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Diffstat (limited to 'net/ipv4/esp4_offload.c')
-rw-r--r--net/ipv4/esp4_offload.c386
1 files changed, 386 insertions, 0 deletions
diff --git a/net/ipv4/esp4_offload.c b/net/ipv4/esp4_offload.c
new file mode 100644
index 0000000000..10e96ed6c9
--- /dev/null
+++ b/net/ipv4/esp4_offload.c
@@ -0,0 +1,386 @@
+// 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/gso.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");