From 87d381973e49404f658d6923a617932eeda9415f Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Sat, 2 Mar 2024 21:24:08 -0800 Subject: genetlink: fit NLMSG_DONE into same read() as families Make sure ctrl_fill_info() returns sensible error codes and propagate them out to netlink core. Let netlink core decide when to return skb->len and when to treat the exit as an error. Netlink core does better job at it, if we always return skb->len the core doesn't know when we're done dumping and NLMSG_DONE ends up in a separate read(). Reviewed-by: Eric Dumazet Signed-off-by: Jakub Kicinski Reviewed-by: Ido Schimmel Signed-off-by: David S. Miller --- net/netlink/genetlink.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) (limited to 'net/netlink') diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c index 50ec599a5cff..3b7666944b11 100644 --- a/net/netlink/genetlink.c +++ b/net/netlink/genetlink.c @@ -1232,7 +1232,7 @@ static int ctrl_fill_info(const struct genl_family *family, u32 portid, u32 seq, hdr = genlmsg_put(skb, portid, seq, &genl_ctrl, flags, cmd); if (hdr == NULL) - return -1; + return -EMSGSIZE; if (nla_put_string(skb, CTRL_ATTR_FAMILY_NAME, family->name) || nla_put_u16(skb, CTRL_ATTR_FAMILY_ID, family->id) || @@ -1355,6 +1355,7 @@ static int ctrl_dumpfamily(struct sk_buff *skb, struct netlink_callback *cb) struct net *net = sock_net(skb->sk); int fams_to_skip = cb->args[0]; unsigned int id; + int err = 0; idr_for_each_entry(&genl_fam_idr, rt, id) { if (!rt->netnsok && !net_eq(net, &init_net)) @@ -1363,16 +1364,17 @@ static int ctrl_dumpfamily(struct sk_buff *skb, struct netlink_callback *cb) if (n++ < fams_to_skip) continue; - if (ctrl_fill_info(rt, NETLINK_CB(cb->skb).portid, - cb->nlh->nlmsg_seq, NLM_F_MULTI, - skb, CTRL_CMD_NEWFAMILY) < 0) { + err = ctrl_fill_info(rt, NETLINK_CB(cb->skb).portid, + cb->nlh->nlmsg_seq, NLM_F_MULTI, + skb, CTRL_CMD_NEWFAMILY); + if (err) { n--; break; } } cb->args[0] = n; - return skb->len; + return err; } static struct sk_buff *ctrl_build_family_msg(const struct genl_family *family, -- cgit v1.2.3-58-ga151