![Eric W. Biederman](/assets/img/avatar_default.png)
Reobert Shearman noticed that mpls_egress is failing to verify that the bytes to be examined are in fact present in the packet before mpls_egress reads those bytes. As suggested by David Miller reduce this to a single pskb_may_pull call so that we don't do unnecessary work in the fast path. Reported-by: Robert Shearman <rshearma@brocade.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
1024 lines
24 KiB
C
1024 lines
24 KiB
C
#include <linux/types.h>
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#include <linux/skbuff.h>
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#include <linux/socket.h>
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#include <linux/sysctl.h>
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#include <linux/net.h>
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#include <linux/module.h>
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#include <linux/if_arp.h>
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#include <linux/ipv6.h>
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#include <linux/mpls.h>
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#include <linux/vmalloc.h>
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#include <net/ip.h>
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#include <net/dst.h>
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#include <net/sock.h>
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#include <net/arp.h>
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#include <net/ip_fib.h>
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#include <net/netevent.h>
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#include <net/netns/generic.h>
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#include "internal.h"
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#define LABEL_NOT_SPECIFIED (1<<20)
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#define MAX_NEW_LABELS 2
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/* This maximum ha length copied from the definition of struct neighbour */
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#define MAX_VIA_ALEN (ALIGN(MAX_ADDR_LEN, sizeof(unsigned long)))
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struct mpls_route { /* next hop label forwarding entry */
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struct net_device __rcu *rt_dev;
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struct rcu_head rt_rcu;
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u32 rt_label[MAX_NEW_LABELS];
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u8 rt_protocol; /* routing protocol that set this entry */
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u8 rt_labels;
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u8 rt_via_alen;
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u8 rt_via_table;
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u8 rt_via[0];
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};
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static int zero = 0;
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static int label_limit = (1 << 20) - 1;
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static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt,
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struct nlmsghdr *nlh, struct net *net, u32 portid,
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unsigned int nlm_flags);
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static struct mpls_route *mpls_route_input_rcu(struct net *net, unsigned index)
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{
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struct mpls_route *rt = NULL;
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if (index < net->mpls.platform_labels) {
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struct mpls_route __rcu **platform_label =
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rcu_dereference(net->mpls.platform_label);
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rt = rcu_dereference(platform_label[index]);
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}
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return rt;
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}
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static bool mpls_output_possible(const struct net_device *dev)
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{
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return dev && (dev->flags & IFF_UP) && netif_carrier_ok(dev);
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}
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static unsigned int mpls_rt_header_size(const struct mpls_route *rt)
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{
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/* The size of the layer 2.5 labels to be added for this route */
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return rt->rt_labels * sizeof(struct mpls_shim_hdr);
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}
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static unsigned int mpls_dev_mtu(const struct net_device *dev)
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{
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/* The amount of data the layer 2 frame can hold */
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return dev->mtu;
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}
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static bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu)
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{
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if (skb->len <= mtu)
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return false;
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if (skb_is_gso(skb) && skb_gso_network_seglen(skb) <= mtu)
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return false;
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return true;
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}
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static bool mpls_egress(struct mpls_route *rt, struct sk_buff *skb,
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struct mpls_entry_decoded dec)
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{
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/* RFC4385 and RFC5586 encode other packets in mpls such that
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* they don't conflict with the ip version number, making
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* decoding by examining the ip version correct in everything
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* except for the strangest cases.
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*
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* The strange cases if we choose to support them will require
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* manual configuration.
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*/
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struct iphdr *hdr4;
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bool success = true;
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/* The IPv4 code below accesses through the IPv4 header
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* checksum, which is 12 bytes into the packet.
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* The IPv6 code below accesses through the IPv6 hop limit
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* which is 8 bytes into the packet.
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*
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* For all supported cases there should always be at least 12
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* bytes of packet data present. The IPv4 header is 20 bytes
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* without options and the IPv6 header is always 40 bytes
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* long.
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*/
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if (!pskb_may_pull(skb, 12))
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return false;
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/* Use ip_hdr to find the ip protocol version */
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hdr4 = ip_hdr(skb);
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if (hdr4->version == 4) {
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skb->protocol = htons(ETH_P_IP);
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csum_replace2(&hdr4->check,
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htons(hdr4->ttl << 8),
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htons(dec.ttl << 8));
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hdr4->ttl = dec.ttl;
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}
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else if (hdr4->version == 6) {
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struct ipv6hdr *hdr6 = ipv6_hdr(skb);
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skb->protocol = htons(ETH_P_IPV6);
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hdr6->hop_limit = dec.ttl;
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}
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else
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/* version 0 and version 1 are used by pseudo wires */
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success = false;
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return success;
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}
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static int mpls_forward(struct sk_buff *skb, struct net_device *dev,
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struct packet_type *pt, struct net_device *orig_dev)
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{
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struct net *net = dev_net(dev);
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struct mpls_shim_hdr *hdr;
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struct mpls_route *rt;
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struct mpls_entry_decoded dec;
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struct net_device *out_dev;
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unsigned int hh_len;
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unsigned int new_header_size;
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unsigned int mtu;
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int err;
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/* Careful this entire function runs inside of an rcu critical section */
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if (skb->pkt_type != PACKET_HOST)
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goto drop;
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if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
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goto drop;
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if (!pskb_may_pull(skb, sizeof(*hdr)))
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goto drop;
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/* Read and decode the label */
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hdr = mpls_hdr(skb);
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dec = mpls_entry_decode(hdr);
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/* Pop the label */
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skb_pull(skb, sizeof(*hdr));
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skb_reset_network_header(skb);
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skb_orphan(skb);
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rt = mpls_route_input_rcu(net, dec.label);
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if (!rt)
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goto drop;
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/* Find the output device */
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out_dev = rcu_dereference(rt->rt_dev);
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if (!mpls_output_possible(out_dev))
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goto drop;
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if (skb_warn_if_lro(skb))
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goto drop;
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skb_forward_csum(skb);
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/* Verify ttl is valid */
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if (dec.ttl <= 1)
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goto drop;
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dec.ttl -= 1;
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/* Verify the destination can hold the packet */
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new_header_size = mpls_rt_header_size(rt);
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mtu = mpls_dev_mtu(out_dev);
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if (mpls_pkt_too_big(skb, mtu - new_header_size))
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goto drop;
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hh_len = LL_RESERVED_SPACE(out_dev);
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if (!out_dev->header_ops)
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hh_len = 0;
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/* Ensure there is enough space for the headers in the skb */
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if (skb_cow(skb, hh_len + new_header_size))
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goto drop;
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skb->dev = out_dev;
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skb->protocol = htons(ETH_P_MPLS_UC);
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if (unlikely(!new_header_size && dec.bos)) {
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/* Penultimate hop popping */
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if (!mpls_egress(rt, skb, dec))
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goto drop;
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} else {
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bool bos;
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int i;
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skb_push(skb, new_header_size);
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skb_reset_network_header(skb);
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/* Push the new labels */
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hdr = mpls_hdr(skb);
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bos = dec.bos;
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for (i = rt->rt_labels - 1; i >= 0; i--) {
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hdr[i] = mpls_entry_encode(rt->rt_label[i], dec.ttl, 0, bos);
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bos = false;
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}
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}
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err = neigh_xmit(rt->rt_via_table, out_dev, rt->rt_via, skb);
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if (err)
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net_dbg_ratelimited("%s: packet transmission failed: %d\n",
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__func__, err);
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return 0;
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drop:
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kfree_skb(skb);
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return NET_RX_DROP;
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}
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static struct packet_type mpls_packet_type __read_mostly = {
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.type = cpu_to_be16(ETH_P_MPLS_UC),
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.func = mpls_forward,
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};
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static const struct nla_policy rtm_mpls_policy[RTA_MAX+1] = {
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[RTA_DST] = { .type = NLA_U32 },
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[RTA_OIF] = { .type = NLA_U32 },
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};
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struct mpls_route_config {
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u32 rc_protocol;
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u32 rc_ifindex;
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u16 rc_via_table;
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u16 rc_via_alen;
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u8 rc_via[MAX_VIA_ALEN];
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u32 rc_label;
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u32 rc_output_labels;
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u32 rc_output_label[MAX_NEW_LABELS];
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u32 rc_nlflags;
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struct nl_info rc_nlinfo;
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};
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static struct mpls_route *mpls_rt_alloc(size_t alen)
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{
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struct mpls_route *rt;
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rt = kzalloc(sizeof(*rt) + alen, GFP_KERNEL);
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if (rt)
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rt->rt_via_alen = alen;
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return rt;
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}
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static void mpls_rt_free(struct mpls_route *rt)
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{
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if (rt)
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kfree_rcu(rt, rt_rcu);
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}
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static void mpls_notify_route(struct net *net, unsigned index,
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struct mpls_route *old, struct mpls_route *new,
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const struct nl_info *info)
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{
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struct nlmsghdr *nlh = info ? info->nlh : NULL;
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unsigned portid = info ? info->portid : 0;
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int event = new ? RTM_NEWROUTE : RTM_DELROUTE;
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struct mpls_route *rt = new ? new : old;
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unsigned nlm_flags = (old && new) ? NLM_F_REPLACE : 0;
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/* Ignore reserved labels for now */
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if (rt && (index >= 16))
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rtmsg_lfib(event, index, rt, nlh, net, portid, nlm_flags);
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}
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static void mpls_route_update(struct net *net, unsigned index,
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struct net_device *dev, struct mpls_route *new,
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const struct nl_info *info)
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{
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struct mpls_route __rcu **platform_label;
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struct mpls_route *rt, *old = NULL;
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ASSERT_RTNL();
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platform_label = rtnl_dereference(net->mpls.platform_label);
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rt = rtnl_dereference(platform_label[index]);
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if (!dev || (rt && (rtnl_dereference(rt->rt_dev) == dev))) {
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rcu_assign_pointer(platform_label[index], new);
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old = rt;
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}
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mpls_notify_route(net, index, old, new, info);
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/* If we removed a route free it now */
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mpls_rt_free(old);
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}
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static unsigned find_free_label(struct net *net)
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{
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struct mpls_route __rcu **platform_label;
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size_t platform_labels;
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unsigned index;
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platform_label = rtnl_dereference(net->mpls.platform_label);
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platform_labels = net->mpls.platform_labels;
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for (index = 16; index < platform_labels; index++) {
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if (!rtnl_dereference(platform_label[index]))
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return index;
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}
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return LABEL_NOT_SPECIFIED;
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}
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static int mpls_route_add(struct mpls_route_config *cfg)
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{
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struct mpls_route __rcu **platform_label;
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struct net *net = cfg->rc_nlinfo.nl_net;
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struct net_device *dev = NULL;
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struct mpls_route *rt, *old;
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unsigned index;
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int i;
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int err = -EINVAL;
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index = cfg->rc_label;
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/* If a label was not specified during insert pick one */
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if ((index == LABEL_NOT_SPECIFIED) &&
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(cfg->rc_nlflags & NLM_F_CREATE)) {
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index = find_free_label(net);
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}
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/* The first 16 labels are reserved, and may not be set */
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if (index < 16)
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goto errout;
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/* The full 20 bit range may not be supported. */
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if (index >= net->mpls.platform_labels)
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goto errout;
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/* Ensure only a supported number of labels are present */
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if (cfg->rc_output_labels > MAX_NEW_LABELS)
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goto errout;
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err = -ENODEV;
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dev = dev_get_by_index(net, cfg->rc_ifindex);
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if (!dev)
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goto errout;
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/* For now just support ethernet devices */
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err = -EINVAL;
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if ((dev->type != ARPHRD_ETHER) && (dev->type != ARPHRD_LOOPBACK))
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goto errout;
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err = -EINVAL;
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if ((cfg->rc_via_table == NEIGH_LINK_TABLE) &&
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(dev->addr_len != cfg->rc_via_alen))
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goto errout;
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/* Append makes no sense with mpls */
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err = -EOPNOTSUPP;
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if (cfg->rc_nlflags & NLM_F_APPEND)
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goto errout;
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err = -EEXIST;
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platform_label = rtnl_dereference(net->mpls.platform_label);
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old = rtnl_dereference(platform_label[index]);
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if ((cfg->rc_nlflags & NLM_F_EXCL) && old)
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goto errout;
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err = -EEXIST;
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if (!(cfg->rc_nlflags & NLM_F_REPLACE) && old)
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goto errout;
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err = -ENOENT;
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if (!(cfg->rc_nlflags & NLM_F_CREATE) && !old)
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goto errout;
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err = -ENOMEM;
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rt = mpls_rt_alloc(cfg->rc_via_alen);
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if (!rt)
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goto errout;
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rt->rt_labels = cfg->rc_output_labels;
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for (i = 0; i < rt->rt_labels; i++)
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rt->rt_label[i] = cfg->rc_output_label[i];
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rt->rt_protocol = cfg->rc_protocol;
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RCU_INIT_POINTER(rt->rt_dev, dev);
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rt->rt_via_table = cfg->rc_via_table;
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memcpy(rt->rt_via, cfg->rc_via, cfg->rc_via_alen);
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mpls_route_update(net, index, NULL, rt, &cfg->rc_nlinfo);
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dev_put(dev);
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return 0;
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errout:
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if (dev)
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dev_put(dev);
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return err;
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}
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static int mpls_route_del(struct mpls_route_config *cfg)
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{
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struct net *net = cfg->rc_nlinfo.nl_net;
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unsigned index;
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int err = -EINVAL;
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index = cfg->rc_label;
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/* The first 16 labels are reserved, and may not be removed */
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if (index < 16)
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goto errout;
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/* The full 20 bit range may not be supported */
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if (index >= net->mpls.platform_labels)
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goto errout;
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mpls_route_update(net, index, NULL, NULL, &cfg->rc_nlinfo);
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err = 0;
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errout:
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return err;
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}
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static void mpls_ifdown(struct net_device *dev)
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{
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struct mpls_route __rcu **platform_label;
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struct net *net = dev_net(dev);
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unsigned index;
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platform_label = rtnl_dereference(net->mpls.platform_label);
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for (index = 0; index < net->mpls.platform_labels; index++) {
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struct mpls_route *rt = rtnl_dereference(platform_label[index]);
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if (!rt)
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continue;
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if (rtnl_dereference(rt->rt_dev) != dev)
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continue;
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rt->rt_dev = NULL;
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}
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}
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static int mpls_dev_notify(struct notifier_block *this, unsigned long event,
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void *ptr)
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{
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struct net_device *dev = netdev_notifier_info_to_dev(ptr);
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switch(event) {
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case NETDEV_UNREGISTER:
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mpls_ifdown(dev);
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break;
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}
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return NOTIFY_OK;
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}
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static struct notifier_block mpls_dev_notifier = {
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.notifier_call = mpls_dev_notify,
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};
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static int nla_put_via(struct sk_buff *skb,
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u8 table, const void *addr, int alen)
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{
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static const int table_to_family[NEIGH_NR_TABLES + 1] = {
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AF_INET, AF_INET6, AF_DECnet, AF_PACKET,
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};
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struct nlattr *nla;
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struct rtvia *via;
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int family = AF_UNSPEC;
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nla = nla_reserve(skb, RTA_VIA, alen + 2);
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if (!nla)
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return -EMSGSIZE;
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if (table <= NEIGH_NR_TABLES)
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family = table_to_family[table];
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via = nla_data(nla);
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via->rtvia_family = family;
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memcpy(via->rtvia_addr, addr, alen);
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return 0;
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}
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int nla_put_labels(struct sk_buff *skb, int attrtype,
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u8 labels, const u32 label[])
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{
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struct nlattr *nla;
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struct mpls_shim_hdr *nla_label;
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bool bos;
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int i;
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nla = nla_reserve(skb, attrtype, labels*4);
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if (!nla)
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return -EMSGSIZE;
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nla_label = nla_data(nla);
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bos = true;
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for (i = labels - 1; i >= 0; i--) {
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nla_label[i] = mpls_entry_encode(label[i], 0, 0, bos);
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bos = false;
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}
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return 0;
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}
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|
|
int nla_get_labels(const struct nlattr *nla,
|
|
u32 max_labels, u32 *labels, u32 label[])
|
|
{
|
|
unsigned len = nla_len(nla);
|
|
unsigned nla_labels;
|
|
struct mpls_shim_hdr *nla_label;
|
|
bool bos;
|
|
int i;
|
|
|
|
/* len needs to be an even multiple of 4 (the label size) */
|
|
if (len & 3)
|
|
return -EINVAL;
|
|
|
|
/* Limit the number of new labels allowed */
|
|
nla_labels = len/4;
|
|
if (nla_labels > max_labels)
|
|
return -EINVAL;
|
|
|
|
nla_label = nla_data(nla);
|
|
bos = true;
|
|
for (i = nla_labels - 1; i >= 0; i--, bos = false) {
|
|
struct mpls_entry_decoded dec;
|
|
dec = mpls_entry_decode(nla_label + i);
|
|
|
|
/* Ensure the bottom of stack flag is properly set
|
|
* and ttl and tc are both clear.
|
|
*/
|
|
if ((dec.bos != bos) || dec.ttl || dec.tc)
|
|
return -EINVAL;
|
|
|
|
label[i] = dec.label;
|
|
}
|
|
*labels = nla_labels;
|
|
return 0;
|
|
}
|
|
|
|
static int rtm_to_route_config(struct sk_buff *skb, struct nlmsghdr *nlh,
|
|
struct mpls_route_config *cfg)
|
|
{
|
|
struct rtmsg *rtm;
|
|
struct nlattr *tb[RTA_MAX+1];
|
|
int index;
|
|
int err;
|
|
|
|
err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_mpls_policy);
|
|
if (err < 0)
|
|
goto errout;
|
|
|
|
err = -EINVAL;
|
|
rtm = nlmsg_data(nlh);
|
|
memset(cfg, 0, sizeof(*cfg));
|
|
|
|
if (rtm->rtm_family != AF_MPLS)
|
|
goto errout;
|
|
if (rtm->rtm_dst_len != 20)
|
|
goto errout;
|
|
if (rtm->rtm_src_len != 0)
|
|
goto errout;
|
|
if (rtm->rtm_tos != 0)
|
|
goto errout;
|
|
if (rtm->rtm_table != RT_TABLE_MAIN)
|
|
goto errout;
|
|
/* Any value is acceptable for rtm_protocol */
|
|
|
|
/* As mpls uses destination specific addresses
|
|
* (or source specific address in the case of multicast)
|
|
* all addresses have universal scope.
|
|
*/
|
|
if (rtm->rtm_scope != RT_SCOPE_UNIVERSE)
|
|
goto errout;
|
|
if (rtm->rtm_type != RTN_UNICAST)
|
|
goto errout;
|
|
if (rtm->rtm_flags != 0)
|
|
goto errout;
|
|
|
|
cfg->rc_label = LABEL_NOT_SPECIFIED;
|
|
cfg->rc_protocol = rtm->rtm_protocol;
|
|
cfg->rc_nlflags = nlh->nlmsg_flags;
|
|
cfg->rc_nlinfo.portid = NETLINK_CB(skb).portid;
|
|
cfg->rc_nlinfo.nlh = nlh;
|
|
cfg->rc_nlinfo.nl_net = sock_net(skb->sk);
|
|
|
|
for (index = 0; index <= RTA_MAX; index++) {
|
|
struct nlattr *nla = tb[index];
|
|
if (!nla)
|
|
continue;
|
|
|
|
switch(index) {
|
|
case RTA_OIF:
|
|
cfg->rc_ifindex = nla_get_u32(nla);
|
|
break;
|
|
case RTA_NEWDST:
|
|
if (nla_get_labels(nla, MAX_NEW_LABELS,
|
|
&cfg->rc_output_labels,
|
|
cfg->rc_output_label))
|
|
goto errout;
|
|
break;
|
|
case RTA_DST:
|
|
{
|
|
u32 label_count;
|
|
if (nla_get_labels(nla, 1, &label_count,
|
|
&cfg->rc_label))
|
|
goto errout;
|
|
|
|
/* The first 16 labels are reserved, and may not be set */
|
|
if (cfg->rc_label < 16)
|
|
goto errout;
|
|
|
|
break;
|
|
}
|
|
case RTA_VIA:
|
|
{
|
|
struct rtvia *via = nla_data(nla);
|
|
if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr))
|
|
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;
|
|
}
|
|
default:
|
|
/* Unsupported attribute */
|
|
goto errout;
|
|
}
|
|
}
|
|
|
|
err = 0;
|
|
errout:
|
|
return err;
|
|
}
|
|
|
|
static int mpls_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh)
|
|
{
|
|
struct mpls_route_config cfg;
|
|
int err;
|
|
|
|
err = rtm_to_route_config(skb, nlh, &cfg);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
return mpls_route_del(&cfg);
|
|
}
|
|
|
|
|
|
static int mpls_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh)
|
|
{
|
|
struct mpls_route_config cfg;
|
|
int err;
|
|
|
|
err = rtm_to_route_config(skb, nlh, &cfg);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
return mpls_route_add(&cfg);
|
|
}
|
|
|
|
static int mpls_dump_route(struct sk_buff *skb, u32 portid, u32 seq, int event,
|
|
u32 label, struct mpls_route *rt, int flags)
|
|
{
|
|
struct net_device *dev;
|
|
struct nlmsghdr *nlh;
|
|
struct rtmsg *rtm;
|
|
|
|
nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags);
|
|
if (nlh == NULL)
|
|
return -EMSGSIZE;
|
|
|
|
rtm = nlmsg_data(nlh);
|
|
rtm->rtm_family = AF_MPLS;
|
|
rtm->rtm_dst_len = 20;
|
|
rtm->rtm_src_len = 0;
|
|
rtm->rtm_tos = 0;
|
|
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_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;
|
|
|
|
nlmsg_end(skb, nlh);
|
|
return 0;
|
|
|
|
nla_put_failure:
|
|
nlmsg_cancel(skb, nlh);
|
|
return -EMSGSIZE;
|
|
}
|
|
|
|
static int mpls_dump_routes(struct sk_buff *skb, struct netlink_callback *cb)
|
|
{
|
|
struct net *net = sock_net(skb->sk);
|
|
struct mpls_route __rcu **platform_label;
|
|
size_t platform_labels;
|
|
unsigned int index;
|
|
|
|
ASSERT_RTNL();
|
|
|
|
index = cb->args[0];
|
|
if (index < 16)
|
|
index = 16;
|
|
|
|
platform_label = rtnl_dereference(net->mpls.platform_label);
|
|
platform_labels = net->mpls.platform_labels;
|
|
for (; index < platform_labels; index++) {
|
|
struct mpls_route *rt;
|
|
rt = rtnl_dereference(platform_label[index]);
|
|
if (!rt)
|
|
continue;
|
|
|
|
if (mpls_dump_route(skb, NETLINK_CB(cb->skb).portid,
|
|
cb->nlh->nlmsg_seq, RTM_NEWROUTE,
|
|
index, rt, NLM_F_MULTI) < 0)
|
|
break;
|
|
}
|
|
cb->args[0] = index;
|
|
|
|
return skb->len;
|
|
}
|
|
|
|
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);
|
|
return payload;
|
|
}
|
|
|
|
static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt,
|
|
struct nlmsghdr *nlh, struct net *net, u32 portid,
|
|
unsigned int nlm_flags)
|
|
{
|
|
struct sk_buff *skb;
|
|
u32 seq = nlh ? nlh->nlmsg_seq : 0;
|
|
int err = -ENOBUFS;
|
|
|
|
skb = nlmsg_new(lfib_nlmsg_size(rt), GFP_KERNEL);
|
|
if (skb == NULL)
|
|
goto errout;
|
|
|
|
err = mpls_dump_route(skb, portid, seq, event, label, rt, nlm_flags);
|
|
if (err < 0) {
|
|
/* -EMSGSIZE implies BUG in lfib_nlmsg_size */
|
|
WARN_ON(err == -EMSGSIZE);
|
|
kfree_skb(skb);
|
|
goto errout;
|
|
}
|
|
rtnl_notify(skb, net, portid, RTNLGRP_MPLS_ROUTE, nlh, GFP_KERNEL);
|
|
|
|
return;
|
|
errout:
|
|
if (err < 0)
|
|
rtnl_set_sk_err(net, RTNLGRP_MPLS_ROUTE, err);
|
|
}
|
|
|
|
static int resize_platform_label_table(struct net *net, size_t limit)
|
|
{
|
|
size_t size = sizeof(struct mpls_route *) * limit;
|
|
size_t old_limit;
|
|
size_t cp_size;
|
|
struct mpls_route __rcu **labels = NULL, **old;
|
|
struct mpls_route *rt0 = NULL, *rt2 = NULL;
|
|
unsigned index;
|
|
|
|
if (size) {
|
|
labels = kzalloc(size, GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY);
|
|
if (!labels)
|
|
labels = vzalloc(size);
|
|
|
|
if (!labels)
|
|
goto nolabels;
|
|
}
|
|
|
|
/* In case the predefined labels need to be populated */
|
|
if (limit > LABEL_IPV4_EXPLICIT_NULL) {
|
|
struct net_device *lo = net->loopback_dev;
|
|
rt0 = mpls_rt_alloc(lo->addr_len);
|
|
if (!rt0)
|
|
goto nort0;
|
|
RCU_INIT_POINTER(rt0->rt_dev, lo);
|
|
rt0->rt_protocol = RTPROT_KERNEL;
|
|
rt0->rt_via_table = NEIGH_LINK_TABLE;
|
|
memcpy(rt0->rt_via, lo->dev_addr, lo->addr_len);
|
|
}
|
|
if (limit > LABEL_IPV6_EXPLICIT_NULL) {
|
|
struct net_device *lo = net->loopback_dev;
|
|
rt2 = mpls_rt_alloc(lo->addr_len);
|
|
if (!rt2)
|
|
goto nort2;
|
|
RCU_INIT_POINTER(rt2->rt_dev, lo);
|
|
rt2->rt_protocol = RTPROT_KERNEL;
|
|
rt2->rt_via_table = NEIGH_LINK_TABLE;
|
|
memcpy(rt2->rt_via, lo->dev_addr, lo->addr_len);
|
|
}
|
|
|
|
rtnl_lock();
|
|
/* Remember the original table */
|
|
old = rtnl_dereference(net->mpls.platform_label);
|
|
old_limit = net->mpls.platform_labels;
|
|
|
|
/* Free any labels beyond the new table */
|
|
for (index = limit; index < old_limit; index++)
|
|
mpls_route_update(net, index, NULL, NULL, NULL);
|
|
|
|
/* Copy over the old labels */
|
|
cp_size = size;
|
|
if (old_limit < limit)
|
|
cp_size = old_limit * sizeof(struct mpls_route *);
|
|
|
|
memcpy(labels, old, cp_size);
|
|
|
|
/* If needed set the predefined labels */
|
|
if ((old_limit <= LABEL_IPV6_EXPLICIT_NULL) &&
|
|
(limit > LABEL_IPV6_EXPLICIT_NULL)) {
|
|
RCU_INIT_POINTER(labels[LABEL_IPV6_EXPLICIT_NULL], rt2);
|
|
rt2 = NULL;
|
|
}
|
|
|
|
if ((old_limit <= LABEL_IPV4_EXPLICIT_NULL) &&
|
|
(limit > LABEL_IPV4_EXPLICIT_NULL)) {
|
|
RCU_INIT_POINTER(labels[LABEL_IPV4_EXPLICIT_NULL], rt0);
|
|
rt0 = NULL;
|
|
}
|
|
|
|
/* Update the global pointers */
|
|
net->mpls.platform_labels = limit;
|
|
rcu_assign_pointer(net->mpls.platform_label, labels);
|
|
|
|
rtnl_unlock();
|
|
|
|
mpls_rt_free(rt2);
|
|
mpls_rt_free(rt0);
|
|
|
|
if (old) {
|
|
synchronize_rcu();
|
|
kvfree(old);
|
|
}
|
|
return 0;
|
|
|
|
nort2:
|
|
mpls_rt_free(rt0);
|
|
nort0:
|
|
kvfree(labels);
|
|
nolabels:
|
|
return -ENOMEM;
|
|
}
|
|
|
|
static int mpls_platform_labels(struct ctl_table *table, int write,
|
|
void __user *buffer, size_t *lenp, loff_t *ppos)
|
|
{
|
|
struct net *net = table->data;
|
|
int platform_labels = net->mpls.platform_labels;
|
|
int ret;
|
|
struct ctl_table tmp = {
|
|
.procname = table->procname,
|
|
.data = &platform_labels,
|
|
.maxlen = sizeof(int),
|
|
.mode = table->mode,
|
|
.extra1 = &zero,
|
|
.extra2 = &label_limit,
|
|
};
|
|
|
|
ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
|
|
|
|
if (write && ret == 0)
|
|
ret = resize_platform_label_table(net, platform_labels);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static struct ctl_table mpls_table[] = {
|
|
{
|
|
.procname = "platform_labels",
|
|
.data = NULL,
|
|
.maxlen = sizeof(int),
|
|
.mode = 0644,
|
|
.proc_handler = mpls_platform_labels,
|
|
},
|
|
{ }
|
|
};
|
|
|
|
static int mpls_net_init(struct net *net)
|
|
{
|
|
struct ctl_table *table;
|
|
|
|
net->mpls.platform_labels = 0;
|
|
net->mpls.platform_label = NULL;
|
|
|
|
table = kmemdup(mpls_table, sizeof(mpls_table), GFP_KERNEL);
|
|
if (table == NULL)
|
|
return -ENOMEM;
|
|
|
|
table[0].data = net;
|
|
net->mpls.ctl = register_net_sysctl(net, "net/mpls", table);
|
|
if (net->mpls.ctl == NULL)
|
|
return -ENOMEM;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void mpls_net_exit(struct net *net)
|
|
{
|
|
struct mpls_route __rcu **platform_label;
|
|
size_t platform_labels;
|
|
struct ctl_table *table;
|
|
unsigned int index;
|
|
|
|
table = net->mpls.ctl->ctl_table_arg;
|
|
unregister_net_sysctl_table(net->mpls.ctl);
|
|
kfree(table);
|
|
|
|
/* An rcu grace period has passed since there was a device in
|
|
* the network namespace (and thus the last in flight packet)
|
|
* left this network namespace. This is because
|
|
* unregister_netdevice_many and netdev_run_todo has completed
|
|
* for each network device that was in this network namespace.
|
|
*
|
|
* As such no additional rcu synchronization is necessary when
|
|
* freeing the platform_label table.
|
|
*/
|
|
rtnl_lock();
|
|
platform_label = rtnl_dereference(net->mpls.platform_label);
|
|
platform_labels = net->mpls.platform_labels;
|
|
for (index = 0; index < platform_labels; index++) {
|
|
struct mpls_route *rt = rtnl_dereference(platform_label[index]);
|
|
RCU_INIT_POINTER(platform_label[index], NULL);
|
|
mpls_rt_free(rt);
|
|
}
|
|
rtnl_unlock();
|
|
|
|
kvfree(platform_label);
|
|
}
|
|
|
|
static struct pernet_operations mpls_net_ops = {
|
|
.init = mpls_net_init,
|
|
.exit = mpls_net_exit,
|
|
};
|
|
|
|
static int __init mpls_init(void)
|
|
{
|
|
int err;
|
|
|
|
BUILD_BUG_ON(sizeof(struct mpls_shim_hdr) != 4);
|
|
|
|
err = register_pernet_subsys(&mpls_net_ops);
|
|
if (err)
|
|
goto out;
|
|
|
|
err = register_netdevice_notifier(&mpls_dev_notifier);
|
|
if (err)
|
|
goto out_unregister_pernet;
|
|
|
|
dev_add_pack(&mpls_packet_type);
|
|
|
|
rtnl_register(PF_MPLS, RTM_NEWROUTE, mpls_rtm_newroute, NULL, NULL);
|
|
rtnl_register(PF_MPLS, RTM_DELROUTE, mpls_rtm_delroute, NULL, NULL);
|
|
rtnl_register(PF_MPLS, RTM_GETROUTE, NULL, mpls_dump_routes, NULL);
|
|
err = 0;
|
|
out:
|
|
return err;
|
|
|
|
out_unregister_pernet:
|
|
unregister_pernet_subsys(&mpls_net_ops);
|
|
goto out;
|
|
}
|
|
module_init(mpls_init);
|
|
|
|
static void __exit mpls_exit(void)
|
|
{
|
|
rtnl_unregister_all(PF_MPLS);
|
|
dev_remove_pack(&mpls_packet_type);
|
|
unregister_netdevice_notifier(&mpls_dev_notifier);
|
|
unregister_pernet_subsys(&mpls_net_ops);
|
|
}
|
|
module_exit(mpls_exit);
|
|
|
|
MODULE_DESCRIPTION("MultiProtocol Label Switching");
|
|
MODULE_LICENSE("GPL v2");
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MODULE_ALIAS_NETPROTO(PF_MPLS);
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