intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

36 files changed, 3192 insertions, 0 deletions

diff --git a/contrib/libs/libc_compat/README.md b/contrib/libs/libc_compat/README.md
new file mode 100644
index 0000000000..fe7a22fbb1
--- /dev/null
+++ b/contrib/libs/libc_compat/README.md
@@ -0,0 +1,24 @@
+This library implements a compatibility layer between various libc implementations.
+
+The rationale for the library implementation is described in https://st.yandex-team.ru/IGNIETFERRO-1439.
+
+The code is taken from multiple sources, thus both LICENSE() and VERSION() tags are not very representative.
+
+
+During development one can make use of the following mapping of `OS_SDK` into glibc version.
+
+| Ubuntu | glibc |
+| ------ | ----- |
+| 20.04 | 2.30 |
+| 18.04 | 2.27 | 
+| 16.04 | 2.23 | 
+| 14.04 | 2.18 | 
+| 12.04 | 2.15 |
+| 10.04 | 2.11 |
+
+Use the following commands to update the table above:
+
+1. `ya make util -DOS_SDK=ubuntu-xx -G | grep OS_SDK_ROOT | head -n 1`
+2. `cd ~/.ya/tools/v4/$RESOURCE_ID`
+3. `readelf -V $(find . -name 'libc.so.6')`
+4. Take the latest version from `.gnu.version_d` section prior to `GLIBC_PRIVATE`
diff --git a/contrib/libs/libc_compat/collate.h b/contrib/libs/libc_compat/collate.h
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/contrib/libs/libc_compat/collate.h
diff --git a/contrib/libs/libc_compat/getrandom.c b/contrib/libs/libc_compat/getrandom.c
new file mode 100644
index 0000000000..2184fad710
--- /dev/null
+++ b/contrib/libs/libc_compat/getrandom.c
@@ -0,0 +1,7 @@
+#include <sys/random.h>
+#include "syscall.h"
+
+ssize_t getrandom(void *buf, size_t buflen, unsigned flags)
+{
+	return syscall(SYS_getrandom, buf, buflen, flags);
+}
diff --git a/contrib/libs/libc_compat/glob.c b/contrib/libs/libc_compat/glob.c
new file mode 100644
index 0000000000..00be637158
--- /dev/null
+++ b/contrib/libs/libc_compat/glob.c
@@ -0,0 +1,1127 @@
+/*-
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * Copyright (c) 1989, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Guido van Rossum.
+ *
+ * Copyright (c) 2011 The FreeBSD Foundation
+ * All rights reserved.
+ * Portions of this software were developed by David Chisnall
+ * under sponsorship from the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__SCCSID("@(#)glob.c	8.3 (Berkeley) 10/13/93");
+__FBSDID("$FreeBSD$");
+
+/*
+ * glob(3) -- a superset of the one defined in POSIX 1003.2.
+ *
+ * The [!...] convention to negate a range is supported (SysV, Posix, ksh).
+ *
+ * Optional extra services, controlled by flags not defined by POSIX:
+ *
+ * GLOB_QUOTE:
+ *	Escaping convention: \ inhibits any special meaning the following
+ *	character might have (except \ at end of string is retained).
+ * GLOB_MAGCHAR:
+ *	Set in gl_flags if pattern contained a globbing character.
+ * GLOB_NOMAGIC:
+ *	Same as GLOB_NOCHECK, but it will only append pattern if it did
+ *	not contain any magic characters.  [Used in csh style globbing]
+ * GLOB_ALTDIRFUNC:
+ *	Use alternately specified directory access functions.
+ * GLOB_TILDE:
+ *	expand ~user/foo to the /home/dir/of/user/foo
+ * GLOB_BRACE:
+ *	expand {1,2}{a,b} to 1a 1b 2a 2b
+ * gl_matchc:
+ *	Number of matches in the current invocation of glob.
+ */
+
+/*
+ * Some notes on multibyte character support:
+ * 1. Patterns with illegal byte sequences match nothing - even if
+ *    GLOB_NOCHECK is specified.
+ * 2. Illegal byte sequences in filenames are handled by treating them as
+ *    single-byte characters with a values of such bytes of the sequence
+ *    cast to wchar_t.
+ * 3. State-dependent encodings are not currently supported.
+ */
+
+#include <sys/param.h>
+#include <sys/stat.h>
+
+#include <ctype.h>
+#include <dirent.h>
+#include <errno.h>
+#include "glob.h"
+#include <limits.h>
+#include <pwd.h>
+#include <stdint.h>
+#include <stdio.h>
+#include "stdlib.h"
+#include <string.h>
+#include "unistd.h"
+#include <wchar.h>
+
+#ifdef USE_LOCALE_COLLATE
+#include "collate.h"
+#endif
+
+/*
+ * glob(3) expansion limits. Stop the expansion if any of these limits
+ * is reached. This caps the runtime in the face of DoS attacks. See
+ * also CVE-2010-2632
+ */
+#define	GLOB_LIMIT_BRACE	128	/* number of brace calls */
+#define	GLOB_LIMIT_PATH		65536	/* number of path elements */
+#define	GLOB_LIMIT_READDIR	16384	/* number of readdirs */
+#define	GLOB_LIMIT_STAT		1024	/* number of stat system calls */
+#define	GLOB_LIMIT_STRING	ARG_MAX	/* maximum total size for paths */
+
+struct glob_limit {
+	size_t	l_brace_cnt;
+	size_t	l_path_lim;
+	size_t	l_readdir_cnt;	
+	size_t	l_stat_cnt;	
+	size_t	l_string_cnt;
+};
+
+#define	DOT		L'.'
+#define	EOS		L'\0'
+#define	LBRACKET	L'['
+#define	NOT		L'!'
+#define	QUESTION	L'?'
+#define	QUOTE		L'\\'
+#define	RANGE		L'-'
+#define	RBRACKET	L']'
+#define	SEP		L'/'
+#define	STAR		L'*'
+#define	TILDE		L'~'
+#define	LBRACE		L'{'
+#define	RBRACE		L'}'
+#define	COMMA		L','
+
+#define	M_QUOTE		0x8000000000ULL
+#define	M_PROTECT	0x4000000000ULL
+#define	M_MASK		0xffffffffffULL
+#define	M_CHAR		0x00ffffffffULL
+
+typedef uint_fast64_t Char;
+
+#define	CHAR(c)		((Char)((c)&M_CHAR))
+#define	META(c)		((Char)((c)|M_QUOTE))
+#define	UNPROT(c)	((c) & ~M_PROTECT)
+#define	M_ALL		META(L'*')
+#define	M_END		META(L']')
+#define	M_NOT		META(L'!')
+#define	M_ONE		META(L'?')
+#define	M_RNG		META(L'-')
+#define	M_SET		META(L'[')
+#define	ismeta(c)	(((c)&M_QUOTE) != 0)
+#ifdef DEBUG
+#define	isprot(c)	(((c)&M_PROTECT) != 0)
+#endif
+
+static int	 compare(const void *, const void *);
+static int	 g_Ctoc(const Char *, char *, size_t);
+static int	 g_lstat(Char *, struct stat *, glob_t *);
+static DIR	*g_opendir(Char *, glob_t *);
+static const Char *g_strchr(const Char *, wchar_t);
+#ifdef notdef
+static Char	*g_strcat(Char *, const Char *);
+#endif
+static int	 g_stat(Char *, struct stat *, glob_t *);
+static int	 glob0(const Char *, glob_t *, struct glob_limit *,
+    const char *);
+static int	 glob1(Char *, glob_t *, struct glob_limit *);
+static int	 glob2(Char *, Char *, Char *, Char *, glob_t *,
+    struct glob_limit *);
+static int	 glob3(Char *, Char *, Char *, Char *, Char *, glob_t *,
+    struct glob_limit *);
+static int	 globextend(const Char *, glob_t *, struct glob_limit *,
+    const char *);
+static const Char *
+		 globtilde(const Char *, Char *, size_t, glob_t *);
+static int	 globexp0(const Char *, glob_t *, struct glob_limit *,
+    const char *);
+static int	 globexp1(const Char *, glob_t *, struct glob_limit *);
+static int	 globexp2(const Char *, const Char *, glob_t *,
+    struct glob_limit *);
+static int	 globfinal(glob_t *, struct glob_limit *, size_t,
+    const char *);
+static int	 match(Char *, Char *, Char *);
+static int	 err_nomatch(glob_t *, struct glob_limit *, const char *);
+static int	 err_aborted(glob_t *, int, char *);
+#ifdef DEBUG
+static void	 qprintf(const char *, Char *);
+#endif
+
+int
+glob(const char * __restrict pattern, int flags,
+	 int (*errfunc)(const char *, int), glob_t * __restrict pglob)
+{
+	struct glob_limit limit = { 0, 0, 0, 0, 0 };
+	const char *patnext;
+	Char *bufnext, *bufend, patbuf[MAXPATHLEN], prot;
+	mbstate_t mbs;
+	wchar_t wc;
+	size_t clen;
+	int too_long;
+
+	patnext = pattern;
+	if (!(flags & GLOB_APPEND)) {
+		pglob->gl_pathc = 0;
+		pglob->gl_pathv = NULL;
+		if (!(flags & GLOB_DOOFFS))
+			pglob->gl_offs = 0;
+	}
+	if (flags & GLOB_LIMIT) {
+		limit.l_path_lim = pglob->gl_matchc;
+		if (limit.l_path_lim == 0)
+			limit.l_path_lim = GLOB_LIMIT_PATH;
+	}
+	pglob->gl_flags = flags & ~GLOB_MAGCHAR;
+	pglob->gl_errfunc = errfunc;
+	pglob->gl_matchc = 0;
+
+	bufnext = patbuf;
+	bufend = bufnext + MAXPATHLEN - 1;
+	too_long = 1;
+	if (flags & GLOB_NOESCAPE) {
+		memset(&mbs, 0, sizeof(mbs));
+		while (bufnext <= bufend) {
+			clen = mbrtowc(&wc, patnext, MB_LEN_MAX, &mbs);
+			if (clen == (size_t)-1 || clen == (size_t)-2)
+				return (err_nomatch(pglob, &limit, pattern));
+			else if (clen == 0) {
+				too_long = 0;
+				break;
+			}
+			*bufnext++ = wc;
+			patnext += clen;
+		}
+	} else {
+		/* Protect the quoted characters. */
+		memset(&mbs, 0, sizeof(mbs));
+		while (bufnext <= bufend) {
+			if (*patnext == '\\') {
+				if (*++patnext == '\0') {
+					*bufnext++ = QUOTE;
+					continue;
+				}
+				prot = M_PROTECT;
+			} else
+				prot = 0;
+			clen = mbrtowc(&wc, patnext, MB_LEN_MAX, &mbs);
+			if (clen == (size_t)-1 || clen == (size_t)-2)
+				return (err_nomatch(pglob, &limit, pattern));
+			else if (clen == 0) {
+				too_long = 0;
+				break;
+			}
+			*bufnext++ = wc | prot;
+			patnext += clen;
+		}
+	}
+	if (too_long)
+		return (err_nomatch(pglob, &limit, pattern));
+	*bufnext = EOS;
+
+	if (flags & GLOB_BRACE)
+	    return (globexp0(patbuf, pglob, &limit, pattern));
+	else
+	    return (glob0(patbuf, pglob, &limit, pattern));
+}
+
+static int
+globexp0(const Char *pattern, glob_t *pglob, struct glob_limit *limit,
+    const char *origpat) {
+	int rv;
+	size_t oldpathc;
+
+	/* Protect a single {}, for find(1), like csh */
+	if (pattern[0] == LBRACE && pattern[1] == RBRACE && pattern[2] == EOS) {
+		if ((pglob->gl_flags & GLOB_LIMIT) &&
+		    limit->l_brace_cnt++ >= GLOB_LIMIT_BRACE) {
+			errno = E2BIG;
+			return (GLOB_NOSPACE);
+		}
+		return (glob0(pattern, pglob, limit, origpat));
+	}
+
+	oldpathc = pglob->gl_pathc;
+
+	if ((rv = globexp1(pattern, pglob, limit)) != 0)
+		return rv;
+
+	return (globfinal(pglob, limit, oldpathc, origpat));
+}
+
+/*
+ * Expand recursively a glob {} pattern. When there is no more expansion
+ * invoke the standard globbing routine to glob the rest of the magic
+ * characters
+ */
+static int
+globexp1(const Char *pattern, glob_t *pglob, struct glob_limit *limit)
+{
+	const Char* ptr;
+
+	if ((ptr = g_strchr(pattern, LBRACE)) != NULL) {
+		if ((pglob->gl_flags & GLOB_LIMIT) &&
+		    limit->l_brace_cnt++ >= GLOB_LIMIT_BRACE) {
+			errno = E2BIG;
+			return (GLOB_NOSPACE);
+		}
+		return (globexp2(ptr, pattern, pglob, limit));
+	}
+
+	return (glob0(pattern, pglob, limit, NULL));
+}
+
+
+/*
+ * Recursive brace globbing helper. Tries to expand a single brace.
+ * If it succeeds then it invokes globexp1 with the new pattern.
+ * If it fails then it tries to glob the rest of the pattern and returns.
+ */
+static int
+globexp2(const Char *ptr, const Char *pattern, glob_t *pglob,
+    struct glob_limit *limit)
+{
+	int     i, rv;
+	Char   *lm, *ls;
+	const Char *pe, *pm, *pm1, *pl;
+	Char    patbuf[MAXPATHLEN];
+
+	/* copy part up to the brace */
+	for (lm = patbuf, pm = pattern; pm != ptr; *lm++ = *pm++)
+		continue;
+	*lm = EOS;
+	ls = lm;
+
+	/* Find the balanced brace */
+	for (i = 0, pe = ++ptr; *pe != EOS; pe++)
+		if (*pe == LBRACKET) {
+			/* Ignore everything between [] */
+			for (pm = pe++; *pe != RBRACKET && *pe != EOS; pe++)
+				continue;
+			if (*pe == EOS) {
+				/*
+				 * We could not find a matching RBRACKET.
+				 * Ignore and just look for RBRACE
+				 */
+				pe = pm;
+			}
+		}
+		else if (*pe == LBRACE)
+			i++;
+		else if (*pe == RBRACE) {
+			if (i == 0)
+				break;
+			i--;
+		}
+
+	/* Non matching braces; just glob the pattern */
+	if (i != 0 || *pe == EOS)
+		return (glob0(pattern, pglob, limit, NULL));
+
+	for (i = 0, pl = pm = ptr; pm <= pe; pm++)
+		switch (*pm) {
+		case LBRACKET:
+			/* Ignore everything between [] */
+			for (pm1 = pm++; *pm != RBRACKET && *pm != EOS; pm++)
+				continue;
+			if (*pm == EOS) {
+				/*
+				 * We could not find a matching RBRACKET.
+				 * Ignore and just look for RBRACE
+				 */
+				pm = pm1;
+			}
+			break;
+
+		case LBRACE:
+			i++;
+			break;
+
+		case RBRACE:
+			if (i) {
+			    i--;
+			    break;
+			}
+			/* FALLTHROUGH */
+		case COMMA:
+			if (i && *pm == COMMA)
+				break;
+			else {
+				/* Append the current string */
+				for (lm = ls; (pl < pm); *lm++ = *pl++)
+					continue;
+				/*
+				 * Append the rest of the pattern after the
+				 * closing brace
+				 */
+				for (pl = pe + 1; (*lm++ = *pl++) != EOS;)
+					continue;
+
+				/* Expand the current pattern */
+#ifdef DEBUG
+				qprintf("globexp2:", patbuf);
+#endif
+				rv = globexp1(patbuf, pglob, limit);
+				if (rv)
+					return (rv);
+
+				/* move after the comma, to the next string */
+				pl = pm + 1;
+			}
+			break;
+
+		default:
+			break;
+		}
+	return (0);
+}
+
+
+
+/*
+ * expand tilde from the passwd file.
+ */
+static const Char *
+globtilde(const Char *pattern, Char *patbuf, size_t patbuf_len, glob_t *pglob)
+{
+	struct passwd *pwd;
+	char *h, *sc;
+	const Char *p;
+	Char *b, *eb;
+	wchar_t wc;
+	wchar_t wbuf[MAXPATHLEN];
+	wchar_t *wbufend, *dc;
+	size_t clen;
+	mbstate_t mbs;
+	int too_long;
+
+	if (*pattern != TILDE || !(pglob->gl_flags & GLOB_TILDE))
+		return (pattern);
+
+	/* 
+	 * Copy up to the end of the string or / 
+	 */
+	eb = &patbuf[patbuf_len - 1];
+	for (p = pattern + 1, b = patbuf;
+	    b < eb && *p != EOS && UNPROT(*p) != SEP; *b++ = *p++)
+		continue;
+
+	if (*p != EOS && UNPROT(*p) != SEP)
+		return (NULL);
+
+	*b = EOS;
+	h = NULL;
+
+	if (patbuf[0] == EOS) {
+		/*
+		 * handle a plain ~ or ~/ by expanding $HOME first (iff
+		 * we're not running setuid or setgid) and then trying
+		 * the password file
+		 */
+		if (issetugid() != 0 ||
+		    (h = getenv("HOME")) == NULL) {
+			if (((h = getlogin()) != NULL &&
+			     (pwd = getpwnam(h)) != NULL) ||
+			    (pwd = getpwuid(getuid())) != NULL)
+				h = pwd->pw_dir;
+			else
+				return (pattern);
+		}
+	}
+	else {
+		/*
+		 * Expand a ~user
+		 */
+		if (g_Ctoc(patbuf, (char *)wbuf, sizeof(wbuf)))
+			return (NULL);
+		if ((pwd = getpwnam((char *)wbuf)) == NULL)
+			return (pattern);
+		else
+			h = pwd->pw_dir;
+	}
+
+	/* Copy the home directory */
+	dc = wbuf;
+	sc = h;
+	wbufend = wbuf + MAXPATHLEN - 1;
+	too_long = 1;
+	memset(&mbs, 0, sizeof(mbs));
+	while (dc <= wbufend) {
+		clen = mbrtowc(&wc, sc, MB_LEN_MAX, &mbs);
+		if (clen == (size_t)-1 || clen == (size_t)-2) {
+			/* XXX See initial comment #2. */
+			wc = (unsigned char)*sc;
+			clen = 1;
+			memset(&mbs, 0, sizeof(mbs));
+		}
+		if ((*dc++ = wc) == EOS) {
+			too_long = 0;
+			break;
+		}
+		sc += clen;
+	}
+	if (too_long)
+		return (NULL);
+
+	dc = wbuf;
+	for (b = patbuf; b < eb && *dc != EOS; *b++ = *dc++ | M_PROTECT)
+		continue;
+	if (*dc != EOS)
+		return (NULL);
+
+	/* Append the rest of the pattern */
+	if (*p != EOS) {
+		too_long = 1;
+		while (b <= eb) {
+			if ((*b++ = *p++) == EOS) {
+				too_long = 0;
+				break;
+			}
+		}
+		if (too_long)
+			return (NULL);
+	} else
+		*b = EOS;
+
+	return (patbuf);
+}
+
+
+/*
+ * The main glob() routine: compiles the pattern (optionally processing
+ * quotes), calls glob1() to do the real pattern matching, and finally
+ * sorts the list (unless unsorted operation is requested).  Returns 0
+ * if things went well, nonzero if errors occurred.
+ */
+static int
+glob0(const Char *pattern, glob_t *pglob, struct glob_limit *limit,
+    const char *origpat) {
+	const Char *qpatnext;
+	int err;
+	size_t oldpathc;
+	Char *bufnext, c, patbuf[MAXPATHLEN];
+
+	qpatnext = globtilde(pattern, patbuf, MAXPATHLEN, pglob);
+	if (qpatnext == NULL) {
+		errno = E2BIG;
+		return (GLOB_NOSPACE);
+	}
+	oldpathc = pglob->gl_pathc;
+	bufnext = patbuf;
+
+	/* We don't need to check for buffer overflow any more. */
+	while ((c = *qpatnext++) != EOS) {
+		switch (c) {
+		case LBRACKET:
+			c = *qpatnext;
+			if (c == NOT)
+				++qpatnext;
+			if (*qpatnext == EOS ||
+			    g_strchr(qpatnext+1, RBRACKET) == NULL) {
+				*bufnext++ = LBRACKET;
+				if (c == NOT)
+					--qpatnext;
+				break;
+			}
+			*bufnext++ = M_SET;
+			if (c == NOT)
+				*bufnext++ = M_NOT;
+			c = *qpatnext++;
+			do {
+				*bufnext++ = CHAR(c);
+				if (*qpatnext == RANGE &&
+				    (c = qpatnext[1]) != RBRACKET) {
+					*bufnext++ = M_RNG;
+					*bufnext++ = CHAR(c);
+					qpatnext += 2;
+				}
+			} while ((c = *qpatnext++) != RBRACKET);
+			pglob->gl_flags |= GLOB_MAGCHAR;
+			*bufnext++ = M_END;
+			break;
+		case QUESTION:
+			pglob->gl_flags |= GLOB_MAGCHAR;
+			*bufnext++ = M_ONE;
+			break;
+		case STAR:
+			pglob->gl_flags |= GLOB_MAGCHAR;
+			/* collapse adjacent stars to one,
+			 * to ensure "**" at the end continues to match the
+			 * empty string
+			 */
+			if (bufnext == patbuf || bufnext[-1] != M_ALL)
+			    *bufnext++ = M_ALL;
+			break;
+		default:
+			*bufnext++ = CHAR(c);
+			break;
+		}
+	}
+	*bufnext = EOS;
+#ifdef DEBUG
+	qprintf("glob0:", patbuf);
+#endif
+
+	if ((err = glob1(patbuf, pglob, limit)) != 0)
+		return(err);
+
+	if (origpat != NULL)
+		return (globfinal(pglob, limit, oldpathc, origpat));
+
+	return (0);
+}
+
+static int
+globfinal(glob_t *pglob, struct glob_limit *limit, size_t oldpathc,
+    const char *origpat) {
+	if (pglob->gl_pathc == oldpathc)
+		return (err_nomatch(pglob, limit, origpat));
+
+	if (!(pglob->gl_flags & GLOB_NOSORT))
+		qsort(pglob->gl_pathv + pglob->gl_offs + oldpathc,
+		    pglob->gl_pathc - oldpathc, sizeof(char *), compare);
+
+	return (0);
+}
+
+static int
+compare(const void *p, const void *q)
+{
+	return (strcoll(*(char **)p, *(char **)q));
+}
+
+static int
+glob1(Char *pattern, glob_t *pglob, struct glob_limit *limit)
+{
+	Char pathbuf[MAXPATHLEN];
+
+	/* A null pathname is invalid -- POSIX 1003.1 sect. 2.4. */
+	if (*pattern == EOS)
+		return (0);
+	return (glob2(pathbuf, pathbuf, pathbuf + MAXPATHLEN - 1,
+	    pattern, pglob, limit));
+}
+
+/*
+ * The functions glob2 and glob3 are mutually recursive; there is one level
+ * of recursion for each segment in the pattern that contains one or more
+ * meta characters.
+ */
+static int
+glob2(Char *pathbuf, Char *pathend, Char *pathend_last, Char *pattern,
+      glob_t *pglob, struct glob_limit *limit)
+{
+	struct stat sb;
+	Char *p, *q;
+	int anymeta;
+
+	/*
+	 * Loop over pattern segments until end of pattern or until
+	 * segment with meta character found.
+	 */
+	for (anymeta = 0;;) {
+		if (*pattern == EOS) {		/* End of pattern? */
+			*pathend = EOS;
+			if (g_lstat(pathbuf, &sb, pglob))
+				return (0);
+
+			if ((pglob->gl_flags & GLOB_LIMIT) &&
+			    limit->l_stat_cnt++ >= GLOB_LIMIT_STAT) {
+				errno = E2BIG;
+				return (GLOB_NOSPACE);
+			}
+			if ((pglob->gl_flags & GLOB_MARK) &&
+			    UNPROT(pathend[-1]) != SEP &&
+			    (S_ISDIR(sb.st_mode) ||
+			    (S_ISLNK(sb.st_mode) &&
+			    g_stat(pathbuf, &sb, pglob) == 0 &&
+			    S_ISDIR(sb.st_mode)))) {
+				if (pathend + 1 > pathend_last) {
+					errno = E2BIG;
+					return (GLOB_NOSPACE);
+				}
+				*pathend++ = SEP;
+				*pathend = EOS;
+			}
+			++pglob->gl_matchc;
+			return (globextend(pathbuf, pglob, limit, NULL));
+		}
+
+		/* Find end of next segment, copy tentatively to pathend. */
+		q = pathend;
+		p = pattern;
+		while (*p != EOS && UNPROT(*p) != SEP) {
+			if (ismeta(*p))
+				anymeta = 1;
+			if (q + 1 > pathend_last) {
+				errno = E2BIG;
+				return (GLOB_NOSPACE);
+			}
+			*q++ = *p++;
+		}
+
+		if (!anymeta) {		/* No expansion, do next segment. */
+			pathend = q;
+			pattern = p;
+			while (UNPROT(*pattern) == SEP) {
+				if (pathend + 1 > pathend_last) {
+					errno = E2BIG;
+					return (GLOB_NOSPACE);
+				}
+				*pathend++ = *pattern++;
+			}
+		} else			/* Need expansion, recurse. */
+			return (glob3(pathbuf, pathend, pathend_last, pattern,
+			    p, pglob, limit));
+	}
+	/* NOTREACHED */
+}
+
+static int
+glob3(Char *pathbuf, Char *pathend, Char *pathend_last,
+      Char *pattern, Char *restpattern,
+      glob_t *pglob, struct glob_limit *limit)
+{
+	struct dirent *dp;
+	DIR *dirp;
+	int err, too_long, saverrno, saverrno2;
+	char buf[MAXPATHLEN + MB_LEN_MAX - 1];
+
+	struct dirent *(*readdirfunc)(DIR *);
+
+	if (pathend > pathend_last) {
+		errno = E2BIG;
+		return (GLOB_NOSPACE);
+	}
+	*pathend = EOS;
+	if (pglob->gl_errfunc != NULL &&
+	    g_Ctoc(pathbuf, buf, sizeof(buf))) {
+		errno = E2BIG;
+		return (GLOB_NOSPACE);
+	}
+
+	saverrno = errno;
+	errno = 0;
+	if ((dirp = g_opendir(pathbuf, pglob)) == NULL) {
+		if (errno == ENOENT || errno == ENOTDIR)
+			return (0);
+		err = err_aborted(pglob, errno, buf);
+		if (errno == 0)
+			errno = saverrno;
+		return (err);
+	}
+
+	err = 0;
+
+	/* pglob->gl_readdir takes a void *, fix this manually */
+	if (pglob->gl_flags & GLOB_ALTDIRFUNC)
+		readdirfunc = (struct dirent *(*)(DIR *))pglob->gl_readdir;
+	else
+		readdirfunc = readdir;
+
+	errno = 0;
+	/* Search directory for matching names. */
+	while ((dp = (*readdirfunc)(dirp)) != NULL) {
+		char *sc;
+		Char *dc;
+		wchar_t wc;
+		size_t clen;
+		mbstate_t mbs;
+
+		if ((pglob->gl_flags & GLOB_LIMIT) &&
+		    limit->l_readdir_cnt++ >= GLOB_LIMIT_READDIR) {
+			errno = E2BIG;
+			err = GLOB_NOSPACE;
+			break;
+		}
+
+		/* Initial DOT must be matched literally. */
+		if (dp->d_name[0] == '.' && UNPROT(*pattern) != DOT) {
+			errno = 0;
+			continue;
+		}
+		memset(&mbs, 0, sizeof(mbs));
+		dc = pathend;
+		sc = dp->d_name;
+		too_long = 1;
+		while (dc <= pathend_last) {
+			clen = mbrtowc(&wc, sc, MB_LEN_MAX, &mbs);
+			if (clen == (size_t)-1 || clen == (size_t)-2) {
+				/* XXX See initial comment #2. */
+				wc = (unsigned char)*sc;
+				clen = 1;
+				memset(&mbs, 0, sizeof(mbs));
+			}
+			if ((*dc++ = wc) == EOS) {
+				too_long = 0;
+				break;
+			}
+			sc += clen;
+		}
+		if (too_long && (err = err_aborted(pglob, ENAMETOOLONG,
+		    buf))) {
+			errno = ENAMETOOLONG;
+			break;
+		}
+		if (too_long || !match(pathend, pattern, restpattern)) {
+			*pathend = EOS;
+			errno = 0;
+			continue;
+		}
+		if (errno == 0)
+			errno = saverrno;
+		err = glob2(pathbuf, --dc, pathend_last, restpattern,
+		    pglob, limit);
+		if (err)
+			break;
+		errno = 0;
+	}
+
+	saverrno2 = errno;
+	if (pglob->gl_flags & GLOB_ALTDIRFUNC)
+		(*pglob->gl_closedir)(dirp);
+	else
+		closedir(dirp);
+	errno = saverrno2;
+
+	if (err)
+		return (err);
+
+	if (dp == NULL && errno != 0 &&
+	    (err = err_aborted(pglob, errno, buf)))
+		return (err);
+
+	if (errno == 0)
+		errno = saverrno;
+	return (0);
+}
+
+
+/*
+ * Extend the gl_pathv member of a glob_t structure to accommodate a new item,
+ * add the new item, and update gl_pathc.
+ *
+ * This assumes the BSD realloc, which only copies the block when its size
+ * crosses a power-of-two boundary; for v7 realloc, this would cause quadratic
+ * behavior.
+ *
+ * Return 0 if new item added, error code if memory couldn't be allocated.
+ *
+ * Invariant of the glob_t structure:
+ *	Either gl_pathc is zero and gl_pathv is NULL; or gl_pathc > 0 and
+ *	gl_pathv points to (gl_offs + gl_pathc + 1) items.
+ */
+static int
+globextend(const Char *path, glob_t *pglob, struct glob_limit *limit,
+    const char *origpat)
+{
+	char **pathv;
+	size_t i, newn, len;
+	char *copy;
+	const Char *p;
+
+	if ((pglob->gl_flags & GLOB_LIMIT) &&
+	    pglob->gl_matchc > limit->l_path_lim) {
+		errno = E2BIG;
+		return (GLOB_NOSPACE);
+	}
+
+	newn = 2 + pglob->gl_pathc + pglob->gl_offs;
+	/* reallocarray(NULL, newn, size) is equivalent to malloc(newn*size). */
+	pathv = reallocarray(pglob->gl_pathv, newn, sizeof(*pathv));
+	if (pathv == NULL)
+		return (GLOB_NOSPACE);
+
+	if (pglob->gl_pathv == NULL && pglob->gl_offs > 0) {
+		/* first time around -- clear initial gl_offs items */
+		pathv += pglob->gl_offs;
+		for (i = pglob->gl_offs + 1; --i > 0; )
+			*--pathv = NULL;
+	}
+	pglob->gl_pathv = pathv;
+
+	if (origpat != NULL)
+		copy = strdup(origpat);
+	else {
+		for (p = path; *p++ != EOS;)
+			continue;
+		len = MB_CUR_MAX * (size_t)(p - path); /* XXX overallocation */
+		if ((copy = malloc(len)) != NULL) {
+			if (g_Ctoc(path, copy, len)) {
+				free(copy);
+				errno = E2BIG;
+				return (GLOB_NOSPACE);
+			}
+		}
+	}
+	if (copy != NULL) {
+		limit->l_string_cnt += strlen(copy) + 1;
+		if ((pglob->gl_flags & GLOB_LIMIT) &&
+		    limit->l_string_cnt >= GLOB_LIMIT_STRING) {
+			free(copy);
+			errno = E2BIG;
+			return (GLOB_NOSPACE);
+		}
+		pathv[pglob->gl_offs + pglob->gl_pathc++] = copy;
+	}
+	pathv[pglob->gl_offs + pglob->gl_pathc] = NULL;
+	return (copy == NULL ? GLOB_NOSPACE : 0);
+}
+
+/*
+ * pattern matching function for filenames.
+ */
+static int
+match(Char *name, Char *pat, Char *patend)
+{
+	int ok, negate_range;
+	Char c, k, *nextp, *nextn;
+#ifdef USE_LOCALE_COLLATE
+	struct xlocale_collate *table =
+		(struct xlocale_collate*)__get_locale()->components[XLC_COLLATE];
+#endif
+
+	nextn = NULL;
+	nextp = NULL;
+
+	while (1) {
+		while (pat < patend) {
+			c = *pat++;
+			switch (c & M_MASK) {
+			case M_ALL:
+				if (pat == patend)
+					return (1);
+				if (*name == EOS)
+					return (0);
+				nextn = name + 1;
+				nextp = pat - 1;
+				break;
+			case M_ONE:
+				if (*name++ == EOS)
+					goto fail;
+				break;
+			case M_SET:
+				ok = 0;
+				if ((k = *name++) == EOS)
+					goto fail;
+				negate_range = ((*pat & M_MASK) == M_NOT);
+				if (negate_range != 0)
+					++pat;
+				while (((c = *pat++) & M_MASK) != M_END)
+					if ((*pat & M_MASK) == M_RNG) {
+#ifdef USE_LOCALE_COLLATE
+						if (table->__collate_load_error ?
+						    CHAR(c) <= CHAR(k) &&
+						    CHAR(k) <= CHAR(pat[1]) :
+						    __wcollate_range_cmp(CHAR(c),
+						    CHAR(k)) <= 0 &&
+						    __wcollate_range_cmp(CHAR(k),
+						    CHAR(pat[1])) <= 0)
+#else
+						if (c <= k && k <= pat[1])
+#endif
+							ok = 1;
+						pat += 2;
+					} else if (c == k)
+						ok = 1;
+				if (ok == negate_range)
+					goto fail;
+				break;
+			default:
+				if (*name++ != c)
+					goto fail;
+				break;
+			}
+		}
+		if (*name == EOS)
+			return (1);
+
+	fail:
+		if (nextn == NULL)
+			break;
+		pat = nextp;
+		name = nextn;
+	}
+	return (0);
+}
+
+/* Free allocated data belonging to a glob_t structure. */
+void
+globfree(glob_t *pglob)
+{
+	size_t i;
+	char **pp;
+
+	if (pglob->gl_pathv != NULL) {
+		pp = pglob->gl_pathv + pglob->gl_offs;
+		for (i = pglob->gl_pathc; i--; ++pp)
+			if (*pp)
+				free(*pp);
+		free(pglob->gl_pathv);
+		pglob->gl_pathv = NULL;
+	}
+}
+
+static DIR *
+g_opendir(Char *str, glob_t *pglob)
+{
+	char buf[MAXPATHLEN + MB_LEN_MAX - 1];
+
+	if (*str == EOS)
+		strcpy(buf, ".");
+	else {
+		if (g_Ctoc(str, buf, sizeof(buf))) {
+			errno = ENAMETOOLONG;
+			return (NULL);
+		}
+	}
+
+	if (pglob->gl_flags & GLOB_ALTDIRFUNC)
+		return ((*pglob->gl_opendir)(buf));
+
+	return (opendir(buf));
+}
+
+static int
+g_lstat(Char *fn, struct stat *sb, glob_t *pglob)
+{
+	char buf[MAXPATHLEN + MB_LEN_MAX - 1];
+
+	if (g_Ctoc(fn, buf, sizeof(buf))) {
+		errno = ENAMETOOLONG;
+		return (-1);
+	}
+	if (pglob->gl_flags & GLOB_ALTDIRFUNC)
+		return((*pglob->gl_lstat)(buf, sb));
+	return (lstat(buf, sb));
+}
+
+static int
+g_stat(Char *fn, struct stat *sb, glob_t *pglob)
+{
+	char buf[MAXPATHLEN + MB_LEN_MAX - 1];
+
+	if (g_Ctoc(fn, buf, sizeof(buf))) {
+		errno = ENAMETOOLONG;
+		return (-1);
+	}
+	if (pglob->gl_flags & GLOB_ALTDIRFUNC)
+		return ((*pglob->gl_stat)(buf, sb));
+	return (stat(buf, sb));
+}
+
+static const Char *
+g_strchr(const Char *str, wchar_t ch)
+{
+
+	do {
+		if (*str == ch)
+			return (str);
+	} while (*str++);
+	return (NULL);
+}
+
+static int
+g_Ctoc(const Char *str, char *buf, size_t len)
+{
+	mbstate_t mbs;
+	size_t clen;
+
+	memset(&mbs, 0, sizeof(mbs));
+	while (len >= MB_CUR_MAX) {
+		clen = wcrtomb(buf, CHAR(*str), &mbs);
+		if (clen == (size_t)-1) {
+			/* XXX See initial comment #2. */
+			*buf = (char)CHAR(*str);
+			clen = 1;
+			memset(&mbs, 0, sizeof(mbs));
+		}
+		if (CHAR(*str) == EOS)
+			return (0);
+		str++;
+		buf += clen;
+		len -= clen;
+	}
+	return (1);
+}
+
+static int
+err_nomatch(glob_t *pglob, struct glob_limit *limit, const char *origpat) {
+	/*
+	 * If there was no match we are going to append the origpat
+	 * if GLOB_NOCHECK was specified or if GLOB_NOMAGIC was specified
+	 * and the origpat did not contain any magic characters
+	 * GLOB_NOMAGIC is there just for compatibility with csh.
+	 */
+	if ((pglob->gl_flags & GLOB_NOCHECK) ||
+	    ((pglob->gl_flags & GLOB_NOMAGIC) &&
+	    !(pglob->gl_flags & GLOB_MAGCHAR)))
+		return (globextend(NULL, pglob, limit, origpat));
+	return (GLOB_NOMATCH);
+}
+
+static int
+err_aborted(glob_t *pglob, int err, char *buf) {
+	if ((pglob->gl_errfunc != NULL && pglob->gl_errfunc(buf, err)) ||
+	    (pglob->gl_flags & GLOB_ERR))
+		return (GLOB_ABORTED);
+	return (0);
+}
+
+#ifdef DEBUG
+static void
+qprintf(const char *str, Char *s)
+{
+	Char *p;
+
+	(void)printf("%s\n", str);
+	if (s != NULL) {
+		for (p = s; *p != EOS; p++)
+			(void)printf("%c", (char)CHAR(*p));
+		(void)printf("\n");
+		for (p = s; *p != EOS; p++)
+			(void)printf("%c", (isprot(*p) ? '\\' : ' '));
+		(void)printf("\n");
+		for (p = s; *p != EOS; p++)
+			(void)printf("%c", (ismeta(*p) ? '_' : ' '));
+		(void)printf("\n");
+	}
+}
+#endif
diff --git a/contrib/libs/libc_compat/glob.h b/contrib/libs/libc_compat/glob.h
new file mode 100644
index 0000000000..783ba51042
--- /dev/null
+++ b/contrib/libs/libc_compat/glob.h
@@ -0,0 +1,104 @@
+/*-
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ * Copyright (c) 1989, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Guido van Rossum.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)glob.h	8.1 (Berkeley) 6/2/93
+ * $FreeBSD$
+ */
+
+#ifndef _GLOB_H_
+#define	_GLOB_H_
+
+#include <sys/cdefs.h>
+#include <sys/types.h>
+
+
+struct stat;
+typedef struct {
+	size_t gl_pathc;	/* Count of total paths so far. */
+	size_t gl_matchc;	/* Count of paths matching pattern. */
+	size_t gl_offs;		/* Reserved at beginning of gl_pathv. */
+	int gl_flags;		/* Copy of flags parameter to glob. */
+	char **gl_pathv;	/* List of paths matching pattern. */
+				/* Copy of errfunc parameter to glob. */
+	int (*gl_errfunc)(const char *, int);
+
+	/*
+	 * Alternate filesystem access methods for glob; replacement
+	 * versions of closedir(3), readdir(3), opendir(3), stat(2)
+	 * and lstat(2).
+	 */
+	void (*gl_closedir)(void *);
+	struct dirent *(*gl_readdir)(void *);
+	void *(*gl_opendir)(const char *);
+	int (*gl_lstat)(const char *, struct stat *);
+	int (*gl_stat)(const char *, struct stat *);
+} glob_t;
+
+// #if __POSIX_VISIBLE >= 199209
+/* Believed to have been introduced in 1003.2-1992 */
+#define	GLOB_APPEND	0x0001	/* Append to output from previous call. */
+#define	GLOB_DOOFFS	0x0002	/* Use gl_offs. */
+#define	GLOB_ERR	0x0004	/* Return on error. */
+#define	GLOB_MARK	0x0008	/* Append / to matching directories. */
+#define	GLOB_NOCHECK	0x0010	/* Return pattern itself if nothing matches. */
+#define	GLOB_NOSORT	0x0020	/* Don't sort. */
+#define	GLOB_NOESCAPE	0x2000	/* Disable backslash escaping. */
+
+/* Error values returned by glob(3) */
+#define	GLOB_NOSPACE	(-1)	/* Malloc call failed. */
+#define	GLOB_ABORTED	(-2)	/* Unignored error. */
+#define	GLOB_NOMATCH	(-3)	/* No match and GLOB_NOCHECK was not set. */
+#define	GLOB_NOSYS	(-4)	/* Obsolete: source comptability only. */
+// #endif /* __POSIX_VISIBLE >= 199209 */
+
+// #if __BSD_VISIBLE
+#define	GLOB_ALTDIRFUNC	0x0040	/* Use alternately specified directory funcs. */
+#define	GLOB_BRACE	0x0080	/* Expand braces ala csh. */
+#define	GLOB_MAGCHAR	0x0100	/* Pattern had globbing characters. */
+#define	GLOB_NOMAGIC	0x0200	/* GLOB_NOCHECK without magic chars (csh). */
+#define	GLOB_QUOTE	0x0400	/* Quote special chars with \. */
+#define	GLOB_TILDE	0x0800	/* Expand tilde names from the passwd file. */
+#define	GLOB_LIMIT	0x1000	/* limit number of returned paths */
+
+/* source compatibility, these are the old names */
+#define GLOB_MAXPATH	GLOB_LIMIT
+#define	GLOB_ABEND	GLOB_ABORTED
+// #endif /* __BSD_VISIBLE */
+
+__BEGIN_DECLS
+int	glob(const char * __restrict, int,
+	int (*)(const char *, int), glob_t * __restrict);
+void	globfree(glob_t *);
+__END_DECLS
+
+#endif /* !_GLOB_H_ */
diff --git a/contrib/libs/libc_compat/ifaddrs.c b/contrib/libs/libc_compat/ifaddrs.c
new file mode 100644
index 0000000000..c59d8bc745
--- /dev/null
+++ b/contrib/libs/libc_compat/ifaddrs.c
@@ -0,0 +1,663 @@
+/*
+Copyright (c) 2013, Kenneth MacKay
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification,
+are permitted provided that the following conditions are met:
+ * Redistributions of source code must retain the above copyright notice, this
+   list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above copyright notice,
+   this list of conditions and the following disclaimer in the documentation
+   and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#include "ifaddrs.h"
+
+#include <string.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <errno.h>
+#include <unistd.h>
+#include <sys/socket.h>
+#include <netpacket/packet.h>
+#include <net/if_arp.h>
+#include <netinet/in.h>
+#include <linux/netlink.h>
+#include <linux/rtnetlink.h>
+
+typedef struct NetlinkList
+{
+    struct NetlinkList *m_next;
+    struct nlmsghdr *m_data;
+    unsigned int m_size;
+} NetlinkList;
+
+static int netlink_socket(void)
+{
+    int l_socket = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
+    if(l_socket < 0)
+    {
+        return -1;
+    }
+    
+    struct sockaddr_nl l_addr;
+    memset(&l_addr, 0, sizeof(l_addr));
+    l_addr.nl_family = AF_NETLINK;
+    if(bind(l_socket, (struct sockaddr *)&l_addr, sizeof(l_addr)) < 0)
+    {
+        close(l_socket);
+        return -1;
+    }
+    
+    return l_socket;
+}
+
+static int netlink_send(int p_socket, int p_request)
+{
+    struct
+    {
+        struct nlmsghdr m_hdr;
+        struct rtgenmsg m_msg;
+    } l_data;
+
+    memset(&l_data, 0, sizeof(l_data));
+    
+    l_data.m_hdr.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtgenmsg));
+    l_data.m_hdr.nlmsg_type = p_request;
+    l_data.m_hdr.nlmsg_flags = NLM_F_ROOT | NLM_F_MATCH | NLM_F_REQUEST;
+    l_data.m_hdr.nlmsg_pid = 0;
+    l_data.m_hdr.nlmsg_seq = p_socket;
+    l_data.m_msg.rtgen_family = AF_UNSPEC;
+    
+    struct sockaddr_nl l_addr;
+    memset(&l_addr, 0, sizeof(l_addr));
+    l_addr.nl_family = AF_NETLINK;
+    return (sendto(p_socket, &l_data.m_hdr, l_data.m_hdr.nlmsg_len, 0, (struct sockaddr *)&l_addr, sizeof(l_addr)));
+}
+
+static int netlink_recv(int p_socket, void *p_buffer, size_t p_len)
+{
+    struct msghdr l_msg;
+    struct iovec l_iov = { p_buffer, p_len };
+    struct sockaddr_nl l_addr;
+
+    for(;;)
+    {
+        l_msg.msg_name = (void *)&l_addr;
+        l_msg.msg_namelen = sizeof(l_addr);
+        l_msg.msg_iov = &l_iov;
+        l_msg.msg_iovlen = 1;
+        l_msg.msg_control = NULL;
+        l_msg.msg_controllen = 0;
+        l_msg.msg_flags = 0;
+        int l_result = recvmsg(p_socket, &l_msg, 0);
+        
+        if(l_result < 0)
+        {
+            if(errno == EINTR)
+            {
+                continue;
+            }
+            return -2;
+        }
+        
+        if(l_msg.msg_flags & MSG_TRUNC)
+        { // buffer was too small
+            return -1;
+        }
+        return l_result;
+    }
+}
+
+static struct nlmsghdr *getNetlinkResponse(int p_socket, int *p_size, int *p_done)
+{
+    size_t l_size = 4096;
+    void *l_buffer = NULL;
+    
+    for(;;)
+    {
+        free(l_buffer);
+        l_buffer = malloc(l_size);
+        if (l_buffer == NULL)
+        {
+            return NULL;
+        }
+        
+        int l_read = netlink_recv(p_socket, l_buffer, l_size);
+        *p_size = l_read;
+        if(l_read == -2)
+        {
+            free(l_buffer);
+            return NULL;
+        }
+        if(l_read >= 0)
+        {
+            pid_t l_pid = getpid();
+            struct nlmsghdr *l_hdr;
+            for(l_hdr = (struct nlmsghdr *)l_buffer; NLMSG_OK(l_hdr, (unsigned int)l_read); l_hdr = (struct nlmsghdr *)NLMSG_NEXT(l_hdr, l_read))
+            {
+                if((pid_t)l_hdr->nlmsg_pid != l_pid || (int)l_hdr->nlmsg_seq != p_socket)
+                {
+                    continue;
+                }
+                
+                if(l_hdr->nlmsg_type == NLMSG_DONE)
+                {
+                    *p_done = 1;
+                    break;
+                }
+                
+                if(l_hdr->nlmsg_type == NLMSG_ERROR)
+                {
+                    free(l_buffer);
+                    return NULL;
+                }
+            }
+            return l_buffer;
+        }
+        
+        l_size *= 2;
+    }
+}
+
+static NetlinkList *newListItem(struct nlmsghdr *p_data, unsigned int p_size)
+{
+    NetlinkList *l_item = malloc(sizeof(NetlinkList));
+    if (l_item == NULL)
+    {
+        return NULL;
+    }
+
+    l_item->m_next = NULL;
+    l_item->m_data = p_data;
+    l_item->m_size = p_size;
+    return l_item;
+}
+
+static void freeResultList(NetlinkList *p_list)
+{
+    NetlinkList *l_cur;
+    while(p_list)
+    {
+        l_cur = p_list;
+        p_list = p_list->m_next;
+        free(l_cur->m_data);
+        free(l_cur);
+    }
+}
+
+static NetlinkList *getResultList(int p_socket, int p_request)
+{
+    if(netlink_send(p_socket, p_request) < 0)
+    {
+        return NULL;
+    }
+
+    NetlinkList *l_list = NULL;
+    NetlinkList *l_end = NULL;
+    int l_size;
+    int l_done = 0;
+    while(!l_done)
+    {
+        struct nlmsghdr *l_hdr = getNetlinkResponse(p_socket, &l_size, &l_done);
+        if(!l_hdr)
+        { // error
+            freeResultList(l_list);
+            return NULL;
+        }
+        
+        NetlinkList *l_item = newListItem(l_hdr, l_size);
+        if (!l_item)
+        {
+            freeResultList(l_list);
+            return NULL;
+        }
+        if(!l_list)
+        {
+            l_list = l_item;
+        }
+        else
+        {
+            l_end->m_next = l_item;
+        }
+        l_end = l_item;
+    }
+    return l_list;
+}
+
+static size_t maxSize(size_t a, size_t b)
+{
+    return (a > b ? a : b);
+}
+
+static size_t calcAddrLen(sa_family_t p_family, int p_dataSize)
+{
+    switch(p_family)
+    {
+        case AF_INET:
+            return sizeof(struct sockaddr_in);
+        case AF_INET6:
+            return sizeof(struct sockaddr_in6);
+        case AF_PACKET:
+            return maxSize(sizeof(struct sockaddr_ll), offsetof(struct sockaddr_ll, sll_addr) + p_dataSize);
+        default:
+            return maxSize(sizeof(struct sockaddr), offsetof(struct sockaddr, sa_data) + p_dataSize);
+    }
+}
+
+static void makeSockaddr(sa_family_t p_family, struct sockaddr *p_dest, void *p_data, size_t p_size)
+{
+    switch(p_family)
+    {
+        case AF_INET:
+            memcpy(&((struct sockaddr_in*)p_dest)->sin_addr, p_data, p_size);
+            break;
+        case AF_INET6:
+            memcpy(&((struct sockaddr_in6*)p_dest)->sin6_addr, p_data, p_size);
+            break;
+        case AF_PACKET:
+            memcpy(((struct sockaddr_ll*)p_dest)->sll_addr, p_data, p_size);
+            ((struct sockaddr_ll*)p_dest)->sll_halen = p_size;
+            break;
+        default:
+            memcpy(p_dest->sa_data, p_data, p_size);
+            break;
+    }
+    p_dest->sa_family = p_family;
+}
+
+static void addToEnd(struct ifaddrs **p_resultList, struct ifaddrs *p_entry)
+{
+    if(!*p_resultList)
+    {
+        *p_resultList = p_entry;
+    }
+    else
+    {
+        struct ifaddrs *l_cur = *p_resultList;
+        while(l_cur->ifa_next)
+        {
+            l_cur = l_cur->ifa_next;
+        }
+        l_cur->ifa_next = p_entry;
+    }
+}
+
+static int interpretLink(struct nlmsghdr *p_hdr, struct ifaddrs **p_resultList)
+{
+    struct ifinfomsg *l_info = (struct ifinfomsg *)NLMSG_DATA(p_hdr);
+
+    size_t l_nameSize = 0;
+    size_t l_addrSize = 0;
+    size_t l_dataSize = 0;
+    
+    size_t l_rtaSize = NLMSG_PAYLOAD(p_hdr, sizeof(struct ifinfomsg));
+    struct rtattr *l_rta;
+    for(l_rta = IFLA_RTA(l_info); RTA_OK(l_rta, l_rtaSize); l_rta = RTA_NEXT(l_rta, l_rtaSize))
+    {
+        void *l_rtaData = RTA_DATA(l_rta);
+        size_t l_rtaDataSize = RTA_PAYLOAD(l_rta);
+        switch(l_rta->rta_type)
+        {
+            case IFLA_ADDRESS:
+            case IFLA_BROADCAST:
+                l_addrSize += NLMSG_ALIGN(calcAddrLen(AF_PACKET, l_rtaDataSize));
+                break;
+            case IFLA_IFNAME:
+                l_nameSize += NLMSG_ALIGN(l_rtaSize + 1);
+                break;
+            case IFLA_STATS:
+                l_dataSize += NLMSG_ALIGN(l_rtaSize);
+                break;
+            default:
+                break;
+        }
+    }
+    
+    struct ifaddrs *l_entry = malloc(sizeof(struct ifaddrs) + sizeof(int) + l_nameSize + l_addrSize + l_dataSize);
+    if (l_entry == NULL)
+    {
+        return -1;
+    }
+    memset(l_entry, 0, sizeof(struct ifaddrs));
+    l_entry->ifa_name = "";
+    
+    char *l_index = ((char *)l_entry) + sizeof(struct ifaddrs);
+    char *l_name = l_index + sizeof(int);
+    char *l_addr = l_name + l_nameSize;
+    char *l_data = l_addr + l_addrSize;
+    
+    // save the interface index so we can look it up when handling the addresses.
+    memcpy(l_index, &l_info->ifi_index, sizeof(int));
+    
+    l_entry->ifa_flags = l_info->ifi_flags;
+    
+    l_rtaSize = NLMSG_PAYLOAD(p_hdr, sizeof(struct ifinfomsg));
+    for(l_rta = IFLA_RTA(l_info); RTA_OK(l_rta, l_rtaSize); l_rta = RTA_NEXT(l_rta, l_rtaSize))
+    {
+        void *l_rtaData = RTA_DATA(l_rta);
+        size_t l_rtaDataSize = RTA_PAYLOAD(l_rta);
+        switch(l_rta->rta_type)
+        {
+            case IFLA_ADDRESS:
+            case IFLA_BROADCAST:
+            {
+                size_t l_addrLen = calcAddrLen(AF_PACKET, l_rtaDataSize);
+                makeSockaddr(AF_PACKET, (struct sockaddr *)l_addr, l_rtaData, l_rtaDataSize);
+                ((struct sockaddr_ll *)l_addr)->sll_ifindex = l_info->ifi_index;
+                ((struct sockaddr_ll *)l_addr)->sll_hatype = l_info->ifi_type;
+                if(l_rta->rta_type == IFLA_ADDRESS)
+                {
+                    l_entry->ifa_addr = (struct sockaddr *)l_addr;
+                }
+                else
+                {
+                    l_entry->ifa_broadaddr = (struct sockaddr *)l_addr;
+                }
+                l_addr += NLMSG_ALIGN(l_addrLen);
+                break;
+            }
+            case IFLA_IFNAME:
+                strncpy(l_name, l_rtaData, l_rtaDataSize);
+                l_name[l_rtaDataSize] = '\0';
+                l_entry->ifa_name = l_name;
+                break;
+            case IFLA_STATS:
+                memcpy(l_data, l_rtaData, l_rtaDataSize);
+                l_entry->ifa_data = l_data;
+                break;
+            default:
+                break;
+        }
+    }
+    
+    addToEnd(p_resultList, l_entry);
+    return 0;
+}
+
+static struct ifaddrs *findInterface(int p_index, struct ifaddrs **p_links, int p_numLinks)
+{
+    int l_num = 0;
+    struct ifaddrs *l_cur = *p_links;
+    while(l_cur && l_num < p_numLinks)
+    {
+        char *l_indexPtr = ((char *)l_cur) + sizeof(struct ifaddrs);
+        int l_index;
+        memcpy(&l_index, l_indexPtr, sizeof(int));
+        if(l_index == p_index)
+        {
+            return l_cur;
+        }
+        
+        l_cur = l_cur->ifa_next;
+        ++l_num;
+    }
+    return NULL;
+}
+
+static int interpretAddr(struct nlmsghdr *p_hdr, struct ifaddrs **p_resultList, int p_numLinks)
+{
+    struct ifaddrmsg *l_info = (struct ifaddrmsg *)NLMSG_DATA(p_hdr);
+    struct ifaddrs *l_interface = findInterface(l_info->ifa_index, p_resultList, p_numLinks);
+    
+    if(l_info->ifa_family == AF_PACKET)
+    {
+        return 0;
+    }
+
+    size_t l_nameSize = 0;
+    size_t l_addrSize = 0;
+    
+    int l_addedNetmask = 0;
+    
+    size_t l_rtaSize = NLMSG_PAYLOAD(p_hdr, sizeof(struct ifaddrmsg));
+    struct rtattr *l_rta;
+    for(l_rta = IFA_RTA(l_info); RTA_OK(l_rta, l_rtaSize); l_rta = RTA_NEXT(l_rta, l_rtaSize))
+    {
+        void *l_rtaData = RTA_DATA(l_rta);
+        size_t l_rtaDataSize = RTA_PAYLOAD(l_rta);
+        
+        switch(l_rta->rta_type)
+        {
+            case IFA_ADDRESS:
+            case IFA_LOCAL:
+                if((l_info->ifa_family == AF_INET || l_info->ifa_family == AF_INET6) && !l_addedNetmask)
+                { // make room for netmask
+                    l_addrSize += NLMSG_ALIGN(calcAddrLen(l_info->ifa_family, l_rtaDataSize));
+                    l_addedNetmask = 1;
+                }
+            case IFA_BROADCAST:
+                l_addrSize += NLMSG_ALIGN(calcAddrLen(l_info->ifa_family, l_rtaDataSize));
+                break;
+            case IFA_LABEL:
+                l_nameSize += NLMSG_ALIGN(l_rtaSize + 1);
+                break;
+            default:
+                break;
+        }
+    }
+    
+    struct ifaddrs *l_entry = malloc(sizeof(struct ifaddrs) + l_nameSize + l_addrSize);
+    if (l_entry == NULL)
+    {
+        return -1;
+    }
+    memset(l_entry, 0, sizeof(struct ifaddrs));
+    l_entry->ifa_name = (l_interface ? l_interface->ifa_name : "");
+    
+    char *l_name = ((char *)l_entry) + sizeof(struct ifaddrs);
+    char *l_addr = l_name + l_nameSize;
+    
+    l_entry->ifa_flags = l_info->ifa_flags;
+    if(l_interface)
+    {
+        l_entry->ifa_flags |= l_interface->ifa_flags;
+    }
+    
+    l_rtaSize = NLMSG_PAYLOAD(p_hdr, sizeof(struct ifaddrmsg));
+    for(l_rta = IFA_RTA(l_info); RTA_OK(l_rta, l_rtaSize); l_rta = RTA_NEXT(l_rta, l_rtaSize))
+    {
+        void *l_rtaData = RTA_DATA(l_rta);
+        size_t l_rtaDataSize = RTA_PAYLOAD(l_rta);
+        switch(l_rta->rta_type)
+        {
+            case IFA_ADDRESS:
+            case IFA_BROADCAST:
+            case IFA_LOCAL:
+            {
+                size_t l_addrLen = calcAddrLen(l_info->ifa_family, l_rtaDataSize);
+                makeSockaddr(l_info->ifa_family, (struct sockaddr *)l_addr, l_rtaData, l_rtaDataSize);
+                if(l_info->ifa_family == AF_INET6)
+                {
+                    if(IN6_IS_ADDR_LINKLOCAL((struct in6_addr *)l_rtaData) || IN6_IS_ADDR_MC_LINKLOCAL((struct in6_addr *)l_rtaData))
+                    {
+                        ((struct sockaddr_in6 *)l_addr)->sin6_scope_id = l_info->ifa_index;
+                    }
+                }
+                
+                if(l_rta->rta_type == IFA_ADDRESS)
+                { // apparently in a point-to-point network IFA_ADDRESS contains the dest address and IFA_LOCAL contains the local address
+                    if(l_entry->ifa_addr)
+                    {
+                        l_entry->ifa_dstaddr = (struct sockaddr *)l_addr;
+                    }
+                    else
+                    {
+                        l_entry->ifa_addr = (struct sockaddr *)l_addr;
+                    }
+                }
+                else if(l_rta->rta_type == IFA_LOCAL)
+                {
+                    if(l_entry->ifa_addr)
+                    {
+                        l_entry->ifa_dstaddr = l_entry->ifa_addr;
+                    }
+                    l_entry->ifa_addr = (struct sockaddr *)l_addr;
+                }
+                else
+                {
+                    l_entry->ifa_broadaddr = (struct sockaddr *)l_addr;
+                }
+                l_addr += NLMSG_ALIGN(l_addrLen);
+                break;
+            }
+            case IFA_LABEL:
+                strncpy(l_name, l_rtaData, l_rtaDataSize);
+                l_name[l_rtaDataSize] = '\0';
+                l_entry->ifa_name = l_name;
+                break;
+            default:
+                break;
+        }
+    }
+    
+    if(l_entry->ifa_addr && (l_entry->ifa_addr->sa_family == AF_INET || l_entry->ifa_addr->sa_family == AF_INET6))
+    {
+        unsigned l_maxPrefix = (l_entry->ifa_addr->sa_family == AF_INET ? 32 : 128);
+        unsigned l_prefix = (l_info->ifa_prefixlen > l_maxPrefix ? l_maxPrefix : l_info->ifa_prefixlen);
+        char l_mask[16] = {0};
+        unsigned i;
+        for(i=0; i<(l_prefix/8); ++i)
+        {
+            l_mask[i] = 0xff;
+        }
+        if(l_prefix % 8)
+        {
+            l_mask[i] = 0xff << (8 - (l_prefix % 8));
+        }
+        
+        makeSockaddr(l_entry->ifa_addr->sa_family, (struct sockaddr *)l_addr, l_mask, l_maxPrefix / 8);
+        l_entry->ifa_netmask = (struct sockaddr *)l_addr;
+    }
+    
+    addToEnd(p_resultList, l_entry);
+    return 0;
+}
+
+static int interpretLinks(int p_socket, NetlinkList *p_netlinkList, struct ifaddrs **p_resultList)
+{
+    int l_numLinks = 0;
+    pid_t l_pid = getpid();
+    for(; p_netlinkList; p_netlinkList = p_netlinkList->m_next)
+    {
+        unsigned int l_nlsize = p_netlinkList->m_size;
+        struct nlmsghdr *l_hdr;
+        for(l_hdr = p_netlinkList->m_data; NLMSG_OK(l_hdr, l_nlsize); l_hdr = NLMSG_NEXT(l_hdr, l_nlsize))
+        {
+            if((pid_t)l_hdr->nlmsg_pid != l_pid || (int)l_hdr->nlmsg_seq != p_socket)
+            {
+                continue;
+            }
+            
+            if(l_hdr->nlmsg_type == NLMSG_DONE)
+            {
+                break;
+            }
+            
+            if(l_hdr->nlmsg_type == RTM_NEWLINK)
+            {
+                if(interpretLink(l_hdr, p_resultList) == -1)
+                {
+                    return -1;
+                }
+                ++l_numLinks;
+            }
+        }
+    }
+    return l_numLinks;
+}
+
+static int interpretAddrs(int p_socket, NetlinkList *p_netlinkList, struct ifaddrs **p_resultList, int p_numLinks)
+{
+    pid_t l_pid = getpid();
+    for(; p_netlinkList; p_netlinkList = p_netlinkList->m_next)
+    {
+        unsigned int l_nlsize = p_netlinkList->m_size;
+        struct nlmsghdr *l_hdr;
+        for(l_hdr = p_netlinkList->m_data; NLMSG_OK(l_hdr, l_nlsize); l_hdr = NLMSG_NEXT(l_hdr, l_nlsize))
+        {
+            if((pid_t)l_hdr->nlmsg_pid != l_pid || (int)l_hdr->nlmsg_seq != p_socket)
+            {
+                continue;
+            }
+            
+            if(l_hdr->nlmsg_type == NLMSG_DONE)
+            {
+                break;
+            }
+            
+            if(l_hdr->nlmsg_type == RTM_NEWADDR)
+            {
+                if (interpretAddr(l_hdr, p_resultList, p_numLinks) == -1)
+                {
+                    return -1;
+                }
+            }
+        }
+    }
+    return 0;
+}
+
+int getifaddrs(struct ifaddrs **ifap)
+{
+    if(!ifap)
+    {
+        return -1;
+    }
+    *ifap = NULL;
+    
+    int l_socket = netlink_socket();
+    if(l_socket < 0)
+    {
+        return -1;
+    }
+    
+    NetlinkList *l_linkResults = getResultList(l_socket, RTM_GETLINK);
+    if(!l_linkResults)
+    {
+        close(l_socket);
+        return -1;
+    }
+    
+    NetlinkList *l_addrResults = getResultList(l_socket, RTM_GETADDR);
+    if(!l_addrResults)
+    {
+        close(l_socket);
+        freeResultList(l_linkResults);
+        return -1;
+    }
+    
+    int l_result = 0;
+    int l_numLinks = interpretLinks(l_socket, l_linkResults, ifap);
+    if(l_numLinks == -1 || interpretAddrs(l_socket, l_addrResults, ifap, l_numLinks) == -1)
+    {
+        l_result = -1;
+    }
+    
+    freeResultList(l_linkResults);
+    freeResultList(l_addrResults);
+    close(l_socket);
+    return l_result;
+}
+
+void freeifaddrs(struct ifaddrs *ifa)
+{
+    struct ifaddrs *l_cur;
+    while(ifa)
+    {
+        l_cur = ifa;
+        ifa = ifa->ifa_next;
+        free(l_cur);
+    }
+}
diff --git a/contrib/libs/libc_compat/include/random/sys/random.h b/contrib/libs/libc_compat/include/random/sys/random.h
new file mode 100644
index 0000000000..8c13837f72
--- /dev/null
+++ b/contrib/libs/libc_compat/include/random/sys/random.h
@@ -0,0 +1,20 @@
+#ifndef _SYS_RANDOM_H
+#define _SYS_RANDOM_H
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <sys/types.h>
+
+#define SYS_getrandom 318
+
+#define GRND_NONBLOCK	0x0001
+#define GRND_RANDOM	0x0002
+#define GRND_INSECURE	0x0004
+
+ssize_t getrandom(void *, size_t, unsigned);
+
+#ifdef __cplusplus
+}
+#endif
+#endif
diff --git a/contrib/libs/libc_compat/include/readpassphrase/readpassphrase.h b/contrib/libs/libc_compat/include/readpassphrase/readpassphrase.h
new file mode 100644
index 0000000000..ba1ee14ef1
--- /dev/null
+++ b/contrib/libs/libc_compat/include/readpassphrase/readpassphrase.h
@@ -0,0 +1,44 @@
+/*	$OpenBSD: readpassphrase.h,v 1.6 2019/01/25 00:19:25 millert Exp $	*/
+
+/*
+ * Copyright (c) 2000, 2002 Todd C. Miller <millert@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ * Sponsored in part by the Defense Advanced Research Projects
+ * Agency (DARPA) and Air Force Research Laboratory, Air Force
+ * Materiel Command, USAF, under agreement number F39502-99-1-0512.
+ */
+
+#ifndef _READPASSPHRASE_H_
+#define _READPASSPHRASE_H_
+
+#define RPP_ECHO_OFF    0x00		/* Turn off echo (default). */
+#define RPP_ECHO_ON     0x01		/* Leave echo on. */
+#define RPP_REQUIRE_TTY 0x02		/* Fail if there is no tty. */
+#define RPP_FORCELOWER  0x04		/* Force input to lower case. */
+#define RPP_FORCEUPPER  0x08		/* Force input to upper case. */
+#define RPP_SEVENBIT    0x10		/* Strip the high bit from input. */
+#define RPP_STDIN       0x20		/* Read from stdin, not /dev/tty */
+
+#include <sys/cdefs.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+char * readpassphrase(const char *, char *, size_t, int);
+#ifdef __cplusplus
+} // extern "C"
+#endif
+
+#endif /* !_READPASSPHRASE_H_ */
diff --git a/contrib/libs/libc_compat/memfd_create.c b/contrib/libs/libc_compat/memfd_create.c
new file mode 100644
index 0000000000..6805d807d6
--- /dev/null
+++ b/contrib/libs/libc_compat/memfd_create.c
@@ -0,0 +1,9 @@
+#define _GNU_SOURCE 1
+#include <sys/mman.h>
+#include "syscall.h"
+#include <linux/unistd.h>
+
+int memfd_create(const char *name, unsigned flags)
+{
+	return syscall(__NR_memfd_create, name, flags);
+}
diff --git a/contrib/libs/libc_compat/memrchr.c b/contrib/libs/libc_compat/memrchr.c
new file mode 100644
index 0000000000..ff3048759f
--- /dev/null
+++ b/contrib/libs/libc_compat/memrchr.c
@@ -0,0 +1,39 @@
+/*	$OpenBSD: memrchr.c,v 1.4 2019/01/25 00:19:25 millert Exp $	*/
+
+/*
+ * Copyright (c) 2007 Todd C. Miller <millert@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <string.h>
+
+/*
+ * Reverse memchr()
+ * Find the last occurrence of 'c' in the buffer 's' of size 'n'.
+ */
+void *
+memrchr(const void *s, int c, size_t n)
+{
+	const unsigned char *cp;
+
+	if (n != 0) {
+		cp = (unsigned char *)s + n;
+		do {
+			if (*(--cp) == (unsigned char)c)
+				return((void *)cp);
+		} while (--n != 0);
+	}
+	return(NULL);
+}
+
diff --git a/contrib/libs/libc_compat/readpassphrase.c b/contrib/libs/libc_compat/readpassphrase.c
new file mode 100644
index 0000000000..df677e9ca5
--- /dev/null
+++ b/contrib/libs/libc_compat/readpassphrase.c
@@ -0,0 +1,192 @@
+/*    $OpenBSD: readpassphrase.c,v 1.27 2019/01/25 00:19:25 millert Exp $    */
+
+/*
+ * Copyright (c) 2000-2002, 2007, 2010
+ *    Todd C. Miller <millert@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ * Sponsored in part by the Defense Advanced Research Projects
+ * Agency (DARPA) and Air Force Research Laboratory, Air Force
+ * Materiel Command, USAF, under agreement number F39502-99-1-0512.
+ */
+
+#include <ctype.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <paths.h>
+#include <pwd.h>
+#include <signal.h>
+#include <string.h>
+#include <termios.h>
+#include <unistd.h>
+#include <readpassphrase.h>
+
+#ifndef TCSASOFT
+/* If we don't have TCSASOFT define it so that ORing it it below is a no-op. */
+# define TCSASOFT 0
+#endif
+
+/* SunOS 4.x which lacks _POSIX_VDISABLE, but has VDISABLE */
+#if !defined(_POSIX_VDISABLE) && defined(VDISABLE)
+#  define _POSIX_VDISABLE       VDISABLE
+#endif
+
+static volatile sig_atomic_t signo[_NSIG];
+
+static void handler(int);
+
+char *
+readpassphrase(const char *prompt, char *buf, size_t bufsiz, int flags)
+{
+    ssize_t nr;
+    int input, output, save_errno, i, need_restart;
+    char ch, *p, *end;
+    struct termios term, oterm;
+    struct sigaction sa, savealrm, saveint, savehup, savequit, saveterm;
+    struct sigaction savetstp, savettin, savettou, savepipe;
+
+    /* I suppose we could alloc on demand in this case (XXX). */
+    if (bufsiz == 0) {
+        errno = EINVAL;
+        return(NULL);
+    }
+
+restart:
+    for (i = 0; i < _NSIG; i++)
+        signo[i] = 0;
+    nr = -1;
+    save_errno = 0;
+    need_restart = 0;
+    /*
+     * Read and write to /dev/tty if available.  If not, read from
+     * stdin and write to stderr unless a tty is required.
+     */
+    if ((flags & RPP_STDIN) ||
+        (input = output = open(_PATH_TTY, O_RDWR)) == -1) {
+        if (flags & RPP_REQUIRE_TTY) {
+            errno = ENOTTY;
+            return(NULL);
+        }
+        input = STDIN_FILENO;
+        output = STDERR_FILENO;
+    }
+
+    /*
+     * Turn off echo if possible.
+     * If we are using a tty but are not the foreground pgrp this will
+     * generate SIGTTOU, so do it *before* installing the signal handlers.
+     */
+    if (input != STDIN_FILENO && tcgetattr(input, &oterm) == 0) {
+        memcpy(&term, &oterm, sizeof(term));
+        if (!(flags & RPP_ECHO_ON))
+            term.c_lflag &= ~(ECHO | ECHONL);
+        (void)tcsetattr(input, TCSAFLUSH|TCSASOFT, &term);
+    } else {
+        memset(&term, 0, sizeof(term));
+        term.c_lflag |= ECHO;
+        memset(&oterm, 0, sizeof(oterm));
+        oterm.c_lflag |= ECHO;
+    }
+
+    /*
+     * Catch signals that would otherwise cause the user to end
+     * up with echo turned off in the shell.  Don't worry about
+     * things like SIGXCPU and SIGVTALRM for now.
+     */
+    sigemptyset(&sa.sa_mask);
+    sa.sa_flags = 0;        /* don't restart system calls */
+    sa.sa_handler = handler;
+    (void)sigaction(SIGALRM, &sa, &savealrm);
+    (void)sigaction(SIGHUP, &sa, &savehup);
+    (void)sigaction(SIGINT, &sa, &saveint);
+    (void)sigaction(SIGPIPE, &sa, &savepipe);
+    (void)sigaction(SIGQUIT, &sa, &savequit);
+    (void)sigaction(SIGTERM, &sa, &saveterm);
+    (void)sigaction(SIGTSTP, &sa, &savetstp);
+    (void)sigaction(SIGTTIN, &sa, &savettin);
+    (void)sigaction(SIGTTOU, &sa, &savettou);
+
+    if (!(flags & RPP_STDIN))
+        (void)write(output, prompt, strlen(prompt));
+    end = buf + bufsiz - 1;
+    p = buf;
+    while ((nr = read(input, &ch, 1)) == 1 && ch != '\n' && ch != '\r') {
+        if (p < end) {
+            if ((flags & RPP_SEVENBIT))
+                ch &= 0x7f;
+            if (isalpha((unsigned char)ch)) {
+                if ((flags & RPP_FORCELOWER))
+                    ch = (char)tolower((unsigned char)ch);
+                if ((flags & RPP_FORCEUPPER))
+                    ch = (char)toupper((unsigned char)ch);
+            }
+            *p++ = ch;
+        }
+    }
+    *p = '\0';
+    save_errno = errno;
+    if (!(term.c_lflag & ECHO))
+        (void)write(output, "\n", 1);
+
+    /* Restore old terminal settings and signals. */
+    if (memcmp(&term, &oterm, sizeof(term)) != 0) {
+        const int sigttou = signo[SIGTTOU];
+
+        /* Ignore SIGTTOU generated when we are not the fg pgrp. */
+        while (tcsetattr(input, TCSAFLUSH|TCSASOFT, &oterm) == -1 &&
+            errno == EINTR && !signo[SIGTTOU])
+            continue;
+        signo[SIGTTOU] = sigttou;
+    }
+    (void)sigaction(SIGALRM, &savealrm, NULL);
+    (void)sigaction(SIGHUP, &savehup, NULL);
+    (void)sigaction(SIGINT, &saveint, NULL);
+    (void)sigaction(SIGQUIT, &savequit, NULL);
+    (void)sigaction(SIGPIPE, &savepipe, NULL);
+    (void)sigaction(SIGTERM, &saveterm, NULL);
+    (void)sigaction(SIGTSTP, &savetstp, NULL);
+    (void)sigaction(SIGTTIN, &savettin, NULL);
+    (void)sigaction(SIGTTOU, &savettou, NULL);
+    if (input != STDIN_FILENO)
+        (void)close(input);
+
+    /*
+     * If we were interrupted by a signal, resend it to ourselves
+     * now that we have restored the signal handlers.
+     */
+    for (i = 0; i < _NSIG; i++) {
+        if (signo[i]) {
+            kill(getpid(), i);
+            switch (i) {
+            case SIGTSTP:
+            case SIGTTIN:
+            case SIGTTOU:
+                need_restart = 1;
+            }
+        }
+    }
+    if (need_restart)
+        goto restart;
+
+    if (save_errno)
+        errno = save_errno;
+    return(nr == -1 ? NULL : buf);
+}
+
+
+static void handler(int s)
+{
+
+    signo[s] = 1;
+}
diff --git a/contrib/libs/libc_compat/reallocarray.c b/contrib/libs/libc_compat/reallocarray.c
new file mode 100644
index 0000000000..21b0914fe4
--- /dev/null
+++ b/contrib/libs/libc_compat/reallocarray.c
@@ -0,0 +1,39 @@
+/*	$OpenBSD: reallocarray.c,v 1.3 2015/09/13 08:31:47 guenther Exp $	*/
+/*
+ * Copyright (c) 2008 Otto Moerbeek <otto@drijf.net>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/types.h>
+#include <errno.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+/*
+ * This is sqrt(SIZE_MAX+1), as s1*s2 <= SIZE_MAX
+ * if both s1 < MUL_NO_OVERFLOW and s2 < MUL_NO_OVERFLOW
+ */
+#define MUL_NO_OVERFLOW	((size_t)1 << (sizeof(size_t) * 4))
+
+void *
+reallocarray(void *optr, size_t nmemb, size_t size)
+{
+	if ((nmemb >= MUL_NO_OVERFLOW || size >= MUL_NO_OVERFLOW) &&
+	    nmemb > 0 && SIZE_MAX / nmemb < size) {
+		errno = ENOMEM;
+		return NULL;
+	}
+	return realloc(optr, size * nmemb);
+}
+
diff --git a/contrib/libs/libc_compat/stdlib.h b/contrib/libs/libc_compat/stdlib.h
new file mode 100644
index 0000000000..ad76fe536b
--- /dev/null
+++ b/contrib/libs/libc_compat/stdlib.h
@@ -0,0 +1,3 @@
+#include <stdlib.h>
+
+void* reallocarray(void*, size_t, size_t);
diff --git a/contrib/libs/libc_compat/stpcpy.c b/contrib/libs/libc_compat/stpcpy.c
new file mode 100644
index 0000000000..5a86541f08
--- /dev/null
+++ b/contrib/libs/libc_compat/stpcpy.c
@@ -0,0 +1,44 @@
+/*	$OpenBSD: stpcpy.c,v 1.3 2017/11/28 06:55:49 tb Exp $	*/
+
+/*
+ * Copyright (c) 1988 Regents of the University of California.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <string.h>
+
+#if defined(APIWARN)
+__warn_references(stpcpy,
+    "stpcpy() is dangerous; do not use it");
+#endif
+
+char *
+stpcpy(char *to, const char *from)
+{
+	for (; (*to = *from) != '\0'; ++from, ++to);
+	return(to);
+}
diff --git a/contrib/libs/libc_compat/strcasestr.c b/contrib/libs/libc_compat/strcasestr.c
new file mode 100644
index 0000000000..ee299b1c01
--- /dev/null
+++ b/contrib/libs/libc_compat/strcasestr.c
@@ -0,0 +1,61 @@
+/*	$OpenBSD: strcasestr.c,v 1.4 2015/08/31 02:53:57 guenther Exp $	*/
+/*	$NetBSD: strcasestr.c,v 1.2 2005/02/09 21:35:47 kleink Exp $	*/
+
+/*-
+ * Copyright (c) 1990, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Chris Torek.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <ctype.h>
+#include "string.h"
+
+/*
+ * Find the first occurrence of find in s, ignore case.
+ */
+char *
+strcasestr(const char *s, const char *find)
+{
+	char c, sc;
+	size_t len;
+
+	if ((c = *find++) != 0) {
+		c = (char)tolower((unsigned char)c);
+		len = strlen(find);
+		do {
+			do {
+				if ((sc = *s++) == 0)
+					return (NULL);
+			} while ((char)tolower((unsigned char)sc) != c);
+		} while (strncasecmp(s, find, len) != 0);
+		s--;
+	}
+	return ((char *)s);
+}
+
diff --git a/contrib/libs/libc_compat/string.c b/contrib/libs/libc_compat/string.c
new file mode 100644
index 0000000000..291f110361
--- /dev/null
+++ b/contrib/libs/libc_compat/string.c
@@ -0,0 +1,16 @@
+#include <ctype.h>
+#include <string.h>
+
+char* strupr(char* s) {
+    char* d;
+    for (d = s; *d; ++d)
+        *d = (char)toupper((int)*d);
+    return s;
+}
+
+char* strlwr(char* s) {
+    char* d;
+    for (d = s; *d; ++d)
+        *d = (char)tolower((int)*d);
+    return s;
+}
diff --git a/contrib/libs/libc_compat/string.h b/contrib/libs/libc_compat/string.h
new file mode 100644
index 0000000000..ad74d9a630
--- /dev/null
+++ b/contrib/libs/libc_compat/string.h
@@ -0,0 +1,44 @@
+#pragma once
+
+#include <stddef.h>
+#include <ctype.h>
+#include <string.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#if !defined(__FreeBSD__) && !defined(__APPLE__)
+size_t strlcpy(char* dst, const char* src, size_t len);
+size_t strlcat(char* dst, const char* src, size_t len);
+#endif
+
+#if (!defined(__linux__) && !defined(__FreeBSD__) && !defined(__APPLE__)) || (defined(__ANDROID__) && __ANDROID_API__ < 21)
+char* stpcpy(char* dst, const char* src);
+#endif
+
+#if !defined(_MSC_VER)
+
+#define stricmp strcasecmp
+#define strnicmp strncasecmp
+
+char* strlwr(char*);
+char* strupr(char*);
+
+#else // _MSC_VER
+
+#define strcasecmp stricmp
+#define strncasecmp strnicmp
+
+char* strcasestr(const char* s1, const char* s2);
+char* strsep(char** stringp, const char* delim);
+
+#endif // _MSC_VER
+
+#if defined(_MSC_VER) || defined(__APPLE__)
+void* memrchr(const void* s, int c, size_t n);
+#endif
+
+#ifdef __cplusplus
+} //extern "C"
+#endif
diff --git a/contrib/libs/libc_compat/strlcat.c b/contrib/libs/libc_compat/strlcat.c
new file mode 100644
index 0000000000..d2198a2bdc
--- /dev/null
+++ b/contrib/libs/libc_compat/strlcat.c
@@ -0,0 +1,56 @@
+/*	$OpenBSD: strlcat.c,v 1.19 2019/01/25 00:19:25 millert Exp $	*/
+
+/*
+ * Copyright (c) 1998, 2015 Todd C. Miller <millert@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/types.h>
+#include <string.h>
+
+/*
+ * Appends src to string dst of size dsize (unlike strncat, dsize is the
+ * full size of dst, not space left).  At most dsize-1 characters
+ * will be copied.  Always NUL terminates (unless dsize <= strlen(dst)).
+ * Returns strlen(src) + MIN(dsize, strlen(initial dst)).
+ * If retval >= dsize, truncation occurred.
+ */
+size_t
+strlcat(char *dst, const char *src, size_t dsize)
+{
+	const char *odst = dst;
+	const char *osrc = src;
+	size_t n = dsize;
+	size_t dlen;
+
+	/* Find the end of dst and adjust bytes left but don't go past end. */
+	while (n-- != 0 && *dst != '\0')
+		dst++;
+	dlen = dst - odst;
+	n = dsize - dlen;
+
+	if (n-- == 0)
+		return(dlen + strlen(src));
+	while (*src != '\0') {
+		if (n != 0) {
+			*dst++ = *src;
+			n--;
+		}
+		src++;
+	}
+	*dst = '\0';
+
+	return(dlen + (src - osrc));	/* count does not include NUL */
+}
+
diff --git a/contrib/libs/libc_compat/strlcpy.c b/contrib/libs/libc_compat/strlcpy.c
new file mode 100644
index 0000000000..1797b86bb6
--- /dev/null
+++ b/contrib/libs/libc_compat/strlcpy.c
@@ -0,0 +1,51 @@
+/*	$OpenBSD: strlcpy.c,v 1.16 2019/01/25 00:19:25 millert Exp $	*/
+
+/*
+ * Copyright (c) 1998, 2015 Todd C. Miller <millert@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/types.h>
+#include <string.h>
+
+/*
+ * Copy string src to buffer dst of size dsize.  At most dsize-1
+ * chars will be copied.  Always NUL terminates (unless dsize == 0).
+ * Returns strlen(src); if retval >= dsize, truncation occurred.
+ */
+size_t
+strlcpy(char *dst, const char *src, size_t dsize)
+{
+	const char *osrc = src;
+	size_t nleft = dsize;
+
+	/* Copy as many bytes as will fit. */
+	if (nleft != 0) {
+		while (--nleft != 0) {
+			if ((*dst++ = *src++) == '\0')
+				break;
+		}
+	}
+
+	/* Not enough room in dst, add NUL and traverse rest of src. */
+	if (nleft == 0) {
+		if (dsize != 0)
+			*dst = '\0';		/* NUL-terminate dst */
+		while (*src++)
+			;
+	}
+
+	return(src - osrc - 1);	/* count does not include NUL */
+}
+
diff --git a/contrib/libs/libc_compat/strsep.c b/contrib/libs/libc_compat/strsep.c
new file mode 100644
index 0000000000..ed605bce97
--- /dev/null
+++ b/contrib/libs/libc_compat/strsep.c
@@ -0,0 +1,71 @@
+/*	$OpenBSD: strsep.c,v 1.8 2015/08/31 02:53:57 guenther Exp $	*/
+
+/*-
+ * Copyright (c) 1990, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <string.h>
+
+/*
+ * Get next token from string *stringp, where tokens are possibly-empty
+ * strings separated by characters from delim.  
+ *
+ * Writes NULs into the string at *stringp to end tokens.
+ * delim need not remain constant from call to call.
+ * On return, *stringp points past the last NUL written (if there might
+ * be further tokens), or is NULL (if there are definitely no more tokens).
+ *
+ * If *stringp is NULL, strsep returns NULL.
+ */
+char *
+strsep(char **stringp, const char *delim)
+{
+	char *s;
+	const char *spanp;
+	int c, sc;
+	char *tok;
+
+	if ((s = *stringp) == NULL)
+		return (NULL);
+	for (tok = s;;) {
+		c = *s++;
+		spanp = delim;
+		do {
+			if ((sc = *spanp++) == c) {
+				if (c == 0)
+					s = NULL;
+				else
+					s[-1] = 0;
+				*stringp = s;
+				return (tok);
+			}
+		} while (sc != 0);
+	}
+	/* NOTREACHED */
+}
+
diff --git a/contrib/libs/libc_compat/ubuntu_14/README.md b/contrib/libs/libc_compat/ubuntu_14/README.md
new file mode 100644
index 0000000000..f7b17a40cc
--- /dev/null
+++ b/contrib/libs/libc_compat/ubuntu_14/README.md
@@ -0,0 +1,91 @@
+## Общие соображения
+
+В библиотеку добавлены реализации символов, появившихся в `libc.so.6` Ubuntu
+14.04 с момента Ubuntu 12.04.
+
+Если какой-либо объектный файл ссылается на один из таких символов, то при
+компоновке этот символ будет взят из нашей библиотеки. В противном случае,
+компоновщик сослался бы на такой символ из `libc.so.6`, добавив к исполняемому
+файлу зависимость от новой версии динамической библиотеки (`GLIBC_2.16`,
+`GLIBC_2.17` или `GLIBC_2.18`). Такой исполняемый файл не может быть запущен на
+Ubuntu 12.04, даже если ни один из новых символов не используется в runtime.
+
+На Ubuntu 14.04 или более новых, в случае если процесс загружает `libc.so.6`, мы
+будем в runtime иметь две реализации символов, нашу и libc. Но все добавленные
+функции не имеют какого-либо состояния и никакими деталями внутренней реализации
+не связаны с другими. Нет разницы, какую из реализаций использовать, и даже
+попеременное использование различных реализаций в одном и том же контексте не
+должно приводить к некорректной работе.
+
+В какой-то момент этот слой совместимости будет отключен: https://st.yandex-team.ru/DEVTOOLS-7436
+
+### Разделяемая реализация
+
+Была идея оформить новые реализации так, чтобы в случае их наличия и в
+загруженной libc динамический компоновщик выбирал для всех ссылок одну
+реализацию.
+
+По всей видимости, для этого требуется собирать исполняемый файл как PIE. Только
+в этом случае для наших реализаций будут сгенерированы дополнительные PLT
+прослойки и вызовы наших реализаций будут проходить через них.
+
+Но в этом случае вообще все вызовы будут происходить таким образом и это
+повлияет на производительность. Ухудшения производительности, наверное, можно
+избежать, явно указав, какие символы в исполняемом файле должны быть публичными,
+но сейчас нет способа сделать это в одном месте, учитывая, что в некоторых
+случаях этот список должен дополняться.
+
+## `getauxval` и `secure_getenv`
+
+Функция `getauxval` требует загрузки и хранения «Auxiliary Vector» (см.
+[здесь](https://refspecs.linuxfoundation.org/LSB_1.3.0/IA64/spec/auxiliaryvector.html)).
+
+Эти данные доступны в момент запуска процесса. libc из новых Ubuntu сохраняет
+эти данные и предоставляет реализацию `getauxval`. В этом случае наша реализация
+перенаправляет вызовы `getauxval` в libc, получив при старте исполняемого файла
+соответствующий указатель.
+
+Если реализация libc недоступна (на старых Ubuntu или если libc не загружена),
+то эти данные можно получить, прочитав `/proc/self/auxv`. Это также делается
+один раз при старте.
+
+В обоих случаях, статически инициализируется синглтон `NUbuntuCompat::TGlibc`,
+который производит эти действия в конструкторе.
+
+`secure_getenv` использует одно из значений `getauxval`, поэтому к нему всё это
+также относится.
+
+Каждый метод новой libc реализован в отдельном объектом файле. `TGlibc` также
+находится в отдельном файле, и ссылки на неё стоят только в местах использования.
+Если при компоновке не понадобились ни `getauxval`, ни `secure_getenv`, то
+объектный файл с `TGlibc` тоже не будет выбран компоновщиком, и в этом случае
+никакой лишней статической инициализации выполняться не будет.
+
+## Патч libc.so
+
+Чтобы иметь возможность использовать `getauxval` (точнее его реализацию
+`__getauxval`) из новой libc, если таковая уже используется процессом,
+библиотека совместимости объявляет этот символ у себя как внешний и слабый. При
+загрузке динамический компоновщик устанавливает значение этого символа из libc
+или `nullptr`, если его там нет. Наша реализация `getauxval` проверяет
+доступность реализации libc, просто сравнивая указатель с `nullptr`.
+
+В Аркадии также есть код, который подобным образом работает с символом
+`__cxa_thread_atexit_impl`.
+
+Однако, если компоновать такую программу с использованием новой libc, то к таким
+символам и самой программе будет приписано требование соответствующей (новой)
+версии libc. Чтобы этого не произошло, при сборке с этой библиотекой
+совместимости используется патченный вариант `libc.so.6`, где у таких символов
+удалена версия.
+
+Также, файлы, проверяющие, что доступна реализация из libc, должны быть собраны
+как PIC. В противном случае вместо значения, заполненного динамическим
+компоновщиком, компилятор ещё на стадии компиляции использует `nullptr` и
+проверка никогда не срабатывает.
+
+## Упоминания
+
+Идея о возможности добавить слой совместимости была взята из ClickHouse.
+* [https://clickhouse.tech/](https://clickhouse.tech/)
+* [https://wiki.yandex-team.ru/clickhouse/](https://wiki.yandex-team.ru/clickhouse/)
diff --git a/contrib/libs/libc_compat/ubuntu_14/aligned_alloc.c b/contrib/libs/libc_compat/ubuntu_14/aligned_alloc.c
new file mode 100644
index 0000000000..c4a1378624
--- /dev/null
+++ b/contrib/libs/libc_compat/ubuntu_14/aligned_alloc.c
@@ -0,0 +1,6 @@
+#include <malloc.h>
+#include <stdlib.h>
+
+__attribute__((weak)) void* aligned_alloc(size_t alignment, size_t size) {
+    return memalign(alignment, size);
+}
diff --git a/contrib/libs/libc_compat/ubuntu_14/c16rtomb.c b/contrib/libs/libc_compat/ubuntu_14/c16rtomb.c
new file mode 100644
index 0000000000..39ca3758fa
--- /dev/null
+++ b/contrib/libs/libc_compat/ubuntu_14/c16rtomb.c
@@ -0,0 +1,35 @@
+#include <uchar.h>
+#include <errno.h>
+#include <wchar.h>
+
+size_t c16rtomb(char *restrict s, char16_t c16, mbstate_t *restrict ps)
+{
+	static unsigned internal_state;
+	if (!ps) ps = (void *)&internal_state;
+	unsigned *x = (unsigned *)ps;
+	wchar_t wc;
+
+	if (!s) {
+		if (*x) goto ilseq;
+		return 1;
+	}
+
+	if (!*x && c16 - 0xd800u < 0x400) {
+		*x = c16 - 0xd7c0 << 10;
+		return 0;
+	}
+
+	if (*x) {
+		if (c16 - 0xdc00u >= 0x400) goto ilseq;
+		else wc = *x + c16 - 0xdc00;
+		*x = 0;
+	} else {
+		wc = c16;
+	}
+	return wcrtomb(s, wc, 0);
+
+ilseq:
+	*x = 0;
+	errno = EILSEQ;
+	return -1;
+}
diff --git a/contrib/libs/libc_compat/ubuntu_14/c32rtomb.c b/contrib/libs/libc_compat/ubuntu_14/c32rtomb.c
new file mode 100644
index 0000000000..67851328e8
--- /dev/null
+++ b/contrib/libs/libc_compat/ubuntu_14/c32rtomb.c
@@ -0,0 +1,7 @@
+#include <uchar.h>
+#include <wchar.h>
+
+size_t c32rtomb(char *restrict s, char32_t c32, mbstate_t *restrict ps)
+{
+	return wcrtomb(s, c32, ps);
+}
diff --git a/contrib/libs/libc_compat/ubuntu_14/features.h b/contrib/libs/libc_compat/ubuntu_14/features.h
new file mode 100644
index 0000000000..9fbab45ab5
--- /dev/null
+++ b/contrib/libs/libc_compat/ubuntu_14/features.h
@@ -0,0 +1,5 @@
+#pragma once
+
+#define weak __attribute__((__weak__))
+#define weak_alias(old, new) \
+        extern __typeof(old) new __attribute__((__weak__, __alias__(#old)))
diff --git a/contrib/libs/libc_compat/ubuntu_14/getauxval.cpp b/contrib/libs/libc_compat/ubuntu_14/getauxval.cpp
new file mode 100644
index 0000000000..9f20dd0195
--- /dev/null
+++ b/contrib/libs/libc_compat/ubuntu_14/getauxval.cpp
@@ -0,0 +1,10 @@
+#include <sys/auxv.h>
+
+#include "glibc.h"
+#include "features.h"
+
+extern "C" {
+    unsigned long getauxval(unsigned long item) noexcept {
+        return NUbuntuCompat::GetGlibc().GetAuxVal(item);
+    }
+}
diff --git a/contrib/libs/libc_compat/ubuntu_14/glibc.cpp b/contrib/libs/libc_compat/ubuntu_14/glibc.cpp
new file mode 100644
index 0000000000..1cc444bce1
--- /dev/null
+++ b/contrib/libs/libc_compat/ubuntu_14/glibc.cpp
@@ -0,0 +1,111 @@
+#include <elf.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include "glibc.h"
+#include "features.h"
+
+namespace {
+    void ReadAuxVector(Elf64_auxv_t** begin, Elf64_auxv_t** end) noexcept {
+        int fd = open("/proc/self/auxv", O_RDONLY | O_CLOEXEC);
+        if (fd == -1) {
+            return;
+        }
+
+        constexpr size_t item_size = sizeof(Elf64_auxv_t);
+        constexpr size_t block_size = item_size * 32;
+
+        size_t bytes_read = 0;
+        size_t size = 0;
+
+        struct TBuffer {
+            ~TBuffer() {
+                free(Pointer);
+            }
+            char* Pointer = nullptr;
+        } buffer;
+
+        while (true) {
+            size_t bytes_left = size - bytes_read;
+
+            if (!bytes_left) {
+                size += block_size;
+                char* new_buffer = (char*)realloc(buffer.Pointer, size);
+                if (!new_buffer) {
+                    return;
+                }
+                buffer.Pointer = new_buffer;
+                continue;
+            }
+
+            ssize_t r = read(fd, buffer.Pointer + bytes_read, bytes_left);
+            if (!r) {
+                break;
+            } else if (r < 0) {
+                if (errno == EINTR) {
+                    continue;
+                } else {
+                    return;
+                }
+            }
+
+            bytes_read += r;
+        }
+
+        size_t item_count = bytes_read / item_size;
+        *begin = (Elf64_auxv_t*)buffer.Pointer;
+        *end = (Elf64_auxv_t*)(buffer.Pointer + item_count * item_size);
+        buffer.Pointer = nullptr;
+    }
+}
+
+extern "C" {
+    weak unsigned long __getauxval(unsigned long item);
+}
+
+namespace NUbuntuCompat {
+
+    TGlibc::TGlibc() noexcept
+        : AuxVectorBegin(nullptr)
+        , AuxVectorEnd(nullptr)
+    {
+        if (!__getauxval) {
+            ReadAuxVector((Elf64_auxv_t**)&AuxVectorBegin, (Elf64_auxv_t**)&AuxVectorEnd);
+        }
+
+        Secure = (bool)GetAuxVal(AT_SECURE);
+    }
+
+    TGlibc::~TGlibc() noexcept {
+        free(AuxVectorBegin);
+    }
+
+    unsigned long TGlibc::GetAuxVal(unsigned long item) noexcept {
+        if (__getauxval) {
+            return __getauxval(item);
+        }
+
+        for (Elf64_auxv_t* p = (Elf64_auxv_t*)AuxVectorBegin; p < (Elf64_auxv_t*)AuxVectorEnd; ++p) {
+            if (p->a_type == item) {
+                return p->a_un.a_val;
+            }
+        }
+
+        errno = ENOENT;
+        return 0;
+    }
+
+    bool TGlibc::IsSecure() noexcept {
+        return Secure;
+    }
+
+    static TGlibc __attribute__((__init_priority__(101))) GlibcInstance;
+
+    TGlibc& GetGlibc() noexcept {
+        return GlibcInstance;
+    }
+}
diff --git a/contrib/libs/libc_compat/ubuntu_14/glibc.h b/contrib/libs/libc_compat/ubuntu_14/glibc.h
new file mode 100644
index 0000000000..fa8f7dd013
--- /dev/null
+++ b/contrib/libs/libc_compat/ubuntu_14/glibc.h
@@ -0,0 +1,20 @@
+#pragma once
+
+typedef unsigned long (*TGetAuxVal)(unsigned long);
+
+namespace NUbuntuCompat {
+    class TGlibc {
+    public:
+        TGlibc() noexcept;
+        ~TGlibc() noexcept;
+        unsigned long GetAuxVal(unsigned long item) noexcept;
+        bool IsSecure() noexcept;
+
+    private:
+        void* AuxVectorBegin;
+        void* AuxVectorEnd;
+        bool Secure;
+    };
+
+    TGlibc& GetGlibc() noexcept;
+};
diff --git a/contrib/libs/libc_compat/ubuntu_14/mbrtoc16.c b/contrib/libs/libc_compat/ubuntu_14/mbrtoc16.c
new file mode 100644
index 0000000000..765ff9037c
--- /dev/null
+++ b/contrib/libs/libc_compat/ubuntu_14/mbrtoc16.c
@@ -0,0 +1,30 @@
+#include <uchar.h>
+#include <wchar.h>
+
+size_t mbrtoc16(char16_t *restrict pc16, const char *restrict s, size_t n, mbstate_t *restrict ps)
+{
+	static unsigned internal_state;
+	if (!ps) ps = (void *)&internal_state;
+	unsigned *pending = (unsigned *)ps;
+
+	if (!s) return mbrtoc16(0, "", 1, ps);
+
+	/* mbrtowc states for partial UTF-8 characters have the high bit set;
+	 * we use nonzero states without high bit for pending surrogates. */
+	if ((int)*pending > 0) {
+ 		if (pc16) *pc16 = *pending;
+		*pending = 0;
+		return -3;
+	}
+
+	wchar_t wc;
+	size_t ret = mbrtowc(&wc, s, n, ps);
+	if (ret <= 4) {
+		if (wc >= 0x10000) {
+			*pending = (wc & 0x3ff) + 0xdc00;
+			wc = 0xd7c0 + (wc >> 10);
+		}
+		if (pc16) *pc16 = wc;
+	}
+	return ret;
+}
diff --git a/contrib/libs/libc_compat/ubuntu_14/mbrtoc32.c b/contrib/libs/libc_compat/ubuntu_14/mbrtoc32.c
new file mode 100644
index 0000000000..9b6b236739
--- /dev/null
+++ b/contrib/libs/libc_compat/ubuntu_14/mbrtoc32.c
@@ -0,0 +1,13 @@
+#include <uchar.h>
+#include <wchar.h>
+
+size_t mbrtoc32(char32_t *restrict pc32, const char *restrict s, size_t n, mbstate_t *restrict ps)
+{
+	static unsigned internal_state;
+	if (!ps) ps = (void *)&internal_state;
+	if (!s) return mbrtoc32(0, "", 1, ps);
+	wchar_t wc;
+	size_t ret = mbrtowc(&wc, s, n, ps);
+	if (ret <= 4 && pc32) *pc32 = wc;
+	return ret;
+}
diff --git a/contrib/libs/libc_compat/ubuntu_14/secure_getenv.cpp b/contrib/libs/libc_compat/ubuntu_14/secure_getenv.cpp
new file mode 100644
index 0000000000..14e3e90906
--- /dev/null
+++ b/contrib/libs/libc_compat/ubuntu_14/secure_getenv.cpp
@@ -0,0 +1,12 @@
+#include <stdlib.h>
+
+#include "glibc.h"
+
+extern "C" {
+    char *secure_getenv(const char *name) noexcept {
+            if (NUbuntuCompat::GetGlibc().IsSecure()) {
+                return nullptr;
+            }
+            return getenv(name);
+    }
+}
diff --git a/contrib/libs/libc_compat/ubuntu_14/timespec_get.c b/contrib/libs/libc_compat/ubuntu_14/timespec_get.c
new file mode 100644
index 0000000000..742b62ec84
--- /dev/null
+++ b/contrib/libs/libc_compat/ubuntu_14/timespec_get.c
@@ -0,0 +1,10 @@
+#include <time.h>
+
+/* There is no other implemented value than TIME_UTC; all other values
+ * are considered erroneous. */
+int timespec_get(struct timespec * ts, int base)
+{
+	if (base != TIME_UTC) return 0;
+	int ret = clock_gettime(CLOCK_REALTIME, ts);
+	return ret < 0 ? 0 : base;
+}
diff --git a/contrib/libs/libc_compat/ubuntu_14/ya.make b/contrib/libs/libc_compat/ubuntu_14/ya.make
new file mode 100644
index 0000000000..7355c4ad9d
--- /dev/null
+++ b/contrib/libs/libc_compat/ubuntu_14/ya.make
@@ -0,0 +1,42 @@
+LIBRARY()
+
+WITHOUT_LICENSE_TEXTS()
+
+LICENSE(BSD-3-Clause)
+
+OWNER(
+    somov
+    g:contrib
+    g:cpp-contrib
+)
+
+NO_PLATFORM()
+
+NO_RUNTIME()
+
+NO_UTIL()
+
+DISABLE(NEED_PLATFORM_PEERDIRS)
+DISABLE(OPENSOURCE_EXPORT)
+
+IF (OS_SDK == "ubuntu-14")
+    PEERDIR(
+        build/platform/linux_sdk
+    )
+    SRCS(
+        aligned_alloc.c
+        c16rtomb.c
+        c32rtomb.c
+        getauxval.cpp
+        mbrtoc16.c
+        mbrtoc32.c
+        secure_getenv.cpp
+        timespec_get.c
+    )
+    SRC_CPP_PIC(
+        glibc.cpp
+        -fno-lto
+    )
+ENDIF()
+
+END()
diff --git a/contrib/libs/libc_compat/unistd.h b/contrib/libs/libc_compat/unistd.h
new file mode 100644
index 0000000000..c62f5f29cd
--- /dev/null
+++ b/contrib/libs/libc_compat/unistd.h
@@ -0,0 +1,3 @@
+#include <unistd.h>
+
+#define issetugid() 0
diff --git a/contrib/libs/libc_compat/update.sh b/contrib/libs/libc_compat/update.sh
new file mode 100755
index 0000000000..4cee160904
--- /dev/null
+++ b/contrib/libs/libc_compat/update.sh
@@ -0,0 +1,60 @@
+#!/bin/sh -e
+
+unweak() {
+    sed --in-place --expression 's/DEF_WEAK(.\+);//g' "$1"
+}
+
+get_string_method() {
+   curl "https://raw.githubusercontent.com/openbsd/src/master/lib/libc/string/$1" --output "$1" && unweak "$1"
+}
+
+fix_tabs() {
+	sed --in-place --expression 's/\t/    /g' "$1"
+}
+
+fix_decls() {
+	sed --in-place --expression 's/__BEGIN_DECLS/#ifdef __cplusplus\nextern "C" {\n#endif/g' "$1"
+	sed --in-place --expression 's/__END_DECLS/#ifdef __cplusplus\n} \/\/ extern "C"\n#endif/g' "$1"
+}
+
+get_string_method "strlcpy.c"
+get_string_method "strlcat.c"
+get_string_method "strsep.c"
+# strcasestr uses strncasecmp, which is platform dependent, so include local string.h
+get_string_method "strcasestr.c" && sed --in-place 's/#include <string.h>/#include "string.h"/g' "strcasestr.c"
+get_string_method "memrchr.c"
+get_string_method "stpcpy.c"
+
+mkdir -p include/windows/sys
+curl "https://raw.githubusercontent.com/openbsd/src/master/sys/sys/queue.h" --output "include/windows/sys/queue.h"
+
+mkdir -p include/readpassphrase
+curl "https://raw.githubusercontent.com/openbsd/src/master/include/readpassphrase.h" --output "include/readpassphrase/readpassphrase.h" && fix_decls "include/readpassphrase/readpassphrase.h"
+curl "https://raw.githubusercontent.com/openbsd/src/master/lib/libc/gen/readpassphrase.c" --output "readpassphrase.c" && unweak "readpassphrase.c" && fix_tabs "readpassphrase.c"
+
+curl "https://raw.githubusercontent.com/freebsd/freebsd/master/include/glob.h" --output "glob.h"
+curl "https://raw.githubusercontent.com/freebsd/freebsd/master/lib/libc/gen/glob.c" --output "glob.c"
+curl "https://raw.githubusercontent.com/openbsd/src/master/lib/libc/stdlib/reallocarray.c" --output "reallocarray.c" && unweak "reallocarray.c"
+> "collate.h"
+> "stdlib.h"
+> "unistd.h"
+
+mkdir -p include/uchar
+curl "https://git.musl-libc.org/cgit/musl/plain/include/uchar.h" --output "include/uchar/uchar.h"
+# TODO: provide c16rtomb, mbrtoc16, c32rtomb, mbrtoc32 implementations for uchar
+# if any code actually needs them
+
+mkdir -p include/random/sys
+curl "https://git.musl-libc.org/cgit/musl/plain/include/sys/random.h" --output "include/random/sys/random.h"
+curl "https://git.musl-libc.org/cgit/musl/plain/src/linux/getrandom.c" --output "getrandom.c"
+curl "https://git.musl-libc.org/cgit/musl/plain/src/linux/memfd_create.c" --output "memfd_create.c"
+
+# WARN: do not use github.com/morristech/android-ifaddrs, it is a long-ago abandoned fork
+curl "https://raw.githubusercontent.com/oliviertilmans/android-ifaddrs/master/ifaddrs.c" --output "ifaddrs.c"
+curl "https://raw.githubusercontent.com/oliviertilmans/android-ifaddrs/master/ifaddrs.h" --output "include/ifaddrs/ifaddrs.h"
+
+# apply patches if necessary
+for patch in patches/*.patch; do
+	echo "Applying patch from $patch"
+	patch -p1 < $patch
+done
diff --git a/contrib/libs/libc_compat/ya.make b/contrib/libs/libc_compat/ya.make
new file mode 100644
index 0000000000..b92184c165
--- /dev/null
+++ b/contrib/libs/libc_compat/ya.make
@@ -0,0 +1,123 @@
+OWNER(g:cpp-contrib)
+
+LIBRARY()
+
+LICENSE(
+    BSD-1-Clause AND
+    BSD-2-Clause AND
+    BSD-3-Clause AND
+    ISC
+)
+
+LICENSE_TEXTS(.yandex_meta/licenses.list.txt)
+
+NO_COMPILER_WARNINGS()
+
+NO_UTIL()
+
+NO_RUNTIME()
+
+IF (NOT OS_WINDOWS)
+    SRCS(
+        string.c
+    )
+ENDIF()
+
+# Android libc function appearance is documented here:
+# https://android.googlesource.com/platform/bionic/+/master/docs/status.md
+#
+# NB: nested IF's are needed due to the lack of lazy evaluation of logical statements: DEVTOOLS-7837
+IF (OS_ANDROID)
+    SRCS(
+        strlcat.c
+        strlcpy.c
+    )
+    IF (ANDROID_API < 28)
+        SRCS(
+            glob.c
+            reallocarray.c
+        )
+    ENDIF()
+    IF (ANDROID_API < 24)
+        SRCS(
+            ifaddrs.c
+        )
+        ADDINCL(
+            GLOBAL contrib/libs/libc_compat/include/ifaddrs
+        )
+    ENDIF()
+    IF (ANDROID_API < 21)
+        SRCS(
+            stpcpy.c
+        )
+    ENDIF()
+ENDIF()
+
+IF (OS_WINDOWS OR OS_DARWIN OR OS_IOS)
+    SRCS(
+        memrchr.c
+    )
+ENDIF()
+
+IF (OS_DARWIN)
+    SRCS(
+        reallocarray.c
+    )
+ENDIF()
+
+IF (OS_WINDOWS)
+    ADDINCL(
+        GLOBAL contrib/libs/libc_compat/include/windows
+    )
+    SRCS(
+        reallocarray.c
+        stpcpy.c
+        strlcat.c
+        strlcpy.c
+        strcasestr.c
+        strsep.c
+        src/windows/sys/uio.c
+    )
+ENDIF()
+
+IF (OS_LINUX)
+    ADDINCL(
+        GLOBAL contrib/libs/libc_compat/include/readpassphrase
+    )
+    SRCS(
+        readpassphrase.c
+    )
+ENDIF()
+
+IF (OS_LINUX AND NOT MUSL)
+    IF (OS_SDK == "ubuntu-12")
+        ADDINCL(
+            # uchar.h was introduced in glibc=2.16
+            GLOBAL contrib/libs/libc_compat/include/uchar
+        )
+    ENDIF()
+    IF (OS_SDK == "ubuntu-12" OR OS_SDK == "ubuntu-14" OR OS_SDK == "ubuntu-16")
+        ADDINCL(
+            GLOBAL contrib/libs/libc_compat/include/random
+        )
+        SRCS(
+            # getrandom was added in glibc=2.25
+            getrandom.c
+            # memfd_create was added in glibc=2.27
+            memfd_create.c
+        )
+    ENDIF()
+    IF (OS_SDK != "ubuntu-20")
+        SRCS(
+            # reallocarray was added in glibc=2.29
+            reallocarray.c
+        )
+    ENDIF()
+    SRCS(
+        # glibc does not offer strlcat / strlcpy yet
+        strlcat.c
+        strlcpy.c
+    )
+ENDIF()
+
+END()