/*      $NetBSD: ninepuffs.c,v 1.35 2025/03/10 21:21:20 riastradh Exp $ */

/*
 * Copyright (c) 2007  Antti Kantee.  All Rights Reserved.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 */

/*
 * 9puffs: access a 9P file server as a vfs via puffs
 */

#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: ninepuffs.c,v 1.35 2025/03/10 21:21:20 riastradh Exp $");
#endif /* !lint */

#include <sys/types.h>
#include <sys/socket.h>
#include <sys/poll.h>

#include <netinet/in.h>

#include <assert.h>
#include <err.h>
#include <errno.h>
#include <netdb.h>
#include <pwd.h>
#include <puffs.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

#include "ninepuffs.h"
#include "nineproto.h"

#define DEFPORT_9P "564" /* "9pfs", but don't depend on it being in services */

__dead static void
usage(void)
{

        fprintf(stderr, "usage: %s [-46su] [-o mntopts] [-p port] "
            "[user@]server[:path] mountpoint\n", getprogname());
        fprintf(stderr, "       %s -c [-su] [-o mntopts] device mountpoint\n",
            getprogname());
        exit(1);
}

/*
 * TCP connection to 9P file server.
 * Return connected socket or exit with error.
 */
static int
serverconnect(const char *hostname, const char *portname, int family)
{
        int ret;

        struct addrinfo hints;
        memset(&hints, 0, sizeof(hints));
        hints.ai_family = family;
        hints.ai_socktype = SOCK_STREAM;

        if (portname == NULL) {
                portname = DEFPORT_9P;
                hints.ai_flags |= AI_NUMERICSERV;
        }

        struct addrinfo *ai0;
        ret = getaddrinfo(hostname, portname, &hints, &ai0);
        if (ret != 0)
                errx(EXIT_FAILURE, "%s", gai_strerror(ret));

        int s = -1;
        const char *cause = NULL;
        for (struct addrinfo *ai = ai0; ai != NULL; ai = ai->ai_next) {
                s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
                if (s < 0) {
                        cause = "socket";
                        continue;
                }

                const int opt = 1;
                ret = setsockopt(s, SOL_SOCKET, SO_NOSIGPIPE, &opt, sizeof(opt));
                if (ret < 0) {
                        cause = "SO_NOSIGPIPE";
                        continue;
                }

                ret = connect(s, ai->ai_addr, ai->ai_addrlen);
                if (ret < 0) {
                        close(s);
                        s = -1;
                        cause = "connect";
                        continue;
                }
        }

        if (s < 0)
                err(EXIT_FAILURE, "%s", cause);

        freeaddrinfo(ai0);
        return s;
}

static int
open_cdev(const char *path)
{
        int s;

        s = open(path, O_RDWR, 0);
        if (s == -1)
                err(1, "%s", path);
        return s;
}

int
main(int argc, char *argv[])
{
        struct puffs9p p9p;
        struct puffs_usermount *pu;
        struct puffs_ops *pops;
        struct puffs_node *pn_root;
        mntoptparse_t mp;
        int family;
        const char *user, *srvhost, *srvpath;
        char *p;
        const char *port;
        int mntflags, pflags, ch;
        int detach;
        int protover;
        int server;
        bool cachename = false;

        setprogname(argv[0]);

        if (argc < 2)
                usage();

        mntflags = pflags = 0;
        detach = 1;
#ifdef INET6
        family = AF_UNSPEC;
#else
        family = AF_INET;
#endif
        port = NULL;
        protover = P9PROTO_VERSION;
        server = P9P_SERVER_TCP;

        while ((ch = getopt(argc, argv, "46cCo:p:su")) != -1) {
                switch (ch) {
                case '4':
                        family = AF_INET;
                        break;
                case '6':
#ifdef INET6
                        family = AF_INET6;
                        break;
#else
                        errno = EPFNOSUPPORT;
                        err(EXIT_FAILURE, "IPv6");
                        /* NOTREACHED */
#endif
                case 'c':
                        server = P9P_SERVER_CDEV;
                        break;
                case 'C':
                        cachename = true;
                        break;
                case 'o':
                        mp = getmntopts(optarg, puffsmopts, &mntflags, &pflags);
                        if (mp == NULL)
                                err(1, "getmntopts");
                        freemntopts(mp);
                        break;
                case 'p':
                        port = optarg;
                        break;
                case 's':
                        detach = 0;
                        break;
                case 'u':
                        protover = P9PROTO_VERSION_U;
                        break;
                default:
                        usage();
                        /*NOTREACHED*/
                }
        }
        argc -= optind;
        argv += optind;

        if (argc != 2)
                usage();

        if (pflags & PUFFS_FLAG_OPDUMP)
                detach = 0;
        pflags |= PUFFS_KFLAG_WTCACHE | PUFFS_KFLAG_IAONDEMAND;

        if (!cachename)
                pflags |= PUFFS_KFLAG_NOCACHE_NAME;

        PUFFSOP_INIT(pops);

        PUFFSOP_SET(pops, puffs9p, fs, unmount);
        PUFFSOP_SETFSNOP(pops, sync);
        PUFFSOP_SETFSNOP(pops, statvfs);

        PUFFSOP_SET(pops, puffs9p, node, lookup);
        PUFFSOP_SET(pops, puffs9p, node, readdir);
        PUFFSOP_SET(pops, puffs9p, node, getattr);
        PUFFSOP_SET(pops, puffs9p, node, setattr);
        PUFFSOP_SET(pops, puffs9p, node, create);
        PUFFSOP_SET(pops, puffs9p, node, open);
        PUFFSOP_SET(pops, puffs9p, node, mkdir);
        PUFFSOP_SET(pops, puffs9p, node, remove);
        PUFFSOP_SET(pops, puffs9p, node, rmdir);
        PUFFSOP_SET(pops, puffs9p, node, read);
        PUFFSOP_SET(pops, puffs9p, node, write);
        PUFFSOP_SET(pops, puffs9p, node, rename);
        PUFFSOP_SET(pops, puffs9p, node, inactive);
        PUFFSOP_SET(pops, puffs9p, node, reclaim);
        PUFFSOP_SET(pops, puffs9p, node, pathconf);
#if 0
        PUFFSOP_SET(pops, puffs9p, node, mknod);
#endif

        pu = puffs_init(pops, argv[0], "9p", &p9p, pflags);
        if (pu == NULL)
                err(1, "puffs_init");

        memset(&p9p, 0, sizeof(p9p));
        p9p.maxreq = P9P_DEFREQLEN;
        p9p.nextfid = 1;
        p9p.protover = protover;
        p9p.server = server;

        /* user@ */
        if ((p = strchr(argv[0], '@')) != NULL) {
                *p = '\0';
                srvhost = p+1;
                user = argv[0];
        } else {
                struct passwd *pw;

                srvhost = argv[0];
                pw = getpwuid(getuid());
                if (pw == NULL)
                        err(1, "getpwuid");
                user = pw->pw_name;
        }

        /* [host] or [host]:/path with square brackets around host */
        if (server == P9P_SERVER_TCP && *srvhost == '[') {
                ++srvhost;
                if ((p = strchr(srvhost, ']')) == NULL)
                        errx(EXIT_FAILURE, "Missing bracket after the host name");
                *p++ = '\0';
                if (*p == '\0')         /* [host] */
                        srvpath = "/";
                else if (*p == ':')     /* [host]:path */
                        srvpath = p+1;
                else                    /* [foo]bar */
                        errx(EXIT_FAILURE, "Invalid brackets in the host name");

        } else { /* host or host:/path without brackets around host */
                if ((p = strchr(srvhost, ':')) != NULL) {
                        *p = '\0';
                        srvpath = p+1;
                } else {
                        srvpath = "/";
                }
        }

        if (*srvpath == '\0')
                errx(1, "Empty path");
        if (*srvpath != '/')
                errx(1, "%s: Not an absolute path", srvpath);


        if (p9p.server == P9P_SERVER_TCP) {
                p9p.servsock = serverconnect(srvhost, port, family);
        } else {
                /* path to a vio9p(4) device, e.g., /dev/vio9p0 */
                p9p.servsock = open_cdev(argv[0]);
        }

        if ((pn_root = p9p_handshake(pu, user, srvpath)) == NULL) {
                close(p9p.servsock);
                puffs_exit(pu, 1);
                exit(1);
        }

        puffs_framev_init(pu, p9pbuf_read, p9pbuf_write, p9pbuf_cmp, NULL,
            puffs_framev_unmountonclose);
        if (puffs_framev_addfd(pu, p9p.servsock,
            PUFFS_FBIO_READ | PUFFS_FBIO_WRITE) == -1)
                err(1, "puffs_framebuf_addfd");

        if (detach)
                if (puffs_daemon(pu, 1, 1) == -1)
                        err(1, "puffs_daemon");

        if (puffs_mount(pu, argv[1], mntflags, pn_root) == -1)
                err(1, "puffs_mount");
        if (puffs_setblockingmode(pu, PUFFSDEV_NONBLOCK) == -1)
                err(1, "setblockingmode");

        if (puffs_mainloop(pu) == -1)
                err(1, "mainloop");
        close(p9p.servsock);
        puffs_exit(pu, 1);

        return 0;
}