So far there was no dedicated mechanism for replacing DNS servers with
new list. Add dns_resolve_reconfigure() API that allows to achieve that
in a thread-safe manner.
Introduce 3rd state in DNS context lifetime by converting from 'bool
is_used' to 'enum dns_resolve_context_state state'. This new
DEACTIVATING state allows to mark a DNS context as busy and safely close
context without holding lock. Closing DNS context with released lock
prevents deadlock in case net_context_close() has to synchronize with a
separate thread executing handler passed to net_context_recv() (which is
the case for example with ESP-AT WiFi driver).
Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
ctx->is_used member seemed to be used sometimes within a mutex acquired
block, sometimes not. Make it consistent by always using it with
acquired mutex.
Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
Query timeout handler is rescheduled if DNS context mutex is locked. So
far there was no timeout used, which means that work is simply put at
the end of system workqueue. This solves cases when mutex is locked by
any higher priority cooperative threads.
If however mutex was locked in application code within lower priority
thread (which is very likely) and query timeout has expired in the
meantime, then system workqueue is busy looping by calling query timeout
handler and trying to acquire DNS context lock.
Reschedule query timeout handler with 10ms delay, so that all
threads, including those with lower priorities, have a chance to move
forward and release DNS context lock.
Signed-off-by: Marcin Niestroj <m.niestroj@grinn-global.com>
Switch to the new API for delayed work related to DNS queries.
In the previous solution it was assumed that the work item could be
immediately cancelled at the point the query slot was released. This
is not true. We need a secondary condition to record the fact that
the query was completed while the work item was still pending, and an
additional check to detect when the work item completed and the slot
reclaimed.
Also annotate functions to indicate when they require the lock on
query content to be held, add some helpers that abstract core
operations like invoking a callback or releasing a query slot, and fix
some more cases where query slot content was accessed outside of the
new lock infrastructure.
Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
It is documented that using transient information like whether a work
item is pending or a delayed work item has time left to determine the
state of the work item before subsequent reconfiguration is prone to
race conditions, and known to produce unexpected behavior in the
presence of preemptive threads, SMP, or use of the work item from
interrupts. As a best practice such pre-validation steps should be
avoided unless algorithmically necessary.
All comparisons of remaining delayed time before canceling a delayed
work item in this module appear to be optimizations subject to the
above race conditions. Remove the checks so that only the inherent
race conditions in the implementation of canceling a work item remain.
Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
This change enables support for DNS service discovery
(RFC 6763) in the mdns_responder service and sample app.
Fixes#29429
Signed-off-by: Christopher Friedt <chrisfriedt@gmail.com>
This change adds support for DNS Service Discovery (DNS-SD)
as described in RFC 6763.
Fixes#29099
Signed-off-by: Christopher Friedt <chrisfriedt@gmail.com>
Now that device_api attribute is unmodified at runtime, as well as all
the other attributes, it is possible to switch all device driver
instance to be constant.
A coccinelle rule is used for this:
@r_const_dev_1
disable optional_qualifier
@
@@
-struct device *
+const struct device *
@r_const_dev_2
disable optional_qualifier
@
@@
-struct device * const
+const struct device *
Fixes#27399
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
Add more tests to verify that we discard malformed packets.
In order to simplify the testing, separate message validation to
dns_validate_msg() function in resolve.c. Allow that function to
be called from unit test. This way we can construct invalid DNS
messages in unit test and verify that they are discarded when
needed.
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
The ANCOUNT has nothing to do with label count so remove the
original while loop and just go through all the labels until
we have read all of them.
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
This is not possible with valid DNS messages but is possible if
we receive malformed DNS packet.
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
-Wimplicit-fallthrough=2 requires a fallthrough comment or a compiler
to tells gcc that this happens intentionally.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
Unit tests were failing to build because random header was included by
kernel_includes.h. The problem is that rand32.h includes a generated
file that is either not generated or not included when building unit
tests. Also, it is better to limit the scope of this file to where it is
used.
Signed-off-by: Flavio Ceolin <flavio.ceolin@intel.com>
It might happen that while we are waiting for the response
to one of our query, we receive a query to resolve another name.
Previously this would make the current name resolution to fail because
only responses were expected to be received.
Signed-off-by: Léonard Bise <leonard.bise@gmail.com>
As mDNS requests set DNS id to 0, we cannot use it to match
the DNS response packet. In order to allow this functionality,
create a hash from query name and type, and use that together
with DNS id to match request and response.
Fixes#21914
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Use this short header style in all Kconfig files:
# <description>
# <copyright>
# <license>
...
Also change all <description>s from
# Kconfig[.extension] - Foo-related options
to just
# Foo-related options
It's clear enough that it's about Kconfig.
The <description> cleanup was done with this command, along with some
manual cleanup (big letter at the start, etc.)
git ls-files '*Kconfig*' | \
xargs sed -i -E '1 s/#\s*Kconfig[\w.-]*\s*-\s*/# /'
Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>
Fix GCC "warning: 'ipv4' defined but not used [-Wunused-variable]" and
"warning: 'ipv6' defined but not used [-Wunused-variable]" when either
IPv4 or IPv6 support is not enabled.
Signed-off-by: Markus Fuchs <markus.fuchs@de.sauter-bc.com>
create_ipv6_answer() function is behind #define's but get used behind
IS_ENABLED(CONFIG_NET_IPV6), which is not allowed.
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
If we are returned IPv4 address but the hints says IPv6, then
return error as currently we do not support AI_V4MAPPED addresses.
Same check for IPv6 if we want only IPv4 address.
Fixes#18870
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
The mDNS packet receive had issues:
* The DNS id needs to be 0 for both sending and receiving, we did
not accepted 0 incoming id.
* The mDNS response does not have any questions in it so we just
need to skip the question count checks in response.
* Skip the Cache-Flush bit in Class field so that we can properly
parse CLASS_IN value.
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
In DNS server init, print information whether the DNS server
is mDNS or LLMNR one. This way we do not need to remember what
IP addresses are used either of them.
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
The source UDP port in all Multicast DNS responses MUST be 5353
as described in RFC 6762 chapter 6.
Fixes#18732
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Simplify algorithm to skip (aka calculate length) of encoded domain
name in a DNS answer. Now it's fully compliant to RFC 1035 regarding
handling of compressed FQDNs. Additionally, bounds checking is now
performed by the parsing code.
Fixes: #18334
Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
If DNS server(s) are added or removed e.g., as part of DHCP
processing, send newly defined net-mgmt events so that
a user application may get this information.
Fixes#16924
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
The hostname needs to have log_strdup() when printing it.
Also it is useful to print information if the sending fails.
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
- answer offset was 1 byte off.
- request offset, when copied into the answer, was off as well.
Fixes#16142
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
Modify dns_unpack_answer() function to check if the answer is
compressed or not, and return correct values regardless.
Fixes#16594
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
The query->len does not take 'Terminator' into account, shift over
one byte to prevent overwriting it with next field (Type).
This fixes mdns_resolver sample.
Fixes: 87eb552dd2 (net/dns: Switch mdns responder to new net_pkt API)
Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
It is possible that UDP header cannot be accessed so we need
to check that we do not do null pointer dereference.
Coverity-CID: 198866
Fixes#16581
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Update the files which contain no license information with the
'Apache-2.0' SPDX license identifier. Many source files in the tree are
missing licensing information, which makes it harder for compliance
tools to determine the correct license.
By default all files without license information are under the default
license of Zephyr, which is Apache version 2.
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
And also to the relevant callbacks.
That parameter is not used anywhere so it is useless.
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
Now that legacy functions are removew, let's rename the new functions by
removing the _new suffix.
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
Unfortunately, most of the dns pack/unpack code is not factorized, and
mdns responder rewrites its own functions to write dns hdr, query,
answer.
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
Unfortunately, most of the dns pack/unpack code is not factorized, and
llmnr responder rewrites its own functions to write dns hdr, query,
answer.
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
So instead of building the net_pkt by itself, dns will pass its message
buffer to net_context_sendto_new(), which in turn will build the net_pkt
relevantly.
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
dns_write was in the middle of this, let's just move it to a more
relevant place so we logically have macros, then local variables then
functions.
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
Some of dns_pack.c macros are also used in resolve.c, so let's just put
the macros in dns_pack.h
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
There are issues using lowercase min and max macros when compiling a C++
application with a third-party toolchain such as GNU ARM Embedded when
using some STL headers i.e. <chrono>.
This is because there are actual C++ functions called min and max
defined in some of the STL headers and these macros interfere with them.
By changing the macros to UPPERCASE, which is consistent with almost all
other pre-processor macros this naming conflict is avoided.
All files that use these macros have been updated.
Signed-off-by: Carlos Stuart <carlosstuart1970@gmail.com>
If status is 0, both ip_hdr and proto_hdr will own a pointer to the
relevant IP and Protocol headers. In order to know which of ipv4/ipv6
and udp/tcp one will need to use respectively net_pkt_family(pkt) and
net_context_get_ip_proto(context).
Having access to those headers directly, many callbacks will not need
to parse the packet again no get the src/dst addresses or the src/dst
ports. This will be change after this commit.
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
