/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2016 Nexenta Systems, Inc.  All rights reserved.
 * Copyright (c) 1989, 2010, Oracle and/or its affiliates. All rights reserved.
 */

/*      Copyright (c) 1988 AT&T */
/*      All Rights Reserved   */

/*
 * svc_generic.c, Server side for RPC.
 *
 */

#include "mt.h"
#include <stdlib.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <netinet/udp.h>
#include <inttypes.h>
#include "rpc_mt.h"
#include <stdio.h>
#include <rpc/rpc.h>
#include <sys/types.h>
#include <errno.h>
#include <syslog.h>
#include <rpc/nettype.h>
#include <malloc.h>
#include <string.h>
#include <stropts.h>
#include <tsol/label.h>
#include <nfs/nfs.h>
#include <nfs/nfs_acl.h>
#include <rpcsvc/mount.h>
#include <rpcsvc/nsm_addr.h>
#include <rpcsvc/rquota.h>
#include <rpcsvc/sm_inter.h>
#include <rpcsvc/nlm_prot.h>

extern int __svc_vc_setflag(SVCXPRT *, int);

extern SVCXPRT *svc_dg_create_private(int, uint_t, uint_t);
extern SVCXPRT *svc_vc_create_private(int, uint_t, uint_t);
extern SVCXPRT *svc_fd_create_private(int, uint_t, uint_t);

extern bool_t __svc_add_to_xlist(SVCXPRT_LIST **, SVCXPRT *, mutex_t *);
extern void __svc_free_xlist(SVCXPRT_LIST **, mutex_t *);

extern bool_t __rpc_try_doors(const char *, bool_t *);

/*
 * The highest level interface for server creation.
 * It tries for all the nettokens in that particular class of token
 * and returns the number of handles it can create and/or find.
 *
 * It creates a link list of all the handles it could create.
 * If svc_create() is called multiple times, it uses the handle
 * created earlier instead of creating a new handle every time.
 */

/* VARIABLES PROTECTED BY xprtlist_lock: xprtlist */

SVCXPRT_LIST *_svc_xprtlist = NULL;
extern mutex_t xprtlist_lock;

static SVCXPRT * svc_tli_create_common(int, const struct netconfig *,
    const struct t_bind *, uint_t, uint_t, boolean_t);

static SVCXPRT *svc_tp_create_bind(void (*dispatch)(),
    const rpcprog_t, const rpcvers_t,
    const struct netconfig *, const struct t_bind *);

boolean_t
is_multilevel(rpcprog_t prognum)
{
        /* This is a list of identified multilevel service provider */
        if ((prognum == MOUNTPROG) || (prognum == NFS_PROGRAM) ||
            (prognum == NFS_ACL_PROGRAM) || (prognum == NLM_PROG) ||
            (prognum == NSM_ADDR_PROGRAM) || (prognum == RQUOTAPROG) ||
            (prognum == SM_PROG))
                return (B_TRUE);

        return (B_FALSE);
}

void
__svc_free_xprtlist(void)
{
        __svc_free_xlist(&_svc_xprtlist, &xprtlist_lock);
}

int
svc_create(void (*dispatch)(), const rpcprog_t prognum, const rpcvers_t versnum,
                                                        const char *nettype)
{
        SVCXPRT_LIST *l;
        int num = 0;
        SVCXPRT *xprt;
        struct netconfig *nconf;
        void *handle;
        bool_t try_others;

        /*
         * Check if service should register over doors transport.
         */
        if (__rpc_try_doors(nettype, &try_others)) {
                if (svc_door_create(dispatch, prognum, versnum, 0) == NULL)
                        (void) syslog(LOG_ERR,
                            "svc_create: could not register over doors");
                else
                        num++;
        }
        if (!try_others)
                return (num);
        if ((handle = __rpc_setconf((char *)nettype)) == NULL) {
                (void) syslog(LOG_ERR, "svc_create: unknown protocol");
                return (0);
        }
        while (nconf = __rpc_getconf(handle)) {
                (void) mutex_lock(&xprtlist_lock);
                for (l = _svc_xprtlist; l; l = l->next) {
                        if (strcmp(l->xprt->xp_netid, nconf->nc_netid) == 0) {
                                /* Found an old one, use it */
                                (void) rpcb_unset(prognum, versnum, nconf);
                                if (svc_reg(l->xprt, prognum, versnum,
                                    dispatch, nconf) == FALSE)
                                        (void) syslog(LOG_ERR, "svc_create: "
                                            "could not register prog %d vers "
                                            "%d on %s",
                                            prognum, versnum, nconf->nc_netid);
                                else
                                        num++;
                                break;
                        }
                }
                (void) mutex_unlock(&xprtlist_lock);
                if (l == NULL) {
                        /* It was not found. Now create a new one */
                        xprt = svc_tp_create(dispatch, prognum, versnum, nconf);
                        if (xprt) {
                                if (!__svc_add_to_xlist(&_svc_xprtlist, xprt,
                                    &xprtlist_lock)) {
                                        (void) syslog(LOG_ERR,
                                            "svc_create: no memory");
                                        return (0);
                                }
                                num++;
                        }
                }
        }
        __rpc_endconf(handle);
        /*
         * In case of num == 0; the error messages are generated by the
         * underlying layers; and hence not needed here.
         */
        return (num);
}

/*
 * The high level interface to svc_tli_create().
 * It tries to create a server for "nconf" and registers the service
 * with the rpcbind.
 */
SVCXPRT *
svc_tp_create(void (*dispatch)(), const rpcprog_t prognum,
    const rpcvers_t versnum, const struct netconfig *nconf)
{
        return (svc_tp_create_bind(dispatch, prognum, versnum, nconf, NULL));
}

/*
 * svc_tp_create_addr()
 * Variant of svc_tp_create() that allows specifying just the
 * the binding address, for convenience.
 */
SVCXPRT *
svc_tp_create_addr(void (*dispatch)(), const rpcprog_t prognum,
    const rpcvers_t versnum, const struct netconfig *nconf,
    const struct netbuf *addr)
{
        struct t_bind bind;
        struct t_bind *bindp = NULL;

        if (addr != NULL) {

                bind.addr = *addr;
                if (!rpc_control(__RPC_SVC_LSTNBKLOG_GET, &bind.qlen)) {
                        syslog(LOG_ERR,
                            "svc_tp_create: can't get listen backlog");
                        return (NULL);
                }
                bindp = &bind;
        }

        /*
         * When bindp == NULL, this is the same as svc_tp_create().
         */
        return (svc_tp_create_bind(dispatch, prognum, versnum,
            nconf, bindp));
}

static SVCXPRT *
svc_tp_create_bind(void (*dispatch)(), const rpcprog_t prognum,
    const rpcvers_t versnum, const struct netconfig *nconf,
    const struct t_bind *bindaddr)
{
        SVCXPRT *xprt;
        boolean_t anon_mlp = B_FALSE;

        if (nconf == NULL) {
                (void) syslog(LOG_ERR, "svc_tp_create: invalid netconfig "
                    "structure for prog %d vers %d", prognum, versnum);
                return (NULL);
        }

        /* Some programs need to allocate MLP for multilevel services */
        if (is_system_labeled() && is_multilevel(prognum))
                anon_mlp = B_TRUE;
        xprt = svc_tli_create_common(RPC_ANYFD, nconf, bindaddr, 0, 0,
            anon_mlp);
        if (xprt == NULL)
                return (NULL);

        (void) rpcb_unset(prognum, versnum, (struct netconfig *)nconf);
        if (svc_reg(xprt, prognum, versnum, dispatch, nconf) == FALSE) {
                (void) syslog(LOG_ERR,
                    "svc_tp_create: Could not register prog %d vers %d on %s",
                    prognum, versnum, nconf->nc_netid);
                SVC_DESTROY(xprt);
                return (NULL);
        }
        return (xprt);
}

SVCXPRT *
svc_tli_create(const int fd, const struct netconfig *nconf,
    const struct t_bind *bindaddr, const uint_t sendsz, const uint_t recvsz)
{
        return (svc_tli_create_common(fd, nconf, bindaddr, sendsz, recvsz, 0));
}

/*
 * If fd is RPC_ANYFD, then it opens a fd for the given transport
 * provider (nconf cannot be NULL then). If the t_state is T_UNBND and
 * bindaddr is NON-NULL, it performs a t_bind using the bindaddr. For
 * NULL bindadr and Connection oriented transports, the value of qlen
 * is set arbitrarily.
 *
 * If sendsz or recvsz are zero, their default values are chosen.
 */
SVCXPRT *
svc_tli_create_common(const int ofd, const struct netconfig *nconf,
        const struct t_bind *bindaddr, const uint_t sendsz,
        const uint_t recvsz, boolean_t mlp_flag)
{
        SVCXPRT *xprt = NULL;           /* service handle */
        struct t_info tinfo;            /* transport info */
        struct t_bind *tres = NULL;     /* bind info */
        bool_t madefd = FALSE;          /* whether fd opened here  */
        int state;                      /* state of the transport provider */
        int fd = ofd;

        if (fd == RPC_ANYFD) {
                if (nconf == NULL) {
                        (void) syslog(LOG_ERR,
                            "svc_tli_create: invalid netconfig");
                        return (NULL);
                }
                fd = t_open(nconf->nc_device, O_RDWR, &tinfo);
                if (fd == -1) {
                        char errorstr[100];

                        __tli_sys_strerror(errorstr, sizeof (errorstr),
                            t_errno, errno);
                        (void) syslog(LOG_ERR, "svc_tli_create: could not open "
                            "connection for %s: %s", nconf->nc_netid, errorstr);
                        return (NULL);
                }
                madefd = TRUE;
                state = T_UNBND;
        } else {
                /*
                 * It is an open descriptor. Sync it & get the transport info.
                 */
                if ((state = t_sync(fd)) == -1) {
                        char errorstr[100];

                        __tli_sys_strerror(errorstr, sizeof (errorstr),
                            t_errno, errno);
                        (void) syslog(LOG_ERR,
                            "svc_tli_create: could not do t_sync: %s",
                            errorstr);
                        return (NULL);
                }
                if (t_getinfo(fd, &tinfo) == -1) {
                        char errorstr[100];

                        __tli_sys_strerror(errorstr, sizeof (errorstr),
                            t_errno, errno);
                        (void) syslog(LOG_ERR, "svc_tli_create: could not get "
                            "transport information: %s", errorstr);
                        return (NULL);
                }
                /* Enable options of returning the ip's for udp */
                if (nconf) {
                        int ret = 0;
                        if (strcmp(nconf->nc_netid, "udp6") == 0) {
                                ret = __rpc_tli_set_options(fd, IPPROTO_IPV6,
                                    IPV6_RECVPKTINFO, 1);
                                if (ret < 0) {
                                        char errorstr[100];

                                        __tli_sys_strerror(errorstr,
                                            sizeof (errorstr), t_errno, errno);
                                        (void) syslog(LOG_ERR,
                                            "svc_tli_create: "
                                            "IPV6_RECVPKTINFO(1): %s",
                                            errorstr);
                                        return (NULL);
                                }
                        } else if (strcmp(nconf->nc_netid, "udp") == 0) {
                                ret = __rpc_tli_set_options(fd, IPPROTO_IP,
                                    IP_RECVDSTADDR, 1);
                                if (ret < 0) {
                                        char errorstr[100];

                                        __tli_sys_strerror(errorstr,
                                            sizeof (errorstr), t_errno, errno);
                                        (void) syslog(LOG_ERR,
                                            "svc_tli_create: "
                                            "IP_RECVDSTADDR(1): %s", errorstr);
                                        return (NULL);
                                }
                        }
                }
        }

        /*
         * If the fd is unbound, try to bind it.
         * In any case, try to get its bound info in tres
         */
/* LINTED pointer alignment */
        tres = (struct t_bind *)t_alloc(fd, T_BIND, T_ADDR);
        if (tres == NULL) {
                (void) syslog(LOG_ERR, "svc_tli_create: No memory!");
                goto freedata;
        }

        switch (state) {
        case T_UNBND:
                /* If this is a labeled system, then ask for an MLP */
                if (is_system_labeled() &&
                    (strcmp(nconf->nc_protofmly, NC_INET) == 0 ||
                    strcmp(nconf->nc_protofmly, NC_INET6) == 0)) {
                        (void) __rpc_tli_set_options(fd, SOL_SOCKET,
                            SO_RECVUCRED, 1);
                        if (mlp_flag)
                                (void) __rpc_tli_set_options(fd, SOL_SOCKET,
                                    SO_ANON_MLP, 1);
                }

                if (bindaddr) {
                        /*
                         * Services that specify a bind address typically
                         * use a fixed service (IP port) so we need to set
                         * SO_REUSEADDR to prevent bind errors on restart.
                         */
                        if (bindaddr->addr.len != 0)
                                (void) __rpc_tli_set_options(fd, SOL_SOCKET,
                                    SO_REUSEADDR, 1);
                        if (t_bind(fd, (struct t_bind *)bindaddr, tres) == -1) {
                                char errorstr[100];

                                __tli_sys_strerror(errorstr, sizeof (errorstr),
                                    t_errno, errno);
                                (void) syslog(LOG_ERR,
                                    "svc_tli_create: could not bind: %s",
                                    errorstr);
                                goto freedata;
                        }
                        /*
                         * Should compare the addresses only if addr.len
                         * was non-zero
                         */
                        if (bindaddr->addr.len &&
                            (memcmp(bindaddr->addr.buf, tres->addr.buf,
                            (int)tres->addr.len) != 0)) {
                                (void) syslog(LOG_ERR, "svc_tli_create: could "
                                    "not bind to requested address: address "
                                    "mismatch");
                                goto freedata;
                        }
                } else {
                        if (rpc_control(__RPC_SVC_LSTNBKLOG_GET, &tres->qlen)
                            == FALSE) {
                                syslog(LOG_ERR,
                                    "svc_tli_create: can't get listen backlog");
                                goto freedata;
                        }
                        tres->addr.len = 0;
                        if (t_bind(fd, tres, tres) == -1) {
                                char errorstr[100];

                                __tli_sys_strerror(errorstr, sizeof (errorstr),
                                    t_errno, errno);
                                (void) syslog(LOG_ERR,
                                    "svc_tli_create: could not bind: %s",
                                    errorstr);
                                goto freedata;
                        }
                }

                /*
                 * If requested, set SO_EXCLBIND on each binding.
                 *
                 * SO_EXCLBIND has the following properties
                 *    - an fd bound to port P via IPv4 will prevent an IPv6
                 *    bind to port P (and vice versa)
                 *    - an fd bound to a wildcard IP address for port P will
                 *    prevent a more specific IP address bind to port P
                 *    (see {tcp,udp}.c for details)
                 *
                 * We use the latter property to prevent hijacking of RPC
                 * services that reside at non-privileged ports.
                 *
                 * When the bind address is not specified, each bind gets a
                 * new port number, and (for IP transports) we should set
                 * the exclusive flag after every IP bind.  That's the
                 * strcmp nc_proto part of the expression below.
                 *
                 * When the bind address IS specified, we need to set the
                 * exclusive flag only after we've bound both IPv6+IPv4,
                 * or the IPv4 bind will fail.  Setting the exclusive flag
                 * after the "tcp" or "udp" transport bind does that.
                 * That's the strcmp nc_netid part below.
                 */
                if (nconf != NULL && ((bindaddr == NULL &&
                    (strcmp(nconf->nc_proto, NC_TCP) == 0 ||
                    strcmp(nconf->nc_proto, NC_UDP) == 0)) ||
                    (strcmp(nconf->nc_netid, "tcp") == 0 ||
                    strcmp(nconf->nc_netid, "udp") == 0))) {
                        bool_t exclbind = FALSE;
                        (void) rpc_control(__RPC_SVC_EXCLBIND_GET, &exclbind);
                        if (exclbind &&
                            __rpc_tli_set_options(fd, SOL_SOCKET,
                            SO_EXCLBIND, 1) < 0) {
                                syslog(LOG_ERR,
                            "svc_tli_create: can't set EXCLBIND [netid='%s']",
                                    nconf->nc_netid);
                                goto freedata;
                        }
                }

                /* Enable options of returning the ip's for udp */
                if (nconf) {
                        int ret = 0;
                        if (strcmp(nconf->nc_netid, "udp6") == 0) {
                                ret = __rpc_tli_set_options(fd, IPPROTO_IPV6,
                                    IPV6_RECVPKTINFO, 1);
                                if (ret < 0) {
                                        char errorstr[100];

                                        __tli_sys_strerror(errorstr,
                                            sizeof (errorstr), t_errno, errno);
                                        (void) syslog(LOG_ERR,
                                            "svc_tli_create: "
                                            "IPV6_RECVPKTINFO(2): %s",
                                            errorstr);
                                        goto freedata;
                                }
                        } else if (strcmp(nconf->nc_netid, "udp") == 0) {
                                ret = __rpc_tli_set_options(fd, IPPROTO_IP,
                                    IP_RECVDSTADDR, 1);
                                if (ret < 0) {
                                        char errorstr[100];

                                        __tli_sys_strerror(errorstr,
                                            sizeof (errorstr), t_errno, errno);
                                        (void) syslog(LOG_ERR,
                                            "svc_tli_create: "
                                            "IP_RECVDSTADDR(2): %s", errorstr);
                                        goto freedata;
                                }
                        }
                }
                break;

        case T_IDLE:
                if (bindaddr) {
                        /* Copy the entire stuff in tres */
                        if (tres->addr.maxlen < bindaddr->addr.len) {
                                (void) syslog(LOG_ERR,
                                "svc_tli_create: illegal netbuf length");
                                goto freedata;
                        }
                        tres->addr.len = bindaddr->addr.len;
                        (void) memcpy(tres->addr.buf, bindaddr->addr.buf,
                            (int)tres->addr.len);
                } else
                        if (t_getname(fd, &(tres->addr), LOCALNAME) == -1)
                                tres->addr.len = 0;
                break;
        case T_INREL:
                (void) t_rcvrel(fd);
                (void) t_sndrel(fd);
                (void) syslog(LOG_ERR, "svc_tli_create: other side wants to "
                    "release connection");
                goto freedata;

        case T_INCON:
                /* Do nothing here. Assume this is handled in rendezvous */
                break;
        case T_DATAXFER:
                /*
                 * This takes care of the case where a fd
                 * is passed on which a connection has already
                 * been accepted.
                 */
                if (t_getname(fd, &(tres->addr), LOCALNAME) == -1)
                        tres->addr.len = 0;
                break;
        default:
                (void) syslog(LOG_ERR,
                    "svc_tli_create: connection in a wierd state (%d)", state);
                goto freedata;
        }

        /*
         * call transport specific function.
         */
        switch (tinfo.servtype) {
                case T_COTS_ORD:
                case T_COTS:
                        if (state == T_DATAXFER)
                                xprt = svc_fd_create_private(fd, sendsz,
                                    recvsz);
                        else
                                xprt = svc_vc_create_private(fd, sendsz,
                                    recvsz);
                        if (!nconf || !xprt)
                                break;
                        if ((tinfo.servtype == T_COTS_ORD) &&
                            (state != T_DATAXFER) &&
                            (strcmp(nconf->nc_protofmly, "inet") == 0))
                                (void) __svc_vc_setflag(xprt, TRUE);
                        break;
                case T_CLTS:
                        xprt = svc_dg_create_private(fd, sendsz, recvsz);
                        break;
                default:
                        (void) syslog(LOG_ERR,
                            "svc_tli_create: bad service type");
                        goto freedata;
        }
        if (xprt == NULL)
                /*
                 * The error messages here are spitted out by the lower layers:
                 * svc_vc_create(), svc_fd_create() and svc_dg_create().
                 */
                goto freedata;

        /* fill in the other xprt information */

        /* Assign the local bind address */
        xprt->xp_ltaddr = tres->addr;
        /* Fill in type of service */
        xprt->xp_type = tinfo.servtype;
        tres->addr.buf = NULL;
        (void) t_free((char *)tres, T_BIND);
        tres = NULL;

        xprt->xp_rtaddr.len = 0;
        xprt->xp_rtaddr.maxlen = __rpc_get_a_size(tinfo.addr);

        /* Allocate space for the remote bind info */
        if ((xprt->xp_rtaddr.buf = malloc(xprt->xp_rtaddr.maxlen)) == NULL) {
                (void) syslog(LOG_ERR, "svc_tli_create: No memory!");
                goto freedata;
        }

        if (nconf) {
                xprt->xp_netid = strdup(nconf->nc_netid);
                if (xprt->xp_netid == NULL) {
                        if (xprt->xp_rtaddr.buf)
                                free(xprt->xp_rtaddr.buf);
                        syslog(LOG_ERR, "svc_tli_create: strdup failed!");
                        goto freedata;
                }
                xprt->xp_tp = strdup(nconf->nc_device);
                if (xprt->xp_tp == NULL) {
                        if (xprt->xp_rtaddr.buf)
                                free(xprt->xp_rtaddr.buf);
                        if (xprt->xp_netid)
                                free(xprt->xp_netid);
                        syslog(LOG_ERR, "svc_tli_create: strdup failed!");
                        goto freedata;
                }
        }

/*
 *      if (madefd && (tinfo.servtype == T_CLTS))
 *              (void) ioctl(fd, I_POP, NULL);
 */
        xprt_register(xprt);
        return (xprt);

freedata:
        if (madefd)
                (void) t_close(fd);
        if (tres)
                (void) t_free((char *)tres, T_BIND);
        if (xprt) {
                if (!madefd) /* so that svc_destroy doesnt close fd */
                        xprt->xp_fd = RPC_ANYFD;
                SVC_DESTROY(xprt);
        }
        return (NULL);
}