diff options
Diffstat (limited to 'net/ipv4/fib_hash.c')
| -rw-r--r-- | net/ipv4/fib_hash.c | 1070 |
1 files changed, 1070 insertions, 0 deletions
diff --git a/net/ipv4/fib_hash.c b/net/ipv4/fib_hash.c new file mode 100644 index 00000000..4ed7e0de --- /dev/null +++ b/net/ipv4/fib_hash.c @@ -0,0 +1,1070 @@ +/* + * INET An implementation of the TCP/IP protocol suite for the LINUX + * operating system. INET is implemented using the BSD Socket + * interface as the means of communication with the user level. + * + * IPv4 FIB: lookup engine and maintenance routines. + * + * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> + * + * 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 (at your option) any later version. + */ + +#include <asm/uaccess.h> +#include <asm/system.h> +#include <linux/bitops.h> +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/string.h> +#include <linux/socket.h> +#include <linux/sockios.h> +#include <linux/errno.h> +#include <linux/in.h> +#include <linux/inet.h> +#include <linux/inetdevice.h> +#include <linux/netdevice.h> +#include <linux/if_arp.h> +#include <linux/proc_fs.h> +#include <linux/skbuff.h> +#include <linux/netlink.h> +#include <linux/init.h> +#include <linux/slab.h> + +#include <net/net_namespace.h> +#include <net/ip.h> +#include <net/protocol.h> +#include <net/route.h> +#include <net/tcp.h> +#include <net/sock.h> +#include <net/ip_fib.h> + +#include "fib_lookup.h" + +static struct kmem_cache *fn_hash_kmem __read_mostly; +static struct kmem_cache *fn_alias_kmem __read_mostly; + +struct fib_node { + struct hlist_node fn_hash; + struct list_head fn_alias; + __be32 fn_key; + struct fib_alias fn_embedded_alias; +}; + +struct fn_zone { + struct fn_zone *fz_next; /* Next not empty zone */ + struct hlist_head *fz_hash; /* Hash table pointer */ + int fz_nent; /* Number of entries */ + + int fz_divisor; /* Hash divisor */ + u32 fz_hashmask; /* (fz_divisor - 1) */ +#define FZ_HASHMASK(fz) ((fz)->fz_hashmask) + + int fz_order; /* Zone order */ + __be32 fz_mask; +#define FZ_MASK(fz) ((fz)->fz_mask) +}; + +/* NOTE. On fast computers evaluation of fz_hashmask and fz_mask + * can be cheaper than memory lookup, so that FZ_* macros are used. + */ + +struct fn_hash { + struct fn_zone *fn_zones[33]; + struct fn_zone *fn_zone_list; +}; + +static inline u32 fn_hash(__be32 key, struct fn_zone *fz) +{ + u32 h = ntohl(key)>>(32 - fz->fz_order); + h ^= (h>>20); + h ^= (h>>10); + h ^= (h>>5); + h &= FZ_HASHMASK(fz); + return h; +} + +static inline __be32 fz_key(__be32 dst, struct fn_zone *fz) +{ + return dst & FZ_MASK(fz); +} + +static DEFINE_RWLOCK(fib_hash_lock); +static unsigned int fib_hash_genid; + +#define FZ_MAX_DIVISOR ((PAGE_SIZE<<MAX_ORDER) / sizeof(struct hlist_head)) + +static struct hlist_head *fz_hash_alloc(int divisor) +{ + unsigned long size = divisor * sizeof(struct hlist_head); + + if (size <= PAGE_SIZE) { + return kzalloc(size, GFP_KERNEL); + } else { + return (struct hlist_head *) + __get_free_pages(GFP_KERNEL | __GFP_ZERO, get_order(size)); + } +} + +/* The fib hash lock must be held when this is called. */ +static inline void fn_rebuild_zone(struct fn_zone *fz, + struct hlist_head *old_ht, + int old_divisor) +{ + int i; + + for (i = 0; i < old_divisor; i++) { + struct hlist_node *node, *n; + struct fib_node *f; + + hlist_for_each_entry_safe(f, node, n, &old_ht[i], fn_hash) { + struct hlist_head *new_head; + + hlist_del(&f->fn_hash); + + new_head = &fz->fz_hash[fn_hash(f->fn_key, fz)]; + hlist_add_head(&f->fn_hash, new_head); + } + } +} + +static void fz_hash_free(struct hlist_head *hash, int divisor) +{ + unsigned long size = divisor * sizeof(struct hlist_head); + + if (size <= PAGE_SIZE) + kfree(hash); + else + free_pages((unsigned long)hash, get_order(size)); +} + +static void fn_rehash_zone(struct fn_zone *fz) +{ + struct hlist_head *ht, *old_ht; + int old_divisor, new_divisor; + u32 new_hashmask; + + old_divisor = fz->fz_divisor; + + switch (old_divisor) { + case 16: + new_divisor = 256; + break; + case 256: + new_divisor = 1024; + break; + default: + if ((old_divisor << 1) > FZ_MAX_DIVISOR) { + printk(KERN_CRIT "route.c: bad divisor %d!\n", old_divisor); + return; + } + new_divisor = (old_divisor << 1); + break; + } + + new_hashmask = (new_divisor - 1); + +#if RT_CACHE_DEBUG >= 2 + printk(KERN_DEBUG "fn_rehash_zone: hash for zone %d grows from %d\n", + fz->fz_order, old_divisor); +#endif + + ht = fz_hash_alloc(new_divisor); + + if (ht) { + write_lock_bh(&fib_hash_lock); + old_ht = fz->fz_hash; + fz->fz_hash = ht; + fz->fz_hashmask = new_hashmask; + fz->fz_divisor = new_divisor; + fn_rebuild_zone(fz, old_ht, old_divisor); + fib_hash_genid++; + write_unlock_bh(&fib_hash_lock); + + fz_hash_free(old_ht, old_divisor); + } +} + +static inline void fn_free_node(struct fib_node * f) +{ + kmem_cache_free(fn_hash_kmem, f); +} + +static inline void fn_free_alias(struct fib_alias *fa, struct fib_node *f) +{ + fib_release_info(fa->fa_info); + if (fa == &f->fn_embedded_alias) + fa->fa_info = NULL; + else + kmem_cache_free(fn_alias_kmem, fa); +} + +static struct fn_zone * +fn_new_zone(struct fn_hash *table, int z) +{ + int i; + struct fn_zone *fz = kzalloc(sizeof(struct fn_zone), GFP_KERNEL); + if (!fz) + return NULL; + + if (z) { + fz->fz_divisor = 16; + } else { + fz->fz_divisor = 1; + } + fz->fz_hashmask = (fz->fz_divisor - 1); + fz->fz_hash = fz_hash_alloc(fz->fz_divisor); + if (!fz->fz_hash) { + kfree(fz); + return NULL; + } + fz->fz_order = z; + fz->fz_mask = inet_make_mask(z); + + /* Find the first not empty zone with more specific mask */ + for (i=z+1; i<=32; i++) + if (table->fn_zones[i]) + break; + write_lock_bh(&fib_hash_lock); + if (i>32) { + /* No more specific masks, we are the first. */ + fz->fz_next = table->fn_zone_list; + table->fn_zone_list = fz; + } else { + fz->fz_next = table->fn_zones[i]->fz_next; + table->fn_zones[i]->fz_next = fz; + } + table->fn_zones[z] = fz; + fib_hash_genid++; + write_unlock_bh(&fib_hash_lock); + return fz; +} + +int fib_table_lookup(struct fib_table *tb, + const struct flowi *flp, struct fib_result *res) +{ + int err; + struct fn_zone *fz; + struct fn_hash *t = (struct fn_hash *)tb->tb_data; + + read_lock(&fib_hash_lock); + for (fz = t->fn_zone_list; fz; fz = fz->fz_next) { + struct hlist_head *head; + struct hlist_node *node; + struct fib_node *f; + __be32 k = fz_key(flp->fl4_dst, fz); + + head = &fz->fz_hash[fn_hash(k, fz)]; + hlist_for_each_entry(f, node, head, fn_hash) { + if (f->fn_key != k) + continue; + + err = fib_semantic_match(&f->fn_alias, + flp, res, + fz->fz_order); + if (err <= 0) + goto out; + } + } + err = 1; +out: + read_unlock(&fib_hash_lock); + return err; +} + +void fib_table_select_default(struct fib_table *tb, + const struct flowi *flp, struct fib_result *res) +{ + int order, last_idx; + struct hlist_node *node; + struct fib_node *f; + struct fib_info *fi = NULL; + struct fib_info *last_resort; + struct fn_hash *t = (struct fn_hash *)tb->tb_data; + struct fn_zone *fz = t->fn_zones[0]; + + if (fz == NULL) + return; + + last_idx = -1; + last_resort = NULL; + order = -1; + + read_lock(&fib_hash_lock); + hlist_for_each_entry(f, node, &fz->fz_hash[0], fn_hash) { + struct fib_alias *fa; + + list_for_each_entry(fa, &f->fn_alias, fa_list) { + struct fib_info *next_fi = fa->fa_info; + + if (fa->fa_scope != res->scope || + fa->fa_type != RTN_UNICAST) + continue; + + if (next_fi->fib_priority > res->fi->fib_priority) + break; + if (!next_fi->fib_nh[0].nh_gw || + next_fi->fib_nh[0].nh_scope != RT_SCOPE_LINK) + continue; + fa->fa_state |= FA_S_ACCESSED; + + if (fi == NULL) { + if (next_fi != res->fi) + break; + } else if (!fib_detect_death(fi, order, &last_resort, + &last_idx, tb->tb_default)) { + fib_result_assign(res, fi); + tb->tb_default = order; + goto out; + } + fi = next_fi; + order++; + } + } + + if (order <= 0 || fi == NULL) { + tb->tb_default = -1; + goto out; + } + + if (!fib_detect_death(fi, order, &last_resort, &last_idx, + tb->tb_default)) { + fib_result_assign(res, fi); + tb->tb_default = order; + goto out; + } + + if (last_idx >= 0) + fib_result_assign(res, last_resort); + tb->tb_default = last_idx; +out: + read_unlock(&fib_hash_lock); +} + +/* Insert node F to FZ. */ +static inline void fib_insert_node(struct fn_zone *fz, struct fib_node *f) +{ + struct hlist_head *head = &fz->fz_hash[fn_hash(f->fn_key, fz)]; + + hlist_add_head(&f->fn_hash, head); +} + +/* Return the node in FZ matching KEY. */ +static struct fib_node *fib_find_node(struct fn_zone *fz, __be32 key) +{ + struct hlist_head *head = &fz->fz_hash[fn_hash(key, fz)]; + struct hlist_node *node; + struct fib_node *f; + + hlist_for_each_entry(f, node, head, fn_hash) { + if (f->fn_key == key) + return f; + } + + return NULL; +} + +int fib_table_insert(struct fib_table *tb, struct fib_config *cfg) +{ + struct fn_hash *table = (struct fn_hash *) tb->tb_data; + struct fib_node *new_f = NULL; + struct fib_node *f; + struct fib_alias *fa, *new_fa; + struct fn_zone *fz; + struct fib_info *fi; + u8 tos = cfg->fc_tos; + __be32 key; + int err; + + if (cfg->fc_dst_len > 32) + return -EINVAL; + + fz = table->fn_zones[cfg->fc_dst_len]; + if (!fz && !(fz = fn_new_zone(table, cfg->fc_dst_len))) + return -ENOBUFS; + + key = 0; + if (cfg->fc_dst) { + if (cfg->fc_dst & ~FZ_MASK(fz)) + return -EINVAL; + key = fz_key(cfg->fc_dst, fz); + } + + fi = fib_create_info(cfg); + if (IS_ERR(fi)) + return PTR_ERR(fi); + + if (fz->fz_nent > (fz->fz_divisor<<1) && + fz->fz_divisor < FZ_MAX_DIVISOR && + (cfg->fc_dst_len == 32 || + (1 << cfg->fc_dst_len) > fz->fz_divisor)) + fn_rehash_zone(fz); + + f = fib_find_node(fz, key); + + if (!f) + fa = NULL; + else + fa = fib_find_alias(&f->fn_alias, tos, fi->fib_priority); + + /* Now fa, if non-NULL, points to the first fib alias + * with the same keys [prefix,tos,priority], if such key already + * exists or to the node before which we will insert new one. + * + * If fa is NULL, we will need to allocate a new one and + * insert to the head of f. + * + * If f is NULL, no fib node matched the destination key + * and we need to allocate a new one of those as well. + */ + + if (fa && fa->fa_tos == tos && + fa->fa_info->fib_priority == fi->fib_priority) { + struct fib_alias *fa_first, *fa_match; + + err = -EEXIST; + if (cfg->fc_nlflags & NLM_F_EXCL) + goto out; + + /* We have 2 goals: + * 1. Find exact match for type, scope, fib_info to avoid + * duplicate routes + * 2. Find next 'fa' (or head), NLM_F_APPEND inserts before it + */ + fa_match = NULL; + fa_first = fa; + fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list); + list_for_each_entry_continue(fa, &f->fn_alias, fa_list) { + if (fa->fa_tos != tos) + break; + if (fa->fa_info->fib_priority != fi->fib_priority) + break; + if (fa->fa_type == cfg->fc_type && + fa->fa_scope == cfg->fc_scope && + fa->fa_info == fi) { + fa_match = fa; + break; + } + } + + if (cfg->fc_nlflags & NLM_F_REPLACE) { + struct fib_info *fi_drop; + u8 state; + + fa = fa_first; + if (fa_match) { + if (fa == fa_match) + err = 0; + goto out; + } + write_lock_bh(&fib_hash_lock); + fi_drop = fa->fa_info; + fa->fa_info = fi; + fa->fa_type = cfg->fc_type; + fa->fa_scope = cfg->fc_scope; + state = fa->fa_state; + fa->fa_state &= ~FA_S_ACCESSED; + fib_hash_genid++; + write_unlock_bh(&fib_hash_lock); + + fib_release_info(fi_drop); + if (state & FA_S_ACCESSED) + rt_cache_flush(cfg->fc_nlinfo.nl_net, -1); + rtmsg_fib(RTM_NEWROUTE, key, fa, cfg->fc_dst_len, tb->tb_id, + &cfg->fc_nlinfo, NLM_F_REPLACE); + return 0; + } + + /* Error if we find a perfect match which + * uses the same scope, type, and nexthop + * information. + */ + if (fa_match) + goto out; + + if (!(cfg->fc_nlflags & NLM_F_APPEND)) + fa = fa_first; + } + + err = -ENOENT; + if (!(cfg->fc_nlflags & NLM_F_CREATE)) + goto out; + + err = -ENOBUFS; + + if (!f) { + new_f = kmem_cache_zalloc(fn_hash_kmem, GFP_KERNEL); + if (new_f == NULL) + goto out; + + INIT_HLIST_NODE(&new_f->fn_hash); + INIT_LIST_HEAD(&new_f->fn_alias); + new_f->fn_key = key; + f = new_f; + } + + new_fa = &f->fn_embedded_alias; + if (new_fa->fa_info != NULL) { + new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL); + if (new_fa == NULL) + goto out; + } + new_fa->fa_info = fi; + new_fa->fa_tos = tos; + new_fa->fa_type = cfg->fc_type; + new_fa->fa_scope = cfg->fc_scope; + new_fa->fa_state = 0; + + /* + * Insert new entry to the list. + */ + + write_lock_bh(&fib_hash_lock); + if (new_f) + fib_insert_node(fz, new_f); + list_add_tail(&new_fa->fa_list, + (fa ? &fa->fa_list : &f->fn_alias)); + fib_hash_genid++; + write_unlock_bh(&fib_hash_lock); + + if (new_f) + fz->fz_nent++; + rt_cache_flush(cfg->fc_nlinfo.nl_net, -1); + + rtmsg_fib(RTM_NEWROUTE, key, new_fa, cfg->fc_dst_len, tb->tb_id, + &cfg->fc_nlinfo, 0); + return 0; + +out: + if (new_f) + kmem_cache_free(fn_hash_kmem, new_f); + fib_release_info(fi); + return err; +} + +int fib_table_delete(struct fib_table *tb, struct fib_config *cfg) +{ + struct fn_hash *table = (struct fn_hash *)tb->tb_data; + struct fib_node *f; + struct fib_alias *fa, *fa_to_delete; + struct fn_zone *fz; + __be32 key; + + if (cfg->fc_dst_len > 32) + return -EINVAL; + + if ((fz = table->fn_zones[cfg->fc_dst_len]) == NULL) + return -ESRCH; + + key = 0; + if (cfg->fc_dst) { + if (cfg->fc_dst & ~FZ_MASK(fz)) + return -EINVAL; + key = fz_key(cfg->fc_dst, fz); + } + + f = fib_find_node(fz, key); + + if (!f) + fa = NULL; + else + fa = fib_find_alias(&f->fn_alias, cfg->fc_tos, 0); + if (!fa) + return -ESRCH; + + fa_to_delete = NULL; + fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list); + list_for_each_entry_continue(fa, &f->fn_alias, fa_list) { + struct fib_info *fi = fa->fa_info; + + if (fa->fa_tos != cfg->fc_tos) + break; + + if ((!cfg->fc_type || + fa->fa_type == cfg->fc_type) && + (cfg->fc_scope == RT_SCOPE_NOWHERE || + fa->fa_scope == cfg->fc_scope) && + (!cfg->fc_protocol || + fi->fib_protocol == cfg->fc_protocol) && + fib_nh_match(cfg, fi) == 0) { + fa_to_delete = fa; + break; + } + } + + if (fa_to_delete) { + int kill_fn; + + fa = fa_to_delete; + rtmsg_fib(RTM_DELROUTE, key, fa, cfg->fc_dst_len, + tb->tb_id, &cfg->fc_nlinfo, 0); + + kill_fn = 0; + write_lock_bh(&fib_hash_lock); + list_del(&fa->fa_list); + if (list_empty(&f->fn_alias)) { + hlist_del(&f->fn_hash); + kill_fn = 1; + } + fib_hash_genid++; + write_unlock_bh(&fib_hash_lock); + + if (fa->fa_state & FA_S_ACCESSED) + rt_cache_flush(cfg->fc_nlinfo.nl_net, -1); + fn_free_alias(fa, f); + if (kill_fn) { + fn_free_node(f); + fz->fz_nent--; + } + + return 0; + } + return -ESRCH; +} + +static int fn_flush_list(struct fn_zone *fz, int idx) +{ + struct hlist_head *head = &fz->fz_hash[idx]; + struct hlist_node *node, *n; + struct fib_node *f; + int found = 0; + + hlist_for_each_entry_safe(f, node, n, head, fn_hash) { + struct fib_alias *fa, *fa_node; + int kill_f; + + kill_f = 0; + list_for_each_entry_safe(fa, fa_node, &f->fn_alias, fa_list) { + struct fib_info *fi = fa->fa_info; + + if (fi && (fi->fib_flags&RTNH_F_DEAD)) { + write_lock_bh(&fib_hash_lock); + list_del(&fa->fa_list); + if (list_empty(&f->fn_alias)) { + hlist_del(&f->fn_hash); + kill_f = 1; + } + fib_hash_genid++; + write_unlock_bh(&fib_hash_lock); + + fn_free_alias(fa, f); + found++; + } + } + if (kill_f) { + fn_free_node(f); + fz->fz_nent--; + } + } + return found; +} + +int fib_table_flush(struct fib_table *tb) +{ + struct fn_hash *table = (struct fn_hash *) tb->tb_data; + struct fn_zone *fz; + int found = 0; + + for (fz = table->fn_zone_list; fz; fz = fz->fz_next) { + int i; + + for (i = fz->fz_divisor - 1; i >= 0; i--) + found += fn_flush_list(fz, i); + } + return found; +} + + +static inline int +fn_hash_dump_bucket(struct sk_buff *skb, struct netlink_callback *cb, + struct fib_table *tb, + struct fn_zone *fz, + struct hlist_head *head) +{ + struct hlist_node *node; + struct fib_node *f; + int i, s_i; + + s_i = cb->args[4]; + i = 0; + hlist_for_each_entry(f, node, head, fn_hash) { + struct fib_alias *fa; + + list_for_each_entry(fa, &f->fn_alias, fa_list) { + if (i < s_i) + goto next; + + if (fib_dump_info(skb, NETLINK_CB(cb->skb).pid, + cb->nlh->nlmsg_seq, + RTM_NEWROUTE, + tb->tb_id, + fa->fa_type, + fa->fa_scope, + f->fn_key, + fz->fz_order, + fa->fa_tos, + fa->fa_info, + NLM_F_MULTI) < 0) { + cb->args[4] = i; + return -1; + } + next: + i++; + } + } + cb->args[4] = i; + return skb->len; +} + +static inline int +fn_hash_dump_zone(struct sk_buff *skb, struct netlink_callback *cb, + struct fib_table *tb, + struct fn_zone *fz) +{ + int h, s_h; + + if (fz->fz_hash == NULL) + return skb->len; + s_h = cb->args[3]; + for (h = s_h; h < fz->fz_divisor; h++) { + if (hlist_empty(&fz->fz_hash[h])) + continue; + if (fn_hash_dump_bucket(skb, cb, tb, fz, &fz->fz_hash[h]) < 0) { + cb->args[3] = h; + return -1; + } + memset(&cb->args[4], 0, + sizeof(cb->args) - 4*sizeof(cb->args[0])); + } + cb->args[3] = h; + return skb->len; +} + +int fib_table_dump(struct fib_table *tb, struct sk_buff *skb, + struct netlink_callback *cb) +{ + int m, s_m; + struct fn_zone *fz; + struct fn_hash *table = (struct fn_hash *)tb->tb_data; + + s_m = cb->args[2]; + read_lock(&fib_hash_lock); + for (fz = table->fn_zone_list, m=0; fz; fz = fz->fz_next, m++) { + if (m < s_m) continue; + if (fn_hash_dump_zone(skb, cb, tb, fz) < 0) { + cb->args[2] = m; + read_unlock(&fib_hash_lock); + return -1; + } + memset(&cb->args[3], 0, + sizeof(cb->args) - 3*sizeof(cb->args[0])); + } + read_unlock(&fib_hash_lock); + cb->args[2] = m; + return skb->len; +} + +void __init fib_hash_init(void) +{ + fn_hash_kmem = kmem_cache_create("ip_fib_hash", sizeof(struct fib_node), + 0, SLAB_PANIC, NULL); + + fn_alias_kmem = kmem_cache_create("ip_fib_alias", sizeof(struct fib_alias), + 0, SLAB_PANIC, NULL); + +} + +struct fib_table *fib_hash_table(u32 id) +{ + struct fib_table *tb; + + tb = kmalloc(sizeof(struct fib_table) + sizeof(struct fn_hash), + GFP_KERNEL); + if (tb == NULL) + return NULL; + + tb->tb_id = id; + tb->tb_default = -1; + + memset(tb->tb_data, 0, sizeof(struct fn_hash)); + return tb; +} + +/* ------------------------------------------------------------------------ */ +#ifdef CONFIG_PROC_FS + +struct fib_iter_state { + struct seq_net_private p; + struct fn_zone *zone; + int bucket; + struct hlist_head *hash_head; + struct fib_node *fn; + struct fib_alias *fa; + loff_t pos; + unsigned int genid; + int valid; +}; + +static struct fib_alias *fib_get_first(struct seq_file *seq) +{ + struct fib_iter_state *iter = seq->private; + struct fib_table *main_table; + struct fn_hash *table; + + main_table = fib_get_table(seq_file_net(seq), RT_TABLE_MAIN); + table = (struct fn_hash *)main_table->tb_data; + + iter->bucket = 0; + iter->hash_head = NULL; + iter->fn = NULL; + iter->fa = NULL; + iter->pos = 0; + iter->genid = fib_hash_genid; + iter->valid = 1; + + for (iter->zone = table->fn_zone_list; iter->zone; + iter->zone = iter->zone->fz_next) { + int maxslot; + + if (!iter->zone->fz_nent) + continue; + + iter->hash_head = iter->zone->fz_hash; + maxslot = iter->zone->fz_divisor; + + for (iter->bucket = 0; iter->bucket < maxslot; + ++iter->bucket, ++iter->hash_head) { + struct hlist_node *node; + struct fib_node *fn; + + hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) { + struct fib_alias *fa; + + list_for_each_entry(fa, &fn->fn_alias, fa_list) { + iter->fn = fn; + iter->fa = fa; + goto out; + } + } + } + } +out: + return iter->fa; +} + +static struct fib_alias *fib_get_next(struct seq_file *seq) +{ + struct fib_iter_state *iter = seq->private; + struct fib_node *fn; + struct fib_alias *fa; + + /* Advance FA, if any. */ + fn = iter->fn; + fa = iter->fa; + if (fa) { + BUG_ON(!fn); + list_for_each_entry_continue(fa, &fn->fn_alias, fa_list) { + iter->fa = fa; + goto out; + } + } + + fa = iter->fa = NULL; + + /* Advance FN. */ + if (fn) { + struct hlist_node *node = &fn->fn_hash; + hlist_for_each_entry_continue(fn, node, fn_hash) { + iter->fn = fn; + + list_for_each_entry(fa, &fn->fn_alias, fa_list) { + iter->fa = fa; + goto out; + } + } + } + + fn = iter->fn = NULL; + + /* Advance hash chain. */ + if (!iter->zone) + goto out; + + for (;;) { + struct hlist_node *node; + int maxslot; + + maxslot = iter->zone->fz_divisor; + + while (++iter->bucket < maxslot) { + iter->hash_head++; + + hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) { + list_for_each_entry(fa, &fn->fn_alias, fa_list) { + iter->fn = fn; + iter->fa = fa; + goto out; + } + } + } + + iter->zone = iter->zone->fz_next; + + if (!iter->zone) + goto out; + + iter->bucket = 0; + iter->hash_head = iter->zone->fz_hash; + + hlist_for_each_entry(fn, node, iter->hash_head, fn_hash) { + list_for_each_entry(fa, &fn->fn_alias, fa_list) { + iter->fn = fn; + iter->fa = fa; + goto out; + } + } + } +out: + iter->pos++; + return fa; +} + +static struct fib_alias *fib_get_idx(struct seq_file *seq, loff_t pos) +{ + struct fib_iter_state *iter = seq->private; + struct fib_alias *fa; + + if (iter->valid && pos >= iter->pos && iter->genid == fib_hash_genid) { + fa = iter->fa; + pos -= iter->pos; + } else + fa = fib_get_first(seq); + + if (fa) + while (pos && (fa = fib_get_next(seq))) + --pos; + return pos ? NULL : fa; +} + +static void *fib_seq_start(struct seq_file *seq, loff_t *pos) + __acquires(fib_hash_lock) +{ + void *v = NULL; + + read_lock(&fib_hash_lock); + if (fib_get_table(seq_file_net(seq), RT_TABLE_MAIN)) + v = *pos ? fib_get_idx(seq, *pos - 1) : SEQ_START_TOKEN; + return v; +} + +static void *fib_seq_next(struct seq_file *seq, void *v, loff_t *pos) +{ + ++*pos; + return v == SEQ_START_TOKEN ? fib_get_first(seq) : fib_get_next(seq); +} + +static void fib_seq_stop(struct seq_file *seq, void *v) + __releases(fib_hash_lock) +{ + read_unlock(&fib_hash_lock); +} + +static unsigned fib_flag_trans(int type, __be32 mask, struct fib_info *fi) +{ + static const unsigned type2flags[RTN_MAX + 1] = { + [7] = RTF_REJECT, [8] = RTF_REJECT, + }; + unsigned flags = type2flags[type]; + + if (fi && fi->fib_nh->nh_gw) + flags |= RTF_GATEWAY; + if (mask == htonl(0xFFFFFFFF)) + flags |= RTF_HOST; + flags |= RTF_UP; + return flags; +} + +/* + * This outputs /proc/net/route. + * + * It always works in backward compatibility mode. + * The format of the file is not supposed to be changed. + */ +static int fib_seq_show(struct seq_file *seq, void *v) +{ + struct fib_iter_state *iter; + int len; + __be32 prefix, mask; + unsigned flags; + struct fib_node *f; + struct fib_alias *fa; + struct fib_info *fi; + + if (v == SEQ_START_TOKEN) { + seq_printf(seq, "%-127s\n", "Iface\tDestination\tGateway " + "\tFlags\tRefCnt\tUse\tMetric\tMask\t\tMTU" + "\tWindow\tIRTT"); + goto out; + } + + iter = seq->private; + f = iter->fn; + fa = iter->fa; + fi = fa->fa_info; + prefix = f->fn_key; + mask = FZ_MASK(iter->zone); + flags = fib_flag_trans(fa->fa_type, mask, fi); + if (fi) + seq_printf(seq, + "%s\t%08X\t%08X\t%04X\t%d\t%u\t%d\t%08X\t%d\t%u\t%u%n", + fi->fib_dev ? fi->fib_dev->name : "*", prefix, + fi->fib_nh->nh_gw, flags, 0, 0, fi->fib_priority, + mask, (fi->fib_advmss ? fi->fib_advmss + 40 : 0), + fi->fib_window, + fi->fib_rtt >> 3, &len); + else + seq_printf(seq, + "*\t%08X\t%08X\t%04X\t%d\t%u\t%d\t%08X\t%d\t%u\t%u%n", + prefix, 0, flags, 0, 0, 0, mask, 0, 0, 0, &len); + + seq_printf(seq, "%*s\n", 127 - len, ""); +out: + return 0; +} + +static const struct seq_operations fib_seq_ops = { + .start = fib_seq_start, + .next = fib_seq_next, + .stop = fib_seq_stop, + .show = fib_seq_show, +}; + +static int fib_seq_open(struct inode *inode, struct file *file) +{ + return seq_open_net(inode, file, &fib_seq_ops, + sizeof(struct fib_iter_state)); +} + +static const struct file_operations fib_seq_fops = { + .owner = THIS_MODULE, + .open = fib_seq_open, + .read = seq_read, + .llseek = seq_lseek, + .release = seq_release_net, +}; + +int __net_init fib_proc_init(struct net *net) +{ + if (!proc_net_fops_create(net, "route", S_IRUGO, &fib_seq_fops)) + return -ENOMEM; + return 0; +} + +void __net_exit fib_proc_exit(struct net *net) +{ + proc_net_remove(net, "route"); +} +#endif /* CONFIG_PROC_FS */ |