[RTNETLINK]: Link creation API

Add rtnetlink API for creating, changing and deleting software devices.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Patrick McHardy 2007-06-13 12:03:51 -07:00 committed by David S. Miller
parent 0157f60c0c
commit 38f7b870d4
4 changed files with 409 additions and 7 deletions

View File

@ -76,6 +76,8 @@ enum
#define IFLA_WEIGHT IFLA_WEIGHT
IFLA_OPERSTATE,
IFLA_LINKMODE,
IFLA_LINKINFO,
#define IFLA_LINKINFO IFLA_LINKINFO
__IFLA_MAX
};
@ -140,4 +142,15 @@ struct ifla_cacheinfo
__u32 retrans_time;
};
enum
{
IFLA_INFO_UNSPEC,
IFLA_INFO_KIND,
IFLA_INFO_DATA,
IFLA_INFO_XSTATS,
__IFLA_INFO_MAX,
};
#define IFLA_INFO_MAX (__IFLA_INFO_MAX - 1)
#endif /* _LINUX_IF_LINK_H */

View File

@ -540,6 +540,9 @@ struct net_device
struct device dev;
/* space for optional statistics and wireless sysfs groups */
struct attribute_group *sysfs_groups[3];
/* rtnetlink link ops */
const struct rtnl_link_ops *rtnl_link_ops;
};
#define to_net_dev(d) container_of(d, struct net_device, dev)

View File

@ -22,4 +22,62 @@ static inline int rtnl_msg_family(struct nlmsghdr *nlh)
return AF_UNSPEC;
}
/**
* struct rtnl_link_ops - rtnetlink link operations
*
* @list: Used internally
* @kind: Identifier
* @maxtype: Highest device specific netlink attribute number
* @policy: Netlink policy for device specific attribute validation
* @validate: Optional validation function for netlink/changelink parameters
* @priv_size: sizeof net_device private space
* @setup: net_device setup function
* @newlink: Function for configuring and registering a new device
* @changelink: Function for changing parameters of an existing device
* @dellink: Function to remove a device
* @get_size: Function to calculate required room for dumping device
* specific netlink attributes
* @fill_info: Function to dump device specific netlink attributes
* @get_xstats_size: Function to calculate required room for dumping devic
* specific statistics
* @fill_xstats: Function to dump device specific statistics
*/
struct rtnl_link_ops {
struct list_head list;
const char *kind;
size_t priv_size;
void (*setup)(struct net_device *dev);
int maxtype;
const struct nla_policy *policy;
int (*validate)(struct nlattr *tb[],
struct nlattr *data[]);
int (*newlink)(struct net_device *dev,
struct nlattr *tb[],
struct nlattr *data[]);
int (*changelink)(struct net_device *dev,
struct nlattr *tb[],
struct nlattr *data[]);
void (*dellink)(struct net_device *dev);
size_t (*get_size)(const struct net_device *dev);
int (*fill_info)(struct sk_buff *skb,
const struct net_device *dev);
size_t (*get_xstats_size)(const struct net_device *dev);
int (*fill_xstats)(struct sk_buff *skb,
const struct net_device *dev);
};
extern int __rtnl_link_register(struct rtnl_link_ops *ops);
extern void __rtnl_link_unregister(struct rtnl_link_ops *ops);
extern int rtnl_link_register(struct rtnl_link_ops *ops);
extern void rtnl_link_unregister(struct rtnl_link_ops *ops);
#define MODULE_ALIAS_RTNL_LINK(kind) MODULE_ALIAS("rtnl-link-" kind)
#endif

View File

@ -243,6 +243,143 @@ void rtnl_unregister_all(int protocol)
EXPORT_SYMBOL_GPL(rtnl_unregister_all);
static LIST_HEAD(link_ops);
/**
* __rtnl_link_register - Register rtnl_link_ops with rtnetlink.
* @ops: struct rtnl_link_ops * to register
*
* The caller must hold the rtnl_mutex. This function should be used
* by drivers that create devices during module initialization. It
* must be called before registering the devices.
*
* Returns 0 on success or a negative error code.
*/
int __rtnl_link_register(struct rtnl_link_ops *ops)
{
list_add_tail(&ops->list, &link_ops);
return 0;
}
EXPORT_SYMBOL_GPL(__rtnl_link_register);
/**
* rtnl_link_register - Register rtnl_link_ops with rtnetlink.
* @ops: struct rtnl_link_ops * to register
*
* Returns 0 on success or a negative error code.
*/
int rtnl_link_register(struct rtnl_link_ops *ops)
{
int err;
rtnl_lock();
err = __rtnl_link_register(ops);
rtnl_unlock();
return err;
}
EXPORT_SYMBOL_GPL(rtnl_link_register);
/**
* __rtnl_link_unregister - Unregister rtnl_link_ops from rtnetlink.
* @ops: struct rtnl_link_ops * to unregister
*
* The caller must hold the rtnl_mutex. This function should be used
* by drivers that unregister devices during module unloading. It must
* be called after unregistering the devices.
*/
void __rtnl_link_unregister(struct rtnl_link_ops *ops)
{
list_del(&ops->list);
}
EXPORT_SYMBOL_GPL(__rtnl_link_unregister);
/**
* rtnl_link_unregister - Unregister rtnl_link_ops from rtnetlink.
* @ops: struct rtnl_link_ops * to unregister
*/
void rtnl_link_unregister(struct rtnl_link_ops *ops)
{
rtnl_lock();
__rtnl_link_unregister(ops);
rtnl_unlock();
}
EXPORT_SYMBOL_GPL(rtnl_link_unregister);
static const struct rtnl_link_ops *rtnl_link_ops_get(const char *kind)
{
const struct rtnl_link_ops *ops;
list_for_each_entry(ops, &link_ops, list) {
if (!strcmp(ops->kind, kind))
return ops;
}
return NULL;
}
static size_t rtnl_link_get_size(const struct net_device *dev)
{
const struct rtnl_link_ops *ops = dev->rtnl_link_ops;
size_t size;
if (!ops)
return 0;
size = nlmsg_total_size(sizeof(struct nlattr)) + /* IFLA_LINKINFO */
nlmsg_total_size(strlen(ops->kind) + 1); /* IFLA_INFO_KIND */
if (ops->get_size)
/* IFLA_INFO_DATA + nested data */
size += nlmsg_total_size(sizeof(struct nlattr)) +
ops->get_size(dev);
if (ops->get_xstats_size)
size += ops->get_xstats_size(dev); /* IFLA_INFO_XSTATS */
return size;
}
static int rtnl_link_fill(struct sk_buff *skb, const struct net_device *dev)
{
const struct rtnl_link_ops *ops = dev->rtnl_link_ops;
struct nlattr *linkinfo, *data;
int err = -EMSGSIZE;
linkinfo = nla_nest_start(skb, IFLA_LINKINFO);
if (linkinfo == NULL)
goto out;
if (nla_put_string(skb, IFLA_INFO_KIND, ops->kind) < 0)
goto err_cancel_link;
if (ops->fill_xstats) {
err = ops->fill_xstats(skb, dev);
if (err < 0)
goto err_cancel_link;
}
if (ops->fill_info) {
data = nla_nest_start(skb, IFLA_INFO_DATA);
if (data == NULL)
goto err_cancel_link;
err = ops->fill_info(skb, dev);
if (err < 0)
goto err_cancel_data;
nla_nest_end(skb, data);
}
nla_nest_end(skb, linkinfo);
return 0;
err_cancel_data:
nla_nest_cancel(skb, data);
err_cancel_link:
nla_nest_cancel(skb, linkinfo);
out:
return err;
}
static const int rtm_min[RTM_NR_FAMILIES] =
{
[RTM_FAM(RTM_NEWLINK)] = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
@ -437,7 +574,7 @@ static void copy_rtnl_link_stats(struct rtnl_link_stats *a,
a->tx_compressed = b->tx_compressed;
};
static inline size_t if_nlmsg_size(void)
static inline size_t if_nlmsg_size(const struct net_device *dev)
{
return NLMSG_ALIGN(sizeof(struct ifinfomsg))
+ nla_total_size(IFNAMSIZ) /* IFLA_IFNAME */
@ -452,7 +589,8 @@ static inline size_t if_nlmsg_size(void)
+ nla_total_size(4) /* IFLA_LINK */
+ nla_total_size(4) /* IFLA_MASTER */
+ nla_total_size(1) /* IFLA_OPERSTATE */
+ nla_total_size(1); /* IFLA_LINKMODE */
+ nla_total_size(1) /* IFLA_LINKMODE */
+ rtnl_link_get_size(dev); /* IFLA_LINKINFO */
}
static int rtnl_fill_ifinfo(struct sk_buff *skb, struct net_device *dev,
@ -522,6 +660,11 @@ static int rtnl_fill_ifinfo(struct sk_buff *skb, struct net_device *dev,
}
}
if (dev->rtnl_link_ops) {
if (rtnl_link_fill(skb, dev) < 0)
goto nla_put_failure;
}
return nlmsg_end(skb, nlh);
nla_put_failure:
@ -553,6 +696,8 @@ cont:
static const struct nla_policy ifla_policy[IFLA_MAX+1] = {
[IFLA_IFNAME] = { .type = NLA_STRING, .len = IFNAMSIZ-1 },
[IFLA_ADDRESS] = { .type = NLA_BINARY, .len = MAX_ADDR_LEN },
[IFLA_BROADCAST] = { .type = NLA_BINARY, .len = MAX_ADDR_LEN },
[IFLA_MAP] = { .len = sizeof(struct rtnl_link_ifmap) },
[IFLA_MTU] = { .type = NLA_U32 },
[IFLA_TXQLEN] = { .type = NLA_U32 },
@ -561,10 +706,15 @@ static const struct nla_policy ifla_policy[IFLA_MAX+1] = {
[IFLA_LINKMODE] = { .type = NLA_U8 },
};
static const struct nla_policy ifla_info_policy[IFLA_INFO_MAX+1] = {
[IFLA_INFO_KIND] = { .type = NLA_STRING },
[IFLA_INFO_DATA] = { .type = NLA_NESTED },
};
static int do_setlink(struct net_device *dev, struct ifinfomsg *ifm,
struct nlattr **tb, char *ifname)
struct nlattr **tb, char *ifname, int modified)
{
int modified = 0, send_addr_notify = 0;
int send_addr_notify = 0;
int err;
if (tb[IFLA_MAP]) {
@ -729,13 +879,189 @@ static int rtnl_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
nla_len(tb[IFLA_BROADCAST]) < dev->addr_len)
goto errout_dev;
err = do_setlink(dev, ifm, tb, ifname);
err = do_setlink(dev, ifm, tb, ifname, 0);
errout_dev:
dev_put(dev);
errout:
return err;
}
static int rtnl_dellink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
{
const struct rtnl_link_ops *ops;
struct net_device *dev;
struct ifinfomsg *ifm;
char ifname[IFNAMSIZ];
struct nlattr *tb[IFLA_MAX+1];
int err;
err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
if (err < 0)
return err;
if (tb[IFLA_IFNAME])
nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
ifm = nlmsg_data(nlh);
if (ifm->ifi_index > 0)
dev = __dev_get_by_index(ifm->ifi_index);
else if (tb[IFLA_IFNAME])
dev = __dev_get_by_name(ifname);
else
return -EINVAL;
if (!dev)
return -ENODEV;
ops = dev->rtnl_link_ops;
if (!ops)
return -EOPNOTSUPP;
ops->dellink(dev);
return 0;
}
static int rtnl_newlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
{
const struct rtnl_link_ops *ops;
struct net_device *dev;
struct ifinfomsg *ifm;
char kind[MODULE_NAME_LEN];
char ifname[IFNAMSIZ];
struct nlattr *tb[IFLA_MAX+1];
struct nlattr *linkinfo[IFLA_INFO_MAX+1];
int err;
replay:
err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy);
if (err < 0)
return err;
if (tb[IFLA_IFNAME])
nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
else
ifname[0] = '\0';
ifm = nlmsg_data(nlh);
if (ifm->ifi_index > 0)
dev = __dev_get_by_index(ifm->ifi_index);
else if (ifname[0])
dev = __dev_get_by_name(ifname);
else
dev = NULL;
if (tb[IFLA_LINKINFO]) {
err = nla_parse_nested(linkinfo, IFLA_INFO_MAX,
tb[IFLA_LINKINFO], ifla_info_policy);
if (err < 0)
return err;
} else
memset(linkinfo, 0, sizeof(linkinfo));
if (linkinfo[IFLA_INFO_KIND]) {
nla_strlcpy(kind, linkinfo[IFLA_INFO_KIND], sizeof(kind));
ops = rtnl_link_ops_get(kind);
} else {
kind[0] = '\0';
ops = NULL;
}
if (1) {
struct nlattr *attr[ops ? ops->maxtype + 1 : 0], **data = NULL;
if (ops) {
if (ops->maxtype && linkinfo[IFLA_INFO_DATA]) {
err = nla_parse_nested(attr, ops->maxtype,
linkinfo[IFLA_INFO_DATA],
ops->policy);
if (err < 0)
return err;
data = attr;
}
if (ops->validate) {
err = ops->validate(tb, data);
if (err < 0)
return err;
}
}
if (dev) {
int modified = 0;
if (nlh->nlmsg_flags & NLM_F_EXCL)
return -EEXIST;
if (nlh->nlmsg_flags & NLM_F_REPLACE)
return -EOPNOTSUPP;
if (linkinfo[IFLA_INFO_DATA]) {
if (!ops || ops != dev->rtnl_link_ops ||
!ops->changelink)
return -EOPNOTSUPP;
err = ops->changelink(dev, tb, data);
if (err < 0)
return err;
modified = 1;
}
return do_setlink(dev, ifm, tb, ifname, modified);
}
if (!(nlh->nlmsg_flags & NLM_F_CREATE))
return -ENODEV;
if (ifm->ifi_index || ifm->ifi_flags || ifm->ifi_change)
return -EOPNOTSUPP;
if (tb[IFLA_ADDRESS] || tb[IFLA_BROADCAST] || tb[IFLA_MAP] ||
tb[IFLA_MASTER] || tb[IFLA_PROTINFO])
return -EOPNOTSUPP;
if (!ops) {
#ifdef CONFIG_KMOD
if (kind[0]) {
__rtnl_unlock();
request_module("rtnl-link-%s", kind);
rtnl_lock();
ops = rtnl_link_ops_get(kind);
if (ops)
goto replay;
}
#endif
return -EOPNOTSUPP;
}
if (!ifname[0])
snprintf(ifname, IFNAMSIZ, "%s%%d", ops->kind);
dev = alloc_netdev(ops->priv_size, ifname, ops->setup);
if (!dev)
return -ENOMEM;
if (strchr(dev->name, '%')) {
err = dev_alloc_name(dev, dev->name);
if (err < 0)
goto err_free;
}
dev->rtnl_link_ops = ops;
if (tb[IFLA_MTU])
dev->mtu = nla_get_u32(tb[IFLA_MTU]);
if (tb[IFLA_TXQLEN])
dev->tx_queue_len = nla_get_u32(tb[IFLA_TXQLEN]);
if (tb[IFLA_WEIGHT])
dev->weight = nla_get_u32(tb[IFLA_WEIGHT]);
if (tb[IFLA_OPERSTATE])
set_operstate(dev, nla_get_u8(tb[IFLA_OPERSTATE]));
if (tb[IFLA_LINKMODE])
dev->link_mode = nla_get_u8(tb[IFLA_LINKMODE]);
err = ops->newlink(dev, tb, data);
err_free:
if (err < 0)
free_netdev(dev);
return err;
}
}
static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
{
struct ifinfomsg *ifm;
@ -756,7 +1082,7 @@ static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
} else
return -EINVAL;
nskb = nlmsg_new(if_nlmsg_size(), GFP_KERNEL);
nskb = nlmsg_new(if_nlmsg_size(dev), GFP_KERNEL);
if (nskb == NULL) {
err = -ENOBUFS;
goto errout;
@ -806,7 +1132,7 @@ void rtmsg_ifinfo(int type, struct net_device *dev, unsigned change)
struct sk_buff *skb;
int err = -ENOBUFS;
skb = nlmsg_new(if_nlmsg_size(), GFP_KERNEL);
skb = nlmsg_new(if_nlmsg_size(dev), GFP_KERNEL);
if (skb == NULL)
goto errout;
@ -961,6 +1287,8 @@ void __init rtnetlink_init(void)
rtnl_register(PF_UNSPEC, RTM_GETLINK, rtnl_getlink, rtnl_dump_ifinfo);
rtnl_register(PF_UNSPEC, RTM_SETLINK, rtnl_setlink, NULL);
rtnl_register(PF_UNSPEC, RTM_NEWLINK, rtnl_newlink, NULL);
rtnl_register(PF_UNSPEC, RTM_DELLINK, rtnl_dellink, NULL);
rtnl_register(PF_UNSPEC, RTM_GETADDR, NULL, rtnl_dump_all);
rtnl_register(PF_UNSPEC, RTM_GETROUTE, NULL, rtnl_dump_all);