Update to sudo 1.6.9p1. Note that the environment handling in sudo

1.6.9 has changed relative to older versions.  Sudo now starts
commands with a minimal environment containing the variables in the
env_keep and env_check lists.  This behavior is configurable in the
sudoers file.  Please see the "SECURITY NOTES" section in the sudo
manual.

1 files changed, 400 insertions, 280 deletions

diff --git a/usr.bin/sudo/visudo.c b/usr.bin/sudo/visudo.c
index 5d500065a2c..f8fbea7445a 100644
--- a/usr.bin/sudo/visudo.c
+++ b/usr.bin/sudo/visudo.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1996, 1998-2004 Todd C. Miller <Todd.Miller@courtesan.com>
+ * Copyright (c) 1996, 1998-2005 Todd C. Miller <Todd.Miller@courtesan.com>
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -28,7 +28,7 @@
 # include <floss.h>
 #endif
 
-#include "config.h"
+#include <config.h>
 
 #include <sys/types.h>
 #include <sys/param.h>
@@ -64,27 +64,47 @@
 #endif /* HAVE_ERR_H */
 #include <ctype.h>
 #include <pwd.h>
-#include <time.h>
+#if TIME_WITH_SYS_TIME
+# include <time.h>
+#endif
 #include <signal.h>
 #include <errno.h>
 #include <fcntl.h>
+#ifndef HAVE_TIMESPEC
+# include <emul/timespec.h>
+#endif
 
 #include "sudo.h"
 #include "version.h"
 
 #ifndef lint
-static const char rcsid[] = "$Sudo: visudo.c,v 1.170 2004/09/08 15:48:23 millert Exp $";
+__unused static const char rcsid[] = "$Sudo: visudo.c,v 1.166.2.9 2007/07/22 19:21:01 millert Exp $";
 #endif /* lint */
 
+struct sudoersfile {
+    char *path;
+    char *tpath;
+    int fd;
+    off_t orig_size;
+    struct timespec orig_mtim;
+};
+
 /*
  * Function prototypes
  */
-static void usage		__P((void));
+static void usage		__P((void)) __attribute__((__noreturn__));
 static char whatnow		__P((void));
 static RETSIGTYPE Exit		__P((int));
+static void edit_sudoers	__P((struct sudoersfile *, char *, char *, int));
+static void visudo		__P((struct sudoersfile *, char *, char *));
 static void setup_signals	__P((void));
+static void install_sudoers	__P((struct sudoersfile *));
+static int check_syntax		__P(());
 static int run_command		__P((char *, char **));
-static int check_syntax		__P((int));
+static char *get_args		__P((char *));
+static char *get_editor		__P((char **));
+static FILE *open_sudoers	__P((struct sudoersfile *));
+
 int command_matches		__P((char *, char *));
 int addr_matches		__P((char *));
 int hostname_matches		__P((char *, char *, char *));
@@ -98,7 +118,7 @@ void yyrestart			__P((FILE *));
 /*
  * External globals exported by the parser
  */
-extern FILE *yyin, *yyout;
+extern FILE *yyin;
 extern int errorlineno;
 extern int pedantic;
 extern int quiet;
@@ -111,30 +131,22 @@ extern int optind;
  * Globals
  */
 char **Argv;
-char *sudoers = _PATH_SUDOERS;
-char *stmp = _PATH_SUDOERS_TMP;
 struct sudo_user sudo_user;
 int Argc, parse_error = FALSE;
+static struct sudoersfile sudoers;
 
 int
 main(argc, argv)
     int argc;
     char **argv;
 {
-    char buf[PATH_MAX*2];		/* buffer used for copying files */
-    char *Editor;			/* editor to use */
-    char *UserEditor;			/* editor user wants to use */
-    char *EditorPath;			/* colon-separated list of editors */
-    char *av[4];			/* argument vector for run_command */
-    int checkonly;			/* only check existing file? */
-    int sudoers_fd;			/* sudoers file descriptor */
-    int stmp_fd;			/* stmp file descriptor */
-    int n;				/* length parameter */
-    int ch;				/* getopt char */
-    struct timespec ts1, ts2;		/* time before and after edit */
-    struct timespec sudoers_mtim;	/* starting mtime of sudoers file */
-    off_t sudoers_size;			/* starting size of sudoers file */
-    struct stat sb;			/* stat buffer */
+    char *args, *editor;
+    int ch, checkonly, n;
+
+    /* Initialize sudoers struct. */
+    sudoers.path = _PATH_SUDOERS;
+    sudoers.tpath = _PATH_SUDOERS_TMP;
+    sudoers.fd = -1;
 
     /* Warn about aliases that are used before being defined. */
     pedantic = 1;
@@ -155,9 +167,9 @@ main(argc, argv)
 	    case 'c':
 		checkonly++;		/* check mode */
 		break;
-	    case 'f':
-		sudoers = optarg;	/* sudoers file path */
-		easprintf(&stmp, "%s.tmp", optarg);
+	    case 'f':			/* sudoers file path */
+		sudoers.path = optarg;
+		easprintf(&sudoers.tpath, "%s.tmp", optarg);
 		break;
 	    case 's':
 		pedantic++;		/* strict mode */
@@ -183,317 +195,242 @@ main(argc, argv)
     init_defaults();
 
     if (checkonly)
-	exit(check_syntax(quiet));
+	exit(check_syntax());
 
     /*
-     * Open sudoers, lock it and stat it.
-     * sudoers_fd must remain open throughout in order to hold the lock.
-     */
-    sudoers_fd = open(sudoers, O_RDWR | O_CREAT, SUDOERS_MODE);
-    if (sudoers_fd == -1)
-	err(1, "%s", sudoers);
-    if (!lock_file(sudoers_fd, SUDO_TLOCK))
-	errx(1, "sudoers file busy, try again later");
-#ifdef HAVE_FSTAT
-    if (fstat(sudoers_fd, &sb) == -1)
-#else
-    if (stat(sudoers, &sb) == -1)
-#endif
-	err(1, "can't stat %s", sudoers);
-    sudoers_size = sb.st_size;
-    sudoers_mtim.tv_sec = mtim_getsec(sb);
-    sudoers_mtim.tv_nsec = mtim_getnsec(sb);
+     * Open and parse the existing sudoers file(s) in quiet mode to highlight
+     * any existing errors and to pull in editor and env_editor conf values.
+     */  
+    if ((yyin = open_sudoers(&sudoers)) == NULL)
+	err(1, "%s", sudoers.path);
+    n = quiet;
+    quiet = 1;
+    init_parser();
+    yyparse();
+    parse_error = FALSE;
+    quiet = n;
 
-    /*
-     * Open sudoers temp file.
-     */
-    stmp_fd = open(stmp, O_WRONLY | O_CREAT | O_TRUNC, 0600);
-    if (stmp_fd < 0)
-	err(1, "%s", stmp);
+    /* Edit sudoers, check for parse errors and re-edit on failure. */
+    editor = get_editor(&args);
+    visudo(&sudoers, editor, args);
 
-    /* Install signal handlers to clean up stmp if we are killed. */
-    setup_signals();
+    /* Install the new sudoers file. */
+    install_sudoers(&sudoers);
 
-    /* Copy sudoers -> stmp and reset the mtime */
-    if (sudoers_size) {
-	while ((n = read(sudoers_fd, buf, sizeof(buf))) > 0)
-	    if (write(stmp_fd, buf, n) != n)
-		err(1, "write error");
+    exit(0);
+}
 
-	/* Add missing newline at EOF if needed. */
-	if (n > 0 && buf[n - 1] != '\n') {
-	    buf[0] = '\n';
-	    write(stmp_fd, buf, 1);
-	}
+/*
+ * Edit the sudoers file.
+ * Returns TRUE on success, else FALSE.
+ */
+static void
+edit_sudoers(sp, editor, args, lineno)
+    struct sudoersfile *sp;
+    char *editor, *args;
+    int lineno;
+{
+    int ac;				/* argument count */
+    char **av;				/* argument vector for run_command */
+    char *cp;				/* scratch char pointer */
+    char linestr[64];			/* string version of lineno */
+    struct timespec ts1, ts2;		/* time before and after edit */
+    struct stat sb;			/* stat buffer */
 
-	(void) touch(stmp_fd, stmp, &sudoers_mtim);
-	(void) close(stmp_fd);
-
-	/* Parse sudoers to pull in editor and env_editor conf values. */
-	if ((yyin = fopen(stmp, "r"))) {
-	    yyout = stdout;
-	    n = quiet;
-	    quiet = 1;
-	    init_parser();
-	    yyparse();
-	    parse_error = FALSE;
-	    quiet = n;
-	    fclose(yyin);
-	}
-    } else
-	(void) close(stmp_fd);
+    /* Make timestamp on temp file match original. */
+    (void) touch(-1, sp->tpath, &sp->orig_mtim);
+
+    /* Find the length of the argument vector */
+    ac = 3 + (lineno > 0);
+    if (args) {
+        int wasblank;
+
+        ac++;
+        for (wasblank = FALSE, cp = args; *cp; cp++) {
+            if (isblank((unsigned char) *cp))
+                wasblank = TRUE;
+            else if (wasblank) {
+                wasblank = FALSE;
+                ac++;
+            }
+        }
+    }
 
-    /*
-     * Check VISUAL and EDITOR environment variables to see which editor
-     * the user wants to use (we may not end up using it though).
-     * If the path is not fully-qualified, make it so and check that
-     * the specified executable actually exists.
-     */
-    if ((UserEditor = getenv("VISUAL")) == NULL || *UserEditor == '\0')
-	UserEditor = getenv("EDITOR");
-    if (UserEditor && *UserEditor == '\0')
-	UserEditor = NULL;
-    else if (UserEditor) {
-	if (find_path(UserEditor, &Editor, NULL, getenv("PATH")) == FOUND) {
-	    UserEditor = Editor;
-	} else {
-	    if (def_env_editor) {
-		/* If we are honoring $EDITOR this is a fatal error. */
-		warnx("specified editor (%s) doesn't exist!", UserEditor);
-		Exit(-1);
-	    } else {
-		/* Otherwise, just ignore $EDITOR. */
-		UserEditor = NULL;
-	    }
-	}
+    /* Build up argument vector for the command */
+    av = emalloc2(ac, sizeof(char *));
+    if ((av[0] = strrchr(editor, '/')) != NULL)
+	av[0]++;
+    else
+	av[0] = editor;
+    ac = 1;
+    if (lineno > 0) {
+	(void) snprintf(linestr, sizeof(linestr), "+%d", lineno);
+	av[ac++] = linestr;
     }
+    if (args) {
+	for ((cp = strtok(args, " \t")); cp; (cp = strtok(NULL, " \t")))
+	    av[ac++] = cp;
+    }
+    av[ac++] = sp->tpath;
+    av[ac++] = NULL;
 
     /*
-     * See if we can use the user's choice of editors either because
-     * we allow any $EDITOR or because $EDITOR is in the allowable list.
+     * Do the edit:
+     *  We cannot check the editor's exit value against 0 since
+     *  XPG4 specifies that vi's exit value is a function of the
+     *  number of errors during editing (?!?!).
      */
-    Editor = EditorPath = NULL;
-    if (def_env_editor && UserEditor)
-	Editor = UserEditor;
-    else if (UserEditor) {
-	struct stat editor_sb;
-	struct stat user_editor_sb;
-	char *base, *userbase;
-
-	if (stat(UserEditor, &user_editor_sb) != 0) {
-	    /* Should never happen since we already checked above. */
-	    warn("unable to stat editor (%s)", UserEditor);
+    gettime(&ts1);
+    if (run_command(editor, av) != -1) {
+	gettime(&ts2);
+	/*
+	 * Sanity checks.
+	 */
+	if (stat(sp->tpath, &sb) < 0) {
+	    warnx("cannot stat temporary file (%s), %s unchanged",
+		sp->tpath, sp->path);
 	    Exit(-1);
 	}
-	EditorPath = estrdup(def_editor);
-	Editor = strtok(EditorPath, ":");
-	do {
-	    /*
-	     * Both Editor and UserEditor should be fully qualified but
-	     * check anyway...
-	     */
-	    if ((base = strrchr(Editor, '/')) == NULL)
-		continue;
-	    if ((userbase = strrchr(UserEditor, '/')) == NULL) {
-		Editor = NULL;
-		break;
-	    }
-	    base++, userbase++;
-
-	    /*
-	     * We compare the basenames first and then use stat to match
-	     * for sure.
-	     */
-	    if (strcmp(base, userbase) == 0) {
-		if (stat(Editor, &editor_sb) == 0 && S_ISREG(editor_sb.st_mode)
-		    && (editor_sb.st_mode & 0000111) &&
-		    editor_sb.st_dev == user_editor_sb.st_dev &&
-		    editor_sb.st_ino == user_editor_sb.st_ino)
-		    break;
-	    }
-	} while ((Editor = strtok(NULL, ":")));
+	if (sb.st_size == 0) {
+	    warnx("zero length temporary file (%s), %s unchanged",
+		sp->tpath, sp->path);
+	    Exit(-1);
+	}
+    } else {
+	warnx("editor (%s) failed, %s unchanged", editor, sp->path);
+	Exit(-1);
     }
 
-    /*
-     * Can't use $EDITOR, try each element of def_editor until we
-     * find one that exists, is regular, and is executable.
-     */
-    if (Editor == NULL || *Editor == '\0') {
-	if (EditorPath != NULL)
-	    free(EditorPath);
-	EditorPath = estrdup(def_editor);
-	Editor = strtok(EditorPath, ":");
-	do {
-	    if (sudo_goodpath(Editor, NULL))
-		break;
-	} while ((Editor = strtok(NULL, ":")));
-
-	/* Bleah, none of the editors existed! */
-	if (Editor == NULL || *Editor == '\0') {
-	    warnx("no editor found (editor path = %s)", def_editor);
-	    Exit(-1);
+    /* Check to see if the user changed the file. */
+    if (sp->orig_size == sb.st_size &&
+	sp->orig_mtim.tv_sec == mtim_getsec(sb) &&
+	sp->orig_mtim.tv_nsec == mtim_getnsec(sb)) {
+	/*
+	 * If mtime and size match but the user spent no measurable
+	 * time in the editor we can't tell if the file was changed.
+	 */
+#ifdef HAVE_TIMESPECSUB2
+	timespecsub(&ts1, &ts2);
+#else
+	timespecsub(&ts1, &ts2, &ts2);
+#endif
+	if (timespecisset(&ts2)) {
+	    warnx("%s unchanged", sp->tpath);
+	    Exit(0);
 	}
     }
+}
+
+/*
+ * Parse sudoers after editing and re-edit any ones that caused a parse error.
+ * Returns TRUE on success, else FALSE.
+ */
+static void
+visudo(sp, editor, args)
+    struct sudoersfile *sp;
+    char *editor, *args;
+{
+    int ch;
 
     /*
-     * Edit the temp file and parse it (for sanity checking)
+     * Parse the edited sudoers file and do sanity checking
      */
     do {
-	char linestr[64];
+	edit_sudoers(sp, editor, args, errorlineno);
 
-	/* Build up argument vector for the command */
-	if ((av[0] = strrchr(Editor, '/')) != NULL)
-	    av[0]++;
-	else
-	    av[0] = Editor;
-	n = 1;
-	if (parse_error == TRUE) {
-	    (void) snprintf(linestr, sizeof(linestr), "+%d", errorlineno);
-	    av[n++] = linestr;
+	yyin = fopen(sp->tpath, "r+");
+	if (yyin == NULL) {
+	    warnx("can't re-open temporary file (%s), %s unchanged.",
+		sp->tpath, sp->path);
+	    Exit(-1);
 	}
-	av[n++] = stmp;
-	av[n++] = NULL;
-
-	/*
-	 * Do the edit:
-	 *  We cannot check the editor's exit value against 0 since
-	 *  XPG4 specifies that vi's exit value is a function of the
-	 *  number of errors during editing (?!?!).
-	 */
-	gettime(&ts1);
-	if (run_command(Editor, av) != -1) {
-	    gettime(&ts2);
-	    /*
-	     * Sanity checks.
-	     */
-	    if (stat(stmp, &sb) < 0) {
-		warnx("cannot stat temporary file (%s), %s unchanged",
-		    stmp, sudoers);
-		Exit(-1);
-	    }
-	    if (sb.st_size == 0) {
-		warnx("zero length temporary file (%s), %s unchanged",
-		    stmp, sudoers);
-		Exit(-1);
-	    }
-
-	    /*
-	     * Passed sanity checks so reopen stmp file and check
-	     * for parse errors.
-	     */
-	    yyout = stdout;
-	    yyin = fopen(stmp, "r+");
-	    if (yyin == NULL) {
-		warnx("can't re-open temporary file (%s), %s unchanged.",
-		    stmp, sudoers);
-		Exit(-1);
-	    }
 
-	    /* Add missing newline at EOF if needed. */
-	    if (fseek(yyin, -1, SEEK_END) == 0 && (ch = fgetc(yyin)) != '\n')
-		fputc('\n', yyin);
-	    rewind(yyin);
-
-	    /* Clean slate for each parse */
-	    user_runas = NULL;
-	    init_defaults();
-	    init_parser();
-
-	    /* Parse the sudoers temp file */
-	    yyrestart(yyin);
-	    if (yyparse() && parse_error != TRUE) {
-		warnx("unabled to parse temporary file (%s), unknown error",
-		    stmp);
-		parse_error = TRUE;
-	    }
-	    fclose(yyin);
-	} else {
-	    warnx("editor (%s) failed, %s unchanged", Editor, sudoers);
-	    Exit(-1);
+	/* Add missing newline at EOF if needed. */
+	if (fseek(yyin, -1, SEEK_END) == 0 && (ch = fgetc(yyin)) != '\n')
+	    fputc('\n', yyin);
+	rewind(yyin);
+
+	/* Clean slate for each parse */
+	user_runas = NULL;
+	init_defaults();
+	init_parser();
+
+	/* Parse the sudoers temp file */
+	yyrestart(yyin);
+	if (yyparse() && parse_error != TRUE) {
+	    warnx("unabled to parse temporary file (%s), unknown error",
+		sp->tpath);
+	    parse_error = TRUE;
 	}
+	fclose(yyin);
 
 	/*
 	 * Got an error, prompt the user for what to do now
 	 */
-	if (parse_error == TRUE) {
+	if (parse_error) {
 	    switch (whatnow()) {
 		case 'Q' :	parse_error = FALSE;	/* ignore parse error */
 				break;
-		case 'x' :	if (sudoers_size == 0)
-				    unlink(sudoers);
-				Exit(0);
+		case 'x' :	Exit(0);
 				break;
 	    }
 	}
-    } while (parse_error == TRUE);
-
-    /*
-     * If the user didn't change the temp file, just unlink it.
-     */
-    if (sudoers_size == sb.st_size &&
-	sudoers_mtim.tv_sec == mtim_getsec(sb) &&
-	sudoers_mtim.tv_nsec == mtim_getnsec(sb)) {
-	/*
-	 * If mtime and size match but the user spent no measurable
-	 * time in the editor we can't tell if the file was changed.
-	 */
-#ifdef HAVE_TIMESPECSUB2
-	timespecsub(&ts1, &ts2);
-#else
-	timespecsub(&ts1, &ts2, &ts2);
-#endif
-	if (timespecisset(&ts2)) {
-	    warnx("sudoers file unchanged");
-	    Exit(0);
-	}
-    }
+    } while (parse_error);
+}
 
+/*
+ * Set the owner and mode on a sudoers temp file and
+ * move it into place.  Returns TRUE on success, else FALSE.
+ */
+static void
+install_sudoers(sp)
+    struct sudoersfile *sp;
+{
     /*
      * Change mode and ownership of temp file so when
-     * we move it to sudoers things are kosher.
+     * we move it to sp->path things are kosher.
      */
-    if (chown(stmp, SUDOERS_UID, SUDOERS_GID)) {
+    if (chown(sp->tpath, SUDOERS_UID, SUDOERS_GID) != 0) {
 	warn("unable to set (uid, gid) of %s to (%d, %d)",
-	    stmp, SUDOERS_UID, SUDOERS_GID);
+	    sp->tpath, SUDOERS_UID, SUDOERS_GID);
 	Exit(-1);
     }
-    if (chmod(stmp, SUDOERS_MODE)) {
-	warn("unable to change mode of %s to 0%o", stmp, SUDOERS_MODE);
+    if (chmod(sp->tpath, SUDOERS_MODE) != 0) {
+	warn("unable to change mode of %s to 0%o", sp->tpath, SUDOERS_MODE);
 	Exit(-1);
     }
 
     /*
-     * Now that we have a sane stmp file (parses ok) it needs to be
-     * rename(2)'d to sudoers.  If the rename(2) fails we try using
-     * mv(1) in case stmp and sudoers are on different file systems.
+     * Now that sp->tpath is sane (parses ok) it needs to be
+     * rename(2)'d to sp->path.  If the rename(2) fails we try using
+     * mv(1) in case sp->tpath and sp->path are on different file systems.
      */
-    if (rename(stmp, sudoers)) {
+    if (rename(sp->tpath, sp->path) != 0) {
 	if (errno == EXDEV) {
+	    char *av[4];
 	    warnx("%s and %s not on the same file system, using mv to rename",
-	      stmp, sudoers);
+	      sp->tpath, sp->path);
 
 	    /* Build up argument vector for the command */
 	    if ((av[0] = strrchr(_PATH_MV, '/')) != NULL)
 		av[0]++;
 	    else
 		av[0] = _PATH_MV;
-	    av[1] = stmp;
-	    av[2] = sudoers;
+	    av[1] = sp->tpath;
+	    av[2] = sp->path;
 	    av[3] = NULL;
 
 	    /* And run it... */
 	    if (run_command(_PATH_MV, av)) {
 		warnx("command failed: '%s %s %s', %s unchanged",
-		    _PATH_MV, stmp, sudoers, sudoers);
+		    _PATH_MV, sp->tpath, sp->path, sp->path);
 		Exit(-1);
 	    }
 	} else {
-	    warn("error renaming %s, %s unchanged", stmp, sudoers);
+	    warn("error renaming %s, %s unchanged", sp->tpath, sp->path);
 	    Exit(-1);
 	}
     }
-
-    exit(0);
 }
 
 /*
@@ -651,6 +588,8 @@ run_command(path, argv)
 	    break;	/* NOTREACHED */
 	case 0:
 	    (void) sigprocmask(SIG_SETMASK, &oset, NULL);
+	    endpwent();
+	    closefrom(STDERR_FILENO + 1);
 	    execv(path, argv);
 	    warn("unable to run %s", path);
 	    _exit(127);
@@ -671,33 +610,214 @@ run_command(path, argv)
 }
 
 static int
-check_syntax(quiet)
-    int quiet;
+check_syntax()
 {
 
-    if ((yyin = fopen(sudoers, "r")) == NULL) {
+    if ((yyin = fopen(sudoers.path, "r")) == NULL) {
 	if (!quiet)
-	    warn("unable to open %s", sudoers);
+	    warn("unable to open %s", sudoers.path);
 	exit(1);
     }
-    yyout = stdout;
     init_parser();
     if (yyparse() && parse_error != TRUE) {
 	if (!quiet)
-	    warnx("failed to parse %s file, unknown error", sudoers);
+	    warnx("failed to parse %s file, unknown error", sudoers.path);
 	parse_error = TRUE;
     }
     if (!quiet){
 	if (parse_error)
-	    (void) printf("parse error in %s near line %d\n", sudoers,
+	    (void) printf("parse error in %s near line %d\n", sudoers.path,
 		errorlineno);
 	else
-	    (void) printf("%s file parsed OK\n", sudoers);
+	    (void) printf("%s file parsed OK\n", sudoers.path);
     }
 
     return(parse_error == TRUE);
 }
 
+static FILE *
+open_sudoers(sp)
+    struct sudoersfile *sp;
+{
+    struct stat sb;
+    ssize_t nread;
+    FILE *fp;
+    char buf[PATH_MAX*2];
+    int tfd;
+
+    /* Open and lock sudoers. */
+    sp->fd = open(sp->path, O_RDWR | O_CREAT, SUDOERS_MODE);
+    if (sp->fd == -1)
+	err(1, "%s", sp->path);
+    if (!lock_file(sp->fd, SUDO_TLOCK))
+	errx(1, "%s busy, try again later", sp->path);
+    if ((fp = fdopen(sp->fd, "r")) == NULL)
+	err(1, "%s", sp->path);
+
+    /* Stash sudoers size and mtime. */
+#ifdef HAVE_FSTAT
+    if (fstat(sp->fd, &sb) == -1)
+#else
+    if (stat(sp->path, &sb) == -1)
+#endif
+	err(1, "can't stat %s", sp->path);
+    sp->orig_size = sb.st_size;
+    sp->orig_mtim.tv_sec = mtim_getsec(sb);
+    sp->orig_mtim.tv_nsec = mtim_getnsec(sb);
+
+    /* Create the temp file. */
+    tfd = open(sp->tpath, O_WRONLY | O_CREAT | O_TRUNC, 0600);
+    if (tfd < 0)
+	err(1, "%s", sp->tpath);
+
+    /* Install signal handlers to clean up temp file if we are killed. */
+    setup_signals();
+
+    /* Copy sp->path -> sp->tpath. */
+    if (sp->orig_size != 0) {
+	while ((nread = read(sp->fd, buf, sizeof(buf))) > 0)
+	    if (write(tfd, buf, nread) != nread) {
+		warn("write error");
+		Exit(-1);
+	    }
+
+	/* Add missing newline at EOF if needed. */
+	if (nread > 0 && buf[nread - 1] != '\n') {
+	    buf[0] = '\n';
+	    write(tfd, buf, 1);
+	}
+    }
+    (void) close(tfd);
+    rewind(fp);
+
+    return(fp);
+}
+
+static char *
+get_editor(args)
+    char **args;
+{
+    char *Editor, *EditorArgs, *EditorPath, *UserEditor, *UserEditorArgs;
+
+    /*
+     * Check VISUAL and EDITOR environment variables to see which editor
+     * the user wants to use (we may not end up using it though).
+     * If the path is not fully-qualified, make it so and check that
+     * the specified executable actually exists.
+     */
+    UserEditorArgs = NULL;
+    if ((UserEditor = getenv("VISUAL")) == NULL || *UserEditor == '\0')
+	UserEditor = getenv("EDITOR");
+    if (UserEditor && *UserEditor == '\0')
+	UserEditor = NULL;
+    else if (UserEditor) {
+	UserEditorArgs = get_args(UserEditor);
+	if (find_path(UserEditor, &Editor, NULL, getenv("PATH")) == FOUND) {
+	    UserEditor = Editor;
+	} else {
+	    if (def_env_editor) {
+		/* If we are honoring $EDITOR this is a fatal error. */
+		warnx("specified editor (%s) doesn't exist!", UserEditor);
+		Exit(-1);
+	    } else {
+		/* Otherwise, just ignore $EDITOR. */
+		UserEditor = NULL;
+	    }
+	}
+    }
+
+    /*
+     * See if we can use the user's choice of editors either because
+     * we allow any $EDITOR or because $EDITOR is in the allowable list.
+     */
+    Editor = EditorArgs = EditorPath = NULL;
+    if (def_env_editor && UserEditor) {
+	Editor = UserEditor;
+	EditorArgs = UserEditorArgs;
+    } else if (UserEditor) {
+	struct stat editor_sb;
+	struct stat user_editor_sb;
+	char *base, *userbase;
+
+	if (stat(UserEditor, &user_editor_sb) != 0) {
+	    /* Should never happen since we already checked above. */
+	    warn("unable to stat editor (%s)", UserEditor);
+	    Exit(-1);
+	}
+	EditorPath = estrdup(def_editor);
+	Editor = strtok(EditorPath, ":");
+	do {
+	    EditorArgs = get_args(Editor);
+	    /*
+	     * Both Editor and UserEditor should be fully qualified but
+	     * check anyway...
+	     */
+	    if ((base = strrchr(Editor, '/')) == NULL)
+		continue;
+	    if ((userbase = strrchr(UserEditor, '/')) == NULL) {
+		Editor = NULL;
+		break;
+	    }
+	    base++, userbase++;
+
+	    /*
+	     * We compare the basenames first and then use stat to match
+	     * for sure.
+	     */
+	    if (strcmp(base, userbase) == 0) {
+		if (stat(Editor, &editor_sb) == 0 && S_ISREG(editor_sb.st_mode)
+		    && (editor_sb.st_mode & 0000111) &&
+		    editor_sb.st_dev == user_editor_sb.st_dev &&
+		    editor_sb.st_ino == user_editor_sb.st_ino)
+		    break;
+	    }
+	} while ((Editor = strtok(NULL, ":")));
+    }
+
+    /*
+     * Can't use $EDITOR, try each element of def_editor until we
+     * find one that exists, is regular, and is executable.
+     */
+    if (Editor == NULL || *Editor == '\0') {
+	efree(EditorPath);
+	EditorPath = estrdup(def_editor);
+	Editor = strtok(EditorPath, ":");
+	do {
+	    EditorArgs = get_args(Editor);
+	    if (sudo_goodpath(Editor, NULL))
+		break;
+	} while ((Editor = strtok(NULL, ":")));
+
+	/* Bleah, none of the editors existed! */
+	if (Editor == NULL || *Editor == '\0') {
+	    warnx("no editor found (editor path = %s)", def_editor);
+	    Exit(-1);
+	}
+    }
+    *args = EditorArgs;
+    return(Editor);
+}
+
+/*
+ * Split out any command line arguments and return them.
+ */
+static char *
+get_args(cmnd)
+    char *cmnd;
+{
+    char *args;
+
+    args = cmnd;
+    while (*args && !isblank((unsigned char) *args))
+	args++;
+    if (*args) {
+	*args++ = '\0';
+	while (*args && isblank((unsigned char) *args))
+	    args++;
+    }
+    return(*args ? args : NULL);
+}
+
 /*
  * Unlink the sudoers temp file (if it exists) and exit.
  * Used in place of a normal exit() and as a signal handler.
@@ -709,7 +829,7 @@ Exit(sig)
 {
 #define	emsg	 " exiting due to signal.\n"
 
-    (void) unlink(stmp);
+    (void) unlink(sudoers.tpath);
 
     if (sig > 0) {
 	write(STDERR_FILENO, getprogname(), strlen(getprogname()));
@@ -722,7 +842,7 @@ Exit(sig)
 static void
 usage()
 {
-    (void) fprintf(stderr, "usage: %s [-c] [-f sudoers] [-q] [-s] [-V]\n",
+    (void) fprintf(stderr, "usage: %s [-c] [-q] [-s] [-V] [-f sudoers]\n",
 	getprogname());
     exit(1);
 }