From a9e3760b0838299649c0d57cca44daaf40ba3c33 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 14 Sep 2026 22:12:34 -1000 Subject: sched_ext: Maintain an online cid mask in the scheduler arena Schedulers on the default cid mapping treat [0, nr_online_cids) as the online set and restart on hotplug. Schedulers that install their own mapping with scx_bpf_cid_override() have no way to learn which cids are online: the count no longer identifies members and the CPU-form cpumask is unusable from cid programs. This is an obvious hole in the cid API. Add scx_bpf_online_cmask(), a kernel-maintained cmask in the scheduler's arena, allocated alongside the per-CPU scratch masks and populated after the cid mapping is finalized and before ops.init(), for child schedulers too. The pointer stays valid through ops.exit() with no reference to take. It is the arena offset as a void pointer, the same form struct_ops arena arguments arrive in. The verifier types the void return as a scalar for the program's arena cast. The mask follows the SCX hotplug notifications: seeded from cpu_active_mask and updated before ops.cid_online/offline() runs, so it lags cpu_online_mask only inside a hotplug transition. Updates walk the scheduler list under the lock that also serializes unlinking. Reads are live, not atomic snapshots. Root initialization excludes hotplug. v2: Reworded the getter kerneldoc (Andrea Righi). Signed-off-by: Tejun Heo Reviewed-by: Andrea Righi --- drivers/net/netdevsim/ipsec.c | 296 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 296 insertions(+) create mode 100644 drivers/net/netdevsim/ipsec.c (limited to 'drivers/net/netdevsim/ipsec.c') diff --git a/drivers/net/netdevsim/ipsec.c b/drivers/net/netdevsim/ipsec.c new file mode 100644 index 000000000..36a1be492 --- /dev/null +++ b/drivers/net/netdevsim/ipsec.c @@ -0,0 +1,296 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright(c) 2018 Oracle and/or its affiliates. All rights reserved. */ + +#include +#include +#include + +#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; + + if (sap->xs->props.family == AF_INET6) + p += scnprintf(p, bufsize - (p - buf), + "sa[%i] %cx ipaddr=%pI6c\n", + i, (sap->rx ? 'r' : 't'), &sap->ipaddr); + else + p += scnprintf(p, bufsize - (p - buf), + "sa[%i] %cx ipaddr=%pI4\n", + i, (sap->rx ? 'r' : 't'), &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 net_device *dev, + struct xfrm_state *xs, + u32 *mykey, u32 *mysalt) +{ + const char aes_gcm_name[] = "rfc4106(gcm(aes))"; + 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 net_device *dev, + struct xfrm_state *xs, + struct netlink_ext_ack *extack) +{ + struct nsim_ipsec *ipsec; + struct netdevsim *ns; + struct nsim_sa sa; + u16 sa_idx; + int ret; + + ns = netdev_priv(dev); + ipsec = &ns->ipsec; + + if (xs->id.proto != IPPROTO_ESP && xs->id.proto != IPPROTO_AH) { + NL_SET_ERR_MSG_MOD(extack, "Unsupported protocol for ipsec offload"); + return -EINVAL; + } + + if (xs->calg) { + NL_SET_ERR_MSG_MOD(extack, "Compression offload not supported"); + return -EINVAL; + } + + if (xs->xso.type != XFRM_DEV_OFFLOAD_CRYPTO) { + NL_SET_ERR_MSG_MOD(extack, "Unsupported ipsec offload type"); + return -EINVAL; + } + + /* find the first unused index */ + ret = nsim_ipsec_find_empty_idx(ipsec); + if (ret < 0) { + NL_SET_ERR_MSG_MOD(extack, "No space for SA in Rx table!"); + 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(dev, xs, sa.key, &sa.salt); + if (ret) { + NL_SET_ERR_MSG_MOD(extack, "Failed to get key data for SA table"); + return ret; + } + + if (xs->xso.dir == XFRM_DEV_OFFLOAD_IN) + 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 net_device *dev, struct xfrm_state *xs) +{ + struct netdevsim *ns = netdev_priv(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 const struct xfrmdev_ops nsim_xfrmdev_ops = { + .xdo_dev_state_add = nsim_ipsec_add_sa, + .xdo_dev_state_delete = nsim_ipsec_del_sa, +}; + +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_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); +} -- cgit v1.3.1