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// SPDX-License-Identifier: GPL-2.0
#include <linux/ip.h>
#include <linux/skbuff.h>
#include <net/ip6_checksum.h>
#include <net/psp.h>
#include <net/sock.h>
#include "netdevsim.h"
void nsim_psp_handle_ext(struct sk_buff *skb, struct skb_ext *psp_ext)
{
if (psp_ext)
__skb_ext_set(skb, SKB_EXT_PSP, psp_ext);
}
enum skb_drop_reason
nsim_do_psp(struct sk_buff *skb, struct netdevsim *ns,
struct netdevsim *peer_ns, struct skb_ext **psp_ext)
{
enum skb_drop_reason rc = 0;
struct psp_assoc *pas;
struct net *net;
void **ptr;
rcu_read_lock();
pas = psp_skb_get_assoc_rcu(skb);
if (!pas) {
rc = SKB_NOT_DROPPED_YET;
goto out_unlock;
}
if (!skb_transport_header_was_set(skb)) {
rc = SKB_DROP_REASON_PSP_OUTPUT;
goto out_unlock;
}
ptr = psp_assoc_drv_data(pas);
if (*ptr != ns) {
rc = SKB_DROP_REASON_PSP_OUTPUT;
goto out_unlock;
}
net = sock_net(skb->sk);
if (!psp_dev_encapsulate(net, skb, pas->tx.spi, pas->version, 0)) {
rc = SKB_DROP_REASON_PSP_OUTPUT;
goto out_unlock;
}
/* Now pretend we just received this frame */
if (peer_ns->psp.dev->config.versions & (1 << pas->version)) {
bool strip_icv = false;
u8 generation;
/* We cheat a bit and put the generation in the key.
* In real life if generation was too old, then decryption would
* fail. Here, we just make it so a bad key causes a bad
* generation too, and psp_sk_rx_policy_check() will fail.
*/
generation = pas->tx.key[0];
skb_ext_reset(skb);
skb->mac_len = ETH_HLEN;
if (psp_dev_rcv(skb, peer_ns->psp.dev->id, generation,
strip_icv)) {
rc = SKB_DROP_REASON_PSP_OUTPUT;
goto out_unlock;
}
*psp_ext = skb->extensions;
refcount_inc(&(*psp_ext)->refcnt);
skb->decrypted = 1;
} else {
struct ipv6hdr *ip6h __maybe_unused;
struct iphdr *iph;
struct udphdr *uh;
__wsum csum;
/* Do not decapsulate. Receive the skb with the udp and psp
* headers still there as if this is a normal udp packet.
* psp_dev_encapsulate() sets udp checksum to 0, so we need to
* provide a valid checksum here, so the skb isn't dropped.
*/
uh = udp_hdr(skb);
csum = skb_checksum(skb, skb_transport_offset(skb),
ntohs(uh->len), 0);
switch (skb->protocol) {
case htons(ETH_P_IP):
iph = ip_hdr(skb);
uh->check = udp_v4_check(ntohs(uh->len), iph->saddr,
iph->daddr, csum);
break;
#if IS_ENABLED(CONFIG_IPV6)
case htons(ETH_P_IPV6):
ip6h = ipv6_hdr(skb);
uh->check = udp_v6_check(ntohs(uh->len), &ip6h->saddr,
&ip6h->daddr, csum);
break;
#endif
}
uh->check = uh->check ?: CSUM_MANGLED_0;
skb->ip_summed = CHECKSUM_NONE;
}
out_unlock:
rcu_read_unlock();
return rc;
}
static int
nsim_psp_set_config(struct psp_dev *psd, struct psp_dev_config *conf,
struct netlink_ext_ack *extack)
{
return 0;
}
static int
nsim_rx_spi_alloc(struct psp_dev *psd, u32 version,
struct psp_key_parsed *assoc,
struct netlink_ext_ack *extack)
{
struct netdevsim *ns = psd->drv_priv;
unsigned int new;
int i;
new = ++ns->psp.spi & PSP_SPI_KEY_ID;
if (psd->generation & 1)
new |= PSP_SPI_KEY_PHASE;
assoc->spi = cpu_to_be32(new);
assoc->key[0] = psd->generation;
for (i = 1; i < PSP_MAX_KEY; i++)
assoc->key[i] = ns->psp.spi + i;
return 0;
}
static int nsim_assoc_add(struct psp_dev *psd, struct psp_assoc *pas,
struct netlink_ext_ack *extack)
{
struct netdevsim *ns = psd->drv_priv;
void **ptr = psp_assoc_drv_data(pas);
/* Copy drv_priv from psd to assoc */
*ptr = psd->drv_priv;
ns->psp.assoc_cnt++;
return 0;
}
static int nsim_key_rotate(struct psp_dev *psd, struct netlink_ext_ack *extack)
{
return 0;
}
static void nsim_assoc_del(struct psp_dev *psd, struct psp_assoc *pas)
{
struct netdevsim *ns = psd->drv_priv;
void **ptr = psp_assoc_drv_data(pas);
*ptr = NULL;
ns->psp.assoc_cnt--;
}
static struct psp_dev_ops nsim_psp_ops = {
.set_config = nsim_psp_set_config,
.rx_spi_alloc = nsim_rx_spi_alloc,
.tx_key_add = nsim_assoc_add,
.tx_key_del = nsim_assoc_del,
.key_rotate = nsim_key_rotate,
};
static struct psp_dev_caps nsim_psp_caps = {
.versions = 1 << PSP_VERSION_HDR0_AES_GCM_128 |
1 << PSP_VERSION_HDR0_AES_GMAC_128 |
1 << PSP_VERSION_HDR0_AES_GCM_256 |
1 << PSP_VERSION_HDR0_AES_GMAC_256,
.assoc_drv_spc = sizeof(void *),
};
void nsim_psp_uninit(struct netdevsim *ns)
{
if (!IS_ERR(ns->psp.dev))
psp_dev_unregister(ns->psp.dev);
WARN_ON(ns->psp.assoc_cnt);
}
static ssize_t
nsim_psp_rereg_write(struct file *file, const char __user *data, size_t count,
loff_t *ppos)
{
struct netdevsim *ns = file->private_data;
int err;
nsim_psp_uninit(ns);
ns->psp.dev = psp_dev_create(ns->netdev, &nsim_psp_ops,
&nsim_psp_caps, ns);
err = PTR_ERR_OR_ZERO(ns->psp.dev);
return err ?: count;
}
static const struct file_operations nsim_psp_rereg_fops = {
.open = simple_open,
.write = nsim_psp_rereg_write,
.llseek = generic_file_llseek,
.owner = THIS_MODULE,
};
int nsim_psp_init(struct netdevsim *ns)
{
struct dentry *ddir = ns->nsim_dev_port->ddir;
int err;
ns->psp.dev = psp_dev_create(ns->netdev, &nsim_psp_ops,
&nsim_psp_caps, ns);
err = PTR_ERR_OR_ZERO(ns->psp.dev);
if (err)
return err;
debugfs_create_file("psp_rereg", 0200, ddir, ns, &nsim_psp_rereg_fops);
return 0;
}
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