In order to optionally take advantage of new features in dnsmasq when
the host's version of dnsmasq supports them, but still be able to run
on hosts that don't support the new features, we need to be able to
detect the version of dnsmasq running on the host, and possibly
determine from the help output what options are in this dnsmasq.
This patch implements a greatly simplified version of the capabilities
code we already have for qemu. A dnsmasqCaps device can be created and
populated either from running a program on disk, reading a file with
the concatenated output of "dnsmasq --version; dnsmasq --help", or
examining a buffer in memory that contains the concatenated output of
those two commands. Simple functions to retrieve capabilities flags,
the version number, and the path of the binary are also included.
bridge_driver.c creates a single dnsmasqCaps object at driver startup,
and disposes of it at driver shutdown. Any time it must be used, the
dnsmasqCapsRefresh method is called - it checks the mtime of the
binary, and re-runs the checks if the binary has changed.
networkxml2argvtest.c creates 2 "artificial" dnsmasqCaps objects at
startup - one "restricted" (doesn't support --bind-dynamic) and one
"full" (does support --bind-dynamic). Some of the test cases use one
and some the other, to make sure both code pathes are tested.
This bug resolves https://bugzilla.redhat.com/show_bug.cgi?id=810100
rpm builds for i686 were failing with a segfault in
networkxml2argvtest. Running under valgrind showed that a region of
memory was being referenced after it had been freed (as the result of
realloc - see the valgrind report in the BZ).
The problem (in replaceTokens() - added in commit 22ec60, meaning this
bug was in 0.9.10 and 0.9.11) was that the pointers token_start and
token_end were being computed based on the value of *buf, then *buf
was being realloc'ed (potentially moving it), then token_start and
token_end were used without recomputing them to account for movement
of *buf.
The solution is to change the code so that token_start and token_end
are offsets into *buf rather than pointers. This way there is only a
single pointer to the buffer, and nothing needs readjusting after a
realloc. (You may note that some uses of token_start/token_end didn't
need to be changed to add in "*buf +" - that's because there ended up
being a +*buf and -*buf which canceled each other out).
DV gets the credit for finding this bug and pointing out the valgrind
report.
Return statements with parameter enclosed in parentheses were modified
and parentheses were removed. The whole change was scripted, here is how:
List of files was obtained using this command:
git grep -l -e '\<return\s*([^()]*\(([^()]*)[^()]*\)*)\s*;' | \
grep -e '\.[ch]$' -e '\.py$'
Found files were modified with this command:
sed -i -e \
's_^\(.*\<return\)\s*(\(\([^()]*([^()]*)[^()]*\)*\))\s*\(;.*$\)_\1 \2\4_' \
-e 's_^\(.*\<return\)\s*(\([^()]*\))\s*\(;.*$\)_\1 \2\3_'
Then checked for nonsense.
The whole command looks like this:
git grep -l -e '\<return\s*([^()]*\(([^()]*)[^()]*\)*)\s*;' | \
grep -e '\.[ch]$' -e '\.py$' | xargs sed -i -e \
's_^\(.*\<return\)\s*(\(\([^()]*([^()]*)[^()]*\)*\))\s*\(;.*$\)_\1 \2\4_' \
-e 's_^\(.*\<return\)\s*(\([^()]*\))\s*\(;.*$\)_\1 \2\3_'
The path to the dnsmasq binary can be configured while in the test data
the path is hard-coded to /usr/bin/. This break the test suite if a the
binary is located in a different location, like /usr/local/sbin/.
Replace the hard coded path in the test data by a token, which is
dynamically replaced in networkxml2argvtest with the configured path
after the test data has been loaded.
(Another option would have been to modify configure.ac to generate the
test data during configure, but I do not know of an easy way do trick
configure into mass-generate those test files without listing every
single one, which I consider less flexible.)
- unit-test the unit-test:
#include <assert.h>
#define TEST(in,token,rep,out) { char *buf = strdup(in); assert(!replaceTokens(&buf, token, rep) && !strcmp(buf, out)); free(buf); }
TEST("", "AA", "B", "");
TEST("A", "AA", "B", "A");
TEST("AA", "AA", "B", "B");
TEST("AAA", "AA", "B", "BA");
TEST("AA", "AA", "BB", "BB");
TEST("AA", "AA", "BBB", "BBB");
TEST("<AA", "AA", "B", "<B");
TEST("<AA", "AA", "BB", "<BB");
TEST("<AA", "AA", "BBB", "<BBB");
TEST("AA>", "AA", "B", "B>");
TEST("AA>", "AA", "BB", "BB>");
TEST("AA>", "AA", "BBB", "BBB>");
TEST("<AA>", "AA", "B", "<B>");
TEST("<AA>", "AA", "BB", "<BB>");
TEST("<AA>", "AA", "BBB", "<BBB>");
TEST("<AA|AA>", "AA", "B", "<B|B>");
TEST("<AA|AA>", "AA", "BB", "<BB|BB>");
TEST("<AA|AA>", "AA", "BBB", "<BBB|BBB>");
TEST("<AAAA>", "AA", "B", "<BB>");
TEST("<AAAA>", "AA", "BB", "<BBBB>");
TEST("<AAAA>", "AA", "BBB", "<BBBBBB>");
TEST("AAAA>", "AA", "B", "BB>");
TEST("AAAA>", "AA", "BB", "BBBB>");
TEST("AAAA>", "AA", "BBB", "BBBBBB>");
TEST("<AAAA", "AA", "B", "<BB");
TEST("<AAAA", "AA", "BB", "<BBBB");
TEST("<AAAA", "AA", "BBB", "<BBBBBB");
alarm(1); /* no infinite loop */
TEST("A", "A", "A", "A");
TEST("AA", "A", "A", "AA");
alarm(0);
Signed-off-by: Philipp Hahn <hahn@univention.de>
Hi,
this is the fifth version of my SRV record for DNSMasq patch rebased
for the current codebase to the bridge driver and libvirt XML file to
include support for the SRV records in the DNS. The syntax is based on
DNSMasq man page and tests for both xml2xml and xml2argv were added as
well. There are some things written a better way in comparison with
version 4, mainly there's no hack in tests/networkxml2argvtest.c and
also the xPath context is changed to use a simpler query using the
virXPathInt() function relative to the current node.
Also, the patch is also fixing the networkxml2argv test to pass both
checks, i.e. both unit tests and also syntax check.
Please review,
Michal
Signed-off-by: Michal Novotny <minovotn@redhat.com>
networkSaveDnsmasqHostsfile was added in 8fa9c22142 (Apr 2010).
It has a force flag. If the dnsmasq hostsfile already exists force
needs to be true to overwrite it. networkBuildDnsmasqArgv sets force
to false, networkDefine sets it to true. This results in the
hostsfile being written only in networkDefine in the common case.
If no error occurred networkSaveDnsmasqHostsfile returns true and
networkBuildDnsmasqArgv adds the --dhcp-hostsfile to the dnsmasq
command line.
networkSaveDnsmasqHostsfile was changed in 89ae9849f7 (24 Jun 2011)
to return a new dnsmasqContext instead of reusing one. This change broke
the logic of the force flag as now networkSaveDnsmasqHostsfile returns
NULL on error, but the early return -- if force was not set and the
hostsfile exists -- returns 0. This turned the early return in an error
case and networkBuildDnsmasqArgv didn't add the --dhcp-hostsfile option
anymore if the hostsfile already exists. It did because networkDefine
created the hostsfile already.
Then 9d4e2845d4 fixed the return 0 case in networkSaveDnsmasqHostsfile
but didn't apply the force option correctly to the new addnhosts file.
Now force doesn't control an early return anymore, but influences the
handling of the hostsfile context creation and dnsmasqSave is always
called now. This commit also added test cases that reveal several
problems. First, the tests now calls functions that try to write the
dnsmasq config files to disk. If someone runs this tests as root this
might overwrite actively used dnsmasq config files, this is a no-go. Also
the tests depend on configure --localstatedir, this needs to be fixed as
well, because it makes the tests fail when localstatedir is different
from /var.
This patch does several things to fix this:
1) Move dnsmasqContext creation and saving out of networkBuildDnsmasqArgv
to the caller to separate the command line generation from the config
file writing. This makes the command line generation testable without the
risk of interfering with system files, because the tests just don't call
dnsmasqSave.
2) This refactoring of networkSaveDnsmasqHostsfile makes the force flag
useless as the saving happens somewhere else now. This fixes the wrong
usage of the force flag in combination with then newly added addnhosts
file by removing the force flag.
3) Adapt the wrong test cases to the correct behavior, by adding the
missing --dhcp-hostsfile option. Both affected tests contain DHCP host
elements but missed the necessary --dhcp-hostsfile option.
4) Rename networkSaveDnsmasqHostsfile to networkBuildDnsmasqHostsfile,
because it doesn't save the dnsmasqContext anymore.
5) Move all directory creations in dnsmasq context handling code from
the *New functions to dnsmasqSave to avoid directory creations in system
paths in the test cases.
6) Now that networkBuildDnsmasqArgv doesn't create the dnsmasqContext
anymore the test case can create one with the localstatedir that is
expected by the tests instead of the configure --localstatedir given one.
Convert networkDnsmasqLeaseFileName to a replaceable function pointer
that allow the testsuite to use a version of that function that is not
depending on configure --localstatedir.
This fixes 5 of 6 test failures, when configure --localstatedir isn't
set to /var.
This commit introduces names definition for the DNS hosts file using
the following syntax:
<dns>
<host ip="192.168.1.1">
<name>alias1</name>
<name>alias2</name>
</host>
</dns>
Some of the improvements and fixes were done by Laine Stump so
I'm putting him into the SOB clause again ;-)
Signed-off-by: Michal Novotny <minovotn@redhat.com>
Signed-off-by: Laine Stump <laine@laine.org>
The regression testing done by comparison of command-line
generated from the network XML file and the expected
command-line arguments (read from file).
Signed-off-by: Michal Novotny <minovotn@redhat.com>
