1 /* $NetBSD: perfused.c,v 1.7 2010/09/07 02:11:04 manu Exp $ */ 2 3 /*- 4 * Copyright (c) 2010 Emmanuel Dreyfus. 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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS 16 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 17 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 18 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 19 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 20 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 21 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 22 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 23 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 24 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 25 * POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #include <stdio.h> 29 #include <unistd.h> 30 #include <stdlib.h> 31 #include <fcntl.h> 32 #include <syslog.h> 33 #include <ctype.h> 34 #include <paths.h> 35 #include <stdarg.h> 36 #include <err.h> 37 #include <errno.h> 38 #include <string.h> 39 #include <sysexits.h> 40 #include <signal.h> 41 #include <puffs.h> 42 #include <sys/wait.h> 43 #include <sys/param.h> 44 #include <sys/queue.h> 45 #include <sys/uio.h> 46 #include <sys/socket.h> 47 #include <sys/un.h> 48 #include <machine/vmparam.h> 49 50 #include "../../lib/libperfuse/perfuse_if.h" 51 #include "perfused.h" 52 53 static int getpeerid(int, pid_t *, uid_t *, gid_t *); 54 static int access_mount(const char *, uid_t, int); 55 static void new_mount(int, int); 56 static int parse_debug(char *); 57 static void siginfo_handler(int); 58 static int parse_options(int, char **); 59 static void get_mount_info(int, struct perfuse_mount_info *); 60 int main(int, char **); 61 62 /* 63 * Flags for new_mount() 64 */ 65 #define PMNT_DEVFUSE 0x0 /* We use /dev/fuse */ 66 #define PMNT_SOCKPAIR 0x1 /* We use socketpair */ 67 68 69 static int 70 getpeerid(s, pidp, uidp, gidp) 71 int s; 72 pid_t *pidp; 73 uid_t *uidp; 74 gid_t *gidp; 75 { 76 struct unpcbid unp; 77 socklen_t len; 78 int error; 79 80 len = sizeof(unp); 81 error = getsockopt(s, 0, LOCAL_PEEREID, &unp, &len); 82 if (error != 0) 83 return error; 84 85 if (pidp != NULL) 86 *pidp = unp.unp_pid; 87 88 if (uidp != NULL) 89 *uidp = unp.unp_euid; 90 91 if (gidp != NULL) 92 *gidp = unp.unp_egid; 93 94 return 0; 95 } 96 97 static int 98 access_mount(mnt, uid, ro) 99 const char *mnt; 100 uid_t uid; 101 int ro; 102 { 103 struct stat st; 104 mode_t mode; 105 106 if (uid == 0) 107 return 0; 108 109 if (stat(mnt, &st) == -1) 110 return -1; 111 112 if (st.st_uid != uid) 113 return -1; 114 115 mode = S_IRUSR; 116 if (!ro) 117 mode |= S_IWUSR; 118 119 if ((st.st_mode & mode) == mode) 120 return 0; 121 122 return -1; 123 } 124 125 static void 126 get_mount_info(fd, pmi) 127 int fd; 128 struct perfuse_mount_info *pmi; 129 { 130 struct perfuse_mount_out *pmo; 131 char *source = NULL; 132 char *target = NULL; 133 char *filesystemtype = NULL; 134 long mountflags = 0; 135 void *data; 136 size_t len; 137 138 pmo = (struct perfuse_mount_out *)perfuse_recv_early(fd, sizeof(*pmo)); 139 if (pmo == NULL) { 140 if (shutdown(fd, SHUT_RDWR) != 0) 141 DERR(EX_OSERR, "shutdown failed"); 142 exit(EX_PROTOCOL); 143 } 144 145 #ifdef PERFUSE_DEBUG 146 if (perfuse_diagflags & PDF_MISC) 147 DPRINTF("perfuse lengths: source = %"PRId32", " 148 "target = %"PRId32", filesystemtype = %"PRId32", " 149 "data = %"PRId32"\n", pmo->pmo_source_len, 150 pmo->pmo_target_len, pmo->pmo_filesystemtype_len, 151 pmo->pmo_data_len); 152 #endif 153 len = pmo->pmo_source_len; 154 source = perfuse_recv_early(fd, len); 155 156 len = pmo->pmo_target_len; 157 target = perfuse_recv_early(fd, len); 158 159 len = pmo->pmo_filesystemtype_len; 160 filesystemtype = perfuse_recv_early(fd, len); 161 162 mountflags = pmo->pmo_mountflags; 163 164 len = pmo->pmo_data_len; 165 data = perfuse_recv_early(fd, len); 166 167 #ifdef PERFUSE_DEBUG 168 if (perfuse_diagflags & PDF_MISC) 169 DPRINTF("%s(\"%s\", \"%s\", \"%s\", 0x%lx, \"%s\")\n", 170 __func__, source, target, filesystemtype, 171 mountflags, (const char *)data); 172 #endif 173 pmi->pmi_source = source; 174 pmi->pmi_target = target; 175 pmi->pmi_filesystemtype = filesystemtype; 176 pmi->pmi_mountflags = (int)mountflags; 177 pmi->pmi_data = data; 178 179 return; 180 } 181 182 static void 183 new_mount(fd, pmnt_flags) 184 int fd; 185 int pmnt_flags; 186 { 187 struct puffs_usermount *pu; 188 struct perfuse_mount_info pmi; 189 struct perfuse_callbacks pc; 190 int ro_flag; 191 pid_t pid; 192 int flags; 193 194 195 pid = (perfuse_diagflags & PDF_FOREGROUND) ? 0 : fork(); 196 switch(pid) { 197 case -1: 198 DERR(EX_OSERR, "cannot fork"); 199 break; 200 case 0: 201 break; 202 default: 203 return; 204 /* NOTREACHED */ 205 break; 206 } 207 208 /* 209 * Mount information (source, target, mount flags...) 210 */ 211 get_mount_info(fd, &pmi); 212 213 /* 214 * Get peer identity. If we use socketpair (-i option), 215 * peer identity if the same as us. 216 */ 217 if (pmnt_flags & PMNT_SOCKPAIR) { 218 pmi.pmi_uid = getuid(); 219 } else { 220 if (getpeerid(fd, NULL, &pmi.pmi_uid, NULL) != 0) { 221 DWARNX("Unable to retreive peer identity"); 222 pmi.pmi_uid = (uid_t)-1; 223 } 224 } 225 226 /* 227 * Check that peer owns mountpoint and read (and write) on it? 228 */ 229 ro_flag = pmi.pmi_mountflags & MNT_RDONLY; 230 if (access_mount(pmi.pmi_target, pmi.pmi_uid, ro_flag) != 0) 231 DERRX(EX_NOPERM, "insuficient privileges to mount on %s", 232 pmi.pmi_target); 233 234 235 /* 236 * Initialize libperfuse, which will initialize libpuffs 237 */ 238 pc.pc_new_msg = perfuse_new_pb; 239 pc.pc_xchg_msg = perfuse_xchg_pb; 240 pc.pc_destroy_msg = (perfuse_destroy_msg_fn)puffs_framebuf_destroy; 241 pc.pc_get_inhdr = perfuse_get_inhdr; 242 pc.pc_get_inpayload = perfuse_get_inpayload; 243 pc.pc_get_outhdr = perfuse_get_outhdr; 244 pc.pc_get_outpayload = perfuse_get_outpayload; 245 246 pu = perfuse_init(&pc, &pmi); 247 248 puffs_framev_init(pu, perfuse_readframe, perfuse_writeframe, 249 perfuse_cmpframe, perfuse_gotframe, perfuse_fdnotify); 250 251 if (puffs_framev_addfd(pu, fd, PUFFS_FBIO_READ|PUFFS_FBIO_WRITE) == -1) 252 DERR(EX_SOFTWARE, "puffs_framev_addfd failed"); 253 254 perfuse_setspecific(pu, (void *)(long)fd); 255 256 setproctitle("perfused %s", pmi.pmi_target); 257 (void)kill(getpid(), SIGINFO); /* This is for -s option */ 258 259 perfuse_fs_init(pu); 260 261 /* 262 * Non blocking I/O on /dev/fuse 263 * This must be done after perfuse_fs_init 264 */ 265 if ((flags = fcntl(fd, F_GETFL, 0)) == -1) 266 DERR(EX_OSERR, "fcntl failed"); 267 if (fcntl(fd, F_SETFL, flags|O_NONBLOCK) != 0) 268 DERR(EX_OSERR, "fcntl failed"); 269 270 /* 271 * Hand over control to puffs main loop. 272 */ 273 (void)perfuse_mainloop(pu); 274 275 DERRX(EX_SOFTWARE, "perfuse_mainloop exit"); 276 277 /* NOTREACHED */ 278 return; 279 } 280 281 static int 282 parse_debug(optstr) 283 char *optstr; 284 { 285 int retval = PDF_SYSLOG; 286 char *opt; 287 char *lastp; 288 289 for (opt = strtok_r(optstr, ",", &lastp); 290 opt; 291 opt = strtok_r(NULL, ",", &lastp)) { 292 if (strcmp(opt, "fuse") == 0) 293 retval |= PDF_FUSE; 294 else if (strcmp(opt, "puffs") == 0) 295 retval |= PDF_PUFFS; 296 else if (strcmp(opt, "dump") == 0) 297 retval |= PDF_DUMP; 298 else if (strcmp(opt, "fh") == 0) 299 retval |= PDF_FH; 300 else if (strcmp(opt, "readdir") == 0) 301 retval |= PDF_READDIR; 302 else if (strcmp(opt, "reclaim") == 0) 303 retval |= PDF_RECLAIM; 304 else if (strcmp(opt, "requeue") == 0) 305 retval |= PDF_REQUEUE; 306 else if (strcmp(opt, "sync") == 0) 307 retval |= PDF_SYNC; 308 else if (strcmp(opt, "misc") == 0) 309 retval |= PDF_MISC; 310 else 311 DERRX(EX_USAGE, "unknown debug flag \"%s\"", opt); 312 } 313 314 return retval; 315 } 316 317 /* ARGSUSED0 */ 318 static void 319 siginfo_handler(sig) 320 int sig; 321 { 322 static int old_flags = 0; 323 int swap; 324 325 swap = perfuse_diagflags; 326 perfuse_diagflags = old_flags; 327 old_flags = swap; 328 329 DWARNX("debug %sabled", old_flags == 0 ? "en" : "dis"); 330 331 return; 332 } 333 334 static int 335 parse_options(argc, argv) 336 int argc; 337 char **argv; 338 { 339 int ch; 340 int foreground = 0; 341 int retval = -1; 342 343 perfuse_diagflags = PDF_FOREGROUND | PDF_SYSLOG; 344 345 while ((ch = getopt(argc, argv, "d:fsi:")) != -1) { 346 switch (ch) { 347 case 'd': 348 perfuse_diagflags |= parse_debug(optarg); 349 break; 350 case 's': 351 if (signal(SIGINFO, siginfo_handler) != 0) 352 DERR(EX_OSERR, "signal failed"); 353 break; 354 case 'f': 355 foreground = 1; 356 perfuse_diagflags |= PDF_MISC; 357 break; 358 case 'i': 359 retval = atoi(optarg); 360 foreground = 1; 361 break; 362 default: 363 DERR(EX_USAGE, "%s [-fs] [-d level] [-i fd]", argv[0]); 364 break; 365 } 366 } 367 368 if (!foreground) 369 perfuse_diagflags &= ~PDF_FOREGROUND; 370 371 return retval; 372 } 373 374 int 375 main(argc, argv) 376 int argc; 377 char **argv; 378 { 379 int s; 380 381 s = parse_options(argc, argv); 382 383 if (perfuse_diagflags & PDF_SYSLOG) 384 openlog("perfused", 0, LOG_DAEMON); 385 386 if (!(perfuse_diagflags & PDF_FOREGROUND)) 387 if (daemon(0, 0) != 0) 388 DERR(EX_OSERR, "daemon failed"); 389 390 if (s != -1) { 391 new_mount(s, PMNT_SOCKPAIR); 392 DERRX(EX_SOFTWARE, "new_mount exit while -i is used"); 393 } 394 395 s = perfuse_open_sock(); 396 397 do { 398 struct sockaddr *sa; 399 struct sockaddr_storage ss; 400 socklen_t ss_len; 401 int fd; 402 403 #ifdef PERFUSE_DEBUG 404 if (perfuse_diagflags & PDF_MISC) 405 DPRINTF("waiting connexion\n"); 406 #endif 407 sa = (struct sockaddr *)(void *)&ss; 408 ss_len = sizeof(ss); 409 if ((fd = accept(s, sa, &ss_len)) == -1) 410 DERR(EX_OSERR, "accept failed"); 411 #ifdef PERFUSE_DEBUG 412 if (perfuse_diagflags & PDF_MISC) 413 DPRINTF("connexion accepted\n"); 414 #endif 415 new_mount(fd, PMNT_DEVFUSE); 416 } while (1 /* CONSTCOND */); 417 418 /* NOTREACHED */ 419 return 0; 420 } 421