[RTNETLINK]: Link creation API
Add rtnetlink API for creating, changing and deleting software devices.
Signed-off-by: Patrick McHardy <[EMAIL PROTECTED]>
---
commit 0323e7d1e7d5042492684264cfcba6d7ff55c473
tree 161530836d43b39ddef42a2c2b48b82187580e3c
parent 40b0b8787c1057d055baa6e3d11ff6db7783c982
author Patrick McHardy <[EMAIL PROTECTED]> Tue, 05 Jun 2007 15:40:12 +0200
committer Patrick McHardy <[EMAIL PROTECTED]> Tue, 05 Jun 2007 15:40:12 +0200
include/linux/if_link.h | 13 ++
include/linux/netdevice.h | 3
include/net/rtnetlink.h | 57 ++++++++
net/core/rtnetlink.c | 338 ++++++++++++++++++++++++++++++++++++++++++++-
4 files changed, 404 insertions(+), 7 deletions(-)
diff --git a/include/linux/if_link.h b/include/linux/if_link.h
index 604c243..e46ed94 100644
--- a/include/linux/if_link.h
+++ b/include/linux/if_link.h
@@ -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_NAME,
+ IFLA_INFO_DATA,
+ IFLA_INFO_XSTATS,
+ __IFLA_INFO_MAX,
+};
+
+#define IFLA_INFO_MAX (__IFLA_INFO_MAX - 1)
+
#endif /* _LINUX_IF_LINK_H */
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 3a70f55..e327ccc 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -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 */
+ struct rtnl_link_ops *rtnl_link_ops;
};
#define to_net_dev(d) container_of(d, struct net_device, dev)
diff --git a/include/net/rtnetlink.h b/include/net/rtnetlink.h
index 3b3d474..d744198 100644
--- a/include/net/rtnetlink.h
+++ b/include/net/rtnetlink.h
@@ -22,4 +22,61 @@ static inline int rtnl_msg_family(struct nlmsghdr *nlh)
return AF_UNSPEC;
}
+/**
+ * struct rtnl_link_ops - rtnetlink link operations
+ *
+ * @list: Used internally
+ * @name: 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
+ * @xstats_size: Size of device specific statistics
+ * @fill_xstats: Function to dump device specific statistics
+ */
+struct rtnl_link_ops {
+ struct list_head list;
+
+ const char *name;
+
+ 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)(struct net_device *dev);
+ int (*fill_info)(struct sk_buff *skb,
+ struct net_device *dev);
+
+ size_t xstats_size;
+ int (*fill_xstats)(struct sk_buff *skb,
+ 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(name) MODULE_ALIAS("rtnl-link-" #name)
+
#endif
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 25ca219..ed17288 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -243,6 +243,141 @@ 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 struct rtnl_link_ops *rtnl_link_ops_get(char *name)
+{
+ struct rtnl_link_ops *ops;
+
+ list_for_each_entry(ops, &link_ops, list) {
+ if (!strcmp(ops->name, name))
+ return ops;
+ }
+ return NULL;
+}
+
+static size_t rtnl_link_get_size(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->name) + 1) + /* IFLA_INFO_NAME */
+ nlmsg_total_size(ops->xstats_size); /* IFLA_INFO_XSTATS */
+
+ if (ops->get_size)
+ /* IFLA_INFO_DATA + nested data */
+ size += nlmsg_total_size(sizeof(struct nlattr)) +
+ ops->get_size(dev);
+
+ return size;
+}
+
+static int rtnl_link_fill(struct sk_buff *skb, 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_NAME, ops->name) < 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 +572,7 @@ 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(struct net_device *dev)
{
return NLMSG_ALIGN(sizeof(struct ifinfomsg))
+ nla_total_size(IFNAMSIZ) /* IFLA_IFNAME */
@@ -452,7 +587,8 @@ 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 +658,11 @@ 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 +694,8 @@ 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 +704,15 @@ 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_NAME] = { .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 +877,187 @@ 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)
+{
+ struct rtnl_link_ops *ops;
+ struct net_device *dev;
+ struct ifinfomsg *ifm;
+ char name[MODULE_NAME_LEN];
+ char ifname[IFNAMSIZ];
+ struct nlattr *tb[IFLA_MAX+1];
+ struct nlattr *linkinfo[IFLA_INFO_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);
+ 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_NAME]) {
+ nla_strlcpy(name, linkinfo[IFLA_INFO_NAME], sizeof(name));
+ ops = rtnl_link_ops_get(name);
+ } else {
+ name[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)
+ return -EINVAL;
+ if (tb[IFLA_ADDRESS] || tb[IFLA_BROADCAST] || tb[IFLA_MAP])
+ return -EOPNOTSUPP;
+
+#ifdef CONFIG_KMOD
+ if (!ops && name[0]) {
+ /* race condition: device may be created while rtnl is
+ * unlocked, final register_netdevice will catch it.
+ */
+ __rtnl_unlock();
+ request_module("rtnl-link-%s", name);
+ rtnl_lock();
+ ops = rtnl_link_ops_get(name);
+ }
+#endif
+ if (!ops)
+ return -EOPNOTSUPP;
+
+ if (!ifname[0])
+ snprintf(ifname, IFNAMSIZ, "%s%%d", ops->name);
+ 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 +1078,7 @@ 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 +1128,7 @@ 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 +1283,8 @@ 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);
-
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