| Message ID | 20240818063344.6969-1-wsh@wshooper.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] net/vmnet: Pad short Ethernet frames | expand |
On Sat, Aug 17, 2024 at 11:33 PM William Hooper <wsh@wshooper.org> wrote: > At least on macOS 12.7.2, vmnet doesn't pad Ethernet frames, such as the > host's ARP replies, to the minimum size (60 bytes before the frame check > sequence) defined in IEEE Std 802.3-2022, so guests' Ethernet device > drivers may drop them with "frame too short" errors. > > This patch calls eth_pad_short_frame() to add padding, as in net/tap.c > and net/slirp.c. Thanks to Bin Meng and Philippe Mathieu-Daudé for > reviewing an earlier version. > > Signed-off-by: William Hooper <wsh@wshooper.org> > Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2058 > --- > net/vmnet-common.m | 22 +++++++++++++++++++--- > 1 file changed, 19 insertions(+), 3 deletions(-) > > diff --git a/net/vmnet-common.m b/net/vmnet-common.m > index 30c4e53c13..bce1cc590d 100644 > --- a/net/vmnet-common.m > +++ b/net/vmnet-common.m > @@ -18,6 +18,7 @@ > #include "qemu/error-report.h" > #include "qapi/error.h" > #include "sysemu/runstate.h" > +#include "net/eth.h" > > #include <vmnet/vmnet.h> > #include <dispatch/dispatch.h> > @@ -147,10 +148,25 @@ static int vmnet_read_packets(VmnetState *s) > */ > static void vmnet_write_packets_to_qemu(VmnetState *s) > { > + uint8_t *pkt; > + size_t pktsz; > + uint8_t min_pkt[ETH_ZLEN]; > + size_t min_pktsz; > + > while (s->packets_send_current_pos < s->packets_send_end_pos) { > - ssize_t size = qemu_send_packet_async(&s->nc, > - s->iov_buf[s->packets_send_current_pos].iov_base, > - s->packets_buf[s->packets_send_current_pos].vm_pkt_size, > + pkt = s->iov_buf[s->packets_send_current_pos].iov_base; > + pktsz = s->packets_buf[s->packets_send_current_pos].vm_pkt_size; > + > + if (net_peer_needs_padding(&s->nc)) { > + min_pktsz = sizeof(min_pkt); > + > + if (eth_pad_short_frame(min_pkt, &min_pktsz, pkt, pktsz)) { > + pkt = min_pkt; > + pktsz = min_pktsz; > + } > + } > + > + ssize_t size = qemu_send_packet_async(&s->nc, pkt, pktsz, > vmnet_send_completed); > > if (size == 0) { > -- > 2.37.1 Ping?
On Sun, 20 Oct 2024 at 05:17, William Hooper <wsh@wshooper.org> wrote: > > On Sat, Aug 17, 2024 at 11:33 PM William Hooper <wsh@wshooper.org> wrote: > > At least on macOS 12.7.2, vmnet doesn't pad Ethernet frames, such as the > > host's ARP replies, to the minimum size (60 bytes before the frame check > > sequence) defined in IEEE Std 802.3-2022, so guests' Ethernet device > > drivers may drop them with "frame too short" errors. > > > > This patch calls eth_pad_short_frame() to add padding, as in net/tap.c > > and net/slirp.c. Thanks to Bin Meng and Philippe Mathieu-Daudé for > > reviewing an earlier version. > > > > Signed-off-by: William Hooper <wsh@wshooper.org> > > Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2058 > > --- > > net/vmnet-common.m | 22 +++++++++++++++++++--- > > 1 file changed, 19 insertions(+), 3 deletions(-) > > > > diff --git a/net/vmnet-common.m b/net/vmnet-common.m > > index 30c4e53c13..bce1cc590d 100644 > > --- a/net/vmnet-common.m > > +++ b/net/vmnet-common.m > > @@ -18,6 +18,7 @@ > > #include "qemu/error-report.h" > > #include "qapi/error.h" > > #include "sysemu/runstate.h" > > +#include "net/eth.h" > > > > #include <vmnet/vmnet.h> > > #include <dispatch/dispatch.h> > > @@ -147,10 +148,25 @@ static int vmnet_read_packets(VmnetState *s) > > */ > > static void vmnet_write_packets_to_qemu(VmnetState *s) > > { > > + uint8_t *pkt; > > + size_t pktsz; > > + uint8_t min_pkt[ETH_ZLEN]; > > + size_t min_pktsz; > > + > > while (s->packets_send_current_pos < s->packets_send_end_pos) { > > - ssize_t size = qemu_send_packet_async(&s->nc, > > - s->iov_buf[s->packets_send_current_pos].iov_base, > > - s->packets_buf[s->packets_send_current_pos].vm_pkt_size, > > + pkt = s->iov_buf[s->packets_send_current_pos].iov_base; > > + pktsz = s->packets_buf[s->packets_send_current_pos].vm_pkt_size; > > + > > + if (net_peer_needs_padding(&s->nc)) { > > + min_pktsz = sizeof(min_pkt); > > + > > + if (eth_pad_short_frame(min_pkt, &min_pktsz, pkt, pktsz)) { > > + pkt = min_pkt; > > + pktsz = min_pktsz; > > + } > > + } > > + > > + ssize_t size = qemu_send_packet_async(&s->nc, pkt, pktsz, > > vmnet_send_completed); Nit: Move the declaration of 'size' up to the function header with the rest of the variables for consistency. Apart from that: Reviewed-by: Phil Dennis-Jordan <phil@philjordan.eu> > > if (size == 0) { > > -- > > 2.37.1 > > Ping? >
diff --git a/net/vmnet-common.m b/net/vmnet-common.m index 30c4e53c13..bce1cc590d 100644 --- a/net/vmnet-common.m +++ b/net/vmnet-common.m @@ -18,6 +18,7 @@ #include "qemu/error-report.h" #include "qapi/error.h" #include "sysemu/runstate.h" +#include "net/eth.h" #include <vmnet/vmnet.h> #include <dispatch/dispatch.h> @@ -147,10 +148,25 @@ static int vmnet_read_packets(VmnetState *s) */ static void vmnet_write_packets_to_qemu(VmnetState *s) { + uint8_t *pkt; + size_t pktsz; + uint8_t min_pkt[ETH_ZLEN]; + size_t min_pktsz; + while (s->packets_send_current_pos < s->packets_send_end_pos) { - ssize_t size = qemu_send_packet_async(&s->nc, - s->iov_buf[s->packets_send_current_pos].iov_base, - s->packets_buf[s->packets_send_current_pos].vm_pkt_size, + pkt = s->iov_buf[s->packets_send_current_pos].iov_base; + pktsz = s->packets_buf[s->packets_send_current_pos].vm_pkt_size; + + if (net_peer_needs_padding(&s->nc)) { + min_pktsz = sizeof(min_pkt); + + if (eth_pad_short_frame(min_pkt, &min_pktsz, pkt, pktsz)) { + pkt = min_pkt; + pktsz = min_pktsz; + } + } + + ssize_t size = qemu_send_packet_async(&s->nc, pkt, pktsz, vmnet_send_completed); if (size == 0) {
At least on macOS 12.7.2, vmnet doesn't pad Ethernet frames, such as the host's ARP replies, to the minimum size (60 bytes before the frame check sequence) defined in IEEE Std 802.3-2022, so guests' Ethernet device drivers may drop them with "frame too short" errors. This patch calls eth_pad_short_frame() to add padding, as in net/tap.c and net/slirp.c. Thanks to Bin Meng and Philippe Mathieu-Daudé for reviewing an earlier version. Signed-off-by: William Hooper <wsh@wshooper.org> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2058 --- net/vmnet-common.m | 22 +++++++++++++++++++--- 1 file changed, 19 insertions(+), 3 deletions(-)