Date: Wed, 30 Aug 2023 10:10:12 GMT From: Zhenlei Huang <zlei@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Subject: git: 96c4b704ec16 - stable/13 - net: Do not overwrite if_vlan's PCP Message-ID: <202308301010.37UAACGk021430@gitrepo.freebsd.org>
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The branch stable/13 has been updated by zlei: URL: https://cgit.FreeBSD.org/src/commit/?id=96c4b704ec169044aa98867965e046a4728bcba1 commit 96c4b704ec169044aa98867965e046a4728bcba1 Author: Zhenlei Huang <zlei@FreeBSD.org> AuthorDate: 2023-08-23 09:48:12 +0000 Commit: Zhenlei Huang <zlei@FreeBSD.org> CommitDate: 2023-08-30 10:09:25 +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 (cherry picked from commit 838c8c47860a0203130bd558d507a0565a2eba8f) --- 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 b935c024541c..7a763c15ff26 100644 --- a/sys/net/ethernet.h +++ b/sys/net/ethernet.h @@ -448,7 +448,7 @@ 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 64cca2452871..87faf9f26df4 100644 --- a/sys/net/if_ethersubr.c +++ b/sys/net/if_ethersubr.c @@ -1355,11 +1355,12 @@ SYSCTL_INT(_net_link_vlan, OID_AUTO, mtag_pcp, CTLFLAG_RW, 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 */ /* @@ -1392,7 +1393,7 @@ 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); } /* @@ -1406,7 +1407,7 @@ 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;
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