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: Chris Larson <clarson@mvista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Chris Larson 2008-08-03 01:10:55 -07:00 committed by David S. Miller
parent bff69732c9
commit 745e203164

View file

@ -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);