1 /* $NetBSD: psshfs.c,v 1.58 2010/01/07 21:26:49 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 1.58 2010/01/07 21:26:49 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 *, const 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, const char *arg) 77 { 78 79 *sshargs = realloc(*sshargs, (*nargs + 2) * sizeof(char*)); 80 if (!*sshargs) 81 err(1, "realloc"); 82 (*sshargs)[(*nargs)++] = estrdup(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 memset(&pctx, 0, sizeof(pctx)); 129 mntflags = pflags = exportfs = nargs = 0; 130 numconnections = 1; 131 detach = 1; 132 refreshival = DEFAULTREFRESH; 133 notfn = puffs_framev_unmountonclose; 134 sshargs = NULL; 135 add_ssharg(&sshargs, &nargs, SSH_PATH); 136 add_ssharg(&sshargs, &nargs, "-axs"); 137 add_ssharg(&sshargs, &nargs, "-oClearAllForwardings=yes"); 138 139 while ((ch = getopt(argc, argv, "c:eF:g:o:O:pr:st:u:")) != -1) { 140 switch (ch) { 141 case 'c': 142 numconnections = atoi(optarg); 143 if (numconnections < 1 || numconnections > 2) { 144 fprintf(stderr, "%s: only 1 or 2 connections " 145 "permitted currently\n", getprogname()); 146 usage(); 147 /*NOTREACHED*/ 148 } 149 break; 150 case 'e': 151 exportfs = 1; 152 break; 153 case 'F': 154 add_ssharg(&sshargs, &nargs, "-F"); 155 add_ssharg(&sshargs, &nargs, optarg); 156 break; 157 case 'g': 158 pctx.domanglegid = 1; 159 pctx.manglegid = atoi(optarg); 160 if (pctx.manglegid == (gid_t)-1) 161 errx(1, "-1 not allowed for -g"); 162 pctx.mygid = getegid(); 163 break; 164 case 'O': 165 add_ssharg(&sshargs, &nargs, "-o"); 166 add_ssharg(&sshargs, &nargs, optarg); 167 break; 168 case 'o': 169 mp = getmntopts(optarg, puffsmopts, &mntflags, &pflags); 170 if (mp == NULL) 171 err(1, "getmntopts"); 172 freemntopts(mp); 173 break; 174 case 'p': 175 notfn = psshfs_notify; 176 break; 177 case 'r': 178 max_reads = atoi(optarg); 179 break; 180 case 's': 181 detach = 0; 182 break; 183 case 't': 184 refreshival = atoi(optarg); 185 if (refreshival < 0 && refreshival != -1) 186 errx(1, "invalid timeout %d", refreshival); 187 break; 188 case 'u': 189 pctx.domangleuid = 1; 190 pctx.mangleuid = atoi(optarg); 191 if (pctx.mangleuid == (uid_t)-1) 192 errx(1, "-1 not allowed for -u"); 193 pctx.myuid = geteuid(); 194 break; 195 default: 196 usage(); 197 /*NOTREACHED*/ 198 } 199 } 200 argc -= optind; 201 argv += optind; 202 203 if (pflags & PUFFS_FLAG_OPDUMP) 204 detach = 0; 205 pflags |= PUFFS_FLAG_BUILDPATH; 206 pflags |= PUFFS_KFLAG_WTCACHE | PUFFS_KFLAG_IAONDEMAND; 207 208 if (argc != 2) 209 usage(); 210 211 PUFFSOP_INIT(pops); 212 213 PUFFSOP_SET(pops, psshfs, fs, unmount); 214 PUFFSOP_SETFSNOP(pops, sync); /* XXX */ 215 PUFFSOP_SET(pops, psshfs, fs, statvfs); 216 PUFFSOP_SET(pops, psshfs, fs, nodetofh); 217 PUFFSOP_SET(pops, psshfs, fs, fhtonode); 218 219 PUFFSOP_SET(pops, psshfs, node, lookup); 220 PUFFSOP_SET(pops, psshfs, node, create); 221 PUFFSOP_SET(pops, psshfs, node, open); 222 PUFFSOP_SET(pops, psshfs, node, inactive); 223 PUFFSOP_SET(pops, psshfs, node, readdir); 224 PUFFSOP_SET(pops, psshfs, node, getattr); 225 PUFFSOP_SET(pops, psshfs, node, setattr); 226 PUFFSOP_SET(pops, psshfs, node, mkdir); 227 PUFFSOP_SET(pops, psshfs, node, remove); 228 PUFFSOP_SET(pops, psshfs, node, readlink); 229 PUFFSOP_SET(pops, psshfs, node, rmdir); 230 PUFFSOP_SET(pops, psshfs, node, symlink); 231 PUFFSOP_SET(pops, psshfs, node, rename); 232 PUFFSOP_SET(pops, psshfs, node, read); 233 PUFFSOP_SET(pops, psshfs, node, write); 234 PUFFSOP_SET(pops, psshfs, node, reclaim); 235 236 pu = puffs_init(pops, argv[0], "psshfs", &pctx, pflags); 237 if (pu == NULL) 238 err(1, "puffs_init"); 239 240 pctx.mounttime = time(NULL); 241 pctx.refreshival = refreshival; 242 pctx.numconnections = numconnections; 243 244 userhost = argv[0]; 245 hostpath = strchr(userhost, ':'); 246 if (hostpath) { 247 *hostpath++ = '\0'; 248 pctx.mountpath = hostpath; 249 } else 250 pctx.mountpath = "."; 251 252 add_ssharg(&sshargs, &nargs, argv[0]); 253 add_ssharg(&sshargs, &nargs, "sftp"); 254 pctx.sshargs = sshargs; 255 256 pctx.nextino = 2; 257 memset(root, 0, sizeof(struct psshfs_node)); 258 pn_root = puffs_pn_new(pu, root); 259 if (pn_root == NULL) 260 return errno; 261 puffs_setroot(pu, pn_root); 262 263 puffs_framev_init(pu, psbuf_read, psbuf_write, psbuf_cmp, NULL, notfn); 264 265 signal(SIGHUP, takehup); 266 puffs_ml_setloopfn(pu, psshfs_loopfn); 267 if (pssh_connect(pu, PSSHFD_META) == -1) 268 err(1, "can't connect meta"); 269 if (puffs_framev_addfd(pu, pctx.sshfd, 270 PUFFS_FBIO_READ | PUFFS_FBIO_WRITE) == -1) 271 err(1, "framebuf addfd meta"); 272 if (numconnections == 2) { 273 if (pssh_connect(pu, PSSHFD_DATA) == -1) 274 err(1, "can't connect data"); 275 if (puffs_framev_addfd(pu, pctx.sshfd_data, 276 PUFFS_FBIO_READ | PUFFS_FBIO_WRITE) == -1) 277 err(1, "framebuf addfd data"); 278 } else { 279 pctx.sshfd_data = pctx.sshfd; 280 } 281 282 if (exportfs) 283 puffs_setfhsize(pu, sizeof(struct psshfs_fid), 284 PUFFS_FHFLAG_NFSV2 | PUFFS_FHFLAG_NFSV3); 285 286 rva = &pn_root->pn_va; 287 rva->va_fileid = pctx.nextino++; 288 rva->va_nlink = 101; /* XXX */ 289 290 if (detach) 291 if (puffs_daemon(pu, 1, 1) == -1) 292 err(1, "puffs_daemon"); 293 294 if (puffs_mount(pu, argv[1], mntflags, puffs_getroot(pu)) == -1) 295 err(1, "puffs_mount"); 296 if (puffs_setblockingmode(pu, PUFFSDEV_NONBLOCK) == -1) 297 err(1, "setblockingmode"); 298 299 if (puffs_mainloop(pu) == -1) 300 err(1, "mainloop"); 301 puffs_exit(pu, 1); 302 303 return 0; 304 } 305 306 #define RETRY_MAX 100 307 308 void 309 psshfs_notify(struct puffs_usermount *pu, int fd, int what) 310 { 311 struct psshfs_ctx *pctx = puffs_getspecific(pu); 312 int nretry, which, newfd, dummy; 313 314 if (fd == pctx->sshfd) { 315 which = PSSHFD_META; 316 } else { 317 assert(fd == pctx->sshfd_data); 318 which = PSSHFD_DATA; 319 } 320 321 if (puffs_getstate(pu) != PUFFS_STATE_RUNNING) 322 return; 323 324 if (what != (PUFFS_FBIO_READ | PUFFS_FBIO_WRITE)) { 325 puffs_framev_removefd(pu, fd, ECONNRESET); 326 return; 327 } 328 close(fd); 329 330 /* deal with zmobies, beware of half-eaten brain */ 331 while (waitpid(-1, &dummy, WNOHANG) > 0) 332 continue; 333 334 for (nretry = 0;;nretry++) { 335 if ((newfd = pssh_connect(pu, which)) == -1) 336 goto retry2; 337 338 if (puffs_framev_addfd(pu, newfd, 339 PUFFS_FBIO_READ | PUFFS_FBIO_WRITE) == -1) 340 goto retry1; 341 342 break; 343 retry1: 344 fprintf(stderr, "reconnect failed... "); 345 close(newfd); 346 retry2: 347 if (nretry < RETRY_MAX) { 348 fprintf(stderr, "retry (%d left)\n", RETRY_MAX-nretry); 349 sleep(nretry); 350 } else { 351 fprintf(stderr, "retry count exceeded, going south\n"); 352 exit(1); /* XXXXXXX */ 353 } 354 } 355 } 356 357 static int 358 pssh_connect(struct puffs_usermount *pu, int which) 359 { 360 struct psshfs_ctx *pctx = puffs_getspecific(pu); 361 char * const *sshargs = pctx->sshargs; 362 int fds[2]; 363 pid_t pid; 364 int dnfd, x; 365 int *sshfd; 366 pid_t *sshpid; 367 368 if (which == PSSHFD_META) { 369 sshfd = &pctx->sshfd; 370 sshpid = &pctx->sshpid; 371 } else { 372 assert(which == PSSHFD_DATA); 373 sshfd = &pctx->sshfd_data; 374 sshpid = &pctx->sshpid_data; 375 } 376 377 if (socketpair(AF_UNIX, SOCK_STREAM, 0, fds) == -1) 378 return -1; 379 380 pid = fork(); 381 switch (pid) { 382 case -1: 383 return -1; 384 /*NOTREACHED*/ 385 case 0: /* child */ 386 if (dup2(fds[0], STDIN_FILENO) == -1) 387 err(1, "child dup2"); 388 if (dup2(fds[0], STDOUT_FILENO) == -1) 389 err(1, "child dup2"); 390 close(fds[0]); 391 close(fds[1]); 392 393 dnfd = open(_PATH_DEVNULL, O_RDWR); 394 if (dnfd != -1) 395 dup2(dnfd, STDERR_FILENO); 396 397 execvp(sshargs[0], sshargs); 398 /*NOTREACHED*/ 399 break; 400 default: 401 *sshpid = pid; 402 *sshfd = fds[1]; 403 close(fds[0]); 404 break; 405 } 406 407 if (psshfs_handshake(pu, *sshfd) != 0) 408 errx(1, "psshfs_handshake %d", which); 409 x = 1; 410 if (ioctl(*sshfd, FIONBIO, &x) == -1) 411 err(1, "nonblocking descriptor %d", which); 412 413 return *sshfd; 414 } 415 416 static void * 417 invalone(struct puffs_usermount *pu, struct puffs_node *pn, void *arg) 418 { 419 struct psshfs_node *psn = pn->pn_data; 420 421 psn->attrread = 0; 422 psn->dentread = 0; 423 psn->slread = 0; 424 425 return NULL; 426 } 427 428 static void 429 psshfs_loopfn(struct puffs_usermount *pu) 430 { 431 432 if (sighup) { 433 puffs_pn_nodewalk(pu, invalone, NULL); 434 sighup = 0; 435 } 436 } 437