diff options
Diffstat (limited to 'net/decnet/dn_route.c')
| -rw-r--r-- | net/decnet/dn_route.c | 1840 |
1 files changed, 1840 insertions, 0 deletions
diff --git a/net/decnet/dn_route.c b/net/decnet/dn_route.c new file mode 100644 index 00000000000..1e7b5c3ea21 --- /dev/null +++ b/net/decnet/dn_route.c @@ -0,0 +1,1840 @@ +/* + * 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 Functions (Endnode and Router) + * + * Authors: Steve Whitehouse <SteveW@ACM.org> + * Eduardo Marcelo Serrat <emserrat@geocities.com> + * + * Changes: + * Steve Whitehouse : Fixes to allow "intra-ethernet" and + * "return-to-sender" bits on outgoing + * packets. + * Steve Whitehouse : Timeouts for cached routes. + * Steve Whitehouse : Use dst cache for input routes too. + * Steve Whitehouse : Fixed error values in dn_send_skb. + * Steve Whitehouse : Rework routing functions to better fit + * DECnet routing design + * Alexey Kuznetsov : New SMP locking + * Steve Whitehouse : More SMP locking changes & dn_cache_dump() + * Steve Whitehouse : Prerouting NF hook, now really is prerouting. + * Fixed possible skb leak in rtnetlink funcs. + * Steve Whitehouse : Dave Miller's dynamic hash table sizing and + * Alexey Kuznetsov's finer grained locking + * from ipv4/route.c. + * Steve Whitehouse : Routing is now starting to look like a + * sensible set of code now, mainly due to + * my copying the IPv4 routing code. The + * hooks here are modified and will continue + * to evolve for a while. + * Steve Whitehouse : Real SMP at last :-) Also new netfilter + * stuff. Look out raw sockets your days + * are numbered! + * Steve Whitehouse : Added return-to-sender functions. Added + * backlog congestion level return codes. + * Steve Whitehouse : Fixed bug where routes were set up with + * no ref count on net devices. + * Steve Whitehouse : RCU for the route cache + * Steve Whitehouse : Preparations for the flow cache + * Steve Whitehouse : Prepare for nonlinear skbs + */ + +/****************************************************************************** + (c) 1995-1998 E.M. Serrat emserrat@geocities.com + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. +*******************************************************************************/ + +#include <linux/config.h> +#include <linux/errno.h> +#include <linux/types.h> +#include <linux/socket.h> +#include <linux/in.h> +#include <linux/kernel.h> +#include <linux/sockios.h> +#include <linux/net.h> +#include <linux/netdevice.h> +#include <linux/inet.h> +#include <linux/route.h> +#include <linux/in_route.h> +#include <net/sock.h> +#include <linux/mm.h> +#include <linux/proc_fs.h> +#include <linux/seq_file.h> +#include <linux/init.h> +#include <linux/rtnetlink.h> +#include <linux/string.h> +#include <linux/netfilter_decnet.h> +#include <linux/rcupdate.h> +#include <linux/times.h> +#include <asm/errno.h> +#include <net/neighbour.h> +#include <net/dst.h> +#include <net/flow.h> +#include <net/dn.h> +#include <net/dn_dev.h> +#include <net/dn_nsp.h> +#include <net/dn_route.h> +#include <net/dn_neigh.h> +#include <net/dn_fib.h> + +struct dn_rt_hash_bucket +{ + struct dn_route *chain; + spinlock_t lock; +} __attribute__((__aligned__(8))); + +extern struct neigh_table dn_neigh_table; + + +static unsigned char dn_hiord_addr[6] = {0xAA,0x00,0x04,0x00,0x00,0x00}; + +static const int dn_rt_min_delay = 2 * HZ; +static const int dn_rt_max_delay = 10 * HZ; +static const int dn_rt_mtu_expires = 10 * 60 * HZ; + +static unsigned long dn_rt_deadline; + +static int dn_dst_gc(void); +static struct dst_entry *dn_dst_check(struct dst_entry *, __u32); +static struct dst_entry *dn_dst_negative_advice(struct dst_entry *); +static void dn_dst_link_failure(struct sk_buff *); +static void dn_dst_update_pmtu(struct dst_entry *dst, u32 mtu); +static int dn_route_input(struct sk_buff *); +static void dn_run_flush(unsigned long dummy); + +static struct dn_rt_hash_bucket *dn_rt_hash_table; +static unsigned dn_rt_hash_mask; + +static struct timer_list dn_route_timer; +static struct timer_list dn_rt_flush_timer = + TIMER_INITIALIZER(dn_run_flush, 0, 0); +int decnet_dst_gc_interval = 2; + +static struct dst_ops dn_dst_ops = { + .family = PF_DECnet, + .protocol = __constant_htons(ETH_P_DNA_RT), + .gc_thresh = 128, + .gc = dn_dst_gc, + .check = dn_dst_check, + .negative_advice = dn_dst_negative_advice, + .link_failure = dn_dst_link_failure, + .update_pmtu = dn_dst_update_pmtu, + .entry_size = sizeof(struct dn_route), + .entries = ATOMIC_INIT(0), +}; + +static __inline__ unsigned dn_hash(unsigned short src, unsigned short dst) +{ + unsigned short tmp = src ^ dst; + tmp ^= (tmp >> 3); + tmp ^= (tmp >> 5); + tmp ^= (tmp >> 10); + return dn_rt_hash_mask & (unsigned)tmp; +} + +static inline void dnrt_free(struct dn_route *rt) +{ + call_rcu_bh(&rt->u.dst.rcu_head, dst_rcu_free); +} + +static inline void dnrt_drop(struct dn_route *rt) +{ + if (rt) + dst_release(&rt->u.dst); + call_rcu_bh(&rt->u.dst.rcu_head, dst_rcu_free); +} + +static void dn_dst_check_expire(unsigned long dummy) +{ + int i; + struct dn_route *rt, **rtp; + unsigned long now = jiffies; + unsigned long expire = 120 * HZ; + + for(i = 0; i <= dn_rt_hash_mask; i++) { + rtp = &dn_rt_hash_table[i].chain; + + spin_lock(&dn_rt_hash_table[i].lock); + while((rt=*rtp) != NULL) { + if (atomic_read(&rt->u.dst.__refcnt) || + (now - rt->u.dst.lastuse) < expire) { + rtp = &rt->u.rt_next; + continue; + } + *rtp = rt->u.rt_next; + rt->u.rt_next = NULL; + dnrt_free(rt); + } + spin_unlock(&dn_rt_hash_table[i].lock); + + if ((jiffies - now) > 0) + break; + } + + mod_timer(&dn_route_timer, now + decnet_dst_gc_interval * HZ); +} + +static int dn_dst_gc(void) +{ + struct dn_route *rt, **rtp; + int i; + unsigned long now = jiffies; + unsigned long expire = 10 * HZ; + + for(i = 0; i <= dn_rt_hash_mask; i++) { + + spin_lock_bh(&dn_rt_hash_table[i].lock); + rtp = &dn_rt_hash_table[i].chain; + + while((rt=*rtp) != NULL) { + if (atomic_read(&rt->u.dst.__refcnt) || + (now - rt->u.dst.lastuse) < expire) { + rtp = &rt->u.rt_next; + continue; + } + *rtp = rt->u.rt_next; + rt->u.rt_next = NULL; + dnrt_drop(rt); + break; + } + spin_unlock_bh(&dn_rt_hash_table[i].lock); + } + + return 0; +} + +/* + * The decnet standards don't impose a particular minimum mtu, what they + * do insist on is that the routing layer accepts a datagram of at least + * 230 bytes long. Here we have to subtract the routing header length from + * 230 to get the minimum acceptable mtu. If there is no neighbour, then we + * assume the worst and use a long header size. + * + * We update both the mtu and the advertised mss (i.e. the segment size we + * advertise to the other end). + */ +static void dn_dst_update_pmtu(struct dst_entry *dst, u32 mtu) +{ + u32 min_mtu = 230; + struct dn_dev *dn = dst->neighbour ? + (struct dn_dev *)dst->neighbour->dev->dn_ptr : NULL; + + if (dn && dn->use_long == 0) + min_mtu -= 6; + else + min_mtu -= 21; + + if (dst->metrics[RTAX_MTU-1] > mtu && mtu >= min_mtu) { + if (!(dst_metric_locked(dst, RTAX_MTU))) { + dst->metrics[RTAX_MTU-1] = mtu; + dst_set_expires(dst, dn_rt_mtu_expires); + } + if (!(dst_metric_locked(dst, RTAX_ADVMSS))) { + u32 mss = mtu - DN_MAX_NSP_DATA_HEADER; + if (dst->metrics[RTAX_ADVMSS-1] > mss) + dst->metrics[RTAX_ADVMSS-1] = mss; + } + } +} + +/* + * When a route has been marked obsolete. (e.g. routing cache flush) + */ +static struct dst_entry *dn_dst_check(struct dst_entry *dst, __u32 cookie) +{ + return NULL; +} + +static struct dst_entry *dn_dst_negative_advice(struct dst_entry *dst) +{ + dst_release(dst); + return NULL; +} + +static void dn_dst_link_failure(struct sk_buff *skb) +{ + return; +} + +static inline int compare_keys(struct flowi *fl1, struct flowi *fl2) +{ + return memcmp(&fl1->nl_u.dn_u, &fl2->nl_u.dn_u, sizeof(fl1->nl_u.dn_u)) == 0 && + fl1->oif == fl2->oif && + fl1->iif == fl2->iif; +} + +static int dn_insert_route(struct dn_route *rt, unsigned hash, struct dn_route **rp) +{ + struct dn_route *rth, **rthp; + unsigned long now = jiffies; + + rthp = &dn_rt_hash_table[hash].chain; + + spin_lock_bh(&dn_rt_hash_table[hash].lock); + while((rth = *rthp) != NULL) { + if (compare_keys(&rth->fl, &rt->fl)) { + /* Put it first */ + *rthp = rth->u.rt_next; + rcu_assign_pointer(rth->u.rt_next, + dn_rt_hash_table[hash].chain); + rcu_assign_pointer(dn_rt_hash_table[hash].chain, rth); + + rth->u.dst.__use++; + dst_hold(&rth->u.dst); + rth->u.dst.lastuse = now; + spin_unlock_bh(&dn_rt_hash_table[hash].lock); + + dnrt_drop(rt); + *rp = rth; + return 0; + } + rthp = &rth->u.rt_next; + } + + rcu_assign_pointer(rt->u.rt_next, dn_rt_hash_table[hash].chain); + rcu_assign_pointer(dn_rt_hash_table[hash].chain, rt); + + dst_hold(&rt->u.dst); + rt->u.dst.__use++; + rt->u.dst.lastuse = now; + spin_unlock_bh(&dn_rt_hash_table[hash].lock); + *rp = rt; + return 0; +} + +void dn_run_flush(unsigned long dummy) +{ + int i; + struct dn_route *rt, *next; + + for(i = 0; i < dn_rt_hash_mask; i++) { + spin_lock_bh(&dn_rt_hash_table[i].lock); + + if ((rt = xchg(&dn_rt_hash_table[i].chain, NULL)) == NULL) + goto nothing_to_declare; + + for(; rt; rt=next) { + next = rt->u.rt_next; + rt->u.rt_next = NULL; + dst_free((struct dst_entry *)rt); + } + +nothing_to_declare: + spin_unlock_bh(&dn_rt_hash_table[i].lock); + } +} + +static DEFINE_SPINLOCK(dn_rt_flush_lock); + +void dn_rt_cache_flush(int delay) +{ + unsigned long now = jiffies; + int user_mode = !in_interrupt(); + + if (delay < 0) + delay = dn_rt_min_delay; + + spin_lock_bh(&dn_rt_flush_lock); + + if (del_timer(&dn_rt_flush_timer) && delay > 0 && dn_rt_deadline) { + long tmo = (long)(dn_rt_deadline - now); + + if (user_mode && tmo < dn_rt_max_delay - dn_rt_min_delay) + tmo = 0; + + if (delay > tmo) + delay = tmo; + } + + if (delay <= 0) { + spin_unlock_bh(&dn_rt_flush_lock); + dn_run_flush(0); + return; + } + + if (dn_rt_deadline == 0) + dn_rt_deadline = now + dn_rt_max_delay; + + dn_rt_flush_timer.expires = now + delay; + add_timer(&dn_rt_flush_timer); + spin_unlock_bh(&dn_rt_flush_lock); +} + +/** + * dn_return_short - Return a short packet to its sender + * @skb: The packet to return + * + */ +static int dn_return_short(struct sk_buff *skb) +{ + struct dn_skb_cb *cb; + unsigned char *ptr; + dn_address *src; + dn_address *dst; + dn_address tmp; + + /* Add back headers */ + skb_push(skb, skb->data - skb->nh.raw); + + if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL) + return NET_RX_DROP; + + cb = DN_SKB_CB(skb); + /* Skip packet length and point to flags */ + ptr = skb->data + 2; + *ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS; + + dst = (dn_address *)ptr; + ptr += 2; + src = (dn_address *)ptr; + ptr += 2; + *ptr = 0; /* Zero hop count */ + + /* Swap source and destination */ + tmp = *src; + *src = *dst; + *dst = tmp; + + skb->pkt_type = PACKET_OUTGOING; + dn_rt_finish_output(skb, NULL, NULL); + return NET_RX_SUCCESS; +} + +/** + * dn_return_long - Return a long packet to its sender + * @skb: The long format packet to return + * + */ +static int dn_return_long(struct sk_buff *skb) +{ + struct dn_skb_cb *cb; + unsigned char *ptr; + unsigned char *src_addr, *dst_addr; + unsigned char tmp[ETH_ALEN]; + + /* Add back all headers */ + skb_push(skb, skb->data - skb->nh.raw); + + if ((skb = skb_unshare(skb, GFP_ATOMIC)) == NULL) + return NET_RX_DROP; + + cb = DN_SKB_CB(skb); + /* Ignore packet length and point to flags */ + ptr = skb->data + 2; + + /* Skip padding */ + if (*ptr & DN_RT_F_PF) { + char padlen = (*ptr & ~DN_RT_F_PF); + ptr += padlen; + } + + *ptr++ = (cb->rt_flags & ~DN_RT_F_RQR) | DN_RT_F_RTS; + ptr += 2; + dst_addr = ptr; + ptr += 8; + src_addr = ptr; + ptr += 6; + *ptr = 0; /* Zero hop count */ + + /* Swap source and destination */ + memcpy(tmp, src_addr, ETH_ALEN); + memcpy(src_addr, dst_addr, ETH_ALEN); + memcpy(dst_addr, tmp, ETH_ALEN); + + skb->pkt_type = PACKET_OUTGOING; + dn_rt_finish_output(skb, dst_addr, src_addr); + return NET_RX_SUCCESS; +} + +/** + * dn_route_rx_packet - Try and find a route for an incoming packet + * @skb: The packet to find a route for + * + * Returns: result of input function if route is found, error code otherwise + */ +static int dn_route_rx_packet(struct sk_buff *skb) +{ + struct dn_skb_cb *cb = DN_SKB_CB(skb); + int err; + + if ((err = dn_route_input(skb)) == 0) + return dst_input(skb); + + if (decnet_debug_level & 4) { + char *devname = skb->dev ? skb->dev->name : "???"; + struct dn_skb_cb *cb = DN_SKB_CB(skb); + printk(KERN_DEBUG + "DECnet: dn_route_rx_packet: rt_flags=0x%02x dev=%s len=%d src=0x%04hx dst=0x%04hx err=%d type=%d\n", + (int)cb->rt_flags, devname, skb->len, cb->src, cb->dst, + err, skb->pkt_type); + } + + if ((skb->pkt_type == PACKET_HOST) && (cb->rt_flags & DN_RT_F_RQR)) { + switch(cb->rt_flags & DN_RT_PKT_MSK) { + case DN_RT_PKT_SHORT: + return dn_return_short(skb); + case DN_RT_PKT_LONG: + return dn_return_long(skb); + } + } + + kfree_skb(skb); + return NET_RX_DROP; +} + +static int dn_route_rx_long(struct sk_buff *skb) +{ + struct dn_skb_cb *cb = DN_SKB_CB(skb); + unsigned char *ptr = skb->data; + + if (!pskb_may_pull(skb, 21)) /* 20 for long header, 1 for shortest nsp */ + goto drop_it; + + skb_pull(skb, 20); + skb->h.raw = skb->data; + + /* Destination info */ + ptr += 2; + cb->dst = dn_htons(dn_eth2dn(ptr)); + if (memcmp(ptr, dn_hiord_addr, 4) != 0) + goto drop_it; + ptr += 6; + + + /* Source info */ + ptr += 2; + cb->src = dn_htons(dn_eth2dn(ptr)); + if (memcmp(ptr, dn_hiord_addr, 4) != 0) + goto drop_it; + ptr += 6; + /* Other junk */ + ptr++; + cb->hops = *ptr++; /* Visit Count */ + + return NF_HOOK(PF_DECnet, NF_DN_PRE_ROUTING, skb, skb->dev, NULL, dn_route_rx_packet); + +drop_it: + kfree_skb(skb); + return NET_RX_DROP; +} + + + +static int dn_route_rx_short(struct sk_buff *skb) +{ + struct dn_skb_cb *cb = DN_SKB_CB(skb); + unsigned char *ptr = skb->data; + + if (!pskb_may_pull(skb, 6)) /* 5 for short header + 1 for shortest nsp */ + goto drop_it; + + skb_pull(skb, 5); + skb->h.raw = skb->data; + + cb->dst = *(dn_address *)ptr; + ptr += 2; + cb->src = *(dn_address *)ptr; + ptr += 2; + cb->hops = *ptr & 0x3f; + + return NF_HOOK(PF_DECnet, NF_DN_PRE_ROUTING, skb, skb->dev, NULL, dn_route_rx_packet); + +drop_it: + kfree_skb(skb); + return NET_RX_DROP; +} + +static int dn_route_discard(struct sk_buff *skb) +{ + /* + * I know we drop the packet here, but thats considered success in + * this case + */ + kfree_skb(skb); + return NET_RX_SUCCESS; +} + +static int dn_route_ptp_hello(struct sk_buff *skb) +{ + dn_dev_hello(skb); + dn_neigh_pointopoint_hello(skb); + return NET_RX_SUCCESS; +} + +int dn_route_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt) +{ + struct dn_skb_cb *cb; + unsigned char flags = 0; + __u16 len = dn_ntohs(*(__u16 *)skb->data); + struct dn_dev *dn = (struct dn_dev *)dev->dn_ptr; + unsigned char padlen = 0; + + if (dn == NULL) + goto dump_it; + + if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL) + goto out; + + if (!pskb_may_pull(skb, 3)) + goto dump_it; + + skb_pull(skb, 2); + + if (len > skb->len) + goto dump_it; + + skb_trim(skb, len); + + flags = *skb->data; + + cb = DN_SKB_CB(skb); + cb->stamp = jiffies; + cb->iif = dev->ifindex; + + /* + * If we have padding, remove it. + */ + if (flags & DN_RT_F_PF) { + padlen = flags & ~DN_RT_F_PF; + if (!pskb_may_pull(skb, padlen + 1)) + goto dump_it; + skb_pull(skb, padlen); + flags = *skb->data; + } + + skb->nh.raw = skb->data; + + /* + * Weed out future version DECnet + */ + if (flags & DN_RT_F_VER) + goto dump_it; + + cb->rt_flags = flags; + + if (decnet_debug_level & 1) + printk(KERN_DEBUG + "dn_route_rcv: got 0x%02x from %s [%d %d %d]\n", + (int)flags, (dev) ? dev->name : "???", len, skb->len, + padlen); + + if (flags & DN_RT_PKT_CNTL) { + if (unlikely(skb_is_nonlinear(skb)) && + skb_linearize(skb, GFP_ATOMIC) != 0) + goto dump_it; + + switch(flags & DN_RT_CNTL_MSK) { + case DN_RT_PKT_INIT: + dn_dev_init_pkt(skb); + break; + case DN_RT_PKT_VERI: + dn_dev_veri_pkt(skb); + break; + } + + if (dn->parms.state != DN_DEV_S_RU) + goto dump_it; + + switch(flags & DN_RT_CNTL_MSK) { + case DN_RT_PKT_HELO: + return NF_HOOK(PF_DECnet, NF_DN_HELLO, skb, skb->dev, NULL, dn_route_ptp_hello); + + case DN_RT_PKT_L1RT: + case DN_RT_PKT_L2RT: + return NF_HOOK(PF_DECnet, NF_DN_ROUTE, skb, skb->dev, NULL, dn_route_discard); + case DN_RT_PKT_ERTH: + return NF_HOOK(PF_DECnet, NF_DN_HELLO, skb, skb->dev, NULL, dn_neigh_router_hello); + + case DN_RT_PKT_EEDH: + return NF_HOOK(PF_DECnet, NF_DN_HELLO, skb, skb->dev, NULL, dn_neigh_endnode_hello); + } + } else { + if (dn->parms.state != DN_DEV_S_RU) + goto dump_it; + + skb_pull(skb, 1); /* Pull flags */ + + switch(flags & DN_RT_PKT_MSK) { + case DN_RT_PKT_LONG: + return dn_route_rx_long(skb); + case DN_RT_PKT_SHORT: + return dn_route_rx_short(skb); + } + } + +dump_it: + kfree_skb(skb); +out: + return NET_RX_DROP; +} + +static int dn_output(struct sk_buff *skb) +{ + struct dst_entry *dst = skb->dst; + struct dn_route *rt = (struct dn_route *)dst; + struct net_device *dev = dst->dev; + struct dn_skb_cb *cb = DN_SKB_CB(skb); + struct neighbour *neigh; + + int err = -EINVAL; + + if ((neigh = dst->neighbour) == NULL) + goto error; + + skb->dev = dev; + + cb->src = rt->rt_saddr; + cb->dst = rt->rt_daddr; + + /* + * Always set the Intra-Ethernet bit on all outgoing packets + * originated on this node. Only valid flag from upper layers + * is return-to-sender-requested. Set hop count to 0 too. + */ + cb->rt_flags &= ~DN_RT_F_RQR; + cb->rt_flags |= DN_RT_F_IE; + cb->hops = 0; + + return NF_HOOK(PF_DECnet, NF_DN_LOCAL_OUT, skb, NULL, dev, neigh->output); + +error: + if (net_ratelimit()) + printk(KERN_DEBUG "dn_output: This should not happen\n"); + + kfree_skb(skb); + + return err; +} + +static int dn_forward(struct sk_buff *skb) +{ + struct dn_skb_cb *cb = DN_SKB_CB(skb); + struct dst_entry *dst = skb->dst; + struct dn_dev *dn_db = dst->dev->dn_ptr; + struct dn_route *rt; + struct neighbour *neigh = dst->neighbour; + int header_len; +#ifdef CONFIG_NETFILTER + struct net_device *dev = skb->dev; +#endif + + if (skb->pkt_type != PACKET_HOST) + goto drop; + + /* Ensure that we have enough space for headers */ + rt = (struct dn_route *)skb->dst; + header_len = dn_db->use_long ? 21 : 6; + if (skb_cow(skb, LL_RESERVED_SPACE(rt->u.dst.dev)+header_len)) + goto drop; + + /* + * Hop count exceeded. + */ + if (++cb->hops > 30) + goto drop; + + skb->dev = rt->u.dst.dev; + + /* + * If packet goes out same interface it came in on, then set + * the Intra-Ethernet bit. This has no effect for short + * packets, so we don't need to test for them here. + */ + cb->rt_flags &= ~DN_RT_F_IE; + if (rt->rt_flags & RTCF_DOREDIRECT) + cb->rt_flags |= DN_RT_F_IE; + + return NF_HOOK(PF_DECnet, NF_DN_FORWARD, skb, dev, skb->dev, neigh->output); + +drop: + kfree_skb(skb); + return NET_RX_DROP; +} + +/* + * Drop packet. This is used for endnodes and for + * when we should not be forwarding packets from + * this dest. + */ +static int dn_blackhole(struct sk_buff *skb) +{ + kfree_skb(skb); + return NET_RX_DROP; +} + +/* + * Used to catch bugs. This should never normally get + * called. + */ +static int dn_rt_bug(struct sk_buff *skb) +{ + if (net_ratelimit()) { + struct dn_skb_cb *cb = DN_SKB_CB(skb); + + printk(KERN_DEBUG "dn_rt_bug: skb from:%04x to:%04x\n", + cb->src, cb->dst); + } + + kfree_skb(skb); + + return NET_RX_BAD; +} + +static int dn_rt_set_next_hop(struct dn_route *rt, struct dn_fib_res *res) +{ + struct dn_fib_info *fi = res->fi; + struct net_device *dev = rt->u.dst.dev; + struct neighbour *n; + unsigned mss; + + if (fi) { + if (DN_FIB_RES_GW(*res) && + DN_FIB_RES_NH(*res).nh_scope == RT_SCOPE_LINK) + rt->rt_gateway = DN_FIB_RES_GW(*res); + memcpy(rt->u.dst.metrics, fi->fib_metrics, + sizeof(rt->u.dst.metrics)); + } + rt->rt_type = res->type; + + if (dev != NULL && rt->u.dst.neighbour == NULL) { + n = __neigh_lookup_errno(&dn_neigh_table, &rt->rt_gateway, dev); + if (IS_ERR(n)) + return PTR_ERR(n); + rt->u.dst.neighbour = n; + } + + if (rt->u.dst.metrics[RTAX_MTU-1] == 0 || + rt->u.dst.metrics[RTAX_MTU-1] > rt->u.dst.dev->mtu) + rt->u.dst.metrics[RTAX_MTU-1] = rt->u.dst.dev->mtu; + mss = dn_mss_from_pmtu(dev, dst_mtu(&rt->u.dst)); + if (rt->u.dst.metrics[RTAX_ADVMSS-1] == 0 || + rt->u.dst.metrics[RTAX_ADVMSS-1] > mss) + rt->u.dst.metrics[RTAX_ADVMSS-1] = mss; + return 0; +} + +static inline int dn_match_addr(__u16 addr1, __u16 addr2) +{ + __u16 tmp = dn_ntohs(addr1) ^ dn_ntohs(addr2); + int match = 16; + while(tmp) { + tmp >>= 1; + match--; + } + return match; +} + +static __u16 dnet_select_source(const struct net_device *dev, __u16 daddr, int scope) +{ + __u16 saddr = 0; + struct dn_dev *dn_db = dev->dn_ptr; + struct dn_ifaddr *ifa; + int best_match = 0; + int ret; + + read_lock(&dev_base_lock); + for(ifa = dn_db->ifa_list; ifa; ifa = ifa->ifa_next) { + if (ifa->ifa_scope > scope) + continue; + if (!daddr) { + saddr = ifa->ifa_local; + break; + } + ret = dn_match_addr(daddr, ifa->ifa_local); + if (ret > best_match) + saddr = ifa->ifa_local; + if (best_match == 0) + saddr = ifa->ifa_local; + } + read_unlock(&dev_base_lock); + + return saddr; +} + +static inline __u16 __dn_fib_res_prefsrc(struct dn_fib_res *res) +{ + return dnet_select_source(DN_FIB_RES_DEV(*res), DN_FIB_RES_GW(*res), res->scope); +} + +static inline __u16 dn_fib_rules_map_destination(__u16 daddr, struct dn_fib_res *res) +{ + __u16 mask = dnet_make_mask(res->prefixlen); + return (daddr&~mask)|res->fi->fib_nh->nh_gw; +} + +static int dn_route_output_slow(struct dst_entry **pprt, const struct flowi *oldflp, int try_hard) +{ + struct flowi fl = { .nl_u = { .dn_u = + { .daddr = oldflp->fld_dst, + .saddr = oldflp->fld_src, + .scope = RT_SCOPE_UNIVERSE, +#ifdef CONFIG_DECNET_ROUTE_FWMARK + .fwmark = oldflp->fld_fwmark +#endif + } }, + .iif = loopback_dev.ifindex, + .oif = oldflp->oif }; + struct dn_route *rt = NULL; + struct net_device *dev_out = NULL; + struct neighbour *neigh = NULL; + unsigned hash; + unsigned flags = 0; + struct dn_fib_res res = { .fi = NULL, .type = RTN_UNICAST }; + int err; + int free_res = 0; + __u16 gateway = 0; + + if (decnet_debug_level & 16) + printk(KERN_DEBUG + "dn_route_output_slow: dst=%04x src=%04x mark=%d" + " iif=%d oif=%d\n", oldflp->fld_dst, oldflp->fld_src, + oldflp->fld_fwmark, loopback_dev.ifindex, oldflp->oif); + + /* If we have an output interface, verify its a DECnet device */ + if (oldflp->oif) { + dev_out = dev_get_by_index(oldflp->oif); + err = -ENODEV; + if (dev_out && dev_out->dn_ptr == NULL) { + dev_put(dev_out); + dev_out = NULL; + } + if (dev_out == NULL) + goto out; + } + + /* If we have a source address, verify that its a local address */ + if (oldflp->fld_src) { + err = -EADDRNOTAVAIL; + + if (dev_out) { + if (dn_dev_islocal(dev_out, oldflp->fld_src)) + goto source_ok; + dev_put(dev_out); + goto out; + } + read_lock(&dev_base_lock); + for(dev_out = dev_base; dev_out; dev_out = dev_out->next) { + if (!dev_out->dn_ptr) + continue; + if (dn_dev_islocal(dev_out, oldflp->fld_src)) + break; + } + read_unlock(&dev_base_lock); + if (dev_out == NULL) + goto out; + dev_hold(dev_out); +source_ok: + ; + } + + /* No destination? Assume its local */ + if (!fl.fld_dst) { + fl.fld_dst = fl.fld_src; + + err = -EADDRNOTAVAIL; + if (dev_out) + dev_put(dev_out); + dev_out = &loopback_dev; + dev_hold(dev_out); + if (!fl.fld_dst) { + fl.fld_dst = + fl.fld_src = dnet_select_source(dev_out, 0, + RT_SCOPE_HOST); + if (!fl.fld_dst) + goto out; + } + fl.oif = loopback_dev.ifindex; + res.type = RTN_LOCAL; + goto make_route; + } + + if (decnet_debug_level & 16) + printk(KERN_DEBUG + "dn_route_output_slow: initial checks complete." + " dst=%o4x src=%04x oif=%d try_hard=%d\n", fl.fld_dst, + fl.fld_src, fl.oif, try_hard); + + /* + * N.B. If the kernel is compiled without router support then + * dn_fib_lookup() will evaluate to non-zero so this if () block + * will always be executed. + */ + err = -ESRCH; + if (try_hard || (err = dn_fib_lookup(&fl, &res)) != 0) { + struct dn_dev *dn_db; + if (err != -ESRCH) + goto out; + /* + * Here the fallback is basically the standard algorithm for + * routing in endnodes which is described in the DECnet routing + * docs + * + * If we are not trying hard, look in neighbour cache. + * The result is tested to ensure that if a specific output + * device/source address was requested, then we honour that + * here + */ + if (!try_hard) { + neigh = neigh_lookup_nodev(&dn_neigh_table, &fl.fld_dst); + if (neigh) { + if ((oldflp->oif && + (neigh->dev->ifindex != oldflp->oif)) || + (oldflp->fld_src && + (!dn_dev_islocal(neigh->dev, + oldflp->fld_src)))) { + neigh_release(neigh); + neigh = NULL; + } else { + if (dev_out) + dev_put(dev_out); + if (dn_dev_islocal(neigh->dev, fl.fld_dst)) { + dev_out = &loopback_dev; + res.type = RTN_LOCAL; + } else { + dev_out = neigh->dev; + } + dev_hold(dev_out); + goto select_source; + } + } + } + + /* Not there? Perhaps its a local address */ + if (dev_out == NULL) + dev_out = dn_dev_get_default(); + err = -ENODEV; + if (dev_out == NULL) + goto out; + dn_db = dev_out->dn_ptr; + /* Possible improvement - check all devices for local addr */ + if (dn_dev_islocal(dev_out, fl.fld_dst)) { + dev_put(dev_out); + dev_out = &loopback_dev; + dev_hold(dev_out); + res.type = RTN_LOCAL; + goto select_source; + } + /* Not local either.... try sending it to the default router */ + neigh = neigh_clone(dn_db->router); + BUG_ON(neigh && neigh->dev != dev_out); + + /* Ok then, we assume its directly connected and move on */ +select_source: + if (neigh) + gateway = ((struct dn_neigh *)neigh)->addr; + if (gateway == 0) + gateway = fl.fld_dst; + if (fl.fld_src == 0) { + fl.fld_src = dnet_select_source(dev_out, gateway, + res.type == RTN_LOCAL ? + RT_SCOPE_HOST : + RT_SCOPE_LINK); + if (fl.fld_src == 0 && res.type != RTN_LOCAL) + goto e_addr; + } + fl.oif = dev_out->ifindex; + goto make_route; + } + free_res = 1; + + if (res.type == RTN_NAT) + goto e_inval; + + if (res.type == RTN_LOCAL) { + if (!fl.fld_src) + fl.fld_src = fl.fld_dst; + if (dev_out) + dev_put(dev_out); + dev_out = &loopback_dev; + dev_hold(dev_out); + fl.oif = dev_out->ifindex; + if (res.fi) + dn_fib_info_put(res.fi); + res.fi = NULL; + goto make_route; + } + + if (res.fi->fib_nhs > 1 && fl.oif == 0) + dn_fib_select_multipath(&fl, &res); + + /* + * We could add some logic to deal with default routes here and + * get rid of some of the special casing above. + */ + + if (!fl.fld_src) + fl.fld_src = DN_FIB_RES_PREFSRC(res); + + if (dev_out) + dev_put(dev_out); + dev_out = DN_FIB_RES_DEV(res); + dev_hold(dev_out); + fl.oif = dev_out->ifindex; + gateway = DN_FIB_RES_GW(res); + +make_route: + if (dev_out->flags & IFF_LOOPBACK) + flags |= RTCF_LOCAL; + + rt = dst_alloc(&dn_dst_ops); + if (rt == NULL) + goto e_nobufs; + + atomic_set(&rt->u.dst.__refcnt, 1); + rt->u.dst.flags = DST_HOST; + + rt->fl.fld_src = oldflp->fld_src; + rt->fl.fld_dst = oldflp->fld_dst; + rt->fl.oif = oldflp->oif; + rt->fl.iif = 0; +#ifdef CONFIG_DECNET_ROUTE_FWMARK + rt->fl.fld_fwmark = oldflp->fld_fwmark; +#endif + + rt->rt_saddr = fl.fld_src; + rt->rt_daddr = fl.fld_dst; + rt->rt_gateway = gateway ? gateway : fl.fld_dst; + rt->rt_local_src = fl.fld_src; + + rt->rt_dst_map = fl.fld_dst; + rt->rt_src_map = fl.fld_src; + + rt->u.dst.dev = dev_out; + dev_hold(dev_out); + rt->u.dst.neighbour = neigh; + neigh = NULL; + + rt->u.dst.lastuse = jiffies; + rt->u.dst.output = dn_output; + rt->u.dst.input = dn_rt_bug; + rt->rt_flags = flags; + if (flags & RTCF_LOCAL) + rt->u.dst.input = dn_nsp_rx; + + err = dn_rt_set_next_hop(rt, &res); + if (err) + goto e_neighbour; + + hash = dn_hash(rt->fl.fld_src, rt->fl.fld_dst); + dn_insert_route(rt, hash, (struct dn_route **)pprt); + +done: + if (neigh) + neigh_release(neigh); + if (free_res) + dn_fib_res_put(&res); + if (dev_out) + dev_put(dev_out); +out: + return err; + +e_addr: + err = -EADDRNOTAVAIL; + goto done; +e_inval: + err = -EINVAL; + goto done; +e_nobufs: + err = -ENOBUFS; + goto done; +e_neighbour: + dst_free(&rt->u.dst); + goto e_nobufs; +} + + +/* + * N.B. The flags may be moved into the flowi at some future stage. + */ +static int __dn_route_output_key(struct dst_entry **pprt, const struct flowi *flp, int flags) +{ + unsigned hash = dn_hash(flp->fld_src, flp->fld_dst); + struct dn_route *rt = NULL; + + if (!(flags & MSG_TRYHARD)) { + rcu_read_lock_bh(); + for(rt = rcu_dereference(dn_rt_hash_table[hash].chain); rt; + rt = rcu_dereference(rt->u.rt_next)) { + if ((flp->fld_dst == rt->fl.fld_dst) && + (flp->fld_src == rt->fl.fld_src) && +#ifdef CONFIG_DECNET_ROUTE_FWMARK + (flp->fld_fwmark == rt->fl.fld_fwmark) && +#endif + (rt->fl.iif == 0) && + (rt->fl.oif == flp->oif)) { + rt->u.dst.lastuse = jiffies; + dst_hold(&rt->u.dst); + rt->u.dst.__use++; + rcu_read_unlock_bh(); + *pprt = &rt->u.dst; + return 0; + } + } + rcu_read_unlock_bh(); + } + + return dn_route_output_slow(pprt, flp, flags); +} + +static int dn_route_output_key(struct dst_entry **pprt, struct flowi *flp, int flags) +{ + int err; + + err = __dn_route_output_key(pprt, flp, flags); + if (err == 0 && flp->proto) { + err = xfrm_lookup(pprt, flp, NULL, 0); + } + return err; +} + +int dn_route_output_sock(struct dst_entry **pprt, struct flowi *fl, struct sock *sk, int flags) +{ + int err; + + err = __dn_route_output_key(pprt, fl, flags & MSG_TRYHARD); + if (err == 0 && fl->proto) { + err = xfrm_lookup(pprt, fl, sk, !(flags & MSG_DONTWAIT)); + } + return err; +} + +static int dn_route_input_slow(struct sk_buff *skb) +{ |