messed up rfnm q's

[unix-history] / usr / src / sys / deprecated / netimp / if_imphost.c

/*      if_imphost.c    4.4     82/02/16        */

#include "imp.h"
#if NIMP > 0
/*
* Host table manipulation routines.
* Only needed when shipping stuff through an IMP.
*/

#include "../h/param.h"
#include "../h/mbuf.h"
#include "../net/in.h"
#include "../net/in_systm.h"
#include "../net/if_imp.h"
#include "../net/if_imphost.h"

/*
* Head of host table hash chains.
*/
struct mbuf *hosts;

/*
* Given an internet address
* return a host structure (if it exists).
*/
struct host *
hostlookup(addr)
       struct in_addr addr;
{
       register struct host *hp;
       register struct mbuf *m;
       register int hash = HOSTHASH(addr);

COUNT(HOSTLOOKUP);
       for (m = hosts; m; m = m->m_next) {
               hp = &mtod(m, struct hmbuf *)->hm_hosts[hash];
               if (hp->h_refcnt == 0)
                       continue;
               if (hp->h_addr.s_addr == addr.s_addr)    
                       return (hp);
       }
       return (0);
}

/*
* Enter a reference to this host's internet
* address.  If no host structure exists, create
* one and hook it into the host database.
*/
struct host *
hostenter(addr)                 
       struct in_addr addr;
{
       register struct mbuf *m, **mprev;
       register struct host *hp, *hp0 = 0;
       register int hash = HOSTHASH(addr);

COUNT(HOSTENTER);
       mprev = &hosts;
       while (m = *mprev) {
               hp = &mtod(m, struct hmbuf *)->hm_hosts[hash];
               if (hp->h_refcnt == 0) {
                       if (hp0 == 0)
                               hp0 = hp;
                       continue;
               }
               if (hp->h_addr.s_addr == addr.s_addr)    
                       goto foundhost;
               mprev = &m->m_next;
       }

       /*
        * No current host structure, make one.
        * If our search ran off the end of the
        * chain of mbuf's, allocate another.
        */
       if (hp0 == 0) {
               m = m_getclr(M_DONTWAIT);
               if (m == 0)
                       return (0);
               *mprev = m;
               m->m_off = MMINOFF;
               hp0 = &mtod(m, struct hmbuf *)->hm_hosts[hash];
       }
       mtod(dtom(hp0), struct hmbuf *)->hm_count++;
       hp = hp0;
       hp->h_addr = addr;
       hp->h_status = HOSTS_UP;

foundhost:
       hp->h_refcnt++;         /* know new structures have 0 val */
       return (hp);
}

/*
* Free a reference to a host.  If this causes the
* host structure to be released do so.
*/
hostfree(hp)                               
       register struct host *hp;
{
       register struct mbuf *m;

COUNT(HOSTFREE);
       if (--hp->h_refcnt)
               return;
       hostrelease(hp);
}

/*
* Reset a given network's host entries.
* This involves clearing all packet queue's
* and releasing host structures.
*/
hostreset(net)      
       int net;
{
       register struct mbuf *m;
       register struct host *hp, *lp;
       struct hmbuf *hm;
       int x;

COUNT(HOSTRESET);
       x = splimp();
       for (m = hosts; m; m = m->m_next) {
               hm = mtod(m, struct hmbuf *);
               hp = hm->hm_hosts; 
               lp = hp + HPMBUF;
               while (hm->hm_count != 0 && hp < lp) {
                       if (hp->h_addr.s_net == net)
                               hostrelease(mtod(m, struct hmbuf *), hp);
                       hp++;
               }
       }
       splx(x);
}

/*
* Remove a host structure and release
* any resources it's accumulated.
*/
hostrelease(hp)
       register struct host *hp;
{
       register struct mbuf *m, **mprev, *mh = dtom(hp);

COUNT(HOSTRELEASE);
       /*
        * Discard any packets left on the waiting q
        */
       if (m = hp->h_q) {
               register struct mbuf *n;

               do {
                       n = m->m_act;
                       m_freem(m);
                       m = n;
               } while (m != hp->h_q);
               hp->h_q = 0;
       }
       if (--mtod(mh, struct hmbuf *)->hm_count)
               return;
       mprev = &hosts;
       while ((m = *mprev) != mh)
               mprev = &m->m_next;
       *mprev = mh->m_next;
       (void) m_free(mh);
}