From: Max Tottenham <mtottenh@xxxxxxxxxx>
[ Upstream commit 6c02568fd1ae53099b4ab86365c5be1ff15f586b ]
Instead of relying on skb->transport_header being set correctly, opt
instead to parse the L3 header length out of the L3 headers for both
IPv4/IPv6 when the Extended Layer Op for tcp/udp is used. This fixes a
bug if GRO is disabled, when GRO is disabled skb->transport_header is
set by __netif_receive_skb_core() to point to the L3 header, it's later
fixed by the upper protocol layers, but act_pedit will receive the SKB
before the fixups are completed. The existing behavior causes the
following to edit the L3 header if GRO is disabled instead of the UDP
header:
tc filter add dev eth0 ingress protocol ip flower ip_proto udp \
dst_ip 192.168.1.3 action pedit ex munge udp set dport 18053
Also re-introduce a rate-limited warning if we were unable to extract
the header offset when using the 'ex' interface.
Fixes: 71d0ed7079df ("net/act_pedit: Support using offset relative to
the conventional network headers")
Signed-off-by: Max Tottenham <mtottenh@xxxxxxxxxx>
Reviewed-by: Josh Hunt <johunt@xxxxxxxxxx>
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Closes: https://lore.kernel.org/oe-kbuild-all/202305261541.N165u9TZ-lkp@xxxxxxxxx/
Reviewed-by: Pedro Tammela <pctammela@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/sched/act_pedit.c | 48 ++++++++++++++++++++++++++++++++++++++-----
1 file changed, 43 insertions(+), 5 deletions(-)
diff --git a/net/sched/act_pedit.c b/net/sched/act_pedit.c
index 1e7e959b90e48..300b5ae760dcc 100644
--- a/net/sched/act_pedit.c
+++ b/net/sched/act_pedit.c
@@ -13,7 +13,10 @@
#include <linux/rtnetlink.h>
#include <linux/module.h>
#include <linux/init.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
#include <linux/slab.h>
+#include <net/ipv6.h>
#include <net/netlink.h>
#include <net/pkt_sched.h>
#include <linux/tc_act/tc_pedit.h>
@@ -313,28 +316,58 @@ static bool offset_valid(struct sk_buff *skb, int offset)
return true;
}
-static void pedit_skb_hdr_offset(struct sk_buff *skb,
+static int pedit_l4_skb_offset(struct sk_buff *skb, int *hoffset, const int header_type)
+{
+ const int noff = skb_network_offset(skb);
+ int ret = -EINVAL;
+ struct iphdr _iph;
+
+ switch (skb->protocol) {
+ case htons(ETH_P_IP): {
+ const struct iphdr *iph = skb_header_pointer(skb, noff, sizeof(_iph), &_iph);
+
+ if (!iph)
+ goto out;
+ *hoffset = noff + iph->ihl * 4;
+ ret = 0;
+ break;
+ }
+ case htons(ETH_P_IPV6):
+ ret = ipv6_find_hdr(skb, hoffset, header_type, NULL, NULL) == header_type ? 0 : -EINVAL;
+ break;
+ }
+out:
+ return ret;
+}
+
+static int pedit_skb_hdr_offset(struct sk_buff *skb,
enum pedit_header_type htype, int *hoffset)
{
+ int ret = -EINVAL;
/* 'htype' is validated in the netlink parsing */
switch (htype) {
case TCA_PEDIT_KEY_EX_HDR_TYPE_ETH:
- if (skb_mac_header_was_set(skb))
+ if (skb_mac_header_was_set(skb)) {
*hoffset = skb_mac_offset(skb);
+ ret = 0;
+ }
break;
case TCA_PEDIT_KEY_EX_HDR_TYPE_NETWORK:
case TCA_PEDIT_KEY_EX_HDR_TYPE_IP4:
case TCA_PEDIT_KEY_EX_HDR_TYPE_IP6:
*hoffset = skb_network_offset(skb);
+ ret = 0;
break;
case TCA_PEDIT_KEY_EX_HDR_TYPE_TCP:
+ ret = pedit_l4_skb_offset(skb, hoffset, IPPROTO_TCP);
+ break;
case TCA_PEDIT_KEY_EX_HDR_TYPE_UDP:
- if (skb_transport_header_was_set(skb))
- *hoffset = skb_transport_offset(skb);
+ ret = pedit_l4_skb_offset(skb, hoffset, IPPROTO_UDP);
break;
default:
break;
}
+ return ret;
}
TC_INDIRECT_SCOPE int tcf_pedit_act(struct sk_buff *skb,
@@ -370,6 +403,7 @@ TC_INDIRECT_SCOPE int tcf_pedit_act(struct sk_buff *skb,
int hoffset = 0;
u32 *ptr, hdata;
u32 val;
+ int rc;
if (tkey_ex) {
htype = tkey_ex->htype;
@@ -378,7 +412,11 @@ TC_INDIRECT_SCOPE int tcf_pedit_act(struct sk_buff *skb,
tkey_ex++;
}
- pedit_skb_hdr_offset(skb, htype, &hoffset);
+ rc = pedit_skb_hdr_offset(skb, htype, &hoffset);
+ if (rc) {
+ pr_info_ratelimited("tc action pedit unable to extract header offset for header type (0x%x)\n", htype);
+ goto bad;
+ }
if (tkey->offmask) {
u8 *d, _d;
--
2.39.2
