path: root/net/atm/mpc.c

// SPDX-License-Identifier: GPL-2.0-only
#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__

#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/timer.h>
#include <linux/init.h>
#include <linux/bitops.h>
#include <linux/capability.h>
#include <linux/seq_file.h>

/* We are an ethernet device */
#include <linux/if_ether.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <net/sock.h>
#include <linux/skbuff.h>
#include <linux/ip.h>
#include <linux/uaccess.h>
#include <asm/byteorder.h>
#include <net/checksum.h>   /* for ip_fast_csum() */
#include <net/arp.h>
#include <net/dst.h>
#include <linux/proc_fs.h>

/* And atm device */
#include <linux/atmdev.h>
#include <linux/atmlec.h>
#include <linux/atmmpc.h>
/* Modular too */
#include <linux/module.h>

#include "lec.h"
#include "mpc.h"
#include "resources.h"

/*
 * mpc.c: Implementation of MPOA client kernel part
 */

#if 0
#define dprintk(format, args...) \
	printk(KERN_DEBUG "mpoa:%s: " format, __func__, ##args)
#define dprintk_cont(format, args...) printk(KERN_CONT format, ##args)
#else
#define dprintk(format, args...)					\
	do { if (0)							\
		printk(KERN_DEBUG "mpoa:%s: " format, __func__, ##args);\
	} while (0)
#define dprintk_cont(format, args...)			\
	do { if (0) printk(KERN_CONT format, ##args); } while (0)
#endif

#if 0
#define ddprintk(format, args...) \
	printk(KERN_DEBUG "mpoa:%s: " format, __func__, ##args)
#define ddprintk_cont(format, args...) printk(KERN_CONT format, ##args)
#else
#define ddprintk(format, args...)					\
	do { if (0)							\
		printk(KERN_DEBUG "mpoa:%s: " format, __func__, ##args);\
	} while (0)
#define ddprintk_cont(format, args...)			\
	do { if (0) printk(KERN_CONT format, ##args); } while (0)
#endif

/* mpc_daemon -> kernel */
static void MPOA_trigger_rcvd(struct k_message *msg, struct mpoa_client *mpc);
static void MPOA_res_reply_rcvd(struct k_message *msg, struct mpoa_client *mpc);
static void ingress_purge_rcvd(struct k_message *msg, struct mpoa_client *mpc);
static void egress_purge_rcvd(struct k_message *msg, struct mpoa_client *mpc);
static void mps_death(struct k_message *msg, struct mpoa_client *mpc);
static void clean_up(struct k_message *msg, struct mpoa_client *mpc,
		     int action);
static void MPOA_cache_impos_rcvd(struct k_message *msg,
				  struct mpoa_client *mpc);
static void set_mpc_ctrl_addr_rcvd(struct k_message *mesg,
				   struct mpoa_client *mpc);
static void set_mps_mac_addr_rcvd(struct k_message *mesg,
				  struct mpoa_client *mpc);

static const uint8_t *copy_macs(struct mpoa_client *mpc,
				const uint8_t *router_mac,
				const uint8_t *tlvs, uint8_t mps_macs,
				uint8_t device_type);
static void purge_egress_shortcut(struct atm_vcc *vcc, eg_cache_entry *entry);

static void send_set_mps_ctrl_addr(const char *addr, struct mpoa_client *mpc);
static void mpoad_close(struct atm_vcc *vcc);
static int msg_from_mpoad(struct atm_vcc *vcc, struct sk_buff *skb);

static void mpc_push(struct atm_vcc *vcc, struct sk_buff *skb);
static netdev_tx_t mpc_send_packet(struct sk_buff *skb,
				   struct net_device *dev);
static int mpoa_event_listener(struct notifier_block *mpoa_notifier,
			       unsigned long event, void *dev);
static void mpc_timer_refresh(void);
static void mpc_cache_check(struct timer_list *unused);

static struct llc_snap_hdr llc_snap_mpoa_ctrl = {
	0xaa, 0xaa, 0x03,
	{0x00, 0x00, 0x5e},
	{0x00, 0x03}         /* For MPOA control PDUs */
};
static struct llc_snap_hdr llc_snap_mpoa_data = {
	0xaa, 0xaa, 0x03,
	{0x00, 0x00, 0x00},
	{0x08, 0x00}         /* This is for IP PDUs only */
};
static struct llc_snap_hdr llc_snap_mpoa_data_tagged = {
	0xaa, 0xaa, 0x03,
	{0x00, 0x00, 0x00},
	{0x88, 0x4c}         /* This is for tagged data PDUs */
};

static struct notifier_block mpoa_notifier = {
	mpoa_event_listener,
	NULL,
	0
};

struct mpoa_client *mpcs = NULL; /* FIXME */
static struct atm_mpoa_qos *qos_head = NULL;
static DEFINE_TIMER(mpc_timer, mpc_cache_check);


static struct mpoa_client *find_mpc_by_itfnum(int itf)
{
	struct mpoa_client *mpc;

	mpc = mpcs;  /* our global linked list */
	while (mpc != NULL) {
		if (mpc->dev_num == itf)
			return mpc;
		mpc = mpc->next;
	}

	return NULL;   /* not found */
}

static struct mpoa_client *find_mpc_by_vcc(struct atm_vcc *vcc)
{
	struct mpoa_client *mpc;

	mpc = mpcs;  /* our global linked list */
	while (mpc != NULL) {
		if (mpc->mpoad_vcc == vcc)
			return mpc;
		mpc = mpc->next;
	}

	return NULL;   /* not found */
}

static struct mpoa_client *find_mpc_by_lec(struct net_device *dev)
{
	struct mpoa_client *mpc;

	mpc = mpcs;  /* our global linked list */
	while (mpc != NULL) {
		if (mpc->dev == dev)
			return mpc;
		mpc = mpc->next;
	}

	return NULL;   /* not found */
}

/*
 * Functions for managing QoS list
 */

/*
 * Overwrites the old entry or makes a new one.
 */
struct atm_mpoa_qos *atm_mpoa_add_qos(__be32 dst_ip, struct atm_qos *qos)
{
	struct atm_mpoa_qos *entry;

	entry = atm_mpoa_search_qos(dst_ip);
	if (entry != NULL) {
		entry->qos = *qos;
		return entry;
	}

	entry = kmalloc(sizeof(struct atm_mpoa_qos), GFP_KERNEL);
	if (entry == NULL) {
		pr_info("mpoa: out of memory\n");
		return entry;
	}

	entry->ipaddr = dst_ip;
	entry->qos = *qos;

	entry->next = qos_head;
	qos_head = entry;

	return entry;
}

struct atm_mpoa_qos *atm_mpoa_search_qos(__be32 dst_ip)
{
	struct atm_mpoa_qos *qos;

	qos = qos_head;
	while (qos) {
		if (qos->ipaddr == dst_ip)
			break;
		qos = qos->next;
	}

	return qos;
}

/*
 * Returns 0 for failure
 */
int atm_mpoa_delete_qos(struct atm_mpoa_qos *entry)
{
	struct atm_mpoa_qos *curr;

	if (entry == NULL)
		return 0;
	if (entry == qos_head) {
		qos_head = qos_head->next;
		kfree(entry);
		return 1;
	}

	curr = qos_head;
	while (curr != NULL) {
		if (curr->next == entry) {
			curr->next = entry->next;
			kfree(entry);
			return 1;
		}
		curr = curr->next;
	}

	return 0;
}

/* this is buggered - we need locking for qos_head */
void atm_mpoa_disp_qos(struct seq_file *m)
{
	struct atm_mpoa_qos *qos;

	qos = qos_head;
	seq_printf(m, "QoS entries for shortcuts:\n");
	seq_printf(m, "IP address\n  TX:max_pcr pcr     min_pcr max_cdv max_sdu\n  RX:max_pcr pcr     min_pcr max_cdv max_sdu\n");

	while (qos != NULL) {
		seq_printf(m, "%pI4\n     %-7d %-7d %-7d %-7d %-7d\n     %-7d %-7d %-7d %-7d %-7d\n",
			   &qos->ipaddr,
			   qos->qos.txtp.max_pcr,
			   qos->qos.txtp.pcr,
			   qos->qos.txtp.min_pcr,
			   qos->qos.txtp.max_cdv,
			   qos->qos.txtp.max_sdu,
			   qos->qos.rxtp.max_pcr,
			   qos->qos.rxtp.pcr,
			   qos->qos.rxtp.min_pcr,
			   qos->qos.rxtp.max_cdv,
			   qos->qos.rxtp.max_sdu);
		qos = qos->next;
	}
}

static struct net_device *find_lec_by_itfnum(int itf)
{
	struct net_device *dev;
	char name[IFNAMSIZ];

	sprintf(name, "lec%d", itf);
	dev = dev_get_by_name(&init_net, name);

	return dev;
}

static struct mpoa_client *alloc_mpc(void)
{
	struct mpoa_client *mpc;

	mpc = kzalloc(sizeof(struct mpoa_client), GFP_KERNEL);
	if (mpc == NULL)
		return NULL;
	rwlock_init(&mpc->ingress_lock);
	rwlock_init(&mpc->egress_lock);
	mpc->next = mpcs;
	atm_mpoa_init_cache(mpc);

	mpc->parameters.mpc_p1 = MPC_P1;
	mpc->parameters.mpc_p2 = MPC_P2;
	memset(mpc->parameters.mpc_p3, 0, sizeof(mpc->parameters.mpc_p3));
	mpc->parameters.mpc_p4 = MPC_P4;
	mpc->parameters.mpc_p5 = MPC_P5;
	mpc->parameters.mpc_p6 = MPC_P6;

	mpcs = mpc;

	return mpc;
}

/*
 *
 * start_mpc() puts the MPC on l