man/sd_event_{add_io,add_time,add_signal,now}: various small fixes
- remove things which are clear from the context
- 0 is a valid descriptor number, hence "positive" → "non-negative"
- "positive" means greater than zero, hence "positive non-zero" → "positive"
- use oxford comma
- reword some things for clarity
resolved: don't forget about lost OPT and RRSIG when downgrading a feature level
Certain Belkin routers appear to implement a broken DNS cache for A RRs and some others, but implement a pass-thru for
AAAA RRs. This has the effect that we quickly recognize the broken logic of the router when we do an A lookup, but for
AAAA everything works fine until we actually try to validate the request. Given that the validation will necessarily
fail ultimately let's make sure we remember even when downgrading a feature level that OPT or RRSIG was missing.
resolved: enforce maximum limit on DNS transactions
given that DNSSEC lookups may result in quite a number of auxiliary transactions, let's better be safe than sorry and
also enforce a limit on the number of total transactions, not just on the number of queries.
resolved: fix how we detect whether auxiliary DNSSEC transactions are ready
Previously, when getting notified about a completed auxiliary DNSSEC transaction we'd immediately act on it, and
possibly abort the main transaction. This is problematic, as DNS transactions that already completed at the time we
started using them will never get the notification event, and hence never be acted on in the same way.
Hence, introduce a new call dns_transaction_dnssec_ready() that checks the state of auxiliary DNSSEC transactions, and
returns 1 when we are ready for the actual DNSSEC validation step. Then, make sure this is invoked when the auxiliary
transactions are first acquired (and thus possibly reused) as well when the notifications explained above take place.
This fixes problems particularly when doing combined A and AAAA lookups where the auxiliary DNSSEC transactions get
reused between them, and where we got confused if we reused an auxiliary DNSSEC transaction from one when it already
got completed from the other.
Move IDNA logic out of the normal domain name processing, and into the bus frontend calls. Previously whenever
comparing two domain names we'd implicitly do IDNA conversion so that "pöttering.de" and "xn--pttering-n4a.de" would be
considered equal. This is problematic not only for DNSSEC, but actually also against he IDNA specs.
Moreover it creates problems when encoding DNS-SD services in classic DNS. There, the specification suggests using
UTF8 encoding for the actual service name, but apply IDNA encoding to the domain suffix.
With this change IDNA conversion is done only:
- When the user passes a non-ASCII hostname when resolving a host name using ResolveHostname()
- When the user passes a non-ASCII domain suffix when resolving a service using ResolveService()
No IDNA encoding is done anymore:
- When the user does raw ResolveRecord() RR resolving
- On the service part of a DNS-SD service name
Previously, IDNA encoding was done when serializing names into packets, at a point where information whether something
is a label that needs IDNA encoding or not was not available, but at a point whether it was known whether to generate a
classic DNS packet (where IDNA applies), or an mDNS/LLMNR packet (where IDNA does not apply, and UTF8 is used instead
for all host names). With this change each DnsQuery object will now maintain two copies of the DnsQuestion to ask: one
encoded in IDNA for use with classic DNS, and one encoded in UTF8 for use with LLMNR and MulticastDNS.
build-sys: allow building man pages even if disabled in ./configure
This is purely for developer convenience: building man pages is slow
so people tend to disable them when not working on documentation. But
sometimes it is useful to build the man page to look something up,
especially when working on an older machine which has outdated
documentation, or to test some change to documentation. The rules to build
man pages are now outside of the ENABLE_MANPAGES conditional, but they
are not used unless manually invoked, and only the inclusion of man
pages in build and install targets is affected by the conditional.
Also, more generated files are removed in clean, which seems to be
good thing, and Makefile.am is simplified.
journal-remote: update to 64bit µhttp api, provide fallback
64 bit offset is now accepted, which is nice. The old function is
deprecated, and generates a compile time warning when used. We only
use an offset of 0, so we really don't care. Adapt to use the new
function, but fall back to the old one on older versions.
journal-remote: fix warning about deprecated µhttpd macro
src/journal-remote/journal-remote.c:590:13: warning: Value MHD_HTTP_METHOD_NOT_ACCEPTABLE is deprecated, use MHD_HTTP_NOT_ACCEPTABLE
return mhd_respond(connection, MHD_HTTP_METHOD_NOT_ACCEPTABLE,
^
The new define was added in 0.9.38. Instead of requiring the new
libmicrohttpd version, provide the fallback, it is trivial.
udevd: initialize fds to -1 and close them before exiting
Little change in practice, because the program will exit soon
afterwards, but the standard style of closing all fds is now followed.
Also gets rid of gcc warning about fd_ctrl and fd_uevent being
unitialized.
manager_{start,stop}_{slice,scope,unit} functions had an optional job
output parameter. But all callers specified job, so make the parameter
mandatory, add asserts. Also extract common job variable handling to
a helper function to avoid duplication.
bus-kernel: reword assignment of dst_id in bus_message_setup_kmsg
Setting of dst_id was based on interplay of two booleans,
making the logic hard to follow (for humans and compilers alike).
gcc was confused and emmitted a warning about an uninitialized
variable. Rework the code to make it obvious that dst_id is
set properly.
basic/escape: merge utf8 and non-utf8 paths in cunescape_one
Not every byte sequence is valid utf8. We allow escaping of non-utf8
sequences in strings by using octal and hexadecimal escape sequences
(\123 and \0xAB) for bytes at or above 128. Users of cunescape_one
could infer whether such use occured when they received an answer
between 128 and 256 in *ret (a non-ascii one byte character). But this
is subtle and misleading: the comments were wrong, because ascii is a
subset of unicode, so c != 0 did not mean non-unicode, but rather
ascii-subset-of-unicode-or-raw-byte. This was all rather confusing, so
make the "single byte" condition explicit.
I'm not convinced that allowing non-utf8 sequences to be produced is
useful in all cases where we allow it (e.g. in config files), but that
behaviour is unchanged, just made more explicit.
This also fixes an (invalid) gcc warning about unitialized variable
(*ret_unicode) in callers of cunescape_one.
bus-error: verify additional error maps during installation
Go over the entries in the map and check that they make sense.
Tests are added. In the future we might want to do additional
checks, e.g. verifying that the error names are in the expected
format.
basic,bus-error: return negative error from errno_from_name
errno_from_name used an unusual return convention where 0 meant
"not found". This tripped up config_parse_syscall_errno(),
which would treat that as success. Return -EINVAL instead,
and adjust bus_error_name_to_errno() for the new convention.
Also remove a goto which was used as a simple if and clean
up surroudning code a bit.
How to reproduce
$ systemctl set-default multi-user # https://github.com/systemd/systemd/issues/2298
$ systemctl preset-all
Failed to execute operation: Too many levels of symbolic links
$ systemctl poweroff
Fixes:
==1==
==1== HEAP SUMMARY:
==1== in use at exit: 65,645 bytes in 7 blocks
==1== total heap usage: 40,539 allocs, 40,532 frees, 30,147,547 bytes allocated
==1==
==1== 109 (24 direct, 85 indirect) bytes in 1 blocks are definitely lost in loss record 2 of 7
==1== at 0x4C2BBCF: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==1== by 0x4C2DE2F: realloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==1== by 0x23DA71: unit_file_changes_add (install.c:233)
==1== by 0x23E45D: remove_marked_symlinks_fd (install.c:453)
==1== by 0x23E267: remove_marked_symlinks_fd (install.c:405)
==1== by 0x23E641: remove_marked_symlinks (install.c:494)
==1== by 0x243A91: execute_preset (install.c:2190)
==1== by 0x244343: unit_file_preset_all (install.c:2351)
==1== by 0x18AAA2: method_preset_all_unit_files (dbus-manager.c:1846)
==1== by 0x1D8157: method_callbacks_run (bus-objects.c:420)
==1== by 0x1DA9E9: object_find_and_run (bus-objects.c:1257)
==1== by 0x1DB02B: bus_process_object (bus-objects.c:1373)
==1==
==1== LEAK SUMMARY:
==1== definitely lost: 24 bytes in 1 blocks
==1== indirectly lost: 85 bytes in 1 blocks
==1== possibly lost: 0 bytes in 0 blocks
==1== still reachable: 65,536 bytes in 5 blocks
==1== suppressed: 0 bytes in 0 blocks
==1== Reachable blocks (those to which a pointer was found) are not shown.
==1== To see them, rerun with: --leak-check=full --show-leak-kinds=all
==1==
==1== For counts of detected and suppressed errors, rerun with: -v
==1== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)
resolved: when we find a DNAME RR, don't insist in a signed CNAME RR
If we have a signed DNAME RR response, there's no need to insist on a signature for a CNAME RR response, after all it
is unlikely to be signed, given the implicit synthethis of CNAME through DNAME RRs.
The functionality of SYSTEMD_USER_WANTS that attaches dependencies to device
units from udev rules was broken since commit b2c23da8. I guess it was due to
a mass replace s/SYSTEMD_USER/MANAGER_USER/.
resolved: try to reduce number or DnsResourceKeys we keep around by merging them
Quite often we read the same RR key multiple times from the same message. Try to replace them by a single object when
we notice this. Do so again when we add things to the cache.
resolved: when the server feature level changes between query and response restart transaction
In some cases we learn something about a server's feature level through its responses. If we notice that after doing
basic checking of a response, and after collecting all auxiliary DNSSEC info the feature level of the server is lower
than where we started, restart the whole transaction.
This is useful to deal with servers that response rubbish when talked to with too high feature levels.
resolved: check OPT RR before accepting a reply for verification of server feature level
Let's make sure we first check if the OPT was lost in the reply, before we accept a reply as successful and use it for
verifying the current feature level.
resolved: when restarting a DNS transaction, remove all auxiliary DNSSEC transactions
When we restart a DNS transaction, remove all connections to any auxiliary DNSSEC transactions, after all we might
acquire completely different data this time, requiring different auxiliary DNSSEC transactions.
resolved: when we receive an reply which is OPT-less or RRSIG-less, downgrade what we verified
If we receive a reply that lacks the OPT RR, then this is reason to downgrade what was verified before, as it's
apparently no longer true, and the previous OPT RR we saw was only superficially OK.
Similar, if we realize that RRSIGs are not augmented, then also downgrade the feature level that was verified, as
DNSSEC is after all not supported. This check is in particular necessary, as we might notice the fact that RRSIG is not
augmented only very late, when verifying the root domain.
Also, when verifying a successful response, actually take in consideration that it might have been reported already
that RRSIG or OPT are missing in the response.
resolved: downgrade server feature level more aggressively when we have reason to
This adds logic to downgrade the feature level more aggressively when we have reason to. Specifically:
- When we get a response packet that lacks an OPT RR for a query that had it. If so, downgrade immediately to UDP mode,
i.e. don't generate EDNS0 packets anymore.
- When we get a response which we are sure should be signed, but lacks RRSIG RRs, we downgrade to EDNS0 mode, i.e.
below DO mode, since DO is apparently not really supported.
This should increase compatibility with servers that generate non-sensical responses if they messages with OPT RRs and
suchlike, for example the situation described here:
resolved: ignore invalid OPT RRs in incoming packets
This validates OPT RRs more rigorously, before honouring them: if we any of the following condition holds, we'll ignore
them:
a) Multiple OPT RRs in the same message
b) OPT RR not owned by the root domain
c) OPT RR in the wrong section (Belkin routers do this)
d) OPT RR contain rfc6975 algorithm data (Belkin routers do this)
e) OPT version is not 0
f) OPT payload doesn't add up with the lengths
Note that d) may be an indication that the server just blindly copied OPT data from the response into the reply.
RFC6975 data is only supposed to be included in queries, and we do so. It's not supposed to be included in responses
(and the RFC is very clear on that). Hence if we get it back in a reply, then the server probably just copied the OPT
RR.
This new test case tries to resolve a couple of known domains, to verify the validation results. It talks to resolved
via the bus, thus comprehensively testing the whole shebang.
Of course, it requires network connectivity and a DNSSEC capable DNS server, hence this is a manual test.
- When checking if a domain is non-existing, also check that no wildcard for it exists
- Ensure we don't base "covering" tests on NSEC RRs from a parent zone
- Refuse to accept expanded wildcard NSEC RRs for absence proofs.
resolved: on negative NODATA replies, properly deal with empty non-terminals
empty non-terminals generally lack NSEC RRs, which means we can deduce their existance only from the fact that there
are other RRs that contain them in their suffix. Specifically, the NSEC proof for NODATA on ENTs works by sending the
NSEC whose next name is a suffix of the queried name to the client. Use this information properly.
resolved: when validating an RRset, store information about the synthesizing source and zone in each RR
Having this information available is useful when we need to check whether various RRs are suitable for proofs. This
information is stored in the RRs as number of labels to skip from the beginning of the owner name to reach the
synthesizing source/signer. Simple accessor calls are then added to retrieve the signer/source from the RR using this
information.
This also moves validation of a a number of RRSIG parameters into a new call dnssec_rrsig_prepare() that as side-effect
initializes the two numeric values.
core: fix memory leak on set-default, enable, disable etc
Fixes:
==1== by 0x23E44C: remove_marked_symlinks_fd (install.c:453)
==1== by 0x23E256: remove_marked_symlinks_fd (install.c:405)
==1== by 0x23E630: remove_marked_symlinks (install.c:494)
==1== by 0x2427A0: unit_file_disable (install.c:1876)
==1== by 0x18A633: method_disable_unit_files_generic (dbus-manager.c:1760)
==1== by 0x18A6CA: method_disable_unit_files (dbus-manager.c:1768)
==1== by 0x1D8146: method_callbacks_run (bus-objects.c:420)
==1== by 0x1DA9D8: object_find_and_run (bus-objects.c:1257)
==1== by 0x1DB01A: bus_process_object (bus-objects.c:1373)
==1==
==1== 228 (48 direct, 180 indirect) bytes in 2 blocks are definitely lost in loss record 8 of 14
==1== at 0x4C2BBCF: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==1== by 0x4C2DE2F: realloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==1== by 0x23DA60: unit_file_changes_add (install.c:233)
==1== by 0x23DDB2: create_symlink (install.c:298)
==1== by 0x240C5C: install_info_symlink_wants (install.c:1328)
==1== by 0x240FC8: install_info_apply (install.c:1384)
==1== by 0x241211: install_context_apply (install.c:1439)
==1== by 0x242563: unit_file_enable (install.c:1830)
==1== by 0x18A06E: method_enable_unit_files_generic (dbus-manager.c:1650)
==1== by 0x18A141: method_enable_unit_files (dbus-manager.c:1660)
==1== by 0x1D8146: method_callbacks_run (bus-objects.c:420)
==1== by 0x1DA9D8: object_find_and_run (bus-objects.c:1257)
==1==
==1== 467 (144 direct, 323 indirect) bytes in 3 blocks are definitely lost in loss record 9 of 14
==1== at 0x4C2DD9F: realloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==1== by 0x23DA60: unit_file_changes_add (install.c:233)
==1== by 0x23DE97: create_symlink (install.c:320)
==1== by 0x242CFC: unit_file_set_default (install.c:1951)
==1== by 0x18A881: method_set_default_target (dbus-manager.c:1802)
==1== by 0x1D8146: method_callbacks_run (bus-objects.c:420)
==1== by 0x1DA9D8: object_find_and_run (bus-objects.c:1257)
==1== by 0x1DB01A: bus_process_object (bus-objects.c:1373)
==1== by 0x259143: process_message (sd-bus.c:2567)
==1== by 0x259326: process_running (sd-bus.c:2609)
==1== by 0x259BDC: bus_process_internal (sd-bus.c:2798)
==1== by 0x259CAD: sd_bus_process (sd-bus.c:2817)
==1==
==1== LEAK SUMMARY:
==1== definitely lost: 216 bytes in 6 blocks
==1== indirectly lost: 560 bytes in 14 blocks
==1== possibly lost: 0 bytes in 0 blocks
==1== still reachable: 65,536 bytes in 5 blocks
==1== suppressed: 0 bytes in 0 blocks
==1== Reachable blocks (those to which a pointer was found) are not shown.
==1== To see them, rerun with: --leak-check=full --show-leak-kinds=all
==1==
Fixes:
==1== HEAP SUMMARY:
==1== in use at exit: 67,182 bytes in 91 blocks
==1== total heap usage: 70,485 allocs, 70,394 frees, 42,184,635 bytes
allocated
==1==
==1== 5,742 (696 direct, 5,046 indirect) bytes in 29 blocks are
definitely lost in loss record 4 of 7
==1== at 0x4C2DD9F: realloc (in
/usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==1== by 0x21ADDD: realloc_multiply (alloc-util.h:67)
==1== by 0x21BFB0: strv_push (strv.c:448)
==1== by 0x21C245: strv_consume (strv.c:520)
==1== by 0x21C33C: strv_extend (strv.c:559)
==1== by 0x278AD7: unit_write_drop_in (unit.c:3352)
==1== by 0x278EEB: unit_write_drop_in_private (unit.c:3403)
==1== by 0x190C21: bus_service_set_transient_property
(dbus-service.c:254)
==1== by 0x190DBC: bus_service_set_property (dbus-service.c:284)
==1== by 0x18F00E: bus_unit_set_properties (dbus-unit.c:1226)
==1== by 0x186F6A: transient_unit_from_message (dbus-manager.c:683)
==1== by 0x1872B7: method_start_transient_unit (dbus-manager.c:763)
==1==
==1== LEAK SUMMARY:
==1== definitely lost: 696 bytes in 29 blocks
==1== indirectly lost: 5,046 bytes in 58 blocks
==1== possibly lost: 0 bytes in 0 blocks
==1== still reachable: 61,440 bytes in 4 blocks
==1== suppressed: 0 bytes in 0 blocks
Franck Bui [Thu, 14 Jan 2016 08:25:18 +0000 (09:25 +0100)]
transaction: downgrade warnings about wanted unit which are not found
If a unit was pulled by a Wants= dependency but its unit file was not
present then we logged this as an error.
However Wants= might be used to configure a soft/optional dependency
on another unit, ie. start an optional service only if it's installed
otherwise simply skip it. In this case emitting an error doesn't look
appropriate.
But it's still an error if the optional dependency exists but its
activation fails for any reasons.