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author | Pablo Neira Ayuso <pablo@netfilter.org> | 2010-09-28 21:06:34 +0200 |
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committer | Patrick McHardy <kaber@trash.net> | 2010-09-28 21:06:34 +0200 |
commit | bc01befdcf3e40979eb518085a075cbf0aacede0 (patch) | |
tree | 8d6c4352e135ade290f2ba0b68b45cbcffde8af8 /net/netfilter/nf_conntrack_netlink.c | |
parent | 8b008faf92ac8f7eeb65e8cd36077601af7c46db (diff) | |
download | kernel_samsung_smdk4412-bc01befdcf3e40979eb518085a075cbf0aacede0.zip kernel_samsung_smdk4412-bc01befdcf3e40979eb518085a075cbf0aacede0.tar.gz kernel_samsung_smdk4412-bc01befdcf3e40979eb518085a075cbf0aacede0.tar.bz2 |
netfilter: ctnetlink: add support for user-space expectation helpers
This patch adds the basic infrastructure to support user-space
expectation helpers via ctnetlink and the netfilter queuing
infrastructure NFQUEUE. Basically, this patch:
* adds NF_CT_EXPECT_USERSPACE flag to identify user-space
created expectations. I have also added a sanity check in
__nf_ct_expect_check() to avoid that kernel-space helpers
may create an expectation if the master conntrack has no
helper assigned.
* adds some branches to check if the master conntrack helper
exists, otherwise we skip the code that refers to kernel-space
helper such as the local expectation list and the expectation
policy.
* allows to set the timeout for user-space expectations with
no helper assigned.
* a list of expectations created from user-space that depends
on ctnetlink (if this module is removed, they are deleted).
* includes USERSPACE in the /proc output for expectations
that have been created by a user-space helper.
This patch also modifies ctnetlink to skip including the helper
name in the Netlink messages if no kernel-space helper is set
(since no user-space expectation has not kernel-space kernel
assigned).
You can access an example user-space FTP conntrack helper at:
http://people.netfilter.org/pablo/userspace-conntrack-helpers/nf-ftp-helper-userspace-POC.tar.bz
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Diffstat (limited to 'net/netfilter/nf_conntrack_netlink.c')
-rw-r--r-- | net/netfilter/nf_conntrack_netlink.c | 46 |
1 files changed, 30 insertions, 16 deletions
diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index 0804e0e..b4077be 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -1560,8 +1560,8 @@ ctnetlink_exp_dump_expect(struct sk_buff *skb, const struct nf_conntrack_expect *exp) { struct nf_conn *master = exp->master; - struct nf_conntrack_helper *helper; long timeout = (exp->timeout.expires - jiffies) / HZ; + struct nf_conn_help *help; if (timeout < 0) timeout = 0; @@ -1578,9 +1578,14 @@ ctnetlink_exp_dump_expect(struct sk_buff *skb, NLA_PUT_BE32(skb, CTA_EXPECT_TIMEOUT, htonl(timeout)); NLA_PUT_BE32(skb, CTA_EXPECT_ID, htonl((unsigned long)exp)); NLA_PUT_BE32(skb, CTA_EXPECT_FLAGS, htonl(exp->flags)); - helper = rcu_dereference(nfct_help(master)->helper); - if (helper) - NLA_PUT_STRING(skb, CTA_EXPECT_HELP_NAME, helper->name); + help = nfct_help(master); + if (help) { + struct nf_conntrack_helper *helper; + + helper = rcu_dereference(help->helper); + if (helper) + NLA_PUT_STRING(skb, CTA_EXPECT_HELP_NAME, helper->name); + } return 0; @@ -1921,24 +1926,32 @@ ctnetlink_create_expect(struct net *net, u16 zone, if (!h) return -ENOENT; ct = nf_ct_tuplehash_to_ctrack(h); - help = nfct_help(ct); - - if (!help || !help->helper) { - /* such conntrack hasn't got any helper, abort */ - err = -EOPNOTSUPP; - goto out; - } - exp = nf_ct_expect_alloc(ct); if (!exp) { err = -ENOMEM; goto out; } + help = nfct_help(ct); + if (!help) { + if (!cda[CTA_EXPECT_TIMEOUT]) { + err = -EINVAL; + goto out; + } + exp->timeout.expires = + jiffies + ntohl(nla_get_be32(cda[CTA_EXPECT_TIMEOUT])) * HZ; - if (cda[CTA_EXPECT_FLAGS]) - exp->flags = ntohl(nla_get_be32(cda[CTA_EXPECT_FLAGS])); - else - exp->flags = 0; + exp->flags = NF_CT_EXPECT_USERSPACE; + if (cda[CTA_EXPECT_FLAGS]) { + exp->flags |= + ntohl(nla_get_be32(cda[CTA_EXPECT_FLAGS])); + } + } else { + if (cda[CTA_EXPECT_FLAGS]) { + exp->flags = ntohl(nla_get_be32(cda[CTA_EXPECT_FLAGS])); + exp->flags &= ~NF_CT_EXPECT_USERSPACE; + } else + exp->flags = 0; + } exp->class = 0; exp->expectfn = NULL; @@ -2109,6 +2122,7 @@ static void __exit ctnetlink_exit(void) { pr_info("ctnetlink: unregistering from nfnetlink.\n"); + nf_ct_remove_userspace_expectations(); #ifdef CONFIG_NF_CONNTRACK_EVENTS nf_ct_expect_unregister_notifier(&ctnl_notifier_exp); nf_conntrack_unregister_notifier(&ctnl_notifier); |