1 files changed, 436 insertions, 0 deletions
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
new file mode 100644
index 000000000..795e0d062
--- /dev/null
+++ b/net/core/rtnetlink.c
@@ -0,0 +1,436 @@
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		Routing netlink socket interface: protocol independent part.
+ *
+ * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
+ *
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/socket.h>
+#include <linux/kernel.h>
+#include <linux/major.h>
+#include <linux/sched.h>
+#include <linux/timer.h>
+#include <linux/string.h>
+#include <linux/sockios.h>
+#include <linux/net.h>
+#include <linux/fcntl.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/skbuff.h>
+#include <linux/init.h>
+
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <asm/string.h>
+
+#include <linux/inet.h>
+#include <linux/netdevice.h>
+#include <net/pkt_sched.h>
+#include <net/ip.h>
+#include <net/protocol.h>
+#include <net/arp.h>
+#include <net/route.h>
+#include <net/tcp.h>
+#include <net/udp.h>
+#include <net/sock.h>
+
+atomic_t rtnl_rlockct;
+struct wait_queue *rtnl_wait;
+
+
+void rtnl_lock()
+{
+	rtnl_shlock();
+	rtnl_exlock();
+}
+
+void rtnl_unlock()
+{
+	rtnl_exunlock();
+	rtnl_shunlock();
+}
+
+#ifdef CONFIG_RTNETLINK
+struct sock *rtnl;
+
+unsigned long rtnl_wlockct;
+
+struct rtnetlink_link * rtnetlink_links[NPROTO];
+
+#define _S	1	/* superuser privileges required */
+#define _X	2	/* exclusive access to tables required */
+#define _G	4	/* GET request */
+
+static unsigned char rtm_properties[RTM_MAX-RTM_BASE+1] =
+{
+	_S|_X,		/* RTM_NEWLINK */
+	_S|_X,		/* RTM_DELLINK */
+	_G,		/* RTM_GETLINK */
+	0,
+
+	_S|_X,		/* RTM_NEWADDR */
+	_S|_X,		/* RTM_DELADDR */
+	_G,		/* RTM_GETADDR */
+	0,
+
+	_S|_X,		/* RTM_NEWROUTE */
+	_S|_X,		/* RTM_DELROUTE */
+	_G,		/* RTM_GETROUTE */
+	0,
+
+	_S|_X,		/* RTM_NEWNEIGH */
+	_S|_X,		/* RTM_DELNEIGH */
+	_G,		/* RTM_GETNEIGH */
+	0,
+
+	_S|_X, 		/* RTM_NEWRULE */
+	_S|_X,		/* RTM_DELRULE */
+	_G,		/* RTM_GETRULE */
+	0
+};
+
+static int rtnetlink_get_rta(struct kern_rta *rta, struct rtattr *attr, int attrlen)
+{
+	void **rta_data = (void**)rta;
+
+	while (RTA_OK(attr, attrlen)) {
+		int type = attr->rta_type;
+		if (type != RTA_UNSPEC) {
+			if (type > RTA_MAX)
+				return -EINVAL;
+			rta_data[type-1] = RTA_DATA(attr);
+		}
+		attr = RTA_NEXT(attr, attrlen);
+	}
+	return 0;
+}
+
+static int rtnetlink_get_ifa(struct kern_ifa *ifa, struct rtattr *attr, int attrlen)
+{
+	void **ifa_data = (void**)ifa;
+
+	while (RTA_OK(attr, attrlen)) {
+		int type = attr->rta_type;
+		if (type != IFA_UNSPEC) {
+			if (type > IFA_MAX)
+				return -EINVAL;
+			ifa_data[type-1] = RTA_DATA(attr);
+		}
+		attr = RTA_NEXT(attr, attrlen);
+	}
+	return 0;
+}
+
+void __rta_fill(struct sk_buff *skb, int attrtype, int attrlen, const void *data)
+{
+	struct rtattr *rta;
+	int size = RTA_LENGTH(attrlen);
+
+	rta = (struct rtattr*)skb_put(skb, RTA_ALIGN(size));
+	rta->rta_type = attrtype;
+	rta->rta_len = size;
+	memcpy(RTA_DATA(rta), data, attrlen);
+}
+
+static int rtnetlink_fill_ifinfo(struct sk_buff *skb, struct device *dev,
+				 int type, pid_t pid, u32 seq)
+{
+	struct ifinfomsg *r;
+	struct nlmsghdr  *nlh;
+
+	nlh = NLMSG_PUT(skb, pid, seq, type, sizeof(*r));
+	if (pid) nlh->nlmsg_flags |= NLM_F_MULTI;
+	r = NLMSG_DATA(nlh);
+	r->ifi_addrlen = dev->addr_len;
+	r->ifi_address.sa_family = dev->type;
+	memcpy(&r->ifi_address.sa_data, dev->dev_addr, dev->addr_len);
+	r->ifi_broadcast.sa_family = dev->type;
+	memcpy(&r->ifi_broadcast.sa_data, dev->broadcast, dev->addr_len);
+	r->ifi_flags = dev->flags;
+	r->ifi_mtu = dev->mtu;
+	r->ifi_index = dev->ifindex;
+	r->ifi_link = dev->iflink;
+	strncpy(r->ifi_name, dev->name, IFNAMSIZ-1);
+	r->ifi_qdiscname[0] = 0;
+	r->ifi_qdisc = dev->qdisc_sleeping->handle;
+	if (dev->qdisc_sleeping->ops)
+		strcpy(r->ifi_qdiscname, dev->qdisc_sleeping->ops->id);
+	return skb->len;
+
+nlmsg_failure:
+	return -1;
+}
+
+int rtnetlink_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	int idx;
+	int s_idx = cb->args[0];
+	struct device *dev;
+
+	for (dev=dev_base, idx=0; dev; dev = dev->next, idx++) {
+		if (idx < s_idx)
+			continue;
+		if (rtnetlink_fill_ifinfo(skb, dev, RTM_NEWLINK, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq) <= 0)
+			break;
+	}
+	cb->args[0] = idx;
+
+	return skb->len;
+}
+
+void rtmsg_ifinfo(int type, struct device *dev)
+{
+	struct sk_buff *skb;
+	int size = NLMSG_SPACE(sizeof(struct ifinfomsg));
+
+	skb = alloc_skb(size, GFP_KERNEL);
+	if (!skb)
+		return;
+
+	if (rtnetlink_fill_ifinfo(skb, dev, type, 0, 0) < 0) {
+		kfree_skb(skb, 0);
+		return;
+	}
+	NETLINK_CB(skb).dst_groups = RTMGRP_LINK;
+	netlink_broadcast(rtnl, skb, 0, RTMGRP_LINK, GFP_KERNEL);
+}
+
+static int rtnetlink_done(struct netlink_callback *cb)
+{
+	if (NETLINK_CREDS(cb->skb)->uid == 0 && cb->nlh->nlmsg_flags&NLM_F_ATOMIC)
+		rtnl_shunlock();
+	return 0;
+}
+
+/* Process one rtnetlink message. */
+
+extern __inline__ int
+rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, int *errp)
+{
+	union {
+		struct kern_rta rta;
+		struct kern_ifa ifa;
+	} u;
+	struct rtmsg *rtm;
+	struct ifaddrmsg *ifm;
+	int exclusive = 0;
+	int family;
+	int type;
+	int err;
+
+	if (!(nlh->nlmsg_flags&NLM_F_REQUEST))
+		return 0;
+	type = nlh->nlmsg_type;
+	if (type < RTM_BASE)
+		return 0;
+	if (type > RTM_MAX)
+		goto err_inval;
+
+	if (nlh->nlmsg_len < NLMSG_LENGTH(sizeof(struct rtgenmsg)))
+		return 0;
+	family = ((struct rtgenmsg*)NLMSG_DATA(nlh))->rtgen_family;
+	if (family > NPROTO || rtnetlink_links[family] == NULL) {
+		*errp = -EAFNOSUPPORT;
+		return -1;
+	}
+	if (rtm_properties[type-RTM_BASE]&_S) {
+		if (NETLINK_CREDS(skb)->uid) {
+			*errp = -EPERM;
+			return -1;
+		}
+	}
+	if (rtm_properties[type-RTM_BASE]&_G && nlh->nlmsg_flags&NLM_F_DUMP) {
+		if (rtnetlink_links[family][type-RTM_BASE].dumpit == NULL)
+			goto err_inval;
+
+		/* Super-user locks all the tables to get atomic snapshot */
+		if (NETLINK_CREDS(skb)->uid == 0 && nlh->nlmsg_flags&NLM_F_ATOMIC)
+			atomic_inc(&rtnl_rlockct);
+		if ((*errp = netlink_dump_start(rtnl, skb, nlh,
+						rtnetlink_links[family][type-RTM_BASE].dumpit,
+						rtnetlink_done)) != 0) {
+			if (NETLINK_CREDS(skb)->uid == 0 && nlh->nlmsg_flags&NLM_F_ATOMIC)
+				atomic_dec(&rtnl_rlockct);
+			return -1;
+		}
+		skb_pull(skb, NLMSG_ALIGN(nlh->nlmsg_len));
+		return -1;
+	}
+	if (rtm_properties[type-RTM_BASE]&_X) {
+		if (rtnl_exlock_nowait()) {
+			*errp = 0;
+			return -1;
+		}
+		exclusive = 1;
+	}
+	
+	memset(&u, 0, sizeof(u));
+
+	switch (nlh->nlmsg_type) {
+	case RTM_NEWROUTE:
+	case RTM_DELROUTE:
+	case RTM_GETROUTE:
+	case RTM_NEWRULE:
+	case RTM_DELRULE:
+	case RTM_GETRULE:
+		rtm = NLMSG_DATA(nlh);
+		if (nlh->nlmsg_len < sizeof(*rtm))
+			goto err_inval;
+
+		if (rtm->rtm_optlen &&
+		    rtnetlink_get_rta(&u.rta, RTM_RTA(rtm), rtm->rtm_optlen) < 0)
+			goto err_inval;
+		break;
+
+	case RTM_NEWADDR:
+	case RTM_DELADDR:
+	case RTM_GETADDR:
+		ifm = NLMSG_DATA(nlh);
+		if (nlh->nlmsg_len < sizeof(*ifm))
+			goto err_inval;
+
+		if (nlh->nlmsg_len > NLMSG_LENGTH(sizeof(*ifm)) &&
+		    rtnetlink_get_ifa(&u.ifa, IFA_RTA(ifm),
+				      nlh->nlmsg_len - NLMSG_LENGTH(sizeof(*ifm))) < 0)
+			goto err_inval;
+		break;
+	
+	case RTM_NEWLINK:
+	case RTM_DELLINK:
+	case RTM_GETLINK:
+	case RTM_NEWNEIGH:
+	case RTM_DELNEIGH:
+	case RTM_GETNEIGH:
+		/* Not urgent and even not necessary */
+	default:
+		goto err_inval;
+	}
+
+	if (rtnetlink_links[family][type-RTM_BASE].doit == NULL)
+		goto err_inval;
+	err = rtnetlink_links[family][type-RTM_BASE].doit(skb, nlh, (void *)&u);
+
+	if (exclusive)
+		rtnl_exunlock();
+	*errp = err;
+	return err;
+
+err_inval:
+	if (exclusive)
+		rtnl_exunlock();
+	*errp = -EINVAL;
+	return -1;
+}
+
+/* 
+ * Process one packet of messages.
+ * Malformed skbs with wrong lengths of messages are discarded silently.
+ */
+
+extern __inline__ int rtnetlink_rcv_skb(struct sk_buff *skb)
+{
+	int err;
+	struct nlmsghdr * nlh;
+
+	while (skb->len >= NLMSG_SPACE(0)) {
+		int rlen;
+
+		nlh = (struct nlmsghdr *)skb->data;
+		if (nlh->nlmsg_len < sizeof(*nlh) || skb->len < nlh->nlmsg_len)
+			return 0;
+		rlen = NLMSG_ALIGN(nlh->nlmsg_len);
+		if (rlen > skb->len)
+			rlen = skb->len;
+		if (rtnetlink_rcv_msg(skb, nlh, &err)) {
+			/* Not error, but we must interrupt processing here:
+			 *   Note, that in this case we do not pull message
+			 *   from skb, it will be processed later.
+			 */
+			if (err == 0)
+				return -1;
+			netlink_ack(skb, nlh, err);
+		} else if (nlh->nlmsg_flags&NLM_F_ACK)
+			netlink_ack(skb, nlh, 0);
+		skb_pull(skb, rlen);
+	}
+
+	return 0;
+}
+
+/*
+ *  rtnetlink input queue processing routine:
+ *	- try to acquire shared lock. If it is failed, defer processing.
+ *	- feed skbs to rtnetlink_rcv_skb, until it refuse a message,
+ *	  that will occur, when a dump started and/or acquisition of
+ *	  exclusive lock failed.
+ */
+
+static void rtnetlink_rcv(struct sock *sk, int len)
+{
+	struct sk_buff *skb;
+
+	if (rtnl_shlock_nowait())
+		return;
+
+	while ((skb = skb_dequeue(&sk->receive_queue)) != NULL) {
+		if (rtnetlink_rcv_skb(skb)) {
+			if (skb->len)
+				skb_queue_head(&sk->receive_queue, skb);
+			else
+				kfree_skb(skb, FREE_READ);
+			break;
+		}
+		kfree_skb(skb, FREE_READ);
+	}
+
+	rtnl_shunlock();
+}
+
+static int rtnetlink_event(struct notifier_block *this, unsigned long event, void *ptr)
+{
+	struct device *dev = ptr;
+	switch (event) {
+	case NETDEV_UNREGISTER:
+		rtmsg_ifinfo(RTM_DELLINK, dev);
+		break;
+	default:
+		rtmsg_ifinfo(RTM_NEWLINK, dev);
+		break;
+	}
+	return NOTIFY_DONE;
+}
+
+struct notifier_block rtnetlink_dev_notifier = {
+	rtnetlink_event,
+	NULL,
+	0
+};
+
+
+__initfunc(void rtnetlink_init(void))
+{
+#ifdef RTNL_DEBUG
+	printk("Initializing RT netlink socket\n");
+#endif
+	rtnl = netlink_kernel_create(NETLINK_ROUTE, rtnetlink_rcv);
+	if (rtnl == NULL)
+		panic("rtnetlink_init: cannot initialize rtnetlink\n");
+	register_netdevice_notifier(&rtnetlink_dev_notifier);
+}
+
+
+
+#endif