Commit Graph

144 Commits

Author SHA1 Message Date
Markus Armbruster
7480874a69 qapi net: Elide redundant has_FOO in generated C
The has_FOO for pointer-valued FOO are redundant, except for arrays.
They are also a nuisance to work with.  Recent commit "qapi: Start to
elide redundant has_FOO in generated C" provided the means to elide
them step by step.  This is the step for qapi/net.json.

Said commit explains the transformation in more detail.  The invariant
violations mentioned there do not occur here.

Cc: Jason Wang <jasowang@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20221104160712.3005652-19-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
[Fixes for MacOS squashed in]
2022-12-14 20:04:47 +01:00
Laurent Vivier
53b85d9574 net: introduce qemu_set_info_str() function
Embed the setting of info_str in a function.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2022-10-28 13:28:52 +08:00
Paolo Bonzini
6222e55d13 net: slirp: add support for CFI-friendly timer API
libslirp 4.7 introduces a CFI-friendly version of the .timer_new callback.
The new callback replaces the function pointer with an enum; invoking the
callback is done with a new function slirp_handle_timer.

Support the new API so that CFI can be made compatible with using a system
libslirp.

Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Reviewed-by: Marc-André Lureau <malureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-05-12 12:29:44 +02:00
Paolo Bonzini
bce63ded20 net: slirp: switch to slirp_new
Replace slirp_init with slirp_new, so that a more recent cfg.version
can be specified.  The function appeared in version 4.1.0.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-05-12 12:29:44 +02:00
Paolo Bonzini
ad2e5b87d7 net: slirp: introduce a wrapper struct for QemuTimer
This struct will be extended in the next few patches to support the
new slirp_handle_timer() call.  For that we need to store an additional
"int" for each SLIRP timer, in addition to the cb_opaque.

Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Reviewed-by: Marc-André Lureau <malureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-05-12 12:29:44 +02:00
Paolo Bonzini
35acbb3058 configure, meson: move smbd options to meson_options.txt
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-02-21 10:35:53 +01:00
Joelle van Dyne
b8e0c4938b slirp: add configure option to disable smbd
Replace Windows specific macro with a more generic feature detection
macro. Allows slirp smb feature to be disabled manually as well.

Acked-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Joelle van Dyne <j@getutm.app>
Message-Id: <20210315180341.31638-5-j@getutm.app>
[Use $default_feature as the default. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-04 14:15:35 +02:00
Jason Wang
bc38e31b4e net: check the existence of peer before trying to pad
There could be case that peer is NULL. This can happen when during
network device hot-add where net device needs to be added first. So
the patch check the existence of peer before trying to do the pad.

Fixes: 969e50b61a ("net: Pad short frames to minimum size before sending from SLiRP/TAP")
Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Stefan Weil <sw@weilnetz.de>
Message-id: 20210423031803.1479-1-jasowang@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2021-04-23 11:11:28 +01:00
Jason Wang
f9bb0c1f98 Revert "qapi: net: Add query-netdev command"
Several issues has been reported for query-netdev series. Consider
it's late in the rc, this reverts commit
d32ad10a14.

Signed-off-by: Jason Wang <jasowang@redhat.com>
2021-04-08 17:33:59 +08:00
Jason Wang
56e6f594bf Revert "net: Move NetClientState.info_str to dynamic allocations"
Several issues has been reported for query-netdev info
series. Consider it's late in the rc, this reverts commit
commit 59b5437eb7.

Signed-off-by: Jason Wang <jasowang@redhat.com>
2021-04-08 17:33:59 +08:00
Jason Wang
d89b4f839f Revert "net: Do not fill legacy info_str for backends"
Several issues has been reported for query-netdev info
series. Consider it's late in the rc, this reverts commit
f2e8319d45.

Signed-off-by: Jason Wang <jasowang@redhat.com>
2021-04-08 17:33:59 +08:00
Bin Meng
969e50b61a net: Pad short frames to minimum size before sending from SLiRP/TAP
The minimum Ethernet frame length is 60 bytes. For short frames with
smaller length like ARP packets (only 42 bytes), on a real world NIC
it can choose either padding its length to the minimum required 60
bytes, or sending it out directly to the wire. Such behavior can be
hardcoded or controled by a register bit. Similarly on the receive
path, NICs can choose either dropping such short frames directly or
handing them over to software to handle.

On the other hand, for the network backends like SLiRP/TAP, they
don't expose a way to control the short frame behavior. As of today
they just send/receive data from/to the other end connected to them,
which means any sized packet is acceptable. So they can send and
receive short frames without any problem. It is observed that ARP
packets sent from SLiRP/TAP are 42 bytes, and SLiRP/TAP just send
these ARP packets to the other end which might be a NIC model that
does not allow short frames to pass through.

To provide better compatibility, for packets sent from QEMU network
backends like SLiRP/TAP, we change to pad short frames before sending
it out to the other end, if the other end does not forbid it via the
nc->do_not_pad flag. This ensures a backend as an Ethernet sender
does not violate the spec. But with this change, the behavior of
dropping short frames from SLiRP/TAP interfaces in the NIC model
cannot be emulated because it always receives a packet that is spec
complaint. The capability of sending short frames from NIC models is
still supported and short frames can still pass through SLiRP/TAP.

This commit should be able to fix the issue as reported with some
NIC models before, that ARP requests get dropped, preventing the
guest from becoming visible on the network. It was workarounded in
these NIC models on the receive path, that when a short frame is
received, it is padded up to 60 bytes.

The following 2 commits seem to be the one to workaround this issue
in e1000 and vmxenet3 before, and should probably be reverted.

  commit 78aeb23ede ("e1000: Pad short frames to minimum size (60 bytes)")
  commit 40a87c6c9b ("vmxnet3: Pad short frames to minimum size (60 bytes)")

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2021-03-22 17:34:31 +08:00
Alexey Kirillov
f2e8319d45 net: Do not fill legacy info_str for backends
As we use QAPI NetClientState->stored_config to store and get information
about backend network devices, we can drop fill of legacy field info_str
for them.

We still use info_str field for NIC and hubports, so we can not completely
remove it.

Signed-off-by: Alexey Kirillov <lekiravi@yandex-team.ru>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2021-03-15 16:41:22 +08:00
Alexey Kirillov
59b5437eb7 net: Move NetClientState.info_str to dynamic allocations
The info_str field of the NetClientState structure is static and has a size
of 256 bytes. This amount is often unclaimed, and the field itself is used
exclusively for HMP "info network".

The patch translates info_str to dynamic memory allocation.

This action is also allows us to painlessly discard usage of this field
for backend devices.

Signed-off-by: Alexey Kirillov <lekiravi@yandex-team.ru>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2021-03-15 16:41:22 +08:00
Alexey Kirillov
d32ad10a14 qapi: net: Add query-netdev command
The query-netdev command is used to get the configuration of the current
network device backends (netdevs).
This is the QMP analog of the HMP command "info network" but only for
netdevs (i.e. excluding NIC and hubports).

The query-netdev command returns an array of objects of the NetdevInfo
type, which are an extension of Netdev type. It means that response can
be used for netdev-add after small modification. This can be useful for
recreate the same netdev configuration.

Information about the network device is filled in when it is created or
modified and is available through the NetClientState->stored_config.

Signed-off-by: Alexey Kirillov <lekiravi@yandex-team.ru>
Acked-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2021-03-15 16:41:22 +08:00
Doug Evans
0c373c0178 net/slirp.c: Fix spelling error in error message
DNS should be DHCP

Signed-off-by: Doug Evans <dje@google.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Message-Id: <20210122004251.843837-1-dje@google.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2021-01-29 09:31:40 +01:00
Peter Maydell
729cc68373 Remove superfluous timer_del() calls
This commit is the result of running the timer-del-timer-free.cocci
script on the whole source tree.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Corey Minyard <cminyard@mvista.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20201215154107.3255-4-peter.maydell@linaro.org
2021-01-08 15:13:38 +00:00
Thomas Huth
b4983c570c net: Remove deprecated [hub_id name] tuple of 'hostfwd_add' / 'hostfwd_remove'
It's been deprecated since QEMU v3.1.0. Time to finally remove it now.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20191205104109.18680-1-thuth@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
  Reworked Thomas's deprecated.texi to the rst
2020-03-09 18:44:04 +00:00
Samuel Thibault
120b721f5b slirp: Allow non-local DNS address when restrict is off
This can be used to set a DNS server to be used by the guest which is
different from the one configured on the host.

Buglink: https://bugs.launchpad.net/qemu/+bug/1010484
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
2019-10-01 19:03:08 +02:00
Dr. David Alan Gilbert
ce62df5378 migration: register_savevm_live doesn't need dev
Commit 78dd48df3 removed the last caller of register_savevm_live for an
instantiable device (rather than a single system wide device);
so trim out the parameter.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20190822115433.12070-1-dgilbert@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
2019-09-12 11:15:03 +01:00
Stefano Garzarella
178a0a5dea net/slirp: fix the IPv6 prefix length error message
Reword and add a missing parentheses at the end of the
error message.

Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
2019-05-17 17:00:12 +08:00
Marc-André Lureau
675b9b5368 build-sys: link with slirp as an external project
Use the "system" libslirp if its present or requested.

Else build with a static libslirp.a if slirp/ is checked
out ("internal") or a submodule ("git").

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20190212162524.31504-7-marcandre.lureau@redhat.com>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
2019-03-07 12:46:31 +01:00
Marc-André Lureau
c2d63650d9 slirp: move sources to src/ subdirectory
Prepare for making slirp/ a standalone project.

Remove some useless includes while at it.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20190212162524.31504-5-marcandre.lureau@redhat.com>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
2019-03-07 12:46:31 +01:00
Marc-André Lureau
d890344166 slirp: use libslirp migration code
slirp migration code uses QEMU vmstate so far, when building WITH_QEMU.

Introduce slirp_state_{load,save,version}() functions to move the
state saving handling to libslirp side.

So far, the bitstream compatibility should remain equal with current
QEMU, as this is effectively using the same code, with the same format
etc. When libslirp is made standalone, we will need some mechanism to
ensure bitstream compatibility regardless of the libslirp version
installed. See the FIXME note in the code.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20190212162524.31504-3-marcandre.lureau@redhat.com>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
2019-03-07 12:46:31 +01:00
Samuel Thibault
ffe02f5585 slirp: Mark pieces missing IPv6 support
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
2019-03-06 23:36:22 +01:00
Paolo Bonzini
4ad6f6cb14 char: allow specifying a GMainContext at opening time
This will be needed by vhost-user-test, when each test switches to
its own GMainLoop and GMainContext.  Otherwise, for a reconnecting
socket the initial connection will happen on the default GMainContext,
and no one will be listening on it.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20190202110834.24880-1-pbonzini@redhat.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
2019-02-13 14:23:39 +01:00
Marc-André Lureau
3e0fad3aa5 slirp: pass opaque to all callbacks
This is friendlier for FFI bindings.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
2019-02-07 15:49:08 +02:00
Marc-André Lureau
deaeb3f71d slirp: use polling callbacks, drop glib requirement
It would be legitimate to use libslirp without glib. Let's
add_poll/get_revents pair of callbacks to provide the same
functionality.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
2019-02-07 15:49:08 +02:00
Marc-André Lureau
1ab67b98cd slirp: replace global polling with per-instance & notifier
Remove hard-coded dependency on slirp in main-loop, and use a "poll"
notifier instead. The notifier is registered per slirp instance.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
2019-02-07 15:49:08 +02:00
Marc-André Lureau
625a526b32 slirp: improve send_packet() callback
Use a more descriptive name for the callback.

Reuse the SlirpWriteCb type. Wrap it to check that all data has been written.

Return a ssize_t for potential error handling and data-loss reporting.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
2019-02-07 15:49:08 +02:00
Marc-André Lureau
c21d959440 slirp: replace qemu_notify_event() with a callback
Introduce a SlirpCb callback to kick the main io-thread.

Add an intermediary sodrop() function that will call SlirpCb.notify
callback when sbdrop() returns true.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
2019-02-07 15:49:08 +02:00
Marc-André Lureau
f6e5aa366f slirp: add unregister_poll_fd() callback
Add a counter-part to register_poll_fd() for completeness.

(so far, register_poll_fd() is called only on struct socket fd)

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
2019-02-07 15:49:08 +02:00
Marc-André Lureau
848c7092ba slirp: replace qemu_set_nonblock()
Replace qemu_set_nonblock() with slirp_set_nonblock()

qemu_set_nonblock() does some event registration with the main
loop. Add a new callback register_poll_fd() for that reason.

Always build the fd-register stub, to avoid #if WIN32.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
2019-02-07 15:49:08 +02:00
Marc-André Lureau
07abf6d43a slirp: add callbacks for timer
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
2019-02-07 15:49:08 +02:00
Marc-André Lureau
8e207c327c net/slirp: fix leaks on forwarding rule registration error
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
2019-02-07 15:49:08 +02:00
Marc-André Lureau
8d45a3b946 net/slirp: free forwarding rules on cleanup
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
2019-02-07 15:49:08 +02:00
Marc-André Lureau
3624730a32 net/slirp: simplify checking for cmd: prefix
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
2019-02-07 15:49:08 +02:00
Marc-André Lureau
44b4ff2488 slirp: generalize guestfwd with a callback based approach
Instead of calling into QEMU chardev directly, and mixing it with
slirp_add_exec() handling, add a new function slirp_add_guestfwd()
which takes a write callback.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
2019-02-07 15:49:08 +02:00
Marc-André Lureau
e6dbff3fb8 slirp: add clock_get_ns() callback
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
2019-01-14 00:44:29 +01:00
Marc-André Lureau
df2ad332da slirp: drop <Vista compatibility
Since commit 12f8def0e0 (v2.9), qemu
requires Vista. Let's remove some conditional code.

Note that this introduces a missing declaration warning with mingw.
warning: implicit declaration of function 'inet_ntop'

See also: https://sourceforge.net/p/mingw-w64/mailman/message/36473782/

We could workaround it by declaring it ourself depending on __MINGW64_VERSION_*:
WINSOCK_API_LINKAGE INT WSAAPI inet_pton(int Family, PCTSTR pszAddrString, PVOID pAddrBuf);

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
2019-01-14 00:44:29 +01:00
Marc-André Lureau
e05ae1d9fb net: do not depend on slirp internals
Only slirp/libslirp.h should be included.

Instead of using some slirp declarations and utility functions directly,
let's copy them in net/util.h.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
2019-01-14 00:44:29 +01:00
Marc-André Lureau
2addc8fb6d slirp: add a callback to log guest errors
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
2019-01-14 00:43:30 +01:00
Marc-André Lureau
d846b927a6 slirp: use a callback structure to interface with qemu
This will bring slirp a bit forward to the state of an independent
project.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
2019-01-14 00:40:54 +01:00
Marc-André Lureau
b7f43bf2f6 slirp: remove Monitor dependency, return a string for info
There is nothing performance-sensitive in returning an allocated
string for info, and handling the monitor_printf() on the caller side.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
2019-01-14 00:40:54 +01:00
Marc-André Lureau
3ed9f823c6 slirp: use a dedicated field for chardev pointer
Let's not mix command line and chardev pointers.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
2019-01-14 00:40:54 +01:00
Marc-André Lureau
62c1d2c483 slirp: associate slirp_output callback with the Slirp context
Let's make the slirp interface a bit more library-like.
Associate the slirp_output() with a Slirp context.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
2019-01-14 00:40:54 +01:00
Paolo Bonzini
b58deb344d qemu/queue.h: leave head structs anonymous unless necessary
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>
2019-01-11 15:46:55 +01:00
Fam Zheng
0fca92b907 slirp: Implement RFC2132 TFTP server name
This new usernet option can be used to add data for option 66 (tftp
server name) in the BOOTP reply, which is useful in PXE based automatic
OS install such as OpenBSD.

Signed-off-by: Fam Zheng <famz@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Tested-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
2018-10-21 21:24:55 +02:00
Fam Zheng
6e157a0339 slirp: Add sanity check for str option length
When user provides a long domainname or hostname that doesn't fit in the
DHCP packet, we mustn't overflow the response packet buffer. Instead,
report errors, following the g_warning() in the slirp->vdnssearch
branch.

Also check the strlen against 256 when initializing slirp, which limit
is also from the protocol where one byte represents the string length.
This gives an early error before the warning which is harder to notice
or diagnose.

Reported-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: Fam Zheng <famz@redhat.com>
Tested-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
2018-10-21 21:22:17 +02:00
Marc-André Lureau
95e30b2a13 chardev: mark the calls that allow an implicit mux monitor
This is mostly for readability of the code. Let's make it clear which
callers can create an implicit monitor when the chardev is muxed.

This will also enforce a safer behaviour, as we don't really support
creating monitor anywhere/anytime at the moment. Add an assert() to
make sure the programmer explicitely wanted that behaviour.

There are documented cases, such as: -serial/-parallel/-virtioconsole
and to less extent -debugcon.

Less obvious and questionable ones are -gdb, SLIRP -guestfwd and Xen
console. Add a FIXME note for those, but keep the support for now.

Other qemu_chr_new() callers either have a fixed parameter/filename
string or do not need it, such as -qtest:

* qtest.c: qtest_init()
  Afaik, only used by tests/libqtest.c, without mux. I don't think we
  support it outside of qemu testing: drop support for implicit mux
  monitor (qemu_chr_new() call: no implicit mux now).

* hw/
  All with literal @filename argument that doesn't enable mux monitor.

* tests/
  All with @filename argument that doesn't enable mux monitor.

On a related note, the list of monitor creation places:

- the chardev creators listed above: all from command line (except
  perhaps Xen console?)

- -gdb & hmp gdbserver will create a "GDB monitor command" chardev
  that is wired to an HMP monitor.

- -mon command line option

From this short study, I would like to think that a monitor may only
be created in the main thread today, though I remain skeptical :)

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
2018-10-03 14:45:05 +04:00