Added environ-replacement detection. For programs that "clean" (i.e., su)

or replace (i.e., zdump) the environment after a call to setenv(), putenv()
or unsetenv() has been made, a few changes were made.
  - getenv() will return the value from the new environ array.
  - setenv() was split into two functions:  __setenv() which is most of the
    previous setenv() without checks on the name and setenv() which
    contains the checks before calling __setenv().
  - setenv(), putenv() and unsetenv() will unset all previous values and
    call __setenv() on all entries in the new environ array which in turn
    adds them to the end of the envVars array.  Calling __setenv() instead
    of setenv() is done to avoid the temporary replacement of the '=' in a
    string with a NUL byte.  Some strings may be read-only data.

Added more regression checks for clearing the environment array.

Replaced gettimeofday() with getrusage() in timing regression check for
better accuracy.

Fixed an off-by-one bug in __remove_putenv() in the use of memmove().  This
went unnoticed due to the allocation of double the number of environ
entries when building envVars.

Fixed a few spelling mistakes in the comments.

Reviewed by:	ache
Approved by:	wes
Approved by:	re (kensmith)

3 files changed, 70 insertions, 34 deletions

diff --git a/tools/regression/environ/envctl.c b/tools/regression/environ/envctl.c
index 2681741..e077e42 100644
--- a/tools/regression/environ/envctl.c
+++ b/tools/regression/environ/envctl.c
@@ -54,17 +54,19 @@ dump_environ(void)
 static void
 usage(const char *program)
 {
-	fprintf(stderr, "Usage:  %s [-DGUcht] [-gu name] [-p name=value] "
+	fprintf(stderr, "Usage:  %s [-CDGUchrt] [-gu name] [-p name=value] "
 	    "[(-S|-s name) value overwrite]\n\n"
 	    "Options:\n"
+	    "  -C\t\t\t\tClear environ variable with NULL pointer\n"
 	    "  -D\t\t\t\tDump environ\n"
 	    "  -G name\t\t\tgetenv(NULL)\n"
 	    "  -S value overwrite\t\tsetenv(NULL, value, overwrite)\n"
 	    "  -U\t\t\t\tunsetenv(NULL)\n"
-	    "  -c\t\t\t\tClear environ variable\n"
+	    "  -c\t\t\t\tClear environ variable with calloc()'d memory\n"
 	    "  -g name\t\t\tgetenv(name)\n"
 	    "  -h\t\t\t\tHelp\n"
 	    "  -p name=value\t\t\tputenv(name=value)\n"
+	    "  -r\t\t\t\treplace environ with { \"FOO=bar\", NULL }\n"
 	    "  -s name value overwrite\tsetenv(name, value, overwrite)\n"
 	    "  -t\t\t\t\tOutput is suitable for testing (no newlines)\n"
 	    "  -u name\t\t\tunsetenv(name)\n",
@@ -77,7 +79,7 @@ usage(const char *program)
 int
 main(int argc, char **argv)
 {
-	char *cleanEnv[] = { NULL };
+	char *staticEnv[] = { "FOO=bar", NULL };
 	char arg;
 	const char *eol = "\n";
 	const char *value;
@@ -87,15 +89,19 @@ main(int argc, char **argv)
 		exit(EXIT_FAILURE);
 	}
 
-	while ((arg = getopt(argc, argv, "DGS:Ucg:hp:s:tu:")) != -1) {
+	while ((arg = getopt(argc, argv, "CDGS:Ucg:hp:rs:tu:")) != -1) {
 		switch (arg) {
-			case 'D':
-				errno = 0;
-				dump_environ();
+			case 'C':
+				environ = NULL;
 				break;
 
 			case 'c':
-				environ = cleanEnv;
+				environ = calloc(1, sizeof(*environ));
+				break;
+
+			case 'D':
+				errno = 0;
+				dump_environ();
 				break;
 
 			case 'G':
@@ -113,6 +119,10 @@ main(int argc, char **argv)
 				printf("%d %d%s", putenv(optarg), errno, eol);
 				break;
 
+			case 'r':
+				environ = staticEnv;
+				break;
+
 			case 'S':
 				errno = 0;
 				printf("%d %d%s", setenv(NULL, optarg,
diff --git a/tools/regression/environ/envtest.t b/tools/regression/environ/envtest.t
index e3aca95..2b2c548 100644
--- a/tools/regression/environ/envtest.t
+++ b/tools/regression/environ/envtest.t
@@ -132,6 +132,9 @@ run_test -s FOO ${NEWBAR} 1 -s FOO ${BAR} 1 -s FOO ${NEWBAR} 1 -s FOO ${BAR} 1\
 	-g FOO
 check_result "0 0 0 0 0 0 0 0 ${BAR}"
 
+run_test -c -s FOO ${BAR} 1 -g FOO -c -s FOO ${NEWBAR} 1 -g FOO
+check_result "0 0 ${BAR} 0 0 ${NEWBAR}"
+
 
 # Unsets.
 run_test -u FOO -g FOO
@@ -152,6 +155,10 @@ check_result "-1 22"
 run_test -c -s FOO ${NEWBAR} 1 -g FOO -u FOO -g FOO
 check_result "0 0 ${NEWBAR} 0 0"
 
+run_test -c -u FOO -s FOO ${BAR} 1 -g FOO -u FOO -g FOO -c -u FOO\
+	-s FOO ${NEWBAR} 1 -g FOO
+check_result "0 0 0 0 ${BAR} 0 0  0 0 0 0 ${NEWBAR}"
+
 
 # Puts.
 run_test -p FOO=${NEWBAR} -g FOO
@@ -180,3 +187,17 @@ check_result "0 0 0 0 0 0"
 
 run_test -s FOO ${NEWBAR} 1 -p FOO=${BAR} -u FOO
 check_result "0 0 0 0 0 0"
+
+run_test -s FOO ${NEWBAR} 1 -p FOO=${BAR} -c -g FOO -p FOO=${NEWBAR} -g FOO
+check_result "0 0 0 0  0 0 ${NEWBAR}"
+
+run_test -c -p FOO=${BAR} -g FOO -c -p FOO=${NEWBAR} -g FOO
+check_result "0 0 ${BAR} 0 0 ${NEWBAR}"
+
+
+# environ replacements.
+run_test -r -g FOO -s FOO ${BAR} 1 -g FOO -u FOO -g FOO
+check_result "${BAR} 0 0 ${BAR} 0 0"
+
+run_test -r -g FOO -u FOO -g FOO -s FOO ${BAR} 1 -g FOO
+check_result "${BAR} 0 0  0 0 ${BAR}"
diff --git a/tools/regression/environ/timings.c b/tools/regression/environ/timings.c
index 1bf3c91..7999fa1 100644
--- a/tools/regression/environ/timings.c
+++ b/tools/regression/environ/timings.c
@@ -23,7 +23,9 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  */
+#include <sys/types.h>
 #include <sys/time.h>
+#include <sys/resource.h>
 #include <err.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -64,43 +66,44 @@ int
 main(int argc, char **argv)
 {
 	int iterations;
-	struct timeval endTime;
-	struct timeval startTime;
+	struct rusage endUsage;
+	struct rusage startUsage;
 
 	/*
 	 * getenv() on the existing environment.
 	 */
-	gettimeofday(&startTime, NULL);
+	getrusage(RUSAGE_SELF, &startUsage);
 
 	/* Iterate over setting variable. */
 	for (iterations = 0; iterations < MaxIterations; iterations++)
 		if (getenv(name) == NULL)
 			err(EXIT_FAILURE, "getenv(name)");
 
-	gettimeofday(&endTime, NULL);
+	getrusage(RUSAGE_SELF, &endUsage);
 
-	report_time("getenv(name)", &startTime, &endTime);
+	report_time("getenv(name)", &startUsage.ru_utime, &endUsage.ru_utime);
 
 
 	/*
 	 * setenv() a variable with a large value.
 	 */
-	gettimeofday(&startTime, NULL);
+	getrusage(RUSAGE_SELF, &startUsage);
 
 	/* Iterate over setting variable. */
 	for (iterations = 0; iterations < MaxIterations; iterations++)
 		if (setenv(name, value1, 1) == -1)
 			err(EXIT_FAILURE, "setenv(name, value1, 1)");
 
-	gettimeofday(&endTime, NULL);
+	getrusage(RUSAGE_SELF, &endUsage);
 
-	report_time("setenv(name, value1, 1)", &startTime, &endTime);
+	report_time("setenv(name, value1, 1)", &startUsage.ru_utime,
+	    &endUsage.ru_utime);
 
 
 	/*
 	 * getenv() the new variable on the new environment.
 	 */
-	gettimeofday(&startTime, NULL);
+	getrusage(RUSAGE_SELF, &startUsage);
 
 	/* Iterate over setting variable. */
 	for (iterations = 0; iterations < MaxIterations; iterations++)
@@ -108,15 +111,15 @@ main(int argc, char **argv)
 		if (getenv(name) == NULL)
 			err(EXIT_FAILURE, "getenv(name)");
 
-	gettimeofday(&endTime, NULL);
+	getrusage(RUSAGE_SELF, &endUsage);
 
-	report_time("getenv(name)", &startTime, &endTime);
+	report_time("getenv(name)", &startUsage.ru_utime, &endUsage.ru_utime);
 
 
 	/*
 	 * getenv() a different variable on the new environment.
 	 */
-	gettimeofday(&startTime, NULL);
+	getrusage(RUSAGE_SELF, &startUsage);
 
 	/* Iterate over setting variable. */
 	for (iterations = 0; iterations < MaxIterations; iterations++)
@@ -124,30 +127,31 @@ main(int argc, char **argv)
 		if (getenv(name2) == NULL)
 			err(EXIT_FAILURE, "getenv(name2)");
 
-	gettimeofday(&endTime, NULL);
+	getrusage(RUSAGE_SELF, &endUsage);
 
-	report_time("getenv(name2)", &startTime, &endTime);
+	report_time("getenv(name2)", &startUsage.ru_utime, &endUsage.ru_utime);
 
 
 	/*
 	 * setenv() a variable with a small value.
 	 */
-	gettimeofday(&startTime, NULL);
+	getrusage(RUSAGE_SELF, &startUsage);
 
 	/* Iterate over setting variable. */
 	for (iterations = 0; iterations < MaxIterations; iterations++)
 		if (setenv(name, value2, 1) == -1)
 			err(EXIT_FAILURE, "setenv(name, value2, 1)");
 
-	gettimeofday(&endTime, NULL);
+	getrusage(RUSAGE_SELF, &endUsage);
 
-	report_time("setenv(name, value2, 1)", &startTime, &endTime);
+	report_time("setenv(name, value2, 1)", &startUsage.ru_utime,
+	    &endUsage.ru_utime);
 
 
 	/*
 	 * getenv() a different variable on the new environment.
 	 */
-	gettimeofday(&startTime, NULL);
+	getrusage(RUSAGE_SELF, &startUsage);
 
 	/* Iterate over setting variable. */
 	for (iterations = 0; iterations < MaxIterations; iterations++)
@@ -155,15 +159,15 @@ main(int argc, char **argv)
 		if (getenv(name2) == NULL)
 			err(EXIT_FAILURE, "getenv(name)");
 
-	gettimeofday(&endTime, NULL);
+	getrusage(RUSAGE_SELF, &endUsage);
 
-	report_time("getenv(name)", &startTime, &endTime);
+	report_time("getenv(name)", &startUsage.ru_utime, &endUsage.ru_utime);
 
 
 	/*
 	 * getenv() a different variable on the new environment.
 	 */
-	gettimeofday(&startTime, NULL);
+	getrusage(RUSAGE_SELF, &startUsage);
 
 	/* Iterate over setting variable. */
 	for (iterations = 0; iterations < MaxIterations; iterations++)
@@ -171,24 +175,25 @@ main(int argc, char **argv)
 		if (getenv(name2) == NULL)
 			err(EXIT_FAILURE, "getenv(name2)");
 
-	gettimeofday(&endTime, NULL);
+	getrusage(RUSAGE_SELF, &endUsage);
 
-	report_time("getenv(name2)", &startTime, &endTime);
+	report_time("getenv(name2)", &startUsage.ru_utime, &endUsage.ru_utime);
 
 
 	/*
 	 * putenv() a variable with a small value.
 	 */
-	gettimeofday(&startTime, NULL);
+	getrusage(RUSAGE_SELF, &startUsage);
 
 	/* Iterate over setting variable. */
 	for (iterations = 0; iterations < MaxIterations; iterations++)
 		if (putenv(nameValuePair) == -1)
 			err(EXIT_FAILURE, "putenv(nameValuePair)");
 
-	gettimeofday(&endTime, NULL);
+	getrusage(RUSAGE_SELF, &endUsage);
 
-	report_time("putenv(nameValuePair)", &startTime, &endTime);
+	report_time("putenv(nameValuePair)", &startUsage.ru_utime,
+	    &endUsage.ru_utime);
 
 
 	exit(EXIT_SUCCESS);