From: Christian Brauner <christian.brauner@ubuntu.com>
Date: Wed, 24 Feb 2021 10:11:08 +0000 (+0100)
Subject: commands: add LXC_CMD_GET_CGROUP_FD and LXC_CMD_GET_LIMIT_CGROUP_FD
X-Git-Tag: lxc-5.0.0~269^2~6
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c206ac24b3d974d9b9f2e07d415dbf851179afa2;p=thirdparty%2Flxc.git

commands: add LXC_CMD_GET_CGROUP_FD and LXC_CMD_GET_LIMIT_CGROUP_FD

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
---

diff --git a/src/lxc/commands.c b/src/lxc/commands.c
index b94b94253..2df32ae22 100644
--- a/src/lxc/commands.c
+++ b/src/lxc/commands.c
@@ -89,6 +89,8 @@ static const char *lxc_cmd_str(lxc_cmd_t cmd)
 		[LXC_CMD_GET_DEVPTS_FD]			= "get_devpts_fd",
 		[LXC_CMD_GET_SECCOMP_NOTIFY_FD]		= "get_seccomp_notify_fd",
 		[LXC_CMD_GET_CGROUP_CTX]		= "get_cgroup_ctx",
+		[LXC_CMD_GET_CGROUP_FD]			= "get_cgroup_fd",
+		[LXC_CMD_GET_LIMIT_CGROUP_FD]		= "get_limit_cgroup_fd",
 	};
 
 	if (cmd >= LXC_CMD_MAX)
@@ -138,6 +140,10 @@ static int lxc_cmd_rsp_recv(int sock, struct lxc_cmd_rr *cmd)
 
 	cur_cmdstr = lxc_cmd_str(cur_cmd);
 	switch (cur_cmd) {
+	case LXC_CMD_GET_CGROUP_FD:
+		__fallthrough;
+	case LXC_CMD_GET_LIMIT_CGROUP_FD:
+		__fallthrough;
 	case LXC_CMD_GET_CGROUP2_FD:
 		__fallthrough;
 	case LXC_CMD_GET_LIMIT_CGROUP2_FD:
@@ -188,6 +194,10 @@ static int lxc_cmd_rsp_recv(int sock, struct lxc_cmd_rr *cmd)
 	}
 
 	switch (cur_cmd) {
+	case LXC_CMD_GET_CGROUP_FD:
+		__fallthrough;
+	case LXC_CMD_GET_LIMIT_CGROUP_FD:
+		__fallthrough;
 	case LXC_CMD_GET_CGROUP2_FD:
 		__fallthrough;
 	case LXC_CMD_GET_LIMIT_CGROUP2_FD:
@@ -1565,6 +1575,94 @@ static int lxc_cmd_unfreeze_callback(int fd, struct lxc_cmd_req *req,
 	return lxc_cmd_rsp_send_reap(fd, &rsp);
 }
 
+int lxc_cmd_get_cgroup_fd(const char *name, const char *lxcpath,
+			  const char *controller, cgroupfs_type_magic_t type)
+{
+	int ret, stopped;
+	struct lxc_cmd_rr cmd = {
+		.req = {
+			.cmd = LXC_CMD_GET_CGROUP_FD,
+		},
+		.rsp = {
+			ret = -ENOSYS,
+		},
+	};
+
+	ret = lxc_cmd(name, &cmd, &stopped, lxcpath, NULL);
+	if (ret < 0)
+		return -1;
+
+	if (cmd.rsp.ret < 0)
+		return syserrno_set(cmd.rsp.ret, "Failed to receive cgroup fd");
+
+	return PTR_TO_INT(cmd.rsp.data);
+}
+
+int lxc_cmd_get_limit_cgroup_fd(const char *name, const char *lxcpath,
+				const char *controller,
+				cgroupfs_type_magic_t type)
+{
+	int ret, stopped;
+	struct lxc_cmd_rr cmd = {
+		.req = {
+			.cmd = LXC_CMD_GET_LIMIT_CGROUP_FD,
+		},
+		.rsp = {
+			ret = -ENOSYS,
+		},
+	};
+
+	ret = lxc_cmd(name, &cmd, &stopped, lxcpath, NULL);
+	if (ret < 0)
+		return -1;
+
+	if (cmd.rsp.ret < 0)
+		return syserrno_set(cmd.rsp.ret, "Failed to receive cgroup fd");
+
+	return PTR_TO_INT(cmd.rsp.data);
+}
+
+static int __lxc_cmd_get_cgroup_fd_callback(int fd, struct lxc_cmd_req *req,
+					    struct lxc_handler *handler,
+					    struct lxc_epoll_descr *descr,
+					    bool limiting_cgroup)
+{
+	struct lxc_cmd_rsp rsp = {
+		.ret = -EINVAL,
+	};
+	struct cgroup_ops *ops = handler->cgroup_ops;
+	int send_fd;
+
+	if (!pure_unified_layout(ops) || !ops->unified)
+		return lxc_cmd_rsp_send_reap(fd, &rsp);
+
+	/* FIXME */
+	send_fd = limiting_cgroup ? ops->unified->dfd_lim
+				  : ops->unified->dfd_con;
+
+	if (send_fd < 0) {
+		rsp.ret = -EBADF;
+		return lxc_cmd_rsp_send_reap(fd, &rsp);
+	}
+
+	rsp.ret = 0;
+	return rsp_one_fd(fd, send_fd, &rsp);
+}
+
+static int lxc_cmd_get_cgroup_fd_callback(int fd, struct lxc_cmd_req *req,
+					  struct lxc_handler *handler,
+					  struct lxc_epoll_descr *descr)
+{
+	return __lxc_cmd_get_cgroup_fd_callback(fd, req, handler, descr, false);
+}
+
+static int lxc_cmd_get_limit_cgroup_fd_callback(int fd, struct lxc_cmd_req *req,
+						struct lxc_handler *handler,
+						struct lxc_epoll_descr *descr)
+{
+	return __lxc_cmd_get_cgroup_fd_callback(fd, req, handler, descr, true);
+}
+
 int lxc_cmd_get_cgroup2_fd(const char *name, const char *lxcpath)
 {
 	int ret, stopped;
@@ -1693,6 +1791,8 @@ static int lxc_cmd_process(int fd, struct lxc_cmd_req *req,
 		[LXC_CMD_GET_DEVPTS_FD]			= lxc_cmd_get_devpts_fd_callback,
 		[LXC_CMD_GET_SECCOMP_NOTIFY_FD]		= lxc_cmd_get_seccomp_notify_fd_callback,
 		[LXC_CMD_GET_CGROUP_CTX]		= lxc_cmd_get_cgroup_ctx_callback,
+		[LXC_CMD_GET_CGROUP_FD]			= lxc_cmd_get_cgroup_fd_callback,
+		[LXC_CMD_GET_LIMIT_CGROUP_FD]		= lxc_cmd_get_limit_cgroup_fd_callback,
 	};
 
 	if (req->cmd >= LXC_CMD_MAX)
diff --git a/src/lxc/commands.h b/src/lxc/commands.h
index 0477a04de..79faf1e83 100644
--- a/src/lxc/commands.h
+++ b/src/lxc/commands.h
@@ -45,6 +45,8 @@ typedef enum {
 	LXC_CMD_GET_DEVPTS_FD			= 21,
 	LXC_CMD_GET_SECCOMP_NOTIFY_FD		= 22,
 	LXC_CMD_GET_CGROUP_CTX			= 23,
+	LXC_CMD_GET_CGROUP_FD			= 24,
+	LXC_CMD_GET_LIMIT_CGROUP_FD		= 25,
 	LXC_CMD_MAX,
 } lxc_cmd_t;
 
@@ -137,11 +139,17 @@ __hidden extern int lxc_cmd_add_bpf_device_cgroup(const char *name, const char *
 __hidden extern int lxc_cmd_freeze(const char *name, const char *lxcpath, int timeout);
 __hidden extern int lxc_cmd_unfreeze(const char *name, const char *lxcpath, int timeout);
 __hidden extern int lxc_cmd_get_cgroup2_fd(const char *name, const char *lxcpath);
+__hidden extern int lxc_cmd_get_cgroup_fd(const char *name, const char *lxcpath,
+					  const char *controller, cgroupfs_type_magic_t type);
 __hidden extern char *lxc_cmd_get_limit_cgroup_path(const char *name,
 						    const char *lxcpath,
 						    const char *subsystem);
 __hidden extern int lxc_cmd_get_limit_cgroup2_fd(const char *name,
 						 const char *lxcpath);
+__hidden extern int lxc_cmd_get_limit_cgroup_fd(const char *name,
+						const char *lxcpath,
+						const char *controller,
+						cgroupfs_type_magic_t type);
 __hidden extern int lxc_cmd_get_devpts_fd(const char *name, const char *lxcpath);
 
 #endif /* __commands_h */