UDP - recvfrom() call
There are two simple programs: A, and B communicating through UDP (socket() called with SOCK_DGRAM). A just bounces all datagrams.
B sends a datagram to A, calls recvfrom and then
examines the sockaddr *from field.
Depedning on:
a) sockaddr_in declaration or allocation
b) recvfrom calling point
c) B's compilation host
I'm getting different results:
Compiled on my machine (RH 6.1):
sockaddr_in | recvfrom() | result
--------------------------
main() | main() | A's address
answer0() | answer0() | EINVAL
B.c | answer1() | 0.0.0.0
malloc() | answer2() | EINVAL
Compiled on my university host:
sockaddr_in | recvfrom() | result
--------------------------
main() | main() | A's address
answer0() | answer0() | 0.0.0.0
B.c | answer1() | 0.0.0.0
malloc() | answer2() | 0.0.0.0
I don't like the idea of putting all my code
in main(), so hope there's someone who has
at least the slightest idea about what's going
on and how to make it work. I'll provide any
additional information, if it is necessary.
Sources of A and B are here: http://rainbow.mimuw.edu.pl/~robson/AB.tgz
B sends a datagram to A, calls recvfrom and then
examines the sockaddr *from field.
Depedning on:
a) sockaddr_in declaration or allocation
b) recvfrom calling point
c) B's compilation host
I'm getting different results:
Compiled on my machine (RH 6.1):
sockaddr_in | recvfrom() | result
--------------------------
main() | main() | A's address
answer0() | answer0() | EINVAL
B.c | answer1() | 0.0.0.0
malloc() | answer2() | EINVAL
Compiled on my university host:
sockaddr_in | recvfrom() | result
--------------------------
main() | main() | A's address
answer0() | answer0() | 0.0.0.0
B.c | answer1() | 0.0.0.0
malloc() | answer2() | 0.0.0.0
I don't like the idea of putting all my code
in main(), so hope there's someone who has
at least the slightest idea about what's going
on and how to make it work. I'll provide any
additional information, if it is necessary.
Sources of A and B are here: http://rainbow.mimuw.edu.pl/~robson/AB.tgz
ASKER
I've put sources of A and B at http://rainbow.mimuw.edu.pl/~robson/AB.tgz
ASKER
Edited text of question.
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ASKER
Thank's a lot, dennis!
This requirement isn't mentioned either in man page, nor in Steven's book (I 've nearly broken its cover in anger). Also in example programs given by my network-programming teacher (he's going to score some, too) initialization isn't made.
Last, but not least:
I MISSED GREAT SCI-FI CONVENTION BECAUSE OF THIS EFFING BUG!
This requirement isn't mentioned either in man page, nor in Steven's book (I 've nearly broken its cover in anger). Also in example programs given by my network-programming teacher (he's going to score some, too) initialization isn't made.
Last, but not least:
I MISSED GREAT SCI-FI CONVENTION BECAUSE OF THIS EFFING BUG!
glad it helped... sorry about the sci-fi convention, though
dennis
dennis
ASKER
NOTE: I was wrong about Stevens' "Un*x Network Programming" - it explains this problem. I promise to read it carefully and with respect - and no more violence, of course :-).
thanks,
dennis