From a69f32af86e389dd232b1bb2269e202c1bfcc60f Mon Sep 17 00:00:00 2001 From: Samuel Ortiz Date: Fri, 4 May 2012 17:04:19 +0200 Subject: [PATCH] NFC: Socket linked list Simplify the LLCP sockets structure by putting all the connected ones into a single linked list. Signed-off-by: Samuel Ortiz --- net/nfc/llcp/llcp.c | 249 ++++++++++++++++++++++++-------------------- net/nfc/llcp/llcp.h | 12 ++- net/nfc/llcp/sock.c | 32 +++--- 3 files changed, 158 insertions(+), 135 deletions(-) diff --git a/net/nfc/llcp/llcp.c b/net/nfc/llcp/llcp.c index 0f6dd3a53dca..262aa827fd7f 100644 --- a/net/nfc/llcp/llcp.c +++ b/net/nfc/llcp/llcp.c @@ -31,45 +31,41 @@ static u8 llcp_magic[3] = {0x46, 0x66, 0x6d}; static struct list_head llcp_devices; -static void nfc_llcp_socket_release(struct nfc_llcp_local *local) +void nfc_llcp_sock_link(struct llcp_sock_list *l, struct sock *sk) { - struct nfc_llcp_sock *parent, *s, *n; - struct sock *sk, *parent_sk; - int i; - - mutex_lock(&local->socket_lock); - - for (i = 0; i < LLCP_MAX_SAP; i++) { - parent = local->sockets[i]; - if (parent == NULL) - continue; - - /* Release all child sockets */ - list_for_each_entry_safe(s, n, &parent->list, list) { - list_del_init(&s->list); - sk = &s->sk; - - lock_sock(sk); + write_lock(&l->lock); + sk_add_node(sk, &l->head); + write_unlock(&l->lock); +} - if (sk->sk_state == LLCP_CONNECTED) - nfc_put_device(s->dev); +void nfc_llcp_sock_unlink(struct llcp_sock_list *l, struct sock *sk) +{ + write_lock(&l->lock); + sk_del_node_init(sk); + write_unlock(&l->lock); +} - sk->sk_state = LLCP_CLOSED; +static void nfc_llcp_socket_release(struct nfc_llcp_local *local) +{ + struct sock *sk; + struct hlist_node *node, *tmp; + struct nfc_llcp_sock *llcp_sock; - release_sock(sk); + write_lock(&local->sockets.lock); - sock_orphan(sk); - } + sk_for_each_safe(sk, node, tmp, &local->sockets.head) { + llcp_sock = nfc_llcp_sock(sk); - parent_sk = &parent->sk; + lock_sock(sk); - lock_sock(parent_sk); + if (sk->sk_state == LLCP_CONNECTED) + nfc_put_device(llcp_sock->dev); - if (parent_sk->sk_state == LLCP_LISTEN) { + if (sk->sk_state == LLCP_LISTEN) { struct nfc_llcp_sock *lsk, *n; struct sock *accept_sk; - list_for_each_entry_safe(lsk, n, &parent->accept_queue, + list_for_each_entry_safe(lsk, n, &llcp_sock->accept_queue, accept_queue) { accept_sk = &lsk->sk; lock_sock(accept_sk); @@ -84,17 +80,16 @@ static void nfc_llcp_socket_release(struct nfc_llcp_local *local) } } - if (parent_sk->sk_state == LLCP_CONNECTED) - nfc_put_device(parent->dev); + sk->sk_state = LLCP_CLOSED; - parent_sk->sk_state = LLCP_CLOSED; + release_sock(sk); - release_sock(parent_sk); + sock_orphan(sk); - sock_orphan(parent_sk); + sk_del_node_init(sk); } - mutex_unlock(&local->socket_lock); + write_unlock(&local->sockets.lock); } struct nfc_llcp_local *nfc_llcp_local_get(struct nfc_llcp_local *local) @@ -122,6 +117,11 @@ static void local_release(struct kref *ref) int nfc_llcp_local_put(struct nfc_llcp_local *local) { + WARN_ON(local == NULL); + + if (local == NULL) + return 0; + return kref_put(&local->ref, local_release); } @@ -465,46 +465,107 @@ static void nfc_llcp_set_nrns(struct nfc_llcp_sock *sock, struct sk_buff *pdu) sock->recv_ack_n = (sock->recv_n - 1) % 16; } +static struct nfc_llcp_sock *nfc_llcp_connecting_sock_get(struct nfc_llcp_local *local, + u8 ssap) +{ + struct sock *sk; + struct nfc_llcp_sock *llcp_sock; + struct hlist_node *node; + + read_lock(&local->connecting_sockets.lock); + + sk_for_each(sk, node, &local->connecting_sockets.head) { + llcp_sock = nfc_llcp_sock(sk); + + if (llcp_sock->ssap == ssap) + goto out; + } + + llcp_sock = NULL; + +out: + read_unlock(&local->connecting_sockets.lock); + + sock_hold(&llcp_sock->sk); + + return llcp_sock; +} + static struct nfc_llcp_sock *nfc_llcp_sock_get(struct nfc_llcp_local *local, u8 ssap, u8 dsap) { - struct nfc_llcp_sock *sock, *llcp_sock, *n; + struct sock *sk; + struct hlist_node *node; + struct nfc_llcp_sock *llcp_sock; pr_debug("ssap dsap %d %d\n", ssap, dsap); if (ssap == 0 && dsap == 0) return NULL; - mutex_lock(&local->socket_lock); - sock = local->sockets[ssap]; - if (sock == NULL) { - mutex_unlock(&local->socket_lock); - return NULL; - } + read_lock(&local->sockets.lock); + + llcp_sock = NULL; - pr_debug("root dsap %d (%d)\n", sock->dsap, dsap); + sk_for_each(sk, node, &local->sockets.head) { + llcp_sock = nfc_llcp_sock(sk); - if (sock->dsap == dsap) { - sock_hold(&sock->sk); - mutex_unlock(&local->socket_lock); - return sock; + if (llcp_sock->ssap == ssap && + llcp_sock->dsap == dsap) + break; } - list_for_each_entry_safe(llcp_sock, n, &sock->list, list) { - pr_debug("llcp_sock %p sk %p dsap %d\n", llcp_sock, - &llcp_sock->sk, llcp_sock->dsap); - if (llcp_sock->dsap == dsap) { - sock_hold(&llcp_sock->sk); - mutex_unlock(&local->socket_lock); - return llcp_sock; - } + read_unlock(&local->sockets.lock); + + if (llcp_sock == NULL) + return NULL; + + sock_hold(&llcp_sock->sk); + + return llcp_sock; +} + +static struct nfc_llcp_sock *nfc_llcp_sock_get_sn(struct nfc_llcp_local *local, + u8 *sn, size_t sn_len) +{ + struct sock *sk; + struct hlist_node *node; + struct nfc_llcp_sock *llcp_sock; + + pr_debug("sn %zd\n", sn_len); + + if (sn == NULL || sn_len == 0) + return NULL; + + read_lock(&local->sockets.lock); + + llcp_sock = NULL; + + sk_for_each(sk, node, &local->sockets.head) { + llcp_sock = nfc_llcp_sock(sk); + + if (llcp_sock->sk.sk_state != LLCP_LISTEN) + continue; + + if (llcp_sock->service_name == NULL || + llcp_sock->service_name_len == 0) + continue; + + if (llcp_sock->service_name_len != sn_len) + continue; + + if (memcmp(sn, llcp_sock->service_name, sn_len) == 0) + break; } - pr_err("Could not find socket for %d %d\n", ssap, dsap); + read_unlock(&local->sockets.lock); - mutex_unlock(&local->socket_lock); + if (llcp_sock == NULL) + return NULL; - return NULL; + sock_hold(&llcp_sock->sk); + + return llcp_sock; } static void nfc_llcp_sock_put(struct nfc_llcp_sock *sock) @@ -540,7 +601,7 @@ static void nfc_llcp_recv_connect(struct nfc_llcp_local *local, { struct sock *new_sk, *parent; struct nfc_llcp_sock *sock, *new_sock; - u8 dsap, ssap, bound_sap, reason; + u8 dsap, ssap, reason; dsap = nfc_llcp_dsap(skb); ssap = nfc_llcp_ssap(skb); @@ -551,24 +612,11 @@ static void nfc_llcp_recv_connect(struct nfc_llcp_local *local, skb->len - LLCP_HEADER_SIZE); if (dsap != LLCP_SAP_SDP) { - bound_sap = dsap; - - mutex_lock(&local->socket_lock); - sock = local->sockets[dsap]; - if (sock == NULL) { - mutex_unlock(&local->socket_lock); + sock = nfc_llcp_sock_get(local, dsap, LLCP_SAP_SDP); + if (sock == NULL || sock->sk.sk_state != LLCP_LISTEN) { reason = LLCP_DM_NOBOUND; goto fail; } - - sock_hold(&sock->sk); - mutex_unlock(&local->socket_lock); - - lock_sock(&sock->sk); - - if (sock->dsap == LLCP_SAP_SDP && - sock->sk.sk_state == LLCP_LISTEN) - goto enqueue; } else { u8 *sn; size_t sn_len; @@ -581,40 +629,15 @@ static void nfc_llcp_recv_connect(struct nfc_llcp_local *local, pr_debug("Service name length %zu\n", sn_len); - mutex_lock(&local->socket_lock); - for (bound_sap = 0; bound_sap < LLCP_LOCAL_SAP_OFFSET; - bound_sap++) { - sock = local->sockets[bound_sap]; - if (sock == NULL) - continue; - - if (sock->service_name == NULL || - sock->service_name_len == 0) - continue; - - if (sock->service_name_len != sn_len) - continue; - - if (sock->dsap == LLCP_SAP_SDP && - sock->sk.sk_state == LLCP_LISTEN && - !memcmp(sn, sock->service_name, sn_len)) { - pr_debug("Found service name at SAP %d\n", - bound_sap); - sock_hold(&sock->sk); - mutex_unlock(&local->socket_lock); - - lock_sock(&sock->sk); - - goto enqueue; - } + sock = nfc_llcp_sock_get_sn(local, sn, sn_len); + if (sock == NULL) { + reason = LLCP_DM_NOBOUND; + goto fail; } - mutex_unlock(&local->socket_lock); } - reason = LLCP_DM_NOBOUND; - goto fail; + lock_sock(&sock->sk); -enqueue: parent = &sock->sk; if (sk_acceptq_is_full(parent)) { @@ -636,13 +659,13 @@ enqueue: new_sock->dev = local->dev; new_sock->local = nfc_llcp_local_get(local); new_sock->nfc_protocol = sock->nfc_protocol; - new_sock->ssap = bound_sap; + new_sock->ssap = sock->ssap; new_sock->dsap = ssap; new_sock->parent = parent; pr_debug("new sock %p sk %p\n", new_sock, &new_sock->sk); - list_add_tail(&new_sock->list, &sock->list); + nfc_llcp_sock_link(&local->sockets, new_sk); nfc_llcp_accept_enqueue(&sock->sk, new_sk); @@ -813,11 +836,7 @@ static void nfc_llcp_recv_cc(struct nfc_llcp_local *local, struct sk_buff *skb) dsap = nfc_llcp_dsap(skb); ssap = nfc_llcp_ssap(skb); - llcp_sock = nfc_llcp_sock_get(local, dsap, ssap); - - if (llcp_sock == NULL) - llcp_sock = nfc_llcp_sock_get(local, dsap, LLCP_SAP_SDP); - + llcp_sock = nfc_llcp_connecting_sock_get(local, dsap); if (llcp_sock == NULL) { pr_err("Invalid CC\n"); nfc_llcp_send_dm(local, dsap, ssap, LLCP_DM_NOCONN); @@ -825,9 +844,13 @@ static void nfc_llcp_recv_cc(struct nfc_llcp_local *local, struct sk_buff *skb) return; } - llcp_sock->dsap = ssap; sk = &llcp_sock->sk; + /* Unlink from connecting and link to the client array */ + nfc_llcp_sock_unlink(&local->connecting_sockets, sk); + nfc_llcp_sock_link(&local->sockets, sk); + llcp_sock->dsap = ssap; + nfc_llcp_parse_tlv(local, &skb->data[LLCP_HEADER_SIZE], skb->len - LLCP_HEADER_SIZE); @@ -967,7 +990,6 @@ int nfc_llcp_register_device(struct nfc_dev *ndev) INIT_LIST_HEAD(&local->list); kref_init(&local->ref); mutex_init(&local->sdp_lock); - mutex_init(&local->socket_lock); init_timer(&local->link_timer); local->link_timer.data = (unsigned long) local; local->link_timer.function = nfc_llcp_symm_timer; @@ -1007,6 +1029,9 @@ int nfc_llcp_register_device(struct nfc_dev *ndev) goto err_rx_wq; } + local->sockets.lock = __RW_LOCK_UNLOCKED(local->sockets.lock); + local->connecting_sockets.lock = __RW_LOCK_UNLOCKED(local->connecting_sockets.lock); + nfc_llcp_build_gb(local); local->remote_miu = LLCP_DEFAULT_MIU; diff --git a/net/nfc/llcp/llcp.h b/net/nfc/llcp/llcp.h index bc619553821b..705330470062 100644 --- a/net/nfc/llcp/llcp.h +++ b/net/nfc/llcp/llcp.h @@ -40,6 +40,11 @@ enum llcp_state { struct nfc_llcp_sock; +struct llcp_sock_list { + struct hlist_head head; + rwlock_t lock; +}; + struct nfc_llcp_local { struct list_head list; struct nfc_dev *dev; @@ -47,7 +52,6 @@ struct nfc_llcp_local { struct kref ref; struct mutex sdp_lock; - struct mutex socket_lock; struct timer_list link_timer; struct sk_buff_head tx_queue; @@ -82,12 +86,12 @@ struct nfc_llcp_local { u8 remote_rw; /* sockets array */ - struct nfc_llcp_sock *sockets[LLCP_MAX_SAP]; + struct llcp_sock_list sockets; + struct llcp_sock_list connecting_sockets; }; struct nfc_llcp_sock { struct sock sk; - struct list_head list; struct nfc_dev *dev; struct nfc_llcp_local *local; u32 target_idx; @@ -166,6 +170,8 @@ struct nfc_llcp_sock { #define LLCP_DM_REJ 0x03 +void nfc_llcp_sock_link(struct llcp_sock_list *l, struct sock *s); +void nfc_llcp_sock_unlink(struct llcp_sock_list *l, struct sock *s); struct nfc_llcp_local *nfc_llcp_find_local(struct nfc_dev *dev); struct nfc_llcp_local *nfc_llcp_local_get(struct nfc_llcp_local *local); int nfc_llcp_local_put(struct nfc_llcp_local *local); diff --git a/net/nfc/llcp/sock.c b/net/nfc/llcp/sock.c index 9ac397b17718..8a60b53579b9 100644 --- a/net/nfc/llcp/sock.c +++ b/net/nfc/llcp/sock.c @@ -124,7 +124,7 @@ static int llcp_sock_bind(struct socket *sock, struct sockaddr *addr, int alen) if (llcp_sock->ssap == LLCP_MAX_SAP) goto put_dev; - local->sockets[llcp_sock->ssap] = llcp_sock; + nfc_llcp_sock_link(&local->sockets, sk); pr_debug("Socket bound to SAP %d\n", llcp_sock->ssap); @@ -379,15 +379,6 @@ static int llcp_sock_release(struct socket *sock) goto out; } - mutex_lock(&local->socket_lock); - - if (llcp_sock == local->sockets[llcp_sock->ssap]) - local->sockets[llcp_sock->ssap] = NULL; - else - list_del_init(&llcp_sock->list); - - mutex_unlock(&local->socket_lock); - lock_sock(sk); /* Send a DISC */ @@ -412,14 +403,12 @@ static int llcp_sock_release(struct socket *sock) } } - /* Freeing the SAP */ - if ((sk->sk_state == LLCP_CONNECTED - && llcp_sock->ssap > LLCP_LOCAL_SAP_OFFSET) || - sk->sk_state == LLCP_BOUND || sk->sk_state == LLCP_LISTEN) - nfc_llcp_put_ssap(llcp_sock->local, llcp_sock->ssap); + nfc_llcp_put_ssap(llcp_sock->local, llcp_sock->ssap); release_sock(sk); + nfc_llcp_sock_unlink(&local->sockets, sk); + out: sock_orphan(sk); sock_put(sk); @@ -505,21 +494,26 @@ static int llcp_sock_connect(struct socket *sock, struct sockaddr *_addr, llcp_sock->service_name_len, GFP_KERNEL); - local->sockets[llcp_sock->ssap] = llcp_sock; + nfc_llcp_sock_link(&local->connecting_sockets, sk); ret = nfc_llcp_send_connect(llcp_sock); if (ret) - goto put_dev; + goto sock_unlink; ret = sock_wait_state(sk, LLCP_CONNECTED, sock_sndtimeo(sk, flags & O_NONBLOCK)); if (ret) - goto put_dev; + goto sock_unlink; release_sock(sk); return 0; +sock_unlink: + nfc_llcp_put_ssap(local, llcp_sock->ssap); + + nfc_llcp_sock_unlink(&local->connecting_sockets, sk); + put_dev: nfc_put_device(dev); @@ -690,7 +684,6 @@ struct sock *nfc_llcp_sock_alloc(struct socket *sock, int type, gfp_t gfp) skb_queue_head_init(&llcp_sock->tx_queue); skb_queue_head_init(&llcp_sock->tx_pending_queue); skb_queue_head_init(&llcp_sock->tx_backlog_queue); - INIT_LIST_HEAD(&llcp_sock->list); INIT_LIST_HEAD(&llcp_sock->accept_queue); if (sock != NULL) @@ -708,7 +701,6 @@ void nfc_llcp_sock_free(struct nfc_llcp_sock *sock) skb_queue_purge(&sock->tx_backlog_queue); list_del_init(&sock->accept_queue); - list_del_init(&sock->list); sock->parent = NULL; -- 2.34.1