diff options
Diffstat (limited to 'cpukit/libnetworking/net/route.c')
| -rw-r--r-- | cpukit/libnetworking/net/route.c | 959 |
1 files changed, 959 insertions, 0 deletions
diff --git a/cpukit/libnetworking/net/route.c b/cpukit/libnetworking/net/route.c new file mode 100644 index 0000000000..0bea64f747 --- /dev/null +++ b/cpukit/libnetworking/net/route.c @@ -0,0 +1,959 @@ +/* + * Copyright (c) 1980, 1986, 1991, 1993 + * The Regents of the University of California. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * @(#)route.c 8.2 (Berkeley) 11/15/93 + * $Id$ + */ + +#include "opt_mrouting.h" + +#include <sys/param.h> +#include <sys/queue.h> +#include <sys/systm.h> +#include <sys/kernel.h> +#include <sys/proc.h> +#include <sys/mbuf.h> +#include <sys/socket.h> +#include <sys/socketvar.h> +#include <sys/domain.h> +#include <sys/protosw.h> +#include <sys/ioctl.h> + +#include <net/if.h> +#include <net/route.h> +#include <net/raw_cb.h> + +#include <netinet/in.h> +#include <netinet/in_var.h> +#include <netinet/ip_mroute.h> + +#define SA(p) ((struct sockaddr *)(p)) + +struct route_cb route_cb; +static struct rtstat rtstat; +struct radix_node_head *rt_tables[AF_MAX+1]; + +static int rttrash; /* routes not in table but not freed */ + +static void rt_maskedcopy __P((struct sockaddr *, + struct sockaddr *, struct sockaddr *)); +static void rtable_init __P((void **)); + +static void +rtable_init(table) + void **table; +{ + struct domain *dom; + for (dom = domains; dom; dom = dom->dom_next) + if (dom->dom_rtattach) + dom->dom_rtattach(&table[dom->dom_family], + dom->dom_rtoffset); +} + +void +route_init() +{ + rn_init(); /* initialize all zeroes, all ones, mask table */ + rtable_init((void **)rt_tables); +} + +/* + * Packet routing routines. + */ +void +rtalloc(ro) + register struct route *ro; +{ + if (ro->ro_rt && ro->ro_rt->rt_ifp && (ro->ro_rt->rt_flags & RTF_UP)) + return; /* XXX */ + ro->ro_rt = rtalloc1(&ro->ro_dst, 1, 0UL); +} + +void +rtalloc_ign(ro, ignore) + register struct route *ro; + u_long ignore; +{ + if (ro->ro_rt && ro->ro_rt->rt_ifp && (ro->ro_rt->rt_flags & RTF_UP)) + return; /* XXX */ + ro->ro_rt = rtalloc1(&ro->ro_dst, 1, ignore); +} + +/* + * Look up the route that matches the address given + * Or, at least try.. Create a cloned route if needed. + */ +struct rtentry * +rtalloc1(dst, report, ignflags) + register struct sockaddr *dst; + int report; + u_long ignflags; +{ + register struct radix_node_head *rnh = rt_tables[dst->sa_family]; + register struct rtentry *rt; + register struct radix_node *rn; + struct rtentry *newrt = 0; + struct rt_addrinfo info; + u_long nflags; + int s = splnet(), err = 0, msgtype = RTM_MISS; + + /* + * Look up the address in the table for that Address Family + */ + if (rnh && (rn = rnh->rnh_matchaddr((caddr_t)dst, rnh)) && + ((rn->rn_flags & RNF_ROOT) == 0)) { + /* + * If we find it and it's not the root node, then + * get a refernce on the rtentry associated. + */ + newrt = rt = (struct rtentry *)rn; + nflags = rt->rt_flags & ~ignflags; + if (report && (nflags & (RTF_CLONING | RTF_PRCLONING))) { + /* + * We are apparently adding (report = 0 in delete). + * If it requires that it be cloned, do so. + * (This implies it wasn't a HOST route.) + */ + err = rtrequest(RTM_RESOLVE, dst, SA(0), + SA(0), 0, &newrt); + if (err) { + /* + * If the cloning didn't succeed, maybe + * what we have will do. Return that. + */ + newrt = rt; + rt->rt_refcnt++; + goto miss; + } + if ((rt = newrt) && (rt->rt_flags & RTF_XRESOLVE)) { + /* + * If the new route specifies it be + * externally resolved, then go do that. + */ + msgtype = RTM_RESOLVE; + goto miss; + } + } else + rt->rt_refcnt++; + } else { + /* + * Either we hit the root or couldn't find any match, + * Which basically means + * "caint get there frm here" + */ + rtstat.rts_unreach++; + miss: if (report) { + /* + * If required, report the failure to the supervising + * Authorities. + * For a delete, this is not an error. (report == 0) + */ + bzero((caddr_t)&info, sizeof(info)); + info.rti_info[RTAX_DST] = dst; + rt_missmsg(msgtype, &info, 0, err); + } + } + splx(s); + return (newrt); +} + +void +rtfree(rt) + register struct rtentry *rt; +{ + register struct radix_node_head *rnh = + rt_tables[rt_key(rt)->sa_family]; + register struct ifaddr *ifa; + + if (rt == 0 || rnh == 0) + panic("rtfree"); + rt->rt_refcnt--; + if(rnh->rnh_close && rt->rt_refcnt == 0) { + rnh->rnh_close((struct radix_node *)rt, rnh); + } + if (rt->rt_refcnt <= 0 && (rt->rt_flags & RTF_UP) == 0) { + if (rt->rt_nodes->rn_flags & (RNF_ACTIVE | RNF_ROOT)) + panic ("rtfree 2"); + rttrash--; + if (rt->rt_refcnt < 0) { + printf("rtfree: %p not freed (neg refs)\n", rt); + return; + } + ifa = rt->rt_ifa; + IFAFREE(ifa); + if (rt->rt_parent) { + RTFREE(rt->rt_parent); + } + Free(rt_key(rt)); + Free(rt); + } +} + +void +ifafree(ifa) + register struct ifaddr *ifa; +{ + if (ifa == NULL) + panic("ifafree"); + if (ifa->ifa_refcnt == 0) + free(ifa, M_IFADDR); + else + ifa->ifa_refcnt--; +} + +/* + * Force a routing table entry to the specified + * destination to go through the given gateway. + * Normally called as a result of a routing redirect + * message from the network layer. + * + * N.B.: must be called at splnet + * + */ +void +rtredirect(dst, gateway, netmask, flags, src, rtp) + struct sockaddr *dst, *gateway, *netmask, *src; + int flags; + struct rtentry **rtp; +{ + register struct rtentry *rt; + int error = 0; + short *stat = 0; + struct rt_addrinfo info; + struct ifaddr *ifa; + + /* verify the gateway is directly reachable */ + if ((ifa = ifa_ifwithnet(gateway)) == 0) { + error = ENETUNREACH; + goto out; + } + rt = rtalloc1(dst, 0, 0UL); + /* + * If the redirect isn't from our current router for this dst, + * it's either old or wrong. If it redirects us to ourselves, + * we have a routing loop, perhaps as a result of an interface + * going down recently. + */ +#define equal(a1, a2) (bcmp((caddr_t)(a1), (caddr_t)(a2), (a1)->sa_len) == 0) + if (!(flags & RTF_DONE) && rt && + (!equal(src, rt->rt_gateway) || rt->rt_ifa != ifa)) + error = EINVAL; + else if (ifa_ifwithaddr(gateway)) + error = EHOSTUNREACH; + if (error) + goto done; + /* + * Create a new entry if we just got back a wildcard entry + * or the the lookup failed. This is necessary for hosts + * which use routing redirects generated by smart gateways + * to dynamically build the routing tables. + */ + if ((rt == 0) || (rt_mask(rt) && rt_mask(rt)->sa_len < 2)) + goto create; + /* + * Don't listen to the redirect if it's + * for a route to an interface. + */ + if (rt->rt_flags & RTF_GATEWAY) { + if (((rt->rt_flags & RTF_HOST) == 0) && (flags & RTF_HOST)) { + /* + * Changing from route to net => route to host. + * Create new route, rather than smashing route to net. + */ + create: + flags |= RTF_GATEWAY | RTF_DYNAMIC; + error = rtrequest((int)RTM_ADD, dst, gateway, + netmask, flags, + (struct rtentry **)0); + stat = &rtstat.rts_dynamic; + } else { + /* + * Smash the current notion of the gateway to + * this destination. Should check about netmask!!! + */ + rt->rt_flags |= RTF_MODIFIED; + flags |= RTF_MODIFIED; + stat = &rtstat.rts_newgateway; + rt_setgate(rt, rt_key(rt), gateway); + } + } else + error = EHOSTUNREACH; +done: + if (rt) { + if (rtp && !error) + *rtp = rt; + else + rtfree(rt); + } +out: + if (error) + rtstat.rts_badredirect++; + else if (stat != NULL) + (*stat)++; + bzero((caddr_t)&info, sizeof(info)); + info.rti_info[RTAX_DST] = dst; + info.rti_info[RTAX_GATEWAY] = gateway; + info.rti_info[RTAX_NETMASK] = netmask; + info.rti_info[RTAX_AUTHOR] = src; + rt_missmsg(RTM_REDIRECT, &info, flags, error); +} + +/* +* Routing table ioctl interface. +*/ +int +rtioctl(req, data, p) + int req; + caddr_t data; + struct proc *p; +{ +#ifdef INET + /* Multicast goop, grrr... */ +#ifdef MROUTING + return mrt_ioctl(req, data); +#else + return mrt_ioctl(req, data, p); +#endif +#else /* INET */ + return ENXIO; +#endif /* INET */ +} + +struct ifaddr * +ifa_ifwithroute(flags, dst, gateway) + int flags; + struct sockaddr *dst, *gateway; +{ + register struct ifaddr *ifa; + if ((flags & RTF_GATEWAY) == 0) { + /* + * If we are adding a route to an interface, + * and the interface is a pt to pt link + * we should search for the destination + * as our clue to the interface. Otherwise + * we can use the local address. + */ + ifa = 0; + if (flags & RTF_HOST) { + ifa = ifa_ifwithdstaddr(dst); + } + if (ifa == 0) + ifa = ifa_ifwithaddr(gateway); + } else { + /* + * If we are adding a route to a remote net + * or host, the gateway may still be on the + * other end of a pt to pt link. + */ + ifa = ifa_ifwithdstaddr(gateway); + } + if (ifa == 0) + ifa = ifa_ifwithnet(gateway); + if (ifa == 0) { + struct rtentry *rt = rtalloc1(dst, 0, 0UL); + if (rt == 0) + return (0); + rt->rt_refcnt--; + if ((ifa = rt->rt_ifa) == 0) + return (0); + } + if (ifa->ifa_addr->sa_family != dst->sa_family) { + struct ifaddr *oifa = ifa; + ifa = ifaof_ifpforaddr(dst, ifa->ifa_ifp); + if (ifa == 0) + ifa = oifa; + } + return (ifa); +} + +#define ROUNDUP(a) (a>0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long)) + +static int rt_fixdelete(struct radix_node *, void *); +static int rt_fixchange(struct radix_node *, void *); + +struct rtfc_arg { + struct rtentry *rt0; + struct radix_node_head *rnh; +}; + +/* + * Do appropriate manipulations of a routing tree given + * all the bits of info needed + */ +int +rtrequest(req, dst, gateway, netmask, flags, ret_nrt) + int req, flags; + struct sockaddr *dst, *gateway, *netmask; + struct rtentry **ret_nrt; +{ + int s = splnet(); int error = 0; + register struct rtentry *rt; + register struct radix_node *rn; + register struct radix_node_head *rnh; + struct ifaddr *ifa; + struct sockaddr *ndst; +#define senderr(x) { error = x ; goto bad; } + + /* + * Find the correct routing tree to use for this Address Family + */ + if ((rnh = rt_tables[dst->sa_family]) == 0) + senderr(ESRCH); + /* + * If we are adding a host route then we don't want to put + * a netmask in the tree + */ + if (flags & RTF_HOST) + netmask = 0; + switch (req) { + case RTM_DELETE: + /* + * Remove the item from the tree and return it. + * Complain if it is not there and do no more processing. + */ + if ((rn = rnh->rnh_deladdr(dst, netmask, rnh)) == 0) + senderr(ESRCH); + if (rn->rn_flags & (RNF_ACTIVE | RNF_ROOT)) + panic ("rtrequest delete"); + rt = (struct rtentry *)rn; + + /* + * Now search what's left of the subtree for any cloned + * routes which might have been formed from this node. + */ + if ((rt->rt_flags & RTF_PRCLONING) && netmask) { + rnh->rnh_walktree_from(rnh, dst, netmask, + rt_fixdelete, rt); + } + + /* + * Remove any external references we may have. + * This might result in another rtentry being freed if + * we held it's last reference. + */ + if (rt->rt_gwroute) { + rt = rt->rt_gwroute; + RTFREE(rt); + (rt = (struct rtentry *)rn)->rt_gwroute = 0; + } + + /* + * NB: RTF_UP must be set during the search above, + * because we might delete the last ref, causing + * rt to get freed prematurely. + */ + rt->rt_flags &= ~RTF_UP; + + /* + * If there is llinfo or similar associated with the + * route, give the interface a chance to deal with it.. + */ + if ((ifa = rt->rt_ifa) && ifa->ifa_rtrequest) + ifa->ifa_rtrequest(RTM_DELETE, rt, SA(0)); + rttrash++; + /* + * If the caller wants it, then it can have it, but it's up to it + * to free the rtentry as we won't be doing it. + */ + if (ret_nrt) + *ret_nrt = rt; + else if (rt->rt_refcnt <= 0) { + rt->rt_refcnt++; /* make a 1->0 transition */ + rtfree(rt); + } + break; + + case RTM_RESOLVE: + if (ret_nrt == 0 || (rt = *ret_nrt) == 0) + senderr(EINVAL); + ifa = rt->rt_ifa; + flags = rt->rt_flags & + ~(RTF_CLONING | RTF_PRCLONING | RTF_STATIC); + flags |= RTF_WASCLONED; + gateway = rt->rt_gateway; + if ((netmask = rt->rt_genmask) == 0) + flags |= RTF_HOST; + goto makeroute; + + case RTM_ADD: + if ((flags & RTF_GATEWAY) && !gateway) + panic("rtrequest: GATEWAY but no gateway"); + + if ((ifa = ifa_ifwithroute(flags, dst, gateway)) == 0) + senderr(ENETUNREACH); + + makeroute: + R_Malloc(rt, struct rtentry *, sizeof(*rt)); + if (rt == 0) + senderr(ENOBUFS); + Bzero(rt, sizeof(*rt)); + rt->rt_flags = RTF_UP | flags; + if (error = rt_setgate(rt, dst, gateway)) { + Free(rt); + senderr(error); + } + ndst = rt_key(rt); + if (netmask) { + rt_maskedcopy(dst, ndst, netmask); + } else + Bcopy(dst, ndst, dst->sa_len); + + /* + * This moved from below so that rnh->rnh_addaddr() can + * examine the ifa and ifp if it so desires. + */ + ifa->ifa_refcnt++; + rt->rt_ifa = ifa; + rt->rt_ifp = ifa->ifa_ifp; + + rn = rnh->rnh_addaddr((caddr_t)ndst, (caddr_t)netmask, + rnh, rt->rt_nodes); + if (rn == 0) { + struct rtentry *rt2; + /* + * Uh-oh, we already have one of these in the tree. + * We do a special hack: if the route that's already + * there was generated by the protocol-cloning + * mechanism, then we just blow it away and retry + * the insertion of the new one. + */ + rt2 = rtalloc1(dst, 0, RTF_PRCLONING); + if (rt2 && rt2->rt_parent) { + rtrequest(RTM_DELETE, + (struct sockaddr *)rt_key(rt2), + rt2->rt_gateway, + rt_mask(rt2), rt2->rt_flags, 0); + RTFREE(rt2); + rn = rnh->rnh_addaddr((caddr_t)ndst, + (caddr_t)netmask, + rnh, rt->rt_nodes); + } else if (rt2) { + RTFREE(rt2); + } + } + + if (rn == 0) { + if (rt->rt_gwroute) + rtfree(rt->rt_gwroute); + if (rt->rt_ifa) { + IFAFREE(rt->rt_ifa); + } + Free(rt_key(rt)); + Free(rt); + senderr(EEXIST); + } + rt->rt_parent = 0; + + if (req == RTM_RESOLVE) { + rt->rt_rmx = (*ret_nrt)->rt_rmx; /* copy metrics */ + if ((*ret_nrt)->rt_flags & RTF_PRCLONING) { + rt->rt_parent = (*ret_nrt); + (*ret_nrt)->rt_refcnt++; + } + } + if (ifa->ifa_rtrequest) + ifa->ifa_rtrequest(req, rt, SA(ret_nrt ? *ret_nrt : 0)); + /* + * We repeat the same procedure from rt_setgate() here because + * it doesn't fire when we call it there because the node + * hasn't been added to the tree yet. + */ + if (!(rt->rt_flags & RTF_HOST) && rt_mask(rt) != 0) { + struct rtfc_arg arg; + arg.rnh = rnh; + arg.rt0 = rt; + rnh->rnh_walktree_from(rnh, rt_key(rt), rt_mask(rt), + rt_fixchange, &arg); + } + + if (ret_nrt) { + *ret_nrt = rt; + rt->rt_refcnt++; + } + break; + } +bad: + splx(s); + return (error); +} + +/* + * Called from rtrequest(RTM_DELETE, ...) to fix up the route's ``family'' + * (i.e., the routes related to it by the operation of cloning). This + * routine is iterated over all potential former-child-routes by way of + * rnh->rnh_walktree_from() above, and those that actually are children of + * the late parent (passed in as VP here) are themselves deleted. + */ +static int +rt_fixdelete(struct radix_node *rn, void *vp) +{ + struct rtentry *rt = (struct rtentry *)rn; + struct rtentry *rt0 = vp; + + if (rt->rt_parent == rt0 && !(rt->rt_flags & RTF_PINNED)) { + return rtrequest(RTM_DELETE, rt_key(rt), + (struct sockaddr *)0, rt_mask(rt), + rt->rt_flags, (struct rtentry **)0); + } + return 0; +} + +/* + * This routine is called from rt_setgate() to do the analogous thing for + * adds and changes. There is the added complication in this case of a + * middle insert; i.e., insertion of a new network route between an older + * network route and (cloned) host routes. For this reason, a simple check + * of rt->rt_parent is insufficient; each candidate route must be tested + * against the (mask, value) of the new route (passed as before in vp) + * to see if the new route matches it. Unfortunately, this has the obnoxious + * property of also triggering for insertion /above/ a pre-existing network + * route and clones. Sigh. This may be fixed some day. + * + * XXX - it may be possible to do fixdelete() for changes and reserve this + * routine just for adds. I'm not sure why I thought it was necessary to do + * changes this way. + */ +#ifdef DEBUG +int rtfcdebug = 0; +#endif + +static int +rt_fixchange(struct radix_node *rn, void *vp) +{ + struct rtentry *rt = (struct rtentry *)rn; + struct rtfc_arg *ap = vp; + struct rtentry *rt0 = ap->rt0; + struct radix_node_head *rnh = ap->rnh; + u_char *xk1, *xm1, *xk2; + int i, len; + +#ifdef DEBUG + if (rtfcdebug) + printf("rt_fixchange: rt %p, rt0 %p\n", rt, rt0); +#endif + + if (!rt->rt_parent || (rt->rt_flags & RTF_PINNED)) { +#ifdef DEBUG + if(rtfcdebug) printf("no parent or pinned\n"); +#endif + return 0; + } + + if (rt->rt_parent == rt0) { +#ifdef DEBUG + if(rtfcdebug) printf("parent match\n"); +#endif + return rtrequest(RTM_DELETE, rt_key(rt), + (struct sockaddr *)0, rt_mask(rt), + rt->rt_flags, (struct rtentry **)0); + } + + /* + * There probably is a function somewhere which does this... + * if not, there should be. + */ + len = imin(((struct sockaddr *)rt_key(rt0))->sa_len, + ((struct sockaddr *)rt_key(rt))->sa_len); + + xk1 = (u_char *)rt_key(rt0); + xm1 = (u_char *)rt_mask(rt0); + xk2 = (u_char *)rt_key(rt); + + for (i = rnh->rnh_treetop->rn_off; i < len; i++) { + if ((xk2[i] & xm1[i]) != xk1[i]) { +#ifdef DEBUG + if(rtfcdebug) printf("no match\n"); +#endif + return 0; + } + } + + /* + * OK, this node is a clone, and matches the node currently being + * changed/added under the node's mask. So, get rid of it. + */ +#ifdef DEBUG + if(rtfcdebug) printf("deleting\n"); +#endif + return rtrequest(RTM_DELETE, rt_key(rt), (struct sockaddr *)0, + rt_mask(rt), rt->rt_flags, (struct rtentry **)0); +} + +int +rt_setgate(rt0, dst, gate) + struct rtentry *rt0; + struct sockaddr *dst, *gate; +{ + caddr_t new, old; + int dlen = ROUNDUP(dst->sa_len), glen = ROUNDUP(gate->sa_len); + register struct rtentry *rt = rt0; + struct radix_node_head *rnh = rt_tables[dst->sa_family]; + + /* + * A host route with the destination equal to the gateway + * will interfere with keeping LLINFO in the routing + * table, so disallow it. + */ + if (((rt0->rt_flags & (RTF_HOST|RTF_GATEWAY|RTF_LLINFO)) == + (RTF_HOST|RTF_GATEWAY)) && + (dst->sa_len == gate->sa_len) && + (bcmp(dst, gate, dst->sa_len) == 0)) { + /* + * The route might already exist if this is an RTM_CHANGE + * or a routing redirect, so try to delete it. + */ + if (rt_key(rt0)) + rtrequest(RTM_DELETE, (struct sockaddr *)rt_key(rt0), + rt0->rt_gateway, rt_mask(rt0), rt0->rt_flags, 0); + return EADDRNOTAVAIL; + } + + if (rt->rt_gateway == 0 || glen > ROUNDUP(rt->rt_gateway->sa_len)) { + old = (caddr_t)rt_key(rt); + R_Malloc(new, caddr_t, dlen + glen); + if (new == 0) + return ENOBUFS; + rt->rt_nodes->rn_key = new; + } else { + new = rt->rt_nodes->rn_key; + old = 0; + } + Bcopy(gate, (rt->rt_gateway = (struct sockaddr *)(new + dlen)), glen); + if (old) { + Bcopy(dst, new, dlen); + Free(old); + } + if (rt->rt_gwroute) { + rt = rt->rt_gwroute; RTFREE(rt); + rt = rt0; rt->rt_gwroute = 0; + } + /* + * Cloning loop avoidance: + * In the presence of protocol-cloning and bad configuration, + * it is possible to get stuck in bottomless mutual recursion + * (rtrequest rt_setgate rtalloc1). We avoid this by not allowing + * protocol-cloning to operate for gateways (which is probably the + * correct choice anyway), and avoid the resulting reference loops + * by disallowing any route to run through itself as a gateway. + * This is obviuosly mandatory when we get rt->rt_output(). + */ + if (rt->rt_flags & RTF_GATEWAY) { + rt->rt_gwroute = rtalloc1(gate, 1, RTF_PRCLONING); + if (rt->rt_gwroute == rt) { + RTFREE(rt->rt_gwroute); + rt->rt_gwroute = 0; + return EDQUOT; /* failure */ + } + } + + /* + * This isn't going to do anything useful for host routes, so + * don't bother. Also make sure we have a reasonable mask + * (we don't yet have one during adds). + */ + if (!(rt->rt_flags & RTF_HOST) && rt_mask(rt) != 0) { + struct rtfc_arg arg; + arg.rnh = rnh; + arg.rt0 = rt; + rnh->rnh_walktree_from(rnh, rt_key(rt), rt_mask(rt), + rt_fixchange, &arg); + } + + return 0; +} + +static void +rt_maskedcopy(src, dst, netmask) + struct sockaddr *src, *dst, *netmask; +{ + register u_char *cp1 = (u_char *)src; + register u_char *cp2 = (u_char *)dst; + register u_char *cp3 = (u_char *)netmask; + u_char *cplim = cp2 + *cp3; + u_char *cplim2 = cp2 + *cp1; + + *cp2++ = *cp1++; *cp2++ = *cp1++; /* copies sa_len & sa_family */ + cp3 += 2; + if (cplim > cplim2) + cplim = cplim2; + while (cp2 < cplim) + *cp2++ = *cp1++ & *cp3++; + if (cp2 < cplim2) + bzero((caddr_t)cp2, (unsigned)(cplim2 - cp2)); +} + +/* + * Set up a routing table entry, normally + * for an interface. + */ +int +rtinit(ifa, cmd, flags) + register struct ifaddr *ifa; + int cmd, flags; +{ + register struct rtentry *rt; + register struct sockaddr *dst; + register struct sockaddr *deldst; + struct mbuf *m = 0; + struct rtentry *nrt = 0; + int error; + + dst = flags & RTF_HOST ? ifa->ifa_dstaddr : ifa->ifa_addr; + /* + * If it's a delete, check that if it exists, it's on the correct + * interface or we might scrub a route to another ifa which would + * be confusing at best and possibly worse. + */ + if (cmd == RTM_DELETE) { + /* + * It's a delete, so it should already exist.. + * If it's a net, mask off the host bits + * (Assuming we have a mask) + */ + if ((flags & RTF_HOST) == 0 && ifa->ifa_netmask) { + m = m_get(M_WAIT, MT_SONAME); + deldst = mtod(m, struct sockaddr *); + rt_maskedcopy(dst, deldst, ifa->ifa_netmask); + dst = deldst; + } + /* + * Get an rtentry that is in the routing tree and + * contains the correct info. (if this fails we can't get there). + * We set "report" to FALSE so that if it doesn't exist, + * it doesn't report an error or clone a route, etc. etc. + */ + rt = rtalloc1(dst, 0, 0UL); + if (rt) { + /* + * Ok so we found the rtentry. it has an extra reference + * for us at this stage. we won't need that so + * lop that off now. + */ + rt->rt_refcnt--; + if (rt->rt_ifa != ifa) { + /* + * If the interface in the rtentry doesn't match + * the interface we are using, then we don't + * want to delete it, so return an error. + * This seems to be the only point of + * this whole RTM_DELETE clause. + */ + if (m) + (void) m_free(m); + return (flags & RTF_HOST ? EHOSTUNREACH + : ENETUNREACH); + } + } + /* XXX */ +#if 0 + else { + /* + * One would think that as we are deleting, and we know + * it doesn't exist, we could just return at this point + * with an "ELSE" clause, but apparently not.. + */ + return (flags & RTF_HOST ? EHOSTUNREACH + : ENETUNREACH); + } +#endif + } + /* + * Do the actual request + */ + error = rtrequest(cmd, dst, ifa->ifa_addr, ifa->ifa_netmask, + flags | ifa->ifa_flags, &nrt); + if (m) + (void) m_free(m); + /* + * If we are deleting, and we found an entry, then + * it's been removed from the tree.. now throw it away. + */ + if (cmd == RTM_DELETE && error == 0 && (rt = nrt)) { + /* + * notify any listenning routing agents of the change + */ + rt_newaddrmsg(cmd, ifa, error, nrt); + if (rt->rt_refcnt <= 0) { + rt->rt_refcnt++; /* need a 1->0 transition to free */ + rtfree(rt); + } + } + + /* + * We are adding, and we have a returned routing entry. + * We need to sanity check the result. + */ + if (cmd == RTM_ADD && error == 0 && (rt = nrt)) { + /* + * We just wanted to add it.. we don't actually need a reference + */ + rt->rt_refcnt--; + /* + * If it came back with an unexpected interface, then it must + * have already existed or something. (XXX) + */ + if (rt->rt_ifa != ifa) { + printf("rtinit: wrong ifa (%p) was (%p)\n", ifa, + rt->rt_ifa); + /* + * Ask that the route we got back be removed + * from the routing tables as we are trying + * to supersede it. + */ + if (rt->rt_ifa->ifa_rtrequest) + rt->rt_ifa->ifa_rtrequest(RTM_DELETE, rt, SA(0)); + /* + * Remove the referenve to the it's ifaddr. + */ + IFAFREE(rt->rt_ifa); + /* + * And substitute in references to the ifaddr + * we are adding. + */ + rt->rt_ifa = ifa; + rt->rt_ifp = ifa->ifa_ifp; + ifa->ifa_refcnt++; + /* + * Now add it to the routing table + * XXX could we have just left it? + * as it might have been in the right place.. + */ + if (ifa->ifa_rtrequest) + ifa->ifa_rtrequest(RTM_ADD, rt, SA(0)); + } + /* + * notify any listenning routing agents of the change + */ + rt_newaddrmsg(cmd, ifa, error, nrt); + } + return (error); +} |