diff options
Diffstat (limited to 'net/netfilter/nf_nat_core.c')
| -rw-r--r-- | net/netfilter/nf_nat_core.c | 88 |
1 files changed, 19 insertions, 69 deletions
diff --git a/net/netfilter/nf_nat_core.c b/net/netfilter/nf_nat_core.c index 2d06a66899b2..e29e4ccb5c5a 100644 --- a/net/netfilter/nf_nat_core.c +++ b/net/netfilter/nf_nat_core.c @@ -16,7 +16,7 @@ #include <linux/siphash.h> #include <linux/rtnetlink.h> -#include <net/netfilter/nf_conntrack.h> +#include <net/netfilter/nf_conntrack_bpf.h> #include <net/netfilter/nf_conntrack_core.h> #include <net/netfilter/nf_conntrack_helper.h> #include <net/netfilter/nf_conntrack_seqadj.h> @@ -468,7 +468,7 @@ find_free_id: if (range->flags & NF_NAT_RANGE_PROTO_OFFSET) off = (ntohs(*keyptr) - ntohs(range->base_proto.all)); else - off = prandom_u32(); + off = get_random_u16(); attempts = range_size; if (attempts > max_attempts) @@ -490,42 +490,10 @@ another_round: if (attempts >= range_size || attempts < 16) return; attempts /= 2; - off = prandom_u32(); + off = get_random_u16(); goto another_round; } -static bool tuple_force_port_remap(const struct nf_conntrack_tuple *tuple) -{ - u16 sp, dp; - - switch (tuple->dst.protonum) { - case IPPROTO_TCP: - sp = ntohs(tuple->src.u.tcp.port); - dp = ntohs(tuple->dst.u.tcp.port); - break; - case IPPROTO_UDP: - case IPPROTO_UDPLITE: - sp = ntohs(tuple->src.u.udp.port); - dp = ntohs(tuple->dst.u.udp.port); - break; - default: - return false; - } - - /* IANA: System port range: 1-1023, - * user port range: 1024-49151, - * private port range: 49152-65535. - * - * Linux default ephemeral port range is 32768-60999. - * - * Enforce port remapping if sport is significantly lower - * than dport to prevent NAT port shadowing, i.e. - * accidental match of 'new' inbound connection vs. - * existing outbound one. - */ - return sp < 16384 && dp >= 32768; -} - /* Manipulate the tuple into the range given. For NF_INET_POST_ROUTING, * we change the source to map into the range. For NF_INET_PRE_ROUTING * and NF_INET_LOCAL_OUT, we change the destination to map into the @@ -539,17 +507,11 @@ get_unique_tuple(struct nf_conntrack_tuple *tuple, struct nf_conn *ct, enum nf_nat_manip_type maniptype) { - bool random_port = range->flags & NF_NAT_RANGE_PROTO_RANDOM_ALL; const struct nf_conntrack_zone *zone; struct net *net = nf_ct_net(ct); zone = nf_ct_zone(ct); - if (maniptype == NF_NAT_MANIP_SRC && - !random_port && - !ct->local_origin) - random_port = tuple_force_port_remap(orig_tuple); - /* 1) If this srcip/proto/src-proto-part is currently mapped, * and that same mapping gives a unique tuple within the given * range, use that. @@ -558,7 +520,8 @@ get_unique_tuple(struct nf_conntrack_tuple *tuple, * So far, we don't do local source mappings, so multiple * manips not an issue. */ - if (maniptype == NF_NAT_MANIP_SRC && !random_port) { + if (maniptype == NF_NAT_MANIP_SRC && + !(range->flags & NF_NAT_RANGE_PROTO_RANDOM_ALL)) { /* try the original tuple first */ if (in_range(orig_tuple, range)) { if (!nf_nat_used_tuple(orig_tuple, ct)) { @@ -582,7 +545,7 @@ get_unique_tuple(struct nf_conntrack_tuple *tuple, */ /* Only bother mapping if it's not already in range and unique */ - if (!random_port) { + if (!(range->flags & NF_NAT_RANGE_PROTO_RANDOM_ALL)) { if (range->flags & NF_NAT_RANGE_PROTO_SPECIFIED) { if (!(range->flags & NF_NAT_RANGE_PROTO_OFFSET) && l4proto_in_range(tuple, maniptype, @@ -838,7 +801,7 @@ static int nf_nat_proto_remove(struct nf_conn *i, void *data) return i->status & IPS_NAT_MASK ? 1 : 0; } -static void __nf_nat_cleanup_conntrack(struct nf_conn *ct) +static void nf_nat_cleanup_conntrack(struct nf_conn *ct) { unsigned int h; @@ -860,7 +823,7 @@ static int nf_nat_proto_clean(struct nf_conn *ct, void *data) * will delete entry from already-freed table. */ if (test_and_clear_bit(IPS_SRC_NAT_DONE_BIT, &ct->status)) - __nf_nat_cleanup_conntrack(ct); + nf_nat_cleanup_conntrack(ct); /* don't delete conntrack. Although that would make things a lot * simpler, we'd end up flushing all conntracks on nat rmmod. @@ -868,20 +831,6 @@ static int nf_nat_proto_clean(struct nf_conn *ct, void *data) return 0; } -/* No one using conntrack by the time this called. */ -static void nf_nat_cleanup_conntrack(struct nf_conn *ct) -{ - if (ct->status & IPS_SRC_NAT_DONE) - __nf_nat_cleanup_conntrack(ct); -} - -static struct nf_ct_ext_type nat_extend __read_mostly = { - .len = sizeof(struct nf_conn_nat), - .align = __alignof__(struct nf_conn_nat), - .destroy = nf_nat_cleanup_conntrack, - .id = NF_CT_EXT_NAT, -}; - #if IS_ENABLED(CONFIG_NF_CT_NETLINK) #include <linux/netfilter/nfnetlink.h> @@ -1173,6 +1122,7 @@ static const struct nf_nat_hook nat_hook = { .decode_session = __nf_nat_decode_session, #endif .manip_pkt = nf_nat_manip_pkt, + .remove_nat_bysrc = nf_nat_cleanup_conntrack, }; static int __init nf_nat_init(void) @@ -1188,19 +1138,11 @@ static int __init nf_nat_init(void) if (!nf_nat_bysource) return -ENOMEM; - ret = nf_ct_extend_register(&nat_extend); - if (ret < 0) { - kvfree(nf_nat_bysource); - pr_err("Unable to register extension\n"); - return ret; - } - for (i = 0; i < CONNTRACK_LOCKS; i++) spin_lock_init(&nf_nat_locks[i]); ret = register_pernet_subsys(&nat_net_ops); if (ret < 0) { - nf_ct_extend_unregister(&nat_extend); kvfree(nf_nat_bysource); return ret; } @@ -1210,7 +1152,16 @@ static int __init nf_nat_init(void) WARN_ON(nf_nat_hook != NULL); RCU_INIT_POINTER(nf_nat_hook, &nat_hook); - return 0; + ret = register_nf_nat_bpf(); + if (ret < 0) { + RCU_INIT_POINTER(nf_nat_hook, NULL); + nf_ct_helper_expectfn_unregister(&follow_master_nat); + synchronize_net(); + unregister_pernet_subsys(&nat_net_ops); + kvfree(nf_nat_bysource); + } + + return ret; } static void __exit nf_nat_cleanup(void) @@ -1219,7 +1170,6 @@ static void __exit nf_nat_cleanup(void) nf_ct_iterate_destroy(nf_nat_proto_clean, &clean); - nf_ct_extend_unregister(&nat_extend); nf_ct_helper_expectfn_unregister(&follow_master_nat); RCU_INIT_POINTER(nf_nat_hook, NULL); |