[SCTP]: Add RCU synchronization around sctp_localaddr_list (29303547) · Commits · e / devices / android_kernel_samsung_universal8895

include/net/sctp/sctp.h

+1 −0

Original line number	Original line	Diff line number	Diff line
	@@ -123,6 +123,7 @@
	* sctp/protocol.c		* sctp/protocol.c
	*/		*/
	extern struct sock *sctp_get_ctl_sock(void);		extern struct sock *sctp_get_ctl_sock(void);
			extern void sctp_local_addr_free(struct rcu_head *head);
	extern int sctp_copy_local_addr_list(struct sctp_bind_addr *,		extern int sctp_copy_local_addr_list(struct sctp_bind_addr *,
	sctp_scope_t, gfp_t gfp,		sctp_scope_t, gfp_t gfp,
	int flags);		int flags);

include/net/sctp/structs.h

+6 −0

Original line number	Original line	Diff line number	Diff line
	@@ -208,6 +208,9 @@ extern struct sctp_globals {
	*/		*/
	struct list_head local_addr_list;		struct list_head local_addr_list;

			/* Lock that protects the local_addr_list writers */
			spinlock_t addr_list_lock;

	/* Flag to indicate if addip is enabled. */		/* Flag to indicate if addip is enabled. */
	int addip_enable;		int addip_enable;

	@@ -242,6 +245,7 @@ extern struct sctp_globals {
	#define sctp_port_alloc_lock (sctp_globals.port_alloc_lock)		#define sctp_port_alloc_lock (sctp_globals.port_alloc_lock)
	#define sctp_port_hashtable (sctp_globals.port_hashtable)		#define sctp_port_hashtable (sctp_globals.port_hashtable)
	#define sctp_local_addr_list (sctp_globals.local_addr_list)		#define sctp_local_addr_list (sctp_globals.local_addr_list)
			#define sctp_local_addr_lock (sctp_globals.addr_list_lock)
	#define sctp_addip_enable (sctp_globals.addip_enable)		#define sctp_addip_enable (sctp_globals.addip_enable)
	#define sctp_prsctp_enable (sctp_globals.prsctp_enable)		#define sctp_prsctp_enable (sctp_globals.prsctp_enable)

	@@ -737,8 +741,10 @@ const union sctp_addr sctp_source(const struct sctp_chunk chunk);
	/* This is a structure for holding either an IPv6 or an IPv4 address. */		/* This is a structure for holding either an IPv6 or an IPv4 address. */
	struct sctp_sockaddr_entry {		struct sctp_sockaddr_entry {
	struct list_head list;		struct list_head list;
			struct rcu_head rcu;
	union sctp_addr a;		union sctp_addr a;
	__u8 use_as_src;		__u8 use_as_src;
			__u8 valid;
	};		};

	typedef struct sctp_chunk (sctp_packet_phandler_t)(struct sctp_association );		typedef struct sctp_chunk (sctp_packet_phandler_t)(struct sctp_association );

net/sctp/bind_addr.c

+2 −0

Original line number	Original line	Diff line number	Diff line
	@@ -163,8 +163,10 @@ int sctp_add_bind_addr(struct sctp_bind_addr bp, union sctp_addr new,
	addr->a.v4.sin_port = htons(bp->port);		addr->a.v4.sin_port = htons(bp->port);

	addr->use_as_src = use_as_src;		addr->use_as_src = use_as_src;
			addr->valid = 1;

	INIT_LIST_HEAD(&addr->list);		INIT_LIST_HEAD(&addr->list);
			INIT_RCU_HEAD(&addr->rcu);
	list_add_tail(&addr->list, &bp->address_list);		list_add_tail(&addr->list, &bp->address_list);
	SCTP_DBG_OBJCNT_INC(addr);		SCTP_DBG_OBJCNT_INC(addr);

net/sctp/ipv6.c

+24 −10

Original line number	Original line	Diff line number	Diff line
	@@ -77,13 +77,18 @@

	#include <asm/uaccess.h>		#include <asm/uaccess.h>

	/* Event handler for inet6 address addition/deletion events. */		/* Event handler for inet6 address addition/deletion events.
			* The sctp_local_addr_list needs to be protocted by a spin lock since
			* multiple notifiers (say IPv4 and IPv6) may be running at the same
			* time and thus corrupt the list.
			* The reader side is protected with RCU.
			*/
	static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev,		static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev,
	void *ptr)		void *ptr)
	{		{
	struct inet6_ifaddr ifa = (struct inet6_ifaddr )ptr;		struct inet6_ifaddr ifa = (struct inet6_ifaddr )ptr;
	struct sctp_sockaddr_entry *addr;		struct sctp_sockaddr_entry *addr = NULL;
	struct list_head pos, temp;		struct sctp_sockaddr_entry *temp;

	switch (ev) {		switch (ev) {
	case NETDEV_UP:		case NETDEV_UP:
	@@ -94,19 +99,26 @@ static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev,
	memcpy(&addr->a.v6.sin6_addr, &ifa->addr,		memcpy(&addr->a.v6.sin6_addr, &ifa->addr,
	sizeof(struct in6_addr));		sizeof(struct in6_addr));
	addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;		addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
	list_add_tail(&addr->list, &sctp_local_addr_list);		addr->valid = 1;
			spin_lock_bh(&sctp_local_addr_lock);
			list_add_tail_rcu(&addr->list, &sctp_local_addr_list);
			spin_unlock_bh(&sctp_local_addr_lock);
	}		}
	break;		break;
	case NETDEV_DOWN:		case NETDEV_DOWN:
	list_for_each_safe(pos, temp, &sctp_local_addr_list) {		spin_lock_bh(&sctp_local_addr_lock);
	addr = list_entry(pos, struct sctp_sockaddr_entry, list);		list_for_each_entry_safe(addr, temp,
	if (ipv6_addr_equal(&addr->a.v6.sin6_addr, &ifa->addr)) {		&sctp_local_addr_list, list) {
	list_del(pos);		if (ipv6_addr_equal(&addr->a.v6.sin6_addr,
	kfree(addr);		&ifa->addr)) {
			addr->valid = 0;
			list_del_rcu(&addr->list);
	break;		break;
	}		}
	}		}
			spin_unlock_bh(&sctp_local_addr_lock);
			if (addr && !addr->valid)
			call_rcu(&addr->rcu, sctp_local_addr_free);
	break;		break;
	}		}

	@@ -367,7 +379,9 @@ static void sctp_v6_copy_addrlist(struct list_head *addrlist,
	addr->a.v6.sin6_port = 0;		addr->a.v6.sin6_port = 0;
	addr->a.v6.sin6_addr = ifp->addr;		addr->a.v6.sin6_addr = ifp->addr;
	addr->a.v6.sin6_scope_id = dev->ifindex;		addr->a.v6.sin6_scope_id = dev->ifindex;
			addr->valid = 1;
	INIT_LIST_HEAD(&addr->list);		INIT_LIST_HEAD(&addr->list);
			INIT_RCU_HEAD(&addr->rcu);
	list_add_tail(&addr->list, addrlist);		list_add_tail(&addr->list, addrlist);
	}		}
	}		}

net/sctp/protocol.c

+39 −15

Original line number	Original line	Diff line number	Diff line
	@@ -153,6 +153,9 @@ static void sctp_v4_copy_addrlist(struct list_head *addrlist,
	addr->a.v4.sin_family = AF_INET;		addr->a.v4.sin_family = AF_INET;
	addr->a.v4.sin_port = 0;		addr->a.v4.sin_port = 0;
	addr->a.v4.sin_addr.s_addr = ifa->ifa_local;		addr->a.v4.sin_addr.s_addr = ifa->ifa_local;
			addr->valid = 1;
			INIT_LIST_HEAD(&addr->list);
			INIT_RCU_HEAD(&addr->rcu);
	list_add_tail(&addr->list, addrlist);		list_add_tail(&addr->list, addrlist);
	}		}
	}		}
	@@ -192,16 +195,24 @@ static void sctp_free_local_addr_list(void)
	}		}
	}		}

			void sctp_local_addr_free(struct rcu_head *head)
			{
			struct sctp_sockaddr_entry *e = container_of(head,
			struct sctp_sockaddr_entry, rcu);
			kfree(e);
			}

	/* Copy the local addresses which are valid for 'scope' into 'bp'. */		/* Copy the local addresses which are valid for 'scope' into 'bp'. */
	int sctp_copy_local_addr_list(struct sctp_bind_addr *bp, sctp_scope_t scope,		int sctp_copy_local_addr_list(struct sctp_bind_addr *bp, sctp_scope_t scope,
	gfp_t gfp, int copy_flags)		gfp_t gfp, int copy_flags)
	{		{
	struct sctp_sockaddr_entry *addr;		struct sctp_sockaddr_entry *addr;
	int error = 0;		int error = 0;
	struct list_head pos, temp;

	list_for_each_safe(pos, temp, &sctp_local_addr_list) {		rcu_read_lock();
	addr = list_entry(pos, struct sctp_sockaddr_entry, list);		list_for_each_entry_rcu(addr, &sctp_local_addr_list, list) {
			if (!addr->valid)
			continue;
	if (sctp_in_scope(&addr->a, scope)) {		if (sctp_in_scope(&addr->a, scope)) {
	/* Now that the address is in scope, check to see if		/* Now that the address is in scope, check to see if
	* the address type is really supported by the local		* the address type is really supported by the local
	@@ -221,6 +232,7 @@ int sctp_copy_local_addr_list(struct sctp_bind_addr *bp, sctp_scope_t scope,
	}		}

	end_copy:		end_copy:
			rcu_read_unlock();
	return error;		return error;
	}		}

	@@ -600,13 +612,18 @@ static void sctp_v4_seq_dump_addr(struct seq_file seq, union sctp_addr addr)
	seq_printf(seq, "%d.%d.%d.%d ", NIPQUAD(addr->v4.sin_addr));		seq_printf(seq, "%d.%d.%d.%d ", NIPQUAD(addr->v4.sin_addr));
	}		}

	/* Event handler for inet address addition/deletion events. */		/* Event handler for inet address addition/deletion events.
			* The sctp_local_addr_list needs to be protocted by a spin lock since
			* multiple notifiers (say IPv4 and IPv6) may be running at the same
			* time and thus corrupt the list.
			* The reader side is protected with RCU.
			*/
	static int sctp_inetaddr_event(struct notifier_block *this, unsigned long ev,		static int sctp_inetaddr_event(struct notifier_block *this, unsigned long ev,
	void *ptr)		void *ptr)
	{		{
	struct in_ifaddr ifa = (struct in_ifaddr )ptr;		struct in_ifaddr ifa = (struct in_ifaddr )ptr;
	struct sctp_sockaddr_entry *addr;		struct sctp_sockaddr_entry *addr = NULL;
	struct list_head pos, temp;		struct sctp_sockaddr_entry *temp;

	switch (ev) {		switch (ev) {
	case NETDEV_UP:		case NETDEV_UP:
	@@ -615,19 +632,25 @@ static int sctp_inetaddr_event(struct notifier_block *this, unsigned long ev,
	addr->a.v4.sin_family = AF_INET;		addr->a.v4.sin_family = AF_INET;
	addr->a.v4.sin_port = 0;		addr->a.v4.sin_port = 0;
	addr->a.v4.sin_addr.s_addr = ifa->ifa_local;		addr->a.v4.sin_addr.s_addr = ifa->ifa_local;
	list_add_tail(&addr->list, &sctp_local_addr_list);		addr->valid = 1;
			spin_lock_bh(&sctp_local_addr_lock);
			list_add_tail_rcu(&addr->list, &sctp_local_addr_list);
			spin_unlock_bh(&sctp_local_addr_lock);
	}		}
	break;		break;
	case NETDEV_DOWN:		case NETDEV_DOWN:
	list_for_each_safe(pos, temp, &sctp_local_addr_list) {		spin_lock_bh(&sctp_local_addr_lock);
	addr = list_entry(pos, struct sctp_sockaddr_entry, list);		list_for_each_entry_safe(addr, temp,
			&sctp_local_addr_list, list) {
	if (addr->a.v4.sin_addr.s_addr == ifa->ifa_local) {		if (addr->a.v4.sin_addr.s_addr == ifa->ifa_local) {
	list_del(pos);		addr->valid = 0;
	kfree(addr);		list_del_rcu(&addr->list);
	break;		break;
	}		}
	}		}
			spin_unlock_bh(&sctp_local_addr_lock);
			if (addr && !addr->valid)
			call_rcu(&addr->rcu, sctp_local_addr_free);
	break;		break;
	}		}

	@@ -1160,6 +1183,7 @@ SCTP_STATIC __init int sctp_init(void)

	/* Initialize the local address list. */		/* Initialize the local address list. */
	INIT_LIST_HEAD(&sctp_local_addr_list);		INIT_LIST_HEAD(&sctp_local_addr_list);
			spin_lock_init(&sctp_local_addr_lock);
	sctp_get_local_addr_list();		sctp_get_local_addr_list();

	/* Register notifier for inet address additions/deletions. */		/* Register notifier for inet address additions/deletions. */
	@@ -1227,6 +1251,9 @@ SCTP_STATIC __exit void sctp_exit(void)
	sctp_v6_del_protocol();		sctp_v6_del_protocol();
	inet_del_protocol(&sctp_protocol, IPPROTO_SCTP);		inet_del_protocol(&sctp_protocol, IPPROTO_SCTP);

			/* Unregister notifier for inet address additions/deletions. */
			unregister_inetaddr_notifier(&sctp_inetaddr_notifier);

	/* Free the local address list. */		/* Free the local address list. */
	sctp_free_local_addr_list();		sctp_free_local_addr_list();

	@@ -1240,9 +1267,6 @@ SCTP_STATIC __exit void sctp_exit(void)
	inet_unregister_protosw(&sctp_stream_protosw);		inet_unregister_protosw(&sctp_stream_protosw);
	inet_unregister_protosw(&sctp_seqpacket_protosw);		inet_unregister_protosw(&sctp_seqpacket_protosw);

	/* Unregister notifier for inet address additions/deletions. */
	unregister_inetaddr_notifier(&sctp_inetaddr_notifier);

	sctp_sysctl_unregister();		sctp_sysctl_unregister();
	list_del(&sctp_ipv4_specific.list);		list_del(&sctp_ipv4_specific.list);