/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1992, 1993, 1994
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Rick Macklem at The University of Guelph.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 * 3. Neither the name of the University 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 REGENTS 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 REGENTS 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.
 */

#include <sys/param.h>
#include <sys/linker.h>
#include <sys/module.h>
#include <sys/mount.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/syslog.h>
#include <sys/uio.h>

#include <rpc/rpc.h>
#include <rpc/pmap_clnt.h>
#include <rpc/pmap_prot.h>
#include <rpcsvc/nfs_prot.h>
#include <rpcsvc/mount.h>

#include <fs/nfs/nfsproto.h>
#include <fs/nfs/nfsv4_errstr.h>

#include <arpa/inet.h>
#include <net/route.h>
#include <net/if.h>

#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <mntopts.h>
#include <netdb.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <strings.h>
#include <sysexits.h>
#include <unistd.h>

#include "mounttab.h"

/* Table for af,sotype -> netid conversions. */
static struct nc_protos {
        const char *netid;
        int af;
        int sotype;
} nc_protos[] = {
        {"udp",         AF_INET,        SOCK_DGRAM},
        {"tcp",         AF_INET,        SOCK_STREAM},
        {"udp6",        AF_INET6,       SOCK_DGRAM},
        {"tcp6",        AF_INET6,       SOCK_STREAM},
        {NULL,          0,              0}
};

struct nfhret {
        u_long          stat;
        long            vers;
        long            auth;
        long            fhsize;
        u_char          nfh[NFS3_FHSIZE];
};
#define BGRND           0x01
#define ISBGRND         0x02
#define OF_NOINET4      0x04
#define OF_NOINET6      0x08
#define BGRNDNOW        0x10
static int retrycnt = -1;
static int opflags = 0;
static int nfsproto = IPPROTO_TCP;
static int mnttcp_ok = 1;
static int noconn = 0;
/* The 'portspec' is the server nfs port; NULL means look up via rpcbind. */
static const char *portspec = NULL;
static struct sockaddr *addr;
static int addrlen = 0;
static u_char *fh = NULL;
static int fhsize = 0;
static int secflavor = -1;
static int got_principal = 0;
static in_port_t mntproto_port = 0;

static enum mountmode {
        ANY,
        V2,
        V3,
        V4
} mountmode = ANY;

/* Return codes for nfs_tryproto. */
enum tryret {
        TRYRET_SUCCESS,
        TRYRET_TIMEOUT,         /* No response received. */
        TRYRET_REMOTEERR,       /* Error received from remote server. */
        TRYRET_LOCALERR         /* Local failure. */
};

static int      sec_name_to_num(const char *sec);
static const char       *sec_num_to_name(int num);
static int      getnfsargs(char **, char **, struct iovec **iov, int *iovlen);
/* void set_rpc_maxgrouplist(int); */
static struct netconfig *getnetconf_cached(const char *netid);
static const char       *netidbytype(int af, int sotype);
static void     usage(void) __dead2;
static int      xdr_dir(XDR *, char *);
static int      xdr_fh(XDR *, struct nfhret *);
static enum tryret nfs_tryproto(struct addrinfo *ai, char *hostp, char *spec,
    char **errstr, struct iovec **iov, int *iovlen);
static enum tryret returncode(enum clnt_stat stat, struct rpc_err *rpcerr);

int
main(int argc, char *argv[])
{
        int c;
        struct iovec *iov;
        int num, iovlen;
        char *host, *mntname, *p, *spec, *tmp;
        char mntpath[MAXPATHLEN], errmsg[255];
        char hostname[MAXHOSTNAMELEN + 1], gssn[MAXHOSTNAMELEN + 50];
        const char *gssname, *nmount_errstr;
        bool softintr;

        softintr = false;
        iov = NULL;
        iovlen = 0;
        memset(errmsg, 0, sizeof(errmsg));
        gssname = NULL;

        while ((c = getopt(argc, argv,
            "23a:bcdD:g:I:iLlNo:PR:r:sTt:w:x:U")) != -1)
                switch (c) {
                case '2':
                        mountmode = V2;
                        break;
                case '3':
                        mountmode = V3;
                        break;
                case 'a':
                        printf("-a deprecated, use -o readahead=<value>\n");
                        build_iovec(&iov, &iovlen, "readahead", optarg, (size_t)-1);
                        break;
                case 'b':
                        opflags |= BGRND;
                        break;
                case 'c':
                        printf("-c deprecated, use -o noconn\n");
                        build_iovec(&iov, &iovlen, "noconn", NULL, 0);
                        noconn = 1;
                        break;
                case 'D':
                        printf("-D deprecated, use -o deadthresh=<value>\n");
                        build_iovec(&iov, &iovlen, "deadthresh", optarg, (size_t)-1);
                        break;
                case 'd':
                        printf("-d deprecated, use -o dumbtimer");
                        build_iovec(&iov, &iovlen, "dumbtimer", NULL, 0);
                        break;
                case 'g':
                        printf("-g deprecated, use -o maxgroups");
                        num = strtol(optarg, &p, 10);
                        if (*p || num <= 0)
                                errx(1, "illegal -g value -- %s", optarg);
                        //set_rpc_maxgrouplist(num);
                        build_iovec(&iov, &iovlen, "maxgroups", optarg, (size_t)-1);
                        break;
                case 'I':
                        printf("-I deprecated, use -o readdirsize=<value>\n");
                        build_iovec(&iov, &iovlen, "readdirsize", optarg, (size_t)-1);
                        break;
                case 'i':
                        printf("-i deprecated, use -o intr\n");
                        build_iovec(&iov, &iovlen, "intr", NULL, 0);
                        softintr = true;
                        break;
                case 'L':
                        printf("-L deprecated, use -o nolockd\n");
                        build_iovec(&iov, &iovlen, "nolockd", NULL, 0);
                        break;
                case 'l':
                        printf("-l deprecated, -o rdirplus\n");
                        build_iovec(&iov, &iovlen, "rdirplus", NULL, 0);
                        break;
                case 'N':
                        printf("-N deprecated, do not specify -o resvport\n");
                        break;
                case 'o': {
                        int pass_flag_to_nmount;
                        char *opt = optarg;
                        while (opt) {
                                char *pval = NULL;
                                char *pnextopt = NULL;
                                const char *val = "";
                                pass_flag_to_nmount = 1;
                                pnextopt = strchr(opt, ',');
                                if (pnextopt != NULL) {
                                        *pnextopt = '\0';
                                        pnextopt++;
                                }
                                pval = strchr(opt, '=');
                                if (pval != NULL) {
                                        *pval = '\0';
                                        val = pval + 1;
                                }
                                if (strcmp(opt, "bg") == 0) {
                                        opflags |= BGRND;
                                        pass_flag_to_nmount=0;
                                } else if (strcmp(opt, "bgnow") == 0) {
                                        opflags |= BGRNDNOW;
                                        pass_flag_to_nmount=0;
                                } else if (strcmp(opt, "fg") == 0) {
                                        /* same as not specifying -o bg */
                                        pass_flag_to_nmount=0;
                                } else if (strcmp(opt, "gssname") == 0) {
                                        pass_flag_to_nmount = 0;
                                        gssname = val;
                                } else if (strcmp(opt, "mntudp") == 0) {
                                        mnttcp_ok = 0;
                                        nfsproto = IPPROTO_UDP;
                                } else if (strcmp(opt, "udp") == 0) {
                                        nfsproto = IPPROTO_UDP;
                                } else if (strcmp(opt, "tcp") == 0) {
                                        nfsproto = IPPROTO_TCP;
                                } else if (strcmp(opt, "noinet4") == 0) {
                                        pass_flag_to_nmount=0;
                                        opflags |= OF_NOINET4;
                                } else if (strcmp(opt, "noinet6") == 0) {
                                        pass_flag_to_nmount=0;
                                        opflags |= OF_NOINET6;
                                } else if (strcmp(opt, "noconn") == 0) {
                                        noconn = 1; 
                                } else if (strcmp(opt, "nfsv2") == 0) {
                                        pass_flag_to_nmount=0;
                                        mountmode = V2;
                                } else if (strcmp(opt, "nfsv3") == 0) {
                                        mountmode = V3;
                                } else if (strcmp(opt, "nfsv4") == 0) {
                                        pass_flag_to_nmount=0;
                                        mountmode = V4;
                                        nfsproto = IPPROTO_TCP;
                                        if (portspec == NULL)
                                                portspec = "2049";
                                } else if (strcmp(opt, "port") == 0) {
                                        pass_flag_to_nmount=0;
                                        asprintf(&tmp, "%d", atoi(val));
                                        if (tmp == NULL)
                                                err(1, "asprintf");
                                        portspec = tmp;
                                } else if (strcmp(opt, "principal") == 0) {
                                        got_principal = 1;
                                } else if (strcmp(opt, "proto") == 0) {
                                        pass_flag_to_nmount=0;
                                        if (strcmp(val, "tcp") == 0) {
                                                nfsproto = IPPROTO_TCP;
                                                opflags |= OF_NOINET6;
                                                build_iovec(&iov, &iovlen,
                                                    "tcp", NULL, 0);
                                        } else if (strcmp(val, "udp") == 0) {
                                                mnttcp_ok = 0;
                                                nfsproto = IPPROTO_UDP;
                                                opflags |= OF_NOINET6;
                                                build_iovec(&iov, &iovlen,
                                                    "udp", NULL, 0);
                                        } else if (strcmp(val, "tcp6") == 0) {
                                                nfsproto = IPPROTO_TCP;
                                                opflags |= OF_NOINET4;
                                                build_iovec(&iov, &iovlen,
                                                    "tcp", NULL, 0);
                                        } else if (strcmp(val, "udp6") == 0) {
                                                mnttcp_ok = 0;
                                                nfsproto = IPPROTO_UDP;
                                                opflags |= OF_NOINET4;
                                                build_iovec(&iov, &iovlen,
                                                    "udp", NULL, 0);
                                        } else {
                                                errx(1,
                                                    "illegal proto value -- %s",
                                                    val);
                                        }
                                } else if (strcmp(opt, "sec") == 0) {
                                        /*
                                         * Don't add this option to
                                         * the iovec yet - we will
                                         * negotiate which sec flavor
                                         * to use with the remote
                                         * mountd.
                                         */
                                        pass_flag_to_nmount=0;
                                        secflavor = sec_name_to_num(val);
                                        if (secflavor < 0) {
                                                errx(1,
                                                    "illegal sec value -- %s",
                                                    val);
                                        }
                                } else if (strcmp(opt, "retrycnt") == 0) {
                                        pass_flag_to_nmount=0;
                                        num = strtol(val, &p, 10);
                                        if (*p || num < 0)
                                                errx(1, "illegal retrycnt value -- %s", val);
                                        retrycnt = num;
                                } else if (strcmp(opt, "maxgroups") == 0) {
                                        num = strtol(val, &p, 10);
                                        if (*p || num <= 0)
                                                errx(1, "illegal maxgroups value -- %s", val);
                                        //set_rpc_maxgrouplist(num);
                                } else if (strcmp(opt, "vers") == 0) {
                                        num = strtol(val, &p, 10);
                                        if (*p || num <= 0)
                                                errx(1, "illegal vers value -- "
                                                    "%s", val);
                                        switch (num) {
                                        case 2:
                                                mountmode = V2;
                                                break;
                                        case 3:
                                                mountmode = V3;
                                                build_iovec(&iov, &iovlen,
                                                    "nfsv3", NULL, 0);
                                                break;
                                        case 4:
                                                mountmode = V4;
                                                nfsproto = IPPROTO_TCP;
                                                if (portspec == NULL)
                                                        portspec = "2049";
                                                break;
                                        default:
                                                errx(1, "illegal nfs version "
                                                    "value -- %s", val);
                                        }
                                        pass_flag_to_nmount=0;
                                } else if (strcmp(opt, "soft") == 0) {
                                        softintr = true;
                                } else if (strcmp(opt, "intr") == 0) {
                                        softintr = true;
                                } else if (strcmp(opt, "mountport") == 0) {
                                        num = strtol(val, &p, 10);
                                        if (*p || num <= 0 || num > IPPORT_MAX)
                                                errx(1, "illegal port num -- "
                                                    "%s", val);
                                        mntproto_port = num;
                                        pass_flag_to_nmount=0;
                                }
                                if (pass_flag_to_nmount) {
                                        build_iovec(&iov, &iovlen, opt,
                                            __DECONST(void *, val),
                                            strlen(val) + 1);
                                }
                                opt = pnextopt;
                        }
                        }
                        break;
                case 'P':
                        /* obsolete for -o noresvport now default */
                        printf("-P deprecated, use -o noresvport\n");
                        build_iovec(&iov, &iovlen, "noresvport", NULL, 0);
                        break;
                case 'R':
                        printf("-R deprecated, use -o retrycnt=<retrycnt>\n");
                        num = strtol(optarg, &p, 10);
                        if (*p || num < 0)
                                errx(1, "illegal -R value -- %s", optarg);
                        retrycnt = num;
                        break;
                case 'r':
                        printf("-r deprecated, use -o rsize=<rsize>\n");
                        build_iovec(&iov, &iovlen, "rsize", optarg, (size_t)-1);
                        break;
                case 's':
                        printf("-s deprecated, use -o soft\n");
                        build_iovec(&iov, &iovlen, "soft", NULL, 0);
                        softintr = true;
                        break;
                case 'T':
                        nfsproto = IPPROTO_TCP;
                        printf("-T deprecated, use -o tcp\n");
                        break;
                case 't':
                        printf("-t deprecated, use -o timeout=<value>\n");
                        build_iovec(&iov, &iovlen, "timeout", optarg, (size_t)-1);
                        break;
                case 'w':
                        printf("-w deprecated, use -o wsize=<value>\n");
                        build_iovec(&iov, &iovlen, "wsize", optarg, (size_t)-1);
                        break;
                case 'x':
                        printf("-x deprecated, use -o retrans=<value>\n");
                        build_iovec(&iov, &iovlen, "retrans", optarg, (size_t)-1);
                        break;
                case 'U':
                        printf("-U deprecated, use -o mntudp\n");
                        mnttcp_ok = 0;
                        nfsproto = IPPROTO_UDP;
                        build_iovec(&iov, &iovlen, "mntudp", NULL, 0);
                        break;
                default:
                        usage();
                        break;
                }
        argc -= optind;
        argv += optind;

        if ((opflags & (BGRND | BGRNDNOW)) == (BGRND | BGRNDNOW))
                errx(1, "Options bg and bgnow are mutually exclusive");

        if (argc != 2) {
                usage();
                /* NOTREACHED */
        }

        /* Warn that NFSv4 mounts only work correctly as hard mounts. */
        if (mountmode == V4 && softintr)
                warnx("Warning, options soft and/or intr cannot be safely used"
                    " for NFSv4. See the BUGS section of mount_nfs(8)");

        spec = *argv++;
        mntname = *argv;

        if (retrycnt == -1)
                /* The default is to keep retrying forever. */
                retrycnt = 0;

        if (modfind("nfscl") < 0) {
                /* Not present in kernel, try loading it */
                if (kldload("nfscl") < 0 ||
                    modfind("nfscl") < 0)
                        errx(1, "nfscl is not available");
        }

        /*
         * Add the fqdn to the gssname, as required.
         */
        if (gssname != NULL) {
                if (strchr(gssname, '@') == NULL &&
                    gethostname(hostname, MAXHOSTNAMELEN) == 0) {
                        snprintf(gssn, sizeof (gssn), "%s@%s", gssname,
                            hostname);
                        gssname = gssn;
                }
                build_iovec(&iov, &iovlen, "gssname",
                    __DECONST(void *, gssname), strlen(gssname) + 1);
        }

        if (!getnfsargs(&spec, &host, &iov, &iovlen))
                exit(1);

        /* resolve the mountpoint with realpath(3) */
        if (checkpath(mntname, mntpath) != 0)
                err(1, "%s", mntpath);

        build_iovec_argf(&iov, &iovlen, "fstype", "nfs");
        build_iovec(&iov, &iovlen, "fspath", mntpath, (size_t)-1);
        build_iovec(&iov, &iovlen, "errmsg", errmsg, sizeof(errmsg));

        if (nmount(iov, iovlen, 0)) {
                nmount_errstr = nfsv4_geterrstr(errno);
                if (mountmode == V4 && nmount_errstr != NULL)
                        errx(1, "nmount: %s, %s", mntpath, nmount_errstr);
                else
                        err(1, "nmount: %s%s%s", mntpath, errmsg[0] ? ", " : "",
                            errmsg);
        } else if (mountmode != V4 && !add_mtab(host, spec)) {
                /* Add mounted file system to PATH_MOUNTTAB */
                warnx("can't update %s for %s:%s", PATH_MOUNTTAB, host, spec);
        }

        exit(0);
}

static int
sec_name_to_num(const char *sec)
{
        if (!strcmp(sec, "krb5"))
                return (RPCSEC_GSS_KRB5);
        if (!strcmp(sec, "krb5i"))
                return (RPCSEC_GSS_KRB5I);
        if (!strcmp(sec, "krb5p"))
                return (RPCSEC_GSS_KRB5P);
        if (!strcmp(sec, "sys"))
                return (AUTH_SYS);
        return (-1);
}

static const char *
sec_num_to_name(int flavor)
{
        switch (flavor) {
        case RPCSEC_GSS_KRB5:
                return ("krb5");
        case RPCSEC_GSS_KRB5I:
                return ("krb5i");
        case RPCSEC_GSS_KRB5P:
                return ("krb5p");
        case AUTH_SYS:
                return ("sys");
        }
        return (NULL);
}

/*
 * Wait for RTM_IFINFO message with interface that is IFF_UP and with
 * link on, or until timeout expires.  Returns seconds left.
 */
static time_t
rtm_ifinfo_sleep(time_t sec)
{
        char buf[2048] __aligned(__alignof(struct if_msghdr));
        fd_set rfds;
        struct timeval tv, start;
        ssize_t nread;
        int n, s;

        s = socket(PF_ROUTE, SOCK_RAW, 0);
        if (s < 0)
                err(EX_OSERR, "socket");
        (void)gettimeofday(&start, NULL);

        for (tv.tv_sec = sec, tv.tv_usec = 0;
            tv.tv_sec > 0;
            (void)gettimeofday(&tv, NULL),
            tv.tv_sec = sec - (tv.tv_sec - start.tv_sec)) {
                FD_ZERO(&rfds);
                FD_SET(s, &rfds);
                n = select(s + 1, &rfds, NULL, NULL, &tv);
                if (n == 0)
                        continue;
                if (n == -1) {
                        if (errno == EINTR)
                                continue;
                        else
                                err(EX_SOFTWARE, "select");
                }
                nread = read(s, buf, 2048);
                if (nread < 0)
                        err(EX_OSERR, "read");
                if ((size_t)nread >= sizeof(struct if_msghdr)) {
                        struct if_msghdr *ifm;

                        ifm = (struct if_msghdr *)buf;
                        if (ifm->ifm_version == RTM_VERSION &&
                            ifm->ifm_type == RTM_IFINFO &&
                            (ifm->ifm_flags & IFF_UP) &&
                            ifm->ifm_data.ifi_link_state != LINK_STATE_DOWN)
                                break;
                }
        }

        close(s);

        return (tv.tv_sec);
}

static int
getnfsargs(char **specp, char **hostpp, struct iovec **iov, int *iovlen)
{
        struct addrinfo hints, *ai_nfs, *ai;
        enum tryret ret;
        int ecode, speclen, remoteerr, offset, have_bracket = 0;
        char *hostp, *delimp, *errstr, *spec;
        size_t len;
        static char nam[MNAMELEN + 1], pname[MAXHOSTNAMELEN + 5];
        bool resolved;

        spec = *specp;
        if (*spec == '[' && (delimp = strchr(spec + 1, ']')) != NULL &&
            *(delimp + 1) == ':') {
                hostp = spec + 1;
                spec = delimp + 2;
                have_bracket = 1;
        } else if ((delimp = strrchr(spec, ':')) != NULL) {
                hostp = spec;
                spec = delimp + 1;
        } else if ((delimp = strrchr(spec, '@')) != NULL) {
                warnx("path@server syntax is deprecated, use server:path");
                hostp = delimp + 1;
        } else {
                warnx("no <host>:<dirpath> nfs-name");
                return (0);
        }
        *delimp = '\0';

        /*
         * If there has been a trailing slash at mounttime it seems
         * that some mountd implementations fail to remove the mount
         * entries from their mountlist while unmounting.
         */
        for (speclen = strlen(spec); 
                speclen > 1 && spec[speclen - 1] == '/';
                speclen--)
                spec[speclen - 1] = '\0';
        if (strlen(hostp) + strlen(spec) + 1 > MNAMELEN) {
                warnx("%s:%s: %s", hostp, spec, strerror(ENAMETOOLONG));
                return (0);
        }
        /* Make both '@' and ':' notations equal */
        if (*hostp != '\0') {
                len = strlen(hostp);
                offset = 0;
                if (have_bracket)
                        nam[offset++] = '[';
                memmove(nam + offset, hostp, len);
                if (have_bracket)
                        nam[len + offset++] = ']';
                nam[len + offset++] = ':';
                memmove(nam + len + offset, spec, speclen);
                nam[len + speclen + offset] = '\0';
        }

        /*
         * Handle an internet host address.
         */
        memset(&hints, 0, sizeof hints);
        hints.ai_flags = AI_NUMERICHOST;
        if (nfsproto == IPPROTO_TCP)
                hints.ai_socktype = SOCK_STREAM;
        else if (nfsproto == IPPROTO_UDP)
                hints.ai_socktype = SOCK_DGRAM;

        resolved = (getaddrinfo(hostp, portspec, &hints, &ai_nfs) == 0);

        if ((opflags & (BGRNDNOW | ISBGRND)) == BGRNDNOW) {
                warnx("Mount %s:%s, backgrounding",
                    hostp, spec);
                opflags |= ISBGRND;
                if (daemon(0, 0) != 0)
                        err(1, "daemon");
        }

        ret = TRYRET_LOCALERR;
        for (;;) {
                if (!resolved) {
                        hints.ai_flags = AI_CANONNAME;
                        if ((ecode = getaddrinfo(hostp, portspec, &hints,
                            &ai_nfs)) != 0) {
                                if (portspec == NULL)
                                        warnx("%s: %s", hostp,
                                            gai_strerror(ecode));
                                else
                                        warnx("%s:%s: %s", hostp, portspec,
                                            gai_strerror(ecode));
                                if (ecode == EAI_AGAIN &&
                                    (opflags & (BGRNDNOW | BGRND)))
                                        goto retry;
                                else
                                        exit(1);
                        }
                        resolved = true;
                        /*
                         * For a Kerberized nfs mount where the
                         * "principal" argument has not been set, add
                         * it here.
                         */
                        if (got_principal == 0 && secflavor != AUTH_SYS &&
                            ai_nfs->ai_canonname != NULL) {
                                snprintf(pname, sizeof (pname), "nfs@%s",
                                    ai_nfs->ai_canonname);
                                build_iovec(iov, iovlen, "principal", pname,
                                    strlen(pname) + 1);
                        }
                }

                /*
                 * Try each entry returned by getaddrinfo(). Note the
                 * occurrence of remote errors by setting `remoteerr'.
                 */
                remoteerr = 0;
                for (ai = ai_nfs; ai != NULL; ai = ai->ai_next) {
                        if ((ai->ai_family == AF_INET6) &&
                            (opflags & OF_NOINET6))
                                continue;
                        if ((ai->ai_family == AF_INET) && 
                            (opflags & OF_NOINET4))
                                continue;
                        ret = nfs_tryproto(ai, hostp, spec, &errstr, iov,
                            iovlen);
                        if (ret == TRYRET_SUCCESS)
                                break;
                        if (ret != TRYRET_LOCALERR)
                                remoteerr = 1;
                        if ((opflags & ISBGRND) == 0)
                                fprintf(stderr, "%s\n", errstr);
                }
                if (ret == TRYRET_SUCCESS)
                        break;

                /* Exit if all errors were local. */
                if (!remoteerr)
                        exit(1);
retry:
                /*
                 * If retrycnt == 0, we are to keep retrying forever.
                 * Otherwise decrement it, and exit if it hits zero.
                 */
                if (retrycnt != 0 && --retrycnt == 0)
                        exit(1);

                if ((opflags & (BGRND | ISBGRND)) == BGRND) {
                        warnx("Cannot immediately mount %s:%s, backgrounding",
                            hostp, spec);
                        opflags |= ISBGRND;
                        if (daemon(0, 0) != 0)
                                err(1, "daemon");
                }
                /*
                 * If rtm_ifinfo_sleep() returns non-zero, don't count
                 * that as a retry attempt.
                 */
                if (rtm_ifinfo_sleep(60) && retrycnt != 0)
                        retrycnt++;
        }
        freeaddrinfo(ai_nfs);

        build_iovec(iov, iovlen, "hostname", nam, (size_t)-1);

        *specp = spec;
        *hostpp = hostp;
        return (1);
}

/*
 * Try to set up the NFS arguments according to the address
 * family, protocol (and possibly port) specified in `ai'.
 *
 * Returns TRYRET_SUCCESS if successful, or:
 *   TRYRET_TIMEOUT             The server did not respond.
 *   TRYRET_REMOTEERR           The server reported an error.
 *   TRYRET_LOCALERR            Local failure.
 *
 * In all error cases, *errstr will be set to a statically-allocated string
 * describing the error.
 */
static enum tryret
nfs_tryproto(struct addrinfo *ai, char *hostp, char *spec, char **errstr,
    struct iovec **iov, int *iovlen)
{
        static char errbuf[256];
        struct sockaddr_storage nfs_ss;
        struct netbuf nfs_nb;
        struct nfhret nfhret;
        struct timeval try;
        struct rpc_err rpcerr;
        CLIENT *clp;
        struct netconfig *nconf, *nconf_mnt;
        const char *netid, *netid_mnt, *secname;
        int doconnect, nfsvers, mntvers, sotype;
        enum clnt_stat clntstat;
        enum mountmode trymntmode;

        sotype = 0;
        trymntmode = mountmode;
        errbuf[0] = '\0';
        *errstr = errbuf;

        if (nfsproto == IPPROTO_TCP)
                sotype = SOCK_STREAM;
        else if (nfsproto == IPPROTO_UDP)
                sotype = SOCK_DGRAM;

        if ((netid = netidbytype(ai->ai_family, sotype)) == NULL) {
                snprintf(errbuf, sizeof errbuf,
                    "af %d sotype %d not supported", ai->ai_family, sotype);
                return (TRYRET_LOCALERR);
        }
        if ((nconf = getnetconf_cached(netid)) == NULL) {
                snprintf(errbuf, sizeof errbuf, "%s: %s", netid, nc_sperror());
                return (TRYRET_LOCALERR);
        }
        /* The RPCPROG_MNT netid may be different. */
        if (mnttcp_ok) {
                netid_mnt = netid;
                nconf_mnt = nconf;
        } else {
                if ((netid_mnt = netidbytype(ai->ai_family, SOCK_DGRAM))
                     == NULL) {
                        snprintf(errbuf, sizeof errbuf,
                            "af %d sotype SOCK_DGRAM not supported",
                             ai->ai_family);
                        return (TRYRET_LOCALERR);
                }
                if ((nconf_mnt = getnetconf_cached(netid_mnt)) == NULL) {
                        snprintf(errbuf, sizeof errbuf, "%s: %s", netid_mnt,
                            nc_sperror());
                        return (TRYRET_LOCALERR);
                }
        }

tryagain:
        if (trymntmode == V4) {
                nfsvers = 4;
                mntvers = 3; /* Workaround for GCC. */
        } else if (trymntmode == V2) {
                nfsvers = 2;
                mntvers = 1;
        } else {
                nfsvers = 3;
                mntvers = 3;
        }

        if (portspec != NULL) {
                /* `ai' contains the complete nfsd sockaddr. */
                nfs_nb.buf = ai->ai_addr;
                nfs_nb.len = nfs_nb.maxlen = ai->ai_addrlen;
        } else {
                /* Ask the remote rpcbind. */
                nfs_nb.buf = &nfs_ss;
                nfs_nb.len = nfs_nb.maxlen = sizeof nfs_ss;

                if (!rpcb_getaddr(NFS_PROGRAM, nfsvers, nconf, &nfs_nb,
                    hostp)) {
                        if (rpc_createerr.cf_stat == RPC_PROGVERSMISMATCH &&
                            trymntmode == ANY) {
                                trymntmode = V2;
                                goto tryagain;
                        }
                        snprintf(errbuf, sizeof errbuf, "[%s] %s:%s: %s",
                            netid, hostp, spec,
                            clnt_spcreateerror("RPCPROG_NFS"));
                        return (returncode(rpc_createerr.cf_stat,
                            &rpc_createerr.cf_error));
                }
        }

        /* Check that the server (nfsd) responds on the port we have chosen. */
        clp = clnt_tli_create(RPC_ANYFD, nconf, &nfs_nb, NFS_PROGRAM, nfsvers,
            0, 0);
        if (clp == NULL) {
                snprintf(errbuf, sizeof errbuf, "[%s] %s:%s: %s", netid,
                    hostp, spec, clnt_spcreateerror("nfsd: RPCPROG_NFS"));
                return (returncode(rpc_createerr.cf_stat,
                    &rpc_createerr.cf_error));
        }
        if (sotype == SOCK_DGRAM && noconn == 0) {
                /*
                 * Use connect(), to match what the kernel does. This
                 * catches cases where the server responds from the
                 * wrong source address.
                 */
                doconnect = 1;
                if (!clnt_control(clp, CLSET_CONNECT, (char *)&doconnect)) {
                        clnt_destroy(clp);
                        snprintf(errbuf, sizeof errbuf,
                            "[%s] %s:%s: CLSET_CONNECT failed", netid, hostp,
                            spec);
                        return (TRYRET_LOCALERR);
                }
        }

        try.tv_sec = 10;
        try.tv_usec = 0;
        clntstat = clnt_call(clp, NFSPROC_NULL, (xdrproc_t)xdr_void, NULL,
                         (xdrproc_t)xdr_void, NULL, try);
        if (clntstat != RPC_SUCCESS) {
                if (clntstat == RPC_PROGVERSMISMATCH && trymntmode == ANY) {
                        clnt_destroy(clp);
                        trymntmode = V2;
                        goto tryagain;
                }
                clnt_geterr(clp, &rpcerr);
                snprintf(errbuf, sizeof errbuf, "[%s] %s:%s: %s", netid,
                    hostp, spec, clnt_sperror(clp, "NFSPROC_NULL"));
                clnt_destroy(clp);
                return (returncode(clntstat, &rpcerr));
        }
        clnt_destroy(clp);

        /*
         * For NFSv4, there is no mount protocol.
         */
        if (trymntmode == V4) {
                /*
                 * Store the server address in nfsargsp, making
                 * sure to copy any locally allocated structures.
                 */
                addrlen = nfs_nb.len;
                addr = malloc(addrlen);
                if (addr == NULL)
                        err(1, "malloc");
                bcopy(nfs_nb.buf, addr, addrlen);

                build_iovec(iov, iovlen, "addr", addr, addrlen);
                secname = sec_num_to_name(secflavor);
                if (secname != NULL) {
                        build_iovec(iov, iovlen, "sec",
                            __DECONST(void *, secname), (size_t)-1);
                }
                build_iovec(iov, iovlen, "nfsv4", NULL, 0);
                build_iovec(iov, iovlen, "dirpath", spec, (size_t)-1);

                return (TRYRET_SUCCESS);
        }

        /*
         * malloc() and copy the address, so that it can be used for
         * nfsargs below.
         */
        addrlen = nfs_nb.len;
        addr = malloc(addrlen);
        if (addr == NULL)
                err(1, "malloc");
        bcopy(nfs_nb.buf, addr, addrlen);

        /* Send the MOUNTPROC_MNT RPC to get the root filehandle. */
        try.tv_sec = 10;
        try.tv_usec = 0;
        if (mntproto_port != 0) {
                struct sockaddr *sad;
                struct sockaddr_in *sin;
                struct sockaddr_in6 *sin6;

                sad = (struct sockaddr *)nfs_nb.buf;
                switch (sad->sa_family) {
                case AF_INET:
                        sin = (struct sockaddr_in *)nfs_nb.buf;
                        sin->sin_port = htons(mntproto_port);
                        break;
                case AF_INET6:
                        sin6 = (struct sockaddr_in6 *)nfs_nb.buf;
                        sin6->sin6_port = htons(mntproto_port);
                        break;
                default:
                        snprintf(errbuf, sizeof(errbuf),
                            "Mnt port bad addr family %d\n", sad->sa_family);
                        return (TRYRET_LOCALERR);
                }
                clp = clnt_tli_create(RPC_ANYFD, nconf_mnt, &nfs_nb, MOUNTPROG,
                    mntvers, 0, 0);
        } else {
                /* Get the Mount protocol port# via rpcbind. */
                clp = clnt_tp_create(hostp, MOUNTPROG, mntvers, nconf_mnt);
        }
        if (clp == NULL) {
                free(addr);
                snprintf(errbuf, sizeof errbuf, "[%s] %s:%s: %s", netid_mnt,
                    hostp, spec, clnt_spcreateerror("RPCMNT: clnt_create"));
                return (returncode(rpc_createerr.cf_stat,
                    &rpc_createerr.cf_error));
        }
        clp->cl_auth = authsys_create_default();
        nfhret.auth = secflavor;
        nfhret.vers = mntvers;
        clntstat = clnt_call(clp, MOUNTPROC_MNT, (xdrproc_t)xdr_dir, spec, 
            (xdrproc_t)xdr_fh, &nfhret, try);
        auth_destroy(clp->cl_auth);
        if (clntstat != RPC_SUCCESS) {
                free(addr);
                if (clntstat == RPC_PROGVERSMISMATCH && trymntmode == ANY) {
                        clnt_destroy(clp);
                        trymntmode = V2;
                        goto tryagain;
                }
                clnt_geterr(clp, &rpcerr);
                snprintf(errbuf, sizeof errbuf, "[%s] %s:%s: %s", netid_mnt,
                    hostp, spec, clnt_sperror(clp, "RPCPROG_MNT"));
                clnt_destroy(clp);
                return (returncode(clntstat, &rpcerr));
        }
        clnt_destroy(clp);

        if (nfhret.stat != 0) {
                free(addr);
                snprintf(errbuf, sizeof errbuf, "[%s] %s:%s: %s", netid_mnt,
                    hostp, spec, strerror(nfhret.stat));
                return (TRYRET_REMOTEERR);
        }

        /*
         * Store the filehandle and server address in nfsargsp, making
         * sure to copy any locally allocated structures.
         */
        fhsize = nfhret.fhsize;
        fh = malloc(fhsize);
        if (fh == NULL)
                err(1, "malloc");
        bcopy(nfhret.nfh, fh, fhsize);

        build_iovec(iov, iovlen, "addr", addr, addrlen);
        build_iovec(iov, iovlen, "fh", fh, fhsize);
        secname = sec_num_to_name(nfhret.auth);
        if (secname) {
                build_iovec(iov, iovlen, "sec",
                    __DECONST(void *, secname), (size_t)-1);
        }
        if (nfsvers == 3)
                build_iovec(iov, iovlen, "nfsv3", NULL, 0);

        return (TRYRET_SUCCESS);
}

/*
 * Catagorise a RPC return status and error into an `enum tryret'
 * return code.
 */
static enum tryret
returncode(enum clnt_stat clntstat, struct rpc_err *rpcerr)
{

        switch (clntstat) {
        case RPC_TIMEDOUT:
                return (TRYRET_TIMEOUT);
        case RPC_PMAPFAILURE:
        case RPC_PROGNOTREGISTERED:
        case RPC_PROGVERSMISMATCH:
        /* XXX, these can be local or remote. */
        case RPC_CANTSEND:
        case RPC_CANTRECV:
                return (TRYRET_REMOTEERR);
        case RPC_SYSTEMERROR:
                switch (rpcerr->re_errno) {
                case ETIMEDOUT:
                        return (TRYRET_TIMEOUT);
                case ENOMEM:
                        break;
                default:
                        return (TRYRET_REMOTEERR);
                }
                /* FALLTHROUGH */
        default:
                break;
        }
        return (TRYRET_LOCALERR);
}

/*
 * Look up a netid based on an address family and socket type.
 * `af' is the address family, and `sotype' is SOCK_DGRAM or SOCK_STREAM.
 *
 * XXX there should be a library function for this.
 */
static const char *
netidbytype(int af, int sotype)
{
        struct nc_protos *p;

        for (p = nc_protos; p->netid != NULL; p++) {
                if (af != p->af || sotype != p->sotype)
                        continue;
                return (p->netid);
        }
        return (NULL);
}

/*
 * Look up a netconfig entry based on a netid, and cache the result so
 * that we don't need to remember to call freenetconfigent().
 *
 * Otherwise it behaves just like getnetconfigent(), so nc_*error()
 * work on failure.
 */
static struct netconfig *
getnetconf_cached(const char *netid)
{
        static struct nc_entry {
                struct netconfig *nconf;
                struct nc_entry *next;
        } *head;
        struct nc_entry *p;
        struct netconfig *nconf;

        for (p = head; p != NULL; p = p->next)
                if (strcmp(netid, p->nconf->nc_netid) == 0)
                        return (p->nconf);

        if ((nconf = getnetconfigent(netid)) == NULL)
                return (NULL);
        if ((p = malloc(sizeof(*p))) == NULL)
                err(1, "malloc");
        p->nconf = nconf;
        p->next = head;
        head = p;

        return (p->nconf);
}

/*
 * xdr routines for mount rpc's
 */
static int
xdr_dir(XDR *xdrsp, char *dirp)
{
        return (xdr_string(xdrsp, &dirp, MNTPATHLEN));
}

static int
xdr_fh(XDR *xdrsp, struct nfhret *np)
{
        int i;
        long auth, authcnt, authfnd = 0;

        if (!xdr_u_long(xdrsp, &np->stat))
                return (0);
        if (np->stat)
                return (1);
        switch (np->vers) {
        case 1:
                np->fhsize = NFS_FHSIZE;
                return (xdr_opaque(xdrsp, (caddr_t)np->nfh, NFS_FHSIZE));
        case 3:
                if (!xdr_long(xdrsp, &np->fhsize))
                        return (0);
                if (np->fhsize <= 0 || np->fhsize > NFS3_FHSIZE)
                        return (0);
                if (!xdr_opaque(xdrsp, (caddr_t)np->nfh, np->fhsize))
                        return (0);
                if (!xdr_long(xdrsp, &authcnt))
                        return (0);
                for (i = 0; i < authcnt; i++) {
                        if (!xdr_long(xdrsp, &auth))
                                return (0);
                        if (np->auth == -1) {
                                np->auth = auth;
                                authfnd++;
                        } else if (auth == np->auth) {
                                authfnd++;
                        }
                }
                /*
                 * Some servers, such as DEC's OSF/1 return a nil authenticator
                 * list to indicate RPCAUTH_UNIX.
                 */
                if (authcnt == 0 && np->auth == -1)
                        np->auth = AUTH_SYS;
                if (!authfnd && (authcnt > 0 || np->auth != AUTH_SYS))
                        np->stat = EAUTH;
                return (1);
        }
        return (0);
}

static void
usage(void)
{
        (void)fprintf(stderr, "%s\n%s\n%s\n%s\n",
"usage: mount_nfs [-23bcdiLlNPsTU] [-a maxreadahead] [-D deadthresh]",
"                 [-g maxgroups] [-I readdirsize] [-o options] [-R retrycnt]",
"                 [-r readsize] [-t timeout] [-w writesize] [-x retrans]",
"                 rhost:path node");
        exit(1);
}