1 /* $NetBSD: psshfs.c,v 1.54 2009/05/20 15:04:36 pooka Exp $ */ 2 3 /* 4 * Copyright (c) 2006-2009 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 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 16 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 18 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 /* 29 * psshfs: puffs sshfs 30 * 31 * psshfs implements sshfs functionality on top of puffs making it 32 * possible to mount a filesystme through the sftp service. 33 * 34 * psshfs can execute multiple operations in "parallel" by using the 35 * puffs_cc framework for continuations. 36 * 37 * Concurrency control is handled currently by vnode locking (this 38 * will change in the future). Context switch locations are easy to 39 * find by grepping for puffs_framebuf_enqueue_cc(). 40 */ 41 42 #include <sys/cdefs.h> 43 #ifndef lint 44 __RCSID("$NetBSD: psshfs.c,v 1.54 2009/05/20 15:04:36 pooka Exp $"); 45 #endif /* !lint */ 46 47 #include <sys/types.h> 48 #include <sys/wait.h> 49 50 #include <assert.h> 51 #include <err.h> 52 #include <errno.h> 53 #include <mntopts.h> 54 #include <paths.h> 55 #include <poll.h> 56 #include <puffs.h> 57 #include <signal.h> 58 #include <stdlib.h> 59 #include <util.h> 60 #include <unistd.h> 61 62 #include "psshfs.h" 63 64 static int pssh_connect(struct puffs_usermount *, int); 65 static void psshfs_loopfn(struct puffs_usermount *); 66 static void usage(void); 67 static void add_ssharg(char ***, int *, char *); 68 static void psshfs_notify(struct puffs_usermount *, int, int); 69 70 #define SSH_PATH "/usr/bin/ssh" 71 72 unsigned int max_reads; 73 static int sighup; 74 75 static void 76 add_ssharg(char ***sshargs, int *nargs, char *arg) 77 { 78 79 *sshargs = realloc(*sshargs, (*nargs + 2) * sizeof(char*)); 80 if (!*sshargs) 81 err(1, "realloc"); 82 (*sshargs)[(*nargs)++] = arg; 83 (*sshargs)[*nargs] = NULL; 84 } 85 86 static void 87 usage() 88 { 89 90 fprintf(stderr, "usage: %s " 91 "[-ceprst] [-F configfile] [-O sshopt=value] [-o opts] " 92 "user@host:path mountpath\n", 93 getprogname()); 94 exit(1); 95 } 96 97 static void 98 takehup(int sig) 99 { 100 101 sighup = 1; 102 } 103 104 int 105 main(int argc, char *argv[]) 106 { 107 struct psshfs_ctx pctx; 108 struct puffs_usermount *pu; 109 struct puffs_ops *pops; 110 struct psshfs_node *root = &pctx.psn_root; 111 struct puffs_node *pn_root; 112 puffs_framev_fdnotify_fn notfn; 113 struct vattr *rva; 114 mntoptparse_t mp; 115 char **sshargs; 116 char *userhost; 117 char *hostpath; 118 int mntflags, pflags, ch; 119 int detach; 120 int exportfs, refreshival, numconnections; 121 int nargs; 122 123 setprogname(argv[0]); 124 125 if (argc < 3) 126 usage(); 127 128 mntflags = pflags = exportfs = nargs = 0; 129 numconnections = 1; 130 detach = 1; 131 refreshival = DEFAULTREFRESH; 132 notfn = puffs_framev_unmountonclose; 133 sshargs = NULL; 134 add_ssharg(&sshargs, &nargs, SSH_PATH); 135 add_ssharg(&sshargs, &nargs, "-axs"); 136 add_ssharg(&sshargs, &nargs, "-oClearAllForwardings=yes"); 137 138 while ((ch = getopt(argc, argv, "c:eF:o:O:pr:st:")) != -1) { 139 switch (ch) { 140 case 'c': 141 numconnections = atoi(optarg); 142 if (numconnections < 1 || numconnections > 2) { 143 fprintf(stderr, "%s: only 1 or 2 connections " 144 "permitted currently\n", getprogname()); 145 usage(); 146 /*NOTREACHED*/ 147 } 148 break; 149 case 'e': 150 exportfs = 1; 151 break; 152 case 'F': 153 add_ssharg(&sshargs, &nargs, "-F"); 154 add_ssharg(&sshargs, &nargs, optarg); 155 break; 156 case 'O': 157 add_ssharg(&sshargs, &nargs, "-o"); 158 add_ssharg(&sshargs, &nargs, optarg); 159 break; 160 case 'o': 161 mp = getmntopts(optarg, puffsmopts, &mntflags, &pflags); 162 if (mp == NULL) 163 err(1, "getmntopts"); 164 freemntopts(mp); 165 break; 166 case 'p': 167 notfn = psshfs_notify; 168 break; 169 case 'r': 170 max_reads = atoi(optarg); 171 break; 172 case 's': 173 detach = 0; 174 break; 175 case 't': 176 refreshival = atoi(optarg); 177 if (refreshival < 0 && refreshival != -1) 178 errx(1, "invalid timeout %d", refreshival); 179 break; 180 default: 181 usage(); 182 /*NOTREACHED*/ 183 } 184 } 185 argc -= optind; 186 argv += optind; 187 188 if (pflags & PUFFS_FLAG_OPDUMP) 189 detach = 0; 190 pflags |= PUFFS_FLAG_BUILDPATH; 191 pflags |= PUFFS_KFLAG_WTCACHE | PUFFS_KFLAG_IAONDEMAND; 192 193 if (argc != 2) 194 usage(); 195 196 PUFFSOP_INIT(pops); 197 198 PUFFSOP_SET(pops, psshfs, fs, unmount); 199 PUFFSOP_SETFSNOP(pops, sync); /* XXX */ 200 PUFFSOP_SET(pops, psshfs, fs, statvfs); 201 PUFFSOP_SET(pops, psshfs, fs, nodetofh); 202 PUFFSOP_SET(pops, psshfs, fs, fhtonode); 203 204 PUFFSOP_SET(pops, psshfs, node, lookup); 205 PUFFSOP_SET(pops, psshfs, node, create); 206 PUFFSOP_SET(pops, psshfs, node, open); 207 PUFFSOP_SET(pops, psshfs, node, inactive); 208 PUFFSOP_SET(pops, psshfs, node, readdir); 209 PUFFSOP_SET(pops, psshfs, node, getattr); 210 PUFFSOP_SET(pops, psshfs, node, setattr); 211 PUFFSOP_SET(pops, psshfs, node, mkdir); 212 PUFFSOP_SET(pops, psshfs, node, remove); 213 PUFFSOP_SET(pops, psshfs, node, readlink); 214 PUFFSOP_SET(pops, psshfs, node, rmdir); 215 PUFFSOP_SET(pops, psshfs, node, symlink); 216 PUFFSOP_SET(pops, psshfs, node, rename); 217 PUFFSOP_SET(pops, psshfs, node, read); 218 PUFFSOP_SET(pops, psshfs, node, write); 219 PUFFSOP_SET(pops, psshfs, node, reclaim); 220 221 pu = puffs_init(pops, argv[0], "psshfs", &pctx, pflags); 222 if (pu == NULL) 223 err(1, "puffs_init"); 224 225 memset(&pctx, 0, sizeof(pctx)); 226 pctx.mounttime = time(NULL); 227 pctx.refreshival = refreshival; 228 pctx.numconnections = numconnections; 229 230 userhost = argv[0]; 231 hostpath = strchr(userhost, ':'); 232 if (hostpath) { 233 *hostpath++ = '\0'; 234 pctx.mountpath = hostpath; 235 } else 236 pctx.mountpath = "."; 237 238 add_ssharg(&sshargs, &nargs, argv[0]); 239 add_ssharg(&sshargs, &nargs, "sftp"); 240 pctx.sshargs = sshargs; 241 242 pctx.nextino = 2; 243 memset(root, 0, sizeof(struct psshfs_node)); 244 pn_root = puffs_pn_new(pu, root); 245 if (pn_root == NULL) 246 return errno; 247 puffs_setroot(pu, pn_root); 248 249 puffs_framev_init(pu, psbuf_read, psbuf_write, psbuf_cmp, NULL, notfn); 250 251 signal(SIGHUP, takehup); 252 puffs_ml_setloopfn(pu, psshfs_loopfn); 253 if (pssh_connect(pu, PSSHFD_META) == -1) 254 err(1, "can't connect meta"); 255 if (puffs_framev_addfd(pu, pctx.sshfd, 256 PUFFS_FBIO_READ | PUFFS_FBIO_WRITE) == -1) 257 err(1, "framebuf addfd meta"); 258 if (numconnections == 2) { 259 if (pssh_connect(pu, PSSHFD_DATA) == -1) 260 err(1, "can't connect data"); 261 if (puffs_framev_addfd(pu, pctx.sshfd_data, 262 PUFFS_FBIO_READ | PUFFS_FBIO_WRITE) == -1) 263 err(1, "framebuf addfd data"); 264 } else { 265 pctx.sshfd_data = pctx.sshfd; 266 } 267 268 if (exportfs) 269 puffs_setfhsize(pu, sizeof(struct psshfs_fid), 270 PUFFS_FHFLAG_NFSV2 | PUFFS_FHFLAG_NFSV3); 271 272 rva = &pn_root->pn_va; 273 rva->va_fileid = pctx.nextino++; 274 rva->va_nlink = 101; /* XXX */ 275 276 if (detach) 277 if (puffs_daemon(pu, 1, 1) == -1) 278 err(1, "puffs_daemon"); 279 280 if (puffs_mount(pu, argv[1], mntflags, puffs_getroot(pu)) == -1) 281 err(1, "puffs_mount"); 282 if (puffs_setblockingmode(pu, PUFFSDEV_NONBLOCK) == -1) 283 err(1, "setblockingmode"); 284 285 if (puffs_mainloop(pu) == -1) 286 err(1, "mainloop"); 287 puffs_exit(pu, 1); 288 289 return 0; 290 } 291 292 #define RETRY_MAX 100 293 294 void 295 psshfs_notify(struct puffs_usermount *pu, int fd, int what) 296 { 297 struct psshfs_ctx *pctx = puffs_getspecific(pu); 298 int nretry, which, newfd, dummy; 299 300 if (fd == pctx->sshfd) { 301 which = PSSHFD_META; 302 } else { 303 assert(fd == pctx->sshfd_data); 304 which = PSSHFD_DATA; 305 } 306 307 if (puffs_getstate(pu) != PUFFS_STATE_RUNNING) 308 return; 309 310 if (what != (PUFFS_FBIO_READ | PUFFS_FBIO_WRITE)) { 311 puffs_framev_removefd(pu, fd, ECONNRESET); 312 return; 313 } 314 close(fd); 315 316 /* deal with zmobies, beware of half-eaten brain */ 317 while (waitpid(-1, &dummy, WNOHANG) > 0) 318 continue; 319 320 for (nretry = 0;;nretry++) { 321 if ((newfd = pssh_connect(pu, which)) == -1) 322 goto retry2; 323 324 if (puffs_framev_addfd(pu, newfd, 325 PUFFS_FBIO_READ | PUFFS_FBIO_WRITE) == -1) 326 goto retry1; 327 328 break; 329 retry1: 330 fprintf(stderr, "reconnect failed... "); 331 close(newfd); 332 retry2: 333 if (nretry < RETRY_MAX) { 334 fprintf(stderr, "retry (%d left)\n", RETRY_MAX-nretry); 335 sleep(nretry); 336 } else { 337 fprintf(stderr, "retry count exceeded, going south\n"); 338 exit(1); /* XXXXXXX */ 339 } 340 } 341 } 342 343 static int 344 pssh_connect(struct puffs_usermount *pu, int which) 345 { 346 struct psshfs_ctx *pctx = puffs_getspecific(pu); 347 char **sshargs = pctx->sshargs; 348 int fds[2]; 349 pid_t pid; 350 int dnfd, x; 351 int *sshfd; 352 pid_t *sshpid; 353 354 if (which == PSSHFD_META) { 355 sshfd = &pctx->sshfd; 356 sshpid = &pctx->sshpid; 357 } else { 358 assert(which == PSSHFD_DATA); 359 sshfd = &pctx->sshfd_data; 360 sshpid = &pctx->sshpid_data; 361 } 362 363 if (socketpair(AF_UNIX, SOCK_STREAM, 0, fds) == -1) 364 return -1; 365 366 pid = fork(); 367 switch (pid) { 368 case -1: 369 return -1; 370 /*NOTREACHED*/ 371 case 0: /* child */ 372 if (dup2(fds[0], STDIN_FILENO) == -1) 373 err(1, "child dup2"); 374 if (dup2(fds[0], STDOUT_FILENO) == -1) 375 err(1, "child dup2"); 376 close(fds[0]); 377 close(fds[1]); 378 379 dnfd = open(_PATH_DEVNULL, O_RDWR); 380 if (dnfd != -1) 381 dup2(dnfd, STDERR_FILENO); 382 383 execvp(sshargs[0], sshargs); 384 /*NOTREACHED*/ 385 break; 386 default: 387 *sshpid = pid; 388 *sshfd = fds[1]; 389 close(fds[0]); 390 break; 391 } 392 393 if (psshfs_handshake(pu, *sshfd) != 0) 394 errx(1, "psshfs_handshake %d", which); 395 x = 1; 396 if (ioctl(*sshfd, FIONBIO, &x) == -1) 397 err(1, "nonblocking descriptor %d", which); 398 399 return *sshfd; 400 } 401 402 static void * 403 invalone(struct puffs_usermount *pu, struct puffs_node *pn, void *arg) 404 { 405 struct psshfs_node *psn = pn->pn_data; 406 407 psn->attrread = 0; 408 psn->dentread = 0; 409 psn->slread = 0; 410 411 return NULL; 412 } 413 414 static void 415 psshfs_loopfn(struct puffs_usermount *pu) 416 { 417 418 if (sighup) { 419 puffs_pn_nodewalk(pu, invalone, NULL); 420 sighup = 0; 421 } 422 } 423