1 /* ip_output.c 1.27 82/03/28 */ 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; 24 struct sockaddr_in tempaddr; /* temp kludge */ 25 struct route iproute; 26 27 COUNT(IP_OUTPUT); 28 if (opt) /* XXX */ 29 (void) m_free(opt); /* XXX */ 30 /* 31 * Fill in IP header. 32 */ 33 ip->ip_v = IPVERSION; 34 ip->ip_hl = hlen >> 2; 35 ip->ip_off &= IP_DF; 36 ip->ip_id = htons(ip_id++); 37 38 #ifdef notdef 39 /* 40 * Find interface for this packet. 41 */ 42 if (ro == 0) { 43 ro = &iproute; 44 bzero((caddr_t)ro, sizeof (*ro)); 45 } 46 if (ro->ro_rt == 0) { 47 ro->ro_dest.sin_addr = ip->ip_dst; 48 ro->ro_dest.sin_family = AF_INET; 49 route(ro); 50 } 51 if (ro->ro_rt == 0 || (ifp = ro->ro_rt->rt_ifp) == 0) 52 goto bad; 53 #else 54 /* interim kludge before routing fallout */ 55 ifp = if_ifonnetof(ip->ip_dst.s_net); 56 if (ifp == 0) 57 goto bad; 58 tempaddr.sin_family = AF_INET; 59 tempaddr.sin_addr = ip->ip_dst; 60 #endif 61 62 if (!allowbroadcast && (ifp->if_flags & IFF_BROADCAST)) { 63 struct sockaddr_in *sin; 64 65 sin = (struct sockaddr_in *)&ifp->if_broadaddr; 66 if (sin->sin_addr.s_addr == ip->ip_dst.s_addr) 67 goto bad; 68 } 69 70 /* 71 * If small enough for interface, can just send directly. 72 */ 73 if (ip->ip_len <= ifp->if_mtu) { 74 #if vax 75 ip->ip_len = htons((u_short)ip->ip_len); 76 ip->ip_off = htons((u_short)ip->ip_off); 77 #endif 78 ip->ip_sum = 0; 79 ip->ip_sum = in_cksum(m, hlen); 80 return ((*ifp->if_output)(ifp, m, 81 #ifdef notdef 82 &ro->ro_rt->rt_dest)); 83 #else 84 (struct sockaddr *)&tempaddr)); 85 #endif 86 } 87 88 /* 89 * Too large for interface; fragment if possible. 90 * Must be able to put at least 8 bytes per fragment. 91 */ 92 if (ip->ip_off & IP_DF) 93 goto bad; 94 len = (ifp->if_mtu - hlen) &~ 7; 95 if (len < 8) 96 goto bad; 97 98 /* 99 * Discard IP header from logical mbuf for m_copy's sake. 100 * Loop through length of segment, make a copy of each 101 * part and output. 102 */ 103 m->m_len -= sizeof (struct ip); 104 m->m_off += sizeof (struct ip); 105 for (off = 0; off < ip->ip_len-hlen; off += len) { 106 struct mbuf *mh = m_get(M_DONTWAIT); 107 struct ip *mhip; 108 109 if (mh == 0) 110 goto bad; 111 mh->m_off = MMAXOFF - hlen; 112 mhip = mtod(mh, struct ip *); 113 *mhip = *ip; 114 if (hlen > sizeof (struct ip)) { 115 int olen = ip_optcopy(ip, mhip, off); 116 mh->m_len = sizeof (struct ip) + olen; 117 } else 118 mh->m_len = sizeof (struct ip); 119 mhip->ip_off = off >> 3; 120 if (off + len >= ip->ip_len-hlen) 121 len = mhip->ip_len = ip->ip_len - hlen - off; 122 else { 123 mhip->ip_len = len; 124 mhip->ip_off |= IP_MF; 125 } 126 mhip->ip_len += sizeof (struct ip); 127 #if vax 128 mhip->ip_len = htons((u_short)mhip->ip_len); 129 #endif 130 mh->m_next = m_copy(m, off, len); 131 if (mh->m_next == 0) { 132 (void) m_free(mh); 133 goto bad; 134 } 135 #if vax 136 mhip->ip_off = htons((u_short)mhip->ip_off); 137 #endif 138 mhip->ip_sum = 0; 139 mhip->ip_sum = in_cksum(mh, hlen); 140 if ((*ifp->if_output)(ifp, mh, 141 #ifdef notdef 142 &ro->ro_rt->rt_dest) == 0) 143 #else 144 (struct sockaddr *)&tempaddr) == 0) 145 #endif 146 goto bad; 147 } 148 m_freem(m); 149 return (1); 150 bad: 151 m_freem(m); 152 return (0); 153 } 154 155 /* 156 * Copy options from ip to jp. 157 * If off is 0 all options are copied 158 * otherwise copy selectively. 159 */ 160 ip_optcopy(ip, jp, off) 161 struct ip *ip, *jp; 162 int off; 163 { 164 register u_char *cp, *dp; 165 int opt, optlen, cnt; 166 167 COUNT(IP_OPTCOPY); 168 cp = (u_char *)(ip + 1); 169 dp = (u_char *)(jp + 1); 170 cnt = (ip->ip_hl << 2) - sizeof (struct ip); 171 for (; cnt > 0; cnt -= optlen, cp += optlen) { 172 opt = cp[0]; 173 if (opt == IPOPT_EOL) 174 break; 175 if (opt == IPOPT_NOP) 176 optlen = 1; 177 else 178 optlen = cp[1]; 179 if (optlen > cnt) /* XXX */ 180 optlen = cnt; /* XXX */ 181 if (off == 0 || IPOPT_COPIED(opt)) { 182 bcopy((caddr_t)cp, (caddr_t)dp, (unsigned)optlen); 183 dp += optlen; 184 } 185 } 186 for (optlen = dp - (u_char *)(jp+1); optlen & 0x3; optlen++) 187 *dp++ = IPOPT_EOL; 188 return (optlen); 189 } 190