4.3BSD - /usr/src/sys/netimp/if_imphost.c

   1: /*
   2:  * Copyright (c) 1982, 1986 Regents of the University of California.
   3:  * All rights reserved.  The Berkeley software License Agreement
   4:  * specifies the terms and conditions for redistribution.
   5:  *
   6:  *	@(#)if_imphost.c	7.1 (Berkeley) 6/4/86
   7:  */
   8: 
   9: #include "imp.h"
  10: #if NIMP > 0
  11: /*
  12:  * Host table manipulation routines.
  13:  * Only needed when shipping stuff through an IMP.
  14:  *
  15:  * Everything in here is called at splimp from
  16:  * from the IMP protocol code (if_imp.c), or
  17:  * interlocks with the code at splimp.
  18:  */
  19: #include "param.h"
  20: #include "mbuf.h"
  21: #include "syslog.h"
  22: 
  23: #include "../netinet/in.h"
  24: #include "../netinet/in_systm.h"
  25: 
  26: #include "if_imp.h"
  27: #include "if_imphost.h"
  28: 
  29: /*
  30:  * Head of host table hash chains.
  31:  */
  32: struct mbuf *hosts;
  33: 
  34: /*
  35:  * Given an internet address
  36:  * return a host structure (if it exists).
  37:  */
  38: struct host *
  39: hostlookup(addr)
  40:     struct in_addr addr;
  41: {
  42:     register struct host *hp;
  43:     register struct mbuf *m;
  44:     register int hash = HOSTHASH(addr);
  45: 
  46:     for (m = hosts; m; m = m->m_next) {
  47:         hp = &mtod(m, struct hmbuf *)->hm_hosts[hash];
  48:             if (hp->h_addr.s_addr == addr.s_addr) {
  49:             hp->h_flags |= HF_INUSE;
  50:             return (hp);
  51:         }
  52:     }
  53:     return ((struct host *)0);
  54: }
  55: 
  56: /*
  57:  * Enter a reference to this host's internet
  58:  * address.  If no host structure exists, create
  59:  * one and hook it into the host database.
  60:  */
  61: struct host *
  62: hostenter(addr)
  63:     struct in_addr addr;
  64: {
  65:     register struct mbuf *m, **mprev;
  66:     register struct host *hp, *hp0 = 0;
  67:     register int hash = HOSTHASH(addr);
  68: 
  69:     mprev = &hosts;
  70:     while (m = *mprev) {
  71:         mprev = &m->m_next;
  72:         hp = &mtod(m, struct hmbuf *)->hm_hosts[hash];
  73:         if ((hp->h_flags & HF_INUSE) == 0) {
  74:             if (hp->h_addr.s_addr == addr.s_addr)
  75:                 goto foundhost;
  76:             if (hp0 == 0)
  77:                 hp0 = hp;
  78:             continue;
  79:         }
  80:             if (hp->h_addr.s_addr == addr.s_addr)
  81:             goto foundhost;
  82:     }
  83: 
  84:     /*
  85: 	 * No current host structure, make one.
  86: 	 * If our search ran off the end of the
  87: 	 * chain of mbuf's, allocate another.
  88: 	 */
  89:     if (hp0 == 0) {
  90:         m = m_getclr(M_DONTWAIT, MT_HTABLE);
  91:         if (m == NULL)
  92:             return ((struct host *)0);
  93:         *mprev = m;
  94:         hp0 = &mtod(m, struct hmbuf *)->hm_hosts[hash];
  95:     }
  96:     mtod(dtom(hp0), struct hmbuf *)->hm_count++;
  97:     hp = hp0;
  98:     hp->h_addr = addr;
  99:     hp->h_timer = 0;
 100:     hp->h_flags = 0;
 101: 
 102: foundhost:
 103:     hp->h_flags |= HF_INUSE;
 104:     return (hp);
 105: }
 106: 
 107: /*
 108:  * Mark a host structure free and set it's
 109:  * timer going.
 110:  */
 111: hostfree(hp)
 112:     register struct host *hp;
 113: {
 114: 
 115:     hp->h_flags &= ~HF_INUSE;
 116:     hp->h_timer = HOSTTIMER;
 117:     hp->h_rfnm = 0;
 118: }
 119: 
 120: /*
 121:  * Reset a given network's host entries.
 122:  */
 123: hostreset(net)
 124:     u_long net;
 125: {
 126:     register struct mbuf *m;
 127:     register struct host *hp, *lp;
 128:     struct hmbuf *hm;
 129:     struct mbuf *mnext;
 130: 
 131:     for (m = hosts; m; m = mnext) {
 132:         mnext = m->m_next;
 133:         hm = mtod(m, struct hmbuf *);
 134:         hp = hm->hm_hosts;
 135:         lp = hp + HPMBUF;
 136:         while (hm->hm_count > 0 && hp < lp) {
 137:             if (in_netof(hp->h_addr) == net) {
 138:                 hp->h_flags &= ~HF_INUSE;
 139:                 hostrelease(hp);
 140:             }
 141:             hp++;
 142:         }
 143:     }
 144: }
 145: 
 146: /*
 147:  * Remove a host structure and release
 148:  * any resources it's accumulated.
 149:  */
 150: hostrelease(hp)
 151:     register struct host *hp;
 152: {
 153:     register struct mbuf *m, **mprev, *mh = dtom(hp);
 154: 
 155:     /*
 156: 	 * Discard any packets left on the waiting q
 157: 	 */
 158:     if (m = hp->h_q) {
 159:         register struct mbuf *n;
 160: 
 161:         do {
 162:             n = m->m_act;
 163:             m_freem(m);
 164:             m = n;
 165:         } while (m != hp->h_q);
 166:         hp->h_q = 0;
 167:     }
 168:     hp->h_flags = 0;
 169:     hp->h_rfnm = 0;
 170:     if (--mtod(mh, struct hmbuf *)->hm_count)
 171:         return;
 172:     mprev = &hosts;
 173:     while ((m = *mprev) != mh)
 174:         mprev = &m->m_next;
 175:     *mprev = m_free(mh);
 176: }
 177: 
 178: /*
 179:  * Remove a packet from the holding q.
 180:  * The RFNM counter is also bumped.
 181:  */
 182: struct mbuf *
 183: hostdeque(hp)
 184:     register struct host *hp;
 185: {
 186:     register struct mbuf *m;
 187: 
 188:     hp->h_rfnm--;
 189:     HOST_DEQUE(hp, m);
 190:     if (m)
 191:         return (m);
 192:     if (hp->h_rfnm == 0)
 193:         hostfree(hp);
 194:     return (0);
 195: }
 196: 
 197: /*
 198:  * Host data base timer routine.
 199:  * Decrement timers on structures which are
 200:  * waiting to be deallocated.  On expiration
 201:  * release resources, possibly deallocating
 202:  * mbuf associated with structure.
 203:  */
 204: hostslowtimo()
 205: {
 206:     register struct mbuf *m;
 207:     register struct host *hp, *lp;
 208:     struct hmbuf *hm;
 209:     struct mbuf *mnext;
 210:     int s = splimp();
 211: 
 212:     for (m = hosts; m; m = mnext) {
 213:         mnext = m->m_next;
 214:         hm = mtod(m, struct hmbuf *);
 215:         hp = hm->hm_hosts;
 216:         lp = hp + HPMBUF;
 217:         for (; hm->hm_count > 0 && hp < lp; hp++) {
 218:             if (hp->h_timer && --hp->h_timer == 0) {
 219:                 if (hp->h_rfnm)
 220:                     log(LOG_WARNING,
 221:                     "imp?: host %x, lost %d rfnms\n",
 222:                     ntohl(hp->h_addr.s_addr), hp->h_rfnm);
 223:                 hostrelease(hp);
 224:             }
 225:         }
 226:     }
 227:     splx(s);
 228: }
 229: #endif

Defined functions

Defined variables