From ae0be8de9a53cda3505865c11826d8ff0640237c Mon Sep 17 00:00:00 2001 From: Michal Kubecek Date: Fri, 26 Apr 2019 11:13:06 +0200 Subject: netlink: make nla_nest_start() add NLA_F_NESTED flag Even if the NLA_F_NESTED flag was introduced more than 11 years ago, most netlink based interfaces (including recently added ones) are still not setting it in kernel generated messages. Without the flag, message parsers not aware of attribute semantics (e.g. wireshark dissector or libmnl's mnl_nlmsg_fprintf()) cannot recognize nested attributes and won't display the structure of their contents. Unfortunately we cannot just add the flag everywhere as there may be userspace applications which check nlattr::nla_type directly rather than through a helper masking out the flags. Therefore the patch renames nla_nest_start() to nla_nest_start_noflag() and introduces nla_nest_start() as a wrapper adding NLA_F_NESTED. The calls which add NLA_F_NESTED manually are rewritten to use nla_nest_start(). Except for changes in include/net/netlink.h, the patch was generated using this semantic patch: @@ expression E1, E2; @@ -nla_nest_start(E1, E2) +nla_nest_start_noflag(E1, E2) @@ expression E1, E2; @@ -nla_nest_start_noflag(E1, E2 | NLA_F_NESTED) +nla_nest_start(E1, E2) Signed-off-by: Michal Kubecek Acked-by: Jiri Pirko Acked-by: David Ahern Signed-off-by: David S. Miller --- net/ipv4/ipmr_base.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/ipv4/ipmr_base.c') diff --git a/net/ipv4/ipmr_base.c b/net/ipv4/ipmr_base.c index 3e614cc824f7..278834d4babc 100644 --- a/net/ipv4/ipmr_base.c +++ b/net/ipv4/ipmr_base.c @@ -228,7 +228,7 @@ int mr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb, if (c->mfc_flags & MFC_OFFLOAD) rtm->rtm_flags |= RTNH_F_OFFLOAD; - mp_attr = nla_nest_start(skb, RTA_MULTIPATH); + mp_attr = nla_nest_start_noflag(skb, RTA_MULTIPATH); if (!mp_attr) return -EMSGSIZE; -- cgit v1.2.3-59-g8ed1b From 7fcd1e033dacedd520abebc943c960dcf5add3ae Mon Sep 17 00:00:00 2001 From: David Ahern Date: Thu, 2 May 2019 15:14:15 -0700 Subject: ipmr_base: Do not reset index in mr_table_dump e is the counter used to save the location of a dump when an skb is filled. Once the walk of the table is complete, mr_table_dump needs to return without resetting that index to 0. Dump of a specific table is looping because of the reset because there is no way to indicate the walk of the table is done. Move the reset to the caller so the dump of each table starts at 0, but the loop counter is maintained if a dump fills an skb. Fixes: e1cedae1ba6b0 ("ipmr: Refactor mr_rtm_dumproute") Signed-off-by: David Ahern Signed-off-by: David S. Miller --- net/ipv4/ipmr_base.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'net/ipv4/ipmr_base.c') diff --git a/net/ipv4/ipmr_base.c b/net/ipv4/ipmr_base.c index 3e614cc824f7..3a1af50bd0a5 100644 --- a/net/ipv4/ipmr_base.c +++ b/net/ipv4/ipmr_base.c @@ -335,8 +335,6 @@ next_entry2: } spin_unlock_bh(lock); err = 0; - e = 0; - out: cb->args[1] = e; return err; @@ -374,6 +372,7 @@ int mr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb, err = mr_table_dump(mrt, skb, cb, fill, lock, filter); if (err < 0) break; + cb->args[1] = 0; next_table: t++; } -- cgit v1.2.3-59-g8ed1b