From 481c52320a26e2e3a3c8a1cdac3d1460b9b15d13 Mon Sep 17 00:00:00 2001 From: Akihiko Odaki Date: Thu, 23 Feb 2023 19:20:05 +0900 Subject: [PATCH] net: Strip virtio-net header when dumping filter-dump specifiees Ethernet as PCAP LinkType, which does not expect virtio-net header. Having virtio-net header in such PCAP file breaks PCAP unconsumable. Unfortunately currently there is no LinkType for virtio-net so for now strip virtio-net header to convert the output to Ethernet. Signed-off-by: Akihiko Odaki Signed-off-by: Jason Wang --- include/net/net.h | 6 ++++++ net/dump.c | 11 +++++++---- net/net.c | 18 ++++++++++++++++++ net/tap.c | 16 ++++++++++++++++ 4 files changed, 47 insertions(+), 4 deletions(-) diff --git a/include/net/net.h b/include/net/net.h index 1d88621c12..1448d00afb 100644 --- a/include/net/net.h +++ b/include/net/net.h @@ -56,8 +56,10 @@ typedef RxFilterInfo *(QueryRxFilter)(NetClientState *); typedef bool (HasUfo)(NetClientState *); typedef bool (HasVnetHdr)(NetClientState *); typedef bool (HasVnetHdrLen)(NetClientState *, int); +typedef bool (GetUsingVnetHdr)(NetClientState *); typedef void (UsingVnetHdr)(NetClientState *, bool); typedef void (SetOffload)(NetClientState *, int, int, int, int, int); +typedef int (GetVnetHdrLen)(NetClientState *); typedef void (SetVnetHdrLen)(NetClientState *, int); typedef int (SetVnetLE)(NetClientState *, bool); typedef int (SetVnetBE)(NetClientState *, bool); @@ -84,8 +86,10 @@ typedef struct NetClientInfo { HasUfo *has_ufo; HasVnetHdr *has_vnet_hdr; HasVnetHdrLen *has_vnet_hdr_len; + GetUsingVnetHdr *get_using_vnet_hdr; UsingVnetHdr *using_vnet_hdr; SetOffload *set_offload; + GetVnetHdrLen *get_vnet_hdr_len; SetVnetHdrLen *set_vnet_hdr_len; SetVnetLE *set_vnet_le; SetVnetBE *set_vnet_be; @@ -185,9 +189,11 @@ void qemu_format_nic_info_str(NetClientState *nc, uint8_t macaddr[6]); bool qemu_has_ufo(NetClientState *nc); bool qemu_has_vnet_hdr(NetClientState *nc); bool qemu_has_vnet_hdr_len(NetClientState *nc, int len); +bool qemu_get_using_vnet_hdr(NetClientState *nc); void qemu_using_vnet_hdr(NetClientState *nc, bool enable); void qemu_set_offload(NetClientState *nc, int csum, int tso4, int tso6, int ecn, int ufo); +int qemu_get_vnet_hdr_len(NetClientState *nc); void qemu_set_vnet_hdr_len(NetClientState *nc, int len); int qemu_set_vnet_le(NetClientState *nc, bool is_le); int qemu_set_vnet_be(NetClientState *nc, bool is_be); diff --git a/net/dump.c b/net/dump.c index 6a63b15359..7d05f16ca7 100644 --- a/net/dump.c +++ b/net/dump.c @@ -61,12 +61,13 @@ struct pcap_sf_pkthdr { uint32_t len; }; -static ssize_t dump_receive_iov(DumpState *s, const struct iovec *iov, int cnt) +static ssize_t dump_receive_iov(DumpState *s, const struct iovec *iov, int cnt, + int offset) { struct pcap_sf_pkthdr hdr; int64_t ts; int caplen; - size_t size = iov_size(iov, cnt); + size_t size = iov_size(iov, cnt) - offset; struct iovec dumpiov[cnt + 1]; /* Early return in case of previous error. */ @@ -84,7 +85,7 @@ static ssize_t dump_receive_iov(DumpState *s, const struct iovec *iov, int cnt) dumpiov[0].iov_base = &hdr; dumpiov[0].iov_len = sizeof(hdr); - cnt = iov_copy(&dumpiov[1], cnt, iov, cnt, 0, caplen); + cnt = iov_copy(&dumpiov[1], cnt, iov, cnt, offset, caplen); if (writev(s->fd, dumpiov, cnt + 1) != sizeof(hdr) + caplen) { error_report("network dump write error - stopping dump"); @@ -153,8 +154,10 @@ static ssize_t filter_dump_receive_iov(NetFilterState *nf, NetClientState *sndr, int iovcnt, NetPacketSent *sent_cb) { NetFilterDumpState *nfds = FILTER_DUMP(nf); + int offset = qemu_get_using_vnet_hdr(nf->netdev) ? + qemu_get_vnet_hdr_len(nf->netdev) : 0; - dump_receive_iov(&nfds->ds, iov, iovcnt); + dump_receive_iov(&nfds->ds, iov, iovcnt, offset); return 0; } diff --git a/net/net.c b/net/net.c index ebc7ce0231..6492ad530e 100644 --- a/net/net.c +++ b/net/net.c @@ -513,6 +513,15 @@ bool qemu_has_vnet_hdr_len(NetClientState *nc, int len) return nc->info->has_vnet_hdr_len(nc, len); } +bool qemu_get_using_vnet_hdr(NetClientState *nc) +{ + if (!nc || !nc->info->get_using_vnet_hdr) { + return false; + } + + return nc->info->get_using_vnet_hdr(nc); +} + void qemu_using_vnet_hdr(NetClientState *nc, bool enable) { if (!nc || !nc->info->using_vnet_hdr) { @@ -532,6 +541,15 @@ void qemu_set_offload(NetClientState *nc, int csum, int tso4, int tso6, nc->info->set_offload(nc, csum, tso4, tso6, ecn, ufo); } +int qemu_get_vnet_hdr_len(NetClientState *nc) +{ + if (!nc || !nc->info->get_vnet_hdr_len) { + return 0; + } + + return nc->info->get_vnet_hdr_len(nc); +} + void qemu_set_vnet_hdr_len(NetClientState *nc, int len) { if (!nc || !nc->info->set_vnet_hdr_len) { diff --git a/net/tap.c b/net/tap.c index 7d7bc1dc5f..1bf085d422 100644 --- a/net/tap.c +++ b/net/tap.c @@ -255,6 +255,13 @@ static bool tap_has_vnet_hdr_len(NetClientState *nc, int len) return !!tap_probe_vnet_hdr_len(s->fd, len); } +static int tap_get_vnet_hdr_len(NetClientState *nc) +{ + TAPState *s = DO_UPCAST(TAPState, nc, nc); + + return s->host_vnet_hdr_len; +} + static void tap_set_vnet_hdr_len(NetClientState *nc, int len) { TAPState *s = DO_UPCAST(TAPState, nc, nc); @@ -268,6 +275,13 @@ static void tap_set_vnet_hdr_len(NetClientState *nc, int len) s->host_vnet_hdr_len = len; } +static bool tap_get_using_vnet_hdr(NetClientState *nc) +{ + TAPState *s = DO_UPCAST(TAPState, nc, nc); + + return s->using_vnet_hdr; +} + static void tap_using_vnet_hdr(NetClientState *nc, bool using_vnet_hdr) { TAPState *s = DO_UPCAST(TAPState, nc, nc); @@ -372,8 +386,10 @@ static NetClientInfo net_tap_info = { .has_ufo = tap_has_ufo, .has_vnet_hdr = tap_has_vnet_hdr, .has_vnet_hdr_len = tap_has_vnet_hdr_len, + .get_using_vnet_hdr = tap_get_using_vnet_hdr, .using_vnet_hdr = tap_using_vnet_hdr, .set_offload = tap_set_offload, + .get_vnet_hdr_len = tap_get_vnet_hdr_len, .set_vnet_hdr_len = tap_set_vnet_hdr_len, .set_vnet_le = tap_set_vnet_le, .set_vnet_be = tap_set_vnet_be,