I am trying to create a socket to listen for a bootp response so I am using a PF_PACKET socket so that I get the response based on my mac. My problem is that I don't want to hear all traffic (as I do now) so would like to use a specific port number and bind to it.
View 1 RepliesI am learning network prgramming in linux in c,and try to build a server and in this server I want to bind the listening socket to a paricular Ip address and port.Bind function is showing error,I did not want to use wild card. Here is the code.
#include<stdio.h>
#include<sys/socket.h>
#include<strings.h>
#include<netinet/in.h>
#include<arpa/inet.h>
#include<string.h>
[Code]...
I am working with simple tcp client to establish connection to sockaddr_in servAddress and send data segment:
...
connect(sockfd,&servAddr,sizeof(servAddr)) < 0)
send(sockfd, pkt, pktLen, 0);
close(sockfd);
...
Elementary... Here's the tricky part: next i have to handle user level ack the server is sending to "client"... To do that i have to open server socket on the same port number the system assigned to my client socket before. How can i get it ( in user level code)?
If I open a raw SCTP socket, am I able to bind to a specific port? (I only want to see SCTP packets from a particular IP address AND port.) Or, any raw SCTP socket, regardless of port binding , will get all SCTP packets received by the OS from that IP address? The port doesn't matter and is ignored.
View 1 Replies View RelatedI'm trying to create a PF_PACKET socket and send a frame to another host, I know the destination's mac address and interface index, and I want to use my own protocol no., so I defined a PROTONO as 0x2323, here's the code of sender
Code:
#define MYPTNO 0x2323
int main(int argc, char **argv)
{
intsockfd;
//struct sockaddr_inservaddr;
struct sockaddr_ll servaddr, bindaddr;
[Code]...
How does bind system call names a socket.Code:bind(server_sockfd, (struct sockaddr *)&server_address, server_len);I see use of bind in majority of programms as above.But any of the arguments is not the name of socket.
View 1 Replies View RelatedHow do I get FTP to use a specific port number? .. I read the manual but cannot work this one out.
View 2 Replies View RelatedI need to search a bunch of files in a specific folder for a specific number and add all the numbers together to a total sum. I use Rsync everyday, everytime I run rsync i get a logfile (rsync output) witch contains the textstring "Total bytes sent: xxxxxx".
The "xxxxx" can vary in lenght. I need to extract the "xxxxxx" from each file and add the numbers together to a total size over a week or a month. Is this possible? And I wish to only use bash. One way of doing stuff at a time my friends .
Is it possible to setup SSH Daemon to listen on multiple ports and only accept specific groups to a given port? In the past I've created a second SSH Daemon by copying the config file and /etc/init.d/ daemon then configuring each port separately / rules however if I was able to maintain just the one Daemon that would be optimal. Is this possible?
View 1 Replies View RelatedIn user mode [non-root] linux machine, tried to bind a socket by using a"ioctl(iInterfaceSocket, SIOCSIFADDR, &stCommand)". I am getting error 13 -> Permission denied because of user mode. If change from usermode to kernel mode everything works fine.I need to bind the socket in user mode only, please suggest solution for the abovewhile explaining the above,
View 2 Replies View RelatedIs it possible to swap a client ip and port ? This is what I am trying to do. Let say you have Comp1 and Comp2 And you have Server between them. My goal is to get Comp1 and Comp2 know each others IP So Comp1 connects to server And server stores comp1's IP In a text file or other place And Comp2 connect to server And server also stores his info And then both comp1 and comp2 dowload the tex file And use the info on it.
View 9 Replies View RelatedI have a customer who is complaining that they can connect to prt y on IP x with telnet. They are seeing the following:
telnet x.x.x.x y
Trying x.x.x.x...
Connected to x.x.x.x.
Escape character is '^]'.
after some time the connection of course times out. Connection closed by foreign host. There is no telnet service running on this port so they cannot do anything, but they are complaining tht the fact that telnet "connects" is a security risk. I am having difficulty explaining why they are able to connect with telnet. I know it has to do with the socket layer API in Linux but I am having difficulty explaining this sufficiently. I also can't just say "this is the way linux works" to them. I am looking through "UNIX Network Programming" by W.
I'm using a single raw socket to read UDP packets from local test network with 1024 ports. Each UDP src and dest port is unique and I need access to IP and UDP header fields. I can stream and process data (in and out) at 100 mbps in linux-rt kernel with very low jitter < 250 usec, 10 usec nominal.
I'd like to prevent kernel from issuing ICMP port unreachable errors back to the sending host, however, I don't want to create 1024 vanilla UDP sockets and bind to each one because of resource constraints. Currently, I'm using iptables to drop the outbound port unreachable messages. Does anyone know of a way (programmatic using C code) to prevent the ICMP unreachable traffic? Perhaps an IOCTL or socket option? I also tried changing /proc/sys/net/ipv4/icmp_ratelimit but that seemed to have no effect. By default the ratemask is set for dest unreachables and a variety of ratelimit values did not change any behavior that I could see.
I would like to parse an input file in which there are two columns per each row. We want to see how many lines are duplicated where we define duplicate to be having the same second field and different first field. For instance if the input file looks like the following:
79874 13131
79873 12309
79820 13131
[code]...
I am going to use "pthread_setaffinity_np" to bind a thread to a specific core. My application has two threads. I have used mutex to assign a specific id to each thread and then bind that thread to a core different from another core. but it seems that the os assigns both thread to one core.What should I do to bind each thread to a specific core?
View 4 Replies View Relatediam just trying to connect to server which accepts one client and server will read(blocking operation) infinitely, but After closing the client socket the server "read operation" is returning zero and "errno variable(in errno.h)" value is also zero. how can i detect whether a client socket is closed/active..?
client.c
Serv_Addr.sin_family = AF_INET;
Serv_Addr.sin_addr.s_addr = inet_addr("127.0.0.1");
Serv_Addr.sin_port = htons(26553);
if( 0 > connect (Serv_Fds,&Serv_Addr,sizeof(Serv_Addr)) )
{
perror("connect");
return 0;
[Code]....
I make an application on GNU/Linux which listening on a MULTICAST stream, so I open my unconnected socket, bind it on a MULTICAST address and a port, join the multicast group with the "setsockopt (IP_ADD_MEMBERSHIP)", then I receive datagram on my socket.
Now I've two different instances of the same application that run with their own MULTICAST address and port. And what I found strange is that, after a misconfiguration, I switch the ports, for example:
Emitting on 225.0.0.1/23451 and 225.0.0.2/23452
Receiving on 225.0.0.1/23452 and 225.0.0.2/23451
And my receiving part doesn't care about the MULTICAST address, it looks like the socket is listening on the port number only! I mean that the receiver [225.0.0.1/23452] take its datagrams from emitter [225.0.0.2/23452] and vice-versa!
I'll explain this in one sentence: Is it possible to program a port-binding shellcode in which people across the Internet can connect to, without being thwarted by the router blocking their data because the port its bound to doesn't allow port-forwarding
View 2 Replies View RelatedI am currently trying to get a B.A.T.M.A.N mesh network up and running. the thing uses UDP port 4305 for broadcasting to nearby nodes and it seems this port is closed or used by something else.
now i have tried to open this port with commands like
Code:
iptables -A INPUT -p udp --dport 4305 -j ACCEPT
iptables -A OUTPUT -p udp --dport 4305 -j ACCEPT
it still gives me the same error saying the socket cannot connect.any way for me to scan that udp port, see what is blocking it and open the thing up ?
i'm writing a simple program of client socket program. Here below is the code sample which i'm writing...
Code:
//tcp_client.c
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include<string.h>
#include<stdlib.h>
[Code].....
the above code works fine.if we copmile and run ./a.exe 192.xx.xx.xxx 1111 and press enter it works fine..everytime it asks "Please enter the message: " and if give that will be displayed in server. but my problem is i dont want to print everytime "Please enter the message: " i just want to feed some words one by one to the socket.
im getting that error in my code for some reason. I compiled my code, and when i try to run this server it throws me an error on my call to setsocketopt(). The only way it can reach that part of my loop is if it succeeds when it calls sock() so I dont understand why the error says its an operation on a non-socket. Im just trying to set up a server to pass messages from a client to it a viceversa. Here is the code:
Code:
int main()
{
int socket_fd, new_socket_fd, k;
struct addrinfo hints, *server_info, *p;
struct sockaddr_storage peer_address;
code....
I'm not that great with mailservers, and just been thrown a curveball with a MS Exchange environment for which there is apparently no solution... yeah, right. But is there a workaround?
The problem is that the site mail (SMTP) needs to be sent via port 26 instead of the commonly used 25. Port 25 is mapped to a mailfilter, which apparently causes havoc with some of the mail, and the techs that have been on site trying to coax the Exchange server to co-operate have said that the only way would be to get rid of the filter.
The problem is that there are number of apps that are unable to have the outgoing port changed and so keep sending mail out on port 25.
I look after the Unix/Linux side of things at work, and I was wondering if there was an easy way to set up a Ubuntu box to receive mail on port 25 and just forward it to the MS box on port 26? So, in other words (and I hope this makes sense): monitor port 25, and forward whatever comes in on port 25 to the server on port 26. Simple portforwarding, or is it? What steps do I need to take?
I am encountering a wierd problem in FC12. When I try to lunch a program that listens to a lower port such as 80 or any one that is less than 1024, I always get "Permission denied" error message (I am running it as root!).Then I try starting httpd service daemon that listens to 80, no errors, the daemon started and listend to 80.PS: I checked selinux, it has been disabled.Do you have any knowledge on this case? BTW, the kernel version is:2.6.31.5-127.fc12.i686.PAE #1 SMP Sat Nov 7 21:25:57 EST 2009 i686 i686 i386 GNU/Linux
View 5 Replies View RelatedI finally got the certs to configure:
openvpn --config server.conf
Tue May 3 17:26:27 2011 OpenVPN 2.1.1 i686-redhat-linux-gnu [SSL] [LZO2] [EPOLL] [PKCS11] built on Jan 5 2010
Tue May 3 17:26:27 2011 NOTE: OpenVPN 2.1 requires '--script-security 2' or higher to call user-defined scripts or executables
Tue May 3 17:26:27 2011 Diffie-Hellman initialized with 1024 bit key
Tue May 3 17:26:27 2011 TLS-Auth MTU parms [ L:1542 D:138 EF:38 EB:0 ET:0 EL:0 ]
Tue May 3 17:26:27 2011 ROUTE default_gateway=192.168.122.1
Tue May 3 17:26:27 2011 TUN/TAP device tun0 opened
Tue May 3 17:26:27 2011 TUN/TAP TX queue length set to 100
Tue May 3 17:26:27 2011 /sbin/ip link set dev tun0 up mtu 1500
Tue May 3 17:26:27 2011 /sbin/ip addr add dev tun0 local 10.8.0.1 peer 10.8.0.2
Tue May 3 17:26:27 2011 /sbin/ip route add 10.8.0.0/24 via 10.8.0.2
Tue May 3 17:26:27 2011 Data Channel MTU parms [ L:1542 D:1450 EF:42 EB:135 ET:0 EL:0 AF:3/1 ]
Tue May 3 17:26:27 2011 Socket Buffers: R=[114688->131072] S=[114688->131072]
Tue May 3 17:26:27 2011 UDPv4 link local (bound): [undef]:1194
Tue May 3 17:26:27 2011 UDPv4 link remote: [undef]
Tue May 3 17:26:27 2011 MULTI: multi_init called, r=256 v=256
Tue May 3 17:26:27 2011 IFCONFIG POOL: base=10.8.0.4 size=62
Tue May 3 17:26:27 2011 IFCONFIG POOL LIST
Tue May 3 17:26:27 2011 Initialization Sequence Completed
But openvpn still won't start; where to go from here.
Tue May 3 17:54:25 2011 TCP/UDP: Socket bind failed on local address 192.168.122.3:1194: Address already in use
Tue May 3 17:54:25 2011 Exiting
I did check the manpath and the files located there.just seems that some pages are missing.
View 8 Replies View RelatedI am created one udp socket. i want to send the data(bytes) to another PC.i need to send 614400 bytes of data. while sending it saying error like" message is too long ". so what is the maximum possible data can i send from a socket?
View 3 Replies View RelatedI want to set my ip as static and port forward it through a specific port can anyone help me with this im using ubuntu 10 with 64 bit OS
View 1 Replies View RelatedDoes anyone know how to measure the traffic (packets per seconds in and out) on a specific TCP socket ?
View 3 Replies View RelatedI have vps box with debian. I have two ip addresses, but first (default) is currently unavailable. In that case there is many problem. Fortunately wget has --bind-address option so I can download. My question is how can i configure apt-get, aptitude to use specific address?
View 1 Replies View RelatedI have the following in my httpd.conf file
Code:
# Listen: Allows you to bind Apache to specific IP addresses and/or
# ports, instead of the default. See also the <VirtualHost>
# directive. Change this to Listen on specific IP addresses as shown below to
# prevent Apache from glomming onto all bound IP addresses.
#Listen 12.34.56.78:80 Listen 80
And when I try to start the server, I get the following
Code:
(98)Address already in use: make_sock: could not bind to address 0.0.0.0:80. I did have an Apache web server up and running about 6 or 7 years ago - but seem to have lost everything