[erlang-patches] [PATCH] Fix SCTP multihoming for IPv6

[Tomas Abrahamsson]

Setting several ip addresses for an SCTP socket worked for IPv4, but
for IPv6 the call to gen_sctp:open/1 failed with badarg.
---
 erts/emulator/drivers/common/inet_drv.c |   12 +++---
 lib/kernel/test/gen_sctp_SUITE.erl      |   64 ++++++++++++++++++++++++++++++-
 2 files changed, 68 insertions(+), 8 deletions(-)

diff --git a/erts/emulator/drivers/common/inet_drv.c b/erts/emulator/drivers/common/inet_drv.c
index eeaa4d2..f712653 100644
--- a/erts/emulator/drivers/common/inet_drv.c
+++ b/erts/emulator/drivers/common/inet_drv.c
@@ -10111,8 +10111,9 @@ static ErlDrvSSizeT packet_inet_ctl(ErlDrvData e, unsigned int cmd, char* buf,
 	    /* Construct the list of addresses we bind to. The curr limit is
 	       256 addrs. Buff structure: Flags(1), ListItem,...:
 	    */
-	    struct sockaddr addrs[256];
+	    inet_address addrs[256];
 	    char* curr;
+	    char* addr_dest;
 	    int   add_flag, n, rflag;
 	    
 	    if (!IS_SCTP(desc))
@@ -10122,6 +10123,7 @@ static ErlDrvSSizeT packet_inet_ctl(ErlDrvData e, unsigned int cmd, char* buf,
 	    add_flag = get_int8(curr);
 	    curr++;
 
+	    addr_dest = (char *)addrs;
 	    for(n=0; n < 256 && curr < buf+len; n++)
 		{
 		    /* List item format: Port(2), IP(4|16) -- compatible with
@@ -10132,16 +10134,14 @@ static ErlDrvSSizeT packet_inet_ctl(ErlDrvData e, unsigned int cmd, char* buf,
 		    if (curr == NULL)
 			return ctl_error(EINVAL, rbuf, rsize);
 
-		    /* Now: we need to squeeze "tmp" into the size of "sockaddr",
-		       which is smaller than "tmp" for IPv6 (extra IN6 info will
-		       be cut off): */
-		    memcpy(addrs + n, &tmp, sizeof(struct sockaddr));
+		    memcpy(addr_dest, &tmp, alen);
+		    addr_dest += alen;
 		}
 	    /* Make the real flags: */
 	    rflag = add_flag ? SCTP_BINDX_ADD_ADDR : SCTP_BINDX_REM_ADDR;
 
 	    /* Invoke the call: */
-	    if (p_sctp_bindx(desc->s, addrs, n, rflag) < 0)
+	    if (p_sctp_bindx(desc->s, (struct sockaddr *)addrs, n, rflag) < 0)
 		return ctl_error(sock_errno(), rbuf, rsize);
 
 	    desc->state = INET_STATE_BOUND;
diff --git a/lib/kernel/test/gen_sctp_SUITE.erl b/lib/kernel/test/gen_sctp_SUITE.erl
index 8f490b6..6d6b154 100644
--- a/lib/kernel/test/gen_sctp_SUITE.erl
+++ b/lib/kernel/test/gen_sctp_SUITE.erl
@@ -31,14 +31,16 @@
    [basic/1,
     api_open_close/1,api_listen/1,api_connect_init/1,api_opts/1,
     xfer_min/1,xfer_active/1,def_sndrcvinfo/1,implicit_inet6/1,
-    basic_stream/1, xfer_stream_min/1, peeloff/1, buffers/1]).
+    basic_stream/1, xfer_stream_min/1, peeloff/1, buffers/1,
+    open_multihoming_ipv4_socket/1, open_multihoming_ipv6_socket/1]).
 
 suite() -> [{ct_hooks,[ts_install_cth]}].
 
 all() -> 
     [basic, api_open_close, api_listen, api_connect_init,
      api_opts, xfer_min, xfer_active, def_sndrcvinfo, implicit_inet6,
-     basic_stream, xfer_stream_min, peeloff, buffers].
+     basic_stream, xfer_stream_min, peeloff, buffers,
+     open_multihoming_ipv4_socket, open_multihoming_ipv6_socket].
 
 groups() -> 
     [].
@@ -1329,3 +1331,61 @@ match_unless_solaris(A, B) ->
 	{unix,sunos} -> B;
 	_ -> A = B
     end.
+
+open_multihoming_ipv4_socket(doc) ->
+    "Test opening a multihoming ipv4 socket";
+open_multihoming_ipv4_socket(suite) ->
+    [];
+open_multihoming_ipv4_socket(Config) when is_list(Config) ->
+    ?line Hostname = ok(inet:gethostname()),
+    ?line HostAddrIPv4 = ok(inet:getaddr(Hostname, inet)),
+    ?line S = ok(gen_sctp:open(0, [{ip,HostAddrIPv4},{ip,{127,0,0,1}}])),
+    ?line ok = gen_sctp:listen(S, true),
+    ?line setup_connection(S, HostAddrIPv4, inet),
+    ?line ok = gen_sctp:close(S).
+
+open_multihoming_ipv6_socket(doc) ->
+    "Test opening a multihoming ipv6 socket";
+open_multihoming_ipv6_socket(suite) ->
+    [];
+open_multihoming_ipv6_socket(Config) when is_list(Config) ->
+    ?line Hostname = ok(inet:gethostname()),
+    ?line LoopbackIPv6 = {0,0,0,0,0,0,0,1},
+    ?line
+	case inet:getaddr(Hostname, inet6) of
+	    {ok,HostAddrIPv6} when HostAddrIPv6 =/= LoopbackIPv6 ->
+		?line
+		    case is_good_ipv6_address(HostAddrIPv6) of
+			true ->
+			    ?line io:format("using ipv6 addresses ~p and ~p~n",
+					    [HostAddrIPv6, LoopbackIPv6]),
+			    ?line S = ok(gen_sctp:open(
+					   0, [{ip,HostAddrIPv6},
+					       {ip,LoopbackIPv6}, inet6])),
+			    ?line ok = gen_sctp:listen(S, true),
+			    ?line setup_connection(S, HostAddrIPv6, inet6),
+			    ?line ok = gen_sctp:close(S);
+			false ->
+			    {skip,"Need 2 good IPv6 addresses"}
+		    end;
+	    {ok,HostAddrIPv6} when HostAddrIPv6 =:= LoopbackIPv6 ->
+		{skip,"Need 2 different IPv6 addresses, found only ::1"};
+	    {error,eafnosupport} ->
+		{skip,"Can not look up IPv6 address"}
+        end.
+
+is_good_ipv6_address({0,0,0,0,0,16#ffff,_,_}) -> false; %% ipv4 mapped
+is_good_ipv6_address({16#fe80,_,_,_,_,_,_,_}) -> false; %% link-local
+is_good_ipv6_address(_)                       -> true.
+
+setup_connection(S1, Addr, IpFamily) ->
+    ?line P1 = ok(inet:port(S1)),
+    ?line S2 = ok(gen_sctp:open(0, [IpFamily])),
+    ?line P2 = ok(inet:port(S2)),
+    ?line #sctp_assoc_change{state=comm_up} =
+	ok(gen_sctp:connect(S2, Addr, P1, [])),
+    ?line case ok(gen_sctp:recv(S1)) of
+	      {Addr,P2,[],#sctp_assoc_change{state=comm_up}} ->
+		  ok
+	  end,
+    ?line ok = gen_sctp:close(S2).
-- 
1.7.5.4