reactos/drivers/lib/oskittcp/oskittcp/ip_input.c

   1 /*
   2  * Copyright (c) 1982, 1986, 1988, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  *      @(#)ip_input.c  8.2 (Berkeley) 1/4/94
  34  */
  35
  36 #include <sys/param.h>
  37 #include <sys/systm.h>
  38 #include <sys/malloc.h>
  39 #include <sys/mbuf.h>
  40 #include <sys/domain.h>
  41 #include <sys/protosw.h>
  42 #include <sys/socket.h>
  43 #include <sys/errno.h>
  44 #include <sys/time.h>
  45 #include <sys/kernel.h>
  46 #include <sys/syslog.h>
  47
  48 #include <vm/vm.h>
  49 #include <sys/sysctl.h>
  50
  51 #include <net/if.h>
  52 #include <net/route.h>
  53 #include <net/netisr.h>
  54
  55 #include <netinet/in.h>
  56 #include <netinet/in_systm.h>
  57 #include <netinet/in_var.h>
  58 #include <netinet/ip.h>
  59 #include <netinet/in_pcb.h>
  60 #include <netinet/in_var.h>
  61 #include <netinet/ip_var.h>
  62 #include <netinet/ip_icmp.h>
  63
  64 #include <netinet/ip_fw.h>
  65
  66 #include <sys/socketvar.h>
  67
  68 u_char inetctlerrmap[PRC_NCMDS] = {
  69         0,              0,              0,              0,
  70         0,              EMSGSIZE,       EHOSTDOWN,      EHOSTUNREACH,
  71         EHOSTUNREACH,   EHOSTUNREACH,   ECONNREFUSED,   ECONNREFUSED,
  72         EMSGSIZE,       EHOSTUNREACH,   0,              0,
  73         0,              0,              0,              0,
  74         ENOPROTOOPT
  75 };
  76
  77 struct  in_ifaddr *in_ifaddr;                   /* first inet address */
  78 int     ip_defttl = IPDEFTTL;
  79 struct ipstat ipstat;
  80
  81 /*
  82  * We need to save the IP options in case a protocol wants to respond
  83  * to an incoming packet over the same route if the packet got here
  84  * using IP source routing.  This allows connection establishment and
  85  * maintenance when the remote end is on a network that is not known
  86  * to us.
  87  */
  88 int     ip_nhops = 0;
  89 static  struct ip_srcrt {
  90         struct  in_addr dst;                    /* final destination */
  91         char    nop;                            /* one NOP to align */
  92         char    srcopt[IPOPT_OFFSET + 1];       /* OPTVAL, OLEN and OFFSET */
  93         struct  in_addr route[MAX_IPOPTLEN/sizeof(struct in_addr)];
  94 } ip_srcrt;
  95
  96 /*
  97  * Strip out IP options, at higher
  98  * level protocol in the kernel.
  99  * Second argument is buffer to which options
 100  * will be moved, and return value is their length.
 101  * XXX should be deleted; last arg currently ignored.
 102  */
 103 void
 104 ip_stripoptions(m, mopt)
 105         register struct mbuf *m;
 106         struct mbuf *mopt;
 107 {
 108         register int i;
 109         struct ip *ip = mtod(m, struct ip *);
 110         register caddr_t opts;
 111         int olen;
 112
 113         olen = (ip->ip_hl<<2) - sizeof (struct ip);
 114         opts = (caddr_t)(ip + 1);
 115         i = m->m_len - (sizeof (struct ip) + olen);
 116         bcopy(opts + olen, opts, (unsigned)i);
 117         m->m_len -= olen;
 118         if (m->m_flags & M_PKTHDR)
 119                 m->m_pkthdr.len -= olen;
 120         ip->ip_hl = sizeof(struct ip) >> 2;
 121 }
 122
 123 /*
 124  * Retrieve incoming source route for use in replies,
 125  * in the same form used by setsockopt.
 126  * The first hop is placed before the options, will be removed later.
 127  */
 128 struct mbuf *
 129 ip_srcroute()
 130 {
 131         register struct in_addr *p, *q;
 132         register struct mbuf *m;
 133
 134         if (ip_nhops == 0)
 135                 return ((struct mbuf *)0);
 136         m = m_get(M_DONTWAIT, MT_SOOPTS);
 137         if (m == 0)
 138                 return ((struct mbuf *)0);
 139
 140 #define OPTSIZ  (sizeof(ip_srcrt.nop) + sizeof(ip_srcrt.srcopt))
 141
 142         /* length is (nhops+1)*sizeof(addr) + sizeof(nop + srcrt header) */
 143         m->m_len = ip_nhops * sizeof(struct in_addr) + sizeof(struct in_addr) +
 144             OPTSIZ;
 145 #ifdef DIAGNOSTIC
 146         if (ipprintfs)
 147                 printf("ip_srcroute: nhops %d mlen %d", ip_nhops, m->m_len);
 148 #endif
 149
 150         /*
 151          * First save first hop for return route
 152          */
 153         p = &ip_srcrt.route[ip_nhops - 1];
 154         *(mtod(m, struct in_addr *)) = *p--;
 155 #ifdef DIAGNOSTIC
 156         if (ipprintfs)
 157                 printf(" hops %lx", ntohl(mtod(m, struct in_addr *)->s_addr));
 158 #endif
 159
 160         /*
 161          * Copy option fields and padding (nop) to mbuf.
 162          */
 163         ip_srcrt.nop = IPOPT_NOP;
 164         ip_srcrt.srcopt[IPOPT_OFFSET] = IPOPT_MINOFF;
 165         (void)memcpy(mtod(m, caddr_t) + sizeof(struct in_addr),
 166             &ip_srcrt.nop, OPTSIZ);
 167         q = (struct in_addr *)(mtod(m, caddr_t) +
 168             sizeof(struct in_addr) + OPTSIZ);
 169 #undef OPTSIZ
 170         /*
 171          * Record return path as an IP source route,
 172          * reversing the path (pointers are now aligned).
 173          */
 174         while (p >= ip_srcrt.route) {
 175 #ifdef DIAGNOSTIC
 176                 if (ipprintfs)
 177                         printf(" %lx", ntohl(q->s_addr));
 178 #endif
 179                 *q++ = *p--;
 180         }
 181         /*
 182          * Last hop goes to final destination.
 183          */
 184         *q = ip_srcrt.dst;
 185 #ifdef DIAGNOSTIC
 186         if (ipprintfs)
 187                 printf(" %lx\n", ntohl(q->s_addr));
 188 #endif
 189         return (m);
 190 }