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#define _GNU_SOURCE
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <talloc/talloc.h>
#include "udev.h"
#include "log.h"
#include "waiter.h"
#include "pb-discover.h"
#define PBOOT_DEVICE_SOCKET "/tmp/petitboot.udev"
#define max(a, b) ((a) > (b) ? (a) : (b))
struct udev {
int socket;
};
static void parse_event_params(struct udev_event *event, char *buf, int len)
{
int param_len, name_len, value_len;
struct param *param;
char *sep;
for (; len > 0; len -= param_len + 1, buf += param_len + 1) {
/* find the length of the whole parameter */
param_len = strnlen(buf, len);
if (!param_len) {
/* multiple NULs? skip over */
param_len = 1;
continue;
}
/* find the separator */
sep = memchr(buf, '=', param_len);
if (!sep)
continue;
name_len = sep - buf;
value_len = param_len - name_len - 1;
/* update the params array */
event->params = talloc_realloc(event, event->params,
struct param, ++event->n_params);
param = &event->params[event->n_params - 1];
param->name = talloc_strndup(event, buf, name_len);
param->value = talloc_strndup(event, sep + 1, value_len);
}
}
static const char *event_param(struct udev_event *event, const char *name)
{
int i;
for (i = 0; i < event->n_params; i++)
if (!strcasecmp(event->params[i].name, name))
return event->params[i].value;
return NULL;
}
static void print_event(struct udev_event *event)
{
const char *action, *params[] = {
"DEVNAME", "ID_TYPE", "ID_BUS", "ID_FS_UUID", "ID_FS_LABEL",
NULL,
};
int i;
action = event->action == UDEV_ACTION_ADD ? "add" : "remove";
pb_log("udev %s event:\n", action);
printf("\tdevice: %s\n", event->device);
for (i = 0; params[i]; i++)
printf("\t%-12s => %s\n",
params[i], event_param(event, params[i]));
}
static void handle_udev_message(struct udev *udev, char *buf, int len)
{
char *sep, *device;
enum udev_action action;
struct udev_event *event;
int device_len;
/* we should see an <action>@<device>\0 at the head of the buffer */
sep = strchr(buf, '@');
if (!sep)
return;
/* terminate the action string */
*sep = '\0';
len -= sep - buf + 1;
if (!strcmp(buf, "add")) {
action = UDEV_ACTION_ADD;
} else if (!strcmp(buf, "remove")) {
action = UDEV_ACTION_REMOVE;
} else {
return;
}
/* initialise the device string */
device = sep + 1;
device_len = strnlen(device, len);
if (!device_len)
return;
/* now we have an action and a device, we can construct an event */
event = talloc(udev, struct udev_event);
event->action = action;
event->device = talloc_strndup(event, device, device_len);
event->n_params = 0;
event->params = NULL;
len -= device_len + 1;
parse_event_params(event, device + device_len + 1, len);
print_event(event);
talloc_free(event);
return;
}
static int udev_process(void *arg)
{
struct udev *udev = arg;
char buf[4096];
int len;
len = recvfrom(udev->socket, buf, sizeof(buf), 0, NULL, NULL);
if (len < 0) {
pb_log("udev socket read failed: %s", strerror(errno));
return -1;
}
if (len == 0)
return 0;
handle_udev_message(udev, buf, len);
return 0;
}
static int udev_destructor(void *p)
{
struct udev *udev = p;
if (udev->socket >= 0)
close(udev->socket);
return 0;
}
struct udev *udev_init(void)
{
struct sockaddr_un addr;
struct udev *udev;
unlink(PBOOT_DEVICE_SOCKET);
udev = talloc(NULL, struct udev);
udev->socket = socket(PF_UNIX, SOCK_DGRAM, 0);
if (udev->socket < 0) {
pb_log("Error creating udev socket: %s\n", strerror(errno));
goto out_err;
}
talloc_set_destructor(udev, udev_destructor);
addr.sun_family = AF_UNIX;
strcpy(addr.sun_path, PBOOT_DEVICE_SOCKET);
if (bind(udev->socket, (struct sockaddr *)&addr, sizeof(addr))) {
pb_log("Error binding udev socket: %s\n", strerror(errno));
goto out_err;
}
waiter_register(udev->socket, WAIT_IN, udev_process, udev);
return udev;
out_err:
talloc_free(udev);
return NULL;
}
void udev_destroy(struct udev *udev)
{
talloc_free(udev);
}
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