[PATCH 3/3] net/af_packet: fix QinQ outer TPID on VLAN reinsertion
From: William Bland <hidden>
Date: 2026-08-24 19:23:51
Subsystem:
networking drivers, the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
eth_af_packet_rx() called rte_vlan_insert(), which hardcodes EtherType
0x8100 (802.1Q). This was wrong when reinserting a stripped tag whose
original TPID was 0x88a8 (802.1ad QinQ).
Fix by reading the actual TPID from tp_vlan_tpid (struct tpacket2_hdr),
then passing it to rte_vlan_insert_tpid().
Fixes: 23deeebfcfa8 ("net/af_packet: support 802.1Q VLAN")
Signed-off-by: William Bland <redacted>
---
app/test/meson.build | 2 +-
app/test/test_net_ether.c | 122 ++++++++++++++++++++++
drivers/net/af_packet/rte_eth_af_packet.c | 10 +-
3 files changed, 131 insertions(+), 3 deletions(-)
diff --git a/app/test/meson.build b/app/test/meson.build
index 51abeeb732..e927d4306a 100644
--- a/app/test/meson.build
+++ b/app/test/meson.build@@ -134,7 +134,7 @@ source_file_deps = { 'test_meter.c': ['meter'], 'test_metrics.c': ['metrics'], 'test_mp_secondary.c': ['hash'], - 'test_net_ether.c': ['net'], + 'test_net_ether.c': ['net', 'mbuf'], 'test_net_ip6.c': ['net'], 'test_pcapng.c': ['net_null', 'net', 'ethdev', 'pcapng', 'bus_vdev'], 'test_pdcp.c': ['eventdev', 'pdcp', 'net', 'timer', 'security'],
diff --git a/app/test/test_net_ether.c b/app/test/test_net_ether.c
index ec11224171..19f9c85e5b 100644
--- a/app/test/test_net_ether.c
+++ b/app/test/test_net_ether.c@@ -3,6 +3,8 @@ */ #include <rte_ether.h> +#include <rte_mbuf.h> +#include <rte_mempool.h> #include <rte_test.h> #include "test.h"
@@ -162,4 +164,124 @@ test_net_ether(void) return 0; } +/* + * Build a minimal Ethernet frame in an mbuf: Ethernet header with the given + * ether_type followed by payload_len zero bytes. + */ +static struct rte_mbuf * +alloc_frame(struct rte_mempool *mp, uint16_t ether_type, uint16_t payload_len) +{ + struct rte_ether_hdr *eh; + struct rte_mbuf *m; + + m = rte_pktmbuf_alloc(mp); + if (m == NULL) + return NULL; + + eh = (struct rte_ether_hdr *)rte_pktmbuf_append(m, + sizeof(*eh) + payload_len); + if (eh == NULL) { + rte_pktmbuf_free(m); + return NULL; + } + + memset(eh->dst_addr.addr_bytes, 0xff, RTE_ETHER_ADDR_LEN); + memset(eh->src_addr.addr_bytes, 0x00, RTE_ETHER_ADDR_LEN); + eh->ether_type = rte_cpu_to_be_16(ether_type); + + return m; +} + +static int +test_vlan_insert_8021q(struct rte_mempool *mp) +{ + struct rte_ether_hdr *eh; + struct rte_vlan_hdr *vh; + struct rte_mbuf *m; + int ret; + + m = alloc_frame(mp, RTE_ETHER_TYPE_IPV4, 46); + TEST_ASSERT_NOT_NULL(m, "Failed to allocate mbuf"); + + m->vlan_tci = 100; + m->ol_flags |= RTE_MBUF_F_RX_VLAN | RTE_MBUF_F_RX_VLAN_STRIPPED; + + ret = rte_vlan_insert(&m); + TEST_ASSERT_SUCCESS(ret, "rte_vlan_insert failed"); + + eh = rte_pktmbuf_mtod(m, struct rte_ether_hdr *); + TEST_ASSERT_EQUAL(rte_be_to_cpu_16(eh->ether_type), RTE_ETHER_TYPE_VLAN, + "Expected 802.1Q TPID 0x%04x, got 0x%04x", + RTE_ETHER_TYPE_VLAN, rte_be_to_cpu_16(eh->ether_type)); + + vh = (struct rte_vlan_hdr *)(eh + 1); + TEST_ASSERT_EQUAL(rte_be_to_cpu_16(vh->vlan_tci), 100, + "Expected VID 100, got %u", rte_be_to_cpu_16(vh->vlan_tci)); + + rte_pktmbuf_free(m); + return TEST_SUCCESS; +} + +static int +test_vlan_insert_tpid(struct rte_mempool *mp) +{ + struct rte_ether_hdr *eh; + struct rte_vlan_hdr *vh; + struct rte_mbuf *m; + int ret; + + m = alloc_frame(mp, RTE_ETHER_TYPE_VLAN, sizeof(*vh) + 46); + TEST_ASSERT_NOT_NULL(m, "Failed to allocate mbuf"); + + vh = (struct rte_vlan_hdr *)(rte_pktmbuf_mtod(m, struct rte_ether_hdr *) + 1); + vh->vlan_tci = rte_cpu_to_be_16(200); + vh->eth_proto = rte_cpu_to_be_16(RTE_ETHER_TYPE_IPV4); + + m->vlan_tci = 50; + m->ol_flags |= RTE_MBUF_F_RX_VLAN | RTE_MBUF_F_RX_VLAN_STRIPPED; + + ret = rte_vlan_insert_tpid(&m, RTE_ETHER_TYPE_QINQ); + TEST_ASSERT_SUCCESS(ret, "rte_vlan_insert_tpid failed"); + + eh = rte_pktmbuf_mtod(m, struct rte_ether_hdr *); + + TEST_ASSERT_EQUAL(rte_be_to_cpu_16(eh->ether_type), RTE_ETHER_TYPE_QINQ, + "Outer TPID: expected 0x%04x (802.1ad) got 0x%04x", + RTE_ETHER_TYPE_QINQ, rte_be_to_cpu_16(eh->ether_type)); + + vh = (struct rte_vlan_hdr *)(eh + 1); + TEST_ASSERT_EQUAL(rte_be_to_cpu_16(vh->vlan_tci), 50, + "Outer VID: expected 50, got %u", + rte_be_to_cpu_16(vh->vlan_tci)); + + rte_pktmbuf_free(m); + return TEST_SUCCESS; +} + +static int +test_vlan_insert(void) +{ + struct rte_mempool *mp; + int ret; + + mp = rte_pktmbuf_pool_create("vlan_insert_test_pool", 64, 0, 0, + RTE_MBUF_DEFAULT_BUF_SIZE, + SOCKET_ID_ANY); + if (mp == NULL) { + fprintf(stderr, "Failed to create mempool\n"); + return -1; + } + + ret = test_vlan_insert_8021q(mp); + if (ret != TEST_SUCCESS) + goto out; + + ret = test_vlan_insert_tpid(mp); + +out: + rte_mempool_free(mp); + return ret; +} + REGISTER_FAST_TEST(net_ether_autotest, NOHUGE_OK, ASAN_OK, test_net_ether); +REGISTER_FAST_TEST(vlan_insert_autotest, NOHUGE_OK, ASAN_OK, test_vlan_insert);
diff --git a/drivers/net/af_packet/rte_eth_af_packet.c b/drivers/net/af_packet/rte_eth_af_packet.c
index b0ff22ea55..8225e0d7f9 100644
--- a/drivers/net/af_packet/rte_eth_af_packet.c
+++ b/drivers/net/af_packet/rte_eth_af_packet.c@@ -222,11 +222,17 @@ eth_af_packet_rx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts) /* check for vlan info */ if (ppd->tp_status & TP_STATUS_VLAN_VALID) { + uint16_t tpid; + mbuf->vlan_tci = ppd->tp_vlan_tci; mbuf->ol_flags |= (RTE_MBUF_F_RX_VLAN | RTE_MBUF_F_RX_VLAN_STRIPPED); - if (!pkt_q->vlan_strip && rte_vlan_insert(&mbuf)) - PMD_LOG(ERR, "Failed to reinsert VLAN tag"); + if (!pkt_q->vlan_strip) { + tpid = (ppd->tp_status & TP_STATUS_VLAN_TPID_VALID) ? + ppd->tp_vlan_tpid : RTE_ETHER_TYPE_VLAN; + if (rte_vlan_insert_tpid(&mbuf, tpid)) + PMD_LOG(ERR, "Failed to reinsert VLAN tag"); + } } /* add kernel provided timestamp when offloading is enabled */
--
2.43.0