Function NgDeliverMsg

tools/libnetgraph/msg.c:203–288

* Send a message to a node using control socket node "cs". * Returns -1 if error and sets errno appropriately, otherwise zero. */

 * Returns -1 if error and sets errno appropriately, otherwise zero.
 */
static int
NgDeliverMsg(int cs, const char *path,
	const struct ng_mesg *hdr, const void *args, size_t arglen)
{
	u_char sgbuf[NG_PATHSIZ + NGSA_OVERHEAD];
	struct sockaddr_ng *const sg = (struct sockaddr_ng *) sgbuf;
	u_char *buf = NULL;
	struct ng_mesg *msg;
	int errnosv = 0;
	int rtn = 0;

	/* Sanity check */
	if (args == NULL)
		arglen = 0;

	/* Get buffer */
	if ((buf = malloc(sizeof(*msg) + arglen)) == NULL) {
		errnosv = errno;
		if (_gNgDebugLevel >= 1)
			NGLOG("malloc");
		rtn = -1;
		goto done;
	}
	msg = (struct ng_mesg *) buf;

	/* Finalize message */
	*msg = *hdr;
	msg->header.arglen = arglen;
	memcpy(msg->data, args, arglen);

	/* Prepare socket address */
	sg->sg_family = AF_NETGRAPH;
	/* XXX handle overflow */
#if __GNUC__ >= 13
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wstringop-overflow"
#endif
	strncpy(sg->sg_data, path, NG_PATHSIZ);
#if __GNUC__ >= 13
#pragma GCC diagnostic pop
#endif
	sg->sg_len = strlen(sg->sg_data) + 1 + NGSA_OVERHEAD;

	/* Debugging */
	if (_gNgDebugLevel >= 2) {
		NGLOGX("SENDING %s:",
		    (msg->header.flags & NGF_RESP) ? "RESPONSE" : "MESSAGE");
		_NgDebugSockaddr(sg);
		_NgDebugMsg(msg, sg->sg_data);
	}

	/* Send it */
	if (sendto(cs, msg, sizeof(*msg) + arglen,
		   0, (struct sockaddr *) sg, sg->sg_len) < 0) {
		errnosv = errno;
		if (_gNgDebugLevel >= 1)
			NGLOG("sendto(%s)", sg->sg_data);
		rtn = -1;