/*
   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 <glusterfs/xlator.h>
#include <glusterfs/glusterfs.h>
#include <glusterfs/syscall.h>
#include <glusterfs/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;
    pmap->max_port = ((glusterd_conf_t *)(this->private))->max_port;
    for (i = pmap->base_port; i <= pmap->max_port; 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;
    int max_port = 0;

    max_port = ((glusterd_conf_t *)(this->private))->max_port;
    if (port > max_port)
        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 <= pmap->max_port; 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, _gf_false);
        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 > pmap->max_port)
        goto out;

    p = port;
    if (pmap->ports[p].type == GF_PMAP_PORT_FREE) {
        /* Because of some crazy race in volume start code path because
         * of friend handshaking with volumes with quorum enabled we
         * might end up into a situation where glusterd would start a
         * brick and get a disconnect and then immediately try to start
         * the same brick instance based on another friend update
         * request. And then if for the very first brick even if the
         * process doesn't come up at the end sign in event gets sent
         * and we end up having two duplicate portmap entries for the
         * same brick. Since in brick start we mark the previous port as
         * free, its better to consider a sign in request as no op if
         * the corresponding port type is marked as free
         */
        goto out;
    }
    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 > pmap->max_port) {
        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,
                     gf_boolean_t brick_disconnect)
{
    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 > pmap->max_port)
            goto out;
    }

    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 (brick_disconnect || !pmap->ports[p].xprt) {
        /* If the signout call is being triggered by brick disconnect
         * then clean up all the bricks (in case of brick mux)
         */
        if (!brick_disconnect) {
            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;
    xlator_t *this = THIS;
    GF_ASSERT(this);

    ret = xdr_to_generic(req->msg[0], &args,
                         (xdrproc_t)xdr_pmap_port_by_brick_req);
    if (ret < 0) {
        req->rpc_err = GARBAGE_ARGS;
        gf_smsg(this->name, GF_LOG_ERROR, errno, GD_MSG_GARBAGE_ARGS, NULL);
        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;
    xlator_t *this = THIS;
    GF_ASSERT(this);

    ret = xdr_to_generic(req->msg[0], &args,
                         (xdrproc_t)xdr_pmap_brick_by_port_req);
    if (ret < 0) {
        req->rpc_err = GARBAGE_ARGS;
        gf_smsg(this->name, GF_LOG_ERROR, errno, GD_MSG_GARBAGE_ARGS, NULL);
        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;
    xlator_t *this = THIS;
    GF_ASSERT(this);

    ret = xdr_to_generic(req->msg[0], &args, (xdrproc_t)xdr_pmap_signin_req);
    if (ret < 0) {
        req->rpc_err = GARBAGE_ARGS;
        gf_smsg(this->name, GF_LOG_ERROR, errno, GD_MSG_GARBAGE_ARGS, NULL);
        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);
    /* Update portmap status in brickinfo */
    if (brickinfo)
        brickinfo->port_registered = _gf_true;

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;
        gf_smsg(this->name, GF_LOG_ERROR, errno, GD_MSG_GARBAGE_ARGS, NULL);
        goto fail;
    }
    rsp.op_ret = pmap_registry_remove(THIS, args.port, args.brick,
                                      GF_PMAP_PORT_BRICKSERVER, req->trans,
                                      _gf_false);

    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,
                                          _gf_false);
    }
    /* Update portmap status on brickinfo */
    if (brickinfo)
        brickinfo->port_registered = _gf_false;

    /* 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, NULL);
            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);
}

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

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,
};