1 files changed, 134 insertions, 0 deletions
diff --git a/discover/event.c b/discover/event.c
new file mode 100644
index 0000000..1314561
--- /dev/null
+++ b/discover/event.c
@@ -0,0 +1,134 @@
+#if defined(HAVE_CONFIG_H)
+#include "config.h"
+#endif
+
+#define _GNU_SOURCE
+#include <string.h>
+
+#include <log/log.h>
+#include <talloc/talloc.h>
+
+#include "event.h"
+
+#define streq(a, b) (!strcasecmp((a), (b)))
+
+/**
+ * event_parse_ad_header - Parse an <action>@<device> event header.
+ *
+ * The buffer is modified in place.
+ * Returns zero on success.
+ */
+
+static int event_parse_ad_header(char *buf, int len, enum event_action *action,
+	char **device)
+{
+	char *sep;
+
+	*action = 0;
+	*device = NULL;
+
+	/* we should see an <action>@<device>\0 at the head of the buffer */
+	sep = strchr(buf, '@');
+	if (!sep) {
+		pb_log("%s: bad header: %s\n", __func__, buf);
+		return -1;
+	}
+
+	/* terminate the action string */
+	*sep = '\0';
+	len -= sep - buf + 1;
+
+	if (streq(buf, "add"))
+		*action = EVENT_ACTION_ADD;
+	else if (streq(buf, "remove"))
+		*action = EVENT_ACTION_REMOVE;
+	else {
+		pb_log("%s: unknown action: %s\n", __func__, buf);
+		return -1;
+	}
+
+	if (!*(sep + 1)) {
+		pb_log("%s: bad device: %s\n", __func__, buf);
+		return -1;
+	}
+
+	*device = sep + 1;
+	return 0;
+}
+
+/**
+ * event_parse_params - Parse a <name>=<value> buffer.
+ *
+ * The buffer is not modified.
+ */
+
+static void event_parse_params(struct event *event, const 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);
+	}
+}
+
+int event_parse_ad_message(struct event *event, char *buf, int len)
+{
+	int result;
+	char *device;
+	enum event_action action;
+	int device_len;
+
+	result = event_parse_ad_header(buf, len, &action, &device);
+
+	if (result)
+		return -1;
+
+	device_len = strlen(device);
+
+	/* now we have an action and a device, we can construct the event */
+	event->action = action;
+	event->device = talloc_strndup(event, device, device_len);
+	event->n_params = 0;
+	event->params = NULL;
+
+	len -= device_len + 1;
+	event_parse_params(event, device + device_len + 1, len);
+
+	return 0;
+}
+
+const char *event_get_param(const struct 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;
+}