Commit 5b76c494 authored by Jan Engelhardt's avatar Jan Engelhardt Committed by Pablo Neira Ayuso
Browse files

netfilter: x_tables: print correct hook names for ARP 



arptables 0.0.4 (released on 10th Jan 2013) supports calling the
CLASSIFY target, but on adding a rule to the wrong chain, the
diagnostic is as follows:

	# arptables -A INPUT -j CLASSIFY --set-class 0:0
	arptables: Invalid argument
	# dmesg | tail -n1
	x_tables: arp_tables: CLASSIFY target: used from hooks
	PREROUTING, but only usable from INPUT/FORWARD

This is incorrect, since xt_CLASSIFY.c does specify
(1 << NF_ARP_OUT) | (1 << NF_ARP_FORWARD).

This patch corrects the x_tables diagnostic message to print the
proper hook names for the NFPROTO_ARP case.

Affects all kernels down to and including v2.6.31.

Signed-off-by: default avatarJan Engelhardt <jengelh@inai.de>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent 1e47ee83

net/netfilter/x_tables.c

+20 −8
Original line number Diff line number Diff line
@@ -345,19 +345,27 @@ int xt_find_revision(u8 af, const char *name, u8 revision, int target, 
}

EXPORT_SYMBOL_GPL(xt_find_revision);



static char *textify_hooks(char *buf, size_t size, unsigned int mask)

static char *

textify_hooks(char *buf, size_t size, unsigned int mask, uint8_t nfproto)

{

	static const char *const names[] = {

	static const char *const inetbr_names[] = {

		"PREROUTING", "INPUT", "FORWARD",

		"OUTPUT", "POSTROUTING", "BROUTING",

	};

	unsigned int i;

	static const char *const arp_names[] = {

		"INPUT", "FORWARD", "OUTPUT",

	};

	const char *const *names;

	unsigned int i, max;

	char *p = buf;

	bool np = false;

	int res;



	names = (nfproto == NFPROTO_ARP) ? arp_names : inetbr_names;

	max   = (nfproto == NFPROTO_ARP) ? ARRAY_SIZE(arp_names) :

	                                   ARRAY_SIZE(inetbr_names);

	*p = '\0';

	for (i = 0; i < ARRAY_SIZE(names); ++i) {

	for (i = 0; i < max; ++i) {

		if (!(mask & (1 << i)))

			continue;

		res = snprintf(p, size, "%s%s", np ? "/" : "", names[i]);
@@ -402,8 +410,10 @@ int xt_check_match(struct xt_mtchk_param *par, 
		pr_err("%s_tables: %s match: used from hooks %s, but only "

		       "valid from %s\n",

		       xt_prefix[par->family], par->match->name,

		       textify_hooks(used, sizeof(used), par->hook_mask),

		       textify_hooks(allow, sizeof(allow), par->match->hooks));

		       textify_hooks(used, sizeof(used), par->hook_mask,

		                     par->family),

		       textify_hooks(allow, sizeof(allow), par->match->hooks,

		                     par->family));

		return -EINVAL;

	}

	if (par->match->proto && (par->match->proto != proto || inv_proto)) {
@@ -575,8 +585,10 @@ int xt_check_target(struct xt_tgchk_param *par, 
		pr_err("%s_tables: %s target: used from hooks %s, but only "

		       "usable from %s\n",

		       xt_prefix[par->family], par->target->name,

		       textify_hooks(used, sizeof(used), par->hook_mask),

		       textify_hooks(allow, sizeof(allow), par->target->hooks));

		       textify_hooks(used, sizeof(used), par->hook_mask,

		                     par->family),

		       textify_hooks(allow, sizeof(allow), par->target->hooks,

		                     par->family));

		return -EINVAL;

	}

	if (par->target->proto && (par->target->proto != proto || inv_proto)) {

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