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psshfs.c revision 1.17
      1 /*	$NetBSD: psshfs.c,v 1.17 2007/05/05 15:49:51 pooka Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 2006  Antti Kantee.  All Rights Reserved.
      5  *
      6  * Redistribution and use in source and binary forms, with or without
      7  * modification, are permitted provided that the following conditions
      8  * are met:
      9  * 1. Redistributions of source code must retain the above copyright
     10  *    notice, this list of conditions and the following disclaimer.
     11  * 2. Redistributions in binary form must reproduce the above copyright
     12  *    notice, this list of conditions and the following disclaimer in the
     13  *    documentation and/or other materials provided with the distribution.
     14  * 3. The name of the company nor the name of the author may be used to
     15  *    endorse or promote products derived from this software without specific
     16  *    prior written permission.
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
     19  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     20  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     21  * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
     24  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     28  * SUCH DAMAGE.
     29  */
     30 
     31 /*
     32  * psshfs: puffs sshfs
     33  *
     34  * psshfs implements sshfs functionality on top of puffs making it
     35  * possible to mount a filesystme through the sftp service.
     36  *
     37  * psshfs can execute multiple operations in "parallel" by using the
     38  * puffs_cc framework for continuations.
     39  *
     40  * Concurrency control is handled currently by vnode locking (this
     41  * will change in the future).  Context switch locations are easy to
     42  * find by grepping for puffs_framebuf_enqueue_cc().
     43  */
     44 
     45 #include <sys/cdefs.h>
     46 #ifndef lint
     47 __RCSID("$NetBSD: psshfs.c,v 1.17 2007/05/05 15:49:51 pooka Exp $");
     48 #endif /* !lint */
     49 
     50 #include <sys/types.h>
     51 
     52 #include <assert.h>
     53 #include <err.h>
     54 #include <errno.h>
     55 #include <mntopts.h>
     56 #include <poll.h>
     57 #include <puffs.h>
     58 #include <signal.h>
     59 #include <stdlib.h>
     60 #include <util.h>
     61 #include <unistd.h>
     62 
     63 #include "psshfs.h"
     64 
     65 static void	pssh_connect(struct psshfs_ctx *, char **);
     66 static void	usage(void);
     67 
     68 #define SSH_PATH "/usr/bin/ssh"
     69 
     70 static void
     71 usage()
     72 {
     73 
     74 	errx(1, "usage: %s [-es][-p port] [-o opts]user@host:path mountpath",
     75 	    getprogname());
     76 }
     77 
     78 int
     79 main(int argc, char *argv[])
     80 {
     81 	struct psshfs_ctx pctx;
     82 	struct puffs_usermount *pu;
     83 	struct puffs_ops *pops;
     84 	mntoptparse_t mp;
     85 	char *sshargs[16];
     86 	char *userhost;
     87 	char *hostpath;
     88 	char *sshport = NULL;
     89 	int mntflags, pflags, ch;
     90 	int detach, exportfs;
     91 	int argi, x;
     92 
     93 	setprogname(argv[0]);
     94 
     95 	if (argc < 3)
     96 		usage();
     97 
     98 	mntflags = pflags = exportfs = 0;
     99 	detach = 1;
    100 	while ((ch = getopt(argc, argv, "eo:p:s")) != -1) {
    101 		switch (ch) {
    102 		case 'e':
    103 			exportfs = 1;
    104 			break;
    105 		case 'o':
    106 			mp = getmntopts(optarg, puffsmopts, &mntflags, &pflags);
    107 			if (mp == NULL)
    108 				err(1, "getmntopts");
    109 			freemntopts(mp);
    110 			break;
    111 		case 'p':
    112 			sshport = optarg;
    113 			break;
    114 		case 's':
    115 			detach = 0;
    116 			break;
    117 		default:
    118 			usage();
    119 			/*NOTREACHED*/
    120 		}
    121 	}
    122 	argc -= optind;
    123 	argv += optind;
    124 
    125 #if 0
    126 	/* XXX: noatime is mandatory for now */
    127 	mntflags |= MNT_NOATIME;
    128 #endif
    129 
    130 	if (pflags & PUFFS_FLAG_OPDUMP)
    131 		detach = 0;
    132 	pflags |= PUFFS_FLAG_BUILDPATH | PUFFS_KFLAG_WTCACHE;
    133 
    134 	if (argc != 2)
    135 		usage();
    136 
    137 	PUFFSOP_INIT(pops);
    138 
    139 	PUFFSOP_SET(pops, psshfs, fs, unmount);
    140 	PUFFSOP_SETFSNOP(pops, sync); /* XXX */
    141 	PUFFSOP_SETFSNOP(pops, statvfs);
    142 	PUFFSOP_SET(pops, psshfs, fs, nodetofh);
    143 	PUFFSOP_SET(pops, psshfs, fs, fhtonode);
    144 
    145 	PUFFSOP_SET(pops, psshfs, node, lookup);
    146 	PUFFSOP_SET(pops, psshfs, node, create);
    147 	PUFFSOP_SET(pops, psshfs, node, readdir);
    148 	PUFFSOP_SET(pops, psshfs, node, getattr);
    149 	PUFFSOP_SET(pops, psshfs, node, setattr);
    150 	PUFFSOP_SET(pops, psshfs, node, mkdir);
    151 	PUFFSOP_SET(pops, psshfs, node, remove);
    152 	PUFFSOP_SET(pops, psshfs, node, readlink);
    153 	PUFFSOP_SET(pops, psshfs, node, rmdir);
    154 	PUFFSOP_SET(pops, psshfs, node, symlink);
    155 	PUFFSOP_SET(pops, psshfs, node, rename);
    156 	PUFFSOP_SET(pops, psshfs, node, read);
    157 	PUFFSOP_SET(pops, psshfs, node, write);
    158 	PUFFSOP_SET(pops, psshfs, node, reclaim);
    159 
    160 	memset(&pctx, 0, sizeof(pctx));
    161 	pctx.mounttime = time(NULL);
    162 
    163 	userhost = argv[0];
    164 	hostpath = strchr(userhost, ':');
    165 	if (hostpath) {
    166 		*hostpath++ = '\0';
    167 		pctx.mountpath = hostpath;
    168 	} else
    169 		pctx.mountpath = ".";
    170 
    171 	/* xblah */
    172 	argi = 0;
    173 	sshargs[argi++] = SSH_PATH;
    174 	sshargs[argi++] = argv[0];
    175 	sshargs[argi++] = "-oClearAllForwardings=yes";
    176 	sshargs[argi++] = "-a";
    177 	sshargs[argi++] = "-x";
    178 	sshargs[argi++] = "-s";
    179 	if (sshport) {
    180 		sshargs[argi++] = "-p";
    181 		sshargs[argi++] = sshport;
    182 	}
    183 	sshargs[argi++] = "sftp";
    184 	sshargs[argi] = 0;
    185 
    186 	pu = puffs_init(pops, "ppshfs", &pctx, pflags);
    187 	if (pu == NULL)
    188 		err(1, "puffs_init");
    189 
    190 	pssh_connect(&pctx, sshargs);
    191 
    192 	if (puffs_setblockingmode(pu, PUFFSDEV_NONBLOCK) == -1)
    193 		err(1, "setblockingmode");
    194 	if (exportfs)
    195 		puffs_setfhsize(pu, sizeof(struct psshfs_fid),
    196 		    PUFFS_FHFLAG_NFSV2 | PUFFS_FHFLAG_NFSV3);
    197 
    198 	if (puffs_domount(pu, argv[1], mntflags) == -1)
    199 		err(1, "puffs_domount");
    200 
    201 	if (psshfs_domount(pu) != 0)
    202 		errx(1, "psshfs_domount");
    203 
    204 	x = 1;
    205 	if (ioctl(pctx.sshfd, FIONBIO, &x) == -1)
    206 		err(1, "nonblocking descriptor");
    207 
    208 	if (detach)
    209 		daemon(1, 0);
    210 
    211 	return puffs_framebuf_eventloop(pu, pctx.sshfd,
    212 	    psbuf_read, psbuf_write, psbuf_cmp, NULL, NULL);
    213 }
    214 
    215 static void
    216 pssh_connect(struct psshfs_ctx *pctx, char **sshargs)
    217 {
    218 	int fds[2];
    219 	pid_t pid;
    220 
    221 	if (socketpair(AF_UNIX, SOCK_STREAM, 0, fds) == -1)
    222 		err(1, "socketpair");
    223 
    224 	pid = fork();
    225 	switch (pid) {
    226 	case -1:
    227 		err(1, "fork");
    228 		/*NOTREACHED*/
    229 	case 0: /* child */
    230 		if (dup2(fds[0], STDIN_FILENO) == -1)
    231 			err(1, "child dup2");
    232 		if (dup2(fds[0], STDOUT_FILENO) == -1)
    233 			err(1, "child dup2");
    234 		close(fds[0]);
    235 		close(fds[1]);
    236 		execvp(sshargs[0], sshargs);
    237 		break;
    238 	default:
    239 		pctx->sshpid = pid;
    240 		pctx->sshfd = fds[1];
    241 		close(fds[0]);
    242 		break;
    243 	}
    244 }
    245