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[NETFILTER]: ip_tables: move compat offset calculation to x_tables
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Its needed by ip6_tables and arp_tables as well.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Patrick McHardy authored and David S. Miller committed Jan 28, 2008
1 parent 73cd598 commit b386d9f
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Showing 3 changed files with 70 additions and 59 deletions.
4 changes: 4 additions & 0 deletions include/linux/netfilter/x_tables.h
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Original file line number Diff line number Diff line change
Expand Up @@ -424,6 +424,10 @@ struct compat_xt_counters_info
extern void xt_compat_lock(int af);
extern void xt_compat_unlock(int af);

extern int xt_compat_add_offset(int af, unsigned int offset, short delta);
extern void xt_compat_flush_offsets(int af);
extern short xt_compat_calc_jump(int af, unsigned int offset);

extern int xt_compat_match_offset(struct xt_match *match);
extern int xt_compat_match_from_user(struct xt_entry_match *m,
void **dstptr, int *size);
Expand Down
67 changes: 8 additions & 59 deletions net/ipv4/netfilter/ip_tables.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1014,63 +1014,12 @@ copy_entries_to_user(unsigned int total_size,
}

#ifdef CONFIG_COMPAT
struct compat_delta {
struct compat_delta *next;
unsigned int offset;
short delta;
};

static struct compat_delta *compat_offsets;

static int compat_add_offset(unsigned int offset, short delta)
{
struct compat_delta *tmp;

tmp = kmalloc(sizeof(struct compat_delta), GFP_KERNEL);
if (!tmp)
return -ENOMEM;
tmp->offset = offset;
tmp->delta = delta;
if (compat_offsets) {
tmp->next = compat_offsets->next;
compat_offsets->next = tmp;
} else {
compat_offsets = tmp;
tmp->next = NULL;
}
return 0;
}

static void compat_flush_offsets(void)
{
struct compat_delta *tmp, *next;

if (compat_offsets) {
for (tmp = compat_offsets; tmp; tmp = next) {
next = tmp->next;
kfree(tmp);
}
compat_offsets = NULL;
}
}

static short compat_calc_jump(unsigned int offset)
{
struct compat_delta *tmp;
short delta;

for (tmp = compat_offsets, delta = 0; tmp; tmp = tmp->next)
if (tmp->offset < offset)
delta += tmp->delta;
return delta;
}

static void compat_standard_from_user(void *dst, void *src)
{
int v = *(compat_int_t *)src;

if (v > 0)
v += compat_calc_jump(v);
v += xt_compat_calc_jump(AF_INET, v);
memcpy(dst, &v, sizeof(v));
}

Expand All @@ -1079,7 +1028,7 @@ static int compat_standard_to_user(void __user *dst, void *src)
compat_int_t cv = *(int *)src;

if (cv > 0)
cv -= compat_calc_jump(cv);
cv -= xt_compat_calc_jump(AF_INET, cv);
return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0;
}

Expand All @@ -1104,7 +1053,7 @@ static int compat_calc_entry(struct ipt_entry *e,
t = ipt_get_target(e);
off += xt_compat_target_offset(t->u.kernel.target);
newinfo->size -= off;
ret = compat_add_offset(entry_offset, off);
ret = xt_compat_add_offset(AF_INET, entry_offset, off);
if (ret)
return ret;

Expand Down Expand Up @@ -1167,7 +1116,7 @@ static int get_info(void __user *user, int *len, int compat)
if (compat) {
struct xt_table_info tmp;
ret = compat_table_info(private, &tmp);
compat_flush_offsets();
xt_compat_flush_offsets(AF_INET);
private = &tmp;
}
#endif
Expand Down Expand Up @@ -1631,7 +1580,7 @@ check_compat_entry_size_and_hooks(struct compat_ipt_entry *e,

off += xt_compat_target_offset(target);
*size += off;
ret = compat_add_offset(entry_offset, off);
ret = xt_compat_add_offset(AF_INET, entry_offset, off);
if (ret)
goto out;

Expand Down Expand Up @@ -1797,7 +1746,7 @@ translate_compat_table(const char *name,
ret = COMPAT_IPT_ENTRY_ITERATE(entry0, total_size,
compat_copy_entry_from_user, &pos, &size,
name, newinfo, entry1);
compat_flush_offsets();
xt_compat_flush_offsets(AF_INET);
xt_compat_unlock(AF_INET);
if (ret)
goto free_newinfo;
Expand Down Expand Up @@ -1834,7 +1783,7 @@ translate_compat_table(const char *name,
COMPAT_IPT_ENTRY_ITERATE(entry0, total_size, compat_release_entry, &j);
return ret;
out_unlock:
compat_flush_offsets();
xt_compat_flush_offsets(AF_INET);
xt_compat_unlock(AF_INET);
goto out;
}
Expand Down Expand Up @@ -1997,7 +1946,7 @@ compat_get_entries(struct compat_ipt_get_entries __user *uptr, int *len)
get.size);
ret = -EINVAL;
}
compat_flush_offsets();
xt_compat_flush_offsets(AF_INET);
module_put(t->me);
xt_table_unlock(t);
} else
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58 changes: 58 additions & 0 deletions net/netfilter/x_tables.c
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Original file line number Diff line number Diff line change
Expand Up @@ -34,12 +34,21 @@ MODULE_DESCRIPTION("[ip,ip6,arp]_tables backend module");

#define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1))

struct compat_delta {
struct compat_delta *next;
unsigned int offset;
short delta;
};

struct xt_af {
struct mutex mutex;
struct list_head match;
struct list_head target;
struct list_head tables;
#ifdef CONFIG_COMPAT
struct mutex compat_mutex;
struct compat_delta *compat_offsets;
#endif
};

static struct xt_af *xt;
Expand Down Expand Up @@ -335,6 +344,54 @@ int xt_check_match(const struct xt_match *match, unsigned short family,
EXPORT_SYMBOL_GPL(xt_check_match);

#ifdef CONFIG_COMPAT
int xt_compat_add_offset(int af, unsigned int offset, short delta)
{
struct compat_delta *tmp;

tmp = kmalloc(sizeof(struct compat_delta), GFP_KERNEL);
if (!tmp)
return -ENOMEM;

tmp->offset = offset;
tmp->delta = delta;

if (xt[af].compat_offsets) {
tmp->next = xt[af].compat_offsets->next;
xt[af].compat_offsets->next = tmp;
} else {
xt[af].compat_offsets = tmp;
tmp->next = NULL;
}
return 0;
}
EXPORT_SYMBOL_GPL(xt_compat_add_offset);

void xt_compat_flush_offsets(int af)
{
struct compat_delta *tmp, *next;

if (xt[af].compat_offsets) {
for (tmp = xt[af].compat_offsets; tmp; tmp = next) {
next = tmp->next;
kfree(tmp);
}
xt[af].compat_offsets = NULL;
}
}
EXPORT_SYMBOL_GPL(xt_compat_flush_offsets);

short xt_compat_calc_jump(int af, unsigned int offset)
{
struct compat_delta *tmp;
short delta;

for (tmp = xt[af].compat_offsets, delta = 0; tmp; tmp = tmp->next)
if (tmp->offset < offset)
delta += tmp->delta;
return delta;
}
EXPORT_SYMBOL_GPL(xt_compat_calc_jump);

int xt_compat_match_offset(struct xt_match *match)
{
u_int16_t csize = match->compatsize ? : match->matchsize;
Expand Down Expand Up @@ -873,6 +930,7 @@ static int __init xt_init(void)
mutex_init(&xt[i].mutex);
#ifdef CONFIG_COMPAT
mutex_init(&xt[i].compat_mutex);
xt[i].compat_offsets = NULL;
#endif
INIT_LIST_HEAD(&xt[i].target);
INIT_LIST_HEAD(&xt[i].match);
Expand Down

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