diff options
Diffstat (limited to 'net/ipv6/ila/ila_common.c')
| -rw-r--r-- | net/ipv6/ila/ila_common.c | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/net/ipv6/ila/ila_common.c b/net/ipv6/ila/ila_common.c new file mode 100644 index 000000000..95e914691 --- /dev/null +++ b/net/ipv6/ila/ila_common.c @@ -0,0 +1,155 @@ +#include <linux/errno.h> +#include <linux/ip.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/skbuff.h> +#include <linux/socket.h> +#include <linux/types.h> +#include <net/checksum.h> +#include <net/ip.h> +#include <net/ip6_fib.h> +#include <net/lwtunnel.h> +#include <net/protocol.h> +#include <uapi/linux/ila.h> +#include "ila.h" + +void ila_init_saved_csum(struct ila_params *p) +{ + if (!p->locator_match.v64) + return; + + p->csum_diff = compute_csum_diff8( + (__be32 *)&p->locator, + (__be32 *)&p->locator_match); +} + +static __wsum get_csum_diff_iaddr(struct ila_addr *iaddr, struct ila_params *p) +{ + if (p->locator_match.v64) + return p->csum_diff; + else + return compute_csum_diff8((__be32 *)&p->locator, + (__be32 *)&iaddr->loc); +} + +static __wsum get_csum_diff(struct ipv6hdr *ip6h, struct ila_params *p) +{ + return get_csum_diff_iaddr(ila_a2i(&ip6h->daddr), p); +} + +static void ila_csum_do_neutral_fmt(struct ila_addr *iaddr, + struct ila_params *p) +{ + __sum16 *adjust = (__force __sum16 *)&iaddr->ident.v16[3]; + __wsum diff, fval; + + diff = get_csum_diff_iaddr(iaddr, p); + + fval = (__force __wsum)(ila_csum_neutral_set(iaddr->ident) ? + CSUM_NEUTRAL_FLAG : ~CSUM_NEUTRAL_FLAG); + + diff = csum_add(diff, fval); + + *adjust = ~csum_fold(csum_add(diff, csum_unfold(*adjust))); + + /* Flip the csum-neutral bit. Either we are doing a SIR->ILA + * translation with ILA_CSUM_NEUTRAL_MAP as the csum_method + * and the C-bit is not set, or we are doing an ILA-SIR + * tranlsation and the C-bit is set. + */ + iaddr->ident.csum_neutral ^= 1; +} + +static void ila_csum_do_neutral_nofmt(struct ila_addr *iaddr, + struct ila_params *p) +{ + __sum16 *adjust = (__force __sum16 *)&iaddr->ident.v16[3]; + __wsum diff; + + diff = get_csum_diff_iaddr(iaddr, p); + + *adjust = ~csum_fold(csum_add(diff, csum_unfold(*adjust))); +} + +static void ila_csum_adjust_transport(struct sk_buff *skb, + struct ila_params *p) +{ + size_t nhoff = sizeof(struct ipv6hdr); + struct ipv6hdr *ip6h = ipv6_hdr(skb); + __wsum diff; + + switch (ip6h->nexthdr) { + case NEXTHDR_TCP: + if (likely(pskb_may_pull(skb, nhoff + sizeof(struct tcphdr)))) { + struct tcphdr *th = (struct tcphdr *) + (skb_network_header(skb) + nhoff); + + diff = get_csum_diff(ip6h, p); + inet_proto_csum_replace_by_diff(&th->check, skb, + diff, true); + } + break; + case NEXTHDR_UDP: + if (likely(pskb_may_pull(skb, nhoff + sizeof(struct udphdr)))) { + struct udphdr *uh = (struct udphdr *) + (skb_network_header(skb) + nhoff); + + if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) { + diff = get_csum_diff(ip6h, p); + inet_proto_csum_replace_by_diff(&uh->check, skb, + diff, true); + if (!uh->check) + uh->check = CSUM_MANGLED_0; + } + } + break; + case NEXTHDR_ICMP: + if (likely(pskb_may_pull(skb, + nhoff + sizeof(struct icmp6hdr)))) { + struct icmp6hdr *ih = (struct icmp6hdr *) + (skb_network_header(skb) + nhoff); + + diff = get_csum_diff(ip6h, p); + inet_proto_csum_replace_by_diff(&ih->icmp6_cksum, skb, + diff, true); + } + break; + } +} + +void ila_update_ipv6_locator(struct sk_buff *skb, struct ila_params *p, + bool sir2ila) +{ + struct ipv6hdr *ip6h = ipv6_hdr(skb); + struct ila_addr *iaddr = ila_a2i(&ip6h->daddr); + + switch (p->csum_mode) { + case ILA_CSUM_ADJUST_TRANSPORT: + ila_csum_adjust_transport(skb, p); + break; + case ILA_CSUM_NEUTRAL_MAP: + if (sir2ila) { + if (WARN_ON(ila_csum_neutral_set(iaddr->ident))) { + /* Checksum flag should never be + * set in a formatted SIR address. + */ + break; + } + } else if (!ila_csum_neutral_set(iaddr->ident)) { + /* ILA to SIR translation and C-bit isn't + * set so we're good. + */ + break; + } + ila_csum_do_neutral_fmt(iaddr, p); + break; + case ILA_CSUM_NEUTRAL_MAP_AUTO: + ila_csum_do_neutral_nofmt(iaddr, p); + break; + case ILA_CSUM_NO_ACTION: + break; + } + + /* Now change destination address */ + iaddr->loc = p->locator; +} |