Implementing basic LLDP server, should send port_id message

to each port once every 30 seconds.
* Additionally fixes the on-ward passing of LLDP frames through
the switch

The ports on the case are marked 1-8 so this should reflect that
rather than being 0-based

We can send the hostname as well, this can be dynamically allocated

Let's send the model as the system description as well

Makefile

@@ -83,6 +83,7 @@ SRCS += \
 	rtl837x_pins.c\
 	rtl837x_port.c \
 	rtl837x_stp.c \
+	rtl837x_lldp.c \
 	rtl837x_storm.c
 SRCS += \
 	httpd/httpd.c \

cmd_parser.c

@@ -16,6 +16,7 @@
 #include "rtl837x_stp.h"
 #include "rtl837x_igmp.h"
 #include "rtl837x_bandwidth.h"
+#include "rtl837x_lldp.h"
 #include "rtl837x_storm.h"
 #include "sfp.h"
 #include "dhcp.h"
@@ -32,6 +33,7 @@
 extern __code const struct machine machine;
 extern __xdata bool stp_enabled;
 extern __code const uint8_t log_to_phys_port[9];
+extern __xdata uint8_t lldp_enabled;
 
 extern volatile __xdata uint32_t ticks;
 extern volatile __xdata uint8_t sfr_data[4];
@@ -2024,6 +2026,14 @@ void cmd_parser(void) __banked
 			parse_ingress();
 		} else if (cmd_compare(0, "session")) {
 			parse_session();
+		} else if (cmd_compare(0, "lldp")) {
+			if (cmd_compare(1, "on")) {
+				print_string("LLDP enabled\n");
+				lldp_enabled = 1;
+			} else {
+				print_string("LLDP disabled\n");
+				lldp_enabled = 0;
+			}
 		}
 		else {
 			cmd_error("Unknown command\n");

cmd_parser.h

@@ -20,6 +20,7 @@ extern __xdata uint8_t err_status;
 #define HEALTH_PH_STP	4
 #define HEALTH_PH_CMD	5
 #define HEALTH_PHASES	6
+#define HEALTH_LLDP     7
 
 extern __xdata uint16_t health_rx_frames;
 #define health_rx_frame()	health_rx_frames++

rtl837x_lldp.c

@@ -0,0 +1,181 @@
+#pragma codeseg BANK2
+#pragma constseg BANK2
+
+#include "rtl837x_common.h"
+#include "rtl837x_lldp.h"
+#include "rtl837x_sfr.h"
+#include "rtl837x_common.h"
+#include "dhcp.h"
+#include "uip.h"
+#include "uip/uip.h"
+#include "machine.h"
+
+extern __xdata uint8_t lldp_enabled;
+extern __code const struct machine machine;
+
+uint8_t lldp_seconds;
+
+void lldp_init(void) __banked
+{
+    lldp_seconds = 0;
+}
+
+void lldp_tick(void) __banked
+{
+    lldp_seconds++;
+
+    if (lldp_seconds < LLDP_TX_INTERVAL_SEC)
+        return;
+
+    lldp_seconds = 0;
+
+    if(lldp_enabled == 1)
+        lldp_send();
+}
+
+//Outgoing LLDP packet.
+
+struct lldp_pkt {
+    struct uip_eth_addr dst;
+    struct uip_eth_addr src;
+    struct rtl_tag rtl_tag;
+    uint16_t ether_type;
+
+    uint8_t payload[64];
+};
+
+#define LLDP_O ((__xdata struct lldp_pkt *)&uip_buf[RTL_FRAME_DESC_SIZE])
+
+// The type is 7 bits and the length is 9 bits
+// we can represent this as the 7 most significant
+// bits of the type bit and leave the least significant
+// bit as 0 always as we're not going to need 2^9 for
+// the length at any point
+#define LLDP_TYPE(value) (value << 1)
+
+void lldp_send(void) __banked __reentrant
+{
+    uint8_t *p;
+    uint16_t len = 0;
+	uint8_t port_position;
+
+    lldp_set_addresses();
+    lldp_set_rtl_wrapper();
+
+    p = LLDP_O->payload;
+
+    //Chassis ID
+    p[len++] = LLDP_TYPE(LLDP_CHASSIS_ID_TLV_TYPE);
+    p[len++] = LLDP_CHASSIS_ID_TLV_LENGTH;
+    p[len++] = LLDP_CHASSIS_ID_TLV_SUBTYPE;
+
+    for (uint8_t i = 0; i < LLDP_MAC_ADDR_LEN; i++)
+    	p[len + i] = uip_ethaddr.addr[i];
+
+	len += LLDP_MAC_ADDR_LEN;
+
+    //Port ID
+    p[len++] = LLDP_TYPE(LLDP_PORT_ID_TLV_TYPE);
+    p[len++] = LLDP_PORT_ID_TLV_LENGTH;
+    p[len++] = LLDP_PORT_ID_TLV_SUBTYPE;
+    port_position = len;
+	p[len++] = '0';       // filled in per port below
+
+    //TTL
+    p[len++] = LLDP_TYPE(LLDP_TTL_TLV_TYPE);
+    p[len++] = LLDP_TTL_TLV_LENGTH;
+    p[len++] = 0x00; //padding
+    p[len++] = LLDP_TTL_TTL_SECONDS;
+
+    lldp_sysname(p, &len);
+    lldp_sysdesc(p, &len);
+
+    // End of LLDPDU TLV
+    p[len++] = 0x00; //padding
+    p[len++] = 0x00; //padding
+
+    while (len < LLDP_MIN_ETHERNET_PAYLOAD_LENGTH)
+        p[len++] = 0x00;
+
+    /*
+     * uip_len is the Ethernet frame length excluding FCS.
+     *
+     * The frame consists of:
+     *
+     *     dst mac
+     *     src mac
+     *     rtl_tag  sizeof(struct rtl_tag)
+     *     EtherType (2 bytes)
+     *     payload   len
+     */
+    uip_len = LLDP_MAC_ADDR_LEN + LLDP_MAC_ADDR_LEN + sizeof(struct rtl_tag) + LLDP_ETHERTYPE_LENGTH + len;
+
+    for (uint8_t port = machine.min_port; port <= machine.max_port; port++) {
+
+        LLDP_O->payload[port_position] = '1' + port;
+        LLDP_O->rtl_tag.pmask = HTONS((uint16_t)1 << port);
+
+        tcpip_output();
+    }
+}
+
+void lldp_set_addresses(void) __banked {
+    // LLDP destination multicast addr: 01:80:c2:00:00:0e
+    LLDP_O->dst.addr[0] = 0x01;
+    LLDP_O->dst.addr[1] = 0x80;
+    LLDP_O->dst.addr[2] = 0xc2;
+    LLDP_O->dst.addr[3] = 0x00;
+    LLDP_O->dst.addr[4] = 0x00;
+    LLDP_O->dst.addr[5] = 0x0e;
+
+    for (uint8_t i = 0; i < LLDP_MAC_ADDR_LEN; i++)
+        LLDP_O->src.addr[i] = uip_ethaddr.addr[i];
+}
+
+void lldp_set_rtl_wrapper(void) __banked {
+    /*
+     * This is the RTL CPU tag, not the Ethernet EtherType.
+     *     port 0 -> 0x0001
+     *     port 1 -> 0x0002
+     *     port 2 -> 0x0004
+     */
+    LLDP_O->rtl_tag.tag = HTONS(RTL_FRAME_TAG_ID);
+    LLDP_O->rtl_tag.version = RTL_FRAME_TAG_VERSION;
+    LLDP_O->rtl_tag.reason = 0x00;
+    LLDP_O->rtl_tag.flags = HTONS(RTL_TAG_LEARN_DIS);
+
+    LLDP_O->ether_type = HTONS(LLDP_ETHERTYPE);
+}
+
+void lldp_sysname(uint8_t *p, uint16_t *len) __banked
+{
+    uint16_t hostname_length = 0;
+    __xdata char *hp = hostname;
+
+    p[(*len)++] = LLDP_TYPE(LLDP_SYSNAME_TLV_TYPE);
+    p[(*len)++] = 0;
+
+    while (*hp)
+    {
+        hostname_length++;
+        p[(*len)++] = *hp++;
+    }
+    p[(*len)-hostname_length-1] = hostname_length;
+
+}
+
+void lldp_sysdesc(uint8_t *p, uint16_t *len) __banked
+{
+    uint16_t machine_name_length = 0;
+    const char *mp = machine.machine_name;
+
+    p[(*len)++] = LLDP_TYPE(LLDP_SYSDESC_TLV_TYPE);
+    p[(*len)++] = 0;
+
+    while (*mp)
+    {
+        machine_name_length++;
+        p[(*len)++] = *mp++;
+    }
+    p[(*len)-machine_name_length-1] = machine_name_length;
+}

rtl837x_lldp.h

@@ -0,0 +1,36 @@
+#ifndef _LLDP_H_
+#define _LLDP_H_
+
+#include <stdint.h>
+
+#define LLDP_MIN_ETHERNET_PAYLOAD_LENGTH 46
+#define LLDP_ETHERTYPE       0x88cc
+#define LLDP_ETHERTYPE_LENGTH 2
+#define LLDP_MAX_FRAME       256
+#define LLDP_MAC_ADDR_LEN    6
+#define LLDP_TX_INTERVAL_SEC 30
+
+#define LLDP_PORT_ID_TLV_TYPE 2
+#define LLDP_PORT_ID_TLV_LENGTH 0x02
+#define LLDP_PORT_ID_TLV_SUBTYPE 0x07
+
+#define LLDP_TTL_TLV_TYPE 3
+#define LLDP_TTL_TLV_LENGTH 2
+#define LLDP_TTL_TTL_SECONDS 120
+
+#define LLDP_CHASSIS_ID_TLV_TYPE 1
+#define LLDP_CHASSIS_ID_TLV_LENGTH 7
+#define LLDP_CHASSIS_ID_TLV_SUBTYPE 4
+
+#define LLDP_SYSNAME_TLV_TYPE 5
+#define LLDP_SYSDESC_TLV_TYPE 6
+
+void lldp_init(void) __banked;
+void lldp_tick(void) __banked;
+void lldp_send(void) __banked;
+void lldp_set_addresses(void) __banked;
+void lldp_set_rtl_wrapper(void) __banked;
+void lldp_sysname(uint8_t *p, uint16_t *len) __banked;
+void lldp_sysdesc(uint8_t *p, uint16_t *len) __banked;
+
+#endif

rtlplayground.c

@@ -16,6 +16,7 @@
 #include "rtl837x_leds.h"
 #include "rtl837x_bandwidth.h"
 #include "rtl837x_init.h"
+#include "rtl837x_lldp.h"
 #include "dhcp.h"
 #include "cmd_parser.h"
 #include "cmd_editor.h"
@@ -127,6 +128,7 @@ __xdata uint8_t tx_seq;
 
 __xdata bool stp_enabled;
 __xdata uint8_t igmpEnabled;
+__xdata uint8_t lldp_enabled;
 __xdata char hostname[24];	/* device hostname, default set at boot, see rtl837x_common.h */
 
 __code const uint16_t bit_mask[16] = {
@@ -1066,6 +1068,13 @@ void handle_rx(void)
 			if (uip_len) {
 				tcpip_output();
 			}
+		} else if (lldp_enabled && uip_buf[0] == 0x01 && uip_buf[1] == 0x80 && uip_buf[2] == 0xc2
+			&& uip_buf[3] == 0x00 && uip_buf[4] == 0x00 && uip_buf[5] == 0x0e && uip_buf[12] == 0x88
+			&& uip_buf[13] == 0xcc) {	//LLDP Mac + EtherType check
+			// LLDP packets shouldn't be passed elsewhere
+			if(uip_len){
+				print_string("LLDP received\n");
+			}
 		} else if (ETH_IN->ether_type == HTONS(0x0806)) { // ARP
 			uip_arp_arpin();
 			if (uip_len) {
@@ -1286,6 +1295,8 @@ static void handle_tick(void)
 		}
 	}
 	health_phase(HEALTH_PH_STP);
+	lldp_tick();
+	health_phase(HEALTH_LLDP);
 }
 
 
@@ -1794,6 +1805,7 @@ void main(void)
 	uip_init();
 	uip_arp_init();
 	httpd_init();
+	lldp_init();
 
 	management_vlan = 1; // Default management VLAN is 1