From 4a19edb60d0203cd5bf95a8b46ea8f63fd41194c Mon Sep 17 00:00:00 2001 From: David Ahern Date: Sun, 7 Oct 2018 20:16:22 -0700 Subject: [PATCH] netlink: Pass extack to dump handlers Declare extack in netlink_dump and pass to dump handlers via netlink_callback. Add any extack message after the dump_done_errno allowing error messages to be returned. This will be useful when strict checking is done on dump requests, returning why the dump fails EINVAL. Signed-off-by: David Ahern Acked-by: Christian Brauner Signed-off-by: David S. Miller --- include/linux/netlink.h | 1 + net/netlink/af_netlink.c | 12 +++++++++++- 2 files changed, 12 insertions(+), 1 deletion(-) diff --git a/include/linux/netlink.h b/include/linux/netlink.h index 71f121b66ca8..88c8a2d83eb3 100644 --- a/include/linux/netlink.h +++ b/include/linux/netlink.h @@ -176,6 +176,7 @@ struct netlink_callback { void *data; /* the module that dump function belong to */ struct module *module; + struct netlink_ext_ack *extack; u16 family; u16 min_dump_alloc; unsigned int prev_seq, seq; diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index e3a0538ec0be..7ac585f33a9e 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -2171,6 +2171,7 @@ EXPORT_SYMBOL(__nlmsg_put); static int netlink_dump(struct sock *sk) { struct netlink_sock *nlk = nlk_sk(sk); + struct netlink_ext_ack extack = {}; struct netlink_callback *cb; struct sk_buff *skb = NULL; struct nlmsghdr *nlh; @@ -2222,8 +2223,11 @@ static int netlink_dump(struct sock *sk) skb_reserve(skb, skb_tailroom(skb) - alloc_size); netlink_skb_set_owner_r(skb, sk); - if (nlk->dump_done_errno > 0) + if (nlk->dump_done_errno > 0) { + cb->extack = &extack; nlk->dump_done_errno = cb->dump(skb, cb); + cb->extack = NULL; + } if (nlk->dump_done_errno > 0 || skb_tailroom(skb) < nlmsg_total_size(sizeof(nlk->dump_done_errno))) { @@ -2246,6 +2250,12 @@ static int netlink_dump(struct sock *sk) memcpy(nlmsg_data(nlh), &nlk->dump_done_errno, sizeof(nlk->dump_done_errno)); + if (extack._msg && nlk->flags & NETLINK_F_EXT_ACK) { + nlh->nlmsg_flags |= NLM_F_ACK_TLVS; + if (!nla_put_string(skb, NLMSGERR_ATTR_MSG, extack._msg)) + nlmsg_end(skb, nlh); + } + if (sk_filter(sk, skb)) kfree_skb(skb); else -- GitLab