From 116254097ad3c07d9f7ed06042dbec7ba4f0f4fd Mon Sep 17 00:00:00 2001 From: Kay Sievers Date: Sun, 29 Mar 2009 04:24:39 +0200 Subject: [PATCH] send monitor events back to netlink socket Instead of of our own private monitor socket, we send the processed event back to our netlink socket, to the multicast group 2 -- so any number of users can listen to udev events, just like they can listen to kernel emitted events on group 1. --- configure.ac | 6 +++--- rules/rules.d/95-udev-late.rules | 4 ---- udev/lib/libudev-monitor.c | 31 ++++++++++++++++++++++--------- udev/lib/libudev.h | 6 +++++- udev/udevadm-monitor.c | 10 +++------- udev/udevd.c | 6 ++++-- 6 files changed, 37 insertions(+), 26 deletions(-) diff --git a/configure.ac b/configure.ac index 001f338d1..3fd51ce36 100644 --- a/configure.ac +++ b/configure.ac @@ -15,9 +15,9 @@ AC_PREFIX_DEFAULT([/usr]) test "$prefix" = NONE && test "$exec_prefix" = NONE && exec_prefix= dnl /* libudev version */ -LIBUDEV_LT_CURRENT=1 -LIBUDEV_LT_REVISION=1 -LIBUDEV_LT_AGE=1 +LIBUDEV_LT_CURRENT=2 +LIBUDEV_LT_REVISION=0 +LIBUDEV_LT_AGE=2 AC_SUBST(LIBUDEV_LT_CURRENT) AC_SUBST(LIBUDEV_LT_REVISION) AC_SUBST(LIBUDEV_LT_AGE) diff --git a/rules/rules.d/95-udev-late.rules b/rules/rules.d/95-udev-late.rules index 7207081d4..eca0faa5c 100644 --- a/rules/rules.d/95-udev-late.rules +++ b/rules/rules.d/95-udev-late.rules @@ -2,7 +2,3 @@ # run a command on remove events ACTION=="remove", ENV{REMOVE_CMD}!="", RUN+="$env{REMOVE_CMD}" - -# event to be catched by udevmonitor -RUN+="socket:@/org/kernel/udev/monitor" - diff --git a/udev/lib/libudev-monitor.c b/udev/lib/libudev-monitor.c index c0aa99c65..b2f76c312 100644 --- a/udev/lib/libudev-monitor.c +++ b/udev/lib/libudev-monitor.c @@ -29,6 +29,7 @@ struct udev_monitor { int refcount; int sock; struct sockaddr_nl snl; + struct sockaddr_nl snl_peer; struct sockaddr_un sun; socklen_t addrlen; }; @@ -90,7 +91,7 @@ struct udev_monitor *udev_monitor_new_from_socket(struct udev *udev, const char return udev_monitor; } -struct udev_monitor *udev_monitor_new_from_netlink(struct udev *udev) +struct udev_monitor *udev_monitor_new_from_netlink(struct udev *udev, unsigned int group) { struct udev_monitor *udev_monitor; @@ -110,10 +111,11 @@ struct udev_monitor *udev_monitor_new_from_netlink(struct udev *udev) } udev_monitor->snl.nl_family = AF_NETLINK; - udev_monitor->snl.nl_pid = getpid(); - udev_monitor->snl.nl_groups = 1; + udev_monitor->snl.nl_groups = group; + udev_monitor->snl_peer.nl_family = AF_NETLINK; + udev_monitor->snl_peer.nl_groups = UDEV_MONITOR_UDEV; - dbg(udev, "monitor %p created with NETLINK_KOBJECT_UEVENT\n", udev_monitor); + dbg(udev, "monitor %p created with NETLINK_KOBJECT_UEVENT (%u)\n", udev_monitor, group); return udev_monitor; } @@ -123,14 +125,16 @@ int udev_monitor_enable_receiving(struct udev_monitor *udev_monitor) const int on = 1; if (udev_monitor->snl.nl_family != 0) { - err = bind(udev_monitor->sock, (struct sockaddr *)&udev_monitor->snl, sizeof(struct sockaddr_nl)); + err = bind(udev_monitor->sock, + (struct sockaddr *)&udev_monitor->snl, sizeof(struct sockaddr_nl)); if (err < 0) { err(udev_monitor->udev, "bind failed: %m\n"); return err; } dbg(udev_monitor->udev, "monitor %p listening on netlink\n", udev_monitor); } else if (udev_monitor->sun.sun_family != 0) { - err = bind(udev_monitor->sock, (struct sockaddr *)&udev_monitor->sun, udev_monitor->addrlen); + err = bind(udev_monitor->sock, + (struct sockaddr *)&udev_monitor->sun, udev_monitor->addrlen); if (err < 0) { err(udev_monitor->udev, "bind failed: %m\n"); return err; @@ -381,9 +385,18 @@ int udev_monitor_send_device(struct udev_monitor *udev_monitor, struct udev_devi len = udev_device_get_properties_monitor_buf(udev_device, &buf); if (len < 32) return -1; - count = sendto(udev_monitor->sock, - buf, len, 0, - (struct sockaddr *)&udev_monitor->sun, udev_monitor->addrlen); + if (udev_monitor->sun.sun_family != 0) { + count = sendto(udev_monitor->sock, + buf, len, 0, + (struct sockaddr *)&udev_monitor->sun, + udev_monitor->addrlen); + } else { + /* no destination besides the muticast group, we will always get -1 ECONNREFUSED */ + count = sendto(udev_monitor->sock, + buf, len, 0, + (struct sockaddr *)&udev_monitor->snl_peer, + sizeof(struct sockaddr_nl)); + } info(udev_monitor->udev, "passed %zi bytes to monitor %p, \n", count, udev_monitor); return count; } diff --git a/udev/lib/libudev.h b/udev/lib/libudev.h index a5d2c22e8..be09ddb75 100644 --- a/udev/lib/libudev.h +++ b/udev/lib/libudev.h @@ -76,8 +76,12 @@ extern const char *udev_device_get_sysattr_value(struct udev_device *udev_device /* udev and kernel device events */ struct udev_monitor; +enum udev_monitor_netlink_group { + UDEV_MONITOR_KERNEL = 1, + UDEV_MONITOR_UDEV = 2, +}; extern struct udev_monitor *udev_monitor_new_from_socket(struct udev *udev, const char *socket_path); -extern struct udev_monitor *udev_monitor_new_from_netlink(struct udev *udev); +extern struct udev_monitor *udev_monitor_new_from_netlink(struct udev *udev, enum udev_monitor_netlink_group group); extern int udev_monitor_enable_receiving(struct udev_monitor *udev_monitor); extern struct udev_monitor *udev_monitor_ref(struct udev_monitor *udev_monitor); extern void udev_monitor_unref(struct udev_monitor *udev_monitor); diff --git a/udev/udevadm-monitor.c b/udev/udevadm-monitor.c index 9be02da16..43c1cc116 100644 --- a/udev/udevadm-monitor.c +++ b/udev/udevadm-monitor.c @@ -115,11 +115,6 @@ int udevadm_monitor(struct udev *udev, int argc, char *argv[]) print_udev =1; } - if (getuid() != 0 && print_kernel) { - fprintf(stderr, "root privileges needed to subscribe to kernel events\n"); - goto out; - } - /* set signal handlers */ memset(&act, 0x00, sizeof(struct sigaction)); act.sa_handler = (void (*)(int)) sig_handler; @@ -130,7 +125,7 @@ int udevadm_monitor(struct udev *udev, int argc, char *argv[]) printf("monitor will print the received events for:\n"); if (print_udev) { - udev_monitor = udev_monitor_new_from_socket(udev, "@/org/kernel/udev/monitor"); + udev_monitor = udev_monitor_new_from_netlink(udev, UDEV_MONITOR_UDEV); if (udev_monitor == NULL) { rc = 1; goto out; @@ -142,8 +137,9 @@ int udevadm_monitor(struct udev *udev, int argc, char *argv[]) printf("UDEV - the event which udev sends out after rule processing\n"); } if (print_kernel) { - kernel_monitor = udev_monitor_new_from_netlink(udev); + kernel_monitor = udev_monitor_new_from_netlink(udev, UDEV_MONITOR_KERNEL); if (kernel_monitor == NULL) { + fprintf(stderr, "unable to subscribe to kernel events\n"); rc = 3; goto out; } diff --git a/udev/udevd.c b/udev/udevd.c index 291655ef0..d9de26ea6 100644 --- a/udev/udevd.c +++ b/udev/udevd.c @@ -195,7 +195,6 @@ static void event_fork(struct udev_event *event) switch (pid) { case 0: /* child */ - udev_monitor_unref(kernel_monitor); udev_ctrl_unref(udev_ctrl); logging_close(); logging_init("udevd-event"); @@ -235,6 +234,9 @@ static void event_fork(struct udev_event *event) udev_device_update_db(event->dev); } + /* send processed event back to the kernel netlink socket */ + udev_monitor_send_device(kernel_monitor, event->dev); + info(event->udev, "seq %llu exit with %i\n", udev_device_get_seqnum(event->dev), err); logging_close(); if (err != 0) @@ -811,7 +813,7 @@ int main(int argc, char *argv[]) goto exit; } - kernel_monitor = udev_monitor_new_from_netlink(udev); + kernel_monitor = udev_monitor_new_from_netlink(udev, UDEV_MONITOR_KERNEL); if (kernel_monitor == NULL || udev_monitor_enable_receiving(kernel_monitor) < 0) { fprintf(stderr, "error initializing netlink socket\n"); err(udev, "error initializing netlink socket\n"); -- 2.30.2