#include <unistd.h>
#include <errno.h>
#include <string.h>
-#include <dirent.h>
-#include <sys/poll.h>
-#include <sys/stat.h>
+#include <poll.h>
#include <sys/socket.h>
-#include <sys/un.h>
-#include <arpa/inet.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
{
struct udev_monitor *udev_monitor;
- udev_monitor = calloc(1, sizeof(struct udev_monitor));
+ udev_monitor = new0(struct udev_monitor, 1);
if (udev_monitor == NULL)
return NULL;
udev_monitor->refcount = 1;
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;
if (name == NULL)
group = UDEV_MONITOR_NONE;
- else if (streq(name, "udev"))
- group = UDEV_MONITOR_UDEV;
- else if (streq(name, "kernel"))
+ 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;
if (fd < 0) {
udev_monitor->sock = socket(PF_NETLINK, SOCK_RAW|SOCK_CLOEXEC|SOCK_NONBLOCK, NETLINK_KOBJECT_UEVENT);
if (udev_monitor->sock == -1) {
- udev_err(udev, "error getting socket: %m\n");
+ log_debug_errno(errno, "error getting socket: %m");
free(udev_monitor);
return NULL;
}
udev_list_get_entry(&udev_monitor->filter_tag_list) == NULL)
return 0;
- memset(ins, 0x00, sizeof(ins));
+ memzero(ins, sizeof(ins));
i = 0;
/* load magic in A */
bpf_stmt(ins, &i, BPF_RET|BPF_K, 0xffffffff);
/* install filter */
- memset(&filter, 0x00, sizeof(filter));
+ memzero(&filter, sizeof(filter));
filter.len = i;
filter.filter = ins;
err = setsockopt(udev_monitor->sock, SOL_SOCKET, SO_ATTACH_FILTER, &filter, sizeof(filter));
if (err == 0)
udev_monitor->snl.nl.nl_pid = snl.nl.nl_pid;
} else {
- udev_err(udev_monitor->udev, "bind failed: %m\n");
+ log_debug_errno(errno, "bind failed: %m");
return -errno;
}
/* enable receiving of sender credentials */
- setsockopt(udev_monitor->sock, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on));
+ 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;
}
struct cmsghdr *cmsg;
union sockaddr_union snl;
struct ucred *cred;
- char buf[8192];
+ 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);
- memset (&smsg, 0x00, sizeof(struct msghdr));
+ memzero(&smsg, sizeof(struct msghdr));
smsg.msg_iov = &iov;
smsg.msg_iovlen = 1;
smsg.msg_control = cred_msg;
buflen = recvmsg(udev_monitor->sock, &smsg, 0);
if (buflen < 0) {
if (errno != EINTR)
- udev_dbg(udev_monitor->udev, "unable to receive message\n");
+ log_debug("unable to receive message");
return NULL;
}
- if (buflen < 32 || (size_t)buflen >= sizeof(buf)) {
- udev_dbg(udev_monitor->udev, "invalid message length\n");
+ if (buflen < 32 || (smsg.msg_flags & MSG_TRUNC)) {
+ log_debug("invalid message length");
return NULL;
}
/* 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) {
- udev_dbg(udev_monitor->udev, "unicast netlink message ignored\n");
+ log_debug("unicast netlink message ignored");
return NULL;
}
} else if (snl.nl.nl_groups == UDEV_MONITOR_KERNEL) {
if (snl.nl.nl_pid > 0) {
- udev_dbg(udev_monitor->udev, "multicast kernel netlink message from pid %d ignored\n",
- snl.nl.nl_pid);
+ 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) {
- udev_dbg(udev_monitor->udev, "no sender credentials received, message ignored\n");
+ log_debug("no sender credentials received, message ignored");
return NULL;
}
cred = (struct ucred *)CMSG_DATA(cmsg);
if (cred->uid != 0) {
- udev_dbg(udev_monitor->udev, "sender uid=%d, message ignored\n", cred->uid);
+ log_debug("sender uid="UID_FMT", message ignored", cred->uid);
return NULL;
}
- udev_device = udev_device_new(udev_monitor->udev);
- if (udev_device == NULL)
- return NULL;
-
- if (memcmp(buf, "libudev", 8) == 0) {
- struct udev_monitor_netlink_header *nlh;
-
+ if (memcmp(buf.raw, "libudev", 8) == 0) {
/* udev message needs proper version magic */
- nlh = (struct udev_monitor_netlink_header *) buf;
- if (nlh->magic != htonl(UDEV_MONITOR_MAGIC)) {
- udev_err(udev_monitor->udev, "unrecognized message signature (%x != %x)\n",
- nlh->magic, htonl(UDEV_MONITOR_MAGIC));
- udev_device_unref(udev_device);
+ 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 (nlh->properties_off+32 > (size_t)buflen) {
- udev_device_unref(udev_device);
+ 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 = nlh->properties_off;
+ bufpos = buf.nlh.properties_off;
/* devices received from udev are always initialized */
- udev_device_set_is_initialized(udev_device);
+ is_initialized = true;
} else {
/* kernel message with header */
- bufpos = strlen(buf) + 1;
+ bufpos = strlen(buf.raw) + 1;
if ((size_t)bufpos < sizeof("a@/d") || bufpos >= buflen) {
- udev_dbg(udev_monitor->udev, "invalid message length\n");
- udev_device_unref(udev_device);
+ log_debug("invalid message length");
return NULL;
}
/* check message header */
- if (strstr(buf, "@/") == NULL) {
- udev_dbg(udev_monitor->udev, "unrecognized message header\n");
- udev_device_unref(udev_device);
+ if (strstr(buf.raw, "@/") == NULL) {
+ log_debug("unrecognized message header");
return NULL;
}
}
- udev_device_set_info_loaded(udev_device);
-
- while (bufpos < buflen) {
- char *key;
- size_t keylen;
-
- key = &buf[bufpos];
- keylen = strlen(key);
- if (keylen == 0)
- break;
- bufpos += keylen + 1;
- udev_device_add_property_from_string_parse(udev_device, key);
- }
-
- if (udev_device_add_property_from_string_parse_finish(udev_device) < 0) {
- udev_dbg(udev_monitor->udev, "missing values, invalid device\n");
- udev_device_unref(udev_device);
+ 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 udev_monitor_send_device(struct udev_monitor *udev_monitor,
struct udev_monitor *destination, struct udev_device *udev_device)
{
- const char *buf;
- ssize_t blen;
- ssize_t count;
- struct msghdr smsg;
- struct iovec iov[2];
- const char *val;
- struct udev_monitor_netlink_header nlh;
+ 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)
+ if (blen < 32) {
+ log_debug("device buffer is too small to contain a valid device");
return -EINVAL;
+ }
- /* add versioned header */
- memset(&nlh, 0x00, sizeof(struct udev_monitor_netlink_header));
- memcpy(nlh.prefix, "libudev", 8);
- nlh.magic = htonl(UDEV_MONITOR_MAGIC);
- nlh.header_size = sizeof(struct udev_monitor_netlink_header);
+ /* 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));
- iov[0].iov_base = &nlh;
- iov[0].iov_len = sizeof(struct udev_monitor_netlink_header);
/* add tag bloom filter */
tag_bloom_bits = 0;
iov[1].iov_base = (char *)buf;
iov[1].iov_len = blen;
- memset(&smsg, 0x00, sizeof(struct msghdr));
- smsg.msg_iov = iov;
- smsg.msg_iovlen = 2;
/*
* 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 != NULL)
+ 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);
- udev_dbg(udev_monitor->udev, "passed %zi bytes to netlink monitor %p\n", count, udev_monitor);
+ 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;
}
~ianmdlvl / elogind.git / blobdiff