If I configure dnsmasq to use dbus and then restart dbus.service with watchers present,
it crashes dnsmasq. The reason is simple, it uses loop to walk over watchers to call
dbus handling code. But from that code the same list can be modified and watchers removed.
But the list iteration continues anyway.
Restart the loop if list were modified.
The code added in6 c596f1cc1d92b2b90ef5ce043ace314eefa868b
fails to free the returned datastructures from gethostinfo()
because sdetails.hostinfo is used to loop through the addresses
and ends up NULL. In some libc implementations this results
in a SEGV when freeaddrinfo() is called.
Also fix FTBFS under BSD. Thanks to Johnny S. Lee for the bug report.
Also Dbus SetDomainServers method.
Revert getaddrinfo hints.ai_socktype to SOCK_DGRAM to eliminate
duplicating every address three times for DGRAM, STREAM and RAW
in the results.
Error: CLANG_WARNING: [#def30]
dnsmasq-2.86test7/src/dbus.c:117:3: warning[deadcode.DeadStores]: Value stored to 'w' is never read
# 115| daemon->watches = w;
# 116|
# 117|-> w = data; /* no warning */
# 118| return TRUE;
# 119| }
Error: CLANG_WARNING: [#def31]
dnsmasq-2.86test7/src/dbus.c:137:3: warning[deadcode.DeadStores]: Value stored to 'w' is never read
# 135| }
# 136|
# 137|-> w = data; /* no warning */
# 138| }
# 139|
Error: CHECKED_RETURN (CWE-252): [#def32]
dnsmasq-2.86test7/src/dbus.c:146: check_return: Calling "dbus_message_iter_init" without checking return value (as is done elsewhere 4 out of 5 times).
dnsmasq-2.86test7/src/dbus.c:460: example_checked: Example 1: "dbus_message_iter_init(message, &iter)" has its value checked in "dbus_message_iter_init(message, &iter)".
dnsmasq-2.86test7/src/dbus.c:573: example_checked: Example 2: "dbus_message_iter_init(message, &iter)" has its value checked in "dbus_message_iter_init(message, &iter)".
dnsmasq-2.86test7/src/dbus.c:257: example_checked: Example 3: "dbus_message_iter_init(message, &iter)" has its value checked in "dbus_message_iter_init(message, &iter)".
dnsmasq-2.86test7/src/dbus.c:427: example_checked: Example 4: "dbus_message_iter_init(message, &iter)" has its value checked in "dbus_message_iter_init(message, &iter)".
# 144| char *domain;
# 145|
# 146|-> dbus_message_iter_init(message, &iter);
# 147|
# 148| mark_servers(SERV_FROM_DBUS);
Error: NEGATIVE_RETURNS (CWE-394): [#def33]
dnsmasq-2.86test7/src/dbus.c:547: negative_return_fn: Function "parse_hex((char *)hwaddr, dhcp_chaddr, 16, NULL, &hw_type)" returns a negative number.
dnsmasq-2.86test7/src/dbus.c:547: assign: Assigning: "hw_len" = "parse_hex((char *)hwaddr, dhcp_chaddr, 16, NULL, &hw_type)".
dnsmasq-2.86test7/src/dbus.c:551: negative_returns: "hw_len" is passed to a parameter that cannot be negative.
# 549| hw_type = ARPHRD_ETHER;
# 550|
# 551|-> lease_set_hwaddr(lease, dhcp_chaddr, clid, hw_len, hw_type,
# 552| clid_len, now, 0);
# 553| lease_set_expires(lease, expires, now);
Error: CLANG_WARNING: [#def34]
dnsmasq-2.86test7/src/dbus.c:722:3: warning[deadcode.DeadStores]: Value stored to 'method' is never read
# 720| clear_cache_and_reload(dnsmasq_time());
# 721|
# 722|-> method = user_data; /* no warning */
# 723|
# 724| /* If no reply or no error, return nothing */
This should be largely transparent, but it drastically
improves performance and reduces memory foot-print when
configuring large numbers domains of the form
local=/adserver.com/
or
local=/adserver.com/#
Lookup times now grow as log-to-base-2 of the number of domains,
rather than greater than linearly, as before.
The change makes multiple addresses associated with a domain work
address=/example.com/1.2.3.4
address=/example.com/5.6.7.8
It also handles multiple upstream servers for a domain better; using
the same try/retry alogrithms as non domain-specific servers. This
also applies to DNSSEC-generated queries.
Finally, some of the oldest and gnarliest code in dnsmasq has had
a significant clean-up. It's far from perfect, but it _is_ better.
This was the source of a large number of #ifdefs, originally
included for use with old embedded libc versions. I'm
sure no-one wants or needs IPv6-free code these days, so this
is a move towards more maintainable code.
