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Fix Virtual DHCP Server: Correct IP reassignment

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This commit is contained in:
hiura 2024-05-08 10:55:00 +09:00
parent 6e5395cc8d
commit 5a88b34ddb
1 changed files with 22 additions and 36 deletions
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58
src/Cedar/Virtual.c
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@ -9349,62 +9349,35 @@ UINT ServeDhcpDiscoverEx(VH *v, UCHAR *mac, UINT request_ip, bool is_static_ip)
// check whether it is a request from the same MAC address
if (Cmp(mac, d->MacAddress, 6) == 0)
{
// Examine whether the specified IP address is within the range of assignment
// Examine whether the specified IP address is within the range of static assignment
if (Endian32(v->DhcpIpStart) > Endian32(request_ip) ||
Endian32(request_ip) > Endian32(v->DhcpIpEnd))
{
// Accept if within the range
// Accept if within the range of static assignment
ret = request_ip;
}
}
else {
// Duplicated IPV4 address found. The DHCP server replies to DHCPREQUEST with DHCP NAK.
// Duplicated IPV4 address found. The specified IP address is not available for use
char ipstr[MAX_HOST_NAME_LEN + 1] = { 0 };
char macstr[128] = { 0 };
IPToStr32(ipstr, sizeof(ipstr), request_ip);
BinToStr(macstr, sizeof(macstr), d->MacAddress, 6);
Debug("Virtual DHC Server: Duplicated IP address detected. Static IP: %s, Used by MAC:%s\n", ipstr, macstr);
return ret;
MacToStr(macstr, sizeof(macstr), d->MacAddress);
Debug("Virtual DHC Server: Duplicated IP address detected. Static IP: %s, with the MAC: %s\n", ipstr, macstr);
}
}
else
{
// Examine whether the specified IP address is within the range of assignment
// Examine whether the specified IP address is within the range of static assignment
if (Endian32(v->DhcpIpStart) > Endian32(request_ip) ||
Endian32(request_ip) > Endian32(v->DhcpIpEnd))
{
// Accept if within the range
// Accept if within the range of static assignment
ret = request_ip;
}
else
{
// Propose an IP in the range since it's a Discover although It is out of range
}
}
if (ret == 0)
{
// If there is any entry with the same MAC address
// that are already registered, use it with priority
DHCP_LEASE *d = SearchDhcpLeaseByMac(v, mac);
if (d != NULL)
{
// Examine whether the found IP address is in the allocation region
if (Endian32(v->DhcpIpStart) > Endian32(d->IpAddress) ||
Endian32(d->IpAddress) > Endian32(v->DhcpIpEnd))
{
// Use the IP address if it's found within the range
ret = d->IpAddress;
}
}
}
if (ret == 0)
{
// For static IP, the requested IP address must NOT be within the range of the DHCP pool
if (Endian32(v->DhcpIpStart) > Endian32(request_ip) ||
Endian32(request_ip) > Endian32(v->DhcpIpEnd))
{
ret = request_ip;
// The specified IP address is not available for use
}
}
@ -9595,6 +9568,11 @@ void VirtualDhcpServer(VH *v, PKT *p)
{
ip = ServeDhcpRequestEx(v, p->MacAddressSrc, opt->RequestedIp, ip_static);
}
// If the IP address in user's note is changed, then reply to DHCP_REQUEST with DHCP_NAK
if (p->L3.IPv4Header->SrcIP && ip != p->L3.IPv4Header->SrcIP)
{
ip = 0;
}
}
if (ip != 0 || opt->Opcode == DHCP_INFORM)
@ -9607,6 +9585,14 @@ void VirtualDhcpServer(VH *v, PKT *p)
char client_mac[MAX_SIZE];
char client_ip[MAX_SIZE];
// If there is any entry with the same MAC address, then remove it
d = SearchDhcpLeaseByMac(v, p->MacAddressSrc);
if (d != NULL)
{
FreeDhcpLease(d);
Delete(v->DhcpLeaseList, d);
}
// Remove old records with the same IP address
d = SearchDhcpLeaseByIp(v, ip);
if (d != NULL)
@ -9765,7 +9751,7 @@ void VirtualDhcpServer(VH *v, PKT *p)
}
else
{
// Reply of DHCP_REQUEST must be either DHCP_ACK or DHCP_NAK.
// Reply of DHCP_REQUEST must be either DHCP_ACK or DHCP_NAK
if (opt->Opcode == DHCP_REQUEST)
{
// There is no IP address that can be provided