From: Thomas Weißschuh <thomas@t-8ch.de>
Date: Mon, 3 Apr 2023 18:44:15 +0000 (+0000)
Subject: nsenter: use explicit argument to follow target PID/GID
X-Git-Tag: v2.39-rc2~12
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=97bb98effd2c2fe976b2e20f87e000f75130c56c;p=thirdparty%2Futil-linux.git

nsenter: use explicit argument to follow target PID/GID

Making the argument to -S and -G optional in #2092 broke the cli
compatability.
So replace it with an explicit "follow" argument that provides the new
functionality with a compatible interface.

Fixes #2143
---

diff --git a/bash-completion/nsenter b/bash-completion/nsenter
index ace7934407..86c76dbc0a 100644
--- a/bash-completion/nsenter
+++ b/bash-completion/nsenter
@@ -6,11 +6,11 @@ _nsenter_module()
 	prev="${COMP_WORDS[COMP_CWORD-1]}"
 	case $prev in
 		'-S'|'--uid')
-			COMPREPLY=( $(compgen -W "uid" -- $cur) )
+			COMPREPLY=( follow $(compgen -W "uid" -- $cur) )
 			return 0
 			;;
 		'-G'|'--gid')
-			COMPREPLY=( $(compgen -W "gid" -- $cur) )
+			COMPREPLY=( follow $(compgen -W "gid" -- $cur) )
 			return 0
 			;;
 		'-t'|'--target')
diff --git a/sys-utils/nsenter.1.adoc b/sys-utils/nsenter.1.adoc
index 009e76ebc7..c6c0515e64 100644
--- a/sys-utils/nsenter.1.adoc
+++ b/sys-utils/nsenter.1.adoc
@@ -103,15 +103,15 @@ Enter the cgroup namespace. If no file is specified, enter the cgroup namespace
 *-T*, *--time*[=_file_]::
 Enter the time namespace. If no file is specified, enter the time namespace of the target process. If _file_ is specified, enter the time namespace specified by _file_.
 
-*-G*, *--setgid*[=_gid_]::
+*-G*, *--setgid* _gid_::
 Set the group ID which will be used in the entered namespace and drop supplementary groups.
 *nsenter* always sets GID for user namespaces, the default is 0.
-If no argument is specified the GID of the target process is used.
+If the argument _follow_ is specified the GID of the target process is used.
 
-*-S*, *--setuid*[=_uid_]::
+*-S*, *--setuid* _uid_::
 Set the user ID which will be used in the entered namespace.
 *nsenter* always sets UID for user namespaces, the default is 0.
-If no argument is specified the UID of the target process is used.
+If the argument _follow_ is specified the UID of the target process is used.
 
 *--preserve-credentials*::
 Don't modify UID and GID when enter user namespace. The default is to drops supplementary groups and sets GID and UID to 0.
diff --git a/sys-utils/nsenter.c b/sys-utils/nsenter.c
index c2c20128f0..56dbf1775c 100644
--- a/sys-utils/nsenter.c
+++ b/sys-utils/nsenter.c
@@ -247,8 +247,8 @@ int main(int argc, char *argv[])
 		{ "user", optional_argument, NULL, 'U' },
 		{ "cgroup", optional_argument, NULL, 'C' },
 		{ "time", optional_argument, NULL, 'T' },
-		{ "setuid", optional_argument, NULL, 'S' },
-		{ "setgid", optional_argument, NULL, 'G' },
+		{ "setuid", required_argument, NULL, 'S' },
+		{ "setgid", required_argument, NULL, 'G' },
 		{ "root", optional_argument, NULL, 'r' },
 		{ "wd", optional_argument, NULL, 'w' },
 		{ "wdns", optional_argument, NULL, 'W' },
@@ -285,7 +285,7 @@ int main(int argc, char *argv[])
 	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::eFZ",
 			    longopts, NULL)) != -1) {
 
 		err_exclusive_options(c, longopts, excl, excl_st);
@@ -347,17 +347,17 @@ int main(int argc, char *argv[])
 				namespaces |= CLONE_NEWTIME;
 			break;
 		case 'S':
-			if (optarg)
-				uid = strtoul_or_err(optarg, _("failed to parse uid"));
-			else
+			if (strcmp(optarg, "follow") == 0)
 				do_uid = true;
+			else
+				uid = strtoul_or_err(optarg, _("failed to parse uid"));
 			force_uid = true;
 			break;
 		case 'G':
-			if (optarg)
-				gid = strtoul_or_err(optarg, _("failed to parse gid"));
-			else
+			if (strcmp(optarg, "follow") == 0)
 				do_gid = true;
+			else
+				gid = strtoul_or_err(optarg, _("failed to parse gid"));
 			force_gid = true;
 			break;
 		case 'F':