IABSD.fr/src/lib/libc/stdlib/setenv.c

Branch : - branch - master - tag -

• Show log

  Commit

• Author : millert
  Date : 2022-08-08 22:40:03
  Hash : 7fd658f2
  Message : For putenv(3), return an error if string starts with a '=' character. Both FreeBSD and NetBSD have this behavior. OK deraadt@

• lib/libc/stdlib/setenv.c

• /*	$OpenBSD: setenv.c,v 1.20 2022/08/08 22:40:03 millert Exp $ */
  /*
   * Copyright (c) 1987 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 <errno.h>
  #include <stdlib.h>
  #include <string.h>
  
  static char **lastenv;				/* last value of environ */
  
  /*
   * putenv --
   *	Add a name=value string directly to the environmental, replacing
   *	any current value.
   */
  int
  putenv(char *str)
  {
  	char **P, *cp;
  	size_t cnt = 0;
  	int offset = 0;
  
  	for (cp = str; *cp && *cp != '='; ++cp)
  		;
  	if (cp == str || *cp != '=') {
  		/* '=' is the first character of string or is missing. */
  		errno = EINVAL;
  		return (-1);
  	}
  
  	if (__findenv(str, (int)(cp - str), &offset) != NULL) {
  		environ[offset++] = str;
  		/* could be set multiple times */
  		while (__findenv(str, (int)(cp - str), &offset)) {
  			for (P = &environ[offset];; ++P)
  				if (!(*P = *(P + 1)))
  					break;
  		}
  		return (0);
  	}
  
  	/* create new slot for string */
  	if (environ != NULL) {
  		for (P = environ; *P != NULL; P++)
  			;
  		cnt = P - environ;
  	}
  	P = reallocarray(lastenv, cnt + 2, sizeof(char *));
  	if (!P)
  		return (-1);
  	if (lastenv != environ && environ != NULL)
  		memcpy(P, environ, cnt * sizeof(char *));
  	lastenv = environ = P;
  	environ[cnt] = str;
  	environ[cnt + 1] = NULL;
  	return (0);
  }
  DEF_WEAK(putenv);
  
  /*
   * setenv --
   *	Set the value of the environmental variable "name" to be
   *	"value".  If rewrite is set, replace any current value.
   */
  int
  setenv(const char *name, const char *value, int rewrite)
  {
  	char *C, **P;
  	const char *np;
  	int l_value, offset = 0;
  
  	if (!name || !*name) {
  		errno = EINVAL;
  		return (-1);
  	}
  	for (np = name; *np && *np != '='; ++np)
  		;
  	if (*np) {
  		errno = EINVAL;
  		return (-1);			/* has `=' in name */
  	}
  
  	l_value = strlen(value);
  	if ((C = __findenv(name, (int)(np - name), &offset)) != NULL) {
  		int tmpoff = offset + 1;
  		if (!rewrite)
  			return (0);
  #if 0 /* XXX - existing entry may not be writable */
  		if (strlen(C) >= l_value) {	/* old larger; copy over */
  			while ((*C++ = *value++))
  				;
  			return (0);
  		}
  #endif
  		/* could be set multiple times */
  		while (__findenv(name, (int)(np - name), &tmpoff)) {
  			for (P = &environ[tmpoff];; ++P)
  				if (!(*P = *(P + 1)))
  					break;
  		}
  	} else {					/* create new slot */
  		size_t cnt = 0;
  
  		if (environ != NULL) {
  			for (P = environ; *P != NULL; P++)
  				;
  			cnt = P - environ;
  		}
  		P = reallocarray(lastenv, cnt + 2, sizeof(char *));
  		if (!P)
  			return (-1);
  		if (lastenv != environ && environ != NULL)
  			memcpy(P, environ, cnt * sizeof(char *));
  		lastenv = environ = P;
  		offset = cnt;
  		environ[cnt + 1] = NULL;
  	}
  	if (!(environ[offset] =			/* name + `=' + value */
  	    malloc((int)(np - name) + l_value + 2)))
  		return (-1);
  	for (C = environ[offset]; (*C = *name++) && *C != '='; ++C)
  		;
  	for (*C++ = '='; (*C++ = *value++); )
  		;
  	return (0);
  }
  DEF_WEAK(setenv);
  
  /*
   * unsetenv(name) --
   *	Delete environmental variable "name".
   */
  int
  unsetenv(const char *name)
  {
  	char **P;
  	const char *np;
  	int offset = 0;
  
  	if (!name || !*name) {
  		errno = EINVAL;
  		return (-1);
  	}
  	for (np = name; *np && *np != '='; ++np)
  		;
  	if (*np) {
  		errno = EINVAL;
  		return (-1);			/* has `=' in name */
  	}
  
  	/* could be set multiple times */
  	while (__findenv(name, (int)(np - name), &offset)) {
  		for (P = &environ[offset];; ++P)
  			if (!(*P = *(P + 1)))
  				break;
  	}
  	return (0);
  }
  DEF_WEAK(unsetenv);