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Commit 7699353d authored by Shannon Nelson's avatar Shannon Nelson Committed by David S. Miller
Browse files

netdevsim: add ipsec offload testing 



Implement the IPsec/XFRM offload API for testing.

Signed-off-by: default avatarShannon Nelson <shannon.nelson@oracle.com>
Reviewed-by: default avatarJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c3eba0a4

drivers/net/netdevsim/Makefile

+4 −0
Original line number Diff line number Diff line
@@ -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

drivers/net/netdevsim/ipsec.c

0 → 100644
+297 −0
Original line number Diff line number Diff line 
// 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 netdevsim *ns = netdev_priv(xs->xso.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(ns->netdev, "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 netdevsim *ns = netdev_priv(xs->xso.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);

}

drivers/net/netdevsim/netdev.c

+7 −0
Original line number Diff line number Diff line
@@ -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;

drivers/net/netdevsim/netdevsim.h

+41 −0
Original line number Diff line number Diff line
@@ -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;
@@ -148,6 +170,25 @@ 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);