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2021-03-15net: introduce qemu_receive_packet()Jason Wang
Some NIC supports loopback mode and this is done by calling nc->info->receive() directly which in fact suppresses the effort of reentrancy check that is done in qemu_net_queue_send(). Unfortunately we can't use qemu_net_queue_send() here since for loopback there's no sender as peer, so this patch introduce a qemu_receive_packet() which is used for implementing loopback mode for a NIC with this check. NIC that supports loopback mode will be converted to this helper. This is intended to address CVE-2021-3416. Cc: Prasad J Pandit <ppandit@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Cc: qemu-stable@nongnu.org Signed-off-by: Jason Wang <jasowang@redhat.com>
2020-07-28net: forbid the reentrant RXJason Wang
The memory API allows DMA into NIC's MMIO area. This means the NIC's RX routine must be reentrant. Instead of auditing all the NIC, we can simply detect the reentrancy and return early. The queue->delivering is set and cleared by qemu_net_queue_deliver() for other queue helpers to know whether the delivering in on going (NIC's receive is being called). We can check it and return early in qemu_net_queue_flush() to forbid reentrant RX. Signed-off-by: Jason Wang <jasowang@redhat.com>
2020-03-16misc: Replace zero-length arrays with flexible array member (automatic)Philippe Mathieu-Daudé
Description copied from Linux kernel commit from Gustavo A. R. Silva (see [3]): --v-- description start --v-- The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member [1], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being unadvertenly introduced [2] to the Linux codebase from now on. --^-- description end --^-- Do the similar housekeeping in the QEMU codebase (which uses C99 since commit 7be41675f7cb). All these instances of code were found with the help of the following Coccinelle script: @@ identifier s, m, a; type t, T; @@ struct s { ... t m; - T a[0]; + T a[]; }; @@ identifier s, m, a; type t, T; @@ struct s { ... t m; - T a[0]; + T a[]; } QEMU_PACKED; [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=76497732932f [3] https://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux.git/commit/?id=17642a2fbd2c1 Inspired-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-01-11qemu/queue.h: leave head structs anonymous unless necessaryPaolo Bonzini
Most list head structs need not be given a name. In most cases the name is given just in case one is going to use QTAILQ_LAST, QTAILQ_PREV or reverse iteration, but this does not apply to lists of other kinds, and even for QTAILQ in practice this is only rarely needed. In addition, we will soon reimplement those macros completely so that they do not need a name for the head struct. So clean up everything, not giving a name except in the rare case where it is necessary. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-04net: Clean up includesPeter Maydell
Clean up includes so that osdep.h is included first and headers which it implies are not included manually. This commit was created with scripts/clean-includes. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Message-id: 1454089805-5470-11-git-send-email-peter.maydell@linaro.org
2015-10-12net/queue: export qemu_net_queue_append_iovYang Hongyang
This will be used by buffer filter implementation later to queue packets. Signed-off-by: Yang Hongyang <yanghy@cn.fujitsu.com> Reviewed-by: Thomas Huth <thuth@redhat.com> Signed-off-by: Jason Wang <jasowang@redhat.com>
2015-10-12net/queue: introduce NetQueueDeliverFuncYang Hongyang
net/queue.c has logic to send/queue/flush packets but a qemu_deliver_packet_iov() call is hardcoded. Abstract this func so that we can use our own deliver function in netfilter. Signed-off-by: Yang Hongyang <yanghy@cn.fujitsu.com> Cc: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Jason Wang <jasowang@redhat.com>
2015-10-12net: merge qemu_deliver_packet and qemu_deliver_packet_iovYang Hongyang
qemu_deliver_packet_iov already have the compat delivery, we can drop qemu_deliver_packet. Signed-off-by: Yang Hongyang <yanghy@cn.fujitsu.com> Signed-off-by: Jason Wang <jasowang@redhat.com>
2014-12-19net: Use g_new() & friends where that makes obvious senseMarkus Armbruster
g_new(T, n) is neater than g_malloc(sizeof(T) * n). It's also safer, for two reasons. One, it catches multiplication overflowing size_t. Two, it returns T * rather than void *, which lets the compiler catch more type errors. This commit only touches allocations with size arguments of the form sizeof(T). Signed-off-by: Markus Armbruster <armbru@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2014-09-04net: invoke callback when purging queueMichael S. Tsirkin
devices rely on packet callbacks eventually running, but we violate this rule whenever we purge the queue. To fix, invoke callbacks on all packets on purge. Set length to 0, this way callers can detect that this happened and re-queue if necessary. Cc: qemu-stable@nongnu.org Cc: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2013-02-27net: fix unbounded NetQueueLuigi Rizzo
In the current implementation of qemu, running without a network backend will cause the queue to grow unbounded when the guest is transmitting traffic. This patch fixes the problem by implementing bounded size NetQueue, used with an arbitrary limit of 10000 packets, and dropping packets when the queue is full _and_ the sender does not pass a callback. The second condition makes sure that we never drop packets that contains a callback (which would be tricky, because the producer expects the callback to be run when all previous packets have been consumed; so we cannot run it when the packet is dropped). If documentation is correct, producers that submit a callback should stop sending when their packet is queued, so there is no real risk that the queue exceeds the max size by large values. Signed-off-by: Luigi Rizzo <rizzo@iet.unipi.it> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2012-12-19misc: move include files to include/qemu/Paolo Bonzini
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-12-19net: reorganize headersPaolo Bonzini
Move public headers to include/net, and leave private headers in net/. Put the virtio headers in include/net/tap.h, removing the multiple copies that existed. Leave include/net/tap.h as the interface for NICs, and net/tap_int.h as the interface for OS-specific parts of the tap backend. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2012-09-14net: do not report queued packets as sentStefan Hajnoczi
Net send functions have a return value where 0 means the packet has not been sent and will be queued. A non-zero value means the packet was sent or an error caused the packet to be dropped. This patch fixes two instances where packets are queued but we return their size. This causes callers to believe the packets were sent. When the caller uses the async send interface this creates a real problem because the callback will be invoked for a packet that the caller believed to be already sent. This bug can cause double-frees in the caller. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2012-09-14net: notify iothread after flushing queuePaolo Bonzini
virtio-net has code to flush the queue and notify the iothread whenever new receive buffers are added by the guest. That is fine, and indeed we need to do the same in all other drivers. However, notifying the iothread should be work for the network subsystem. And since we are at it we can add a little smartness: if some of the queued packets already could not be delivered, there is no need to notify the iothread. Reported-by: Luigi Rizzo <rizzo@iet.unipi.it> Cc: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Cc: Jan Kiszka <jan.kiszka@siemens.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Amos Kong <akong@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
2012-08-01net: determine if packets can be sent before net queue deliver packetsZhi Yong Wu
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Reviewed-by: Laszlo Ersek <lersek@redhat.com>
2012-08-01net: cleanup deliver/deliver_iov func pointersZhi Yong Wu
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Reviewed-by: Laszlo Ersek <lersek@redhat.com>
2012-08-01net: Rename VLANClientState to NetClientStateStefan Hajnoczi
The vlan feature is no longer part of net core. Rename VLANClientState to NetClientState because net clients are not explicitly associated with a vlan at all, instead they have a peer net client to which they are connected. This patch is a mechanical search-and-replace except for a few whitespace fixups where changing VLANClientState to NetClientState misaligned whitespace. Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com> Signed-off-by: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com> Reviewed-by: Laszlo Ersek <lersek@redhat.com>
2011-08-20Use glib memory allocation and free functionsAnthony Liguori
qemu_malloc/qemu_free no longer exist after this commit. Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-11-09net/queue: queue packets even if sender doesn't supply a callbackMark McLoughlin
Now that we disable any receiver whose queue is full, we do not require senders to handle a zero return by supplying a sent callback. This is a second step towards allowing can_receive() handlers to return true even if no buffer space is available. Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2009-10-30net: move net-queue.[ch] under net/Mark McLoughlin
[v2: handle building in a separate dir] Signed-off-by: Mark McLoughlin <markmc@redhat.com> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>