cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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ila_common.c (3916B)

      1#include <linux/errno.h>
      2#include <linux/ip.h>
      3#include <linux/kernel.h>
      4#include <linux/module.h>
      5#include <linux/skbuff.h>
      6#include <linux/socket.h>
      7#include <linux/types.h>
      8#include <net/checksum.h>
      9#include <net/ip.h>
     10#include <net/ip6_fib.h>
     11#include <net/lwtunnel.h>
     12#include <net/protocol.h>
     13#include <uapi/linux/ila.h>
     14#include "ila.h"
     15
     16void ila_init_saved_csum(struct ila_params *p)
     17{
     18	if (!p->locator_match.v64)
     19		return;
     20
     21	p->csum_diff = compute_csum_diff8(
     22				(__be32 *)&p->locator,
     23				(__be32 *)&p->locator_match);
     24}
     25
     26static __wsum get_csum_diff_iaddr(struct ila_addr *iaddr, struct ila_params *p)
     27{
     28	if (p->locator_match.v64)
     29		return p->csum_diff;
     30	else
     31		return compute_csum_diff8((__be32 *)&p->locator,
     32					  (__be32 *)&iaddr->loc);
     33}
     34
     35static __wsum get_csum_diff(struct ipv6hdr *ip6h, struct ila_params *p)
     36{
     37	return get_csum_diff_iaddr(ila_a2i(&ip6h->daddr), p);
     38}
     39
     40static void ila_csum_do_neutral_fmt(struct ila_addr *iaddr,
     41				    struct ila_params *p)
     42{
     43	__sum16 *adjust = (__force __sum16 *)&iaddr->ident.v16[3];
     44	__wsum diff, fval;
     45
     46	diff = get_csum_diff_iaddr(iaddr, p);
     47
     48	fval = (__force __wsum)(ila_csum_neutral_set(iaddr->ident) ?
     49			CSUM_NEUTRAL_FLAG : ~CSUM_NEUTRAL_FLAG);
     50
     51	diff = csum_add(diff, fval);
     52
     53	*adjust = ~csum_fold(csum_add(diff, csum_unfold(*adjust)));
     54
     55	/* Flip the csum-neutral bit. Either we are doing a SIR->ILA
     56	 * translation with ILA_CSUM_NEUTRAL_MAP as the csum_method
     57	 * and the C-bit is not set, or we are doing an ILA-SIR
     58	 * tranlsation and the C-bit is set.
     59	 */
     60	iaddr->ident.csum_neutral ^= 1;
     61}
     62
     63static void ila_csum_do_neutral_nofmt(struct ila_addr *iaddr,
     64				      struct ila_params *p)
     65{
     66	__sum16 *adjust = (__force __sum16 *)&iaddr->ident.v16[3];
     67	__wsum diff;
     68
     69	diff = get_csum_diff_iaddr(iaddr, p);
     70
     71	*adjust = ~csum_fold(csum_add(diff, csum_unfold(*adjust)));
     72}
     73
     74static void ila_csum_adjust_transport(struct sk_buff *skb,
     75				      struct ila_params *p)
     76{
     77	size_t nhoff = sizeof(struct ipv6hdr);
     78	struct ipv6hdr *ip6h = ipv6_hdr(skb);
     79	__wsum diff;
     80
     81	switch (ip6h->nexthdr) {
     82	case NEXTHDR_TCP:
     83		if (likely(pskb_may_pull(skb, nhoff + sizeof(struct tcphdr)))) {
     84			struct tcphdr *th = (struct tcphdr *)
     85					(skb_network_header(skb) + nhoff);
     86
     87			diff = get_csum_diff(ip6h, p);
     88			inet_proto_csum_replace_by_diff(&th->check, skb,
     89							diff, true);
     90		}
     91		break;
     92	case NEXTHDR_UDP:
     93		if (likely(pskb_may_pull(skb, nhoff + sizeof(struct udphdr)))) {
     94			struct udphdr *uh = (struct udphdr *)
     95					(skb_network_header(skb) + nhoff);
     96
     97			if (uh->check || skb->ip_summed == CHECKSUM_PARTIAL) {
     98				diff = get_csum_diff(ip6h, p);
     99				inet_proto_csum_replace_by_diff(&uh->check, skb,
    100								diff, true);
    101				if (!uh->check)
    102					uh->check = CSUM_MANGLED_0;
    103			}
    104		}
    105		break;
    106	case NEXTHDR_ICMP:
    107		if (likely(pskb_may_pull(skb,
    108					 nhoff + sizeof(struct icmp6hdr)))) {
    109			struct icmp6hdr *ih = (struct icmp6hdr *)
    110					(skb_network_header(skb) + nhoff);
    111
    112			diff = get_csum_diff(ip6h, p);
    113			inet_proto_csum_replace_by_diff(&ih->icmp6_cksum, skb,
    114							diff, true);
    115		}
    116		break;
    117	}
    118}
    119
    120void ila_update_ipv6_locator(struct sk_buff *skb, struct ila_params *p,
    121			     bool sir2ila)
    122{
    123	struct ipv6hdr *ip6h = ipv6_hdr(skb);
    124	struct ila_addr *iaddr = ila_a2i(&ip6h->daddr);
    125
    126	switch (p->csum_mode) {
    127	case ILA_CSUM_ADJUST_TRANSPORT:
    128		ila_csum_adjust_transport(skb, p);
    129		break;
    130	case ILA_CSUM_NEUTRAL_MAP:
    131		if (sir2ila) {
    132			if (WARN_ON(ila_csum_neutral_set(iaddr->ident))) {
    133				/* Checksum flag should never be
    134				 * set in a formatted SIR address.
    135				 */
    136				break;
    137			}
    138		} else if (!ila_csum_neutral_set(iaddr->ident)) {
    139			/* ILA to SIR translation and C-bit isn't
    140			 * set so we're good.
    141			 */
    142			break;
    143		}
    144		ila_csum_do_neutral_fmt(iaddr, p);
    145		break;
    146	case ILA_CSUM_NEUTRAL_MAP_AUTO:
    147		ila_csum_do_neutral_nofmt(iaddr, p);
    148		break;
    149	case ILA_CSUM_NO_ACTION:
    150		break;
    151	}
    152
    153	/* Now change destination address */
    154	iaddr->loc = p->locator;
    155}