Vito Caputo [Mon, 7 Dec 2015 19:28:18 +0000 (11:28 -0800)]
sd-event: instrument sd_event_run() for profiling delays
Set SD_EVENT_PROFILE_DELAYS to activate accounting and periodic logging
of the distribution of delays between sd_event_run() calls.
Time spent in dispatching as well as time spent outside of
sd_event_run() is measured and accounted for. Every 5 seconds a
logarithmic histogram loop iteration delays since 5 seconds previous is
logged.
This is useful in identifying the frequency and magnitude of latencies
affecting the event loop, which should be kept to a minimum.
Ismo Puustinen [Thu, 31 Dec 2015 12:54:44 +0000 (14:54 +0200)]
capabilities: added support for ambient capabilities.
This patch adds support for ambient capabilities in service files. The
idea with ambient capabilities is that the execed processes can run with
non-root user and get some inherited capabilities, without having any
need to add the capabilities to the executable file.
You need at least Linux 4.3 to use ambient capabilities. SecureBit
keep-caps is automatically added when you use ambient capabilities and
wish to change the user.
An example system service file might look like this:
Ismo Puustinen [Thu, 7 Jan 2016 22:00:04 +0000 (00:00 +0200)]
capabilities: keep bounding set in non-inverted format.
Change the capability bounding set parser and logic so that the bounding
set is kept as a positive set internally. This means that the set
reflects those capabilities that we want to keep instead of drop.
Fix miscalculated buffer size and uses of size-unlimited sprintf()
function.
Not sure if this results in an exploitable buffer overflow, probably not
since the the int value is likely sanitized somewhere earlier and it's
being put through a bit mask shortly before being used.
resolved: refuse doing queries for known-obsolete RR types
Given how fragile DNS servers are with some DNS types, and given that we really should avoid confusing them with
known-weird lookups, refuse doing lookups for known-obsolete RR types.
resolved: rework how and when we detect whether our chosen DNS server knows DNSSEC
Move detection into a set of new functions, that check whether one specific server can do DNSSEC, whether a server and
a specific transaction can do DNSSEC, or whether a transaction and all its auxiliary transactions could do so.
Also, do these checks both before we acquire additional RRs for the validation (so that we can skip them if the server
doesn't do DNSSEC anyway), and after we acquired them all (to see if any of the lookups changed our opinion about the
servers).
THis also tightens the checks a bit: a server that lacks TCP support is considered incompatible with DNSSEC too.
This changes the DnsServer logic to count failed UDP and TCP failures separately. This is useful so that we don't end
up downgrading the feature level from one UDP level to a lower UDP level just because a TCP connection we did because
of a TC response failed.
This also adds accounting of truncated packets. If we detect incoming truncated packets, and count too many failed TCP
connections (which is the normal fall back if we get a trucnated UDP packet) we downgrade the feature level, given that
the responses at the current levels don't get through, and we somehow need to make sure they become smaller, which they
will do if we don't request DNSSEC or EDNS support.
This makes resolved work much better with crappy DNS servers that do not implement TCP and only limited UDP packet
sizes, but otherwise support DNSSEC RRs. They end up choking on the generally larger DNSSEC RRs and there's no way to
retrieve the full data.
resolved: don't attempt to send queries for DNSSEC RR types to servers not supporting them
If we already degraded the feature level below DO don't bother with sending requests for DS, DNSKEY, RRSIG, NSEC, NSEC3
or NSEC3PARAM RRs. After all, we cannot do DNSSEC validation then anyway, and we better not press a legacy server like
this with such modern concepts.
This also has the benefit that when we try to validate a response we received using DNSSEC, and we detect a limited
server support level while doing so, all further auxiliary DNSSEC queries will fail right-away.
resolved: when we get a packet failure from a server, don't downgrade UDP to TCP or vice versa
Under the assumption that packet failures (i.e. FORMERR, SERVFAIL, NOTIMP) are caused by packet contents, not used
transport, we shouldn't switch between UDP and TCP when we get them, but only downgrade the higher levels down to UDP.
resolved: properly handle UDP ICMP errors as lost packets
UDP ICMP errors are reported to us via recvmsg() when we read a reply. Handle this properly, and consider this a lost
packet, and retry the connection.
This also adds some additional logging for invalid incoming packets.
resolved: when we get a TCP connection failure, try again
Previously, when we couldn't connect to a DNS server via TCP we'd abort the whole transaction using a
"connection-failure" state. This change removes that, and counts failed connections as "lost packet" events, so that
we switch back to the UDP protocol again.
resolved: when DNS/TCP doesn't work, try DNS/UDP again
If we failed to contact a DNS server via TCP, bump of the feature level to UDP again. This way we'll switch back
between UDP and TCP if we fail to contact a host.
Generally, we prefer UDP over TCP, which is why UDP is a higher feature level. But some servers only support UDP but
not TCP hence when reaching the lowest feature level of TCP and want to downgrade from there, pick UDP again. We this
keep downgrading until we reach TCP and then we cycle through UDP and TCP.
Let's be a bit more precise with the editor configuration and specify a higher fill column of 119. This isn't as emacs'
default of 70, but also not particularly high on today's screens.
While we are at it, also set a couple of other emacs C coding style variables.
resolved: properly look for NSEC/NSEC3 RRs when getting a positive wildcard response
This implements RFC 5155, Section 8.8 and RFC 4035, Section 5.3.4:
When we receive a response with an RRset generated from a wildcard we
need to look for one NSEC/NSEC3 RR that proves that there's no explicit RR
around before we accept the wildcard RRset as response.
This patch does a couple of things: the validation calls will now
identify wildcard signatures for us, and let us know the RRSIG used (so
that the RRSIG's signer field let's us know what the wildcard was that
generate the entry). Moreover, when iterating trough the RRsets of a
response we now employ three phases instead of just two.
a) in the first phase we only look for DNSKEYs RRs
b) in the second phase we only look for NSEC RRs
c) in the third phase we look for all kinds of RRs
Phase a) is necessary, since DNSKEYs "unlock" more signatures for us,
hence we shouldn't assume a key is missing until all DNSKEY RRs have
been processed.
Phase b) is necessary since NSECs need to be validated before we can
validate wildcard RRs due to the logic explained above.
Phase c) validates everything else. This phase also handles RRsets that
cannot be fully validated and removes them or lets the transaction fail.
resolved: split up nsec3_hashed_domain() into two calls
There's now nsec3_hashed_domain_format() and nsec3_hashed_domain_make().
The former takes a hash value and formats it as domain, the latter takes
a domain name, hashes it and then invokes nsec3_hashed_domain_format().
This way we can reuse more code, as the formatting logic can be unified
between this call and another place.
resolved: when validating, first strip revoked trust anchor keys from validated keys list
When validating a transaction we initially collect DNSKEY, DS, SOA RRs
in the "validated_keys" list, that we need for the proofs. This includes
DNSKEY and DS data from our trust anchor database. Quite possibly we
learn that some of these DNSKEY/DS RRs have been revoked between the
time we request and collect those additional RRs and we begin the
validation step. In this case we need to make sure that the respective
DS/DNSKEY RRs are removed again from our list. This patch adds that, and
strips known revoked trust anchor RRs from the validated list before we
begin the actual validation proof, and each time we add more DNSKEY
material to it while we are doing the proof.
Instead of first iterating through all DNSKEYs in the DnsAnswer in
dns_transaction_check_revoked_trust_anchors(), and
then doing that a second time in dns_trust_anchor_check_revoked(), do so
only once in the former, and pass the dnskey we found directly to the
latter.
resolved: look for revoked trust anchors before validating a message
There's not reason to wait for checking for revoked trust anchors until
after validation, after all revoked DNSKEYs only need to be self-signed,
but not have a full trust chain.
This way, we can be sure that all trust anchor lookups we do during
validation already honour that some keys might have been revoked.
The domain name for this NSEC3 RR was originally stored in a variable
called "suffix", which was then renamed to "zone" in d1511b3338f431de3c95a50a9c1aca297e0c0734. Hence also rename the
RR variable accordingly.
Daniel Mack [Sun, 10 Jan 2016 17:11:22 +0000 (18:11 +0100)]
macro.h: provide a switch-case statement generator for IN_SET
Rather than walking a list of valid values one-by-one, generate a
switch-case statement for the IN_SET() macro. This allows the compiler to
further optimize its code output, possibly by generating jump tables.
This effectively decreases the binary size slightly.
The implementation is based on macro overloading depending on the number of
arguments. h/t to the following post:
Casey Schaufler [Fri, 8 Nov 2013 17:42:26 +0000 (09:42 -0800)]
smack: Handling network
- Set Smack ambient to match run label
- Set Smack netlabel host rules
Set Smack ambient to match run label
------------------------------------
Set the Smack networking ambient label to match the
run label of systemd. System services may expect to
communicate with external services over IP. Setting
the ambient label assigns that label to IP packets
that do not include CIPSO headers. This allows systemd
and the services it spawns access to unlabeled IP
packets, and hence external services.
A system may choose to restrict network access to
particular services later in the startup process.
This is easily done by resetting the ambient label
elsewhere.
Set Smack netlabel host rules
-----------------------------
If SMACK_RUN_LABEL is defined set all other hosts to be
single label hosts at the specified label. Set the loopback
address to be a CIPSO host.
If any netlabel host rules are defined in /etc/smack/netlabel.d
install them into the smackfs netlabel interface.
[Patrick Ohly: copied from https://review.tizen.org/git/?p=platform/upstream/systemd.git;a=commit;h=db4f6c9a074644aa2bf]
[Patrick Ohly: adapt to write_string_file() change in "fileio: consolidate write_string_file*()"]
[Patrick Ohly: create write_netlabel_rules() based on the original write_rules() that was removed in "smack: support smack access change-rule"]
[Patrick Ohly: adapted to upstream code review feedback: error logging, string constants]
Vito Caputo [Fri, 8 Jan 2016 20:11:44 +0000 (12:11 -0800)]
journal: normalize priority of logging sources
The stream event source has a priority of SD_EVENT_PRIORITY_NORMAL+5,
and stdout source +10, but the native and syslog event sources are left
at the default of 0.
As a result, any heavy native or syslog logger can cause starvation of
the other loggers. This is trivially demonstrated by running:
Hui Wang [Wed, 6 Jan 2016 02:37:53 +0000 (10:37 +0800)]
keymap: remap microphone mute keycode for Lenovo Thinkcentre M800z
This Lenovo machine use codec Line2 to implement a microphone mute
button, it depends on the unsolicited interrupt to generate key event,
the scan code for this button is assigned to 0x00 in the linux kernel
driver, and the keycode is KEY_MICMUTE(248), we need to remap this
keycode to KEY_F20 to make this hotkey work in X11.
resolved: populate negative trust anchor by default
Let's increase compatibility with many private domains by default, and
ship a default NTA list of wel-known private domains, where it is
unlikely they will be deployed as official TLD anytime soon.
projects / thirdparty / systemd.git / log
