From 7e4975f7e7fb0eba3cbb69d9c467750a1c3ce131 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Thu, 18 Apr 2024 09:51:05 +0000 Subject: neighbour: fix neigh_dump_info() return value Change neigh_dump_table() and pneigh_dump_table() to either return 0 or -EMSGSIZE if not enough space was available in the skb. Then neigh_dump_info() can do the same. This allows NLMSG_DONE to be appended to the current skb at the end of a dump, saving a couple of recvmsg() system calls. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/core/neighbour.c | 31 +++++++++++++------------------ 1 file changed, 13 insertions(+), 18 deletions(-) diff --git a/net/core/neighbour.c b/net/core/neighbour.c index ccb770539f1a..d8c3ffdee29f 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -2715,7 +2715,7 @@ static int neigh_dump_table(struct neigh_table *tbl, struct sk_buff *skb, { struct net *net = sock_net(skb->sk); struct neighbour *n; - int rc, h, s_h = cb->args[1]; + int err = 0, h, s_h = cb->args[1]; int idx, s_idx = idx = cb->args[2]; struct neigh_hash_table *nht; unsigned int flags = NLM_F_MULTI; @@ -2737,23 +2737,20 @@ static int neigh_dump_table(struct neigh_table *tbl, struct sk_buff *skb, if (neigh_ifindex_filtered(n->dev, filter->dev_idx) || neigh_master_filtered(n->dev, filter->master_idx)) goto next; - if (neigh_fill_info(skb, n, NETLINK_CB(cb->skb).portid, - cb->nlh->nlmsg_seq, - RTM_NEWNEIGH, - flags) < 0) { - rc = -1; + err = neigh_fill_info(skb, n, NETLINK_CB(cb->skb).portid, + cb->nlh->nlmsg_seq, + RTM_NEWNEIGH, flags); + if (err < 0) goto out; - } next: idx++; } } - rc = skb->len; out: rcu_read_unlock(); cb->args[1] = h; cb->args[2] = idx; - return rc; + return err; } static int pneigh_dump_table(struct neigh_table *tbl, struct sk_buff *skb, @@ -2762,7 +2759,7 @@ static int pneigh_dump_table(struct neigh_table *tbl, struct sk_buff *skb, { struct pneigh_entry *n; struct net *net = sock_net(skb->sk); - int rc, h, s_h = cb->args[3]; + int err = 0, h, s_h = cb->args[3]; int idx, s_idx = idx = cb->args[4]; unsigned int flags = NLM_F_MULTI; @@ -2780,11 +2777,11 @@ static int pneigh_dump_table(struct neigh_table *tbl, struct sk_buff *skb, if (neigh_ifindex_filtered(n->dev, filter->dev_idx) || neigh_master_filtered(n->dev, filter->master_idx)) goto next; - if (pneigh_fill_info(skb, n, NETLINK_CB(cb->skb).portid, - cb->nlh->nlmsg_seq, - RTM_NEWNEIGH, flags, tbl) < 0) { + err = pneigh_fill_info(skb, n, NETLINK_CB(cb->skb).portid, + cb->nlh->nlmsg_seq, + RTM_NEWNEIGH, flags, tbl); + if (err < 0) { read_unlock_bh(&tbl->lock); - rc = -1; goto out; } next: @@ -2793,12 +2790,10 @@ static int pneigh_dump_table(struct neigh_table *tbl, struct sk_buff *skb, } read_unlock_bh(&tbl->lock); - rc = skb->len; out: cb->args[3] = h; cb->args[4] = idx; - return rc; - + return err; } static int neigh_valid_dump_req(const struct nlmsghdr *nlh, @@ -2905,7 +2900,7 @@ static int neigh_dump_info(struct sk_buff *skb, struct netlink_callback *cb) } cb->args[0] = t; - return skb->len; + return err; } static int neigh_valid_get_req(const struct nlmsghdr *nlh, -- cgit v1.2.3