| All Forums |
Register |
Login |
Search |
Subscriptions |
My Profile |
Inbox |
| Tool Warehouse |
FAQs |
Resources |
Help |
Member List |
Address Book |
Logout |
|
|
ioctl does not work
|
Logged in as: Guest |
| Users viewing this topic: none |
|
Login  |
|
|
 ioctl does not work - Jun. 26, '06, 4:38:00 AM
|
|
|
shailishi
Posts: 15
Joined: Jan. 6, '06,
Status: offline
|
ioctl call does not give correct information about the data available on socket read buffer Interix. Is there any other call that can be used for obtaining information about the bytes available in socket buffer to read and how this can be used? Thanks
|
|
|
|
|
RE: ioctl does not work - Jun. 26, '06, 11:49:59 AM
|
|
|
Rodney
Posts: 3695
Joined: Jul. 9, '02,
From: /Tools lab
Status: offline
|
Which ioctl request? It helps if you name it.
|
|
|
|
|
RE: ioctl does not work - Jun. 26, '06, 11:57:28 AM
|
|
|
shailishi
Posts: 15
Joined: Jan. 6, '06,
Status: offline
|
Thanks for reply.
it is FIONREAD request for socket (to read available bytes on socket buffer).
Thanks,
|
|
|
|
|
RE: ioctl does not work - Jun. 26, '06, 2:45:00 PM
|
|
|
Rodney
Posts: 3695
Joined: Jul. 9, '02,
From: /Tools lab
Status: offline
|
FIONREAD is the only ioctl request for seeing what's available (in bytes) to read.
This request applies to other types of file descriptors besides sockets.
It's difficult of this request to mess up since it only sets a value (bytes available).
Why do you think it is not working?
|
|
|
|
|
RE: ioctl does not work - Jun. 27, '06, 12:05:14 AM
|
|
|
shailishi
Posts: 15
Joined: Jan. 6, '06,
Status: offline
|
We are migrating one of our linux server apllication to Windows 2003-SUA. We saw that ioctl call always returns a larger value(in the range 500000 somtimes) but when we call recvfrom to read available data, recvfrom returns much less data in the buffer(most of the time it is less then 200 bytes). Also sometime recvfrom returns 'connection reset error', for open connections.
Thanks
|
|
|
|
|
RE: ioctl does not work - Jun. 27, '06, 1:16:09 AM
|
|
|
Rodney
Posts: 3695
Joined: Jul. 9, '02,
From: /Tools lab
Status: offline
|
Well... recvfrom() was introduced in 5.2/SUA and there have been reports of
this API not always working correctly. The use of recvfrom() can usually
be replaced with recv() since most code doesn't use revfrom() for
sending file handles. Recv() has been good for the past 10 years. I'd suggest
any matching sendto()'s to send()'s for balance.
If you've been using the scatter/gather of sendto/recvfrom then blending it into
a single memory point is easy enough. Or you can use libport which will
do this conversion for you (meaning it's a makefile change rather than a source
code change).
Doing this should clear up the reset thing. I don't know if as a side effect this
would correct the ioctl() return, but "you never know until ya try".
Otherwise you'll have to contact MS support (PSS) to report the bug and see what
can be done for you.
|
|
|
|
|
RE: ioctl does not work - Jul. 28, '06, 5:38:39 AM
|
|
|
RSanjay
Posts: 2
Joined: Apr. 27, '06,
Status: offline
|
recvmsg/sendmsg is added in SUA.
recvfrom/sendto is available in previous releases also.
If it is INET socket then recvfrom works fine on SUA/3.5.
For the ioctl behavior, please check the sendto call parameters more precisely size of buffer (IIIrd argument).
A snapshot of sendto usage and its effect on recvfrom:
char buf[2024];
"if(sendto(sd, buf, ****strlen(buf)****, 0, (struct sockaddr *)&server_addr, sizeof(server_addr))"
Output From SUA m/c and SFU 3.5:
/tmp > a.out
sendto: passed data= Hi from client...............size 765
ioctl ret = 0 bufsize = 765
recvfrom: got=[Hi from clientHi.................] size = 765
"if(sendto(sd, buf, ****sizeof(buf)****, 0, (struct sockaddr *)&server_addr, sizeof(server_addr))"
Output From SUA m/c and SFU 3.5:
/tmp > a.out
sendto: passed data= Hi from client...............size 765
ioctl ret = 0 bufsize = 2024
recvfrom: got=[Hi from clientHi.................] size = 765
This can be the case of ioctl giving different value and recvfrom returning different one as raised by shailishi.This behaviour is seen on other posix complaint OS's.
[Note: Ioctl API is not applicable on local sockets on SUA and for local DGRAM sockets, recvmsg/sendmsg is suggested.]
|
|
|
|
 New Messages |
 No New Messages |
 Hot Topic w/ New Messages |
 Hot Topic w/o New Messages |
|
 Locked w/ New Messages |
 Locked w/o New Messages |
|
 Post New Thread
Reply to Message
Post New Poll
Submit Vote
Delete My Own Post
Delete My Own Thread
Rate Posts |
|
|
|
Printable Version
