[Devel] [PATCH RHEL9 COMMIT] net: ipv6: add skb drop reasons to TLV parse
Konstantin Khorenko
khorenko at virtuozzo.com
Mon Jan 16 20:56:51 MSK 2023
The commit is pushed to "branch-rh9-5.14.0-162.6.1.vz9.18.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh9-5.14.0-162.6.1.vz9.18.2
------>
commit 43de889e69a52d88cff0e5577768957700c67e01
Author: Menglong Dong <imagedong at tencent.com>
Date: Tue Jan 3 17:39:34 2023 +0200
net: ipv6: add skb drop reasons to TLV parse
Replace kfree_skb() used in TLV encoded option header parsing with
kfree_skb_reason(). Following functions are involved:
ip6_parse_tlv()
ipv6_hop_ra()
ipv6_hop_ioam()
ipv6_hop_jumbo()
ipv6_hop_calipso()
ipv6_dest_hao()
Most skb drops during this process are regarded as 'InHdrErrors',
as 'IPSTATS_MIB_INHDRERRORS' is used when ip6_parse_tlv() fails,
which make we use 'SKB_DROP_REASON_IP_INHDR' correspondingly.
However, 'IP_INHDR' is a relatively general reason. Therefore, we
can use other reasons with higher priority in some cases. For example,
'SKB_DROP_REASON_UNHANDLED_PROTO' is used for unknown TLV options.
Signed-off-by: Menglong Dong <imagedong at tencent.com>
Reviewed-by: Jiang Biao <benbjiang at tencent.com>
Reviewed-by: Hao Peng <flyingpeng at tencent.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Acked-by: Nikolay Borisov <nborisov at suse.com>
Signed-off-by: Nikolay Borisov <nikolay.borisov at virtuozzo.com>
======
Patchset description:
ms/net: Annotate skb free sites with reason
This series backports most of the patches that add a reason to skb free sites.
https://jira.sw.ru/browse/PSBM-143302
Feature: net: improve verbosity of dropped packets reporting
---
net/ipv6/exthdrs.c | 31 +++++++++++++++++++++----------
1 file changed, 21 insertions(+), 10 deletions(-)
diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c
index 26882e165c9e..8a75de2eacd2 100644
--- a/net/ipv6/exthdrs.c
+++ b/net/ipv6/exthdrs.c
@@ -100,12 +100,13 @@ static bool ip6_tlvopt_unknown(struct sk_buff *skb, int optoff,
break;
fallthrough;
case 2: /* send ICMP PARM PROB regardless and drop packet */
- icmpv6_param_prob(skb, ICMPV6_UNK_OPTION, optoff);
+ icmpv6_param_prob_reason(skb, ICMPV6_UNK_OPTION, optoff,
+ SKB_DROP_REASON_UNHANDLED_PROTO);
return false;
}
drop:
- kfree_skb(skb);
+ kfree_skb_reason(skb, SKB_DROP_REASON_UNHANDLED_PROTO);
return false;
}
@@ -196,7 +197,7 @@ static bool ip6_parse_tlv(const struct tlvtype_proc *procs,
if (len == 0)
return true;
bad:
- kfree_skb(skb);
+ kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR);
return false;
}
@@ -210,6 +211,7 @@ static bool ipv6_dest_hao(struct sk_buff *skb, int optoff)
struct ipv6_destopt_hao *hao;
struct inet6_skb_parm *opt = IP6CB(skb);
struct ipv6hdr *ipv6h = ipv6_hdr(skb);
+ SKB_DR(reason);
int ret;
if (opt->dsthao) {
@@ -224,19 +226,23 @@ static bool ipv6_dest_hao(struct sk_buff *skb, int optoff)
if (hao->length != 16) {
net_dbg_ratelimited("hao invalid option length = %d\n",
hao->length);
+ SKB_DR_SET(reason, IP_INHDR);
goto discard;
}
if (!(ipv6_addr_type(&hao->addr) & IPV6_ADDR_UNICAST)) {
net_dbg_ratelimited("hao is not an unicast addr: %pI6\n",
&hao->addr);
+ SKB_DR_SET(reason, INVALID_PROTO);
goto discard;
}
ret = xfrm6_input_addr(skb, (xfrm_address_t *)&ipv6h->daddr,
(xfrm_address_t *)&hao->addr, IPPROTO_DSTOPTS);
- if (unlikely(ret < 0))
+ if (unlikely(ret < 0)) {
+ SKB_DR_SET(reason, XFRM_POLICY);
goto discard;
+ }
if (skb_cloned(skb)) {
if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
@@ -259,7 +265,7 @@ static bool ipv6_dest_hao(struct sk_buff *skb, int optoff)
return true;
discard:
- kfree_skb(skb);
+ kfree_skb_reason(skb, reason);
return false;
}
#endif
@@ -924,7 +930,7 @@ static bool ipv6_hop_ra(struct sk_buff *skb, int optoff)
}
net_dbg_ratelimited("ipv6_hop_ra: wrong RA length %d\n",
nh[optoff + 1]);
- kfree_skb(skb);
+ kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR);
return false;
}
@@ -935,29 +941,34 @@ static bool ipv6_hop_jumbo(struct sk_buff *skb, int optoff)
const unsigned char *nh = skb_network_header(skb);
struct inet6_dev *idev = __in6_dev_get_safely(skb->dev);
struct net *net = ipv6_skb_net(skb);
+ SKB_DR(reason);
u32 pkt_len;
if (nh[optoff + 1] != 4 || (optoff & 3) != 2) {
net_dbg_ratelimited("ipv6_hop_jumbo: wrong jumbo opt length/alignment %d\n",
nh[optoff+1]);
__IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
+ SKB_DR_SET(reason, IP_INHDR);
goto drop;
}
pkt_len = ntohl(*(__be32 *)(nh + optoff + 2));
if (pkt_len <= IPV6_MAXPLEN) {
__IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
- icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff+2);
+ icmpv6_param_prob_reason(skb, ICMPV6_HDR_FIELD, optoff+2,
+ SKB_DROP_REASON_IP_INHDR);
return false;
}
if (ipv6_hdr(skb)->payload_len) {
__IP6_INC_STATS(net, idev, IPSTATS_MIB_INHDRERRORS);
- icmpv6_param_prob(skb, ICMPV6_HDR_FIELD, optoff);
+ icmpv6_param_prob_reason(skb, ICMPV6_HDR_FIELD, optoff,
+ SKB_DROP_REASON_IP_INHDR);
return false;
}
if (pkt_len > skb->len - sizeof(struct ipv6hdr)) {
__IP6_INC_STATS(net, idev, IPSTATS_MIB_INTRUNCATEDPKTS);
+ SKB_DR_SET(reason, PKT_TOO_SMALL);
goto drop;
}
@@ -968,7 +979,7 @@ static bool ipv6_hop_jumbo(struct sk_buff *skb, int optoff)
return true;
drop:
- kfree_skb(skb);
+ kfree_skb_reason(skb, reason);
return false;
}
@@ -990,7 +1001,7 @@ static bool ipv6_hop_calipso(struct sk_buff *skb, int optoff)
return true;
drop:
- kfree_skb(skb);
+ kfree_skb_reason(skb, SKB_DROP_REASON_IP_INHDR);
return false;
}
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