| /* |
| * IPV6 GSO/GRO offload support |
| * Linux INET implementation |
| * |
| * Copyright (C) 2016 secunet Security Networks AG |
| * Author: Steffen Klassert <steffen.klassert@secunet.com> |
| * |
| * This program is free software; you can redistribute it and/or modify it |
| * under the terms and conditions of the GNU General Public License, |
| * version 2, as published by the Free Software Foundation. |
| * |
| * ESP GRO support |
| */ |
| |
| #include <linux/skbuff.h> |
| #include <linux/init.h> |
| #include <net/protocol.h> |
| #include <crypto/aead.h> |
| #include <crypto/authenc.h> |
| #include <linux/err.h> |
| #include <linux/module.h> |
| #include <net/ip.h> |
| #include <net/xfrm.h> |
| #include <net/esp.h> |
| #include <linux/scatterlist.h> |
| #include <linux/kernel.h> |
| #include <linux/slab.h> |
| #include <linux/spinlock.h> |
| #include <net/ip6_route.h> |
| #include <net/ipv6.h> |
| #include <linux/icmpv6.h> |
| |
| static __u16 esp6_nexthdr_esp_offset(struct ipv6hdr *ipv6_hdr, int nhlen) |
| { |
| int off = sizeof(struct ipv6hdr); |
| struct ipv6_opt_hdr *exthdr; |
| |
| if (likely(ipv6_hdr->nexthdr == NEXTHDR_ESP)) |
| return offsetof(struct ipv6hdr, nexthdr); |
| |
| while (off < nhlen) { |
| exthdr = (void *)ipv6_hdr + off; |
| if (exthdr->nexthdr == NEXTHDR_ESP) |
| return off; |
| |
| off += ipv6_optlen(exthdr); |
| } |
| |
| return 0; |
| } |
| |
| static struct sk_buff *esp6_gro_receive(struct list_head *head, |
| struct sk_buff *skb) |
| { |
| int offset = skb_gro_offset(skb); |
| struct xfrm_offload *xo; |
| struct xfrm_state *x; |
| __be32 seq; |
| __be32 spi; |
| int nhoff; |
| int err; |
| |
| if (!pskb_pull(skb, offset)) |
| return NULL; |
| |
| if ((err = xfrm_parse_spi(skb, IPPROTO_ESP, &spi, &seq)) != 0) |
| goto out; |
| |
| xo = xfrm_offload(skb); |
| if (!xo || !(xo->flags & CRYPTO_DONE)) { |
| struct sec_path *sp = secpath_set(skb); |
| |
| if (!sp) |
| goto out; |
| |
| if (sp->len == XFRM_MAX_DEPTH) |
| goto out_reset; |
| |
| x = xfrm_state_lookup(dev_net(skb->dev), skb->mark, |
| (xfrm_address_t *)&ipv6_hdr(skb)->daddr, |
| spi, IPPROTO_ESP, AF_INET6); |
| if (!x) |
| goto out_reset; |
| |
| sp->xvec[sp->len++] = x; |
| sp->olen++; |
| |
| xo = xfrm_offload(skb); |
| if (!xo) { |
| xfrm_state_put(x); |
| goto out_reset; |
| } |
| } |
| |
| xo->flags |= XFRM_GRO; |
| |
| nhoff = esp6_nexthdr_esp_offset(ipv6_hdr(skb), offset); |
| if (!nhoff) |
| goto out; |
| |
| IP6CB(skb)->nhoff = nhoff; |
| XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip6 = NULL; |
| XFRM_SPI_SKB_CB(skb)->family = AF_INET6; |
| XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct ipv6hdr, daddr); |
| XFRM_SPI_SKB_CB(skb)->seq = seq; |
| |
| /* We don't need to handle errors from xfrm_input, it does all |
| * the error handling and frees the resources on error. */ |
| xfrm_input(skb, IPPROTO_ESP, spi, -2); |
| |
| return ERR_PTR(-EINPROGRESS); |
| out_reset: |
| secpath_reset(skb); |
| out: |
| skb_push(skb, offset); |
| NAPI_GRO_CB(skb)->same_flow = 0; |
| NAPI_GRO_CB(skb)->flush = 1; |
| |
| return NULL; |
| } |
| |
| static void esp6_gso_encap(struct xfrm_state *x, struct sk_buff *skb) |
| { |
| struct ip_esp_hdr *esph; |
| struct ipv6hdr *iph = ipv6_hdr(skb); |
| struct xfrm_offload *xo = xfrm_offload(skb); |
| int proto = iph->nexthdr; |
| |
| skb_push(skb, -skb_network_offset(skb)); |
| esph = ip_esp_hdr(skb); |
| *skb_mac_header(skb) = IPPROTO_ESP; |
| |
| esph->spi = x->id.spi; |
| esph->seq_no = htonl(XFRM_SKB_CB(skb)->seq.output.low); |
| |
| xo->proto = proto; |
| } |
| |
| static struct sk_buff *esp6_gso_segment(struct sk_buff *skb, |
| netdev_features_t features) |
| { |
| struct xfrm_state *x; |
| struct ip_esp_hdr *esph; |
| struct crypto_aead *aead; |
| netdev_features_t esp_features = features; |
| struct xfrm_offload *xo = xfrm_offload(skb); |
| struct sec_path *sp; |
| |
| if (!xo) |
| return ERR_PTR(-EINVAL); |
| |
| if (!(skb_shinfo(skb)->gso_type & SKB_GSO_ESP)) |
| return ERR_PTR(-EINVAL); |
| |
| sp = skb_sec_path(skb); |
| x = sp->xvec[sp->len - 1]; |
| aead = x->data; |
| esph = ip_esp_hdr(skb); |
| |
| if (esph->spi != x->id.spi) |
| return ERR_PTR(-EINVAL); |
| |
| if (!pskb_may_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead))) |
| return ERR_PTR(-EINVAL); |
| |
| __skb_pull(skb, sizeof(*esph) + crypto_aead_ivsize(aead)); |
| |
| skb->encap_hdr_csum = 1; |
| |
| if (!(features & NETIF_F_HW_ESP) || x->xso.dev != skb->dev) |
| esp_features = features & ~(NETIF_F_SG | NETIF_F_CSUM_MASK); |
| else if (!(features & NETIF_F_HW_ESP_TX_CSUM)) |
| esp_features = features & ~NETIF_F_CSUM_MASK; |
| |
| xo->flags |= XFRM_GSO_SEGMENT; |
| |
| return x->outer_mode->gso_segment(x, skb, esp_features); |
| } |
| |
| static int esp6_input_tail(struct xfrm_state *x, struct sk_buff *skb) |
| { |
| struct crypto_aead *aead = x->data; |
| struct xfrm_offload *xo = xfrm_offload(skb); |
| |
| if (!pskb_may_pull(skb, sizeof(struct ip_esp_hdr) + crypto_aead_ivsize(aead))) |
| return -EINVAL; |
| |
| if (!(xo->flags & CRYPTO_DONE)) |
| skb->ip_summed = CHECKSUM_NONE; |
| |
| return esp6_input_done2(skb, 0); |
| } |
| |
| static int esp6_xmit(struct xfrm_state *x, struct sk_buff *skb, netdev_features_t features) |
| { |
| int len; |
| int err; |
| int alen; |
| int blksize; |
| struct xfrm_offload *xo; |
| struct ip_esp_hdr *esph; |
| struct crypto_aead *aead; |
| struct esp_info esp; |
| bool hw_offload = true; |
| __u32 seq; |
| |
| esp.inplace = true; |
| |
| xo = xfrm_offload(skb); |
| |
| if (!xo) |
| return -EINVAL; |
| |
| if (!(features & NETIF_F_HW_ESP) || x->xso.dev != skb->dev) { |
| xo->flags |= CRYPTO_FALLBACK; |
| hw_offload = false; |
| } |
| |
| esp.proto = xo->proto; |
| |
| /* skb is pure payload to encrypt */ |
| |
| aead = x->data; |
| alen = crypto_aead_authsize(aead); |
| |
| esp.tfclen = 0; |
| /* XXX: Add support for tfc padding here. */ |
| |
| blksize = ALIGN(crypto_aead_blocksize(aead), 4); |
| esp.clen = ALIGN(skb->len + 2 + esp.tfclen, blksize); |
| esp.plen = esp.clen - skb->len - esp.tfclen; |
| esp.tailen = esp.tfclen + esp.plen + alen; |
| |
| if (!hw_offload || (hw_offload && !skb_is_gso(skb))) { |
| esp.nfrags = esp6_output_head(x, skb, &esp); |
| if (esp.nfrags < 0) |
| return esp.nfrags; |
| } |
| |
| seq = xo->seq.low; |
| |
| esph = ip_esp_hdr(skb); |
| esph->spi = x->id.spi; |
| |
| skb_push(skb, -skb_network_offset(skb)); |
| |
| if (xo->flags & XFRM_GSO_SEGMENT) { |
| esph->seq_no = htonl(seq); |
| |
| if (!skb_is_gso(skb)) |
| xo->seq.low++; |
| else |
| xo->seq.low += skb_shinfo(skb)->gso_segs; |
| } |
| |
| esp.seqno = cpu_to_be64(xo->seq.low + ((u64)xo->seq.hi << 32)); |
| |
| len = skb->len - sizeof(struct ipv6hdr); |
| if (len > IPV6_MAXPLEN) |
| len = 0; |
| |
| ipv6_hdr(skb)->payload_len = htons(len); |
| |
| if (hw_offload) |
| return 0; |
| |
| err = esp6_output_tail(x, skb, &esp); |
| if (err) |
| return err; |
| |
| secpath_reset(skb); |
| |
| return 0; |
| } |
| |
| static const struct net_offload esp6_offload = { |
| .callbacks = { |
| .gro_receive = esp6_gro_receive, |
| .gso_segment = esp6_gso_segment, |
| }, |
| }; |
| |
| static const struct xfrm_type_offload esp6_type_offload = { |
| .description = "ESP6 OFFLOAD", |
| .owner = THIS_MODULE, |
| .proto = IPPROTO_ESP, |
| .input_tail = esp6_input_tail, |
| .xmit = esp6_xmit, |
| .encap = esp6_gso_encap, |
| }; |
| |
| static int __init esp6_offload_init(void) |
| { |
| if (xfrm_register_type_offload(&esp6_type_offload, AF_INET6) < 0) { |
| pr_info("%s: can't add xfrm type offload\n", __func__); |
| return -EAGAIN; |
| } |
| |
| return inet6_add_offload(&esp6_offload, IPPROTO_ESP); |
| } |
| |
| static void __exit esp6_offload_exit(void) |
| { |
| if (xfrm_unregister_type_offload(&esp6_type_offload, AF_INET6) < 0) |
| pr_info("%s: can't remove xfrm type offload\n", __func__); |
| |
| inet6_del_offload(&esp6_offload, IPPROTO_ESP); |
| } |
| |
| module_init(esp6_offload_init); |
| module_exit(esp6_offload_exit); |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>"); |
| MODULE_ALIAS_XFRM_OFFLOAD_TYPE(AF_INET6, XFRM_PROTO_ESP); |