From 4d8b9319282ae84f5a17b28d8b5b5d1e7e537312 Mon Sep 17 00:00:00 2001 From: Matt Johnston Date: Thu, 29 Jul 2021 10:20:47 +0800 Subject: [PATCH] mctp: Add neighbour implementation Add an initial neighbour table implementation, to be used in the route output path. Signed-off-by: Matt Johnston Signed-off-by: David S. Miller --- include/net/mctp.h | 25 +++++++++ include/net/mctpdevice.h | 1 + include/net/netns/mctp.h | 4 ++ net/mctp/Makefile | 2 +- net/mctp/af_mctp.c | 5 ++ net/mctp/device.c | 1 + net/mctp/neigh.c | 141 +++++++++++++++++++++++++++++++++++++++++++++++ 7 files changed, 178 insertions(+), 1 deletion(-) create mode 100644 net/mctp/neigh.c diff --git a/include/net/mctp.h b/include/net/mctp.h index bc36e37e8198..53f035c8b59c 100644 --- a/include/net/mctp.h +++ b/include/net/mctp.h @@ -117,6 +117,31 @@ int mctp_route_add_local(struct mctp_dev *mdev, mctp_eid_t addr); int mctp_route_remove_local(struct mctp_dev *mdev, mctp_eid_t addr); void mctp_route_remove_dev(struct mctp_dev *mdev); +/* neighbour definitions */ +enum mctp_neigh_source { + MCTP_NEIGH_STATIC, + MCTP_NEIGH_DISCOVER, +}; + +struct mctp_neigh { + struct mctp_dev *dev; + mctp_eid_t eid; + enum mctp_neigh_source source; + + unsigned char ha[MAX_ADDR_LEN]; + + struct list_head list; + struct rcu_head rcu; +}; + +int mctp_neigh_init(void); +void mctp_neigh_exit(void); + +// ret_hwaddr may be NULL, otherwise must have space for MAX_ADDR_LEN +int mctp_neigh_lookup(struct mctp_dev *dev, mctp_eid_t eid, + void *ret_hwaddr); +void mctp_neigh_remove_dev(struct mctp_dev *mdev); + int mctp_routes_init(void); void mctp_routes_exit(void); diff --git a/include/net/mctpdevice.h b/include/net/mctpdevice.h index 71a11012fac7..57e773ff08bb 100644 --- a/include/net/mctpdevice.h +++ b/include/net/mctpdevice.h @@ -31,5 +31,6 @@ struct mctp_dev { struct mctp_dev *mctp_dev_get_rtnl(const struct net_device *dev); struct mctp_dev *__mctp_dev_get(const struct net_device *dev); +struct mctp_dev *mctp_dev_get_rtnl(const struct net_device *dev); #endif /* __NET_MCTPDEVICE_H */ diff --git a/include/net/netns/mctp.h b/include/net/netns/mctp.h index 508459b08a59..2f5ebeeb320e 100644 --- a/include/net/netns/mctp.h +++ b/include/net/netns/mctp.h @@ -11,6 +11,10 @@ struct netns_mctp { /* Only updated under RTNL, entries freed via RCU */ struct list_head routes; + + /* neighbour table */ + struct mutex neigh_lock; + struct list_head neighbours; }; #endif /* __NETNS_MCTP_H__ */ diff --git a/net/mctp/Makefile b/net/mctp/Makefile index b1a330e9d82a..0171333384d7 100644 --- a/net/mctp/Makefile +++ b/net/mctp/Makefile @@ -1,3 +1,3 @@ # SPDX-License-Identifier: GPL-2.0 obj-$(CONFIG_MCTP) += mctp.o -mctp-objs := af_mctp.o device.o route.o +mctp-objs := af_mctp.o device.o route.o neigh.o diff --git a/net/mctp/af_mctp.c b/net/mctp/af_mctp.c index 8085f5912101..58701e6b282c 100644 --- a/net/mctp/af_mctp.c +++ b/net/mctp/af_mctp.c @@ -161,6 +161,10 @@ static __init int mctp_init(void) if (rc) goto err_unreg_proto; + rc = mctp_neigh_init(); + if (rc) + goto err_unreg_proto; + mctp_device_init(); return 0; @@ -176,6 +180,7 @@ err_unreg_sock: static __exit void mctp_exit(void) { mctp_device_exit(); + mctp_neigh_exit(); mctp_routes_exit(); proto_unregister(&mctp_proto); sock_unregister(PF_MCTP); diff --git a/net/mctp/device.c b/net/mctp/device.c index 5f1b18c17351..aa049590acda 100644 --- a/net/mctp/device.c +++ b/net/mctp/device.c @@ -342,6 +342,7 @@ static void mctp_unregister(struct net_device *dev) RCU_INIT_POINTER(mdev->dev->mctp_ptr, NULL); mctp_route_remove_dev(mdev); + mctp_neigh_remove_dev(mdev); kfree(mdev->addrs); mctp_dev_destroy(mdev); diff --git a/net/mctp/neigh.c b/net/mctp/neigh.c new file mode 100644 index 000000000000..8603f0c45a8f --- /dev/null +++ b/net/mctp/neigh.c @@ -0,0 +1,141 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Management Component Transport Protocol (MCTP) - routing + * implementation. + * + * This is currently based on a simple routing table, with no dst cache. The + * number of routes should stay fairly small, so the lookup cost is small. + * + * Copyright (c) 2021 Code Construct + * Copyright (c) 2021 Google + */ + +#include +#include +#include +#include +#include + +#include +#include +#include +#include + +static int __always_unused mctp_neigh_add(struct mctp_dev *mdev, mctp_eid_t eid, + enum mctp_neigh_source source, + size_t lladdr_len, const void *lladdr) +{ + struct net *net = dev_net(mdev->dev); + struct mctp_neigh *neigh; + int rc; + + mutex_lock(&net->mctp.neigh_lock); + if (mctp_neigh_lookup(mdev, eid, NULL) == 0) { + rc = -EEXIST; + goto out; + } + + if (lladdr_len > sizeof(neigh->ha)) { + rc = -EINVAL; + goto out; + } + + neigh = kzalloc(sizeof(*neigh), GFP_KERNEL); + if (!neigh) { + rc = -ENOMEM; + goto out; + } + INIT_LIST_HEAD(&neigh->list); + neigh->dev = mdev; + dev_hold(neigh->dev->dev); + neigh->eid = eid; + neigh->source = source; + memcpy(neigh->ha, lladdr, lladdr_len); + + list_add_rcu(&neigh->list, &net->mctp.neighbours); + rc = 0; +out: + mutex_unlock(&net->mctp.neigh_lock); + return rc; +} + +static void __mctp_neigh_free(struct rcu_head *rcu) +{ + struct mctp_neigh *neigh = container_of(rcu, struct mctp_neigh, rcu); + + dev_put(neigh->dev->dev); + kfree(neigh); +} + +/* Removes all neighbour entries referring to a device */ +void mctp_neigh_remove_dev(struct mctp_dev *mdev) +{ + struct net *net = dev_net(mdev->dev); + struct mctp_neigh *neigh, *tmp; + + mutex_lock(&net->mctp.neigh_lock); + list_for_each_entry_safe(neigh, tmp, &net->mctp.neighbours, list) { + if (neigh->dev == mdev) { + list_del_rcu(&neigh->list); + /* TODO: immediate RTM_DELNEIGH */ + call_rcu(&neigh->rcu, __mctp_neigh_free); + } + } + + mutex_unlock(&net->mctp.neigh_lock); +} + +int mctp_neigh_lookup(struct mctp_dev *mdev, mctp_eid_t eid, void *ret_hwaddr) +{ + struct net *net = dev_net(mdev->dev); + struct mctp_neigh *neigh; + int rc = -EHOSTUNREACH; // TODO: or ENOENT? + + rcu_read_lock(); + list_for_each_entry_rcu(neigh, &net->mctp.neighbours, list) { + if (mdev == neigh->dev && eid == neigh->eid) { + if (ret_hwaddr) + memcpy(ret_hwaddr, neigh->ha, + sizeof(neigh->ha)); + rc = 0; + break; + } + } + rcu_read_unlock(); + return rc; +} + +/* namespace registration */ +static int __net_init mctp_neigh_net_init(struct net *net) +{ + struct netns_mctp *ns = &net->mctp; + + INIT_LIST_HEAD(&ns->neighbours); + return 0; +} + +static void __net_exit mctp_neigh_net_exit(struct net *net) +{ + struct netns_mctp *ns = &net->mctp; + struct mctp_neigh *neigh; + + list_for_each_entry(neigh, &ns->neighbours, list) + call_rcu(&neigh->rcu, __mctp_neigh_free); +} + +/* net namespace implementation */ + +static struct pernet_operations mctp_net_ops = { + .init = mctp_neigh_net_init, + .exit = mctp_neigh_net_exit, +}; + +int __init mctp_neigh_init(void) +{ + return register_pernet_subsys(&mctp_net_ops); +} + +void __exit mctp_neigh_exit(void) +{ + unregister_pernet_subsys(&mctp_net_ops); +} -- 2.11.0