1 /* 2 * Copyright (c) 1983 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 7 #ifndef lint 8 static char sccsid[] = "@(#)inet.c 5.4 (Berkeley) 06/03/86"; 9 #endif not lint 10 11 /* 12 * Temporarily, copy these routines from the kernel, 13 * as we need to know about subnets. 14 */ 15 #include "defs.h" 16 17 extern struct interface *ifnet; 18 19 /* 20 * Formulate an Internet address from network + host. 21 */ 22 struct in_addr 23 inet_makeaddr(net, host) 24 u_long net, host; 25 { 26 register struct interface *ifp; 27 register u_long mask; 28 u_long addr; 29 30 if (IN_CLASSA(net)) 31 mask = IN_CLASSA_HOST; 32 else if (IN_CLASSB(net)) 33 mask = IN_CLASSB_HOST; 34 else 35 mask = IN_CLASSC_HOST; 36 for (ifp = ifnet; ifp; ifp = ifp->int_next) 37 if ((ifp->int_netmask & net) == ifp->int_net) { 38 mask = ~ifp->int_subnetmask; 39 break; 40 } 41 addr = net | (host & mask); 42 addr = htonl(addr); 43 return (*(struct in_addr *)&addr); 44 } 45 46 /* 47 * Return the network number from an internet address. 48 */ 49 inet_netof(in) 50 struct in_addr in; 51 { 52 register u_long i = ntohl(in.s_addr); 53 register u_long net; 54 register struct interface *ifp; 55 56 if (IN_CLASSA(i)) 57 net = i & IN_CLASSA_NET; 58 else if (IN_CLASSB(i)) 59 net = i & IN_CLASSB_NET; 60 else 61 net = i & IN_CLASSC_NET; 62 63 /* 64 * Check whether network is a subnet; 65 * if so, return subnet number. 66 */ 67 for (ifp = ifnet; ifp; ifp = ifp->int_next) 68 if ((ifp->int_netmask & net) == ifp->int_net) 69 return (i & ifp->int_subnetmask); 70 return (net); 71 } 72 73 /* 74 * Return the host portion of an internet address. 75 */ 76 inet_lnaof(in) 77 struct in_addr in; 78 { 79 register u_long i = ntohl(in.s_addr); 80 register u_long net, host; 81 register struct interface *ifp; 82 83 if (IN_CLASSA(i)) { 84 net = i & IN_CLASSA_NET; 85 host = i & IN_CLASSA_HOST; 86 } else if (IN_CLASSB(i)) { 87 net = i & IN_CLASSB_NET; 88 host = i & IN_CLASSB_HOST; 89 } else { 90 net = i & IN_CLASSC_NET; 91 host = i & IN_CLASSC_HOST; 92 } 93 94 /* 95 * Check whether network is a subnet; 96 * if so, use the modified interpretation of `host'. 97 */ 98 for (ifp = ifnet; ifp; ifp = ifp->int_next) 99 if ((ifp->int_netmask & net) == ifp->int_net) 100 return (host &~ ifp->int_subnetmask); 101 return (host); 102 } 103 104 /* 105 * Return RTF_HOST if the address is 106 * for an Internet host, RTF_SUBNET for a subnet, 107 * 0 for a network. 108 */ 109 inet_rtflags(sin) 110 struct sockaddr_in *sin; 111 { 112 register u_long i = ntohl(sin->sin_addr.s_addr); 113 register u_long net, host; 114 register struct interface *ifp; 115 116 if (IN_CLASSA(i)) { 117 net = i & IN_CLASSA_NET; 118 host = i & IN_CLASSA_HOST; 119 } else if (IN_CLASSB(i)) { 120 net = i & IN_CLASSB_NET; 121 host = i & IN_CLASSB_HOST; 122 } else { 123 net = i & IN_CLASSC_NET; 124 host = i & IN_CLASSC_HOST; 125 } 126 127 /* 128 * Check whether this network is subnetted; 129 * if so, check whether this is a subnet or a host. 130 */ 131 for (ifp = ifnet; ifp; ifp = ifp->int_next) 132 if (net == ifp->int_net) { 133 if (host &~ ifp->int_subnetmask) 134 return (RTF_HOST); 135 else if (ifp->int_subnetmask != ifp->int_netmask) 136 return (RTF_SUBNET); 137 else 138 return (0); /* network */ 139 } 140 if (host == 0) 141 return (0); /* network */ 142 else 143 return (RTF_HOST); 144 } 145 146 /* 147 * Return true if a route to subnet of route rt should be sent to dst. 148 * Send it only if dst is on the same logical network, 149 * or the route is the "internal" route for the net. 150 */ 151 inet_sendsubnet(rt, dst) 152 struct rt_entry *rt; 153 struct sockaddr_in *dst; 154 { 155 register u_long r = 156 ntohl(((struct sockaddr_in *)&rt->rt_dst)->sin_addr.s_addr); 157 register u_long d = ntohl(dst->sin_addr.s_addr); 158 159 if (IN_CLASSA(r)) { 160 if ((r & IN_CLASSA_NET) == (d & IN_CLASSA_NET)) { 161 if ((r & IN_CLASSA_HOST) == 0) 162 return ((rt->rt_state & RTS_INTERNAL) == 0); 163 return (1); 164 } 165 if (r & IN_CLASSA_HOST) 166 return (0); 167 return ((rt->rt_state & RTS_INTERNAL) != 0); 168 } else if (IN_CLASSB(r)) { 169 if ((r & IN_CLASSB_NET) == (d & IN_CLASSB_NET)) { 170 if ((r & IN_CLASSB_HOST) == 0) 171 return ((rt->rt_state & RTS_INTERNAL) == 0); 172 return (1); 173 } 174 if (r & IN_CLASSB_HOST) 175 return (0); 176 return ((rt->rt_state & RTS_INTERNAL) != 0); 177 } else { 178 if ((r & IN_CLASSC_NET) == (d & IN_CLASSC_NET)) { 179 if ((r & IN_CLASSC_HOST) == 0) 180 return ((rt->rt_state & RTS_INTERNAL) == 0); 181 return (1); 182 } 183 if (r & IN_CLASSC_HOST) 184 return (0); 185 return ((rt->rt_state & RTS_INTERNAL) != 0); 186 } 187 } 188