[Asterisk-code-review] chan sip: Resolve externhost not to IPv6; instead go for IPv4. (asterisk[master])

[Anonymous Coward]

Anonymous Coward #1000019 has submitted this change and it was merged.

Change subject: chan_sip: Resolve externhost not to IPv6; instead go for IPv4.
......................................................................


chan_sip: Resolve externhost not to IPv6; instead go for IPv4.

For the channel driver chan_sip, you specify externhost=example.com in sip.conf
when your Asterisk is behind a NAT and your IP address is assigned dynamically.
Or stated differently: You do not have a static IP address to use "externaddr"
directly. This NAT support is quite handy but just about IPv4. Previously,
Asterisk resolved "externhost" to any IP version. When the first DNS answer
resolved to an IPv6, Asterisk sent an IPv6 in SIP/SDP for origin (o=) and
connection (c=). This happened in outgoing SIP-REGISTER and while answering
SIP-INVITE. If the remote peer is IPv4-only, it might not handle o=/c= with an
IPv6. This change makes sure, no IPv6 is resolved anymore for "externhost".

ASTERISK-18232 #close
Reported by: Jacek Kowalski
Tested by: Alexander Traud
patches:
 changes.patch submitted by Alessandro Crespi

Change-Id: If68eedbeff65bd1c1d8a9ed921c02ba464b32dac
---
M channels/chan_sip.c
1 file changed, 2 insertions(+), 2 deletions(-)

Approvals:
  George Joseph: Looks good to me, approved
  Anonymous Coward #1000019: Verified
  Joshua Colp: Looks good to me, but someone else must approve



diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index 08a1680..fadb349 100644
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -3843,7 +3843,7 @@
 	    (!sip_cfg.matchexternaddrlocally || !ast_apply_ha(localaddr, us)) ) {
 		/* if we used externhost, see if it is time to refresh the info */
 		if (externexpire && time(NULL) >= externexpire) {
-			if (ast_sockaddr_resolve_first(&externaddr, externhost, 0)) {
+			if (ast_sockaddr_resolve_first_af(&externaddr, externhost, 0, AST_AF_INET)) {
 				ast_log(LOG_NOTICE, "Warning: Re-lookup of '%s' failed!\n", externhost);
 			}
 			externexpire = time(NULL) + externrefresh;
@@ -32573,7 +32573,7 @@
 			externexpire = 0;
 		} else if (!strcasecmp(v->name, "externhost")) {
 			ast_copy_string(externhost, v->value, sizeof(externhost));
-			if (ast_sockaddr_resolve_first(&externaddr, externhost, 0)) {
+			if (ast_sockaddr_resolve_first_af(&externaddr, externhost, 0, AST_AF_INET)) {
 				ast_log(LOG_WARNING, "Invalid address for externhost keyword: %s\n", externhost);
 			}
 			externexpire = time(NULL);

-- 
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Gerrit-MessageType: merged
Gerrit-Change-Id: If68eedbeff65bd1c1d8a9ed921c02ba464b32dac
Gerrit-PatchSet: 1
Gerrit-Project: asterisk
Gerrit-Branch: master
Gerrit-Owner: Alexander Traud <pabstraud at compuserve.com>
Gerrit-Reviewer: Anonymous Coward #1000019
Gerrit-Reviewer: George Joseph <gjoseph at digium.com>
Gerrit-Reviewer: Joshua Colp <jcolp at digium.com>