From: Pablo Neira Ayuso <pablo@netfilter.org>
To: netdev@vger.kernel.org
Cc: davem@davemloft.net, kuba@kernel.org, pabeni@redhat.com,
edumazet@google.com, laforge@osmocom.org, pespin@sysmocom.de,
osmith@sysmocom.de
Subject: [PATCH net-next 10/12] gtp: add helper function to build GTP packets from an IPv6 packet
Date: Wed, 24 Apr 2024 00:39:17 +0200 [thread overview]
Message-ID: <20240423223919.3385493-11-pablo@netfilter.org> (raw)
In-Reply-To: <20240423223919.3385493-1-pablo@netfilter.org>
Add routine to attach an IPv6 route for the encapsulated packet, deal
with Path MTU and push GTP header.
This helper function will be used to deal with IPv4-in-IPv6-GTP.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
drivers/net/gtp.c | 109 ++++++++++++++++++++++++++--------------------
1 file changed, 62 insertions(+), 47 deletions(-)
diff --git a/drivers/net/gtp.c b/drivers/net/gtp.c
index 5d1247eab382..c38dfe6a0673 100644
--- a/drivers/net/gtp.c
+++ b/drivers/net/gtp.c
@@ -1046,6 +1046,63 @@ static int gtp_build_skb_outer_ip4(struct sk_buff *skb, struct net_device *dev,
return -EBADMSG;
}
+static int gtp_build_skb_outer_ip6(struct net *net, struct sk_buff *skb,
+ struct net_device *dev,
+ struct gtp_pktinfo *pktinfo,
+ struct pdp_ctx *pctx, __u8 tos)
+{
+ struct dst_entry *dst;
+ struct rt6_info *rt;
+ struct flowi6 fl6;
+ int mtu;
+
+ rt = ip6_route_output_gtp(net, &fl6, pctx->sk, &pctx->peer.addr6,
+ &inet6_sk(pctx->sk)->saddr);
+ if (IS_ERR(rt)) {
+ netdev_dbg(dev, "no route to SSGN %pI6\n",
+ &pctx->peer.addr6);
+ dev->stats.tx_carrier_errors++;
+ goto err;
+ }
+ dst = &rt->dst;
+
+ if (rt->dst.dev == dev) {
+ netdev_dbg(dev, "circular route to SSGN %pI6\n",
+ &pctx->peer.addr6);
+ dev->stats.collisions++;
+ goto err_rt;
+ }
+
+ mtu = dst_mtu(&rt->dst) - dev->hard_header_len -
+ sizeof(struct ipv6hdr) - sizeof(struct udphdr);
+ switch (pctx->gtp_version) {
+ case GTP_V0:
+ mtu -= sizeof(struct gtp0_header);
+ break;
+ case GTP_V1:
+ mtu -= sizeof(struct gtp1_header);
+ break;
+ }
+
+ skb_dst_update_pmtu_no_confirm(skb, mtu);
+
+ if ((!skb_is_gso(skb) && skb->len > mtu) ||
+ (skb_is_gso(skb) && !skb_gso_validate_network_len(skb, mtu))) {
+ netdev_dbg(dev, "packet too big, fragmentation needed\n");
+ icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
+ goto err_rt;
+ }
+
+ gtp_set_pktinfo_ipv6(pktinfo, pctx->sk, tos, pctx, rt, &fl6, dev);
+ gtp_push_header(skb, pktinfo);
+
+ return 0;
+err_rt:
+ dst_release(dst);
+err:
+ return -EBADMSG;
+}
+
static int gtp_build_skb_ip4(struct sk_buff *skb, struct net_device *dev,
struct gtp_pktinfo *pktinfo)
{
@@ -1086,13 +1143,10 @@ static int gtp_build_skb_ip6(struct sk_buff *skb, struct net_device *dev,
{
struct gtp_dev *gtp = netdev_priv(dev);
struct net *net = gtp->net;
- struct dst_entry *dst;
struct pdp_ctx *pctx;
struct ipv6hdr *ip6h;
- struct rt6_info *rt;
- struct flowi6 fl6;
__u8 tos;
- int mtu;
+ int ret;
/* Read the IP destination address and resolve the PDP context.
* Prepend PDP header with TEI/TID from PDP ctx.
@@ -1110,55 +1164,16 @@ static int gtp_build_skb_ip6(struct sk_buff *skb, struct net_device *dev,
}
netdev_dbg(dev, "found PDP context %p\n", pctx);
- rt = ip6_route_output_gtp(net, &fl6, pctx->sk, &pctx->peer.addr6,
- &inet6_sk(pctx->sk)->saddr);
- if (IS_ERR(rt)) {
- netdev_dbg(dev, "no route to SSGN %pI6\n",
- &pctx->peer.addr6);
- dev->stats.tx_carrier_errors++;
- goto err;
- }
- dst = &rt->dst;
-
- if (rt->dst.dev == dev) {
- netdev_dbg(dev, "circular route to SSGN %pI6\n",
- &pctx->peer.addr6);
- dev->stats.collisions++;
- goto err_rt;
- }
-
- mtu = dst_mtu(&rt->dst) - dev->hard_header_len -
- sizeof(struct ipv6hdr) - sizeof(struct udphdr);
- switch (pctx->gtp_version) {
- case GTP_V0:
- mtu -= sizeof(struct gtp0_header);
- break;
- case GTP_V1:
- mtu -= sizeof(struct gtp1_header);
- break;
- }
-
- skb_dst_update_pmtu_no_confirm(skb, mtu);
-
- if ((!skb_is_gso(skb) && skb->len > mtu) ||
- (skb_is_gso(skb) && !skb_gso_validate_network_len(skb, mtu))) {
- netdev_dbg(dev, "packet too big, fragmentation needed\n");
- icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
- goto err_rt;
- }
-
tos = ipv6_get_dsfield(ip6h);
- gtp_set_pktinfo_ipv6(pktinfo, pctx->sk, tos, pctx, rt, &fl6, dev);
- gtp_push_header(skb, pktinfo);
+
+ ret = gtp_build_skb_outer_ip6(net, skb, dev, pktinfo, pctx, tos);
+ if (ret < 0)
+ return ret;
netdev_dbg(dev, "gtp -> IP src: %pI6 dst: %pI6\n",
&ip6h->saddr, &ip6h->daddr);
return 0;
-err_rt:
- dst_release(dst);
-err:
- return -EBADMSG;
}
static netdev_tx_t gtp_dev_xmit(struct sk_buff *skb, struct net_device *dev)
--
2.30.2
next prev parent reply other threads:[~2024-04-23 22:39 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-23 22:39 [PATCH net-next 00/12] GTP driver updates for net-next Pablo Neira Ayuso
2024-04-23 22:39 ` [PATCH net-next 01/12] gtp: remove useless initialization Pablo Neira Ayuso
2024-04-23 22:39 ` [PATCH net-next 02/12] gtp: properly parse extension headers Pablo Neira Ayuso
2024-04-23 22:39 ` [PATCH net-next 03/12] gtp: prepare for IPv6 support Pablo Neira Ayuso
2024-04-23 22:39 ` [PATCH net-next 04/12] gtp: add " Pablo Neira Ayuso
2024-04-23 22:39 ` [PATCH net-next 05/12] gtp: use IPv6 address /64 prefix for UE/MS Pablo Neira Ayuso
2024-04-24 0:44 ` Jakub Kicinski
2024-04-23 22:39 ` [PATCH net-next 06/12] gtp: pass up link local traffic to userspace socket Pablo Neira Ayuso
2024-04-23 22:39 ` [PATCH net-next 07/12] gtp: move debugging to skbuff build helper function Pablo Neira Ayuso
2024-04-23 22:39 ` [PATCH net-next 08/12] gtp: remove IPv4 and IPv6 header from context object Pablo Neira Ayuso
2024-04-23 22:39 ` [PATCH net-next 09/12] gtp: add helper function to build GTP packets from an IPv4 packet Pablo Neira Ayuso
2024-04-23 22:39 ` Pablo Neira Ayuso [this message]
2024-04-23 22:39 ` [PATCH net-next 11/12] gtp: support for IPv4-in-IPv6-GTP and IPv6-in-IPv4-GTP Pablo Neira Ayuso
2024-04-23 22:39 ` [PATCH net-next 12/12] gtp: identify tunnel via GTP device + GTP version + TEID + family Pablo Neira Ayuso
-- strict thread matches above, loose matches on Subject: below --
2024-04-25 10:51 [PATCH net-next 00/12] gtp updates for net-next (v2) Pablo Neira Ayuso
2024-04-25 10:51 ` [PATCH net-next 10/12] gtp: add helper function to build GTP packets from an IPv6 packet Pablo Neira Ayuso
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