/* network i/o */

#include "all.h"
#include "io.h"

/*
* the kernel file server read packets directly from
* its ethernet(s) and did all the protocol processing.
* if the incoming packets were 9p (over il/ip), they
* were queued for the server processes to operate upon.
*
* in user mode, we have one process per incoming connection
* instead, and those processes get just the data, minus
* tcp and ip headers, so they just see a stream of 9p messages,
* which they then queue for the server processes.
*
* there used to be more queueing (in the kernel), with separate
* processes for ethernet input, il input, 9p processing, il output
* and ethernet output, and queues connecting them.  we now let
* the kernel's network queues, protocol stacks and processes do
* much of this work.
*
* partly as a result of this, we can now process 9p messages
* transported via tcp, exploit multiple x86 processors, and
* were able to shed 70% of the file server's source, by line count.
*
* the upshot is that Ether (now Network) is no longer a perfect fit for
* the way network i/o is done now.  the notion of `connection'
* is being introduced to complement it.
*/

typedef struct Network Network;

/* a network, not necessarily an ethernet */
struct Network {
       int     ctlrno;
       char    name[NAMELEN];

       char    *dialstr;
       char    anndir[40];
       char    lisdir[40];
       int     annfd;                  /* fd from announce */
};

static Network netif[Maxnets];

char *annstrs[Maxnets];

static void
neti(void *v)
{
       NetConnInfo *nci;
       Network *net;
       char *addr;
       int nctl, data;

       net = v;
       for(;;) {
               if((nctl = listen(net->anndir, net->lisdir)) < 0){
                       fprint(2, "%s: listen %s failed: %r\n", argv0, net->anndir);
                       break;
               }
               if((data = accept(nctl, net->lisdir)) < 0){
                       fprint(2, "%s: accept %s failed: %r\n", argv0, net->lisdir);
                       close(nctl);
                       continue;
               }
               close(nctl);
               nci = getnetconninfo(net->lisdir, data);
               addr = nci == nil ? "unknown" : nci->raddr;
               if(srvchan(data, addr) == nil){
                       fprint(2, "%s: srvchan failed for: %s\n", argv0, addr);
                       close(data);
               }
               freenetconninfo(nci);
       }
}

void
netstart(void)
{
       Network *net;

       for(net = &netif[0]; net < &netif[Maxnets]; net++){
               if(net->dialstr == nil || *net->anndir == 0)
                       continue;
               sprint(net->name, "net%di", net->ctlrno);
               newproc(neti, net, net->name);
       }
}

void
netinit(void)
{
       Network *net;

       for (net = netif; net < netif + Maxnets; net++) {
               net->dialstr = annstrs[net - netif];
               if(net->dialstr == nil)
                       continue;
               if((net->annfd = announce(net->dialstr, net->anndir)) < 0){
                       fprint(2, "can't announce %s: %r", net->dialstr);
                       net->dialstr = nil;
                       continue;
               }
               if(chatty)
                       print("netinit: announced on %s\n", net->dialstr);
       }
}