From 5abd363f738dcd048ee790fb9b84d0768a8a407f Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Mon, 14 Apr 2008 11:15:46 +0200 Subject: [PATCH] [NETFILTER]: nf_nat: fix random mode not to overwrite port rover The port rover should not get overwritten when using random mode, otherwise other rules will also use more or less random ports. Signed-off-by: Patrick McHardy --- net/ipv4/netfilter/nf_nat_proto_common.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/net/ipv4/netfilter/nf_nat_proto_common.c b/net/ipv4/netfilter/nf_nat_proto_common.c index a124213fb9da..871ab0eb325d 100644 --- a/net/ipv4/netfilter/nf_nat_proto_common.c +++ b/net/ipv4/netfilter/nf_nat_proto_common.c @@ -42,6 +42,7 @@ int nf_nat_proto_unique_tuple(struct nf_conntrack_tuple *tuple, { unsigned int range_size, min, i; __be16 *portptr; + u_int16_t off; if (maniptype == IP_NAT_MANIP_SRC) portptr = &tuple->src.u.all; @@ -72,13 +73,17 @@ int nf_nat_proto_unique_tuple(struct nf_conntrack_tuple *tuple, range_size = ntohs(range->max.all) - min + 1; } + off = *rover; if (range->flags & IP_NAT_RANGE_PROTO_RANDOM) - *rover = net_random(); + off = net_random(); - for (i = 0; i < range_size; i++, (*rover)++) { - *portptr = htons(min + *rover % range_size); - if (!nf_nat_used_tuple(tuple, ct)) - return 1; + for (i = 0; i < range_size; i++, off++) { + *portptr = htons(min + off % range_size); + if (nf_nat_used_tuple(tuple, ct)) + continue; + if (!(range->flags & IP_NAT_RANGE_PROTO_RANDOM)) + *rover = off; + return 1; } return 0; } -- 2.20.1