1 /* route.c 4.8 82/05/11 */ 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/ioctl.h" 9 #include "../net/in.h" 10 #include "../net/in_systm.h" 11 #include "../net/if.h" 12 #include "../net/af.h" 13 #include "../net/route.h" 14 #include <errno.h> 15 16 /* 17 * Packet routing routines. 18 */ 19 20 rtalloc(ro) 21 register struct route *ro; 22 { 23 register struct rtentry *rt, *rtmin; 24 register struct mbuf *m; 25 register int hash, (*match)(); 26 struct afhash h; 27 struct sockaddr *dst = &ro->ro_dst; 28 int af = dst->sa_family; 29 30 COUNT(RTALLOC); 31 if (ro->ro_rt && ro->ro_rt->rt_ifp) /* XXX */ 32 return; 33 if (af >= AF_MAX) 34 return; 35 (*afswitch[af].af_hash)(dst, &h); 36 rtmin = 0, hash = h.afh_hosthash; 37 for (m = rthost[hash % RTHASHSIZ]; m; m = m->m_next) { 38 rt = mtod(m, struct rtentry *); 39 if (rt->rt_hash != hash) 40 continue; 41 if ((rt->rt_flags & RTF_UP) == 0 || 42 (rt->rt_ifp->if_flags & IFF_UP) == 0) 43 continue; 44 if (bcmp((caddr_t)&rt->rt_dst, (caddr_t)dst, sizeof (*dst))) 45 continue; 46 if (rtmin == 0 || rt->rt_use < rtmin->rt_use) 47 rtmin = rt; 48 } 49 if (rtmin) 50 goto found; 51 52 hash = h.afh_nethash; 53 match = afswitch[af].af_netmatch; 54 for (m = rtnet[hash % RTHASHSIZ]; m; m = m->m_next) { 55 rt = mtod(m, struct rtentry *); 56 if (rt->rt_hash != hash) 57 continue; 58 if ((rt->rt_flags & RTF_UP) == 0 || 59 (rt->rt_ifp->if_flags & IFF_UP) == 0) 60 continue; 61 if (rt->rt_dst.sa_family != af || !(*match)(&rt->rt_dst, dst)) 62 continue; 63 if (rtmin == 0 || rt->rt_use < rtmin->rt_use) 64 rtmin = rt; 65 } 66 found: 67 ro->ro_rt = rtmin; 68 if (rtmin) 69 rtmin->rt_refcnt++; 70 } 71 72 rtfree(rt) 73 register struct rtentry *rt; 74 { 75 76 if (rt == 0) 77 panic("freeroute"); 78 rt->rt_refcnt--; 79 /* on refcnt == 0 reclaim? notify someone? */ 80 } 81 82 #define equal(a1, a2) \ 83 (bcmp((caddr_t)(a1), (caddr_t)(a2), sizeof (struct sockaddr)) == 0) 84 /* 85 * Carry out a request to change the routing table. Called by 86 * interfaces at boot time to make their ``local routes'' known 87 * and for ioctl's. 88 */ 89 rtrequest(req, new) 90 int req; 91 register struct rtentry *new; 92 { 93 register struct rtentry *rt; 94 register struct mbuf *m, **mprev; 95 register int hash, (*match)(); 96 register struct sockaddr *sa = &new->rt_dst; 97 register struct sockaddr *gate = &new->rt_gateway; 98 struct afhash h; 99 struct mbuf **oldmprev; 100 int af = sa->sa_family, doinghost, s, error = 0; 101 102 COUNT(RTREQUEST); 103 if (af >= AF_MAX) 104 return (EAFNOSUPPORT); 105 (*afswitch[af].af_hash)(sa, &h); 106 hash = h.afh_hosthash; 107 mprev = &rthost[hash % RTHASHSIZ]; 108 doinghost = 1; 109 s = splimp(); 110 again: 111 for (; m = *mprev; mprev = &m->m_next) { 112 rt = mtod(m, struct rtentry *); 113 if (rt->rt_hash != hash) 114 continue; 115 if (doinghost) { 116 if (!equal(&rt->rt_dst, sa)) 117 continue; 118 } else { 119 if (rt->rt_dst.sa_family != sa->sa_family || 120 (*match)(&rt->rt_dst, sa) == 0) 121 continue; 122 } 123 /* require full match on deletions */ 124 if (req == SIOCDELRT && !equal(&rt->rt_gateway, gate)) 125 continue; 126 /* don't keep multiple identical entries */ 127 if (req == SIOCADDRT && equal(&rt->rt_gateway, gate)) { 128 error = EEXIST; 129 goto bad; 130 } 131 break; 132 } 133 if (m == 0 && doinghost) { 134 hash = h.afh_nethash; 135 oldmprev = mprev; 136 mprev = &rtnet[hash % RTHASHSIZ]; 137 match = afswitch[af].af_netmatch; 138 doinghost = 0; 139 goto again; 140 } 141 142 if (m == 0 && req != SIOCADDRT) { 143 error = ESRCH; 144 goto bad; 145 } 146 found: 147 switch (req) { 148 149 case SIOCDELRT: 150 rt->rt_flags &= ~RTF_UP; 151 if (rt->rt_refcnt > 0) /* should we notify protocols? */ 152 error = EBUSY; 153 else 154 *mprev = m_free(m); 155 break; 156 157 case SIOCCHGRT: 158 rt->rt_flags = new->rt_flags; 159 if (rt->rt_refcnt > 0) 160 error = EBUSY; 161 else if (!equal(&rt->rt_gateway, gate)) 162 goto newneighbor; 163 break; 164 165 case SIOCADDRT: 166 m = m_get(M_DONTWAIT); 167 if (m == 0) { 168 error = ENOBUFS; 169 break; 170 } 171 m->m_off = MMINOFF; 172 m->m_len = sizeof (struct rtentry); 173 rt = mtod(m, struct rtentry *); 174 *rt = *new; 175 if (new->rt_flags & RTF_HOST) { 176 rt->rt_hash = h.afh_hosthash; 177 *oldmprev = m; 178 } else { 179 rt->rt_hash = h.afh_nethash; 180 *mprev = m; 181 } 182 rt->rt_use = 0; 183 rt->rt_refcnt = 0; 184 newneighbor: 185 rt->rt_ifp = if_ifwithnet(gate); 186 if (rt->rt_ifp == 0) 187 rt->rt_flags &= ~RTF_UP; 188 break; 189 } 190 bad: 191 splx(s); 192 return (error); 193 } 194 195 /* 196 * Set up a routing table entry, normally 197 * for an interface. 198 */ 199 rtinit(dst, gateway, flags) 200 struct sockaddr *dst, *gateway; 201 int flags; 202 { 203 struct rtentry route; 204 struct route ro; 205 206 route.rt_dst = *dst; 207 route.rt_gateway = *gateway; 208 route.rt_flags = flags; 209 route.rt_use = 0; 210 (void) rtrequest(SIOCADDRT, &route); 211 ro.ro_rt = 0; 212 ro.ro_dst = *dst; 213 rtalloc(&ro); 214 } 215