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Date: Tue, 06 Oct 2015 15:11:59 -0500
From: ebiederm@...ssion.com (Eric W. Biederman)
To: Roopa Prabhu <roopa@...ulusnetworks.com>
Cc: davem@...emloft.net, netdev@...r.kernel.org, rshearma@...cade.com
Subject: Re: [PATCH net-next v2 1/2] mpls: multipath support
ebiederm@...ssion.com (Eric W. Biederman) writes:
> Roopa Prabhu <roopa@...ulusnetworks.com> writes:
>
>> From: Roopa Prabhu <roopa@...ulusnetworks.com>
>>
>> This patch adds support for MPLS multipath routes.
>>
>> Includes following changes to support multipath:
>> - splits struct mpls_route into 'struct mpls_route + struct mpls_nh'
>>
>> - 'struct mpls_nh' represents a mpls nexthop label forwarding entry
>>
>> - moves mpls route and nexthop structures into internal.h
>>
>> - A mpls_route can point to multiple mpls_nh structs
>>
>> - the nexthops are maintained as a list
>
> So I am not certain I like nexthops being a list. In the practical case
> introducing this list guarantees that everyone will see at least an
> extra cache line miss in the forwarding path.
>
> In the more abstract sense a list is the wrong data structure. If the
> list is so short we can afford to walk it an array is a better data
> structure. If we need enough entries to make the memory consumption
> of an array a concern we want some kind of hash table or tree data
> structure, because a list will be too long in that case.
>
> So can we please not use a list?
>
> I expect we can simplify the data structures by noting that rt_via must
> be an ethernet mac today so that 6 bytes are enough and 8 bytes gives us
> a bit extra and aligns things nicely.
Grr. My mistake. The current worst case is 16 bytes for an ipv6
address in rt_via. But the point remains that a fixed sized array of
bytes in rt_via allows the use of an array and not a list for nexthops.
At least for the single nexthop case I really want something that is
small enough it fits in a single 64byte cache line. The performance
compared to anything else is going to be noticable.
Eric
> Also I know it goes away in the next patch but a spinlock taken for
> every transit through the forwarding path really bugs me.
>
> Eric
>
>> - In the process of restructuring, this patch also consistently changes all
>> labels to u8
>>
>> - Adds support to parse/fill RTA_MULTIPATH netlink attribute for
>> multipath routes similar to ipv4/v6 fib
>>
>> - In this patch, the multipath route nexthop selection algorithm
>> is a simple round robin picked up from ipv4 fib code and is replaced by
>> a hash based algorithm from Robert Shearman in the next patch
>>
>> - mpls_route_update cleanup: remove 'dev' handling in mpls_route_update.
>> mpls_route_update though implemented to update based on dev, it was never
>> used that way. And the dev handling gets tricky with multiple nexthops. Cannot
>> match against any single nexthops dev. So, this patch removes the unused
>> 'dev' handling in mpls_route_update.
>
>>
>> Example:
>>
>> $ip -f mpls route add 100 nexthop as 200 via inet 10.1.1.2 dev swp1 \
>> nexthop as 700 via inet 10.1.1.6 dev swp2 \
>> nexthop as 800 via inet 40.1.1.2 dev swp3
>>
>> $ip -f mpls route show
>> 100
>> nexthop as to 200 via inet 10.1.1.2 dev swp1
>> nexthop as to 700 via inet 10.1.1.6 dev swp2
>> nexthop as to 800 via inet 40.1.1.2 dev swp3
>>
>> Signed-off-by: Roopa Prabhu <roopa@...ulusnetworks.com>
>> ---
>> include/net/mpls_iptunnel.h | 2 +-
>> net/mpls/af_mpls.c | 627 +++++++++++++++++++++++++++++++++-----------
>> net/mpls/internal.h | 43 ++-
>> 3 files changed, 516 insertions(+), 156 deletions(-)
>>
>> diff --git a/include/net/mpls_iptunnel.h b/include/net/mpls_iptunnel.h
>> index 4757997..179253f 100644
>> --- a/include/net/mpls_iptunnel.h
>> +++ b/include/net/mpls_iptunnel.h
>> @@ -18,7 +18,7 @@
>>
>> struct mpls_iptunnel_encap {
>> u32 label[MAX_NEW_LABELS];
>> - u32 labels;
>> + u8 labels;
>> };
>>
>> static inline struct mpls_iptunnel_encap *mpls_lwtunnel_encap(struct lwtunnel_state *lwtstate)
>> diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
>> index 8c5707d..ae9e153 100644
>> --- a/net/mpls/af_mpls.c
>> +++ b/net/mpls/af_mpls.c
>> @@ -19,39 +19,12 @@
>> #include <net/ipv6.h>
>> #include <net/addrconf.h>
>> #endif
>> +#include <net/nexthop.h>
>> #include "internal.h"
>>
>> -#define LABEL_NOT_SPECIFIED (1<<20)
>> -#define MAX_NEW_LABELS 2
>> -
>> -/* This maximum ha length copied from the definition of struct neighbour */
>> -#define MAX_VIA_ALEN (ALIGN(MAX_ADDR_LEN, sizeof(unsigned long)))
>> -
>> -enum mpls_payload_type {
>> - MPT_UNSPEC, /* IPv4 or IPv6 */
>> - MPT_IPV4 = 4,
>> - MPT_IPV6 = 6,
>> -
>> - /* Other types not implemented:
>> - * - Pseudo-wire with or without control word (RFC4385)
>> - * - GAL (RFC5586)
>> - */
>> -};
>> -
>> -struct mpls_route { /* next hop label forwarding entry */
>> - struct net_device __rcu *rt_dev;
>> - struct rcu_head rt_rcu;
>> - u32 rt_label[MAX_NEW_LABELS];
>> - u8 rt_protocol; /* routing protocol that set this entry */
>> - u8 rt_payload_type;
>> - u8 rt_labels;
>> - u8 rt_via_alen;
>> - u8 rt_via_table;
>> - u8 rt_via[0];
>> -};
>> -
>> static int zero = 0;
>> static int label_limit = (1 << 20) - 1;
>> +static DEFINE_SPINLOCK(mpls_multipath_lock);
>>
>> static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt,
>> struct nlmsghdr *nlh, struct net *net, u32 portid,
>> @@ -80,10 +53,10 @@ bool mpls_output_possible(const struct net_device *dev)
>> }
>> EXPORT_SYMBOL_GPL(mpls_output_possible);
>>
>> -static unsigned int mpls_rt_header_size(const struct mpls_route *rt)
>> +static unsigned int mpls_nh_header_size(const struct mpls_nh *nh)
>> {
>> /* The size of the layer 2.5 labels to be added for this route */
>> - return rt->rt_labels * sizeof(struct mpls_shim_hdr);
>> + return nh->nh_labels * sizeof(struct mpls_shim_hdr);
>> }
>>
>> unsigned int mpls_dev_mtu(const struct net_device *dev)
>> @@ -105,8 +78,58 @@ bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu)
>> }
>> EXPORT_SYMBOL_GPL(mpls_pkt_too_big);
>>
>> -static bool mpls_egress(struct mpls_route *rt, struct sk_buff *skb,
>> - struct mpls_entry_decoded dec)
>> +/* This is a cut/copy/modify from fib_select_multipath */
>> +static struct mpls_nh *mpls_select_multipath(struct mpls_route *rt)
>> +{
>> + struct mpls_nh *nh;
>> + struct mpls_nh *ret_nh;
>> + int nhsel = 0;
>> + int w;
>> +
>> + spin_lock_bh(&mpls_multipath_lock);
>> + ret_nh = list_first_entry_or_null(&rt->rt_nhs, struct mpls_nh,
>> + nh_next);
>> + if (rt->rt_power <= 0) {
>> + int power = 0;
>> +
>> + list_for_each_entry(nh, &rt->rt_nhs, nh_next) {
>> + power += nh->nh_weight;
>> + nh->nh_power = nh->nh_weight;
>> + }
>> + rt->rt_power = power;
>> + if (power <= 0) {
>> + spin_unlock_bh(&mpls_multipath_lock);
>> + /* Race condition: route has just become dead. */
>> + return ret_nh;
>> + }
>> + }
>> +
>> + /* w should be random number [0..rt->rt_power-1],
>> + * it is pretty bad approximation.
>> + */
>> + w = jiffies % rt->rt_power;
>> +
>> + list_for_each_entry(nh, &rt->rt_nhs, nh_next) {
>> + if (nh->nh_power) {
>> + w -= nh->nh_power;
>> + if (w <= 0) {
>> + nh->nh_power--;
>> + rt->rt_power--;
>> + ret_nh = nh;
>> + spin_unlock_bh(&mpls_multipath_lock);
>> + return ret_nh;
>> + }
>> + }
>> + nhsel++;
>> + }
>> +
>> + /* Race condition: route has just become dead. */
>> + spin_unlock_bh(&mpls_multipath_lock);
>> + return ret_nh;
>> +}
>> +
>> +static bool mpls_egress(struct mpls_route *rt, struct mpls_nh *nh,
>> + struct sk_buff *skb, struct mpls_entry_decoded dec)
>> {
>> enum mpls_payload_type payload_type;
>> bool success = false;
>> @@ -159,6 +182,7 @@ static int mpls_forward(struct sk_buff *skb, struct net_device *dev,
>> struct net *net = dev_net(dev);
>> struct mpls_shim_hdr *hdr;
>> struct mpls_route *rt;
>> + struct mpls_nh *nh;
>> struct mpls_entry_decoded dec;
>> struct net_device *out_dev;
>> struct mpls_dev *mdev;
>> @@ -196,9 +220,13 @@ static int mpls_forward(struct sk_buff *skb, struct net_device *dev,
>> if (!rt)
>> goto drop;
>>
>> + nh = mpls_select_multipath(rt);
>> + if (!nh)
>> + goto drop;
>> +
>> /* Find the output device */
>> - out_dev = rcu_dereference(rt->rt_dev);
>> - if (!mpls_output_possible(out_dev))
>> + out_dev = rcu_dereference(nh->nh_dev);
>> + if (!out_dev || !mpls_output_possible(out_dev))
>> goto drop;
>>
>> if (skb_warn_if_lro(skb))
>> @@ -212,7 +240,7 @@ static int mpls_forward(struct sk_buff *skb, struct net_device *dev,
>> dec.ttl -= 1;
>>
>> /* Verify the destination can hold the packet */
>> - new_header_size = mpls_rt_header_size(rt);
>> + new_header_size = mpls_nh_header_size(nh);
>> mtu = mpls_dev_mtu(out_dev);
>> if (mpls_pkt_too_big(skb, mtu - new_header_size))
>> goto drop;
>> @@ -230,7 +258,7 @@ static int mpls_forward(struct sk_buff *skb, struct net_device *dev,
>>
>> if (unlikely(!new_header_size && dec.bos)) {
>> /* Penultimate hop popping */
>> - if (!mpls_egress(rt, skb, dec))
>> + if (!mpls_egress(rt, nh, skb, dec))
>> goto drop;
>> } else {
>> bool bos;
>> @@ -240,13 +268,14 @@ static int mpls_forward(struct sk_buff *skb, struct net_device *dev,
>> /* Push the new labels */
>> hdr = mpls_hdr(skb);
>> bos = dec.bos;
>> - for (i = rt->rt_labels - 1; i >= 0; i--) {
>> - hdr[i] = mpls_entry_encode(rt->rt_label[i], dec.ttl, 0, bos);
>> + for (i = nh->nh_labels - 1; i >= 0; i--) {
>> + hdr[i] = mpls_entry_encode(nh->nh_label[i],
>> + dec.ttl, 0, bos);
>> bos = false;
>> }
>> }
>>
>> - err = neigh_xmit(rt->rt_via_table, out_dev, rt->rt_via, skb);
>> + err = neigh_xmit(nh->nh_via_table, out_dev, nh->nh_via, skb);
>> if (err)
>> net_dbg_ratelimited("%s: packet transmission failed: %d\n",
>> __func__, err);
>> @@ -270,31 +299,43 @@ static const struct nla_policy rtm_mpls_policy[RTA_MAX+1] = {
>> struct mpls_route_config {
>> u32 rc_protocol;
>> u32 rc_ifindex;
>> - u16 rc_via_table;
>> - u16 rc_via_alen;
>> + u8 rc_via_table;
>> + u8 rc_via_alen;
>> u8 rc_via[MAX_VIA_ALEN];
>> + u8 rc_output_labels;
>> u32 rc_label;
>> - u32 rc_output_labels;
>> u32 rc_output_label[MAX_NEW_LABELS];
>> u32 rc_nlflags;
>> enum mpls_payload_type rc_payload_type;
>> struct nl_info rc_nlinfo;
>> + struct rtnexthop *rc_mp;
>> + int rc_mp_len;
>> };
>>
>> -static struct mpls_route *mpls_rt_alloc(size_t alen)
>> +static struct mpls_route *mpls_rt_alloc(int num_nh)
>> {
>> struct mpls_route *rt;
>>
>> - rt = kzalloc(sizeof(*rt) + alen, GFP_KERNEL);
>> - if (rt)
>> - rt->rt_via_alen = alen;
>> + rt = kzalloc(sizeof(*rt), GFP_KERNEL);
>> + if (rt) {
>> + rt->rt_nhn = num_nh;
>> + INIT_LIST_HEAD(&rt->rt_nhs);
>> + }
>> +
>> return rt;
>> }
>>
>> static void mpls_rt_free(struct mpls_route *rt)
>> {
>> - if (rt)
>> + struct mpls_nh *nh, *nh_safe;
>> +
>> + if (rt) {
>> + list_for_each_entry_safe(nh, nh_safe, &rt->rt_nhs, nh_next) {
>> + list_del(&nh->nh_next);
>> + kfree(nh);
>> + }
>> kfree_rcu(rt, rt_rcu);
>> + }
>> }
>>
>> static void mpls_notify_route(struct net *net, unsigned index,
>> @@ -312,25 +353,22 @@ static void mpls_notify_route(struct net *net, unsigned index,
>> }
>>
>> static void mpls_route_update(struct net *net, unsigned index,
>> - struct net_device *dev, struct mpls_route *new,
>> + struct mpls_route *new,
>> const struct nl_info *info)
>> {
>> struct mpls_route __rcu **platform_label;
>> - struct mpls_route *rt, *old = NULL;
>> + struct mpls_route *rt;
>>
>> ASSERT_RTNL();
>>
>> platform_label = rtnl_dereference(net->mpls.platform_label);
>> rt = rtnl_dereference(platform_label[index]);
>> - if (!dev || (rt && (rtnl_dereference(rt->rt_dev) == dev))) {
>> - rcu_assign_pointer(platform_label[index], new);
>> - old = rt;
>> - }
>> + rcu_assign_pointer(platform_label[index], new);
>>
>> - mpls_notify_route(net, index, old, new, info);
>> + mpls_notify_route(net, index, rt, new, info);
>>
>> /* If we removed a route free it now */
>> - mpls_rt_free(old);
>> + mpls_rt_free(rt);
>> }
>>
>> static unsigned find_free_label(struct net *net)
>> @@ -406,23 +444,23 @@ static struct net_device *inet6_fib_lookup_dev(struct net *net, void *addr)
>> #endif
>>
>> static struct net_device *find_outdev(struct net *net,
>> - struct mpls_route_config *cfg)
>> + struct mpls_nh *nh, int oif)
>> {
>> struct net_device *dev = NULL;
>>
>> - if (!cfg->rc_ifindex) {
>> - switch (cfg->rc_via_table) {
>> + if (!oif) {
>> + switch (nh->nh_via_table) {
>> case NEIGH_ARP_TABLE:
>> - dev = inet_fib_lookup_dev(net, cfg->rc_via);
>> + dev = inet_fib_lookup_dev(net, nh->nh_via);
>> break;
>> case NEIGH_ND_TABLE:
>> - dev = inet6_fib_lookup_dev(net, cfg->rc_via);
>> + dev = inet6_fib_lookup_dev(net, nh->nh_via);
>> break;
>> case NEIGH_LINK_TABLE:
>> break;
>> }
>> } else {
>> - dev = dev_get_by_index(net, cfg->rc_ifindex);
>> + dev = dev_get_by_index(net, oif);
>> }
>>
>> if (!dev)
>> @@ -431,15 +469,208 @@ static struct net_device *find_outdev(struct net *net,
>> return dev;
>> }
>>
>> +static int mpls_nh_assign_dev(struct net *net, struct mpls_nh *nh, int oif)
>> +{
>> + struct net_device *dev = NULL;
>> + int err = -ENODEV;
>> +
>> + dev = find_outdev(net, nh, oif);
>> + if (IS_ERR(dev)) {
>> + err = PTR_ERR(dev);
>> + dev = NULL;
>> + goto errout;
>> + }
>> +
>> + /* Ensure this is a supported device */
>> + err = -EINVAL;
>> + if (!mpls_dev_get(dev))
>> + goto errout;
>> +
>> + RCU_INIT_POINTER(nh->nh_dev, dev);
>> + dev_put(dev);
>> +
>> + return 0;
>> +
>> +errout:
>> + if (dev)
>> + dev_put(dev);
>> + return err;
>> +}
>> +
>> +static struct mpls_nh *mpls_nh_alloc(size_t alen)
>> +{
>> + struct mpls_nh *nh;
>> +
>> + nh = kzalloc(sizeof(*nh) + alen, GFP_KERNEL);
>> + if (nh)
>> + nh->nh_via_alen = alen;
>> +
>> + return nh;
>> +}
>> +
>> +static int mpls_nh_build_from_cfg(struct mpls_route_config *cfg,
>> + struct mpls_route *rt)
>> +{
>> + struct net *net = cfg->rc_nlinfo.nl_net;
>> + struct mpls_nh *nh = NULL;
>> + int err;
>> + int i;
>> +
>> + err = -EINVAL;
>> + /* Ensure only a supported number of labels are present */
>> + if (cfg->rc_output_labels > MAX_NEW_LABELS)
>> + goto errout;
>> +
>> + err = -ENOMEM;
>> + nh = mpls_nh_alloc(cfg->rc_via_alen);
>> + if (!nh)
>> + goto errout;
>> +
>> + nh->nh_labels = cfg->rc_output_labels;
>> + for (i = 0; i < nh->nh_labels; i++)
>> + nh->nh_label[i] = cfg->rc_output_label[i];
>> +
>> + nh->nh_via_table = cfg->rc_via_table;
>> + memcpy(nh->nh_via, cfg->rc_via, cfg->rc_via_alen);
>> + nh->nh_via_alen = cfg->rc_via_alen;
>> +
>> + err = mpls_nh_assign_dev(net, nh, cfg->rc_ifindex);
>> + if (err)
>> + goto errout;
>> +
>> + list_add_tail(&nh->nh_next, &rt->rt_nhs);
>> +
>> + return 0;
>> +
>> +errout:
>> + kfree(nh);
>> +
>> + return err;
>> +}
>> +
>> +static int mpls_nh_build(struct net *net, struct mpls_nh **rt_nh,
>> + int oif, struct nlattr *via_attr,
>> + struct nlattr *newdst)
>> +{
>> + struct mpls_nh *nh = NULL;
>> + int err;
>> + u8 via_alen;
>> + u8 via_table;
>> + u8 via[MAX_VIA_ALEN];
>> +
>> + err = nla_get_via(via_attr, &via_alen, &via_table,
>> + via);
>> + if (err)
>> + goto errout;
>> +
>> + nh = mpls_nh_alloc(via_alen);
>> + if (!nh)
>> + goto errout;
>> +
>> + if (newdst) {
>> + err = nla_get_labels(newdst, MAX_NEW_LABELS,
>> + &nh->nh_labels, nh->nh_label);
>> + if (err)
>> + goto errout;
>> + }
>> + nh->nh_via_table = via_table;
>> + memcpy(nh->nh_via, via, via_alen);
>> +
>> + err = mpls_nh_assign_dev(net, nh, oif);
>> + if (err)
>> + goto errout;
>> +
>> + *rt_nh = nh;
>> +
>> + return 0;
>> +
>> +errout:
>> + kfree(nh);
>> +
>> + return err;
>> +}
>> +
>> +static int mpls_count_nexthops(struct rtnexthop *rtnh, int len)
>> +{
>> + int nhs = 0;
>> + int remaining = len;
>> +
>> + while (rtnh_ok(rtnh, remaining)) {
>> + nhs++;
>> + rtnh = rtnh_next(rtnh, &remaining);
>> + }
>> +
>> + /* leftover implies invalid nexthop configuration, discard it */
>> + return remaining > 0 ? 0 : nhs;
>> +}
>> +
>> +static int mpls_nh_build_multi(struct mpls_route_config *cfg,
>> + struct mpls_route *rt)
>> +{
>> + struct rtnexthop *rtnh = cfg->rc_mp;
>> + struct nlattr *nla_via, *nla_newdst;
>> + int remaining = cfg->rc_mp_len;
>> + struct mpls_nh *nh, *nh_safe;
>> + int nhs = 0;
>> + int err = 0;
>> +
>> + while (rtnh_ok(rtnh, remaining)) {
>> + int attrlen;
>> +
>> + nla_via = NULL;
>> + nla_newdst = NULL;
>> + nh = NULL;
>> +
>> + err = -EINVAL;
>> + if (!rtnh_ok(rtnh, remaining))
>> + goto errout;
>> +
>> + attrlen = rtnh_attrlen(rtnh);
>> + if (attrlen > 0) {
>> + struct nlattr *attrs = rtnh_attrs(rtnh);
>> +
>> + nla_via = nla_find(attrs, attrlen, RTA_VIA);
>> + nla_newdst = nla_find(attrs, attrlen, RTA_NEWDST);
>> + }
>> +
>> + err = -EINVAL;
>> + if (!nla_via)
>> + goto errout;
>> +
>> + err = mpls_nh_build(cfg->rc_nlinfo.nl_net, &nh,
>> + rtnh->rtnh_ifindex, nla_via,
>> + nla_newdst);
>> + if (err)
>> + goto errout;
>> +
>> + nh->nh_weight = rtnh->rtnh_hops + 1;
>> + list_add_tail(&nh->nh_next, &rt->rt_nhs);
>> +
>> + rtnh = rtnh_next(rtnh, &remaining);
>> + nhs++;
>> + }
>> +
>> + rt->rt_nhn = nhs;
>> +
>> + return 0;
>> +
>> +errout:
>> + list_for_each_entry_safe(nh, nh_safe, &rt->rt_nhs, nh_next) {
>> + list_del(&nh->nh_next);
>> + kfree(nh);
>> + }
>> +
>> + return err;
>> +}
>> +
>> static int mpls_route_add(struct mpls_route_config *cfg)
>> {
>> struct mpls_route __rcu **platform_label;
>> struct net *net = cfg->rc_nlinfo.nl_net;
>> - struct net_device *dev = NULL;
>> struct mpls_route *rt, *old;
>> - unsigned index;
>> - int i;
>> int err = -EINVAL;
>> + unsigned index;
>> + int nhs = 1; /* default to one nexthop */
>>
>> index = cfg->rc_label;
>>
>> @@ -457,27 +688,6 @@ static int mpls_route_add(struct mpls_route_config *cfg)
>> if (index >= net->mpls.platform_labels)
>> goto errout;
>>
>> - /* Ensure only a supported number of labels are present */
>> - if (cfg->rc_output_labels > MAX_NEW_LABELS)
>> - goto errout;
>> -
>> - dev = find_outdev(net, cfg);
>> - if (IS_ERR(dev)) {
>> - err = PTR_ERR(dev);
>> - dev = NULL;
>> - goto errout;
>> - }
>> -
>> - /* Ensure this is a supported device */
>> - err = -EINVAL;
>> - if (!mpls_dev_get(dev))
>> - goto errout;
>> -
>> - err = -EINVAL;
>> - if ((cfg->rc_via_table == NEIGH_LINK_TABLE) &&
>> - (dev->addr_len != cfg->rc_via_alen))
>> - goto errout;
>> -
>> /* Append makes no sense with mpls */
>> err = -EOPNOTSUPP;
>> if (cfg->rc_nlflags & NLM_F_APPEND)
>> @@ -497,28 +707,34 @@ static int mpls_route_add(struct mpls_route_config *cfg)
>> if (!(cfg->rc_nlflags & NLM_F_CREATE) && !old)
>> goto errout;
>>
>> + if (cfg->rc_mp) {
>> + err = -EINVAL;
>> + nhs = mpls_count_nexthops(cfg->rc_mp, cfg->rc_mp_len);
>> + if (nhs == 0)
>> + goto errout;
>> + }
>> +
>> err = -ENOMEM;
>> - rt = mpls_rt_alloc(cfg->rc_via_alen);
>> + rt = mpls_rt_alloc(nhs);
>> if (!rt)
>> goto errout;
>> -
>> - rt->rt_labels = cfg->rc_output_labels;
>> - for (i = 0; i < rt->rt_labels; i++)
>> - rt->rt_label[i] = cfg->rc_output_label[i];
>> rt->rt_protocol = cfg->rc_protocol;
>> - RCU_INIT_POINTER(rt->rt_dev, dev);
>> rt->rt_payload_type = cfg->rc_payload_type;
>> - rt->rt_via_table = cfg->rc_via_table;
>> - memcpy(rt->rt_via, cfg->rc_via, cfg->rc_via_alen);
>>
>> - mpls_route_update(net, index, NULL, rt, &cfg->rc_nlinfo);
>> + if (cfg->rc_mp)
>> + err = mpls_nh_build_multi(cfg, rt);
>> + else
>> + err = mpls_nh_build_from_cfg(cfg, rt);
>> + if (err)
>> + goto freert;
>> +
>> + mpls_route_update(net, index, rt, &cfg->rc_nlinfo);
>>
>> - dev_put(dev);
>> return 0;
>>
>> +freert:
>> + mpls_rt_free(rt);
>> errout:
>> - if (dev)
>> - dev_put(dev);
>> return err;
>> }
>>
>> @@ -538,7 +754,7 @@ static int mpls_route_del(struct mpls_route_config *cfg)
>> if (index >= net->mpls.platform_labels)
>> goto errout;
>>
>> - mpls_route_update(net, index, NULL, NULL, &cfg->rc_nlinfo);
>> + mpls_route_update(net, index, NULL, &cfg->rc_nlinfo);
>>
>> err = 0;
>> errout:
>> @@ -628,6 +844,7 @@ static void mpls_ifdown(struct net_device *dev)
>> struct mpls_route __rcu **platform_label;
>> struct net *net = dev_net(dev);
>> struct mpls_dev *mdev;
>> + struct mpls_nh *nh;
>> unsigned index;
>>
>> platform_label = rtnl_dereference(net->mpls.platform_label);
>> @@ -635,9 +852,14 @@ static void mpls_ifdown(struct net_device *dev)
>> struct mpls_route *rt = rtnl_dereference(platform_label[index]);
>> if (!rt)
>> continue;
>> - if (rtnl_dereference(rt->rt_dev) != dev)
>> - continue;
>> - rt->rt_dev = NULL;
>> + list_for_each_entry(nh, &rt->rt_nhs, nh_next) {
>> + struct net_device *mdev;
>> +
>> + mdev = rtnl_dereference(nh->nh_dev);
>> + if (mdev != dev)
>> + continue;
>> + nh->nh_dev = NULL;
>> + }
>> }
>>
>> mdev = mpls_dev_get(dev);
>> @@ -736,7 +958,7 @@ int nla_put_labels(struct sk_buff *skb, int attrtype,
>> EXPORT_SYMBOL_GPL(nla_put_labels);
>>
>> int nla_get_labels(const struct nlattr *nla,
>> - u32 max_labels, u32 *labels, u32 label[])
>> + u8 max_labels, u8 *labels, u32 label[])
>> {
>> unsigned len = nla_len(nla);
>> unsigned nla_labels;
>> @@ -781,6 +1003,48 @@ int nla_get_labels(const struct nlattr *nla,
>> }
>> EXPORT_SYMBOL_GPL(nla_get_labels);
>>
>> +int nla_get_via(const struct nlattr *nla, u8 *via_alen,
>> + u8 *via_table, u8 via_addr[])
>> +{
>> + struct rtvia *via = nla_data(nla);
>> + int err = -EINVAL;
>> + u8 alen;
>> +
>> + if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr))
>> + goto errout;
>> + alen = nla_len(nla) -
>> + offsetof(struct rtvia, rtvia_addr);
>> + if (alen > MAX_VIA_ALEN)
>> + goto errout;
>> +
>> + /* Validate the address family */
>> + switch (via->rtvia_family) {
>> + case AF_PACKET:
>> + *via_table = NEIGH_LINK_TABLE;
>> + break;
>> + case AF_INET:
>> + *via_table = NEIGH_ARP_TABLE;
>> + if (alen != 4)
>> + goto errout;
>> + break;
>> + case AF_INET6:
>> + *via_table = NEIGH_ND_TABLE;
>> + if (alen != 16)
>> + goto errout;
>> + break;
>> + default:
>> + /* Unsupported address family */
>> + goto errout;
>> + }
>> +
>> + memcpy(via_addr, via->rtvia_addr, alen);
>> + *via_alen = alen;
>> + err = 0;
>> +
>> +errout:
>> + return err;
>> +}
>> +
>> static int rtm_to_route_config(struct sk_buff *skb, struct nlmsghdr *nlh,
>> struct mpls_route_config *cfg)
>> {
>> @@ -844,7 +1108,7 @@ static int rtm_to_route_config(struct sk_buff *skb, struct nlmsghdr *nlh,
>> break;
>> case RTA_DST:
>> {
>> - u32 label_count;
>> + u8 label_count;
>> if (nla_get_labels(nla, 1, &label_count,
>> &cfg->rc_label))
>> goto errout;
>> @@ -857,35 +1121,15 @@ static int rtm_to_route_config(struct sk_buff *skb, struct nlmsghdr *nlh,
>> }
>> case RTA_VIA:
>> {
>> - struct rtvia *via = nla_data(nla);
>> - if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr))
>> + if (nla_get_via(nla, &cfg->rc_via_alen,
>> + &cfg->rc_via_table, cfg->rc_via))
>> goto errout;
>> - cfg->rc_via_alen = nla_len(nla) -
>> - offsetof(struct rtvia, rtvia_addr);
>> - if (cfg->rc_via_alen > MAX_VIA_ALEN)
>> - goto errout;
>> -
>> - /* Validate the address family */
>> - switch(via->rtvia_family) {
>> - case AF_PACKET:
>> - cfg->rc_via_table = NEIGH_LINK_TABLE;
>> - break;
>> - case AF_INET:
>> - cfg->rc_via_table = NEIGH_ARP_TABLE;
>> - if (cfg->rc_via_alen != 4)
>> - goto errout;
>> - break;
>> - case AF_INET6:
>> - cfg->rc_via_table = NEIGH_ND_TABLE;
>> - if (cfg->rc_via_alen != 16)
>> - goto errout;
>> - break;
>> - default:
>> - /* Unsupported address family */
>> - goto errout;
>> - }
>> -
>> - memcpy(cfg->rc_via, via->rtvia_addr, cfg->rc_via_alen);
>> + break;
>> + }
>> + case RTA_MULTIPATH:
>> + {
>> + cfg->rc_mp = nla_data(nla);
>> + cfg->rc_mp_len = nla_len(nla);
>> break;
>> }
>> default:
>> @@ -946,16 +1190,56 @@ static int mpls_dump_route(struct sk_buff *skb, u32 portid, u32 seq, int event,
>> rtm->rtm_type = RTN_UNICAST;
>> rtm->rtm_flags = 0;
>>
>> - if (rt->rt_labels &&
>> - nla_put_labels(skb, RTA_NEWDST, rt->rt_labels, rt->rt_label))
>> - goto nla_put_failure;
>> - if (nla_put_via(skb, rt->rt_via_table, rt->rt_via, rt->rt_via_alen))
>> - goto nla_put_failure;
>> - dev = rtnl_dereference(rt->rt_dev);
>> - if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex))
>> - goto nla_put_failure;
>> if (nla_put_labels(skb, RTA_DST, 1, &label))
>> goto nla_put_failure;
>> + if (rt->rt_nhn == 1) {
>> + struct mpls_nh *nh = list_first_entry_or_null(&rt->rt_nhs,
>> + struct mpls_nh,
>> + nh_next);
>> +
>> + if (nh->nh_labels &&
>> + nla_put_labels(skb, RTA_NEWDST, nh->nh_labels,
>> + nh->nh_label))
>> + goto nla_put_failure;
>> + if (nla_put_via(skb, nh->nh_via_table, nh->nh_via,
>> + nh->nh_via_alen))
>> + goto nla_put_failure;
>> + dev = rtnl_dereference(nh->nh_dev);
>> + if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex))
>> + goto nla_put_failure;
>> + } else {
>> + struct rtnexthop *rtnh;
>> + struct nlattr *mp;
>> + struct mpls_nh *nh;
>> +
>> + mp = nla_nest_start(skb, RTA_MULTIPATH);
>> + if (!mp)
>> + goto nla_put_failure;
>> +
>> + list_for_each_entry(nh, &rt->rt_nhs, nh_next) {
>> + rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh));
>> + if (!rtnh)
>> + goto nla_put_failure;
>> +
>> + rtnh->rtnh_flags = nh->nh_flags & 0xFF;
>> + dev = rtnl_dereference(nh->nh_dev);
>> + if (dev)
>> + rtnh->rtnh_ifindex = dev->ifindex;
>> + if (nh->nh_labels &&
>> + nla_put_labels(skb, RTA_NEWDST, nh->nh_labels,
>> + nh->nh_label))
>> + goto nla_put_failure;
>> + if (nla_put_via(skb, nh->nh_via_table,
>> + nh->nh_via,
>> + nh->nh_via_alen))
>> + goto nla_put_failure;
>> +
>> + /* length of rtnetlink header + attributes */
>> + rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *)rtnh;
>> + }
>> +
>> + nla_nest_end(skb, mp);
>> + }
>>
>> nlmsg_end(skb, nlh);
>> return 0;
>> @@ -1000,12 +1284,34 @@ static inline size_t lfib_nlmsg_size(struct mpls_route *rt)
>> {
>> size_t payload =
>> NLMSG_ALIGN(sizeof(struct rtmsg))
>> - + nla_total_size(2 + rt->rt_via_alen) /* RTA_VIA */
>> + nla_total_size(4); /* RTA_DST */
>> - if (rt->rt_labels) /* RTA_NEWDST */
>> - payload += nla_total_size(rt->rt_labels * 4);
>> - if (rt->rt_dev) /* RTA_OIF */
>> - payload += nla_total_size(4);
>> +
>> + if (rt->rt_nhn == 1) {
>> + struct mpls_nh *nh = list_first_entry_or_null(&rt->rt_nhs,
>> + struct mpls_nh,
>> + nh_next);
>> +
>> + if (nh->nh_dev)
>> + payload += nla_total_size(4); /* RTA_OIF */
>> + payload += nla_total_size(2 + nh->nh_via_alen); /* RTA_VIA */
>> + if (nh->nh_labels) /* RTA_NEWDST */
>> + payload += nla_total_size(nh->nh_labels * 4);
>> + } else {
>> + struct mpls_nh *nh;
>> + /* each nexthop is packed in an attribute */
>> + size_t nhsize = 0;
>> +
>> + list_for_each_entry(nh, &rt->rt_nhs, nh_next) {
>> + nhsize += nla_total_size(sizeof(struct rtnexthop)) +
>> + nla_total_size(nh->nh_via_alen +
>> + 2); /* RTA_VIA */
>> + if (nh->nh_labels) /* RTA_NEWDST */
>> + nhsize += nla_total_size(nh->nh_labels * 4);
>> + }
>> + /* nested attribute */
>> + payload += nla_total_size(nhsize);
>> + }
>> +
>> return payload;
>> }
>>
>> @@ -1057,25 +1363,37 @@ static int resize_platform_label_table(struct net *net, size_t limit)
>> /* In case the predefined labels need to be populated */
>> if (limit > MPLS_LABEL_IPV4NULL) {
>> struct net_device *lo = net->loopback_dev;
>> - rt0 = mpls_rt_alloc(lo->addr_len);
>> + struct mpls_nh *nh;
>> +
>> + rt0 = mpls_rt_alloc(1);
>> if (!rt0)
>> goto nort0;
>> - RCU_INIT_POINTER(rt0->rt_dev, lo);
>> rt0->rt_protocol = RTPROT_KERNEL;
>> rt0->rt_payload_type = MPT_IPV4;
>> - rt0->rt_via_table = NEIGH_LINK_TABLE;
>> - memcpy(rt0->rt_via, lo->dev_addr, lo->addr_len);
>> + nh = mpls_nh_alloc(lo->addr_len);
>> + if (!nh)
>> + goto nort2;
>> + RCU_INIT_POINTER(nh->nh_dev, lo);
>> + nh->nh_via_table = NEIGH_LINK_TABLE;
>> + memcpy(nh->nh_via, lo->dev_addr, lo->addr_len);
>> + list_add_tail(&nh->nh_next, &rt0->rt_nhs);
>> }
>> if (limit > MPLS_LABEL_IPV6NULL) {
>> struct net_device *lo = net->loopback_dev;
>> - rt2 = mpls_rt_alloc(lo->addr_len);
>> + struct mpls_nh *nh;
>> +
>> + rt2 = mpls_rt_alloc(1);
>> if (!rt2)
>> goto nort2;
>> - RCU_INIT_POINTER(rt2->rt_dev, lo);
>> rt2->rt_protocol = RTPROT_KERNEL;
>> rt2->rt_payload_type = MPT_IPV6;
>> - rt2->rt_via_table = NEIGH_LINK_TABLE;
>> - memcpy(rt2->rt_via, lo->dev_addr, lo->addr_len);
>> + nh = mpls_nh_alloc(lo->addr_len);
>> + if (!nh)
>> + goto nort2;
>> + RCU_INIT_POINTER(nh->nh_dev, lo);
>> + nh->nh_via_table = NEIGH_LINK_TABLE;
>> + memcpy(nh->nh_via, lo->dev_addr, lo->addr_len);
>> + list_add_tail(&nh->nh_next, &rt2->rt_nhs);
>> }
>>
>> rtnl_lock();
>> @@ -1085,7 +1403,7 @@ static int resize_platform_label_table(struct net *net, size_t limit)
>>
>> /* Free any labels beyond the new table */
>> for (index = limit; index < old_limit; index++)
>> - mpls_route_update(net, index, NULL, NULL, NULL);
>> + mpls_route_update(net, index, NULL, NULL);
>>
>> /* Copy over the old labels */
>> cp_size = size;
>> @@ -1124,6 +1442,7 @@ static int resize_platform_label_table(struct net *net, size_t limit)
>>
>> nort2:
>> mpls_rt_free(rt0);
>> + mpls_rt_free(rt2);
>> nort0:
>> kvfree(labels);
>> nolabels:
>> diff --git a/net/mpls/internal.h b/net/mpls/internal.h
>> index 2681a4b..9e18b58 100644
>> --- a/net/mpls/internal.h
>> +++ b/net/mpls/internal.h
>> @@ -1,6 +1,17 @@
>> #ifndef MPLS_INTERNAL_H
>> #define MPLS_INTERNAL_H
>>
>> +enum mpls_payload_type {
>> + MPT_UNSPEC, /* IPv4 or IPv6 */
>> + MPT_IPV4 = 4,
>> + MPT_IPV6 = 6,
>> +
>> + /* Other types not implemented:
>> + * - Pseudo-wire with or without control word (RFC4385)
>> + * - GAL (RFC5586)
>> + */
>> +};
>> +
>> struct mpls_shim_hdr {
>> __be32 label_stack_entry;
>> };
>> @@ -21,6 +32,34 @@ struct mpls_dev {
>>
>> struct sk_buff;
>>
>> +#define LABEL_NOT_SPECIFIED (1 << 20)
>> +#define MAX_NEW_LABELS 2
>> +
>> +/* This maximum ha length copied from the definition of struct neighbour */
>> +#define MAX_VIA_ALEN (ALIGN(MAX_ADDR_LEN, sizeof(unsigned long)))
>> +
>> +struct mpls_nh {
>> + struct net_device __rcu *nh_dev;
>> + u32 nh_label[MAX_NEW_LABELS];
>> + unsigned int nh_flags;
>> + int nh_weight;
>> + int nh_power;
>> + struct list_head nh_next;
>> + u8 nh_labels;
>> + u8 nh_via_alen;
>> + u8 nh_via_table;
>> + u8 nh_via[0];
>> +};
>> +
>> +struct mpls_route {
>> + struct rcu_head rt_rcu;
>> + u8 rt_protocol;
>> + u8 rt_payload_type;
>> + int rt_power;
>> + int rt_nhn;
>> + struct list_head rt_nhs;
>> +};
>> +
>> static inline struct mpls_shim_hdr *mpls_hdr(const struct sk_buff *skb)
>> {
>> return (struct mpls_shim_hdr *)skb_network_header(skb);
>> @@ -52,8 +91,10 @@ static inline struct mpls_entry_decoded mpls_entry_decode(struct mpls_shim_hdr *
>>
>> int nla_put_labels(struct sk_buff *skb, int attrtype, u8 labels,
>> const u32 label[]);
>> -int nla_get_labels(const struct nlattr *nla, u32 max_labels, u32 *labels,
>> +int nla_get_labels(const struct nlattr *nla, u8 max_labels, u8 *labels,
>> u32 label[]);
>> +int nla_get_via(const struct nlattr *nla, u8 *via_alen, u8 *via_table,
>> + u8 via[]);
>> bool mpls_output_possible(const struct net_device *dev);
>> unsigned int mpls_dev_mtu(const struct net_device *dev);
>> bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu);
--
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