This is a note to let you know that I've just added the patch titled seg6: export get_srh() for ICMP handling to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: seg6-export-get_srh-for-icmp-handling.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 1209c59482fc19ddbe5dc2f5d0881a709083be5e Author: Andrew Lunn <andrew@xxxxxxx> Date: Mon Jan 3 18:11:30 2022 +0100 seg6: export get_srh() for ICMP handling [ Upstream commit fa55a7d745de2d10489295b0674a403e2a5d490d ] An ICMP error message can contain in its message body part of an IPv6 packet which invoked the error. Such a packet might contain a segment router header. Export get_srh() so the ICMP code can make use of it. Since his changes the scope of the function from local to global, add the seg6_ prefix to keep the namespace clean. And move it into seg6.c so it is always available, not just when IPV6_SEG6_LWTUNNEL is enabled. Signed-off-by: Andrew Lunn <andrew@xxxxxxx> Reviewed-by: David Ahern <dsahern@xxxxxxxxxx> Reviewed-by: Willem de Bruijn <willemb@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/include/net/seg6.h b/include/net/seg6.h index 9d19c15e8545c..a6f25983670aa 100644 --- a/include/net/seg6.h +++ b/include/net/seg6.h @@ -58,6 +58,7 @@ extern int seg6_local_init(void); extern void seg6_local_exit(void); extern bool seg6_validate_srh(struct ipv6_sr_hdr *srh, int len, bool reduced); +extern struct ipv6_sr_hdr *seg6_get_srh(struct sk_buff *skb, int flags); 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); diff --git a/net/ipv6/seg6.c b/net/ipv6/seg6.c index e412817fba2f3..0718529088930 100644 --- a/net/ipv6/seg6.c +++ b/net/ipv6/seg6.c @@ -75,6 +75,35 @@ bool seg6_validate_srh(struct ipv6_sr_hdr *srh, int len, bool reduced) return true; } +struct ipv6_sr_hdr *seg6_get_srh(struct sk_buff *skb, int flags) +{ + struct ipv6_sr_hdr *srh; + int len, srhoff = 0; + + if (ipv6_find_hdr(skb, &srhoff, IPPROTO_ROUTING, NULL, &flags) < 0) + return NULL; + + if (!pskb_may_pull(skb, srhoff + sizeof(*srh))) + return NULL; + + srh = (struct ipv6_sr_hdr *)(skb->data + srhoff); + + len = (srh->hdrlen + 1) << 3; + + if (!pskb_may_pull(skb, srhoff + len)) + return NULL; + + /* note that pskb_may_pull may change pointers in header; + * for this reason it is necessary to reload them when needed. + */ + srh = (struct ipv6_sr_hdr *)(skb->data + srhoff); + + if (!seg6_validate_srh(srh, len, true)) + return NULL; + + return srh; +} + static struct genl_family seg6_genl_family; static const struct nla_policy seg6_genl_policy[SEG6_ATTR_MAX + 1] = { diff --git a/net/ipv6/seg6_local.c b/net/ipv6/seg6_local.c index 2dc40b3f373ef..ef88489c71f52 100644 --- a/net/ipv6/seg6_local.c +++ b/net/ipv6/seg6_local.c @@ -150,40 +150,11 @@ static struct seg6_local_lwt *seg6_local_lwtunnel(struct lwtunnel_state *lwt) return (struct seg6_local_lwt *)lwt->data; } -static struct ipv6_sr_hdr *get_srh(struct sk_buff *skb, int flags) -{ - struct ipv6_sr_hdr *srh; - int len, srhoff = 0; - - if (ipv6_find_hdr(skb, &srhoff, IPPROTO_ROUTING, NULL, &flags) < 0) - return NULL; - - if (!pskb_may_pull(skb, srhoff + sizeof(*srh))) - return NULL; - - srh = (struct ipv6_sr_hdr *)(skb->data + srhoff); - - len = (srh->hdrlen + 1) << 3; - - if (!pskb_may_pull(skb, srhoff + len)) - return NULL; - - /* note that pskb_may_pull may change pointers in header; - * for this reason it is necessary to reload them when needed. - */ - srh = (struct ipv6_sr_hdr *)(skb->data + srhoff); - - if (!seg6_validate_srh(srh, len, true)) - return NULL; - - return srh; -} - static struct ipv6_sr_hdr *get_and_validate_srh(struct sk_buff *skb) { struct ipv6_sr_hdr *srh; - srh = get_srh(skb, IP6_FH_F_SKIP_RH); + srh = seg6_get_srh(skb, IP6_FH_F_SKIP_RH); if (!srh) return NULL; @@ -200,7 +171,7 @@ static bool decap_and_validate(struct sk_buff *skb, int proto) struct ipv6_sr_hdr *srh; unsigned int off = 0; - srh = get_srh(skb, 0); + srh = seg6_get_srh(skb, 0); if (srh && srh->segments_left > 0) return false;