The branch main has been updated by zlei:
URL:
https://cgit.FreeBSD.org/src/commit/?id=838c8c47860a0203130bd558d507a0565a2eba8f
commit 838c8c47860a0203130bd558d507a0565a2eba8f
Author: Zhenlei Huang <z...@freebsd.org>
AuthorDate: 2023-08-23 09:48:12 +0000
Commit: Zhenlei Huang <z...@freebsd.org>
CommitDate: 2023-08-23 09:53:48 +0000
net: Do not overwrite if_vlan's PCP
In commit c7cffd65c5d8 the function ether_8021q_frame() was slightly
refactored to use pointer of struct ether_8021q_tag as parameter qtag to
include the new option proto.
It is wrong to write to qtag->pcp as it will effectively change the memory
that qtag points to. Unfortunately the transmit routine of if_vlan parses
pointer of the member ifv_qtag of its softc which stores vlan interface's
PCP internally, when transmitting mbufs that contains PCP the vlan
interface's PCP will get overwritten.
Fix by operating on a local copy of qtag->pcp. Also mark 'struct
ether_8021q_tag'
as const so that compilers can pick up such kind of bug.
PR: 273304
Reviewed by: kp
Fixes: c7cffd65c5d85 Add support for stacked VLANs (IEEE 802.1ad, AKA
Q-in-Q)
MFC after: 3 days
Differential Revision: https://reviews.freebsd.org/D39505
---
sys/net/ethernet.h | 2 +-
sys/net/if_ethersubr.c | 7 ++++---
2 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/sys/net/ethernet.h b/sys/net/ethernet.h
index 8a4b9336b9cc..fca6748a0da7 100644
--- a/sys/net/ethernet.h
+++ b/sys/net/ethernet.h
@@ -446,7 +446,7 @@ void ether_vlan_mtap(struct bpf_if *, struct mbuf *,
void *, u_int);
struct mbuf *ether_vlanencap_proto(struct mbuf *, uint16_t, uint16_t);
bool ether_8021q_frame(struct mbuf **mp, struct ifnet *ife,
- struct ifnet *p, struct ether_8021q_tag *);
+ struct ifnet *p, const struct ether_8021q_tag *);
void ether_gen_addr(struct ifnet *ifp, struct ether_addr *hwaddr);
static __inline struct mbuf *ether_vlanencap(struct mbuf *m, uint16_t tag)
diff --git a/sys/net/if_ethersubr.c b/sys/net/if_ethersubr.c
index 25f4d151866e..63ea5e7591c2 100644
--- a/sys/net/if_ethersubr.c
+++ b/sys/net/if_ethersubr.c
@@ -1400,11 +1400,12 @@ SYSCTL_INT(_net_link_vlan, OID_AUTO, mtag_pcp,
CTLFLAG_RW | CTLFLAG_VNET,
bool
ether_8021q_frame(struct mbuf **mp, struct ifnet *ife, struct ifnet *p,
- struct ether_8021q_tag *qtag)
+ const struct ether_8021q_tag *qtag)
{
struct m_tag *mtag;
int n;
uint16_t tag;
+ uint8_t pcp = qtag->pcp;
static const char pad[8]; /* just zeros */
/*
@@ -1437,7 +1438,7 @@ ether_8021q_frame(struct mbuf **mp, struct ifnet *ife,
struct ifnet *p,
* If PCP is set in mbuf, use it
*/
if ((*mp)->m_flags & M_VLANTAG) {
- qtag->pcp = EVL_PRIOFTAG((*mp)->m_pkthdr.ether_vtag);
+ pcp = EVL_PRIOFTAG((*mp)->m_pkthdr.ether_vtag);
}
/*
@@ -1451,7 +1452,7 @@ ether_8021q_frame(struct mbuf **mp, struct ifnet *ife,
struct ifnet *p,
MTAG_8021Q_PCP_OUT, NULL)) != NULL)
tag = EVL_MAKETAG(qtag->vid, *(uint8_t *)(mtag + 1), 0);
else
- tag = EVL_MAKETAG(qtag->vid, qtag->pcp, 0);
+ tag = EVL_MAKETAG(qtag->vid, pcp, 0);
if ((p->if_capenable & IFCAP_VLAN_HWTAGGING) &&
(qtag->proto == ETHERTYPE_VLAN)) {
(*mp)->m_pkthdr.ether_vtag = tag;
