logo
down
shadow

UDP Socket: recvfrom() returns -1 (SOCKET_ERROR)


UDP Socket: recvfrom() returns -1 (SOCKET_ERROR)

By : aszac
Date : November 14 2020, 04:51 PM
seems to work fine Your datagram is too big, or your buffer is too small.
The datagram is larger than your buffer, so it gets trucated, you get an error return from recvfrom and GetLastError() returns 10040, ('WSAEMSGSIZE').
code :


Share : facebook icon twitter icon
why bind() returns SOCKET_ERROR

why bind() returns SOCKET_ERROR


By : Hikaru
Date : March 29 2020, 07:55 AM
it helps some times If that's your real code, you've got the brackets in the wrong place in the bind call. One of the two at the end should be moved to immediately after the "sizeof(sin)".
In other words, change it from:
code :
if(bind(server, (sockaddr *)&sin, sizeof(sin) == SOCKET_ERROR))
if(bind(server, (sockaddr *)&sin, sizeof(sin)) == SOCKET_ERROR)
socket.recvfrom(1024) throws socket.error invalid argument supplied

socket.recvfrom(1024) throws socket.error invalid argument supplied


By : guy lancaster
Date : March 29 2020, 07:55 AM
it fixes the issue UDP datagram communications take place between source and destination ports. You can assign a port with a bind call or let the network stack choose one for you by simply calling one of the send/recv methods. If you call sendto (and you have no bound a port), the stack will assign a number in the dynamic port range. If you call recvfrom, the stack will typically assign port 0. But there is no port 0. What happens next is platform dependent. Windows will attempt to bind you as a promiscuous listener. But that is a privileged call and you will likely get an invalid argument error. But it may work if you are administrator - i'm not sure.
To start a conversation, the first entity to send something needs to know what destination port to use. That means that the entity that receives the first communication needs to bind to a port number that the other side knows about in advance. This could be a well-known port number, a port hardwired into your code, something in a config file or even something advertised with a name service protocol such as LDAP.
code :
import socket

s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.bind(('', 9999))
while 1:
    data, addr = s.recvfrom(8096)
    s.sendto(data, addr)
import socket

s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
for i in range(10):
    s.sendto(str(i), ('', 9999))
    print(s.recvfrom(1024))
recvfrom() returns -1 for RAW socket when used in a thread?

recvfrom() returns -1 for RAW socket when used in a thread?


By : JInhan Yoo
Date : March 29 2020, 07:55 AM
help you fix your problem i want to use multithreading for capturing and processing the IP packets.one thread will only capture and store the packets for say 2 seconds and after that send(using pipe) this chunk to another thread where necessary informations will be extracted. to capture ip packets, am using RAW sockets and recvfrom() but recvfrom() returns -1 for each loop iteration. I think socket is not capturing the packets but i could not find out the reason...any help?? here is the Code... , Your two last arguments here is wrong,
code :
rbytes = recvfrom (Rsock , buffer , 65536 , 0 , &saddr ,(socklen_t *)sizeof saddr);
struct sockaddr_storage saddr; //Or sockaddr_in if you are certain you
                               // only deal with IPv4...
socklen_t slen = sizeof saddr;

rbytes = recvfrom (Rsock , buffer , 65536 , 0 , (struct sockaddr*)&saddr ,&slen);
accept() returns SOCKET_ERROR without connection request

accept() returns SOCKET_ERROR without connection request


By : user2295219
Date : March 29 2020, 07:55 AM
To fix this issue The function accept third parameter addrlen is a pointer. It must point to a valid memory location. Additionally it's an in/out pointer, i.e. a variable. So you must create a variable with a value the is the size of your adrIncomming variable. After return from accept the variable will have the actual length of the address.
This code is more appropriate.
code :
int adrLength = sizeof(adrIncomming);
wsocket = accept(wserver, (struct sockaddr*)&adrIncomming, &adrLength);
Socket.io cdn won't connect and returns a socket.io folder with socket.io.js script that returns an html file in console

Socket.io cdn won't connect and returns a socket.io folder with socket.io.js script that returns an html file in console


By : user3729177
Date : March 29 2020, 07:55 AM
wish of those help Your analysis is correct. The link to script is wrong.
Here's Socket.io's link: https://cdnjs.cloudflare.com/ajax/libs/socket.io/2.3.0/socket.io.js
Related Posts Related Posts :
  • Why does C# also not allow empty conditions in while loops?
  • Unable to get a block of code into my regex match groups
  • What is difference between dbcontext.Add and dbcontext.AddObject
  • How do I update the file version number of C# DLL without recompiling?
  • Value for html control always null
  • HttpClient hangs when timeout is setting (Windows Phone)
  • Handle Multiple Form tag in asp.net page?
  • create word document with html content in c#
  • Confusion about Find And Replace
  • Format sms messages in Clickatell
  • Automated Function Overload
  • String to date in MS Access SQL statement gives type mismatch error
  • ShowDialog exiting on certain events
  • Is there a try Convert.ToInt32... avoiding exceptions
  • How to move wpf application into minimize tray at Window Start-up C#?
  • How to change display format of long variable?
  • How to use Addfields in MongoDB C# Aggregation Pipeline
  • MsTest TestCleanup method not called when an unhandled exception is thrown
  • missing last data when exporting gridview to excel
  • How to add array of objects to List in c#
  • Lambda Expression to order (sort) my list collection
  • Library for displaying music notation
  • How to compare two dictionaries in c# and get the output as True and False after validation
  • specify fields to be serialized with JSON
  • How do you obtain the content of a specific node using XmlDocument in C#?
  • How to ignore the first line in a csv file when you read the csv file in C#
  • c# - Problem calling public void from class
  • How to tell a class which objects it should create? Type vs. object confusion :(
  • Save CheckBox state to xml
  • WIX CAQuietExec NETSH Command Fails
  • Issues sending http put request every 60 seconds to RoR app
  • ConfigurationManager.ConnectionStrings.ConnectionString Issue
  • Real size WPF controls for printing
  • How to cancel properly?
  • C# String multiplication error
  • Using Solrnet and Assigning Attributes with Entity Framework Generated POCOs
  • Regex pattern for single backslash
  • TextBox: insert spaces for credit card number?
  • C# DLL loaded for exe-application is not found when launching similar DLL by rundll32.exe
  • Debug a Windows Service with WCF library
  • Open a file from an external assembly?
  • Servicestack RegistrationFeature Unable to bind request
  • Index was outside the bounds of the array confusion
  • Error in Xml to List code. The ':' character, hexadecimal value 0x3A, cannot be included in a name
  • I am trying to do a while loop with a string conditional statement in C#
  • C# 'Cannot access a disposed object. Object name: 'SslStream'.'
  • How to make Gecko use seperate CookieContainer per instance?
  • C# Advanced form "please wait"
  • Send and Receive data C# using network stream
  • How to discover that appsettings changed in C#?
  • Check what needs full trust
  • What is the execution order of an MVC Razor view/layout
  • Table designer (Entity Framework) is too resource intense
  • How to clean up an exception string so it can be displayed via Javascript Alert?
  • Configuring Amazon SES Feedback Notifications via Amazon SNS in ASP.NET MVC (C#)
  • C# api responce and request
  • Dynamodb putitem function not working properly
  • theme in windows phone(light or dark) using c#
  • Backup attached database file(.mdf) using c# and SQL Server
  • What is 'TextFile' and where it is uses in WPF project
  • shadow
    Privacy Policy - Terms - Contact Us © ourworld-yourmove.org