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![Mathieu Xhonneux](/assets/img/avatar_default.png)
The seg6local LWT provides the End.DT6 action, which allows to decapsulate an outer IPv6 header containing a Segment Routing Header (SRH), full specification is available here: https://tools.ietf.org/html/draft-filsfils-spring-srv6-network-programming-05 This patch adds this action now to the seg6local BPF interface. Since it is not mandatory that the inner IPv6 header also contains a SRH, seg6_bpf_srh_state has been extended with a pointer to a possible SRH of the outermost IPv6 header. This helps assessing if the validation must be triggered or not, and avoids some calls to ipv6_find_hdr. v3: s/1/true, s/0/false for boolean values v2: - changed true/false -> 1/0 - preempt_enable no longer called in first conditional block Signed-off-by: Mathieu Xhonneux <m.xhonneux@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
1114 lines
23 KiB
C
1114 lines
23 KiB
C
/*
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* SR-IPv6 implementation
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*
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* Authors:
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* David Lebrun <david.lebrun@uclouvain.be>
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* eBPF support: Mathieu Xhonneux <m.xhonneux@gmail.com>
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*
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/types.h>
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#include <linux/skbuff.h>
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#include <linux/net.h>
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#include <linux/module.h>
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#include <net/ip.h>
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#include <net/lwtunnel.h>
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#include <net/netevent.h>
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#include <net/netns/generic.h>
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#include <net/ip6_fib.h>
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#include <net/route.h>
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#include <net/seg6.h>
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#include <linux/seg6.h>
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#include <linux/seg6_local.h>
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#include <net/addrconf.h>
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#include <net/ip6_route.h>
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#include <net/dst_cache.h>
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#ifdef CONFIG_IPV6_SEG6_HMAC
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#include <net/seg6_hmac.h>
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#endif
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#include <net/seg6_local.h>
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#include <linux/etherdevice.h>
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#include <linux/bpf.h>
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struct seg6_local_lwt;
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struct seg6_action_desc {
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int action;
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unsigned long attrs;
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int (*input)(struct sk_buff *skb, struct seg6_local_lwt *slwt);
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int static_headroom;
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};
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struct bpf_lwt_prog {
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struct bpf_prog *prog;
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char *name;
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};
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struct seg6_local_lwt {
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int action;
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struct ipv6_sr_hdr *srh;
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int table;
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struct in_addr nh4;
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struct in6_addr nh6;
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int iif;
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int oif;
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struct bpf_lwt_prog bpf;
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int headroom;
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struct seg6_action_desc *desc;
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};
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static struct seg6_local_lwt *seg6_local_lwtunnel(struct lwtunnel_state *lwt)
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{
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return (struct seg6_local_lwt *)lwt->data;
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}
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static struct ipv6_sr_hdr *get_srh(struct sk_buff *skb)
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{
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struct ipv6_sr_hdr *srh;
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int len, srhoff = 0;
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if (ipv6_find_hdr(skb, &srhoff, IPPROTO_ROUTING, NULL, NULL) < 0)
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return NULL;
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if (!pskb_may_pull(skb, srhoff + sizeof(*srh)))
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return NULL;
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srh = (struct ipv6_sr_hdr *)(skb->data + srhoff);
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len = (srh->hdrlen + 1) << 3;
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if (!pskb_may_pull(skb, srhoff + len))
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return NULL;
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if (!seg6_validate_srh(srh, len))
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return NULL;
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return srh;
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}
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static struct ipv6_sr_hdr *get_and_validate_srh(struct sk_buff *skb)
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{
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struct ipv6_sr_hdr *srh;
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srh = get_srh(skb);
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if (!srh)
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return NULL;
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if (srh->segments_left == 0)
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return NULL;
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#ifdef CONFIG_IPV6_SEG6_HMAC
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if (!seg6_hmac_validate_skb(skb))
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return NULL;
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#endif
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return srh;
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}
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static bool decap_and_validate(struct sk_buff *skb, int proto)
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{
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struct ipv6_sr_hdr *srh;
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unsigned int off = 0;
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srh = get_srh(skb);
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if (srh && srh->segments_left > 0)
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return false;
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#ifdef CONFIG_IPV6_SEG6_HMAC
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if (srh && !seg6_hmac_validate_skb(skb))
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return false;
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#endif
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if (ipv6_find_hdr(skb, &off, proto, NULL, NULL) < 0)
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return false;
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if (!pskb_pull(skb, off))
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return false;
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skb_postpull_rcsum(skb, skb_network_header(skb), off);
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skb_reset_network_header(skb);
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skb_reset_transport_header(skb);
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skb->encapsulation = 0;
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return true;
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}
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static void advance_nextseg(struct ipv6_sr_hdr *srh, struct in6_addr *daddr)
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{
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struct in6_addr *addr;
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srh->segments_left--;
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addr = srh->segments + srh->segments_left;
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*daddr = *addr;
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}
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int seg6_lookup_nexthop(struct sk_buff *skb, struct in6_addr *nhaddr,
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u32 tbl_id)
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{
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struct net *net = dev_net(skb->dev);
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struct ipv6hdr *hdr = ipv6_hdr(skb);
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int flags = RT6_LOOKUP_F_HAS_SADDR;
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struct dst_entry *dst = NULL;
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struct rt6_info *rt;
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struct flowi6 fl6;
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fl6.flowi6_iif = skb->dev->ifindex;
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fl6.daddr = nhaddr ? *nhaddr : hdr->daddr;
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fl6.saddr = hdr->saddr;
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fl6.flowlabel = ip6_flowinfo(hdr);
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fl6.flowi6_mark = skb->mark;
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fl6.flowi6_proto = hdr->nexthdr;
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if (nhaddr)
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fl6.flowi6_flags = FLOWI_FLAG_KNOWN_NH;
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if (!tbl_id) {
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dst = ip6_route_input_lookup(net, skb->dev, &fl6, skb, flags);
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} else {
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struct fib6_table *table;
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table = fib6_get_table(net, tbl_id);
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if (!table)
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goto out;
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rt = ip6_pol_route(net, table, 0, &fl6, skb, flags);
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dst = &rt->dst;
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}
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if (dst && dst->dev->flags & IFF_LOOPBACK && !dst->error) {
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dst_release(dst);
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dst = NULL;
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}
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out:
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if (!dst) {
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rt = net->ipv6.ip6_blk_hole_entry;
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dst = &rt->dst;
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dst_hold(dst);
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}
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skb_dst_drop(skb);
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skb_dst_set(skb, dst);
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return dst->error;
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}
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/* regular endpoint function */
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static int input_action_end(struct sk_buff *skb, struct seg6_local_lwt *slwt)
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{
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struct ipv6_sr_hdr *srh;
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srh = get_and_validate_srh(skb);
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if (!srh)
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goto drop;
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advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
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seg6_lookup_nexthop(skb, NULL, 0);
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return dst_input(skb);
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drop:
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kfree_skb(skb);
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return -EINVAL;
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}
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/* regular endpoint, and forward to specified nexthop */
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static int input_action_end_x(struct sk_buff *skb, struct seg6_local_lwt *slwt)
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{
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struct ipv6_sr_hdr *srh;
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srh = get_and_validate_srh(skb);
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if (!srh)
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goto drop;
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advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
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seg6_lookup_nexthop(skb, &slwt->nh6, 0);
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return dst_input(skb);
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drop:
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kfree_skb(skb);
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return -EINVAL;
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}
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static int input_action_end_t(struct sk_buff *skb, struct seg6_local_lwt *slwt)
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{
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struct ipv6_sr_hdr *srh;
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srh = get_and_validate_srh(skb);
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if (!srh)
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goto drop;
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advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
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seg6_lookup_nexthop(skb, NULL, slwt->table);
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return dst_input(skb);
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drop:
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kfree_skb(skb);
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return -EINVAL;
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}
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/* decapsulate and forward inner L2 frame on specified interface */
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static int input_action_end_dx2(struct sk_buff *skb,
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struct seg6_local_lwt *slwt)
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{
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struct net *net = dev_net(skb->dev);
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struct net_device *odev;
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struct ethhdr *eth;
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if (!decap_and_validate(skb, NEXTHDR_NONE))
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goto drop;
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if (!pskb_may_pull(skb, ETH_HLEN))
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goto drop;
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skb_reset_mac_header(skb);
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eth = (struct ethhdr *)skb->data;
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/* To determine the frame's protocol, we assume it is 802.3. This avoids
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* a call to eth_type_trans(), which is not really relevant for our
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* use case.
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*/
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if (!eth_proto_is_802_3(eth->h_proto))
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goto drop;
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odev = dev_get_by_index_rcu(net, slwt->oif);
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if (!odev)
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goto drop;
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/* As we accept Ethernet frames, make sure the egress device is of
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* the correct type.
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*/
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if (odev->type != ARPHRD_ETHER)
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goto drop;
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if (!(odev->flags & IFF_UP) || !netif_carrier_ok(odev))
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goto drop;
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skb_orphan(skb);
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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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if (skb->len - ETH_HLEN > odev->mtu)
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goto drop;
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skb->dev = odev;
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skb->protocol = eth->h_proto;
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return dev_queue_xmit(skb);
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drop:
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kfree_skb(skb);
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return -EINVAL;
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}
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/* decapsulate and forward to specified nexthop */
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static int input_action_end_dx6(struct sk_buff *skb,
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struct seg6_local_lwt *slwt)
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{
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struct in6_addr *nhaddr = NULL;
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/* this function accepts IPv6 encapsulated packets, with either
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* an SRH with SL=0, or no SRH.
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*/
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if (!decap_and_validate(skb, IPPROTO_IPV6))
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goto drop;
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if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
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goto drop;
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/* The inner packet is not associated to any local interface,
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* so we do not call netif_rx().
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*
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* If slwt->nh6 is set to ::, then lookup the nexthop for the
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* inner packet's DA. Otherwise, use the specified nexthop.
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*/
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if (!ipv6_addr_any(&slwt->nh6))
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nhaddr = &slwt->nh6;
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seg6_lookup_nexthop(skb, nhaddr, 0);
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return dst_input(skb);
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drop:
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kfree_skb(skb);
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return -EINVAL;
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}
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static int input_action_end_dx4(struct sk_buff *skb,
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struct seg6_local_lwt *slwt)
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{
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struct iphdr *iph;
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__be32 nhaddr;
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int err;
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if (!decap_and_validate(skb, IPPROTO_IPIP))
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goto drop;
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if (!pskb_may_pull(skb, sizeof(struct iphdr)))
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goto drop;
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skb->protocol = htons(ETH_P_IP);
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iph = ip_hdr(skb);
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nhaddr = slwt->nh4.s_addr ?: iph->daddr;
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skb_dst_drop(skb);
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|
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err = ip_route_input(skb, nhaddr, iph->saddr, 0, skb->dev);
|
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if (err)
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goto drop;
|
|
|
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return dst_input(skb);
|
|
|
|
drop:
|
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kfree_skb(skb);
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return -EINVAL;
|
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}
|
|
|
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static int input_action_end_dt6(struct sk_buff *skb,
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struct seg6_local_lwt *slwt)
|
|
{
|
|
if (!decap_and_validate(skb, IPPROTO_IPV6))
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goto drop;
|
|
|
|
if (!pskb_may_pull(skb, sizeof(struct ipv6hdr)))
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|
goto drop;
|
|
|
|
seg6_lookup_nexthop(skb, NULL, slwt->table);
|
|
|
|
return dst_input(skb);
|
|
|
|
drop:
|
|
kfree_skb(skb);
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return -EINVAL;
|
|
}
|
|
|
|
/* push an SRH on top of the current one */
|
|
static int input_action_end_b6(struct sk_buff *skb, struct seg6_local_lwt *slwt)
|
|
{
|
|
struct ipv6_sr_hdr *srh;
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int err = -EINVAL;
|
|
|
|
srh = get_and_validate_srh(skb);
|
|
if (!srh)
|
|
goto drop;
|
|
|
|
err = seg6_do_srh_inline(skb, slwt->srh);
|
|
if (err)
|
|
goto drop;
|
|
|
|
ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
|
|
skb_set_transport_header(skb, sizeof(struct ipv6hdr));
|
|
|
|
seg6_lookup_nexthop(skb, NULL, 0);
|
|
|
|
return dst_input(skb);
|
|
|
|
drop:
|
|
kfree_skb(skb);
|
|
return err;
|
|
}
|
|
|
|
/* encapsulate within an outer IPv6 header and a specified SRH */
|
|
static int input_action_end_b6_encap(struct sk_buff *skb,
|
|
struct seg6_local_lwt *slwt)
|
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{
|
|
struct ipv6_sr_hdr *srh;
|
|
int err = -EINVAL;
|
|
|
|
srh = get_and_validate_srh(skb);
|
|
if (!srh)
|
|
goto drop;
|
|
|
|
advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
|
|
|
|
skb_reset_inner_headers(skb);
|
|
skb->encapsulation = 1;
|
|
|
|
err = seg6_do_srh_encap(skb, slwt->srh, IPPROTO_IPV6);
|
|
if (err)
|
|
goto drop;
|
|
|
|
ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
|
|
skb_set_transport_header(skb, sizeof(struct ipv6hdr));
|
|
|
|
seg6_lookup_nexthop(skb, NULL, 0);
|
|
|
|
return dst_input(skb);
|
|
|
|
drop:
|
|
kfree_skb(skb);
|
|
return err;
|
|
}
|
|
|
|
DEFINE_PER_CPU(struct seg6_bpf_srh_state, seg6_bpf_srh_states);
|
|
|
|
bool seg6_bpf_has_valid_srh(struct sk_buff *skb)
|
|
{
|
|
struct seg6_bpf_srh_state *srh_state =
|
|
this_cpu_ptr(&seg6_bpf_srh_states);
|
|
struct ipv6_sr_hdr *srh = srh_state->srh;
|
|
|
|
if (unlikely(srh == NULL))
|
|
return false;
|
|
|
|
if (unlikely(!srh_state->valid)) {
|
|
if ((srh_state->hdrlen & 7) != 0)
|
|
return false;
|
|
|
|
srh->hdrlen = (u8)(srh_state->hdrlen >> 3);
|
|
if (!seg6_validate_srh(srh, (srh->hdrlen + 1) << 3))
|
|
return false;
|
|
|
|
srh_state->valid = true;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
static int input_action_end_bpf(struct sk_buff *skb,
|
|
struct seg6_local_lwt *slwt)
|
|
{
|
|
struct seg6_bpf_srh_state *srh_state =
|
|
this_cpu_ptr(&seg6_bpf_srh_states);
|
|
struct ipv6_sr_hdr *srh;
|
|
int ret;
|
|
|
|
srh = get_and_validate_srh(skb);
|
|
if (!srh) {
|
|
kfree_skb(skb);
|
|
return -EINVAL;
|
|
}
|
|
advance_nextseg(srh, &ipv6_hdr(skb)->daddr);
|
|
|
|
/* preempt_disable is needed to protect the per-CPU buffer srh_state,
|
|
* which is also accessed by the bpf_lwt_seg6_* helpers
|
|
*/
|
|
preempt_disable();
|
|
srh_state->srh = srh;
|
|
srh_state->hdrlen = srh->hdrlen << 3;
|
|
srh_state->valid = true;
|
|
|
|
rcu_read_lock();
|
|
bpf_compute_data_pointers(skb);
|
|
ret = bpf_prog_run_save_cb(slwt->bpf.prog, skb);
|
|
rcu_read_unlock();
|
|
|
|
switch (ret) {
|
|
case BPF_OK:
|
|
case BPF_REDIRECT:
|
|
break;
|
|
case BPF_DROP:
|
|
goto drop;
|
|
default:
|
|
pr_warn_once("bpf-seg6local: Illegal return value %u\n", ret);
|
|
goto drop;
|
|
}
|
|
|
|
if (srh_state->srh && !seg6_bpf_has_valid_srh(skb))
|
|
goto drop;
|
|
|
|
preempt_enable();
|
|
if (ret != BPF_REDIRECT)
|
|
seg6_lookup_nexthop(skb, NULL, 0);
|
|
|
|
return dst_input(skb);
|
|
|
|
drop:
|
|
preempt_enable();
|
|
kfree_skb(skb);
|
|
return -EINVAL;
|
|
}
|
|
|
|
static struct seg6_action_desc seg6_action_table[] = {
|
|
{
|
|
.action = SEG6_LOCAL_ACTION_END,
|
|
.attrs = 0,
|
|
.input = input_action_end,
|
|
},
|
|
{
|
|
.action = SEG6_LOCAL_ACTION_END_X,
|
|
.attrs = (1 << SEG6_LOCAL_NH6),
|
|
.input = input_action_end_x,
|
|
},
|
|
{
|
|
.action = SEG6_LOCAL_ACTION_END_T,
|
|
.attrs = (1 << SEG6_LOCAL_TABLE),
|
|
.input = input_action_end_t,
|
|
},
|
|
{
|
|
.action = SEG6_LOCAL_ACTION_END_DX2,
|
|
.attrs = (1 << SEG6_LOCAL_OIF),
|
|
.input = input_action_end_dx2,
|
|
},
|
|
{
|
|
.action = SEG6_LOCAL_ACTION_END_DX6,
|
|
.attrs = (1 << SEG6_LOCAL_NH6),
|
|
.input = input_action_end_dx6,
|
|
},
|
|
{
|
|
.action = SEG6_LOCAL_ACTION_END_DX4,
|
|
.attrs = (1 << SEG6_LOCAL_NH4),
|
|
.input = input_action_end_dx4,
|
|
},
|
|
{
|
|
.action = SEG6_LOCAL_ACTION_END_DT6,
|
|
.attrs = (1 << SEG6_LOCAL_TABLE),
|
|
.input = input_action_end_dt6,
|
|
},
|
|
{
|
|
.action = SEG6_LOCAL_ACTION_END_B6,
|
|
.attrs = (1 << SEG6_LOCAL_SRH),
|
|
.input = input_action_end_b6,
|
|
},
|
|
{
|
|
.action = SEG6_LOCAL_ACTION_END_B6_ENCAP,
|
|
.attrs = (1 << SEG6_LOCAL_SRH),
|
|
.input = input_action_end_b6_encap,
|
|
.static_headroom = sizeof(struct ipv6hdr),
|
|
},
|
|
{
|
|
.action = SEG6_LOCAL_ACTION_END_BPF,
|
|
.attrs = (1 << SEG6_LOCAL_BPF),
|
|
.input = input_action_end_bpf,
|
|
},
|
|
|
|
};
|
|
|
|
static struct seg6_action_desc *__get_action_desc(int action)
|
|
{
|
|
struct seg6_action_desc *desc;
|
|
int i, count;
|
|
|
|
count = ARRAY_SIZE(seg6_action_table);
|
|
for (i = 0; i < count; i++) {
|
|
desc = &seg6_action_table[i];
|
|
if (desc->action == action)
|
|
return desc;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
static int seg6_local_input(struct sk_buff *skb)
|
|
{
|
|
struct dst_entry *orig_dst = skb_dst(skb);
|
|
struct seg6_action_desc *desc;
|
|
struct seg6_local_lwt *slwt;
|
|
|
|
if (skb->protocol != htons(ETH_P_IPV6)) {
|
|
kfree_skb(skb);
|
|
return -EINVAL;
|
|
}
|
|
|
|
slwt = seg6_local_lwtunnel(orig_dst->lwtstate);
|
|
desc = slwt->desc;
|
|
|
|
return desc->input(skb, slwt);
|
|
}
|
|
|
|
static const struct nla_policy seg6_local_policy[SEG6_LOCAL_MAX + 1] = {
|
|
[SEG6_LOCAL_ACTION] = { .type = NLA_U32 },
|
|
[SEG6_LOCAL_SRH] = { .type = NLA_BINARY },
|
|
[SEG6_LOCAL_TABLE] = { .type = NLA_U32 },
|
|
[SEG6_LOCAL_NH4] = { .type = NLA_BINARY,
|
|
.len = sizeof(struct in_addr) },
|
|
[SEG6_LOCAL_NH6] = { .type = NLA_BINARY,
|
|
.len = sizeof(struct in6_addr) },
|
|
[SEG6_LOCAL_IIF] = { .type = NLA_U32 },
|
|
[SEG6_LOCAL_OIF] = { .type = NLA_U32 },
|
|
[SEG6_LOCAL_BPF] = { .type = NLA_NESTED },
|
|
};
|
|
|
|
static int parse_nla_srh(struct nlattr **attrs, struct seg6_local_lwt *slwt)
|
|
{
|
|
struct ipv6_sr_hdr *srh;
|
|
int len;
|
|
|
|
srh = nla_data(attrs[SEG6_LOCAL_SRH]);
|
|
len = nla_len(attrs[SEG6_LOCAL_SRH]);
|
|
|
|
/* SRH must contain at least one segment */
|
|
if (len < sizeof(*srh) + sizeof(struct in6_addr))
|
|
return -EINVAL;
|
|
|
|
if (!seg6_validate_srh(srh, len))
|
|
return -EINVAL;
|
|
|
|
slwt->srh = kmemdup(srh, len, GFP_KERNEL);
|
|
if (!slwt->srh)
|
|
return -ENOMEM;
|
|
|
|
slwt->headroom += len;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int put_nla_srh(struct sk_buff *skb, struct seg6_local_lwt *slwt)
|
|
{
|
|
struct ipv6_sr_hdr *srh;
|
|
struct nlattr *nla;
|
|
int len;
|
|
|
|
srh = slwt->srh;
|
|
len = (srh->hdrlen + 1) << 3;
|
|
|
|
nla = nla_reserve(skb, SEG6_LOCAL_SRH, len);
|
|
if (!nla)
|
|
return -EMSGSIZE;
|
|
|
|
memcpy(nla_data(nla), srh, len);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int cmp_nla_srh(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
|
|
{
|
|
int len = (a->srh->hdrlen + 1) << 3;
|
|
|
|
if (len != ((b->srh->hdrlen + 1) << 3))
|
|
return 1;
|
|
|
|
return memcmp(a->srh, b->srh, len);
|
|
}
|
|
|
|
static int parse_nla_table(struct nlattr **attrs, struct seg6_local_lwt *slwt)
|
|
{
|
|
slwt->table = nla_get_u32(attrs[SEG6_LOCAL_TABLE]);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int put_nla_table(struct sk_buff *skb, struct seg6_local_lwt *slwt)
|
|
{
|
|
if (nla_put_u32(skb, SEG6_LOCAL_TABLE, slwt->table))
|
|
return -EMSGSIZE;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int cmp_nla_table(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
|
|
{
|
|
if (a->table != b->table)
|
|
return 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int parse_nla_nh4(struct nlattr **attrs, struct seg6_local_lwt *slwt)
|
|
{
|
|
memcpy(&slwt->nh4, nla_data(attrs[SEG6_LOCAL_NH4]),
|
|
sizeof(struct in_addr));
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int put_nla_nh4(struct sk_buff *skb, struct seg6_local_lwt *slwt)
|
|
{
|
|
struct nlattr *nla;
|
|
|
|
nla = nla_reserve(skb, SEG6_LOCAL_NH4, sizeof(struct in_addr));
|
|
if (!nla)
|
|
return -EMSGSIZE;
|
|
|
|
memcpy(nla_data(nla), &slwt->nh4, sizeof(struct in_addr));
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int cmp_nla_nh4(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
|
|
{
|
|
return memcmp(&a->nh4, &b->nh4, sizeof(struct in_addr));
|
|
}
|
|
|
|
static int parse_nla_nh6(struct nlattr **attrs, struct seg6_local_lwt *slwt)
|
|
{
|
|
memcpy(&slwt->nh6, nla_data(attrs[SEG6_LOCAL_NH6]),
|
|
sizeof(struct in6_addr));
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int put_nla_nh6(struct sk_buff *skb, struct seg6_local_lwt *slwt)
|
|
{
|
|
struct nlattr *nla;
|
|
|
|
nla = nla_reserve(skb, SEG6_LOCAL_NH6, sizeof(struct in6_addr));
|
|
if (!nla)
|
|
return -EMSGSIZE;
|
|
|
|
memcpy(nla_data(nla), &slwt->nh6, sizeof(struct in6_addr));
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int cmp_nla_nh6(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
|
|
{
|
|
return memcmp(&a->nh6, &b->nh6, sizeof(struct in6_addr));
|
|
}
|
|
|
|
static int parse_nla_iif(struct nlattr **attrs, struct seg6_local_lwt *slwt)
|
|
{
|
|
slwt->iif = nla_get_u32(attrs[SEG6_LOCAL_IIF]);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int put_nla_iif(struct sk_buff *skb, struct seg6_local_lwt *slwt)
|
|
{
|
|
if (nla_put_u32(skb, SEG6_LOCAL_IIF, slwt->iif))
|
|
return -EMSGSIZE;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int cmp_nla_iif(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
|
|
{
|
|
if (a->iif != b->iif)
|
|
return 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int parse_nla_oif(struct nlattr **attrs, struct seg6_local_lwt *slwt)
|
|
{
|
|
slwt->oif = nla_get_u32(attrs[SEG6_LOCAL_OIF]);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int put_nla_oif(struct sk_buff *skb, struct seg6_local_lwt *slwt)
|
|
{
|
|
if (nla_put_u32(skb, SEG6_LOCAL_OIF, slwt->oif))
|
|
return -EMSGSIZE;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int cmp_nla_oif(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
|
|
{
|
|
if (a->oif != b->oif)
|
|
return 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
#define MAX_PROG_NAME 256
|
|
static const struct nla_policy bpf_prog_policy[SEG6_LOCAL_BPF_PROG_MAX + 1] = {
|
|
[SEG6_LOCAL_BPF_PROG] = { .type = NLA_U32, },
|
|
[SEG6_LOCAL_BPF_PROG_NAME] = { .type = NLA_NUL_STRING,
|
|
.len = MAX_PROG_NAME },
|
|
};
|
|
|
|
static int parse_nla_bpf(struct nlattr **attrs, struct seg6_local_lwt *slwt)
|
|
{
|
|
struct nlattr *tb[SEG6_LOCAL_BPF_PROG_MAX + 1];
|
|
struct bpf_prog *p;
|
|
int ret;
|
|
u32 fd;
|
|
|
|
ret = nla_parse_nested(tb, SEG6_LOCAL_BPF_PROG_MAX,
|
|
attrs[SEG6_LOCAL_BPF], bpf_prog_policy, NULL);
|
|
if (ret < 0)
|
|
return ret;
|
|
|
|
if (!tb[SEG6_LOCAL_BPF_PROG] || !tb[SEG6_LOCAL_BPF_PROG_NAME])
|
|
return -EINVAL;
|
|
|
|
slwt->bpf.name = nla_memdup(tb[SEG6_LOCAL_BPF_PROG_NAME], GFP_KERNEL);
|
|
if (!slwt->bpf.name)
|
|
return -ENOMEM;
|
|
|
|
fd = nla_get_u32(tb[SEG6_LOCAL_BPF_PROG]);
|
|
p = bpf_prog_get_type(fd, BPF_PROG_TYPE_LWT_SEG6LOCAL);
|
|
if (IS_ERR(p)) {
|
|
kfree(slwt->bpf.name);
|
|
return PTR_ERR(p);
|
|
}
|
|
|
|
slwt->bpf.prog = p;
|
|
return 0;
|
|
}
|
|
|
|
static int put_nla_bpf(struct sk_buff *skb, struct seg6_local_lwt *slwt)
|
|
{
|
|
struct nlattr *nest;
|
|
|
|
if (!slwt->bpf.prog)
|
|
return 0;
|
|
|
|
nest = nla_nest_start(skb, SEG6_LOCAL_BPF);
|
|
if (!nest)
|
|
return -EMSGSIZE;
|
|
|
|
if (nla_put_u32(skb, SEG6_LOCAL_BPF_PROG, slwt->bpf.prog->aux->id))
|
|
return -EMSGSIZE;
|
|
|
|
if (slwt->bpf.name &&
|
|
nla_put_string(skb, SEG6_LOCAL_BPF_PROG_NAME, slwt->bpf.name))
|
|
return -EMSGSIZE;
|
|
|
|
return nla_nest_end(skb, nest);
|
|
}
|
|
|
|
static int cmp_nla_bpf(struct seg6_local_lwt *a, struct seg6_local_lwt *b)
|
|
{
|
|
if (!a->bpf.name && !b->bpf.name)
|
|
return 0;
|
|
|
|
if (!a->bpf.name || !b->bpf.name)
|
|
return 1;
|
|
|
|
return strcmp(a->bpf.name, b->bpf.name);
|
|
}
|
|
|
|
struct seg6_action_param {
|
|
int (*parse)(struct nlattr **attrs, struct seg6_local_lwt *slwt);
|
|
int (*put)(struct sk_buff *skb, struct seg6_local_lwt *slwt);
|
|
int (*cmp)(struct seg6_local_lwt *a, struct seg6_local_lwt *b);
|
|
};
|
|
|
|
static struct seg6_action_param seg6_action_params[SEG6_LOCAL_MAX + 1] = {
|
|
[SEG6_LOCAL_SRH] = { .parse = parse_nla_srh,
|
|
.put = put_nla_srh,
|
|
.cmp = cmp_nla_srh },
|
|
|
|
[SEG6_LOCAL_TABLE] = { .parse = parse_nla_table,
|
|
.put = put_nla_table,
|
|
.cmp = cmp_nla_table },
|
|
|
|
[SEG6_LOCAL_NH4] = { .parse = parse_nla_nh4,
|
|
.put = put_nla_nh4,
|
|
.cmp = cmp_nla_nh4 },
|
|
|
|
[SEG6_LOCAL_NH6] = { .parse = parse_nla_nh6,
|
|
.put = put_nla_nh6,
|
|
.cmp = cmp_nla_nh6 },
|
|
|
|
[SEG6_LOCAL_IIF] = { .parse = parse_nla_iif,
|
|
.put = put_nla_iif,
|
|
.cmp = cmp_nla_iif },
|
|
|
|
[SEG6_LOCAL_OIF] = { .parse = parse_nla_oif,
|
|
.put = put_nla_oif,
|
|
.cmp = cmp_nla_oif },
|
|
|
|
[SEG6_LOCAL_BPF] = { .parse = parse_nla_bpf,
|
|
.put = put_nla_bpf,
|
|
.cmp = cmp_nla_bpf },
|
|
|
|
};
|
|
|
|
static int parse_nla_action(struct nlattr **attrs, struct seg6_local_lwt *slwt)
|
|
{
|
|
struct seg6_action_param *param;
|
|
struct seg6_action_desc *desc;
|
|
int i, err;
|
|
|
|
desc = __get_action_desc(slwt->action);
|
|
if (!desc)
|
|
return -EINVAL;
|
|
|
|
if (!desc->input)
|
|
return -EOPNOTSUPP;
|
|
|
|
slwt->desc = desc;
|
|
slwt->headroom += desc->static_headroom;
|
|
|
|
for (i = 0; i < SEG6_LOCAL_MAX + 1; i++) {
|
|
if (desc->attrs & (1 << i)) {
|
|
if (!attrs[i])
|
|
return -EINVAL;
|
|
|
|
param = &seg6_action_params[i];
|
|
|
|
err = param->parse(attrs, slwt);
|
|
if (err < 0)
|
|
return err;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int seg6_local_build_state(struct nlattr *nla, unsigned int family,
|
|
const void *cfg, struct lwtunnel_state **ts,
|
|
struct netlink_ext_ack *extack)
|
|
{
|
|
struct nlattr *tb[SEG6_LOCAL_MAX + 1];
|
|
struct lwtunnel_state *newts;
|
|
struct seg6_local_lwt *slwt;
|
|
int err;
|
|
|
|
if (family != AF_INET6)
|
|
return -EINVAL;
|
|
|
|
err = nla_parse_nested(tb, SEG6_LOCAL_MAX, nla, seg6_local_policy,
|
|
extack);
|
|
|
|
if (err < 0)
|
|
return err;
|
|
|
|
if (!tb[SEG6_LOCAL_ACTION])
|
|
return -EINVAL;
|
|
|
|
newts = lwtunnel_state_alloc(sizeof(*slwt));
|
|
if (!newts)
|
|
return -ENOMEM;
|
|
|
|
slwt = seg6_local_lwtunnel(newts);
|
|
slwt->action = nla_get_u32(tb[SEG6_LOCAL_ACTION]);
|
|
|
|
err = parse_nla_action(tb, slwt);
|
|
if (err < 0)
|
|
goto out_free;
|
|
|
|
newts->type = LWTUNNEL_ENCAP_SEG6_LOCAL;
|
|
newts->flags = LWTUNNEL_STATE_INPUT_REDIRECT;
|
|
newts->headroom = slwt->headroom;
|
|
|
|
*ts = newts;
|
|
|
|
return 0;
|
|
|
|
out_free:
|
|
kfree(slwt->srh);
|
|
kfree(newts);
|
|
return err;
|
|
}
|
|
|
|
static void seg6_local_destroy_state(struct lwtunnel_state *lwt)
|
|
{
|
|
struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt);
|
|
|
|
kfree(slwt->srh);
|
|
|
|
if (slwt->desc->attrs & (1 << SEG6_LOCAL_BPF)) {
|
|
kfree(slwt->bpf.name);
|
|
bpf_prog_put(slwt->bpf.prog);
|
|
}
|
|
|
|
return;
|
|
}
|
|
|
|
static int seg6_local_fill_encap(struct sk_buff *skb,
|
|
struct lwtunnel_state *lwt)
|
|
{
|
|
struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt);
|
|
struct seg6_action_param *param;
|
|
int i, err;
|
|
|
|
if (nla_put_u32(skb, SEG6_LOCAL_ACTION, slwt->action))
|
|
return -EMSGSIZE;
|
|
|
|
for (i = 0; i < SEG6_LOCAL_MAX + 1; i++) {
|
|
if (slwt->desc->attrs & (1 << i)) {
|
|
param = &seg6_action_params[i];
|
|
err = param->put(skb, slwt);
|
|
if (err < 0)
|
|
return err;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int seg6_local_get_encap_size(struct lwtunnel_state *lwt)
|
|
{
|
|
struct seg6_local_lwt *slwt = seg6_local_lwtunnel(lwt);
|
|
unsigned long attrs;
|
|
int nlsize;
|
|
|
|
nlsize = nla_total_size(4); /* action */
|
|
|
|
attrs = slwt->desc->attrs;
|
|
|
|
if (attrs & (1 << SEG6_LOCAL_SRH))
|
|
nlsize += nla_total_size((slwt->srh->hdrlen + 1) << 3);
|
|
|
|
if (attrs & (1 << SEG6_LOCAL_TABLE))
|
|
nlsize += nla_total_size(4);
|
|
|
|
if (attrs & (1 << SEG6_LOCAL_NH4))
|
|
nlsize += nla_total_size(4);
|
|
|
|
if (attrs & (1 << SEG6_LOCAL_NH6))
|
|
nlsize += nla_total_size(16);
|
|
|
|
if (attrs & (1 << SEG6_LOCAL_IIF))
|
|
nlsize += nla_total_size(4);
|
|
|
|
if (attrs & (1 << SEG6_LOCAL_OIF))
|
|
nlsize += nla_total_size(4);
|
|
|
|
if (attrs & (1 << SEG6_LOCAL_BPF))
|
|
nlsize += nla_total_size(sizeof(struct nlattr)) +
|
|
nla_total_size(MAX_PROG_NAME) +
|
|
nla_total_size(4);
|
|
|
|
return nlsize;
|
|
}
|
|
|
|
static int seg6_local_cmp_encap(struct lwtunnel_state *a,
|
|
struct lwtunnel_state *b)
|
|
{
|
|
struct seg6_local_lwt *slwt_a, *slwt_b;
|
|
struct seg6_action_param *param;
|
|
int i;
|
|
|
|
slwt_a = seg6_local_lwtunnel(a);
|
|
slwt_b = seg6_local_lwtunnel(b);
|
|
|
|
if (slwt_a->action != slwt_b->action)
|
|
return 1;
|
|
|
|
if (slwt_a->desc->attrs != slwt_b->desc->attrs)
|
|
return 1;
|
|
|
|
for (i = 0; i < SEG6_LOCAL_MAX + 1; i++) {
|
|
if (slwt_a->desc->attrs & (1 << i)) {
|
|
param = &seg6_action_params[i];
|
|
if (param->cmp(slwt_a, slwt_b))
|
|
return 1;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct lwtunnel_encap_ops seg6_local_ops = {
|
|
.build_state = seg6_local_build_state,
|
|
.destroy_state = seg6_local_destroy_state,
|
|
.input = seg6_local_input,
|
|
.fill_encap = seg6_local_fill_encap,
|
|
.get_encap_size = seg6_local_get_encap_size,
|
|
.cmp_encap = seg6_local_cmp_encap,
|
|
.owner = THIS_MODULE,
|
|
};
|
|
|
|
int __init seg6_local_init(void)
|
|
{
|
|
return lwtunnel_encap_add_ops(&seg6_local_ops,
|
|
LWTUNNEL_ENCAP_SEG6_LOCAL);
|
|
}
|
|
|
|
void seg6_local_exit(void)
|
|
{
|
|
lwtunnel_encap_del_ops(&seg6_local_ops, LWTUNNEL_ENCAP_SEG6_LOCAL);
|
|
}
|