Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 1 | /* |
| 2 | * net/dccp/output.c |
Arnaldo Carvalho de Melo | 8109b02 | 2006-12-10 16:01:18 -0200 | [diff] [blame] | 3 | * |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 4 | * An implementation of the DCCP protocol |
| 5 | * Arnaldo Carvalho de Melo <acme@conectiva.com.br> |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or |
| 8 | * modify it under the terms of the GNU General Public License |
| 9 | * as published by the Free Software Foundation; either version |
| 10 | * 2 of the License, or (at your option) any later version. |
| 11 | */ |
| 12 | |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 13 | #include <linux/dccp.h> |
Herbert Xu | 48918a4 | 2005-10-30 11:20:59 +1100 | [diff] [blame] | 14 | #include <linux/kernel.h> |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 15 | #include <linux/skbuff.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 16 | #include <linux/slab.h> |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 17 | |
Arnaldo Carvalho de Melo | 14c8502 | 2005-12-27 02:43:12 -0200 | [diff] [blame] | 18 | #include <net/inet_sock.h> |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 19 | #include <net/sock.h> |
| 20 | |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 21 | #include "ackvec.h" |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 22 | #include "ccid.h" |
| 23 | #include "dccp.h" |
| 24 | |
| 25 | static inline void dccp_event_ack_sent(struct sock *sk) |
| 26 | { |
| 27 | inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK); |
| 28 | } |
| 29 | |
Gerrit Renker | 8695e80 | 2011-07-03 09:51:29 -0600 | [diff] [blame] | 30 | /* enqueue @skb on sk_send_head for retransmission, return clone to send now */ |
| 31 | static struct sk_buff *dccp_skb_entail(struct sock *sk, struct sk_buff *skb) |
Herbert Xu | 48918a4 | 2005-10-30 11:20:59 +1100 | [diff] [blame] | 32 | { |
| 33 | skb_set_owner_w(skb, sk); |
| 34 | WARN_ON(sk->sk_send_head); |
| 35 | sk->sk_send_head = skb; |
Gerrit Renker | 8695e80 | 2011-07-03 09:51:29 -0600 | [diff] [blame] | 36 | return skb_clone(sk->sk_send_head, gfp_any()); |
Herbert Xu | 48918a4 | 2005-10-30 11:20:59 +1100 | [diff] [blame] | 37 | } |
| 38 | |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 39 | /* |
| 40 | * All SKB's seen here are completely headerless. It is our |
| 41 | * job to build the DCCP header, and pass the packet down to |
| 42 | * IP so it can do the same plus pass the packet off to the |
| 43 | * device. |
| 44 | */ |
Herbert Xu | 48918a4 | 2005-10-30 11:20:59 +1100 | [diff] [blame] | 45 | static int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb) |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 46 | { |
| 47 | if (likely(skb != NULL)) { |
David S. Miller | d9d8da8 | 2011-05-06 22:23:20 -0700 | [diff] [blame] | 48 | struct inet_sock *inet = inet_sk(sk); |
Arnaldo Carvalho de Melo | 57cca05 | 2005-12-13 23:16:16 -0800 | [diff] [blame] | 49 | const struct inet_connection_sock *icsk = inet_csk(sk); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 50 | struct dccp_sock *dp = dccp_sk(sk); |
| 51 | struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb); |
| 52 | struct dccp_hdr *dh; |
| 53 | /* XXX For now we're using only 48 bits sequence numbers */ |
Arnaldo Carvalho de Melo | 118b2c9 | 2006-03-20 22:31:09 -0800 | [diff] [blame] | 54 | const u32 dccp_header_size = sizeof(*dh) + |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 55 | sizeof(struct dccp_hdr_ext) + |
Arnaldo Carvalho de Melo | 7690af3 | 2005-08-13 20:34:54 -0300 | [diff] [blame] | 56 | dccp_packet_hdr_len(dcb->dccpd_type); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 57 | int err, set_ack = 1; |
| 58 | u64 ackno = dp->dccps_gsr; |
Gerrit Renker | 73f18fd | 2008-07-26 11:59:10 +0100 | [diff] [blame] | 59 | /* |
| 60 | * Increment GSS here already in case the option code needs it. |
| 61 | * Update GSS for real only if option processing below succeeds. |
| 62 | */ |
| 63 | dcb->dccpd_seq = ADD48(dp->dccps_gss, 1); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 64 | |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 65 | switch (dcb->dccpd_type) { |
| 66 | case DCCP_PKT_DATA: |
| 67 | set_ack = 0; |
Herbert Xu | edc9e81 | 2005-10-30 11:20:59 +1100 | [diff] [blame] | 68 | /* fall through */ |
| 69 | case DCCP_PKT_DATAACK: |
Gerrit Renker | ee1a159 | 2007-09-26 11:30:02 -0300 | [diff] [blame] | 70 | case DCCP_PKT_RESET: |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 71 | break; |
Herbert Xu | edc9e81 | 2005-10-30 11:20:59 +1100 | [diff] [blame] | 72 | |
Andrea Bittau | afe0025 | 2006-03-20 17:43:56 -0800 | [diff] [blame] | 73 | case DCCP_PKT_REQUEST: |
| 74 | set_ack = 0; |
Gerrit Renker | 73f18fd | 2008-07-26 11:59:10 +0100 | [diff] [blame] | 75 | /* Use ISS on the first (non-retransmitted) Request. */ |
| 76 | if (icsk->icsk_retransmits == 0) |
| 77 | dcb->dccpd_seq = dp->dccps_iss; |
Andrea Bittau | afe0025 | 2006-03-20 17:43:56 -0800 | [diff] [blame] | 78 | /* fall through */ |
| 79 | |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 80 | case DCCP_PKT_SYNC: |
| 81 | case DCCP_PKT_SYNCACK: |
Gerrit Renker | b0d045c | 2007-09-25 22:42:27 -0700 | [diff] [blame] | 82 | ackno = dcb->dccpd_ack_seq; |
Herbert Xu | edc9e81 | 2005-10-30 11:20:59 +1100 | [diff] [blame] | 83 | /* fall through */ |
| 84 | default: |
| 85 | /* |
Gerrit Renker | ee1a159 | 2007-09-26 11:30:02 -0300 | [diff] [blame] | 86 | * Set owner/destructor: some skbs are allocated via |
| 87 | * alloc_skb (e.g. when retransmission may happen). |
| 88 | * Only Data, DataAck, and Reset packets should come |
| 89 | * through here with skb->sk set. |
Herbert Xu | edc9e81 | 2005-10-30 11:20:59 +1100 | [diff] [blame] | 90 | */ |
| 91 | WARN_ON(skb->sk); |
| 92 | skb_set_owner_w(skb, sk); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 93 | break; |
| 94 | } |
Arnaldo Carvalho de Melo | 2411772 | 2005-08-21 05:40:16 -0300 | [diff] [blame] | 95 | |
Arnaldo Carvalho de Melo | 2d0817d | 2006-03-20 22:32:06 -0800 | [diff] [blame] | 96 | if (dccp_insert_options(sk, skb)) { |
| 97 | kfree_skb(skb); |
| 98 | return -EPROTO; |
| 99 | } |
YOSHIFUJI Hideaki | c9eaf17 | 2007-02-09 23:24:38 +0900 | [diff] [blame] | 100 | |
Herbert Xu | fda0fd6 | 2005-10-14 16:38:49 +1000 | [diff] [blame] | 101 | |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 102 | /* Build DCCP header and checksum it. */ |
Gerrit Renker | 9b42078 | 2006-11-10 11:22:32 -0200 | [diff] [blame] | 103 | dh = dccp_zeroed_hdr(skb, dccp_header_size); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 104 | dh->dccph_type = dcb->dccpd_type; |
Eric Dumazet | c720c7e | 2009-10-15 06:30:45 +0000 | [diff] [blame] | 105 | dh->dccph_sport = inet->inet_sport; |
| 106 | dh->dccph_dport = inet->inet_dport; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 107 | dh->dccph_doff = (dccp_header_size + dcb->dccpd_opt_len) / 4; |
| 108 | dh->dccph_ccval = dcb->dccpd_ccval; |
Gerrit Renker | 6f4e5ff | 2006-11-10 17:43:06 -0200 | [diff] [blame] | 109 | dh->dccph_cscov = dp->dccps_pcslen; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 110 | /* XXX For now we're using only 48 bits sequence numbers */ |
| 111 | dh->dccph_x = 1; |
| 112 | |
Gerrit Renker | 73f18fd | 2008-07-26 11:59:10 +0100 | [diff] [blame] | 113 | dccp_update_gss(sk, dcb->dccpd_seq); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 114 | dccp_hdr_set_seq(dh, dp->dccps_gss); |
| 115 | if (set_ack) |
| 116 | dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), ackno); |
| 117 | |
| 118 | switch (dcb->dccpd_type) { |
| 119 | case DCCP_PKT_REQUEST: |
Arnaldo Carvalho de Melo | 7690af3 | 2005-08-13 20:34:54 -0300 | [diff] [blame] | 120 | dccp_hdr_request(skb)->dccph_req_service = |
Arnaldo Carvalho de Melo | 67e6b62 | 2005-09-16 16:58:40 -0700 | [diff] [blame] | 121 | dp->dccps_service; |
Gerrit Renker | 73f18fd | 2008-07-26 11:59:10 +0100 | [diff] [blame] | 122 | /* |
| 123 | * Limit Ack window to ISS <= P.ackno <= GSS, so that |
| 124 | * only Responses to Requests we sent are considered. |
| 125 | */ |
| 126 | dp->dccps_awl = dp->dccps_iss; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 127 | break; |
| 128 | case DCCP_PKT_RESET: |
Arnaldo Carvalho de Melo | 7690af3 | 2005-08-13 20:34:54 -0300 | [diff] [blame] | 129 | dccp_hdr_reset(skb)->dccph_reset_code = |
| 130 | dcb->dccpd_reset_code; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 131 | break; |
| 132 | } |
| 133 | |
Herbert Xu | bb29624 | 2010-04-11 02:15:55 +0000 | [diff] [blame] | 134 | icsk->icsk_af_ops->send_check(sk, skb); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 135 | |
Arnaldo Carvalho de Melo | 7ad07e7 | 2005-08-23 21:50:06 -0700 | [diff] [blame] | 136 | if (set_ack) |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 137 | dccp_event_ack_sent(sk); |
| 138 | |
| 139 | DCCP_INC_STATS(DCCP_MIB_OUTSEGS); |
| 140 | |
Eric Dumazet | b0270e9 | 2014-04-15 12:58:34 -0400 | [diff] [blame] | 141 | err = icsk->icsk_af_ops->queue_xmit(sk, skb, &inet->cork.fl); |
Gerrit Renker | b9df3cb | 2006-11-14 11:21:36 -0200 | [diff] [blame] | 142 | return net_xmit_eval(err); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 143 | } |
| 144 | return -ENOBUFS; |
| 145 | } |
| 146 | |
Gerrit Renker | 6179983 | 2007-12-13 23:37:55 -0200 | [diff] [blame] | 147 | /** |
Lucas De Marchi | 25985ed | 2011-03-30 22:57:33 -0300 | [diff] [blame] | 148 | * dccp_determine_ccmps - Find out about CCID-specific packet-size limits |
Gerrit Renker | 6179983 | 2007-12-13 23:37:55 -0200 | [diff] [blame] | 149 | * We only consider the HC-sender CCID for setting the CCMPS (RFC 4340, 14.), |
| 150 | * since the RX CCID is restricted to feedback packets (Acks), which are small |
| 151 | * in comparison with the data traffic. A value of 0 means "no current CCMPS". |
| 152 | */ |
| 153 | static u32 dccp_determine_ccmps(const struct dccp_sock *dp) |
| 154 | { |
| 155 | const struct ccid *tx_ccid = dp->dccps_hc_tx_ccid; |
| 156 | |
| 157 | if (tx_ccid == NULL || tx_ccid->ccid_ops == NULL) |
| 158 | return 0; |
| 159 | return tx_ccid->ccid_ops->ccid_ccmps; |
| 160 | } |
| 161 | |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 162 | unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu) |
| 163 | { |
Arnaldo Carvalho de Melo | d83d846 | 2005-12-13 23:26:10 -0800 | [diff] [blame] | 164 | struct inet_connection_sock *icsk = inet_csk(sk); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 165 | struct dccp_sock *dp = dccp_sk(sk); |
Gerrit Renker | 6179983 | 2007-12-13 23:37:55 -0200 | [diff] [blame] | 166 | u32 ccmps = dccp_determine_ccmps(dp); |
Gerrit Renker | 361a5c1 | 2009-02-27 22:38:28 +0000 | [diff] [blame] | 167 | u32 cur_mps = ccmps ? min(pmtu, ccmps) : pmtu; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 168 | |
Gerrit Renker | 6179983 | 2007-12-13 23:37:55 -0200 | [diff] [blame] | 169 | /* Account for header lengths and IPv4/v6 option overhead */ |
| 170 | cur_mps -= (icsk->icsk_af_ops->net_header_len + icsk->icsk_ext_hdr_len + |
| 171 | sizeof(struct dccp_hdr) + sizeof(struct dccp_hdr_ext)); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 172 | |
| 173 | /* |
Gerrit Renker | 361a5c1 | 2009-02-27 22:38:28 +0000 | [diff] [blame] | 174 | * Leave enough headroom for common DCCP header options. |
| 175 | * This only considers options which may appear on DCCP-Data packets, as |
| 176 | * per table 3 in RFC 4340, 5.8. When running out of space for other |
| 177 | * options (eg. Ack Vector which can take up to 255 bytes), it is better |
| 178 | * to schedule a separate Ack. Thus we leave headroom for the following: |
| 179 | * - 1 byte for Slow Receiver (11.6) |
| 180 | * - 6 bytes for Timestamp (13.1) |
| 181 | * - 10 bytes for Timestamp Echo (13.3) |
| 182 | * - 8 bytes for NDP count (7.7, when activated) |
| 183 | * - 6 bytes for Data Checksum (9.3) |
| 184 | * - %DCCPAV_MIN_OPTLEN bytes for Ack Vector size (11.4, when enabled) |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 185 | */ |
Gerrit Renker | 361a5c1 | 2009-02-27 22:38:28 +0000 | [diff] [blame] | 186 | cur_mps -= roundup(1 + 6 + 10 + dp->dccps_send_ndp_count * 8 + 6 + |
| 187 | (dp->dccps_hc_rx_ackvec ? DCCPAV_MIN_OPTLEN : 0), 4); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 188 | |
| 189 | /* And store cached results */ |
Arnaldo Carvalho de Melo | d83d846 | 2005-12-13 23:26:10 -0800 | [diff] [blame] | 190 | icsk->icsk_pmtu_cookie = pmtu; |
Gerrit Renker | 6179983 | 2007-12-13 23:37:55 -0200 | [diff] [blame] | 191 | dp->dccps_mss_cache = cur_mps; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 192 | |
Gerrit Renker | 6179983 | 2007-12-13 23:37:55 -0200 | [diff] [blame] | 193 | return cur_mps; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 194 | } |
| 195 | |
Arnaldo Carvalho de Melo | f21e68c | 2005-12-13 23:24:16 -0800 | [diff] [blame] | 196 | EXPORT_SYMBOL_GPL(dccp_sync_mss); |
| 197 | |
Arnaldo Carvalho de Melo | c530cfb | 2005-08-29 02:15:54 -0300 | [diff] [blame] | 198 | void dccp_write_space(struct sock *sk) |
| 199 | { |
Eric Dumazet | 4381548 | 2010-04-29 11:01:49 +0000 | [diff] [blame] | 200 | struct socket_wq *wq; |
Arnaldo Carvalho de Melo | c530cfb | 2005-08-29 02:15:54 -0300 | [diff] [blame] | 201 | |
Eric Dumazet | 4381548 | 2010-04-29 11:01:49 +0000 | [diff] [blame] | 202 | rcu_read_lock(); |
| 203 | wq = rcu_dereference(sk->sk_wq); |
| 204 | if (wq_has_sleeper(wq)) |
| 205 | wake_up_interruptible(&wq->wait); |
Arnaldo Carvalho de Melo | c530cfb | 2005-08-29 02:15:54 -0300 | [diff] [blame] | 206 | /* Should agree with poll, otherwise some programs break */ |
| 207 | if (sock_writeable(sk)) |
Pavel Emelyanov | 8d8ad9d | 2007-11-26 20:10:50 +0800 | [diff] [blame] | 208 | sk_wake_async(sk, SOCK_WAKE_SPACE, POLL_OUT); |
Arnaldo Carvalho de Melo | c530cfb | 2005-08-29 02:15:54 -0300 | [diff] [blame] | 209 | |
Eric Dumazet | 4381548 | 2010-04-29 11:01:49 +0000 | [diff] [blame] | 210 | rcu_read_unlock(); |
Arnaldo Carvalho de Melo | c530cfb | 2005-08-29 02:15:54 -0300 | [diff] [blame] | 211 | } |
| 212 | |
Arnaldo Carvalho de Melo | d6809c1 | 2005-08-27 03:06:35 -0300 | [diff] [blame] | 213 | /** |
Gerrit Renker | b1fcf55 | 2010-10-27 19:16:27 +0000 | [diff] [blame] | 214 | * dccp_wait_for_ccid - Await CCID send permission |
Gerrit Renker | bc84987 | 2007-10-04 14:38:49 -0700 | [diff] [blame] | 215 | * @sk: socket to wait for |
Gerrit Renker | b1fcf55 | 2010-10-27 19:16:27 +0000 | [diff] [blame] | 216 | * @delay: timeout in jiffies |
Ben Hutchings | 2c53040 | 2012-07-10 10:55:09 +0000 | [diff] [blame] | 217 | * |
Gerrit Renker | b1fcf55 | 2010-10-27 19:16:27 +0000 | [diff] [blame] | 218 | * This is used by CCIDs which need to delay the send time in process context. |
Arnaldo Carvalho de Melo | d6809c1 | 2005-08-27 03:06:35 -0300 | [diff] [blame] | 219 | */ |
Gerrit Renker | b1fcf55 | 2010-10-27 19:16:27 +0000 | [diff] [blame] | 220 | static int dccp_wait_for_ccid(struct sock *sk, unsigned long delay) |
Arnaldo Carvalho de Melo | d6809c1 | 2005-08-27 03:06:35 -0300 | [diff] [blame] | 221 | { |
Arnaldo Carvalho de Melo | d6809c1 | 2005-08-27 03:06:35 -0300 | [diff] [blame] | 222 | DEFINE_WAIT(wait); |
Gerrit Renker | b1fcf55 | 2010-10-27 19:16:27 +0000 | [diff] [blame] | 223 | long remaining; |
Arnaldo Carvalho de Melo | d6809c1 | 2005-08-27 03:06:35 -0300 | [diff] [blame] | 224 | |
Gerrit Renker | b1fcf55 | 2010-10-27 19:16:27 +0000 | [diff] [blame] | 225 | prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); |
| 226 | sk->sk_write_pending++; |
| 227 | release_sock(sk); |
Gerrit Renker | bc84987 | 2007-10-04 14:38:49 -0700 | [diff] [blame] | 228 | |
Gerrit Renker | b1fcf55 | 2010-10-27 19:16:27 +0000 | [diff] [blame] | 229 | remaining = schedule_timeout(delay); |
Arnaldo Carvalho de Melo | d6809c1 | 2005-08-27 03:06:35 -0300 | [diff] [blame] | 230 | |
Gerrit Renker | b1fcf55 | 2010-10-27 19:16:27 +0000 | [diff] [blame] | 231 | lock_sock(sk); |
| 232 | sk->sk_write_pending--; |
Eric Dumazet | aa39514 | 2010-04-20 13:03:51 +0000 | [diff] [blame] | 233 | finish_wait(sk_sleep(sk), &wait); |
Arnaldo Carvalho de Melo | d6809c1 | 2005-08-27 03:06:35 -0300 | [diff] [blame] | 234 | |
Gerrit Renker | b1fcf55 | 2010-10-27 19:16:27 +0000 | [diff] [blame] | 235 | if (signal_pending(current) || sk->sk_err) |
| 236 | return -1; |
| 237 | return remaining; |
Arnaldo Carvalho de Melo | d6809c1 | 2005-08-27 03:06:35 -0300 | [diff] [blame] | 238 | } |
| 239 | |
Gerrit Renker | dc841e3 | 2010-10-27 19:16:26 +0000 | [diff] [blame] | 240 | /** |
| 241 | * dccp_xmit_packet - Send data packet under control of CCID |
| 242 | * Transmits next-queued payload and informs CCID to account for the packet. |
| 243 | */ |
| 244 | static void dccp_xmit_packet(struct sock *sk) |
| 245 | { |
| 246 | int err, len; |
| 247 | struct dccp_sock *dp = dccp_sk(sk); |
Tomasz Grobelny | 871a2c1 | 2010-12-04 13:38:01 +0100 | [diff] [blame] | 248 | struct sk_buff *skb = dccp_qpolicy_pop(sk); |
Gerrit Renker | dc841e3 | 2010-10-27 19:16:26 +0000 | [diff] [blame] | 249 | |
| 250 | if (unlikely(skb == NULL)) |
| 251 | return; |
| 252 | len = skb->len; |
| 253 | |
| 254 | if (sk->sk_state == DCCP_PARTOPEN) { |
| 255 | const u32 cur_mps = dp->dccps_mss_cache - DCCP_FEATNEG_OVERHEAD; |
| 256 | /* |
| 257 | * See 8.1.5 - Handshake Completion. |
| 258 | * |
| 259 | * For robustness we resend Confirm options until the client has |
| 260 | * entered OPEN. During the initial feature negotiation, the MPS |
| 261 | * is smaller than usual, reduced by the Change/Confirm options. |
| 262 | */ |
| 263 | if (!list_empty(&dp->dccps_featneg) && len > cur_mps) { |
| 264 | DCCP_WARN("Payload too large (%d) for featneg.\n", len); |
| 265 | dccp_send_ack(sk); |
| 266 | dccp_feat_list_purge(&dp->dccps_featneg); |
| 267 | } |
| 268 | |
| 269 | inet_csk_schedule_ack(sk); |
| 270 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, |
| 271 | inet_csk(sk)->icsk_rto, |
| 272 | DCCP_RTO_MAX); |
| 273 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_DATAACK; |
| 274 | } else if (dccp_ack_pending(sk)) { |
| 275 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_DATAACK; |
| 276 | } else { |
| 277 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_DATA; |
| 278 | } |
| 279 | |
| 280 | err = dccp_transmit_skb(sk, skb); |
| 281 | if (err) |
| 282 | dccp_pr_debug("transmit_skb() returned err=%d\n", err); |
| 283 | /* |
| 284 | * Register this one as sent even if an error occurred. To the remote |
| 285 | * end a local packet drop is indistinguishable from network loss, i.e. |
| 286 | * any local drop will eventually be reported via receiver feedback. |
| 287 | */ |
| 288 | ccid_hc_tx_packet_sent(dp->dccps_hc_tx_ccid, sk, len); |
Gerrit Renker | d83447f | 2010-11-14 17:25:46 +0100 | [diff] [blame] | 289 | |
| 290 | /* |
| 291 | * If the CCID needs to transfer additional header options out-of-band |
| 292 | * (e.g. Ack Vectors or feature-negotiation options), it activates this |
| 293 | * flag to schedule a Sync. The Sync will automatically incorporate all |
| 294 | * currently pending header options, thus clearing the backlog. |
| 295 | */ |
| 296 | if (dp->dccps_sync_scheduled) |
| 297 | dccp_send_sync(sk, dp->dccps_gsr, DCCP_PKT_SYNC); |
Gerrit Renker | dc841e3 | 2010-10-27 19:16:26 +0000 | [diff] [blame] | 298 | } |
| 299 | |
Gerrit Renker | b1fcf55 | 2010-10-27 19:16:27 +0000 | [diff] [blame] | 300 | /** |
| 301 | * dccp_flush_write_queue - Drain queue at end of connection |
| 302 | * Since dccp_sendmsg queues packets without waiting for them to be sent, it may |
| 303 | * happen that the TX queue is not empty at the end of a connection. We give the |
| 304 | * HC-sender CCID a grace period of up to @time_budget jiffies. If this function |
| 305 | * returns with a non-empty write queue, it will be purged later. |
| 306 | */ |
| 307 | void dccp_flush_write_queue(struct sock *sk, long *time_budget) |
| 308 | { |
| 309 | struct dccp_sock *dp = dccp_sk(sk); |
| 310 | struct sk_buff *skb; |
| 311 | long delay, rc; |
| 312 | |
| 313 | while (*time_budget > 0 && (skb = skb_peek(&sk->sk_write_queue))) { |
| 314 | rc = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb); |
| 315 | |
| 316 | switch (ccid_packet_dequeue_eval(rc)) { |
| 317 | case CCID_PACKET_WILL_DEQUEUE_LATER: |
| 318 | /* |
| 319 | * If the CCID determines when to send, the next sending |
| 320 | * time is unknown or the CCID may not even send again |
| 321 | * (e.g. remote host crashes or lost Ack packets). |
| 322 | */ |
| 323 | DCCP_WARN("CCID did not manage to send all packets\n"); |
| 324 | return; |
| 325 | case CCID_PACKET_DELAY: |
| 326 | delay = msecs_to_jiffies(rc); |
| 327 | if (delay > *time_budget) |
| 328 | return; |
| 329 | rc = dccp_wait_for_ccid(sk, delay); |
| 330 | if (rc < 0) |
| 331 | return; |
| 332 | *time_budget -= (delay - rc); |
| 333 | /* check again if we can send now */ |
| 334 | break; |
| 335 | case CCID_PACKET_SEND_AT_ONCE: |
| 336 | dccp_xmit_packet(sk); |
| 337 | break; |
| 338 | case CCID_PACKET_ERR: |
| 339 | skb_dequeue(&sk->sk_write_queue); |
| 340 | kfree_skb(skb); |
| 341 | dccp_pr_debug("packet discarded due to err=%ld\n", rc); |
| 342 | } |
| 343 | } |
| 344 | } |
| 345 | |
| 346 | void dccp_write_xmit(struct sock *sk) |
Arnaldo Carvalho de Melo | 27258ee | 2005-08-09 20:30:56 -0700 | [diff] [blame] | 347 | { |
Ian McDonald | 97e5848 | 2006-08-26 19:16:45 -0700 | [diff] [blame] | 348 | struct dccp_sock *dp = dccp_sk(sk); |
| 349 | struct sk_buff *skb; |
Ian McDonald | 97e5848 | 2006-08-26 19:16:45 -0700 | [diff] [blame] | 350 | |
Tomasz Grobelny | 871a2c1 | 2010-12-04 13:38:01 +0100 | [diff] [blame] | 351 | while ((skb = dccp_qpolicy_top(sk))) { |
Gerrit Renker | dc841e3 | 2010-10-27 19:16:26 +0000 | [diff] [blame] | 352 | int rc = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb); |
Arnaldo Carvalho de Melo | d6809c1 | 2005-08-27 03:06:35 -0300 | [diff] [blame] | 353 | |
Gerrit Renker | dc841e3 | 2010-10-27 19:16:26 +0000 | [diff] [blame] | 354 | switch (ccid_packet_dequeue_eval(rc)) { |
| 355 | case CCID_PACKET_WILL_DEQUEUE_LATER: |
| 356 | return; |
| 357 | case CCID_PACKET_DELAY: |
Gerrit Renker | b1fcf55 | 2010-10-27 19:16:27 +0000 | [diff] [blame] | 358 | sk_reset_timer(sk, &dp->dccps_xmit_timer, |
| 359 | jiffies + msecs_to_jiffies(rc)); |
| 360 | return; |
Gerrit Renker | dc841e3 | 2010-10-27 19:16:26 +0000 | [diff] [blame] | 361 | case CCID_PACKET_SEND_AT_ONCE: |
| 362 | dccp_xmit_packet(sk); |
| 363 | break; |
| 364 | case CCID_PACKET_ERR: |
Tomasz Grobelny | 871a2c1 | 2010-12-04 13:38:01 +0100 | [diff] [blame] | 365 | dccp_qpolicy_drop(sk, skb); |
Gerrit Renker | dc841e3 | 2010-10-27 19:16:26 +0000 | [diff] [blame] | 366 | dccp_pr_debug("packet discarded due to err=%d\n", rc); |
Gerrit Renker | f6282f4 | 2006-12-10 00:05:12 -0200 | [diff] [blame] | 367 | } |
Ian McDonald | 97e5848 | 2006-08-26 19:16:45 -0700 | [diff] [blame] | 368 | } |
Arnaldo Carvalho de Melo | 27258ee | 2005-08-09 20:30:56 -0700 | [diff] [blame] | 369 | } |
| 370 | |
Gerrit Renker | 5943544 | 2008-07-26 11:59:09 +0100 | [diff] [blame] | 371 | /** |
| 372 | * dccp_retransmit_skb - Retransmit Request, Close, or CloseReq packets |
| 373 | * There are only four retransmittable packet types in DCCP: |
| 374 | * - Request in client-REQUEST state (sec. 8.1.1), |
| 375 | * - CloseReq in server-CLOSEREQ state (sec. 8.3), |
| 376 | * - Close in node-CLOSING state (sec. 8.3), |
| 377 | * - Acks in client-PARTOPEN state (sec. 8.1.5, handled by dccp_delack_timer()). |
| 378 | * This function expects sk->sk_send_head to contain the original skb. |
| 379 | */ |
| 380 | int dccp_retransmit_skb(struct sock *sk) |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 381 | { |
Gerrit Renker | 5943544 | 2008-07-26 11:59:09 +0100 | [diff] [blame] | 382 | WARN_ON(sk->sk_send_head == NULL); |
| 383 | |
Arnaldo Carvalho de Melo | 57cca05 | 2005-12-13 23:16:16 -0800 | [diff] [blame] | 384 | if (inet_csk(sk)->icsk_af_ops->rebuild_header(sk) != 0) |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 385 | return -EHOSTUNREACH; /* Routing failure or similar. */ |
| 386 | |
Gerrit Renker | 5943544 | 2008-07-26 11:59:09 +0100 | [diff] [blame] | 387 | /* this count is used to distinguish original and retransmitted skb */ |
| 388 | inet_csk(sk)->icsk_retransmits++; |
| 389 | |
| 390 | return dccp_transmit_skb(sk, skb_clone(sk->sk_send_head, GFP_ATOMIC)); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 391 | } |
| 392 | |
| 393 | struct sk_buff *dccp_make_response(struct sock *sk, struct dst_entry *dst, |
| 394 | struct request_sock *req) |
| 395 | { |
| 396 | struct dccp_hdr *dh; |
Arnaldo Carvalho de Melo | 67e6b62 | 2005-09-16 16:58:40 -0700 | [diff] [blame] | 397 | struct dccp_request_sock *dreq; |
Arnaldo Carvalho de Melo | 118b2c9 | 2006-03-20 22:31:09 -0800 | [diff] [blame] | 398 | const u32 dccp_header_size = sizeof(struct dccp_hdr) + |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 399 | sizeof(struct dccp_hdr_ext) + |
| 400 | sizeof(struct dccp_hdr_response); |
Arnaldo Carvalho de Melo | 118b2c9 | 2006-03-20 22:31:09 -0800 | [diff] [blame] | 401 | struct sk_buff *skb = sock_wmalloc(sk, sk->sk_prot->max_header, 1, |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 402 | GFP_ATOMIC); |
| 403 | if (skb == NULL) |
| 404 | return NULL; |
| 405 | |
| 406 | /* Reserve space for headers. */ |
Arnaldo Carvalho de Melo | 118b2c9 | 2006-03-20 22:31:09 -0800 | [diff] [blame] | 407 | skb_reserve(skb, sk->sk_prot->max_header); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 408 | |
Eric Dumazet | adf3090 | 2009-06-02 05:19:30 +0000 | [diff] [blame] | 409 | skb_dst_set(skb, dst_clone(dst)); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 410 | |
Arnaldo Carvalho de Melo | 67e6b62 | 2005-09-16 16:58:40 -0700 | [diff] [blame] | 411 | dreq = dccp_rsk(req); |
Samuel Jero | f541fb7 | 2012-02-26 18:22:02 -0700 | [diff] [blame] | 412 | if (inet_rsk(req)->acked) /* increase GSS upon retransmission */ |
| 413 | dccp_inc_seqno(&dreq->dreq_gss); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 414 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESPONSE; |
Samuel Jero | f541fb7 | 2012-02-26 18:22:02 -0700 | [diff] [blame] | 415 | DCCP_SKB_CB(skb)->dccpd_seq = dreq->dreq_gss; |
Arnaldo Carvalho de Melo | 2d0817d | 2006-03-20 22:32:06 -0800 | [diff] [blame] | 416 | |
Gerrit Renker | 0c11683 | 2008-11-16 22:49:52 -0800 | [diff] [blame] | 417 | /* Resolve feature dependencies resulting from choice of CCID */ |
| 418 | if (dccp_feat_server_ccid_dependencies(dreq)) |
| 419 | goto response_failed; |
| 420 | |
| 421 | if (dccp_insert_options_rsk(dreq, skb)) |
| 422 | goto response_failed; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 423 | |
Gerrit Renker | 09dbc38 | 2006-11-14 12:57:34 -0200 | [diff] [blame] | 424 | /* Build and checksum header */ |
Gerrit Renker | 9b42078 | 2006-11-10 11:22:32 -0200 | [diff] [blame] | 425 | dh = dccp_zeroed_hdr(skb, dccp_header_size); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 426 | |
Eric Dumazet | b44084c | 2013-10-10 00:04:37 -0700 | [diff] [blame] | 427 | dh->dccph_sport = htons(inet_rsk(req)->ir_num); |
Eric Dumazet | 634fb979 | 2013-10-09 15:21:29 -0700 | [diff] [blame] | 428 | dh->dccph_dport = inet_rsk(req)->ir_rmt_port; |
Arnaldo Carvalho de Melo | 7690af3 | 2005-08-13 20:34:54 -0300 | [diff] [blame] | 429 | dh->dccph_doff = (dccp_header_size + |
| 430 | DCCP_SKB_CB(skb)->dccpd_opt_len) / 4; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 431 | dh->dccph_type = DCCP_PKT_RESPONSE; |
| 432 | dh->dccph_x = 1; |
Samuel Jero | f541fb7 | 2012-02-26 18:22:02 -0700 | [diff] [blame] | 433 | dccp_hdr_set_seq(dh, dreq->dreq_gss); |
| 434 | dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dreq->dreq_gsr); |
Arnaldo Carvalho de Melo | 67e6b62 | 2005-09-16 16:58:40 -0700 | [diff] [blame] | 435 | dccp_hdr_response(skb)->dccph_resp_service = dreq->dreq_service; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 436 | |
Gerrit Renker | 6f4e5ff | 2006-11-10 17:43:06 -0200 | [diff] [blame] | 437 | dccp_csum_outgoing(skb); |
| 438 | |
Gerrit Renker | e11d9d3 | 2006-11-13 13:12:07 -0200 | [diff] [blame] | 439 | /* We use `acked' to remember that a Response was already sent. */ |
| 440 | inet_rsk(req)->acked = 1; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 441 | DCCP_INC_STATS(DCCP_MIB_OUTSEGS); |
| 442 | return skb; |
Gerrit Renker | 0c11683 | 2008-11-16 22:49:52 -0800 | [diff] [blame] | 443 | response_failed: |
| 444 | kfree_skb(skb); |
| 445 | return NULL; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 446 | } |
| 447 | |
Arnaldo Carvalho de Melo | f21e68c | 2005-12-13 23:24:16 -0800 | [diff] [blame] | 448 | EXPORT_SYMBOL_GPL(dccp_make_response); |
| 449 | |
Gerrit Renker | e356d37 | 2007-09-26 14:35:19 -0300 | [diff] [blame] | 450 | /* answer offending packet in @rcv_skb with Reset from control socket @ctl */ |
Denis V. Lunev | 7630f02 | 2008-04-03 14:20:52 -0700 | [diff] [blame] | 451 | struct sk_buff *dccp_ctl_make_reset(struct sock *sk, struct sk_buff *rcv_skb) |
Gerrit Renker | e356d37 | 2007-09-26 14:35:19 -0300 | [diff] [blame] | 452 | { |
| 453 | struct dccp_hdr *rxdh = dccp_hdr(rcv_skb), *dh; |
| 454 | struct dccp_skb_cb *dcb = DCCP_SKB_CB(rcv_skb); |
| 455 | const u32 dccp_hdr_reset_len = sizeof(struct dccp_hdr) + |
| 456 | sizeof(struct dccp_hdr_ext) + |
| 457 | sizeof(struct dccp_hdr_reset); |
| 458 | struct dccp_hdr_reset *dhr; |
| 459 | struct sk_buff *skb; |
| 460 | |
Denis V. Lunev | 7630f02 | 2008-04-03 14:20:52 -0700 | [diff] [blame] | 461 | skb = alloc_skb(sk->sk_prot->max_header, GFP_ATOMIC); |
Gerrit Renker | e356d37 | 2007-09-26 14:35:19 -0300 | [diff] [blame] | 462 | if (skb == NULL) |
| 463 | return NULL; |
| 464 | |
Denis V. Lunev | 7630f02 | 2008-04-03 14:20:52 -0700 | [diff] [blame] | 465 | skb_reserve(skb, sk->sk_prot->max_header); |
Gerrit Renker | e356d37 | 2007-09-26 14:35:19 -0300 | [diff] [blame] | 466 | |
| 467 | /* Swap the send and the receive. */ |
| 468 | dh = dccp_zeroed_hdr(skb, dccp_hdr_reset_len); |
| 469 | dh->dccph_type = DCCP_PKT_RESET; |
| 470 | dh->dccph_sport = rxdh->dccph_dport; |
| 471 | dh->dccph_dport = rxdh->dccph_sport; |
| 472 | dh->dccph_doff = dccp_hdr_reset_len / 4; |
| 473 | dh->dccph_x = 1; |
| 474 | |
| 475 | dhr = dccp_hdr_reset(skb); |
| 476 | dhr->dccph_reset_code = dcb->dccpd_reset_code; |
| 477 | |
| 478 | switch (dcb->dccpd_reset_code) { |
| 479 | case DCCP_RESET_CODE_PACKET_ERROR: |
| 480 | dhr->dccph_reset_data[0] = rxdh->dccph_type; |
| 481 | break; |
| 482 | case DCCP_RESET_CODE_OPTION_ERROR: /* fall through */ |
| 483 | case DCCP_RESET_CODE_MANDATORY_ERROR: |
| 484 | memcpy(dhr->dccph_reset_data, dcb->dccpd_reset_data, 3); |
| 485 | break; |
| 486 | } |
| 487 | /* |
| 488 | * From RFC 4340, 8.3.1: |
| 489 | * If P.ackno exists, set R.seqno := P.ackno + 1. |
| 490 | * Else set R.seqno := 0. |
| 491 | */ |
| 492 | if (dcb->dccpd_ack_seq != DCCP_PKT_WITHOUT_ACK_SEQ) |
| 493 | dccp_hdr_set_seq(dh, ADD48(dcb->dccpd_ack_seq, 1)); |
| 494 | dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dcb->dccpd_seq); |
| 495 | |
| 496 | dccp_csum_outgoing(skb); |
| 497 | return skb; |
| 498 | } |
| 499 | |
| 500 | EXPORT_SYMBOL_GPL(dccp_ctl_make_reset); |
| 501 | |
Gerrit Renker | ee1a159 | 2007-09-26 11:30:02 -0300 | [diff] [blame] | 502 | /* send Reset on established socket, to close or abort the connection */ |
Arnaldo Carvalho de Melo | 017487d | 2006-03-20 19:25:24 -0800 | [diff] [blame] | 503 | int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code) |
| 504 | { |
Gerrit Renker | ee1a159 | 2007-09-26 11:30:02 -0300 | [diff] [blame] | 505 | struct sk_buff *skb; |
Arnaldo Carvalho de Melo | 017487d | 2006-03-20 19:25:24 -0800 | [diff] [blame] | 506 | /* |
| 507 | * FIXME: what if rebuild_header fails? |
| 508 | * Should we be doing a rebuild_header here? |
| 509 | */ |
Gerrit Renker | f53dc67 | 2007-11-28 08:35:08 +0000 | [diff] [blame] | 510 | int err = inet_csk(sk)->icsk_af_ops->rebuild_header(sk); |
Arnaldo Carvalho de Melo | 017487d | 2006-03-20 19:25:24 -0800 | [diff] [blame] | 511 | |
Gerrit Renker | ee1a159 | 2007-09-26 11:30:02 -0300 | [diff] [blame] | 512 | if (err != 0) |
| 513 | return err; |
Arnaldo Carvalho de Melo | 017487d | 2006-03-20 19:25:24 -0800 | [diff] [blame] | 514 | |
Gerrit Renker | ee1a159 | 2007-09-26 11:30:02 -0300 | [diff] [blame] | 515 | skb = sock_wmalloc(sk, sk->sk_prot->max_header, 1, GFP_ATOMIC); |
| 516 | if (skb == NULL) |
| 517 | return -ENOBUFS; |
| 518 | |
| 519 | /* Reserve space for headers and prepare control bits. */ |
| 520 | skb_reserve(skb, sk->sk_prot->max_header); |
| 521 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESET; |
| 522 | DCCP_SKB_CB(skb)->dccpd_reset_code = code; |
| 523 | |
| 524 | return dccp_transmit_skb(sk, skb); |
Arnaldo Carvalho de Melo | 017487d | 2006-03-20 19:25:24 -0800 | [diff] [blame] | 525 | } |
| 526 | |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 527 | /* |
| 528 | * Do all connect socket setups that can be done AF independent. |
| 529 | */ |
Gerrit Renker | 93344af | 2010-10-11 20:36:33 +0200 | [diff] [blame] | 530 | int dccp_connect(struct sock *sk) |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 531 | { |
Gerrit Renker | 93344af | 2010-10-11 20:36:33 +0200 | [diff] [blame] | 532 | struct sk_buff *skb; |
Arnaldo Carvalho de Melo | f21e68c | 2005-12-13 23:24:16 -0800 | [diff] [blame] | 533 | struct dccp_sock *dp = dccp_sk(sk); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 534 | struct dst_entry *dst = __sk_dst_get(sk); |
| 535 | struct inet_connection_sock *icsk = inet_csk(sk); |
| 536 | |
| 537 | sk->sk_err = 0; |
| 538 | sock_reset_flag(sk, SOCK_DONE); |
YOSHIFUJI Hideaki | c9eaf17 | 2007-02-09 23:24:38 +0900 | [diff] [blame] | 539 | |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 540 | dccp_sync_mss(sk, dst_mtu(dst)); |
| 541 | |
Gerrit Renker | 9eca0a4 | 2008-11-12 00:48:44 -0800 | [diff] [blame] | 542 | /* do not connect if feature negotiation setup fails */ |
| 543 | if (dccp_feat_finalise_settings(dccp_sk(sk))) |
| 544 | return -EPROTO; |
| 545 | |
Gerrit Renker | 93344af | 2010-10-11 20:36:33 +0200 | [diff] [blame] | 546 | /* Initialise GAR as per 8.5; AWL/AWH are set in dccp_transmit_skb() */ |
| 547 | dp->dccps_gar = dp->dccps_iss; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 548 | |
Arnaldo Carvalho de Melo | 118b2c9 | 2006-03-20 22:31:09 -0800 | [diff] [blame] | 549 | skb = alloc_skb(sk->sk_prot->max_header, sk->sk_allocation); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 550 | if (unlikely(skb == NULL)) |
| 551 | return -ENOBUFS; |
| 552 | |
| 553 | /* Reserve space for headers. */ |
Arnaldo Carvalho de Melo | 118b2c9 | 2006-03-20 22:31:09 -0800 | [diff] [blame] | 554 | skb_reserve(skb, sk->sk_prot->max_header); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 555 | |
| 556 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_REQUEST; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 557 | |
Gerrit Renker | 8695e80 | 2011-07-03 09:51:29 -0600 | [diff] [blame] | 558 | dccp_transmit_skb(sk, dccp_skb_entail(sk, skb)); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 559 | DCCP_INC_STATS(DCCP_MIB_ACTIVEOPENS); |
| 560 | |
| 561 | /* Timer for repeating the REQUEST until an answer. */ |
Gerrit Renker | 93344af | 2010-10-11 20:36:33 +0200 | [diff] [blame] | 562 | icsk->icsk_retransmits = 0; |
Arnaldo Carvalho de Melo | 27258ee | 2005-08-09 20:30:56 -0700 | [diff] [blame] | 563 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, |
| 564 | icsk->icsk_rto, DCCP_RTO_MAX); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 565 | return 0; |
| 566 | } |
| 567 | |
Arnaldo Carvalho de Melo | f21e68c | 2005-12-13 23:24:16 -0800 | [diff] [blame] | 568 | EXPORT_SYMBOL_GPL(dccp_connect); |
| 569 | |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 570 | void dccp_send_ack(struct sock *sk) |
| 571 | { |
| 572 | /* If we have been reset, we may not send again. */ |
| 573 | if (sk->sk_state != DCCP_CLOSED) { |
Arnaldo Carvalho de Melo | 118b2c9 | 2006-03-20 22:31:09 -0800 | [diff] [blame] | 574 | struct sk_buff *skb = alloc_skb(sk->sk_prot->max_header, |
| 575 | GFP_ATOMIC); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 576 | |
| 577 | if (skb == NULL) { |
| 578 | inet_csk_schedule_ack(sk); |
| 579 | inet_csk(sk)->icsk_ack.ato = TCP_ATO_MIN; |
Arnaldo Carvalho de Melo | 7690af3 | 2005-08-13 20:34:54 -0300 | [diff] [blame] | 580 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, |
| 581 | TCP_DELACK_MAX, |
| 582 | DCCP_RTO_MAX); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 583 | return; |
| 584 | } |
| 585 | |
| 586 | /* Reserve space for headers */ |
Arnaldo Carvalho de Melo | 118b2c9 | 2006-03-20 22:31:09 -0800 | [diff] [blame] | 587 | skb_reserve(skb, sk->sk_prot->max_header); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 588 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_ACK; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 589 | dccp_transmit_skb(sk, skb); |
| 590 | } |
| 591 | } |
| 592 | |
| 593 | EXPORT_SYMBOL_GPL(dccp_send_ack); |
| 594 | |
Gerrit Renker | 1e2f0e5e | 2008-06-11 11:19:09 +0100 | [diff] [blame] | 595 | #if 0 |
Gerrit Renker | 727ecc5 | 2007-09-26 11:26:04 -0300 | [diff] [blame] | 596 | /* FIXME: Is this still necessary (11.3) - currently nowhere used by DCCP. */ |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 597 | void dccp_send_delayed_ack(struct sock *sk) |
| 598 | { |
| 599 | struct inet_connection_sock *icsk = inet_csk(sk); |
| 600 | /* |
| 601 | * FIXME: tune this timer. elapsed time fixes the skew, so no problem |
| 602 | * with using 2s, and active senders also piggyback the ACK into a |
| 603 | * DATAACK packet, so this is really for quiescent senders. |
| 604 | */ |
| 605 | unsigned long timeout = jiffies + 2 * HZ; |
| 606 | |
| 607 | /* Use new timeout only if there wasn't a older one earlier. */ |
| 608 | if (icsk->icsk_ack.pending & ICSK_ACK_TIMER) { |
| 609 | /* If delack timer was blocked or is about to expire, |
| 610 | * send ACK now. |
| 611 | * |
| 612 | * FIXME: check the "about to expire" part |
| 613 | */ |
| 614 | if (icsk->icsk_ack.blocked) { |
| 615 | dccp_send_ack(sk); |
| 616 | return; |
| 617 | } |
| 618 | |
| 619 | if (!time_before(timeout, icsk->icsk_ack.timeout)) |
| 620 | timeout = icsk->icsk_ack.timeout; |
| 621 | } |
| 622 | icsk->icsk_ack.pending |= ICSK_ACK_SCHED | ICSK_ACK_TIMER; |
| 623 | icsk->icsk_ack.timeout = timeout; |
| 624 | sk_reset_timer(sk, &icsk->icsk_delack_timer, timeout); |
| 625 | } |
Gerrit Renker | 1e2f0e5e | 2008-06-11 11:19:09 +0100 | [diff] [blame] | 626 | #endif |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 627 | |
Gerrit Renker | b0d045c | 2007-09-25 22:42:27 -0700 | [diff] [blame] | 628 | void dccp_send_sync(struct sock *sk, const u64 ackno, |
Arnaldo Carvalho de Melo | e92ae93 | 2005-08-17 03:10:59 -0300 | [diff] [blame] | 629 | const enum dccp_pkt_type pkt_type) |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 630 | { |
| 631 | /* |
| 632 | * We are not putting this on the write queue, so |
| 633 | * dccp_transmit_skb() will set the ownership to this |
| 634 | * sock. |
| 635 | */ |
Arnaldo Carvalho de Melo | 118b2c9 | 2006-03-20 22:31:09 -0800 | [diff] [blame] | 636 | struct sk_buff *skb = alloc_skb(sk->sk_prot->max_header, GFP_ATOMIC); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 637 | |
Gerrit Renker | b0d045c | 2007-09-25 22:42:27 -0700 | [diff] [blame] | 638 | if (skb == NULL) { |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 639 | /* FIXME: how to make sure the sync is sent? */ |
Gerrit Renker | b0d045c | 2007-09-25 22:42:27 -0700 | [diff] [blame] | 640 | DCCP_CRIT("could not send %s", dccp_packet_name(pkt_type)); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 641 | return; |
Gerrit Renker | b0d045c | 2007-09-25 22:42:27 -0700 | [diff] [blame] | 642 | } |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 643 | |
| 644 | /* Reserve space for headers and prepare control bits. */ |
Arnaldo Carvalho de Melo | 118b2c9 | 2006-03-20 22:31:09 -0800 | [diff] [blame] | 645 | skb_reserve(skb, sk->sk_prot->max_header); |
Arnaldo Carvalho de Melo | e92ae93 | 2005-08-17 03:10:59 -0300 | [diff] [blame] | 646 | DCCP_SKB_CB(skb)->dccpd_type = pkt_type; |
Gerrit Renker | b0d045c | 2007-09-25 22:42:27 -0700 | [diff] [blame] | 647 | DCCP_SKB_CB(skb)->dccpd_ack_seq = ackno; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 648 | |
Gerrit Renker | d83447f | 2010-11-14 17:25:46 +0100 | [diff] [blame] | 649 | /* |
| 650 | * Clear the flag in case the Sync was scheduled for out-of-band data, |
| 651 | * such as carrying a long Ack Vector. |
| 652 | */ |
| 653 | dccp_sk(sk)->dccps_sync_scheduled = 0; |
| 654 | |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 655 | dccp_transmit_skb(sk, skb); |
| 656 | } |
| 657 | |
Arnaldo Carvalho de Melo | b61fafc | 2006-03-20 21:25:11 -0800 | [diff] [blame] | 658 | EXPORT_SYMBOL_GPL(dccp_send_sync); |
| 659 | |
Arnaldo Carvalho de Melo | 7690af3 | 2005-08-13 20:34:54 -0300 | [diff] [blame] | 660 | /* |
| 661 | * Send a DCCP_PKT_CLOSE/CLOSEREQ. The caller locks the socket for us. This |
| 662 | * cannot be allowed to fail queueing a DCCP_PKT_CLOSE/CLOSEREQ frame under |
| 663 | * any circumstances. |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 664 | */ |
Arnaldo Carvalho de Melo | 7ad07e7 | 2005-08-23 21:50:06 -0700 | [diff] [blame] | 665 | void dccp_send_close(struct sock *sk, const int active) |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 666 | { |
| 667 | struct dccp_sock *dp = dccp_sk(sk); |
| 668 | struct sk_buff *skb; |
Al Viro | 7d877f3 | 2005-10-21 03:20:43 -0400 | [diff] [blame] | 669 | const gfp_t prio = active ? GFP_KERNEL : GFP_ATOMIC; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 670 | |
Arnaldo Carvalho de Melo | 7ad07e7 | 2005-08-23 21:50:06 -0700 | [diff] [blame] | 671 | skb = alloc_skb(sk->sk_prot->max_header, prio); |
| 672 | if (skb == NULL) |
| 673 | return; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 674 | |
| 675 | /* Reserve space for headers and prepare control bits. */ |
| 676 | skb_reserve(skb, sk->sk_prot->max_header); |
Gerrit Renker | b8599d2 | 2007-12-13 12:25:01 -0200 | [diff] [blame] | 677 | if (dp->dccps_role == DCCP_ROLE_SERVER && !dp->dccps_server_timewait) |
| 678 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_CLOSEREQ; |
| 679 | else |
| 680 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_CLOSE; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 681 | |
Arnaldo Carvalho de Melo | 7ad07e7 | 2005-08-23 21:50:06 -0700 | [diff] [blame] | 682 | if (active) { |
Gerrit Renker | 8695e80 | 2011-07-03 09:51:29 -0600 | [diff] [blame] | 683 | skb = dccp_skb_entail(sk, skb); |
Gerrit Renker | 92d3192 | 2007-12-13 12:02:43 -0200 | [diff] [blame] | 684 | /* |
| 685 | * Retransmission timer for active-close: RFC 4340, 8.3 requires |
| 686 | * to retransmit the Close/CloseReq until the CLOSING/CLOSEREQ |
| 687 | * state can be left. The initial timeout is 2 RTTs. |
| 688 | * Since RTT measurement is done by the CCIDs, there is no easy |
| 689 | * way to get an RTT sample. The fallback RTT from RFC 4340, 3.4 |
| 690 | * is too low (200ms); we use a high value to avoid unnecessary |
| 691 | * retransmissions when the link RTT is > 0.2 seconds. |
| 692 | * FIXME: Let main module sample RTTs and use that instead. |
| 693 | */ |
| 694 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, |
| 695 | DCCP_TIMEOUT_INIT, DCCP_RTO_MAX); |
Gerrit Renker | 8695e80 | 2011-07-03 09:51:29 -0600 | [diff] [blame] | 696 | } |
| 697 | dccp_transmit_skb(sk, skb); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 698 | } |