/*      $NetBSD: rpc_generic.c,v 1.4 2000/09/28 09:07:04 kleink Exp $   */

/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 2009, Sun Microsystems, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without 
 * modification, are permitted provided that the following conditions are met:
 * - Redistributions of source code must retain the above copyright notice, 
 *   this list of conditions and the following disclaimer.
 * - 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.
 * - Neither the name of Sun Microsystems, Inc. nor the names of its 
 *   contributors may be used to endorse or promote products derived 
 *   from this software without specific prior written permission.
 * 
 * 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 HOLDER 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.
 */
/*
 * Copyright (c) 1986-1991 by Sun Microsystems Inc. 
 */

/*
 * rpc_generic.c, Miscl routines for RPC.
 *
 */

#include "namespace.h"
#include "reentrant.h"
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/un.h>
#include <sys/resource.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <rpc/rpc.h>
#include <ctype.h>
#include <stddef.h>
#include <stdio.h>
#include <netdb.h>
#include <netconfig.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <rpc/nettype.h>
#include "un-namespace.h"
#include "rpc_com.h"
#include "mt_misc.h"

struct handle {
        NCONF_HANDLE *nhandle;
        int nflag;              /* Whether NETPATH or NETCONFIG */
        int nettype;
};

static const struct _rpcnettype {
        const char *name;
        const int type;
} _rpctypelist[] = {
        { "netpath", _RPC_NETPATH },
        { "visible", _RPC_VISIBLE },
        { "circuit_v", _RPC_CIRCUIT_V },
        { "datagram_v", _RPC_DATAGRAM_V },
        { "circuit_n", _RPC_CIRCUIT_N },
        { "datagram_n", _RPC_DATAGRAM_N },
        { "tcp", _RPC_TCP },
        { "udp", _RPC_UDP },
        { 0, _RPC_NONE }
};

struct netid_af {
        const char      *netid;
        int             af;
        int             protocol;
};

static const struct netid_af na_cvt[] = {
        { "udp",  AF_INET,  IPPROTO_UDP },
        { "tcp",  AF_INET,  IPPROTO_TCP },
#ifdef INET6
        { "udp6", AF_INET6, IPPROTO_UDP },
        { "tcp6", AF_INET6, IPPROTO_TCP },
#endif
        { "local", AF_LOCAL, 0 },
        { "netlink", AF_NETLINK, 0 },
};

#if 0
static char *strlocase(char *);
#endif
static int getnettype(const char *);


/*
 * Find the appropriate buffer size
 *
 * size - Size requested
 */
u_int
/*ARGSUSED*/
__rpc_get_t_size(int af, int proto, int size)
{
        int maxsize, defsize;

        maxsize = 256 * 1024;   /* XXX */
        switch (proto) {
        case IPPROTO_TCP:
                defsize = 64 * 1024;    /* XXX */
                break;
        case IPPROTO_UDP:
                defsize = UDPMSGSIZE;
                break;
        default:
                defsize = RPC_MAXDATASIZE;
                break;
        }
        if (size == 0)
                return defsize;

        /* Check whether the value is within the upper max limit */
        return (size > maxsize ? (u_int)maxsize : (u_int)size);
}

/*
 * Find the appropriate address buffer size
 */
u_int
__rpc_get_a_size(int af)
{
        switch (af) {
        case AF_INET:
                return sizeof (struct sockaddr_in);
#ifdef INET6
        case AF_INET6:
                return sizeof (struct sockaddr_in6);
#endif
        case AF_LOCAL:
                return sizeof (struct sockaddr_un);
        default:
                break;
        }
        return ((u_int)RPC_MAXADDRSIZE);
}

#if 0
static char *
strlocase(char *p)
{
        char *t = p;

        for (; *p; p++)
                if (isupper(*p))
                        *p = tolower(*p);
        return (t);
}
#endif

/*
 * Returns the type of the network as defined in <rpc/nettype.h>
 * If nettype is NULL, it defaults to NETPATH.
 */
static int
getnettype(const char *nettype)
{
        int i;

        if ((nettype == NULL) || (nettype[0] == 0)) {
                return (_RPC_NETPATH);  /* Default */
        }

#if 0
        nettype = strlocase(nettype);
#endif
        for (i = 0; _rpctypelist[i].name; i++)
                if (strcasecmp(nettype, _rpctypelist[i].name) == 0) {
                        return (_rpctypelist[i].type);
                }
        return (_rpctypelist[i].type);
}

static thread_key_t tcp_key, udp_key;
static once_t keys_once = ONCE_INITIALIZER;
static int tcp_key_error, udp_key_error;

static void
keys_init(void)
{

        tcp_key_error = thr_keycreate(&tcp_key, free);
        udp_key_error = thr_keycreate(&udp_key, free);
}

/*
 * For the given nettype (tcp or udp only), return the first structure found.
 * This should be freed by calling freenetconfigent()
 */
struct netconfig *
__rpc_getconfip(const char *nettype)
{
        char *netid;
        char *netid_tcp = (char *) NULL;
        char *netid_udp = (char *) NULL;
        static char *netid_tcp_main;
        static char *netid_udp_main;
        struct netconfig *dummy;
        int main_thread;

        if ((main_thread = thr_main())) {
                netid_udp = netid_udp_main;
                netid_tcp = netid_tcp_main;
        } else {
                if (thr_once(&keys_once, keys_init) != 0 ||
                    tcp_key_error != 0 || udp_key_error != 0)
                        return (NULL);
                netid_tcp = (char *)thr_getspecific(tcp_key);
                netid_udp = (char *)thr_getspecific(udp_key);
        }
        if (!netid_udp && !netid_tcp) {
                struct netconfig *nconf;
                void *confighandle;

                if (!(confighandle = setnetconfig())) {
                        syslog (LOG_ERR, "rpc: failed to open " NETCONFIG);
                        return (NULL);
                }
                while ((nconf = getnetconfig(confighandle)) != NULL) {
                        if (strcmp(nconf->nc_protofmly, NC_INET) == 0) {
                                if (strcmp(nconf->nc_proto, NC_TCP) == 0 &&
                                    netid_tcp == NULL) {
                                        netid_tcp = strdup(nconf->nc_netid);
                                        if (main_thread)
                                                netid_tcp_main = netid_tcp;
                                        else
                                                thr_setspecific(tcp_key,
                                                        (void *) netid_tcp);
                                } else
                                if (strcmp(nconf->nc_proto, NC_UDP) == 0 &&
                                    netid_udp == NULL) {
                                        netid_udp = strdup(nconf->nc_netid);
                                        if (main_thread)
                                                netid_udp_main = netid_udp;
                                        else
                                                thr_setspecific(udp_key,
                                                (void *) netid_udp);
                                }
                        }
                }
                endnetconfig(confighandle);
        }
        if (strcmp(nettype, "udp") == 0)
                netid = netid_udp;
        else if (strcmp(nettype, "tcp") == 0)
                netid = netid_tcp;
        else {
                return (NULL);
        }
        if ((netid == NULL) || (netid[0] == 0)) {
                return (NULL);
        }
        dummy = getnetconfigent(netid);
        return (dummy);
}

/*
 * Returns the type of the nettype, which should then be used with
 * __rpc_getconf().
 */
void *
__rpc_setconf(const char *nettype)
{
        struct handle *handle;

        handle = (struct handle *) malloc(sizeof (struct handle));
        if (handle == NULL) {
                return (NULL);
        }
        switch (handle->nettype = getnettype(nettype)) {
        case _RPC_NETPATH:
        case _RPC_CIRCUIT_N:
        case _RPC_DATAGRAM_N:
                if (!(handle->nhandle = setnetpath()))
                        goto failed;
                handle->nflag = TRUE;
                break;
        case _RPC_VISIBLE:
        case _RPC_CIRCUIT_V:
        case _RPC_DATAGRAM_V:
        case _RPC_TCP:
        case _RPC_UDP:
                if (!(handle->nhandle = setnetconfig())) {
                        syslog (LOG_ERR, "rpc: failed to open " NETCONFIG);
                        goto failed;
                }
                handle->nflag = FALSE;
                break;
        default:
                goto failed;
        }

        return (handle);

failed:
        free(handle);
        return (NULL);
}

/*
 * Returns the next netconfig struct for the given "net" type.
 * __rpc_setconf() should have been called previously.
 */
struct netconfig *
__rpc_getconf(void *vhandle)
{
        struct handle *handle;
        struct netconfig *nconf;

        handle = (struct handle *)vhandle;
        if (handle == NULL) {
                return (NULL);
        }
        for (;;) {
                if (handle->nflag)
                        nconf = getnetpath(handle->nhandle);
                else
                        nconf = getnetconfig(handle->nhandle);
                if (nconf == NULL)
                        break;
                if ((nconf->nc_semantics != NC_TPI_CLTS) &&
                        (nconf->nc_semantics != NC_TPI_COTS) &&
                        (nconf->nc_semantics != NC_TPI_COTS_ORD))
                        continue;
                switch (handle->nettype) {
                case _RPC_VISIBLE:
                        if (!(nconf->nc_flag & NC_VISIBLE))
                                continue;
                        /* FALLTHROUGH */
                case _RPC_NETPATH:      /* Be happy */
                        break;
                case _RPC_CIRCUIT_V:
                        if (!(nconf->nc_flag & NC_VISIBLE))
                                continue;
                        /* FALLTHROUGH */
                case _RPC_CIRCUIT_N:
                        if ((nconf->nc_semantics != NC_TPI_COTS) &&
                                (nconf->nc_semantics != NC_TPI_COTS_ORD))
                                continue;
                        break;
                case _RPC_DATAGRAM_V:
                        if (!(nconf->nc_flag & NC_VISIBLE))
                                continue;
                        /* FALLTHROUGH */
                case _RPC_DATAGRAM_N:
                        if (nconf->nc_semantics != NC_TPI_CLTS)
                                continue;
                        break;
                case _RPC_TCP:
                        if (((nconf->nc_semantics != NC_TPI_COTS) &&
                                (nconf->nc_semantics != NC_TPI_COTS_ORD)) ||
                                (strcmp(nconf->nc_protofmly, NC_INET)
#ifdef INET6
                                 && strcmp(nconf->nc_protofmly, NC_INET6))
#else
                                )
#endif
                                ||
                                strcmp(nconf->nc_proto, NC_TCP))
                                continue;
                        break;
                case _RPC_UDP:
                        if ((nconf->nc_semantics != NC_TPI_CLTS) ||
                                (strcmp(nconf->nc_protofmly, NC_INET)
#ifdef INET6
                                && strcmp(nconf->nc_protofmly, NC_INET6))
#else
                                )
#endif
                                ||
                                strcmp(nconf->nc_proto, NC_UDP))
                                continue;
                        break;
                }
                break;
        }
        return (nconf);
}

void
__rpc_endconf(void *vhandle)
{
        struct handle *handle;

        handle = (struct handle *) vhandle;
        if (handle == NULL) {
                return;
        }
        if (handle->nflag) {
                endnetpath(handle->nhandle);
        } else {
                endnetconfig(handle->nhandle);
        }
        free(handle);
}

/*
 * Used to ping the NULL procedure for clnt handle.
 * Returns NULL if fails, else a non-NULL pointer.
 */
void *
rpc_nullproc(CLIENT *clnt)
{
        struct timeval TIMEOUT = {25, 0};

        if (clnt_call(clnt, NULLPROC, (xdrproc_t) xdr_void, NULL,
                (xdrproc_t) xdr_void, NULL, TIMEOUT) != RPC_SUCCESS) {
                return (NULL);
        }
        return ((void *) clnt);
}

/*
 * Try all possible transports until
 * one succeeds in finding the netconf for the given fd.
 */
struct netconfig *
__rpcgettp(int fd)
{
        const char *netid;
        struct __rpc_sockinfo si;

        if (!__rpc_fd2sockinfo(fd, &si))
                return NULL;

        if (!__rpc_sockinfo2netid(&si, &netid))
                return NULL;

        /*LINTED const castaway*/
        return getnetconfigent((char *)netid);
}

int
__rpc_fd2sockinfo(int fd, struct __rpc_sockinfo *sip)
{
        socklen_t len;
        int type, proto;
        struct sockaddr_storage ss;

        len = sizeof ss;
        if (_getsockname(fd, (struct sockaddr *)(void *)&ss, &len) < 0)
                return 0;
        sip->si_alen = len;

        len = sizeof type;
        if (_getsockopt(fd, SOL_SOCKET, SO_TYPE, &type, &len) < 0)
                return 0;

        /* XXX */
        if (ss.ss_family != AF_LOCAL) {
                if (type == SOCK_STREAM)
                        proto = IPPROTO_TCP;
                else if (type == SOCK_DGRAM)
                        proto = IPPROTO_UDP;
                else
                        return 0;
        } else
                proto = 0;

        sip->si_af = ss.ss_family;
        sip->si_proto = proto;
        sip->si_socktype = type;

        return 1;
}

/*
 * Linear search, but the number of entries is small.
 */
int
__rpc_nconf2sockinfo(const struct netconfig *nconf, struct __rpc_sockinfo *sip)
{
        int i;

        for (i = 0; i < (sizeof na_cvt) / (sizeof (struct netid_af)); i++)
                if (strcmp(na_cvt[i].netid, nconf->nc_netid) == 0 || (
                    strcmp(nconf->nc_netid, "unix") == 0 &&
                    strcmp(na_cvt[i].netid, "local") == 0)) {
                        sip->si_af = na_cvt[i].af;
                        sip->si_proto = na_cvt[i].protocol;
                        sip->si_socktype =
                            __rpc_seman2socktype((int)nconf->nc_semantics);
                        if (sip->si_socktype == -1)
                                return 0;
                        sip->si_alen = __rpc_get_a_size(sip->si_af);
                        return 1;
                }

        return 0;
}

int
__rpc_nconf2fd(const struct netconfig *nconf)
{
        struct __rpc_sockinfo si;

        if (!__rpc_nconf2sockinfo(nconf, &si))
                return 0;

        return _socket(si.si_af, si.si_socktype, si.si_proto);
}

int
__rpc_sockinfo2netid(struct __rpc_sockinfo *sip, const char **netid)
{
        int i;
        struct netconfig *nconf;

        nconf = getnetconfigent("local");

        for (i = 0; i < (sizeof na_cvt) / (sizeof (struct netid_af)); i++) {
                if (na_cvt[i].af == sip->si_af &&
                    na_cvt[i].protocol == sip->si_proto) {
                        if (strcmp(na_cvt[i].netid, "local") == 0 && nconf == NULL) {
                                if (netid)
                                        *netid = "unix";
                        } else {
                                if (netid)
                                        *netid = na_cvt[i].netid;
                        }
                        if (nconf != NULL)
                                freenetconfigent(nconf);
                        return 1;
                }
        }
        if (nconf != NULL)
                freenetconfigent(nconf);

        return 0;
}

char *
taddr2uaddr(const struct netconfig *nconf, const struct netbuf *nbuf)
{
        struct __rpc_sockinfo si;

        if (!__rpc_nconf2sockinfo(nconf, &si))
                return NULL;
        return __rpc_taddr2uaddr_af(si.si_af, nbuf);
}

struct netbuf *
uaddr2taddr(const struct netconfig *nconf, const char *uaddr)
{
        struct __rpc_sockinfo si;
        
        if (!__rpc_nconf2sockinfo(nconf, &si))
                return NULL;
        return __rpc_uaddr2taddr_af(si.si_af, uaddr);
}

char *
__rpc_taddr2uaddr_af(int af, const struct netbuf *nbuf)
{
        char *ret;
        struct sockaddr_in *sin;
        struct sockaddr_un *sun;
        char namebuf[INET_ADDRSTRLEN];
#ifdef INET6
        struct sockaddr_in6 *sin6;
        char namebuf6[INET6_ADDRSTRLEN];
#endif
        u_int16_t port;

        switch (af) {
        case AF_INET:
                if (nbuf->len < sizeof(*sin))
                        return NULL;
                sin = nbuf->buf;
                if (inet_ntop(af, &sin->sin_addr, namebuf, sizeof namebuf)
                    == NULL)
                        return NULL;
                port = ntohs(sin->sin_port);
                if (asprintf(&ret, "%s.%u.%u", namebuf, ((u_int32_t)port) >> 8,
                    port & 0xff) < 0)
                        return NULL;
                break;
#ifdef INET6
        case AF_INET6:
                if (nbuf->len < sizeof(*sin6))
                        return NULL;
                sin6 = nbuf->buf;
                if (inet_ntop(af, &sin6->sin6_addr, namebuf6, sizeof namebuf6)
                    == NULL)
                        return NULL;
                port = ntohs(sin6->sin6_port);
                if (asprintf(&ret, "%s.%u.%u", namebuf6, ((u_int32_t)port) >> 8,
                    port & 0xff) < 0)
                        return NULL;
                break;
#endif
        case AF_NETLINK:
                if (asprintf(&ret, "%s", (char *)nbuf->buf) < 0)
                        return NULL;
                break;
        case AF_LOCAL:
                sun = nbuf->buf;
                if (asprintf(&ret, "%.*s", (int)(sun->sun_len -
                    offsetof(struct sockaddr_un, sun_path)),
                    sun->sun_path) < 0)
                        return (NULL);
                break;
        default:
                return NULL;
        }

        return ret;
}

struct netbuf *
__rpc_uaddr2taddr_af(int af, const char *uaddr)
{
        struct netbuf *ret = NULL;
        char *addrstr, *p;
        unsigned port, portlo, porthi;
        struct sockaddr_in *sin;
#ifdef INET6
        struct sockaddr_in6 *sin6;
#endif
        struct sockaddr_un *sun;

        port = 0;
        sin = NULL;

        if (uaddr == NULL)
                return NULL;

        addrstr = strdup(uaddr);
        if (addrstr == NULL)
                return NULL;

        /*
         * AF_LOCAL addresses are expected to be absolute
         * pathnames, anything else will be AF_INET or AF_INET6.
         */
        if (*addrstr != '/') {
                p = strrchr(addrstr, '.');
                if (p == NULL)
                        goto out;
                portlo = (unsigned)atoi(p + 1);
                *p = '\0';

                p = strrchr(addrstr, '.');
                if (p == NULL)
                        goto out;
                porthi = (unsigned)atoi(p + 1);
                *p = '\0';
                port = (porthi << 8) | portlo;
        }

        ret = (struct netbuf *)malloc(sizeof *ret);
        if (ret == NULL)
                goto out;
        
        switch (af) {
        case AF_INET:
                sin = (struct sockaddr_in *)malloc(sizeof *sin);
                if (sin == NULL)
                        goto out;
                memset(sin, 0, sizeof *sin);
                sin->sin_family = AF_INET;
                sin->sin_port = htons(port);
                if (inet_pton(AF_INET, addrstr, &sin->sin_addr) <= 0) {
                        free(sin);
                        free(ret);
                        ret = NULL;
                        goto out;
                }
                sin->sin_len = ret->maxlen = ret->len = sizeof *sin;
                ret->buf = sin;
                break;
#ifdef INET6
        case AF_INET6:
                sin6 = (struct sockaddr_in6 *)malloc(sizeof *sin6);
                if (sin6 == NULL)
                        goto out;
                memset(sin6, 0, sizeof *sin6);
                sin6->sin6_family = AF_INET6;
                sin6->sin6_port = htons(port);
                if (inet_pton(AF_INET6, addrstr, &sin6->sin6_addr) <= 0) {
                        free(sin6);
                        free(ret);
                        ret = NULL;
                        goto out;
                }
                sin6->sin6_len = ret->maxlen = ret->len = sizeof *sin6;
                ret->buf = sin6;
                break;
#endif
        case AF_LOCAL:
                sun = (struct sockaddr_un *)malloc(sizeof *sun);
                if (sun == NULL)
                        goto out;
                memset(sun, 0, sizeof *sun);
                sun->sun_family = AF_LOCAL;
                strncpy(sun->sun_path, addrstr, sizeof(sun->sun_path) - 1);
                ret->len = ret->maxlen = sun->sun_len = SUN_LEN(sun);
                ret->buf = sun;
                break;
        default:
                break;
        }
out:
        free(addrstr);
        return ret;
}

int
__rpc_seman2socktype(int semantics)
{
        switch (semantics) {
        case NC_TPI_CLTS:
                return SOCK_DGRAM;
        case NC_TPI_COTS_ORD:
                return SOCK_STREAM;
        case NC_TPI_RAW:
                return SOCK_RAW;
        default:
                break;
        }

        return -1;
}

int
__rpc_socktype2seman(int socktype)
{
        switch (socktype) {
        case SOCK_DGRAM:
                return NC_TPI_CLTS;
        case SOCK_STREAM:
                return NC_TPI_COTS_ORD;
        case SOCK_RAW:
                return NC_TPI_RAW;
        default:
                break;
        }

        return -1;
}

/*
 * XXXX - IPv6 scope IDs can't be handled in universal addresses.
 * Here, we compare the original server address to that of the RPC
 * service we just received back from a call to rpcbind on the remote
 * machine. If they are both "link local" or "site local", copy
 * the scope id of the server address over to the service address.
 */
int
__rpc_fixup_addr(struct netbuf *new, const struct netbuf *svc)
{
#ifdef INET6
        struct sockaddr *sa_new, *sa_svc;
        struct sockaddr_in6 *sin6_new, *sin6_svc;

        sa_svc = (struct sockaddr *)svc->buf;
        sa_new = (struct sockaddr *)new->buf;

        if (sa_new->sa_family == sa_svc->sa_family &&
            sa_new->sa_family == AF_INET6) {
                sin6_new = (struct sockaddr_in6 *)new->buf;
                sin6_svc = (struct sockaddr_in6 *)svc->buf;

                if ((IN6_IS_ADDR_LINKLOCAL(&sin6_new->sin6_addr) &&
                     IN6_IS_ADDR_LINKLOCAL(&sin6_svc->sin6_addr)) ||
                    (IN6_IS_ADDR_SITELOCAL(&sin6_new->sin6_addr) &&
                     IN6_IS_ADDR_SITELOCAL(&sin6_svc->sin6_addr))) {
                        sin6_new->sin6_scope_id = sin6_svc->sin6_scope_id;
                }
        }
#endif
        return 1;
}

int
__rpc_sockisbound(int fd)
{
        struct sockaddr_storage ss;
        socklen_t slen;

        slen = sizeof (struct sockaddr_storage);
        if (_getsockname(fd, (struct sockaddr *)(void *)&ss, &slen) < 0)
                return 0;

        switch (ss.ss_family) {
                case AF_INET:
                        return (((struct sockaddr_in *)
                            (void *)&ss)->sin_port != 0);
#ifdef INET6
                case AF_INET6:
                        return (((struct sockaddr_in6 *)
                            (void *)&ss)->sin6_port != 0);
#endif
                case AF_LOCAL:
                        /* XXX check this */
                        return (((struct sockaddr_un *)
                            (void *)&ss)->sun_path[0] != '\0');
                default:
                        break;
        }

        return 0;
}