config.c

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/*
 * net/tipc/config.c: TIPC configuration management code
 *
 * Copyright (c) 2002-2006, Ericsson AB
 * Copyright (c) 2004-2007, 2010-2012, Wind River Systems
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the names of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include "core.h"
#include "port.h"
#include "name_table.h"
#include "config.h"

#define REPLY_TRUNCATED "<truncated>\n"

static u32 config_port_ref;

static DEFINE_SPINLOCK(config_lock);

static const void *req_tlv_area;    /* request message TLV area */
static int req_tlv_space;       /* request message TLV area size */
static int rep_headroom;        /* reply message headroom to use */


struct sk_buff *tipc_cfg_reply_alloc(int payload_size)
{
    struct sk_buff *buf;

    buf = alloc_skb(rep_headroom + payload_size, GFP_ATOMIC);
    if (buf)
        skb_reserve(buf, rep_headroom);
    return buf;
}

int tipc_cfg_append_tlv(struct sk_buff *buf, int tlv_type,
            void *tlv_data, int tlv_data_size)
{
    struct tlv_desc *tlv = (struct tlv_desc *)skb_tail_pointer(buf);
    int new_tlv_space = TLV_SPACE(tlv_data_size);

    if (skb_tailroom(buf) < new_tlv_space)
        return 0;
    skb_put(buf, new_tlv_space);
    tlv->tlv_type = htons(tlv_type);
    tlv->tlv_len  = htons(TLV_LENGTH(tlv_data_size));
    if (tlv_data_size && tlv_data)
        memcpy(TLV_DATA(tlv), tlv_data, tlv_data_size);
    return 1;
}

static struct sk_buff *tipc_cfg_reply_unsigned_type(u16 tlv_type, u32 value)
{
    struct sk_buff *buf;
    __be32 value_net;

    buf = tipc_cfg_reply_alloc(TLV_SPACE(sizeof(value)));
    if (buf) {
        value_net = htonl(value);
        tipc_cfg_append_tlv(buf, tlv_type, &value_net,
                    sizeof(value_net));
    }
    return buf;
}

static struct sk_buff *tipc_cfg_reply_unsigned(u32 value)
{
    return tipc_cfg_reply_unsigned_type(TIPC_TLV_UNSIGNED, value);
}

struct sk_buff *tipc_cfg_reply_string_type(u16 tlv_type, char *string)
{
    struct sk_buff *buf;
    int string_len = strlen(string) + 1;

    buf = tipc_cfg_reply_alloc(TLV_SPACE(string_len));
    if (buf)
        tipc_cfg_append_tlv(buf, tlv_type, string, string_len);
    return buf;
}

static struct sk_buff *tipc_show_stats(void)
{
    struct sk_buff *buf;
    struct tlv_desc *rep_tlv;
    char *pb;
    int pb_len;
    int str_len;
    u32 value;

    if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_UNSIGNED))
        return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);

    value = ntohl(*(u32 *)TLV_DATA(req_tlv_area));
    if (value != 0)
        return tipc_cfg_reply_error_string("unsupported argument");

    buf = tipc_cfg_reply_alloc(TLV_SPACE(ULTRA_STRING_MAX_LEN));
    if (buf == NULL)
        return NULL;

    rep_tlv = (struct tlv_desc *)buf->data;
    pb = TLV_DATA(rep_tlv);
    pb_len = ULTRA_STRING_MAX_LEN;

    str_len = tipc_snprintf(pb, pb_len, "TIPC version " TIPC_MOD_VER "\n");
    str_len += 1;   /* for "\0" */
    skb_put(buf, TLV_SPACE(str_len));
    TLV_SET(rep_tlv, TIPC_TLV_ULTRA_STRING, NULL, str_len);

    return buf;
}

static struct sk_buff *cfg_enable_bearer(void)
{
    struct tipc_bearer_config *args;

    if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_BEARER_CONFIG))
        return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);

    args = (struct tipc_bearer_config *)TLV_DATA(req_tlv_area);
    if (tipc_enable_bearer(args->name,
                   ntohl(args->disc_domain),
                   ntohl(args->priority)))
        return tipc_cfg_reply_error_string("unable to enable bearer");

    return tipc_cfg_reply_none();
}

static struct sk_buff *cfg_disable_bearer(void)
{
    if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_BEARER_NAME))
        return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);

    if (tipc_disable_bearer((char *)TLV_DATA(req_tlv_area)))
        return tipc_cfg_reply_error_string("unable to disable bearer");

    return tipc_cfg_reply_none();
}

static struct sk_buff *cfg_set_own_addr(void)
{
    u32 addr;

    if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR))
        return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);

    addr = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
    if (addr == tipc_own_addr)
        return tipc_cfg_reply_none();
    if (!tipc_addr_node_valid(addr))
        return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
                           " (node address)");
    if (tipc_own_addr)
        return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
                           " (cannot change node address once assigned)");

    /*
     * Must temporarily release configuration spinlock while switching into
     * networking mode as it calls tipc_eth_media_start(), which may sleep.
     * Releasing the lock is harmless as other locally-issued configuration
     * commands won't occur until this one completes, and remotely-issued
     * configuration commands can't be received until a local configuration
     * command to enable the first bearer is received and processed.
     */
    spin_unlock_bh(&config_lock);
    tipc_core_start_net(addr);
    spin_lock_bh(&config_lock);
    return tipc_cfg_reply_none();
}

static struct sk_buff *cfg_set_remote_mng(void)
{
    u32 value;

    if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_UNSIGNED))
        return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);

    value = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
    tipc_remote_management = (value != 0);
    return tipc_cfg_reply_none();
}

static struct sk_buff *cfg_set_max_ports(void)
{
    u32 value;

    if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_UNSIGNED))
        return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
    value = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
    if (value == tipc_max_ports)
        return tipc_cfg_reply_none();
    if (value < 127 || value > 65535)
        return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
                           " (max ports must be 127-65535)");
    return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
        " (cannot change max ports while TIPC is active)");
}

static struct sk_buff *cfg_set_netid(void)
{
    u32 value;

    if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_UNSIGNED))
        return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
    value = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
    if (value == tipc_net_id)
        return tipc_cfg_reply_none();
    if (value < 1 || value > 9999)
        return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
                           " (network id must be 1-9999)");
    if (tipc_own_addr)
        return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
            " (cannot change network id once TIPC has joined a network)");
    tipc_net_id = value;
    return tipc_cfg_reply_none();
}

struct sk_buff *tipc_cfg_do_cmd(u32 orig_node, u16 cmd, const void *request_area,
                int request_space, int reply_headroom)
{
    struct sk_buff *rep_tlv_buf;

    spin_lock_bh(&config_lock);

    /* Save request and reply details in a well-known location */
    req_tlv_area = request_area;
    req_tlv_space = request_space;
    rep_headroom = reply_headroom;

    /* Check command authorization */
    if (likely(in_own_node(orig_node))) {
        /* command is permitted */
    } else if (cmd >= 0x8000) {
        rep_tlv_buf = tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
                              " (cannot be done remotely)");
        goto exit;
    } else if (!tipc_remote_management) {
        rep_tlv_buf = tipc_cfg_reply_error_string(TIPC_CFG_NO_REMOTE);
        goto exit;
    } else if (cmd >= 0x4000) {
        u32 domain = 0;

        if ((tipc_nametbl_translate(TIPC_ZM_SRV, 0, &domain) == 0) ||
            (domain != orig_node)) {
            rep_tlv_buf = tipc_cfg_reply_error_string(TIPC_CFG_NOT_ZONE_MSTR);
            goto exit;
        }
    }

    /* Call appropriate processing routine */
    switch (cmd) {
    case TIPC_CMD_NOOP:
        rep_tlv_buf = tipc_cfg_reply_none();
        break;
    case TIPC_CMD_GET_NODES:
        rep_tlv_buf = tipc_node_get_nodes(req_tlv_area, req_tlv_space);
        break;
    case TIPC_CMD_GET_LINKS:
        rep_tlv_buf = tipc_node_get_links(req_tlv_area, req_tlv_space);
        break;
    case TIPC_CMD_SHOW_LINK_STATS:
        rep_tlv_buf = tipc_link_cmd_show_stats(req_tlv_area, req_tlv_space);
        break;
    case TIPC_CMD_RESET_LINK_STATS:
        rep_tlv_buf = tipc_link_cmd_reset_stats(req_tlv_area, req_tlv_space);
        break;
    case TIPC_CMD_SHOW_NAME_TABLE:
        rep_tlv_buf = tipc_nametbl_get(req_tlv_area, req_tlv_space);
        break;
    case TIPC_CMD_GET_BEARER_NAMES:
        rep_tlv_buf = tipc_bearer_get_names();
        break;
    case TIPC_CMD_GET_MEDIA_NAMES:
        rep_tlv_buf = tipc_media_get_names();
        break;
    case TIPC_CMD_SHOW_PORTS:
        rep_tlv_buf = tipc_port_get_ports();
        break;
    case TIPC_CMD_SHOW_STATS:
        rep_tlv_buf = tipc_show_stats();
        break;
    case TIPC_CMD_SET_LINK_TOL:
    case TIPC_CMD_SET_LINK_PRI:
    case TIPC_CMD_SET_LINK_WINDOW:
        rep_tlv_buf = tipc_link_cmd_config(req_tlv_area, req_tlv_space, cmd);
        break;
    case TIPC_CMD_ENABLE_BEARER:
        rep_tlv_buf = cfg_enable_bearer();
        break;
    case TIPC_CMD_DISABLE_BEARER:
        rep_tlv_buf = cfg_disable_bearer();
        break;
    case TIPC_CMD_SET_NODE_ADDR:
        rep_tlv_buf = cfg_set_own_addr();
        break;
    case TIPC_CMD_SET_REMOTE_MNG:
        rep_tlv_buf = cfg_set_remote_mng();
        break;
    case TIPC_CMD_SET_MAX_PORTS:
        rep_tlv_buf = cfg_set_max_ports();
        break;
    case TIPC_CMD_SET_NETID:
        rep_tlv_buf = cfg_set_netid();
        break;
    case TIPC_CMD_GET_REMOTE_MNG:
        rep_tlv_buf = tipc_cfg_reply_unsigned(tipc_remote_management);
        break;
    case TIPC_CMD_GET_MAX_PORTS:
        rep_tlv_buf = tipc_cfg_reply_unsigned(tipc_max_ports);
        break;
    case TIPC_CMD_GET_NETID:
        rep_tlv_buf = tipc_cfg_reply_unsigned(tipc_net_id);
        break;
    case TIPC_CMD_NOT_NET_ADMIN:
        rep_tlv_buf =
            tipc_cfg_reply_error_string(TIPC_CFG_NOT_NET_ADMIN);
        break;
    case TIPC_CMD_SET_MAX_ZONES:
    case TIPC_CMD_GET_MAX_ZONES:
    case TIPC_CMD_SET_MAX_SLAVES:
    case TIPC_CMD_GET_MAX_SLAVES:
    case TIPC_CMD_SET_MAX_CLUSTERS:
    case TIPC_CMD_GET_MAX_CLUSTERS:
    case TIPC_CMD_SET_MAX_NODES:
    case TIPC_CMD_GET_MAX_NODES:
    case TIPC_CMD_SET_MAX_SUBSCR:
    case TIPC_CMD_GET_MAX_SUBSCR:
    case TIPC_CMD_SET_MAX_PUBL:
    case TIPC_CMD_GET_MAX_PUBL:
    case TIPC_CMD_SET_LOG_SIZE:
    case TIPC_CMD_DUMP_LOG:
        rep_tlv_buf = tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
                              " (obsolete command)");
        break;
    default:
        rep_tlv_buf = tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
                              " (unknown command)");
        break;
    }

    WARN_ON(rep_tlv_buf->len > TLV_SPACE(ULTRA_STRING_MAX_LEN));

    /* Append an error message if we cannot return all requested data */
    if (rep_tlv_buf->len == TLV_SPACE(ULTRA_STRING_MAX_LEN)) {
        if (*(rep_tlv_buf->data + ULTRA_STRING_MAX_LEN) != '\0')
            sprintf(rep_tlv_buf->data + rep_tlv_buf->len -
                sizeof(REPLY_TRUNCATED) - 1, REPLY_TRUNCATED);
    }

    /* Return reply buffer */
exit:
    spin_unlock_bh(&config_lock);
    return rep_tlv_buf;
}

static void cfg_named_msg_event(void *userdata,
                u32 port_ref,
                struct sk_buff **buf,
                const unchar *msg,
                u32 size,
                u32 importance,
                struct tipc_portid const *orig,
                struct tipc_name_seq const *dest)
{
    struct tipc_cfg_msg_hdr *req_hdr;
    struct tipc_cfg_msg_hdr *rep_hdr;
    struct sk_buff *rep_buf;

    /* Validate configuration message header (ignore invalid message) */
    req_hdr = (struct tipc_cfg_msg_hdr *)msg;
    if ((size < sizeof(*req_hdr)) ||
        (size != TCM_ALIGN(ntohl(req_hdr->tcm_len))) ||
        (ntohs(req_hdr->tcm_flags) != TCM_F_REQUEST)) {
        pr_warn("Invalid configuration message discarded\n");
        return;
    }

    /* Generate reply for request (if can't, return request) */
    rep_buf = tipc_cfg_do_cmd(orig->node,
                  ntohs(req_hdr->tcm_type),
                  msg + sizeof(*req_hdr),
                  size - sizeof(*req_hdr),
                  BUF_HEADROOM + MAX_H_SIZE + sizeof(*rep_hdr));
    if (rep_buf) {
        skb_push(rep_buf, sizeof(*rep_hdr));
        rep_hdr = (struct tipc_cfg_msg_hdr *)rep_buf->data;
        memcpy(rep_hdr, req_hdr, sizeof(*rep_hdr));
        rep_hdr->tcm_len = htonl(rep_buf->len);
        rep_hdr->tcm_flags &= htons(~TCM_F_REQUEST);
    } else {
        rep_buf = *buf;
        *buf = NULL;
    }

    /* NEED TO ADD CODE TO HANDLE FAILED SEND (SUCH AS CONGESTION) */
    tipc_send_buf2port(port_ref, orig, rep_buf, rep_buf->len);
}

int tipc_cfg_init(void)
{
    struct tipc_name_seq seq;
    int res;

    res = tipc_createport(NULL, TIPC_CRITICAL_IMPORTANCE,
                  NULL, NULL, NULL,
                  NULL, cfg_named_msg_event, NULL,
                  NULL, &config_port_ref);
    if (res)
        goto failed;

    seq.type = TIPC_CFG_SRV;
    seq.lower = seq.upper = tipc_own_addr;
    res = tipc_publish(config_port_ref, TIPC_ZONE_SCOPE, &seq);
    if (res)
        goto failed;

    return 0;

failed:
    pr_err("Unable to create configuration service\n");
    return res;
}

void tipc_cfg_reinit(void)
{
    struct tipc_name_seq seq;
    int res;

    seq.type = TIPC_CFG_SRV;
    seq.lower = seq.upper = 0;
    tipc_withdraw(config_port_ref, TIPC_ZONE_SCOPE, &seq);

    seq.lower = seq.upper = tipc_own_addr;
    res = tipc_publish(config_port_ref, TIPC_ZONE_SCOPE, &seq);
    if (res)
        pr_err("Unable to reinitialize configuration service\n");
}

void tipc_cfg_stop(void)
{
    tipc_deleteport(config_port_ref);
    config_port_ref = 0;
}