Commit 745e2031 authored by Chris Larson's avatar Chris Larson Committed by David S. Miller
Browse files

net: fix missing pneigh entries in the neighbor seq_file code 



When pneigh entries exist, but the user's read buffer isn't sufficient to
hold them all, one of the pneigh entries will be missing from the results.

In neigh_get_idx_any, the number of elements which neigh_get_idx
encountered is not correctly subtracted from the position number before
the call to pneigh_get_idx.  neigh_get_idx reduces the position by 1 for
each call to neigh_get_next, but it does not reduce it by one for the
first element (neigh_get_first). The patch alters the neigh_get_idx and
pneigh_get_idx functions to subtract one from pos, for the first element,
when pos is non-zero.

Signed-off-by: default avatarChris Larson <clarson@mvista.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent bff69732

net/core/neighbour.c

+6 −5
Original line number Diff line number Diff line
@@ -2281,6 +2281,7 @@ static struct neighbour *neigh_get_idx(struct seq_file *seq, loff_t *pos) 
	struct neighbour *n = neigh_get_first(seq);



	if (n) {

		--(*pos);

		while (*pos) {

			n = neigh_get_next(seq, n, pos);

			if (!n)
@@ -2341,6 +2342,7 @@ static struct pneigh_entry *pneigh_get_idx(struct seq_file *seq, loff_t *pos) 
	struct pneigh_entry *pn = pneigh_get_first(seq);



	if (pn) {

		--(*pos);

		while (*pos) {

			pn = pneigh_get_next(seq, pn, pos);

			if (!pn)
@@ -2354,10 +2356,11 @@ static void *neigh_get_idx_any(struct seq_file *seq, loff_t *pos) 
{

	struct neigh_seq_state *state = seq->private;

	void *rc;

	loff_t idxpos = *pos;



	rc = neigh_get_idx(seq, pos);

	rc = neigh_get_idx(seq, &idxpos);

	if (!rc && !(state->flags & NEIGH_SEQ_NEIGH_ONLY))

		rc = pneigh_get_idx(seq, pos);

		rc = pneigh_get_idx(seq, &idxpos);



	return rc;

}
@@ -2366,7 +2369,6 @@ void *neigh_seq_start(struct seq_file *seq, loff_t *pos, struct neigh_table *tbl 
	__acquires(tbl->lock)

{

	struct neigh_seq_state *state = seq->private;

	loff_t pos_minus_one;



	state->tbl = tbl;

	state->bucket = 0;
@@ -2374,8 +2376,7 @@ void *neigh_seq_start(struct seq_file *seq, loff_t *pos, struct neigh_table *tbl 


	read_lock_bh(&tbl->lock);



	pos_minus_one = *pos - 1;

	return *pos ? neigh_get_idx_any(seq, &pos_minus_one) : SEQ_START_TOKEN;

	return *pos ? neigh_get_idx_any(seq, pos) : SEQ_START_TOKEN;

}

EXPORT_SYMBOL(neigh_seq_start);

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