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ab5617b3 SW |
1 | /* $NetBSD: psshfs.c,v 1.63 2011/05/19 15:07:16 riastradh 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/types.h> | |
43 | #include <sys/wait.h> | |
44 | #include <sys/ioctl.h> | |
45 | #include <sys/socket.h> | |
46 | #include <sys/uio.h> | |
47 | ||
48 | #include <assert.h> | |
49 | #include <err.h> | |
50 | #include <errno.h> | |
51 | #include <paths.h> | |
52 | #include <poll.h> | |
53 | #include <puffs.h> | |
54 | #include <signal.h> | |
55 | #include <stdlib.h> | |
56 | #include <stdio.h> | |
57 | #include <unistd.h> | |
58 | ||
59 | #include "psshfs.h" | |
60 | #include "util_compat.h" | |
61 | ||
62 | static int pssh_connect(struct puffs_usermount *, int); | |
63 | static void psshfs_loopfn(struct puffs_usermount *); | |
64 | static void usage(void); | |
65 | static void add_ssharg(char ***, int *, const char *); | |
66 | static void psshfs_notify(struct puffs_usermount *, int, int); | |
67 | ||
68 | #define SSH_PATH "/usr/bin/ssh" | |
69 | ||
70 | unsigned int max_reads; | |
71 | static int sighup; | |
72 | ||
73 | static void | |
74 | add_ssharg(char ***sshargs, int *nargs, const char *arg) | |
75 | { | |
76 | ||
77 | *sshargs = realloc(*sshargs, (*nargs + 2) * sizeof(char*)); | |
78 | if (!*sshargs) | |
79 | err(1, "realloc"); | |
80 | (*sshargs)[(*nargs)++] = estrdup(arg); | |
81 | (*sshargs)[*nargs] = NULL; | |
82 | } | |
83 | ||
84 | static void | |
89a89091 | 85 | usage(void) |
ab5617b3 SW |
86 | { |
87 | ||
88 | fprintf(stderr, "usage: %s " | |
89 | "[-ceprst] [-F configfile] [-O sshopt=value] [-o opts] " | |
90 | "user@host:path mountpath\n", | |
91 | getprogname()); | |
92 | exit(1); | |
93 | } | |
94 | ||
95 | static void | |
96 | takehup(int sig) | |
97 | { | |
98 | ||
99 | sighup = 1; | |
100 | } | |
101 | ||
102 | int | |
103 | main(int argc, char *argv[]) | |
104 | { | |
105 | struct psshfs_ctx pctx; | |
106 | struct puffs_usermount *pu; | |
107 | struct puffs_ops *pops; | |
108 | struct psshfs_node *root = &pctx.psn_root; | |
109 | struct puffs_node *pn_root; | |
110 | puffs_framev_fdnotify_fn notfn; | |
111 | struct vattr *rva; | |
112 | char **sshargs; | |
113 | char *userhost; | |
114 | char *hostpath; | |
115 | int mntflags, pflags, ch; | |
116 | int detach; | |
117 | int exportfs, refreshival, numconnections; | |
118 | int nargs; | |
119 | ||
120 | setprogname(argv[0]); | |
121 | puffs_unmountonsignal(SIGINT, true); | |
122 | puffs_unmountonsignal(SIGTERM, true); | |
123 | ||
124 | if (argc < 3) | |
125 | usage(); | |
126 | ||
127 | memset(&pctx, 0, sizeof(pctx)); | |
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:g:o:O:pr:st:u:")) != -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 'g': | |
157 | pctx.domanglegid = 1; | |
158 | pctx.manglegid = atoi(optarg); | |
159 | if (pctx.manglegid == (gid_t)-1) | |
160 | errx(1, "-1 not allowed for -g"); | |
161 | pctx.mygid = getegid(); | |
162 | break; | |
163 | case 'O': | |
164 | add_ssharg(&sshargs, &nargs, "-o"); | |
165 | add_ssharg(&sshargs, &nargs, optarg); | |
166 | break; | |
167 | case 'o': | |
168 | getmntopts(optarg, puffsmopts, &mntflags, &pflags); | |
169 | break; | |
170 | case 'p': | |
171 | notfn = psshfs_notify; | |
172 | break; | |
173 | case 'r': | |
174 | max_reads = atoi(optarg); | |
175 | break; | |
176 | case 's': | |
177 | detach = 0; | |
178 | break; | |
179 | case 't': | |
180 | refreshival = atoi(optarg); | |
181 | if (refreshival < 0 && refreshival != -1) | |
182 | errx(1, "invalid timeout %d", refreshival); | |
183 | break; | |
184 | case 'u': | |
185 | pctx.domangleuid = 1; | |
186 | pctx.mangleuid = atoi(optarg); | |
187 | if (pctx.mangleuid == (uid_t)-1) | |
188 | errx(1, "-1 not allowed for -u"); | |
189 | pctx.myuid = geteuid(); | |
190 | break; | |
191 | default: | |
192 | usage(); | |
193 | /*NOTREACHED*/ | |
194 | } | |
195 | } | |
196 | argc -= optind; | |
197 | argv += optind; | |
198 | ||
199 | if (pflags & PUFFS_FLAG_OPDUMP) | |
200 | detach = 0; | |
201 | pflags |= PUFFS_FLAG_BUILDPATH; | |
202 | pflags |= PUFFS_KFLAG_WTCACHE | PUFFS_KFLAG_IAONDEMAND; | |
203 | ||
204 | if (argc != 2) | |
205 | usage(); | |
206 | ||
207 | PUFFSOP_INIT(pops); | |
208 | ||
209 | PUFFSOP_SET(pops, psshfs, fs, unmount); | |
210 | PUFFSOP_SETFSNOP(pops, sync); /* XXX */ | |
211 | PUFFSOP_SET(pops, psshfs, fs, statvfs); | |
212 | PUFFSOP_SET(pops, psshfs, fs, nodetofh); | |
213 | PUFFSOP_SET(pops, psshfs, fs, fhtonode); | |
214 | ||
215 | PUFFSOP_SET(pops, psshfs, node, lookup); | |
216 | PUFFSOP_SET(pops, psshfs, node, create); | |
217 | PUFFSOP_SET(pops, psshfs, node, open); | |
218 | PUFFSOP_SET(pops, psshfs, node, inactive); | |
219 | PUFFSOP_SET(pops, psshfs, node, readdir); | |
220 | PUFFSOP_SET(pops, psshfs, node, getattr); | |
221 | PUFFSOP_SET(pops, psshfs, node, setattr); | |
222 | PUFFSOP_SET(pops, psshfs, node, mkdir); | |
223 | PUFFSOP_SET(pops, psshfs, node, remove); | |
224 | PUFFSOP_SET(pops, psshfs, node, readlink); | |
225 | PUFFSOP_SET(pops, psshfs, node, rmdir); | |
3f35aa53 | 226 | PUFFSOP_SET(pops, psshfs, node, link); |
ab5617b3 SW |
227 | PUFFSOP_SET(pops, psshfs, node, symlink); |
228 | PUFFSOP_SET(pops, psshfs, node, rename); | |
229 | PUFFSOP_SET(pops, psshfs, node, read); | |
230 | PUFFSOP_SET(pops, psshfs, node, write); | |
231 | PUFFSOP_SET(pops, psshfs, node, reclaim); | |
232 | ||
233 | pu = puffs_init(pops, argv[0], "psshfs", &pctx, pflags); | |
234 | if (pu == NULL) | |
235 | err(1, "puffs_init"); | |
236 | ||
237 | pctx.mounttime = time(NULL); | |
238 | pctx.refreshival = refreshival; | |
239 | pctx.numconnections = numconnections; | |
240 | ||
241 | userhost = argv[0]; | |
242 | hostpath = strchr(userhost, ':'); | |
243 | if (hostpath) { | |
244 | *hostpath++ = '\0'; | |
245 | pctx.mountpath = hostpath; | |
246 | } else | |
247 | pctx.mountpath = "."; | |
248 | ||
249 | add_ssharg(&sshargs, &nargs, argv[0]); | |
250 | add_ssharg(&sshargs, &nargs, "sftp"); | |
251 | pctx.sshargs = sshargs; | |
252 | ||
253 | pctx.nextino = 2; | |
254 | memset(root, 0, sizeof(struct psshfs_node)); | |
255 | TAILQ_INIT(&root->pw); | |
256 | pn_root = puffs_pn_new(pu, root); | |
257 | if (pn_root == NULL) | |
258 | return errno; | |
259 | puffs_setroot(pu, pn_root); | |
260 | ||
261 | puffs_framev_init(pu, psbuf_read, psbuf_write, psbuf_cmp, NULL, notfn); | |
262 | ||
263 | signal(SIGHUP, takehup); | |
264 | puffs_ml_setloopfn(pu, psshfs_loopfn); | |
265 | if (pssh_connect(pu, PSSHFD_META) == -1) | |
266 | err(1, "can't connect meta"); | |
267 | if (puffs_framev_addfd(pu, pctx.sshfd, | |
268 | PUFFS_FBIO_READ | PUFFS_FBIO_WRITE) == -1) | |
269 | err(1, "framebuf addfd meta"); | |
270 | if (numconnections == 2) { | |
271 | if (pssh_connect(pu, PSSHFD_DATA) == -1) | |
272 | err(1, "can't connect data"); | |
273 | if (puffs_framev_addfd(pu, pctx.sshfd_data, | |
274 | PUFFS_FBIO_READ | PUFFS_FBIO_WRITE) == -1) | |
275 | err(1, "framebuf addfd data"); | |
276 | } else { | |
277 | pctx.sshfd_data = pctx.sshfd; | |
278 | } | |
279 | ||
280 | if (exportfs) | |
281 | puffs_setfhsize(pu, sizeof(struct psshfs_fid), | |
282 | PUFFS_FHFLAG_NFSV2 | PUFFS_FHFLAG_NFSV3); | |
283 | ||
284 | rva = &pn_root->pn_va; | |
285 | rva->va_fileid = pctx.nextino++; | |
286 | ||
287 | /* | |
288 | * For root link count, just guess something ridiculously high. | |
289 | * Guessing too high has no known adverse effects, but fts(3) | |
290 | * doesn't like too low values. This guess will be replaced | |
291 | * with the real value when readdir is first called for | |
292 | * the root directory. | |
293 | */ | |
294 | rva->va_nlink = 8811; | |
295 | ||
296 | if (detach) | |
297 | if (puffs_daemon(pu, 1, 1) == -1) | |
298 | err(1, "puffs_daemon"); | |
299 | ||
300 | if (puffs_mount(pu, argv[1], mntflags, puffs_getroot(pu)) == -1) | |
301 | err(1, "puffs_mount"); | |
302 | if (puffs_setblockingmode(pu, PUFFSDEV_NONBLOCK) == -1) | |
303 | err(1, "setblockingmode"); | |
304 | ||
305 | if (puffs_mainloop(pu) == -1) | |
306 | err(1, "mainloop"); | |
307 | puffs_exit(pu, 1); | |
308 | ||
309 | return 0; | |
310 | } | |
311 | ||
312 | #define RETRY_MAX 100 | |
313 | ||
314 | void | |
315 | psshfs_notify(struct puffs_usermount *pu, int fd, int what) | |
316 | { | |
317 | struct psshfs_ctx *pctx = puffs_getspecific(pu); | |
318 | int nretry, which, newfd, dummy; | |
319 | ||
320 | if (fd == pctx->sshfd) { | |
321 | which = PSSHFD_META; | |
322 | } else { | |
323 | assert(fd == pctx->sshfd_data); | |
324 | which = PSSHFD_DATA; | |
325 | } | |
326 | ||
327 | if (puffs_getstate(pu) != PUFFS_STATE_RUNNING) | |
328 | return; | |
329 | ||
330 | if (what != (PUFFS_FBIO_READ | PUFFS_FBIO_WRITE)) { | |
331 | puffs_framev_removefd(pu, fd, ECONNRESET); | |
332 | return; | |
333 | } | |
334 | close(fd); | |
335 | ||
336 | /* deal with zmobies, beware of half-eaten brain */ | |
337 | while (waitpid(-1, &dummy, WNOHANG) > 0) | |
338 | continue; | |
339 | ||
340 | for (nretry = 0;;nretry++) { | |
341 | if ((newfd = pssh_connect(pu, which)) == -1) | |
342 | goto retry2; | |
343 | ||
344 | if (puffs_framev_addfd(pu, newfd, | |
345 | PUFFS_FBIO_READ | PUFFS_FBIO_WRITE) == -1) | |
346 | goto retry1; | |
347 | ||
348 | break; | |
349 | retry1: | |
350 | fprintf(stderr, "reconnect failed... "); | |
351 | close(newfd); | |
352 | retry2: | |
353 | if (nretry < RETRY_MAX) { | |
354 | fprintf(stderr, "retry (%d left)\n", RETRY_MAX-nretry); | |
355 | sleep(nretry); | |
356 | } else { | |
357 | fprintf(stderr, "retry count exceeded, going south\n"); | |
358 | exit(1); /* XXXXXXX */ | |
359 | } | |
360 | } | |
361 | } | |
362 | ||
363 | static int | |
364 | pssh_connect(struct puffs_usermount *pu, int which) | |
365 | { | |
366 | struct psshfs_ctx *pctx = puffs_getspecific(pu); | |
367 | char * const *sshargs = pctx->sshargs; | |
368 | int fds[2]; | |
369 | pid_t pid; | |
370 | int dnfd, x; | |
371 | int *sshfd; | |
372 | pid_t *sshpid; | |
373 | ||
374 | if (which == PSSHFD_META) { | |
375 | sshfd = &pctx->sshfd; | |
376 | sshpid = &pctx->sshpid; | |
377 | } else { | |
378 | assert(which == PSSHFD_DATA); | |
379 | sshfd = &pctx->sshfd_data; | |
380 | sshpid = &pctx->sshpid_data; | |
381 | } | |
382 | ||
383 | if (socketpair(AF_UNIX, SOCK_STREAM, 0, fds) == -1) | |
384 | return -1; | |
385 | ||
386 | pid = fork(); | |
387 | switch (pid) { | |
388 | case -1: | |
389 | return -1; | |
390 | /*NOTREACHED*/ | |
391 | case 0: /* child */ | |
392 | if (dup2(fds[0], STDIN_FILENO) == -1) | |
393 | err(1, "child dup2"); | |
394 | if (dup2(fds[0], STDOUT_FILENO) == -1) | |
395 | err(1, "child dup2"); | |
396 | close(fds[0]); | |
397 | close(fds[1]); | |
398 | ||
399 | dnfd = open(_PATH_DEVNULL, O_RDWR); | |
400 | if (dnfd != -1) | |
401 | dup2(dnfd, STDERR_FILENO); | |
402 | ||
403 | execvp(sshargs[0], sshargs); | |
404 | /*NOTREACHED*/ | |
405 | break; | |
406 | default: | |
407 | *sshpid = pid; | |
408 | *sshfd = fds[1]; | |
409 | close(fds[0]); | |
410 | break; | |
411 | } | |
412 | ||
413 | if (psshfs_handshake(pu, *sshfd) != 0) | |
414 | errx(1, "handshake failed, server does not support sftp?"); | |
415 | x = 1; | |
416 | if (ioctl(*sshfd, FIONBIO, &x) == -1) | |
417 | err(1, "nonblocking descriptor %d", which); | |
418 | ||
419 | return *sshfd; | |
420 | } | |
421 | ||
422 | static void * | |
423 | invalone(struct puffs_usermount *pu, struct puffs_node *pn, void *arg) | |
424 | { | |
425 | struct psshfs_node *psn = pn->pn_data; | |
426 | ||
427 | psn->attrread = 0; | |
428 | psn->dentread = 0; | |
429 | psn->slread = 0; | |
430 | ||
431 | return NULL; | |
432 | } | |
433 | ||
434 | static void | |
435 | psshfs_loopfn(struct puffs_usermount *pu) | |
436 | { | |
437 | ||
438 | if (sighup) { | |
439 | puffs_pn_nodewalk(pu, invalone, NULL); | |
440 | sighup = 0; | |
441 | } | |
442 | } |