svn commit: r328487 - head/bin/pax

[Pedro F. Giffuni]

Author: pfg
Date: Sat Jan 27 18:24:13 2018
New Revision: 328487
URL: https://svnweb.freebsd.org/changeset/base/328487

Log:
  pax(1): Honour the restrict in sigaction().
  
  Use a setup_sig() helper and make it fail when either of sigaction fails.
  
  While there, do not leak fds for "." + minor cleanup.
  
  Obtained from:	OpenBSD (through DragonFly git eca362d0f9bd086cc56d6b5bc4f03f09e040b9db)

Modified:
  head/bin/pax/pax.c

Modified: head/bin/pax/pax.c
==============================================================================
--- head/bin/pax/pax.c	Sat Jan 27 17:43:09 2018	(r328486)
+++ head/bin/pax/pax.c	Sat Jan 27 18:24:13 2018	(r328487)
@@ -109,7 +109,7 @@ char	*tempbase;		/* basename of tempfile to use for mk
 /*
  *	PAX - Portable Archive Interchange
  *
- * 	A utility to read, write, and write lists of the members of archive
+ *	A utility to read, write, and write lists of the members of archive
  *	files and copy directory hierarchies. A variety of archive formats
  *	are supported (some are described in POSIX 1003.1 10.1):
  *
@@ -237,7 +237,7 @@ main(int argc, char *argv[])
 	/*
 	 * Keep a reference to cwd, so we can always come back home.
 	 */
-	cwdfd = open(".", O_RDONLY);
+	cwdfd = open(".", O_RDONLY | O_CLOEXEC);
 	if (cwdfd < 0) {
 		syswarn(0, errno, "Can't open current working directory.");
 		return(exit_val);
@@ -249,7 +249,7 @@ main(int argc, char *argv[])
 	if ((tmpdir = getenv("TMPDIR")) == NULL || *tmpdir == '\0')
 		tmpdir = _PATH_TMP;
 	tdlen = strlen(tmpdir);
-	while(tdlen > 0 && tmpdir[tdlen - 1] == '/')
+	while (tdlen > 0 && tmpdir[tdlen - 1] == '/')
 		tdlen--;
 	tempfile = malloc(tdlen + 1 + sizeof(_TFILE_BASE));
 	if (tempfile == NULL) {
@@ -271,7 +271,7 @@ main(int argc, char *argv[])
 	/*
 	 * select a primary operation mode
 	 */
-	switch(act) {
+	switch (act) {
 	case EXTRACT:
 		extract();
 		break;
@@ -325,6 +325,25 @@ sig_cleanup(int which_sig)
 }
 
 /*
+ * setup_sig()
+ *	set a signal to be caught, but only if it isn't being ignored already
+ */
+
+static int
+setup_sig(int sig, const struct sigaction *n_hand)
+{
+	struct sigaction o_hand;
+
+	if (sigaction(sig, NULL, &o_hand) < 0)
+		return (-1);
+
+	if (o_hand.sa_handler == SIG_IGN)
+		return (0);
+
+	return (sigaction(sig, n_hand, NULL));
+}
+
+/*
  * gen_init()
  *	general setup routines. Not all are required, but they really help
  *	when dealing with a medium to large sized archives.
@@ -335,7 +354,6 @@ gen_init(void)
 {
 	struct rlimit reslimit;
 	struct sigaction n_hand;
-	struct sigaction o_hand;
 
 	/*
 	 * Really needed to handle large archives. We can run out of memory for
@@ -389,34 +407,16 @@ gen_init(void)
 	n_hand.sa_flags = 0;
 	n_hand.sa_handler = sig_cleanup;
 
-	if ((sigaction(SIGHUP, &n_hand, &o_hand) < 0) &&
-	    (o_hand.sa_handler == SIG_IGN) &&
-	    (sigaction(SIGHUP, &o_hand, &o_hand) < 0))
+	if (setup_sig(SIGHUP,  &n_hand) ||
+	   setup_sig(SIGTERM, &n_hand) ||
+	   setup_sig(SIGINT,  &n_hand) ||
+	   setup_sig(SIGQUIT, &n_hand) ||
+	   setup_sig(SIGXCPU, &n_hand))
 		goto out;
 
-	if ((sigaction(SIGTERM, &n_hand, &o_hand) < 0) &&
-	    (o_hand.sa_handler == SIG_IGN) &&
-	    (sigaction(SIGTERM, &o_hand, &o_hand) < 0))
-		goto out;
-
-	if ((sigaction(SIGINT, &n_hand, &o_hand) < 0) &&
-	    (o_hand.sa_handler == SIG_IGN) &&
-	    (sigaction(SIGINT, &o_hand, &o_hand) < 0))
-		goto out;
-
-	if ((sigaction(SIGQUIT, &n_hand, &o_hand) < 0) &&
-	    (o_hand.sa_handler == SIG_IGN) &&
-	    (sigaction(SIGQUIT, &o_hand, &o_hand) < 0))
-		goto out;
-
-	if ((sigaction(SIGXCPU, &n_hand, &o_hand) < 0) &&
-	    (o_hand.sa_handler == SIG_IGN) &&
-	    (sigaction(SIGXCPU, &o_hand, &o_hand) < 0))
-		goto out;
-
 	n_hand.sa_handler = SIG_IGN;
-	if ((sigaction(SIGPIPE, &n_hand, &o_hand) < 0) ||
-	    (sigaction(SIGXFSZ, &n_hand, &o_hand) < 0))
+	if ((sigaction(SIGPIPE, &n_hand, NULL) < 0) ||
+	    (sigaction(SIGXFSZ, &n_hand, NULL) < 0))
 		goto out;
 	return(0);