blob: 3811f1bde84e709a132d378a2411b67616d25290 [file] [log] [blame]
// 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 += scnprintf(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 += scnprintf(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 += scnprintf(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 += scnprintf(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 sec_path *sp = skb_sec_path(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 (!sp)
return true;
if (unlikely(!sp->len)) {
netdev_err(ns->netdev, "no xfrm state len = %d\n",
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->nsim_dev_port->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);
}