fib_trie: Correct /proc/net/route off by one error (fd0285a3) · Commits · 戴 / test

The display of /proc/net/route has had a couple issues due to the fact that when I originally rewrote most of fib_trie I made it so that the iterator was tracking the next value to use instead of the current. In addition it had an off by 1 error where I was tracking the first piece of data as position 0, even though in reality that belonged to the SEQ_START_TOKEN. This patch updates the code so the iterator tracks the last reported position and key instead of the next expected position and key. In addition it shifts things so that all of the leaves start at 1 instead of trying to report leaves starting with offset 0 as being valid. With these two issues addressed this should resolve any off by one errors that were present in the display of /proc/net/route. Fixes: ("ipv4: off-by-one in continuation handling in /proc/net/route") Cc: Andy Whitcroft <apw@canonical.com> Reported-by:

Jason Baron <jbaron@akamai.com> Tested-by:

Jason Baron <jbaron@akamai.com> Signed-off-by:

Alexander Duyck <alexander.h.duyck@intel.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/ipv4/fib_trie.c

+9 −12

Original line number	Diff line number	Diff line
		@@ -2413,22 +2413,19 @@ static struct key_vector fib_route_get_idx(struct fib_route_iter iter,
		struct key_vector l, *tp = &iter->tnode;
		t_key key;

		/* use cache location of next-to-find key */
		/* use cached location of previously found key */
		if (iter->pos > 0 && pos >= iter->pos) {
		pos -= iter->pos;
		key = iter->key;
		} else {
		iter->pos = 0;
		iter->pos = 1;
		key = 0;
		}

		while ((l = leaf_walk_rcu(tp, key)) != NULL) {
		pos -= iter->pos;

		while ((l = leaf_walk_rcu(tp, key)) && (pos-- > 0)) {
		key = l->key + 1;
		iter->pos++;

		if (--pos <= 0)
		break;

		l = NULL;

		/* handle unlikely case of a key wrap */
		@@ -2437,7 +2434,7 @@ static struct key_vector fib_route_get_idx(struct fib_route_iter iter,
		}

		if (l)
		iter->key = key; /* remember it */
		iter->key = l->key; /* remember it */
		else
		iter->pos = 0; /* forget it */

		@@ -2465,7 +2462,7 @@ static void fib_route_seq_start(struct seq_file seq, loff_t *pos)
		return fib_route_get_idx(iter, *pos);

		iter->pos = 0;
		iter->key = 0;
		iter->key = KEY_MAX;

		return SEQ_START_TOKEN;
		}
		@@ -2474,7 +2471,7 @@ static void fib_route_seq_next(struct seq_file seq, void v, loff_t pos)
		{
		struct fib_route_iter *iter = seq->private;
		struct key_vector *l = NULL;
		t_key key = iter->key;
		t_key key = iter->key + 1;

		++*pos;

		@@ -2483,7 +2480,7 @@ static void fib_route_seq_next(struct seq_file seq, void v, loff_t pos)
		l = leaf_walk_rcu(&iter->tnode, key);

		if (l) {
		iter->key = l->key + 1;
		iter->key = l->key;
		iter->pos++;
		} else {
		iter->pos = 0;

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