diff options
author | Florian Westphal <fw@strlen.de> | 2022-09-06 17:20:35 +0200 |
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committer | Florian Westphal <fw@strlen.de> | 2022-09-07 16:46:04 +0200 |
commit | c92c27171040554cfda7a3fc925e9dbcb5b4a698 (patch) | |
tree | 59d7fc3e6dbecbee86cb99add3454a1f999f5047 /net/netfilter/nf_nat_helper.c | |
parent | 8556bceb9c409946eebd2303d2f19e87844195ae (diff) | |
download | linux-c92c27171040554cfda7a3fc925e9dbcb5b4a698.tar.gz |
netfilter: nat: move repetitive nat port reserve loop to a helper
Almost all nat helpers reserve an expecation port the same way:
Try the port inidcated by the peer, then move to next port if that
port is already in use.
We can squash this into a helper.
Suggested-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
Diffstat (limited to 'net/netfilter/nf_nat_helper.c')
-rw-r--r-- | net/netfilter/nf_nat_helper.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/net/netfilter/nf_nat_helper.c b/net/netfilter/nf_nat_helper.c index a263505455fcc1..067d6d6f6b7dc2 100644 --- a/net/netfilter/nf_nat_helper.c +++ b/net/netfilter/nf_nat_helper.c @@ -198,3 +198,22 @@ void nf_nat_follow_master(struct nf_conn *ct, nf_nat_setup_info(ct, &range, NF_NAT_MANIP_DST); } EXPORT_SYMBOL(nf_nat_follow_master); + +u16 nf_nat_exp_find_port(struct nf_conntrack_expect *exp, u16 port) +{ + /* Try to get same port: if not, try to change it. */ + for (; port != 0; port++) { + int res; + + exp->tuple.dst.u.tcp.port = htons(port); + res = nf_ct_expect_related(exp, 0); + if (res == 0) + return port; + + if (res != -EBUSY) + break; + } + + return 0; +} +EXPORT_SYMBOL_GPL(nf_nat_exp_find_port); |