that that camera will only read/write to 1gb memory cards. I don't suppose there's any way to format these 2gb cards so that the camera sees them as 1gb cards?
View 6 Replies View RelatedI have a hardware device with two ethernet ports, eth0 and eth1 running Centos 5. Basically my goal is to forward packets from eth0->eth1 and eth1->eth0 as well as get a copy of these packets for analysis. If I set IP routing to do the forwarding then I won't get a copy of the packets for analysis.
View 3 Replies View RelatedI have a 8GB USB drive that recently started to behave improperly. And by started I mean that my dad decided he'd use itke a bootable drive and succeeded in breaking it.I tried formatting and zeroing the drive with dd but no luck. It seems to finish normally, but everything remains the same. Then I read a similar thread here that worked for one guy and tried working it that way but again could not manage it. It using sfdisk and the negative result might have been because I hadn't used it before so didn't know exactly what I was doing.
Anyway, the situation is absolutely the same: cannot format/erase partition, cannot format/erase/write data, errors are spewed out like -Error creating partition table: helper exited with exit code 1: Error calling fsync(2) on /dev/sdb: Input/output errorOR Error creating partition table: helper exited with exit code 1: Error calling fsync(2) on /dev/sdb:
What I am trying to do is reasonably simple, I have 1 Ubuntu Desktop PC and 2 Ubuntu Laptops that are all connected via wireless network (remote desktop works perfect so no network issues)All I want to do is utilise the huge drive space on the desktop machine as a kind of fileshare for the two laptops so backups and music/photo sync can be done.
I have managed to do this using Samba in that from the laptops I can write files in Nautilus to the fileshare BUT the files have no owner, no group, and no permissions, this is the if I view from the client or server side.
IE I can navigate on the laptop to the shared are by the URL...in Nautilus right click and add a blank document and call it say "test".If I now have a look at the permissions it says "The permissions of test could not be determined"
My flash memory does not okI can`t make format , capy or delet any file how can i format it
View 2 Replies View RelatedAt present I have to live with a 5Gb/month data volume limitation. Due to having to monitor this usage, I have been forced to use the software that came with the web dongle - and that means having to use Windows (spit!)
Can anyone recommend a Linux package I could download that readily shows how much data one has uploaded/downloaded over a set period?
I have to get soem statistic about interfaces from /proc/net/dev. but statistic on this file is reset when get reach more than 4G byte.I think linux has limitation on this case.
View 1 Replies View Relatedhow to format flash drives in ubuntu. In windows there was a "format" on the right click menu but I did not find one in ubuntu. i am using ubuntu jaunty.
View 4 Replies View RelatedI am trying to format 4 GB sd memory using mkfs.vfat. I want to use the card both in linux and windows so I am formatting with Vfat filesystem. When I format the card from command line with "mkfs.vfat -F 32 /dev/mmcblk1" I am getting a warning message like
"unable to get drive geometry, using default 255/63" but the data in the card is erased.
But when I mount the card and checks for the size using df -h its showing 1 GB instead of 4 GB. how to format the SD memory card or any other alternate way to format the card.
Using places>networking. Tried to drag files from windows to ubunto: works ok
Tries to drag from ubunto to windows, getting there was an error copying the file to smb://<computer name>/<folder name>/permission denied
Ubuntu 10.04, Windows Vista home premium
How to write a value to a specific memory location in C language and how to access the same value ?
I am trying the same on fedora linux and i am trying to write the value to the 32-bit address.
I have encountered this problem of memory usage is increasing as the during the my program is being run until 1Mb is left then it stays at that.A part of the program is this:
Code:
#define WRITE_BUF_SIZE (1024*1024)
void post_data(const void *data, unsigned long size)
[code]....
I have a flash drive that is write protected and in RAW format(so not formatted). I've tried everything I can find to make it usable again in Windows but I ran out of options. I quickly found about the Gnome Partition Editor, but when I try to start it, it gets an icon in the taskbar that says "Starting GParted" and then it closes. Is some other way I can format my flash drive or do I need to find out why gparted isn't running?
View 6 Replies View RelatedI am new to linux at driver level. I want to read/write at specified memory location in microSD card in linux. I do not want to used SD card with any file system. How to do that. My linux distribution is Fedora13.
View 3 Replies View Related