]> pilppa.org Git - linux-2.6-omap-h63xx.git/blobdiff - net/dccp/output.c
Merge branch 'for-linus' of master.kernel.org:/pub/scm/linux/kernel/git/cooloney...
[linux-2.6-omap-h63xx.git] / net / dccp / output.c
index aa21cc4de37f7b77c84cd38d6d901a1027810471..f49544618f2007857dcf31c59512e5d1d2faca2c 100644 (file)
@@ -61,6 +61,7 @@ static int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb)
                        set_ack = 0;
                        /* fall through */
                case DCCP_PKT_DATAACK:
+               case DCCP_PKT_RESET:
                        break;
 
                case DCCP_PKT_REQUEST:
@@ -69,12 +70,14 @@ static int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb)
 
                case DCCP_PKT_SYNC:
                case DCCP_PKT_SYNCACK:
-                       ackno = dcb->dccpd_seq;
+                       ackno = dcb->dccpd_ack_seq;
                        /* fall through */
                default:
                        /*
-                        * Only data packets should come through with skb->sk
-                        * set.
+                        * Set owner/destructor: some skbs are allocated via
+                        * alloc_skb (e.g. when retransmission may happen).
+                        * Only Data, DataAck, and Reset packets should come
+                        * through here with skb->sk set.
                         */
                        WARN_ON(skb->sk);
                        skb_set_owner_w(skb, sk);
@@ -174,33 +177,38 @@ void dccp_write_space(struct sock *sk)
 
 /**
  * dccp_wait_for_ccid - Wait for ccid to tell us we can send a packet
- * @sk: socket to wait for
+ * @sk:    socket to wait for
+ * @skb:   current skb to pass on for waiting
+ * @delay: sleep timeout in milliseconds (> 0)
+ * This function is called by default when the socket is closed, and
+ * when a non-zero linger time is set on the socket. For consistency
  */
-static int dccp_wait_for_ccid(struct sock *sk, struct sk_buff *skb)
+static int dccp_wait_for_ccid(struct sock *sk, struct sk_buff *skb, int delay)
 {
        struct dccp_sock *dp = dccp_sk(sk);
        DEFINE_WAIT(wait);
-       unsigned long delay;
+       unsigned long jiffdelay;
        int rc;
 
-       while (1) {
+       do {
+               dccp_pr_debug("delayed send by %d msec\n", delay);
+               jiffdelay = msecs_to_jiffies(delay);
+
                prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
 
+               sk->sk_write_pending++;
+               release_sock(sk);
+               schedule_timeout(jiffdelay);
+               lock_sock(sk);
+               sk->sk_write_pending--;
+
                if (sk->sk_err)
                        goto do_error;
                if (signal_pending(current))
                        goto do_interrupted;
 
                rc = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb);
-               if (rc <= 0)
-                       break;
-               delay = msecs_to_jiffies(rc);
-               sk->sk_write_pending++;
-               release_sock(sk);
-               schedule_timeout(delay);
-               lock_sock(sk);
-               sk->sk_write_pending--;
-       }
+       } while ((delay = rc) > 0);
 out:
        finish_wait(sk->sk_sleep, &wait);
        return rc;
@@ -227,7 +235,7 @@ void dccp_write_xmit(struct sock *sk, int block)
                                                msecs_to_jiffies(err)+jiffies);
                                break;
                        } else
-                               err = dccp_wait_for_ccid(sk, skb);
+                               err = dccp_wait_for_ccid(sk, skb, err);
                        if (err && err != -EINTR)
                                DCCP_BUG("err=%d after dccp_wait_for_ccid", err);
                }
@@ -255,7 +263,7 @@ void dccp_write_xmit(struct sock *sk, int block)
                                DCCP_BUG("err=%d after ccid_hc_tx_packet_sent",
                                         err);
                } else {
-                       dccp_pr_debug("packet discarded\n");
+                       dccp_pr_debug("packet discarded due to err=%d\n", err);
                        kfree_skb(skb);
                }
        }
@@ -323,72 +331,81 @@ struct sk_buff *dccp_make_response(struct sock *sk, struct dst_entry *dst,
 
 EXPORT_SYMBOL_GPL(dccp_make_response);
 
-static struct sk_buff *dccp_make_reset(struct sock *sk, struct dst_entry *dst,
-                                      const enum dccp_reset_codes code)
+/* answer offending packet in @rcv_skb with Reset from control socket @ctl */
+struct sk_buff *dccp_ctl_make_reset(struct socket *ctl, struct sk_buff *rcv_skb)
 {
-       struct dccp_hdr *dh;
-       struct dccp_sock *dp = dccp_sk(sk);
-       const u32 dccp_header_size = sizeof(struct dccp_hdr) +
-                                    sizeof(struct dccp_hdr_ext) +
-                                    sizeof(struct dccp_hdr_reset);
-       struct sk_buff *skb = sock_wmalloc(sk, sk->sk_prot->max_header, 1,
-                                          GFP_ATOMIC);
-       if (skb == NULL)
-               return NULL;
-
-       /* Reserve space for headers. */
-       skb_reserve(skb, sk->sk_prot->max_header);
-
-       skb->dst = dst_clone(dst);
-
-       dccp_inc_seqno(&dp->dccps_gss);
-
-       DCCP_SKB_CB(skb)->dccpd_reset_code = code;
-       DCCP_SKB_CB(skb)->dccpd_type       = DCCP_PKT_RESET;
-       DCCP_SKB_CB(skb)->dccpd_seq        = dp->dccps_gss;
+       struct dccp_hdr *rxdh = dccp_hdr(rcv_skb), *dh;
+       struct dccp_skb_cb *dcb = DCCP_SKB_CB(rcv_skb);
+       const u32 dccp_hdr_reset_len = sizeof(struct dccp_hdr) +
+                                      sizeof(struct dccp_hdr_ext) +
+                                      sizeof(struct dccp_hdr_reset);
+       struct dccp_hdr_reset *dhr;
+       struct sk_buff *skb;
 
-       if (dccp_insert_options(sk, skb)) {
-               kfree_skb(skb);
+       skb = alloc_skb(ctl->sk->sk_prot->max_header, GFP_ATOMIC);
+       if (skb == NULL)
                return NULL;
-       }
 
-       dh = dccp_zeroed_hdr(skb, dccp_header_size);
+       skb_reserve(skb, ctl->sk->sk_prot->max_header);
 
-       dh->dccph_sport = inet_sk(sk)->sport;
-       dh->dccph_dport = inet_sk(sk)->dport;
-       dh->dccph_doff  = (dccp_header_size +
-                          DCCP_SKB_CB(skb)->dccpd_opt_len) / 4;
+       /* Swap the send and the receive. */
+       dh = dccp_zeroed_hdr(skb, dccp_hdr_reset_len);
        dh->dccph_type  = DCCP_PKT_RESET;
+       dh->dccph_sport = rxdh->dccph_dport;
+       dh->dccph_dport = rxdh->dccph_sport;
+       dh->dccph_doff  = dccp_hdr_reset_len / 4;
        dh->dccph_x     = 1;
-       dccp_hdr_set_seq(dh, dp->dccps_gss);
-       dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dp->dccps_gsr);
 
-       dccp_hdr_reset(skb)->dccph_reset_code = code;
-       inet_csk(sk)->icsk_af_ops->send_check(sk, 0, skb);
+       dhr = dccp_hdr_reset(skb);
+       dhr->dccph_reset_code = dcb->dccpd_reset_code;
+
+       switch (dcb->dccpd_reset_code) {
+       case DCCP_RESET_CODE_PACKET_ERROR:
+               dhr->dccph_reset_data[0] = rxdh->dccph_type;
+               break;
+       case DCCP_RESET_CODE_OPTION_ERROR:      /* fall through */
+       case DCCP_RESET_CODE_MANDATORY_ERROR:
+               memcpy(dhr->dccph_reset_data, dcb->dccpd_reset_data, 3);
+               break;
+       }
+       /*
+        * From RFC 4340, 8.3.1:
+        *   If P.ackno exists, set R.seqno := P.ackno + 1.
+        *   Else set R.seqno := 0.
+        */
+       if (dcb->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ)
+               dccp_hdr_set_seq(dh, ADD48(dcb->dccpd_ack_seq, 1));
+       dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dcb->dccpd_seq);
 
-       DCCP_INC_STATS(DCCP_MIB_OUTSEGS);
+       dccp_csum_outgoing(skb);
        return skb;
 }
 
+EXPORT_SYMBOL_GPL(dccp_ctl_make_reset);
+
+/* send Reset on established socket, to close or abort the connection */
 int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code)
 {
+       struct sk_buff *skb;
        /*
         * FIXME: what if rebuild_header fails?
         * Should we be doing a rebuild_header here?
         */
        int err = inet_sk_rebuild_header(sk);
 
-       if (err == 0) {
-               struct sk_buff *skb = dccp_make_reset(sk, sk->sk_dst_cache,
-                                                     code);
-               if (skb != NULL) {
-                       memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
-                       err = inet_csk(sk)->icsk_af_ops->queue_xmit(skb, 0);
-                       return net_xmit_eval(err);
-               }
-       }
+       if (err != 0)
+               return err;
+
+       skb = sock_wmalloc(sk, sk->sk_prot->max_header, 1, GFP_ATOMIC);
+       if (skb == NULL)
+               return -ENOBUFS;
 
-       return err;
+       /* Reserve space for headers and prepare control bits. */
+       skb_reserve(skb, sk->sk_prot->max_header);
+       DCCP_SKB_CB(skb)->dccpd_type       = DCCP_PKT_RESET;
+       DCCP_SKB_CB(skb)->dccpd_reset_code = code;
+
+       return dccp_transmit_skb(sk, skb);
 }
 
 /*
@@ -476,6 +493,7 @@ void dccp_send_ack(struct sock *sk)
 
 EXPORT_SYMBOL_GPL(dccp_send_ack);
 
+/* FIXME: Is this still necessary (11.3) - currently nowhere used by DCCP. */
 void dccp_send_delayed_ack(struct sock *sk)
 {
        struct inet_connection_sock *icsk = inet_csk(sk);
@@ -506,7 +524,7 @@ void dccp_send_delayed_ack(struct sock *sk)
        sk_reset_timer(sk, &icsk->icsk_delack_timer, timeout);
 }
 
-void dccp_send_sync(struct sock *sk, const u64 seq,
+void dccp_send_sync(struct sock *sk, const u64 ackno,
                    const enum dccp_pkt_type pkt_type)
 {
        /*
@@ -516,14 +534,16 @@ void dccp_send_sync(struct sock *sk, const u64 seq,
         */
        struct sk_buff *skb = alloc_skb(sk->sk_prot->max_header, GFP_ATOMIC);
 
-       if (skb == NULL)
+       if (skb == NULL) {
                /* FIXME: how to make sure the sync is sent? */
+               DCCP_CRIT("could not send %s", dccp_packet_name(pkt_type));
                return;
+       }
 
        /* Reserve space for headers and prepare control bits. */
        skb_reserve(skb, sk->sk_prot->max_header);
        DCCP_SKB_CB(skb)->dccpd_type = pkt_type;
-       DCCP_SKB_CB(skb)->dccpd_seq = seq;
+       DCCP_SKB_CB(skb)->dccpd_ack_seq = ackno;
 
        dccp_transmit_skb(sk, skb);
 }