| 1 | /* |
| 2 | * Copyright (c) 1982, 1986 Regents of the University of California. |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * Redistribution and use in source and binary forms are permitted |
| 6 | * provided that the above copyright notice and this paragraph are |
| 7 | * duplicated in all such forms and that any documentation, |
| 8 | * advertising materials, and other materials related to such |
| 9 | * distribution and use acknowledge that the software was developed |
| 10 | * by the University of California, Berkeley. The name of the |
| 11 | * University may not be used to endorse or promote products derived |
| 12 | * from this software without specific prior written permission. |
| 13 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR |
| 14 | * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED |
| 15 | * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. |
| 16 | * |
| 17 | * @(#)in.c 7.9 (Berkeley) %G% |
| 18 | */ |
| 19 | |
| 20 | #include "param.h" |
| 21 | #include "ioctl.h" |
| 22 | #include "mbuf.h" |
| 23 | #include "protosw.h" |
| 24 | #include "socket.h" |
| 25 | #include "socketvar.h" |
| 26 | #include "uio.h" |
| 27 | #include "dir.h" |
| 28 | #include "user.h" |
| 29 | #include "in_systm.h" |
| 30 | #include "../net/if.h" |
| 31 | #include "../net/route.h" |
| 32 | #include "../net/af.h" |
| 33 | #include "in.h" |
| 34 | #include "in_var.h" |
| 35 | |
| 36 | #ifdef INET |
| 37 | inet_hash(sin, hp) |
| 38 | register struct sockaddr_in *sin; |
| 39 | struct afhash *hp; |
| 40 | { |
| 41 | register u_long n; |
| 42 | |
| 43 | n = in_netof(sin->sin_addr); |
| 44 | if (n) |
| 45 | while ((n & 0xff) == 0) |
| 46 | n >>= 8; |
| 47 | hp->afh_nethash = n; |
| 48 | hp->afh_hosthash = ntohl(sin->sin_addr.s_addr); |
| 49 | } |
| 50 | |
| 51 | inet_netmatch(sin1, sin2) |
| 52 | struct sockaddr_in *sin1, *sin2; |
| 53 | { |
| 54 | |
| 55 | return (in_netof(sin1->sin_addr) == in_netof(sin2->sin_addr)); |
| 56 | } |
| 57 | |
| 58 | /* |
| 59 | * Formulate an Internet address from network + host. |
| 60 | */ |
| 61 | struct in_addr |
| 62 | in_makeaddr(net, host) |
| 63 | u_long net, host; |
| 64 | { |
| 65 | register struct in_ifaddr *ia; |
| 66 | register u_long mask; |
| 67 | u_long addr; |
| 68 | |
| 69 | if (IN_CLASSA(net)) |
| 70 | mask = IN_CLASSA_HOST; |
| 71 | else if (IN_CLASSB(net)) |
| 72 | mask = IN_CLASSB_HOST; |
| 73 | else |
| 74 | mask = IN_CLASSC_HOST; |
| 75 | for (ia = in_ifaddr; ia; ia = ia->ia_next) |
| 76 | if ((ia->ia_netmask & net) == ia->ia_net) { |
| 77 | mask = ~ia->ia_subnetmask; |
| 78 | break; |
| 79 | } |
| 80 | addr = htonl(net | (host & mask)); |
| 81 | return (*(struct in_addr *)&addr); |
| 82 | } |
| 83 | |
| 84 | /* |
| 85 | * Return the network number from an internet address. |
| 86 | */ |
| 87 | u_long |
| 88 | in_netof(in) |
| 89 | struct in_addr in; |
| 90 | { |
| 91 | register u_long i = ntohl(in.s_addr); |
| 92 | register u_long net; |
| 93 | register struct in_ifaddr *ia; |
| 94 | |
| 95 | if (IN_CLASSA(i)) |
| 96 | net = i & IN_CLASSA_NET; |
| 97 | else if (IN_CLASSB(i)) |
| 98 | net = i & IN_CLASSB_NET; |
| 99 | else if (IN_CLASSC(i)) |
| 100 | net = i & IN_CLASSC_NET; |
| 101 | else |
| 102 | return (0); |
| 103 | |
| 104 | /* |
| 105 | * Check whether network is a subnet; |
| 106 | * if so, return subnet number. |
| 107 | */ |
| 108 | for (ia = in_ifaddr; ia; ia = ia->ia_next) |
| 109 | if (net == ia->ia_net) |
| 110 | return (i & ia->ia_subnetmask); |
| 111 | return (net); |
| 112 | } |
| 113 | |
| 114 | /* |
| 115 | * Return the host portion of an internet address. |
| 116 | */ |
| 117 | u_long |
| 118 | in_lnaof(in) |
| 119 | struct in_addr in; |
| 120 | { |
| 121 | register u_long i = ntohl(in.s_addr); |
| 122 | register u_long net, host; |
| 123 | register struct in_ifaddr *ia; |
| 124 | |
| 125 | if (IN_CLASSA(i)) { |
| 126 | net = i & IN_CLASSA_NET; |
| 127 | host = i & IN_CLASSA_HOST; |
| 128 | } else if (IN_CLASSB(i)) { |
| 129 | net = i & IN_CLASSB_NET; |
| 130 | host = i & IN_CLASSB_HOST; |
| 131 | } else if (IN_CLASSC(i)) { |
| 132 | net = i & IN_CLASSC_NET; |
| 133 | host = i & IN_CLASSC_HOST; |
| 134 | } else |
| 135 | return (i); |
| 136 | |
| 137 | /* |
| 138 | * Check whether network is a subnet; |
| 139 | * if so, use the modified interpretation of `host'. |
| 140 | */ |
| 141 | for (ia = in_ifaddr; ia; ia = ia->ia_next) |
| 142 | if (net == ia->ia_net) |
| 143 | return (host &~ ia->ia_subnetmask); |
| 144 | return (host); |
| 145 | } |
| 146 | |
| 147 | #ifndef SUBNETSARELOCAL |
| 148 | #define SUBNETSARELOCAL 1 |
| 149 | #endif |
| 150 | int subnetsarelocal = SUBNETSARELOCAL; |
| 151 | /* |
| 152 | * Return 1 if an internet address is for a ``local'' host |
| 153 | * (one to which we have a connection). If subnetsarelocal |
| 154 | * is true, this includes other subnets of the local net. |
| 155 | * Otherwise, it includes only the directly-connected (sub)nets. |
| 156 | */ |
| 157 | in_localaddr(in) |
| 158 | struct in_addr in; |
| 159 | { |
| 160 | register u_long i = ntohl(in.s_addr); |
| 161 | register struct in_ifaddr *ia; |
| 162 | |
| 163 | if (subnetsarelocal) { |
| 164 | for (ia = in_ifaddr; ia; ia = ia->ia_next) |
| 165 | if ((i & ia->ia_netmask) == ia->ia_net) |
| 166 | return (1); |
| 167 | } else { |
| 168 | for (ia = in_ifaddr; ia; ia = ia->ia_next) |
| 169 | if ((i & ia->ia_subnetmask) == ia->ia_subnet) |
| 170 | return (1); |
| 171 | } |
| 172 | return (0); |
| 173 | } |
| 174 | |
| 175 | /* |
| 176 | * Determine whether an IP address is in a reserved set of addresses |
| 177 | * that may not be forwarded, or whether datagrams to that destination |
| 178 | * may be forwarded. |
| 179 | */ |
| 180 | in_canforward(in) |
| 181 | struct in_addr in; |
| 182 | { |
| 183 | register u_long i = ntohl(in.s_addr); |
| 184 | register u_long net; |
| 185 | |
| 186 | if (IN_EXPERIMENTAL(i)) |
| 187 | return (0); |
| 188 | if (IN_CLASSA(i)) { |
| 189 | net = i & IN_CLASSA_NET; |
| 190 | if (net == 0 || net == IN_LOOPBACKNET) |
| 191 | return (0); |
| 192 | } |
| 193 | return (1); |
| 194 | } |
| 195 | |
| 196 | int in_interfaces; /* number of external internet interfaces */ |
| 197 | extern struct ifnet loif; |
| 198 | |
| 199 | /* |
| 200 | * Generic internet control operations (ioctl's). |
| 201 | * Ifp is 0 if not an interface-specific ioctl. |
| 202 | */ |
| 203 | /* ARGSUSED */ |
| 204 | in_control(so, cmd, data, ifp) |
| 205 | struct socket *so; |
| 206 | int cmd; |
| 207 | caddr_t data; |
| 208 | register struct ifnet *ifp; |
| 209 | { |
| 210 | register struct ifreq *ifr = (struct ifreq *)data; |
| 211 | register struct in_ifaddr *ia = 0; |
| 212 | struct ifaddr *ifa; |
| 213 | struct mbuf *m; |
| 214 | int error; |
| 215 | |
| 216 | /* |
| 217 | * Find address for this interface, if it exists. |
| 218 | */ |
| 219 | if (ifp) |
| 220 | for (ia = in_ifaddr; ia; ia = ia->ia_next) |
| 221 | if (ia->ia_ifp == ifp) |
| 222 | break; |
| 223 | |
| 224 | switch (cmd) { |
| 225 | |
| 226 | case SIOCSIFADDR: |
| 227 | case SIOCSIFNETMASK: |
| 228 | case SIOCSIFDSTADDR: |
| 229 | if (!suser()) |
| 230 | return (u.u_error); |
| 231 | |
| 232 | if (ifp == 0) |
| 233 | panic("in_control"); |
| 234 | if (ia == (struct in_ifaddr *)0) { |
| 235 | m = m_getclr(M_WAIT, MT_IFADDR); |
| 236 | if (m == (struct mbuf *)NULL) |
| 237 | return (ENOBUFS); |
| 238 | if (ia = in_ifaddr) { |
| 239 | for ( ; ia->ia_next; ia = ia->ia_next) |
| 240 | ; |
| 241 | ia->ia_next = mtod(m, struct in_ifaddr *); |
| 242 | } else |
| 243 | in_ifaddr = mtod(m, struct in_ifaddr *); |
| 244 | ia = mtod(m, struct in_ifaddr *); |
| 245 | if (ifa = ifp->if_addrlist) { |
| 246 | for ( ; ifa->ifa_next; ifa = ifa->ifa_next) |
| 247 | ; |
| 248 | ifa->ifa_next = (struct ifaddr *) ia; |
| 249 | } else |
| 250 | ifp->if_addrlist = (struct ifaddr *) ia; |
| 251 | ia->ia_ifp = ifp; |
| 252 | IA_SIN(ia)->sin_family = AF_INET; |
| 253 | if (ifp != &loif) |
| 254 | in_interfaces++; |
| 255 | } |
| 256 | break; |
| 257 | |
| 258 | case SIOCSIFBRDADDR: |
| 259 | if (!suser()) |
| 260 | return (u.u_error); |
| 261 | /* FALLTHROUGH */ |
| 262 | |
| 263 | default: |
| 264 | if (ia == (struct in_ifaddr *)0) |
| 265 | return (EADDRNOTAVAIL); |
| 266 | break; |
| 267 | } |
| 268 | |
| 269 | switch (cmd) { |
| 270 | |
| 271 | case SIOCGIFADDR: |
| 272 | ifr->ifr_addr = ia->ia_addr; |
| 273 | break; |
| 274 | |
| 275 | case SIOCGIFBRDADDR: |
| 276 | if ((ifp->if_flags & IFF_BROADCAST) == 0) |
| 277 | return (EINVAL); |
| 278 | ifr->ifr_dstaddr = ia->ia_broadaddr; |
| 279 | break; |
| 280 | |
| 281 | case SIOCGIFDSTADDR: |
| 282 | if ((ifp->if_flags & IFF_POINTOPOINT) == 0) |
| 283 | return (EINVAL); |
| 284 | ifr->ifr_dstaddr = ia->ia_dstaddr; |
| 285 | break; |
| 286 | |
| 287 | case SIOCGIFNETMASK: |
| 288 | #define satosin(sa) ((struct sockaddr_in *)(sa)) |
| 289 | satosin(&ifr->ifr_addr)->sin_family = AF_INET; |
| 290 | satosin(&ifr->ifr_addr)->sin_addr.s_addr = htonl(ia->ia_subnetmask); |
| 291 | break; |
| 292 | |
| 293 | case SIOCSIFDSTADDR: |
| 294 | { |
| 295 | struct sockaddr oldaddr; |
| 296 | |
| 297 | if ((ifp->if_flags & IFF_POINTOPOINT) == 0) |
| 298 | return (EINVAL); |
| 299 | oldaddr = ia->ia_dstaddr; |
| 300 | ia->ia_dstaddr = ifr->ifr_dstaddr; |
| 301 | if (ifp->if_ioctl && |
| 302 | (error = (*ifp->if_ioctl)(ifp, SIOCSIFDSTADDR, ia))) { |
| 303 | ia->ia_dstaddr = oldaddr; |
| 304 | return (error); |
| 305 | } |
| 306 | if (ia->ia_flags & IFA_ROUTE) { |
| 307 | rtinit(&oldaddr, &ia->ia_addr, (int)SIOCDELRT, |
| 308 | RTF_HOST); |
| 309 | rtinit(&ia->ia_dstaddr, &ia->ia_addr, (int)SIOCADDRT, |
| 310 | RTF_HOST|RTF_UP); |
| 311 | } |
| 312 | } |
| 313 | break; |
| 314 | |
| 315 | case SIOCSIFBRDADDR: |
| 316 | if ((ifp->if_flags & IFF_BROADCAST) == 0) |
| 317 | return (EINVAL); |
| 318 | ia->ia_broadaddr = ifr->ifr_broadaddr; |
| 319 | break; |
| 320 | |
| 321 | case SIOCSIFADDR: |
| 322 | return (in_ifinit(ifp, ia, |
| 323 | (struct sockaddr_in *) &ifr->ifr_addr)); |
| 324 | |
| 325 | case SIOCSIFNETMASK: |
| 326 | ia->ia_subnetmask = ntohl(satosin(&ifr->ifr_addr)->sin_addr.s_addr); |
| 327 | break; |
| 328 | |
| 329 | default: |
| 330 | if (ifp == 0 || ifp->if_ioctl == 0) |
| 331 | return (EOPNOTSUPP); |
| 332 | return ((*ifp->if_ioctl)(ifp, cmd, data)); |
| 333 | } |
| 334 | return (0); |
| 335 | } |
| 336 | |
| 337 | /* |
| 338 | * Initialize an interface's internet address |
| 339 | * and routing table entry. |
| 340 | */ |
| 341 | in_ifinit(ifp, ia, sin) |
| 342 | register struct ifnet *ifp; |
| 343 | register struct in_ifaddr *ia; |
| 344 | struct sockaddr_in *sin; |
| 345 | { |
| 346 | register u_long i = ntohl(sin->sin_addr.s_addr); |
| 347 | struct sockaddr oldaddr; |
| 348 | struct sockaddr_in netaddr; |
| 349 | int s = splimp(), error; |
| 350 | |
| 351 | oldaddr = ia->ia_addr; |
| 352 | ia->ia_addr = *(struct sockaddr *)sin; |
| 353 | |
| 354 | /* |
| 355 | * Give the interface a chance to initialize |
| 356 | * if this is its first address, |
| 357 | * and to validate the address if necessary. |
| 358 | */ |
| 359 | if (ifp->if_ioctl && (error = (*ifp->if_ioctl)(ifp, SIOCSIFADDR, ia))) { |
| 360 | splx(s); |
| 361 | ia->ia_addr = oldaddr; |
| 362 | return (error); |
| 363 | } |
| 364 | |
| 365 | /* |
| 366 | * Delete any previous route for an old address. |
| 367 | */ |
| 368 | bzero((caddr_t)&netaddr, sizeof (netaddr)); |
| 369 | netaddr.sin_family = AF_INET; |
| 370 | if (ia->ia_flags & IFA_ROUTE) { |
| 371 | if (ifp->if_flags & IFF_LOOPBACK) |
| 372 | rtinit(&oldaddr, &oldaddr, (int)SIOCDELRT, RTF_HOST); |
| 373 | else if (ifp->if_flags & IFF_POINTOPOINT) |
| 374 | rtinit(&ia->ia_dstaddr, &oldaddr, (int)SIOCDELRT, |
| 375 | RTF_HOST); |
| 376 | else { |
| 377 | netaddr.sin_addr = in_makeaddr(ia->ia_subnet, |
| 378 | INADDR_ANY); |
| 379 | rtinit((struct sockaddr *)&netaddr, &oldaddr, |
| 380 | (int)SIOCDELRT, 0); |
| 381 | } |
| 382 | ia->ia_flags &= ~IFA_ROUTE; |
| 383 | } |
| 384 | if (IN_CLASSA(i)) |
| 385 | ia->ia_netmask = IN_CLASSA_NET; |
| 386 | else if (IN_CLASSB(i)) |
| 387 | ia->ia_netmask = IN_CLASSB_NET; |
| 388 | else |
| 389 | ia->ia_netmask = IN_CLASSC_NET; |
| 390 | ia->ia_net = i & ia->ia_netmask; |
| 391 | /* |
| 392 | * The subnet mask includes at least the standard network part, |
| 393 | * but may already have been set to a larger value. |
| 394 | */ |
| 395 | ia->ia_subnetmask |= ia->ia_netmask; |
| 396 | ia->ia_subnet = i & ia->ia_subnetmask; |
| 397 | if (ifp->if_flags & IFF_BROADCAST) { |
| 398 | ia->ia_broadaddr.sa_family = AF_INET; |
| 399 | ((struct sockaddr_in *)(&ia->ia_broadaddr))->sin_addr = |
| 400 | in_makeaddr(ia->ia_subnet, INADDR_BROADCAST); |
| 401 | ia->ia_netbroadcast.s_addr = |
| 402 | htonl(ia->ia_net | (INADDR_BROADCAST &~ ia->ia_netmask)); |
| 403 | } |
| 404 | /* |
| 405 | * Add route for the network. |
| 406 | */ |
| 407 | if (ifp->if_flags & IFF_LOOPBACK) |
| 408 | rtinit(&ia->ia_addr, &ia->ia_addr, (int)SIOCADDRT, |
| 409 | RTF_HOST|RTF_UP); |
| 410 | else if (ifp->if_flags & IFF_POINTOPOINT) |
| 411 | rtinit(&ia->ia_dstaddr, &ia->ia_addr, (int)SIOCADDRT, |
| 412 | RTF_HOST|RTF_UP); |
| 413 | else { |
| 414 | netaddr.sin_addr = in_makeaddr(ia->ia_subnet, INADDR_ANY); |
| 415 | rtinit((struct sockaddr *)&netaddr, &ia->ia_addr, |
| 416 | (int)SIOCADDRT, RTF_UP); |
| 417 | } |
| 418 | ia->ia_flags |= IFA_ROUTE; |
| 419 | splx(s); |
| 420 | return (0); |
| 421 | } |
| 422 | |
| 423 | /* |
| 424 | * Return address info for specified internet network. |
| 425 | */ |
| 426 | struct in_ifaddr * |
| 427 | in_iaonnetof(net) |
| 428 | u_long net; |
| 429 | { |
| 430 | register struct in_ifaddr *ia; |
| 431 | |
| 432 | for (ia = in_ifaddr; ia; ia = ia->ia_next) |
| 433 | if (ia->ia_subnet == net) |
| 434 | return (ia); |
| 435 | return ((struct in_ifaddr *)0); |
| 436 | } |
| 437 | |
| 438 | /* |
| 439 | * Return 1 if the address might be a local broadcast address. |
| 440 | */ |
| 441 | in_broadcast(in) |
| 442 | struct in_addr in; |
| 443 | { |
| 444 | register struct in_ifaddr *ia; |
| 445 | u_long t; |
| 446 | |
| 447 | /* |
| 448 | * Look through the list of addresses for a match |
| 449 | * with a broadcast address. |
| 450 | */ |
| 451 | for (ia = in_ifaddr; ia; ia = ia->ia_next) |
| 452 | if (ia->ia_ifp->if_flags & IFF_BROADCAST) { |
| 453 | if (satosin(&ia->ia_broadaddr)->sin_addr.s_addr == in.s_addr) |
| 454 | return (1); |
| 455 | /* |
| 456 | * Check for old-style (host 0) broadcast. |
| 457 | */ |
| 458 | if ((t = ntohl(in.s_addr)) == ia->ia_subnet || t == ia->ia_net) |
| 459 | return (1); |
| 460 | } |
| 461 | if (in.s_addr == INADDR_BROADCAST || in.s_addr == INADDR_ANY) |
| 462 | return (1); |
| 463 | return (0); |
| 464 | } |
| 465 | #endif |