Re: Sending a broadcast message using raw sockets
Yes, raw sockets need admin privileges, I knew that. The app I'm writing runs as root so that's not a problem. It runs during the %pre script stage of a kickstart controlled install. On Tuesday, January 22, 2013 1:58:07 PM UTC-8, Rob Williscroft wrote: > Try > > s = socket.socket( socket.AF_INET, socket.SOCK_RAW ) > > > > I tried this on windows and it needed admin privaleges to > > run. > > > > Rob. > > -- -- http://mail.python.org/mailman/listinfo/python-list
Re: Sending a broadcast message using raw sockets
Peter Steele wrote in news:96947c45-f16b-4e97-b055-edc1241ee...@googlegroups.com in comp.lang.python: > I just tried running you code, and the "sendto" call fails with > "Network is unreachable". That's what I expected, based on other tests > I've done. That's why I was asking about how to do raw sockets, since > tools like dhclient use raw sockets to do what they do. It can clearly > be duplicated in Python, I just need to find some code samples on how > to construct a raw packet. > Try s = socket.socket( socket.AF_INET, socket.SOCK_RAW ) I tried this on windows and it needed admin privaleges to run. Rob. -- -- http://mail.python.org/mailman/listinfo/python-list
Re: Sending a broadcast message using raw sockets
Actually, I used to teach C, so yeah, I know it pretty well. :-) Scapy is a possibility, I just need to add it to my environment (which doesn't have a C compiler). I can jury rig something though. On Tuesday, January 22, 2013 1:19:14 PM UTC-8, Chris Angelico wrote: > On Wed, Jan 23, 2013 at 4:57 AM, Peter Steele wrote: > > > In fact, I have used scapy in the past, but I am working in a restricted > > environment and don't have this package available. It provides tones more > > than I really need anyway, and I figured a simple raw socket send/receive > > can't be *that* hard. I may have to reverse engineer some C code, such as > > dhclient... > > > > Yeah, I think you're working with something fairly esoteric there - > > bypassing the lower tiers of support (routing etc). Chances are you > > won't find any good Python examples, and C's all you'll have. Are you > > reasonably familiar with C? > > > > Point to note: Raw sockets *may* require special privileges. Some > > systems require that only root employ them, for security's sake. > > > > ChrisA -- http://mail.python.org/mailman/listinfo/python-list
Re: Sending a broadcast message using raw sockets
On Wed, Jan 23, 2013 at 4:57 AM, Peter Steele wrote: > In fact, I have used scapy in the past, but I am working in a restricted > environment and don't have this package available. It provides tones more > than I really need anyway, and I figured a simple raw socket send/receive > can't be *that* hard. I may have to reverse engineer some C code, such as > dhclient... Yeah, I think you're working with something fairly esoteric there - bypassing the lower tiers of support (routing etc). Chances are you won't find any good Python examples, and C's all you'll have. Are you reasonably familiar with C? Point to note: Raw sockets *may* require special privileges. Some systems require that only root employ them, for security's sake. ChrisA -- http://mail.python.org/mailman/listinfo/python-list
Re: Sending a broadcast message using raw sockets
In fact, I have used scapy in the past, but I am working in a restricted environment and don't have this package available. It provides tones more than I really need anyway, and I figured a simple raw socket send/receive can't be *that* hard. I may have to reverse engineer some C code, such as dhclient... On Tuesday, January 22, 2013 8:07:12 AM UTC-8, Corey LeBleu wrote: > If you don't *have* to use the actual socket library, you might want to have > a look at scapy. It's a packet manipulation program/library. It might make > things a little easier. > > http://www.secdev.org/projects/scapy/ > > > > On Jan 22, 2013 9:17 AM, "Peter Steele" wrote: > > I just tried running you code, and the "sendto" call fails with "Network is > unreachable". That's what I expected, based on other tests I've done. That's > why I was asking about how to do raw sockets, since tools like dhclient use > raw sockets to do what they do. It can clearly be duplicated in Python, I > just need to find some code samples on how to construct a raw packet. > > > > > -- > > http://mail.python.org/mailman/listinfo/python-list -- http://mail.python.org/mailman/listinfo/python-list
Re: Sending a broadcast message using raw sockets
If you don't *have* to use the actual socket library, you might want to have a look at scapy. It's a packet manipulation program/library. It might make things a little easier. http://www.secdev.org/projects/scapy/ On Jan 22, 2013 9:17 AM, "Peter Steele" wrote: > I just tried running you code, and the "sendto" call fails with "Network > is unreachable". That's what I expected, based on other tests I've done. > That's why I was asking about how to do raw sockets, since tools like > dhclient use raw sockets to do what they do. It can clearly be duplicated > in Python, I just need to find some code samples on how to construct a raw > packet. > > -- > http://mail.python.org/mailman/listinfo/python-list > -- http://mail.python.org/mailman/listinfo/python-list
Re: Sending a broadcast message using raw sockets
I just tried running you code, and the "sendto" call fails with "Network is unreachable". That's what I expected, based on other tests I've done. That's why I was asking about how to do raw sockets, since tools like dhclient use raw sockets to do what they do. It can clearly be duplicated in Python, I just need to find some code samples on how to construct a raw packet. -- http://mail.python.org/mailman/listinfo/python-list
Re: Sending a broadcast message using raw sockets
Peter Steele wrote in news:0c2b3482-df46-4324-8bf9-2c45d3f6b...@googlegroups.com in comp.lang.python: > On Monday, January 21, 2013 1:10:06 AM UTC-8, Rob Williscroft wrote: >> Peter Steele wrote in >> >> news:f37ccb35-8439-42cd-a063-962249b44...@googlegroups.com in >> >> comp.lang.python: >> >> > I want to write a program in Python that sends a broadcast message [snip] >> This is part of my Wake-On-Lan script: >> >> def WOL_by_mac( mac, ip = '', port = 9 ): [snip] > Thanks for the code sample. Does this code work if the box has no IP > or default route assigned? I'm away from the office at the moment so I > can't test this. No idea, but the sockets system must be up and running before the card (interface) has an IP (otherwise how would it ever get assigned) and I presume DHCP works in a similar manner. However the "route assignemt" is irrelevent, broadcast messages never get routed. Rob -- -- http://mail.python.org/mailman/listinfo/python-list
Re: Sending a broadcast message using raw sockets
On Monday, January 21, 2013 1:10:06 AM UTC-8, Rob Williscroft wrote: > Peter Steele wrote in > > news:f37ccb35-8439-42cd-a063-962249b44...@googlegroups.com in > > comp.lang.python: > > > I want to write a program in Python that sends a broadcast message > > using raw sockets. The system where this program will run has no IP or > > default route defined, hence the reason I need to use a broadcast > > message. > > > > I've done some searches and found some bits and pieces about using raw > > sockets in Python, but I haven't been able to find an example that > > explains how to construct a broadcast message using raw sockets. > > > > Any pointers would be appreciated. > > This is part of my Wake-On-Lan script: > > def WOL_by_mac( mac, ip = '', port = 9 ): > > import struct, socket > > a = mac.replace( ':', '-' ).split( '-' ) > addr = struct.pack( 'B'*6, *[ int(_, 16) for _ in a ] ) > msg = b'\xff' * 6 + addr * 16 > > s = socket.socket( socket.AF_INET, socket.SOCK_DGRAM ) > s.setsockopt( socket.SOL_SOCKET, socket.SO_BROADCAST, 1 ) > s.sendto( msg, ( ip, port ) ) > s.close() > > The mac address is 6 pairs of hex digits seperated by '-' or ':'. Thanks for the code sample. Does this code work if the box has no IP or default route assigned? I'm away from the office at the moment so I can't test this. -- http://mail.python.org/mailman/listinfo/python-list
Re: Sending a broadcast message using raw sockets
Peter Steele wrote in news:f37ccb35-8439-42cd-a063-962249b44...@googlegroups.com in comp.lang.python: > I want to write a program in Python that sends a broadcast message > using raw sockets. The system where this program will run has no IP or > default route defined, hence the reason I need to use a broadcast > message. > > I've done some searches and found some bits and pieces about using raw > sockets in Python, but I haven't been able to find an example that > explains how to construct a broadcast message using raw sockets. > > Any pointers would be appreciated. This is part of my Wake-On-Lan script: def WOL_by_mac( mac, ip = '', port = 9 ): import struct, socket a = mac.replace( ':', '-' ).split( '-' ) addr = struct.pack( 'B'*6, *[ int(_, 16) for _ in a ] ) msg = b'\xff' * 6 + addr * 16 s = socket.socket( socket.AF_INET, socket.SOCK_DGRAM ) s.setsockopt( socket.SOL_SOCKET, socket.SO_BROADCAST, 1 ) s.sendto( msg, ( ip, port ) ) s.close() The mac address is 6 pairs of hex digits seperated by '-' or ':'. http://en.wikipedia.org/wiki/Wake-on-LAN Rob. -- http://mail.python.org/mailman/listinfo/python-list
