b20ab9cc63
Connection tracking helpers have to drop packets under exceptional situations. Currently, the user gets the following logging message in case that happens: nf_ct_%s: dropping packet ... However, depending on the helper, there are different reasons why a packet can be dropped. This patch modifies the existing code to provide more specific error message in the scope of each helper to help users to debug the reason why the packet has been dropped, ie: nf_ct_%s: dropping packet: reason ... Thanks to Joe Perches for many formatting suggestions. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
118 lines
3.5 KiB
C
118 lines
3.5 KiB
C
/*
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* connection tracking helpers.
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*
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* 16 Dec 2003: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
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* - generalize L3 protocol dependent part.
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*
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* Derived from include/linux/netfiter_ipv4/ip_conntrack_helper.h
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*/
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#ifndef _NF_CONNTRACK_HELPER_H
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#define _NF_CONNTRACK_HELPER_H
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#include <net/netfilter/nf_conntrack.h>
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#include <net/netfilter/nf_conntrack_extend.h>
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#include <net/netfilter/nf_conntrack_expect.h>
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struct module;
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enum nf_ct_helper_flags {
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NF_CT_HELPER_F_USERSPACE = (1 << 0),
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NF_CT_HELPER_F_CONFIGURED = (1 << 1),
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};
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#define NF_CT_HELPER_NAME_LEN 16
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struct nf_conntrack_helper {
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struct hlist_node hnode; /* Internal use. */
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char name[NF_CT_HELPER_NAME_LEN]; /* name of the module */
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struct module *me; /* pointer to self */
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const struct nf_conntrack_expect_policy *expect_policy;
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/* length of internal data, ie. sizeof(struct nf_ct_*_master) */
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size_t data_len;
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/* Tuple of things we will help (compared against server response) */
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struct nf_conntrack_tuple tuple;
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/* Function to call when data passes; return verdict, or -1 to
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invalidate. */
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int (*help)(struct sk_buff *skb,
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unsigned int protoff,
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struct nf_conn *ct,
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enum ip_conntrack_info conntrackinfo);
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void (*destroy)(struct nf_conn *ct);
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int (*from_nlattr)(struct nlattr *attr, struct nf_conn *ct);
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int (*to_nlattr)(struct sk_buff *skb, const struct nf_conn *ct);
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unsigned int expect_class_max;
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unsigned int flags;
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unsigned int queue_num; /* For user-space helpers. */
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};
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extern struct nf_conntrack_helper *
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__nf_conntrack_helper_find(const char *name, u16 l3num, u8 protonum);
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extern struct nf_conntrack_helper *
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nf_conntrack_helper_try_module_get(const char *name, u16 l3num, u8 protonum);
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extern int nf_conntrack_helper_register(struct nf_conntrack_helper *);
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extern void nf_conntrack_helper_unregister(struct nf_conntrack_helper *);
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extern struct nf_conn_help *nf_ct_helper_ext_add(struct nf_conn *ct, struct nf_conntrack_helper *helper, gfp_t gfp);
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extern int __nf_ct_try_assign_helper(struct nf_conn *ct, struct nf_conn *tmpl,
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gfp_t flags);
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extern void nf_ct_helper_destroy(struct nf_conn *ct);
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static inline struct nf_conn_help *nfct_help(const struct nf_conn *ct)
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{
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return nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
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}
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static inline void *nfct_help_data(const struct nf_conn *ct)
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{
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struct nf_conn_help *help;
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help = nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
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return (void *)help->data;
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}
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extern int nf_conntrack_helper_pernet_init(struct net *net);
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extern void nf_conntrack_helper_pernet_fini(struct net *net);
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extern int nf_conntrack_helper_init(void);
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extern void nf_conntrack_helper_fini(void);
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extern int nf_conntrack_broadcast_help(struct sk_buff *skb,
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unsigned int protoff,
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struct nf_conn *ct,
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enum ip_conntrack_info ctinfo,
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unsigned int timeout);
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struct nf_ct_helper_expectfn {
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struct list_head head;
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const char *name;
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void (*expectfn)(struct nf_conn *ct, struct nf_conntrack_expect *exp);
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};
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__printf(3,4)
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void nf_ct_helper_log(struct sk_buff *skb, const struct nf_conn *ct,
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const char *fmt, ...);
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void nf_ct_helper_expectfn_register(struct nf_ct_helper_expectfn *n);
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void nf_ct_helper_expectfn_unregister(struct nf_ct_helper_expectfn *n);
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struct nf_ct_helper_expectfn *
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nf_ct_helper_expectfn_find_by_name(const char *name);
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struct nf_ct_helper_expectfn *
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nf_ct_helper_expectfn_find_by_symbol(const void *symbol);
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extern struct hlist_head *nf_ct_helper_hash;
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extern unsigned int nf_ct_helper_hsize;
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#endif /*_NF_CONNTRACK_HELPER_H*/
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