diff options
Diffstat (limited to 'include/linux/netdevice.h')
| -rw-r--r-- | include/linux/netdevice.h | 43 |
1 files changed, 32 insertions, 11 deletions
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 083b5989cecb..8b266390b9e2 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -63,27 +63,48 @@ struct wireless_dev; #define HAVE_FREE_NETDEV /* free_netdev() */ #define HAVE_NETDEV_PRIV /* netdev_priv() */ -#define NET_XMIT_SUCCESS 0 -#define NET_XMIT_DROP 1 /* skb dropped */ -#define NET_XMIT_CN 2 /* congestion notification */ -#define NET_XMIT_POLICED 3 /* skb is shot by police */ -#define NET_XMIT_MASK 0xFFFF /* qdisc flags in net/sch_generic.h */ +/* + * Transmit return codes: transmit return codes originate from three different + * namespaces: + * + * - qdisc return codes + * - driver transmit return codes + * - errno values + * + * Drivers are allowed to return any one of those in their hard_start_xmit() + * function. Real network devices commonly used with qdiscs should only return + * the driver transmit return codes though - when qdiscs are used, the actual + * transmission happens asynchronously, so the value is not propagated to + * higher layers. Virtual network devices transmit synchronously, in this case + * the driver transmit return codes are consumed by dev_queue_xmit(), all + * others are propagated to higher layers. + */ + +/* qdisc ->enqueue() return codes. */ +#define NET_XMIT_SUCCESS 0x00 +#define NET_XMIT_DROP 0x10 /* skb dropped */ +#define NET_XMIT_CN 0x20 /* congestion notification */ +#define NET_XMIT_POLICED 0x30 /* skb is shot by police */ +#define NET_XMIT_MASK 0xf0 /* qdisc flags in net/sch_generic.h */ /* Backlog congestion levels */ -#define NET_RX_SUCCESS 0 /* keep 'em coming, baby */ -#define NET_RX_DROP 1 /* packet dropped */ +#define NET_RX_SUCCESS 0 /* keep 'em coming, baby */ +#define NET_RX_DROP 1 /* packet dropped */ /* NET_XMIT_CN is special. It does not guarantee that this packet is lost. It * indicates that the device will soon be dropping packets, or already drops * some packets of the same priority; prompting us to send less aggressively. */ -#define net_xmit_eval(e) ((e) == NET_XMIT_CN? 0 : (e)) +#define net_xmit_eval(e) ((e) == NET_XMIT_CN ? 0 : (e)) #define net_xmit_errno(e) ((e) != NET_XMIT_CN ? -ENOBUFS : 0) /* Driver transmit return codes */ +#define NETDEV_TX_MASK 0xf + enum netdev_tx { - NETDEV_TX_OK = 0, /* driver took care of packet */ - NETDEV_TX_BUSY, /* driver tx path was busy*/ - NETDEV_TX_LOCKED = -1, /* driver tx lock was already taken */ + __NETDEV_TX_MIN = INT_MIN, /* make sure enum is signed */ + NETDEV_TX_OK = 0, /* driver took care of packet */ + NETDEV_TX_BUSY = 1, /* driver tx path was busy*/ + NETDEV_TX_LOCKED = 2, /* driver tx lock was already taken */ }; typedef enum netdev_tx netdev_tx_t; |