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-rw-r--r--net/core/rtnetlink.c298
1 files changed, 184 insertions, 114 deletions
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 33ea8eac7fe..cec11110915 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -50,11 +50,13 @@
#include <net/sock.h>
#include <net/pkt_sched.h>
#include <net/fib_rules.h>
-#include <net/netlink.h>
-#ifdef CONFIG_NET_WIRELESS_RTNETLINK
-#include <linux/wireless.h>
-#include <net/iw_handler.h>
-#endif /* CONFIG_NET_WIRELESS_RTNETLINK */
+#include <net/rtnetlink.h>
+
+struct rtnl_link
+{
+ rtnl_doit_func doit;
+ rtnl_dumpit_func dumpit;
+};
static DEFINE_MUTEX(rtnl_mutex);
static struct sock *rtnl;
@@ -95,7 +97,151 @@ int rtattr_parse(struct rtattr *tb[], int maxattr, struct rtattr *rta, int len)
return 0;
}
-struct rtnetlink_link * rtnetlink_links[NPROTO];
+static 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[msgindex].doit == NULL)
+ tab = rtnl_msg_handlers[PF_UNSPEC];
+
+ return tab ? tab[msgindex].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[msgindex].dumpit == NULL)
+ tab = rtnl_msg_handlers[PF_UNSPEC];
+
+ return tab ? tab[msgindex].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] =
{
@@ -249,7 +395,7 @@ static void set_operstate(struct net_device *dev, unsigned char transition)
operstate == IF_OPER_UNKNOWN)
operstate = IF_OPER_DORMANT;
break;
- };
+ }
if (dev->operstate != operstate) {
write_lock_bh(&dev_base_lock);
@@ -393,7 +539,6 @@ static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
int s_idx = cb->args[0];
struct net_device *dev;
- read_lock(&dev_base_lock);
for (dev=dev_base, idx=0; dev; dev = dev->next, idx++) {
if (idx < s_idx)
continue;
@@ -402,7 +547,6 @@ static int rtnl_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
cb->nlh->nlmsg_seq, 0, NLM_F_MULTI) <= 0)
break;
}
- read_unlock(&dev_base_lock);
cb->args[0] = idx;
return skb->len;
@@ -536,17 +680,6 @@ static int rtnl_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
modified = 1;
}
-#ifdef CONFIG_NET_WIRELESS_RTNETLINK
- if (tb[IFLA_WIRELESS]) {
- /* Call Wireless Extensions.
- * Various stuff checked in there... */
- err = wireless_rtnetlink_set(dev, nla_data(tb[IFLA_WIRELESS]),
- nla_len(tb[IFLA_WIRELESS]));
- if (err < 0)
- goto errout_dev;
- }
-#endif /* CONFIG_NET_WIRELESS_RTNETLINK */
-
if (tb[IFLA_BROADCAST]) {
nla_memcpy(dev->broadcast, tb[IFLA_BROADCAST], dev->addr_len);
send_addr_notify = 1;
@@ -610,22 +743,6 @@ static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
} else
return -EINVAL;
-
-#ifdef CONFIG_NET_WIRELESS_RTNETLINK
- if (tb[IFLA_WIRELESS]) {
- /* Call Wireless Extensions. We need to know the size before
- * we can alloc. Various stuff checked in there... */
- err = wireless_rtnetlink_get(dev, nla_data(tb[IFLA_WIRELESS]),
- nla_len(tb[IFLA_WIRELESS]),
- &iw_buf, &iw_buf_len);
- if (err < 0)
- goto errout;
-
- /* Payload is at an offset in buffer */
- iw = iw_buf + IW_EV_POINT_OFF;
- }
-#endif /* CONFIG_NET_WIRELESS_RTNETLINK */
-
nskb = nlmsg_new(if_nlmsg_size(iw_buf_len), GFP_KERNEL);
if (nskb == NULL) {
err = -ENOBUFS;
@@ -659,12 +776,12 @@ 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;
@@ -700,30 +817,18 @@ static int rtattr_max;
/* Process one rtnetlink message. */
-static __inline__ int
-rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, int *errp)
+static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
{
- struct rtnetlink_link *link;
- struct rtnetlink_link *link_tab;
+ rtnl_doit_func doit;
int sz_idx, kind;
int min_len;
int family;
int type;
int err;
- /* Only requests are handled by kernel now */
- if (!(nlh->nlmsg_flags&NLM_F_REQUEST))
- return 0;
-
type = nlh->nlmsg_type;
-
- /* A control message: ignore them */
- if (type < RTM_BASE)
- return 0;
-
- /* Unknown message: reply with EINVAL */
if (type > RTM_MAX)
- goto err_inval;
+ return -EOPNOTSUPP;
type -= RTM_BASE;
@@ -732,45 +837,33 @@ rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, int *errp)
return 0;
family = ((struct rtgenmsg*)NLMSG_DATA(nlh))->rtgen_family;
- if (family >= NPROTO) {
- *errp = -EAFNOSUPPORT;
- return -1;
- }
-
- link_tab = rtnetlink_links[family];
- if (link_tab == NULL)
- link_tab = rtnetlink_links[PF_UNSPEC];
- link = &link_tab[type];
+ if (family >= NPROTO)
+ return -EAFNOSUPPORT;
sz_idx = type>>2;
kind = type&3;
- if (kind != 2 && security_netlink_recv(skb, CAP_NET_ADMIN)) {
- *errp = -EPERM;
- return -1;
- }
+ if (kind != 2 && security_netlink_recv(skb, CAP_NET_ADMIN))
+ return -EPERM;
if (kind == 2 && nlh->nlmsg_flags&NLM_F_DUMP) {
- if (link->dumpit == NULL)
- link = &(rtnetlink_links[PF_UNSPEC][type]);
-
- if (link->dumpit == NULL)
- goto err_inval;
+ rtnl_dumpit_func dumpit;
- if ((*errp = netlink_dump_start(rtnl, skb, nlh,
- link->dumpit, NULL)) != 0) {
- return -1;
- }
+ dumpit = rtnl_get_dumpit(family, type);
+ if (dumpit == NULL)
+ return -EOPNOTSUPP;
- netlink_queue_skip(nlh, skb);
- return -1;
+ __rtnl_unlock();
+ err = netlink_dump_start(rtnl, skb, nlh, dumpit, NULL);
+ rtnl_lock();
+ return err;
}
memset(rta_buf, 0, (rtattr_max * sizeof(struct rtattr *)));
min_len = rtm_min[sz_idx];
if (nlh->nlmsg_len < min_len)
- goto err_inval;
+ return -EINVAL;
if (nlh->nlmsg_len > min_len) {
int attrlen = nlh->nlmsg_len - NLMSG_ALIGN(min_len);
@@ -780,25 +873,18 @@ rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, int *errp)
unsigned flavor = attr->rta_type;
if (flavor) {
if (flavor > rta_max[sz_idx])
- goto err_inval;
+ return -EINVAL;
rta_buf[flavor-1] = attr;
}
attr = RTA_NEXT(attr, attrlen);
}
}
- if (link->doit == NULL)
- link = &(rtnetlink_links[PF_UNSPEC][type]);
- if (link->doit == NULL)
- goto err_inval;
- err = link->doit(skb, nlh, (void *)&rta_buf[0]);
+ doit = rtnl_get_doit(family, type);
+ if (doit == NULL)
+ return -EOPNOTSUPP;
- *errp = err;
- return err;
-
-err_inval:
- *errp = -EINVAL;
- return -1;
+ return doit(skb, nlh, (void *)&rta_buf[0]);
}
static void rtnetlink_rcv(struct sock *sk, int len)
@@ -814,25 +900,6 @@ static void rtnetlink_rcv(struct sock *sk, int len)
} while (qlen);
}
-static struct rtnetlink_link link_rtnetlink_table[RTM_NR_MSGTYPES] =
-{
- [RTM_GETLINK - RTM_BASE] = { .doit = rtnl_getlink,
- .dumpit = rtnl_dump_ifinfo },
- [RTM_SETLINK - RTM_BASE] = { .doit = rtnl_setlink },
- [RTM_GETADDR - RTM_BASE] = { .dumpit = rtnl_dump_all },
- [RTM_GETROUTE - RTM_BASE] = { .dumpit = rtnl_dump_all },
- [RTM_NEWNEIGH - RTM_BASE] = { .doit = neigh_add },
- [RTM_DELNEIGH - RTM_BASE] = { .doit = neigh_delete },
- [RTM_GETNEIGH - RTM_BASE] = { .dumpit = neigh_dump_info },
-#ifdef CONFIG_FIB_RULES
- [RTM_NEWRULE - RTM_BASE] = { .doit = fib_nl_newrule },
- [RTM_DELRULE - RTM_BASE] = { .doit = fib_nl_delrule },
-#endif
- [RTM_GETRULE - RTM_BASE] = { .dumpit = rtnl_dump_all },
- [RTM_GETNEIGHTBL - RTM_BASE] = { .dumpit = neightbl_dump_info },
- [RTM_SETNEIGHTBL - RTM_BASE] = { .doit = neightbl_set },
-};
-
static int rtnetlink_event(struct notifier_block *this, unsigned long event, void *ptr)
{
struct net_device *dev = ptr;
@@ -874,19 +941,22 @@ void __init rtnetlink_init(void)
panic("rtnetlink_init: cannot allocate rta_buf\n");
rtnl = netlink_kernel_create(NETLINK_ROUTE, RTNLGRP_MAX, rtnetlink_rcv,
- THIS_MODULE);
+ &rtnl_mutex, THIS_MODULE);
if (rtnl == NULL)
panic("rtnetlink_init: cannot initialize rtnetlink\n");
netlink_set_nonroot(NETLINK_ROUTE, NL_NONROOT_RECV);
register_netdevice_notifier(&rtnetlink_dev_notifier);
- rtnetlink_links[PF_UNSPEC] = link_rtnetlink_table;
- rtnetlink_links[PF_PACKET] = link_rtnetlink_table;
+
+ 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_GETADDR, NULL, rtnl_dump_all);
+ rtnl_register(PF_UNSPEC, RTM_GETROUTE, NULL, rtnl_dump_all);
}
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);