From 38f7b870d4a6a5d3ec21557e849620cb7d032965 Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Wed, 13 Jun 2007 12:03:51 -0700 Subject: [PATCH] [RTNETLINK]: Link creation API Add rtnetlink API for creating, changing and deleting software devices. Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller --- include/linux/if_link.h | 13 ++ include/linux/netdevice.h | 3 + include/net/rtnetlink.h | 58 +++++++ net/core/rtnetlink.c | 342 +++++++++++++++++++++++++++++++++++++- 4 files changed, 409 insertions(+), 7 deletions(-) diff --git a/include/linux/if_link.h b/include/linux/if_link.h index 604c2434f71..3144babd235 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_KIND, + 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 94cc77cd3aa..e7913ee5581 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 */ + const 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 3b3d4745618..3861c05cdf0 100644 --- a/include/net/rtnetlink.h +++ b/include/net/rtnetlink.h @@ -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 diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 25ca219154e..06c0c5afabf 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -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);