netfilter: nf_ct_ext: support variable length extensions

We can now define conntrack extensions of variable size. This
patch is useful to get rid of these unions:

union nf_conntrack_help
union nf_conntrack_proto
union nf_conntrack_nat_help

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Pablo Neira Ayuso 2012-02-01 16:18:31 +01:00
parent 3a8fc53a45
commit 3cf4c7e381
2 changed files with 15 additions and 10 deletions

View file

@ -80,10 +80,13 @@ static inline void nf_ct_ext_free(struct nf_conn *ct)
}
/* Add this type, returns pointer to data or NULL. */
void *
__nf_ct_ext_add(struct nf_conn *ct, enum nf_ct_ext_id id, gfp_t gfp);
void *__nf_ct_ext_add_length(struct nf_conn *ct, enum nf_ct_ext_id id,
size_t var_alloc_len, gfp_t gfp);
#define nf_ct_ext_add(ct, id, gfp) \
((id##_TYPE *)__nf_ct_ext_add((ct), (id), (gfp)))
((id##_TYPE *)__nf_ct_ext_add_length((ct), (id), 0, (gfp)))
#define nf_ct_ext_add_length(ct, id, len, gfp) \
((id##_TYPE *)__nf_ct_ext_add_length((ct), (id), (len), (gfp)))
#define NF_CT_EXT_F_PREALLOC 0x0001

View file

@ -44,7 +44,8 @@ void __nf_ct_ext_destroy(struct nf_conn *ct)
EXPORT_SYMBOL(__nf_ct_ext_destroy);
static void *
nf_ct_ext_create(struct nf_ct_ext **ext, enum nf_ct_ext_id id, gfp_t gfp)
nf_ct_ext_create(struct nf_ct_ext **ext, enum nf_ct_ext_id id,
size_t var_alloc_len, gfp_t gfp)
{
unsigned int off, len;
struct nf_ct_ext_type *t;
@ -54,8 +55,8 @@ nf_ct_ext_create(struct nf_ct_ext **ext, enum nf_ct_ext_id id, gfp_t gfp)
t = rcu_dereference(nf_ct_ext_types[id]);
BUG_ON(t == NULL);
off = ALIGN(sizeof(struct nf_ct_ext), t->align);
len = off + t->len;
alloc_size = t->alloc_size;
len = off + t->len + var_alloc_len;
alloc_size = t->alloc_size + var_alloc_len;
rcu_read_unlock();
*ext = kzalloc(alloc_size, gfp);
@ -68,7 +69,8 @@ nf_ct_ext_create(struct nf_ct_ext **ext, enum nf_ct_ext_id id, gfp_t gfp)
return (void *)(*ext) + off;
}
void *__nf_ct_ext_add(struct nf_conn *ct, enum nf_ct_ext_id id, gfp_t gfp)
void *__nf_ct_ext_add_length(struct nf_conn *ct, enum nf_ct_ext_id id,
size_t var_alloc_len, gfp_t gfp)
{
struct nf_ct_ext *old, *new;
int i, newlen, newoff;
@ -79,7 +81,7 @@ void *__nf_ct_ext_add(struct nf_conn *ct, enum nf_ct_ext_id id, gfp_t gfp)
old = ct->ext;
if (!old)
return nf_ct_ext_create(&ct->ext, id, gfp);
return nf_ct_ext_create(&ct->ext, id, var_alloc_len, gfp);
if (__nf_ct_ext_exist(old, id))
return NULL;
@ -89,7 +91,7 @@ void *__nf_ct_ext_add(struct nf_conn *ct, enum nf_ct_ext_id id, gfp_t gfp)
BUG_ON(t == NULL);
newoff = ALIGN(old->len, t->align);
newlen = newoff + t->len;
newlen = newoff + t->len + var_alloc_len;
rcu_read_unlock();
new = __krealloc(old, newlen, gfp);
@ -117,7 +119,7 @@ void *__nf_ct_ext_add(struct nf_conn *ct, enum nf_ct_ext_id id, gfp_t gfp)
memset((void *)new + newoff, 0, newlen - newoff);
return (void *)new + newoff;
}
EXPORT_SYMBOL(__nf_ct_ext_add);
EXPORT_SYMBOL(__nf_ct_ext_add_length);
static void update_alloc_size(struct nf_ct_ext_type *type)
{