reading partially from sockets

Posted by nomad.alien on Stack Overflow See other posts from Stack Overflow or by nomad.alien
Published on 2010-06-18T11:30:13Z Indexed on 2010/06/18 11:33 UTC
Read the original article Hit count: 184

Filed under:

sockets

|

udp

|

reading

I'm having a little test program that sends a lot of udp packets between client->server->client (ping/pong test). The packets are fixed size on each run(last run is max allowable size of udp packet) I'm filling the packets with random data except for the beginning of each packet that contains the packet number. So I'm only interested to see if I receive all the packets back at the client.

I'm using sendto() and recvfrom() and I only read the sizeof(packet_number) (which in this case is an int). What happens to the rest of the data? Does it end up in fairyland (gets discarded)? or does the new packet that arrives gets appended to this "old" data?

(using linux)

© Stack Overflow or respective owner

Related posts about sockets

Performance implications of Synchronous Sockets vs Asynchronous Sockets

as seen on Stack Overflow - Search for 'Stack Overflow'
We are trying to build an SMTP Server to receive mail notifications from various clients over internet. As each of the communication will be longer and it needs to log everything, doing this Asynchronous way is little challenging as well as by using Socket's Asynchronous methods we are not sure of… >>> More
Multiple INET sockets (mulple IP's too) connected to UNIX sockets

as seen on Server Fault - Search for 'Server Fault'
HOST = same host all the time, accepts multiple connection. I have a dedicated server and I will buy extra IP's. Socket 1 connects to HOST:PORT, from IP-1 Socket 2 connects to HOST:PORT, from IP-1 Socket 3 connects to HOST:PORT, from IP-1 Socket 4 connects to HOST:PORT, from IP-2 Socket 5 connects… >>> More
Multiple INET sockets (mulple IP's too) connected to UNIX sockets

as seen on Stack Overflow - Search for 'Stack Overflow'
HOST = same host all the time, accepts multiple connection. I have a dedicated server and I will buy extra IP's. Socket 1 connects to HOST:PORT, from IP-1 Socket 2 connects to HOST:PORT, from IP-1 Socket 3 connects to HOST:PORT, from IP-1 Socket 4 connects to HOST:PORT, from IP-2 Socket 5 connects… >>> More
Do WebSockets have exclusive access to their sockets?

as seen on Stack Overflow - Search for 'Stack Overflow'
I'm curious to know if, after a WebSocket has been established (after having received the proper handshake from a server that supports them), whether or not the TCP socket used by the "WebSocket connection" is used exclusively by the WebSocket, or if the browser may still make regular HTTP requests… >>> More
What Parallel computing APIs make good use of sockets?

as seen on Stack Overflow - Search for 'Stack Overflow'
My program uses sockets, what Parallel computing APIs could I use that would help me without obligating me to go from sockets to anything else? When we are on a cluster with a special, non-socket infrastructure system this API would emulate something like sockets but using that infrastructure (so… >>> More

Related posts about udp

Forwarding udp ports iptables packets "lost"?

as seen on Server Fault - Search for 'Server Fault'
I have a Linux router (Debian 6.x) where i forward some ports to internal services. Some tcp ports (like 80, 22...) are OK. I have one Application listening on port 54277udp. No return is coming from this app, i only get Data on this port. Router: cat /proc/sys/net/ipv4/conf/all/rp_filter = 1 cat… >>> More
Why can blocked IPs get through my iptables? What's wrong with this configuration?

as seen on Server Fault - Search for 'Server Fault'
(Why can/How are) blocked IPs (get/getting) through my iptables? Hello and thanks for your consideration... I have configured iptables and included (below) output from the command "iptables --line-numbers -n -L" yet IP addresses (like 31.41.219.180) from IP blocks I have already blocked are getting… >>> More
iptables rules keep showing up

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I just installed an ubuntu precise server, after a few weird communications issues I checked the iptables list and found: Chain INPUT (policy DROP) target prot opt source destination ACCEPT all -- anywhere anywhere ACCEPT all -- anywhere… >>> More
if I put accept all 0.0.0.0/0 means this server is totally open for any ip ?

as seen on Server Fault - Search for 'Server Fault'
ACCEPT all -- 0.0.0.0/0 0.0.0.0/0 is this means allow all ip from all port? but I still can not visit the server except I go through the allowed ip address and if I put this line in any line, did I make this server totally open for any connection? the full iptable list is below Chain… >>> More
Is there a way to receive receive data as unsugned char over UDP on QT

as seen on Stack Overflow - Search for 'Stack Overflow'
I need to send floating point numbers using UDP connection to a QT application. Now in QT the only function available is qint64 readDatagram ( char * data, qint64 maxSize, QHostAddress * address = 0, quint16 * port = 0 ) which accepts data in the form of signed character buffer. I can convert… >>> More