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Message-Id: <20180901004954.7145-12-dsahern@kernel.org>
Date: Fri, 31 Aug 2018 17:49:46 -0700
From: dsahern@...nel.org
To: netdev@...r.kernel.org
Cc: roopa@...ulusnetworks.com, sharpd@...ulusnetworks.com,
idosch@...lanox.com, davem@...emloft.net,
David Ahern <dsahern@...il.com>
Subject: [PATCH RFC net-next 11/18] net: Initial nexthop code
From: David Ahern <dsahern@...il.com>
Initial import of nexthop code.
- Add new RTM commands for nexthop objects.
- Add new uapi attributes for creating nexthops. Attributes are similar
to the current nexthop attributes for routes.
- Add basic helpers for ipv4 and ipv6 references to nexthop data
Similar to routes nexthops are configured per namespace, so add
netns_nexthop struct and add it to struct net.
Signed-off-by: David Ahern <dsahern@...il.com>
---
include/net/net_namespace.h | 2 +
include/net/netns/nexthop.h | 18 +
include/net/nexthop.h | 121 +++++
include/uapi/linux/nexthop.h | 56 +++
include/uapi/linux/rtnetlink.h | 7 +
net/ipv4/Makefile | 2 +-
net/ipv4/nexthop.c | 1080 ++++++++++++++++++++++++++++++++++++++++
security/selinux/nlmsgtab.c | 5 +-
8 files changed, 1289 insertions(+), 2 deletions(-)
create mode 100644 include/net/netns/nexthop.h
create mode 100644 include/net/nexthop.h
create mode 100644 include/uapi/linux/nexthop.h
create mode 100644 net/ipv4/nexthop.c
diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
index 9b5fdc50519a..d3d678814b93 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -19,6 +19,7 @@
#include <net/netns/packet.h>
#include <net/netns/ipv4.h>
#include <net/netns/ipv6.h>
+#include <net/netns/nexthop.h>
#include <net/netns/ieee802154_6lowpan.h>
#include <net/netns/sctp.h>
#include <net/netns/dccp.h>
@@ -105,6 +106,7 @@ struct net {
struct netns_mib mib;
struct netns_packet packet;
struct netns_unix unx;
+ struct netns_nexthop nexthop;
struct netns_ipv4 ipv4;
#if IS_ENABLED(CONFIG_IPV6)
struct netns_ipv6 ipv6;
diff --git a/include/net/netns/nexthop.h b/include/net/netns/nexthop.h
new file mode 100644
index 000000000000..91627c35e9d3
--- /dev/null
+++ b/include/net/netns/nexthop.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * nexthops in net namespaces
+ */
+
+#ifndef __NETNS_NEXTHOP_H__
+#define __NETNS_NEXTHOP_H__
+
+#include <linux/rbtree.h>
+
+struct netns_nexthop {
+ struct rb_root root; /* tree of nexthops by id */
+ struct hlist_head *devhash; /* nexthops by device */
+
+ unsigned int seq; /* protected by rtnl_mutex */
+ u32 last_id_allocated;
+};
+#endif
diff --git a/include/net/nexthop.h b/include/net/nexthop.h
new file mode 100644
index 000000000000..1c59d04d1da6
--- /dev/null
+++ b/include/net/nexthop.h
@@ -0,0 +1,121 @@
+/*
+ * Generic nexthop implementation
+ *
+ * Copyright (C) 2017-18 Cumulus Networks
+ * Copyright (c) 2017-18 David Ahern <dsa@...ulusnetworks.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef __LINUX_NEXTHOP_H
+#define __LINUX_NEXTHOP_H
+
+#include <linux/netdevice.h>
+#include <linux/types.h>
+#include <net/ip_fib.h>
+#include <net/ip6_fib.h>
+#include <net/netlink.h>
+
+#define NEXTHOP_VALID_USER_FLAGS RTNH_F_ONLINK
+
+struct nexthop;
+
+struct nh_info {
+ struct hlist_node dev_hash;
+ struct net *net;
+ struct nexthop *nh_parent;
+
+ u8 family;
+ u8 reject_nh:1,
+ has_gw:1,
+ unused:6;
+
+ union {
+ /* fib_nh used for device only nexthops as well */
+ struct fib_nh fib_nh;
+ struct fib6_nh fib6_nh;
+ };
+};
+
+struct nexthop {
+ struct rb_node rb_node;
+ struct list_head fi_list; /* v4 entries using nh */
+ struct list_head f6i_list; /* v6 entries using nh */
+
+ u32 id;
+
+ u8 protocol;
+ u8 nh_flags;
+
+ refcount_t refcnt;
+ struct rcu_head rcu;
+
+ union {
+ struct nh_info __rcu *nh_info;
+ };
+};
+
+struct nh_config {
+ u8 nh_family;
+ u8 nh_scope;
+ u8 nh_protocol;
+ u8 nh_blackhole;
+ u32 nh_flags;
+
+ u32 nh_id;
+ u32 tclassid;
+
+ int nh_ifindex;
+ struct net_device *dev;
+ u32 nh_table;
+ union {
+ __be32 ipv4;
+ struct in6_addr ipv6;
+ } gw;
+
+ u32 nlflags;
+ struct nl_info nlinfo;
+};
+
+void nexthop_get(struct nexthop *nh);
+void nexthop_put(struct nexthop *nh);
+
+/* caller is holding rtnl; no reference taken to nexthop */
+struct nexthop *nexthop_find_by_id(struct net *net, u32 id);
+
+static inline bool nexthop_cmp(struct nexthop *nh1, struct nexthop *nh2)
+{
+ return nh1 == nh2;
+}
+
+static inline int nexthop_num_path(struct nexthop *nh)
+{
+ return 1;
+}
+
+/* called with rcu lock */
+static inline bool nexthop_has_gw(struct nexthop *nh)
+{
+ struct nh_info *nhi;
+
+ nhi = rcu_dereference(nh->nh_info);
+ return !!nhi->has_gw;
+}
+
+/* called with rcu lock */
+static inline bool nexthop_is_blackhole(struct nexthop *nh)
+{
+ struct nh_info *nhi;
+
+ nhi = rcu_dereference(nh->nh_info);
+ return !!nhi->reject_nh;
+}
+#endif
diff --git a/include/uapi/linux/nexthop.h b/include/uapi/linux/nexthop.h
new file mode 100644
index 000000000000..f40ef188b529
--- /dev/null
+++ b/include/uapi/linux/nexthop.h
@@ -0,0 +1,56 @@
+#ifndef _UAPI_LINUX_NEXTHOP_H
+#define _UAPI_LINUX_NEXTHOP_H
+
+#include <linux/types.h>
+
+struct nhmsg {
+ unsigned char nh_family;
+ unsigned char nh_scope; /* one of RT_SCOPE */
+ unsigned char nh_protocol; /* Routing protocol that installed nh */
+ unsigned char resvd;
+ unsigned int nh_flags; /* RTNH_F flags */
+};
+
+struct nexthop_grp {
+ __u32 id;
+ __u32 weight;
+};
+
+enum {
+ NEXTHOP_GRP_TYPE_MPATH, /* default type if not specified */
+ __NEXTHOP_GRP_TYPE_MAX,
+};
+
+#define NEXTHOP_GRP_TYPE_MAX (__NEXTHOP_GRP_TYPE_MAX - 1)
+
+
+/* NHA_ID 32-bit id for nexthop. id must be greater than 0.
+ * id == 0 means assign an unused id.
+ */
+enum {
+ NHA_UNSPEC,
+ NHA_ID, /* u32 */
+ NHA_GROUP, /* array of nexthop_grp */
+ NHA_GROUP_TYPE, /* u16 one of NEXTHOP_GRP_TYPE;
+ * default is NEXTHOP_GRP_TYPE_MPATH */
+
+ /* if NHA_GROUP attribute is added, no other attributes can be set */
+
+ NHA_BLACKHOLE, /* flag; nexthop used to blackhole packets */
+ NHA_OIF, /* u32 */
+ NHA_FLOW, /* u32 */
+
+ NHA_TABLE_ID, /* u32 - table id to validate gateway */
+ NHA_GATEWAY, /* be32 (IPv4) or in6_addr (IPv6) gw address */
+
+ /* Dump control attributes */
+ NHA_GROUPS, /* flag; only return nexthop groups in dump */
+ NHA_MASTER, /* u32; only return nexthops with given master dev */
+
+ NHA_SADDR, /* return only: IPv4 or IPv6 source address */
+
+ __NHA_MAX,
+};
+
+#define NHA_MAX (__NHA_MAX - 1)
+#endif
diff --git a/include/uapi/linux/rtnetlink.h b/include/uapi/linux/rtnetlink.h
index 46399367627f..4a0615797e5e 100644
--- a/include/uapi/linux/rtnetlink.h
+++ b/include/uapi/linux/rtnetlink.h
@@ -157,6 +157,13 @@ enum {
RTM_GETCHAIN,
#define RTM_GETCHAIN RTM_GETCHAIN
+ RTM_NEWNEXTHOP = 104,
+#define RTM_NEWNEXTHOP RTM_NEWNEXTHOP
+ RTM_DELNEXTHOP,
+#define RTM_DELNEXTHOP RTM_DELNEXTHOP
+ RTM_GETNEXTHOP,
+#define RTM_GETNEXTHOP RTM_GETNEXTHOP
+
__RTM_MAX,
#define RTM_MAX (((__RTM_MAX + 3) & ~3) - 1)
};
diff --git a/net/ipv4/Makefile b/net/ipv4/Makefile
index 7446b98661d8..2ee5129a070c 100644
--- a/net/ipv4/Makefile
+++ b/net/ipv4/Makefile
@@ -14,7 +14,7 @@ obj-y := route.o inetpeer.o protocol.o \
udp_offload.o arp.o icmp.o devinet.o af_inet.o igmp.o \
fib_frontend.o fib_semantics.o fib_trie.o fib_notifier.o \
inet_fragment.o ping.o ip_tunnel_core.o gre_offload.o \
- metrics.o netlink.o
+ metrics.o netlink.o nexthop.o
obj-$(CONFIG_BPFILTER) += bpfilter/
diff --git a/net/ipv4/nexthop.c b/net/ipv4/nexthop.c
new file mode 100644
index 000000000000..24c4aa383c9d
--- /dev/null
+++ b/net/ipv4/nexthop.c
@@ -0,0 +1,1080 @@
+/* Generic nexthop implementation
+ *
+ * Copyright (C) 2017-18 Cumulus Networks
+ * Copyright (c) 2017-18 David Ahern <dsa@...ulusnetworks.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/inetdevice.h>
+#include <linux/nexthop.h>
+#include <linux/rtnetlink.h>
+#include <linux/slab.h>
+#include <net/nexthop.h>
+#include <net/route.h>
+#include <net/ip6_route.h>
+
+static void remove_nexthop(struct net *net, struct nexthop *nh,
+ bool skip_fib, struct nl_info *nlinfo);
+
+#define NH_DEV_HASHBITS 8
+#define NH_DEV_HASHSIZE (1U << NH_DEV_HASHBITS)
+
+static const struct nla_policy rtm_nh_policy[NHA_MAX + 1] = {
+ [NHA_ID] = { .type = NLA_U32 },
+ [NHA_OIF] = { .type = NLA_U32 },
+ [NHA_FLOW] = { .type = NLA_U32 },
+ [NHA_TABLE_ID] = { .type = NLA_U32 },
+ [NHA_BLACKHOLE] = { .type = NLA_FLAG },
+ [NHA_MASTER] = { .type = NLA_U32 },
+};
+
+static unsigned int nh_dev_hashfn(unsigned int val)
+{
+ unsigned int mask = NH_DEV_HASHSIZE - 1;
+
+ return (val ^
+ (val >> NH_DEV_HASHBITS) ^
+ (val >> (NH_DEV_HASHBITS * 2))) & mask;
+}
+
+static void nexthop_devhash_add(struct net *net, struct nh_info *nhi)
+{
+ struct hlist_head *head;
+ struct net_device *dev;
+ unsigned int hash;
+
+ if (nhi->family == AF_INET6)
+ dev = nhi->fib6_nh.nh_dev;
+ else
+ dev = nhi->fib_nh.nh_dev;
+
+ WARN_ON(!dev);
+
+ hash = nh_dev_hashfn(dev->ifindex);
+ head = &net->nexthop.devhash[hash];
+ hlist_add_head(&nhi->dev_hash, head);
+}
+
+static void nexthop_free_rcu(struct rcu_head *head)
+{
+ struct nexthop *nh = container_of(head, struct nexthop, rcu);
+ struct nh_info *nhi;
+
+ nhi = rcu_dereference_raw(nh->nh_info);
+ switch (nhi->family) {
+ case AF_INET:
+ case AF_UNSPEC:
+ fib_nh_release(nhi->net, &nhi->fib_nh);
+ break;
+ case AF_INET6:
+ fib6_nh_release(&nhi->fib6_nh);
+ break;
+ }
+ kfree(nhi);
+
+ kfree(nh);
+}
+
+static struct nexthop *nexthop_alloc(void)
+{
+ return kzalloc(sizeof(struct nexthop), GFP_KERNEL);
+}
+
+static void nh_base_seq_inc(struct net *net)
+{
+ while (++net->nexthop.seq == 0)
+ ;
+}
+
+void nexthop_put(struct nexthop *nh)
+{
+ if (refcount_dec_and_test(&nh->refcnt))
+ call_rcu(&nh->rcu, nexthop_free_rcu);
+}
+
+void nexthop_get(struct nexthop *nh)
+{
+ refcount_inc(&nh->refcnt);
+}
+
+/* no reference taken; rcu lock or rtnl must be held */
+struct nexthop *nexthop_find_by_id(struct net *net, u32 id)
+{
+ struct rb_node **pp, *parent = NULL, *next;
+
+ pp = &net->nexthop.root.rb_node;
+ while (1) {
+ struct nexthop *nh;
+
+ next = rtnl_dereference(*pp);
+ if (!next)
+ break;
+ parent = next;
+
+ nh = rb_entry(parent, struct nexthop, rb_node);
+ if (id < nh->id)
+ pp = &next->rb_left;
+ else if (id > nh->id)
+ pp = &next->rb_right;
+ else
+ return nh;
+ }
+ return NULL;
+}
+
+/* find an unused id - used for auto id allocation
+ * called with rtnl lock held
+ */
+static u32 nh_find_unused_id(struct net *net)
+{
+ u32 id_start = net->nexthop.last_id_allocated;
+
+ while (1) {
+ net->nexthop.last_id_allocated++;
+ if (net->nexthop.last_id_allocated == id_start)
+ break;
+
+ if (!nexthop_find_by_id(net, net->nexthop.last_id_allocated))
+ return net->nexthop.last_id_allocated;
+ }
+ return 0;
+}
+
+static size_t nh_nlmsg_size_ipv6(struct nh_info *nhi)
+{
+ size_t sz = 0;
+
+ sz = nla_total_size(sizeof(nhi->fib6_nh.nh_gw));
+
+ return sz;
+}
+
+static size_t nh_nlmsg_size_ipv4(struct nh_info *nhi)
+{
+ size_t sz;
+
+ sz = nla_total_size(4) /* NHA_GATEWAY */
+#ifdef CONFIG_IP_ROUTE_CLASSID
+ + nla_total_size(4) /* NHA_FLOW */
+#endif
+ + nla_total_size(4); /* NHA_SADDR_IPV4 */
+
+ return sz;
+}
+
+static size_t nh_nlmsg_size(struct nexthop *nh)
+{
+ struct nh_info *nhi = rtnl_dereference(nh->nh_info);
+ size_t sz = nla_total_size(4); /* NHA_ID */
+
+ /* covers NHA_BLACKHOLE since NHA_OIF and BLACKHOLE
+ * are mutually exclusive
+ */
+ sz += nla_total_size(4); /* NHA_OIF */
+
+ if (nhi->family == AF_INET)
+ sz += nh_nlmsg_size_ipv4(nhi);
+
+ else if (nhi->family == AF_INET6)
+ sz += nh_nlmsg_size_ipv6(nhi);
+
+ return sz;
+}
+
+static const struct net_device *nh_info_dev(const struct nh_info *nhi)
+{
+ switch (nhi->family) {
+ case AF_INET:
+ case AF_UNSPEC: /* dev only re-uses IPv4 struct */
+ return nhi->fib_nh.nh_dev;
+ case AF_INET6:
+ return nhi->fib6_nh.nh_dev;
+ }
+ return NULL;
+}
+
+static bool nh_info_uses_dev(const struct nh_info *nhi,
+ const struct net_device *dev)
+{
+ const struct net_device *nh_dev;
+
+ nh_dev = nh_info_dev(nhi);
+ if (nh_dev == dev || l3mdev_master_dev_rcu(nh_dev) == dev)
+ return true;
+
+ return false;
+}
+
+bool nexthop_uses_dev(const struct nexthop *nh, const struct net_device *dev)
+{
+ const struct nh_info *nhi;
+ bool dev_match = false;
+
+ nhi = rcu_dereference(nh->nh_info);
+ dev_match = nh_info_uses_dev(nhi, dev);
+
+ return dev_match;
+}
+
+static int nh_fill_node(struct sk_buff *skb, struct nexthop *nh,
+ int event, u32 portid, u32 seq, unsigned int nlflags)
+{
+ const struct net_device *dev;
+ struct fib6_nh *fib6_nh;
+ struct fib_nh *fib_nh;
+ struct nlmsghdr *nlh;
+ struct nh_info *nhi;
+ struct nhmsg *nhm;
+
+ nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nhm), nlflags);
+ if (!nlh)
+ return -EMSGSIZE;
+
+ nhm = nlmsg_data(nlh);
+ nhm->nh_family = AF_UNSPEC;
+ nhm->nh_flags = nh->nh_flags;
+ nhm->nh_protocol = nh->protocol;
+ nhm->nh_scope = 0;
+ nhm->resvd = 0;
+
+ if (nla_put_u32(skb, NHA_ID, nh->id))
+ goto nla_put_failure;
+
+ nhi = rtnl_dereference(nh->nh_info);
+ if (nhi->reject_nh && nla_put_flag(skb, NHA_BLACKHOLE))
+ goto nla_put_failure;
+
+ dev = nh_info_dev(nhi);
+ if (dev && nla_put_u32(skb, NHA_OIF, dev->ifindex))
+ goto nla_put_failure;
+
+ nhm->nh_family = nhi->family;
+ switch (nhi->family) {
+ case AF_INET:
+ fib_nh = &nhi->fib_nh;
+
+ nhm->nh_scope = fib_nh->nh_scope;
+ if (nla_put_u32(skb, NHA_GATEWAY, fib_nh->nh_gw))
+ goto nla_put_failure;
+ if (nla_put_u32(skb, NHA_SADDR, fib_nh->nh_saddr))
+ goto nla_put_failure;
+#ifdef CONFIG_IP_ROUTE_CLASSID
+ if (fib_nh->nh_tclassid &&
+ nla_put_u32(skb, NHA_FLOW, fib_nh->nh_tclassid))
+ goto nla_put_failure;
+#endif
+ break;
+
+ case AF_INET6:
+ fib6_nh = &nhi->fib6_nh;
+ if (nla_put_in6_addr(skb, NHA_GATEWAY, &fib6_nh->nh_gw) < 0)
+ goto nla_put_failure;
+ break;
+ }
+
+ nlmsg_end(skb, nlh);
+ return 0;
+
+nla_put_failure:
+ return -EMSGSIZE;
+}
+
+static void nexthop_notify(int event, struct nexthop *nh, struct nl_info *info)
+{
+ unsigned int nlflags = info->nlh ? info->nlh->nlmsg_flags : 0;
+ u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
+ struct sk_buff *skb;
+ int err = -ENOBUFS;
+
+ skb = nlmsg_new(nh_nlmsg_size(nh), gfp_any());
+ if (!skb)
+ goto errout;
+
+ err = nh_fill_node(skb, nh, event, info->portid, seq, nlflags);
+ if (err < 0) {
+ /* -EMSGSIZE implies BUG in nh_nlmsg_size() */
+ WARN_ON(err == -EMSGSIZE);
+ kfree_skb(skb);
+ goto errout;
+ }
+
+ rtnl_notify(skb, info->nl_net, info->portid, RTNLGRP_IPV4_ROUTE,
+ info->nlh, gfp_any());
+ return;
+errout:
+ if (err < 0)
+ rtnl_set_sk_err(info->nl_net, RTNLGRP_IPV4_ROUTE, err);
+}
+
+/* called on insert failure too */
+static void __remove_nexthop(struct net *net, struct nexthop *nh,
+ bool skip_fib, struct nl_info *nlinfo)
+{
+ const struct net_device *dev;
+ struct nh_info *nhi;
+
+ nhi = rtnl_dereference(nh->nh_info);
+ dev = nh_info_dev(nhi);
+ if (dev)
+ hlist_del(&nhi->dev_hash);
+}
+
+static void remove_nexthop(struct net *net, struct nexthop *nh,
+ bool skip_fib, struct nl_info *nlinfo)
+{
+ /* remove from the tree */
+ rb_erase(&nh->rb_node, &net->nexthop.root);
+
+ __remove_nexthop(net, nh, skip_fib, nlinfo);
+
+ nh_base_seq_inc(net);
+
+ nexthop_put(nh);
+
+ nexthop_notify(RTM_DELNEXTHOP, nh, nlinfo);
+}
+
+static int replace_nexthop(struct net *net, struct nexthop *old,
+ struct nexthop *new, struct netlink_ext_ack *extack)
+{
+ struct nh_info *oldi, *newi;
+
+ oldi = rtnl_dereference(old->nh_info);
+ newi = rtnl_dereference(new->nh_info);
+ rcu_assign_pointer(old->nh_info, newi);
+ rcu_assign_pointer(new->nh_info, oldi);
+
+ newi->nh_parent = old;
+ oldi->nh_parent = new;
+
+ old->protocol = new->protocol;
+ old->nh_flags = new->nh_flags;
+
+ rt_cache_flush(net);
+ // TO-DO: ipv6 equiv
+
+ __remove_nexthop(net, new, true, NULL);
+ nexthop_put(new);
+
+ return 0;
+}
+
+/* called with rtnl_lock held */
+static int insert_nexthop(struct net *net, struct nexthop *new_nh,
+ struct nh_config *cfg, struct netlink_ext_ack *extack)
+{
+ struct rb_node **pp, *parent = NULL, *next;
+ struct rb_root *root = &net->nexthop.root;
+ bool replace = !!(cfg->nlflags & NLM_F_REPLACE);
+ bool create = !!(cfg->nlflags & NLM_F_CREATE);
+ u32 new_id = new_nh->id;
+ int rc = -EEXIST;
+
+ pp = &root->rb_node;
+ while (1) {
+ struct nexthop *nh;
+
+ next = rtnl_dereference(*pp);
+ if (!next)
+ break;
+
+ parent = next;
+
+ nh = rb_entry(parent, struct nexthop, rb_node);
+ if (new_id < nh->id) {
+ pp = &next->rb_left;
+ } else if (new_id > nh->id) {
+ pp = &next->rb_right;
+ } else if (replace) {
+ rc = replace_nexthop(net, nh, new_nh, extack);
+ if (!rc)
+ new_nh = nh; /* send notification with old nh */
+ goto out;
+ } else {
+ /* id already exists and not a replace */
+ goto out;
+ }
+ }
+
+ if (replace && !create) {
+ NL_SET_ERR_MSG(extack, "Replace specified without create and no entry exists");
+ rc = -ENOENT;
+ goto out;
+ }
+
+ rb_link_node_rcu(&new_nh->rb_node, parent, pp);
+ rb_insert_color(&new_nh->rb_node, root);
+ rc = 0;
+out:
+ if (!rc) {
+ nh_base_seq_inc(net);
+ nexthop_notify(RTM_NEWNEXTHOP, new_nh, &cfg->nlinfo);
+ }
+
+ return rc;
+}
+
+/* rtnl */
+/* remove all nexthops tied to a device being deleted */
+static void nexthop_flush_dev(struct net_device *dev)
+{
+ unsigned int hash = nh_dev_hashfn(dev->ifindex);
+ struct net *net = dev_net(dev);
+ struct hlist_head *head = &net->nexthop.devhash[hash];
+ struct nl_info nlinfo = {
+ .nl_net = net,
+ };
+ struct hlist_node *n;
+ struct nh_info *nhi;
+
+ hlist_for_each_entry_safe(nhi, n, head, dev_hash) {
+ if (nh_info_dev(nhi) != dev)
+ continue;
+
+ remove_nexthop(net, nhi->nh_parent, false, &nlinfo);
+ }
+}
+
+/* rtnl */
+static void flush_all_nexthops(struct net *net)
+{
+ struct rb_root *root = &net->nexthop.root;
+ struct rb_node *node;
+ struct nexthop *nh;
+ struct nl_info nlinfo = {
+ .nl_net = net,
+ };
+
+ while ((node = rb_first(root))) {
+ nh = rb_entry(node, struct nexthop, rb_node);
+ remove_nexthop(net, nh, true, &nlinfo);
+ cond_resched();
+ }
+}
+
+static int nh_check_attr(struct nhmsg *nhm, struct nlattr *tb[],
+ struct net *net, struct netlink_ext_ack *extack)
+{
+ int err = -EINVAL;
+
+ if (nhm->nh_flags & ~NEXTHOP_VALID_USER_FLAGS) {
+ NL_SET_ERR_MSG(extack,
+ "Invalid nexthop flags in ancillary header");
+ goto out;
+ }
+
+ err = 0;
+out:
+ return err;
+}
+
+static int rtm_to_nh_config(struct net *net, struct sk_buff *skb,
+ struct nlmsghdr *nlh, struct nh_config *cfg,
+ struct netlink_ext_ack *extack)
+{
+ struct nhmsg *nhm = nlmsg_data(nlh);
+ struct nlattr *tb[NHA_MAX + 1];
+ int err;
+
+ err = nlmsg_parse(nlh, sizeof(*nhm), tb, NHA_MAX,
+ rtm_nh_policy, extack);
+ if (err < 0)
+ return err;
+
+ if (nhm->resvd) {
+ NL_SET_ERR_MSG(extack, "Invalid value in reserved field of ancillary header");
+ return -EINVAL;
+ }
+
+ err = nh_check_attr(nhm, tb, net, extack);
+ if (err < 0)
+ return err;
+
+ memset(cfg, 0, sizeof(*cfg));
+ cfg->nlflags = nlh->nlmsg_flags;
+ cfg->nlinfo.portid = NETLINK_CB(skb).portid;
+ cfg->nlinfo.nlh = nlh;
+ cfg->nlinfo.nl_net = net;
+
+ cfg->nh_family = nhm->nh_family;
+ cfg->nh_protocol = nhm->nh_protocol;
+ cfg->nh_flags = nhm->nh_flags;
+ cfg->nh_scope = nhm->nh_scope;
+
+ if (tb[NHA_ID])
+ cfg->nh_id = nla_get_u32(tb[NHA_ID]);
+
+ if (tb[NHA_OIF]) {
+ cfg->nh_ifindex = nla_get_u32(tb[NHA_OIF]);
+
+ if (cfg->nh_ifindex)
+ cfg->dev = __dev_get_by_index(net, cfg->nh_ifindex);
+
+ if (!cfg->dev) {
+ NL_SET_ERR_MSG(extack, "Invalid device index");
+ goto out;
+ } else if (!(cfg->dev->flags & IFF_UP)) {
+ NL_SET_ERR_MSG(extack, "Nexthop device is not up");
+ err = -ENETDOWN;
+ goto out;
+ } else if (!netif_carrier_ok(cfg->dev)) {
+ NL_SET_ERR_MSG(extack,
+ "Carrier for nexthop device is down");
+ err = -ENETDOWN;
+ goto out;
+ }
+
+ cfg->nh_table = l3mdev_fib_table(cfg->dev);
+ }
+
+ if (tb[NHA_TABLE_ID])
+ cfg->nh_table = nla_get_u32(tb[NHA_TABLE_ID]);
+
+ err = -EINVAL;
+ if (tb[NHA_FLOW]) {
+#ifndef CONFIG_IP_ROUTE_CLASSID
+ NL_SET_ERR_MSG(extack, "Classid not enabled in kernel");
+ goto out;
+#else
+ cfg->tclassid = nla_get_u32(tb[NHA_FLOW]);
+#endif
+ }
+
+ if (tb[NHA_GATEWAY]) {
+ struct nlattr *gwa = tb[NHA_GATEWAY];
+
+ switch (cfg->nh_family) {
+ case AF_INET:
+ if (nla_len(gwa) != sizeof(u32)) {
+ NL_SET_ERR_MSG(extack, "Invalid gateway");
+ goto out;
+ }
+ cfg->gw.ipv4 = nla_get_be32(gwa);
+ break;
+ case AF_INET6:
+ if (nla_len(gwa) != sizeof(struct in6_addr)) {
+ NL_SET_ERR_MSG(extack, "Invalid gateway");
+ goto out;
+ }
+ cfg->gw.ipv6 = nla_get_in6_addr(gwa);
+ break;
+ default:
+ NL_SET_ERR_MSG(extack,
+ "Unknown address family for gateway");
+ goto out;
+ }
+ } else {
+ cfg->nh_family = AF_UNSPEC;
+
+ /* device only nexthop (no gateway) */
+ if (cfg->nh_flags & RTNH_F_ONLINK) {
+ NL_SET_ERR_MSG(extack,
+ "ONLINK flag can not be set for nexthop without a gateway");
+ goto out;
+ }
+ cfg->nh_scope = RT_SCOPE_LINK;
+ }
+
+ if (tb[NHA_BLACKHOLE]) {
+ if (tb[NHA_GATEWAY]) {
+ NL_SET_ERR_MSG(extack,
+ "Blackhole attribute can not be used with gateway");
+ goto out;
+ }
+
+ cfg->nh_blackhole = 1;
+ }
+
+ if (cfg->tclassid && cfg->nh_family != AF_INET) {
+ NL_SET_ERR_MSG(extack,
+ "FLOW attribute only relevant for IPv4 nexthops");
+ goto out;
+ }
+
+ err = 0;
+out:
+ return err;
+}
+
+/* rtnl */
+static int rtm_get_nexthop(struct sk_buff *in_skb, struct nlmsghdr *nlh,
+ struct netlink_ext_ack *extack)
+{
+ struct net *net = sock_net(in_skb->sk);
+ struct nhmsg *nhm = nlmsg_data(nlh);
+ struct nlattr *tb[NHA_MAX + 1];
+ struct sk_buff *skb = NULL;
+ struct nexthop *nh;
+ int err;
+ u32 id;
+
+ err = nlmsg_parse(nlh, sizeof(*nhm), tb, NHA_MAX,
+ rtm_nh_policy, extack);
+ if (err < 0)
+ goto out;
+
+ err = -EINVAL;
+ if (!tb[NHA_ID]) {
+ NL_SET_ERR_MSG(extack, "Nexthop id is missing");
+ goto out;
+ }
+ id = nla_get_u32(tb[NHA_ID]);
+ if (!id) {
+ NL_SET_ERR_MSG(extack, "Invalid nexthop id");
+ goto out;
+ }
+
+ err = -ENOBUFS;
+ skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
+ if (!skb)
+ goto out;
+
+ err = -ENOENT;
+ nh = nexthop_find_by_id(net, id);
+ if (!nh)
+ goto errout_free;
+
+ err = nh_fill_node(skb, nh, RTM_NEWNEXTHOP, NETLINK_CB(in_skb).portid,
+ nlh->nlmsg_seq, 0);
+ if (err < 0)
+ goto errout_free;
+
+ err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
+out:
+ return err;
+errout_free:
+ kfree_skb(skb);
+ goto out;
+}
+
+/* rtnl */
+static int rtm_del_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh,
+ struct netlink_ext_ack *extack)
+{
+ struct net *net = sock_net(skb->sk);
+ struct nlattr *tb[NHA_MAX + 1];
+ struct nl_info nlinfo = {
+ .nlh = nlh,
+ .nl_net = net,
+ .portid = NETLINK_CB(skb).portid,
+ };
+ struct nexthop *nh;
+ struct nhmsg *nhm;
+ int err, i;
+ u32 id;
+
+ err = nlmsg_parse(nlh, sizeof(*nhm), tb, NHA_MAX,
+ rtm_nh_policy, extack);
+ if (err < 0)
+ return err;
+
+ nhm = nlmsg_data(nlh);
+
+ /* validate expected attribute and check for unexpected attributes */
+ for (i = 1; i < __NHA_MAX; ++i) {
+ switch (i) {
+ case NHA_ID:
+ if (!tb[NHA_ID]) {
+ NL_SET_ERR_MSG(extack, "Nexthop id is missing");
+ return -EINVAL;
+ }
+ break;
+ default:
+ if (!tb[i])
+ break;
+
+ NL_SET_ERR_MSG_ATTR(extack, tb[i],
+ "Unexpected attribute in request");
+ return -EINVAL;
+ }
+ }
+
+ id = nla_get_u32(tb[NHA_ID]);
+ nh = nexthop_find_by_id(net, id);
+ if (!nh)
+ return -ENOENT;
+
+ remove_nexthop(net, nh, false, &nlinfo);
+
+ return 0;
+}
+
+static int nh_create_ipv4(struct net *net, struct nexthop *nh,
+ struct nh_info *nhi, struct nh_config *cfg,
+ struct netlink_ext_ack *extack)
+{
+ struct fib_nh *fib_nh = &nhi->fib_nh;
+ struct fib_config fib_cfg = {
+ .fc_oif = cfg->nh_ifindex,
+ .fc_flow = cfg->tclassid,
+ .fc_gw = cfg->gw.ipv4,
+ .fc_flags = cfg->nh_flags,
+ };
+ int err;
+
+ err = fib_nh_init(net, fib_nh, &fib_cfg, 1, extack);
+ if (err)
+ goto out;
+
+ err = fib_check_nh(net, fib_nh, cfg->nh_table, cfg->nh_scope, extack);
+ if (!err) {
+ /* v4 code normally allows a nexthop device to have
+ * carrier down; this code does not allow it
+ */
+ if (fib_nh->nh_flags & RTNH_F_LINKDOWN) {
+ NL_SET_ERR_MSG(extack,
+ "Carrier for nexthop device is down");
+ dev_put(fib_nh->nh_dev);
+ err = -ENETDOWN;
+ goto out;
+ }
+
+ nh->nh_flags = fib_nh->nh_flags;
+ fib_info_update_nh_saddr(net, fib_nh, fib_nh->nh_scope);
+ }
+
+ nhi->has_gw = !!fib_nh->nh_gw;
+out:
+ return err;
+}
+
+static int nh_create_ipv6(struct net *net, struct nexthop *nh,
+ struct nh_info *nhi, struct nh_config *cfg,
+ struct netlink_ext_ack *extack)
+{
+ struct fib6_nh *fib6_nh = &nhi->fib6_nh;
+ struct fib6_config fib6_cfg = {
+ .fc_table = cfg->nh_table,
+ .fc_ifindex = cfg->nh_ifindex,
+ .fc_gateway = cfg->gw.ipv6,
+ .fc_flags = cfg->nh_flags,
+ };
+ int err;
+
+ if (!ipv6_addr_any(&cfg->gw.ipv6)) {
+ fib6_cfg.fc_flags |= RTF_GATEWAY;
+ nhi->has_gw = true;
+ }
+
+ err = ipv6_stub->fib6_nh_init(net, fib6_nh, &fib6_cfg, extack);
+ if (!err) {
+ if (fib6_cfg.fc_flags & RTF_REJECT) {
+ NL_SET_ERR_MSG(extack,
+ "Nexthop can not use RTF_REJECT");
+ err = -EINVAL;
+ goto out;
+ }
+
+ if (fib6_nh->nh_flags & RTNH_F_LINKDOWN) {
+ NL_SET_ERR_MSG(extack,
+ "Carrier for nexthop device is down");
+ err = -ENETDOWN;
+ goto out;
+ }
+
+ nh->nh_flags = fib6_nh->nh_flags;
+ }
+
+out:
+ if (err && fib6_nh->nh_dev)
+ dev_put(fib6_nh->nh_dev);
+ return err;
+}
+
+static int nh_create_unspec(struct net *net, struct nexthop *nh,
+ struct nh_info *nhi, struct nh_config *cfg,
+ struct netlink_ext_ack *extack)
+{
+ struct net_device *dev = cfg->dev;
+ int err = 0;
+
+ if (cfg->nh_blackhole) {
+ nhi->reject_nh = 1;
+ } else if (!dev) {
+ NL_SET_ERR_MSG(extack, "No device for nexthop");
+ err = -ENODEV;
+ } else {
+ /* leverage ipv4 infra for non-gw nexthop */
+ err = nh_create_ipv4(net, nh, nhi, cfg, extack);
+ }
+
+ return err;
+}
+
+static void nexthop_init_common(struct nexthop *nh)
+{
+ INIT_LIST_HEAD(&nh->fi_list);
+ INIT_LIST_HEAD(&nh->f6i_list);
+}
+
+static struct nexthop *nexthop_create(struct net *net, struct nh_config *cfg,
+ struct netlink_ext_ack *extack)
+{
+ struct nh_info *nhi;
+ struct nexthop *nh;
+ int err;
+
+ nh = nexthop_alloc();
+ if (!nh)
+ return ERR_PTR(-ENOMEM);
+
+ nhi = kzalloc(sizeof(*nhi), GFP_KERNEL);
+ if (!nhi) {
+ kfree(nh);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ nh->nh_flags = cfg->nh_flags;
+ nexthop_init_common(nh);
+
+ nhi->nh_parent = nh;
+ nhi->family = cfg->nh_family;
+ nhi->net = net;
+ switch (cfg->nh_family) {
+ case AF_INET:
+ err = nh_create_ipv4(net, nh, nhi, cfg, extack);
+ break;
+ case AF_INET6:
+ err = nh_create_ipv6(net, nh, nhi, cfg, extack);
+ break;
+ default:
+ err = nh_create_unspec(net, nh, nhi, cfg, extack);
+ }
+
+ if (err) {
+ kfree(nhi);
+ kfree(nh);
+ return ERR_PTR(err);
+ }
+
+ /* add the entry to the device based hash */
+ if (!nhi->reject_nh)
+ nexthop_devhash_add(net, nhi);
+
+ rcu_assign_pointer(nh->nh_info, nhi);
+
+ return nh;
+}
+
+/* called with rtnl lock held */
+static struct nexthop *nexthop_add(struct net *net, struct nh_config *cfg,
+ struct netlink_ext_ack *extack)
+{
+ struct nexthop *nh;
+ int err;
+
+ if (cfg->nlflags & NLM_F_REPLACE && !cfg->nh_id) {
+ NL_SET_ERR_MSG(extack, "Replace requires nexthop id");
+ return ERR_PTR(-EINVAL);
+ }
+
+ if (!cfg->nh_id) {
+ cfg->nh_id = nh_find_unused_id(net);
+ if (!cfg->nh_id) {
+ NL_SET_ERR_MSG(extack, "No unused id.");
+ return ERR_PTR(-EINVAL);
+ }
+ }
+
+ nh = nexthop_create(net, cfg, extack);
+ if (IS_ERR(nh))
+ return nh;
+
+ refcount_set(&nh->refcnt, 1);
+ nh->id = cfg->nh_id;
+ nh->protocol = cfg->nh_protocol;
+
+ err = insert_nexthop(net, nh, cfg, extack);
+ if (err)
+ goto out_err;
+
+ return nh;
+out_err:
+ __remove_nexthop(net, nh, true, NULL);
+ nexthop_put(nh);
+
+ return ERR_PTR(err);
+}
+
+/* rtnl */
+static int rtm_new_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh,
+ struct netlink_ext_ack *extack)
+{
+ struct net *net = sock_net(skb->sk);
+ struct nh_config cfg;
+ struct nexthop *nh;
+ int err;
+
+ err = rtm_to_nh_config(net, skb, nlh, &cfg, extack);
+ if (!err) {
+ nh = nexthop_add(net, &cfg, extack);
+ if (IS_ERR(nh))
+ err = PTR_ERR(nh);
+ }
+
+ return err;
+}
+
+static bool nh_dump_filtered(struct nexthop *nh, int dev_idx,
+ int master_idx, u8 family)
+{
+ const struct net_device *dev;
+ const struct nh_info *nhi;
+
+ if (dev_idx || master_idx || family)
+ return true;
+
+ nhi = rtnl_dereference(nh->nh_info);
+ if (family && nhi->family != family)
+ return true;
+
+ dev = nh_info_dev(nhi);
+ if (dev_idx && (!dev || dev->ifindex != dev_idx))
+ return true;
+
+ if (master_idx) {
+ struct net_device *master;
+
+ master = netdev_master_upper_dev_get((struct net_device *)dev);
+ if (!master || master->ifindex != master_idx)
+ return true;
+ }
+ return false;
+}
+
+/* rtnl */
+static int rtm_dump_nexthop(struct sk_buff *skb, struct netlink_callback *cb)
+{
+ int dev_filter_idx = 0, master_idx = 0;
+ struct net *net = sock_net(skb->sk);
+ struct rb_root *root = &net->nexthop.root;
+ struct nlattr *tb[NHA_MAX + 1];
+ struct rb_node *node;
+ struct nhmsg *nhm;
+ int idx = 0;
+ int s_idx;
+ int err;
+
+ if (nlmsg_parse(cb->nlh, sizeof(*nhm), tb, NHA_MAX,
+ rtm_nh_policy, NULL) >= 0) {
+ if (tb[NHA_OIF])
+ dev_filter_idx = nla_get_u32(tb[NHA_OIF]);
+
+ if (tb[NHA_MASTER])
+ master_idx = nla_get_u32(tb[NHA_MASTER]);
+ }
+
+ nhm = nlmsg_data(cb->nlh);
+
+ s_idx = cb->args[0];
+ for (node = rb_first(root); node; node = rb_next(node)) {
+ struct nexthop *nh;
+
+ if (idx < s_idx)
+ goto cont;
+
+ nh = rb_entry(node, struct nexthop, rb_node);
+ if (nh_dump_filtered(nh, dev_filter_idx, master_idx,
+ nhm->nh_family))
+ goto cont;
+
+ err = nh_fill_node(skb, nh, RTM_NEWNEXTHOP,
+ NETLINK_CB(cb->skb).portid,
+ cb->nlh->nlmsg_seq, NLM_F_MULTI);
+ if (err < 0) {
+ if (likely(skb->len))
+ goto out;
+
+ goto out_err;
+ }
+cont:
+ idx++;
+ }
+
+out:
+ err = skb->len;
+out_err:
+ cb->args[0] = idx;
+ cb->seq = net->nexthop.seq;
+ nl_dump_check_consistent(cb, nlmsg_hdr(skb));
+
+ return err;
+}
+
+/* rtnl */
+static int nh_netdev_event(struct notifier_block *this,
+ unsigned long event, void *ptr)
+{
+ struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+
+ switch (event) {
+ case NETDEV_DOWN:
+ case NETDEV_UNREGISTER:
+ nexthop_flush_dev(dev);
+ break;
+ case NETDEV_CHANGE:
+ if (!(dev_get_flags(dev) & (IFF_RUNNING | IFF_LOWER_UP)))
+ nexthop_flush_dev(dev);
+ break;
+ }
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block nh_netdev_notifier = {
+ .notifier_call = nh_netdev_event,
+};
+
+static void __net_exit nexthop_net_exit(struct net *net)
+{
+ rtnl_lock();
+ flush_all_nexthops(net);
+ rtnl_unlock();
+ kfree(net->nexthop.devhash);
+}
+
+static int __net_init nexthop_net_init(struct net *net)
+{
+ size_t sz = sizeof(struct hlist_head) * NH_DEV_HASHSIZE;
+
+ net->nexthop.root = RB_ROOT;
+ net->nexthop.devhash = kzalloc(sz, GFP_KERNEL);
+ if (!net->nexthop.devhash)
+ return -ENOMEM;
+
+ return 0;
+}
+
+static struct pernet_operations nexthop_net_ops = {
+ .init = nexthop_net_init,
+ .exit = nexthop_net_exit,
+};
+
+static int __init nexthop_init(void)
+{
+ register_pernet_subsys(&nexthop_net_ops);
+
+ register_netdevice_notifier(&nh_netdev_notifier);
+
+ rtnl_register(PF_UNSPEC, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0);
+ rtnl_register(PF_UNSPEC, RTM_DELNEXTHOP, rtm_del_nexthop, NULL, 0);
+ rtnl_register(PF_UNSPEC, RTM_GETNEXTHOP, rtm_get_nexthop,
+ rtm_dump_nexthop, 0);
+
+ rtnl_register(PF_INET, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0);
+ rtnl_register(PF_INET, RTM_GETNEXTHOP, NULL, rtm_dump_nexthop, 0);
+
+ rtnl_register(PF_INET6, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0);
+ rtnl_register(PF_INET6, RTM_GETNEXTHOP, NULL, rtm_dump_nexthop, 0);
+
+ return 0;
+}
+subsys_initcall(nexthop_init);
diff --git a/security/selinux/nlmsgtab.c b/security/selinux/nlmsgtab.c
index 74b951f55608..7a852d5af14e 100644
--- a/security/selinux/nlmsgtab.c
+++ b/security/selinux/nlmsgtab.c
@@ -80,6 +80,9 @@ static const struct nlmsg_perm nlmsg_route_perms[] =
{ RTM_NEWSTATS, NETLINK_ROUTE_SOCKET__NLMSG_READ },
{ RTM_GETSTATS, NETLINK_ROUTE_SOCKET__NLMSG_READ },
{ RTM_NEWCACHEREPORT, NETLINK_ROUTE_SOCKET__NLMSG_READ },
+ { RTM_NEWNEXTHOP, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
+ { RTM_DELNEXTHOP, NETLINK_ROUTE_SOCKET__NLMSG_WRITE },
+ { RTM_GETNEXTHOP, NETLINK_ROUTE_SOCKET__NLMSG_READ },
};
static const struct nlmsg_perm nlmsg_tcpdiag_perms[] =
@@ -159,7 +162,7 @@ int selinux_nlmsg_lookup(u16 sclass, u16 nlmsg_type, u32 *perm)
switch (sclass) {
case SECCLASS_NETLINK_ROUTE_SOCKET:
/* RTM_MAX always point to RTM_SETxxxx, ie RTM_NEWxxx + 3 */
- BUILD_BUG_ON(RTM_MAX != (RTM_NEWCHAIN + 3));
+ BUILD_BUG_ON(RTM_MAX != (RTM_NEWNEXTHOP + 3));
err = nlmsg_perm(nlmsg_type, perm, nlmsg_route_perms,
sizeof(nlmsg_route_perms));
break;
--
2.11.0
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