/* * 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 (Rules) * * Author: Steve Whitehouse <SteveW@ACM.org> * Mostly copied from Alexey Kuznetsov's ipv4/fib_rules.c * * * Changes: * */ #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 <linux/in_route.h> #include <linux/list.h> #include <linux/rcupdate.h> #include <asm/atomic.h> #include <asm/uaccess.h> #include <net/neighbour.h> #include <net/dst.h> #include <net/flow.h> #include <net/dn.h> #include <net/dn_fib.h> #include <net/dn_neigh.h> #include <net/dn_dev.h> struct dn_fib_rule { struct hlist_node r_hlist; atomic_t r_clntref; u32 r_preference; unsigned char r_table; unsigned char r_action; unsigned char r_dst_len; unsigned char r_src_len; __le16 r_src; __le16 r_srcmask; __le16 r_dst; __le16 r_dstmask; __le16 r_srcmap; u8 r_flags; #ifdef CONFIG_DECNET_ROUTE_FWMARK u32 r_fwmark; #endif int r_ifindex; char r_ifname[IFNAMSIZ]; int r_dead; struct rcu_head rcu; }; static struct dn_fib_rule default_rule = { .r_clntref = ATOMIC_INIT(2), .r_preference = 0x7fff, .r_table = RT_TABLE_MAIN, .r_action = RTN_UNICAST }; static struct hlist_head dn_fib_rules; int dn_fib_rtm_delrule(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) { struct rtattr **rta = arg; struct rtmsg *rtm = NLMSG_DATA(nlh); struct dn_fib_rule *r; struct hlist_node *node; int err = -ESRCH; hlist_for_each_entry(r, node, &dn_fib_rules, r_hlist) { if ((!rta[RTA_SRC-1] || memcmp(RTA_DATA(rta[RTA_SRC-1]), &r->r_src, 2) == 0) && rtm->rtm_src_len == r->r_src_len && rtm->rtm_dst_len == r->r_dst_len && (!rta[RTA_DST-1] || memcmp(RTA_DATA(rta[RTA_DST-1]), &r->r_dst, 2) == 0) && #ifdef CONFIG_DECNET_ROUTE_FWMARK (!rta[RTA_PROTOINFO-1] || memcmp(RTA_DATA(rta[RTA_PROTOINFO-1]), &r->r_fwmark, 4) == 0) && #endif (!rtm->rtm_type || rtm->rtm_type == r->r_action) && (!rta[RTA_PRIORITY-1] || memcmp(RTA_DATA(rta[RTA_PRIORITY-1]), &r->r_preference, 4) == 0) && (!rta[RTA_IIF-1] || rtattr_strcmp(rta[RTA_IIF-1], r->r_ifname) == 0) && (!rtm->rtm_table || (r && rtm->rtm_table == r->r_table))) { err = -EPERM; if (r == &default_rule) break; hlist_del_rcu(&r->r_hlist); r->r_dead = 1; dn_fib_rule_put(r); err = 0; break; } } return err; } static inline void dn_fib_rule_put_rcu(struct rcu_head *head) { struct dn_fib_rule *r = container_of(head, struct dn_fib_rule, rcu); kfree(r); } void dn_fib_rule_put(struct dn_fib_rule *r) { if (atomic_dec_and_test(&r->r_clntref)) { if (r->r_dead) call_rcu(&r->rcu, dn_fib_rule_put_rcu); else printk(KERN_DEBUG "Attempt to free alive dn_fib_rule\n"); } } int dn_fib_rtm_newrule(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) { struct rtattr **rta = arg; struct rtmsg *rtm = NLMSG_DATA(nlh); struct dn_fib_rule *r, *new_r, *last = NULL; struct hlist_node *node = NULL; unsigned char table_id; if (rtm->rtm_src_len > 16 || rtm->rtm_dst_len > 16) return -EINVAL; if (rta[RTA_IIF-1] && RTA_PAYLOAD(rta[RTA_IIF-1]) > IFNAMSIZ) return -EINVAL; if (rtm->rtm_type == RTN_NAT) return -EINVAL; table_id = rtm->rtm_table; if (table_id == RT_TABLE_UNSPEC) { struct dn_fib_table *tb; if (rtm->rtm_type == RTN_UNICAST) { if ((tb = dn_fib_empty_table()) == NULL) return -ENOBUFS; table_id = tb->n; } } new_r = kmalloc(sizeof(*new_r), GFP_KERNEL); if (!new_r) return -ENOMEM; memset(new_r, 0, sizeof(*new_r)); if (rta[RTA_SRC-1]) memcpy(&new_r->r_src, RTA_DATA(rta[RTA_SRC-1]), 2); if (rta[RTA_DST-1]) memcpy(&new_r->r_dst, RTA_DATA(rta[RTA_DST-1]), 2); if (rta[RTA_GATEWAY-1]) memcpy(&new_r->r_srcmap, RTA_DATA(rta[RTA_GATEWAY-1]), 2); new_r->r_src_len = rtm->rtm_src_len; new_r->r_dst_len = rtm->rtm_dst_len; new_r->r_srcmask = dnet_make_mask(rtm->rtm_src_len); new_r->r_dstmask = dnet_make_mask(rtm->rtm_dst_len); #ifdef CONFIG_DECNET_ROUTE_FWMARK if (rta[RTA_PROTOINFO-1]) memcpy(&new_r->r_fwmark, RTA_DATA(rta[RTA_PROTOINFO-1]), 4); #endif new_r->r_action = rtm->rtm_type; new_r->r_flags = rtm->rtm_flags; if (rta[RTA_PRIORITY-1]) memcpy(&new_r->r_preference, RTA_DATA(rta[RTA_PRIORITY-1]), 4); new_r->r_table = table_id; if (rta[RTA_IIF-1]) { struct net_device *dev; rtattr_strlcpy(new_r->r_ifname, rta[RTA_IIF-1], IFNAMSIZ); new_r->r_ifindex = -1; dev = dev_get_by_name(new_r->r_ifname); if (dev) { new_r->r_ifindex = dev->ifindex; dev_put(dev); } } r = container_of(dn_fib_rules.first, struct dn_fib_rule, r_hlist); if (!new_r->r_preference) { if (r && r->r_hlist.next != NULL) { r = container_of(r->r_hlist.next, struct dn_fib_rule, r_hlist); if (r->r_preference) new_r->r_preference = r->r_preference - 1; } } hlist_for_each_entry(r, node, &dn_fib_rules, r_hlist) { if (r->r_preference > new_r->r_preference) break; last = r; } atomic_inc(&new_r->r_clntref); if (last) hlist_add_after_rcu(&last->r_hlist, &new_r->r_hlist); else hlist_add_before_rcu(&new_r->r_hlist, &r->r_hlist); return 0; } int dn_fib_lookup(const struct flowi *flp, struct dn_fib_res *res) { struct dn_fib_rule *r, *policy; struct dn_fib_table *tb; __le16 saddr = flp->fld_src; __le16 daddr = flp->fld_dst; struct hlist_node *node; int err; rcu_read_lock(); hlist_for_each_entry_rcu(r, node, &dn_fib_rules, r_hlist) { if (((saddr^r->r_src) & r->r_srcmask) || ((daddr^r->r_dst) & r->r_dstmask) || #ifdef CONFIG_DECNET_ROUTE_FWMARK (r->r_fwmark && r->r_fwmark != flp->fld_fwmark) || #endif (r->r_ifindex && r->r_ifindex != flp->iif)) continue; switch(r->r_action) { case RTN_UNICAST: case RTN_NAT: policy = r; break; case RTN_UNREACHABLE: rcu_read_unlock(); return -ENETUNREACH; default: case RTN_BLACKHOLE: rcu_read_unlock(); return -EINVAL; case RTN_PROHIBIT: rcu_read_unlock(); return -EACCES; } if ((tb = dn_fib_get_table(r->r_table, 0)) == NULL) continue; err = tb->lookup(tb, flp, res); if (err == 0) { res->r = policy; if (policy) atomic_inc(&policy->r_clntref); rcu_read_unlock(); return 0; } if (err < 0 && err != -EAGAIN) { rcu_read_unlock(); return err; } } rcu_read_unlock(); return -ESRCH; } unsigned dnet_addr_type(__le16 addr) { struct flowi fl = { .nl_u = { .dn_u = { .daddr = addr } } }; struct dn_fib_res res; unsigned ret = RTN_UNICAST; struct dn_fib_table *tb = dn_fib_tables[RT_TABLE_LOCAL]; res.r = NULL; if (tb) { if (!tb->lookup(tb, &fl, &res)) { ret = res.type; dn_fib_res_put(&res); } } return ret; } __le16 dn_fib_rules_policy(__le16 saddr, struct dn_fib_res *res, unsigned *flags) { struct dn_fib_rule *r = res->r; if (r->r_action == RTN_NAT) { int addrtype = dnet_addr_type(r->r_srcmap); if (addrtype == RTN_NAT) { saddr = (saddr&~r->r_srcmask)|r->r_srcmap; *flags |= RTCF_SNAT; } else if (addrtype == RTN_LOCAL || r->r_srcmap == 0) { saddr = r->r_srcmap; *flags |= RTCF_MASQ; } } return saddr; } static void dn_fib_rules_detach(struct net_device *dev) { struct hlist_node *node; struct dn_fib_rule *r; hlist_for_each_entry(r, node, &dn_fib_rules, r_hlist) { if (r->r_ifindex == dev->ifindex) r->r_ifindex = -1; } } static void dn_fib_rules_attach(struct net_device *dev) { struct hlist_node *node; struct dn_fib_rule *r; hlist_for_each_entry(r, node, &dn_fib_rules, r_hlist) { if (r->r_ifindex == -1 && strcmp(dev->name, r->r_ifname) == 0) r->r_ifindex = dev->ifindex; } } static int dn_fib_rules_event(struct notifier_block *this, unsigned long event, void *ptr) { struct net_device *dev = ptr; switch(event) { case NETDEV_UNREGISTER: dn_fib_rules_detach(dev); dn_fib_sync_down(0, dev, 1); case NETDEV_REGISTER: dn_fib_rules_attach(dev); dn_fib_sync_up(dev); } return NOTIFY_DONE; } static struct notifier_block dn_fib_rules_notifier = { .notifier_call = dn_fib_rules_event, }; static int dn_fib_fill_rule(struct sk_buff *skb, struct dn_fib_rule *r, struct netlink_callback *cb, unsigned int flags) { struct rtmsg *rtm; struct nlmsghdr *nlh; unsigned char *b = skb->tail; nlh = NLMSG_NEW_ANSWER(skb, cb, RTM_NEWRULE, sizeof(*rtm), flags); rtm = NLMSG_DATA(nlh); rtm->rtm_family = AF_DECnet; rtm->rtm_dst_len = r->r_dst_len; rtm->rtm_src_len = r->r_src_len; rtm->rtm_tos = 0; #ifdef CONFIG_DECNET_ROUTE_FWMARK if (r->r_fwmark) RTA_PUT(skb, RTA_PROTOINFO, 4, &r->r_fwmark); #endif rtm->rtm_table = r->r_table; rtm->rtm_protocol = 0; rtm->rtm_scope = 0; rtm->rtm_type = r->r_action; rtm->rtm_flags = r->r_flags; if (r->r_dst_len) RTA_PUT(skb, RTA_DST, 2, &r->r_dst); if (r->r_src_len) RTA_PUT(skb, RTA_SRC, 2, &r->r_src); if (r->r_ifname[0]) RTA_PUT(skb, RTA_IIF, IFNAMSIZ, &r->r_ifname); if (r->r_preference) RTA_PUT(skb, RTA_PRIORITY, 4, &r->r_preference); if (r->r_srcmap) RTA_PUT(skb, RTA_GATEWAY, 2, &r->r_srcmap); nlh->nlmsg_len = skb->tail - b; return skb->len; nlmsg_failure: rtattr_failure: skb_trim(skb, b - skb->data); return -1; } int dn_fib_dump_rules(struct sk_buff *skb, struct netlink_callback *cb) { int idx = 0; int s_idx = cb->args[0]; struct dn_fib_rule *r; struct hlist_node *node; rcu_read_lock(); hlist_for_each_entry(r, node, &dn_fib_rules, r_hlist) { if (idx < s_idx) continue; if (dn_fib_fill_rule(skb, r, cb, NLM_F_MULTI) < 0) break; idx++; } rcu_read_unlock(); cb->args[0] = idx; return skb->len; } void __init dn_fib_rules_init(void) { INIT_HLIST_HEAD(&dn_fib_rules); hlist_add_head(&default_rule.r_hlist, &dn_fib_rules); register_netdevice_notifier(&dn_fib_rules_notifier); } void __exit dn_fib_rules_cleanup(void) { unregister_netdevice_notifier(&dn_fib_rules_notifier); }