diff options
| -rw-r--r-- | src/libudev/libudev-monitor.c | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/src/libudev/libudev-monitor.c b/src/libudev/libudev-monitor.c index 4d824ced8d..8e254975db 100644 --- a/src/libudev/libudev-monitor.c +++ b/src/libudev/libudev-monitor.c @@ -35,6 +35,7 @@ #include "libudev.h" #include "libudev-private.h" #include "socket-util.h" +#include "missing.h" /** * SECTION:libudev-monitor @@ -105,6 +106,62 @@ static struct udev_monitor *udev_monitor_new(struct udev *udev) return udev_monitor; } +/* we consider udev running when /dev is on devtmpfs */ +static bool udev_has_devtmpfs(struct udev *udev) { + struct file_handle *h; + int mount_id; + _cleanup_fclose_ FILE *f = NULL; + char line[LINE_MAX], *e; + int r; + + h = alloca(MAX_HANDLE_SZ); + + r = name_to_handle_at(AT_FDCWD, "/dev", h, &mount_id, 0); + if (r < 0) + return false; + + + f = fopen("/proc/self/mountinfo", "re"); + if (!f) + return false; + + FOREACH_LINE(line, f, return false) { + _cleanup_free_ char *opts = NULL; + int mid; + + if (sscanf(line, "%i", &mid) != 1) + continue; + + if (mid != mount_id) + continue; + + e = strstr(line, " - "); + if (!e) + continue; + + /* accept any name that starts with the currently expected type */ + if (startswith(e + 3, "devtmpfs")) + return true; + } + + return false; +} + +/* we consider udev running when we have running udev service */ +static bool udev_has_service(struct udev *udev) { + struct udev_queue *queue; + bool active; + + queue = udev_queue_new(udev); + if (!queue) + return false; + + active = udev_queue_get_udev_is_active(queue); + udev_queue_unref(queue); + + return active; +} + struct udev_monitor *udev_monitor_new_from_netlink_fd(struct udev *udev, const char *name, int fd) { struct udev_monitor *udev_monitor; @@ -127,8 +184,15 @@ struct udev_monitor *udev_monitor_new_from_netlink_fd(struct udev *udev, const c * is running. Uevents would otherwise broadcast the processing data * of the host into containers, which is not acceptable. Containers * will currently just not get any uevents. + * + * We clear the netlink multicast group here, so the socket will + * not receive any messages. */ + if (!udev_has_service(udev) && !udev_has_devtmpfs(udev)) { + udev_dbg(udev, "udev seems not to be active, disable the monitor\n"); + group = 0; + } udev_monitor = udev_monitor_new(udev); if (udev_monitor == NULL) |