From 1c1e761ef1a08a878a040e67979711015cfc163e Mon Sep 17 00:00:00 2001 From: Mathieu Xhonneux Date: Sun, 20 May 2018 14:58:13 +0100 Subject: [PATCH] ipv6: sr: export function lookup_nexthop The function lookup_nexthop is essential to implement most of the seg6local actions. As we want to provide a BPF helper allowing to apply some of these actions on the packet being processed, the helper should be able to call this function, hence the need to make it public. Moreover, if one argument is incorrect or if the next hop can not be found, an error should be returned by the BPF helper so the BPF program can adapt its processing of the packet (return an error, properly force the drop, ...). This patch hence makes this function return dst->error to indicate a possible error. Signed-off-by: Mathieu Xhonneux Acked-by: David Lebrun Signed-off-by: Daniel Borkmann --- include/net/seg6.h | 3 ++- include/net/seg6_local.h | 24 ++++++++++++++++++++++++ net/ipv6/seg6_local.c | 20 +++++++++++--------- 3 files changed, 37 insertions(+), 10 deletions(-) create mode 100644 include/net/seg6_local.h diff --git a/include/net/seg6.h b/include/net/seg6.h index 70b4cfac52d7..e029e301faa5 100644 --- a/include/net/seg6.h +++ b/include/net/seg6.h @@ -67,5 +67,6 @@ extern bool seg6_validate_srh(struct ipv6_sr_hdr *srh, int len); extern int seg6_do_srh_encap(struct sk_buff *skb, struct ipv6_sr_hdr *osrh, int proto); extern int seg6_do_srh_inline(struct sk_buff *skb, struct ipv6_sr_hdr *osrh); - +extern int seg6_lookup_nexthop(struct sk_buff *skb, struct in6_addr *nhaddr, + u32 tbl_id); #endif diff --git a/include/net/seg6_local.h b/include/net/seg6_local.h new file mode 100644 index 000000000000..57498b23085d --- /dev/null +++ b/include/net/seg6_local.h @@ -0,0 +1,24 @@ +/* + * SR-IPv6 implementation + * + * Authors: + * David Lebrun + * eBPF support: Mathieu Xhonneux + * + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#ifndef _NET_SEG6_LOCAL_H +#define _NET_SEG6_LOCAL_H + +#include +#include + +extern int seg6_lookup_nexthop(struct sk_buff *skb, struct in6_addr *nhaddr, + u32 tbl_id); + +#endif diff --git a/net/ipv6/seg6_local.c b/net/ipv6/seg6_local.c index 45722327375a..e9b23fb924ad 100644 --- a/net/ipv6/seg6_local.c +++ b/net/ipv6/seg6_local.c @@ -30,6 +30,7 @@ #ifdef CONFIG_IPV6_SEG6_HMAC #include #endif +#include #include struct seg6_local_lwt; @@ -140,8 +141,8 @@ static void advance_nextseg(struct ipv6_sr_hdr *srh, struct in6_addr *daddr) *daddr = *addr; } -static void lookup_nexthop(struct sk_buff *skb, struct in6_addr *nhaddr, - u32 tbl_id) +int seg6_lookup_nexthop(struct sk_buff *skb, struct in6_addr *nhaddr, + u32 tbl_id) { struct net *net = dev_net(skb->dev); struct ipv6hdr *hdr = ipv6_hdr(skb); @@ -187,6 +188,7 @@ static void lookup_nexthop(struct sk_buff *skb, struct in6_addr *nhaddr, skb_dst_drop(skb); skb_dst_set(skb, dst); + return dst->error; } /* regular endpoint function */ @@ -200,7 +202,7 @@ static int input_action_end(struct sk_buff *skb, struct seg6_local_lwt *slwt) advance_nextseg(srh, &ipv6_hdr(skb)->daddr); - lookup_nexthop(skb, NULL, 0); + seg6_lookup_nexthop(skb, NULL, 0); return dst_input(skb); @@ -220,7 +222,7 @@ static int input_action_end_x(struct sk_buff *skb, struct seg6_local_lwt *slwt) advance_nextseg(srh, &ipv6_hdr(skb)->daddr); - lookup_nexthop(skb, &slwt->nh6, 0); + seg6_lookup_nexthop(skb, &slwt->nh6, 0); return dst_input(skb); @@ -239,7 +241,7 @@ static int input_action_end_t(struct sk_buff *skb, struct seg6_local_lwt *slwt) advance_nextseg(srh, &ipv6_hdr(skb)->daddr); - lookup_nexthop(skb, NULL, slwt->table); + seg6_lookup_nexthop(skb, NULL, slwt->table); return dst_input(skb); @@ -331,7 +333,7 @@ static int input_action_end_dx6(struct sk_buff *skb, if (!ipv6_addr_any(&slwt->nh6)) nhaddr = &slwt->nh6; - lookup_nexthop(skb, nhaddr, 0); + seg6_lookup_nexthop(skb, nhaddr, 0); return dst_input(skb); drop: @@ -380,7 +382,7 @@ static int input_action_end_dt6(struct sk_buff *skb, if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) goto drop; - lookup_nexthop(skb, NULL, slwt->table); + seg6_lookup_nexthop(skb, NULL, slwt->table); return dst_input(skb); @@ -406,7 +408,7 @@ static int input_action_end_b6(struct sk_buff *skb, struct seg6_local_lwt *slwt) ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr)); skb_set_transport_header(skb, sizeof(struct ipv6hdr)); - lookup_nexthop(skb, NULL, 0); + seg6_lookup_nexthop(skb, NULL, 0); return dst_input(skb); @@ -438,7 +440,7 @@ static int input_action_end_b6_encap(struct sk_buff *skb, ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr)); skb_set_transport_header(skb, sizeof(struct ipv6hdr)); - lookup_nexthop(skb, NULL, 0); + seg6_lookup_nexthop(skb, NULL, 0); return dst_input(skb);