1 files changed, 208 insertions, 0 deletions
diff --git a/discover/udev.c b/discover/udev.c
new file mode 100644
index 0000000..9c1b399
--- /dev/null
+++ b/discover/udev.c
@@ -0,0 +1,208 @@
+
+#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);
+}