2.11BSD#431 - /usr/src/sys/net/if_loop.c

   1: /*
   2:  * Copyright (c) 1982, 1986 Regents of the University of California.
   3:  * All rights reserved.
   4:  *
   5:  * Redistribution and use in source and binary forms are permitted
   6:  * provided that this notice is preserved and that due credit is given
   7:  * to the University of California at Berkeley. The name of the University
   8:  * may not be used to endorse or promote products derived from this
   9:  * software without specific prior written permission. This software
  10:  * is provided ``as is'' without express or implied warranty.
  11:  *
  12:  *	@(#)if_loop.c	7.3 (Berkeley) 12/30/87
  13:  */
  14: 
  15: /*
  16:  * Loopback interface driver for protocol testing and timing.
  17:  */
  18: 
  19: #include "param.h"
  20: #include "systm.h"
  21: #include "mbuf.h"
  22: #include "socket.h"
  23: #include "errno.h"
  24: #include "ioctl.h"
  25: 
  26: #include "domain.h"
  27: #include "protosw.h"
  28: 
  29: #include "../net/if.h"
  30: #include "../net/netisr.h"
  31: #include "../net/route.h"
  32: 
  33: #ifdef  INET
  34: #include "../netinet/in.h"
  35: #include "../netinet/in_systm.h"
  36: #include "../netinet/in_var.h"
  37: #include "../netinet/ip.h"
  38: #endif
  39: 
  40: #ifdef NS
  41: #include "../netns/ns.h"
  42: #include "../netns/ns_if.h"
  43: #endif
  44: 
  45: #define LOMTU   (1024+512)
  46: 
  47: struct  ifnet loif;
  48: int looutput(), loioctl();
  49: 
  50: loattach()
  51: {
  52:     register struct ifnet *ifp = &loif;
  53: 
  54:     ifp->if_name = "lo";
  55:     ifp->if_mtu = LOMTU;
  56:     ifp->if_flags = IFF_LOOPBACK;
  57:     ifp->if_ioctl = loioctl;
  58:     ifp->if_output = looutput;
  59:     if_attach(ifp);
  60: }
  61: 
  62: looutput(ifp, m0, dst)
  63:     struct ifnet *ifp;
  64:     register struct mbuf *m0;
  65:     struct sockaddr *dst;
  66: {
  67:     int s;
  68:     register struct ifqueue *ifq;
  69:     struct mbuf *m;
  70: 
  71:     /*
  72: 	 * Place interface pointer before the data
  73: 	 * for the receiving protocol.
  74: 	 */
  75:     if (m0->m_off <= MMAXOFF &&
  76:         m0->m_off >= MMINOFF + sizeof(struct ifnet *)) {
  77:         m0->m_off -= sizeof(struct ifnet *);
  78:         m0->m_len += sizeof(struct ifnet *);
  79:     } else {
  80:         MGET(m, M_DONTWAIT, MT_HEADER);
  81:         if (m == (struct mbuf *)0)
  82:             return (ENOBUFS);
  83:         m->m_off = MMINOFF;
  84:         m->m_len = sizeof(struct ifnet *);
  85:         m->m_next = m0;
  86:         m0 = m;
  87:     }
  88:     *(mtod(m0, struct ifnet **)) = ifp;
  89:     s = splimp();
  90:     ifp->if_opackets++;
  91:     switch (dst->sa_family) {
  92: 
  93: #ifdef INET
  94:     case AF_INET:
  95:         ifq = &ipintrq;
  96:         if (IF_QFULL(ifq)) {
  97:             IF_DROP(ifq);
  98:             m_freem(m0);
  99:             splx(s);
 100:             return (ENOBUFS);
 101:         }
 102:         IF_ENQUEUE(ifq, m0);
 103:         schednetisr(NETISR_IP);
 104:         break;
 105: #endif
 106: #ifdef NS
 107:     case AF_NS:
 108:         ifq = &nsintrq;
 109:         if (IF_QFULL(ifq)) {
 110:             IF_DROP(ifq);
 111:             m_freem(m0);
 112:             splx(s);
 113:             return (ENOBUFS);
 114:         }
 115:         IF_ENQUEUE(ifq, m0);
 116:         schednetisr(NETISR_NS);
 117:         break;
 118: #endif
 119:     default:
 120:         splx(s);
 121:         printf("lo%d: can't handle af%d\n", ifp->if_unit,
 122:             dst->sa_family);
 123:         m_freem(m0);
 124:         return (EAFNOSUPPORT);
 125:     }
 126:     ifp->if_ipackets++;
 127:     splx(s);
 128:     return (0);
 129: }
 130: 
 131: /*
 132:  * Process an ioctl request.
 133:  */
 134: /* ARGSUSED */
 135: loioctl(ifp, cmd, data)
 136:     register struct ifnet *ifp;
 137:     int cmd;
 138:     caddr_t data;
 139: {
 140:     int error = 0;
 141: 
 142:     switch (cmd) {
 143: 
 144:     case SIOCSIFADDR:
 145:         ifp->if_flags |= IFF_UP;
 146:         /*
 147: 		 * Everything else is done at a higher level.
 148: 		 */
 149:         break;
 150: 
 151:     default:
 152:         error = EINVAL;
 153:     }
 154:     return (error);
 155: }

Defined functions

Defined variables

Defined macros