| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <20240529231847.16719-3-ekinzie@labn.net>
Date: Wed, 29 May 2024 19:18:45 -0400
From: Eric Kinzie <ekinzie@...n.net>
To: "David S . Miller" <davem@...emloft.net>,
David Ahern <dsahern@...nel.org>,
Eric Dumazet <edumazet@...gle.com>,
Jakub Kicinski <kuba@...nel.org>,
Paolo Abeni <pabeni@...hat.com>
Cc: Eric H Kinzie <ekinzie@...n.net>,
netdev@...r.kernel.org
Subject: [RFC net-next 2/2] net: mpls: support point-to-multipoint LSPs
From: Eric H Kinzie <ekinzie@...n.net>
MPLS can multicast packets through point-to-multipoint LSPs.
The structure mpls_route has space to store multiple next-hops for the
purposes of multipath forwarding. Alternatively, use this area to store
multiple next-hops for p2mp. This change is consistent with RFC5332
section 4 for downstream-assigned labels, in that it continues to use
the unicast ether type (ETH_P_MPLS_UC) for multicast Ethernet frames.
p2mp routes are added by declaring a route type to be RTN_MULTICAST.
For example:
ip -f mpls route add multicast 100 \
nexthop as 200 via inet 10.0.2.1 \
nexthop as 300 via inet 10.0.3.1 \
nexthop as 400 via inet 10.0.4.1
Signed-off-by: Eric H Kinzie <ekinzie@...n.net>
---
net/mpls/af_mpls.c | 218 ++++++++++++++++++++++++++++++--------------
net/mpls/internal.h | 6 +-
2 files changed, 153 insertions(+), 71 deletions(-)
diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
index 2dc7a908a6bb..e7f39ee05c19 100644
--- a/net/mpls/af_mpls.c
+++ b/net/mpls/af_mpls.c
@@ -339,76 +339,18 @@ static bool mpls_egress(struct net *net, struct mpls_route *rt,
return success;
}
-static int mpls_forward(struct sk_buff *skb, struct net_device *dev,
- struct packet_type *pt, struct net_device *orig_dev)
+static int mpls_forward_finish(struct sk_buff *skb, struct mpls_dev *mdev,
+ struct mpls_entry_decoded *dec,
+ struct mpls_route *rt, const struct mpls_nh *nh)
{
- struct net *net = dev_net(dev);
struct mpls_shim_hdr *hdr;
- const struct mpls_nh *nh;
- struct mpls_route *rt;
- struct mpls_entry_decoded dec;
struct net_device *out_dev;
struct mpls_dev *out_mdev;
- struct mpls_dev *mdev;
unsigned int hh_len;
unsigned int new_header_size;
unsigned int mtu;
int err;
- /* Careful this entire function runs inside of an rcu critical section */
-
- mdev = mpls_dev_get(dev);
- if (!mdev)
- goto drop;
-
- MPLS_INC_STATS_LEN(mdev, skb->len, rx_packets,
- rx_bytes);
-
- if (!mdev->input_enabled) {
- MPLS_INC_STATS(mdev, rx_dropped);
- goto drop;
- }
-
- if (skb->pkt_type != PACKET_HOST)
- goto err;
-
- if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
- goto err;
-
- if (!pskb_may_pull(skb, sizeof(*hdr)))
- goto err;
-
- skb_dst_drop(skb);
-
- /* Read and decode the label */
- hdr = mpls_hdr(skb);
- dec = mpls_entry_decode(hdr);
-
- rt = mpls_route_input_rcu(net, dec.label);
- if (!rt) {
- MPLS_INC_STATS(mdev, rx_noroute);
- goto drop;
- }
-
- nh = mpls_select_multipath(rt, skb);
- if (!nh)
- goto err;
-
- /* Pop the label */
- skb_pull(skb, sizeof(*hdr));
- skb_reset_network_header(skb);
-
- skb_orphan(skb);
-
- if (skb_warn_if_lro(skb))
- goto err;
-
- skb_forward_csum(skb);
-
- /* Verify ttl is valid */
- if (dec.ttl <= 1)
- goto err;
-
/* Find the output device */
out_dev = nh->nh_dev;
if (!mpls_output_possible(out_dev))
@@ -431,10 +373,9 @@ static int mpls_forward(struct sk_buff *skb, struct net_device *dev,
skb->dev = out_dev;
skb->protocol = htons(ETH_P_MPLS_UC);
- dec.ttl -= 1;
- if (unlikely(!new_header_size && dec.bos)) {
+ if (unlikely(!new_header_size && dec->bos)) {
/* Penultimate hop popping */
- if (!mpls_egress(dev_net(out_dev), rt, skb, dec))
+ if (!mpls_egress(dev_net(out_dev), rt, skb, *dec))
goto err;
} else {
bool bos;
@@ -443,10 +384,10 @@ static int mpls_forward(struct sk_buff *skb, struct net_device *dev,
skb_reset_network_header(skb);
/* Push the new labels */
hdr = mpls_hdr(skb);
- bos = dec.bos;
+ bos = dec->bos;
for (i = nh->nh_labels - 1; i >= 0; i--) {
hdr[i] = mpls_entry_encode(nh->nh_label[i],
- dec.ttl, 0, bos);
+ dec->ttl, 0, bos);
bos = false;
}
}
@@ -477,6 +418,139 @@ static int mpls_forward(struct sk_buff *skb, struct net_device *dev,
return NET_RX_DROP;
}
+static int mpls_forward_p2mp(struct sk_buff *skb, struct mpls_dev *mdev,
+ struct mpls_entry_decoded *dec,
+ struct mpls_route *rt)
+{
+ unsigned int nh_flags;
+ int one_err;
+ int err = 0;
+ u8 alive;
+
+ if (rt->rt_nhn == 1)
+ goto out;
+
+ alive = READ_ONCE(rt->rt_nhn_alive);
+ if (alive == 0)
+ goto drop;
+
+ for_nexthops(rt) {
+ struct sk_buff *clone;
+
+ /* Skip the first next-hop for now and handle this one
+ * on the way out to avoid one clone.
+ */
+ if (nhsel == 0)
+ continue;
+
+ nh_flags = READ_ONCE(nh->nh_flags);
+ if (nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN))
+ continue;
+
+ clone = skb_clone(skb, GFP_ATOMIC);
+ if (!clone)
+ goto drop;
+
+ one_err = mpls_forward_finish(clone, mdev, dec, rt, nh);
+ if (one_err)
+ err = one_err;
+ }
+ endfor_nexthops(rt);
+
+out:
+ nh_flags = READ_ONCE(rt->rt_nh->nh_flags);
+ if (nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)) {
+ kfree_skb(skb);
+ return err;
+ }
+
+ one_err = mpls_forward_finish(skb, mdev, dec, rt, rt->rt_nh);
+ if (one_err)
+ err = one_err;
+ return err;
+drop:
+ kfree_skb(skb);
+ return NET_RX_DROP;
+}
+
+static int mpls_forward(struct sk_buff *skb, struct net_device *dev,
+ struct packet_type *pt, struct net_device *orig_dev)
+{
+ struct net *net = dev_net(dev);
+ struct mpls_shim_hdr *hdr;
+ const struct mpls_nh *nh;
+ struct mpls_route *rt;
+ struct mpls_entry_decoded dec;
+ struct mpls_dev *mdev;
+
+ /* Careful this entire function runs inside of an rcu critical section */
+
+ mdev = mpls_dev_get(dev);
+ if (!mdev)
+ goto drop;
+
+ MPLS_INC_STATS_LEN(mdev, skb->len, rx_packets, rx_bytes);
+
+ if (!mdev->input_enabled) {
+ MPLS_INC_STATS(mdev, rx_dropped);
+ goto drop;
+ }
+
+ if (skb->pkt_type != PACKET_HOST)
+ goto err;
+
+ skb = skb_share_check(skb, GFP_ATOMIC);
+ if (!skb)
+ goto err;
+
+ if (!pskb_may_pull(skb, sizeof(*hdr)))
+ goto err;
+
+ skb_dst_drop(skb);
+
+ /* Read and decode the label */
+ hdr = mpls_hdr(skb);
+ dec = mpls_entry_decode(hdr);
+
+ rt = mpls_route_input_rcu(net, dec.label);
+ if (!rt) {
+ MPLS_INC_STATS(mdev, rx_noroute);
+ goto drop;
+ }
+
+ if (!(rt->rt_flags & MPLS_RT_F_P2MP)) {
+ nh = mpls_select_multipath(rt, skb);
+ if (!nh)
+ goto err;
+ }
+
+ /* Pop the label */
+ skb_pull(skb, sizeof(*hdr));
+ skb_reset_network_header(skb);
+
+ skb_orphan(skb);
+
+ if (skb_warn_if_lro(skb))
+ goto err;
+
+ skb_forward_csum(skb);
+
+ /* Verify ttl is valid */
+ if (dec.ttl <= 1)
+ goto err;
+
+ dec.ttl -= 1;
+ if (rt->rt_flags & MPLS_RT_F_P2MP)
+ return mpls_forward_p2mp(skb, mdev, &dec, rt);
+
+ return mpls_forward_finish(skb, mdev, &dec, rt, nh);
+err:
+ MPLS_INC_STATS(mdev, rx_errors);
+drop:
+ kfree_skb(skb);
+ return NET_RX_DROP;
+}
+
static struct packet_type mpls_packet_type __read_mostly = {
.type = cpu_to_be16(ETH_P_MPLS_UC),
.func = mpls_forward,
@@ -491,6 +565,7 @@ static const struct nla_policy rtm_mpls_policy[RTA_MAX+1] = {
struct mpls_route_config {
u32 rc_protocol;
u32 rc_ifindex;
+ u8 rc_flags;
u8 rc_via_table;
u8 rc_via_alen;
u8 rc_via[MAX_VIA_ALEN];
@@ -1029,6 +1104,7 @@ static int mpls_route_add(struct mpls_route_config *cfg,
rt->rt_protocol = cfg->rc_protocol;
rt->rt_payload_type = cfg->rc_payload_type;
rt->rt_ttl_propagate = cfg->rc_ttl_propagate;
+ rt->rt_flags = cfg->rc_flags;
if (cfg->rc_mp)
err = mpls_nh_build_multi(cfg, rt, max_labels, extack);
@@ -1837,9 +1913,11 @@ static int rtm_to_route_config(struct sk_buff *skb,
"Invalid route scope - MPLS only supports UNIVERSE");
goto errout;
}
- if (rtm->rtm_type != RTN_UNICAST) {
+ if (rtm->rtm_type == RTN_MULTICAST) {
+ cfg->rc_flags = MPLS_RT_F_P2MP;
+ } else if (rtm->rtm_type != RTN_UNICAST) {
NL_SET_ERR_MSG(extack,
- "Invalid route type - MPLS only supports UNICAST");
+ "Invalid route type - MPLS only supports UNICAST and MULTICAST");
goto errout;
}
if (rtm->rtm_flags != 0) {
@@ -1988,7 +2066,7 @@ static int mpls_dump_route(struct sk_buff *skb, u32 portid, u32 seq, int event,
rtm->rtm_table = RT_TABLE_MAIN;
rtm->rtm_protocol = rt->rt_protocol;
rtm->rtm_scope = RT_SCOPE_UNIVERSE;
- rtm->rtm_type = RTN_UNICAST;
+ rtm->rtm_type = rt->rt_flags & MPLS_RT_F_P2MP ? RTN_MULTICAST : RTN_UNICAST;
rtm->rtm_flags = 0;
if (nla_put_labels(skb, RTA_DST, 1, &label))
@@ -2386,7 +2464,7 @@ static int mpls_getroute(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,
goto errout;
}
- if (rtm->rtm_flags & RTM_F_FIB_MATCH) {
+ if (rtm->rtm_flags & RTM_F_FIB_MATCH || rt->rt_flags & MPLS_RT_F_P2MP) {
skb = nlmsg_new(lfib_nlmsg_size(rt), GFP_KERNEL);
if (!skb) {
err = -ENOBUFS;
diff --git a/net/mpls/internal.h b/net/mpls/internal.h
index b9f492ddf93b..585dd9ac1076 100644
--- a/net/mpls/internal.h
+++ b/net/mpls/internal.h
@@ -153,10 +153,14 @@ struct mpls_route { /* next hop label forwarding entry */
u8 rt_nhn_alive;
u8 rt_nh_size;
u8 rt_via_offset;
- u8 rt_reserved1;
+ u8 rt_flags;
struct mpls_nh rt_nh[];
};
+/* rt_flags */
+#define MPLS_RT_F_P2MP 0x01
+#define MPLS_RT_F_UPSTREAM_ASSIGNED 0x02 /* upstream assigned labels - rfc5332 */
+
#define for_nexthops(rt) { \
int nhsel; const struct mpls_nh *nh; \
for (nhsel = 0, nh = (rt)->rt_nh; \
--
2.43.2
Powered by blists - more mailing lists