is a data communications endpoint for exchanging data between processes executing within the same host operating system.

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0answers
24 views

What does the “ss -s” result “Total:” value represent? How to get details on each of them?

I am trying to understand what the ss -s result line Total: value represents, along with how this number is related to the other numbers. Note, the following values are equivalent: ss -s Total: == ...
3
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2answers
58 views

Distinguish TCP server from client within netstat output

I have a socket connection between a client process and a server process, both running on my machine. There are two entries shown for the connection as, sudo netstat -ntp | grep 56442 tcp 1 ...
0
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1answer
32 views

Is the return value “-1” of the function socket close() method possible?

Under which circumstances is it possible to produce a return value of -1 when closing a network socket using it's close(int fildesc) method? I suppose it is possible with an invalid fildesc number, ...
-1
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2answers
116 views

Free or cheap shell (i.e., platform) to run a Linux C program with root privileges (raw socket)

I'm working on a Linux C program that needs root privileges (raw socket). I would like to run it on a host located in the US (I am in EU) to compare results. Is there any free (or cheap) shell ...
9
votes
1answer
111 views

Does Linux automatically clean up abstract domain sockets?

There's a great answer on StackOverflow about providing a better lock for daemons (synthesized from here) that doesn't depend on the common PID file lock mechanism for daemons. There are lots of good ...
0
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1answer
38 views

Path to unix socket

I'm using p0f to fingerprint network OSs from traffic captures. p0f has a feature allowing it to be set up as a daemon and listen in the background for a connection from a p0f-client (ie: ...
-1
votes
1answer
16 views

Need to write an automated web navigator with “click” and “retrieve” capabilities

In our company, several clients provide the detailed information information that we need in a web site. The amount of time that our employees spend navigating the remote website is simply ridiculous, ...
0
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1answer
64 views

Finding out the number of dropped packets in raw sockets

I am developing a program that sniffs network packets using a raw socket (AF_PACKET, SOCK_RAW) and processes them in some way. I am not sure whether my program runs fast enough and succeeds to ...
0
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1answer
60 views

Who opened a file descriptor? (socket)

I am using strace to track a program. In this line: recvfrom(7, "\0\260R\0\0\1\364\6\215\r\257\330\210\341\0\270\240\0\260R\0\0\0\0\0\0\0\0\0\0\0\0"..., 3000, 0, {sa_family=AF_PACKET, proto=0x88e1, ...
4
votes
2answers
101 views

What does an @ symbol denotes in the beginning of a unix domain socket path in Linux?

When I run netstat --protocol unix or lsof -U I see that some unix socket paths are prepended with @ symbol, for example, @/tmp/dbus-qj8V39Yrpa. Then when I run ls -l /tmp I don't see file named ...
1
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0answers
69 views

How to know file name of sockets or pipes in /proc/[pid]/fd

In Android, #ls -l 15843/fd gives following output, lrwx------ u0_a179 u0_a179 2015-05-28 11:58 90 -> socket:[193728] lrwx------ u0_a179 u0_a179 2015-05-28 11:58 91 -> ...
0
votes
1answer
83 views

Forwarding a udp socket connection to a range of ip addresses

I have a program which is a udp socket client. I can determine an IP adress to which this program should send. Unfortunately, I configured the computer as Access Point and don't know the address of ...
2
votes
1answer
45 views

using a pty like a socket?

I'm writing a collection of scripts to talk to an external program. My problem is that the scripts are only "alive" for a short time (triggered by a keypress in a larger program) but the external ...
2
votes
0answers
95 views

What does an inode for a socket contain?

I read somewhere that the inode for a TCP socket would contain the buffer space. Is that true, and if so, does it mean that the inode contains a memory address for the buffer space used by the ...
3
votes
0answers
89 views

Scripted write-then-read from Unix domain socket using socat

I have a simple server listening on a Unix domain socket (on a CentOS box in case that's important). When I send the command "DATE" to the socket it writes back a welcome message and then "APRIL 15 ...
1
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1answer
56 views

how do applications communicate via sockets

On my computer audio works sometimes and sometimes not. I want to troubleshoot this. First I verified I am using pulseaudio. I did this by strace'ing the pulseaudio process: [pid 2289] send(28, ...
1
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1answer
76 views

Is it possible to establish a Socket session (between Server and Client) using shell commands ?

From what I read (only the very outline, i do not know C Language) a Socket session is established between a server and a client by calling functions for both of them in a certain order. It starts ...
12
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0answers
785 views

What is the purpose of sockets in layman terms? [duplicate]

I met several times the term "socket", so I looked it up on different sites, but each of them required too much knowledge in order to understand the explanation. What I read were things like: ...
1
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1answer
2k views

Installing vsftpd - 500 OOPS: could not bind listening IPv4 socket?

I have to set up a FTP server on my machine. I have installed vsftpd using the command: sudo apt-get install vsftpd I then edited the configuration file vsftpd.conf in the location /etc. The file ...
1
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1answer
15 views

What setsockopts() 'name' values are used by the running Linux kernel?

I am introducing some new socket commands with nf_register_sockopt(&my_new_socket_options). How can I find, what setsockopt commands are already used (registered?) by the currently running kernel, ...
3
votes
1answer
332 views

cannot start chrome browser - bind failed: Permission denied

I am using grsecurity kernel with CONFIG_GRKERNSEC_SOCKET_SERVER enabled: [*] Socket restrictions [ ] Deny any sockets to group (NEW) [ ] Deny client sockets to group (NEW) [*] Deny ...
2
votes
1answer
133 views

How to report receive queue size for AF_UNIX sockets

netstat -a reports Recv-Q (amount of unread data pending for a reading application) for AF_INET sockets, but not AF_UNIX sockets (at least not for SOCK_DGRAM). Does anybody know a way to obtain this ...
1
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1answer
156 views

ss is replacing netstat, how can I get it to list ports similarly to what I am used to?

I've been trying to modernise my way with Linux by, for one thing, ditching netstat for ss. I looked up my favourite command line flag for netstat in the ss man pages, and was very glad to find that ...
0
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1answer
351 views

Opening a socket in Kali Linux using bash scripts

I know how to open a TCP or UDP socket in Ubuntu, with the following command : exec 3<>/dev/tcp/google.com/80 for example: we can open a TCP socket on port 80, but in Kali Linux there's no ...
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0answers
137 views

linux + what are the messages bad tty under /var/log/messages file

under /var/log/messages I see the following messages "bad tty" what the meaning of these messages? second is it caused because some application that called - owstd ? as we can see from the log? ...
2
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0answers
29 views

Placing OpenSSH control socket in /run

OpenSSH has a feature that allows you to multiplex connections over a controlsocket. It is generally accepted that these control sockets should not reside in a common area, due to the security issues ...
0
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2answers
196 views

Runs perfectly through the command line, will not work through systemd ExecStart

I've installed Butterfly http terminal server, written in python, on my Arch machine. I'm new to systemd, but I'm having an issue with one of the command line parameters. /usr/bin/butterfly.server.py ...
2
votes
1answer
256 views

Connect through different interfaces to the same server (SO_BINDTODEVICE): Destination Host Unreachable

I have 2 interfaces: eth0 and wlan0, each one connected to a different router. Their network specs are these: eth0: ip: 192.168.1.7 Gateway: 192.168.1.1 Submask: 255.255.255.0 wlan0: ...
1
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0answers
128 views

/private/var socket not created with postfix/dovecot sasl

I'm currently running into a problem I have with my email server. I try to setup Postfix and Dovecot with SASL authentication but I get the following error when I connect with telnet (port 25) to the ...
7
votes
1answer
373 views

How does moving a unix domain socket enable socat to monitor traffic?

socat can be used to monitor traffic across a Unix domain socket: sudo mv /path/to/sock /path/to/sock.original sudo socat -t100 -x -v UNIX-LISTEN:/path/to/sock,mode=777,reuseaddr,fork ...
1
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0answers
54 views

Which Privileges Should Assign For Create Raw Sockets

I want to run an ICMP command to ping an IP Adress at Java: InetAddress.getByAddress("XXX.XXX.XXX.XXX".getBytes()).isReachable(1000); However there is a security restriction that: Normal users are ...
0
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0answers
59 views

how to fix a port no statically for client request on client side?

I have an assignment to implement: unicast multicast broadcast in Java socket programming. While implementing the multicast part I decided to do it on my own system itself, so for the purpose of ...
19
votes
4answers
1k views

Are Unix Internet sockets files?

I understand that "Everything is a file" is one of the major concepts of Unix, but sockets use different APIs that are provided by the kernel (like socket, sendto, recv, etc.), not like normal file ...
2
votes
3answers
463 views

Nginx leaves old socket

I'm running Nginx 1.6.2 (the nginx-full package from the nginx/stable PPA). I'm using the unmodified configuration /etc/nginx/nginx.conf: user www-data; worker_processes 4; pid /run/nginx.pid; ...
1
vote
1answer
20 views

How to apply a parameter to packet so TC can prioritize\classify it

I want to add a parameter to the packet so that I can later let TC (HTB in specific) prioritize my packet (based on filtering that parameter). I thought about filtering by socket but as I understand ...
2
votes
1answer
286 views

Advantages of using named pipes and sockets rather than temporary files

I have two cooperating programs. One program just writes its output to a file and the other one then reads from the file and spits the data out for the front end to work with. I have been reading ...
0
votes
0answers
131 views

Stopping syslogd also closes /dev/log UNIX domain socket

I am working on a project and from some testing I found out that stopping syslogd daemon also closes /dev/log socket. Is there some other way so that even if syslogd is down, /dev/log socket still ...
2
votes
0answers
133 views

Emulate console by sending data on one UDP port, and receive text from another

Note: I also posted this question on SuperUser, because I'm not sure where it belongs I'm trying to establish a "console-like" connection with a National Instruments cRIO-FRC. It broadcasts its ...
16
votes
3answers
4k views

Why are TCP/IP sockets considered “open files”?

I need some assistance grasping what I'm sure is a fundamental concept in Linux: the limit for open files. Specifically, I'm confused on why open sockets can count towards the total number of "open ...
1
vote
1answer
156 views

ip forwarding to remotely connect to a socket listening to localhost only?

I must transfer data from PC1 to PC2 using a specific port, but the socket opened on PC2 only listens to local host. Is there a way to "trick" the socket into accepting the connection from PC1?
1
vote
3answers
166 views

Server running on guest Linux VM will not accept connections from Windows host

I have a simple echo server program running on CentOS 7. If I run both the client and the server in the VM, I can connect to the server. I'm using VirtualBox with the "bridged" network configuration. ...
0
votes
1answer
200 views

Archlinux ARM Apache server fails to start

I am currently setting up an Apache web server on my Pi running on Archlinux ARM. After installing and making the first small configurations I have tested it and it works. Then I stop the server and ...
1
vote
0answers
85 views

Why was n't kqueue socket polling mechanism not implemented in Linux?

Linux has epoll for socket polling mechanism. kqueue seems to be better than epoll. Why did linux went with epoll rather than kqueue? I read about libkqueue. But that is implemented in user space and ...
2
votes
0answers
375 views

X11 bad access at first try but working on successive tries

I use the following setup to forward X11 output from my local machine to the server. I will outline the setup: X11 server and the client are on the same local machine. The X11 server runs on my ...
0
votes
1answer
98 views

What are the differences between socket polling mechanisms of kqueue and epolling?

kqueue socket polling mechanism is used in FreeBSD and epolling in Linux. I would like to know what are the differences between the two mechanisms?
1
vote
3answers
417 views

nc not waiting for server disconnect on OS X

How to make nc client on OS X Mavericks keep socket open and read data until server disconnects the socket? I want to send data to a server through nc and then use the response. Problem is that nc ...
2
votes
1answer
99 views

Is there a system call to bind a file descriptor directly into another?

A read() & write() loop would probably be as good as what I'm looking for, but nevertheless is anything like that around or is it impossible because of an obstacle I didn't envisage ? I'm curious
0
votes
0answers
159 views

closing socket after forcing terminal close

I'm running Bluetooth socket server, this server is listening to incoming connection. but I forced the terminal close ctrl + Z . after that the server is not listeing any more and show me the output ...
3
votes
1answer
88 views

Can close() block?

For example, if you close a pipe or socket that still has data in its write buffer that hasn't been read by the process on the other end, does close() block until the data is read or the other process ...
0
votes
1answer
101 views

A script to identify whether a file descriptor has gone bad

Problem : I have a server program running which connects to a remote program using TCP sockets. There many of them (say 20). My problem is one of the socket descriptor has gone bad and has recieved ...