[PATCH 3.16 298/305] netfilter: arp_tables: simplify translate_compat_table args

Ben Hutchings
2016-08-14T11:25:50Z

From: Florian Westphal <fw@strlen.de>

commit 8dddd32756f6fe8e4e82a63361119b7e2384e02f upstream.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
[bwh: Backported to 3.6: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
net/ipv4/netfilter/arp_tables.c | 82 ++++++++++++++++++-----------------------
1 file changed, 36 insertions(+), 46 deletions(-)

--- a/net/ipv4/netfilter/arp_tables.c
+++ b/net/ipv4/netfilter/arp_tables.c
@@ -1205,6 +1205,18 @@ static int do_add_counters(struct net *n
}

#ifdef CONFIG_COMPAT
+struct compat_arpt_replace {
+ char name[XT_TABLE_MAXNAMELEN];
+ u32 valid_hooks;
+ u32 num_entries;
+ u32 size;
+ u32 hook_entry[NF_ARP_NUMHOOKS];
+ u32 underflow[NF_ARP_NUMHOOKS];
+ u32 num_counters;
+ compat_uptr_t counters;
+ struct compat_arpt_entry entries[0];
+};
+
static inline void compat_release_entry(struct compat_arpt_entry *e)
{
struct xt_entry_target *t;
@@ -1220,8 +1232,7 @@ check_compat_entry_size_and_hooks(struct
const unsigned char *base,
const unsigned char *limit,
const unsigned int *hook_entries,
- const unsigned int *underflows,
- const char *name)
+ const unsigned int *underflows)
{
struct xt_entry_target *t;
struct xt_target *target;
@@ -1292,7 +1303,7 @@ out:

static int
compat_copy_entry_from_user(struct compat_arpt_entry *e, void **dstptr,
- unsigned int *size, const char *name,
+ unsigned int *size,
struct xt_table_info *newinfo, unsigned char *base)
{
struct xt_entry_target *t;
@@ -1325,14 +1336,9 @@ compat_copy_entry_from_user(struct compa
return ret;
}

-static int translate_compat_table(const char *name,
- unsigned int valid_hooks,
- struct xt_table_info **pinfo,
+static int translate_compat_table(struct xt_table_info **pinfo,
void **pentry0,
- unsigned int total_size,
- unsigned int number,
- unsigned int *hook_entries,
- unsigned int *underflows)
+ const struct compat_arpt_replace *compatr)
{
unsigned int i, j;
struct xt_table_info *newinfo, *info;
@@ -1344,8 +1350,8 @@ static int translate_compat_table(const

info = *pinfo;
entry0 = *pentry0;
- size = total_size;
- info->number = number;
+ size = compatr->size;
+ info->number = compatr->num_entries;

/* Init all hooks to impossible value. */
for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
@@ -1356,40 +1362,39 @@ static int translate_compat_table(const
duprintf("translate_compat_table: size %u\n", info->size);
j = 0;
xt_compat_lock(NFPROTO_ARP);
- xt_compat_init_offsets(NFPROTO_ARP, number);
+ xt_compat_init_offsets(NFPROTO_ARP, compatr->num_entries);
/* Walk through entries, checking offsets. */
- xt_entry_foreach(iter0, entry0, total_size) {
+ xt_entry_foreach(iter0, entry0, compatr->size) {
ret = check_compat_entry_size_and_hooks(iter0, info, &size,
entry0,
- entry0 + total_size,
- hook_entries,
- underflows,
- name);
+ entry0 + compatr->size,
+ compatr->hook_entry,
+ compatr->underflow);
if (ret != 0)
goto out_unlock;
++j;
}

ret = -EINVAL;
- if (j != number) {
+ if (j != compatr->num_entries) {
duprintf("translate_compat_table: %u not %u entries\n",
- j, number);
+ j, compatr->num_entries);
goto out_unlock;
}

/* Check hooks all assigned */
for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
/* Only hooks which are valid */
- if (!(valid_hooks & (1 << i)))
+ if (!(compatr->valid_hooks & (1 << i)))
continue;
if (info->hook_entry[i] == 0xFFFFFFFF) {
duprintf("Invalid hook entry %u %u\n",
- i, hook_entries[i]);
+ i, info->hook_entry[i]);
goto out_unlock;
}
if (info->underflow[i] == 0xFFFFFFFF) {
duprintf("Invalid underflow %u %u\n",
- i, underflows[i]);
+ i, info->underflow[i]);
goto out_unlock;
}
}
@@ -1399,17 +1404,17 @@ static int translate_compat_table(const
if (!newinfo)
goto out_unlock;

- newinfo->number = number;
+ newinfo->number = compatr->num_entries;
for (i = 0; i < NF_ARP_NUMHOOKS; i++) {
newinfo->hook_entry[i] = info->hook_entry[i];
newinfo->underflow[i] = info->underflow[i];
}
entry1 = newinfo->entries[raw_smp_processor_id()];
pos = entry1;
- size = total_size;
- xt_entry_foreach(iter0, entry0, total_size) {
+ size = compatr->size;
+ xt_entry_foreach(iter0, entry0, compatr->size) {
ret = compat_copy_entry_from_user(iter0, &pos, &size,
- name, newinfo, entry1);
+ newinfo, entry1);
if (ret != 0)
break;
}
@@ -1419,12 +1424,12 @@ static int translate_compat_table(const
goto free_newinfo;

ret = -ELOOP;
- if (!mark_source_chains(newinfo, valid_hooks, entry1))
+ if (!mark_source_chains(newinfo, compatr->valid_hooks, entry1))
goto free_newinfo;

i = 0;
xt_entry_foreach(iter1, entry1, newinfo->size) {
- ret = check_target(iter1, name);
+ ret = check_target(iter1, compatr->name);
if (ret != 0)
break;
++i;
@@ -1469,7 +1474,7 @@ static int translate_compat_table(const
free_newinfo:
xt_free_table_info(newinfo);
out:
- xt_entry_foreach(iter0, entry0, total_size) {
+ xt_entry_foreach(iter0, entry0, compatr->size) {
if (j-- == 0)
break;
compat_release_entry(iter0);
@@ -1481,18 +1486,6 @@ out_unlock:
goto out;
}

-struct compat_arpt_replace {
- char name[XT_TABLE_MAXNAMELEN];
- u32 valid_hooks;
- u32 num_entries;
- u32 size;
- u32 hook_entry[NF_ARP_NUMHOOKS];
- u32 underflow[NF_ARP_NUMHOOKS];
- u32 num_counters;
- compat_uptr_t counters;
- struct compat_arpt_entry entries[0];
-};
-
static int compat_do_replace(struct net *net, void __user *user,
unsigned int len)
{
@@ -1523,10 +1516,7 @@ static int compat_do_replace(struct net
goto free_newinfo;
}

- ret = translate_compat_table(tmp.name, tmp.valid_hooks,
- &newinfo, &loc_cpu_entry, tmp.size,
- tmp.num_entries, tmp.hook_entry,
- tmp.underflow);
+ ret = translate_compat_table(&newinfo, &loc_cpu_entry, &tmp);
if (ret != 0)
goto free_newinfo;