ISO/IEC 9899:1999 §7.21.1/2 says:
Where an argument declared as size_t n specifies the length of the array
for a function, n can have the value zero on a call to that
function. Unless explicitly stated otherwise in the description of a
particular function in this subclause, pointer arguments on such a call
shall still have valid values, as described in 7.1.4.
In base64_append_width memcpy was called as memcpy(x, NULL, 0). GCC 4.9
started making use of this and assumes This worked fine under -O0, but
does something strange under -O3.
This patch fixes a bug in base64_append_width(), fixes a possible bug in
journal_file_append_entry_internal(), and makes use of the new function
to simplify the code in other places.
I'm not defining _DNS_SERVER_TYPE_MAX/INVALID as usual in the enum,
because it wouldn't be used, and then gcc would complain that
various enums don't test for _DNS_SERVER_TYPE_MAX. It seems better
to define the macro rather than add assert_not_reached() in multiple
places.
We try to fit the lengthy key data into available space. If the other
fields take less than half of the available columns, we use align everything
in the remaining columns. Otherwise, we put everything after a newline,
indented with 8 spaces.
This is similar to dig and other tools do.
$ COLUMNS=78 ./systemd-resolve -t any .
. IN SOA a.root-servers.net nstld.verisign-grs.com 2016012701 1800 900 604800 86400
. IN RRSIG SOA RSASHA256 0 86400 20160206170000 20160127160000 54549
S1uhUoBAReAFi5wH/KczVDgwLb+B9Zp57dSYj9aX4XxBhKuzccIducpg0wWXhjCRAWuzY
fQ/J2anm4+C4BLUTdlytPIemd42SUffQk2WGuuukI8e67nkrNF3WFtoeXQ4OchsyO24t2
rxi682Zo9ViqmXZ+MSsjWKt1jdem4noaY=
. IN NS h.root-servers.net
. IN NS k.root-servers.net
. IN NS e.root-servers.net
. IN NS c.root-servers.net
. IN NS b.root-servers.net
. IN NS g.root-servers.net
. IN NS d.root-servers.net
. IN NS f.root-servers.net
. IN NS i.root-servers.net
. IN NS j.root-servers.net
. IN NS m.root-servers.net
. IN NS a.root-servers.net
. IN NS l.root-servers.net
. IN RRSIG NS RSASHA256 0 518400 20160206170000 20160127160000 54549
rxhmTVKUgs72G3VzL+1JRuD0nGLIrPM+ISfmUx0eYUH5wZD5XMu2X+8PfkAsEQT1dziPs
ac+zK1YZPbNgr3yGI5H/wEbK8S7DmlvO+/I9WKTLp/Zxn3yncvnTOdjFMZxkAqHbjVOm+
BFz7RjQuvCQlEJX4PQBFphgEnkiOnmMdI=
. IN NSEC aaa ( NS SOA RRSIG NSEC DNSKEY )
. IN RRSIG NSEC RSASHA256 0 86400 20160206170000 20160127160000 54549
HY49/nGkUJJP1zLmH33MIKnkNH33jQ7bsAHE9itEjvC4wfAzgq8+Oh9fjYav1R1GDeJ2Z
HOu3Z2uDRif10R8RsmZbxyZXJs7eHui9KcAMot1U4uKCCooC/5GImf+oUDbvaraUCMQRU
D3mUzoa0BGWfxgZEDqZ55raVFT/olEgG8=
. IN DNSKEY 257 3 RSASHA256 AwEAAagAIKlVZrpC6Ia7gEzahOR+9W29euxhJhVVLOyQbSEW0
O8gcCjFFVQUTf6v58fLjwBd0YI0EzrAcQqBGCzh/RStIoO8g0
NfnfL2MTJRkxoXbfDaUeVPQuYEhg37NZWAJQ9VnMVDxP/VHL4
96M/QZxkjf5/Efucp2gaDX6RS6CXpoY68LsvPVjR0ZSwzz1ap
AzvN9dlzEheX7ICJBBtuA6G3LQpzW5hOA2hzCTMjJPJ8LbqF6
dsV6DoBQzgul0sGIcGOYl7OyQdXfZ57relSQageu+ipAdTTJ2
5AsRTAoub8ONGcLmqrAmRLKBP1dfwhYB4N7knNnulqQxA+Uk1
ihz0=
. IN DNSKEY 256 3 RSASHA256 AwEAAbr/RV0stAWYbmKOldjShp4AOQGOyY3ATI1NUpP4X1qBs
6lsXpc+1ABgv6zkg02IktjZrHnmD0HsElu3wqXMrT5KL1W7Sp
mg0Pou9WZ8QttdTKXwrVXrASsaGI2z/pLBSnK8EdzqUrTVxY4
TEGZtxV519isM06CCMihxTn5cfFBF
. IN RRSIG DNSKEY RSASHA256 0 172800 20160204235959 20160121000000 19036
XYewrVdYKRDfZptAATwT+W4zng04riExV36+z04kok09W0RmOtDlQrlrwHLlD2iN/zYpg
EqGgDF5T2xlrQdNpn+PFHhypHM7NQAgLTrwmiw6mGbV0bsZN3rhFxHwW7QVUFAvo9eNVu
INrjm+sArwxq3DnPkmA+3K4ikKD2iiT/jT91VYr9SHFqXXURccLjI+nmaE7m31hXcirX/
r5i3J+B4Fx4415IavSD72r7cmruocnCVjcp+ZAUKeMyW+RwigzevLz3oEcCZ4nrTpGLEj
wFaVePYoP+rfdmfLfTdmkkm4APRJa2My3XOdGFlgNS1pW1pH4az5LapLE2vMO7p1aQ==
-- Information acquired via protocol DNS in 14.4ms.
-- Data is authenticated: no
This gets rid of the private DNSSEC TODO and moves it in the main TODO dump site, as the DNSSEC implementation is
pretty complete now, and the remaining bits are low-priority.
Lets make sure we always take notice of network changes before answering client requests.
This way, calls like SetLinkDNS() become race-free as the specified interface index is guarantee to have been processed
if it exists before we make changes to it.
If we encounter NXDOMAIN, but find at least one matching RR in a response, then patch it to become SUCCESS. This should
clean up handling of CNAME/DNAMEs, and makes sure broken servers and those conforming to RFC 6604 are treated the same
way. The new behaviour opposes the logic suggested in RFC 6604, but given that some servers don't implement it
correctly, and given that in some ways the CNAME/DNAME chains will be incomplete anyway, and given that DNSSEC
generally only allows us to prove the first element of a CNAME/DNAME chain, this should simplify things for us.
Following the changes to expose the "routing" and "search" domain concepts in networkd, actually make resolved use
them. It will now use routing domains exclusively for making DNS routing decisions, and use search domains additionally
for extending single-label names.
Previously, .network files only knew a vaguely defined "Domains=" concept, for which the documentation declared it was
the "DNS domain" for the network connection, without specifying what that means.
With this the Domains setting is reworked, so that there are now "routing" domains and "search" domains. The former are
to be used by resolved to route DNS request to specific network interfaces, the latter is to be used for searching
single-label hostnames with (in addition to being used for routing). Both settings are configured in the "Domains="
setting. Normal domain names listed in it are now considered search domains (for compatibility with existing setups),
while those prefixed with "~" are considered routing domains only. To route all lookups to a specific interface the
routing domain "." may be used, referring to the root domain. An alternative syntax for this is the "*", as was already
implemented before using the "wildcard" domain concept.
This commit adds proper parsers for this new logic, and exposes this via the sd-network API. This information is not
used by resolved yet, this will be added in a later commit.
So far, abritrary NSEC and NSEC3 RRs were implicitly consider "primary" for any transaction, meaning we'd abort the
transaction immediately if we couldn't validate it. With this patch this logic is removed, and the NSEC/NSEC3 RRs will
not be considered primary anymore. This has the effect that they will be dropped from the message if they don't
validate, but processing continues. This is safe to do, as they are required anyway to validate positive wildcard and
negative responses, and if they are missing then, then message will be considered unsigned, which hence means the
outcome is effectively the same.
This is benefical in case the server sends us NSEC/NSEC3 RRs that are not directly related to the lookup we did, but
simply auxiliary information. Previously, if we couldn't authenticate those RRs we'd fail the entire lookup while with
this change we'll simply drop the auxiliary information and proceed without it.
In some cases we get NSEC3 RRs that have not been authenticated (because the chain of trust to the root is somewhere
broken). We can use these for checking negative replies, as long as we don't claim they were ultimately authenticated.
This means we need to be able to deal with NSEC3 RRs that lack RRSIG metadata.
We already properly propagate errors from transactions to queries. Make sure that errors that happened during handling
of query candidates are propagated to the query, too.
Whenever we encounter an OS error we did not expect, we so far put the transaction into DNS_TRANSACTION_RESOURCES
state. Rename this state to DNS_TRANSACTION_ERRNO, and save + propagate the actual system error to the caller. This
should make error messages triggered by system errors much more readable by the user.
If we downgrade from DNSSEC to non-DNSSEC mode, let's log about this in a recognizable way (i.e. with a message ID),
after all, this is of major importance.
When we synthesize A/AAAA for domains like "localhost", then make sure we generate ENODATA if the user asks for RR
types such a RP to be solved on the name. Previously, we'd pass the error back in that case that was generated from the
usual lookup procedure.
The LLMNR spec suggests to do do reverse address lookups by doing direct LLMNR/TCP connections to the indicated
address, instead of doing any LLMNR multicast queries. When we do this and the peer doesn't actually implement LLMNR
this will result in a TCP connection error, which we need to handle. In contrast to most LLMNR lookups this will give
us a quick response on whether we can find a suitable name. Report this as new transaction state, since this should
mostly be treated like an NXDOMAIN rcode, except that it's not one.
When using NSEC/NSEC3 RRs from the cache to derive existance of arbitrary RRs, we should not get confused by the fact
that NSEC/NSEC3 RRs exist twice at zone cuts: once in the parent zone, and once in the child zone. For most RR types we
should only consult the latter since that's where the beef is. However, for DS lookups we have to check the former.
This change makes sure we never cache NSEC/NSEC3 RRs from any parent zone of a zone-cut. It also makes sure that when
we look for a DS RR in the cache we never consider any cached NSEC RR, as those are now always from the child zone.
We already maintain statistics about positive DNSSEC proofs, and count them up by 1 for each validated RRset. Now,
update the same counters each time we validated a negative query, so that the statistics are the combined result of all
validation checks, both positive and negative.
If we are looking for a DS RR we need to check the NSEC3 bitmap of the parent zone's NSEC3 RR, not the one from the
child. For any other RR we need to look at the child's however, hence enforce this with the bitmaps.
Note that not coverign checks only the lower zone's NSEC3 bitmaps matter, hence the existing check is fine.
The tool resolves way more than just hosts, hence give it a more generic name. This should be safe, as the tool is
currently undocumented. Before we add documentation for it, let's get the name right.
This also moves the C source into src/resolve/ (from src/resolve-host/), since the old name is a misnomer now. Also,
since it links directly to many of the C files of resolved it really belongs into resolved's directory anyway.
