commands: introduce lxc_cmd_rsp_send_reap()

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

diff --git a/src/lxc/commands.c b/src/lxc/commands.c
index 0ccb1d8f3fa81667476399f3853f732ec2384c7c..c00afde6535b52f63e4a9fde4319fa5347c875d7 100644 (file)
--- a/src/lxc/commands.c
+++ b/src/lxc/commands.c
@@ -210,26 +210,35 @@ static int lxc_cmd_rsp_recv(int sock, struct lxc_cmd_rr *cmd)
  *
  * Returns 0 on success, < 0 on failure
  */
-static int lxc_cmd_rsp_send(int fd, struct lxc_cmd_rsp *rsp)
+static int __lxc_cmd_rsp_send(int fd, struct lxc_cmd_rsp *rsp)
 {
        ssize_t ret;
 
-       errno = EMSGSIZE;
        ret = lxc_send_nointr(fd, rsp, sizeof(*rsp), MSG_NOSIGNAL);
        if (ret < 0 || (size_t)ret != sizeof(*rsp))
-               return log_error_errno(-1, errno, "Failed to send command response %zd", ret);
+               return syserrno(-errno, "Failed to send command response %zd", ret);
 
        if (!rsp->data || rsp->datalen <= 0)
                return 0;
 
-       errno = EMSGSIZE;
        ret = lxc_send_nointr(fd, rsp->data, rsp->datalen, MSG_NOSIGNAL);
        if (ret < 0 || ret != (ssize_t)rsp->datalen)
-               return log_warn_errno(-1, errno, "Failed to send command response data %zd", ret);
+               return syswarn(-errno, "Failed to send command response %zd", ret);
 
        return 0;
 }
 
+static inline int lxc_cmd_rsp_send_reap(int fd, struct lxc_cmd_rsp *rsp)
+{
+       int ret;
+
+       ret = __lxc_cmd_rsp_send(fd, rsp);
+       if (ret < 0)
+               return ret;
+
+       return LXC_CMD_REAP_CLIENT_FD;
+}
+
 static int lxc_cmd_send(const char *name, struct lxc_cmd_rr *cmd,
                        const char *lxcpath, const char *hashed_sock_name)
 {
@@ -352,7 +361,6 @@ int lxc_try_cmd(const char *name, const char *lxcpath)
  */
 static int validate_string_request(int fd, const struct lxc_cmd_req *req)
 {
-       int ret;
        size_t maxlen = req->datalen - 1;
        const char *data = req->data;
 
@@ -365,11 +373,7 @@ static int validate_string_request(int fd, const struct lxc_cmd_req *req)
                .data           = NULL,
        };
 
-       ret = lxc_cmd_rsp_send(fd, &rsp);
-       if (ret < 0)
-               return LXC_CMD_REAP_CLIENT_FD;
-
-       return -1;
+       return lxc_cmd_rsp_send_reap(fd, &rsp);
 }
 
 /* Implementations of the commands and their callbacks */
@@ -413,16 +417,11 @@ static int lxc_cmd_get_init_pid_callback(int fd, struct lxc_cmd_req *req,
                                         struct lxc_handler *handler,
                                         struct lxc_epoll_descr *descr)
 {
-       int ret;
        struct lxc_cmd_rsp rsp = {
-               .data = PID_TO_PTR(handler->pid)
+               .data = PID_TO_PTR(handler->pid),
        };
 
-       ret = lxc_cmd_rsp_send(fd, &rsp);
-       if (ret < 0)
-               return LXC_CMD_REAP_CLIENT_FD;
-
-       return 0;
+       return lxc_cmd_rsp_send_reap(fd, &rsp);
 }
 
 int lxc_cmd_get_init_pidfd(const char *name, const char *lxcpath)
@@ -449,17 +448,19 @@ static int lxc_cmd_get_init_pidfd_callback(int fd, struct lxc_cmd_req *req,
                                           struct lxc_epoll_descr *descr)
 {
        struct lxc_cmd_rsp rsp = {
-               .ret = 0,
+           .ret = -EBADF,
        };
        int ret;
 
        if (handler->pidfd < 0)
-               rsp.ret = -EBADF;
+               return lxc_cmd_rsp_send_reap(fd, &rsp);
+
+       rsp.ret = 0;
        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 syserrno(ret, "Failed to send init pidfd");
 
-       return 0;
+       return log_trace(LXC_CMD_REAP_CLIENT_FD, "Sent init pidfd");
 }
 
 int lxc_cmd_get_devpts_fd(const char *name, const char *lxcpath)
@@ -486,20 +487,19 @@ static int lxc_cmd_get_devpts_fd_callback(int fd, struct lxc_cmd_req *req,
                                          struct lxc_epoll_descr *descr)
 {
        struct lxc_cmd_rsp rsp = {
-               .ret = 0,
+           .ret = -EBADF,
        };
        int ret;
 
-       if (!handler->conf || handler->conf->devpts_fd < 0) {
-               rsp.ret = -EBADF;
-               ret = lxc_abstract_unix_send_fds(fd, NULL, 0, &rsp, sizeof(rsp));
-       } else {
-               ret = lxc_abstract_unix_send_fds(fd, &handler->conf->devpts_fd, 1, &rsp, sizeof(rsp));
-       }
+       if (!handler->conf || handler->conf->devpts_fd < 0)
+               return lxc_cmd_rsp_send_reap(fd, &rsp);
+
+       rsp.ret = 0;
+       ret = lxc_abstract_unix_send_fds(fd, &handler->conf->devpts_fd, 1, &rsp, sizeof(rsp));
        if (ret < 0)
-               return log_error(LXC_CMD_REAP_CLIENT_FD, "Failed to send devpts fd");
+               return syserrno(ret, "Failed to send devpts fd");
 
-       return 0;
+       return log_trace(LXC_CMD_REAP_CLIENT_FD, "Sent devpts fd");
 }
 
 int lxc_cmd_get_seccomp_notify_fd(const char *name, const char *lxcpath)
@@ -531,19 +531,21 @@ static int lxc_cmd_get_seccomp_notify_fd_callback(int fd, struct lxc_cmd_req *re
 {
 #ifdef HAVE_SECCOMP_NOTIFY
        struct lxc_cmd_rsp rsp = {
-               .ret = 0,
+               .ret = -EBADF,
        };
        int ret;
 
        if (!handler->conf || handler->conf->seccomp.notifier.notify_fd < 0)
-               rsp.ret = -EBADF;
+               return lxc_cmd_rsp_send_reap(fd, &rsp);
+
+       rsp.ret = 0;
        ret = lxc_abstract_unix_send_fds(fd, &handler->conf->seccomp.notifier.notify_fd, 1, &rsp, sizeof(rsp));
        if (ret < 0)
-               return log_error(LXC_CMD_REAP_CLIENT_FD, "Failed to send seccomp notify fd");
+               return syserrno(ret, "Failed to send seccomp notify fd");
 
-       return 0;
+       return log_trace(LXC_CMD_REAP_CLIENT_FD, "Failed to send seccomp notify fd");
 #else
-       return ret_errno(EOPNOTSUPP);
+       return syserrno_set(-EOPNOTSUPP, "Seccomp notifier not supported");
 #endif
 }
 
@@ -575,16 +577,11 @@ static int lxc_cmd_get_clone_flags_callback(int fd, struct lxc_cmd_req *req,
                                            struct lxc_handler *handler,
                                            struct lxc_epoll_descr *descr)
 {
-       int ret;
        struct lxc_cmd_rsp rsp = {
                .data = INT_TO_PTR(handler->ns_clone_flags),
        };
 
-       ret = lxc_cmd_rsp_send(fd, &rsp);
-       if (ret < 0)
-               return LXC_CMD_REAP_CLIENT_FD;
-
-       return 0;
+       return lxc_cmd_rsp_send_reap(fd, &rsp);
 }
 
 static char *lxc_cmd_get_cgroup_path_do(const char *name, const char *lxcpath,
@@ -704,11 +701,7 @@ static int lxc_cmd_get_cgroup_callback_do(int fd, struct lxc_cmd_req *req,
        rsp.datalen = strlen(path) + 1;
        rsp.data = (char *)path;
 
-       ret = lxc_cmd_rsp_send(fd, &rsp);
-       if (ret < 0)
-               return LXC_CMD_REAP_CLIENT_FD;
-
-       return 0;
+       return lxc_cmd_rsp_send_reap(fd, &rsp);
 }
 
 static int lxc_cmd_get_cgroup_callback(int fd, struct lxc_cmd_req *req,
@@ -787,11 +780,7 @@ static int lxc_cmd_get_config_item_callback(int fd, struct lxc_cmd_req *req,
 err1:
        rsp.ret = -1;
 out:
-       cilen = lxc_cmd_rsp_send(fd, &rsp);
-       if (cilen < 0)
-               return LXC_CMD_REAP_CLIENT_FD;
-
-       return 0;
+       return lxc_cmd_rsp_send_reap(fd, &rsp);
 }
 
 /*
@@ -830,16 +819,11 @@ static int lxc_cmd_get_state_callback(int fd, struct lxc_cmd_req *req,
                                      struct lxc_handler *handler,
                                      struct lxc_epoll_descr *descr)
 {
-       int ret;
        struct lxc_cmd_rsp rsp = {
                .data = INT_TO_PTR(handler->state),
        };
 
-       ret = lxc_cmd_rsp_send(fd, &rsp);
-       if (ret < 0)
-               return LXC_CMD_REAP_CLIENT_FD;
-
-       return 0;
+       return lxc_cmd_rsp_send_reap(fd, &rsp);
 }
 
 /*
@@ -912,11 +896,7 @@ static int lxc_cmd_stop_callback(int fd, struct lxc_cmd_req *req,
                rsp.ret = -errno;
        }
 
-       ret = lxc_cmd_rsp_send(fd, &rsp);
-       if (ret < 0)
-               return LXC_CMD_REAP_CLIENT_FD;
-
-       return 0;
+       return lxc_cmd_rsp_send_reap(fd, &rsp);
 }
 
 /*
@@ -988,23 +968,24 @@ static int lxc_cmd_console_callback(int fd, struct lxc_cmd_req *req,
                                    struct lxc_epoll_descr *descr)
 {
        int ptxfd, ret;
-       struct lxc_cmd_rsp rsp;
+       struct lxc_cmd_rsp rsp = {
+           .ret = -EBADF,
+       };
        int ttynum = PTR_TO_INT(req->data);
 
        ptxfd = lxc_terminal_allocate(handler->conf, fd, &ttynum);
        if (ptxfd < 0)
-               return LXC_CMD_REAP_CLIENT_FD;
+               return lxc_cmd_rsp_send_reap(fd, &rsp);
 
-       memset(&rsp, 0, sizeof(rsp));
+       rsp.ret = 0;
        rsp.data = INT_TO_PTR(ttynum);
        ret = lxc_abstract_unix_send_fds(fd, &ptxfd, 1, &rsp, sizeof(rsp));
        if (ret < 0) {
                lxc_terminal_free(handler->conf, fd);
-               return log_error_errno(LXC_CMD_REAP_CLIENT_FD, errno,
-                                      "Failed to send tty to client");
+               return ret;
        }
 
-       return 0;
+       return log_debug(0, "Send tty to client");
 }
 
 /*
@@ -1037,7 +1018,6 @@ static int lxc_cmd_get_name_callback(int fd, struct lxc_cmd_req *req,
                                     struct lxc_handler *handler,
                                     struct lxc_epoll_descr *descr)
 {
-       int ret;
        struct lxc_cmd_rsp rsp;
 
        memset(&rsp, 0, sizeof(rsp));
@@ -1046,11 +1026,7 @@ static int lxc_cmd_get_name_callback(int fd, struct lxc_cmd_req *req,
        rsp.datalen = strlen(handler->name) + 1;
        rsp.ret = 0;
 
-       ret = lxc_cmd_rsp_send(fd, &rsp);
-       if (ret < 0)
-               return LXC_CMD_REAP_CLIENT_FD;
-
-       return 0;
+       return lxc_cmd_rsp_send_reap(fd, &rsp);
 }
 
 /*
@@ -1083,18 +1059,13 @@ static int lxc_cmd_get_lxcpath_callback(int fd, struct lxc_cmd_req *req,
                                        struct lxc_handler *handler,
                                        struct lxc_epoll_descr *descr)
 {
-       int ret;
        struct lxc_cmd_rsp rsp = {
                .ret            = 0,
                .data           = (char *)handler->lxcpath,
                .datalen        = strlen(handler->lxcpath) + 1,
        };
 
-       ret = lxc_cmd_rsp_send(fd, &rsp);
-       if (ret < 0)
-               return LXC_CMD_REAP_CLIENT_FD;
-
-       return 0;
+       return lxc_cmd_rsp_send_reap(fd, &rsp);
 }
 
 int lxc_cmd_add_state_client(const char *name, const char *lxcpath,
@@ -1143,29 +1114,27 @@ static int lxc_cmd_add_state_client_callback(__owns int fd, struct lxc_cmd_req *
                                             struct lxc_handler *handler,
                                             struct lxc_epoll_descr *descr)
 {
-       int ret;
-       struct lxc_cmd_rsp rsp = {0};
+       struct lxc_cmd_rsp rsp = {
+               .ret = -EINVAL,
+       };
 
        if (req->datalen < 0)
-               return LXC_CMD_REAP_CLIENT_FD;
+               goto out;
 
        if (req->datalen != (sizeof(lxc_state_t) * MAX_STATE))
-               return LXC_CMD_REAP_CLIENT_FD;
+               goto out;
 
        if (!req->data)
-               return LXC_CMD_REAP_CLIENT_FD;
+               goto out;
 
        rsp.ret = lxc_add_state_client(fd, handler, (lxc_state_t *)req->data);
        if (rsp.ret < 0)
-               return LXC_CMD_REAP_CLIENT_FD;
+               goto out;
 
        rsp.data = INT_TO_PTR(rsp.ret);
 
-       ret = lxc_cmd_rsp_send(fd, &rsp);
-       if (ret < 0)
-               return LXC_CMD_REAP_CLIENT_FD;
-
-       return 0;
+out:
+       return lxc_cmd_rsp_send_reap(fd, &rsp);
 }
 
 int lxc_cmd_add_bpf_device_cgroup(const char *name, const char *lxcpath,
@@ -1196,18 +1165,19 @@ static int lxc_cmd_add_bpf_device_cgroup_callback(int fd, struct lxc_cmd_req *re
                                                  struct lxc_handler *handler,
                                                  struct lxc_epoll_descr *descr)
 {
-       int ret;
-       struct lxc_cmd_rsp rsp = {};
+       struct lxc_cmd_rsp rsp = {
+               .ret = -EINVAL,
+       };
        struct lxc_conf *conf;
 
        if (req->datalen <= 0)
-               return LXC_CMD_REAP_CLIENT_FD;
+               goto out;
 
        if (req->datalen != sizeof(struct device_item))
-               return LXC_CMD_REAP_CLIENT_FD;
+               goto out;
 
        if (!req->data)
-               return LXC_CMD_REAP_CLIENT_FD;
+               goto out;
 
        conf = handler->conf;
        if (!bpf_cgroup_devices_update(handler->cgroup_ops,
@@ -1217,11 +1187,8 @@ static int lxc_cmd_add_bpf_device_cgroup_callback(int fd, struct lxc_cmd_req *re
        else
                rsp.ret = 0;
 
-       ret = lxc_cmd_rsp_send(fd, &rsp);
-       if (ret < 0)
-               return LXC_CMD_REAP_CLIENT_FD;
-
-       return 0;
+out:
+       return lxc_cmd_rsp_send_reap(fd, &rsp);
 }
 
 int lxc_cmd_console_log(const char *name, const char *lxcpath,
@@ -1297,7 +1264,7 @@ static int lxc_cmd_console_log_callback(int fd, struct lxc_cmd_req *req,
                lxc_ringbuf_move_read_addr(buf, rsp.datalen);
 
 out:
-       return lxc_cmd_rsp_send(fd, &rsp);
+       return lxc_cmd_rsp_send_reap(fd, &rsp);
 }
 
 int lxc_cmd_serve_state_clients(const char *name, const char *lxcpath,
@@ -1329,13 +1296,9 @@ static int lxc_cmd_serve_state_clients_callback(int fd, struct lxc_cmd_req *req,
 
        ret = lxc_serve_state_clients(handler->name, handler, state);
        if (ret < 0)
-               return LXC_CMD_REAP_CLIENT_FD;
-
-       ret = lxc_cmd_rsp_send(fd, &rsp);
-       if (ret < 0)
-               return LXC_CMD_REAP_CLIENT_FD;
+               return ret;
 
-       return 0;
+       return lxc_cmd_rsp_send_reap(fd, &rsp);
 }
 
 int lxc_cmd_seccomp_notify_add_listener(const char *name, const char *lxcpath,
@@ -1400,7 +1363,7 @@ out:
        rsp.ret = -ENOSYS;
 
 #endif
-       return lxc_cmd_rsp_send(fd, &rsp);
+       return lxc_cmd_rsp_send_reap(fd, &rsp);
 }
 
 int lxc_cmd_freeze(const char *name, const char *lxcpath, int timeout)
@@ -1433,7 +1396,7 @@ static int lxc_cmd_freeze_callback(int fd, struct lxc_cmd_req *req,
        if (pure_unified_layout(ops))
                rsp.ret = ops->freeze(ops, timeout);
 
-       return lxc_cmd_rsp_send(fd, &rsp);
+       return lxc_cmd_rsp_send_reap(fd, &rsp);
 }
 
 int lxc_cmd_unfreeze(const char *name, const char *lxcpath, int timeout)
@@ -1466,7 +1429,7 @@ static int lxc_cmd_unfreeze_callback(int fd, struct lxc_cmd_req *req,
        if (pure_unified_layout(ops))
                rsp.ret = ops->unfreeze(ops, timeout);
 
-       return lxc_cmd_rsp_send(fd, &rsp);
+       return lxc_cmd_rsp_send_reap(fd, &rsp);
 }
 
 int lxc_cmd_get_cgroup2_fd(const char *name, const char *lxcpath)
@@ -1519,17 +1482,22 @@ static int lxc_cmd_get_cgroup2_fd_callback_do(int fd, struct lxc_cmd_req *req,
        int ret, send_fd;
 
        if (!pure_unified_layout(ops) || !ops->unified)
-               return lxc_cmd_rsp_send(fd, &rsp);
+               return lxc_cmd_rsp_send_reap(fd, &rsp);
 
        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;
        ret = lxc_abstract_unix_send_fds(fd, &send_fd, 1, &rsp, sizeof(rsp));
        if (ret < 0)
-               return log_error(LXC_CMD_REAP_CLIENT_FD, "Failed to send cgroup2 fd");
+               return syserrno(ret, "Failed to send cgroup2 fd");
 
-       return 0;
+       return log_trace(LXC_CMD_REAP_CLIENT_FD, "Sent cgroup2 fd");
 }
 
 static int lxc_cmd_get_cgroup2_fd_callback(int fd, struct lxc_cmd_req *req,
@@ -1651,7 +1619,7 @@ static int lxc_cmd_handler(int fd, uint32_t events, void *data,
                                .ret = -EPERM,
                        };
 
-                       lxc_cmd_rsp_send(fd, &rsp);
+                       __lxc_cmd_rsp_send(fd, &rsp);
                }
 
                goto out_close;