cmservice.c

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/* AFS Cache Manager Service
 *
 * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells ([email protected])
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/ip.h>
#include "internal.h"
#include "afs_cm.h"

#if 0
struct workqueue_struct *afs_cm_workqueue;
#endif  /*  0  */

static int afs_deliver_cb_init_call_back_state(struct afs_call *,
                           struct sk_buff *, bool);
static int afs_deliver_cb_init_call_back_state3(struct afs_call *,
                        struct sk_buff *, bool);
static int afs_deliver_cb_probe(struct afs_call *, struct sk_buff *, bool);
static int afs_deliver_cb_callback(struct afs_call *, struct sk_buff *, bool);
static int afs_deliver_cb_probe_uuid(struct afs_call *, struct sk_buff *, bool);
static int afs_deliver_cb_tell_me_about_yourself(struct afs_call *,
                         struct sk_buff *, bool);
static void afs_cm_destructor(struct afs_call *);

/*
 * CB.CallBack operation type
 */
static const struct afs_call_type afs_SRXCBCallBack = {
    .name       = "CB.CallBack",
    .deliver    = afs_deliver_cb_callback,
    .abort_to_error = afs_abort_to_error,
    .destructor = afs_cm_destructor,
};

/*
 * CB.InitCallBackState operation type
 */
static const struct afs_call_type afs_SRXCBInitCallBackState = {
    .name       = "CB.InitCallBackState",
    .deliver    = afs_deliver_cb_init_call_back_state,
    .abort_to_error = afs_abort_to_error,
    .destructor = afs_cm_destructor,
};

/*
 * CB.InitCallBackState3 operation type
 */
static const struct afs_call_type afs_SRXCBInitCallBackState3 = {
    .name       = "CB.InitCallBackState3",
    .deliver    = afs_deliver_cb_init_call_back_state3,
    .abort_to_error = afs_abort_to_error,
    .destructor = afs_cm_destructor,
};

/*
 * CB.Probe operation type
 */
static const struct afs_call_type afs_SRXCBProbe = {
    .name       = "CB.Probe",
    .deliver    = afs_deliver_cb_probe,
    .abort_to_error = afs_abort_to_error,
    .destructor = afs_cm_destructor,
};

/*
 * CB.ProbeUuid operation type
 */
static const struct afs_call_type afs_SRXCBProbeUuid = {
    .name       = "CB.ProbeUuid",
    .deliver    = afs_deliver_cb_probe_uuid,
    .abort_to_error = afs_abort_to_error,
    .destructor = afs_cm_destructor,
};

/*
 * CB.TellMeAboutYourself operation type
 */
static const struct afs_call_type afs_SRXCBTellMeAboutYourself = {
    .name       = "CB.TellMeAboutYourself",
    .deliver    = afs_deliver_cb_tell_me_about_yourself,
    .abort_to_error = afs_abort_to_error,
    .destructor = afs_cm_destructor,
};

/*
 * route an incoming cache manager call
 * - return T if supported, F if not
 */
bool afs_cm_incoming_call(struct afs_call *call)
{
    u32 operation_id = ntohl(call->operation_ID);

    _enter("{CB.OP %u}", operation_id);

    switch (operation_id) {
    case CBCallBack:
        call->type = &afs_SRXCBCallBack;
        return true;
    case CBInitCallBackState:
        call->type = &afs_SRXCBInitCallBackState;
        return true;
    case CBInitCallBackState3:
        call->type = &afs_SRXCBInitCallBackState3;
        return true;
    case CBProbe:
        call->type = &afs_SRXCBProbe;
        return true;
    case CBTellMeAboutYourself:
        call->type = &afs_SRXCBTellMeAboutYourself;
        return true;
    default:
        return false;
    }
}

/*
 * clean up a cache manager call
 */
static void afs_cm_destructor(struct afs_call *call)
{
    _enter("");

    afs_put_server(call->server);
    call->server = NULL;
    kfree(call->buffer);
    call->buffer = NULL;
}

/*
 * allow the fileserver to see if the cache manager is still alive
 */
static void SRXAFSCB_CallBack(struct work_struct *work)
{
    struct afs_call *call = container_of(work, struct afs_call, work);

    _enter("");

    /* be sure to send the reply *before* attempting to spam the AFS server
     * with FSFetchStatus requests on the vnodes with broken callbacks lest
     * the AFS server get into a vicious cycle of trying to break further
     * callbacks because it hadn't received completion of the CBCallBack op
     * yet */
    afs_send_empty_reply(call);

    afs_break_callbacks(call->server, call->count, call->request);
    _leave("");
}

/*
 * deliver request data to a CB.CallBack call
 */
static int afs_deliver_cb_callback(struct afs_call *call, struct sk_buff *skb,
                   bool last)
{
    struct afs_callback *cb;
    struct afs_server *server;
    struct in_addr addr;
    __be32 *bp;
    u32 tmp;
    int ret, loop;

    _enter("{%u},{%u},%d", call->unmarshall, skb->len, last);

    switch (call->unmarshall) {
    case 0:
        call->offset = 0;
        call->unmarshall++;

        /* extract the FID array and its count in two steps */
    case 1:
        _debug("extract FID count");
        ret = afs_extract_data(call, skb, last, &call->tmp, 4);
        switch (ret) {
        case 0:     break;
        case -EAGAIN:   return 0;
        default:    return ret;
        }

        call->count = ntohl(call->tmp);
        _debug("FID count: %u", call->count);
        if (call->count > AFSCBMAX)
            return -EBADMSG;

        call->buffer = kmalloc(call->count * 3 * 4, GFP_KERNEL);
        if (!call->buffer)
            return -ENOMEM;
        call->offset = 0;
        call->unmarshall++;

    case 2:
        _debug("extract FID array");
        ret = afs_extract_data(call, skb, last, call->buffer,
                       call->count * 3 * 4);
        switch (ret) {
        case 0:     break;
        case -EAGAIN:   return 0;
        default:    return ret;
        }

        _debug("unmarshall FID array");
        call->request = kcalloc(call->count,
                    sizeof(struct afs_callback),
                    GFP_KERNEL);
        if (!call->request)
            return -ENOMEM;

        cb = call->request;
        bp = call->buffer;
        for (loop = call->count; loop > 0; loop--, cb++) {
            cb->fid.vid = ntohl(*bp++);
            cb->fid.vnode   = ntohl(*bp++);
            cb->fid.unique  = ntohl(*bp++);
            cb->type    = AFSCM_CB_UNTYPED;
        }

        call->offset = 0;
        call->unmarshall++;

        /* extract the callback array and its count in two steps */
    case 3:
        _debug("extract CB count");
        ret = afs_extract_data(call, skb, last, &call->tmp, 4);
        switch (ret) {
        case 0:     break;
        case -EAGAIN:   return 0;
        default:    return ret;
        }

        tmp = ntohl(call->tmp);
        _debug("CB count: %u", tmp);
        if (tmp != call->count && tmp != 0)
            return -EBADMSG;
        call->offset = 0;
        call->unmarshall++;
        if (tmp == 0)
            goto empty_cb_array;

    case 4:
        _debug("extract CB array");
        ret = afs_extract_data(call, skb, last, call->request,
                       call->count * 3 * 4);
        switch (ret) {
        case 0:     break;
        case -EAGAIN:   return 0;
        default:    return ret;
        }

        _debug("unmarshall CB array");
        cb = call->request;
        bp = call->buffer;
        for (loop = call->count; loop > 0; loop--, cb++) {
            cb->version = ntohl(*bp++);
            cb->expiry  = ntohl(*bp++);
            cb->type    = ntohl(*bp++);
        }

    empty_cb_array:
        call->offset = 0;
        call->unmarshall++;

    case 5:
        _debug("trailer");
        if (skb->len != 0)
            return -EBADMSG;
        break;
    }

    if (!last)
        return 0;

    call->state = AFS_CALL_REPLYING;

    /* we'll need the file server record as that tells us which set of
     * vnodes to operate upon */
    memcpy(&addr, &ip_hdr(skb)->saddr, 4);
    server = afs_find_server(&addr);
    if (!server)
        return -ENOTCONN;
    call->server = server;

    INIT_WORK(&call->work, SRXAFSCB_CallBack);
    queue_work(afs_wq, &call->work);
    return 0;
}

/*
 * allow the fileserver to request callback state (re-)initialisation
 */
static void SRXAFSCB_InitCallBackState(struct work_struct *work)
{
    struct afs_call *call = container_of(work, struct afs_call, work);

    _enter("{%p}", call->server);

    afs_init_callback_state(call->server);
    afs_send_empty_reply(call);
    _leave("");
}

/*
 * deliver request data to a CB.InitCallBackState call
 */
static int afs_deliver_cb_init_call_back_state(struct afs_call *call,
                           struct sk_buff *skb,
                           bool last)
{
    struct afs_server *server;
    struct in_addr addr;

    _enter(",{%u},%d", skb->len, last);

    if (skb->len > 0)
        return -EBADMSG;
    if (!last)
        return 0;

    /* no unmarshalling required */
    call->state = AFS_CALL_REPLYING;

    /* we'll need the file server record as that tells us which set of
     * vnodes to operate upon */
    memcpy(&addr, &ip_hdr(skb)->saddr, 4);
    server = afs_find_server(&addr);
    if (!server)
        return -ENOTCONN;
    call->server = server;

    INIT_WORK(&call->work, SRXAFSCB_InitCallBackState);
    queue_work(afs_wq, &call->work);
    return 0;
}

/*
 * deliver request data to a CB.InitCallBackState3 call
 */
static int afs_deliver_cb_init_call_back_state3(struct afs_call *call,
                        struct sk_buff *skb,
                        bool last)
{
    struct afs_server *server;
    struct in_addr addr;

    _enter(",{%u},%d", skb->len, last);

    if (!last)
        return 0;

    /* no unmarshalling required */
    call->state = AFS_CALL_REPLYING;

    /* we'll need the file server record as that tells us which set of
     * vnodes to operate upon */
    memcpy(&addr, &ip_hdr(skb)->saddr, 4);
    server = afs_find_server(&addr);
    if (!server)
        return -ENOTCONN;
    call->server = server;

    INIT_WORK(&call->work, SRXAFSCB_InitCallBackState);
    queue_work(afs_wq, &call->work);
    return 0;
}

/*
 * allow the fileserver to see if the cache manager is still alive
 */
static void SRXAFSCB_Probe(struct work_struct *work)
{
    struct afs_call *call = container_of(work, struct afs_call, work);

    _enter("");
    afs_send_empty_reply(call);
    _leave("");
}

/*
 * deliver request data to a CB.Probe call
 */
static int afs_deliver_cb_probe(struct afs_call *call, struct sk_buff *skb,
                bool last)
{
    _enter(",{%u},%d", skb->len, last);

    if (skb->len > 0)
        return -EBADMSG;
    if (!last)
        return 0;

    /* no unmarshalling required */
    call->state = AFS_CALL_REPLYING;

    INIT_WORK(&call->work, SRXAFSCB_Probe);
    queue_work(afs_wq, &call->work);
    return 0;
}

/*
 * allow the fileserver to quickly find out if the fileserver has been rebooted
 */
static void SRXAFSCB_ProbeUuid(struct work_struct *work)
{
    struct afs_call *call = container_of(work, struct afs_call, work);
    struct afs_uuid *r = call->request;

    struct {
        __be32  match;
    } reply;

    _enter("");


    if (memcmp(r, &afs_uuid, sizeof(afs_uuid)) == 0)
        reply.match = htonl(0);
    else
        reply.match = htonl(1);

    afs_send_simple_reply(call, &reply, sizeof(reply));
    _leave("");
}

/*
 * deliver request data to a CB.ProbeUuid call
 */
static int afs_deliver_cb_probe_uuid(struct afs_call *call, struct sk_buff *skb,
                     bool last)
{
    struct afs_uuid *r;
    unsigned loop;
    __be32 *b;
    int ret;

    _enter("{%u},{%u},%d", call->unmarshall, skb->len, last);

    if (skb->len > 0)
        return -EBADMSG;
    if (!last)
        return 0;

    switch (call->unmarshall) {
    case 0:
        call->offset = 0;
        call->buffer = kmalloc(11 * sizeof(__be32), GFP_KERNEL);
        if (!call->buffer)
            return -ENOMEM;
        call->unmarshall++;

    case 1:
        _debug("extract UUID");
        ret = afs_extract_data(call, skb, last, call->buffer,
                       11 * sizeof(__be32));
        switch (ret) {
        case 0:     break;
        case -EAGAIN:   return 0;
        default:    return ret;
        }

        _debug("unmarshall UUID");
        call->request = kmalloc(sizeof(struct afs_uuid), GFP_KERNEL);
        if (!call->request)
            return -ENOMEM;

        b = call->buffer;
        r = call->request;
        r->time_low         = ntohl(b[0]);
        r->time_mid         = ntohl(b[1]);
        r->time_hi_and_version      = ntohl(b[2]);
        r->clock_seq_hi_and_reserved    = ntohl(b[3]);
        r->clock_seq_low        = ntohl(b[4]);

        for (loop = 0; loop < 6; loop++)
            r->node[loop] = ntohl(b[loop + 5]);

        call->offset = 0;
        call->unmarshall++;

    case 2:
        _debug("trailer");
        if (skb->len != 0)
            return -EBADMSG;
        break;
    }

    if (!last)
        return 0;

    call->state = AFS_CALL_REPLYING;

    INIT_WORK(&call->work, SRXAFSCB_ProbeUuid);
    queue_work(afs_wq, &call->work);
    return 0;
}

/*
 * allow the fileserver to ask about the cache manager's capabilities
 */
static void SRXAFSCB_TellMeAboutYourself(struct work_struct *work)
{
    struct afs_interface *ifs;
    struct afs_call *call = container_of(work, struct afs_call, work);
    int loop, nifs;

    struct {
        struct /* InterfaceAddr */ {
            __be32 nifs;
            __be32 uuid[11];
            __be32 ifaddr[32];
            __be32 netmask[32];
            __be32 mtu[32];
        } ia;
        struct /* Capabilities */ {
            __be32 capcount;
            __be32 caps[1];
        } cap;
    } reply;

    _enter("");

    nifs = 0;
    ifs = kcalloc(32, sizeof(*ifs), GFP_KERNEL);
    if (ifs) {
        nifs = afs_get_ipv4_interfaces(ifs, 32, false);
        if (nifs < 0) {
            kfree(ifs);
            ifs = NULL;
            nifs = 0;
        }
    }

    memset(&reply, 0, sizeof(reply));
    reply.ia.nifs = htonl(nifs);

    reply.ia.uuid[0] = htonl(afs_uuid.time_low);
    reply.ia.uuid[1] = htonl(afs_uuid.time_mid);
    reply.ia.uuid[2] = htonl(afs_uuid.time_hi_and_version);
    reply.ia.uuid[3] = htonl((s8) afs_uuid.clock_seq_hi_and_reserved);
    reply.ia.uuid[4] = htonl((s8) afs_uuid.clock_seq_low);
    for (loop = 0; loop < 6; loop++)
        reply.ia.uuid[loop + 5] = htonl((s8) afs_uuid.node[loop]);

    if (ifs) {
        for (loop = 0; loop < nifs; loop++) {
            reply.ia.ifaddr[loop] = ifs[loop].address.s_addr;
            reply.ia.netmask[loop] = ifs[loop].netmask.s_addr;
            reply.ia.mtu[loop] = htonl(ifs[loop].mtu);
        }
        kfree(ifs);
    }

    reply.cap.capcount = htonl(1);
    reply.cap.caps[0] = htonl(AFS_CAP_ERROR_TRANSLATION);
    afs_send_simple_reply(call, &reply, sizeof(reply));

    _leave("");
}

/*
 * deliver request data to a CB.TellMeAboutYourself call
 */
static int afs_deliver_cb_tell_me_about_yourself(struct afs_call *call,
                         struct sk_buff *skb, bool last)
{
    _enter(",{%u},%d", skb->len, last);

    if (skb->len > 0)
        return -EBADMSG;
    if (!last)
        return 0;

    /* no unmarshalling required */
    call->state = AFS_CALL_REPLYING;

    INIT_WORK(&call->work, SRXAFSCB_TellMeAboutYourself);
    queue_work(afs_wq, &call->work);
    return 0;
}