Re: icmp and raw sockets in python
On 13/12/2011 16:50, Sagy Drucker wrote: hello Hi i am relatively new to python, so please be considerate... As I am only responding to one of your questions, perhaps it would be best if you don't get any other more helpful replies to split your questions up and post them separately. i'm implementing a server and a client via raw_sockets. i have the necessary privileges. now, the server i defined so: host = socket.gethostbyname(socket.gethostname()) address = (host, 4) sockSer = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.IPPROTO_ICMP) sockSer.bind(address) sockSer.ioctl(socket.SIO_RCVALL, socket.RCVALL_ON) packet, addr = sockSer .recvfrom(4096) # wait for packet from client Q1) why can't i simply type: hosts = 'localhost'. if i do so, it doesn't allow me to write the line: sockSer.ioctl(socket.SIO_RCVALL, socket.RCVALL_ON). only when doing gethostbyname(socket.gethostname()) i get 192.168.1.101 and then it works. Well localhost should resolve to 127.0.0.1/8 which is attached to the loopback interface, my gut feeling is that this interface has a particular set of restrictions which you are encountering. Sorry I can't be more helpful. -- mph -- http://mail.python.org/mailman/listinfo/python-list
icmp and raw sockets in python
hello i am relatively new to python, so please be considerate... i'm implementing a server and a client via raw_sockets. i have the necessary privileges. now, the server i defined so: host = socket.gethostbyname(socket.gethostname()) address = (host, 4) sockSer = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.IPPROTO_ICMP) sockSer.bind(address) sockSer.ioctl(socket.SIO_RCVALL, socket.RCVALL_ON) packet, addr = sockSer .recvfrom(4096) # wait for packet from client Q1) why can't i simply type: hosts = 'localhost'. if i do so, it doesn't allow me to write the line: sockSer.ioctl(socket.SIO_RCVALL, socket.RCVALL_ON). only when doing gethostbyname(socket.gethostname()) i get 192.168.1.101 and then it works. in a different class: the client socket: host = socket.gethostbyname(socket.gethostname()) address = (host, 4) sockCli = socket.socket(socket.AF_INET, socket.SOCK_RAW, socket.IPPROTO_ICMP) Q2) do i also need to type: sockCli.ioctl(socket.SIO_RCVALL, socket.RCVALL_ON) or maybe sockCli.connect(address) for the client socket? now, the problems arise when i do the following: 1) send a packet from client to socket: header=... payload='a' sockCli.sendto(header + payload, address) 2) receive packet in server and send file to client: while(true): data, addr = sockSer.recvfrom(4096) header2=... payload2='b' sockSer.sendto(header2 + payload2, addr) now, my important question is: Q3) the server sent only 1 packet to client, with payload 'b'. what happens is, my client actually receives 2 packets in the while loop: first packet is what the client itself sent to server, and the other packet is from the client got from the server. hence my output is 'ab' instead of simply 'b' why is this happening??? NOTE: i didn't type the entire code, but i think my syntax,parsing,header composition etc.. are correct. is there an obvious problem in my code? if necessary i'll upload the entire code. thanks -- http://mail.python.org/mailman/listinfo/python-list
Re: Sockets in python
OneMustFall a écrit : > >> What's your set-up and which cord are you pulling? >> > > Well i now i think the clue is in the OS, i have sniffed and it seems > that Twisted have no magic. > It is seems that i simply tested things in a wrong way - > when i pulled cord from ethernet card windows determined that network > lost and started to closing all sockets opened to that network (and so > EINVAL or other OS error raised when twisted tryed to read wrom that > socket), > while the server did had a network - and it was right thing that server > was thinking that socket is alive. Stupid Windows behaviour btw! I hate that, it makes testing code stability for temporary network lags much much harder to do. And don't get me started on when we reboot the switch which causes all open sockets on my computer to fail, even though the reboot only takes a few seconds and though the internet connection doesn't change. -- http://mail.python.org/mailman/listinfo/python-list
Re: Sockets in python
> What's your set-up and which cord are you pulling? > Well i now i think the clue is in the OS, i have sniffed and it seems that Twisted have no magic. It is seems that i simply tested things in a wrong way - when i pulled cord from ethernet card windows determined that network lost and started to closing all sockets opened to that network (and so EINVAL or other OS error raised when twisted tryed to read wrom that socket), while the server did had a network - and it was right thing that server was thinking that socket is alive. -- http://mail.python.org/mailman/listinfo/python-list
Re: Sockets in python
OneMustFall wrote: > Reciently i wrote a simple client (in twisted) using Reconnecting > Factory. > That client logins to my socket server.. and that`s it. > > Interesting thing is that it is seems that twisted client, > sends some ping on a TCP level without sending any data to the > socket directly. > Because when i pull out cord from the ethernet card simulating > network falure, client in about 10-15 seconds determines that > connection lost!! (pretty cool) > While my server thinks that client is connected. What's your set-up and which cord are you pulling? -- --Bryan -- http://mail.python.org/mailman/listinfo/python-list
Sockets in python
Reciently i wrote a simple client (in twisted) using Reconnecting
Factory.
That client logins to my socket server.. and that`s it.
Interesting thing is that it is seems that twisted client,
sends some ping on a TCP level without sending any data to the
socket directly.
Because when i pull out cord from the ethernet card simulating
network falure, client in about 10-15 seconds determines that
connection lost!! (pretty cool)
While my server thinks that client is connected.
I know that sockets ware designed to behave so.. to be tolarate
to
network problems, but in my case this is bad.. i want it to
behave like in twisted.
I have searched in a socketmodule.c from python source code for a
magic variables, but did not found anything that fits.
I am using SO_KEEPALIVE on server - but documentations says
it will only ping (and so timed outed) in a few hours.
How do i make my server act the same way as twisted client?
(to make some sort of a low level checking if a connections is
broken without actualy sending anything to socket)
The only suspicious lines intwisted is seems :
---
SO_UPDATE_ACCEPT_CONTEXT = 0x700B
SO_UPDATE_CONNECT_CONTEXT = 0x7010
--
try:
acc_sock.setsockopt(socket.SOL_SOCKET,
SO_UPDATE_ACCEPT_CONTEXT, struct.pack("I", handle))
except socket.error, se:
self.transport.acceptErr(ret, bytes)
else:
self.transport.acceptDone(acc_sock,
acc_sock.getpeername())
--
if have_connectex:
try:
sock.setsockopt(socket.SOL_SOCKET,
SO_UPDATE_CONNECT_CONTEXT, "")
except socket.error, se:
self.transport.connectErr(failure.Failure(error.ConnectError()))
self.transport.connectDone()
---
I tried this all but it trows an exeption and not working and also
i have no i idea what
SO_UPDATE_ACCEPT_CONTEXT , andSO_UPDATE_CONNECT_CONTEXT means.
Huh. Any Suggestions?
--
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