[PATCH net 1/2] ipv4: fix value of ->nlmsg_flags reported in RTM_NEWROUTE events
flat view
STALE3688d
From: Guillaume Nault <hidden>
Date: 2016-09-07 15:20:53
Subsystem:
networking [general], networking [ipv4/ipv6], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
fib_table_insert() inconsistently fills the nlmsg_flags field in its
notification messages.
Since commit b8f558313506 ("[RTNETLINK]: Fix sending netlink message
when replace route."), the netlink message has its nlmsg_flags set to
NLM_F_REPLACE if the route replaced a preexisting one.
Then commit a2bb6d7d6f42 ("ipv4: include NLM_F_APPEND flag in append
route notifications") started setting nlmsg_flags to NLM_F_APPEND if
the route matched a preexisting one but was appended.
In other cases (exclusive creation or prepend), nlmsg_flags is 0.
This patch sets ->nlmsg_flags in all situations, preserving the
semantic of the NLM_F_* bits:
* NLM_F_CREATE: a new fib entry has been created for this route.
* NLM_F_EXCL: no other fib entry existed for this route.
* NLM_F_REPLACE: this route has overwritten a preexisting fib entry.
* NLM_F_APPEND: the new fib entry was added after other entries for
the same route.
As a result, the possible flag combination can now be reported
(iproute2's terminology into parentheses):
* NLM_F_CREATE | NLM_F_EXCL: route didn't exist, exclusive creation
("add").
* NLM_F_CREATE | NLM_F_APPEND: route did already exist, new route
added after preexisting ones ("append").
* NLM_F_CREATE: route did already exist, new route added before
preexisting ones ("prepend").
* NLM_F_REPLACE: route did already exist, new route replaced the
first preexisting one ("change").
Signed-off-by: Guillaume Nault <redacted>
---
net/ipv4/fib_trie.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index e2ffc2a..241f27b 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c@@ -1081,7 +1081,7 @@ int fib_table_insert(struct fib_table *tb, struct fib_config *cfg) struct trie *t = (struct trie *)tb->tb_data; struct fib_alias *fa, *new_fa; struct key_vector *l, *tp; - unsigned int nlflags = 0; + u16 nlflags = NLM_F_EXCL; struct fib_info *fi; u8 plen = cfg->fc_dst_len; u8 slen = KEYLENGTH - plen;
@@ -1126,6 +1126,8 @@ int fib_table_insert(struct fib_table *tb, struct fib_config *cfg) if (cfg->fc_nlflags & NLM_F_EXCL) goto out; + nlflags &= ~NLM_F_EXCL; + /* We have 2 goals: * 1. Find exact match for type, scope, fib_info to avoid * duplicate routes
@@ -1151,6 +1153,7 @@ int fib_table_insert(struct fib_table *tb, struct fib_config *cfg) struct fib_info *fi_drop; u8 state; + nlflags |= NLM_F_REPLACE; fa = fa_first; if (fa_match) { if (fa == fa_match)
@@ -1191,7 +1194,7 @@ int fib_table_insert(struct fib_table *tb, struct fib_config *cfg) if (state & FA_S_ACCESSED) rt_cache_flush(cfg->fc_nlinfo.nl_net); rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, - tb->tb_id, &cfg->fc_nlinfo, NLM_F_REPLACE); + tb->tb_id, &cfg->fc_nlinfo, nlflags); goto succeeded; }
@@ -1203,7 +1206,7 @@ int fib_table_insert(struct fib_table *tb, struct fib_config *cfg) goto out; if (cfg->fc_nlflags & NLM_F_APPEND) - nlflags = NLM_F_APPEND; + nlflags |= NLM_F_APPEND; else fa = fa_first; }
@@ -1211,6 +1214,7 @@ int fib_table_insert(struct fib_table *tb, struct fib_config *cfg) if (!(cfg->fc_nlflags & NLM_F_CREATE)) goto out; + nlflags |= NLM_F_CREATE; err = -ENOBUFS; new_fa = kmem_cache_alloc(fn_alias_kmem, GFP_KERNEL); if (!new_fa)
--
2.9.3