path: root/net/smc/smc_clc.c

// SPDX-License-Identifier: GPL-2.0
/*
 *  Shared Memory Communications over RDMA (SMC-R) and RoCE
 *
 *  CLC (connection layer control) handshake over initial TCP socket to
 *  prepare for RDMA traffic
 *
 *  Copyright IBM Corp. 2016, 2018
 *
 *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
 */

#include <linux/in.h>
#include <linux/inetdevice.h>
#include <linux/if_ether.h>
#include <linux/sched/signal.h>
#include <linux/utsname.h>
#include <linux/ctype.h>

#include <net/addrconf.h>
#include <net/sock.h>
#include <net/tcp.h>

#include "smc.h"
#include "smc_core.h"
#include "smc_clc.h"
#include "smc_ib.h"
#include "smc_ism.h"
#include "smc_netlink.h"

#define SMCR_CLC_ACCEPT_CONFIRM_LEN 68
#define SMCD_CLC_ACCEPT_CONFIRM_LEN 48
#define SMCD_CLC_ACCEPT_CONFIRM_LEN_V2 78
#define SMCR_CLC_ACCEPT_CONFIRM_LEN_V2 108
#define SMC_CLC_RECV_BUF_LEN	100

/* eye catcher "SMCR" EBCDIC for CLC messages */
static const char SMC_EYECATCHER[4] = {'\xe2', '\xd4', '\xc3', '\xd9'};
/* eye catcher "SMCD" EBCDIC for CLC messages */
static const char SMCD_EYECATCHER[4] = {'\xe2', '\xd4', '\xc3', '\xc4'};

static u8 smc_hostname[SMC_MAX_HOSTNAME_LEN];

struct smc_clc_eid_table {
	rwlock_t lock;
	struct list_head list;
	u8 ueid_cnt;
	u8 seid_enabled;
};

static struct smc_clc_eid_table smc_clc_eid_table;

struct smc_clc_eid_entry {
	struct list_head list;
	u8 eid[SMC_MAX_EID_LEN];
};

/* The size of a user EID is 32 characters.
 * Valid characters should be (single-byte character set) A-Z, 0-9, '.' and '-'.
 * Blanks should only be used to pad to the expected size.
 * First character must be alphanumeric.
 */
static bool smc_clc_ueid_valid(char *ueid)
{
	char *end = ueid + SMC_MAX_EID_LEN;

	while (--end >= ueid && isspace(*end))
		;
	if (end < ueid)
		return false;
	if (!isalnum(*ueid) || islower(*ueid))
		return false;
	while (ueid <= end) {
		if ((!isalnum(*ueid) || islower(*ueid)) && *ueid != '.' &&
		    *ueid != '-')
			return false;
		ueid++;
	}
	return true;
}

static int smc_clc_ueid_add(char *ueid)
{
	struct smc_clc_eid_entry *new_ueid, *tmp_ueid;
	int rc;

	if (!smc_clc_ueid_valid(ueid))
		return -EINVAL;

	/* add a new ueid entry to the ueid table if there isn't one */
	new_ueid = kzalloc(sizeof(*new_ueid), GFP_KERNEL);
	if (!new_ueid)
		return -ENOMEM;
	memcpy(new_ueid->eid, ueid, SMC_MAX_EID_LEN);

	write_lock(&smc_clc_eid_table.lock);
	if (smc_clc_eid_table.ueid_cnt >= SMC_MAX_UEID) {
		rc = -ERANGE;
		goto err_out;
	}
	list_for_each_entry(tmp_ueid, &smc_clc_eid_table.list, list) {
		if (!memcmp(tmp_ueid->eid, ueid, SMC_MAX_EID_LEN)) {
			rc = -EEXIST;
			goto err_out;
		}
	}
	list_add_tail(&new_ueid->list, &smc_clc_eid_table.list);
	smc_clc_eid_table.ueid_cnt++;
	write_unlock(&smc_clc_eid_table.lock);
	return 0;

err_out:
	write_unlock(&smc_clc_eid_table.lock);
	kfree(new_ueid);
	return rc;
}

int smc_clc_ueid_count(void)
{
	int count;

	read_lock(&smc_clc_eid_table.lock);
	count = smc_clc_eid_table.ueid_cnt;
	read_unlock(&smc_clc_eid_table.lock);

	return count;
}

int smc_nl_add_ueid(struct sk_buff *skb, struct genl_info *info)
{
	struct nlattr *nla_ueid = info->attrs[SMC_NLA_EID_TABLE_ENTRY];
	char *ueid;

	if (!nla_ueid || nla_len(nla_ueid) != SMC_MAX_EID_LEN + 1)
		return -EINVAL;
	ueid = (char *)nla_data(nla_ueid);

	return smc_clc_ueid_add(ueid);
}

/* remove one or all ueid entries from the table */
static int smc_clc_ueid_remove(char *ueid)
{
	struct smc_clc_eid_entry *lst_ueid, *tmp_ueid;
	int rc = -ENOENT;

	/* remove table entry */
	write_lock(&smc_clc_eid_table.lock);
	list_for_each_entry_safe(