diff options
Diffstat (limited to 'drivers/net/netdevsim/ipsec.c')
| -rw-r--r-- | drivers/net/netdevsim/ipsec.c | 297 |
1 files changed, 297 insertions, 0 deletions
diff --git a/drivers/net/netdevsim/ipsec.c b/drivers/net/netdevsim/ipsec.c new file mode 100644 index 000000000000..2dcf6cc269d0 --- /dev/null +++ b/drivers/net/netdevsim/ipsec.c @@ -0,0 +1,297 @@ +// 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); +} |