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Commit 103a9778 authored by Florian Westphal's avatar Florian Westphal Committed by Pablo Neira Ayuso
Browse files

netfilter: ebtables: only call xt_compat_add_offset once per rule 



The optimizations in commit 255d0dc3
(netfilter: x_table: speedup compat operations) assume that
xt_compat_add_offset is called once per rule.

ebtables however called it for each match/target found in a rule.

The match/watcher/target parser already returns the needed delta, so it
is sufficient to move the xt_compat_add_offset call to a more reasonable
location.

While at it, also get rid of the unused COMPAT iterator macros.

Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
parent 5a6351ee

net/bridge/netfilter/ebtables.c

+9 −52
Original line number Diff line number Diff line
@@ -1882,7 +1882,7 @@ static int compat_mtw_from_user(struct compat_ebt_entry_mwt *mwt, 
	struct xt_match *match;

	struct xt_target *wt;

	void *dst = NULL;

	int off, pad = 0, ret = 0;

	int off, pad = 0;

	unsigned int size_kern, entry_offset, match_size = mwt->match_size;



	strlcpy(name, mwt->u.name, sizeof(name));
@@ -1935,13 +1935,6 @@ static int compat_mtw_from_user(struct compat_ebt_entry_mwt *mwt, 
		break;

	}



	if (!dst) {

		ret = xt_compat_add_offset(NFPROTO_BRIDGE, entry_offset,

					off + ebt_compat_entry_padsize());

		if (ret < 0)

			return ret;

	}



	state->buf_kern_offset += match_size + off;

	state->buf_user_offset += match_size;

	pad = XT_ALIGN(size_kern) - size_kern;
@@ -2016,50 +2009,6 @@ static int ebt_size_mwt(struct compat_ebt_entry_mwt *match32, 
	return growth;

}



#define EBT_COMPAT_WATCHER_ITERATE(e, fn, args...)          \

({                                                          \

	unsigned int __i;                                   \

	int __ret = 0;                                      \

	struct compat_ebt_entry_mwt *__watcher;             \

	                                                    \

	for (__i = e->watchers_offset;                      \

	     __i < (e)->target_offset;                      \

	     __i += __watcher->watcher_size +               \

	     sizeof(struct compat_ebt_entry_mwt)) {         \

		__watcher = (void *)(e) + __i;              \

		__ret = fn(__watcher , ## args);            \

		if (__ret != 0)                             \

			break;                              \

	}                                                   \

	if (__ret == 0) {                                   \

		if (__i != (e)->target_offset)              \

			__ret = -EINVAL;                    \

	}                                                   \

	__ret;                                              \

})



#define EBT_COMPAT_MATCH_ITERATE(e, fn, args...)            \

({                                                          \

	unsigned int __i;                                   \

	int __ret = 0;                                      \

	struct compat_ebt_entry_mwt *__match;               \

	                                                    \

	for (__i = sizeof(struct ebt_entry);                \

	     __i < (e)->watchers_offset;                    \

	     __i += __match->match_size +                   \

	     sizeof(struct compat_ebt_entry_mwt)) {         \

		__match = (void *)(e) + __i;                \

		__ret = fn(__match , ## args);              \

		if (__ret != 0)                             \

			break;                              \

	}                                                   \

	if (__ret == 0) {                                   \

		if (__i != (e)->watchers_offset)            \

			__ret = -EINVAL;                    \

	}                                                   \

	__ret;                                              \

})



/* called for all ebt_entry structures. */

static int size_entry_mwt(struct ebt_entry *entry, const unsigned char *base,

			  unsigned int *total,
@@ -2132,6 +2081,14 @@ static int size_entry_mwt(struct ebt_entry *entry, const unsigned char *base, 
		}

	}



	if (state->buf_kern_start == NULL) {

		unsigned int offset = buf_start - (char *) base;



		ret = xt_compat_add_offset(NFPROTO_BRIDGE, offset, new_offset);

		if (ret < 0)

			return ret;

	}



	startoff = state->buf_user_offset - startoff;



	BUG_ON(*total < startoff);