diff options
-rw-r--r-- | sys-utils/unshare.1 | 6 | ||||
-rw-r--r-- | sys-utils/unshare.c | 31 |
2 files changed, 33 insertions, 4 deletions
diff --git a/sys-utils/unshare.1 b/sys-utils/unshare.1 index bd0f13eb5..c387cebfd 100644 --- a/sys-utils/unshare.1 +++ b/sys-utils/unshare.1 @@ -56,13 +56,17 @@ Unshare the mount namespace. Unshare the network namespace. .TP .BR \-p , " \-\-pid" -Unshare the pid namespace. +Unshare the pid namespace. See also \fB--fork\fP option. .TP .BR \-u , " \-\-uts" Unshare the UTS namespace. .TP .BR \-U , " \-\-user" Unshare the user namespace. +.TP +.BR \-f , " \-\-fork" +Fork the specified process as a child of unshare rather than running it +directly. This is useful when creating a new pid namespace. .SH SEE ALSO .BR unshare (2), .BR clone (2) diff --git a/sys-utils/unshare.c b/sys-utils/unshare.c index 8cc9c46c8..a889eee9f 100644 --- a/sys-utils/unshare.c +++ b/sys-utils/unshare.c @@ -24,6 +24,7 @@ #include <stdio.h> #include <stdlib.h> #include <unistd.h> +#include <sys/wait.h> #include "nls.h" #include "c.h" @@ -46,6 +47,7 @@ static void usage(int status) fputs(_(" -n, --net unshare network namespace\n"), out); fputs(_(" -p, --pid unshare pid namespace\n"), out); fputs(_(" -U, --user unshare user namespace\n"), out); + fputs(_(" -f, --fork fork before launching <program>\n"), out); fputs(USAGE_SEPARATOR, out); fputs(USAGE_HELP, out); @@ -66,20 +68,23 @@ int main(int argc, char *argv[]) { "net", no_argument, 0, 'n' }, { "pid", no_argument, 0, 'p' }, { "user", no_argument, 0, 'U' }, + { "fork", no_argument, 0, 'f' }, { NULL, 0, 0, 0 } }; int unshare_flags = 0; - - int c; + int c, forkit = 0; setlocale(LC_MESSAGES, ""); bindtextdomain(PACKAGE, LOCALEDIR); textdomain(PACKAGE); atexit(close_stdout); - while ((c = getopt_long(argc, argv, "hVmuinpU", longopts, NULL)) != -1) { + while ((c = getopt_long(argc, argv, "fhVmuinpU", longopts, NULL)) != -1) { switch (c) { + case 'f': + forkit = 1; + break; case 'h': usage(EXIT_SUCCESS); case 'V': @@ -111,6 +116,26 @@ int main(int argc, char *argv[]) if (-1 == unshare(unshare_flags)) err(EXIT_FAILURE, _("unshare failed")); + if (forkit) { + int status; + pid_t pid = fork(); + + switch(pid) { + case -1: + err(EXIT_FAILURE, _("fork failed")); + case 0: /* child */ + break; + default: /* parent */ + if (waitpid(pid, &status, 0) == -1) + err(EXIT_FAILURE, _("waitpid failed")); + if (WIFEXITED(status)) + return WEXITSTATUS(status); + else if (WIFSIGNALED(status)) + kill(getpid(), WTERMSIG(status)); + err(EXIT_FAILURE, _("child exit failed")); + } + } + if (optind < argc) { execvp(argv[optind], argv + optind); err(EXIT_FAILURE, _("failed to execute %s"), argv[optind]); |