1 /* route.c 4.14 82/12/14 */ 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/if.h" 10 #include "../net/af.h" 11 #include "../net/route.h" 12 #include <errno.h> 13 14 int rttrash; /* routes not in table but not freed */ 15 /* 16 * Packet routing routines. 17 */ 18 rtalloc(ro) 19 register struct route *ro; 20 { 21 register struct rtentry *rt, *rtmin; 22 register struct mbuf *m; 23 register int hash, (*match)(); 24 struct afhash h; 25 struct sockaddr *dst = &ro->ro_dst; 26 int af = dst->sa_family; 27 28 if (ro->ro_rt && ro->ro_rt->rt_ifp) /* XXX */ 29 return; 30 if (af >= AF_MAX) 31 return; 32 (*afswitch[af].af_hash)(dst, &h); 33 rtmin = 0, hash = h.afh_hosthash; 34 for (m = rthost[hash % RTHASHSIZ]; m; m = m->m_next) { 35 rt = mtod(m, struct rtentry *); 36 if (rt->rt_hash != hash) 37 continue; 38 if ((rt->rt_flags & RTF_UP) == 0 || 39 (rt->rt_ifp->if_flags & IFF_UP) == 0) 40 continue; 41 if (bcmp((caddr_t)&rt->rt_dst, (caddr_t)dst, sizeof (*dst))) 42 continue; 43 if (rtmin == 0 || rt->rt_use < rtmin->rt_use) 44 rtmin = rt; 45 } 46 if (rtmin) 47 goto found; 48 49 hash = h.afh_nethash; 50 match = afswitch[af].af_netmatch; 51 for (m = rtnet[hash % RTHASHSIZ]; m; m = m->m_next) { 52 rt = mtod(m, struct rtentry *); 53 if (rt->rt_hash != hash) 54 continue; 55 if ((rt->rt_flags & RTF_UP) == 0 || 56 (rt->rt_ifp->if_flags & IFF_UP) == 0) 57 continue; 58 if (rt->rt_dst.sa_family != af || !(*match)(&rt->rt_dst, dst)) 59 continue; 60 if (rtmin == 0 || rt->rt_use < rtmin->rt_use) 61 rtmin = rt; 62 } 63 found: 64 ro->ro_rt = rtmin; 65 if (rtmin) 66 rtmin->rt_refcnt++; 67 } 68 69 rtfree(rt) 70 register struct rtentry *rt; 71 { 72 73 if (rt == 0) 74 panic("rtfree"); 75 rt->rt_refcnt--; 76 if (rt->rt_refcnt == 0 && (rt->rt_flags&RTF_UP) == 0) { 77 rttrash--; 78 (void) m_free(dtom(rt)); 79 } 80 } 81 82 /* 83 * Carry out a request to change the routing table. Called by 84 * interfaces at boot time to make their ``local routes'' known 85 * and for ioctl's. 86 */ 87 rtrequest(req, entry) 88 int req; 89 register struct rtentry *entry; 90 { 91 register struct mbuf *m, **mprev; 92 register struct rtentry *rt; 93 struct afhash h; 94 int af, s, error = 0, hash, (*match)(); 95 struct ifnet *ifp; 96 97 af = entry->rt_dst.sa_family; 98 if (af >= AF_MAX) 99 return (EAFNOSUPPORT); 100 (*afswitch[af].af_hash)(&entry->rt_dst, &h); 101 if (entry->rt_flags & RTF_HOST) { 102 hash = h.afh_hosthash; 103 mprev = &rthost[hash % RTHASHSIZ]; 104 } else { 105 hash = h.afh_nethash; 106 mprev = &rtnet[hash % RTHASHSIZ]; 107 } 108 match = afswitch[af].af_netmatch; 109 s = splimp(); 110 for (; m = *mprev; mprev = &m->m_next) { 111 rt = mtod(m, struct rtentry *); 112 if (rt->rt_hash != hash) 113 continue; 114 if (entry->rt_flags & RTF_HOST) { 115 #define equal(a1, a2) \ 116 (bcmp((caddr_t)(a1), (caddr_t)(a2), sizeof (struct sockaddr)) == 0) 117 if (!equal(&rt->rt_dst, &entry->rt_dst)) 118 continue; 119 } else { 120 if (rt->rt_dst.sa_family != entry->rt_dst.sa_family || 121 (*match)(&rt->rt_dst, &entry->rt_dst) == 0) 122 continue; 123 } 124 if (equal(&rt->rt_gateway, &entry->rt_gateway)) 125 break; 126 } 127 switch (req) { 128 129 case SIOCDELRT: 130 if (m == 0) { 131 error = ESRCH; 132 goto bad; 133 } 134 *mprev = m->m_next; 135 if (rt->rt_refcnt > 0) { 136 rt->rt_flags &= ~RTF_UP; 137 rttrash++; 138 m->m_next = 0; 139 } else 140 (void) m_free(m); 141 break; 142 143 case SIOCADDRT: 144 if (m) { 145 error = EEXIST; 146 goto bad; 147 } 148 ifp = if_ifwithaddr(&entry->rt_gateway); 149 if (ifp == 0) { 150 ifp = if_ifwithnet(&entry->rt_gateway); 151 if (ifp == 0) { 152 error = ENETUNREACH; 153 goto bad; 154 } 155 } 156 m = m_get(M_DONTWAIT, MT_RTABLE); 157 if (m == 0) { 158 error = ENOBUFS; 159 goto bad; 160 } 161 *mprev = m; 162 m->m_off = MMINOFF; 163 m->m_len = sizeof (struct rtentry); 164 rt = mtod(m, struct rtentry *); 165 rt->rt_hash = hash; 166 rt->rt_dst = entry->rt_dst; 167 rt->rt_gateway = entry->rt_gateway; 168 rt->rt_flags = 169 RTF_UP | (entry->rt_flags & (RTF_HOST|RTF_GATEWAY)); 170 rt->rt_refcnt = 0; 171 rt->rt_use = 0; 172 rt->rt_ifp = ifp; 173 break; 174 } 175 bad: 176 splx(s); 177 return (error); 178 } 179 180 /* 181 * Set up a routing table entry, normally 182 * for an interface. 183 */ 184 rtinit(dst, gateway, flags) 185 struct sockaddr *dst, *gateway; 186 int flags; 187 { 188 struct rtentry route; 189 190 bzero((caddr_t)&route, sizeof (route)); 191 route.rt_dst = *dst; 192 route.rt_gateway = *gateway; 193 route.rt_flags = flags; 194 (void) rtrequest((int)SIOCADDRT, &route); 195 } 196