Programming :: C - For System Calls, Is Blocking Or Non-blocking Default?
Mar 23, 2010For system calls, is blocking or non-blocking default in C? Simple question, just am not seeing the answer super quickly.
View 4 Replies
ADVERTISEMENT
Programming :: Blocking And Non Blocking TCP Send/recv?
Dec 25, 2010I have a device that is working on modbus protocol andI have written a small program(with block TCP read method ) to read its registers via modbus protocol.my program is working very well but except those times that I unplug the Ethernet cable or turning off the modbus gateway during programs work.at this time my program stops on recv system call (if it reach this system call exacly when I unplug Ethernet cable or turning off the modbus gateway during programs work).I changed my source to work in nonblock TCP method, at this time with the same situation my program does not stop/block on recv system call but after pluging back the Ethernet cable or resuming the connectivity situation back it reads data incorrectly .this is my code:Quote:
#define DEBUG
#include <fcntl.h>
#include <string.h>
[code]...
Programming :: Real Difference Between System Calls And Normal Function Calls?
Oct 26, 2010What is the real difference between system calls and normal function calls. Ultimately function calls too would be passed to kernel for some or the other work.
View 7 Replies View RelatedProgramming :: Non Blocking Socket Send
Mar 7, 2011Been trying all sorts of different things to implement a non-blocking send on a TCP server socket.As I kill the client, the server keeps blocking on the send no matter what. Am I missing something? Any other way to do that without involving any additional thread?
View 4 Replies View RelatedProgramming :: Temporarily Blocking Or Disconnecting A GTK+ Signal?
May 21, 2010I'm just beginning to program with GTK+, and I'm facing this issue: I want to inhibit a signal emission inside one and only one function. I've down cut my code into the smallest example I can to show you what I want to do:The "Emitter" contains a "GtkSpinBox" and it relays the "value-changed" signal, it's header:
Code:
#ifndef EMITTER_H
#define EMITTER_H
[code]....
Ubuntu :: How To Check Windows 7 For File System Errors Since Grub Is Blocking It
Apr 25, 2010Dual booting Mint 8 and Windows 7. Windows is reporting a file system error. I go into properties and check for errors, but since it's in use it asks me to reboot. I do, and grub comes up. I select windows and it just takes me to windows without checking the file system.
View 1 Replies View RelatedSoftware :: Blocking Socket Vs Non-blocking Socket?
Mar 31, 2010My question is quite simple:What are type of applications where socket in blocking mode can be used ?
And where non-blocking mode to be used ??
TCP is blocking by default.
General :: Run Programs From System Terminal Without Blocking Terminal?
Jun 19, 2010Right now when I start a program from a terminal I can't use that terminal instance again until I close the program.
I am a new user of linux, and I want to know if there is a way to execute a program/application from a terminal without blocking the terminal until the program ends.
Programming :: How To Include Variables In System() Calls
Mar 12, 2010I need to include variables in a system() call. This is that I have:
[code]#include <iostream>
#include <stdio.h>
#include <stdlib.h>
using namespace std;
[Code]....
P.S.: I know this is a pointless redundant program, but it's part of a larger project learning process.
Ubuntu Servers :: SSH Behind NAT Blocking IP Using UFW?
Mar 18, 2011I have a SSH server on Ubuntu 10.04 running behind a NAT. I have done the port-forwarding at the router. However say for example I want to restrict people connecting to the SSH server by country IP's. When I configure ufw with the following rule it still lets the IPs that are restricted through. Any idea why
sudo ufw allow from xxx.xxx.xxx.xxx/24 to any port 2556
Ubuntu :: ISP - Cox - Is Blocking Port 80
Jun 7, 2011My ISP (Cox) is blocking port 80 and I would like to know if there is a way to open it again. I am to taking about 8080, 8000 or 81 I want to use 80 so I can host my website and every one can access it without the need to put [url]:[PORT] at the URL
View 2 Replies View RelatedUbuntu :: Package Seems To Be Blocking Itself?
Jun 8, 2011I'm trying to install libbz2-dev on my labtop.I'm running Kubuntu 10.04.Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming.
View 3 Replies View RelatedServer :: CSF Is Blocking Emails To Be Sent Out
Jan 3, 2011I've a CentOS Box with no control panel.. I used to manage it via SSH. Any way, I've installed CSF/LFD on it.. and it seemed to be working just fine. The only problem I've encountered is that when I start and enable CSF, messages and emails keeps stocked in the mail queue.. I've double checked and made sure needed ports are opined.. But, I still have the problem.
View 2 Replies View RelatedProgramming :: Calling System Calls In C Runtime (in The Run-time)?
Sep 23, 2010I know there is a way to call winapi in runtime in windows. I want to ask how can I call a system call in gcc in runtime (when I don't know what it can be)? I don't mean syscall that I think is for calling only system calls and not library functions.
View 4 Replies View RelatedUbuntu :: Invalid Blocking Factor With Tar
Mar 3, 2010I am trying to backup my system with a script I found here. It gives me an error message of invalid blocking factor for --exclude=lost+found I have no idea what this means. I tried to search this form for that message and received no hits.
View 2 Replies View RelatedUbuntu Security :: How To Check What The UFW Is Blocking
Mar 26, 2010I can see what Firestarter is blocking in the Firestarter/Events tab, but after reading all the man pages of UFW, I still don't know how to check what the UFW is blocking.
View 9 Replies View RelatedUbuntu Security :: Ufw Not Blocking Ports?
Apr 1, 2010After reading a lot about networking and security I decided to check the security of my own ubuntu box. So I went installing Nmap and discovered that port 139 was "open". Since I 'd read how to use ufw I created a deny rule for port 139. After a second scan with Nmap it still said that port 139 was open as shown below.
[Code]...
Ubuntu :: Keyring Error Blocking VNC?
May 11, 2010I'm trying to use VNC on my headless desktop server that's running lucid, but I can only use SSH because a pop asking me to unlock the keyring shows up every time I try to use VNC. I don't have a monitor for that desktop, so I was wondering, is there any way to remove the keyring/to automatically unlock it during autologin? I don't remember what a site I found it on, but I used this to remove my keyring yesterday. It's no longer working today.
View 4 Replies View RelatedUbuntu Installation :: Blocking The Application In 10.04?
May 25, 2010I need assistance blocking application in Ubuntu 10.04. block all applications for certain users if they do not exist in a certain directory.For example,we would like to prevent users from launching a portable copy of Firefox from a portable HDD or Flash drive.
View 1 Replies View RelatedUbuntu Security :: Firestarter Keeps Blocking Ip's?
Mar 8, 2011im having a bit of a problem with Firestarter, i have Transmission opened and i am downloading a movie but when i check Firestarter i see hundreds and hundreds of Ip's that are blocked, and like 10ip's every second that get blocked.
[Code].....
Ubuntu Security :: Ufw Is Blocking Some Port 80 And Should Not?
Apr 15, 2011I have the default to deny all. The only rule I have in there is:
Code:
To Action From
-- ------ ----
[code]....
Ubuntu Security :: UFW Is Blocking Connections Even Though It's Set To Allow For In/Out
Aug 1, 2011I might be misunderstanding the log but it looks like UFW is blocking connections. I want to allow all incoming and outgoing. I guess what I'm saying is that the servers on my computer will open ports but all other ports should respond with closed just like a default Ubuntu install. Trying to use UFW to monitor connections without really doing any firewalling.
Code:
Aug 1 07:14:07 universal-mechanism kernel: [311111.963762] [UFW BLOCK] IN=eth0 OUT= MAC=00:1f:c6:8a:e9:66:00:01:5c:32:f4:c1:08:00 SRC=72.21.203.146 DST=174.44.178.56 LEN=40 TOS=0x00 PREC=0x00 TTL=233 ID=51984 DF PROTO=TCP SPT=80 DPT=54466 WINDOW=8201 RES=0x00 RST URGP=0
Red Hat / Fedora :: Blocking The ICMP Through IPTABLES?
Nov 12, 2009I want to block the icmp packets(ping) from the other computer to my RHEL-4 what's the syntax I should use to do so in IPTABLES.
View 2 Replies View RelatedUbuntu :: Ufw Blocking RST And ACK Packets When Rules Should Allow It
Aug 31, 2010I've setup ufw rules on my system but noticed that the rule i created to allow traffic from my local network is still dropping some RST and ACK packets. here's part of the output of dmesg
[Code]...
Networking :: Blocking Download For LAN Users?
Jul 15, 2010I would like to block downloading for my LAN users through squid or other.
View 2 Replies View RelatedGeneral :: Blocking Outgoing Ssh Using Iptables?
Aug 19, 2009I want to block all the outgoing ssh form my machine, i.e my machine will not be able to ssh to any outside machine using iptables. The distro is RHEL, I added the following entry in the iptables but unfortunately it didnt worked, -A OUTPUT -p tcp -m tcp --dport 22 -j DROP
View 13 Replies View RelatedGeneral :: Blocking The Traffic Using Iptables?
Mar 17, 2010i used the angry ip scan software and found alot of the public ip addresses on our network are accessable from outside when they are not suppose to, For eg printers/ pcs etc. to make a start on locking down the network i was wondering if anybody knew th iptables command to add a rule which blocked all incoming traffic to specific ip adresses on the network and to a range of ip addresses.
View 7 Replies View RelatedSecurity :: Blocking Web Content With Iptables?
Aug 8, 2010Is possible blocking web with content for adults with iptables?
View 3 Replies View RelatedSecurity :: Logging/Blocking LAN Traffic?
Apr 26, 2010Where I work we have a lan, it is almost 100% windows machines except for 2 CentOS machines in which some clients connect to, via VPN. (very small network, <50 ip's used)
I would like to know if there is a way to block access from that machines to others in the network. I'm already logging traffic (with IPTraff) to see if they're accessing other machines in the network others than the ones they should connect.
Security :: Red Hat SeLinux Is Blocking Ssh And Http?
Feb 3, 2011When I turn on my SeLinux to enforcing mode on my Red Hat system ssh stops working and my http server stops responding.
I went into the SeLinux GUI and enabled things in there but still it wont work.
Any thoughts on what to check?
permissive mode and disabled they work
I read several articles that say it should not be affect by SeLinux and the setting look correct but the only thing I do is turn on SeLinux and ssh /httpd stop working
ps -eZ | grep sshd
system_u:system_r:unconfined_t:SystemLow-SystemHigh 432 ? 00:00:00 sshd
system_u:system_r:unconfined_t:SystemLow-SystemHigh 2426 ? 00:00:00 sshd
[root@goxsa1340 ~]# ps -eZ | grep httpd
user_u:system_r:httpd_t 3044 ? 00:00:00 httpd
[Code].....