nsenter: allow arguments to be specified in any order

Allows 'nsenter -mt $PID', which would fail previously.

[kzak@redhat.com: - fix open_target_fd() arguments]

Signed-off-by: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>
Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/sys-utils/nsenter.c b/sys-utils/nsenter.c
index ce2c64d6b036305729b8c61fc701bad09d0f6b49..f377f2b849fc53f59738c00a5a7453009221dd3c 100644 (file)
--- a/sys-utils/nsenter.c
+++ b/sys-utils/nsenter.c
@@ -25,6 +25,7 @@
 #include <sched.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <stdbool.h>
 #include <unistd.h>
 
 #include "strutils.h"
@@ -173,7 +174,8 @@ int main(int argc, char *argv[])
 
        struct namespace_file *nsfile;
        int do_fork = 0;
-       int c;
+       int c, namespaces = 0;
+       bool do_rd = false, do_wd = false;
 
        setlocale(LC_MESSAGES, "");
        bindtextdomain(PACKAGE, LOCALEDIR);
@@ -191,32 +193,56 @@ int main(int argc, char *argv[])
                        namespace_target_pid = strtoul_or_err(optarg, _("failed to parse pid"));
                        break;
                case 'm':
-                       open_namespace_fd(CLONE_NEWNS, optarg);
+                       if (optarg)
+                               open_namespace_fd(CLONE_NEWNS, optarg);
+                       else
+                               namespaces |= CLONE_NEWNS;
                        break;
                case 'u':
-                       open_namespace_fd(CLONE_NEWUTS, optarg);
+                       if (optarg)
+                               open_namespace_fd(CLONE_NEWUTS, optarg);
+                       else
+                               namespaces |= CLONE_NEWUTS;
                        break;
                case 'i':
-                       open_namespace_fd(CLONE_NEWIPC, optarg);
+                       if (optarg)
+                               open_namespace_fd(CLONE_NEWIPC, optarg);
+                       else
+                               namespaces |= CLONE_NEWIPC;
                        break;
                case 'n':
-                       open_namespace_fd(CLONE_NEWNET, optarg);
+                       if (optarg)
+                               open_namespace_fd(CLONE_NEWNET, optarg);
+                       else
+                               namespaces |= CLONE_NEWNET;
                        break;
                case 'p':
                        do_fork = 1;
-                       open_namespace_fd(CLONE_NEWPID, optarg);
+                       if (optarg)
+                               open_namespace_fd(CLONE_NEWPID, optarg);
+                       else
+                               namespaces |= CLONE_NEWPID;
                        break;
                case 'U':
-                       open_namespace_fd(CLONE_NEWUSER, optarg);
+                       if (optarg)
+                               open_namespace_fd(CLONE_NEWUSER, optarg);
+                       else
+                               namespaces |= CLONE_NEWUSER;
                        break;
                case 'e':
                        do_fork = 0;
                        break;
                case 'r':
-                       open_target_fd(&root_fd, "root", optarg);
+                       if (optarg)
+                               open_target_fd(&root_fd, "root", optarg);
+                       else
+                               do_rd = true;
                        break;
                case 'w':
-                       open_target_fd(&wd_fd, "cwd", optarg);
+                       if (optarg)
+                               open_target_fd(&wd_fd, "cwd", optarg);
+                       else
+                               do_wd = true;
                        break;
                default:
                        usage(EXIT_FAILURE);
@@ -226,6 +252,17 @@ int main(int argc, char *argv[])
        if(optind >= argc)
                usage(EXIT_FAILURE);
 
+       /*
+        * Open remaining namespace and directory descriptors.
+        */
+       for (nsfile = namespace_files; nsfile->nstype; nsfile++)
+               if (nsfile->nstype & namespaces)
+                       open_namespace_fd(nsfile->nstype, NULL);
+       if (do_rd)
+               open_target_fd(&root_fd, "root", NULL);
+       if (do_wd)
+               open_target_fd(&wd_fd, "cwd", NULL);
+
        /*
         * Now that we know which namespaces we want to enter, enter them.
         */