commands: LXC_CMD_GET_INIT_PIDFD

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

diff --git a/src/lxc/commands.c b/src/lxc/commands.c
index e2156c618120119955860b940282c5a10e3900f6..ec3f4233a1ec04b51d02f014a3389f35fbd184a4 100644 (file)
--- a/src/lxc/commands.c
+++ b/src/lxc/commands.c
@@ -83,6 +83,7 @@ static const char *lxc_cmd_str(lxc_cmd_t cmd)
                [LXC_CMD_FREEZE]                        = "freeze",
                [LXC_CMD_UNFREEZE]                      = "unfreeze",
                [LXC_CMD_GET_CGROUP2_FD]                = "get_cgroup2_fd",
+               [LXC_CMD_GET_INIT_PIDFD]                = "get_init_pidfd",
        };
 
        if (cmd >= LXC_CMD_MAX)
@@ -146,6 +147,11 @@ static int lxc_cmd_rsp_recv(int sock, struct lxc_cmd_rr *cmd)
                rsp->data = INT_TO_PTR(cgroup2_fd);
        }
 
+       if (cmd->req.cmd == LXC_CMD_GET_INIT_PIDFD) {
+               int init_pidfd = move_fd(fd_rsp);
+               rsp->data = INT_TO_PTR(init_pidfd);
+       }
+
        if (rsp->datalen == 0)
                return log_debug(ret,
                                 "Response data length for command \"%s\" is 0",
@@ -372,6 +378,43 @@ static int lxc_cmd_get_init_pid_callback(int fd, struct lxc_cmd_req *req,
        return 0;
 }
 
+int lxc_cmd_get_init_pidfd(const char *name, const char *lxcpath)
+{
+       int ret, stopped;
+       struct lxc_cmd_rr cmd = {
+               .req = {
+                       .cmd = LXC_CMD_GET_INIT_PIDFD,
+               },
+       };
+
+       ret = lxc_cmd(name, &cmd, &stopped, lxcpath, NULL);
+       if (ret < 0)
+               return log_debug_errno(-1, errno, "Failed to process init pidfd command");
+
+       if (cmd.rsp.ret < 0)
+               return log_debug_errno(-EBADF, errno, "Failed to receive init pidfd");
+
+       return PTR_TO_INT(cmd.rsp.data);
+}
+
+static int lxc_cmd_get_init_pidfd_callback(int fd, struct lxc_cmd_req *req,
+                                          struct lxc_handler *handler,
+                                          struct lxc_epoll_descr *descr)
+{
+       struct lxc_cmd_rsp rsp = {
+               .ret = 0,
+       };
+       int ret;
+
+       if (handler->pidfd < 0)
+               rsp.ret = -EBADF;
+       ret = lxc_abstract_unix_send_fds(fd, &handler->pidfd, 1, &rsp, sizeof(rsp));
+       if (ret < 0)
+               return log_error(LXC_CMD_REAP_CLIENT_FD, "Failed to send init pidfd");
+
+       return 0;
+}
+
 /*
  * lxc_cmd_get_clone_flags: Get clone flags container was spawned with
  *
@@ -1329,6 +1372,7 @@ static int lxc_cmd_process(int fd, struct lxc_cmd_req *req,
                [LXC_CMD_FREEZE]                        = lxc_cmd_freeze_callback,
                [LXC_CMD_UNFREEZE]                      = lxc_cmd_unfreeze_callback,
                [LXC_CMD_GET_CGROUP2_FD]                = lxc_cmd_get_cgroup2_fd_callback,
+               [LXC_CMD_GET_INIT_PIDFD]                = lxc_cmd_get_init_pidfd_callback,
        };
 
        if (req->cmd >= LXC_CMD_MAX)

diff --git a/src/lxc/commands.h b/src/lxc/commands.h
index cd78a61a213a87d1375842385af507df79bf99fa..9e5248424968b783b1488ab14c12f485e954226d 100644 (file)
--- a/src/lxc/commands.h
+++ b/src/lxc/commands.h
@@ -37,6 +37,7 @@ typedef enum {
        LXC_CMD_FREEZE,
        LXC_CMD_UNFREEZE,
        LXC_CMD_GET_CGROUP2_FD,
+       LXC_CMD_GET_INIT_PIDFD,
        LXC_CMD_MAX,
 } lxc_cmd_t;
 
@@ -84,6 +85,7 @@ extern char *lxc_cmd_get_config_item(const char *name, const char *item, const c
 extern char *lxc_cmd_get_name(const char *hashed_sock);
 extern char *lxc_cmd_get_lxcpath(const char *hashed_sock);
 extern pid_t lxc_cmd_get_init_pid(const char *name, const char *lxcpath);
+extern int lxc_cmd_get_init_pidfd(const char *name, const char *lxcpath);
 extern int lxc_cmd_get_state(const char *name, const char *lxcpath);
 extern int lxc_cmd_stop(const char *name, const char *lxcpath);