From 55d23b19a270b2caeb4dcd9435a91bc9c55383e2 Mon Sep 17 00:00:00 2001 From: Michael Brown Date: Sat, 14 Nov 2009 02:28:16 +0000 Subject: [PATCH] [ipv4] Allow calculation of default subnet mask ipv4.c calculates the default subnet mask before calling fetch_ipv4_setting() to retrieve the configured subnet mask (if any). However, as of commit 612f4e7 "[settings] Avoid returning uninitialised data on error in fetch_xxx_setting()", fetch_ipv4_setting() will zero the IP address if the setting does not exist, rather than leaving it unaltered. Fix by fetching the setting first and calculating the default subnet mask only if necessary. --- src/net/ipv4.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/src/net/ipv4.c b/src/net/ipv4.c index 25cc7ffa..6b78ad77 100644 --- a/src/net/ipv4.c +++ b/src/net/ipv4.c @@ -600,18 +600,18 @@ static int ipv4_create_routes ( void ) { fetch_ipv4_setting ( settings, &ip_setting, &address ); if ( ! address.s_addr ) continue; - /* Calculate default netmask */ - if ( IN_CLASSA ( ntohl ( address.s_addr ) ) ) { - netmask.s_addr = htonl ( IN_CLASSA_NET ); - } else if ( IN_CLASSB ( ntohl ( address.s_addr ) ) ) { - netmask.s_addr = htonl ( IN_CLASSB_NET ); - } else if ( IN_CLASSC ( ntohl ( address.s_addr ) ) ) { - netmask.s_addr = htonl ( IN_CLASSC_NET ); - } else { - netmask.s_addr = 0; - } - /* Override with subnet mask, if present */ + /* Get subnet mask */ fetch_ipv4_setting ( settings, &netmask_setting, &netmask ); + /* Calculate default netmask, if necessary */ + if ( ! netmask.s_addr ) { + if ( IN_CLASSA ( ntohl ( address.s_addr ) ) ) { + netmask.s_addr = htonl ( IN_CLASSA_NET ); + } else if ( IN_CLASSB ( ntohl ( address.s_addr ) ) ) { + netmask.s_addr = htonl ( IN_CLASSB_NET ); + } else if ( IN_CLASSC ( ntohl ( address.s_addr ) ) ) { + netmask.s_addr = htonl ( IN_CLASSC_NET ); + } + } /* Get default gateway, if present */ fetch_ipv4_setting ( settings, &gateway_setting, &gateway ); /* Configure route */