From 3f0465a9ef02624e0a36db9e7c9bedcafcd6f6fe Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Wed, 16 Oct 2019 14:24:01 +0200 Subject: netfilter: nf_tables: dynamically allocate hooks per net_device in flowtables Use a list of hooks per device instead an array. Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 253 +++++++++++++++++++++++++----------------- 1 file changed, 151 insertions(+), 102 deletions(-) (limited to 'net') diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index bfea0d6effc5..d6224c7b0e28 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -1508,6 +1508,76 @@ static void nf_tables_chain_destroy(struct nft_ctx *ctx) } } +static struct nft_hook *nft_netdev_hook_alloc(struct net *net, + const struct nlattr *attr) +{ + struct net_device *dev; + char ifname[IFNAMSIZ]; + struct nft_hook *hook; + int err; + + hook = kmalloc(sizeof(struct nft_hook), GFP_KERNEL); + if (!hook) { + err = -ENOMEM; + goto err_hook_alloc; + } + + nla_strlcpy(ifname, attr, IFNAMSIZ); + dev = __dev_get_by_name(net, ifname); + if (!dev) { + err = -ENOENT; + goto err_hook_dev; + } + hook->ops.dev = dev; + + return hook; + +err_hook_dev: + kfree(hook); +err_hook_alloc: + return ERR_PTR(err); +} + +static int nf_tables_parse_netdev_hooks(struct net *net, + const struct nlattr *attr, + struct list_head *hook_list) +{ + struct nft_hook *hook, *next; + const struct nlattr *tmp; + int rem, n = 0, err; + + nla_for_each_nested(tmp, attr, rem) { + if (nla_type(tmp) != NFTA_DEVICE_NAME) { + err = -EINVAL; + goto err_hook; + } + + hook = nft_netdev_hook_alloc(net, tmp); + if (IS_ERR(hook)) { + err = PTR_ERR(hook); + goto err_hook; + } + list_add_tail(&hook->list, hook_list); + n++; + + if (n == NFT_FLOWTABLE_DEVICE_MAX) { + err = -EFBIG; + goto err_hook; + } + } + if (!n) + return -EINVAL; + + return 0; + +err_hook: + list_for_each_entry_safe(hook, next, hook_list, list) { + list_del(&hook->list); + kfree(hook); + } + return err; +} + struct nft_chain_hook { u32 num; s32 priority; @@ -5628,43 +5698,6 @@ nft_flowtable_lookup_byhandle(const struct nft_table *table, return ERR_PTR(-ENOENT); } -static int nf_tables_parse_devices(const struct nft_ctx *ctx, - const struct nlattr *attr, - struct net_device *dev_array[], int *len) -{ - const struct nlattr *tmp; - struct net_device *dev; - char ifname[IFNAMSIZ]; - int rem, n = 0, err; - - nla_for_each_nested(tmp, attr, rem) { - if (nla_type(tmp) != NFTA_DEVICE_NAME) { - err = -EINVAL; - goto err1; - } - - nla_strlcpy(ifname, tmp, IFNAMSIZ); - dev = __dev_get_by_name(ctx->net, ifname); - if (!dev) { - err = -ENOENT; - goto err1; - } - - dev_array[n++] = dev; - if (n == NFT_FLOWTABLE_DEVICE_MAX) { - err = -EFBIG; - goto err1; - } - } - if (!len) - return -EINVAL; - - err = 0; -err1: - *len = n; - return err; -} - static const struct nla_policy nft_flowtable_hook_policy[NFTA_FLOWTABLE_HOOK_MAX + 1] = { [NFTA_FLOWTABLE_HOOK_NUM] = { .type = NLA_U32 }, [NFTA_FLOWTABLE_HOOK_PRIORITY] = { .type = NLA_U32 }, @@ -5675,11 +5708,10 @@ static int nf_tables_flowtable_parse_hook(const struct nft_ctx *ctx, const struct nlattr *attr, struct nft_flowtable *flowtable) { - struct net_device *dev_array[NFT_FLOWTABLE_DEVICE_MAX]; struct nlattr *tb[NFTA_FLOWTABLE_HOOK_MAX + 1]; - struct nf_hook_ops *ops; + struct nft_hook *hook; int hooknum, priority; - int err, n = 0, i; + int err; err = nla_parse_nested_deprecated(tb, NFTA_FLOWTABLE_HOOK_MAX, attr, nft_flowtable_hook_policy, NULL); @@ -5697,27 +5729,21 @@ static int nf_tables_flowtable_parse_hook(const struct nft_ctx *ctx, priority = ntohl(nla_get_be32(tb[NFTA_FLOWTABLE_HOOK_PRIORITY])); - err = nf_tables_parse_devices(ctx, tb[NFTA_FLOWTABLE_HOOK_DEVS], - dev_array, &n); + err = nf_tables_parse_netdev_hooks(ctx->net, + tb[NFTA_FLOWTABLE_HOOK_DEVS], + &flowtable->hook_list); if (err < 0) return err; - ops = kcalloc(n, sizeof(struct nf_hook_ops), GFP_KERNEL); - if (!ops) - return -ENOMEM; - flowtable->hooknum = hooknum; flowtable->data.priority = priority; - flowtable->ops = ops; - flowtable->ops_len = n; - for (i = 0; i < n; i++) { - flowtable->ops[i].pf = NFPROTO_NETDEV; - flowtable->ops[i].hooknum = hooknum; - flowtable->ops[i].priority = priority; - flowtable->ops[i].priv = &flowtable->data; - flowtable->ops[i].hook = flowtable->data.type->hook; - flowtable->ops[i].dev = dev_array[i]; + list_for_each_entry(hook, &flowtable->hook_list, list) { + hook->ops.pf = NFPROTO_NETDEV; + hook->ops.hooknum = hooknum; + hook->ops.priority = priority; + hook->ops.priv = &flowtable->data; + hook->ops.hook = flowtable->data.type->hook; } return err; @@ -5757,14 +5783,51 @@ nft_flowtable_type_get(struct net *net, u8 family) static void nft_unregister_flowtable_net_hooks(struct net *net, struct nft_flowtable *flowtable) { - int i; + struct nft_hook *hook; - for (i = 0; i < flowtable->ops_len; i++) { - if (!flowtable->ops[i].dev) - continue; + list_for_each_entry(hook, &flowtable->hook_list, list) + nf_unregister_net_hook(net, &hook->ops); +} + +static int nft_register_flowtable_net_hooks(struct net *net, + struct nft_table *table, + struct nft_flowtable *flowtable) +{ + struct nft_hook *hook, *hook2, *next; + struct nft_flowtable *ft; + int err, i = 0; + + list_for_each_entry(hook, &flowtable->hook_list, list) { + list_for_each_entry(ft, &table->flowtables, list) { + list_for_each_entry(hook2, &ft->hook_list, list) { + if (hook->ops.dev == hook2->ops.dev && + hook->ops.pf == hook2->ops.pf) { + err = -EBUSY; + goto err_unregister_net_hooks; + } + } + } - nf_unregister_net_hook(net, &flowtable->ops[i]); + err = nf_register_net_hook(net, &hook->ops); + if (err < 0) + goto err_unregister_net_hooks; + + i++; } + + return 0; + +err_unregister_net_hooks: + list_for_each_entry_safe(hook, next, &flowtable->hook_list, list) { + if (i-- <= 0) + break; + + nf_unregister_net_hook(net, &hook->ops); + list_del_rcu(&hook->list); + kfree_rcu(hook, rcu); + } + + return err; } static int nf_tables_newflowtable(struct net *net, struct sock *nlsk, @@ -5775,12 +5838,13 @@ static int nf_tables_newflowtable(struct net *net, struct sock *nlsk, { const struct nfgenmsg *nfmsg = nlmsg_data(nlh); const struct nf_flowtable_type *type; - struct nft_flowtable *flowtable, *ft; u8 genmask = nft_genmask_next(net); int family = nfmsg->nfgen_family; + struct nft_flowtable *flowtable; + struct nft_hook *hook, *next; struct nft_table *table; struct nft_ctx ctx; - int err, i, k; + int err; if (!nla[NFTA_FLOWTABLE_TABLE] || !nla[NFTA_FLOWTABLE_NAME] || @@ -5819,6 +5883,7 @@ static int nf_tables_newflowtable(struct net *net, struct sock *nlsk, flowtable->table = table; flowtable->handle = nf_tables_alloc_handle(table); + INIT_LIST_HEAD(&flowtable->hook_list); flowtable->name = nla_strdup(nla[NFTA_FLOWTABLE_NAME], GFP_KERNEL); if (!flowtable->name) { @@ -5842,43 +5907,24 @@ static int nf_tables_newflowtable(struct net *net, struct sock *nlsk, if (err < 0) goto err4; - for (i = 0; i < flowtable->ops_len; i++) { - if (!flowtable->ops[i].dev) - continue; - - list_for_each_entry(ft, &table->flowtables, list) { - for (k = 0; k < ft->ops_len; k++) { - if (!ft->ops[k].dev) - continue; - - if (flowtable->ops[i].dev == ft->ops[k].dev && - flowtable->ops[i].pf == ft->ops[k].pf) { - err = -EBUSY; - goto err5; - } - } - } - - err = nf_register_net_hook(net, &flowtable->ops[i]); - if (err < 0) - goto err5; - } + err = nft_register_flowtable_net_hooks(ctx.net, table, flowtable); + if (err < 0) + goto err4; err = nft_trans_flowtable_add(&ctx, NFT_MSG_NEWFLOWTABLE, flowtable); if (err < 0) - goto err6; + goto err5; list_add_tail_rcu(&flowtable->list, &table->flowtables); table->use++; return 0; -err6: - i = flowtable->ops_len; err5: - for (k = i - 1; k >= 0; k--) - nf_unregister_net_hook(net, &flowtable->ops[k]); - - kfree(flowtable->ops); + list_for_each_entry_safe(hook, next, &flowtable->hook_list, list) { + nf_unregister_net_hook(net, &hook->ops); + list_del_rcu(&hook->list); + kfree_rcu(hook, rcu); + } err4: flowtable->data.type->free(&flowtable->data); err3: @@ -5945,8 +5991,8 @@ static int nf_tables_fill_flowtable_info(struct sk_buff *skb, struct net *net, { struct nlattr *nest, *nest_devs; struct nfgenmsg *nfmsg; + struct nft_hook *hook; struct nlmsghdr *nlh; - int i; event = nfnl_msg_type(NFNL_SUBSYS_NFTABLES, event); nlh = nlmsg_put(skb, portid, seq, event, sizeof(struct nfgenmsg), flags); @@ -5976,11 +6022,8 @@ static int nf_tables_fill_flowtable_info(struct sk_buff *skb, struct net *net, if (!nest_devs) goto nla_put_failure; - for (i = 0; i < flowtable->ops_len; i++) { - const struct net_device *dev = READ_ONCE(flowtable->ops[i].dev); - - if (dev && - nla_put_string(skb, NFTA_DEVICE_NAME, dev->name)) + list_for_each_entry_rcu(hook, &flowtable->hook_list, list) { + if (nla_put_string(skb, NFTA_DEVICE_NAME, hook->ops.dev->name)) goto nla_put_failure; } nla_nest_end(skb, nest_devs); @@ -6171,7 +6214,12 @@ err: static void nf_tables_flowtable_destroy(struct nft_flowtable *flowtable) { - kfree(flowtable->ops); + struct nft_hook *hook, *next; + + list_for_each_entry_safe(hook, next, &flowtable->hook_list, list) { + list_del_rcu(&hook->list); + kfree(hook); + } kfree(flowtable->name); flowtable->data.type->free(&flowtable->data); module_put(flowtable->data.type->owner); @@ -6211,14 +6259,15 @@ nla_put_failure: static void nft_flowtable_event(unsigned long event, struct net_device *dev, struct nft_flowtable *flowtable) { - int i; + struct nft_hook *hook; - for (i = 0; i < flowtable->ops_len; i++) { - if (flowtable->ops[i].dev != dev) + list_for_each_entry(hook, &flowtable->hook_list, list) { + if (hook->ops.dev != dev) continue; - nf_unregister_net_hook(dev_net(dev), &flowtable->ops[i]); - flowtable->ops[i].dev = NULL; + nf_unregister_net_hook(dev_net(dev), &hook->ops); + list_del_rcu(&hook->list); + kfree_rcu(hook, rcu); break; } } -- cgit v1.2.3-58-ga151