Socket states

I’m trying to write something similar to netstat. I’ve got most of the information needed apart from the last column which would show the status any TCP sockets.

Where would I find that information?

I’m writing the program in C using the DDE, but finding some things declared in the TCPIPLibs header files not being exported, such as functions in sys/socketvar.h

Not so sure this will help.

But, in the absence of any other replies.

Typing INETSTAT, will list the current sockets and show each to be in one of the following states:-

State         Description
CLOSED        Indicates that the server has received an ACK signal from the client and the connection is closed
CLOSE_WAIT    Indicates that the server has received the first FIN signal from the client and the connection is in the process of being closed
ESTABLISHED   Indicates that the server received the SYN signal from the client and the session is established
FIN_WAIT_1    Indicates that the connection is still active but not currently being used
FIN_WAIT_2    Indicates that the client just received acknowledgment of the first FIN signal from the server
LAST_ACK      Indicates that the server is in the process of sending its own FIN signal
LISTENING     Indicates that the server is ready to accept a connection
SYN_RECEIVED  Indicates that the server just received a SYN signal from the client
SYN_SEND      Indicates that this particular connection is open and active
TIME_WAIT     Indicates that the client recognizes the connection as still active but not currently being used 

Where you would find that information documented for RISC OS, I do not know, but maybe this reply will prompt somebody else to give you a better reply :)

Thanks Bryan, that list is useful. However, as you say, where that information is documented I also don’t know. I think some info could be extracted from the status field in the struct socket structure, but accessing that should be easy using the function
struct socket *getsock(int);
Prototype in sys/socketvar.h
But the function is not exported by any library. I’ll keep looking.

inetstat uses the sysctl call net.inet.tcp.pcblist. I didn’t find it in the man pages – I think it’s a case of looking at the inetstat source.

Thanks Julie, I’ve been trawling through the sources to see what I can find, thanks for the pointer I’ll have a look there.
So far my output looks like that below, added the socket number as the first column, but the State column is just a guess, if it’s TCP and not connected to a remote endpoint then the socket is probably LISTENING. However I’d rather get the info from some setting. Also, the sockets which are connected may be in one of the states Bryan has listed. It’s not in the order netstat usually displays the data, early days yet, something else to sort. Seems strange RiscOS doesn’t have a utility like this, it’s fairly standard for investigating networking issues.

I was viewing www.riscosopen.org website when I ran my program.

*netstat
Socket Proto  Local Address            Foreign Address      State

  0     UDP   0.0.0.0:68               *:*                     
  1     UDP   0.0.0.0:137              *:*                     
  2     UDP   0.0.0.0:32770            *:*                     
  3     UDP   0.0.0.0:32771            *:*                     
  4     UDP   0.0.0.0:49171            *:*                     
  5     UDP   0.0.0.0:49152            *:*                     
  6     TCP   0.0.0.0:5900                                  LISTENING
  7     TCP   0.0.0.0:13                                    LISTENING
  8     UDP   0.0.0.0:13               *:*                     
  9     TCP   0.0.0.0:7                                     LISTENING
 10     UDP   0.0.0.0:7                *:*                     
 11     TCP   0.0.0.0:17                                    LISTENING
 12     UDP   0.0.0.0:17               *:*                     
 13     TCP   0.0.0.0:9                                     LISTENING
 14     UDP   0.0.0.0:9                *:*                     
 15     TCP   0.0.0.0:37                                    LISTENING
 16     UDP   0.0.0.0:37               *:*                     
 17     TCP   0.0.0.0:19                                    LISTENING
 18     UDP   0.0.0.0:19               *:*                     
 19     TCP   192.168.6.109:49180      91.203.57.172:443       
 20     TCP   192.168.6.109:49181      91.203.57.172:443       
 21     TCP   192.168.6.109:49182      91.203.57.172:443       
 22     TCP   192.168.6.109:49183      91.203.57.172:443       
 23     TCP   192.168.6.109:49184      91.203.57.172:443 

Ahhh… Found this trawling through the source code!

*inetstat -h
Usage:   inetstat [-Aan] [-f <address_family>] [-M <core>] [-N <system>]
         inetstat [-bdghimnrs] [-f <address_family>] [-M <core>] [-N <system>]
         inetstat [-bdn] [-I <interface>] [-M <core>] [-N <system>] [-w <wait>]
         inetstat [-M <core>] [-N <system>] [-p <protocol>]
         shows network status
Options: -A  show addresses of protocol control blocks associated with sockets
         -a  show the state of all sockets
         -b  show the number of bytes in and out
         -d  show the number of dropped packets
         -g  show information relating to group address (multicast)
         -h  show the state of the IMP host table
         -i  show the state of interfaces which have been autoconfigured
         -m  show statistics recorded by the memory management routines
         -n  do not attempt to lookup names using DNS
         -r  show routing tables
         -f  limit statistics to the given address family
         -M  extract values associated with the name list from the given core
         -N  extract the namelist from the given system
         -I  show information about the specified interface only
         -w  show statistics at intervals of wait seconds
         -p  show only statistics for the named protocol
         -s  show per protocol statistics

*inetstat -an
Active Internet connections (including servers)
Proto Recv-Q Send-Q  Local Address          Foreign Address        (state)
tcp       31      0  192.168.6.109.49165    192.0.73.2.443         CLOSE_WAIT
tcp       31      0  192.168.6.109.49164    192.0.73.2.443         CLOSE_WAIT
tcp       31      0  192.168.6.109.49163    192.0.73.2.443         CLOSE_WAIT
tcp       31      0  192.168.6.109.49159    91.203.57.172.443      CLOSE_WAIT
tcp       31      0  192.168.6.109.49158    91.203.57.172.443      CLOSE_WAIT
tcp       31      0  192.168.6.109.49157    91.203.57.172.443      CLOSE_WAIT
tcp       31      0  192.168.6.109.49156    91.203.57.172.443      CLOSE_WAIT
tcp       31      0  192.168.6.109.49155    91.203.57.172.443      CLOSE_WAIT
tcp        0      0  *.19                   *.*                    LISTEN
tcp        0      0  *.37                   *.*                    LISTEN
tcp        0      0  *.9                    *.*                    LISTEN
tcp        0      0  *.17                   *.*                    LISTEN
tcp        0      0  *.7                    *.*                    LISTEN
tcp        0      0  *.13                   *.*                    LISTEN
tcp        0      0  *.5900                 *.*                    LISTEN
udp        0      0  *.19                   *.*                   
udp        0      0  *.37                   *.*                   
udp        0      0  *.9                    *.*                   
udp        0      0  *.17                   *.*                   
udp        0      0  *.7                    *.*                   
udp        0      0  *.13                   *.*                   
udp        0      0  *.49152                *.*                   
udp        0      0  *.49171                *.*                   
udp        0      0  *.32771                *.*                   
udp        0      0  *.32770                *.*                   
udp        0      0  *.137                  *.*                   
udp        0      0  *.*                    *.*                   
udp        0      0  *.68                   *.*  

So there is an equivalent to netstat

In Acorn land there was a pre-existing *NetStat command which returns stats about Econet/AUN, and generally anything called Net refers to that – the NetPrint module, the icon on the iconbar labelled Net, and so on. When the internet was invented the similarly named netstat command clashed, so got named inetstat instead, but it’s 100% based on Johnny-come-lately Unix netstat.