diff options
author | Pablo Neira Ayuso <pablo@netfilter.org> | 2021-03-17 17:55:25 +0300 |
---|---|---|
committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2021-03-18 02:44:00 +0300 |
commit | f4401262b927b84d2f1861e347627fa0d77d4eb7 (patch) | |
tree | aa34442e71293795566efcfe4a2326ade2079ef3 /net/netfilter/nf_flow_table_ip.c | |
parent | 4f08f173d08cad4664e447e580dc0c5aa6332db3 (diff) | |
download | linux-f4401262b927b84d2f1861e347627fa0d77d4eb7.tar.xz |
netfilter: flowtable: fast NAT functions never fail
Simplify existing fast NAT routines by returning void. After the
skb_try_make_writable() call consolidation, these routines cannot ever
fail.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/netfilter/nf_flow_table_ip.c')
-rw-r--r-- | net/netfilter/nf_flow_table_ip.c | 147 |
1 files changed, 62 insertions, 85 deletions
diff --git a/net/netfilter/nf_flow_table_ip.c b/net/netfilter/nf_flow_table_ip.c index 0579e15c4968..714dc083f093 100644 --- a/net/netfilter/nf_flow_table_ip.c +++ b/net/netfilter/nf_flow_table_ip.c @@ -34,19 +34,17 @@ static int nf_flow_state_check(struct flow_offload *flow, int proto, return 0; } -static int nf_flow_nat_ip_tcp(struct sk_buff *skb, unsigned int thoff, - __be32 addr, __be32 new_addr) +static void nf_flow_nat_ip_tcp(struct sk_buff *skb, unsigned int thoff, + __be32 addr, __be32 new_addr) { struct tcphdr *tcph; tcph = (void *)(skb_network_header(skb) + thoff); inet_proto_csum_replace4(&tcph->check, skb, addr, new_addr, true); - - return 0; } -static int nf_flow_nat_ip_udp(struct sk_buff *skb, unsigned int thoff, - __be32 addr, __be32 new_addr) +static void nf_flow_nat_ip_udp(struct sk_buff *skb, unsigned int thoff, + __be32 addr, __be32 new_addr) { struct udphdr *udph; @@ -57,31 +55,25 @@ static int nf_flow_nat_ip_udp(struct sk_buff *skb, unsigned int thoff, if (!udph->check) udph->check = CSUM_MANGLED_0; } - - return 0; } -static int nf_flow_nat_ip_l4proto(struct sk_buff *skb, struct iphdr *iph, - unsigned int thoff, __be32 addr, - __be32 new_addr) +static void nf_flow_nat_ip_l4proto(struct sk_buff *skb, struct iphdr *iph, + unsigned int thoff, __be32 addr, + __be32 new_addr) { switch (iph->protocol) { case IPPROTO_TCP: - if (nf_flow_nat_ip_tcp(skb, thoff, addr, new_addr) < 0) - return NF_DROP; + nf_flow_nat_ip_tcp(skb, thoff, addr, new_addr); break; case IPPROTO_UDP: - if (nf_flow_nat_ip_udp(skb, thoff, addr, new_addr) < 0) - return NF_DROP; + nf_flow_nat_ip_udp(skb, thoff, addr, new_addr); break; } - - return 0; } -static int nf_flow_snat_ip(const struct flow_offload *flow, struct sk_buff *skb, - struct iphdr *iph, unsigned int thoff, - enum flow_offload_tuple_dir dir) +static void nf_flow_snat_ip(const struct flow_offload *flow, + struct sk_buff *skb, struct iphdr *iph, + unsigned int thoff, enum flow_offload_tuple_dir dir) { __be32 addr, new_addr; @@ -99,12 +91,12 @@ static int nf_flow_snat_ip(const struct flow_offload *flow, struct sk_buff *skb, } csum_replace4(&iph->check, addr, new_addr); - return nf_flow_nat_ip_l4proto(skb, iph, thoff, addr, new_addr); + nf_flow_nat_ip_l4proto(skb, iph, thoff, addr, new_addr); } -static int nf_flow_dnat_ip(const struct flow_offload *flow, struct sk_buff *skb, - struct iphdr *iph, unsigned int thoff, - enum flow_offload_tuple_dir dir) +static void nf_flow_dnat_ip(const struct flow_offload *flow, + struct sk_buff *skb, struct iphdr *iph, + unsigned int thoff, enum flow_offload_tuple_dir dir) { __be32 addr, new_addr; @@ -122,24 +114,21 @@ static int nf_flow_dnat_ip(const struct flow_offload *flow, struct sk_buff *skb, } csum_replace4(&iph->check, addr, new_addr); - return nf_flow_nat_ip_l4proto(skb, iph, thoff, addr, new_addr); + nf_flow_nat_ip_l4proto(skb, iph, thoff, addr, new_addr); } -static int nf_flow_nat_ip(const struct flow_offload *flow, struct sk_buff *skb, +static void nf_flow_nat_ip(const struct flow_offload *flow, struct sk_buff *skb, unsigned int thoff, enum flow_offload_tuple_dir dir, struct iphdr *iph) { - if (test_bit(NF_FLOW_SNAT, &flow->flags) && - (nf_flow_snat_port(flow, skb, thoff, iph->protocol, dir) < 0 || - nf_flow_snat_ip(flow, skb, iph, thoff, dir) < 0)) - return -1; - - if (test_bit(NF_FLOW_DNAT, &flow->flags) && - (nf_flow_dnat_port(flow, skb, thoff, iph->protocol, dir) < 0 || - nf_flow_dnat_ip(flow, skb, iph, thoff, dir) < 0)) - return -1; - - return 0; + if (test_bit(NF_FLOW_SNAT, &flow->flags)) { + nf_flow_snat_port(flow, skb, thoff, iph->protocol, dir); + nf_flow_snat_ip(flow, skb, iph, thoff, dir); + } + if (test_bit(NF_FLOW_DNAT, &flow->flags)) { + nf_flow_dnat_port(flow, skb, thoff, iph->protocol, dir); + nf_flow_dnat_ip(flow, skb, iph, thoff, dir); + } } static bool ip_has_options(unsigned int thoff) @@ -276,8 +265,7 @@ nf_flow_offload_ip_hook(void *priv, struct sk_buff *skb, return NF_DROP; iph = ip_hdr(skb); - if (nf_flow_nat_ip(flow, skb, thoff, dir, iph) < 0) - return NF_DROP; + nf_flow_nat_ip(flow, skb, thoff, dir, iph); ip_decrease_ttl(iph); skb->tstamp = 0; @@ -301,22 +289,21 @@ nf_flow_offload_ip_hook(void *priv, struct sk_buff *skb, } EXPORT_SYMBOL_GPL(nf_flow_offload_ip_hook); -static int nf_flow_nat_ipv6_tcp(struct sk_buff *skb, unsigned int thoff, - struct in6_addr *addr, - struct in6_addr *new_addr) +static void nf_flow_nat_ipv6_tcp(struct sk_buff *skb, unsigned int thoff, + struct in6_addr *addr, + struct in6_addr *new_addr, + struct ipv6hdr *ip6h) { struct tcphdr *tcph; tcph = (void *)(skb_network_header(skb) + thoff); inet_proto_csum_replace16(&tcph->check, skb, addr->s6_addr32, new_addr->s6_addr32, true); - - return 0; } -static int nf_flow_nat_ipv6_udp(struct sk_buff *skb, unsigned int thoff, - struct in6_addr *addr, - struct in6_addr *new_addr) +static void nf_flow_nat_ipv6_udp(struct sk_buff *skb, unsigned int thoff, + struct in6_addr *addr, + struct in6_addr *new_addr) { struct udphdr *udph; @@ -327,32 +314,26 @@ static int nf_flow_nat_ipv6_udp(struct sk_buff *skb, unsigned int thoff, if (!udph->check) udph->check = CSUM_MANGLED_0; } - - return 0; } -static int nf_flow_nat_ipv6_l4proto(struct sk_buff *skb, struct ipv6hdr *ip6h, - unsigned int thoff, struct in6_addr *addr, - struct in6_addr *new_addr) +static void nf_flow_nat_ipv6_l4proto(struct sk_buff *skb, struct ipv6hdr *ip6h, + unsigned int thoff, struct in6_addr *addr, + struct in6_addr *new_addr) { switch (ip6h->nexthdr) { case IPPROTO_TCP: - if (nf_flow_nat_ipv6_tcp(skb, thoff, addr, new_addr) < 0) - return NF_DROP; + nf_flow_nat_ipv6_tcp(skb, thoff, addr, new_addr, ip6h); break; case IPPROTO_UDP: - if (nf_flow_nat_ipv6_udp(skb, thoff, addr, new_addr) < 0) - return NF_DROP; + nf_flow_nat_ipv6_udp(skb, thoff, addr, new_addr); break; } - - return 0; } -static int nf_flow_snat_ipv6(const struct flow_offload *flow, - struct sk_buff *skb, struct ipv6hdr *ip6h, - unsigned int thoff, - enum flow_offload_tuple_dir dir) +static void nf_flow_snat_ipv6(const struct flow_offload *flow, + struct sk_buff *skb, struct ipv6hdr *ip6h, + unsigned int thoff, + enum flow_offload_tuple_dir dir) { struct in6_addr addr, new_addr; @@ -369,13 +350,13 @@ static int nf_flow_snat_ipv6(const struct flow_offload *flow, break; } - return nf_flow_nat_ipv6_l4proto(skb, ip6h, thoff, &addr, &new_addr); + nf_flow_nat_ipv6_l4proto(skb, ip6h, thoff, &addr, &new_addr); } -static int nf_flow_dnat_ipv6(const struct flow_offload *flow, - struct sk_buff *skb, struct ipv6hdr *ip6h, - unsigned int thoff, - enum flow_offload_tuple_dir dir) +static void nf_flow_dnat_ipv6(const struct flow_offload *flow, + struct sk_buff *skb, struct ipv6hdr *ip6h, + unsigned int thoff, + enum flow_offload_tuple_dir dir) { struct in6_addr addr, new_addr; @@ -392,27 +373,24 @@ static int nf_flow_dnat_ipv6(const struct flow_offload *flow, break; } - return nf_flow_nat_ipv6_l4proto(skb, ip6h, thoff, &addr, &new_addr); + nf_flow_nat_ipv6_l4proto(skb, ip6h, thoff, &addr, &new_addr); } -static int nf_flow_nat_ipv6(const struct flow_offload *flow, - struct sk_buff *skb, - enum flow_offload_tuple_dir dir, - struct ipv6hdr *ip6h) +static void nf_flow_nat_ipv6(const struct flow_offload *flow, + struct sk_buff *skb, + enum flow_offload_tuple_dir dir, + struct ipv6hdr *ip6h) { unsigned int thoff = sizeof(*ip6h); - if (test_bit(NF_FLOW_SNAT, &flow->flags) && - (nf_flow_snat_port(flow, skb, thoff, ip6h->nexthdr, dir) < 0 || - nf_flow_snat_ipv6(flow, skb, ip6h, thoff, dir) < 0)) - return -1; - - if (test_bit(NF_FLOW_DNAT, &flow->flags) && - (nf_flow_dnat_port(flow, skb, thoff, ip6h->nexthdr, dir) < 0 || - nf_flow_dnat_ipv6(flow, skb, ip6h, thoff, dir) < 0)) - return -1; - - return 0; + if (test_bit(NF_FLOW_SNAT, &flow->flags)) { + nf_flow_snat_port(flow, skb, thoff, ip6h->nexthdr, dir); + nf_flow_snat_ipv6(flow, skb, ip6h, thoff, dir); + } + if (test_bit(NF_FLOW_DNAT, &flow->flags)) { + nf_flow_dnat_port(flow, skb, thoff, ip6h->nexthdr, dir); + nf_flow_dnat_ipv6(flow, skb, ip6h, thoff, dir); + } } static int nf_flow_tuple_ipv6(struct sk_buff *skb, const struct net_device *dev, @@ -507,8 +485,7 @@ nf_flow_offload_ipv6_hook(void *priv, struct sk_buff *skb, return NF_DROP; ip6h = ipv6_hdr(skb); - if (nf_flow_nat_ipv6(flow, skb, dir, ip6h) < 0) - return NF_DROP; + nf_flow_nat_ipv6(flow, skb, dir, ip6h); ip6h->hop_limit--; skb->tstamp = 0; |