projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 5edbb07d VY |
1 | /* |
| 2 | * IPV6 GSO/GRO offload support | |
| 3 | * Linux INET6 implementation | |
| 4 | * | |
| 5 | * This program is free software; you can redistribute it and/or | |
| 6 | * modify it under the terms of the GNU General Public License | |
| 7 | * as published by the Free Software Foundation; either version | |
| 8 | * 2 of the License, or (at your option) any later version. | |
| 9 | * | |
| 10 | * UDPv6 GSO support | |
| 11 | */ | |
| 12 | #include <linux/skbuff.h> | |
| 13 | #include <net/protocol.h> | |
| 14 | #include <net/ipv6.h> | |
| 15 | #include <net/udp.h> | |
| d4d0d355 | 16 | #include <net/ip6_checksum.h> |
| 5edbb07d VY |
17 | #include "ip6_offload.h" |
| 18 | ||
| 19 | static int udp6_ufo_send_check(struct sk_buff *skb) | |
| 20 | { | |
| 21 | const struct ipv6hdr *ipv6h; | |
| 22 | struct udphdr *uh; | |
| 23 | ||
| 24 | if (!pskb_may_pull(skb, sizeof(*uh))) | |
| 25 | return -EINVAL; | |
| 26 | ||
| 27 | ipv6h = ipv6_hdr(skb); | |
| 28 | uh = udp_hdr(skb); | |
| 29 | ||
| 30 | uh->check = ~csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr, skb->len, | |
| 31 | IPPROTO_UDP, 0); | |
| 32 | skb->csum_start = skb_transport_header(skb) - skb->head; | |
| 33 | skb->csum_offset = offsetof(struct udphdr, check); | |
| 34 | skb->ip_summed = CHECKSUM_PARTIAL; | |
| 35 | return 0; | |
| 36 | } | |
| 37 | ||
| 38 | static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb, | |
| 39 | netdev_features_t features) | |
| 40 | { | |
| 41 | struct sk_buff *segs = ERR_PTR(-EINVAL); | |
| 42 | unsigned int mss; | |
| 43 | unsigned int unfrag_ip6hlen, unfrag_len; | |
| 44 | struct frag_hdr *fptr; | |
| 45 | u8 *mac_start, *prevhdr; | |
| 46 | u8 nexthdr; | |
| 47 | u8 frag_hdr_sz = sizeof(struct frag_hdr); | |
| 48 | int offset; | |
| 49 | __wsum csum; | |
| 50 | ||
| 51 | mss = skb_shinfo(skb)->gso_size; | |
| 52 | if (unlikely(skb->len <= mss)) | |
| 53 | goto out; | |
| 54 | ||
| 55 | if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) { | |
| 56 | /* Packet is from an untrusted source, reset gso_segs. */ | |
| 57 | int type = skb_shinfo(skb)->gso_type; | |
| 58 | ||
| 68c33163 PS |
59 | if (unlikely(type & ~(SKB_GSO_UDP | SKB_GSO_DODGY | |
| 60 | SKB_GSO_GRE) || | |
| 5edbb07d VY |
61 | !(type & (SKB_GSO_UDP)))) |
| 62 | goto out; | |
| 63 | ||
| 64 | skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(skb->len, mss); | |
| 65 | ||
| 66 | segs = NULL; | |
| 67 | goto out; | |
| 68 | } | |
| 69 | ||
| 70 | /* Do software UFO. Complete and fill in the UDP checksum as HW cannot | |
| 71 | * do checksum of UDP packets sent as multiple IP fragments. | |
| 72 | */ | |
| 73 | offset = skb_checksum_start_offset(skb); | |
| 74 | csum = skb_checksum(skb, offset, skb->len - offset, 0); | |
| 75 | offset += skb->csum_offset; | |
| 76 | *(__sum16 *)(skb->data + offset) = csum_fold(csum); | |
| 77 | skb->ip_summed = CHECKSUM_NONE; | |
| 78 | ||
| 79 | /* Check if there is enough headroom to insert fragment header. */ | |
| 80 | if ((skb_mac_header(skb) < skb->head + frag_hdr_sz) && | |
| 81 | pskb_expand_head(skb, frag_hdr_sz, 0, GFP_ATOMIC)) | |
| 82 | goto out; | |
| 83 | ||
| 84 | /* Find the unfragmentable header and shift it left by frag_hdr_sz | |
| 85 | * bytes to insert fragment header. | |
| 86 | */ | |
| 87 | unfrag_ip6hlen = ip6_find_1stfragopt(skb, &prevhdr); | |
| 88 | nexthdr = *prevhdr; | |
| 89 | *prevhdr = NEXTHDR_FRAGMENT; | |
| 90 | unfrag_len = skb_network_header(skb) - skb_mac_header(skb) + | |
| 91 | unfrag_ip6hlen; | |
| 92 | mac_start = skb_mac_header(skb); | |
| 93 | memmove(mac_start-frag_hdr_sz, mac_start, unfrag_len); | |
| 94 | ||
| 95 | skb->mac_header -= frag_hdr_sz; | |
| 96 | skb->network_header -= frag_hdr_sz; | |
| 97 | ||
| 98 | fptr = (struct frag_hdr *)(skb_network_header(skb) + unfrag_ip6hlen); | |
| 99 | fptr->nexthdr = nexthdr; | |
| 100 | fptr->reserved = 0; | |
| 101 | ipv6_select_ident(fptr, (struct rt6_info *)skb_dst(skb)); | |
| 102 | ||
| 103 | /* Fragment the skb. ipv6 header and the remaining fields of the | |
| 104 | * fragment header are updated in ipv6_gso_segment() | |
| 105 | */ | |
| 106 | segs = skb_segment(skb, features); | |
| 107 | ||
| 108 | out: | |
| 109 | return segs; | |
| 110 | } | |
| 111 | static const struct net_offload udpv6_offload = { | |
| f191a1d1 VY |
112 | .callbacks = { |
| 113 | .gso_send_check = udp6_ufo_send_check, | |
| 114 | .gso_segment = udp6_ufo_fragment, | |
| 115 | }, | |
| 5edbb07d VY |
116 | }; |
| 117 | ||
| 118 | int __init udp_offload_init(void) | |
| 119 | { | |
| 120 | return inet6_add_offload(&udpv6_offload, IPPROTO_UDP); | |
| 121 | } |