Replace '\n' with '<br>', as this allows doxygen to understand reference
names followed by newline. For some cases just drop the newline if it's
not required.
Doxygen 1.8.15 doesn't like if the name of reference is followed by
anything else than (selected?) punctuation or whitespace.
bug #56004
Two new API:
err_t mdns_search_service(const char *name, const char *service, enum mdns_sd_proto proto,
struct netif *netif, search_result_fn_t result_fn, void *arg,
s8_t *request_id);
void mdns_search_stop(s8_t request_id);
One compilation flags:
LWIP_MDNS_SEARCH
One options flags:
MDNS_MAX_REQUESTS
Some structure declarations moved to allow use by callback result function.
Result domain names are early uncompress before calling application callback
because it cannot be made by application itself.
Allow search services with multiples labels included, like '_services._dns-sd'.
Search for `_services._dns-sd._udp.local.` is handled in a special way.
Only `PTR` answers are send back to the application.
The `mdns_search_service()` function won't assert if no more space in `mdns_request`
table, just return an error if too many simultanous requests.
src/apps/mdns/mdns.c: In function 'mdns_debug_print_answer':
src/apps/mdns/mdns.c:796:24: warning: ', rdata = ' directive output may be truncated writing 10 bytes into a region of size between 8 and 15 [-Wformat-truncation=]
snprintf(string, 35, "Type = %2d, class = %1d, rdata = ", a->info.type, a->info.klass);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
src/apps/mdns/mdns.c:796:3: note: 'snprintf' output between 31 and 38 bytes into a destination of size 35
snprintf(string, 35, "Type = %2d, class = %1d, rdata = ", a->info.type, a->info.klass);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
If the host observes a response (after probing) containing RR's
that he thought were unique to him, there is a conflict. If a host
observes such conflict, it resets back to probing and the probing
procedures will resolve the conflict. (RFC6762 section 9)
According to RFC6762 section 8.1:
If fifteen conflicts occur within any ten-second period, then the
host MUST wait at least five seconds before each successive
additional probe attempt.
If the host restarts mDNS, instead of a probe wait timeout randomly
chosen between 0 and 250ms, we wait 5s if more then 15 conflicts
occured in 10seconds. This flag is reset from the moment probing
succeeded.
mDNS: first version probe tiebreaking added
This first version works for our MCU boards but does only compare
the first question and answer. It does not sort the list of answers
and it does not search for answers or questions.
mDNS: improved probe question handling
For every probe question in our packet, we check the presence
in the incomming packet until we find a match. then we perform
the tiebreaking. At the moment we still only look at the first
answer.
mDNS: evaluate all answers in the authoritative section
The authoritative sections of both messages are evaluated.
The records that answer the probe question are sorted in to lists.
Then the lists are compared pairwise. A winner and a loser are
chosen and the host reacts on the outcome (ignore or stop probing).
mDNS: add support for name decompression in rdata when comparing.
For probe tiebreaking we need to compare RR's. It is possible that
the rdata of an RR contains compessed names (SRV record). We need
to decompress it first before we do the comparison.
Probe packet creation -> by splitting the definition and the sending
we can use the definition function for probe tiebreaking.
outpkt creation -> by splitting the creation and sending we can use
the creation function for probe tiebreaking.
The host only responded to a probe query via unicast because
according to the RFC, a probe should have the QU bit on.
This is a should and not a must so we need to be careful.
We added multicast probe answering support with the needed timouts.
Avahi for example probes with the QM queries. With this commit the
conflict is resolved.
The implementation was not fully to the standard. This commit adds
a nicer state machine implementation and multiple announce messages
with a minimum of 2.
See below commit messages for more information
mDNS: support for direct and delayed sends
There are two ways to send a response, directly and after a delay.
A probe or an announce msg are now send via the direct way and
all responses are send via the delayed way.
mDNS improved delay vs direct send behavior on questions
All multicast answers are delayed at the moment. While all unicast
answers are send out directly. A unicast answer is send when this
is requested by the QU bit, when a unicast question was send or
when the question originated from a legacy querier.
mDNS: add probe query detection.
If a probe query is detected a direct unicast respond is send.
Independent of the QU/QM bit.
mDNS split delayed multicast msgs into ipv4 and ipv6 buffers.
We are implementing a two resolvers in one (IPv6 and IPv4 together).
For directly send answers, this does not matter. But for delayed
answers, we need to make a separate buffer for both.
mDNS: addr bug, we should not clear full outmsg
memset deleted also the dest_addr and dest_port, which should remain
and is constant. This commit contains a function that resets only the
needed parts of the outmsg struct.
mDNS: do not multicast a rr within one second.
RFC6762 section 6: prevent network flooding. When a multicast packet
is send out, we start a timeout of 1s within this 1 second all
multicast requests are ignored. We do not make a difference between
the records, we set the delay for all records.
mDNS: improved split for unicast vs multicast and direct vs delayed
unicast delayed message are now possible and multicast direct msgs to.
MDNS: changed printfs to lwip debug messages
MDNS: change timeouts from max time to random time
mDNS: send multicast response on QU questions if not multicasted recently.
If a QU question is received, the responder should multicast the
answer if it did not multicast that record within 25% of it's ttl.
we implemented a stripped down version, meaning that we look at the
records as one set and use one timer for all records. So if the
responder multicasted a record within 30s of the QU question it
will respond with a unicast answer. if not, it will respond
multicast.
mDNS: timeouts -> create function for mdns timeout handling
mdns_set_timeout will check if the timer is running or not and will
update the flag to running after starting the timer.
Multicast timeouts were not set everywhere they needed to be. This
is solved.
mulit <-> multi typo fixed.
mDNS: solve commenting and style issues
mDNS: add #if LWIP_IPVx to new code
LWIP_IPV4/6 can be enabled or disabled, all combination should work.
it's more practical to use netif as a wrapper instead of wrapping
netif in the mdns packets. netif contains all information.
Netif is passed along were needed.
MDNS_TTL changed to MDNS_IP_TTL for clarity.
The mDNS RR ttl does not need to be settalbe, this is against the
RFC. RFC6762 states that for rr's with the hostname in them
somewhere, the ttl should be 120s. If it's not in their it should
be 75 minutes and if the answer is send to a legacy dns querier,
it should be no more then 10s.
This patch corrects the ttl behavior to the RFC.
see RFC 6762 section 8.2: for tiebreaking to work correctly in all
cases, the Authority section must contain all the records and
proposed rdata being probed for uniqueness.
mDNS.c needed to become cleaner. Domain related functions are
moved to the mdns_domain.c util module. The output related
functions are split off (clear separation between defining the
packet and generating the packet). The output functions can
now be found in mdns_out.c.
mDNS move probe question packet generation to mdns_send_outpacket
The probe any questions were added to the pbuf in the send_probe
routine. It is better if we move all pbuf generation to the output
function so later on packets can be delayed etc. keep it all in
one place.
mDNS: move legacy question generation to mdns_send_outpacket
It's better to do the pbuf generation in one place.
Especially important for message delaying etc.
mDNS take out domain related functionality and put in other file.
The mDNS file is getting very big and a lot still needs to be added.
For clarity reasons it's better to split these domain functions
from the main mDNS file.
mDNS split off output related functionality and put in other file
A lot of functions are only needed for the generation of the pbuf,
by separating them into another file we clean up the mdns file.
We only need the mdns_send_outpacket function as interface.
Packet definition is now completely separated from packet
generation.
e.g. if the calling stack should not invoke the mdns functions due
to high stack usage, disable the option and trigger it yourself.
Signed-off-by: Simon Goldschmidt <goldsimon@gmx.de>
This reverts commit 6934bb442832406b5c41fc86bd934091b021f7ad.
Need to revert commit d6e58d02a619813a4187ab53ab0ffc2f0b864ad7 first, and that one produced merge conflicts.
This broke when IPv6 got scopes added. Scopes/zones are checked
even if none of the compared addresses are link local.
Result of the bug was that IPv6 replies were always sent unicast to
the source instead of to the multicast address.
Add ip-generic version that ignores IP zone info, since the v6 group
address is not tied to any netif.
Changes made by me:
- Move all error handling code into mdns_resp_announce() so it can be safely used by external code
- Remove mdns_resp_netif_settings_changed() because it is the same as mdns_resp_announce() after my changes
- Declare #define for a "thread-safe" version of mdns_resp_announce in mdns.h instead of netifapi.h - I don't want to intermix netif API with APPs
