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Commit a4ac8c98 authored by David Ahern's avatar David Ahern Committed by David S. Miller
Browse files

net: mpls: bump maximum number of labels 



Allow users to push down more labels per MPLS route. With the previous
patches, no memory allocations are based on MAX_NEW_LABELS; the limit
is only used to keep userspace in check.

At this point MAX_NEW_LABELS is only used for mpls_route_config (copying
route data from userspace) and processing nexthops looking for the max
number of labels across the route spec.

Signed-off-by: default avatarDavid Ahern <dsa@cumulusnetworks.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent df1c6316

net/mpls/af_mpls.c

+70 −33
Original line number Diff line number Diff line
@@ -24,7 +24,10 @@ 
#include <net/nexthop.h>

#include "internal.h"



#define MAX_NEW_LABELS 2

/* put a reasonable limit on the number of labels

 * we will accept from userspace

 */

#define MAX_NEW_LABELS	30



/* max memory we will use for mpls_route */

#define MAX_MPLS_ROUTE_MEM	4096
@@ -698,9 +701,6 @@ static int mpls_nh_build_from_cfg(struct mpls_route_config *cfg, 
		return -ENOMEM;



	err = -EINVAL;

	/* Ensure only a supported number of labels are present */

	if (cfg->rc_output_labels > MAX_NEW_LABELS)

		goto errout;



	nh->nh_labels = cfg->rc_output_labels;

	for (i = 0; i < nh->nh_labels; i++)
@@ -725,7 +725,7 @@ static int mpls_nh_build_from_cfg(struct mpls_route_config *cfg, 


static int mpls_nh_build(struct net *net, struct mpls_route *rt,

			 struct mpls_nh *nh, int oif, struct nlattr *via,

			 struct nlattr *newdst)

			 struct nlattr *newdst, u8 max_labels)

{

	int err = -ENOMEM;
@@ -733,7 +733,7 @@ static int mpls_nh_build(struct net *net, struct mpls_route *rt, 
		goto errout;



	if (newdst) {

		err = nla_get_labels(newdst, MAX_NEW_LABELS,

		err = nla_get_labels(newdst, max_labels,

				     &nh->nh_labels, nh->nh_label);

		if (err)

			goto errout;
@@ -759,21 +759,19 @@ static int mpls_nh_build(struct net *net, struct mpls_route *rt, 
}



static u8 mpls_count_nexthops(struct rtnexthop *rtnh, int len,

			      u8 cfg_via_alen, u8 *max_via_alen)

			      u8 cfg_via_alen, u8 *max_via_alen,

			      u8 *max_labels)

{

	int remaining = len;

	u8 nhs = 0;



	if (!rtnh) {

		*max_via_alen = cfg_via_alen;

		return 1;

	}



	*max_via_alen = 0;

	*max_labels = 0;



	while (rtnh_ok(rtnh, remaining)) {

		struct nlattr *nla, *attrs = rtnh_attrs(rtnh);

		int attrlen;

		u8 n_labels = 0;



		attrlen = rtnh_attrlen(rtnh);

		nla = nla_find(attrs, attrlen, RTA_VIA);
@@ -787,6 +785,13 @@ static u8 mpls_count_nexthops(struct rtnexthop *rtnh, int len, 
						      via_alen);

		}



		nla = nla_find(attrs, attrlen, RTA_NEWDST);

		if (nla &&

		    nla_get_labels(nla, MAX_NEW_LABELS, &n_labels, NULL) != 0)

			return 0;



		*max_labels = max_t(u8, *max_labels, n_labels);



		/* number of nexthops is tracked by a u8.

		 * Check for overflow.

		 */
@@ -802,7 +807,7 @@ static u8 mpls_count_nexthops(struct rtnexthop *rtnh, int len, 
}



static int mpls_nh_build_multi(struct mpls_route_config *cfg,

			       struct mpls_route *rt)

			       struct mpls_route *rt, u8 max_labels)

{

	struct rtnexthop *rtnh = cfg->rc_mp;

	struct nlattr *nla_via, *nla_newdst;
@@ -835,7 +840,8 @@ static int mpls_nh_build_multi(struct mpls_route_config *cfg, 
		}



		err = mpls_nh_build(cfg->rc_nlinfo.nl_net, rt, nh,

				    rtnh->rtnh_ifindex, nla_via, nla_newdst);

				    rtnh->rtnh_ifindex, nla_via, nla_newdst,

				    max_labels);

		if (err)

			goto errout;
@@ -862,6 +868,7 @@ static int mpls_route_add(struct mpls_route_config *cfg) 
	int err = -EINVAL;

	u8 max_via_alen;

	unsigned index;

	u8 max_labels;

	u8 nhs;



	index = cfg->rc_label;
@@ -900,13 +907,21 @@ static int mpls_route_add(struct mpls_route_config *cfg) 
		goto errout;



	err = -EINVAL;

	if (cfg->rc_mp) {

		nhs = mpls_count_nexthops(cfg->rc_mp, cfg->rc_mp_len,

				  cfg->rc_via_alen, &max_via_alen);

					  cfg->rc_via_alen, &max_via_alen,

					  &max_labels);

	} else {

		max_via_alen = cfg->rc_via_alen;

		max_labels = cfg->rc_output_labels;

		nhs = 1;

	}



	if (nhs == 0)

		goto errout;



	err = -ENOMEM;

	rt = mpls_rt_alloc(nhs, max_via_alen, MAX_NEW_LABELS);

	rt = mpls_rt_alloc(nhs, max_via_alen, max_labels);

	if (IS_ERR(rt)) {

		err = PTR_ERR(rt);

		goto errout;
@@ -917,7 +932,7 @@ static int mpls_route_add(struct mpls_route_config *cfg) 
	rt->rt_ttl_propagate = cfg->rc_ttl_propagate;



	if (cfg->rc_mp)

		err = mpls_nh_build_multi(cfg, rt);

		err = mpls_nh_build_multi(cfg, rt, max_labels);

	else

		err = mpls_nh_build_from_cfg(cfg, rt);

	if (err)
@@ -1531,16 +1546,18 @@ 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, u8 *labels, u32 label[])

		   u8 max_labels, u8 *labels, u32 label[])

{

	unsigned len = nla_len(nla);

	unsigned nla_labels;

	struct mpls_shim_hdr *nla_label;

	u8 nla_labels;

	bool bos;

	int i;



	/* len needs to be an even multiple of 4 (the label size) */

	if (len & 3)

	/* len needs to be an even multiple of 4 (the label size). Number

	 * of labels is a u8 so check for overflow.

	 */

	if (len & 3 || len / 4 > 255)

		return -EINVAL;



	/* Limit the number of new labels allowed */
@@ -1548,6 +1565,10 @@ int nla_get_labels(const struct nlattr *nla, 
	if (nla_labels > max_labels)

		return -EINVAL;



	/* when label == NULL, caller wants number of labels */

	if (!label)

		goto out;



	nla_label = nla_data(nla);

	bos = true;

	for (i = nla_labels - 1; i >= 0; i--, bos = false) {
@@ -1571,6 +1592,7 @@ int nla_get_labels(const struct nlattr *nla, 


		label[i] = dec.label;

	}

out:

	*labels = nla_labels;

	return 0;

}
@@ -1632,7 +1654,6 @@ static int rtm_to_route_config(struct sk_buff *skb, struct nlmsghdr *nlh, 


	err = -EINVAL;

	rtm = nlmsg_data(nlh);

	memset(cfg, 0, sizeof(*cfg));



	if (rtm->rtm_family != AF_MPLS)

		goto errout;
@@ -1731,27 +1752,43 @@ static int rtm_to_route_config(struct sk_buff *skb, struct nlmsghdr *nlh, 


static int mpls_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh)

{

	struct mpls_route_config cfg;

	struct mpls_route_config *cfg;

	int err;



	err = rtm_to_route_config(skb, nlh, &cfg);

	cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);

	if (!cfg)

		return -ENOMEM;



	err = rtm_to_route_config(skb, nlh, cfg);

	if (err < 0)

		return err;

		goto out;



	return mpls_route_del(&cfg);

	err = mpls_route_del(cfg);

out:

	kfree(cfg);



	return err;

}





static int mpls_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh)

{

	struct mpls_route_config cfg;

	struct mpls_route_config *cfg;

	int err;



	err = rtm_to_route_config(skb, nlh, &cfg);

	cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);

	if (!cfg)

		return -ENOMEM;



	err = rtm_to_route_config(skb, nlh, cfg);

	if (err < 0)

		return err;

		goto out;



	return mpls_route_add(&cfg);

	err = mpls_route_add(cfg);

out:

	kfree(cfg);



	return err;

}



static int mpls_dump_route(struct sk_buff *skb, u32 portid, u32 seq, int event,
@@ -1980,7 +2017,7 @@ 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(1, lo->addr_len, MAX_NEW_LABELS);

		rt0 = mpls_rt_alloc(1, lo->addr_len, 0);

		if (IS_ERR(rt0))

			goto nort0;

		RCU_INIT_POINTER(rt0->rt_nh->nh_dev, lo);
@@ -1994,7 +2031,7 @@ static int resize_platform_label_table(struct net *net, size_t limit) 
	}

	if (limit > MPLS_LABEL_IPV6NULL) {

		struct net_device *lo = net->loopback_dev;

		rt2 = mpls_rt_alloc(1, lo->addr_len, MAX_NEW_LABELS);

		rt2 = mpls_rt_alloc(1, lo->addr_len, 0);

		if (IS_ERR(rt2))

			goto nort2;

		RCU_INIT_POINTER(rt2->rt_nh->nh_dev, lo);

net/mpls/internal.h

+1 −1
Original line number Diff line number Diff line
@@ -197,7 +197,7 @@ static inline struct mpls_dev *mpls_dev_get(const struct net_device *dev) 


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, u8 *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[]);