1 /* ip_output.c 1.28 82/03/29 */ 2 3 #include "../h/param.h" 4 #include "../h/mbuf.h" 5 #include "../h/mtpr.h" 6 #include "../h/socket.h" 7 #include "../h/socketvar.h" 8 #include "../net/in.h" 9 #include "../net/in_systm.h" 10 #include "../net/if.h" 11 #include "../net/ip.h" 12 #include "../net/ip_var.h" 13 #include "../net/route.h" 14 15 ip_output(m, opt, ro, allowbroadcast) 16 struct mbuf *m; 17 struct mbuf *opt; 18 struct route *ro; 19 int allowbroadcast; 20 { 21 register struct ip *ip = mtod(m, struct ip *); 22 register struct ifnet *ifp; 23 int len, hlen = sizeof (struct ip), off, direct; 24 struct sockaddr_in tempaddr; /* temp kludge */ 25 struct route iproute; 26 struct sockaddr *dst; 27 28 COUNT(IP_OUTPUT); 29 if (opt) /* XXX */ 30 (void) m_free(opt); /* XXX */ 31 /* 32 * Fill in IP header. 33 */ 34 ip->ip_v = IPVERSION; 35 ip->ip_hl = hlen >> 2; 36 ip->ip_off &= IP_DF; 37 ip->ip_id = htons(ip_id++); 38 39 #ifdef notdef 40 /* 41 * Find interface for this packet in the routing 42 * table. Note each interface has placed itself 43 * in there at boot time, so call on route degenerates 44 * to if_ifonnetof(ip->ip_dst.s_net). 45 */ 46 if (ro == 0) { 47 ro = &iproute; 48 bzero((caddr_t)ro, sizeof (*ro)); 49 } 50 if (ro->ro_rt == 0) { 51 ro->ro_dest.sin_addr = ip->ip_dst; 52 ro->ro_dest.sin_family = AF_INET; 53 direct = allocroute(ro); 54 } 55 if (ro->ro_rt == 0 || (ifp = ro->ro_rt->rt_ifp) == 0) 56 goto bad; 57 dst = direct ? (struct sockaddr *)&ro->ro_dest : 58 &ro->ro_rt->rt_gateway; 59 #else 60 /* interim kludge before routing fallout */ 61 ifp = if_ifonnetof(ip->ip_dst.s_net); 62 if (ifp == 0) 63 goto bad; 64 tempaddr.sin_family = AF_INET; 65 tempaddr.sin_addr = ip->ip_dst; 66 #endif 67 68 if (!allowbroadcast && (ifp->if_flags & IFF_BROADCAST)) { 69 struct sockaddr_in *sin; 70 71 sin = (struct sockaddr_in *)&ifp->if_broadaddr; 72 if (sin->sin_addr.s_addr == ip->ip_dst.s_addr) 73 goto bad; 74 } 75 76 /* 77 * If small enough for interface, can just send directly. 78 */ 79 if (ip->ip_len <= ifp->if_mtu) { 80 #if vax 81 ip->ip_len = htons((u_short)ip->ip_len); 82 ip->ip_off = htons((u_short)ip->ip_off); 83 #endif 84 ip->ip_sum = 0; 85 ip->ip_sum = in_cksum(m, hlen); 86 #ifdef notdef 87 return ((*ifp->if_output)(ifp, m, dst)); 88 #else 89 return ((*ifp->if_output)(ifp, m, 90 (struct sockaddr *)&tempaddr)); 91 #endif 92 } 93 94 /* 95 * Too large for interface; fragment if possible. 96 * Must be able to put at least 8 bytes per fragment. 97 */ 98 if (ip->ip_off & IP_DF) 99 goto bad; 100 len = (ifp->if_mtu - hlen) &~ 7; 101 if (len < 8) 102 goto bad; 103 104 /* 105 * Discard IP header from logical mbuf for m_copy's sake. 106 * Loop through length of segment, make a copy of each 107 * part and output. 108 */ 109 m->m_len -= sizeof (struct ip); 110 m->m_off += sizeof (struct ip); 111 for (off = 0; off < ip->ip_len-hlen; off += len) { 112 struct mbuf *mh = m_get(M_DONTWAIT); 113 struct ip *mhip; 114 115 if (mh == 0) 116 goto bad; 117 mh->m_off = MMAXOFF - hlen; 118 mhip = mtod(mh, struct ip *); 119 *mhip = *ip; 120 if (hlen > sizeof (struct ip)) { 121 int olen = ip_optcopy(ip, mhip, off); 122 mh->m_len = sizeof (struct ip) + olen; 123 } else 124 mh->m_len = sizeof (struct ip); 125 mhip->ip_off = off >> 3; 126 if (off + len >= ip->ip_len-hlen) 127 len = mhip->ip_len = ip->ip_len - hlen - off; 128 else { 129 mhip->ip_len = len; 130 mhip->ip_off |= IP_MF; 131 } 132 mhip->ip_len += sizeof (struct ip); 133 #if vax 134 mhip->ip_len = htons((u_short)mhip->ip_len); 135 #endif 136 mh->m_next = m_copy(m, off, len); 137 if (mh->m_next == 0) { 138 (void) m_free(mh); 139 goto bad; 140 } 141 #if vax 142 mhip->ip_off = htons((u_short)mhip->ip_off); 143 #endif 144 mhip->ip_sum = 0; 145 mhip->ip_sum = in_cksum(mh, hlen); 146 #ifdef notdef 147 if ((*ifp->if_output)(ifp, mh, dst) == 0) 148 #else 149 if ((*ifp->if_output)(ifp, mh, 150 (struct sockaddr *)&tempaddr) == 0) 151 #endif 152 goto bad; 153 } 154 m_freem(m); 155 return (1); 156 bad: 157 m_freem(m); 158 return (0); 159 } 160 161 /* 162 * Copy options from ip to jp. 163 * If off is 0 all options are copied 164 * otherwise copy selectively. 165 */ 166 ip_optcopy(ip, jp, off) 167 struct ip *ip, *jp; 168 int off; 169 { 170 register u_char *cp, *dp; 171 int opt, optlen, cnt; 172 173 COUNT(IP_OPTCOPY); 174 cp = (u_char *)(ip + 1); 175 dp = (u_char *)(jp + 1); 176 cnt = (ip->ip_hl << 2) - sizeof (struct ip); 177 for (; cnt > 0; cnt -= optlen, cp += optlen) { 178 opt = cp[0]; 179 if (opt == IPOPT_EOL) 180 break; 181 if (opt == IPOPT_NOP) 182 optlen = 1; 183 else 184 optlen = cp[1]; 185 if (optlen > cnt) /* XXX */ 186 optlen = cnt; /* XXX */ 187 if (off == 0 || IPOPT_COPIED(opt)) { 188 bcopy((caddr_t)cp, (caddr_t)dp, (unsigned)optlen); 189 dp += optlen; 190 } 191 } 192 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 193 *dp++ = IPOPT_EOL; 194 return (optlen); 195 } 196