Implement the IPsec/XFRM offload API for testing.
Signed-off-by: Shannon Nelson <shannon.nelson@xxxxxxxxxx>
---
V2 - addressed formatting comments from Jakub Kicinski
drivers/net/netdevsim/Makefile | 4 +
drivers/net/netdevsim/ipsec.c | 298 ++++++++++++++++++++++++++++++++++++++
drivers/net/netdevsim/netdev.c | 7 +
drivers/net/netdevsim/netdevsim.h | 41 ++++++
4 files changed, 350 insertions(+)
create mode 100644 drivers/net/netdevsim/ipsec.c
diff --git a/drivers/net/netdevsim/Makefile b/drivers/net/netdevsim/Makefile
index 449b2a1..0fee1d0 100644
--- a/drivers/net/netdevsim/Makefile
+++ b/drivers/net/netdevsim/Makefile
@@ -13,3 +13,7 @@ endif
ifneq ($(CONFIG_NET_DEVLINK),)
netdevsim-objs += devlink.o fib.o
endif
+
+ifneq ($(CONFIG_XFRM_OFFLOAD),)
+netdevsim-objs += ipsec.o
+endif
diff --git a/drivers/net/netdevsim/ipsec.c b/drivers/net/netdevsim/ipsec.c
new file mode 100644
index 0000000..1a23426
--- /dev/null
+++ b/drivers/net/netdevsim/ipsec.c
@@ -0,0 +1,298 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright(c) 2018 Oracle and/or its affiliates. All rights reserved. */
+
+#include <crypto/aead.h>
+#include <linux/debugfs.h>
+#include <net/xfrm.h>
+
+#include "netdevsim.h"
+
+#define NSIM_IPSEC_AUTH_BITS 128
+
+static ssize_t nsim_dbg_netdev_ops_read(struct file *filp,
+ char __user *buffer,
+ size_t count, loff_t *ppos)
+{
+ struct netdevsim *ns = filp->private_data;
+ struct nsim_ipsec *ipsec = &ns->ipsec;
+ size_t bufsize;
+ char *buf, *p;
+ int len;
+ int i;
+
+ /* the buffer needed is
+ * (num SAs * 3 lines each * ~60 bytes per line) + one more line
+ */
+ bufsize = (ipsec->count * 4 * 60) + 60;
+ buf = kzalloc(bufsize, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ p = buf;
+ p += snprintf(p, bufsize - (p - buf),
+ "SA count=%u tx=%u\n",
+ ipsec->count, ipsec->tx);
+
+ for (i = 0; i < NSIM_IPSEC_MAX_SA_COUNT; i++) {
+ struct nsim_sa *sap = &ipsec->sa[i];
+
+ if (!sap->used)
+ continue;
+
+ p += snprintf(p, bufsize - (p - buf),
+ "sa[%i] %cx ipaddr=0x%08x %08x %08x %08x\n",
+ i, (sap->rx ? 'r' : 't'), sap->ipaddr[0],
+ sap->ipaddr[1], sap->ipaddr[2], sap->ipaddr[3]);
+ p += snprintf(p, bufsize - (p - buf),
+ "sa[%i] spi=0x%08x proto=0x%x salt=0x%08x crypt=%d\n",
+ i, be32_to_cpu(sap->xs->id.spi),
+ sap->xs->id.proto, sap->salt, sap->crypt);
+ p += snprintf(p, bufsize - (p - buf),
+ "sa[%i] key=0x%08x %08x %08x %08x\n",
+ i, sap->key[0], sap->key[1],
+ sap->key[2], sap->key[3]);
+ }
+
+ len = simple_read_from_buffer(buffer, count, ppos, buf, p - buf);
+
+ kfree(buf);
+ return len;
+}
+
+static const struct file_operations ipsec_dbg_fops = {
+ .owner = THIS_MODULE,
+ .open = simple_open,
+ .read = nsim_dbg_netdev_ops_read,
+};
+
+static int nsim_ipsec_find_empty_idx(struct nsim_ipsec *ipsec)
+{
+ u32 i;
+
+ if (ipsec->count == NSIM_IPSEC_MAX_SA_COUNT)
+ return -ENOSPC;
+
+ /* search sa table */
+ for (i = 0; i < NSIM_IPSEC_MAX_SA_COUNT; i++) {
+ if (!ipsec->sa[i].used)
+ return i;
+ }
+
+ return -ENOSPC;
+}
+
+static int nsim_ipsec_parse_proto_keys(struct xfrm_state *xs,
+ u32 *mykey, u32 *mysalt)
+{
+ const char aes_gcm_name[] = "rfc4106(gcm(aes))";
+ struct net_device *dev = xs->xso.dev;
+ unsigned char *key_data;
+ char *alg_name = NULL;
+ int key_len;
+
+ if (!xs->aead) {
+ netdev_err(dev, "Unsupported IPsec algorithm\n");
+ return -EINVAL;
+ }
+
+ if (xs->aead->alg_icv_len != NSIM_IPSEC_AUTH_BITS) {
+ netdev_err(dev, "IPsec offload requires %d bit authentication\n",
+ NSIM_IPSEC_AUTH_BITS);
+ return -EINVAL;
+ }
+
+ key_data = &xs->aead->alg_key[0];
+ key_len = xs->aead->alg_key_len;
+ alg_name = xs->aead->alg_name;
+
+ if (strcmp(alg_name, aes_gcm_name)) {
+ netdev_err(dev, "Unsupported IPsec algorithm - please use %s\n",
+ aes_gcm_name);
+ return -EINVAL;
+ }
+
+ /* 160 accounts for 16 byte key and 4 byte salt */
+ if (key_len > NSIM_IPSEC_AUTH_BITS) {
+ *mysalt = ((u32 *)key_data)[4];
+ } else if (key_len == NSIM_IPSEC_AUTH_BITS) {
+ *mysalt = 0;
+ } else {
+ netdev_err(dev, "IPsec hw offload only supports 128 bit keys with optional 32 bit salt\n");
+ return -EINVAL;
+ }
+ memcpy(mykey, key_data, 16);
+
+ return 0;
+}
+
+static int nsim_ipsec_add_sa(struct xfrm_state *xs)
+{
+ struct nsim_ipsec *ipsec;
+ struct net_device *dev;
+ struct netdevsim *ns;
+ struct nsim_sa sa;
+ u16 sa_idx;
+ int ret;
+
+ dev = xs->xso.dev;
+ ns = netdev_priv(dev);
+ ipsec = &ns->ipsec;
+
+ if (xs->id.proto != IPPROTO_ESP && xs->id.proto != IPPROTO_AH) {
+ netdev_err(dev, "Unsupported protocol 0x%04x for ipsec offload\n",
+ xs->id.proto);
+ return -EINVAL;
+ }
+
+ if (xs->calg) {
+ netdev_err(dev, "Compression offload not supported\n");
+ return -EINVAL;
+ }
+
+ /* find the first unused index */
+ ret = nsim_ipsec_find_empty_idx(ipsec);
+ if (ret < 0) {
+ netdev_err(dev, "No space for SA in Rx table!\n");
+ return ret;
+ }
+ sa_idx = (u16)ret;
+
+ memset(&sa, 0, sizeof(sa));
+ sa.used = true;
+ sa.xs = xs;
+
+ if (sa.xs->id.proto & IPPROTO_ESP)
+ sa.crypt = xs->ealg || xs->aead;
+
+ /* get the key and salt */
+ ret = nsim_ipsec_parse_proto_keys(xs, sa.key, &sa.salt);
+ if (ret) {
+ netdev_err(dev, "Failed to get key data for SA table\n");
+ return ret;
+ }
+
+ if (xs->xso.flags & XFRM_OFFLOAD_INBOUND) {
+ sa.rx = true;
+
+ if (xs->props.family == AF_INET6)
+ memcpy(sa.ipaddr, &xs->id.daddr.a6, 16);
+ else
+ memcpy(&sa.ipaddr[3], &xs->id.daddr.a4, 4);
+ }
+
+ /* the preparations worked, so save the info */
+ memcpy(&ipsec->sa[sa_idx], &sa, sizeof(sa));
+
+ /* the XFRM stack doesn't like offload_handle == 0,
+ * so add a bitflag in case our array index is 0
+ */
+ xs->xso.offload_handle = sa_idx | NSIM_IPSEC_VALID;
+ ipsec->count++;
+
+ return 0;
+}
+
+static void nsim_ipsec_del_sa(struct xfrm_state *xs)
+{
+ struct net_device *dev = xs->xso.dev;
+ struct netdevsim *ns = netdev_priv(dev);
+ struct nsim_ipsec *ipsec = &ns->ipsec;
+ u16 sa_idx;
+
+ sa_idx = xs->xso.offload_handle & ~NSIM_IPSEC_VALID;
+ if (!ipsec->sa[sa_idx].used) {
+ netdev_err(dev, "Invalid SA for delete sa_idx=%d\n", sa_idx);
+ return;
+ }
+
+ memset(&ipsec->sa[sa_idx], 0, sizeof(struct nsim_sa));
+ ipsec->count--;
+}
+
+static bool nsim_ipsec_offload_ok(struct sk_buff *skb, struct xfrm_state *xs)
+{
+ struct net_device *dev = xs->xso.dev;
+ struct netdevsim *ns = netdev_priv(dev);
+ struct nsim_ipsec *ipsec = &ns->ipsec;
+
+ ipsec->ok++;
+
+ return true;
+}
+
+static const struct xfrmdev_ops nsim_xfrmdev_ops = {
+ .xdo_dev_state_add = nsim_ipsec_add_sa,
+ .xdo_dev_state_delete = nsim_ipsec_del_sa,
+ .xdo_dev_offload_ok = nsim_ipsec_offload_ok,
+};
+
+bool nsim_ipsec_tx(struct netdevsim *ns, struct sk_buff *skb)
+{
+ struct nsim_ipsec *ipsec = &ns->ipsec;
+ struct xfrm_state *xs;
+ struct nsim_sa *tsa;
+ u32 sa_idx;
+
+ /* do we even need to check this packet? */
+ if (!skb->sp)
+ return true;
+
+ if (unlikely(!skb->sp->len)) {
+ netdev_err(ns->netdev, "no xfrm state len = %d\n",
+ skb->sp->len);
+ return false;
+ }
+
+ xs = xfrm_input_state(skb);
+ if (unlikely(!xs)) {
+ netdev_err(ns->netdev, "no xfrm_input_state() xs = %p\n", xs);
+ return false;
+ }
+
+ sa_idx = xs->xso.offload_handle & ~NSIM_IPSEC_VALID;
+ if (unlikely(sa_idx > NSIM_IPSEC_MAX_SA_COUNT)) {
+ netdev_err(ns->netdev, "bad sa_idx=%d max=%d\n",
+ sa_idx, NSIM_IPSEC_MAX_SA_COUNT);
+ return false;
+ }
+
+ tsa = &ipsec->sa[sa_idx];
+ if (unlikely(!tsa->used)) {
+ netdev_err(ns->netdev, "unused sa_idx=%d\n", sa_idx);
+ return false;
+ }
+
+ if (xs->id.proto != IPPROTO_ESP && xs->id.proto != IPPROTO_AH) {
+ netdev_err(ns->netdev, "unexpected proto=%d\n", xs->id.proto);
+ return false;
+ }
+
+ ipsec->tx++;
+
+ return true;
+}
+
+void nsim_ipsec_init(struct netdevsim *ns)
+{
+ ns->netdev->xfrmdev_ops = &nsim_xfrmdev_ops;
+
+#define NSIM_ESP_FEATURES (NETIF_F_HW_ESP | \
+ NETIF_F_HW_ESP_TX_CSUM | \
+ NETIF_F_GSO_ESP)
+
+ ns->netdev->features |= NSIM_ESP_FEATURES;
+ ns->netdev->hw_enc_features |= NSIM_ESP_FEATURES;
+
+ ns->ipsec.pfile = debugfs_create_file("ipsec", 0400, ns->ddir, ns,
+ &ipsec_dbg_fops);
+}
+
+void nsim_ipsec_teardown(struct netdevsim *ns)
+{
+ struct nsim_ipsec *ipsec = &ns->ipsec;
+
+ if (ipsec->count)
+ netdev_err(ns->netdev, "tearing down IPsec offload with %d SAs left\n",
+ ipsec->count);
+ debugfs_remove_recursive(ipsec->pfile);
+}
diff --git a/drivers/net/netdevsim/netdev.c b/drivers/net/netdevsim/netdev.c
index ec68f38..6ce8604d 100644
--- a/drivers/net/netdevsim/netdev.c
+++ b/drivers/net/netdevsim/netdev.c
@@ -171,6 +171,8 @@ static int nsim_init(struct net_device *dev)
if (err)
goto err_unreg_dev;
+ nsim_ipsec_init(ns);
+
return 0;
err_unreg_dev:
@@ -186,6 +188,7 @@ static void nsim_uninit(struct net_device *dev)
{
struct netdevsim *ns = netdev_priv(dev);
+ nsim_ipsec_teardown(ns);
nsim_devlink_teardown(ns);
debugfs_remove_recursive(ns->ddir);
nsim_bpf_uninit(ns);
@@ -203,11 +206,15 @@ static netdev_tx_t nsim_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct netdevsim *ns = netdev_priv(dev);
+ if (!nsim_ipsec_tx(ns, skb))
+ goto out;
+
u64_stats_update_begin(&ns->syncp);
ns->tx_packets++;
ns->tx_bytes += skb->len;
u64_stats_update_end(&ns->syncp);
+out:
dev_kfree_skb(skb);
return NETDEV_TX_OK;
diff --git a/drivers/net/netdevsim/netdevsim.h b/drivers/net/netdevsim/netdevsim.h
index 3a8581a..29448e8 100644
--- a/drivers/net/netdevsim/netdevsim.h
+++ b/drivers/net/netdevsim/netdevsim.h
@@ -29,6 +29,27 @@ struct bpf_prog;
struct dentry;
struct nsim_vf_config;
+#define NSIM_IPSEC_MAX_SA_COUNT 33
+#define NSIM_IPSEC_VALID BIT(31)
+
+struct nsim_sa {
+ struct xfrm_state *xs;
+ __be32 ipaddr[4];
+ u32 key[4];
+ u32 salt;
+ bool used;
+ bool crypt;
+ bool rx;
+};
+
+struct nsim_ipsec {
+ struct nsim_sa sa[NSIM_IPSEC_MAX_SA_COUNT];
+ struct dentry *pfile;
+ u32 count;
+ u32 tx;
+ u32 ok;
+};
+
struct netdevsim {
struct net_device *netdev;
@@ -67,6 +88,7 @@ struct netdevsim {
#if IS_ENABLED(CONFIG_NET_DEVLINK)
struct devlink *devlink;
#endif
+ struct nsim_ipsec ipsec;
};
extern struct dentry *nsim_ddir;
@@ -147,6 +169,25 @@ static inline void nsim_devlink_exit(void)
}
#endif
+#if IS_ENABLED(CONFIG_XFRM_OFFLOAD)
+void nsim_ipsec_init(struct netdevsim *ns);
+void nsim_ipsec_teardown(struct netdevsim *ns);
+bool nsim_ipsec_tx(struct netdevsim *ns, struct sk_buff *skb);
+#else
+static inline void nsim_ipsec_init(struct netdevsim *ns)
+{
+}
+
+static inline void nsim_ipsec_teardown(struct netdevsim *ns)
+{
+}
+
+static inline bool nsim_ipsec_tx(struct netdevsim *ns, struct sk_buff *skb)
+{
+ return true;
+}
+#endif
+
static inline struct netdevsim *to_nsim(struct device *ptr)
{
return container_of(ptr, struct netdevsim, dev);
--
2.7.4
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