| 1 | /* route.c 6.3 83/12/15 */ |
| 2 | |
| 3 | #include "../h/param.h" |
| 4 | #include "../h/systm.h" |
| 5 | #include "../h/mbuf.h" |
| 6 | #include "../h/protosw.h" |
| 7 | #include "../h/socket.h" |
| 8 | #include "../h/dir.h" |
| 9 | #include "../h/user.h" |
| 10 | #include "../h/ioctl.h" |
| 11 | #include "../h/errno.h" |
| 12 | |
| 13 | #include "../net/if.h" |
| 14 | #include "../net/af.h" |
| 15 | #include "../net/route.h" |
| 16 | |
| 17 | int rttrash; /* routes not in table but not freed */ |
| 18 | struct sockaddr wildcard; /* zero valued cookie for wildcard searches */ |
| 19 | |
| 20 | /* |
| 21 | * Packet routing routines. |
| 22 | */ |
| 23 | rtalloc(ro) |
| 24 | register struct route *ro; |
| 25 | { |
| 26 | register struct rtentry *rt; |
| 27 | register struct mbuf *m; |
| 28 | register u_long hash; |
| 29 | struct sockaddr *dst = &ro->ro_dst; |
| 30 | int (*match)(), doinghost; |
| 31 | struct afhash h; |
| 32 | u_int af = dst->sa_family; |
| 33 | struct rtentry *rtmin; |
| 34 | struct mbuf **table; |
| 35 | |
| 36 | if (ro->ro_rt && ro->ro_rt->rt_ifp && (ro->ro_rt->rt_flags & RTF_UP)) |
| 37 | return; /* XXX */ |
| 38 | if (af >= AF_MAX) |
| 39 | return; |
| 40 | (*afswitch[af].af_hash)(dst, &h); |
| 41 | rtmin = 0; |
| 42 | match = afswitch[af].af_netmatch; |
| 43 | hash = h.afh_hosthash, table = rthost, doinghost = 1; |
| 44 | again: |
| 45 | for (m = table[hash % RTHASHSIZ]; m; m = m->m_next) { |
| 46 | rt = mtod(m, struct rtentry *); |
| 47 | if (rt->rt_hash != hash) |
| 48 | continue; |
| 49 | if ((rt->rt_flags & RTF_UP) == 0 || |
| 50 | (rt->rt_ifp->if_flags & IFF_UP) == 0) |
| 51 | continue; |
| 52 | if (doinghost) { |
| 53 | if (bcmp((caddr_t)&rt->rt_dst, (caddr_t)dst, |
| 54 | sizeof (*dst))) |
| 55 | continue; |
| 56 | } else { |
| 57 | if (rt->rt_dst.sa_family != af || |
| 58 | !(*match)(&rt->rt_dst, dst)) |
| 59 | continue; |
| 60 | } |
| 61 | if (rtmin == 0 || rt->rt_use < rtmin->rt_use) |
| 62 | rtmin = rt; |
| 63 | } |
| 64 | if (rtmin == 0 && doinghost) { |
| 65 | doinghost = 0; |
| 66 | hash = h.afh_nethash, table = rtnet; |
| 67 | goto again; |
| 68 | } |
| 69 | /* |
| 70 | * Check for wildcard gateway, by convention network 0. |
| 71 | */ |
| 72 | if (rtmin == 0 && dst != &wildcard) { |
| 73 | dst = &wildcard, hash = 0; |
| 74 | goto again; |
| 75 | } |
| 76 | ro->ro_rt = rtmin; |
| 77 | if (rtmin == 0) { |
| 78 | rtstat.rts_unreach++; |
| 79 | return; |
| 80 | } |
| 81 | rtmin->rt_refcnt++; |
| 82 | if (dst == &wildcard) |
| 83 | rtstat.rts_wildcard++; |
| 84 | } |
| 85 | |
| 86 | rtfree(rt) |
| 87 | register struct rtentry *rt; |
| 88 | { |
| 89 | |
| 90 | if (rt == 0) |
| 91 | panic("rtfree"); |
| 92 | rt->rt_refcnt--; |
| 93 | if (rt->rt_refcnt == 0 && (rt->rt_flags&RTF_UP) == 0) { |
| 94 | rttrash--; |
| 95 | (void) m_free(dtom(rt)); |
| 96 | } |
| 97 | } |
| 98 | |
| 99 | /* |
| 100 | * Force a routing table entry to the specified |
| 101 | * destination to go through the given gateway. |
| 102 | * Normally called as a result of a routing redirect |
| 103 | * message from the network layer. |
| 104 | * |
| 105 | * N.B.: must be called at splnet or higher |
| 106 | * |
| 107 | * Should notify all parties with a reference to |
| 108 | * the route that it's changed (so, for instance, |
| 109 | * current round trip time estimates could be flushed), |
| 110 | * but we have no back pointers at the moment. |
| 111 | */ |
| 112 | rtredirect(dst, gateway, flags) |
| 113 | struct sockaddr *dst, *gateway; |
| 114 | int flags; |
| 115 | { |
| 116 | struct route ro; |
| 117 | register struct rtentry *rt; |
| 118 | |
| 119 | /* verify the gateway is directly reachable */ |
| 120 | if (if_ifwithnet(gateway) == 0) { |
| 121 | rtstat.rts_badredirect++; |
| 122 | return; |
| 123 | } |
| 124 | ro.ro_dst = *dst; |
| 125 | ro.ro_rt = 0; |
| 126 | rtalloc(&ro); |
| 127 | rt = ro.ro_rt; |
| 128 | /* |
| 129 | * Create a new entry if we just got back a wildcard entry |
| 130 | * or the the lookup failed. This is necessary for hosts |
| 131 | * which use routing redirects generated by smart gateways |
| 132 | * to dynamically build the routing tables. |
| 133 | */ |
| 134 | if (rt && |
| 135 | (*afswitch[dst->sa_family].af_netmatch)(&wildcard, &rt->rt_dst)) { |
| 136 | rtfree(rt); |
| 137 | rt = 0; |
| 138 | } |
| 139 | if (rt == 0) { |
| 140 | rtinit(dst, gateway, RTF_GATEWAY); |
| 141 | rtstat.rts_dynamic++; |
| 142 | return; |
| 143 | } |
| 144 | /* |
| 145 | * Don't listen to the redirect if it's |
| 146 | * for a route to an interface. |
| 147 | */ |
| 148 | if (rt->rt_flags & RTF_GATEWAY) { |
| 149 | if (((rt->rt_flags & RTF_HOST) == 0) && (flags & RTF_HOST)) { |
| 150 | /* |
| 151 | * Changing from route to gateway => route to host. |
| 152 | * Create new route, rather than smashing route to net. |
| 153 | */ |
| 154 | rtfree(rt); |
| 155 | rtinit(dst, gateway, flags); |
| 156 | rtstat.rts_newgateway++; |
| 157 | } else { |
| 158 | /* |
| 159 | * Smash the current notion of the gateway to |
| 160 | * this destination. This is probably not right, |
| 161 | * as it's conceivable a flurry of redirects could |
| 162 | * cause the gateway value to fluctuate wildly during |
| 163 | * dynamic routing reconfiguration. |
| 164 | */ |
| 165 | rt->rt_gateway = *gateway; |
| 166 | rtfree(rt); |
| 167 | rtstat.rts_newgateway++; |
| 168 | } |
| 169 | } |
| 170 | } |
| 171 | |
| 172 | /* |
| 173 | * Routing table ioctl interface. |
| 174 | */ |
| 175 | rtioctl(cmd, data) |
| 176 | int cmd; |
| 177 | caddr_t data; |
| 178 | { |
| 179 | |
| 180 | if (cmd != SIOCADDRT && cmd != SIOCDELRT) |
| 181 | return (EINVAL); |
| 182 | if (!suser()) |
| 183 | return (u.u_error); |
| 184 | return (rtrequest(cmd, (struct rtentry *)data)); |
| 185 | } |
| 186 | |
| 187 | /* |
| 188 | * Carry out a request to change the routing table. Called by |
| 189 | * interfaces at boot time to make their ``local routes'' known, |
| 190 | * for ioctl's, and as the result of routing redirects. |
| 191 | */ |
| 192 | rtrequest(req, entry) |
| 193 | int req; |
| 194 | register struct rtentry *entry; |
| 195 | { |
| 196 | register struct mbuf *m, **mprev; |
| 197 | register struct rtentry *rt; |
| 198 | struct afhash h; |
| 199 | int s, error = 0, (*match)(); |
| 200 | u_int af; |
| 201 | u_long hash; |
| 202 | struct ifnet *ifp; |
| 203 | |
| 204 | af = entry->rt_dst.sa_family; |
| 205 | if (af >= AF_MAX) |
| 206 | return (EAFNOSUPPORT); |
| 207 | (*afswitch[af].af_hash)(&entry->rt_dst, &h); |
| 208 | if (entry->rt_flags & RTF_HOST) { |
| 209 | hash = h.afh_hosthash; |
| 210 | mprev = &rthost[hash % RTHASHSIZ]; |
| 211 | } else { |
| 212 | hash = h.afh_nethash; |
| 213 | mprev = &rtnet[hash % RTHASHSIZ]; |
| 214 | } |
| 215 | match = afswitch[af].af_netmatch; |
| 216 | s = splimp(); |
| 217 | for (; m = *mprev; mprev = &m->m_next) { |
| 218 | rt = mtod(m, struct rtentry *); |
| 219 | if (rt->rt_hash != hash) |
| 220 | continue; |
| 221 | if (entry->rt_flags & RTF_HOST) { |
| 222 | #define equal(a1, a2) \ |
| 223 | (bcmp((caddr_t)(a1), (caddr_t)(a2), sizeof (struct sockaddr)) == 0) |
| 224 | if (!equal(&rt->rt_dst, &entry->rt_dst)) |
| 225 | continue; |
| 226 | } else { |
| 227 | if (rt->rt_dst.sa_family != entry->rt_dst.sa_family || |
| 228 | (*match)(&rt->rt_dst, &entry->rt_dst) == 0) |
| 229 | continue; |
| 230 | } |
| 231 | if (equal(&rt->rt_gateway, &entry->rt_gateway)) |
| 232 | break; |
| 233 | } |
| 234 | switch (req) { |
| 235 | |
| 236 | case SIOCDELRT: |
| 237 | if (m == 0) { |
| 238 | error = ESRCH; |
| 239 | goto bad; |
| 240 | } |
| 241 | *mprev = m->m_next; |
| 242 | if (rt->rt_refcnt > 0) { |
| 243 | rt->rt_flags &= ~RTF_UP; |
| 244 | rttrash++; |
| 245 | m->m_next = 0; |
| 246 | } else |
| 247 | (void) m_free(m); |
| 248 | break; |
| 249 | |
| 250 | case SIOCADDRT: |
| 251 | if (m) { |
| 252 | error = EEXIST; |
| 253 | goto bad; |
| 254 | } |
| 255 | ifp = if_ifwithaddr(&entry->rt_gateway); |
| 256 | if (ifp == 0) { |
| 257 | ifp = if_ifwithnet(&entry->rt_gateway); |
| 258 | if (ifp == 0) { |
| 259 | error = ENETUNREACH; |
| 260 | goto bad; |
| 261 | } |
| 262 | } |
| 263 | m = m_get(M_DONTWAIT, MT_RTABLE); |
| 264 | if (m == 0) { |
| 265 | error = ENOBUFS; |
| 266 | goto bad; |
| 267 | } |
| 268 | *mprev = m; |
| 269 | m->m_off = MMINOFF; |
| 270 | m->m_len = sizeof (struct rtentry); |
| 271 | rt = mtod(m, struct rtentry *); |
| 272 | rt->rt_hash = hash; |
| 273 | rt->rt_dst = entry->rt_dst; |
| 274 | rt->rt_gateway = entry->rt_gateway; |
| 275 | rt->rt_flags = |
| 276 | RTF_UP | (entry->rt_flags & (RTF_HOST|RTF_GATEWAY)); |
| 277 | rt->rt_refcnt = 0; |
| 278 | rt->rt_use = 0; |
| 279 | rt->rt_ifp = ifp; |
| 280 | break; |
| 281 | } |
| 282 | bad: |
| 283 | splx(s); |
| 284 | return (error); |
| 285 | } |
| 286 | |
| 287 | /* |
| 288 | * Set up a routing table entry, normally |
| 289 | * for an interface. |
| 290 | */ |
| 291 | rtinit(dst, gateway, flags) |
| 292 | struct sockaddr *dst, *gateway; |
| 293 | int flags; |
| 294 | { |
| 295 | struct rtentry route; |
| 296 | int cmd; |
| 297 | |
| 298 | if (flags == -1) { |
| 299 | cmd = (int)SIOCDELRT; |
| 300 | flags = 0; |
| 301 | } else { |
| 302 | cmd = (int)SIOCADDRT; |
| 303 | } |
| 304 | bzero((caddr_t)&route, sizeof (route)); |
| 305 | route.rt_dst = *dst; |
| 306 | route.rt_gateway = *gateway; |
| 307 | route.rt_flags = flags; |
| 308 | (void) rtrequest(cmd, &route); |
| 309 | } |