diff options
Diffstat (limited to 'net/ipv6/exthdrs.c')
| -rw-r--r-- | net/ipv6/exthdrs.c | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c index 139ceb68bd37..b8ba3961ff8a 100644 --- a/net/ipv6/exthdrs.c +++ b/net/ipv6/exthdrs.c @@ -47,6 +47,8 @@ #if IS_ENABLED(CONFIG_IPV6_MIP6) #include <net/xfrm.h> #endif +#include <linux/seg6.h> +#include <net/seg6.h> #include <linux/uaccess.h> @@ -286,6 +288,175 @@ static int ipv6_destopt_rcv(struct sk_buff *skb) return -1; } +static void seg6_update_csum(struct sk_buff *skb) +{ + struct ipv6_sr_hdr *hdr; + struct in6_addr *addr; + __be32 from, to; + + /* srh is at transport offset and seg_left is already decremented + * but daddr is not yet updated with next segment + */ + + hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb); + addr = hdr->segments + hdr->segments_left; + + hdr->segments_left++; + from = *(__be32 *)hdr; + + hdr->segments_left--; + to = *(__be32 *)hdr; + + /* update skb csum with diff resulting from seg_left decrement */ + + update_csum_diff4(skb, from, to); + + /* compute csum diff between current and next segment and update */ + + update_csum_diff16(skb, (__be32 *)(&ipv6_hdr(skb)->daddr), + (__be32 *)addr); +} + +static int ipv6_srh_rcv(struct sk_buff *skb) +{ + struct inet6_skb_parm *opt = IP6CB(skb); + struct net *net = dev_net(skb->dev); + struct ipv6_sr_hdr *hdr; + struct inet6_dev *idev; + struct in6_addr *addr; + bool cleanup = false; + int accept_seg6; + + hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb); + + idev = __in6_dev_get(skb->dev); + + accept_seg6 = net->ipv6.devconf_all->seg6_enabled; + if (accept_seg6 > idev->cnf.seg6_enabled) + accept_seg6 = idev->cnf.seg6_enabled; + + if (!accept_seg6) { + kfree_skb(skb); + return -1; + } + +looped_back: + if (hdr->segments_left > 0) { + if (hdr->nexthdr != NEXTHDR_IPV6 && hdr->segments_left == 1 && + sr_has_cleanup(hdr)) + cleanup = true; + } else { + if (hdr->nexthdr == NEXTHDR_IPV6) { + int offset = (hdr->hdrlen + 1) << 3; + + skb_postpull_rcsum(skb, skb_network_header(skb), + skb_network_header_len(skb)); + + if (!pskb_pull(skb, offset)) { + kfree_skb(skb); + return -1; + } + skb_postpull_rcsum(skb, skb_transport_header(skb), + offset); + + skb_reset_network_header(skb); + skb_reset_transport_header(skb); + skb->encapsulation = 0; + + __skb_tunnel_rx(skb, skb->dev, net); + + netif_rx(skb); + return -1; + } + + opt->srcrt = skb_network_header_len(skb); + opt->lastopt = opt->srcrt; + skb->transport_header += (hdr->hdrlen + 1) << 3; + opt->nhoff = (&hdr->nexthdr) - skb_network_header(skb); + + return 1; + } + + if (hdr->segments_left >= (hdr->hdrlen >> 1)) { + __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), + IPSTATS_MIB_INHDRERRORS); + icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, + ((&hdr->segments_left) - + skb_network_header(skb))); + kfree_skb(skb); + return -1; + } + + if (skb_cloned(skb)) { + if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) { + __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), + IPSTATS_MIB_OUTDISCARDS); + kfree_skb(skb); + return -1; + } + } + + hdr = (struct ipv6_sr_hdr *)skb_transport_header(skb); + + hdr->segments_left--; + addr = hdr->segments + hdr->segments_left; + + skb_push(skb, sizeof(struct ipv6hdr)); + + if (skb->ip_summed == CHECKSUM_COMPLETE) + seg6_update_csum(skb); + + ipv6_hdr(skb)->daddr = *addr; + + if (cleanup) { + int srhlen = (hdr->hdrlen + 1) << 3; + int nh = hdr->nexthdr; + + skb_pull_rcsum(skb, sizeof(struct ipv6hdr) + srhlen); + memmove(skb_network_header(skb) + srhlen, + skb_network_header(skb), + (unsigned char *)hdr - skb_network_header(skb)); + skb->network_header += srhlen; + ipv6_hdr(skb)->nexthdr = nh; + ipv6_hdr(skb)->payload_len = htons(skb->len - + sizeof(struct ipv6hdr)); + skb_push_rcsum(skb, sizeof(struct ipv6hdr)); + } + + skb_dst_drop(skb); + + ip6_route_input(skb); + + if (skb_dst(skb)->error) { + dst_input(skb); + return -1; + } + + if (skb_dst(skb)->dev->flags & IFF_LOOPBACK) { + if (ipv6_hdr(skb)->hop_limit <= 1) { + __IP6_INC_STATS(net, ip6_dst_idev(skb_dst(skb)), + IPSTATS_MIB_INHDRERRORS); + icmpv6_send(skb, ICMPV6_TIME_EXCEED, + ICMPV6_EXC_HOPLIMIT, 0); + kfree_skb(skb); + return -1; + } + ipv6_hdr(skb)->hop_limit--; + + /* be sure that srh is still present before reinjecting */ + if (!cleanup) { + skb_pull(skb, sizeof(struct ipv6hdr)); + goto looped_back; + } + skb_set_transport_header(skb, sizeof(struct ipv6hdr)); + IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr); + } + + dst_input(skb); + + return -1; +} + /******************************** Routing header. ********************************/ @@ -326,6 +497,10 @@ static int ipv6_rthdr_rcv(struct sk_buff *skb) return -1; } + /* segment routing */ + if (hdr->type == IPV6_SRCRT_TYPE_4) + return ipv6_srh_rcv(skb); + looped_back: if (hdr->segments_left == 0) { switch (hdr->type) { |