Add an implementation for IGMP

This adds an implementation for trapping IGMP packets to the CPU
which will identify IGMPv1/2/3 packets, but handle only v3.
The implementation then inserts/updates/deletes L3 MC entries
in the L3 lookup table. The entries consist of an Ipv4
Destination IP (the IPv4 MC address), a Source IP (0.0.0.0) and
a Portmask. Note that this implementation is not VLAN aware,
as there is no hardware support in the device.

An alternative strategy is to control switching of the L2-MC packets
in which the IPv4-MC packets are transported (dst-MaC is
01:00:5e:xx:yy:zz, with xx:yy:zz corresponding to bits in the Ipv4-MC
address). This will allow to use VLAN-aware packet switching. While
code support is there for table insert/update/deletes, some further
L2 configuration is missing.

There is no support for IPv6 MC, yet.
This commit is contained in:
logicog
2025-12-15 06:54:41 +01:00
parent 96977b5d88
commit c8c524b71f
6 changed files with 310 additions and 36 deletions
+3 -4
View File
@@ -74,12 +74,11 @@ extern __xdata uint8_t uip_buf[UIP_CONF_BUFFER_SIZE+2];
struct rtl_tag {
uint16_t tag;
uint8_t version;
uint16_t dummy;
uint8_t flag;
uint16_t pmask;
uint8_t reason;
uint16_t flags;
uint16_t pmask; // A bit mask for a TX pkt, 4-bit port-number for RX
};
// Headers for calls in the common code area (HOME/BANK0)
void print_string(__code char *p);
void print_long(__xdata uint32_t a);