/* * Copyright (c) 2009, 2010 Nicira Networks. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at: * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #ifndef NETDEV_PROVIDER_H #define NETDEV_PROVIDER_H 1 /* Generic interface to network devices. */ #include #include "netdev.h" #include "list.h" #include "shash.h" struct arg { char *key; char *value; }; /* A network device (e.g. an Ethernet device). * * This structure should be treated as opaque by network device * implementations. */ struct netdev_dev { char *name; /* Name of network device. */ const struct netdev_class *class; /* Functions to control this device. */ int ref_cnt; /* Times this devices was opened. */ struct shash_node *node; /* Pointer to element in global map. */ struct arg *args; /* Argument list from last config. */ int n_args; /* Number of arguments in 'args'. */ }; void netdev_dev_init(struct netdev_dev *, const char *name, const struct netdev_class *); void netdev_dev_uninit(struct netdev_dev *, bool destroy); const char *netdev_dev_get_type(const struct netdev_dev *); const char *netdev_dev_get_name(const struct netdev_dev *); struct netdev_dev *netdev_dev_from_name(const char *name); void netdev_dev_get_devices(const struct netdev_class *, struct shash *device_list); static inline void netdev_dev_assert_class(const struct netdev_dev *netdev_dev, const struct netdev_class *class) { assert(netdev_dev->class == class); } /* A instance of an open network device. * * This structure should be treated as opaque by network device * implementations. */ struct netdev { struct netdev_dev *netdev_dev; /* Parent netdev_dev. */ struct list node; /* Element in global list. */ enum netdev_flags save_flags; /* Initial device flags. */ enum netdev_flags changed_flags; /* Flags that we changed. */ }; void netdev_init(struct netdev *, struct netdev_dev *); void netdev_uninit(struct netdev *, bool close); struct netdev_dev *netdev_get_dev(const struct netdev *); static inline void netdev_assert_class(const struct netdev *netdev, const struct netdev_class *class) { netdev_dev_assert_class(netdev_get_dev(netdev), class); } /* A network device notifier. * * Network device implementations should use netdev_notifier_init() to * initialize this structure, but they may freely read its members after * initialization. */ struct netdev_notifier { struct netdev *netdev; void (*cb)(struct netdev_notifier *); void *aux; }; void netdev_notifier_init(struct netdev_notifier *, struct netdev *, void (*cb)(struct netdev_notifier *), void *aux); /* Network device class structure, to be defined by each implementation of a * network device. * * These functions return 0 if successful or a positive errno value on failure, * except where otherwise noted. */ struct netdev_class { /* Type of netdevs in this class, e.g. "system", "tap", "gre", etc. * * One of the providers should supply a "system" type, since this is * the type assumed if no type is specified when opening a netdev. * The "system" type corresponds to an existing network device on * the system. */ const char *type; /* Called when the netdev provider is registered, typically at program * startup. Returning an error from this function will prevent any network * device in this class from being opened. * * This function may be set to null if a network device class needs no * initialization at registration time. */ int (*init)(void); /* Performs periodic work needed by netdevs of this class. May be null if * no periodic work is necessary. */ void (*run)(void); /* Arranges for poll_block() to wake up if the "run" member function needs * to be called. May be null if nothing is needed here. */ void (*wait)(void); /* Attempts to create a network device of 'type' with 'name'. * 'type' corresponds to the 'type' field used in the netdev_class * structure. On success sets 'netdev_devp' to the newly created device. */ int (*create)(const char *name, const char *type, const struct shash *args, struct netdev_dev **netdev_devp); /* Destroys 'netdev_dev'. * * Netdev devices maintain a reference count that is incremented on * netdev_open() and decremented on netdev_close(). If 'netdev_dev' * has a non-zero reference count, then this function will not be * called. */ void (*destroy)(struct netdev_dev *netdev_dev); /* Reconfigures the device 'netdev_dev' with 'args'. * * If this netdev class does not support reconfiguring a netdev * device, this may be a null pointer. */ int (*reconfigure)(struct netdev_dev *netdev_dev, const struct shash *args); /* Attempts to open a network device. On success, sets 'netdevp' * to the new network device. * * 'ethertype' may be a 16-bit Ethernet protocol value in host byte order * to capture frames of that type received on the device. It may also be * one of the 'enum netdev_pseudo_ethertype' values to receive frames in * one of those categories. */ int (*open)(struct netdev_dev *netdev_dev, int ethertype, struct netdev **netdevp); /* Closes 'netdev'. */ void (*close)(struct netdev *netdev); /* Enumerates the names of all network devices of this class. * * The caller has already initialized 'all_names' and might already have * added some names to it. This function should not disturb any existing * names in 'all_names'. * * If this netdev class does not support enumeration, this may be a null * pointer. */ int (*enumerate)(struct svec *all_names); /* Attempts to receive a packet from 'netdev' into the 'size' bytes in * 'buffer'. If successful, returns the number of bytes in the received * packet, otherwise a negative errno value. Returns -EAGAIN immediately * if no packet is ready to be received. */ int (*recv)(struct netdev *netdev, void *buffer, size_t size); /* Registers with the poll loop to wake up from the next call to * poll_block() when a packet is ready to be received with netdev_recv() on * 'netdev'. */ void (*recv_wait)(struct netdev *netdev); /* Discards all packets waiting to be received from 'netdev'. */ int (*drain)(struct netdev *netdev); /* Sends the 'size'-byte packet in 'buffer' on 'netdev'. Returns 0 if * successful, otherwise a positive errno value. Returns EAGAIN without * blocking if the packet cannot be queued immediately. Returns EMSGSIZE * if a partial packet was transmitted or if the packet is too big or too * small to transmit on the device. * * The caller retains ownership of 'buffer' in all cases. * * The network device is expected to maintain a packet transmission queue, * so that the caller does not ordinarily have to do additional queuing of * packets. */ int (*send)(struct netdev *netdev, const void *buffer, size_t size); /* Registers with the poll loop to wake up from the next call to * poll_block() when the packet transmission queue for 'netdev' has * sufficient room to transmit a packet with netdev_send(). * * The network device is expected to maintain a packet transmission queue, * so that the caller does not ordinarily have to do additional queuing of * packets. Thus, this function is unlikely to ever be useful. */ void (*send_wait)(struct netdev *netdev); /* Sets 'netdev''s Ethernet address to 'mac' */ int (*set_etheraddr)(struct netdev *netdev, const uint8_t mac[6]); /* Retrieves 'netdev''s Ethernet address into 'mac'. */ int (*get_etheraddr)(const struct netdev *netdev, uint8_t mac[6]); /* Retrieves 'netdev''s MTU into '*mtup'. * * The MTU is the maximum size of transmitted (and received) packets, in * bytes, not including the hardware header; thus, this is typically 1500 * bytes for Ethernet devices.*/ int (*get_mtu)(const struct netdev *netdev, int *mtup); /* Returns the ifindex of 'netdev', if successful, as a positive number. * On failure, returns a negative errno value. * * The desired semantics of the ifindex value are a combination of those * specified by POSIX for if_nametoindex() and by SNMP for ifIndex. An * ifindex value should be unique within a host and remain stable at least * until reboot. SNMP says an ifindex "ranges between 1 and the value of * ifNumber" but many systems do not follow this rule anyhow. */ int (*get_ifindex)(const struct netdev *netdev); /* Sets 'carrier' to true if carrier is active (link light is on) on * 'netdev'. */ int (*get_carrier)(const struct netdev *netdev, bool *carrier); /* Retrieves current device stats for 'netdev' into 'stats'. * * A network device that supports some statistics but not others, it should * set the values of the unsupported statistics to all-1-bits * (UINT64_MAX). */ int (*get_stats)(const struct netdev *netdev, struct netdev_stats *); /* Stores the features supported by 'netdev' into each of '*current', * '*advertised', '*supported', and '*peer'. Each value is a bitmap of * "enum ofp_port_features" bits, in host byte order. */ int (*get_features)(struct netdev *netdev, uint32_t *current, uint32_t *advertised, uint32_t *supported, uint32_t *peer); /* Set the features advertised by 'netdev' to 'advertise', which is a * bitmap of "enum ofp_port_features" bits, in host byte order. * * This function may be set to null for a network device that does not * support configuring advertisements. */ int (*set_advertisements)(struct netdev *netdev, uint32_t advertise); /* If 'netdev' is a VLAN network device (e.g. one created with vconfig(8)), * sets '*vlan_vid' to the VLAN VID associated with that device and returns * 0. * * Returns ENOENT if 'netdev' is a network device that is not a * VLAN device. * * This function should be set to null if it doesn't make any sense for * your network device (it probably doesn't). */ int (*get_vlan_vid)(const struct netdev *netdev, int *vlan_vid); /* Attempts to set input rate limiting (policing) policy, such that up to * 'kbits_rate' kbps of traffic is accepted, with a maximum accumulative * burst size of 'kbits' kb. * * This function may be set to null if policing is not supported. */ int (*set_policing)(struct netdev *netdev, unsigned int kbits_rate, unsigned int kbits_burst); /* If 'netdev' has an assigned IPv4 address, sets '*address' to that * address and '*netmask' to the associated netmask. * * The following error values have well-defined meanings: * * - EADDRNOTAVAIL: 'netdev' has no assigned IPv4 address. * * - EOPNOTSUPP: No IPv4 network stack attached to 'netdev'. * * This function may be set to null if it would always return EOPNOTSUPP * anyhow. */ int (*get_in4)(const struct netdev *netdev, struct in_addr *address, struct in_addr *netmask); /* Assigns 'addr' as 'netdev''s IPv4 address and 'mask' as its netmask. If * 'addr' is INADDR_ANY, 'netdev''s IPv4 address is cleared. * * This function may be set to null if it would always return EOPNOTSUPP * anyhow. */ int (*set_in4)(struct netdev *netdev, struct in_addr addr, struct in_addr mask); /* If 'netdev' has an assigned IPv6 address, sets '*in6' to that address. * * The following error values have well-defined meanings: * * - EADDRNOTAVAIL: 'netdev' has no assigned IPv6 address. * * - EOPNOTSUPP: No IPv6 network stack attached to 'netdev'. * * This function may be set to null if it would always return EOPNOTSUPP * anyhow. */ int (*get_in6)(const struct netdev *netdev, struct in6_addr *in6); /* Adds 'router' as a default IP gateway for the TCP/IP stack that * corresponds to 'netdev'. * * This function may be set to null if it would always return EOPNOTSUPP * anyhow. */ int (*add_router)(struct netdev *netdev, struct in_addr router); /* Looks up the next hop for 'host'. If succesful, stores the next hop * gateway's address (0 if 'host' is on a directly connected network) in * '*next_hop' and a copy of the name of the device to reach 'host' in * '*netdev_name', and returns 0. The caller is responsible for freeing * '*netdev_name' (by calling free()). * * This function may be set to null if it would always return EOPNOTSUPP * anyhow. */ int (*get_next_hop)(const struct in_addr *host, struct in_addr *next_hop, char **netdev_name); /* Looks up the ARP table entry for 'ip' on 'netdev' and stores the * corresponding MAC address in 'mac'. A return value of ENXIO, in * particular, indicates that there is no ARP table entry for 'ip' on * 'netdev'. * * This function may be set to null if it would always return EOPNOTSUPP * anyhow. */ int (*arp_lookup)(const struct netdev *netdev, uint32_t ip, uint8_t mac[6]); /* Retrieves the current set of flags on 'netdev' into '*old_flags'. * Then, turns off the flags that are set to 1 in 'off' and turns on the * flags that are set to 1 in 'on'. (No bit will be set to 1 in both 'off' * and 'on'; that is, off & on == 0.) * * This function may be invoked from a signal handler. Therefore, it * should not do anything that is not signal-safe (such as logging). */ int (*update_flags)(struct netdev *netdev, enum netdev_flags off, enum netdev_flags on, enum netdev_flags *old_flags); /* Arranges for 'cb' to be called whenever one of the attributes of * 'netdev' changes and sets '*notifierp' to a newly created * netdev_notifier that represents this arrangement. The created notifier * will have its 'netdev', 'cb', and 'aux' members set to the values of the * corresponding parameters. */ int (*poll_add)(struct netdev *netdev, void (*cb)(struct netdev_notifier *notifier), void *aux, struct netdev_notifier **notifierp); /* Cancels poll notification for 'notifier'. */ void (*poll_remove)(struct netdev_notifier *notifier); }; extern const struct netdev_class netdev_linux_class; extern const struct netdev_class netdev_tap_class; extern const struct netdev_class netdev_gre_class; #endif /* netdev.h */