Bug#881362: libpjlib-util2: resolution of DNS SRV targets fails if target has no AAAA record

[Joachim Förster]

Package: libpjlib-util2
Version: 2.5.5~dfsg-6
Severity: important
Tags: patch upstream


While trying to use Asterisk with its newer PJSIP-based SIP channel 
support, it turned out that registering to a SIP server fails if the SRV 
targets do not have an AAAA record, but only an A record.

The effect, which can be seen via Wireshark, is that essentially no SIP 
registration is taking place at all, after all necessary DNS requests 
have been sent out. Asterisk then just says:

No response received from 'sip:xxx' on registration attempt to 
'sip:xxx at xxx', retrying in '30'

After some debugging it became clear, that the DNS resolution is 
successful as far as resolving the A records of the SRV targets. However 
in case a SIP server does not have an AAAA record, libpjlib-util2 
skips/aborts the whole resolution and treats it as failed, no matter if 
an A record has been found or not.

Applying upstream's GitHub commit 4ab1838 (part of pjproject 2.6) onto 
Debian stable's version 2.5.5 solves the problem.

https://github.com/pjsip/pjproject/commit/4ab1838

Conclusion: Please apply the mentioned patch and release a new stable 
version.


-- System Information:
Debian Release: 9.2
   APT prefers stable-updates
   APT policy: (500, 'stable-updates'), (500, 'stable')
Architecture: amd64 (x86_64)

Kernel: Linux 4.9.0-4-amd64 (SMP w/1 CPU core)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), 
LANGUAGE=en_US:en (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages libpjlib-util2 depends on:
ii  libavcodec57        7:3.2.8-1~deb9u1
ii  libavdevice57       7:3.2.8-1~deb9u1
ii  libavformat57       7:3.2.8-1~deb9u1
ii  libavutil55         7:3.2.8-1~deb9u1
ii  libc6               2.24-11+deb9u1
ii  libopencore-amrnb0  0.1.3-2.1+b2
ii  libpj2              2.5.5~dfsg-6
ii  libsdl2-2.0-0       2.0.5+dfsg1-2
ii  libswscale4         7:3.2.8-1~deb9u1
ii  libv4l-0            1.12.3-1

libpjlib-util2 recommends no packages.

libpjlib-util2 suggests no packages.

-- no debconf information