qemu/net.h
Mark McLoughlin f3b6c7fcf8 net: add qemu_send_packet_async()
Add a qemu_send_packet() variant which will queue up the packet
if it cannot be sent when all client queues are full. It later
invokes the supplied callback when the packet has been sent.

If qemu_send_packet_async() returns zero, the caller is expected
to not send any more packets until the queued packet has been
sent.

Packets are queued iff a receive() handler returns zero (indicating
queue full) and the caller has provided a sent notification callback
(indicating it will stop and start its own queue).

We need the packet sending API to support queueing because:

  - a sending client should process all available packets in one go
    (e.g. virtio-net emptying its tx ring)

  - a receiving client may not be able to handle the packet
    (e.g. -EAGAIN from write() to tapfd)

  - the sending client could detect this condition in advance
    (e.g. by select() for writable on tapfd)

  - that's too much overhead (e.g. a select() call per packet)

  - therefore the sending client must handle the condition by
    dropping the packet or queueing it

  - dropping packets is poor form; we should queue.

However, we don't want queueing to be completely transparent. We
want the sending client to stop sending packets as soon as a
packet is queued. This allows the sending client to be throttled
by the receiver.

Signed-off-by: Mark McLoughlin <markmc@redhat.com>
2009-06-09 11:38:50 +01:00

149 lines
5.0 KiB
C

#ifndef QEMU_NET_H
#define QEMU_NET_H
#include "qemu-common.h"
/* VLANs support */
typedef struct VLANClientState VLANClientState;
typedef int (NetCanReceive)(VLANClientState *);
typedef ssize_t (NetReceive)(VLANClientState *, const uint8_t *, size_t);
typedef ssize_t (NetReceiveIOV)(VLANClientState *, const struct iovec *, int);
typedef void (NetCleanup) (VLANClientState *);
typedef void (LinkStatusChanged)(VLANClientState *);
struct VLANClientState {
NetReceive *receive;
NetReceiveIOV *receive_iov;
/* Packets may still be sent if this returns zero. It's used to
rate-limit the slirp code. */
NetCanReceive *can_receive;
NetCleanup *cleanup;
LinkStatusChanged *link_status_changed;
int link_down;
void *opaque;
struct VLANClientState *next;
struct VLANState *vlan;
char *model;
char *name;
char info_str[256];
};
typedef struct VLANPacket VLANPacket;
typedef void (NetPacketSent) (VLANClientState *);
struct VLANPacket {
struct VLANPacket *next;
VLANClientState *sender;
int size;
NetPacketSent *sent_cb;
uint8_t data[0];
};
struct VLANState {
int id;
VLANClientState *first_client;
struct VLANState *next;
unsigned int nb_guest_devs, nb_host_devs;
VLANPacket *send_queue;
int delivering;
};
VLANState *qemu_find_vlan(int id);
VLANClientState *qemu_new_vlan_client(VLANState *vlan,
const char *model,
const char *name,
NetCanReceive *can_receive,
NetReceive *receive,
NetReceiveIOV *receive_iov,
NetCleanup *cleanup,
void *opaque);
void qemu_del_vlan_client(VLANClientState *vc);
VLANClientState *qemu_find_vlan_client(VLANState *vlan, void *opaque);
int qemu_can_send_packet(VLANClientState *vc);
ssize_t qemu_sendv_packet(VLANClientState *vc, const struct iovec *iov,
int iovcnt);
ssize_t qemu_sendv_packet_async(VLANClientState *vc, const struct iovec *iov,
int iovcnt, NetPacketSent *sent_cb);
void qemu_send_packet(VLANClientState *vc, const uint8_t *buf, int size);
ssize_t qemu_send_packet_async(VLANClientState *vc, const uint8_t *buf,
int size, NetPacketSent *sent_cb);
void qemu_flush_queued_packets(VLANClientState *vc);
void qemu_format_nic_info_str(VLANClientState *vc, uint8_t macaddr[6]);
void qemu_check_nic_model(NICInfo *nd, const char *model);
void qemu_check_nic_model_list(NICInfo *nd, const char * const *models,
const char *default_model);
void qemu_handler_true(void *opaque);
void do_info_network(Monitor *mon);
int do_set_link(Monitor *mon, const char *name, const char *up_or_down);
/* NIC info */
#define MAX_NICS 8
struct NICInfo {
uint8_t macaddr[6];
const char *model;
const char *name;
VLANState *vlan;
void *private;
int used;
};
extern int nb_nics;
extern NICInfo nd_table[MAX_NICS];
/* BT HCI info */
struct HCIInfo {
int (*bdaddr_set)(struct HCIInfo *hci, const uint8_t *bd_addr);
void (*cmd_send)(struct HCIInfo *hci, const uint8_t *data, int len);
void (*sco_send)(struct HCIInfo *hci, const uint8_t *data, int len);
void (*acl_send)(struct HCIInfo *hci, const uint8_t *data, int len);
void *opaque;
void (*evt_recv)(void *opaque, const uint8_t *data, int len);
void (*acl_recv)(void *opaque, const uint8_t *data, int len);
};
struct HCIInfo *qemu_next_hci(void);
/* checksumming functions (net-checksum.c) */
uint32_t net_checksum_add(int len, uint8_t *buf);
uint16_t net_checksum_finish(uint32_t sum);
uint16_t net_checksum_tcpudp(uint16_t length, uint16_t proto,
uint8_t *addrs, uint8_t *buf);
void net_checksum_calculate(uint8_t *data, int length);
/* from net.c */
int net_client_init(Monitor *mon, const char *device, const char *p);
void net_client_uninit(NICInfo *nd);
int net_client_parse(const char *str);
void net_slirp_smb(const char *exported_dir);
void net_slirp_redir(Monitor *mon, const char *redir_str, const char *redir_opt2);
void net_cleanup(void);
int slirp_is_inited(void);
void net_client_check(void);
void net_host_device_add(Monitor *mon, const char *device, const char *opts);
void net_host_device_remove(Monitor *mon, int vlan_id, const char *device);
#define DEFAULT_NETWORK_SCRIPT "/etc/qemu-ifup"
#define DEFAULT_NETWORK_DOWN_SCRIPT "/etc/qemu-ifdown"
#ifdef __sun__
#define SMBD_COMMAND "/usr/sfw/sbin/smbd"
#else
#define SMBD_COMMAND "/usr/sbin/smbd"
#endif
void qdev_get_macaddr(DeviceState *dev, uint8_t *macaddr);
VLANClientState *qdev_get_vlan_client(DeviceState *dev,
NetCanReceive *can_receive,
NetReceive *receive,
NetReceiveIOV *receive_iov,
NetCleanup *cleanup,
void *opaque);
#endif