Significantly reduce the memory leak as noted in BUGS section for

setenv(3) by tracking the size of the memory allocated instead of using
strlen() on the current value.

Convert all calls to POSIX from historic BSD API:
 - unsetenv returns an int.
 - putenv takes a char * instead of const char *.
 - putenv no longer makes a copy of the input string.
 - errno is set appropriately for POSIX.  Exceptions involve bad environ
   variable and internal initialization code.  These both set errno to
   EFAULT.

Several patches to base utilities to handle the POSIX changes from
Andrey Chernov's previous commit.  A few I re-wrote to use setenv()
instead of putenv().

New regression module for tools/regression/environ to test these
functions.  It also can be used to test the performance.

Bump __FreeBSD_version to 700050 due to API change.

PR:		kern/99826
Approved by:	wes
Approved by:	re (kensmith)

bin/df/df.c

@@ -131,14 +131,14 @@ main(int argc, char *argv[])
 			 */
 			if (kflag)
 				break;
-			putenv("BLOCKSIZE=512");
+			setenv("BLOCKSIZE", "512", 1);
 			hflag = 0;
 			break;
 		case 'c':
 			cflag = 1;
 			break;
 		case 'g':
-			putenv("BLOCKSIZE=1g");
+			setenv("BLOCKSIZE", "1g", 1);
 			hflag = 0;
 			break;
 		case 'H':
@@ -152,7 +152,7 @@ main(int argc, char *argv[])
 			break;
 		case 'k':
 			kflag++;
-			putenv("BLOCKSIZE=1024");
+			setenv("BLOCKSIZE", "1024", 1);
 			hflag = 0;
 			break;
 		case 'l':
@@ -162,7 +162,7 @@ main(int argc, char *argv[])
 			lflag = 1;
 			break;
 		case 'm':
-			putenv("BLOCKSIZE=1m");
+			setenv("BLOCKSIZE", "1m", 1);
 			hflag = 0;
 			break;
 		case 'n':

bin/sh/var.c

@@ -289,6 +289,7 @@ void
 setvareq(char *s, int flags)
 {
 	struct var *vp, **vpp;
+	char *p;
 	int len;
 
 	if (aflag)
@@ -319,7 +320,10 @@ setvareq(char *s, int flags)
 			if (vp == &vmpath || (vp == &vmail && ! mpathset()))
 				chkmail(1);
 			if ((vp->flags & VEXPORT) && localevar(s)) {
-				putenv(s);
+				p = strchr(s, '=');
+				*p = '\0';
+				(void) setenv(s, p + 1, 1);
+				*p = '=';
 				(void) setlocale(LC_ALL, "");
 			}
 			INTON;
@@ -335,7 +339,10 @@ setvareq(char *s, int flags)
 	INTOFF;
 	*vpp = vp;
 	if ((vp->flags & VEXPORT) && localevar(s)) {
-		putenv(s);
+		p = strchr(s, '=');
+		*p = '\0';
+		(void) setenv(s, p + 1, 1);
+		*p = '=';
 		(void) setlocale(LC_ALL, "");
 	}
 	INTON;
@@ -596,7 +603,10 @@ exportcmd(int argc, char **argv)
 
 						vp->flags |= flag;
 						if ((vp->flags & VEXPORT) && localevar(vp->text)) {
-							putenv(vp->text);
+							p = strchr(vp->text, '=');
+							*p = '\0';
+							(void) setenv(vp->text, p + 1, 1);
+							*p = '=';
 							(void) setlocale(LC_ALL, "");
 						}
 						goto found;

include/stdlib.h

@@ -161,7 +161,7 @@ void	 _Exit(int) __dead2;
 int	 posix_memalign(void **, size_t, size_t); /* (ADV) */
 int	 rand_r(unsigned *);			/* (TSF) */
 int	 setenv(const char *, const char *, int);
-void	 unsetenv(const char *);
+int	 unsetenv(const char *);
 #endif
 
 /*
@@ -197,7 +197,7 @@ long	 mrand48(void);
 long	 nrand48(unsigned short[3]);
 int	 posix_openpt(int);
 char	*ptsname(int);
-int	 putenv(const char *);
+int	 putenv(char *);
 long	 random(void);
 char	*realpath(const char *, char resolved_path[]);
 unsigned short

lib/libc/stdlib/Makefile.inc

@@ -8,10 +8,10 @@ MISRCS+=_Exit.c a64l.c abort.c abs.c atexit.c atof.c atoi.c atol.c atoll.c \
 	bsearch.c div.c exit.c getenv.c getopt.c getopt_long.c \
 	getsubopt.c grantpt.c hcreate.c heapsort.c imaxabs.c imaxdiv.c \
 	insque.c l64a.c labs.c ldiv.c llabs.c lldiv.c lsearch.c malloc.c \
-	merge.c putenv.c qsort.c qsort_r.c radixsort.c rand.c random.c \
-	reallocf.c realpath.c remque.c setenv.c strfmon.c strtoimax.c \
-	strtol.c strtoll.c strtoq.c strtoul.c strtonum.c strtoull.c strtoumax.c \
-	strtouq.c system.c tdelete.c tfind.c tsearch.c twalk.c
+	merge.c qsort.c qsort_r.c radixsort.c rand.c random.c \
+	reallocf.c realpath.c remque.c strfmon.c strtoimax.c \
+	strtol.c strtoll.c strtoq.c strtoul.c strtonum.c strtoull.c \
+        strtoumax.c strtouq.c system.c tdelete.c tfind.c tsearch.c twalk.c
 
 SYM_MAPS+= ${.CURDIR}/stdlib/Symbol.map
 

lib/libc/stdlib/getenv.3

@@ -32,7 +32,7 @@
 .\"     @(#)getenv.3	8.2 (Berkeley) 12/11/93
 .\" $FreeBSD$
 .\"
-.Dd October 12, 2006
+.Dd June 20, 2007
 .Dt GETENV 3
 .Os
 .Sh NAME
@@ -50,22 +50,13 @@
 .Ft int
 .Fn setenv "const char *name" "const char *value" "int overwrite"
 .Ft int
-.Fn putenv "const char *string"
-.Ft void
+.Fn putenv "char *string"
+.Ft int
 .Fn unsetenv "const char *name"
 .Sh DESCRIPTION
 These functions set, unset and fetch environment variables from the
 host
 .Em environment list .
-For compatibility with differing environment conventions,
-the given arguments
-.Fa name
-and
-.Fa value
-may be appended and prepended,
-respectively,
-with an equal sign
-.Dq Li \&= .
 .Pp
 The
 .Fn getenv
@@ -97,11 +88,18 @@ to the given
 .Pp
 The
 .Fn putenv
-function takes an argument of the form ``name=value'' and is
-equivalent to:
-.Bd -literal -offset indent
-setenv(name, value, 1);
-.Ed
+function takes an argument of the form ``name=value'' and
+puts it directly into the current environment,
+so altering the argument shall change the environment.
+If the variable
+.Fa name
+does not exist in the list,
+it is inserted with the given
+.Fa value .
+If the variable
+.Fa name
+does exist, it is reset to the given
+.Fa value .
 .Pp
 The
 .Fn unsetenv
@@ -121,15 +119,55 @@ is not in the current environment,
 .Dv NULL
 is returned.
 .Pp
-.Rv -std setenv putenv
+.Rv -std setenv putenv unsetenv
 .Sh ERRORS
 .Bl -tag -width Er
-.It Bq Er ENOMEM
+.It Bq Er EINVAL
 The function
+.Fn getenv ,
 .Fn setenv
 or
+.Fn unsetenv
+failed because the
+.Fa name
+is a
+.Dv NULL
+pointer, points to an empty string, or points to a string containing an
+.Dq Li \&=
+character.
+.Pp
+The function
+.Fn putenv
+failed because
+.Fa string
+is a
+.Dv NULL
+pointer,
+.Fa string is without an
+.Dq Li \&=
+character or
+.Dq Li \&=
+is the first character in
+.Fa string .
+This does not follow the
+.Tn POSIX
+specification.
+.It Bq Er ENOMEM
+The function
+.Fn setenv ,
+.Fn unsetenv
+or
 .Fn putenv
 failed because they were unable to allocate memory for the environment.
+.It Bq Er EFAULT
+The functions
+.Fn setenv ,
+.Fn unsetenv
+or
+.Fn putenv
+failed to make a valid copy of the environment due to the environment being
+corrupt (i.e., a name without a value).  A warning will be output to stderr with
+information about the issue.
 .El
 .Sh SEE ALSO
 .Xr csh 1 ,
@@ -141,6 +179,13 @@ The
 .Fn getenv
 function conforms to
 .St -isoC .
+The
+.Fn setenv ,
+.Fn putenv
+and
+.Fn unsetenv
+functions conforms to
+.St -p1003.1-2001 .
 .Sh HISTORY
 The functions
 .Fn setenv
@@ -152,19 +197,30 @@ The
 .Fn putenv
 function appeared in
 .Bx 4.3 Reno .
+.Pp
+Until
+.Fx 7.0 ,
+.Fn putenv
+would make a copy of 
+.Fa string
+and insert it into the environment using
+.Fn setenv .
+This was changed to use
+.Fa string
+as the memory location of the ``name=value'' pair to follow the
+.Tn POSIX
+specification.
 .Sh BUGS
 Successive calls to
 .Fn setenv
-or
-.Fn putenv
-assigning a differently sized
+that assign a larger-sized
 .Fa value
-to the same
+than any previous value to the same
 .Fa name
 will result in a memory leak.
 The
 .Fx
-semantics for these functions
+semantics for this function
 (namely, that the contents of
 .Fa value
 are copied and that old values remain accessible indefinitely) make this