+++ /dev/null
-/***
- This file is part of systemd.
-
- Copyright 2008-2012 Kay Sievers <kay@vrfy.org>
-
- systemd is free software; you can redistribute it and/or modify it
- under the terms of the GNU Lesser General Public License as published by
- the Free Software Foundation; either version 2.1 of the License, or
- (at your option) any later version.
-
- systemd is distributed in the hope that it will be useful, but
- WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public License
- along with systemd; If not, see <http://www.gnu.org/licenses/>.
-***/
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <stddef.h>
-#include <unistd.h>
-#include <errno.h>
-#include <string.h>
-#include <poll.h>
-#include <sys/socket.h>
-#include <linux/netlink.h>
-#include <linux/filter.h>
-
-#include "libudev.h"
-#include "libudev-private.h"
-#include "socket-util.h"
-#include "missing.h"
-
-/**
- * SECTION:libudev-monitor
- * @short_description: device event source
- *
- * Connects to a device event source.
- */
-
-/**
- * udev_monitor:
- *
- * Opaque object handling an event source.
- */
-struct udev_monitor {
- struct udev *udev;
- int refcount;
- int sock;
- union sockaddr_union snl;
- union sockaddr_union snl_trusted_sender;
- union sockaddr_union snl_destination;
- socklen_t addrlen;
- struct udev_list filter_subsystem_list;
- struct udev_list filter_tag_list;
- bool bound;
-};
-
-enum udev_monitor_netlink_group {
- UDEV_MONITOR_NONE,
- UDEV_MONITOR_KERNEL,
- UDEV_MONITOR_UDEV,
-};
-
-#define UDEV_MONITOR_MAGIC 0xfeedcafe
-struct udev_monitor_netlink_header {
- /* "libudev" prefix to distinguish libudev and kernel messages */
- char prefix[8];
- /*
- * magic to protect against daemon <-> library message format mismatch
- * used in the kernel from socket filter rules; needs to be stored in network order
- */
- unsigned int magic;
- /* total length of header structure known to the sender */
- unsigned int header_size;
- /* properties string buffer */
- unsigned int properties_off;
- unsigned int properties_len;
- /*
- * hashes of primary device properties strings, to let libudev subscribers
- * use in-kernel socket filters; values need to be stored in network order
- */
- unsigned int filter_subsystem_hash;
- unsigned int filter_devtype_hash;
- unsigned int filter_tag_bloom_hi;
- unsigned int filter_tag_bloom_lo;
-};
-
-static struct udev_monitor *udev_monitor_new(struct udev *udev)
-{
- struct udev_monitor *udev_monitor;
-
- udev_monitor = new0(struct udev_monitor, 1);
- if (udev_monitor == NULL)
- return NULL;
- udev_monitor->refcount = 1;
- udev_monitor->udev = udev;
- udev_list_init(udev, &udev_monitor->filter_subsystem_list, false);
- udev_list_init(udev, &udev_monitor->filter_tag_list, true);
- return udev_monitor;
-}
-
-/* we consider udev running when /dev is on devtmpfs */
-static bool udev_has_devtmpfs(struct udev *udev) {
-
- union file_handle_union h = FILE_HANDLE_INIT;
- _cleanup_fclose_ FILE *f = NULL;
- char line[LINE_MAX], *e;
- int mount_id;
- int r;
-
- r = name_to_handle_at(AT_FDCWD, "/dev", &h.handle, &mount_id, 0);
- if (r < 0) {
- if (errno != EOPNOTSUPP)
- log_debug_errno(errno, "name_to_handle_at on /dev: %m");
- return false;
- }
-
- f = fopen("/proc/self/mountinfo", "re");
- if (!f)
- return false;
-
- FOREACH_LINE(line, f, return false) {
- 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;
-}
-
-struct udev_monitor *udev_monitor_new_from_netlink_fd(struct udev *udev, const char *name, int fd)
-{
- struct udev_monitor *udev_monitor;
- unsigned int group;
-
- if (udev == NULL)
- return NULL;
-
- if (name == NULL)
- group = UDEV_MONITOR_NONE;
- else if (streq(name, "udev")) {
- /*
- * We do not support subscribing to uevents if no instance of
- * udev is running. Uevents would otherwise broadcast the
- * processing data of the host into containers, which is not
- * desired.
- *
- * Containers will currently not get any udev uevents, until
- * a supporting infrastructure is available.
- *
- * We do not set a netlink multicast group here, so the socket
- * will not receive any messages.
- */
- if (access("/run/udev/control", F_OK) < 0 && !udev_has_devtmpfs(udev)) {
- log_debug("the udev service seems not to be active, disable the monitor");
- group = UDEV_MONITOR_NONE;
- } else
- group = UDEV_MONITOR_UDEV;
- } else if (streq(name, "kernel"))
- group = UDEV_MONITOR_KERNEL;
- else
- return NULL;
-
- udev_monitor = udev_monitor_new(udev);
- if (udev_monitor == NULL)
- return NULL;
-
- if (fd < 0) {
- udev_monitor->sock = socket(PF_NETLINK, SOCK_RAW|SOCK_CLOEXEC|SOCK_NONBLOCK, NETLINK_KOBJECT_UEVENT);
- if (udev_monitor->sock == -1) {
- log_debug_errno(errno, "error getting socket: %m");
- free(udev_monitor);
- return NULL;
- }
- } else {
- udev_monitor->bound = true;
- udev_monitor->sock = fd;
- }
-
- udev_monitor->snl.nl.nl_family = AF_NETLINK;
- udev_monitor->snl.nl.nl_groups = group;
-
- /* default destination for sending */
- udev_monitor->snl_destination.nl.nl_family = AF_NETLINK;
- udev_monitor->snl_destination.nl.nl_groups = UDEV_MONITOR_UDEV;
-
- return udev_monitor;
-}
-
-/**
- * udev_monitor_new_from_netlink:
- * @udev: udev library context
- * @name: name of event source
- *
- * Create new udev monitor and connect to a specified event
- * source. Valid sources identifiers are "udev" and "kernel".
- *
- * Applications should usually not connect directly to the
- * "kernel" events, because the devices might not be useable
- * at that time, before udev has configured them, and created
- * device nodes. Accessing devices at the same time as udev,
- * might result in unpredictable behavior. The "udev" events
- * are sent out after udev has finished its event processing,
- * all rules have been processed, and needed device nodes are
- * created.
- *
- * The initial refcount is 1, and needs to be decremented to
- * release the resources of the udev monitor.
- *
- * Returns: a new udev monitor, or #NULL, in case of an error
- **/
-_public_ struct udev_monitor *udev_monitor_new_from_netlink(struct udev *udev, const char *name)
-{
- return udev_monitor_new_from_netlink_fd(udev, name, -1);
-}
-
-static inline void bpf_stmt(struct sock_filter *inss, unsigned int *i,
- unsigned short code, unsigned int data)
-{
- struct sock_filter *ins = &inss[*i];
-
- ins->code = code;
- ins->k = data;
- (*i)++;
-}
-
-static inline void bpf_jmp(struct sock_filter *inss, unsigned int *i,
- unsigned short code, unsigned int data,
- unsigned short jt, unsigned short jf)
-{
- struct sock_filter *ins = &inss[*i];
-
- ins->code = code;
- ins->jt = jt;
- ins->jf = jf;
- ins->k = data;
- (*i)++;
-}
-
-/**
- * udev_monitor_filter_update:
- * @udev_monitor: monitor
- *
- * Update the installed socket filter. This is only needed,
- * if the filter was removed or changed.
- *
- * Returns: 0 on success, otherwise a negative error value.
- */
-_public_ int udev_monitor_filter_update(struct udev_monitor *udev_monitor)
-{
- struct sock_filter ins[512];
- struct sock_fprog filter;
- unsigned int i;
- struct udev_list_entry *list_entry;
- int err;
-
- if (udev_list_get_entry(&udev_monitor->filter_subsystem_list) == NULL &&
- udev_list_get_entry(&udev_monitor->filter_tag_list) == NULL)
- return 0;
-
- memzero(ins, sizeof(ins));
- i = 0;
-
- /* load magic in A */
- bpf_stmt(ins, &i, BPF_LD|BPF_W|BPF_ABS, offsetof(struct udev_monitor_netlink_header, magic));
- /* jump if magic matches */
- bpf_jmp(ins, &i, BPF_JMP|BPF_JEQ|BPF_K, UDEV_MONITOR_MAGIC, 1, 0);
- /* wrong magic, pass packet */
- bpf_stmt(ins, &i, BPF_RET|BPF_K, 0xffffffff);
-
- if (udev_list_get_entry(&udev_monitor->filter_tag_list) != NULL) {
- int tag_matches;
-
- /* count tag matches, to calculate end of tag match block */
- tag_matches = 0;
- udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_monitor->filter_tag_list))
- tag_matches++;
-
- /* add all tags matches */
- udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_monitor->filter_tag_list)) {
- uint64_t tag_bloom_bits = util_string_bloom64(udev_list_entry_get_name(list_entry));
- uint32_t tag_bloom_hi = tag_bloom_bits >> 32;
- uint32_t tag_bloom_lo = tag_bloom_bits & 0xffffffff;
-
- /* load device bloom bits in A */
- bpf_stmt(ins, &i, BPF_LD|BPF_W|BPF_ABS, offsetof(struct udev_monitor_netlink_header, filter_tag_bloom_hi));
- /* clear bits (tag bits & bloom bits) */
- bpf_stmt(ins, &i, BPF_ALU|BPF_AND|BPF_K, tag_bloom_hi);
- /* jump to next tag if it does not match */
- bpf_jmp(ins, &i, BPF_JMP|BPF_JEQ|BPF_K, tag_bloom_hi, 0, 3);
-
- /* load device bloom bits in A */
- bpf_stmt(ins, &i, BPF_LD|BPF_W|BPF_ABS, offsetof(struct udev_monitor_netlink_header, filter_tag_bloom_lo));
- /* clear bits (tag bits & bloom bits) */
- bpf_stmt(ins, &i, BPF_ALU|BPF_AND|BPF_K, tag_bloom_lo);
- /* jump behind end of tag match block if tag matches */
- tag_matches--;
- bpf_jmp(ins, &i, BPF_JMP|BPF_JEQ|BPF_K, tag_bloom_lo, 1 + (tag_matches * 6), 0);
- }
-
- /* nothing matched, drop packet */
- bpf_stmt(ins, &i, BPF_RET|BPF_K, 0);
- }
-
- /* add all subsystem matches */
- if (udev_list_get_entry(&udev_monitor->filter_subsystem_list) != NULL) {
- udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_monitor->filter_subsystem_list)) {
- unsigned int hash = util_string_hash32(udev_list_entry_get_name(list_entry));
-
- /* load device subsystem value in A */
- bpf_stmt(ins, &i, BPF_LD|BPF_W|BPF_ABS, offsetof(struct udev_monitor_netlink_header, filter_subsystem_hash));
- if (udev_list_entry_get_value(list_entry) == NULL) {
- /* jump if subsystem does not match */
- bpf_jmp(ins, &i, BPF_JMP|BPF_JEQ|BPF_K, hash, 0, 1);
- } else {
- /* jump if subsystem does not match */
- bpf_jmp(ins, &i, BPF_JMP|BPF_JEQ|BPF_K, hash, 0, 3);
-
- /* load device devtype value in A */
- bpf_stmt(ins, &i, BPF_LD|BPF_W|BPF_ABS, offsetof(struct udev_monitor_netlink_header, filter_devtype_hash));
- /* jump if value does not match */
- hash = util_string_hash32(udev_list_entry_get_value(list_entry));
- bpf_jmp(ins, &i, BPF_JMP|BPF_JEQ|BPF_K, hash, 0, 1);
- }
-
- /* matched, pass packet */
- bpf_stmt(ins, &i, BPF_RET|BPF_K, 0xffffffff);
-
- if (i+1 >= ELEMENTSOF(ins))
- return -E2BIG;
- }
-
- /* nothing matched, drop packet */
- bpf_stmt(ins, &i, BPF_RET|BPF_K, 0);
- }
-
- /* matched, pass packet */
- bpf_stmt(ins, &i, BPF_RET|BPF_K, 0xffffffff);
-
- /* install filter */
- memzero(&filter, sizeof(filter));
- filter.len = i;
- filter.filter = ins;
- err = setsockopt(udev_monitor->sock, SOL_SOCKET, SO_ATTACH_FILTER, &filter, sizeof(filter));
- return err < 0 ? -errno : 0;
-}
-
-int udev_monitor_allow_unicast_sender(struct udev_monitor *udev_monitor, struct udev_monitor *sender)
-{
- udev_monitor->snl_trusted_sender.nl.nl_pid = sender->snl.nl.nl_pid;
- return 0;
-}
-/**
- * udev_monitor_enable_receiving:
- * @udev_monitor: the monitor which should receive events
- *
- * Binds the @udev_monitor socket to the event source.
- *
- * Returns: 0 on success, otherwise a negative error value.
- */
-_public_ int udev_monitor_enable_receiving(struct udev_monitor *udev_monitor)
-{
- int err = 0;
- const int on = 1;
-
- udev_monitor_filter_update(udev_monitor);
-
- if (!udev_monitor->bound) {
- err = bind(udev_monitor->sock,
- &udev_monitor->snl.sa, sizeof(struct sockaddr_nl));
- if (err == 0)
- udev_monitor->bound = true;
- }
-
- if (err >= 0) {
- union sockaddr_union snl;
- socklen_t addrlen;
-
- /*
- * get the address the kernel has assigned us
- * it is usually, but not necessarily the pid
- */
- addrlen = sizeof(struct sockaddr_nl);
- err = getsockname(udev_monitor->sock, &snl.sa, &addrlen);
- if (err == 0)
- udev_monitor->snl.nl.nl_pid = snl.nl.nl_pid;
- } else {
- log_debug_errno(errno, "bind failed: %m");
- return -errno;
- }
-
- /* enable receiving of sender credentials */
- err = setsockopt(udev_monitor->sock, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on));
- if (err < 0)
- log_debug_errno(errno, "setting SO_PASSCRED failed: %m");
-
- return 0;
-}
-
-/**
- * udev_monitor_set_receive_buffer_size:
- * @udev_monitor: the monitor which should receive events
- * @size: the size in bytes
- *
- * Set the size of the kernel socket buffer. This call needs the
- * appropriate privileges to succeed.
- *
- * Returns: 0 on success, otherwise -1 on error.
- */
-_public_ int udev_monitor_set_receive_buffer_size(struct udev_monitor *udev_monitor, int size)
-{
- if (udev_monitor == NULL)
- return -EINVAL;
- 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 < 0 ? -errno : 0;
-}
-
-/**
- * udev_monitor_ref:
- * @udev_monitor: udev monitor
- *
- * Take a reference of a udev monitor.
- *
- * Returns: the passed udev monitor
- **/
-_public_ struct udev_monitor *udev_monitor_ref(struct udev_monitor *udev_monitor)
-{
- if (udev_monitor == NULL)
- return NULL;
- udev_monitor->refcount++;
- return udev_monitor;
-}
-
-/**
- * udev_monitor_unref:
- * @udev_monitor: udev monitor
- *
- * Drop a reference of a udev monitor. If the refcount reaches zero,
- * the bound socket will be closed, and the resources of the monitor
- * will be released.
- *
- * Returns: #NULL
- **/
-_public_ struct udev_monitor *udev_monitor_unref(struct udev_monitor *udev_monitor)
-{
- if (udev_monitor == NULL)
- return NULL;
- udev_monitor->refcount--;
- if (udev_monitor->refcount > 0)
- return NULL;
- if (udev_monitor->sock >= 0)
- close(udev_monitor->sock);
- udev_list_cleanup(&udev_monitor->filter_subsystem_list);
- udev_list_cleanup(&udev_monitor->filter_tag_list);
- free(udev_monitor);
- return NULL;
-}
-
-/**
- * udev_monitor_get_udev:
- * @udev_monitor: udev monitor
- *
- * Retrieve the udev library context the monitor was created with.
- *
- * Returns: the udev library context
- **/
-_public_ struct udev *udev_monitor_get_udev(struct udev_monitor *udev_monitor)
-{
- if (udev_monitor == NULL)
- return NULL;
- return udev_monitor->udev;
-}
-
-/**
- * udev_monitor_get_fd:
- * @udev_monitor: udev monitor
- *
- * Retrieve the socket file descriptor associated with the monitor.
- *
- * Returns: the socket file descriptor
- **/
-_public_ int udev_monitor_get_fd(struct udev_monitor *udev_monitor)
-{
- if (udev_monitor == NULL)
- return -EINVAL;
- return udev_monitor->sock;
-}
-
-static int passes_filter(struct udev_monitor *udev_monitor, struct udev_device *udev_device)
-{
- struct udev_list_entry *list_entry;
-
- if (udev_list_get_entry(&udev_monitor->filter_subsystem_list) == NULL)
- goto tag;
- udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_monitor->filter_subsystem_list)) {
- const char *subsys = udev_list_entry_get_name(list_entry);
- const char *dsubsys = udev_device_get_subsystem(udev_device);
- const char *devtype;
- const char *ddevtype;
-
- if (!streq(dsubsys, subsys))
- continue;
-
- devtype = udev_list_entry_get_value(list_entry);
- if (devtype == NULL)
- goto tag;
- ddevtype = udev_device_get_devtype(udev_device);
- if (ddevtype == NULL)
- continue;
- if (streq(ddevtype, devtype))
- goto tag;
- }
- return 0;
-
-tag:
- if (udev_list_get_entry(&udev_monitor->filter_tag_list) == NULL)
- return 1;
- udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_monitor->filter_tag_list)) {
- const char *tag = udev_list_entry_get_name(list_entry);
-
- if (udev_device_has_tag(udev_device, tag))
- return 1;
- }
- return 0;
-}
-
-/**
- * udev_monitor_receive_device:
- * @udev_monitor: udev monitor
- *
- * Receive data from the udev monitor socket, allocate a new udev
- * device, fill in the received data, and return the device.
- *
- * Only socket connections with uid=0 are accepted.
- *
- * The monitor socket is by default set to NONBLOCK. A variant of poll() on
- * the file descriptor returned by udev_monitor_get_fd() should to be used to
- * wake up when new devices arrive, or alternatively the file descriptor
- * switched into blocking mode.
- *
- * The initial refcount is 1, and needs to be decremented to
- * release the resources of the udev device.
- *
- * Returns: a new udev device, or #NULL, in case of an error
- **/
-_public_ struct udev_device *udev_monitor_receive_device(struct udev_monitor *udev_monitor)
-{
- struct udev_device *udev_device;
- struct msghdr smsg;
- struct iovec iov;
- char cred_msg[CMSG_SPACE(sizeof(struct ucred))];
- struct cmsghdr *cmsg;
- union sockaddr_union snl;
- struct ucred *cred;
- union {
- struct udev_monitor_netlink_header nlh;
- char raw[8192];
- } buf;
- ssize_t buflen;
- ssize_t bufpos;
- bool is_initialized = false;
-
-retry:
- if (udev_monitor == NULL)
- return NULL;
- iov.iov_base = &buf;
- iov.iov_len = sizeof(buf);
- memzero(&smsg, sizeof(struct msghdr));
- smsg.msg_iov = &iov;
- smsg.msg_iovlen = 1;
- smsg.msg_control = cred_msg;
- smsg.msg_controllen = sizeof(cred_msg);
- smsg.msg_name = &snl;
- smsg.msg_namelen = sizeof(snl);
-
- buflen = recvmsg(udev_monitor->sock, &smsg, 0);
- if (buflen < 0) {
- if (errno != EINTR)
- log_debug("unable to receive message");
- return NULL;
- }
-
- if (buflen < 32 || (smsg.msg_flags & MSG_TRUNC)) {
- log_debug("invalid message length");
- return NULL;
- }
-
- if (snl.nl.nl_groups == 0) {
- /* unicast message, check if we trust the sender */
- if (udev_monitor->snl_trusted_sender.nl.nl_pid == 0 ||
- snl.nl.nl_pid != udev_monitor->snl_trusted_sender.nl.nl_pid) {
- log_debug("unicast netlink message ignored");
- return NULL;
- }
- } else if (snl.nl.nl_groups == UDEV_MONITOR_KERNEL) {
- if (snl.nl.nl_pid > 0) {
- log_debug("multicast kernel netlink message from PID %"PRIu32" ignored",
- snl.nl.nl_pid);
- return NULL;
- }
- }
-
- cmsg = CMSG_FIRSTHDR(&smsg);
- if (cmsg == NULL || cmsg->cmsg_type != SCM_CREDENTIALS) {
- log_debug("no sender credentials received, message ignored");
- return NULL;
- }
-
- cred = (struct ucred *)CMSG_DATA(cmsg);
- if (cred->uid != 0) {
- log_debug("sender uid="UID_FMT", message ignored", cred->uid);
- return NULL;
- }
-
- if (memcmp(buf.raw, "libudev", 8) == 0) {
- /* udev message needs proper version magic */
- if (buf.nlh.magic != htonl(UDEV_MONITOR_MAGIC)) {
- log_debug("unrecognized message signature (%x != %x)",
- buf.nlh.magic, htonl(UDEV_MONITOR_MAGIC));
- return NULL;
- }
- if (buf.nlh.properties_off+32 > (size_t)buflen) {
- log_debug("message smaller than expected (%u > %zd)",
- buf.nlh.properties_off+32, buflen);
- return NULL;
- }
-
- bufpos = buf.nlh.properties_off;
-
- /* devices received from udev are always initialized */
- is_initialized = true;
- } else {
- /* kernel message with header */
- bufpos = strlen(buf.raw) + 1;
- if ((size_t)bufpos < sizeof("a@/d") || bufpos >= buflen) {
- log_debug("invalid message length");
- return NULL;
- }
-
- /* check message header */
- if (strstr(buf.raw, "@/") == NULL) {
- log_debug("unrecognized message header");
- return NULL;
- }
- }
-
- udev_device = udev_device_new_from_nulstr(udev_monitor->udev, &buf.raw[bufpos], buflen - bufpos);
- if (!udev_device) {
- log_debug("could not create device: %m");
- return NULL;
- }
-
- if (is_initialized)
- udev_device_set_is_initialized(udev_device);
-
- /* skip device, if it does not pass the current filter */
- if (!passes_filter(udev_monitor, udev_device)) {
- struct pollfd pfd[1];
- int rc;
-
- udev_device_unref(udev_device);
-
- /* if something is queued, get next device */
- pfd[0].fd = udev_monitor->sock;
- pfd[0].events = POLLIN;
- rc = poll(pfd, 1, 0);
- if (rc > 0)
- goto retry;
- return NULL;
- }
-
- return udev_device;
-}
-
-int udev_monitor_send_device(struct udev_monitor *udev_monitor,
- struct udev_monitor *destination, struct udev_device *udev_device)
-{
- const char *buf, *val;
- ssize_t blen, count;
- struct udev_monitor_netlink_header nlh = {
- .prefix = "libudev",
- .magic = htonl(UDEV_MONITOR_MAGIC),
- .header_size = sizeof nlh,
- };
- struct iovec iov[2] = {
- { .iov_base = &nlh, .iov_len = sizeof nlh },
- };
- struct msghdr smsg = {
- .msg_iov = iov,
- .msg_iovlen = 2,
- };
- struct udev_list_entry *list_entry;
- uint64_t tag_bloom_bits;
-
- blen = udev_device_get_properties_monitor_buf(udev_device, &buf);
- if (blen < 32) {
- log_debug("device buffer is too small to contain a valid device");
- return -EINVAL;
- }
-
- /* fill in versioned header */
- val = udev_device_get_subsystem(udev_device);
- nlh.filter_subsystem_hash = htonl(util_string_hash32(val));
-
- val = udev_device_get_devtype(udev_device);
- if (val != NULL)
- nlh.filter_devtype_hash = htonl(util_string_hash32(val));
-
- /* add tag bloom filter */
- tag_bloom_bits = 0;
- udev_list_entry_foreach(list_entry, udev_device_get_tags_list_entry(udev_device))
- tag_bloom_bits |= util_string_bloom64(udev_list_entry_get_name(list_entry));
- if (tag_bloom_bits > 0) {
- nlh.filter_tag_bloom_hi = htonl(tag_bloom_bits >> 32);
- nlh.filter_tag_bloom_lo = htonl(tag_bloom_bits & 0xffffffff);
- }
-
- /* add properties list */
- nlh.properties_off = iov[0].iov_len;
- nlh.properties_len = blen;
- iov[1].iov_base = (char *)buf;
- iov[1].iov_len = blen;
-
- /*
- * Use custom address for target, or the default one.
- *
- * If we send to a multicast group, we will get
- * ECONNREFUSED, which is expected.
- */
- if (destination)
- smsg.msg_name = &destination->snl;
- else
- smsg.msg_name = &udev_monitor->snl_destination;
- smsg.msg_namelen = sizeof(struct sockaddr_nl);
- count = sendmsg(udev_monitor->sock, &smsg, 0);
- if (count < 0) {
- if (!destination && errno == ECONNREFUSED) {
- log_debug("passed unknown number of bytes to netlink monitor %p", udev_monitor);
- return 0;
- } else
- return -errno;
- }
-
- log_debug("passed %zi bytes to netlink monitor %p", count, udev_monitor);
- return count;
-}
-
-/**
- * udev_monitor_filter_add_match_subsystem_devtype:
- * @udev_monitor: the monitor
- * @subsystem: the subsystem value to match the incoming devices against
- * @devtype: the devtype value to match the incoming devices against
- *
- * This filter is efficiently executed inside the kernel, and libudev subscribers
- * will usually not be woken up for devices which do not match.
- *
- * The filter must be installed before the monitor is switched to listening mode.
- *
- * Returns: 0 on success, otherwise a negative error value.
- */
-_public_ int udev_monitor_filter_add_match_subsystem_devtype(struct udev_monitor *udev_monitor, const char *subsystem, const char *devtype)
-{
- if (udev_monitor == NULL)
- return -EINVAL;
- if (subsystem == NULL)
- return -EINVAL;
- if (udev_list_entry_add(&udev_monitor->filter_subsystem_list, subsystem, devtype) == NULL)
- return -ENOMEM;
- return 0;
-}
-
-/**
- * udev_monitor_filter_add_match_tag:
- * @udev_monitor: the monitor
- * @tag: the name of a tag
- *
- * This filter is efficiently executed inside the kernel, and libudev subscribers
- * will usually not be woken up for devices which do not match.
- *
- * The filter must be installed before the monitor is switched to listening mode.
- *
- * Returns: 0 on success, otherwise a negative error value.
- */
-_public_ int udev_monitor_filter_add_match_tag(struct udev_monitor *udev_monitor, const char *tag)
-{
- if (udev_monitor == NULL)
- return -EINVAL;
- if (tag == NULL)
- return -EINVAL;
- if (udev_list_entry_add(&udev_monitor->filter_tag_list, tag, NULL) == NULL)
- return -ENOMEM;
- return 0;
-}
-
-/**
- * udev_monitor_filter_remove:
- * @udev_monitor: monitor
- *
- * Remove all filters from monitor.
- *
- * Returns: 0 on success, otherwise a negative error value.
- */
-_public_ int udev_monitor_filter_remove(struct udev_monitor *udev_monitor)
-{
- static struct sock_fprog filter = { 0, NULL };
-
- udev_list_cleanup(&udev_monitor->filter_subsystem_list);
- return setsockopt(udev_monitor->sock, SOL_SOCKET, SO_ATTACH_FILTER, &filter, sizeof(filter));
-}
~ianmdlvl / elogind.git / blobdiff