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libudev: monitor - switch to filter_add_match_subsystem_devtype()

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This commit is contained in:
Kay Sievers 2009-04-23 03:24:38 +02:00
parent c7dff03e05
commit dacea9ff6b
5 changed files with 47 additions and 23 deletions
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2
udev/lib/exported_symbols
View File

@ -56,7 +56,7 @@ udev_monitor_unref
udev_monitor_get_udev
udev_monitor_get_fd
udev_monitor_receive_device
udev_monitor_filter_add_match_subsystem
udev_monitor_filter_add_match_subsystem_devtype
udev_queue_new
udev_queue_ref
udev_queue_unref

58
udev/lib/libudev-monitor.c
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@ -56,11 +56,12 @@ struct udev_monitor_netlink_header {
unsigned short properties_off;
unsigned short properties_len;
/*
* hashes of some common device propertie strings to filter with socket filters in
* 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
*/
unsigned int filter_subsystem;
unsigned int filter_devtype;
};
static struct udev_monitor *udev_monitor_new(struct udev *udev)
@ -236,23 +237,34 @@ static int filter_apply(struct udev_monitor *udev_monitor)
memset(ins, 0x00, sizeof(ins));
i = 0;
/* load magic in accu */
/* 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, drop packet */
bpf_stmt(ins, &i, BPF_RET|BPF_K, 0);
/* load filter_subsystem value in accu */
bpf_stmt(ins, &i, BPF_LD|BPF_W|BPF_ABS, offsetof(struct udev_monitor_netlink_header, filter_subsystem));
/* add all subsystem match values */
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);
unsigned int hash;
hash = util_string_hash32(subsys);
/* jump if value does not match */
bpf_jmp(ins, &i, BPF_JMP|BPF_JEQ|BPF_K, hash, 0, 1);
/* 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);
}
/* matched, pass packet */
bpf_stmt(ins, &i, BPF_RET|BPF_K, 0xffffffff);
@ -374,20 +386,29 @@ int udev_monitor_get_fd(struct udev_monitor *udev_monitor)
static int passes_filter(struct udev_monitor *udev_monitor, struct udev_device *udev_device)
{
struct udev_list_entry *list_entry;
int pass = 0;
if (udev_list_get_entry(&udev_monitor->filter_subsystem_list) == NULL)
return 1;
udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_monitor->filter_subsystem_list)) {
const char *subsys = udev_device_get_subsystem(udev_device);
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 (strcmp(udev_list_entry_get_name(list_entry), subsys) == 0) {
pass= 1;
break;
}
if (strcmp(dsubsys, subsys) != 0)
continue;
devtype = udev_list_entry_get_value(list_entry);
if (devtype == NULL)
return 1;
ddevtype = udev_device_get_devtype(udev_device);
if (ddevtype == NULL)
continue;
if (strcmp(ddevtype, devtype) == 0)
return 1;
}
return pass;
return 0;
}
/**
@ -648,6 +669,9 @@ int udev_monitor_send_device(struct udev_monitor *udev_monitor, struct udev_devi
nlh.magic = htonl(UDEV_MONITOR_MAGIC);
val = udev_device_get_subsystem(udev_device);
nlh.filter_subsystem = htonl(util_string_hash32(val));
val = udev_device_get_devtype(udev_device);
if (val != NULL)
nlh.filter_devtype = htonl(util_string_hash32(val));
iov[0].iov_base = &nlh;
iov[0].iov_len = sizeof(struct udev_monitor_netlink_header);
@ -672,14 +696,14 @@ int udev_monitor_send_device(struct udev_monitor *udev_monitor, struct udev_devi
return count;
}
int udev_monitor_filter_add_match_subsystem(struct udev_monitor *udev_monitor, const char *subsystem)
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 0;
if (udev_list_entry_add(udev_monitor->udev,
&udev_monitor->filter_subsystem_list, subsystem, NULL, 1, 0) == NULL)
&udev_monitor->filter_subsystem_list, subsystem, devtype, 0, 0) == NULL)
return -ENOMEM;
return 0;
}

2
udev/lib/libudev.h
View File

@ -84,7 +84,7 @@ extern void udev_monitor_unref(struct udev_monitor *udev_monitor);
extern struct udev *udev_monitor_get_udev(struct udev_monitor *udev_monitor);
extern int udev_monitor_get_fd(struct udev_monitor *udev_monitor);
extern struct udev_device *udev_monitor_receive_device(struct udev_monitor *udev_monitor);
extern int udev_monitor_filter_add_match_subsystem(struct udev_monitor *udev_monitor, const char *subsystem);
extern int udev_monitor_filter_add_match_subsystem_devtype(struct udev_monitor *udev_monitor, const char *subsystem, const char *devtype);
/* sys enumeration */
struct udev_enumerate;

6
udev/lib/test-libudev.c
View File

@ -228,9 +228,9 @@ static int test_monitor(struct udev *udev)
printf("no socket\n");
return -1;
}
if (udev_monitor_filter_add_match_subsystem(udev_monitor, "block") < 0 ||
udev_monitor_filter_add_match_subsystem(udev_monitor, "tty") < 0 ||
udev_monitor_filter_add_match_subsystem(udev_monitor, "usb") < 0) {
if (udev_monitor_filter_add_match_subsystem_devtype(udev_monitor, "block", NULL) < 0 ||
udev_monitor_filter_add_match_subsystem_devtype(udev_monitor, "tty", NULL) < 0 ||
udev_monitor_filter_add_match_subsystem_devtype(udev_monitor, "usb", "usb_device") < 0) {
printf("filter failed\n");
return -1;
}

2
udev/udevadm-monitor.c
View File

@ -143,7 +143,7 @@ int udevadm_monitor(struct udev *udev, int argc, char *argv[])
udev_list_entry_foreach(entry, udev_list_get_entry(&subsystem_match_list)) {
const char *subsys = udev_list_entry_get_name(entry);
if (udev_monitor_filter_add_match_subsystem(udev_monitor, subsys) < 0)
if (udev_monitor_filter_add_match_subsystem_devtype(udev_monitor, subsys, NULL) < 0)
fprintf(stderr, "error: unable to apply subsystem filter '%s'\n", subsys);
}