Pi-Hole/dnsmasq
1
0
Fork 0
mirror of https://github.com/pi-hole/dnsmasq.git synced 2025-12-19 02:08:24 +00:00
Code Issues Packages Projects Releases Wiki Activity

Support PXE proxy-DHCP and DHCP-relay at the same time.

Browse Source 
When using PXE proxy-DHCP, dnsmasq supplies PXE information to
the client, which also talks to another "normal" DHCP server
for address allocation and similar. The normal DHCP server may
be on the local network, but it may also be remote, and accessed via
a DHCP relay. This change allows dnsmasq to act as both a
PXE proxy-DHCP server AND a DHCP relay for the same network.
This commit is contained in:
Simon Kelley
2024-12-05 17:25:38 +00:00
parent 7199531ff1
commit 5483fead6a
3 changed files with 20 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files

9
CHANGELOG
View File

@@ -64,7 +64,14 @@ version 2.91
175 to iPXE. Thanks to Jason Berry for finding the requirement for
this.
Support PXE proxy-DHCP and DHCP-relay at the same time.
When using PXE proxy-DHCP, dnsmasq supplies PXE information to
the client, which also talks to another "normal" DHCP server
for address allocation and similar. The normal DHCP server may
be on the local network, but it may also be remote, and accessed via
a DHCP relay. This change allows dnsmasq to act as both a
PXE proxy-DHCP server AND a DHCP relay for the same network.
version 2.90
Fix reversion in --rev-server introduced in 2.88 which

5
man/dnsmasq.8
View File

@@ -1680,6 +1680,11 @@ to allow netbooting. This mode is enabled using the
.B proxy
keyword in
.B --dhcp-range.
If the "other" DHCP server is on a remote network, it is
possible, and useful, to configure dnsmasq as both a PXE proxy-DHCP server
and a DHCP relay to the remote DHCP server. See
.B --dhcp-relay
for details. PXE is only supported over IPv4 at this time.
.TP
.B --dhcp-pxe-vendor=<vendor>[,...]
According to UEFI and PXE specifications, DHCP packets between PXE clients and

20
src/dhcp.c
View File

@@ -32,7 +32,7 @@ static int complete_context(struct in_addr local, int if_index, char *label,
struct in_addr netmask, struct in_addr broadcast, void *vparam);
static int check_listen_addrs(struct in_addr local, int if_index, char *label,
struct in_addr netmask, struct in_addr broadcast, void *vparam);
static int relay_upstream4(int iface_index, struct dhcp_packet *mess, size_t sz);
static void relay_upstream4(int iface_index, struct dhcp_packet *mess, size_t sz);
static struct dhcp_relay *relay_reply4(struct dhcp_packet *mess, char *arrival_interface);
static int make_fd(int port)
@@ -327,17 +327,10 @@ void dhcp_packet(time_t now, int pxe_fd)
complete_context(match.addr, iface_index, NULL, match.netmask, match.broadcast, &parm);
}
if (relay_upstream4(iface_index, mess, (size_t)sz))
return;
if (!iface_enumerate(AF_INET, &parm, (callback_t){.af_inet=complete_context}))
return;
/* Check for a relay again after iface_enumerate/complete_context has had
chance to fill in relay->iface_index fields. This handles first time through
and any changes in interface config. */
if (relay_upstream4(iface_index, mess, (size_t)sz))
return;
relay_upstream4(iface_index, mess, (size_t)sz);
/* May have configured relay, but not DHCP server */
if (!daemon->dhcp)
@@ -1077,14 +1070,14 @@ char *host_from_dns(struct in_addr addr)
return NULL;
}
static int relay_upstream4(int iface_index, struct dhcp_packet *mess, size_t sz)
static void relay_upstream4(int iface_index, struct dhcp_packet *mess, size_t sz)
{
struct in_addr giaddr = mess->giaddr;
u8 hops = mess->hops;
struct dhcp_relay *relay;
if (mess->op != BOOTREQUEST)
return 0;
return;
for (relay = daemon->relay4; relay; relay = relay->next)
if (relay->iface_index != 0 && relay->iface_index == iface_index)
@@ -1092,7 +1085,7 @@ static int relay_upstream4(int iface_index, struct dhcp_packet *mess, size_t sz)
/* No relay config. */
if (!relay)
return 0;
return;
for (; relay; relay = relay->next)
if (relay->iface_index != 0 && relay->iface_index == iface_index)
@@ -1171,7 +1164,8 @@ static int relay_upstream4(int iface_index, struct dhcp_packet *mess, size_t sz)
}
}
return 1;
/* restore in case of a local reply. */
mess->giaddr = giaddr;
}