NetBSD/usr.sbin/puffs/mount_psshfs/psshfs.c

447 lines
11 KiB
C

/* $NetBSD: psshfs.c,v 1.62 2010/10/29 16:13:51 pooka Exp $ */
/*
* Copyright (c) 2006-2009 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.
*/
/*
* psshfs: puffs sshfs
*
* psshfs implements sshfs functionality on top of puffs making it
* possible to mount a filesystme through the sftp service.
*
* psshfs can execute multiple operations in "parallel" by using the
* puffs_cc framework for continuations.
*
* Concurrency control is handled currently by vnode locking (this
* will change in the future). Context switch locations are easy to
* find by grepping for puffs_framebuf_enqueue_cc().
*/
#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: psshfs.c,v 1.62 2010/10/29 16:13:51 pooka Exp $");
#endif /* !lint */
#include <sys/types.h>
#include <sys/wait.h>
#include <assert.h>
#include <err.h>
#include <errno.h>
#include <mntopts.h>
#include <paths.h>
#include <poll.h>
#include <puffs.h>
#include <signal.h>
#include <stdlib.h>
#include <util.h>
#include <unistd.h>
#include "psshfs.h"
static int pssh_connect(struct puffs_usermount *, int);
static void psshfs_loopfn(struct puffs_usermount *);
static void usage(void);
static void add_ssharg(char ***, int *, const char *);
static void psshfs_notify(struct puffs_usermount *, int, int);
#define SSH_PATH "/usr/bin/ssh"
unsigned int max_reads;
static int sighup;
static void
add_ssharg(char ***sshargs, int *nargs, const char *arg)
{
*sshargs = realloc(*sshargs, (*nargs + 2) * sizeof(char*));
if (!*sshargs)
err(1, "realloc");
(*sshargs)[(*nargs)++] = estrdup(arg);
(*sshargs)[*nargs] = NULL;
}
static void
usage()
{
fprintf(stderr, "usage: %s "
"[-ceprst] [-F configfile] [-O sshopt=value] [-o opts] "
"user@host:path mountpath\n",
getprogname());
exit(1);
}
static void
takehup(int sig)
{
sighup = 1;
}
int
main(int argc, char *argv[])
{
struct psshfs_ctx pctx;
struct puffs_usermount *pu;
struct puffs_ops *pops;
struct psshfs_node *root = &pctx.psn_root;
struct puffs_node *pn_root;
puffs_framev_fdnotify_fn notfn;
struct vattr *rva;
mntoptparse_t mp;
char **sshargs;
char *userhost;
char *hostpath;
int mntflags, pflags, ch;
int detach;
int exportfs, refreshival, numconnections;
int nargs;
setprogname(argv[0]);
puffs_unmountonsignal(SIGINT, true);
puffs_unmountonsignal(SIGTERM, true);
if (argc < 3)
usage();
memset(&pctx, 0, sizeof(pctx));
mntflags = pflags = exportfs = nargs = 0;
numconnections = 1;
detach = 1;
refreshival = DEFAULTREFRESH;
notfn = puffs_framev_unmountonclose;
sshargs = NULL;
add_ssharg(&sshargs, &nargs, SSH_PATH);
add_ssharg(&sshargs, &nargs, "-axs");
add_ssharg(&sshargs, &nargs, "-oClearAllForwardings=yes");
while ((ch = getopt(argc, argv, "c:eF:g:o:O:pr:st:u:")) != -1) {
switch (ch) {
case 'c':
numconnections = atoi(optarg);
if (numconnections < 1 || numconnections > 2) {
fprintf(stderr, "%s: only 1 or 2 connections "
"permitted currently\n", getprogname());
usage();
/*NOTREACHED*/
}
break;
case 'e':
exportfs = 1;
break;
case 'F':
add_ssharg(&sshargs, &nargs, "-F");
add_ssharg(&sshargs, &nargs, optarg);
break;
case 'g':
pctx.domanglegid = 1;
pctx.manglegid = atoi(optarg);
if (pctx.manglegid == (gid_t)-1)
errx(1, "-1 not allowed for -g");
pctx.mygid = getegid();
break;
case 'O':
add_ssharg(&sshargs, &nargs, "-o");
add_ssharg(&sshargs, &nargs, optarg);
break;
case 'o':
mp = getmntopts(optarg, puffsmopts, &mntflags, &pflags);
if (mp == NULL)
err(1, "getmntopts");
freemntopts(mp);
break;
case 'p':
notfn = psshfs_notify;
break;
case 'r':
max_reads = atoi(optarg);
break;
case 's':
detach = 0;
break;
case 't':
refreshival = atoi(optarg);
if (refreshival < 0 && refreshival != -1)
errx(1, "invalid timeout %d", refreshival);
break;
case 'u':
pctx.domangleuid = 1;
pctx.mangleuid = atoi(optarg);
if (pctx.mangleuid == (uid_t)-1)
errx(1, "-1 not allowed for -u");
pctx.myuid = geteuid();
break;
default:
usage();
/*NOTREACHED*/
}
}
argc -= optind;
argv += optind;
if (pflags & PUFFS_FLAG_OPDUMP)
detach = 0;
pflags |= PUFFS_FLAG_BUILDPATH;
pflags |= PUFFS_KFLAG_WTCACHE | PUFFS_KFLAG_IAONDEMAND;
if (argc != 2)
usage();
PUFFSOP_INIT(pops);
PUFFSOP_SET(pops, psshfs, fs, unmount);
PUFFSOP_SETFSNOP(pops, sync); /* XXX */
PUFFSOP_SET(pops, psshfs, fs, statvfs);
PUFFSOP_SET(pops, psshfs, fs, nodetofh);
PUFFSOP_SET(pops, psshfs, fs, fhtonode);
PUFFSOP_SET(pops, psshfs, node, lookup);
PUFFSOP_SET(pops, psshfs, node, create);
PUFFSOP_SET(pops, psshfs, node, open);
PUFFSOP_SET(pops, psshfs, node, inactive);
PUFFSOP_SET(pops, psshfs, node, readdir);
PUFFSOP_SET(pops, psshfs, node, getattr);
PUFFSOP_SET(pops, psshfs, node, setattr);
PUFFSOP_SET(pops, psshfs, node, mkdir);
PUFFSOP_SET(pops, psshfs, node, remove);
PUFFSOP_SET(pops, psshfs, node, readlink);
PUFFSOP_SET(pops, psshfs, node, rmdir);
PUFFSOP_SET(pops, psshfs, node, symlink);
PUFFSOP_SET(pops, psshfs, node, rename);
PUFFSOP_SET(pops, psshfs, node, read);
PUFFSOP_SET(pops, psshfs, node, write);
PUFFSOP_SET(pops, psshfs, node, reclaim);
pu = puffs_init(pops, argv[0], "psshfs", &pctx, pflags);
if (pu == NULL)
err(1, "puffs_init");
pctx.mounttime = time(NULL);
pctx.refreshival = refreshival;
pctx.numconnections = numconnections;
userhost = argv[0];
hostpath = strchr(userhost, ':');
if (hostpath) {
*hostpath++ = '\0';
pctx.mountpath = hostpath;
} else
pctx.mountpath = ".";
add_ssharg(&sshargs, &nargs, argv[0]);
add_ssharg(&sshargs, &nargs, "sftp");
pctx.sshargs = sshargs;
pctx.nextino = 2;
memset(root, 0, sizeof(struct psshfs_node));
pn_root = puffs_pn_new(pu, root);
if (pn_root == NULL)
return errno;
puffs_setroot(pu, pn_root);
puffs_framev_init(pu, psbuf_read, psbuf_write, psbuf_cmp, NULL, notfn);
signal(SIGHUP, takehup);
puffs_ml_setloopfn(pu, psshfs_loopfn);
if (pssh_connect(pu, PSSHFD_META) == -1)
err(1, "can't connect meta");
if (puffs_framev_addfd(pu, pctx.sshfd,
PUFFS_FBIO_READ | PUFFS_FBIO_WRITE) == -1)
err(1, "framebuf addfd meta");
if (numconnections == 2) {
if (pssh_connect(pu, PSSHFD_DATA) == -1)
err(1, "can't connect data");
if (puffs_framev_addfd(pu, pctx.sshfd_data,
PUFFS_FBIO_READ | PUFFS_FBIO_WRITE) == -1)
err(1, "framebuf addfd data");
} else {
pctx.sshfd_data = pctx.sshfd;
}
if (exportfs)
puffs_setfhsize(pu, sizeof(struct psshfs_fid),
PUFFS_FHFLAG_NFSV2 | PUFFS_FHFLAG_NFSV3);
rva = &pn_root->pn_va;
rva->va_fileid = pctx.nextino++;
/*
* For root link count, just guess something ridiculously high.
* Guessing too high has no known adverse effects, but fts(3)
* doesn't like too low values. This guess will be replaced
* with the real value when readdir is first called for
* the root directory.
*/
rva->va_nlink = 8811;
if (detach)
if (puffs_daemon(pu, 1, 1) == -1)
err(1, "puffs_daemon");
if (puffs_mount(pu, argv[1], mntflags, puffs_getroot(pu)) == -1)
err(1, "puffs_mount");
if (puffs_setblockingmode(pu, PUFFSDEV_NONBLOCK) == -1)
err(1, "setblockingmode");
if (puffs_mainloop(pu) == -1)
err(1, "mainloop");
puffs_exit(pu, 1);
return 0;
}
#define RETRY_MAX 100
void
psshfs_notify(struct puffs_usermount *pu, int fd, int what)
{
struct psshfs_ctx *pctx = puffs_getspecific(pu);
int nretry, which, newfd, dummy;
if (fd == pctx->sshfd) {
which = PSSHFD_META;
} else {
assert(fd == pctx->sshfd_data);
which = PSSHFD_DATA;
}
if (puffs_getstate(pu) != PUFFS_STATE_RUNNING)
return;
if (what != (PUFFS_FBIO_READ | PUFFS_FBIO_WRITE)) {
puffs_framev_removefd(pu, fd, ECONNRESET);
return;
}
close(fd);
/* deal with zmobies, beware of half-eaten brain */
while (waitpid(-1, &dummy, WNOHANG) > 0)
continue;
for (nretry = 0;;nretry++) {
if ((newfd = pssh_connect(pu, which)) == -1)
goto retry2;
if (puffs_framev_addfd(pu, newfd,
PUFFS_FBIO_READ | PUFFS_FBIO_WRITE) == -1)
goto retry1;
break;
retry1:
fprintf(stderr, "reconnect failed... ");
close(newfd);
retry2:
if (nretry < RETRY_MAX) {
fprintf(stderr, "retry (%d left)\n", RETRY_MAX-nretry);
sleep(nretry);
} else {
fprintf(stderr, "retry count exceeded, going south\n");
exit(1); /* XXXXXXX */
}
}
}
static int
pssh_connect(struct puffs_usermount *pu, int which)
{
struct psshfs_ctx *pctx = puffs_getspecific(pu);
char * const *sshargs = pctx->sshargs;
int fds[2];
pid_t pid;
int dnfd, x;
int *sshfd;
pid_t *sshpid;
if (which == PSSHFD_META) {
sshfd = &pctx->sshfd;
sshpid = &pctx->sshpid;
} else {
assert(which == PSSHFD_DATA);
sshfd = &pctx->sshfd_data;
sshpid = &pctx->sshpid_data;
}
if (socketpair(AF_UNIX, SOCK_STREAM, 0, fds) == -1)
return -1;
pid = fork();
switch (pid) {
case -1:
return -1;
/*NOTREACHED*/
case 0: /* child */
if (dup2(fds[0], STDIN_FILENO) == -1)
err(1, "child dup2");
if (dup2(fds[0], STDOUT_FILENO) == -1)
err(1, "child dup2");
close(fds[0]);
close(fds[1]);
dnfd = open(_PATH_DEVNULL, O_RDWR);
if (dnfd != -1)
dup2(dnfd, STDERR_FILENO);
execvp(sshargs[0], sshargs);
/*NOTREACHED*/
break;
default:
*sshpid = pid;
*sshfd = fds[1];
close(fds[0]);
break;
}
if (psshfs_handshake(pu, *sshfd) != 0)
errx(1, "handshake failed, server does not support sftp?");
x = 1;
if (ioctl(*sshfd, FIONBIO, &x) == -1)
err(1, "nonblocking descriptor %d", which);
return *sshfd;
}
static void *
invalone(struct puffs_usermount *pu, struct puffs_node *pn, void *arg)
{
struct psshfs_node *psn = pn->pn_data;
psn->attrread = 0;
psn->dentread = 0;
psn->slread = 0;
return NULL;
}
static void
psshfs_loopfn(struct puffs_usermount *pu)
{
if (sighup) {
puffs_pn_nodewalk(pu, invalone, NULL);
sighup = 0;
}
}