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Diffstat (limited to 'libudev/libudev-monitor.c')
-rw-r--r--libudev/libudev-monitor.c218
1 files changed, 158 insertions, 60 deletions
diff --git a/libudev/libudev-monitor.c b/libudev/libudev-monitor.c
index 97e52c42db..24e8aead26 100644
--- a/libudev/libudev-monitor.c
+++ b/libudev/libudev-monitor.c
@@ -1,7 +1,7 @@
/*
* libudev - interface to udev device information
*
- * Copyright (C) 2008-2009 Kay Sievers <kay.sievers@vrfy.org>
+ * Copyright (C) 2008-2010 Kay Sievers <kay.sievers@vrfy.org>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
@@ -49,6 +49,7 @@ struct udev_monitor {
struct sockaddr_un sun;
socklen_t addrlen;
struct udev_list_node filter_subsystem_list;
+ struct udev_list_node filter_tag_list;
};
enum udev_monitor_netlink_group {
@@ -57,25 +58,28 @@ enum udev_monitor_netlink_group {
UDEV_MONITOR_UDEV,
};
-#define UDEV_MONITOR_MAGIC 0xcafe1dea
+#define UDEV_MONITOR_MAGIC 0xfeedcafe
struct udev_monitor_netlink_header {
- /* udev version text */
- char version[16];
+ /* "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;
- /* properties buffer */
- unsigned short properties_off;
- unsigned short properties_len;
+ /* 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 some common device properties strings to filter with socket filters in
- * the client used in the kernel from socket filter rules; needs to be stored in
- * network order
+ * 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;
- unsigned int filter_devtype;
+ 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)
@@ -88,6 +92,7 @@ static struct udev_monitor *udev_monitor_new(struct udev *udev)
udev_monitor->refcount = 1;
udev_monitor->udev = udev;
udev_list_init(&udev_monitor->filter_subsystem_list);
+ udev_list_init(&udev_monitor->filter_tag_list);
return udev_monitor;
}
@@ -247,13 +252,14 @@ static inline void bpf_jmp(struct sock_filter *inss, unsigned int *i,
*/
int udev_monitor_filter_update(struct udev_monitor *udev_monitor)
{
- static struct sock_filter ins[256];
- static struct sock_fprog filter;
+ 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)
+ if (udev_list_get_entry(&udev_monitor->filter_subsystem_list) == NULL &&
+ udev_list_get_entry(&udev_monitor->filter_tag_list) == NULL)
return 0;
memset(ins, 0x00, sizeof(ins));
@@ -266,35 +272,74 @@ int udev_monitor_filter_update(struct udev_monitor *udev_monitor)
/* wrong magic, pass packet */
bpf_stmt(ins, &i, BPF_RET|BPF_K, 0xffffffff);
- /* add all subsystem match values */
- udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_monitor->filter_subsystem_list)) {
- unsigned int hash;
-
- /* load filter_subsystem value in A */
- bpf_stmt(ins, &i, BPF_LD|BPF_W|BPF_ABS, offsetof(struct udev_monitor_netlink_header, filter_subsystem));
- hash = util_string_hash32(udev_list_entry_get_name(list_entry));
- 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 filter_devtype value in A */
- bpf_stmt(ins, &i, BPF_LD|BPF_W|BPF_ABS, offsetof(struct udev_monitor_netlink_header, filter_devtype));
- /* 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);
+ 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);
}
- /* matched, pass packet */
- bpf_stmt(ins, &i, BPF_RET|BPF_K, 0xffffffff);
+ /* nothing matched, drop packet */
+ bpf_stmt(ins, &i, BPF_RET|BPF_K, 0);
+ }
- if (i+1 >= ARRAY_SIZE(ins))
- return -1;
+ /* 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 >= ARRAY_SIZE(ins))
+ return -1;
+ }
+
+ /* nothing matched, drop packet */
+ bpf_stmt(ins, &i, BPF_RET|BPF_K, 0);
}
- /* 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 */
filter.len = i;
@@ -406,6 +451,7 @@ void udev_monitor_unref(struct udev_monitor *udev_monitor)
if (udev_monitor->sock >= 0)
close(udev_monitor->sock);
udev_list_cleanup_entries(udev_monitor->udev, &udev_monitor->filter_subsystem_list);
+ udev_list_cleanup_entries(udev_monitor->udev, &udev_monitor->filter_tag_list);
dbg(udev_monitor->udev, "monitor %p released\n", udev_monitor);
free(udev_monitor);
}
@@ -445,8 +491,7 @@ static int passes_filter(struct udev_monitor *udev_monitor, struct udev_device *
struct udev_list_entry *list_entry;
if (udev_list_get_entry(&udev_monitor->filter_subsystem_list) == NULL)
- return 1;
-
+ 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);
@@ -458,11 +503,22 @@ static int passes_filter(struct udev_monitor *udev_monitor, struct udev_device *
devtype = udev_list_entry_get_value(list_entry);
if (devtype == NULL)
- return 1;
+ goto tag;
ddevtype = udev_device_get_devtype(udev_device);
if (ddevtype == NULL)
continue;
if (strcmp(ddevtype, devtype) == 0)
+ 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;
@@ -556,13 +612,11 @@ retry:
return NULL;
}
- if (strncmp(buf, "udev-", 5) == 0) {
+ if (memcmp(buf, "libudev", 8) == 0) {
/* udev message needs proper version magic */
nlh = (struct udev_monitor_netlink_header *) buf;
if (nlh->magic != htonl(UDEV_MONITOR_MAGIC))
return NULL;
- if (nlh->properties_off < sizeof(struct udev_monitor_netlink_header))
- return NULL;
if (nlh->properties_off+32 > buflen)
return NULL;
bufpos = nlh->properties_off;
@@ -626,17 +680,17 @@ retry:
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];
const char *buf;
ssize_t blen;
ssize_t count;
blen = udev_device_get_properties_monitor_buf(udev_device, &buf);
if (blen < 32)
- return -1;
+ return -EINVAL;
if (udev_monitor->sun.sun_family != 0) {
+ struct msghdr smsg;
+ struct iovec iov[2];
const char *action;
char header[2048];
char *s;
@@ -660,23 +714,41 @@ int udev_monitor_send_device(struct udev_monitor *udev_monitor,
smsg.msg_iovlen = 2;
smsg.msg_name = &udev_monitor->sun;
smsg.msg_namelen = udev_monitor->addrlen;
- } else if (udev_monitor->snl.nl_family != 0) {
+ count = sendmsg(udev_monitor->sock, &smsg, 0);
+ info(udev_monitor->udev, "passed %zi bytes to socket monitor %p\n", count, udev_monitor);
+ return count;
+ }
+
+ if (udev_monitor->snl.nl_family != 0) {
+ struct msghdr smsg;
+ struct iovec iov[2];
const char *val;
struct udev_monitor_netlink_header nlh;
-
+ struct udev_list_entry *list_entry;
+ uint64_t tag_bloom_bits;
/* add versioned header */
memset(&nlh, 0x00, sizeof(struct udev_monitor_netlink_header));
- util_strscpy(nlh.version, sizeof(nlh.version), "udev-" VERSION);
+ memcpy(nlh.prefix, "libudev", 8);
nlh.magic = htonl(UDEV_MONITOR_MAGIC);
+ nlh.header_size = sizeof(struct udev_monitor_netlink_header);
val = udev_device_get_subsystem(udev_device);
- nlh.filter_subsystem = htonl(util_string_hash32(val));
+ nlh.filter_subsystem_hash = htonl(util_string_hash32(val));
val = udev_device_get_devtype(udev_device);
if (val != NULL)
- nlh.filter_devtype = htonl(util_string_hash32(val));
+ 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;
+ 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;
@@ -697,13 +769,12 @@ int udev_monitor_send_device(struct udev_monitor *udev_monitor,
else
smsg.msg_name = &udev_monitor->snl_destination;
smsg.msg_namelen = sizeof(struct sockaddr_nl);
- } else {
- return -1;
+ count = sendmsg(udev_monitor->sock, &smsg, 0);
+ info(udev_monitor->udev, "passed %zi bytes to netlink monitor %p\n", count, udev_monitor);
+ return count;
}
- count = sendmsg(udev_monitor->sock, &smsg, 0);
- info(udev_monitor->udev, "passed %zi bytes to monitor %p\n", count, udev_monitor);
- return count;
+ return -EINVAL;
}
/**
@@ -712,6 +783,9 @@ int udev_monitor_send_device(struct udev_monitor *udev_monitor,
* @subsystem: the subsystem value to match the incoming devices against
* @devtype: the devtype value to match the incoming devices against
*
+ * This filer 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.
@@ -721,7 +795,7 @@ int udev_monitor_filter_add_match_subsystem_devtype(struct udev_monitor *udev_mo
if (udev_monitor == NULL)
return -EINVAL;
if (subsystem == NULL)
- return 0;
+ return -EINVAL;
if (udev_list_entry_add(udev_monitor->udev,
&udev_monitor->filter_subsystem_list, subsystem, devtype, 0, 0) == NULL)
return -ENOMEM;
@@ -729,6 +803,30 @@ int udev_monitor_filter_add_match_subsystem_devtype(struct udev_monitor *udev_mo
}
/**
+ * udev_monitor_filter_add_match_tag:
+ * @udev_monitor: the monitor
+ * @tag: the name of a tag
+ *
+ * This filer 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.
+ */
+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->udev,
+ &udev_monitor->filter_tag_list, tag, NULL, 0, 0) == NULL)
+ return -ENOMEM;
+ return 0;
+}
+
+/**
* udev_monitor_filter_remove:
* @udev_monitor: monitor
*
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-16 17:37:47 +0000