* sctp/protocol.c
*/
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 *,
sctp_scope_t, gfp_t gfp,
int flags);
* It is a list of sctp_sockaddr_entry.
*/
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. */
int addip_enable;
#define sctp_port_alloc_lock (sctp_globals.port_alloc_lock)
#define sctp_port_hashtable (sctp_globals.port_hashtable)
#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_prsctp_enable (sctp_globals.prsctp_enable)
/* This is a structure for holding either an IPv6 or an IPv4 address. */
struct sctp_sockaddr_entry {
struct list_head list;
+ struct rcu_head rcu;
union sctp_addr a;
__u8 use_as_src;
+ __u8 valid;
};
typedef struct sctp_chunk *(sctp_packet_phandler_t)(struct sctp_association *);
addr->a.v4.sin_port = htons(bp->port);
addr->use_as_src = use_as_src;
+ addr->valid = 1;
INIT_LIST_HEAD(&addr->list);
+ INIT_RCU_HEAD(&addr->rcu);
list_add_tail(&addr->list, &bp->address_list);
SCTP_DBG_OBJCNT_INC(addr);
#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,
void *ptr)
{
struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
- struct sctp_sockaddr_entry *addr;
- struct list_head *pos, *temp;
+ struct sctp_sockaddr_entry *addr = NULL;
+ struct sctp_sockaddr_entry *temp;
switch (ev) {
case NETDEV_UP:
memcpy(&addr->a.v6.sin6_addr, &ifa->addr,
sizeof(struct in6_addr));
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;
case NETDEV_DOWN:
- list_for_each_safe(pos, temp, &sctp_local_addr_list) {
- addr = list_entry(pos, struct sctp_sockaddr_entry, list);
- if (ipv6_addr_equal(&addr->a.v6.sin6_addr, &ifa->addr)) {
- list_del(pos);
- kfree(addr);
+ spin_lock_bh(&sctp_local_addr_lock);
+ list_for_each_entry_safe(addr, temp,
+ &sctp_local_addr_list, list) {
+ if (ipv6_addr_equal(&addr->a.v6.sin6_addr,
+ &ifa->addr)) {
+ addr->valid = 0;
+ list_del_rcu(&addr->list);
break;
}
}
-
+ spin_unlock_bh(&sctp_local_addr_lock);
+ if (addr && !addr->valid)
+ call_rcu(&addr->rcu, sctp_local_addr_free);
break;
}
addr->a.v6.sin6_port = 0;
addr->a.v6.sin6_addr = ifp->addr;
addr->a.v6.sin6_scope_id = dev->ifindex;
+ addr->valid = 1;
INIT_LIST_HEAD(&addr->list);
+ INIT_RCU_HEAD(&addr->rcu);
list_add_tail(&addr->list, addrlist);
}
}
addr->a.v4.sin_family = AF_INET;
addr->a.v4.sin_port = 0;
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);
}
}
}
}
+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'. */
int sctp_copy_local_addr_list(struct sctp_bind_addr *bp, sctp_scope_t scope,
gfp_t gfp, int copy_flags)
{
struct sctp_sockaddr_entry *addr;
int error = 0;
- struct list_head *pos, *temp;
- list_for_each_safe(pos, temp, &sctp_local_addr_list) {
- addr = list_entry(pos, struct sctp_sockaddr_entry, list);
+ rcu_read_lock();
+ list_for_each_entry_rcu(addr, &sctp_local_addr_list, list) {
+ if (!addr->valid)
+ continue;
if (sctp_in_scope(&addr->a, scope)) {
/* Now that the address is in scope, check to see if
* the address type is really supported by the local
}
end_copy:
+ rcu_read_unlock();
return error;
}
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,
void *ptr)
{
struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
- struct sctp_sockaddr_entry *addr;
- struct list_head *pos, *temp;
+ struct sctp_sockaddr_entry *addr = NULL;
+ struct sctp_sockaddr_entry *temp;
switch (ev) {
case NETDEV_UP:
addr->a.v4.sin_family = AF_INET;
addr->a.v4.sin_port = 0;
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;
case NETDEV_DOWN:
- list_for_each_safe(pos, temp, &sctp_local_addr_list) {
- addr = list_entry(pos, struct sctp_sockaddr_entry, list);
+ spin_lock_bh(&sctp_local_addr_lock);
+ list_for_each_entry_safe(addr, temp,
+ &sctp_local_addr_list, list) {
if (addr->a.v4.sin_addr.s_addr == ifa->ifa_local) {
- list_del(pos);
- kfree(addr);
+ addr->valid = 0;
+ list_del_rcu(&addr->list);
break;
}
}
-
+ spin_unlock_bh(&sctp_local_addr_lock);
+ if (addr && !addr->valid)
+ call_rcu(&addr->rcu, sctp_local_addr_free);
break;
}
/* Initialize the local address list. */
INIT_LIST_HEAD(&sctp_local_addr_list);
+ spin_lock_init(&sctp_local_addr_lock);
sctp_get_local_addr_list();
/* Register notifier for inet address additions/deletions. */
sctp_v6_del_protocol();
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. */
sctp_free_local_addr_list();
inet_unregister_protosw(&sctp_stream_protosw);
inet_unregister_protosw(&sctp_seqpacket_protosw);
- /* Unregister notifier for inet address additions/deletions. */
- unregister_inetaddr_notifier(&sctp_inetaddr_notifier);
-
sctp_sysctl_unregister();
list_del(&sctp_ipv4_specific.list);
int __user *optlen)
{
sctp_assoc_t id;
+ struct list_head *pos;
struct sctp_bind_addr *bp;
struct sctp_association *asoc;
- struct list_head *pos, *temp;
struct sctp_sockaddr_entry *addr;
rwlock_t *addr_lock;
int cnt = 0;
addr = list_entry(bp->address_list.next,
struct sctp_sockaddr_entry, list);
if (sctp_is_any(&addr->a)) {
- list_for_each_safe(pos, temp, &sctp_local_addr_list) {
- addr = list_entry(pos,
- struct sctp_sockaddr_entry,
- list);
+ rcu_read_lock();
+ list_for_each_entry_rcu(addr,
+ &sctp_local_addr_list, list) {
+ if (!addr->valid)
+ continue;
+
if ((PF_INET == sk->sk_family) &&
(AF_INET6 == addr->a.sa.sa_family))
continue;
+
cnt++;
}
+ rcu_read_unlock();
} else {
cnt = 1;
}
int max_addrs, void *to,
int *bytes_copied)
{
- struct list_head *pos, *next;
struct sctp_sockaddr_entry *addr;
union sctp_addr temp;
int cnt = 0;
int addrlen;
- list_for_each_safe(pos, next, &sctp_local_addr_list) {
- addr = list_entry(pos, struct sctp_sockaddr_entry, list);
+ rcu_read_lock();
+ list_for_each_entry_rcu(addr, &sctp_local_addr_list, list) {
+ if (!addr->valid)
+ continue;
+
if ((PF_INET == sk->sk_family) &&
(AF_INET6 == addr->a.sa.sa_family))
continue;
cnt ++;
if (cnt >= max_addrs) break;
}
+ rcu_read_unlock();
return cnt;
}
static int sctp_copy_laddrs(struct sock *sk, __u16 port, void *to,
size_t space_left, int *bytes_copied)
{
- struct list_head *pos, *next;
struct sctp_sockaddr_entry *addr;
union sctp_addr temp;
int cnt = 0;
int addrlen;
- list_for_each_safe(pos, next, &sctp_local_addr_list) {
- addr = list_entry(pos, struct sctp_sockaddr_entry, list);
+ rcu_read_lock();
+ list_for_each_entry_rcu(addr, &sctp_local_addr_list, list) {
+ if (!addr->valid)
+ continue;
+
if ((PF_INET == sk->sk_family) &&
(AF_INET6 == addr->a.sa.sa_family))
continue;
sctp_get_pf_specific(sk->sk_family)->addr_v4map(sctp_sk(sk),
&temp);
addrlen = sctp_get_af_specific(temp.sa.sa_family)->sockaddr_len;
- if (space_left < addrlen)
- return -ENOMEM;
+ if (space_left < addrlen) {
+ cnt = -ENOMEM;
+ break;
+ }
memcpy(to, &temp, addrlen);
to += addrlen;
space_left -= addrlen;
*bytes_copied += addrlen;
}
+ rcu_read_unlock();
return cnt;
}