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 16 void 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 26 static __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 35 static __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 40 static 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 63 static 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 74 static 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 } 119 120 void 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 } 156