busybox/libbb/xfuncs_printf.c

/* vi: set sw=4 ts=4: */
/*
 * Utility routines.
 *
 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
 * Copyright (C) 2006 Rob Landley
 * Copyright (C) 2006 Denys Vlasenko
 *
 * Licensed under GPL version 2, see file LICENSE in this tarball for details.
 */

/* We need to have separate xfuncs.c and xfuncs_printf.c because
 * with current linkers, even with section garbage collection,
 * if *.o module references any of XXXprintf functions, you pull in
 * entire printf machinery. Even if you do not use the function
 * which uses XXXprintf.
 *
 * xfuncs.c contains functions (not necessarily xfuncs)
 * which do not pull in printf, directly or indirectly.
 * xfunc_printf.c contains those which do.
 */

#include "libbb.h"


/* All the functions starting with "x" call bb_error_msg_and_die() if they
 * fail, so callers never need to check for errors.  If it returned, it
 * succeeded. */

#ifndef DMALLOC
/* dmalloc provides variants of these that do abort() on failure.
 * Since dmalloc's prototypes overwrite the impls here as they are
 * included after these prototypes in libbb.h, all is well.
 */
// Warn if we can't allocate size bytes of memory.
void* FAST_FUNC malloc_or_warn(size_t size)
{
	void *ptr = malloc(size);
	if (ptr == NULL && size != 0)
		bb_error_msg(bb_msg_memory_exhausted);
	return ptr;
}

// Die if we can't allocate size bytes of memory.
void* FAST_FUNC xmalloc(size_t size)
{
	void *ptr = malloc(size);
	if (ptr == NULL && size != 0)
		bb_error_msg_and_die(bb_msg_memory_exhausted);
	return ptr;
}

// Die if we can't resize previously allocated memory.  (This returns a pointer
// to the new memory, which may or may not be the same as the old memory.
// It'll copy the contents to a new chunk and free the old one if necessary.)
void* FAST_FUNC xrealloc(void *ptr, size_t size)
{
	ptr = realloc(ptr, size);
	if (ptr == NULL && size != 0)
		bb_error_msg_and_die(bb_msg_memory_exhausted);
	return ptr;
}
#endif /* DMALLOC */

// Die if we can't allocate and zero size bytes of memory.
void* FAST_FUNC xzalloc(size_t size)
{
	void *ptr = xmalloc(size);
	memset(ptr, 0, size);
	return ptr;
}

// Die if we can't copy a string to freshly allocated memory.
char* FAST_FUNC xstrdup(const char *s)
{
	char *t;

	if (s == NULL)
		return NULL;

	t = strdup(s);

	if (t == NULL)
		bb_error_msg_and_die(bb_msg_memory_exhausted);

	return t;
}

// Die if we can't allocate n+1 bytes (space for the null terminator) and copy
// the (possibly truncated to length n) string into it.
char* FAST_FUNC xstrndup(const char *s, int n)
{
	int m;
	char *t;

	if (ENABLE_DEBUG && s == NULL)
		bb_error_msg_and_die("xstrndup bug");

	/* We can just xmalloc(n+1) and strncpy into it, */
	/* but think about xstrndup("abc", 10000) wastage! */
	m = n;
	t = (char*) s;
	while (m) {
		if (!*t) break;
		m--;
		t++;
	}
	n -= m;
	t = xmalloc(n + 1);
	t[n] = '\0';

	return memcpy(t, s, n);
}

// Die if we can't open a file and return a FILE* to it.
// Notice we haven't got xfread(), This is for use with fscanf() and friends.
FILE* FAST_FUNC xfopen(const char *path, const char *mode)
{
	FILE *fp = fopen(path, mode);
	if (fp == NULL)
		bb_perror_msg_and_die("can't open '%s'", path);
	return fp;
}

// Die if we can't open a file and return a fd.
int FAST_FUNC xopen3(const char *pathname, int flags, int mode)
{
	int ret;

	ret = open(pathname, flags, mode);
	if (ret < 0) {
		bb_perror_msg_and_die("can't open '%s'", pathname);
	}
	return ret;
}

// Die if we can't open an existing file and return a fd.
int FAST_FUNC xopen(const char *pathname, int flags)
{
	return xopen3(pathname, flags, 0666);
}

/* Die if we can't open an existing file readonly with O_NONBLOCK
 * and return the fd.
 * Note that for ioctl O_RDONLY is sufficient.
 */
int FAST_FUNC xopen_nonblocking(const char *pathname)
{
	return xopen(pathname, O_RDONLY | O_NONBLOCK);
}

// Warn if we can't open a file and return a fd.
int FAST_FUNC open3_or_warn(const char *pathname, int flags, int mode)
{
	int ret;

	ret = open(pathname, flags, mode);
	if (ret < 0) {
		bb_perror_msg("can't open '%s'", pathname);
	}
	return ret;
}

// Warn if we can't open a file and return a fd.
int FAST_FUNC open_or_warn(const char *pathname, int flags)
{
	return open3_or_warn(pathname, flags, 0666);
}

void FAST_FUNC xunlink(const char *pathname)
{
	if (unlink(pathname))
		bb_perror_msg_and_die("can't remove file '%s'", pathname);
}

void FAST_FUNC xrename(const char *oldpath, const char *newpath)
{
	if (rename(oldpath, newpath))
		bb_perror_msg_and_die("can't move '%s' to '%s'", oldpath, newpath);
}

int FAST_FUNC rename_or_warn(const char *oldpath, const char *newpath)
{
	int n = rename(oldpath, newpath);
	if (n)
		bb_perror_msg("can't move '%s' to '%s'", oldpath, newpath);
	return n;
}

void FAST_FUNC xpipe(int filedes[2])
{
	if (pipe(filedes))
		bb_perror_msg_and_die("can't create pipe");
}

void FAST_FUNC xdup2(int from, int to)
{
	if (dup2(from, to) != to)
		bb_perror_msg_and_die("can't duplicate file descriptor");
}

// "Renumber" opened fd
void FAST_FUNC xmove_fd(int from, int to)
{
	if (from == to)
		return;
	xdup2(from, to);
	close(from);
}

// Die with an error message if we can't write the entire buffer.
void FAST_FUNC xwrite(int fd, const void *buf, size_t count)
{
	if (count) {
		ssize_t size = full_write(fd, buf, count);
		if ((size_t)size != count)
			bb_error_msg_and_die("short write");
	}
}
void FAST_FUNC xwrite_str(int fd, const char *str)
{
	xwrite(fd, str, strlen(str));
}

void FAST_FUNC xclose(int fd)
{
	if (close(fd))
		bb_perror_msg_and_die("close failed");
}

// Die with an error message if we can't lseek to the right spot.
off_t FAST_FUNC xlseek(int fd, off_t offset, int whence)
{
	off_t off = lseek(fd, offset, whence);
	if (off == (off_t)-1) {
		if (whence == SEEK_SET)
			bb_perror_msg_and_die("lseek(%"OFF_FMT"u)", offset);
		bb_perror_msg_and_die("lseek");
	}
	return off;
}

// Die with supplied filename if this FILE* has ferror set.
void FAST_FUNC die_if_ferror(FILE *fp, const char *fn)
{
	if (ferror(fp)) {
		/* ferror doesn't set useful errno */
		bb_error_msg_and_die("%s: I/O error", fn);
	}
}

// Die with an error message if stdout has ferror set.
void FAST_FUNC die_if_ferror_stdout(void)
{
	die_if_ferror(stdout, bb_msg_standard_output);
}

int FAST_FUNC fflush_all(void)
{
	return fflush(NULL);
}


int FAST_FUNC bb_putchar(int ch)
{
	return putchar(ch);
}

/* Die with an error message if we can't copy an entire FILE* to stdout,
 * then close that file. */
void FAST_FUNC xprint_and_close_file(FILE *file)
{
	fflush_all();
	// copyfd outputs error messages for us.
	if (bb_copyfd_eof(fileno(file), STDOUT_FILENO) == -1)
		xfunc_die();

	fclose(file);
}

// Die with an error message if we can't malloc() enough space and do an
// sprintf() into that space.
char* FAST_FUNC xasprintf(const char *format, ...)
{
	va_list p;
	int r;
	char *string_ptr;

	va_start(p, format);
	r = vasprintf(&string_ptr, format, p);
	va_end(p);

	if (r < 0)
		bb_error_msg_and_die(bb_msg_memory_exhausted);
	return string_ptr;
}

void FAST_FUNC xsetenv(const char *key, const char *value)
{
	if (setenv(key, value, 1))
		bb_error_msg_and_die(bb_msg_memory_exhausted);
}

/* Handles "VAR=VAL" strings, even those which are part of environ
 * _right now_
 */
void FAST_FUNC bb_unsetenv(const char *var)
{
	char *tp = strchr(var, '=');

	if (!tp) {
		unsetenv(var);
		return;
	}

	/* In case var was putenv'ed, we can't replace '='
	 * with NUL and unsetenv(var) - it won't work,
	 * env is modified by the replacement, unsetenv
	 * sees "VAR" instead of "VAR=VAL" and does not remove it!
	 * horror :( */
	tp = xstrndup(var, tp - var);
	unsetenv(tp);
	free(tp);
}

void FAST_FUNC bb_unsetenv_and_free(char *var)
{
	bb_unsetenv(var);
	free(var);
}

// Die with an error message if we can't set gid.  (Because resource limits may
// limit this user to a given number of processes, and if that fills up the
// setgid() will fail and we'll _still_be_root_, which is bad.)
void FAST_FUNC xsetgid(gid_t gid)
{
	if (setgid(gid)) bb_perror_msg_and_die("setgid");
}

// Die with an error message if we can't set uid.  (See xsetgid() for why.)
void FAST_FUNC xsetuid(uid_t uid)
{
	if (setuid(uid)) bb_perror_msg_and_die("setuid");
}

// Die if we can't chdir to a new path.
void FAST_FUNC xchdir(const char *path)
{
	if (chdir(path))
		bb_perror_msg_and_die("chdir(%s)", path);
}

void FAST_FUNC xchroot(const char *path)
{
	if (chroot(path))
		bb_perror_msg_and_die("can't change root directory to %s", path);
}

// Print a warning message if opendir() fails, but don't die.
DIR* FAST_FUNC warn_opendir(const char *path)
{
	DIR *dp;

	dp = opendir(path);
	if (!dp)
		bb_perror_msg("can't open '%s'", path);
	return dp;
}

// Die with an error message if opendir() fails.
DIR* FAST_FUNC xopendir(const char *path)
{
	DIR *dp;

	dp = opendir(path);
	if (!dp)
		bb_perror_msg_and_die("can't open '%s'", path);
	return dp;
}

// Die with an error message if we can't open a new socket.
int FAST_FUNC xsocket(int domain, int type, int protocol)
{
	int r = socket(domain, type, protocol);

	if (r < 0) {
		/* Hijack vaguely related config option */
#if ENABLE_VERBOSE_RESOLUTION_ERRORS
		const char *s = "INET";
		if (domain == AF_PACKET) s = "PACKET";
		if (domain == AF_NETLINK) s = "NETLINK";
IF_FEATURE_IPV6(if (domain == AF_INET6) s = "INET6";)
		bb_perror_msg_and_die("socket(AF_%s,%d,%d)", s, type, protocol);
#else
		bb_perror_msg_and_die("socket");
#endif
	}

	return r;
}

// Die with an error message if we can't bind a socket to an address.
void FAST_FUNC xbind(int sockfd, struct sockaddr *my_addr, socklen_t addrlen)
{
	if (bind(sockfd, my_addr, addrlen)) bb_perror_msg_and_die("bind");
}

// Die with an error message if we can't listen for connections on a socket.
void FAST_FUNC xlisten(int s, int backlog)
{
	if (listen(s, backlog)) bb_perror_msg_and_die("listen");
}

/* Die with an error message if sendto failed.
 * Return bytes sent otherwise  */
ssize_t FAST_FUNC xsendto(int s, const void *buf, size_t len, const struct sockaddr *to,
				socklen_t tolen)
{
	ssize_t ret = sendto(s, buf, len, 0, to, tolen);
	if (ret < 0) {
		if (ENABLE_FEATURE_CLEAN_UP)
			close(s);
		bb_perror_msg_and_die("sendto");
	}
	return ret;
}

// xstat() - a stat() which dies on failure with meaningful error message
void FAST_FUNC xstat(const char *name, struct stat *stat_buf)
{
	if (stat(name, stat_buf))
		bb_perror_msg_and_die("can't stat '%s'", name);
}

// selinux_or_die() - die if SELinux is disabled.
void FAST_FUNC selinux_or_die(void)
{
#if ENABLE_SELINUX
	int rc = is_selinux_enabled();
	if (rc == 0) {
		bb_error_msg_and_die("SELinux is disabled");
	} else if (rc < 0) {
		bb_error_msg_and_die("is_selinux_enabled() failed");
	}
#else
	bb_error_msg_and_die("SELinux support is disabled");
#endif
}

int FAST_FUNC ioctl_or_perror_and_die(int fd, unsigned request, void *argp, const char *fmt,...)
{
	int ret;
	va_list p;

	ret = ioctl(fd, request, argp);
	if (ret < 0) {
		va_start(p, fmt);
		bb_verror_msg(fmt, p, strerror(errno));
		/* xfunc_die can actually longjmp, so be nice */
		va_end(p);
		xfunc_die();
	}
	return ret;
}

int FAST_FUNC ioctl_or_perror(int fd, unsigned request, void *argp, const char *fmt,...)
{
	va_list p;
	int ret = ioctl(fd, request, argp);

	if (ret < 0) {
		va_start(p, fmt);
		bb_verror_msg(fmt, p, strerror(errno));
		va_end(p);
	}
	return ret;
}

#if ENABLE_IOCTL_HEX2STR_ERROR
int FAST_FUNC bb_ioctl_or_warn(int fd, unsigned request, void *argp, const char *ioctl_name)
{
	int ret;

	ret = ioctl(fd, request, argp);
	if (ret < 0)
		bb_simple_perror_msg(ioctl_name);
	return ret;
}
int FAST_FUNC bb_xioctl(int fd, unsigned request, void *argp, const char *ioctl_name)
{
	int ret;

	ret = ioctl(fd, request, argp);
	if (ret < 0)
		bb_simple_perror_msg_and_die(ioctl_name);
	return ret;
}
#else
int FAST_FUNC bb_ioctl_or_warn(int fd, unsigned request, void *argp)
{
	int ret;

	ret = ioctl(fd, request, argp);
	if (ret < 0)
		bb_perror_msg("ioctl %#x failed", request);
	return ret;
}
int FAST_FUNC bb_xioctl(int fd, unsigned request, void *argp)
{
	int ret;

	ret = ioctl(fd, request, argp);
	if (ret < 0)
		bb_perror_msg_and_die("ioctl %#x failed", request);
	return ret;
}
#endif

char* FAST_FUNC xmalloc_ttyname(int fd)
{
	char *buf = xzalloc(128);
	int r = ttyname_r(fd, buf, 127);
	if (r) {
		free(buf);
		buf = NULL;
	}
	return buf;
}

void FAST_FUNC generate_uuid(uint8_t *buf)
{
	/* http://www.ietf.org/rfc/rfc4122.txt
	 *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
	 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	 * |                          time_low                             |
	 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	 * |       time_mid                |         time_hi_and_version   |
	 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	 * |clk_seq_and_variant            |         node (0-1)            |
	 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	 * |                         node (2-5)                            |
	 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	 * IOW, uuid has this layout:
	 * uint32_t time_low (big endian)
	 * uint16_t time_mid (big endian)
	 * uint16_t time_hi_and_version (big endian)
	 *  version is a 4-bit field:
	 *   1 Time-based
	 *   2 DCE Security, with embedded POSIX UIDs
	 *   3 Name-based (MD5)
	 *   4 Randomly generated
	 *   5 Name-based (SHA-1)
	 * uint16_t clk_seq_and_variant (big endian)
	 *  variant is a 3-bit field:
	 *   0xx Reserved, NCS backward compatibility
	 *   10x The variant specified in rfc4122
	 *   110 Reserved, Microsoft backward compatibility
	 *   111 Reserved for future definition
	 * uint8_t node[6]
	 *
	 * For version 4, these bits are set/cleared:
	 * time_hi_and_version & 0x0fff | 0x4000
	 * clk_seq_and_variant & 0x3fff | 0x8000
	 */
	pid_t pid;
	int i;

	i = open("/dev/urandom", O_RDONLY);
	if (i >= 0) {
		read(i, buf, 16);
		close(i);
	}
	/* Paranoia. /dev/urandom may be missing.
	 * rand() is guaranteed to generate at least [0, 2^15) range,
	 * but lowest bits in some libc are not so "random".  */
	srand(monotonic_us()); /* pulls in printf */
	pid = getpid();
	while (1) {
		for (i = 0; i < 16; i++)
			buf[i] ^= rand() >> 5;
		if (pid == 0)
			break;
		srand(pid);
		pid = 0;
	}

	/* version = 4 */
	buf[4 + 2    ] = (buf[4 + 2    ] & 0x0f) | 0x40;
	/* variant = 10x */
	buf[4 + 2 + 2] = (buf[4 + 2 + 2] & 0x3f) | 0x80;
}

#if BB_MMU
pid_t FAST_FUNC xfork(void)
{
	pid_t pid;
	pid = fork();
	if (pid < 0) /* wtf? */
		bb_perror_msg_and_die("vfork"+1);
	return pid;
}
#endif
1	/* vi: set sw=4 ts=4: */
2	/*
3	* Utility routines.
4	*
5	* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
6	* Copyright (C) 2006 Rob Landley
7	* Copyright (C) 2006 Denys Vlasenko
8	*
9	* Licensed under GPL version 2, see file LICENSE in this tarball for details.
10	*/
11
12	/* We need to have separate xfuncs.c and xfuncs_printf.c because
13	* with current linkers, even with section garbage collection,
14	* if *.o module references any of XXXprintf functions, you pull in
15	* entire printf machinery. Even if you do not use the function
16	* which uses XXXprintf.
17	*
18	* xfuncs.c contains functions (not necessarily xfuncs)
19	* which do not pull in printf, directly or indirectly.
20	* xfunc_printf.c contains those which do.
21	*/
22
23	#include "libbb.h"
24
25
26	/* All the functions starting with "x" call bb_error_msg_and_die() if they
27	* fail, so callers never need to check for errors. If it returned, it
28	* succeeded. */
29
30	#ifndef DMALLOC
31	/* dmalloc provides variants of these that do abort() on failure.
32	* Since dmalloc's prototypes overwrite the impls here as they are
33	* included after these prototypes in libbb.h, all is well.
34	*/
35	// Warn if we can't allocate size bytes of memory.
36	void* FAST_FUNC malloc_or_warn(size_t size)
37	{
38	void *ptr = malloc(size);
39	if (ptr == NULL && size != 0)
40	bb_error_msg(bb_msg_memory_exhausted);
41	return ptr;
42	}
43
44	// Die if we can't allocate size bytes of memory.
45	void* FAST_FUNC xmalloc(size_t size)
46	{
47	void *ptr = malloc(size);
48	if (ptr == NULL && size != 0)
49	bb_error_msg_and_die(bb_msg_memory_exhausted);
50	return ptr;
51	}
52
53	// Die if we can't resize previously allocated memory. (This returns a pointer
54	// to the new memory, which may or may not be the same as the old memory.
55	// It'll copy the contents to a new chunk and free the old one if necessary.)
56	void* FAST_FUNC xrealloc(void *ptr, size_t size)
57	{
58	ptr = realloc(ptr, size);
59	if (ptr == NULL && size != 0)
60	bb_error_msg_and_die(bb_msg_memory_exhausted);
61	return ptr;
62	}
63	#endif /* DMALLOC */
64
65	// Die if we can't allocate and zero size bytes of memory.
66	void* FAST_FUNC xzalloc(size_t size)
67	{
68	void *ptr = xmalloc(size);
69	memset(ptr, 0, size);
70	return ptr;
71	}
72
73	// Die if we can't copy a string to freshly allocated memory.
74	char* FAST_FUNC xstrdup(const char *s)
75	{
76	char *t;
77
78	if (s == NULL)
79	return NULL;
80
81	t = strdup(s);
82
83	if (t == NULL)
84	bb_error_msg_and_die(bb_msg_memory_exhausted);
85
86	return t;
87	}
88
89	// Die if we can't allocate n+1 bytes (space for the null terminator) and copy
90	// the (possibly truncated to length n) string into it.
91	char* FAST_FUNC xstrndup(const char *s, int n)
92	{
93	int m;
94	char *t;
95
96	if (ENABLE_DEBUG && s == NULL)
97	bb_error_msg_and_die("xstrndup bug");
98
99	/* We can just xmalloc(n+1) and strncpy into it, */
100	/* but think about xstrndup("abc", 10000) wastage! */
101	m = n;
102	t = (char*) s;
103	while (m) {
104	if (!*t) break;
105	m--;
106	t++;
107	}
108	n -= m;
109	t = xmalloc(n + 1);
110	t[n] = '\0';
111
112	return memcpy(t, s, n);
113	}
114
115	// Die if we can't open a file and return a FILE* to it.
116	// Notice we haven't got xfread(), This is for use with fscanf() and friends.
117	FILE* FAST_FUNC xfopen(const char path, const char mode)
118	{
119	FILE *fp = fopen(path, mode);
120	if (fp == NULL)
121	bb_perror_msg_and_die("can't open '%s'", path);
122	return fp;
123	}
124
125	// Die if we can't open a file and return a fd.
126	int FAST_FUNC xopen3(const char *pathname, int flags, int mode)
127	{
128	int ret;
129
130	ret = open(pathname, flags, mode);
131	if (ret < 0) {
132	bb_perror_msg_and_die("can't open '%s'", pathname);
133	}
134	return ret;
135	}
136
137	// Die if we can't open an existing file and return a fd.
138	int FAST_FUNC xopen(const char *pathname, int flags)
139	{
140	return xopen3(pathname, flags, 0666);
141	}
142
143	/* Die if we can't open an existing file readonly with O_NONBLOCK
144	* and return the fd.
145	* Note that for ioctl O_RDONLY is sufficient.
146	*/
147	int FAST_FUNC xopen_nonblocking(const char *pathname)
148	{
149	return xopen(pathname, O_RDONLY \| O_NONBLOCK);
150	}
151
152	// Warn if we can't open a file and return a fd.
153	int FAST_FUNC open3_or_warn(const char *pathname, int flags, int mode)
154	{
155	int ret;
156
157	ret = open(pathname, flags, mode);
158	if (ret < 0) {
159	bb_perror_msg("can't open '%s'", pathname);
160	}
161	return ret;
162	}
163
164	// Warn if we can't open a file and return a fd.
165	int FAST_FUNC open_or_warn(const char *pathname, int flags)
166	{
167	return open3_or_warn(pathname, flags, 0666);
168	}
169
170	void FAST_FUNC xunlink(const char *pathname)
171	{
172	if (unlink(pathname))
173	bb_perror_msg_and_die("can't remove file '%s'", pathname);
174	}
175
176	void FAST_FUNC xrename(const char oldpath, const char newpath)
177	{
178	if (rename(oldpath, newpath))
179	bb_perror_msg_and_die("can't move '%s' to '%s'", oldpath, newpath);
180	}
181
182	int FAST_FUNC rename_or_warn(const char oldpath, const char newpath)
183	{
184	int n = rename(oldpath, newpath);
185	if (n)
186	bb_perror_msg("can't move '%s' to '%s'", oldpath, newpath);
187	return n;
188	}
189
190	void FAST_FUNC xpipe(int filedes[2])
191	{
192	if (pipe(filedes))
193	bb_perror_msg_and_die("can't create pipe");
194	}
195
196	void FAST_FUNC xdup2(int from, int to)
197	{
198	if (dup2(from, to) != to)
199	bb_perror_msg_and_die("can't duplicate file descriptor");
200	}
201
202	// "Renumber" opened fd
203	void FAST_FUNC xmove_fd(int from, int to)
204	{
205	if (from == to)
206	return;
207	xdup2(from, to);
208	close(from);
209	}
210
211	// Die with an error message if we can't write the entire buffer.
212	void FAST_FUNC xwrite(int fd, const void *buf, size_t count)
213	{
214	if (count) {
215	ssize_t size = full_write(fd, buf, count);
216	if ((size_t)size != count)
217	bb_error_msg_and_die("short write");
218	}
219	}
220	void FAST_FUNC xwrite_str(int fd, const char *str)
221	{
222	xwrite(fd, str, strlen(str));
223	}
224
225	void FAST_FUNC xclose(int fd)
226	{
227	if (close(fd))
228	bb_perror_msg_and_die("close failed");
229	}
230
231	// Die with an error message if we can't lseek to the right spot.
232	off_t FAST_FUNC xlseek(int fd, off_t offset, int whence)
233	{
234	off_t off = lseek(fd, offset, whence);
235	if (off == (off_t)-1) {
236	if (whence == SEEK_SET)
237	bb_perror_msg_and_die("lseek(%"OFF_FMT"u)", offset);
238	bb_perror_msg_and_die("lseek");
239	}
240	return off;
241	}
242
243	// Die with supplied filename if this FILE* has ferror set.
244	void FAST_FUNC die_if_ferror(FILE fp, const char fn)
245	{
246	if (ferror(fp)) {
247	/* ferror doesn't set useful errno */
248	bb_error_msg_and_die("%s: I/O error", fn);
249	}
250	}
251
252	// Die with an error message if stdout has ferror set.
253	void FAST_FUNC die_if_ferror_stdout(void)
254	{
255	die_if_ferror(stdout, bb_msg_standard_output);
256	}
257
258	int FAST_FUNC fflush_all(void)
259	{
260	return fflush(NULL);
261	}
262
263
264	int FAST_FUNC bb_putchar(int ch)
265	{
266	return putchar(ch);
267	}
268
269	/* Die with an error message if we can't copy an entire FILE* to stdout,
270	* then close that file. */
271	void FAST_FUNC xprint_and_close_file(FILE *file)
272	{
273	fflush_all();
274	// copyfd outputs error messages for us.
275	if (bb_copyfd_eof(fileno(file), STDOUT_FILENO) == -1)
276	xfunc_die();
277
278	fclose(file);
279	}
280
281	// Die with an error message if we can't malloc() enough space and do an
282	// sprintf() into that space.
283	char* FAST_FUNC xasprintf(const char *format, ...)
284	{
285	va_list p;
286	int r;
287	char *string_ptr;
288
289	va_start(p, format);
290	r = vasprintf(&string_ptr, format, p);
291	va_end(p);
292
293	if (r < 0)
294	bb_error_msg_and_die(bb_msg_memory_exhausted);
295	return string_ptr;
296	}
297
298	void FAST_FUNC xsetenv(const char key, const char value)
299	{
300	if (setenv(key, value, 1))
301	bb_error_msg_and_die(bb_msg_memory_exhausted);
302	}
303
304	/* Handles "VAR=VAL" strings, even those which are part of environ
305	* _right now_
306	*/
307	void FAST_FUNC bb_unsetenv(const char *var)
308	{
309	char *tp = strchr(var, '=');
310
311	if (!tp) {
312	unsetenv(var);
313	return;
314	}
315
316	/* In case var was putenv'ed, we can't replace '='
317	* with NUL and unsetenv(var) - it won't work,
318	* env is modified by the replacement, unsetenv
319	* sees "VAR" instead of "VAR=VAL" and does not remove it!
320	* horror :( */
321	tp = xstrndup(var, tp - var);
322	unsetenv(tp);
323	free(tp);
324	}
325
326	void FAST_FUNC bb_unsetenv_and_free(char *var)
327	{
328	bb_unsetenv(var);
329	free(var);
330	}
331
332	// Die with an error message if we can't set gid. (Because resource limits may
333	// limit this user to a given number of processes, and if that fills up the
334	// setgid() will fail and we'll _still_be_root_, which is bad.)
335	void FAST_FUNC xsetgid(gid_t gid)
336	{
337	if (setgid(gid)) bb_perror_msg_and_die("setgid");
338	}
339
340	// Die with an error message if we can't set uid. (See xsetgid() for why.)
341	void FAST_FUNC xsetuid(uid_t uid)
342	{
343	if (setuid(uid)) bb_perror_msg_and_die("setuid");
344	}
345
346	// Die if we can't chdir to a new path.
347	void FAST_FUNC xchdir(const char *path)
348	{
349	if (chdir(path))
350	bb_perror_msg_and_die("chdir(%s)", path);
351	}
352
353	void FAST_FUNC xchroot(const char *path)
354	{
355	if (chroot(path))
356	bb_perror_msg_and_die("can't change root directory to %s", path);
357	}
358
359	// Print a warning message if opendir() fails, but don't die.
360	DIR* FAST_FUNC warn_opendir(const char *path)
361	{
362	DIR *dp;
363
364	dp = opendir(path);
365	if (!dp)
366	bb_perror_msg("can't open '%s'", path);
367	return dp;
368	}
369
370	// Die with an error message if opendir() fails.
371	DIR* FAST_FUNC xopendir(const char *path)
372	{
373	DIR *dp;
374
375	dp = opendir(path);
376	if (!dp)
377	bb_perror_msg_and_die("can't open '%s'", path);
378	return dp;
379	}
380
381	// Die with an error message if we can't open a new socket.
382	int FAST_FUNC xsocket(int domain, int type, int protocol)
383	{
384	int r = socket(domain, type, protocol);
385
386	if (r < 0) {
387	/* Hijack vaguely related config option */
388	#if ENABLE_VERBOSE_RESOLUTION_ERRORS
389	const char *s = "INET";
390	if (domain == AF_PACKET) s = "PACKET";
391	if (domain == AF_NETLINK) s = "NETLINK";
392	IF_FEATURE_IPV6(if (domain == AF_INET6) s = "INET6";)
393	bb_perror_msg_and_die("socket(AF_%s,%d,%d)", s, type, protocol);
394	#else
395	bb_perror_msg_and_die("socket");
396	#endif
397	}
398
399	return r;
400	}
401
402	// Die with an error message if we can't bind a socket to an address.
403	void FAST_FUNC xbind(int sockfd, struct sockaddr *my_addr, socklen_t addrlen)
404	{
405	if (bind(sockfd, my_addr, addrlen)) bb_perror_msg_and_die("bind");
406	}
407
408	// Die with an error message if we can't listen for connections on a socket.
409	void FAST_FUNC xlisten(int s, int backlog)
410	{
411	if (listen(s, backlog)) bb_perror_msg_and_die("listen");
412	}
413
414	/* Die with an error message if sendto failed.
415	* Return bytes sent otherwise */
416	ssize_t FAST_FUNC xsendto(int s, const void buf, size_t len, const struct sockaddr to,
417	socklen_t tolen)
418	{
419	ssize_t ret = sendto(s, buf, len, 0, to, tolen);
420	if (ret < 0) {
421	if (ENABLE_FEATURE_CLEAN_UP)
422	close(s);
423	bb_perror_msg_and_die("sendto");
424	}
425	return ret;
426	}
427
428	// xstat() - a stat() which dies on failure with meaningful error message
429	void FAST_FUNC xstat(const char name, struct stat stat_buf)
430	{
431	if (stat(name, stat_buf))
432	bb_perror_msg_and_die("can't stat '%s'", name);
433	}
434
435	// selinux_or_die() - die if SELinux is disabled.
436	void FAST_FUNC selinux_or_die(void)
437	{
438	#if ENABLE_SELINUX
439	int rc = is_selinux_enabled();
440	if (rc == 0) {
441	bb_error_msg_and_die("SELinux is disabled");
442	} else if (rc < 0) {
443	bb_error_msg_and_die("is_selinux_enabled() failed");
444	}
445	#else
446	bb_error_msg_and_die("SELinux support is disabled");
447	#endif
448	}
449
450	int FAST_FUNC ioctl_or_perror_and_die(int fd, unsigned request, void argp, const char fmt,...)
451	{
452	int ret;
453	va_list p;
454
455	ret = ioctl(fd, request, argp);
456	if (ret < 0) {
457	va_start(p, fmt);
458	bb_verror_msg(fmt, p, strerror(errno));
459	/* xfunc_die can actually longjmp, so be nice */
460	va_end(p);
461	xfunc_die();
462	}
463	return ret;
464	}
465
466	int FAST_FUNC ioctl_or_perror(int fd, unsigned request, void argp, const char fmt,...)
467	{
468	va_list p;
469	int ret = ioctl(fd, request, argp);
470
471	if (ret < 0) {
472	va_start(p, fmt);
473	bb_verror_msg(fmt, p, strerror(errno));
474	va_end(p);
475	}
476	return ret;
477	}
478
479	#if ENABLE_IOCTL_HEX2STR_ERROR
480	int FAST_FUNC bb_ioctl_or_warn(int fd, unsigned request, void argp, const char ioctl_name)
481	{
482	int ret;
483
484	ret = ioctl(fd, request, argp);
485	if (ret < 0)
486	bb_simple_perror_msg(ioctl_name);
487	return ret;
488	}
489	int FAST_FUNC bb_xioctl(int fd, unsigned request, void argp, const char ioctl_name)
490	{
491	int ret;
492
493	ret = ioctl(fd, request, argp);
494	if (ret < 0)
495	bb_simple_perror_msg_and_die(ioctl_name);
496	return ret;
497	}
498	#else
499	int FAST_FUNC bb_ioctl_or_warn(int fd, unsigned request, void *argp)
500	{
501	int ret;
502
503	ret = ioctl(fd, request, argp);
504	if (ret < 0)
505	bb_perror_msg("ioctl %#x failed", request);
506	return ret;
507	}
508	int FAST_FUNC bb_xioctl(int fd, unsigned request, void *argp)
509	{
510	int ret;
511
512	ret = ioctl(fd, request, argp);
513	if (ret < 0)
514	bb_perror_msg_and_die("ioctl %#x failed", request);
515	return ret;
516	}
517	#endif
518
519	char* FAST_FUNC xmalloc_ttyname(int fd)
520	{
521	char *buf = xzalloc(128);
522	int r = ttyname_r(fd, buf, 127);
523	if (r) {
524	free(buf);
525	buf = NULL;
526	}
527	return buf;
528	}
529
530	void FAST_FUNC generate_uuid(uint8_t *buf)
531	{
532	/* http://www.ietf.org/rfc/rfc4122.txt
533	* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
534	* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
535	* \| time_low \|
536	* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
537	* \| time_mid \| time_hi_and_version \|
538	* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
539	* \|clk_seq_and_variant \| node (0-1) \|
540	* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
541	* \| node (2-5) \|
542	* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
543	* IOW, uuid has this layout:
544	* uint32_t time_low (big endian)
545	* uint16_t time_mid (big endian)
546	* uint16_t time_hi_and_version (big endian)
547	* version is a 4-bit field:
548	* 1 Time-based
549	* 2 DCE Security, with embedded POSIX UIDs
550	* 3 Name-based (MD5)
551	* 4 Randomly generated
552	* 5 Name-based (SHA-1)
553	* uint16_t clk_seq_and_variant (big endian)
554	* variant is a 3-bit field:
555	* 0xx Reserved, NCS backward compatibility
556	* 10x The variant specified in rfc4122
557	* 110 Reserved, Microsoft backward compatibility
558	* 111 Reserved for future definition
559	* uint8_t node[6]
560	*
561	* For version 4, these bits are set/cleared:
562	* time_hi_and_version & 0x0fff \| 0x4000
563	* clk_seq_and_variant & 0x3fff \| 0x8000
564	*/
565	pid_t pid;
566	int i;
567
568	i = open("/dev/urandom", O_RDONLY);
569	if (i >= 0) {
570	read(i, buf, 16);
571	close(i);
572	}
573	/* Paranoia. /dev/urandom may be missing.
574	* rand() is guaranteed to generate at least [0, 2^15) range,
575	* but lowest bits in some libc are not so "random". */
576	srand(monotonic_us()); /* pulls in printf */
577	pid = getpid();
578	while (1) {
579	for (i = 0; i < 16; i++)
580	buf[i] ^= rand() >> 5;
581	if (pid == 0)
582	break;
583	srand(pid);
584	pid = 0;
585	}
586
587	/* version = 4 */
588	buf[4 + 2 ] = (buf[4 + 2 ] & 0x0f) \| 0x40;
589	/* variant = 10x */
590	buf[4 + 2 + 2] = (buf[4 + 2 + 2] & 0x3f) \| 0x80;
591	}
592
593	#if BB_MMU
594	pid_t FAST_FUNC xfork(void)
595	{
596	pid_t pid;
597	pid = fork();
598	if (pid < 0) /* wtf? */
599	bb_perror_msg_and_die("vfork"+1);
600	return pid;
601	}
602	#endif