Home » Mailing lists » Devel » [PATCH 1/2] iptables 32bit compat layer
| Re: [PATCH] iptables 32bit compat layer [message #2327 is a reply to message #2325] |
Wed, 29 March 2006 11:36   |
Mishin Dmitry
Messages: 112
Registered: February 2006
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Senior Member |
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On Wednesday 29 March 2006 13:28, Patrick McHardy wrote:
> Dmitry Mishin wrote:
> > This patch extends current iptables compatibility layer in order to get
> > 32bit iptables to work on 64bit kernel. Current layer is insufficient due
> > to alignment checks both in kernel and user space tools.
> >
> > Patch is for current net-2.6.17 with addition of move of
> > ipt_entry_{match| target} definitions to xt_entry_{match|target}.
>
> Thanks, this looks good. Two small issues so far:
> > diff --git a/net/compat.c b/net/compat.c
> > index 13177a1..6a7028e 100644
> > --- a/net/compat.c
> > +++ b/net/compat.c
> > @@ -476,8 +476,7 @@ asmlinkage long compat_sys_setsockopt(in
> > int err;
> > struct socket *sock;
> >
> > - /* SO_SET_REPLACE seems to be the same in all levels */
> > - if (optname == IPT_SO_SET_REPLACE)
> > + if (level == SOL_IPV6 && optname == IPT_SO_SET_REPLACE)
> > return do_netfilter_replace(fd, level, optname,
> > optval, optlen);
>
> I don't understand the reason for this change. If its not a mistake,
> it would make more sense to check for IP6T_SO_SET_REPLACE I guess ..
IP6T_SO_SET_REPLACE == IPT_SO_SET_REPLACE == XT_SO_SET_REPLACE.
Rename will require respective #include directive rename, so, I just leave
this as it is. BTW, I'll make respective patch for IPV6 in the near future
and this hunk will be removed at all.
>
> > +#ifdef CONFIG_COMPAT
> > +void xt_compat_lock(int af)
> > +{
> > + down(&xt[af].compat_mutex);
> > +}
> > +EXPORT_SYMBOL_GPL(xt_compat_lock);
> > +
> > +void xt_compat_unlock(int af)
> > +{
> > + up(&xt[af].compat_mutex);
> > +}
> > +EXPORT_SYMBOL_GPL(xt_compat_unlock);
> > +#endif
>
> Won't a seperate compat-mutex introduce races between compat- and
> non-compat users? BTW, the up/down calls have been replaced by the
> new mutex API in Linus' tree, please resend the patch against the
> current tree.
compat_mutex is always over xt[af].mutex and can't be taken under the last
one, so, there should be no races.
New patch is attached.
--
Thanks,
Dmitry.
diff --git a/include/linux/netfilter/x_tables.h b/include/linux/netfilter/x_tables.h
index 1350e47..f6bdef8 100644
--- a/include/linux/netfilter/x_tables.h
+++ b/include/linux/netfilter/x_tables.h
@@ -142,6 +142,12 @@ struct xt_counters_info
#define ASSERT_WRITE_LOCK(x)
#include <linux/netfilter_ipv4/listhelp.h>
+#ifdef CONFIG_COMPAT
+#define COMPAT_TO_USER 1
+#define COMPAT_FROM_USER -1
+#define COMPAT_CALC_SIZE 0
+#endif
+
struct xt_match
{
struct list_head list;
@@ -175,6 +181,9 @@ struct xt_match
void (*destroy)(const struct xt_match *match, void *matchinfo,
unsigned int matchinfosize);
+ /* Called when userspace align differs from kernel space one */
+ int (*compat)(void *match, void **dstptr, int *size, int convert);
+
/* Set this to THIS_MODULE if you are a module, otherwise NULL */
struct module *me;
@@ -220,6 +229,9 @@ struct xt_target
void (*destroy)(const struct xt_target *target, void *targinfo,
unsigned int targinfosize);
+ /* Called when userspace align differs from kernel space one */
+ int (*compat)(void *target, void **dstptr, int *size, int convert);
+
/* Set this to THIS_MODULE if you are a module, otherwise NULL */
struct module *me;
@@ -314,6 +326,61 @@ extern void xt_proto_fini(int af);
extern struct xt_table_info *xt_alloc_table_info(unsigned int size);
extern void xt_free_table_info(struct xt_table_info *info);
+#ifdef CONFIG_COMPAT
+#include <net/compat.h>
+
+struct compat_xt_entry_match
+{
+ union {
+ struct {
+ u_int16_t match_size;
+ char name[XT_FUNCTION_MAXNAMELEN - 1];
+ u_int8_t revision;
+ } user;
+ u_int16_t match_size;
+ } u;
+ unsigned char data[0];
+};
+
+struct compat_xt_entry_target
+{
+ union {
+ struct {
+ u_int16_t target_size;
+ char name[XT_FUNCTION_MAXNAMELEN - 1];
+ u_int8_t revision;
+ } user;
+ u_int16_t target_size;
+ } u;
+ unsigned char data[0];
+};
+
+/* FIXME: this works only on 32 bit tasks
+ * need to change whole approach in order to calculate align as function of
+ * current task alignment */
+
+struct compat_xt_counters
+{
+ u_int32_t cnt[4];
+};
+
+struct compat_xt_counters_info
+{
+ char name[XT_TABLE_MAXNAMELEN];
+ compat_uint_t num_counters;
+ struct compat_xt_counters counters[0];
+};
+
+#define COMPAT_XT_ALIGN(s) (((s) + (__alignof__(struct compat_xt_counters)-1)) \
+ & ~(__alignof__(struct compat_xt_counters)-1))
+
+extern void xt_compat_lock(int af);
+extern void xt_compat_unlock(int af);
+extern int xt_compat_match(void *match, void **dstptr, int *size, int convert);
+extern int xt_compat_target(void *target, void **dstptr, int *size,
+ int convert);
+
+#endif /* CONFIG_COMPAT */
#endif /* __KERNEL__ */
#endif /* _X_TABLES_H */
diff --git a/include/linux/netfilter_ipv4/ip_tables.h b/include/linux/netfilter_ipv4/ip_tables.h
index d5b8c0d..c0dac16 100644
--- a/include/linux/netfilter_ipv4/ip_tables.h
+++ b/include/linux/netfilter_ipv4/ip_tables.h
@@ -316,5 +316,23 @@ extern unsigned int ipt_do_table(struct
void *userdata);
#define IPT_ALIGN(s) XT_ALIGN(s)
+
+#ifdef CONFIG_COMPAT
+#include <net/compat.h>
+
+struct compat_ipt_entry
+{
+ struct ipt_ip ip;
+ compat_uint_t nfcache;
+ u_int16_t target_offset;
+ u_int16_t next_offset;
+ compat_uint_t comefrom;
+ struct compat_xt_counters counters;
+ unsigned char elems[0];
+};
+
+#define COMPAT_IPT_ALIGN(s) COMPAT_XT_ALIGN(s)
+
+#endif /* CONFIG_COMPAT */
#endif /*__KERNEL__*/
#endif /* _IPTABLES_H */
diff --git a/net/compat.c b/net/compat.c
index 8fd37cd..d5d69fa 100644
--- a/net/compat.c
+++ b/net/compat.c
@@ -476,8 +476,7 @@ asmlinkage long compat_sys_setsockopt(in
int err;
struct socket *sock;
- /* SO_SET_REPLACE seems to be the same in all levels */
- if (optname == IPT_SO_SET_REPLACE)
+ if (level == SOL_IPV6 && optname == IPT_SO_SET_REPLACE)
return do_netfilter_replace(fd, level, optname,
optval, optlen);
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index a7b194c..34df287 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -24,6 +24,7 @@
#include <linux/module.h>
#include <linux/icmp.h>
#include <net/ip.h>
+#include <net/compat.h>
#include <asm/uaccess.h>
#include <linux/mutex.h>
#include <linux/proc_fs.h>
@@ -799,17 +800,11 @@ get_counters(const struct xt_table_info
}
}
-static int
-copy_entries_to_user(unsigned int total_size,
- struct ipt_table *table,
- void __user *userptr)
+static inline struct xt_counters * alloc_counters(struct ipt_table *table)
{
- unsigned int off, num, countersize;
- struct ipt_entry *e;
+ unsigned int countersize;
struct xt_counters *counters;
struct xt_table_info *private = table->private;
- int ret = 0;
- void *loc_cpu_entry;
/* We need atomic snapshot of counters: rest doesn't change
(other than comefrom, which userspace doesn't care
@@ -818,13 +813,32 @@ copy_entries_to_user(unsigned int total_
counters = vmalloc_node(countersize, numa_node_id());
if (counters == NULL)
- return -ENOMEM;
+ return ERR_PTR(-ENOMEM);
/* First, sum counters... */
write_lock_bh(&table->lock);
get_counters(private, counters);
write_unlock_bh(&table->lock);
+ return counters;
+}
+
+static int
+copy_entries_to_user(unsigned int total_size,
+ struct ipt_table *table,
+ void __user *userptr)
+{
+ unsigned int off, num;
+ struct ipt_entry *e;
+ struct xt_counters *counters;
+ struct xt_table_info *private = table->private;
+ int ret = 0;
+ void *loc_cpu_entry;
+
+ counters = alloc_counters(table);
+ if (IS_ERR(counters))
+ return PTR_ERR(counters);
+
/* choose the copy that is on our node/cpu, ...
* This choice is lazy (because current thread is
* allowed to migrate to another cpu)
@@ -878,50 +892,905 @@ copy_entries_to_user(unsigned int total_
goto free_counters;
}
}
-
- free_counters:
- vfree(counters);
+
+ free_counters:
+ vfree(counters);
+ return ret;
+}
+
+#ifdef CONFIG_COMPAT
+struct compat_delta {
+ struct compat_delta *next;
+ u_int16_t offset;
+ short delta;
+};
+
+static struct compat_delta *compat_offsets = NULL;
+
+static int compat_add_offset(u_int16_t 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(u_int16_t 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;
+}
+
+struct compat_ipt_standard_target
+{
+ struct compat_xt_entry_target target;
+ compat_int_t verdict;
+};
+
+#define IPT_ST_OFFSET (sizeof(struct ipt_standard_target) - \
+ sizeof(struct compat_ipt_standard_target))
+
+struct compat_ipt_standard
+{
+ struct compat_ipt_entry entry;
+ struct compat_ipt_standard_target target;
+};
+
+static int compat_ipt_standard_fn(void *target,
+ void **dstptr, int *size, int convert)
+{
+ struct compat_ipt_standard_target compat_st, *pcompat_st;
+ struct ipt_standard_target st, *pst;
+ int ret;
+
+ ret = 0;
+ switch (convert) {
+ case COMPAT_TO_USER:
+ pst = (struct ipt_stand
...
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