diff options
Diffstat (limited to '')
-rw-r--r-- | net/ipv4/esp4_offload.c | 385 |
1 files changed, 385 insertions, 0 deletions
diff --git a/net/ipv4/esp4_offload.c b/net/ipv4/esp4_offload.c new file mode 100644 index 000000000..ee848be59 --- /dev/null +++ b/net/ipv4/esp4_offload.c @@ -0,0 +1,385 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * IPV4 GSO/GRO offload support + * Linux INET implementation + * + * Copyright (C) 2016 secunet Security Networks AG + * Author: Steffen Klassert <steffen.klassert@secunet.com> + * + * 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/gro.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/udp.h> + +static struct sk_buff *esp4_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; + + if (!pskb_pull(skb, offset)) + return NULL; + + if (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 *)&ip_hdr(skb)->daddr, + spi, IPPROTO_ESP, AF_INET); + if (!x) + goto out_reset; + + skb->mark = xfrm_smark_get(skb->mark, x); + + sp->xvec[sp->len++] = x; + sp->olen++; + + xo = xfrm_offload(skb); + if (!xo) + goto out_reset; + } + + xo->flags |= XFRM_GRO; + + XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = NULL; + XFRM_SPI_SKB_CB(skb)->family = AF_INET; + XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, 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 esp4_gso_encap(struct xfrm_state *x, struct sk_buff *skb) +{ + struct ip_esp_hdr *esph; + struct iphdr *iph = ip_hdr(skb); + struct xfrm_offload *xo = xfrm_offload(skb); + int proto = iph->protocol; + + 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 *xfrm4_tunnel_gso_segment(struct xfrm_state *x, + struct sk_buff *skb, + netdev_features_t features) +{ + __be16 type = x->inner_mode.family == AF_INET6 ? htons(ETH_P_IPV6) + : htons(ETH_P_IP); + + return skb_eth_gso_segment(skb, features, type); +} + +static struct sk_buff *xfrm4_transport_gso_segment(struct xfrm_state *x, + struct sk_buff *skb, + netdev_features_t features) +{ + const struct net_offload *ops; + struct sk_buff *segs = ERR_PTR(-EINVAL); + struct xfrm_offload *xo = xfrm_offload(skb); + + skb->transport_header += x->props.header_len; + ops = rcu_dereference(inet_offloads[xo->proto]); + if (likely(ops && ops->callbacks.gso_segment)) + segs = ops->callbacks.gso_segment(skb, features); + + return segs; +} + +static struct sk_buff *xfrm4_beet_gso_segment(struct xfrm_state *x, + struct sk_buff *skb, + netdev_features_t features) +{ + struct xfrm_offload *xo = xfrm_offload(skb); + struct sk_buff *segs = ERR_PTR(-EINVAL); + const struct net_offload *ops; + u8 proto = xo->proto; + + skb->transport_header += x->props.header_len; + + if (x->sel.family != AF_INET6) { + if (proto == IPPROTO_BEETPH) { + struct ip_beet_phdr *ph = + (struct ip_beet_phdr *)skb->data; + + skb->transport_header += ph->hdrlen * 8; + proto = ph->nexthdr; + } else { + skb->transport_header -= IPV4_BEET_PHMAXLEN; + } + } else { + __be16 frag; + + skb->transport_header += + ipv6_skip_exthdr(skb, 0, &proto, &frag); + if (proto == IPPROTO_TCP) + skb_shinfo(skb)->gso_type |= SKB_GSO_TCPV4; + } + + if (proto == IPPROTO_IPV6) + skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP4; + + __skb_pull(skb, skb_transport_offset(skb)); + ops = rcu_dereference(inet_offloads[proto]); + if (likely(ops && ops->callbacks.gso_segment)) + segs = ops->callbacks.gso_segment(skb, features); + + return segs; +} + +static struct sk_buff *xfrm4_outer_mode_gso_segment(struct xfrm_state *x, + struct sk_buff *skb, + netdev_features_t features) +{ + switch (x->outer_mode.encap) { + case XFRM_MODE_TUNNEL: + return xfrm4_tunnel_gso_segment(x, skb, features); + case XFRM_MODE_TRANSPORT: + return xfrm4_transport_gso_segment(x, skb, features); + case XFRM_MODE_BEET: + return xfrm4_beet_gso_segment(x, skb, features); + } + + return ERR_PTR(-EOPNOTSUPP); +} + +static struct sk_buff *esp4_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 ((!(skb->dev->gso_partial_features & NETIF_F_HW_ESP) && + !(features & NETIF_F_HW_ESP)) || x->xso.dev != skb->dev) + esp_features = features & ~(NETIF_F_SG | NETIF_F_CSUM_MASK | + NETIF_F_SCTP_CRC); + else if (!(features & NETIF_F_HW_ESP_TX_CSUM) && + !(skb->dev->gso_partial_features & NETIF_F_HW_ESP_TX_CSUM)) + esp_features = features & ~(NETIF_F_CSUM_MASK | + NETIF_F_SCTP_CRC); + + xo->flags |= XFRM_GSO_SEGMENT; + + return xfrm4_outer_mode_gso_segment(x, skb, esp_features); +} + +static int esp_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 esp_input_done2(skb, 0); +} + +static int esp_xmit(struct xfrm_state *x, struct sk_buff *skb, netdev_features_t features) +{ + 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) && + !(skb->dev->gso_partial_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; + + esp.esph = ip_esp_hdr(skb); + + + if (!hw_offload || !skb_is_gso(skb)) { + esp.nfrags = esp_output_head(x, skb, &esp); + if (esp.nfrags < 0) + return esp.nfrags; + } + + seq = xo->seq.low; + + esph = esp.esph; + 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; + } + + if (xo->seq.low < seq) + xo->seq.hi++; + + esp.seqno = cpu_to_be64(seq + ((u64)xo->seq.hi << 32)); + + ip_hdr(skb)->tot_len = htons(skb->len); + ip_send_check(ip_hdr(skb)); + + if (hw_offload) { + if (!skb_ext_add(skb, SKB_EXT_SEC_PATH)) + return -ENOMEM; + + xo = xfrm_offload(skb); + if (!xo) + return -EINVAL; + + xo->flags |= XFRM_XMIT; + return 0; + } + + err = esp_output_tail(x, skb, &esp); + if (err) + return err; + + secpath_reset(skb); + + if (skb_needs_linearize(skb, skb->dev->features) && + __skb_linearize(skb)) + return -ENOMEM; + return 0; +} + +static const struct net_offload esp4_offload = { + .callbacks = { + .gro_receive = esp4_gro_receive, + .gso_segment = esp4_gso_segment, + }, +}; + +static const struct xfrm_type_offload esp_type_offload = { + .owner = THIS_MODULE, + .proto = IPPROTO_ESP, + .input_tail = esp_input_tail, + .xmit = esp_xmit, + .encap = esp4_gso_encap, +}; + +static int __init esp4_offload_init(void) +{ + if (xfrm_register_type_offload(&esp_type_offload, AF_INET) < 0) { + pr_info("%s: can't add xfrm type offload\n", __func__); + return -EAGAIN; + } + + return inet_add_offload(&esp4_offload, IPPROTO_ESP); +} + +static void __exit esp4_offload_exit(void) +{ + xfrm_unregister_type_offload(&esp_type_offload, AF_INET); + inet_del_offload(&esp4_offload, IPPROTO_ESP); +} + +module_init(esp4_offload_init); +module_exit(esp4_offload_exit); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>"); +MODULE_ALIAS_XFRM_OFFLOAD_TYPE(AF_INET, XFRM_PROTO_ESP); +MODULE_DESCRIPTION("IPV4 GSO/GRO offload support"); |