diff options
author | WANG Cong <xiyou.wangcong@gmail.com> | 2014-11-11 02:59:36 +0300 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2014-11-11 23:23:54 +0300 |
commit | d7480fd3b1738a8eae6a76098b17af318cf9b9cc (patch) | |
tree | 559ba1e8e583fec97c223f31b3657023e71febfb /net/core/neighbour.c | |
parent | b2e2f0c779fefede3a871781c8827bd8e76c7c0f (diff) | |
download | linux-d7480fd3b1738a8eae6a76098b17af318cf9b9cc.tar.xz |
neigh: remove dynamic neigh table registration support
Currently there are only three neigh tables in the whole kernel:
arp table, ndisc table and decnet neigh table. What's more,
we don't support registering multiple tables per family.
Therefore we can just make these tables statically built-in.
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/neighbour.c')
-rw-r--r-- | net/core/neighbour.c | 247 |
1 files changed, 112 insertions, 135 deletions
diff --git a/net/core/neighbour.c b/net/core/neighbour.c index edd04116ecb7..8e38f17288d3 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -56,7 +56,6 @@ static void __neigh_notify(struct neighbour *n, int type, int flags); static void neigh_update_notify(struct neighbour *neigh); static int pneigh_ifdown(struct neigh_table *tbl, struct net_device *dev); -static struct neigh_table *neigh_tables; #ifdef CONFIG_PROC_FS static const struct file_operations neigh_stat_seq_fops; #endif @@ -87,13 +86,8 @@ static const struct file_operations neigh_stat_seq_fops; the most complicated procedure, which we allow is dev->hard_header. It is supposed, that dev->hard_header is simplistic and does not make callbacks to neighbour tables. - - The last lock is neigh_tbl_lock. It is pure SMP lock, protecting - list of neighbour tables. This list is used only in process context, */ -static DEFINE_RWLOCK(neigh_tbl_lock); - static int neigh_blackhole(struct neighbour *neigh, struct sk_buff *skb) { kfree_skb(skb); @@ -1520,7 +1514,9 @@ static void neigh_parms_destroy(struct neigh_parms *parms) static struct lock_class_key neigh_table_proxy_queue_class; -static void neigh_table_init_no_netlink(struct neigh_table *tbl) +static struct neigh_table *neigh_tables[NEIGH_NR_TABLES] __read_mostly; + +void neigh_table_init(int index, struct neigh_table *tbl) { unsigned long now = jiffies; unsigned long phsize; @@ -1566,34 +1562,14 @@ static void neigh_table_init_no_netlink(struct neigh_table *tbl) tbl->last_flush = now; tbl->last_rand = now + tbl->parms.reachable_time * 20; -} - -void neigh_table_init(struct neigh_table *tbl) -{ - struct neigh_table *tmp; - neigh_table_init_no_netlink(tbl); - write_lock(&neigh_tbl_lock); - for (tmp = neigh_tables; tmp; tmp = tmp->next) { - if (tmp->family == tbl->family) - break; - } - tbl->next = neigh_tables; - neigh_tables = tbl; - write_unlock(&neigh_tbl_lock); - - if (unlikely(tmp)) { - pr_err("Registering multiple tables for family %d\n", - tbl->family); - dump_stack(); - } + neigh_tables[index] = tbl; } EXPORT_SYMBOL(neigh_table_init); -int neigh_table_clear(struct neigh_table *tbl) +int neigh_table_clear(int index, struct neigh_table *tbl) { - struct neigh_table **tp; - + neigh_tables[index] = NULL; /* It is not clean... Fix it to unload IPv6 module safely */ cancel_delayed_work_sync(&tbl->gc_work); del_timer_sync(&tbl->proxy_timer); @@ -1601,14 +1577,6 @@ int neigh_table_clear(struct neigh_table *tbl) neigh_ifdown(tbl, NULL); if (atomic_read(&tbl->entries)) pr_crit("neighbour leakage\n"); - write_lock(&neigh_tbl_lock); - for (tp = &neigh_tables; *tp; tp = &(*tp)->next) { - if (*tp == tbl) { - *tp = tbl->next; - break; - } - } - write_unlock(&neigh_tbl_lock); call_rcu(&rcu_dereference_protected(tbl->nht, 1)->rcu, neigh_hash_free_rcu); @@ -1626,12 +1594,32 @@ int neigh_table_clear(struct neigh_table *tbl) } EXPORT_SYMBOL(neigh_table_clear); +static struct neigh_table *neigh_find_table(int family) +{ + struct neigh_table *tbl = NULL; + + switch (family) { + case AF_INET: + tbl = neigh_tables[NEIGH_ARP_TABLE]; + break; + case AF_INET6: + tbl = neigh_tables[NEIGH_ND_TABLE]; + break; + case AF_DECnet: + tbl = neigh_tables[NEIGH_DN_TABLE]; + break; + } + + return tbl; +} + static int neigh_delete(struct sk_buff *skb, struct nlmsghdr *nlh) { struct net *net = sock_net(skb->sk); struct ndmsg *ndm; struct nlattr *dst_attr; struct neigh_table *tbl; + struct neighbour *neigh; struct net_device *dev = NULL; int err = -EINVAL; @@ -1652,39 +1640,31 @@ static int neigh_delete(struct sk_buff *skb, struct nlmsghdr *nlh) } } - read_lock(&neigh_tbl_lock); - for (tbl = neigh_tables; tbl; tbl = tbl->next) { - struct neighbour *neigh; - - if (tbl->family != ndm->ndm_family) - continue; - read_unlock(&neigh_tbl_lock); - - if (nla_len(dst_attr) < tbl->key_len) - goto out; + tbl = neigh_find_table(ndm->ndm_family); + if (tbl == NULL) + return -EAFNOSUPPORT; - if (ndm->ndm_flags & NTF_PROXY) { - err = pneigh_delete(tbl, net, nla_data(dst_attr), dev); - goto out; - } + if (nla_len(dst_attr) < tbl->key_len) + goto out; - if (dev == NULL) - goto out; + if (ndm->ndm_flags & NTF_PROXY) { + err = pneigh_delete(tbl, net, nla_data(dst_attr), dev); + goto out; + } - neigh = neigh_lookup(tbl, nla_data(dst_attr), dev); - if (neigh == NULL) { - err = -ENOENT; - goto out; - } + if (dev == NULL) + goto out; - err = neigh_update(neigh, NULL, NUD_FAILED, - NEIGH_UPDATE_F_OVERRIDE | - NEIGH_UPDATE_F_ADMIN); - neigh_release(neigh); + neigh = neigh_lookup(tbl, nla_data(dst_attr), dev); + if (neigh == NULL) { + err = -ENOENT; goto out; } - read_unlock(&neigh_tbl_lock); - err = -EAFNOSUPPORT; + + err = neigh_update(neigh, NULL, NUD_FAILED, + NEIGH_UPDATE_F_OVERRIDE | + NEIGH_UPDATE_F_ADMIN); + neigh_release(neigh); out: return err; @@ -1692,11 +1672,14 @@ out: static int neigh_add(struct sk_buff *skb, struct nlmsghdr *nlh) { + int flags = NEIGH_UPDATE_F_ADMIN | NEIGH_UPDATE_F_OVERRIDE; struct net *net = sock_net(skb->sk); struct ndmsg *ndm; struct nlattr *tb[NDA_MAX+1]; struct neigh_table *tbl; struct net_device *dev = NULL; + struct neighbour *neigh; + void *dst, *lladdr; int err; ASSERT_RTNL(); @@ -1720,70 +1703,60 @@ static int neigh_add(struct sk_buff *skb, struct nlmsghdr *nlh) goto out; } - read_lock(&neigh_tbl_lock); - for (tbl = neigh_tables; tbl; tbl = tbl->next) { - int flags = NEIGH_UPDATE_F_ADMIN | NEIGH_UPDATE_F_OVERRIDE; - struct neighbour *neigh; - void *dst, *lladdr; + tbl = neigh_find_table(ndm->ndm_family); + if (tbl == NULL) + return -EAFNOSUPPORT; - if (tbl->family != ndm->ndm_family) - continue; - read_unlock(&neigh_tbl_lock); + if (nla_len(tb[NDA_DST]) < tbl->key_len) + goto out; + dst = nla_data(tb[NDA_DST]); + lladdr = tb[NDA_LLADDR] ? nla_data(tb[NDA_LLADDR]) : NULL; - if (nla_len(tb[NDA_DST]) < tbl->key_len) - goto out; - dst = nla_data(tb[NDA_DST]); - lladdr = tb[NDA_LLADDR] ? nla_data(tb[NDA_LLADDR]) : NULL; + if (ndm->ndm_flags & NTF_PROXY) { + struct pneigh_entry *pn; + + err = -ENOBUFS; + pn = pneigh_lookup(tbl, net, dst, dev, 1); + if (pn) { + pn->flags = ndm->ndm_flags; + err = 0; + } + goto out; + } - if (ndm->ndm_flags & NTF_PROXY) { - struct pneigh_entry *pn; + if (dev == NULL) + goto out; - err = -ENOBUFS; - pn = pneigh_lookup(tbl, net, dst, dev, 1); - if (pn) { - pn->flags = ndm->ndm_flags; - err = 0; - } + neigh = neigh_lookup(tbl, dst, dev); + if (neigh == NULL) { + if (!(nlh->nlmsg_flags & NLM_F_CREATE)) { + err = -ENOENT; goto out; } - if (dev == NULL) + neigh = __neigh_lookup_errno(tbl, dst, dev); + if (IS_ERR(neigh)) { + err = PTR_ERR(neigh); + goto out; + } + } else { + if (nlh->nlmsg_flags & NLM_F_EXCL) { + err = -EEXIST; + neigh_release(neigh); goto out; - - neigh = neigh_lookup(tbl, dst, dev); - if (neigh == NULL) { - if (!(nlh->nlmsg_flags & NLM_F_CREATE)) { - err = -ENOENT; - goto out; - } - - neigh = __neigh_lookup_errno(tbl, dst, dev); - if (IS_ERR(neigh)) { - err = PTR_ERR(neigh); - goto out; - } - } else { - if (nlh->nlmsg_flags & NLM_F_EXCL) { - err = -EEXIST; - neigh_release(neigh); - goto out; - } - - if (!(nlh->nlmsg_flags & NLM_F_REPLACE)) - flags &= ~NEIGH_UPDATE_F_OVERRIDE; } - if (ndm->ndm_flags & NTF_USE) { - neigh_event_send(neigh, NULL); - err = 0; - } else - err = neigh_update(neigh, lladdr, ndm->ndm_state, flags); - neigh_release(neigh); - goto out; + if (!(nlh->nlmsg_flags & NLM_F_REPLACE)) + flags &= ~NEIGH_UPDATE_F_OVERRIDE; } - read_unlock(&neigh_tbl_lock); - err = -EAFNOSUPPORT; + if (ndm->ndm_flags & NTF_USE) { + neigh_event_send(neigh, NULL); + err = 0; + } else + err = neigh_update(neigh, lladdr, ndm->ndm_state, flags); + neigh_release(neigh); + out: return err; } @@ -1982,7 +1955,8 @@ static int neightbl_set(struct sk_buff *skb, struct nlmsghdr *nlh) struct neigh_table *tbl; struct ndtmsg *ndtmsg; struct nlattr *tb[NDTA_MAX+1]; - int err; + bool found = false; + int err, tidx; err = nlmsg_parse(nlh, sizeof(*ndtmsg), tb, NDTA_MAX, nl_neightbl_policy); @@ -1995,19 +1969,21 @@ static int neightbl_set(struct sk_buff *skb, struct nlmsghdr *nlh) } ndtmsg = nlmsg_data(nlh); - read_lock(&neigh_tbl_lock); - for (tbl = neigh_tables; tbl; tbl = tbl->next) { + + for (tidx = 0; tidx < NEIGH_NR_TABLES; tidx++) { + tbl = neigh_tables[tidx]; + if (!tbl) + continue; if (ndtmsg->ndtm_family && tbl->family != ndtmsg->ndtm_family) continue; - - if (nla_strcmp(tb[NDTA_NAME], tbl->id) == 0) + if (nla_strcmp(tb[NDTA_NAME], tbl->id) == 0) { + found = true; break; + } } - if (tbl == NULL) { - err = -ENOENT; - goto errout_locked; - } + if (!found) + return -ENOENT; /* * We acquire tbl->lock to be nice to the periodic timers and @@ -2118,8 +2094,6 @@ static int neightbl_set(struct sk_buff *skb, struct nlmsghdr *nlh) errout_tbl_lock: write_unlock_bh(&tbl->lock); -errout_locked: - read_unlock(&neigh_tbl_lock); errout: return err; } @@ -2134,10 +2108,13 @@ static int neightbl_dump_info(struct sk_buff *skb, struct netlink_callback *cb) family = ((struct rtgenmsg *) nlmsg_data(cb->nlh))->rtgen_family; - read_lock(&neigh_tbl_lock); - for (tbl = neigh_tables, tidx = 0; tbl; tbl = tbl->next, tidx++) { + for (tidx = 0; tidx < NEIGH_NR_TABLES; tidx++) { struct neigh_parms *p; + tbl = neigh_tables[tidx]; + if (!tbl) + continue; + if (tidx < tbl_skip || (family && tbl->family != family)) continue; @@ -2168,7 +2145,6 @@ static int neightbl_dump_info(struct sk_buff *skb, struct netlink_callback *cb) neigh_skip = 0; } out: - read_unlock(&neigh_tbl_lock); cb->args[0] = tidx; cb->args[1] = nidx; @@ -2351,7 +2327,6 @@ static int neigh_dump_info(struct sk_buff *skb, struct netlink_callback *cb) int proxy = 0; int err; - read_lock(&neigh_tbl_lock); family = ((struct rtgenmsg *) nlmsg_data(cb->nlh))->rtgen_family; /* check for full ndmsg structure presence, family member is @@ -2363,8 +2338,11 @@ static int neigh_dump_info(struct sk_buff *skb, struct netlink_callback *cb) s_t = cb->args[0]; - for (tbl = neigh_tables, t = 0; tbl; - tbl = tbl->next, t++) { + for (t = 0; t < NEIGH_NR_TABLES; t++) { + tbl = neigh_tables[t]; + + if (!tbl) + continue; if (t < s_t || (family && tbl->family != family)) continue; if (t > s_t) @@ -2377,7 +2355,6 @@ static int neigh_dump_info(struct sk_buff *skb, struct netlink_callback *cb) if (err < 0) break; } - read_unlock(&neigh_tbl_lock); cb->args[0] = t; return skb->len; |