| 1 | /* route.c 4.6 82/03/31 */ |
| 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 | (*afswitch[af].af_hash)(dst, &h); |
| 34 | rtmin = 0, hash = h.afh_hosthash; |
| 35 | for (m = rthost[hash % RTHASHSIZ]; m; m = m->m_next) { |
| 36 | rt = mtod(m, struct rtentry *); |
| 37 | if (rt->rt_hash != hash) |
| 38 | continue; |
| 39 | if (bcmp((caddr_t)&rt->rt_dst, (caddr_t)dst, sizeof (*dst))) |
| 40 | continue; |
| 41 | if (rtmin == 0 || rt->rt_use < rtmin->rt_use) |
| 42 | rtmin = rt; |
| 43 | } |
| 44 | if (rtmin) |
| 45 | goto found; |
| 46 | |
| 47 | hash = h.afh_nethash; |
| 48 | match = afswitch[af].af_netmatch; |
| 49 | for (m = rtnet[hash % RTHASHSIZ]; m; m = m->m_next) { |
| 50 | rt = mtod(m, struct rtentry *); |
| 51 | if (rt->rt_hash != hash) |
| 52 | continue; |
| 53 | if (rt->rt_dst.sa_family != af || !(*match)(&rt->rt_dst, dst)) |
| 54 | continue; |
| 55 | if (rtmin == 0 || rt->rt_use < rtmin->rt_use) |
| 56 | rtmin = rt; |
| 57 | } |
| 58 | found: |
| 59 | ro->ro_rt = rtmin; |
| 60 | if (rtmin) |
| 61 | rtmin->rt_refcnt++; |
| 62 | } |
| 63 | |
| 64 | rtfree(rt) |
| 65 | register struct rtentry *rt; |
| 66 | { |
| 67 | |
| 68 | if (rt == 0) |
| 69 | panic("freeroute"); |
| 70 | rt->rt_refcnt--; |
| 71 | /* on refcnt == 0 reclaim? notify someone? */ |
| 72 | } |
| 73 | |
| 74 | #define equal(a1, a2) \ |
| 75 | (bcmp((caddr_t)(a1), (caddr_t)(a2), sizeof (struct sockaddr)) == 0) |
| 76 | /* |
| 77 | * Carry out a request to change the routing table. Called by |
| 78 | * interfaces at boot time to make their ``local routes'' known |
| 79 | * and for ioctl's. |
| 80 | */ |
| 81 | rtrequest(req, new) |
| 82 | int req; |
| 83 | register struct rtentry *new; |
| 84 | { |
| 85 | register struct rtentry *rt; |
| 86 | register struct mbuf *m, **mprev; |
| 87 | register int hash, (*match)(); |
| 88 | register struct sockaddr *sa = &new->rt_dst; |
| 89 | register struct sockaddr *gate = &new->rt_gateway; |
| 90 | struct afhash h; |
| 91 | struct mbuf **oldmprev; |
| 92 | int af = sa->sa_family, doinghost, s, error = 0; |
| 93 | |
| 94 | COUNT(RTREQUEST); |
| 95 | (*afswitch[af].af_hash)(sa, &h); |
| 96 | hash = h.afh_hosthash; |
| 97 | mprev = &rthost[hash % RTHASHSIZ]; |
| 98 | doinghost = 1; |
| 99 | s = splimp(); |
| 100 | again: |
| 101 | for (; m = *mprev; mprev = &m->m_next) { |
| 102 | rt = mtod(m, struct rtentry *); |
| 103 | if (rt->rt_hash != hash) |
| 104 | continue; |
| 105 | if (doinghost) { |
| 106 | if (!equal(&rt->rt_dst, sa)) |
| 107 | continue; |
| 108 | } else { |
| 109 | if (rt->rt_dst.sa_family != sa->sa_family || |
| 110 | (*match)(&rt->rt_dst, sa) == 0) |
| 111 | continue; |
| 112 | } |
| 113 | /* require full match on deletions */ |
| 114 | if (req == SIOCDELRT && !equal(&rt->rt_gateway, gate)) |
| 115 | continue; |
| 116 | /* don't keep multiple identical entries */ |
| 117 | if (req == SIOCADDRT && equal(&rt->rt_gateway, gate)) { |
| 118 | error = EEXIST; |
| 119 | goto bad; |
| 120 | } |
| 121 | break; |
| 122 | } |
| 123 | if (m == 0 && doinghost) { |
| 124 | hash = h.afh_nethash; |
| 125 | oldmprev = mprev; |
| 126 | mprev = &rtnet[hash % RTHASHSIZ]; |
| 127 | match = afswitch[af].af_netmatch; |
| 128 | doinghost = 0; |
| 129 | goto again; |
| 130 | } |
| 131 | |
| 132 | if (m == 0 && req != SIOCADDRT) { |
| 133 | error = ESRCH; |
| 134 | goto bad; |
| 135 | } |
| 136 | found: |
| 137 | switch (req) { |
| 138 | |
| 139 | case SIOCDELRT: |
| 140 | rt->rt_flags &= ~RTF_UP; |
| 141 | if (rt->rt_refcnt > 0) /* should we notify protocols? */ |
| 142 | error = EBUSY; |
| 143 | else |
| 144 | *mprev = m_free(m); |
| 145 | break; |
| 146 | |
| 147 | case SIOCCHGRT: |
| 148 | rt->rt_flags = new->rt_flags; |
| 149 | if (rt->rt_refcnt > 0) |
| 150 | error = EBUSY; |
| 151 | else if (!equal(&rt->rt_gateway, gate)) |
| 152 | goto newneighbor; |
| 153 | break; |
| 154 | |
| 155 | case SIOCADDRT: |
| 156 | m = m_get(M_DONTWAIT); |
| 157 | if (m == 0) { |
| 158 | error = ENOBUFS; |
| 159 | break; |
| 160 | } |
| 161 | m->m_off = MMINOFF; |
| 162 | m->m_len = sizeof (struct rtentry); |
| 163 | rt = mtod(m, struct rtentry *); |
| 164 | *rt = *new; |
| 165 | if (new->rt_flags & RTF_HOST) { |
| 166 | rt->rt_hash = h.afh_hosthash; |
| 167 | *oldmprev = m; |
| 168 | } else { |
| 169 | rt->rt_hash = h.afh_nethash; |
| 170 | *mprev = m; |
| 171 | } |
| 172 | rt->rt_use = 0; |
| 173 | rt->rt_refcnt = 0; |
| 174 | newneighbor: |
| 175 | rt->rt_ifp = if_ifwithnet(gate); |
| 176 | if (rt->rt_ifp == 0) |
| 177 | rt->rt_flags &= ~RTF_UP; |
| 178 | break; |
| 179 | } |
| 180 | bad: |
| 181 | splx(s); |
| 182 | return (error); |
| 183 | } |
| 184 | |
| 185 | /* |
| 186 | * Set up a routing table entry, normally |
| 187 | * for an interface. |
| 188 | */ |
| 189 | rtinit(dst, gateway, flags) |
| 190 | struct sockaddr *dst, *gateway; |
| 191 | int flags; |
| 192 | { |
| 193 | struct rtentry route; |
| 194 | struct route ro; |
| 195 | |
| 196 | route.rt_dst = *dst; |
| 197 | route.rt_gateway = *gateway; |
| 198 | route.rt_flags = flags; |
| 199 | route.rt_use = 0; |
| 200 | (void) rtrequest(SIOCADDRT, &route); |
| 201 | ro.ro_rt = 0; |
| 202 | ro.ro_dst = *dst; |
| 203 | rtalloc(&ro); |
| 204 | } |