dn_fib.c
上传用户:lgb322
上传日期:2013-02-24
资源大小:30529k
文件大小:16k
- /*
- * DECnet An implementation of the DECnet protocol suite for the LINUX
- * operating system. DECnet is implemented using the BSD Socket
- * interface as the means of communication with the user level.
- *
- * DECnet Routing Forwarding Information Base (Glue/Info List)
- *
- * Author: Steve Whitehouse <SteveW@ACM.org>
- *
- *
- * Changes:
- * Alexey Kuznetsov : SMP locking changes
- * Steve Whitehouse : Rewrote it... Well to be more correct, I
- * copied most of it from the ipv4 fib code.
- *
- */
- #include <linux/config.h>
- #include <linux/string.h>
- #include <linux/net.h>
- #include <linux/socket.h>
- #include <linux/sockios.h>
- #include <linux/init.h>
- #include <linux/skbuff.h>
- #include <linux/netlink.h>
- #include <linux/rtnetlink.h>
- #include <linux/proc_fs.h>
- #include <linux/netdevice.h>
- #include <linux/timer.h>
- #include <linux/spinlock.h>
- #include <asm/atomic.h>
- #include <asm/uaccess.h>
- #include <net/neighbour.h>
- #include <net/dst.h>
- #include <net/dn.h>
- #include <net/dn_route.h>
- #include <net/dn_fib.h>
- #include <net/dn_neigh.h>
- #include <net/dn_dev.h>
- #define for_fib_info() { struct dn_fib_info *fi;
- for(fi = dn_fib_info_list; fi; fi = fi->fib_next)
- #define endfor_fib_info() }
- #define for_nexthops(fi) { int nhsel; const struct dn_fib_nh *nh;
- for(nhsel = 0, nh = (fi)->fib_nh; nhsel < (fi)->fib_nhs; nh++, nhsel++)
- #define change_nexthops(fi) { int nhsel; struct dn_fib_nh *nh;
- for(nhsel = 0, nh = (struct dn_fib_nh *)((fi)->fib_nh); nhsel < (fi)->fib_nhs; nh++, nhsel++)
- #define endfor_nexthops(fi) }
- extern int dn_cache_dump(struct sk_buff *skb, struct netlink_callback *cb);
- static struct dn_fib_info *dn_fib_info_list;
- static rwlock_t dn_fib_info_lock = RW_LOCK_UNLOCKED;
- int dn_fib_info_cnt;
- static struct
- {
- int error;
- u8 scope;
- } dn_fib_props[RTA_MAX+1] = {
- { 0, RT_SCOPE_NOWHERE }, /* RTN_UNSPEC */
- { 0, RT_SCOPE_UNIVERSE }, /* RTN_UNICAST */
- { 0, RT_SCOPE_HOST }, /* RTN_LOCAL */
- { -EINVAL, RT_SCOPE_NOWHERE }, /* RTN_BROADCAST */
- { -EINVAL, RT_SCOPE_NOWHERE }, /* RTN_ANYCAST */
- { -EINVAL, RT_SCOPE_NOWHERE }, /* RTN_MULTICAST */
- { -EINVAL, RT_SCOPE_UNIVERSE }, /* RTN_BLACKHOLE */
- { -EHOSTUNREACH, RT_SCOPE_UNIVERSE }, /* RTN_UNREACHABLE */
- { -EACCES, RT_SCOPE_UNIVERSE }, /* RTN_PROHIBIT */
- { -EAGAIN, RT_SCOPE_UNIVERSE }, /* RTN_THROW */
- { -EINVAL, RT_SCOPE_NOWHERE }, /* RTN_NAT */
- { -EINVAL, RT_SCOPE_NOWHERE } /* RTN_XRESOLVE */
- };
- void dn_fib_free_info(struct dn_fib_info *fi)
- {
- if (fi->fib_dead == 0) {
- printk(KERN_DEBUG "DECnet: BUG! Attempt to free alive dn_fib_infon");
- return;
- }
- change_nexthops(fi) {
- if (nh->nh_dev)
- dev_put(nh->nh_dev);
- nh->nh_dev = NULL;
- } endfor_nexthops(fi);
- dn_fib_info_cnt--;
- kfree(fi);
- }
- void dn_fib_release_info(struct dn_fib_info *fi)
- {
- write_lock(&dn_fib_info_lock);
- if (fi && --fi->fib_treeref == 0) {
- if (fi->fib_next)
- fi->fib_next->fib_prev = fi->fib_prev;
- if (fi->fib_prev)
- fi->fib_prev->fib_next = fi->fib_next;
- if (fi == dn_fib_info_list)
- dn_fib_info_list = fi->fib_next;
- fi->fib_dead = 1;
- dn_fib_info_put(fi);
- }
- write_unlock(&dn_fib_info_lock);
- }
- static __inline__ int dn_fib_nh_comp(const struct dn_fib_info *fi, const struct dn_fib_info *ofi)
- {
- const struct dn_fib_nh *onh = ofi->fib_nh;
- for_nexthops(fi) {
- if (nh->nh_oif != onh->nh_oif ||
- nh->nh_gw != onh->nh_gw ||
- nh->nh_scope != onh->nh_scope ||
- nh->nh_weight != onh->nh_weight ||
- ((nh->nh_flags^onh->nh_flags)&~RTNH_F_DEAD))
- return -1;
- onh++;
- } endfor_nexthops(fi);
- return 0;
- }
- static __inline__ struct dn_fib_info *dn_fib_find_info(const struct dn_fib_info *nfi)
- {
- for_fib_info() {
- if (fi->fib_nhs != nfi->fib_nhs)
- continue;
- if (nfi->fib_protocol == fi->fib_protocol &&
- nfi->fib_prefsrc == fi->fib_prefsrc &&
- nfi->fib_priority == fi->fib_priority &&
- ((nfi->fib_flags^fi->fib_flags)&~RTNH_F_DEAD) == 0 &&
- (nfi->fib_nhs == 0 || dn_fib_nh_comp(fi, nfi) == 0))
- return fi;
- } endfor_fib_info();
- return NULL;
- }
- u16 dn_fib_get_attr16(struct rtattr *attr, int attrlen, int type)
- {
- while(RTA_OK(attr,attrlen)) {
- if (attr->rta_type == type)
- return *(u16*)RTA_DATA(attr);
- attr = RTA_NEXT(attr, attrlen);
- }
- return 0;
- }
- static int dn_fib_count_nhs(struct rtattr *rta)
- {
- int nhs = 0;
- struct rtnexthop *nhp = RTA_DATA(rta);
- int nhlen = RTA_PAYLOAD(rta);
- while(nhlen >= (int)sizeof(struct rtnexthop)) {
- if ((nhlen -= nhp->rtnh_len) < 0)
- return 0;
- nhs++;
- nhp = RTNH_NEXT(nhp);
- }
- return nhs;
- }
- static int dn_fib_get_nhs(struct dn_fib_info *fi, const struct rtattr *rta, const struct rtmsg *r)
- {
- struct rtnexthop *nhp = RTA_DATA(rta);
- int nhlen = RTA_PAYLOAD(rta);
- change_nexthops(fi) {
- int attrlen = nhlen - sizeof(struct rtnexthop);
- if (attrlen < 0 || (nhlen -= nhp->rtnh_len) < 0)
- return -EINVAL;
- nh->nh_flags = (r->rtm_flags&~0xFF) | nhp->rtnh_flags;
- nh->nh_oif = nhp->rtnh_ifindex;
- nh->nh_weight = nhp->rtnh_hops + 1;
- if (attrlen) {
- nh->nh_gw = dn_fib_get_attr16(RTNH_DATA(nhp), attrlen, RTA_GATEWAY);
- }
- nhp = RTNH_NEXT(nhp);
- } endfor_nexthops(fi);
- return 0;
- }
- static int dn_fib_check_nh(const struct rtmsg *r, struct dn_fib_info *fi, struct dn_fib_nh *nh)
- {
- int err;
- if (nh->nh_gw) {
- struct dn_fib_key key;
- struct dn_fib_res res;
- if (nh->nh_flags&RTNH_F_ONLINK) {
- struct net_device *dev;
- if (r->rtm_scope >= RT_SCOPE_LINK)
- return -EINVAL;
- if ((dev = __dev_get_by_index(nh->nh_oif)) == NULL)
- return -ENODEV;
- if (!(dev->flags&IFF_UP))
- return -ENETDOWN;
- nh->nh_dev = dev;
- atomic_inc(&dev->refcnt);
- nh->nh_scope = RT_SCOPE_LINK;
- return 0;
- }
- memset(&key, 0, sizeof(key));
- key.dst = nh->nh_gw;
- key.oif = nh->nh_oif;
- key.scope = r->rtm_scope + 1;
- if (key.scope < RT_SCOPE_LINK)
- key.scope = RT_SCOPE_LINK;
- if ((err = dn_fib_lookup(&key, &res)) != 0)
- return err;
- nh->nh_scope = res.scope;
- nh->nh_oif = DN_FIB_RES_OIF(res);
- nh->nh_dev = DN_FIB_RES_DEV(res);
- if (nh->nh_dev)
- atomic_inc(&nh->nh_dev->refcnt);
- dn_fib_res_put(&res);
- } else {
- struct net_device *dev;
- if (nh->nh_flags&(RTNH_F_PERVASIVE|RTNH_F_ONLINK))
- return -EINVAL;
- dev = __dev_get_by_index(nh->nh_oif);
- if (dev == NULL || dev->dn_ptr == NULL)
- return -ENODEV;
- if (!(dev->flags&IFF_UP))
- return -ENETDOWN;
- nh->nh_dev = dev;
- atomic_inc(&nh->nh_dev->refcnt);
- nh->nh_scope = RT_SCOPE_HOST;
- }
- return 0;
- }
- struct dn_fib_info *dn_fib_create_info(const struct rtmsg *r, struct dn_kern_rta *rta, const struct nlmsghdr *nlh, int *errp)
- {
- int err;
- struct dn_fib_info *fi = NULL;
- struct dn_fib_info *ofi;
- int nhs = 1;
- if (dn_fib_props[r->rtm_type].scope > r->rtm_scope)
- goto err_inval;
- if (rta->rta_mp) {
- nhs = dn_fib_count_nhs(rta->rta_mp);
- if (nhs == 0)
- goto err_inval;
- }
- fi = kmalloc(sizeof(*fi)+nhs*sizeof(struct dn_fib_nh), GFP_KERNEL);
- err = -ENOBUFS;
- if (fi == NULL)
- goto failure;
- memset(fi, 0, sizeof(*fi)+nhs*sizeof(struct dn_fib_nh));
- fi->fib_protocol = r->rtm_protocol;
- fi->fib_nhs = nhs;
- fi->fib_flags = r->rtm_flags;
- if (rta->rta_priority)
- fi->fib_priority = *rta->rta_priority;
- if (rta->rta_prefsrc)
- memcpy(&fi->fib_prefsrc, rta->rta_prefsrc, 2);
- if (rta->rta_mp) {
- if ((err = dn_fib_get_nhs(fi, rta->rta_mp, r)) != 0)
- goto failure;
- if (rta->rta_oif && fi->fib_nh->nh_oif != *rta->rta_oif)
- goto err_inval;
- if (rta->rta_gw && memcmp(&fi->fib_nh->nh_gw, rta->rta_gw, 2))
- goto err_inval;
- } else {
- struct dn_fib_nh *nh = fi->fib_nh;
- if (rta->rta_oif)
- nh->nh_oif = *rta->rta_oif;
- if (rta->rta_gw)
- memcpy(&nh->nh_gw, rta->rta_gw, 2);
- nh->nh_flags = r->rtm_flags;
- nh->nh_weight = 1;
- }
- if (dn_fib_props[r->rtm_type].error) {
- if (rta->rta_gw || rta->rta_oif || rta->rta_mp)
- goto err_inval;
- goto link_it;
- }
- if (r->rtm_scope > RT_SCOPE_HOST)
- goto err_inval;
- if (r->rtm_scope == RT_SCOPE_HOST) {
- struct dn_fib_nh *nh = fi->fib_nh;
- /* Local address is added */
- if (nhs != 1 || nh->nh_gw)
- goto err_inval;
- nh->nh_scope = RT_SCOPE_NOWHERE;
- nh->nh_dev = dev_get_by_index(fi->fib_nh->nh_oif);
- err = -ENODEV;
- if (nh->nh_dev == NULL)
- goto failure;
- } else {
- change_nexthops(fi) {
- if ((err = dn_fib_check_nh(r, fi, nh)) != 0)
- goto failure;
- } endfor_nexthops(fi)
- }
- #if I_GET_AROUND_TO_FIXING_PREFSRC
- if (fi->fib_prefsrc) {
- if (r->rtm_type != RTN_LOCAL || rta->rta_dst == NULL ||
- memcmp(&fi->fib_prefsrc, rta->rta_dst, 2))
- if (dn_addr_type(fi->fib_prefsrc) != RTN_LOCAL)
- goto err_inval;
- }
- #endif
- link_it:
- if ((ofi = dn_fib_find_info(fi)) != NULL) {
- fi->fib_dead = 1;
- dn_fib_free_info(fi);
- ofi->fib_treeref++;
- return ofi;
- }
- fi->fib_treeref++;
- atomic_inc(&fi->fib_clntref);
- write_lock(&dn_fib_info_lock);
- fi->fib_next = dn_fib_info_list;
- fi->fib_prev = NULL;
- if (dn_fib_info_list)
- dn_fib_info_list->fib_prev = fi;
- dn_fib_info_list = fi;
- dn_fib_info_cnt++;
- write_unlock(&dn_fib_info_lock);
- return fi;
- err_inval:
- err = -EINVAL;
- failure:
- *errp = err;
- if (fi) {
- fi->fib_dead = 1;
- dn_fib_free_info(fi);
- }
- return NULL;
- }
- void dn_fib_select_multipath(const struct dn_fib_key *key, struct dn_fib_res *res)
- {
- struct dn_fib_info *fi = res->fi;
- int w;
- if (fi->fib_power <= 0) {
- int power = 0;
- change_nexthops(fi) {
- if (!(nh->nh_flags&RTNH_F_DEAD)) {
- power += nh->nh_weight;
- nh->nh_power = nh->nh_weight;
- }
- } endfor_nexthops(fi);
- fi->fib_power = power;
- }
- w = jiffies % fi->fib_power;
- change_nexthops(fi) {
- if (!(nh->nh_flags&RTNH_F_DEAD) && nh->nh_power) {
- if ((w -= nh->nh_power) <= 0) {
- nh->nh_power--;
- fi->fib_power--;
- res->nh_sel = nhsel;
- return;
- }
- }
- } endfor_nexthops(fi);
- printk(KERN_DEBUG "DECnet: BUG! dn_fib_select_multipathn");
- }
- /*
- * Punt to user via netlink for example, but for now
- * we just drop it.
- */
- int dn_fib_rt_message(struct sk_buff *skb)
- {
- kfree_skb(skb);
- return 0;
- }
- static int dn_fib_check_attr(struct rtmsg *r, struct rtattr **rta)
- {
- int i;
- for(i = 1; i <= RTA_MAX; i++) {
- struct rtattr *attr = rta[i-1];
- if (attr) {
- if (RTA_PAYLOAD(attr) < 4 && RTA_PAYLOAD(attr) != 2)
- return -EINVAL;
- if (i != RTA_MULTIPATH && i != RTA_METRICS)
- rta[i-1] = (struct rtattr *)RTA_DATA(attr);
- }
- }
- return 0;
- }
- int dn_fib_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
- {
- struct dn_fib_table *tb;
- struct rtattr **rta = arg;
- struct rtmsg *r = NLMSG_DATA(nlh);
- if (dn_fib_check_attr(r, rta))
- return -EINVAL;
- tb = dn_fib_get_table(r->rtm_table, 0);
- if (tb)
- return tb->delete(tb, r, (struct dn_kern_rta *)rta, nlh, &NETLINK_CB(skb));
- return -ESRCH;
- }
- int dn_fib_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
- {
- struct dn_fib_table *tb;
- struct rtattr **rta = arg;
- struct rtmsg *r = NLMSG_DATA(nlh);
- if (dn_fib_check_attr(r, rta))
- return -EINVAL;
- tb = dn_fib_get_table(r->rtm_table, 1);
- if (tb)
- return tb->insert(tb, r, (struct dn_kern_rta *)rta, nlh, &NETLINK_CB(skb));
- return -ENOBUFS;
- }
- int dn_fib_dump(struct sk_buff *skb, struct netlink_callback *cb)
- {
- int t;
- int s_t;
- struct dn_fib_table *tb;
- if (NLMSG_PAYLOAD(cb->nlh, 0) >= sizeof(struct rtmsg) &&
- ((struct rtmsg *)NLMSG_DATA(cb->nlh))->rtm_flags&RTM_F_CLONED)
- return dn_cache_dump(skb, cb);
- s_t = cb->args[0];
- if (s_t == 0)
- s_t = cb->args[0] = DN_MIN_TABLE;
- for(t = s_t; t < DN_NUM_TABLES; t++) {
- if (t < s_t)
- continue;
- if (t > s_t)
- memset(&cb->args[1], 0, sizeof(cb->args)-sizeof(int));
- tb = dn_fib_get_table(t, 0);
- if (tb == NULL)
- continue;
- if (tb->dump(tb, skb, cb) < 0)
- break;
- }
- cb->args[0] = t;
- return skb->len;
- }
- int dn_fib_sync_down(dn_address local, struct net_device *dev, int force)
- {
- int ret = 0;
- int scope = RT_SCOPE_NOWHERE;
- if (force)
- scope = -1;
- for_fib_info() {
- /*
- * This makes no sense for DECnet.... we will almost
- * certainly have more than one local address the same
- * over all our interfaces. It needs thinking about
- * some more.
- */
- if (local && fi->fib_prefsrc == local) {
- fi->fib_flags |= RTNH_F_DEAD;
- ret++;
- } else if (dev && fi->fib_nhs) {
- int dead = 0;
- change_nexthops(fi) {
- if (nh->nh_flags&RTNH_F_DEAD)
- dead++;
- else if (nh->nh_dev == dev &&
- nh->nh_scope != scope) {
- nh->nh_flags |= RTNH_F_DEAD;
- fi->fib_power -= nh->nh_power;
- nh->nh_power = 0;
- dead++;
- }
- } endfor_nexthops(fi)
- if (dead == fi->fib_nhs) {
- fi->fib_flags |= RTNH_F_DEAD;
- ret++;
- }
- }
- } endfor_fib_info();
- return ret;
- }
- int dn_fib_sync_up(struct net_device *dev)
- {
- int ret = 0;
- if (!(dev->flags&IFF_UP))
- return 0;
- for_fib_info() {
- int alive = 0;
- change_nexthops(fi) {
- if (!(nh->nh_flags&RTNH_F_DEAD)) {
- alive++;
- continue;
- }
- if (nh->nh_dev == NULL || !(nh->nh_dev->flags&IFF_UP))
- continue;
- if (nh->nh_dev != dev || dev->dn_ptr == NULL)
- continue;
- alive++;
- nh->nh_power = 0;
- nh->nh_flags &= ~RTNH_F_DEAD;
- } endfor_nexthops(fi);
- if (alive == fi->fib_nhs) {
- fi->fib_flags &= ~RTNH_F_DEAD;
- ret++;
- }
- } endfor_fib_info();
- return ret;
- }
- void dn_fib_flush(void)
- {
- int flushed = 0;
- struct dn_fib_table *tb;
- int id;
- for(id = DN_NUM_TABLES; id > 0; id--) {
- if ((tb = dn_fib_get_table(id, 0)) == NULL)
- continue;
- flushed += tb->flush(tb);
- }
- if (flushed)
- dn_rt_cache_flush(-1);
- }
- int dn_fib_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
- {
- if (!capable(CAP_NET_ADMIN))
- return -EPERM;
- switch(cmd) {
- case SIOCADDRT:
- case SIOCDELRT:
- return 0;
- }
- return -EINVAL;
- }
- #ifdef CONFIG_PROC_FS
- static int decnet_rt_get_info(char *buffer, char **start, off_t offset, int length)
- {
- int first = offset / 128;
- char *ptr = buffer;
- int count = (length + 127) / 128;
- int len;
- int i;
- struct dn_fib_table *tb;
- *start = buffer + (offset % 128);
- if (--first < 0) {
- sprintf(buffer, "%-127sn", "IfacetDesttGW tFlagstRefCnttUsetMetrictMaskttMTUtWindowtIRTT");
- --count;
- ptr += 128;
- first = 0;
- }
- for(i = DN_MIN_TABLE; (i <= DN_NUM_TABLES) && (count > 0); i++) {
- if ((tb = dn_fib_get_table(i, 0)) != NULL) {
- int n = tb->get_info(tb, ptr, first, count);
- count -= n;
- ptr += n * 128;
- }
- }
- len = ptr - *start;
- if (len >= length)
- return length;
- if (len >= 0)
- return len;
- return 0;
- }
- #endif /* CONFIG_PROC_FS */
- void __exit dn_fib_cleanup(void)
- {
- proc_net_remove("decnet_route");
- dn_fib_table_cleanup();
- dn_fib_rules_cleanup();
- }
- void __init dn_fib_init(void)
- {
- #ifdef CONFIG_PROC_FS
- proc_net_create("decnet_route", 0, decnet_rt_get_info);
- #endif
- dn_fib_table_init();
- dn_fib_rules_init();
- }