conf, pasta: With --config-net, copy all addresses by default

Use the newly-introduced NL_DUP mode for nl_addr() to copy all the
addresses associated to the template interface in the outer
namespace, unless --no-copy-addrs (also implied by -a) is given.

This option is introduced as deprecated right away: it's not expected
to be of any use, but it's helpful to keep it around for a while to
debug any suspected issue with this change.

This is done mostly for consistency with routes. It might partially
cover the issue at:
  https://bugs.passt.top/show_bug.cgi?id=47
  Support multiple addresses per address family

for some use cases, but not the originally intended one: we'll still
use a single outbound address (unless the routing table specifies
different preferred source addresses depending on the destination),
regardless of the address used in the target namespace.

Link: https://bugs.passt.top/show_bug.cgi?id=47
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>

1 files changed, 16 insertions, 2 deletions

diff --git a/conf.c b/conf.c
index cb1e09a..d8414fe 100644
--- a/conf.c
+++ b/conf.c
@@ -902,6 +902,8 @@ pasta_opts:
 	info(   "  --config-net		Configure tap interface in namespace");
 	info(   "  --no-copy-routes	DEPRECATED:");
 	info(   "			Don't copy all routes to namespace");
+	info(   "  --no-copy-addrs	DEPRECATED:");
+	info(   "			Don't copy all addresses to namespace");
 	info(   "  --ns-mac-addr ADDR	Set MAC address on tap interface");
 
 	exit(EXIT_FAILURE);
@@ -1178,6 +1180,7 @@ void conf(struct ctx *c, int argc, char **argv)
 		{"outbound-if6", required_argument,	NULL,		16 },
 		{"config-net",	no_argument,		NULL,		17 },
 		{"no-copy-routes", no_argument,		NULL,		18 },
+		{"no-copy-addrs", no_argument,		NULL,		19 },
 		{ 0 },
 	};
 	struct get_bound_ports_ns_arg ns_ports_arg = { .c = c };
@@ -1349,6 +1352,13 @@ void conf(struct ctx *c, int argc, char **argv)
 			warn("--no-copy-routes will be dropped soon");
 			c->no_copy_routes = 1;
 			break;
+		case 19:
+			if (c->mode != MODE_PASTA)
+				die("--no-copy-addrs is for pasta mode only");
+
+			warn("--no-copy-addrs will be dropped soon");
+			c->no_copy_addrs = 1;
+			break;
 		case 'd':
 			if (c->debug)
 				die("Multiple --debug options given");
@@ -1634,8 +1644,12 @@ void conf(struct ctx *c, int argc, char **argv)
 	if (*c->sock_path && c->fd_tap >= 0)
 		die("Options --socket and --fd are mutually exclusive");
 
-	if (c->mode == MODE_PASTA && c->no_copy_routes && !c->pasta_conf_ns)
-		die("Option --no-copy-routes needs --config-net");
+	if (c->mode == MODE_PASTA && !c->pasta_conf_ns) {
+		if (c->no_copy_routes)
+			die("Option --no-copy-routes needs --config-net");
+		if (c->no_copy_addrs)
+			die("Option --no-copy-addrs needs --config-net");
+	}
 
 	if (!ifi4 && *c->ip4.ifname_out)
 		ifi4 = if_nametoindex(c->ip4.ifname_out);