udevd: convert to event worker processes

[elogind.git] / udev / lib / libudev-monitor.c

diff --git a/udev/lib/libudev-monitor.c b/udev/lib/libudev-monitor.c
index 395a4d27e1ee9f7904a42f8c549685e50d06bae6..33a0605492a128f174b080b2b84b6206907fc81c 100644 (file)
--- a/udev/lib/libudev-monitor.c
+++ b/udev/lib/libudev-monitor.c
@@ -32,15 +32,17 @@ struct udev_monitor {
        int refcount;
        int sock;
        struct sockaddr_nl snl;
-       struct sockaddr_nl snl_peer;
+       struct sockaddr_nl snl_trusted_sender;
+       struct sockaddr_nl snl_destination;
        struct sockaddr_un sun;
        socklen_t addrlen;
        struct udev_list_node filter_subsystem_list;
 };
 
 enum udev_monitor_netlink_group {
-       UDEV_MONITOR_KERNEL     = 1,
-       UDEV_MONITOR_UDEV       = 2,
+       UDEV_MONITOR_NONE,
+       UDEV_MONITOR_KERNEL,
+       UDEV_MONITOR_UDEV,
 };
 
 #define UDEV_MONITOR_MAGIC             0xcafe1dea
@@ -171,11 +173,11 @@ struct udev_monitor *udev_monitor_new_from_netlink(struct udev *udev, const char
                return NULL;
 
        if (name == NULL)
-               return NULL;
-       if (strcmp(name, "kernel") == 0)
-               group = UDEV_MONITOR_KERNEL;
+               group = UDEV_MONITOR_NONE;
        else if (strcmp(name, "udev") == 0)
                group = UDEV_MONITOR_UDEV;
+       else if (strcmp(name, "kernel") == 0)
+               group = UDEV_MONITOR_KERNEL;
        else
                return NULL;
 
@@ -193,8 +195,10 @@ struct udev_monitor *udev_monitor_new_from_netlink(struct udev *udev, const char
 
        udev_monitor->snl.nl_family = AF_NETLINK;
        udev_monitor->snl.nl_groups = group;
-       udev_monitor->snl_peer.nl_family = AF_NETLINK;
-       udev_monitor->snl_peer.nl_groups = UDEV_MONITOR_UDEV;
+
+       /* default destination for sending */
+       udev_monitor->snl_destination.nl_family = AF_NETLINK;
+       udev_monitor->snl_destination.nl_groups = UDEV_MONITOR_UDEV;
 
        dbg(udev, "monitor %p created with NETLINK_KOBJECT_UEVENT (%u)\n", udev_monitor, group);
        return udev_monitor;
@@ -281,6 +285,12 @@ int udev_monitor_filter_update(struct udev_monitor *udev_monitor)
        return err;
 }
 
+int udev_monitor_allow_unicast_sender(struct udev_monitor *udev_monitor, struct udev_monitor *sender)
+{
+       udev_monitor->snl_trusted_sender.nl_pid = sender->snl.nl_pid;
+       return 0;
+}
+
 int udev_monitor_enable_receiving(struct udev_monitor *udev_monitor)
 {
        int err;
@@ -293,6 +303,19 @@ int udev_monitor_enable_receiving(struct udev_monitor *udev_monitor)
                udev_monitor_filter_update(udev_monitor);
                err = bind(udev_monitor->sock,
                           (struct sockaddr *)&udev_monitor->snl, sizeof(struct sockaddr_nl));
+               if (err == 0) {
+                       struct sockaddr_nl snl;
+                       socklen_t addrlen;
+
+                       /*
+                        * get the address the kernel has assigned us
+                        * it is usually, but not neccessarily the pid
+                        */
+                       addrlen = sizeof(struct sockaddr_nl);
+                       err = getsockname(udev_monitor->sock, (struct sockaddr *)&snl, &addrlen);
+                       if (err == 0)
+                               udev_monitor->snl.nl_pid = snl.nl_pid;
+               }
        } else {
                return -EINVAL;
        }
@@ -314,6 +337,15 @@ int udev_monitor_set_receive_buffer_size(struct udev_monitor *udev_monitor, int
        return setsockopt(udev_monitor->sock, SOL_SOCKET, SO_RCVBUFFORCE, &size, sizeof(size));
 }
 
+int udev_monitor_disconnect(struct udev_monitor *udev_monitor)
+{
+       int err;
+
+       err = close(udev_monitor->sock);
+       udev_monitor->sock = -1;
+       return err;
+}
+
 /**
  * udev_monitor_ref:
  * @udev_monitor: udev monitor
@@ -478,10 +510,13 @@ retry:
 
        if (udev_monitor->snl.nl_family != 0) {
                if (snl.nl_groups == 0) {
-                       info(udev_monitor->udev, "unicast netlink message ignored\n");
-                       return NULL;
-               }
-               if (snl.nl_groups == UDEV_MONITOR_KERNEL) {
+                       /* unicast message, check if we trust the sender */
+                       if (udev_monitor->snl_trusted_sender.nl_pid == 0 ||
+                           snl.nl_pid != udev_monitor->snl_trusted_sender.nl_pid) {
+                               info(udev_monitor->udev, "unicast netlink message ignored\n");
+                               return NULL;
+                       }
+               } else if (snl.nl_groups == UDEV_MONITOR_KERNEL) {
                        if (snl.nl_pid > 0) {
                                info(udev_monitor->udev, "multicast kernel netlink message from pid %d ignored\n", snl.nl_pid);
                                return NULL;
@@ -621,7 +656,8 @@ retry:
        return udev_device;
 }
 
-int udev_monitor_send_device(struct udev_monitor *udev_monitor, struct udev_device *udev_device)
+int udev_monitor_send_device(struct udev_monitor *udev_monitor,
+                            struct udev_monitor *destination, struct udev_device *udev_device)
 {
        struct msghdr smsg;
        struct iovec iov[2];
@@ -683,8 +719,16 @@ int udev_monitor_send_device(struct udev_monitor *udev_monitor, struct udev_devi
                memset(&smsg, 0x00, sizeof(struct msghdr));
                smsg.msg_iov = iov;
                smsg.msg_iovlen = 2;
-               /* no destination besides the muticast group, we will always get ECONNREFUSED */
-               smsg.msg_name = &udev_monitor->snl_peer;
+               /*
+                * Use custom address for target, or the default one.
+                *
+                * If we send to a muticast group, we will get
+                * ECONNREFUSED, which is expected.
+                */
+               if (destination != NULL)
+                       smsg.msg_name = &destination->snl;
+               else
+                       smsg.msg_name = &udev_monitor->snl_destination;
                smsg.msg_namelen = sizeof(struct sockaddr_nl);
        } else {
                return -1;