neigh: sysctl - simplify address calculation of gc_* variables (9ecf07a1) · Commits · 戴 / test

The code in neigh_sysctl_register() relies on a specific layout of struct neigh_table, namely that the 'gc_*' variables are directly following the 'parms' member in a specific order. The code, though, expresses this in the most ugly way. Get rid of the ugly casts and use the 'tbl' pointer to get a handle to the table. This way we can refer to the 'gc_*' variables directly. Similarly seen in the grsecurity patch, written by Brad Spengler. Signed-off-by:

Mathias Krause <minipli@googlemail.com> Cc: Brad Spengler <spender@grsecurity.net> Signed-off-by:

David S. Miller <davem@davemloft.net>

include/net/neighbour.h

+0 −1

Original line number	Diff line number	Diff line
		@@ -203,7 +203,6 @@ struct neigh_table {
		void (proxy_redo)(struct sk_buff skb);
		char *id;
		struct neigh_parms parms;
		/* HACK. gc_* should follow parms without a gap! */
		int gc_interval;
		int gc_thresh1;
		int gc_thresh2;

net/core/neighbour.c

+5 −4

Original line number	Diff line number	Diff line
		@@ -3059,11 +3059,12 @@ int neigh_sysctl_register(struct net_device dev, struct neigh_parms p,
		memset(&t->neigh_vars[NEIGH_VAR_GC_INTERVAL], 0,
		sizeof(t->neigh_vars[NEIGH_VAR_GC_INTERVAL]));
		} else {
		struct neigh_table *tbl = p->tbl;
		dev_name_source = "default";
		t->neigh_vars[NEIGH_VAR_GC_INTERVAL].data = (int *)(p + 1);
		t->neigh_vars[NEIGH_VAR_GC_THRESH1].data = (int *)(p + 1) + 1;
		t->neigh_vars[NEIGH_VAR_GC_THRESH2].data = (int *)(p + 1) + 2;
		t->neigh_vars[NEIGH_VAR_GC_THRESH3].data = (int *)(p + 1) + 3;
		t->neigh_vars[NEIGH_VAR_GC_INTERVAL].data = &tbl->gc_interval;
		t->neigh_vars[NEIGH_VAR_GC_THRESH1].data = &tbl->gc_thresh1;
		t->neigh_vars[NEIGH_VAR_GC_THRESH2].data = &tbl->gc_thresh2;
		t->neigh_vars[NEIGH_VAR_GC_THRESH3].data = &tbl->gc_thresh3;
		}

		if (handler) {

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