Merge branch 'nsenter/target-uid-gid' of https://github.com/t-8ch/util-linux

[kzak@redhat.com: - resolve conflict with 4e9ec856a1b91fb3ff10de10f2dac94f711705e1
                  - fix --help output]

* 'nsenter/target-uid-gid' of https://github.com/t-8ch/util-linux:
  nsenter: read default UID and GID from target process

diff --cc sys-utils/nsenter.1.adoc
Simple merge

diff --cc sys-utils/nsenter.c
index c1456691794652aa934abe8139ebc02184af132b,c55cf173c341299d8c0d13d11fbe1023a90ba27d..c2c20128f0ac442ff20f8f40bf593032c2d61d37
--- 1/sys-utils/nsenter.c
--- 2/sys-utils/nsenter.c
+++ b/sys-utils/nsenter.c
@@@ -92,8 -89,8 +92,8 @@@ static void __attribute__((__noreturn__
        fputs(_(" -C, --cgroup[=<file>]  enter cgroup namespace\n"), out);
        fputs(_(" -U, --user[=<file>]    enter user namespace\n"), out);
        fputs(_(" -T, --time[=<file>]    enter time namespace\n"), out);
-       fputs(_(" -S, --setuid <uid>     set uid in entered namespace\n"), out);
-       fputs(_(" -G, --setgid <gid>     set gid in entered namespace\n"), out);
 -      fputs(_(" -S, --setuid=[<uid>]   set uid in entered namespace\n"), out);
 -      fputs(_(" -G, --setgid=[<gid>]   set gid in entered namespace\n"), out);
++      fputs(_(" -S, --setuid[=<uid>]   set uid in entered namespace\n"), out);
++      fputs(_(" -G, --setgid[=<gid>]   set gid in entered namespace\n"), out);
        fputs(_("     --preserve-credentials do not touch uids or gids\n"), out);
        fputs(_(" -r, --root[=<dir>]     set the root directory\n"), out);
        fputs(_(" -w, --wd[=<dir>]       set the working directory\n"), out);
@@@ -114,7 -110,7 +114,8 @@@
  static pid_t namespace_target_pid = 0;
  static int root_fd = -1;
  static int wd_fd = -1;
 +static int env_fd = -1;
+ static int uid_gid_fd = -1;
  
  static void open_target_fd(int *fd, const char *type, const char *path)
  {
@@@ -267,8 -262,8 +268,8 @@@ int main(int argc, char *argv[]
  
        struct namespace_file *nsfile;
        int c, pass, namespaces = 0, setgroups_nerrs = 0, preserve_cred = 0;
-       bool do_rd = false, do_wd = false, force_uid = false, force_gid = false, do_env = false;
 -      bool do_rd = false, do_wd = false, do_uid = false, force_uid = false, do_gid = false, force_gid = false;
--      bool do_all = false;
++      bool do_rd = false, do_wd = false, do_uid = false, force_uid = false,
++           do_gid = false, force_gid = false, do_env = false, do_all = false;
        int do_fork = -1; /* unknown yet */
        char *wdns = NULL;
        uid_t uid = 0;
@@@ -284,7 -278,7 +285,7 @@@
        close_stdout_atexit();
  
        while ((c =
-               getopt_long(argc, argv, "+ahVt:m::u::i::n::p::C::U::T::S:G:r::w::W::eFZ",
 -              getopt_long(argc, argv, "+ahVt:m::u::i::n::p::C::U::T::S::G::r::w::W:FZ",
++              getopt_long(argc, argv, "+ahVt:m::u::i::n::p::C::U::T::S::G::r::w::W::eFZ",
                            longopts, NULL)) != -1) {
  
                err_exclusive_options(c, longopts, excl, excl_st);
@@@ -430,8 -427,8 +437,10 @@@
                open_target_fd(&root_fd, "root", NULL);
        if (do_wd)
                open_target_fd(&wd_fd, "cwd", NULL);
 +      if (do_env)
 +              open_target_fd(&env_fd, "environ", NULL);
+       if (do_uid || do_gid)
+               open_target_fd(&uid_gid_fd, "", NULL);
  
        /*
         * Update namespaces variable to contain all requested namespaces
@@@ -522,17 -519,21 +531,32 @@@
                wd_fd = -1;
        }
  
 +      /* Pass environment variables of the target process to the spawned process */
 +      if (env_fd >= 0) {
 +              if ((envls = env_from_fd(env_fd)) == NULL)
 +                      err(EXIT_FAILURE, _("failed to get environment variables"));
 +              clearenv();
 +              if (env_list_setenv(envls) < 0)
 +                      err(EXIT_FAILURE, _("failed to set environment variables"));
 +              env_list_free(envls);
 +              close(env_fd);
 +      }
 +
+       if (uid_gid_fd >= 0) {
+               struct stat st;
+ 
+               if (fstat(uid_gid_fd, &st) > 0)
+                       err(EXIT_FAILURE, _("can not get process stat"));
+ 
+               close(uid_gid_fd);
+               uid_gid_fd = -1;
+ 
+               if (do_uid)
+                       uid = st.st_uid;
+               if (do_gid)
+                       gid = st.st_gid;
+       }
+ 
        if (do_fork == 1)
                continue_as_child();