sravan/system76-edk2
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

MdeModulePkg: Update IP4 stack to support point-to-point link with 31-bit mask.

Browse Source 
V2 update: Directly use NetIp4IsUnicast() to check station address in IP driver.

This patch is to follow RFC3021 which allows to use 31-bit mask
in point-to-point link.
If a 31-bit subnet mask is assigned to a point-to-point link, it
leaves the <Host-number> with only 1 bit.  Consequently, only two
possible addresses may result:
  {<Network-number>, 0} and {<Network-number>, -1}
These addresses have historically been associated with network and
broadcast addresses (see Section 2.2).  In a point-to-point link with
a 31-bit subnet mask, the two addresses above MUST be interpreted as
host addresses.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Fu Siyuan <siyuan.fu@intel.com>
Reviewed-by: Wu Jiaxin <jiaxin.wu@intel.com>
This commit is contained in:
Fu Siyuan
2017-10-18 10:13:39 +08:00
parent db04b706b7
commit 29788f178e
3 changed files with 18 additions and 27 deletions
Download Patch File Download Diff File Expand all files Collapse all files

25
MdeModulePkg/Universal/Network/Ip4Dxe/Ip4Common.c
View File

@@ -287,10 +287,6 @@ Ip4StationAddressValid (
IN IP4_ADDR Netmask
)
{
IP4_ADDR NetBrdcastMask;
INTN Len;
INTN Type;
//
// Only support the station address with 0.0.0.0/0 to enable DHCP client.
//
@@ -301,29 +297,16 @@ Ip4StationAddressValid (
//
// Only support the continuous net masks
//
if ((Len = NetGetMaskLength (Netmask)) == (IP4_MASK_MAX + 1)) {
if (NetGetMaskLength (Netmask) == (IP4_MASK_MAX + 1)) {
return FALSE;
}
//
// Station address can't be class D or class E address
//
if ((Type = NetGetIpClass (Ip)) > IP4_ADDR_CLASSC) {
if (NetGetIpClass (Ip) > IP4_ADDR_CLASSC) {
return FALSE;
}
//
// Station address can't be subnet broadcast/net broadcast address
//
if ((Ip == (Ip & Netmask)) || (Ip == (Ip | ~Netmask))) {
return FALSE;
}
NetBrdcastMask = gIp4AllMasks[MIN (Len, Type << 3)];
if (Ip == (Ip | ~NetBrdcastMask)) {
return FALSE;
}
return TRUE;
}
return NetIp4IsUnicast (Ip, Netmask);
}