Handle relative path arguments in Killfilter

KillFilter currently expects an absolute path
to be specified for the process name to kill. This
is inconvenient when the exact location of the running
binary is not known or differs accross installs.

Extend KillFilter to accept also commands in $PATH
to be killed if the given argument is not absolute.

Change-Id: I6b90206b587ff3f949af2c256a78ca21af31867a

1 files changed, 22 insertions, 13 deletions

diff --git a/openstack/common/rootwrap/filters.py b/openstack/common/rootwrap/filters.py
index ae7c62c..0cc55ce 100644
--- a/openstack/common/rootwrap/filters.py
+++ b/openstack/common/rootwrap/filters.py
@@ -34,7 +34,7 @@ class CommandFilter(object):
         if self.real_exec is not None:
             return self.real_exec
         self.real_exec = ""
-        if self.exec_path.startswith('/'):
+        if os.path.isabs(self.exec_path):
             if os.access(self.exec_path, os.X_OK):
                 self.real_exec = self.exec_path
         else:
@@ -164,8 +164,10 @@ class DeprecatedDnsmasqFilter(DnsmasqFilter):
 
 class KillFilter(CommandFilter):
     """Specific filter for the kill calls.
+
        1st argument is the user to run /bin/kill under
        2nd argument is the location of the affected executable
+           if the argument is not absolute, it is checked against $PATH
        Subsequent arguments list the accepted signals (if any)
 
        This filter relies on /proc to accurately determine affected
@@ -194,21 +196,28 @@ class KillFilter(CommandFilter):
                 return False
         try:
             command = os.readlink("/proc/%d/exe" % int(args[1]))
-            # NOTE(yufang521247): /proc/PID/exe may have '\0' on the
-            # end, because python doen't stop at '\0' when read the
-            # target path.
-            command = command.split('\0')[0]
-            # NOTE(dprince): /proc/PID/exe may have ' (deleted)' on
-            # the end if an executable is updated or deleted
-            if command.endswith(" (deleted)"):
-                command = command[:command.rindex(" ")]
-            if command != self.args[0]:
-                # Affected executable does not match
-                return False
         except (ValueError, OSError):
             # Incorrect PID
             return False
-        return True
+
+        # NOTE(yufang521247): /proc/PID/exe may have '\0' on the
+        # end, because python doen't stop at '\0' when read the
+        # target path.
+        command = command.partition('\0')[0]
+
+        # NOTE(dprince): /proc/PID/exe may have ' (deleted)' on
+        # the end if an executable is updated or deleted
+        if command.endswith(" (deleted)"):
+            command = command[:-len(" (deleted)")]
+
+        kill_command = self.args[0]
+
+        if os.path.isabs(kill_command):
+            return kill_command == command
+
+        return (os.path.isabs(command) and
+                kill_command == os.path.basename(command) and
+                os.path.dirname(command) in os.environ['PATH'].split(':'))
 
 
 class ReadFileFilter(CommandFilter):