update-alternatives: add more checks on --install parameters

Check that links and alternative paths are absolute. Check that the
master alternative path exists. Forbid "/" and spaces in alternative names.
Closes: #423176
Add corresponding tests in the test-suite.

ChangeLog

@@ -1,3 +1,12 @@
+2009-02-22  Raphael Hertzog  <hertzog@debian.org>
+
+	* scripts/update-alternatives.pl: Add more sanity check for
+	--install: ensure alternative path and links are absolute, ensure
+	master alternative path exists, forbid / and spaces in alternative
+	names.
+	* scripts/t/900_update_alternatives.t: Add corresponding tests in
+	the test suite.
+
 2009-02-22  Raphael Hertzog  <hertzog@debian.org>
 
 	* scripts/update-alternatives.pl: Checks that --install does not

debian/changelog

@@ -160,6 +160,7 @@ dpkg (1.15.0) UNRELEASED; urgency=low
     - it forbids reusing master alternative as slave and vice-versa.
       Closes: #342566
     - it forbids reusing alternative links managed by other alternatives
+    - new sanity checks on --install parameters. Closes: #423176
 
   [ Pierre Habouzit ]
   * Add a --query option to update-alternatives. Closes: #336091, #441904

scripts/t/900_update_alternatives.t

@@ -53,7 +53,7 @@ my @choices = (
 );
 my $nb_slaves = 2;
 plan tests => (4 * ($nb_slaves + 1) + 2) * 18 # number of check_choices
-		+ 44;			      # rest
+		+ 49;			      # rest
 
 sub cleanup {
     system("rm -rf $srcdir/t.tmp/ua && mkdir -p $admindir && mkdir -p $altdir");
@@ -281,5 +281,21 @@ call_ua(["--install", "$bindir/slave1", "testmaster", "/bin/date", "10"],
 call_ua(["--install", "$bindir/testmaster", "testmaster", "/bin/date", "10",
 	 "--slave", "$bindir/generic-test", "testslave", "/bin/true" ],
 	expect_failure => 1, to_file => "/dev/null", error_to_file => "/dev/null");
+# lack of absolute filenames in links or file path, non-existing path,
+call_ua(["--install", "../testmaster", "testmaster", "/bin/date", "10"],
+        expect_failure => 1, to_file => "/dev/null", error_to_file => "/dev/null");
+call_ua(["--install", "$bindir/testmaster", "testmaster", "./update-alternatives.pl", "10"],
+        expect_failure => 1, to_file => "/dev/null", error_to_file => "/dev/null");
+# non-existing alternative path
+call_ua(["--install", "$bindir/testmaster", "testmaster", "$bindir/doesntexist", "10"],
+        expect_failure => 1, to_file => "/dev/null", error_to_file => "/dev/null");
+# invalid alternative name in master
+call_ua(["--install", "$bindir/testmaster", "test/master", "/bin/date", "10"],
+        expect_failure => 1, to_file => "/dev/null", error_to_file => "/dev/null");
+# invalid alternative name in slave
+call_ua(["--install", "$bindir/testmaster", "testmaster", "/bin/date", "10",
+	 "--slave", "$bindir/testslave", "test slave", "/bin/true" ],
+	expect_failure => 1, to_file => "/dev/null", error_to_file => "/dev/null");
 
-# TODO: add checks for invalid values of parameters, install in non-existing dir
+# TODO: install in non-existing dir, handle of pre-existing files in place
+# of alternative links

scripts/update-alternatives.pl

@@ -122,9 +122,10 @@ foreach my $alt_name (get_all_alternatives()) {
     }
 }
 # Check that caller don't mix links between alternatives and don't mix
-# alternatives between
+# alternatives between slave/master, and that the various parameters
+# are fine
 if ($action eq "install") {
-    my ($name, $link) = ($inst_alt->name(), $inst_alt->link());
+    my ($name, $link, $file) = ($inst_alt->name(), $inst_alt->link(), $fileset->master());
     if (exists $ALL{parent}{$name} and $ALL{parent}{$name} ne $name) {
         badusage(_g("Alternative %s can't be master: %s"), $name,
                  sprintf(_g("it is a slave of %s"), $ALL{parent}{$name}));
@@ -133,8 +134,16 @@ if ($action eq "install") {
         badusage(_g("Alternative link %s is already managed by %s."),
                  $link, $ALL{parent}{$ALL{links}{$link}});
     }
+    badusage(_g("Alternative link (%s) is not absolute as it should be."),
+             $link) unless $link =~ m|^/|;
+    badusage(_g("Alternative path (%s) is not absolute as it should be."),
+             $file) unless $file =~ m|^/|;
+    badusage(_g("Alternative path (%s) doesn't exist."), $file)
+        unless -e $file;
+    badusage(_g("Alternative name (%s) is invalid."), $name) if $name =~ m|[/\s]|;
     foreach my $slave ($inst_alt->slaves()) {
         $link = $inst_alt->slave_link($slave);
+        $file = $fileset->slave($slave);
         if (exists $ALL{parent}{$slave} and $ALL{parent}{$slave} ne $name) {
             badusage(_g("Alternative %s can't be slave of %s: %s"),
                      $slave, $name, ($ALL{parent}{$slave} eq $slave) ?
@@ -146,6 +155,12 @@ if ($action eq "install") {
             badusage(_g("Alternative link %s is already managed by %s."),
                      $link, $ALL{parent}{$ALL{links}{$link}});
         }
+        badusage(_g("Alternative link (%s) is not absolute as it should be."),
+                 $link) unless $link =~ m|^/|;
+        badusage(_g("Alternative path (%s) is not absolute as it should be."),
+                 $file) unless $file =~ m|^/|;
+        badusage(_g("Alternative name (%s) is invalid."), $slave)
+            if $slave =~ m|[/\s]|;
     }
 }