diff options
Diffstat (limited to 'drivers/net/netdevsim/psp.c')
| -rw-r--r-- | drivers/net/netdevsim/psp.c | 225 |
1 files changed, 225 insertions, 0 deletions
diff --git a/drivers/net/netdevsim/psp.c b/drivers/net/netdevsim/psp.c new file mode 100644 index 000000000000..332b5b744f01 --- /dev/null +++ b/drivers/net/netdevsim/psp.c @@ -0,0 +1,225 @@ +// 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; +} |