xref: /netbsd/lib/librumphijack/hijack.c (revision 537651af)
1 /*      $NetBSD: hijack.c,v 1.59 2011/02/20 23:47:04 pooka Exp $	*/
2 
3 /*-
4  * Copyright (c) 2011 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 #include <sys/cdefs.h>
29 __RCSID("$NetBSD: hijack.c,v 1.59 2011/02/20 23:47:04 pooka Exp $");
30 
31 #define __ssp_weak_name(fun) _hijack_ ## fun
32 
33 #include <sys/param.h>
34 #include <sys/types.h>
35 #include <sys/event.h>
36 #include <sys/ioctl.h>
37 #include <sys/mount.h>
38 #include <sys/poll.h>
39 #include <sys/socket.h>
40 #include <sys/statvfs.h>
41 
42 #include <rump/rumpclient.h>
43 #include <rump/rump_syscalls.h>
44 
45 #include <assert.h>
46 #include <dlfcn.h>
47 #include <err.h>
48 #include <errno.h>
49 #include <fcntl.h>
50 #include <poll.h>
51 #include <pthread.h>
52 #include <signal.h>
53 #include <stdarg.h>
54 #include <stdbool.h>
55 #include <stdio.h>
56 #include <stdlib.h>
57 #include <string.h>
58 #include <time.h>
59 #include <unistd.h>
60 
61 enum dualcall {
62 	DUALCALL_WRITE, DUALCALL_WRITEV,
63 	DUALCALL_IOCTL, DUALCALL_FCNTL,
64 	DUALCALL_SOCKET, DUALCALL_ACCEPT, DUALCALL_BIND, DUALCALL_CONNECT,
65 	DUALCALL_GETPEERNAME, DUALCALL_GETSOCKNAME, DUALCALL_LISTEN,
66 	DUALCALL_RECVFROM, DUALCALL_RECVMSG,
67 	DUALCALL_SENDTO, DUALCALL_SENDMSG,
68 	DUALCALL_GETSOCKOPT, DUALCALL_SETSOCKOPT,
69 	DUALCALL_SHUTDOWN,
70 	DUALCALL_READ, DUALCALL_READV,
71 	DUALCALL_DUP2,
72 	DUALCALL_CLOSE,
73 	DUALCALL_POLLTS,
74 	DUALCALL_KEVENT,
75 	DUALCALL_STAT, DUALCALL_LSTAT, DUALCALL_FSTAT,
76 	DUALCALL_CHMOD, DUALCALL_LCHMOD, DUALCALL_FCHMOD,
77 	DUALCALL_CHOWN, DUALCALL_LCHOWN, DUALCALL_FCHOWN,
78 	DUALCALL_OPEN,
79 	DUALCALL_STATVFS1, DUALCALL_FSTATVFS1,
80 	DUALCALL_CHDIR, DUALCALL_FCHDIR,
81 	DUALCALL_LSEEK,
82 	DUALCALL_GETDENTS,
83 	DUALCALL_UNLINK, DUALCALL_SYMLINK, DUALCALL_READLINK,
84 	DUALCALL_RENAME,
85 	DUALCALL_MKDIR, DUALCALL_RMDIR,
86 	DUALCALL_UTIMES, DUALCALL_LUTIMES, DUALCALL_FUTIMES,
87 	DUALCALL_TRUNCATE, DUALCALL_FTRUNCATE,
88 	DUALCALL_FSYNC, DUALCALL_FSYNC_RANGE,
89 	DUALCALL_MOUNT, DUALCALL_UNMOUNT,
90 	DUALCALL___GETCWD,
91 	DUALCALL__NUM
92 };
93 
94 #define RSYS_STRING(a) __STRING(a)
95 #define RSYS_NAME(a) RSYS_STRING(__CONCAT(RUMP_SYS_RENAME_,a))
96 
97 /*
98  * Would be nice to get this automatically in sync with libc.
99  * Also, this does not work for compat-using binaries!
100  */
101 #if !__NetBSD_Prereq__(5,99,7)
102 #define REALSELECT select
103 #define REALPOLLTS pollts
104 #define REALKEVENT kevent
105 #define REALSTAT __stat30
106 #define REALLSTAT __lstat30
107 #define REALFSTAT __fstat30
108 #define REALUTIMES utimes
109 #define REALLUTIMES lutimes
110 #define REALFUTIMES futimes
111 #else
112 #define REALSELECT _sys___select50
113 #define REALPOLLTS _sys___pollts50
114 #define REALKEVENT _sys___kevent50
115 #define REALSTAT __stat50
116 #define REALLSTAT __lstat50
117 #define REALFSTAT __fstat50
118 #define REALUTIMES __utimes50
119 #define REALLUTIMES __lutimes50
120 #define REALFUTIMES __futimes50
121 #endif
122 #define REALREAD _sys_read
123 #define REALGETDENTS __getdents30
124 #define REALMOUNT __mount50
125 #define REALLSEEK _lseek
126 
127 int REALSELECT(int, fd_set *, fd_set *, fd_set *, struct timeval *);
128 int REALPOLLTS(struct pollfd *, nfds_t,
129 	       const struct timespec *, const sigset_t *);
130 int REALKEVENT(int, const struct kevent *, size_t, struct kevent *, size_t,
131 	       const struct timespec *);
132 ssize_t REALREAD(int, void *, size_t);
133 int REALSTAT(const char *, struct stat *);
134 int REALLSTAT(const char *, struct stat *);
135 int REALFSTAT(int, struct stat *);
136 int REALGETDENTS(int, char *, size_t);
137 int REALUTIMES(const char *, const struct timeval [2]);
138 int REALLUTIMES(const char *, const struct timeval [2]);
139 int REALFUTIMES(int, const struct timeval [2]);
140 int REALMOUNT(const char *, const char *, int, void *, size_t);
141 off_t REALLSEEK(int, off_t, int);
142 int __getcwd(char *, size_t);
143 
144 #define S(a) __STRING(a)
145 struct sysnames {
146 	enum dualcall scm_callnum;
147 	const char *scm_hostname;
148 	const char *scm_rumpname;
149 } syscnames[] = {
150 	{ DUALCALL_SOCKET,	"__socket30",	RSYS_NAME(SOCKET)	},
151 	{ DUALCALL_ACCEPT,	"accept",	RSYS_NAME(ACCEPT)	},
152 	{ DUALCALL_BIND,	"bind",		RSYS_NAME(BIND)		},
153 	{ DUALCALL_CONNECT,	"connect",	RSYS_NAME(CONNECT)	},
154 	{ DUALCALL_GETPEERNAME,	"getpeername",	RSYS_NAME(GETPEERNAME)	},
155 	{ DUALCALL_GETSOCKNAME,	"getsockname",	RSYS_NAME(GETSOCKNAME)	},
156 	{ DUALCALL_LISTEN,	"listen",	RSYS_NAME(LISTEN)	},
157 	{ DUALCALL_RECVFROM,	"recvfrom",	RSYS_NAME(RECVFROM)	},
158 	{ DUALCALL_RECVMSG,	"recvmsg",	RSYS_NAME(RECVMSG)	},
159 	{ DUALCALL_SENDTO,	"sendto",	RSYS_NAME(SENDTO)	},
160 	{ DUALCALL_SENDMSG,	"sendmsg",	RSYS_NAME(SENDMSG)	},
161 	{ DUALCALL_GETSOCKOPT,	"getsockopt",	RSYS_NAME(GETSOCKOPT)	},
162 	{ DUALCALL_SETSOCKOPT,	"setsockopt",	RSYS_NAME(SETSOCKOPT)	},
163 	{ DUALCALL_SHUTDOWN,	"shutdown",	RSYS_NAME(SHUTDOWN)	},
164 	{ DUALCALL_READ,	S(REALREAD),	RSYS_NAME(READ)		},
165 	{ DUALCALL_READV,	"readv",	RSYS_NAME(READV)	},
166 	{ DUALCALL_WRITE,	"write",	RSYS_NAME(WRITE)	},
167 	{ DUALCALL_WRITEV,	"writev",	RSYS_NAME(WRITEV)	},
168 	{ DUALCALL_IOCTL,	"ioctl",	RSYS_NAME(IOCTL)	},
169 	{ DUALCALL_FCNTL,	"fcntl",	RSYS_NAME(FCNTL)	},
170 	{ DUALCALL_DUP2,	"dup2",		RSYS_NAME(DUP2)		},
171 	{ DUALCALL_CLOSE,	"close",	RSYS_NAME(CLOSE)	},
172 	{ DUALCALL_POLLTS,	S(REALPOLLTS),	RSYS_NAME(POLLTS)	},
173 	{ DUALCALL_KEVENT,	S(REALKEVENT),	RSYS_NAME(KEVENT)	},
174 	{ DUALCALL_STAT,	S(REALSTAT),	RSYS_NAME(STAT)		},
175 	{ DUALCALL_LSTAT,	S(REALLSTAT),	RSYS_NAME(LSTAT)	},
176 	{ DUALCALL_FSTAT,	S(REALFSTAT),	RSYS_NAME(FSTAT)	},
177 	{ DUALCALL_CHOWN,	"chown",	RSYS_NAME(CHOWN)	},
178 	{ DUALCALL_LCHOWN,	"lchown",	RSYS_NAME(LCHOWN)	},
179 	{ DUALCALL_FCHOWN,	"fchown",	RSYS_NAME(FCHOWN)	},
180 	{ DUALCALL_CHMOD,	"chmod",	RSYS_NAME(CHMOD)	},
181 	{ DUALCALL_LCHMOD,	"lchmod",	RSYS_NAME(LCHMOD)	},
182 	{ DUALCALL_FCHMOD,	"fchmod",	RSYS_NAME(FCHMOD)	},
183 	{ DUALCALL_UTIMES,	S(REALUTIMES),	RSYS_NAME(UTIMES)	},
184 	{ DUALCALL_LUTIMES,	S(REALLUTIMES),	RSYS_NAME(LUTIMES)	},
185 	{ DUALCALL_FUTIMES,	S(REALFUTIMES),	RSYS_NAME(FUTIMES)	},
186 	{ DUALCALL_OPEN,	"open",		RSYS_NAME(OPEN)		},
187 	{ DUALCALL_STATVFS1,	"statvfs1",	RSYS_NAME(STATVFS1)	},
188 	{ DUALCALL_FSTATVFS1,	"fstatvfs1",	RSYS_NAME(FSTATVFS1)	},
189 	{ DUALCALL_CHDIR,	"chdir",	RSYS_NAME(CHDIR)	},
190 	{ DUALCALL_FCHDIR,	"fchdir",	RSYS_NAME(FCHDIR)	},
191 	{ DUALCALL_LSEEK,	S(REALLSEEK),	RSYS_NAME(LSEEK)	},
192 	{ DUALCALL_GETDENTS,	"__getdents30",	RSYS_NAME(GETDENTS)	},
193 	{ DUALCALL_UNLINK,	"unlink",	RSYS_NAME(UNLINK)	},
194 	{ DUALCALL_SYMLINK,	"symlink",	RSYS_NAME(SYMLINK)	},
195 	{ DUALCALL_READLINK,	"readlink",	RSYS_NAME(READLINK)	},
196 	{ DUALCALL_RENAME,	"rename",	RSYS_NAME(RENAME)	},
197 	{ DUALCALL_MKDIR,	"mkdir",	RSYS_NAME(MKDIR)	},
198 	{ DUALCALL_RMDIR,	"rmdir",	RSYS_NAME(RMDIR)	},
199 	{ DUALCALL_TRUNCATE,	"truncate",	RSYS_NAME(TRUNCATE)	},
200 	{ DUALCALL_FTRUNCATE,	"ftruncate",	RSYS_NAME(FTRUNCATE)	},
201 	{ DUALCALL_FSYNC,	"fsync",	RSYS_NAME(FSYNC)	},
202 	{ DUALCALL_FSYNC_RANGE,	"fsync_range",	RSYS_NAME(FSYNC_RANGE)	},
203 	{ DUALCALL_MOUNT,	S(REALMOUNT),	RSYS_NAME(MOUNT)	},
204 	{ DUALCALL_UNMOUNT,	"unmount",	RSYS_NAME(UNMOUNT)	},
205 	{ DUALCALL___GETCWD,	"__getcwd",	RSYS_NAME(__GETCWD)	},
206 };
207 #undef S
208 
209 struct bothsys {
210 	void *bs_host;
211 	void *bs_rump;
212 } syscalls[DUALCALL__NUM];
213 #define GETSYSCALL(which, name) syscalls[DUALCALL_##name].bs_##which
214 
215 pid_t	(*host_fork)(void);
216 int	(*host_daemon)(int, int);
217 int	(*host_execve)(const char *, char *const[], char *const[]);
218 
219 /* ok, we need *two* bits per dup2'd fd to track fd+HIJACKOFF aliases */
220 static uint32_t dup2mask;
221 #define ISDUP2D(fd) (((fd) < 16) && (1<<(fd) & dup2mask))
222 #define SETDUP2(fd) \
223     do { if ((fd) < 16) dup2mask |= (1<<(fd)); } while (/*CONSTCOND*/0)
224 #define CLRDUP2(fd) \
225     do { if ((fd) < 16) dup2mask &= ~(1<<(fd)); } while (/*CONSTCOND*/0)
226 #define ISDUP2ALIAS(fd) (((fd) < 16) && (1<<((fd)+16) & dup2mask))
227 #define SETDUP2ALIAS(fd) \
228     do { if ((fd) < 16) dup2mask |= (1<<((fd)+16)); } while (/*CONSTCOND*/0)
229 #define CLRDUP2ALIAS(fd) \
230     do { if ((fd) < 16) dup2mask &= ~(1<<((fd)+16)); } while (/*CONSTCOND*/0)
231 
232 //#define DEBUGJACK
233 #ifdef DEBUGJACK
234 #define DPRINTF(x) mydprintf x
235 static void
236 mydprintf(const char *fmt, ...)
237 {
238 	va_list ap;
239 
240 	if (ISDUP2D(STDERR_FILENO))
241 		return;
242 
243 	va_start(ap, fmt);
244 	vfprintf(stderr, fmt, ap);
245 	va_end(ap);
246 }
247 
248 #else
249 #define DPRINTF(x)
250 #endif
251 
252 #define FDCALL(type, name, rcname, args, proto, vars)			\
253 type name args								\
254 {									\
255 	type (*fun) proto;						\
256 									\
257 	DPRINTF(("%s -> %d\n", __STRING(name), fd));			\
258 	if (fd_isrump(fd)) {						\
259 		fun = syscalls[rcname].bs_rump;				\
260 		fd = fd_host2rump(fd);					\
261 	} else {							\
262 		fun = syscalls[rcname].bs_host;				\
263 	}								\
264 									\
265 	return fun vars;						\
266 }
267 
268 #define PATHCALL(type, name, rcname, args, proto, vars)			\
269 type name args								\
270 {									\
271 	type (*fun) proto;						\
272 									\
273 	DPRINTF(("%s -> %s\n", __STRING(name), path));			\
274 	if (path_isrump(path)) {					\
275 		fun = syscalls[rcname].bs_rump;				\
276 		path = path_host2rump(path);				\
277 	} else {							\
278 		fun = syscalls[rcname].bs_host;				\
279 	}								\
280 									\
281 	return fun vars;						\
282 }
283 
284 /*
285  * This is called from librumpclient in case of LD_PRELOAD.
286  * It ensures correct RTLD_NEXT.
287  *
288  * ... except, it's apparently extremely difficult to force
289  * at least gcc to generate an actual stack frame here.  So
290  * sprinkle some volatile foobar and baz to throw the optimizer
291  * off the scent and generate a variable assignment with the
292  * return value.  The posterboy for this meltdown is amd64
293  * with -O2.  At least with gcc 4.1.3 i386 works regardless of
294  * optimization.
295  */
296 volatile int rumphijack_unrope; /* there, unhang yourself */
297 static void *
298 hijackdlsym(void *handle, const char *symbol)
299 {
300 	void *rv;
301 
302 	rv = dlsym(handle, symbol);
303 	rumphijack_unrope = *(volatile int *)rv;
304 
305 	return (void *)rv;
306 }
307 
308 /*
309  * This tracks if our process is in a subdirectory of /rump.
310  * It's preserved over exec.
311  */
312 static bool pwdinrump = false;
313 
314 /*
315  * These variables are set from the RUMPHIJACK string and control
316  * which operations can product rump kernel file descriptors.
317  * This should be easily extendable for future needs.
318  */
319 #define RUMPHIJACK_DEFAULT "path=/rump,socket=all:nolocal"
320 static bool rumpsockets[PF_MAX];
321 static const char *rumpprefix;
322 static size_t rumpprefixlen;
323 
324 static struct {
325 	int pf;
326 	const char *name;
327 } socketmap[] = {
328 	{ PF_LOCAL, "local" },
329 	{ PF_INET, "inet" },
330 	{ PF_LINK, "link" },
331 #ifdef PF_OROUTE
332 	{ PF_OROUTE, "oroute" },
333 #endif
334 	{ PF_ROUTE, "route" },
335 	{ PF_INET6, "inet6" },
336 #ifdef PF_MPLS
337 	{ PF_MPLS, "mpls" },
338 #endif
339 	{ -1, NULL }
340 };
341 
342 static void
343 sockparser(char *buf)
344 {
345 	char *p, *l;
346 	bool value;
347 	int i;
348 
349 	/* if "all" is present, it must be specified first */
350 	if (strncmp(buf, "all", strlen("all")) == 0) {
351 		for (i = 0; i < (int)__arraycount(rumpsockets); i++) {
352 			rumpsockets[i] = true;
353 		}
354 		buf += strlen("all");
355 		if (*buf == ':')
356 			buf++;
357 	}
358 
359 	for (p = strtok_r(buf, ":", &l); p; p = strtok_r(NULL, ":", &l)) {
360 		value = true;
361 		if (strncmp(p, "no", strlen("no")) == 0) {
362 			value = false;
363 			p += strlen("no");
364 		}
365 
366 		for (i = 0; socketmap[i].name; i++) {
367 			if (strcmp(p, socketmap[i].name) == 0) {
368 				rumpsockets[socketmap[i].pf] = value;
369 				break;
370 			}
371 		}
372 		if (socketmap[i].name == NULL) {
373 			warnx("invalid socket specifier %s", p);
374 		}
375 	}
376 }
377 
378 static void
379 pathparser(char *buf)
380 {
381 
382 	/* sanity-check */
383 	if (*buf != '/')
384 		errx(1, "hijack path specifier must begin with ``/''");
385 	rumpprefixlen = strlen(buf);
386 	if (rumpprefixlen < 2)
387 		errx(1, "invalid hijack prefix: %s", buf);
388 	if (buf[rumpprefixlen-1] == '/' && strspn(buf, "/") != rumpprefixlen)
389 		errx(1, "hijack prefix may end in slash only if pure "
390 		    "slash, gave %s", buf);
391 
392 	if ((rumpprefix = strdup(buf)) == NULL)
393 		err(1, "strdup");
394 	rumpprefixlen = strlen(rumpprefix);
395 }
396 
397 static struct {
398 	void (*parsefn)(char *);
399 	const char *name;
400 } hijackparse[] = {
401 	{ sockparser, "socket" },
402 	{ pathparser, "path" },
403 	{ NULL, NULL },
404 };
405 
406 static void
407 parsehijack(char *hijack)
408 {
409 	char *p, *p2, *l;
410 	const char *hijackcopy;
411 	int i;
412 
413 	if ((hijackcopy = strdup(hijack)) == NULL)
414 		err(1, "strdup");
415 
416 	/* disable everything explicitly */
417 	for (i = 0; i < PF_MAX; i++)
418 		rumpsockets[i] = false;
419 
420 	for (p = strtok_r(hijack, ",", &l); p; p = strtok_r(NULL, ",", &l)) {
421 		p2 = strchr(p, '=');
422 		if (!p2)
423 			errx(1, "invalid hijack specifier: %s", hijackcopy);
424 
425 		for (i = 0; hijackparse[i].parsefn; i++) {
426 			if (strncmp(hijackparse[i].name, p,
427 			    (size_t)(p2-p)) == 0) {
428 				hijackparse[i].parsefn(p2+1);
429 				break;
430 			}
431 		}
432 	}
433 
434 }
435 
436 static void __attribute__((constructor))
437 rcinit(void)
438 {
439 	char buf[1024];
440 	extern void *(*rumpclient_dlsym)(void *, const char *);
441 	unsigned i, j;
442 
443 	rumpclient_dlsym = hijackdlsym;
444 	host_fork = dlsym(RTLD_NEXT, "fork");
445 	host_daemon = dlsym(RTLD_NEXT, "daemon");
446 	host_execve = dlsym(RTLD_NEXT, "execve");
447 
448 	/*
449 	 * In theory cannot print anything during lookups because
450 	 * we might not have the call vector set up.  so, the errx()
451 	 * is a bit of a strech, but it might work.
452 	 */
453 
454 	for (i = 0; i < DUALCALL__NUM; i++) {
455 		/* build runtime O(1) access */
456 		for (j = 0; j < __arraycount(syscnames); j++) {
457 			if (syscnames[j].scm_callnum == i)
458 				break;
459 		}
460 
461 		if (j == __arraycount(syscnames))
462 			errx(1, "rumphijack error: syscall pos %d missing", i);
463 
464 		syscalls[i].bs_host = dlsym(RTLD_NEXT,
465 		    syscnames[j].scm_hostname);
466 		if (syscalls[i].bs_host == NULL)
467 			errx(1, "hostcall %s not found missing",
468 			    syscnames[j].scm_hostname);
469 
470 		syscalls[i].bs_rump = dlsym(RTLD_NEXT,
471 		    syscnames[j].scm_rumpname);
472 		if (syscalls[i].bs_rump == NULL)
473 			errx(1, "rumpcall %s not found missing",
474 			    syscnames[j].scm_rumpname);
475 	}
476 
477 	if (rumpclient_init() == -1)
478 		err(1, "rumpclient init");
479 
480 	/* check which syscalls we're supposed to hijack */
481 	if (getenv_r("RUMPHIJACK", buf, sizeof(buf)) == -1) {
482 		strcpy(buf, RUMPHIJACK_DEFAULT);
483 	}
484 	parsehijack(buf);
485 
486 	/* set client persistence level */
487 	if (getenv_r("RUMPHIJACK_RETRYCONNECT", buf, sizeof(buf)) != -1) {
488 		if (strcmp(buf, "die") == 0)
489 			rumpclient_setconnretry(RUMPCLIENT_RETRYCONN_DIE);
490 		else if (strcmp(buf, "inftime") == 0)
491 			rumpclient_setconnretry(RUMPCLIENT_RETRYCONN_INFTIME);
492 		else if (strcmp(buf, "once") == 0)
493 			rumpclient_setconnretry(RUMPCLIENT_RETRYCONN_ONCE);
494 		else {
495 			time_t timeout;
496 			char *ep;
497 
498 			timeout = (time_t)strtoll(buf, &ep, 10);
499 			if (timeout <= 0 || ep != buf + strlen(buf))
500 				errx(1, "RUMPHIJACK_RETRYCONNECT must be "
501 				    "keyword or integer, got: %s", buf);
502 
503 			rumpclient_setconnretry(timeout);
504 		}
505 	}
506 
507 	if (getenv_r("RUMPHIJACK__DUP2MASK", buf, sizeof(buf)) == 0) {
508 		dup2mask = strtoul(buf, NULL, 10);
509 		unsetenv("RUMPHIJACK__DUP2MASK");
510 	}
511 	if (getenv_r("RUMPHIJACK__PWDINRUMP", buf, sizeof(buf)) == 0) {
512 		pwdinrump = true;
513 		unsetenv("RUMPHIJACK__PWDINRUMP");
514 	}
515 }
516 
517 /* XXX: need runtime selection.  low for now due to FD_SETSIZE */
518 #define HIJACK_FDOFF 128
519 static int
520 fd_rump2host(int fd)
521 {
522 
523 	if (fd == -1)
524 		return fd;
525 
526 	if (!ISDUP2D(fd))
527 		fd += HIJACK_FDOFF;
528 
529 	return fd;
530 }
531 
532 static int
533 fd_host2rump(int fd)
534 {
535 
536 	if (!ISDUP2D(fd))
537 		fd -= HIJACK_FDOFF;
538 	return fd;
539 }
540 
541 static bool
542 fd_isrump(int fd)
543 {
544 
545 	return ISDUP2D(fd) || fd >= HIJACK_FDOFF;
546 }
547 
548 #define assertfd(_fd_) assert(ISDUP2D(_fd_) || (_fd_) >= HIJACK_FDOFF)
549 
550 static bool
551 path_isrump(const char *path)
552 {
553 
554 	if (rumpprefix == NULL)
555 		return false;
556 
557 	if (*path == '/') {
558 		if (strncmp(path, rumpprefix, rumpprefixlen) == 0)
559 			return true;
560 		return false;
561 	} else {
562 		return pwdinrump;
563 	}
564 }
565 
566 static const char *rootpath = "/";
567 static const char *
568 path_host2rump(const char *path)
569 {
570 	const char *rv;
571 
572 	if (*path == '/') {
573 		rv = path + rumpprefixlen;
574 		if (*rv == '\0')
575 			rv = rootpath;
576 	} else {
577 		rv = path;
578 	}
579 
580 	return rv;
581 }
582 
583 static int
584 dodup(int oldd, int minfd)
585 {
586 	int (*op_fcntl)(int, int, ...);
587 	int newd;
588 	int isrump;
589 
590 	DPRINTF(("dup -> %d (minfd %d)\n", oldd, minfd));
591 	if (fd_isrump(oldd)) {
592 		op_fcntl = GETSYSCALL(rump, FCNTL);
593 		oldd = fd_host2rump(oldd);
594 		isrump = 1;
595 	} else {
596 		op_fcntl = GETSYSCALL(host, FCNTL);
597 		isrump = 0;
598 	}
599 
600 	newd = op_fcntl(oldd, F_DUPFD, minfd);
601 
602 	if (isrump)
603 		newd = fd_rump2host(newd);
604 	DPRINTF(("dup <- %d\n", newd));
605 
606 	return newd;
607 }
608 
609 /*
610  * dup a host file descriptor so that it doesn't collide with the dup2mask
611  */
612 static int
613 fd_dupgood(int fd)
614 {
615 	int (*op_fcntl)(int, int, ...) = GETSYSCALL(host, FCNTL);
616 	int (*op_close)(int) = GETSYSCALL(host, CLOSE);
617 	int ofd, i;
618 
619 	for (i = 1; ISDUP2D(fd); i++) {
620 		ofd = fd;
621 		fd = op_fcntl(ofd, F_DUPFD, i);
622 		op_close(ofd);
623 	}
624 
625 	return fd;
626 }
627 
628 int
629 open(const char *path, int flags, ...)
630 {
631 	int (*op_open)(const char *, int, ...);
632 	bool isrump;
633 	va_list ap;
634 	int fd;
635 
636 	if (path_isrump(path)) {
637 		path = path_host2rump(path);
638 		op_open = GETSYSCALL(rump, OPEN);
639 		isrump = true;
640 	} else {
641 		op_open = GETSYSCALL(host, OPEN);
642 		isrump = false;
643 	}
644 
645 	va_start(ap, flags);
646 	fd = op_open(path, flags, va_arg(ap, mode_t));
647 	va_end(ap);
648 
649 	if (isrump)
650 		fd = fd_rump2host(fd);
651 	else
652 		fd = fd_dupgood(fd);
653 	return fd;
654 }
655 
656 int
657 chdir(const char *path)
658 {
659 	int (*op_chdir)(const char *);
660 	bool isrump;
661 	int rv;
662 
663 	if (path_isrump(path)) {
664 		op_chdir = GETSYSCALL(rump, CHDIR);
665 		isrump = true;
666 		path = path_host2rump(path);
667 	} else {
668 		op_chdir = GETSYSCALL(host, CHDIR);
669 		isrump = false;
670 	}
671 
672 	rv = op_chdir(path);
673 	if (rv == 0) {
674 		if (isrump)
675 			pwdinrump = true;
676 		else
677 			pwdinrump = false;
678 	}
679 
680 	return rv;
681 }
682 
683 int
684 fchdir(int fd)
685 {
686 	int (*op_fchdir)(int);
687 	bool isrump;
688 	int rv;
689 
690 	if (fd_isrump(fd)) {
691 		op_fchdir = GETSYSCALL(rump, FCHDIR);
692 		isrump = true;
693 		fd = fd_host2rump(fd);
694 	} else {
695 		op_fchdir = GETSYSCALL(host, FCHDIR);
696 		isrump = false;
697 	}
698 
699 	rv = op_fchdir(fd);
700 	if (rv == 0) {
701 		if (isrump)
702 			pwdinrump = true;
703 		else
704 			pwdinrump = false;
705 	}
706 
707 	return rv;
708 }
709 
710 int
711 __getcwd(char *bufp, size_t len)
712 {
713 	int (*op___getcwd)(char *, size_t);
714 	int rv;
715 
716 	if (pwdinrump) {
717 		size_t prefixgap;
718 		bool iamslash;
719 
720 		if (rumpprefix[rumpprefixlen-1] == '/')
721 			iamslash = true;
722 		else
723 			iamslash = false;
724 
725 		if (iamslash)
726 			prefixgap = rumpprefixlen - 1; /* ``//+path'' */
727 		else
728 			prefixgap = rumpprefixlen; /* ``/pfx+/path'' */
729 		if (len <= prefixgap) {
730 			return ERANGE;
731 		}
732 
733 		op___getcwd = GETSYSCALL(rump, __GETCWD);
734 		rv = op___getcwd(bufp + prefixgap, len - prefixgap);
735 		if (rv == -1)
736 			return rv;
737 
738 		/* augment the "/" part only for a non-root path */
739 		memcpy(bufp, rumpprefix, rumpprefixlen);
740 
741 		/* append / only to non-root cwd */
742 		if (rv != 2)
743 			bufp[prefixgap] = '/';
744 
745 		/* don't append extra slash in the purely-slash case */
746 		if (rv == 2 && !iamslash)
747 			bufp[rumpprefixlen] = '\0';
748 
749 		return rv;
750 	} else {
751 		op___getcwd = GETSYSCALL(host, __GETCWD);
752 		return op___getcwd(bufp, len);
753 	}
754 }
755 
756 int
757 rename(const char *from, const char *to)
758 {
759 	int (*op_rename)(const char *, const char *);
760 
761 	if (path_isrump(from)) {
762 		if (!path_isrump(to))
763 			return EXDEV;
764 
765 		from = path_host2rump(from);
766 		to = path_host2rump(to);
767 		op_rename = GETSYSCALL(rump, RENAME);
768 	} else {
769 		if (path_isrump(to))
770 			return EXDEV;
771 
772 		op_rename = GETSYSCALL(host, RENAME);
773 	}
774 
775 	return op_rename(from, to);
776 }
777 
778 int __socket30(int, int, int);
779 int
780 __socket30(int domain, int type, int protocol)
781 {
782 	int (*op_socket)(int, int, int);
783 	int fd;
784 	bool isrump;
785 
786 	isrump = domain < PF_MAX && rumpsockets[domain];
787 
788 	if (isrump)
789 		op_socket = GETSYSCALL(rump, SOCKET);
790 	else
791 		op_socket = GETSYSCALL(host, SOCKET);
792 	fd = op_socket(domain, type, protocol);
793 
794 	if (isrump)
795 		fd = fd_rump2host(fd);
796 	else
797 		fd = fd_dupgood(fd);
798 	DPRINTF(("socket <- %d\n", fd));
799 
800 	return fd;
801 }
802 
803 int
804 accept(int s, struct sockaddr *addr, socklen_t *addrlen)
805 {
806 	int (*op_accept)(int, struct sockaddr *, socklen_t *);
807 	int fd;
808 	bool isrump;
809 
810 	isrump = fd_isrump(s);
811 
812 	DPRINTF(("accept -> %d", s));
813 	if (isrump) {
814 		op_accept = GETSYSCALL(rump, ACCEPT);
815 		s = fd_host2rump(s);
816 	} else {
817 		op_accept = GETSYSCALL(host, ACCEPT);
818 	}
819 	fd = op_accept(s, addr, addrlen);
820 	if (fd != -1 && isrump)
821 		fd = fd_rump2host(fd);
822 	else
823 		fd = fd_dupgood(fd);
824 
825 	DPRINTF((" <- %d\n", fd));
826 
827 	return fd;
828 }
829 
830 /*
831  * ioctl and fcntl are varargs calls and need special treatment
832  */
833 int
834 ioctl(int fd, unsigned long cmd, ...)
835 {
836 	int (*op_ioctl)(int, unsigned long cmd, ...);
837 	va_list ap;
838 	int rv;
839 
840 	DPRINTF(("ioctl -> %d\n", fd));
841 	if (fd_isrump(fd)) {
842 		fd = fd_host2rump(fd);
843 		op_ioctl = GETSYSCALL(rump, IOCTL);
844 	} else {
845 		op_ioctl = GETSYSCALL(host, IOCTL);
846 	}
847 
848 	va_start(ap, cmd);
849 	rv = op_ioctl(fd, cmd, va_arg(ap, void *));
850 	va_end(ap);
851 	return rv;
852 }
853 
854 #include <syslog.h>
855 int
856 fcntl(int fd, int cmd, ...)
857 {
858 	int (*op_fcntl)(int, int, ...);
859 	va_list ap;
860 	int rv, minfd, i;
861 
862 	DPRINTF(("fcntl -> %d (cmd %d)\n", fd, cmd));
863 
864 	switch (cmd) {
865 	case F_DUPFD:
866 		va_start(ap, cmd);
867 		minfd = va_arg(ap, int);
868 		va_end(ap);
869 		return dodup(fd, minfd);
870 
871 	case F_CLOSEM:
872 		/*
873 		 * So, if fd < HIJACKOFF, we want to do a host closem.
874 		 */
875 
876 		if (fd < HIJACK_FDOFF) {
877 			int closemfd = fd;
878 
879 			if (rumpclient__closenotify(&closemfd,
880 			    RUMPCLIENT_CLOSE_FCLOSEM) == -1)
881 				return -1;
882 			op_fcntl = GETSYSCALL(host, FCNTL);
883 			rv = op_fcntl(closemfd, cmd);
884 			if (rv)
885 				return rv;
886 		}
887 
888 		/*
889 		 * Additionally, we want to do a rump closem, but only
890 		 * for the file descriptors not within the dup2mask.
891 		 */
892 
893 		/* why don't we offer fls()? */
894 		for (i = 15; i >= 0; i--) {
895 			if (ISDUP2D(i))
896 				break;
897 		}
898 
899 		if (fd >= HIJACK_FDOFF)
900 			fd -= HIJACK_FDOFF;
901 		else
902 			fd = 0;
903 		fd = MAX(i+1, fd);
904 
905 		/* hmm, maybe we should close rump fd's not within dup2mask? */
906 
907 		return rump_sys_fcntl(fd, F_CLOSEM);
908 
909 	case F_MAXFD:
910 		/*
911 		 * For maxfd, if there's a rump kernel fd, return
912 		 * it hostified.  Otherwise, return host's MAXFD
913 		 * return value.
914 		 */
915 		if ((rv = rump_sys_fcntl(fd, F_MAXFD)) != -1) {
916 			/*
917 			 * This might go a little wrong in case
918 			 * of dup2 to [012], but I'm not sure if
919 			 * there's a justification for tracking
920 			 * that info.  Consider e.g.
921 			 * dup2(rumpfd, 2) followed by rump_sys_open()
922 			 * returning 1.  We should return 1+HIJACKOFF,
923 			 * not 2+HIJACKOFF.  However, if [01] is not
924 			 * open, the correct return value is 2.
925 			 */
926 			return fd_rump2host(fd);
927 		} else {
928 			op_fcntl = GETSYSCALL(host, FCNTL);
929 			return op_fcntl(fd, F_MAXFD);
930 		}
931 		/*NOTREACHED*/
932 
933 	default:
934 		if (fd_isrump(fd)) {
935 			fd = fd_host2rump(fd);
936 			op_fcntl = GETSYSCALL(rump, FCNTL);
937 		} else {
938 			op_fcntl = GETSYSCALL(host, FCNTL);
939 		}
940 
941 		va_start(ap, cmd);
942 		rv = op_fcntl(fd, cmd, va_arg(ap, void *));
943 		va_end(ap);
944 		return rv;
945 	}
946 	/*NOTREACHED*/
947 }
948 
949 int
950 close(int fd)
951 {
952 	int (*op_close)(int);
953 	int rv;
954 
955 	DPRINTF(("close -> %d\n", fd));
956 	if (fd_isrump(fd)) {
957 		int undup2 = 0;
958 
959 		fd = fd_host2rump(fd);
960 		if (ISDUP2ALIAS(fd)) {
961 			_DIAGASSERT(ISDUP2D(fd));
962 			CLRDUP2ALIAS(fd);
963 			return 0;
964 		}
965 
966 		if (ISDUP2D(fd))
967 			undup2 = 1;
968 		op_close = GETSYSCALL(rump, CLOSE);
969 		rv = op_close(fd);
970 		if (rv == 0 && undup2)
971 			CLRDUP2(fd);
972 	} else {
973 		if (rumpclient__closenotify(&fd, RUMPCLIENT_CLOSE_CLOSE) == -1)
974 			return -1;
975 		op_close = GETSYSCALL(host, CLOSE);
976 		rv = op_close(fd);
977 	}
978 
979 	return rv;
980 }
981 
982 /*
983  * write cannot issue a standard debug printf due to recursion
984  */
985 ssize_t
986 write(int fd, const void *buf, size_t blen)
987 {
988 	ssize_t (*op_write)(int, const void *, size_t);
989 
990 	if (fd_isrump(fd)) {
991 		fd = fd_host2rump(fd);
992 		op_write = GETSYSCALL(rump, WRITE);
993 	} else {
994 		op_write = GETSYSCALL(host, WRITE);
995 	}
996 
997 	return op_write(fd, buf, blen);
998 }
999 
1000 /*
1001  * dup2 is special.  we allow dup2 of a rump kernel fd to 0-2 since
1002  * many programs do that.  dup2 of a rump kernel fd to another value
1003  * not >= fdoff is an error.
1004  *
1005  * Note: cannot rump2host newd, because it is often hardcoded.
1006  */
1007 int
1008 dup2(int oldd, int newd)
1009 {
1010 	int (*host_dup2)(int, int);
1011 	int rv;
1012 
1013 	DPRINTF(("dup2 -> %d (o) -> %d (n)\n", oldd, newd));
1014 
1015 	if (fd_isrump(oldd)) {
1016 		if (!(newd >= 0 && newd <= 2))
1017 			return EBADF;
1018 		oldd = fd_host2rump(oldd);
1019 		if (oldd == newd) {
1020 			SETDUP2(newd);
1021 			SETDUP2ALIAS(newd);
1022 			return newd;
1023 		}
1024 		rv = rump_sys_dup2(oldd, newd);
1025 		if (rv != -1)
1026 			SETDUP2(newd);
1027 	} else {
1028 		host_dup2 = syscalls[DUALCALL_DUP2].bs_host;
1029 		if (rumpclient__closenotify(&newd, RUMPCLIENT_CLOSE_DUP2) == -1)
1030 			return -1;
1031 		rv = host_dup2(oldd, newd);
1032 	}
1033 
1034 	return rv;
1035 }
1036 
1037 int
1038 dup(int oldd)
1039 {
1040 
1041 	return dodup(oldd, 0);
1042 }
1043 
1044 pid_t
1045 fork()
1046 {
1047 	pid_t rv;
1048 
1049 	DPRINTF(("fork\n"));
1050 
1051 	rv = rumpclient__dofork(host_fork);
1052 
1053 	DPRINTF(("fork returns %d\n", rv));
1054 	return rv;
1055 }
1056 /* we do not have the luxury of not requiring a stackframe */
1057 __strong_alias(__vfork14,fork);
1058 
1059 int
1060 daemon(int nochdir, int noclose)
1061 {
1062 	struct rumpclient_fork *rf;
1063 
1064 	if ((rf = rumpclient_prefork()) == NULL)
1065 		return -1;
1066 
1067 	if (host_daemon(nochdir, noclose) == -1)
1068 		return -1;
1069 
1070 	if (rumpclient_fork_init(rf) == -1)
1071 		return -1;
1072 
1073 	return 0;
1074 }
1075 
1076 int
1077 execve(const char *path, char *const argv[], char *const envp[])
1078 {
1079 	char buf[128];
1080 	char *dup2str;
1081 	const char *pwdinrumpstr;
1082 	char **newenv;
1083 	size_t nelem;
1084 	int rv, sverrno;
1085 	int bonus = 1, i = 0;
1086 
1087 	if (dup2mask) {
1088 		snprintf(buf, sizeof(buf), "RUMPHIJACK__DUP2MASK=%u", dup2mask);
1089 		dup2str = malloc(strlen(buf)+1);
1090 		if (dup2str == NULL)
1091 			return ENOMEM;
1092 		strcpy(dup2str, buf);
1093 		bonus++;
1094 	} else {
1095 		dup2str = NULL;
1096 	}
1097 
1098 	if (pwdinrump) {
1099 		pwdinrumpstr = "RUMPHIJACK__PWDINRUMP=true";
1100 		bonus++;
1101 	} else {
1102 		pwdinrumpstr = NULL;
1103 	}
1104 
1105 	for (nelem = 0; envp && envp[nelem]; nelem++)
1106 		continue;
1107 	newenv = malloc(sizeof(*newenv) * nelem+bonus);
1108 	if (newenv == NULL) {
1109 		free(dup2str);
1110 		return ENOMEM;
1111 	}
1112 	memcpy(newenv, envp, nelem*sizeof(*newenv));
1113 	if (dup2str) {
1114 		newenv[nelem+i] = dup2str;
1115 		i++;
1116 	}
1117 	if (pwdinrumpstr) {
1118 		newenv[nelem+i] = __UNCONST(pwdinrumpstr);
1119 		i++;
1120 	}
1121 	newenv[nelem+i] = NULL;
1122 	_DIAGASSERT(i < bonus);
1123 
1124 	rv = rumpclient_exec(path, argv, newenv);
1125 
1126 	_DIAGASSERT(rv != 0);
1127 	sverrno = errno;
1128 	free(newenv);
1129 	free(dup2str);
1130 	errno = sverrno;
1131 	return rv;
1132 }
1133 
1134 /*
1135  * select is done by calling poll.
1136  */
1137 int
1138 REALSELECT(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
1139 	struct timeval *timeout)
1140 {
1141 	struct pollfd *pfds;
1142 	struct timespec ts, *tsp = NULL;
1143 	nfds_t realnfds;
1144 	int i, j;
1145 	int rv, incr;
1146 
1147 	DPRINTF(("select\n"));
1148 
1149 	/*
1150 	 * Well, first we must scan the fds to figure out how many
1151 	 * fds there really are.  This is because up to and including
1152 	 * nb5 poll() silently refuses nfds > process_maxopen_fds.
1153 	 * Seems to be fixed in current, thank the maker.
1154 	 * god damn cluster...bomb.
1155 	 */
1156 
1157 	for (i = 0, realnfds = 0; i < nfds; i++) {
1158 		if (readfds && FD_ISSET(i, readfds)) {
1159 			realnfds++;
1160 			continue;
1161 		}
1162 		if (writefds && FD_ISSET(i, writefds)) {
1163 			realnfds++;
1164 			continue;
1165 		}
1166 		if (exceptfds && FD_ISSET(i, exceptfds)) {
1167 			realnfds++;
1168 			continue;
1169 		}
1170 	}
1171 
1172 	if (realnfds) {
1173 		pfds = calloc(realnfds, sizeof(*pfds));
1174 		if (!pfds)
1175 			return -1;
1176 	} else {
1177 		pfds = NULL;
1178 	}
1179 
1180 	for (i = 0, j = 0; i < nfds; i++) {
1181 		incr = 0;
1182 		if (readfds && FD_ISSET(i, readfds)) {
1183 			pfds[j].fd = i;
1184 			pfds[j].events |= POLLIN;
1185 			incr=1;
1186 		}
1187 		if (writefds && FD_ISSET(i, writefds)) {
1188 			pfds[j].fd = i;
1189 			pfds[j].events |= POLLOUT;
1190 			incr=1;
1191 		}
1192 		if (exceptfds && FD_ISSET(i, exceptfds)) {
1193 			pfds[j].fd = i;
1194 			pfds[j].events |= POLLHUP|POLLERR;
1195 			incr=1;
1196 		}
1197 		if (incr)
1198 			j++;
1199 	}
1200 	assert(j == (int)realnfds);
1201 
1202 	if (timeout) {
1203 		TIMEVAL_TO_TIMESPEC(timeout, &ts);
1204 		tsp = &ts;
1205 	}
1206 	rv = REALPOLLTS(pfds, realnfds, tsp, NULL);
1207 	/*
1208 	 * "If select() returns with an error the descriptor sets
1209 	 * will be unmodified"
1210 	 */
1211 	if (rv < 0)
1212 		goto out;
1213 
1214 	/*
1215 	 * zero out results (can't use FD_ZERO for the
1216 	 * obvious select-me-not reason).  whee.
1217 	 *
1218 	 * We do this here since some software ignores the return
1219 	 * value of select, and hence if the timeout expires, it may
1220 	 * assume all input descriptors have activity.
1221 	 */
1222 	for (i = 0; i < nfds; i++) {
1223 		if (readfds)
1224 			FD_CLR(i, readfds);
1225 		if (writefds)
1226 			FD_CLR(i, writefds);
1227 		if (exceptfds)
1228 			FD_CLR(i, exceptfds);
1229 	}
1230 	if (rv == 0)
1231 		goto out;
1232 
1233 	/*
1234 	 * We have >0 fds with activity.  Harvest the results.
1235 	 */
1236 	for (i = 0; i < (int)realnfds; i++) {
1237 		if (readfds) {
1238 			if (pfds[i].revents & POLLIN) {
1239 				FD_SET(pfds[i].fd, readfds);
1240 			}
1241 		}
1242 		if (writefds) {
1243 			if (pfds[i].revents & POLLOUT) {
1244 				FD_SET(pfds[i].fd, writefds);
1245 			}
1246 		}
1247 		if (exceptfds) {
1248 			if (pfds[i].revents & (POLLHUP|POLLERR)) {
1249 				FD_SET(pfds[i].fd, exceptfds);
1250 			}
1251 		}
1252 	}
1253 
1254  out:
1255 	free(pfds);
1256 	return rv;
1257 }
1258 
1259 static void
1260 checkpoll(struct pollfd *fds, nfds_t nfds, int *hostcall, int *rumpcall)
1261 {
1262 	nfds_t i;
1263 
1264 	for (i = 0; i < nfds; i++) {
1265 		if (fds[i].fd == -1)
1266 			continue;
1267 
1268 		if (fd_isrump(fds[i].fd))
1269 			(*rumpcall)++;
1270 		else
1271 			(*hostcall)++;
1272 	}
1273 }
1274 
1275 static void
1276 adjustpoll(struct pollfd *fds, nfds_t nfds, int (*fdadj)(int))
1277 {
1278 	nfds_t i;
1279 
1280 	for (i = 0; i < nfds; i++) {
1281 		fds[i].fd = fdadj(fds[i].fd);
1282 	}
1283 }
1284 
1285 /*
1286  * poll is easy as long as the call comes in the fds only in one
1287  * kernel.  otherwise its quite tricky...
1288  */
1289 struct pollarg {
1290 	struct pollfd *pfds;
1291 	nfds_t nfds;
1292 	const struct timespec *ts;
1293 	const sigset_t *sigmask;
1294 	int pipefd;
1295 	int errnum;
1296 };
1297 
1298 static void *
1299 hostpoll(void *arg)
1300 {
1301 	int (*op_pollts)(struct pollfd *, nfds_t, const struct timespec *,
1302 			 const sigset_t *);
1303 	struct pollarg *parg = arg;
1304 	intptr_t rv;
1305 
1306 	op_pollts = GETSYSCALL(host, POLLTS);
1307 	rv = op_pollts(parg->pfds, parg->nfds, parg->ts, parg->sigmask);
1308 	if (rv == -1)
1309 		parg->errnum = errno;
1310 	rump_sys_write(parg->pipefd, &rv, sizeof(rv));
1311 
1312 	return (void *)(intptr_t)rv;
1313 }
1314 
1315 int
1316 REALPOLLTS(struct pollfd *fds, nfds_t nfds, const struct timespec *ts,
1317 	const sigset_t *sigmask)
1318 {
1319 	int (*op_pollts)(struct pollfd *, nfds_t, const struct timespec *,
1320 			 const sigset_t *);
1321 	int (*host_close)(int);
1322 	int hostcall = 0, rumpcall = 0;
1323 	pthread_t pt;
1324 	nfds_t i;
1325 	int rv;
1326 
1327 	DPRINTF(("poll\n"));
1328 	checkpoll(fds, nfds, &hostcall, &rumpcall);
1329 
1330 	if (hostcall && rumpcall) {
1331 		struct pollfd *pfd_host = NULL, *pfd_rump = NULL;
1332 		int rpipe[2] = {-1,-1}, hpipe[2] = {-1,-1};
1333 		struct pollarg parg;
1334 		uintptr_t lrv;
1335 		int sverrno = 0, trv;
1336 
1337 		/*
1338 		 * ok, this is where it gets tricky.  We must support
1339 		 * this since it's a very common operation in certain
1340 		 * types of software (telnet, netcat, etc).  We allocate
1341 		 * two vectors and run two poll commands in separate
1342 		 * threads.  Whichever returns first "wins" and the
1343 		 * other kernel's fds won't show activity.
1344 		 */
1345 		rv = -1;
1346 
1347 		/* allocate full vector for O(n) joining after call */
1348 		pfd_host = malloc(sizeof(*pfd_host)*(nfds+1));
1349 		if (!pfd_host)
1350 			goto out;
1351 		pfd_rump = malloc(sizeof(*pfd_rump)*(nfds+1));
1352 		if (!pfd_rump) {
1353 			goto out;
1354 		}
1355 
1356 		/*
1357 		 * then, open two pipes, one for notifications
1358 		 * to each kernel.
1359 		 */
1360 		if ((rv = rump_sys_pipe(rpipe)) == -1) {
1361 			sverrno = errno;
1362 		}
1363 		if (rv == 0 && (rv = pipe(hpipe)) == -1) {
1364 			sverrno = errno;
1365 		}
1366 
1367 		/* split vectors (or signal errors) */
1368 		for (i = 0; i < nfds; i++) {
1369 			int fd;
1370 
1371 			fds[i].revents = 0;
1372 			if (fds[i].fd == -1) {
1373 				pfd_host[i].fd = -1;
1374 				pfd_rump[i].fd = -1;
1375 			} else if (fd_isrump(fds[i].fd)) {
1376 				pfd_host[i].fd = -1;
1377 				fd = fd_host2rump(fds[i].fd);
1378 				if (fd == rpipe[0] || fd == rpipe[1]) {
1379 					fds[i].revents = POLLNVAL;
1380 					if (rv != -1)
1381 						rv++;
1382 				}
1383 				pfd_rump[i].fd = fd;
1384 				pfd_rump[i].events = fds[i].events;
1385 			} else {
1386 				pfd_rump[i].fd = -1;
1387 				fd = fds[i].fd;
1388 				if (fd == hpipe[0] || fd == hpipe[1]) {
1389 					fds[i].revents = POLLNVAL;
1390 					if (rv != -1)
1391 						rv++;
1392 				}
1393 				pfd_host[i].fd = fd;
1394 				pfd_host[i].events = fds[i].events;
1395 			}
1396 			pfd_rump[i].revents = pfd_host[i].revents = 0;
1397 		}
1398 		if (rv) {
1399 			goto out;
1400 		}
1401 
1402 		pfd_host[nfds].fd = hpipe[0];
1403 		pfd_host[nfds].events = POLLIN;
1404 		pfd_rump[nfds].fd = rpipe[0];
1405 		pfd_rump[nfds].events = POLLIN;
1406 
1407 		/*
1408 		 * then, create a thread to do host part and meanwhile
1409 		 * do rump kernel part right here
1410 		 */
1411 
1412 		parg.pfds = pfd_host;
1413 		parg.nfds = nfds+1;
1414 		parg.ts = ts;
1415 		parg.sigmask = sigmask;
1416 		parg.pipefd = rpipe[1];
1417 		pthread_create(&pt, NULL, hostpoll, &parg);
1418 
1419 		op_pollts = GETSYSCALL(rump, POLLTS);
1420 		lrv = op_pollts(pfd_rump, nfds+1, ts, NULL);
1421 		sverrno = errno;
1422 		write(hpipe[1], &rv, sizeof(rv));
1423 		pthread_join(pt, (void *)&trv);
1424 
1425 		/* check who "won" and merge results */
1426 		if (lrv != 0 && pfd_host[nfds].revents & POLLIN) {
1427 			rv = trv;
1428 
1429 			for (i = 0; i < nfds; i++) {
1430 				if (pfd_rump[i].fd != -1)
1431 					fds[i].revents = pfd_rump[i].revents;
1432 			}
1433 			sverrno = parg.errnum;
1434 		} else if (trv != 0 && pfd_rump[nfds].revents & POLLIN) {
1435 			rv = trv;
1436 
1437 			for (i = 0; i < nfds; i++) {
1438 				if (pfd_host[i].fd != -1)
1439 					fds[i].revents = pfd_host[i].revents;
1440 			}
1441 		} else {
1442 			rv = 0;
1443 		}
1444 
1445  out:
1446 		host_close = GETSYSCALL(host, CLOSE);
1447 		if (rpipe[0] != -1)
1448 			rump_sys_close(rpipe[0]);
1449 		if (rpipe[1] != -1)
1450 			rump_sys_close(rpipe[1]);
1451 		if (hpipe[0] != -1)
1452 			host_close(hpipe[0]);
1453 		if (hpipe[1] != -1)
1454 			host_close(hpipe[1]);
1455 		free(pfd_host);
1456 		free(pfd_rump);
1457 		errno = sverrno;
1458 	} else {
1459 		if (hostcall) {
1460 			op_pollts = GETSYSCALL(host, POLLTS);
1461 		} else {
1462 			op_pollts = GETSYSCALL(rump, POLLTS);
1463 			adjustpoll(fds, nfds, fd_host2rump);
1464 		}
1465 
1466 		rv = op_pollts(fds, nfds, ts, sigmask);
1467 		if (rumpcall)
1468 			adjustpoll(fds, nfds, fd_rump2host);
1469 	}
1470 
1471 	return rv;
1472 }
1473 
1474 int
1475 poll(struct pollfd *fds, nfds_t nfds, int timeout)
1476 {
1477 	struct timespec ts;
1478 	struct timespec *tsp = NULL;
1479 
1480 	if (timeout != INFTIM) {
1481 		ts.tv_sec = timeout / 1000;
1482 		ts.tv_nsec = (timeout % 1000) * 1000*1000;
1483 
1484 		tsp = &ts;
1485 	}
1486 
1487 	return REALPOLLTS(fds, nfds, tsp, NULL);
1488 }
1489 
1490 int
1491 REALKEVENT(int kq, const struct kevent *changelist, size_t nchanges,
1492 	struct kevent *eventlist, size_t nevents,
1493 	const struct timespec *timeout)
1494 {
1495 	int (*op_kevent)(int, const struct kevent *, size_t,
1496 		struct kevent *, size_t, const struct timespec *);
1497 	const struct kevent *ev;
1498 	size_t i;
1499 
1500 	/*
1501 	 * Check that we don't attempt to kevent rump kernel fd's.
1502 	 * That needs similar treatment to select/poll, but is slightly
1503 	 * trickier since we need to manage to different kq descriptors.
1504 	 * (TODO, in case you're wondering).
1505 	 */
1506 	for (i = 0; i < nchanges; i++) {
1507 		ev = &changelist[i];
1508 		if (ev->filter == EVFILT_READ || ev->filter == EVFILT_WRITE ||
1509 		    ev->filter == EVFILT_VNODE) {
1510 			if (fd_isrump((int)ev->ident))
1511 				return ENOTSUP;
1512 		}
1513 	}
1514 
1515 	op_kevent = GETSYSCALL(host, KEVENT);
1516 	return op_kevent(kq, changelist, nchanges, eventlist, nevents, timeout);
1517 }
1518 
1519 /*
1520  * Rest are std type calls.
1521  */
1522 
1523 FDCALL(int, bind, DUALCALL_BIND,					\
1524 	(int fd, const struct sockaddr *name, socklen_t namelen),	\
1525 	(int, const struct sockaddr *, socklen_t),			\
1526 	(fd, name, namelen))
1527 
1528 FDCALL(int, connect, DUALCALL_CONNECT,					\
1529 	(int fd, const struct sockaddr *name, socklen_t namelen),	\
1530 	(int, const struct sockaddr *, socklen_t),			\
1531 	(fd, name, namelen))
1532 
1533 FDCALL(int, getpeername, DUALCALL_GETPEERNAME,				\
1534 	(int fd, struct sockaddr *name, socklen_t *namelen),		\
1535 	(int, struct sockaddr *, socklen_t *),				\
1536 	(fd, name, namelen))
1537 
1538 FDCALL(int, getsockname, DUALCALL_GETSOCKNAME, 				\
1539 	(int fd, struct sockaddr *name, socklen_t *namelen),		\
1540 	(int, struct sockaddr *, socklen_t *),				\
1541 	(fd, name, namelen))
1542 
1543 FDCALL(int, listen, DUALCALL_LISTEN,	 				\
1544 	(int fd, int backlog),						\
1545 	(int, int),							\
1546 	(fd, backlog))
1547 
1548 FDCALL(ssize_t, recvfrom, DUALCALL_RECVFROM, 				\
1549 	(int fd, void *buf, size_t len, int flags,			\
1550 	    struct sockaddr *from, socklen_t *fromlen),			\
1551 	(int, void *, size_t, int, struct sockaddr *, socklen_t *),	\
1552 	(fd, buf, len, flags, from, fromlen))
1553 
1554 FDCALL(ssize_t, sendto, DUALCALL_SENDTO, 				\
1555 	(int fd, const void *buf, size_t len, int flags,		\
1556 	    const struct sockaddr *to, socklen_t tolen),		\
1557 	(int, const void *, size_t, int,				\
1558 	    const struct sockaddr *, socklen_t),			\
1559 	(fd, buf, len, flags, to, tolen))
1560 
1561 FDCALL(ssize_t, recvmsg, DUALCALL_RECVMSG, 				\
1562 	(int fd, struct msghdr *msg, int flags),			\
1563 	(int, struct msghdr *, int),					\
1564 	(fd, msg, flags))
1565 
1566 FDCALL(ssize_t, sendmsg, DUALCALL_SENDMSG, 				\
1567 	(int fd, const struct msghdr *msg, int flags),			\
1568 	(int, const struct msghdr *, int),				\
1569 	(fd, msg, flags))
1570 
1571 FDCALL(int, getsockopt, DUALCALL_GETSOCKOPT, 				\
1572 	(int fd, int level, int optn, void *optval, socklen_t *optlen),	\
1573 	(int, int, int, void *, socklen_t *),				\
1574 	(fd, level, optn, optval, optlen))
1575 
1576 FDCALL(int, setsockopt, DUALCALL_SETSOCKOPT, 				\
1577 	(int fd, int level, int optn,					\
1578 	    const void *optval, socklen_t optlen),			\
1579 	(int, int, int, const void *, socklen_t),			\
1580 	(fd, level, optn, optval, optlen))
1581 
1582 FDCALL(int, shutdown, DUALCALL_SHUTDOWN, 				\
1583 	(int fd, int how),						\
1584 	(int, int),							\
1585 	(fd, how))
1586 
1587 #if _FORTIFY_SOURCE > 0
1588 #define STUB(fun) __ssp_weak_name(fun)
1589 ssize_t _sys_readlink(const char * __restrict, char * __restrict, size_t);
1590 ssize_t
1591 STUB(readlink)(const char * __restrict path, char * __restrict buf,
1592     size_t bufsiz)
1593 {
1594 	return _sys_readlink(path, buf, bufsiz);
1595 }
1596 
1597 char *_sys_getcwd(char *, size_t);
1598 char *
1599 STUB(getcwd)(char *buf, size_t size)
1600 {
1601 	return _sys_getcwd(buf, size);
1602 }
1603 #else
1604 #define STUB(fun) fun
1605 #endif
1606 
1607 FDCALL(ssize_t, REALREAD, DUALCALL_READ,				\
1608 	(int fd, void *buf, size_t buflen),				\
1609 	(int, void *, size_t),						\
1610 	(fd, buf, buflen))
1611 
1612 FDCALL(ssize_t, readv, DUALCALL_READV, 					\
1613 	(int fd, const struct iovec *iov, int iovcnt),			\
1614 	(int, const struct iovec *, int),				\
1615 	(fd, iov, iovcnt))
1616 
1617 FDCALL(ssize_t, writev, DUALCALL_WRITEV, 				\
1618 	(int fd, const struct iovec *iov, int iovcnt),			\
1619 	(int, const struct iovec *, int),				\
1620 	(fd, iov, iovcnt))
1621 
1622 FDCALL(int, REALFSTAT, DUALCALL_FSTAT,					\
1623 	(int fd, struct stat *sb),					\
1624 	(int, struct stat *),						\
1625 	(fd, sb))
1626 
1627 FDCALL(int, fstatvfs1, DUALCALL_FSTATVFS1,				\
1628 	(int fd, struct statvfs *buf, int flags),			\
1629 	(int, struct statvfs *, int),					\
1630 	(fd, buf, flags))
1631 
1632 FDCALL(off_t, REALLSEEK, DUALCALL_LSEEK,				\
1633 	(int fd, off_t offset, int whence),				\
1634 	(int, off_t, int),						\
1635 	(fd, offset, whence))
1636 
1637 FDCALL(int, REALGETDENTS, DUALCALL_GETDENTS,				\
1638 	(int fd, char *buf, size_t nbytes),				\
1639 	(int, char *, size_t),						\
1640 	(fd, buf, nbytes))
1641 
1642 FDCALL(int, fchown, DUALCALL_FCHOWN,					\
1643 	(int fd, uid_t owner, gid_t group),				\
1644 	(int, uid_t, gid_t),						\
1645 	(fd, owner, group))
1646 
1647 FDCALL(int, fchmod, DUALCALL_FCHMOD,					\
1648 	(int fd, mode_t mode),						\
1649 	(int, mode_t),							\
1650 	(fd, mode))
1651 
1652 FDCALL(int, ftruncate, DUALCALL_FTRUNCATE,				\
1653 	(int fd, off_t length),						\
1654 	(int, off_t),							\
1655 	(fd, length))
1656 
1657 FDCALL(int, fsync, DUALCALL_FSYNC,					\
1658 	(int fd),							\
1659 	(int),								\
1660 	(fd))
1661 
1662 FDCALL(int, fsync_range, DUALCALL_FSYNC_RANGE,				\
1663 	(int fd, int how, off_t start, off_t length),			\
1664 	(int, int, off_t, off_t),					\
1665 	(fd, how, start, length))
1666 
1667 FDCALL(int, futimes, DUALCALL_FUTIMES,					\
1668 	(int fd, const struct timeval *tv),				\
1669 	(int, const struct timeval *),					\
1670 	(fd, tv))
1671 
1672 /*
1673  * path-based selectors
1674  */
1675 
1676 PATHCALL(int, REALSTAT, DUALCALL_STAT,					\
1677 	(const char *path, struct stat *sb),				\
1678 	(const char *, struct stat *),					\
1679 	(path, sb))
1680 
1681 PATHCALL(int, REALLSTAT, DUALCALL_LSTAT,				\
1682 	(const char *path, struct stat *sb),				\
1683 	(const char *, struct stat *),					\
1684 	(path, sb))
1685 
1686 PATHCALL(int, chown, DUALCALL_CHOWN,					\
1687 	(const char *path, uid_t owner, gid_t group),			\
1688 	(const char *, uid_t, gid_t),					\
1689 	(path, owner, group))
1690 
1691 PATHCALL(int, lchown, DUALCALL_LCHOWN,					\
1692 	(const char *path, uid_t owner, gid_t group),			\
1693 	(const char *, uid_t, gid_t),					\
1694 	(path, owner, group))
1695 
1696 PATHCALL(int, chmod, DUALCALL_CHMOD,					\
1697 	(const char *path, mode_t mode),				\
1698 	(const char *, mode_t),						\
1699 	(path, mode))
1700 
1701 PATHCALL(int, lchmod, DUALCALL_LCHMOD,					\
1702 	(const char *path, mode_t mode),				\
1703 	(const char *, mode_t),						\
1704 	(path, mode))
1705 
1706 PATHCALL(int, statvfs1, DUALCALL_STATVFS1,				\
1707 	(const char *path, struct statvfs *buf, int flags),		\
1708 	(const char *, struct statvfs *, int),				\
1709 	(path, buf, flags))
1710 
1711 PATHCALL(int, unlink, DUALCALL_UNLINK,					\
1712 	(const char *path),						\
1713 	(const char *),							\
1714 	(path))
1715 
1716 PATHCALL(int, symlink, DUALCALL_SYMLINK,				\
1717 	(const char *target, const char *path),				\
1718 	(const char *, const char *),					\
1719 	(target, path))
1720 
1721 PATHCALL(ssize_t, readlink, DUALCALL_READLINK,				\
1722 	(const char *path, char *buf, size_t bufsiz),			\
1723 	(const char *, char *, size_t),					\
1724 	(path, buf, bufsiz))
1725 
1726 PATHCALL(int, mkdir, DUALCALL_MKDIR,					\
1727 	(const char *path, mode_t mode),				\
1728 	(const char *, mode_t),						\
1729 	(path, mode))
1730 
1731 PATHCALL(int, rmdir, DUALCALL_RMDIR,					\
1732 	(const char *path),						\
1733 	(const char *),							\
1734 	(path))
1735 
1736 PATHCALL(int, utimes, DUALCALL_UTIMES,					\
1737 	(const char *path, const struct timeval *tv),			\
1738 	(const char *, const struct timeval *),				\
1739 	(path, tv))
1740 
1741 PATHCALL(int, lutimes, DUALCALL_LUTIMES,				\
1742 	(const char *path, const struct timeval *tv),			\
1743 	(const char *, const struct timeval *),				\
1744 	(path, tv))
1745 
1746 PATHCALL(int, truncate, DUALCALL_TRUNCATE,				\
1747 	(const char *path, off_t length),				\
1748 	(const char *, off_t),						\
1749 	(path, length))
1750 
1751 /*
1752  * Note: with mount the decisive parameter is the mount
1753  * destination directory.  This is because we don't really know
1754  * about the "source" directory in a generic call (and besides,
1755  * it might not even exist, cf. nfs).
1756  */
1757 PATHCALL(int, REALMOUNT, DUALCALL_MOUNT,				\
1758 	(const char *type, const char *path, int flags,			\
1759 	    void *data, size_t dlen),					\
1760 	(const char *, const char *, int, void *, size_t),		\
1761 	(type, path, flags, data, dlen))
1762 
1763 PATHCALL(int, unmount, DUALCALL_UNMOUNT,				\
1764 	(const char *path, int flags),					\
1765 	(const char *, int),						\
1766 	(path, flags))
1767