/*
   Copyright (c) 2010-2013 Red Hat, Inc. <http://www.redhat.com>
   This file is part of GlusterFS.

   This file is licensed to you under your choice of the GNU Lesser
   General Public License, version 3 or any later version (LGPLv3 or
   later), or the GNU General Public License, version 2 (GPLv2), in all
   cases as published by the Free Software Foundation.
*/

#include "xlator.h"
#include "glusterfs.h"
#include "syscall.h"
#include "compat-errno.h"

#include "glusterd.h"
#include "glusterd-utils.h"

#include "portmap-xdr.h"
#include "xdr-generic.h"
#include "protocol-common.h"
#include "glusterd-messages.h"
#include "rpcsvc.h"

#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>


static int
pmap_port_isfree (int port)
{
        struct sockaddr_in sin;
        int                sock = -1;
        int                ret = 0;

        memset (&sin, 0, sizeof (sin));
        sin.sin_family = PF_INET;
        sin.sin_port = hton16 (port);

        sock = socket (PF_INET, SOCK_STREAM, 0);
        if (sock == -1)
                return -1;

        ret = bind (sock, (struct sockaddr *)&sin, sizeof (sin));
        sys_close (sock);

        return (ret == 0) ? 1 : 0;
}


static struct pmap_registry *
pmap_registry_new (xlator_t *this)
{
        struct pmap_registry *pmap = NULL;
        int                   i = 0;

        pmap = CALLOC (sizeof (*pmap), 1);
        if (!pmap)
                return NULL;

        pmap->base_port = pmap->last_alloc =
                ((glusterd_conf_t *)(this->private))->base_port;

        for (i = pmap->base_port; i <= GF_PORT_MAX; i++) {
                if (pmap_port_isfree (i))
                        pmap->ports[i].type = GF_PMAP_PORT_FREE;
                else
                        pmap->ports[i].type = GF_PMAP_PORT_FOREIGN;
        }

        return pmap;
}


struct pmap_registry *
pmap_registry_get (xlator_t *this)
{
        glusterd_conf_t      *priv = NULL;
        struct pmap_registry *pmap = NULL;

        priv = this->private;

        pmap = priv->pmap;
        if (!pmap) {
                pmap = pmap_registry_new (this);
                if (!pmap)
                        return NULL;
                priv->pmap = pmap;
        }

        return pmap;
}


/*
 * The "destroy" argument avoids a double search in pmap_registry_remove - one
 * to find the entry in the table, and the other to find the particular
 * brickname within that entry (which might cover multiple bricks).  We do the
 * actual deletion here by "whiting out" the brick name with spaces.  It's up
 * to pmap_registry_remove to figure out what to do from there.
 */
int
pmap_registry_search (xlator_t *this, const char *brickname,
                      gf_pmap_port_type_t type, gf_boolean_t destroy)
{
        struct pmap_registry *pmap = NULL;
        int                   p = 0;
        char                 *brck = NULL;
        size_t                i;

        pmap = pmap_registry_get (this);

        for (p = pmap->last_alloc; p >= pmap->base_port; p--) {
                if (!pmap->ports[p].brickname || pmap->ports[p].type != type)
                        continue;

                brck = pmap->ports[p].brickname;
                for (;;) {
                        for (i = 0; brck[i] && !isspace (brck[i]); ++i)
                                ;
                        if (i == 0 && brck[i] == '\0')
                                break;

                        if (strncmp (brck, brickname, i) == 0) {
                                /*
                                 * Without this check, we'd break when brck
                                 * is merely a substring of brickname.
                                 */
                                if (brickname[i] == '\0') {
                                        if (destroy) do {
                                                *(brck++) = ' ';
                                        } while (--i);
                                        return p;
                                }
                        }

                        brck += i;

                        /*
                         * Skip over *any* amount of whitespace, including
                         * none (if we're already at the end of the string).
                         */
                        while (isspace (*brck))
                                ++brck;
                        /*
                         * We're either at the end of the string (which will be
                         * handled above strncmp on the next iteration) or at
                         * the next non-whitespace substring (which will be
                         * handled by strncmp itself).
                         */
                }
        }

        return 0;
}

static int
pmap_registry_search_by_xprt (xlator_t *this, void *xprt,
                              gf_pmap_port_type_t type)
{
        struct pmap_registry *pmap = NULL;
        int                   p    = 0;
        int                   port = 0;

        pmap = pmap_registry_get (this);

        for (p = pmap->last_alloc; p >= pmap->base_port; p--) {
                if (!pmap->ports[p].xprt)
                        continue;
                if (pmap->ports[p].xprt == xprt) {
                        if (pmap->ports[p].type == type ||
                                        type == GF_PMAP_PORT_ANY) {
                                port = p;
                                break;
                        }
                }
        }

        return port;
}


static char *
pmap_registry_search_by_port (xlator_t *this, int port)
{
        struct pmap_registry *pmap = NULL;
        char *brickname = NULL;

        if (port > GF_PORT_MAX)
                goto out;

        pmap = pmap_registry_get (this);

        if (pmap->ports[port].type == GF_PMAP_PORT_BRICKSERVER)
                brickname = pmap->ports[port].brickname;

out:
        return brickname;
}


int
pmap_registry_alloc (xlator_t *this)
{
        struct pmap_registry *pmap = NULL;
        int                   p = 0;
        int                   port = 0;

        pmap = pmap_registry_get (this);

        for (p = pmap->base_port; p <= GF_PORT_MAX; p++) {
                /* GF_PMAP_PORT_FOREIGN may be freed up ? */
                if ((pmap->ports[p].type == GF_PMAP_PORT_FREE) ||
                    (pmap->ports[p].type == GF_PMAP_PORT_FOREIGN)) {

                        if (pmap_port_isfree (p)) {
                                pmap->ports[p].type = GF_PMAP_PORT_LEASED;
                                port = p;
                                break;
                        }
                }
        }

        if (port > pmap->last_alloc)
                pmap->last_alloc = port;

        return port;
}

/* pmap_assign_port does a pmap_registry_remove followed by pmap_registry_alloc,
 * the reason for the former is to ensure we don't end up with stale ports
 */
int
pmap_assign_port (xlator_t *this, int old_port, const char *path)
{
        int ret = -1;
        int new_port = 0;

        if (old_port) {
                ret = pmap_registry_remove (this, 0, path,
                                            GF_PMAP_PORT_BRICKSERVER, NULL);
                if (ret) {
                        gf_msg (this->name, GF_LOG_WARNING,
                                GD_MSG_PMAP_REGISTRY_REMOVE_FAIL, 0, "Failed to"
                                "remove pmap registry for older signin for path"
                                " %s", path);
                }
        }
        new_port = pmap_registry_alloc (this);
        return new_port;
}

int
pmap_registry_bind (xlator_t *this, int port, const char *brickname,
                    gf_pmap_port_type_t type, void *xprt)
{
        struct pmap_registry *pmap = NULL;
        int                   p = 0;

        pmap = pmap_registry_get (this);

        if (port > GF_PORT_MAX)
                goto out;

        p = port;
        if (pmap->ports[p].brickname) {
                char *tmp = pmap->ports[p].brickname;
                asprintf (&pmap->ports[p].brickname, "%s %s", tmp, brickname);
                free (tmp);
        } else {
                pmap->ports[p].brickname = strdup (brickname);
        }
        pmap->ports[p].type = type;
        pmap->ports[p].xprt = xprt;

        gf_msg ("pmap", GF_LOG_INFO, 0,
                GD_MSG_BRICK_ADD, "adding brick %s on port %d",
                brickname, port);

        if (pmap->last_alloc < p)
                pmap->last_alloc = p;
out:
        return 0;
}

int
pmap_registry_extend (xlator_t *this, int port, const char *brickname)
{
        struct pmap_registry *pmap = NULL;
        char                 *old_bn;
        char                 *new_bn;
        size_t               bn_len;
        char                 *entry;
        int                  found = 0;

        pmap = pmap_registry_get (this);

        if (port > GF_PORT_MAX) {
                return -1;
        }

        switch (pmap->ports[port].type) {
        case GF_PMAP_PORT_LEASED:
        case GF_PMAP_PORT_BRICKSERVER:
                break;
        default:
                return -1;
        }

        old_bn = pmap->ports[port].brickname;
        if (old_bn) {
                bn_len = strlen(brickname);
                entry = strstr (old_bn, brickname);
                while (entry) {
                        found = 1;
                        if ((entry != old_bn) && (entry[-1] != ' ')) {
                                found = 0;
                        }
                        if ((entry[bn_len] != ' ') && (entry[bn_len] != '\0')) {
                                found = 0;
                        }
                        if (found) {
                                return 0;
                        }
                        entry = strstr (entry + bn_len, brickname);
                }
                asprintf (&new_bn, "%s %s", old_bn, brickname);
        } else {
                new_bn = strdup (brickname);
        }

        if (!new_bn) {
                return -1;
        }

        pmap->ports[port].brickname = new_bn;
        free (old_bn);

        return 0;
}

int
pmap_registry_remove (xlator_t *this, int port, const char *brickname,
                      gf_pmap_port_type_t type, void *xprt)
{
        struct pmap_registry *pmap = NULL;
        int                   p = 0;
        glusterd_conf_t      *priv = NULL;
        char                 *brick_str;

        priv = this->private;
        pmap = priv->pmap;
        if (!pmap)
                goto out;

        if (port) {
                if (port > GF_PORT_MAX)
                        goto out;

                p = port;
        }

        if (brickname) {
                p = pmap_registry_search (this, brickname, type, _gf_true);
                if (p)
                        goto remove;
        }

        if (xprt) {
                p = pmap_registry_search_by_xprt (this, xprt, type);
                if (p)
                        goto remove;
        }

        goto out;
remove:
        gf_msg ("pmap", GF_LOG_INFO, 0, GD_MSG_BRICK_REMOVE,
                "removing brick %s on port %d", brickname, p);

        if (xprt && (xprt == pmap->ports[p].xprt)) {
                pmap->ports[p].xprt = NULL;
        }

        /*
         * This is where we garbage-collect.  If all of the brick names have
         * been "whited out" by pmap_registry_search(...,destroy=_gf_true) and
         * there's no xprt either, then we have nothing left worth saving and
         * can delete the entire entry.
         */
        if (!pmap->ports[p].xprt) {
                brick_str = pmap->ports[p].brickname;
                if (brick_str) {
                        while (*brick_str != '\0') {
                                if (*(brick_str++) != ' ') {
                                        goto out;
                                }
                        }
                }
                free (pmap->ports[p].brickname);
                pmap->ports[p].brickname = NULL;
                pmap->ports[p].type = GF_PMAP_PORT_FREE;
        }

out:
        return 0;
}

int
__gluster_pmap_portbybrick (rpcsvc_request_t *req)
{
        pmap_port_by_brick_req    args = {0,};
        pmap_port_by_brick_rsp    rsp  = {0,};
        char                     *brick = NULL;
        int                       port = 0;
        int                       ret = -1;

        ret = xdr_to_generic (req->msg[0], &args,
                              (xdrproc_t)xdr_pmap_port_by_brick_req);
        if (ret < 0) {
                req->rpc_err = GARBAGE_ARGS;
                goto fail;
        }

        brick = args.brick;

        port = pmap_registry_search (THIS, brick, GF_PMAP_PORT_BRICKSERVER,
                                     _gf_false);

        if (!port)
                rsp.op_ret = -1;

        rsp.port = port;

fail:
        glusterd_submit_reply (req, &rsp, NULL, 0, NULL,
                               (xdrproc_t)xdr_pmap_port_by_brick_rsp);
        free (args.brick);//malloced by xdr

        return 0;
}


int
gluster_pmap_portbybrick (rpcsvc_request_t *req)
{
        return glusterd_big_locked_handler (req, __gluster_pmap_portbybrick);
}


int
__gluster_pmap_brickbyport (rpcsvc_request_t *req)
{
        pmap_brick_by_port_req    args = {0,};
        pmap_brick_by_port_rsp    rsp  = {0,};
        int                       ret = -1;

        ret = xdr_to_generic (req->msg[0], &args,
                              (xdrproc_t)xdr_pmap_brick_by_port_req);
        if (ret < 0) {
                req->rpc_err = GARBAGE_ARGS;
                goto fail;
        }

        rsp.brick = pmap_registry_search_by_port (THIS, args.port);
        if (!rsp.brick) {
                rsp.op_ret = -1;
                rsp.brick = "";
        }
fail:

        glusterd_submit_reply (req, &rsp, NULL, 0, NULL,
                               (xdrproc_t)xdr_pmap_brick_by_port_rsp);

        return 0;
}


int
gluster_pmap_brickbyport (rpcsvc_request_t *req)
{
        return glusterd_big_locked_handler (req, __gluster_pmap_brickbyport);
}


int
__gluster_pmap_signin (rpcsvc_request_t *req)
{
        pmap_signin_req    args = {0,};
        pmap_signin_rsp    rsp  = {0,};
        int                ret = -1;
        glusterd_brickinfo_t    *brickinfo = NULL;

        ret = xdr_to_generic (req->msg[0], &args,
                              (xdrproc_t)xdr_pmap_signin_req);
        if (ret < 0) {
                req->rpc_err = GARBAGE_ARGS;
                goto fail;
        }

        rsp.op_ret = pmap_registry_bind (THIS, args.port, args.brick,
                                         GF_PMAP_PORT_BRICKSERVER, req->trans);

        ret = glusterd_get_brickinfo (THIS, args.brick, args.port, &brickinfo);

fail:
        glusterd_submit_reply (req, &rsp, NULL, 0, NULL,
                               (xdrproc_t)xdr_pmap_signin_rsp);
        free (args.brick);//malloced by xdr

        return 0;
}


int
gluster_pmap_signin (rpcsvc_request_t *req)
{
        return glusterd_big_locked_handler (req, __gluster_pmap_signin);
}


int
__gluster_pmap_signout (rpcsvc_request_t *req)
{
        pmap_signout_req      args                 = {0,};
        pmap_signout_rsp      rsp                  = {0,};
        int                   ret                  = -1;
        xlator_t             *this                 = NULL;
        glusterd_conf_t      *conf                 = NULL;
        glusterd_volinfo_t   *volinfo              = NULL;
        glusterd_brickinfo_t *brickinfo            = NULL;
        char                  pidfile[PATH_MAX]    = {0};
        char                  brick_path[PATH_MAX] = {0,};

        this = THIS;
        GF_VALIDATE_OR_GOTO ("glusterd", this, fail);
        conf = this->private;
        GF_VALIDATE_OR_GOTO (this->name, conf, fail);

        ret = xdr_to_generic (req->msg[0], &args,
                              (xdrproc_t)xdr_pmap_signout_req);
        if (ret < 0) {
                //failed to decode msg;
                req->rpc_err = GARBAGE_ARGS;
                goto fail;
        }
        rsp.op_ret = pmap_registry_remove (THIS, args.port, args.brick,
                                           GF_PMAP_PORT_BRICKSERVER, req->trans);

        ret = glusterd_get_brickinfo (THIS, args.brick, args.port, &brickinfo);
        if (args.rdma_port) {
                snprintf(brick_path, PATH_MAX, "%s.rdma", args.brick);
                rsp.op_ret = pmap_registry_remove (THIS, args.rdma_port,
                                brick_path, GF_PMAP_PORT_BRICKSERVER,
                                req->trans);
        }
        /* Clean up the pidfile for this brick given glusterfsd doesn't clean it
         * any more. This is required to ensure we don't end up with having
         * stale pid files in case a brick is killed from the backend
         */
        ret = glusterd_get_volinfo_from_brick (args.brick, &volinfo);
        if (!ret) {
                if (volinfo && brickinfo) {
                        GLUSTERD_GET_BRICK_PIDFILE (pidfile, volinfo, brickinfo,
                                                    conf);
                        sys_unlink (pidfile);

                        /* Setting the brick status to GF_BRICK_STOPPED to
                         * ensure correct brick status is maintained on the
                         * glusterd end when a brick is killed from the
                         * backend */
                        brickinfo->status = GF_BRICK_STOPPED;

                        /* Remove brick from brick process if not already
                         * removed in the brick op phase. This situation would
                         * arise when the brick is killed explicitly from the
                         * backend */
                        ret = glusterd_brick_process_remove_brick (brickinfo);
                        if (ret) {
                                gf_msg_debug (this->name, 0, "Couldn't remove "
                                              "brick %s:%s from brick process",
                                              brickinfo->hostname,
                                              brickinfo->path);
                                /* Ignore 'ret' here since the brick might
                                 * have already been deleted in brick op phase
                                 */
                                ret = 0;
                        }
                }
        }

fail:
        glusterd_submit_reply (req, &rsp, NULL, 0, NULL,
                               (xdrproc_t)xdr_pmap_signout_rsp);
        free (args.brick);//malloced by xdr

        return 0;
}

int
gluster_pmap_signout (rpcsvc_request_t *req)
{
        return glusterd_big_locked_handler (req, __gluster_pmap_signout);
}

rpcsvc_actor_t gluster_pmap_actors[GF_PMAP_MAXVALUE] = {
        [GF_PMAP_NULL]        = {"NULL",        GF_PMAP_NULL,        NULL,                     NULL, 0, DRC_NA},
        [GF_PMAP_PORTBYBRICK] = {"PORTBYBRICK", GF_PMAP_PORTBYBRICK, gluster_pmap_portbybrick, NULL, 0, DRC_NA},
        [GF_PMAP_BRICKBYPORT] = {"BRICKBYPORT", GF_PMAP_BRICKBYPORT, gluster_pmap_brickbyport, NULL, 0, DRC_NA},
        [GF_PMAP_SIGNIN]      = {"SIGNIN",      GF_PMAP_SIGNIN,      gluster_pmap_signin,      NULL, 0, DRC_NA},
        [GF_PMAP_SIGNOUT]     = {"SIGNOUT",     GF_PMAP_SIGNOUT,     gluster_pmap_signout,     NULL, 0, DRC_NA},
};


struct rpcsvc_program gluster_pmap_prog = {
        .progname  = "Gluster Portmap",
        .prognum   = GLUSTER_PMAP_PROGRAM,
        .progver   = GLUSTER_PMAP_VERSION,
        .actors    = gluster_pmap_actors,
        .numactors = GF_PMAP_MAXVALUE,
};