In BIND 9.11 and earlier, dig and similar tools used liblwres for
parsing /etc/resolv.conf. After getting a list of servers from
liblwres, a tool would check the address family of each server found and
reject those unusable. When the resulting list of usable servers was
empty, localhost addresses were queried as a fallback.
When liblwres was removed in BIND 9.12, dig and similar tools were
updated to parse /etc/resolv.conf using libirs instead. As part of that
process, the localhost fallback was removed from bin/dig/dighost.c since
the localhost fallback built into libirs was deemed to be sufficient.
However, libirs only falls back to localhost if it does not find any
name servers at all; if it does find any valid nameserver entry in
/etc/resolv.conf, it just returns it to the caller because it is
oblivious to whether the caller supports IPv4 and/or IPv6 or not. The
code in bin/dig/dighost.c subsequently filters the returned list of
servers in get_server_list() according to the requested address family
restrictions. This may result in none of the addresses returned by
libirs being usable, in which case a tool will attempt to work with an
empty server list, causing a hang and subsequently a crash upon user
interruption.
Restore the localhost fallback in bin/dig/dighost.c to prevent the
aforementioned hangs and crashes and ensure recent BIND versions behave
identically to the older ones in the circumstances described above.
(cherry picked from commit 18758392da)
If a tool using the routines defined in bin/dig/dighost.c is sent an
interruption signal around the time a connection timeout is scheduled to
fire, connect_timeout() may be executed after destroy_libs() detaches
from the global task (setting 'global_task' to NULL), which results in a
crash upon a UDP retry due to bringup_timer() attempting to create a
timer with 'task' set to NULL. Fix by preventing connect_timeout() from
attempting a retry when shutdown is in progress.
(cherry picked from commit 4621756596)
While implementing the new unit testing framework cmocka, it was found that the
BIND 9 code doesn't compile when assertions are disabled or replaced with any
function (such as mock_assert() from cmocka unit testing framework) that's not
directly recognized as assertion by the compiler.
This made the compiler to complain about blocks of code that was recognized as
unreachable before, but now it isn't.
The changes in this commit include:
* assigns default values to couple of local variables,
* moves some return statements around INSIST assertions,
* adds __builtin_unreachable(); annotations after some INSIST assertions,
* fixes one broken assertion (= instead of ==)
(cherry picked from commit fbd2e47f51)
The "exitcode" variable is set to 9 if a TCP connection fails, but is
not reset to 0 if a subsequent TCP connection succeeds. This causes dig
to return a non-zero exit code if it succeeds in getting a TCP response
after a retry. Fix by resetting "exitcode" to 0 if connect_done()
receives an event with the "result" field set to ISC_R_SUCCESS.
(cherry picked from commit deb3b85cb2)
Make will choose modified manual from build directory or original from source
directory automagically. Take advantage of install tool feature.
Install all files in single command instead of iterating on each of them.
(cherry picked from commit 88f913ac81)
While idn2_to_unicode_8zlz() takes a 'flags' argument, it is ignored and
thus cannot be used to perform IDN checks on the output string.
The bug in libidn2 versions before 2.0.5 was not that a call to
idn2_to_unicode_8zlz() with certain flags set did not cause IDN checks
to be performed. The bug was that idn2_to_unicode_8zlz() did not check
whether a conversion can be performed between UTF-8 and the current
locale's character encoding. In other words, with libidn2 version
2.0.5+, if the current locale's character encoding is ASCII, then
idn2_to_unicode_8zlz() will fail when it is passed any Punycode string
which decodes to a non-ASCII string, even if it is a valid IDNA2008
name.
Rework idn_ace_to_locale() so that invalid IDNA2008 names are properly
and consistently detected for all libidn2 versions and locales.
Update the "idna" system test accordingly. Add checks for processing a
server response containing Punycode which decodes to an invalid IDNA2008
name. Fix invalid subtest description.
(cherry picked from commit b896fc4972)
Replace dns_fixedname_init() calls followed by dns_fixedname_name()
calls with calls to dns_fixedname_initname() where it is possible
without affecting current behavior and/or performance.
This patch was mostly prepared using Coccinelle and the following
semantic patch:
@@
expression fixedname, name;
@@
- dns_fixedname_init(&fixedname);
...
- name = dns_fixedname_name(&fixedname);
+ name = dns_fixedname_initname(&fixedname);
The resulting set of changes was then manually reviewed to exclude false
positives and apply minor tweaks.
It is likely that more occurrences of this pattern can be refactored in
an identical way. This commit only takes care of the low-hanging fruit.
(cherry picked from commit 4df4a8e731)
Emit fatal failures on locale to ACE encoding
Separate idnout support, disable it for libidn2 < 2.0
Add custom path to libidn. Leave default path for multilib support.
Allow turning off IDN input processing by dig option
Improve documentation, fix support in host
Fix configure changes to adjust help text
Use strlcpy with size guard
Improve IDN variants choosing. Fix idn2 function name.
Remove immediate idn_locale_to_ace and idn_ace_to_locale.
Signed-off-by: Petr Menšík <pemensik@redhat.com>
(cherry picked from commit 94757c1545)
Added two new configure options:
--with-libidn2 - to enable IDN using GNU libidn2
idnkit, libidn and libidn2 support can not be used at the same time.
NOTE: libidn2 does not support punycode back to Unicode
characters, so support for this is missing.
Signed-off-by: Tomas Hozza <thozza@redhat.com>
Removed iconv, convert directly from locale to ACE
Fix libidn2 and idnkit origin appending
Make IDN options in help less different
Signed-off-by: Petr Menšík <pemensik@redhat.com>
(cherry picked from commit 505f673451)
Added new configure option:
--with-libidn - to enable IDN using GNU libidn
Renamed configure option:
--with-idn to --with-idnkit to make the option usage more clear
idnkit and libidn support can not be used at the same time.
Signed-off-by: Tomas Hozza <thozza@redhat.com>
(cherry picked from commit 2320443f63)
4756. [bug] Interrupting dig could lead to an INSIST failure after
certain errors were encountered while querying a host
whose name resolved to more than one address. Change
4537 increased the odds of triggering this issue by
causing dig to hang indefinitely when certain error
paths were evaluated. dig now also retries TCP queries
(once) if the server gracefully closes the connection
before sending a response. [RT #42832, #45159]
