How to List TCP/UDP Connections in iOS 4

Question

I am interested in deriving a list of active TCP/UDP network connections on an iOS 4.3 device. Basically, I'm looking for the same type of information one gets from issuing a "netstat -anp tcp" (or the same, but with udp) command under OS X Darwin.

I've searched Apple's iOS Developer Library (especially NSNetServices, CFNetServices, and the iOS Manual Pages) and the Internet, but with no good results. Yet, there is an iOS Netstat app (see http://itunes.apple.com/us/app/netstat/id400071873?mt=8&ign-mpt=uo%3D2) out there, so it appears possible.

Thanks in advance for any useful pointers/suggestions/thoughts.

Answer 1

I believe I have now answered my own question. Thought I had taken a close enough look at the sysctl() library function, but I hadn't! For example, the following will yield information about the current TCP connections:

sysctlbyname("net.inet.tcp.pcblist", ...)

To get information about UDP connection, simply use a different Management Information Base (MIB) name: net.inet.udp.pcblist.

For convenience, here's a link to the appropriate iOS man page:

http://developer.apple.com/library/ios/#documentation/System/Conceptual/ManPages_iPhoneOS/man3/sysctlbyname.3.html