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>
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index a57de75..9d92e41 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -2281,6 +2281,7 @@
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 @@
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 @@
{
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 @@
__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 @@
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);