[PATCH v3 06/10] Revert "conf: Adjust netmask on mismatch between IPv4 address/netmask and gateway"

[Stefano Brivio <sbrivio@redhat.com>]

This reverts commit 7656a6f8888237b9e23d63666e921528b6aaf950: now, by
default, we copy all the routes associated to the outbound interface
into the routing table of the container, so there's no need for this
horrible workaround anymore.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
---
 conf.c | 25 +------------------------
 1 file changed, 1 insertion(+), 24 deletions(-)

diff --git a/conf.c b/conf.c
index 0a01983..d3d58a7 100644
--- a/conf.c
+++ b/conf.c
@@ -634,9 +634,6 @@ static int conf_ip4_prefix(const char *arg)
 static unsigned int conf_ip4(unsigned int ifi,
 			     struct ip4_ctx *ip4, unsigned char *mac)
 {
-	in_addr_t addr, gw;
-	int shift;
-
 	if (!ifi)
 		ifi = nl_get_ext_if(AF_INET);
 
@@ -651,10 +648,8 @@ static unsigned int conf_ip4(unsigned int ifi,
 	if (IN4_IS_ADDR_UNSPECIFIED(&ip4->addr))
 		nl_addr(0, ifi, AF_INET, &ip4->addr, &ip4->prefix_len, NULL);
 
-	addr = ntohl(ip4->addr.s_addr);
-	gw = ntohl(ip4->gw.s_addr);
-
 	if (!ip4->prefix_len) {
+		in_addr_t addr = ntohl(ip4->addr.s_addr);
 		if (IN_CLASSA(addr))
 			ip4->prefix_len = (32 - IN_CLASSA_NSHIFT);
 		else if (IN_CLASSB(addr))
@@ -665,24 +660,6 @@ static unsigned int conf_ip4(unsigned int ifi,
 			ip4->prefix_len = 32;
 	}
 
-	/* We might get an address with a netmask that makes the default
-	 * gateway unreachable, and in that case we would fail to configure
-	 * the default route, with --config-net, or presumably a DHCP client
-	 * in the guest or container would face the same issue.
-	 *
-	 * The host might have another route, to the default gateway itself,
-	 * fixing the situation, but we only read default routes.
-	 *
-	 * Fix up the mask to allow reaching the default gateway from our
-	 * configured address, if needed, and only if we find a non-zero
-	 * mask that makes the gateway reachable.
-	 */
-	shift = 32 - ip4->prefix_len;
-	while (shift < 32 && addr >> shift != gw >> shift)
-		shift++;
-	if (shift < 32)
-		ip4->prefix_len = 32 - shift;
-
 	memcpy(&ip4->addr_seen, &ip4->addr, sizeof(ip4->addr_seen));
 
 	if (MAC_IS_ZERO(mac))
-- 
@@ -634,9 +634,6 @@ static int conf_ip4_prefix(const char *arg)
 static unsigned int conf_ip4(unsigned int ifi,
 			     struct ip4_ctx *ip4, unsigned char *mac)
 {
-	in_addr_t addr, gw;
-	int shift;
-
 	if (!ifi)
 		ifi = nl_get_ext_if(AF_INET);
 
@@ -651,10 +648,8 @@ static unsigned int conf_ip4(unsigned int ifi,
 	if (IN4_IS_ADDR_UNSPECIFIED(&ip4->addr))
 		nl_addr(0, ifi, AF_INET, &ip4->addr, &ip4->prefix_len, NULL);
 
-	addr = ntohl(ip4->addr.s_addr);
-	gw = ntohl(ip4->gw.s_addr);
-
 	if (!ip4->prefix_len) {
+		in_addr_t addr = ntohl(ip4->addr.s_addr);
 		if (IN_CLASSA(addr))
 			ip4->prefix_len = (32 - IN_CLASSA_NSHIFT);
 		else if (IN_CLASSB(addr))
@@ -665,24 +660,6 @@ static unsigned int conf_ip4(unsigned int ifi,
 			ip4->prefix_len = 32;
 	}
 
-	/* We might get an address with a netmask that makes the default
-	 * gateway unreachable, and in that case we would fail to configure
-	 * the default route, with --config-net, or presumably a DHCP client
-	 * in the guest or container would face the same issue.
-	 *
-	 * The host might have another route, to the default gateway itself,
-	 * fixing the situation, but we only read default routes.
-	 *
-	 * Fix up the mask to allow reaching the default gateway from our
-	 * configured address, if needed, and only if we find a non-zero
-	 * mask that makes the gateway reachable.
-	 */
-	shift = 32 - ip4->prefix_len;
-	while (shift < 32 && addr >> shift != gw >> shift)
-		shift++;
-	if (shift < 32)
-		ip4->prefix_len = 32 - shift;
-
 	memcpy(&ip4->addr_seen, &ip4->addr, sizeof(ip4->addr_seen));
 
 	if (MAC_IS_ZERO(mac))
-- 
2.39.2