diff options
| -rw-r--r-- | include/linux/rtnetlink.h | 7 | ||||
| -rw-r--r-- | include/net/rtnetlink.h | 18 | ||||
| -rw-r--r-- | net/core/rtnetlink.c | 188 |
3 files changed, 184 insertions, 29 deletions
diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h index 3a4cb24..1fae30a 100644 --- a/include/linux/rtnetlink.h +++ b/include/linux/rtnetlink.h @@ -574,13 +574,6 @@ extern int rtattr_parse(struct rtattr *tb[], int maxattr, struct rtattr *rta, in #define rtattr_parse_nested(tb, max, rta) \ rtattr_parse((tb), (max), RTA_DATA((rta)), RTA_PAYLOAD((rta))) -struct rtnetlink_link -{ - int (*doit)(struct sk_buff *, struct nlmsghdr*, void *attr); - int (*dumpit)(struct sk_buff *, struct netlink_callback *cb); -}; - -extern struct rtnetlink_link * rtnetlink_links[NPROTO]; extern int rtnetlink_send(struct sk_buff *skb, u32 pid, u32 group, int echo); extern int rtnl_unicast(struct sk_buff *skb, u32 pid); extern int rtnl_notify(struct sk_buff *skb, u32 pid, u32 group, diff --git a/include/net/rtnetlink.h b/include/net/rtnetlink.h new file mode 100644 index 0000000..dce7072 --- /dev/null +++ b/include/net/rtnetlink.h @@ -0,0 +1,18 @@ +#ifndef __NET_RTNETLINK_H +#define __NET_RTNETLINK_H + +#include <linux/rtnetlink.h> +#include <net/netlink.h> + +typedef int (*rtnl_doit_func)(struct sk_buff *, struct nlmsghdr *, void *); +typedef int (*rtnl_dumpit_func)(struct sk_buff *, struct netlink_callback *); + +extern int __rtnl_register(int protocol, int msgtype, + rtnl_doit_func, rtnl_dumpit_func); +extern void rtnl_register(int protocol, int msgtype, + rtnl_doit_func, rtnl_dumpit_func); +extern int rtnl_unregister(int protocol, int msgtype); +extern void rtnl_unregister_all(int protocol); +extern int rtnl_dump_all(struct sk_buff *skb, struct netlink_callback *cb); + +#endif diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 33ea8ea..fb1630d 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -50,12 +50,18 @@ #include <net/sock.h> #include <net/pkt_sched.h> #include <net/fib_rules.h> -#include <net/netlink.h> +#include <net/rtnetlink.h> #ifdef CONFIG_NET_WIRELESS_RTNETLINK #include <linux/wireless.h> #include <net/iw_handler.h> #endif /* CONFIG_NET_WIRELESS_RTNETLINK */ +struct rtnl_link +{ + rtnl_doit_func doit; + rtnl_dumpit_func dumpit; +}; + static DEFINE_MUTEX(rtnl_mutex); static struct sock *rtnl; @@ -95,7 +101,151 @@ int rtattr_parse(struct rtattr *tb[], int maxattr, struct rtattr *rta, int len) return 0; } -struct rtnetlink_link * rtnetlink_links[NPROTO]; +struct rtnl_link *rtnl_msg_handlers[NPROTO]; + +static inline int rtm_msgindex(int msgtype) +{ + int msgindex = msgtype - RTM_BASE; + + /* + * msgindex < 0 implies someone tried to register a netlink + * control code. msgindex >= RTM_NR_MSGTYPES may indicate that + * the message type has not been added to linux/rtnetlink.h + */ + BUG_ON(msgindex < 0 || msgindex >= RTM_NR_MSGTYPES); + + return msgindex; +} + +static rtnl_doit_func rtnl_get_doit(int protocol, int msgindex) +{ + struct rtnl_link *tab; + + tab = rtnl_msg_handlers[protocol]; + if (tab == NULL || tab->doit == NULL) + tab = rtnl_msg_handlers[PF_UNSPEC]; + + return tab ? tab->doit : NULL; +} + +static rtnl_dumpit_func rtnl_get_dumpit(int protocol, int msgindex) +{ + struct rtnl_link *tab; + + tab = rtnl_msg_handlers[protocol]; + if (tab == NULL || tab->dumpit == NULL) + tab = rtnl_msg_handlers[PF_UNSPEC]; + + return tab ? tab->dumpit : NULL; +} + +/** + * __rtnl_register - Register a rtnetlink message type + * @protocol: Protocol family or PF_UNSPEC + * @msgtype: rtnetlink message type + * @doit: Function pointer called for each request message + * @dumpit: Function pointer called for each dump request (NLM_F_DUMP) message + * + * Registers the specified function pointers (at least one of them has + * to be non-NULL) to be called whenever a request message for the + * specified protocol family and message type is received. + * + * The special protocol family PF_UNSPEC may be used to define fallback + * function pointers for the case when no entry for the specific protocol + * family exists. + * + * Returns 0 on success or a negative error code. + */ +int __rtnl_register(int protocol, int msgtype, + rtnl_doit_func doit, rtnl_dumpit_func dumpit) +{ + struct rtnl_link *tab; + int msgindex; + + BUG_ON(protocol < 0 || protocol >= NPROTO); + msgindex = rtm_msgindex(msgtype); + + tab = rtnl_msg_handlers[protocol]; + if (tab == NULL) { + tab = kcalloc(RTM_NR_MSGTYPES, sizeof(*tab), GFP_KERNEL); + if (tab == NULL) + return -ENOBUFS; + + rtnl_msg_handlers[protocol] = tab; + } + + if (doit) + tab[msgindex].doit = doit; + + if (dumpit) + tab[msgindex].dumpit = dumpit; + + return 0; +} + +EXPORT_SYMBOL_GPL(__rtnl_register); + +/** + * rtnl_register - Register a rtnetlink message type + * + * Identical to __rtnl_register() but panics on failure. This is useful + * as failure of this function is very unlikely, it can only happen due + * to lack of memory when allocating the chain to store all message + * handlers for a protocol. Meant for use in init functions where lack + * of memory implies no sense in continueing. + */ +void rtnl_register(int protocol, int msgtype, + rtnl_doit_func doit, rtnl_dumpit_func dumpit) +{ + if (__rtnl_register(protocol, msgtype, doit, dumpit) < 0) + panic("Unable to register rtnetlink message handler, " + "protocol = %d, message type = %d\n", + protocol, msgtype); +} + +EXPORT_SYMBOL_GPL(rtnl_register); + +/** + * rtnl_unregister - Unregister a rtnetlink message type + * @protocol: Protocol family or PF_UNSPEC + * @msgtype: rtnetlink message type + * + * Returns 0 on success or a negative error code. + */ +int rtnl_unregister(int protocol, int msgtype) +{ + int msgindex; + + BUG_ON(protocol < 0 || protocol >= NPROTO); + msgindex = rtm_msgindex(msgtype); + + if (rtnl_msg_handlers[protocol] == NULL) + return -ENOENT; + + rtnl_msg_handlers[protocol][msgindex].doit = NULL; + rtnl_msg_handlers[protocol][msgindex].dumpit = NULL; + + return 0; +} + +EXPORT_SYMBOL_GPL(rtnl_unregister); + +/** + * rtnl_unregister_all - Unregister all rtnetlink message type of a protocol + * @protocol : Protocol family or PF_UNSPEC + * + * Identical to calling rtnl_unregster() for all registered message types + * of a certain protocol family. + */ +void rtnl_unregister_all(int protocol) +{ + BUG_ON(protocol < 0 || protocol >= NPROTO); + + kfree(rtnl_msg_handlers[protocol]); + rtnl_msg_handlers[protocol] = NULL; +} + +EXPORT_SYMBOL_GPL(rtnl_unregister_all); static const int rtm_min[RTM_NR_FAMILIES] = { @@ -648,7 +798,7 @@ errout: return err; } -static int rtnl_dump_all(struct sk_buff *skb, struct netlink_callback *cb) +int rtnl_dump_all(struct sk_buff *skb, struct netlink_callback *cb) { int idx; int s_idx = cb->family; @@ -659,12 +809,12 @@ static int rtnl_dump_all(struct sk_buff *skb, struct netlink_callback *cb) int type = cb->nlh->nlmsg_type-RTM_BASE; if (idx < s_idx || idx == PF_PACKET) continue; - if (rtnetlink_links[idx] == NULL || - rtnetlink_links[idx][type].dumpit == NULL) + if (rtnl_msg_handlers[idx] == NULL || + rtnl_msg_handlers[idx][type].dumpit == NULL) continue; if (idx > s_idx) memset(&cb->args[0], 0, sizeof(cb->args)); - if (rtnetlink_links[idx][type].dumpit(skb, cb)) + if (rtnl_msg_handlers[idx][type].dumpit(skb, cb)) break; } cb->family = idx; @@ -672,6 +822,8 @@ static int rtnl_dump_all(struct sk_buff *skb, struct netlink_callback *cb) return skb->len; } +EXPORT_SYMBOL_GPL(rtnl_dump_all); + void rtmsg_ifinfo(int type, struct net_device *dev, unsigned change) { struct sk_buff *skb; @@ -703,8 +855,7 @@ static int rtattr_max; static __inline__ int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, int *errp) { - struct rtnetlink_link *link; - struct rtnetlink_link *link_tab; + rtnl_doit_func doit; int sz_idx, kind; int min_len; int family; @@ -737,11 +888,6 @@ rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, int *errp) return -1; } - link_tab = rtnetlink_links[family]; - if (link_tab == NULL) - link_tab = rtnetlink_links[PF_UNSPEC]; - link = &link_tab[type]; - sz_idx = type>>2; kind = type&3; @@ -751,14 +897,14 @@ rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, int *errp) } if (kind == 2 && nlh->nlmsg_flags&NLM_F_DUMP) { - if (link->dumpit == NULL) - link = &(rtnetlink_links[PF_UNSPEC][type]); + rtnl_dumpit_func dumpit; - if (link->dumpit == NULL) + dumpit = rtnl_get_dumpit(family, type); + if (dumpit == NULL) goto err_inval; if ((*errp = netlink_dump_start(rtnl, skb, nlh, - link->dumpit, NULL)) != 0) { + dumpit, NULL)) != 0) { return -1; } @@ -787,11 +933,10 @@ rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, int *errp) } } - if (link->doit == NULL) - link = &(rtnetlink_links[PF_UNSPEC][type]); - if (link->doit == NULL) + doit = rtnl_get_doit(family, type); + if (doit == NULL) goto err_inval; - err = link->doit(skb, nlh, (void *)&rta_buf[0]); + err = doit(skb, nlh, (void *)&rta_buf[0]); *errp = err; return err; @@ -886,7 +1031,6 @@ void __init rtnetlink_init(void) EXPORT_SYMBOL(__rta_fill); EXPORT_SYMBOL(rtattr_strlcpy); EXPORT_SYMBOL(rtattr_parse); -EXPORT_SYMBOL(rtnetlink_links); EXPORT_SYMBOL(rtnetlink_put_metrics); EXPORT_SYMBOL(rtnl_lock); EXPORT_SYMBOL(rtnl_trylock); |