4.3BSD - /usr/src/sys/net/if_loop.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_loop.c	7.1 (Berkeley) 6/4/86
   7:  */
   8: 
   9: /*
  10:  * Loopback interface driver for protocol testing and timing.
  11:  */
  12: 
  13: #include "param.h"
  14: #include "systm.h"
  15: #include "mbuf.h"
  16: #include "socket.h"
  17: #include "errno.h"
  18: #include "ioctl.h"
  19: 
  20: #include "../net/if.h"
  21: #include "../net/netisr.h"
  22: #include "../net/route.h"
  23: 
  24: #ifdef  INET
  25: #include "../netinet/in.h"
  26: #include "../netinet/in_systm.h"
  27: #include "../netinet/in_var.h"
  28: #include "../netinet/ip.h"
  29: #endif
  30: 
  31: #ifdef vax
  32: #include "../vax/mtpr.h"
  33: #endif
  34: 
  35: #ifdef NS
  36: #include "../netns/ns.h"
  37: #include "../netns/ns_if.h"
  38: #endif
  39: 
  40: #define LOMTU   (1024+512)
  41: 
  42: struct  ifnet loif;
  43: int looutput(), loioctl();
  44: 
  45: loattach()
  46: {
  47:     register struct ifnet *ifp = &loif;
  48: 
  49:     ifp->if_name = "lo";
  50:     ifp->if_mtu = LOMTU;
  51:     ifp->if_flags = IFF_LOOPBACK;
  52:     ifp->if_ioctl = loioctl;
  53:     ifp->if_output = looutput;
  54:     if_attach(ifp);
  55: }
  56: 
  57: looutput(ifp, m0, dst)
  58:     struct ifnet *ifp;
  59:     register struct mbuf *m0;
  60:     struct sockaddr *dst;
  61: {
  62:     int s;
  63:     register struct ifqueue *ifq;
  64:     struct mbuf *m;
  65: 
  66:     /*
  67: 	 * Place interface pointer before the data
  68: 	 * for the receiving protocol.
  69: 	 */
  70:     if (m0->m_off <= MMAXOFF &&
  71:         m0->m_off >= MMINOFF + sizeof(struct ifnet *)) {
  72:         m0->m_off -= sizeof(struct ifnet *);
  73:         m0->m_len += sizeof(struct ifnet *);
  74:     } else {
  75:         MGET(m, M_DONTWAIT, MT_HEADER);
  76:         if (m == (struct mbuf *)0)
  77:             return (ENOBUFS);
  78:         m->m_off = MMINOFF;
  79:         m->m_len = sizeof(struct ifnet *);
  80:         m->m_next = m0;
  81:         m0 = m;
  82:     }
  83:     *(mtod(m0, struct ifnet **)) = ifp;
  84:     s = splimp();
  85:     ifp->if_opackets++;
  86:     switch (dst->sa_family) {
  87: 
  88: #ifdef INET
  89:     case AF_INET:
  90:         ifq = &ipintrq;
  91:         if (IF_QFULL(ifq)) {
  92:             IF_DROP(ifq);
  93:             m_freem(m0);
  94:             splx(s);
  95:             return (ENOBUFS);
  96:         }
  97:         IF_ENQUEUE(ifq, m0);
  98:         schednetisr(NETISR_IP);
  99:         break;
 100: #endif
 101: #ifdef NS
 102:     case AF_NS:
 103:         ifq = &nsintrq;
 104:         if (IF_QFULL(ifq)) {
 105:             IF_DROP(ifq);
 106:             m_freem(m0);
 107:             splx(s);
 108:             return (ENOBUFS);
 109:         }
 110:         IF_ENQUEUE(ifq, m0);
 111:         schednetisr(NETISR_NS);
 112:         break;
 113: #endif
 114:     default:
 115:         splx(s);
 116:         printf("lo%d: can't handle af%d\n", ifp->if_unit,
 117:             dst->sa_family);
 118:         m_freem(m0);
 119:         return (EAFNOSUPPORT);
 120:     }
 121:     ifp->if_ipackets++;
 122:     splx(s);
 123:     return (0);
 124: }
 125: 
 126: /*
 127:  * Process an ioctl request.
 128:  */
 129: /* ARGSUSED */
 130: loioctl(ifp, cmd, data)
 131:     register struct ifnet *ifp;
 132:     int cmd;
 133:     caddr_t data;
 134: {
 135:     int error = 0;
 136: 
 137:     switch (cmd) {
 138: 
 139:     case SIOCSIFADDR:
 140:         ifp->if_flags |= IFF_UP;
 141:         /*
 142: 		 * Everything else is done at a higher level.
 143: 		 */
 144:         break;
 145: 
 146:     default:
 147:         error = EINVAL;
 148:     }
 149:     return (error);
 150: }

Defined functions

Defined variables

Defined macros