diff options
-rw-r--r-- | net/tipc/link.c | 104 | ||||
-rw-r--r-- | net/tipc/msg.h | 28 |
2 files changed, 60 insertions, 72 deletions
diff --git a/net/tipc/link.c b/net/tipc/link.c index b9325a1bddaa..58e2460682da 100644 --- a/net/tipc/link.c +++ b/net/tipc/link.c @@ -367,28 +367,43 @@ void tipc_link_delete_list(struct net *net, unsigned int bearer_id, } /** - * link_schedule_user - schedule user for wakeup after congestion + * link_schedule_user - schedule a message sender for wakeup after congestion * @link: congested link - * @oport: sending port - * @chain_sz: size of buffer chain that was attempted sent - * @imp: importance of message attempted sent + * @list: message that was attempted sent * Create pseudo msg to send back to user when congestion abates + * Only consumes message if there is an error */ -static bool link_schedule_user(struct tipc_link *link, u32 oport, - uint chain_sz, uint imp) +static int link_schedule_user(struct tipc_link *link, struct sk_buff_head *list) { - struct sk_buff *buf; + struct tipc_msg *msg = buf_msg(skb_peek(list)); + int imp = msg_importance(msg); + u32 oport = msg_origport(msg); + u32 addr = link_own_addr(link); + struct sk_buff *skb; - buf = tipc_msg_create(SOCK_WAKEUP, 0, INT_H_SIZE, 0, - link_own_addr(link), link_own_addr(link), - oport, 0, 0); - if (!buf) - return false; - TIPC_SKB_CB(buf)->chain_sz = chain_sz; - TIPC_SKB_CB(buf)->chain_imp = imp; - skb_queue_tail(&link->wakeupq, buf); + /* This really cannot happen... */ + if (unlikely(imp > TIPC_CRITICAL_IMPORTANCE)) { + pr_warn("%s<%s>, send queue full", link_rst_msg, link->name); + tipc_link_reset(link); + goto err; + } + /* Non-blocking sender: */ + if (TIPC_SKB_CB(skb_peek(list))->wakeup_pending) + return -ELINKCONG; + + /* Create and schedule wakeup pseudo message */ + skb = tipc_msg_create(SOCK_WAKEUP, 0, INT_H_SIZE, 0, + addr, addr, oport, 0, 0); + if (!skb) + goto err; + TIPC_SKB_CB(skb)->chain_sz = skb_queue_len(list); + TIPC_SKB_CB(skb)->chain_imp = imp; + skb_queue_tail(&link->wakeupq, skb); link->stats.link_congs++; - return true; + return -ELINKCONG; +err: + __skb_queue_purge(list); + return -ENOBUFS; } /** @@ -708,48 +723,15 @@ static void link_state_event(struct tipc_link *l_ptr, unsigned int event) } } -/* tipc_link_cong: determine return value and how to treat the - * sent buffer during link congestion. - * - For plain, errorless user data messages we keep the buffer and - * return -ELINKONG. - * - For all other messages we discard the buffer and return -EHOSTUNREACH - * - For TIPC internal messages we also reset the link - */ -static int tipc_link_cong(struct tipc_link *link, struct sk_buff_head *list) -{ - struct sk_buff *skb = skb_peek(list); - struct tipc_msg *msg = buf_msg(skb); - int imp = msg_importance(msg); - u32 oport = msg_tot_origport(msg); - - if (unlikely(imp > TIPC_CRITICAL_IMPORTANCE)) { - pr_warn("%s<%s>, send queue full", link_rst_msg, link->name); - tipc_link_reset(link); - goto drop; - } - if (unlikely(msg_errcode(msg))) - goto drop; - if (unlikely(msg_reroute_cnt(msg))) - goto drop; - if (TIPC_SKB_CB(skb)->wakeup_pending) - return -ELINKCONG; - if (link_schedule_user(link, oport, skb_queue_len(list), imp)) - return -ELINKCONG; -drop: - __skb_queue_purge(list); - return -EHOSTUNREACH; -} - /** * __tipc_link_xmit(): same as tipc_link_xmit, but destlink is known & locked * @link: link to use * @list: chain of buffers containing message * - * Consumes the buffer chain, except when returning -ELINKCONG - * Returns 0 if success, otherwise errno: -ELINKCONG, -EMSGSIZE (plain socket - * user data messages) or -EHOSTUNREACH (all other messages/senders) - * Only the socket functions tipc_send_stream() and tipc_send_packet() need - * to act on the return value, since they may need to do more send attempts. + * Consumes the buffer chain, except when returning -ELINKCONG, + * since the caller then may want to make more send attempts. + * Returns 0 if success, or errno: -ELINKCONG, -EMSGSIZE or -ENOBUFS + * Messages at TIPC_SYSTEM_IMPORTANCE are always accepted */ int __tipc_link_xmit(struct net *net, struct tipc_link *link, struct sk_buff_head *list) @@ -768,7 +750,7 @@ int __tipc_link_xmit(struct net *net, struct tipc_link *link, /* Match backlog limit against msg importance: */ if (unlikely(link->backlog[imp].len >= link->backlog[imp].limit)) - return tipc_link_cong(link, list); + return link_schedule_user(link, list); if (unlikely(msg_size(msg) > mtu)) { __skb_queue_purge(list); @@ -820,13 +802,25 @@ static int __tipc_link_xmit_skb(struct tipc_link *link, struct sk_buff *skb) return __tipc_link_xmit(link->owner->net, link, &head); } +/* tipc_link_xmit_skb(): send single buffer to destination + * Buffers sent via this functon are generally TIPC_SYSTEM_IMPORTANCE + * messages, which will not be rejected + * The only exception is datagram messages rerouted after secondary + * lookup, which are rare and safe to dispose of anyway. + * TODO: Return real return value, and let callers use + * tipc_wait_for_sendpkt() where applicable + */ int tipc_link_xmit_skb(struct net *net, struct sk_buff *skb, u32 dnode, u32 selector) { struct sk_buff_head head; + int rc; skb2list(skb, &head); - return tipc_link_xmit(net, &head, dnode, selector); + rc = tipc_link_xmit(net, &head, dnode, selector); + if (rc == -ELINKCONG) + kfree_skb(skb); + return 0; } /** diff --git a/net/tipc/msg.h b/net/tipc/msg.h index bd3969a80dd4..6445db09c0c4 100644 --- a/net/tipc/msg.h +++ b/net/tipc/msg.h @@ -240,6 +240,15 @@ static inline void msg_set_size(struct tipc_msg *m, u32 sz) m->hdr[0] = htonl((msg_word(m, 0) & ~0x1ffff) | sz); } +static inline unchar *msg_data(struct tipc_msg *m) +{ + return ((unchar *)m) + msg_hdr_sz(m); +} + +static inline struct tipc_msg *msg_get_wrapped(struct tipc_msg *m) +{ + return (struct tipc_msg *)msg_data(m); +} /* * Word 1 @@ -372,6 +381,8 @@ static inline void msg_set_prevnode(struct tipc_msg *m, u32 a) static inline u32 msg_origport(struct tipc_msg *m) { + if (msg_user(m) == MSG_FRAGMENTER) + m = msg_get_wrapped(m); return msg_word(m, 4); } @@ -467,16 +478,6 @@ static inline void msg_set_nameupper(struct tipc_msg *m, u32 n) msg_set_word(m, 10, n); } -static inline unchar *msg_data(struct tipc_msg *m) -{ - return ((unchar *)m) + msg_hdr_sz(m); -} - -static inline struct tipc_msg *msg_get_wrapped(struct tipc_msg *m) -{ - return (struct tipc_msg *)msg_data(m); -} - /* * Constants and routines used to read and write TIPC internal message headers */ @@ -753,13 +754,6 @@ static inline void msg_set_link_tolerance(struct tipc_msg *m, u32 n) msg_set_bits(m, 9, 0, 0xffff, n); } -static inline u32 msg_tot_origport(struct tipc_msg *m) -{ - if ((msg_user(m) == MSG_FRAGMENTER) && (msg_type(m) == FIRST_FRAGMENT)) - return msg_origport(msg_get_wrapped(m)); - return msg_origport(m); -} - struct sk_buff *tipc_buf_acquire(u32 size); bool tipc_msg_validate(struct sk_buff *skb); bool tipc_msg_reverse(u32 own_addr, struct sk_buff *buf, u32 *dnode, |