diff options
Diffstat (limited to 'src/libudev/libudev-monitor.c')
| -rw-r--r-- | src/libudev/libudev-monitor.c | 832 |
1 files changed, 0 insertions, 832 deletions
diff --git a/src/libudev/libudev-monitor.c b/src/libudev/libudev-monitor.c deleted file mode 100644 index c48ac78908..0000000000 --- a/src/libudev/libudev-monitor.c +++ /dev/null @@ -1,832 +0,0 @@ -/*** - 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)); -} |