Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 1 | /* |
| 2 | * net/dccp/output.c |
| 3 | * |
| 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> |
| 16 | |
Arnaldo Carvalho de Melo | 14c8502 | 2005-12-27 02:43:12 -0200 | [diff] [blame] | 17 | #include <net/inet_sock.h> |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 18 | #include <net/sock.h> |
| 19 | |
Arnaldo Carvalho de Melo | ae31c33 | 2005-09-18 00:17:51 -0700 | [diff] [blame] | 20 | #include "ackvec.h" |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 21 | #include "ccid.h" |
| 22 | #include "dccp.h" |
| 23 | |
| 24 | static inline void dccp_event_ack_sent(struct sock *sk) |
| 25 | { |
| 26 | inet_csk_clear_xmit_timer(sk, ICSK_TIME_DACK); |
| 27 | } |
| 28 | |
Arnaldo Carvalho de Melo | c25a18b | 2006-03-20 21:58:56 -0800 | [diff] [blame] | 29 | static void dccp_skb_entail(struct sock *sk, struct sk_buff *skb) |
Herbert Xu | 48918a4 | 2005-10-30 11:20:59 +1100 | [diff] [blame] | 30 | { |
| 31 | skb_set_owner_w(skb, sk); |
| 32 | WARN_ON(sk->sk_send_head); |
| 33 | sk->sk_send_head = skb; |
| 34 | } |
| 35 | |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 36 | /* |
| 37 | * All SKB's seen here are completely headerless. It is our |
| 38 | * job to build the DCCP header, and pass the packet down to |
| 39 | * IP so it can do the same plus pass the packet off to the |
| 40 | * device. |
| 41 | */ |
Herbert Xu | 48918a4 | 2005-10-30 11:20:59 +1100 | [diff] [blame] | 42 | 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] | 43 | { |
| 44 | if (likely(skb != NULL)) { |
| 45 | const struct inet_sock *inet = inet_sk(sk); |
Arnaldo Carvalho de Melo | 57cca05 | 2005-12-13 23:16:16 -0800 | [diff] [blame] | 46 | const struct inet_connection_sock *icsk = inet_csk(sk); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 47 | struct dccp_sock *dp = dccp_sk(sk); |
| 48 | struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb); |
| 49 | struct dccp_hdr *dh; |
| 50 | /* 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] | 51 | const u32 dccp_header_size = sizeof(*dh) + |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 52 | sizeof(struct dccp_hdr_ext) + |
Arnaldo Carvalho de Melo | 7690af3 | 2005-08-13 20:34:54 -0300 | [diff] [blame] | 53 | dccp_packet_hdr_len(dcb->dccpd_type); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 54 | int err, set_ack = 1; |
| 55 | u64 ackno = dp->dccps_gsr; |
| 56 | |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 57 | dccp_inc_seqno(&dp->dccps_gss); |
| 58 | |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 59 | switch (dcb->dccpd_type) { |
| 60 | case DCCP_PKT_DATA: |
| 61 | set_ack = 0; |
Herbert Xu | edc9e81 | 2005-10-30 11:20:59 +1100 | [diff] [blame] | 62 | /* fall through */ |
| 63 | case DCCP_PKT_DATAACK: |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 64 | break; |
Herbert Xu | edc9e81 | 2005-10-30 11:20:59 +1100 | [diff] [blame] | 65 | |
Andrea Bittau | afe0025 | 2006-03-20 17:43:56 -0800 | [diff] [blame] | 66 | case DCCP_PKT_REQUEST: |
| 67 | set_ack = 0; |
| 68 | /* fall through */ |
| 69 | |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 70 | case DCCP_PKT_SYNC: |
| 71 | case DCCP_PKT_SYNCACK: |
| 72 | ackno = dcb->dccpd_seq; |
Herbert Xu | edc9e81 | 2005-10-30 11:20:59 +1100 | [diff] [blame] | 73 | /* fall through */ |
| 74 | default: |
| 75 | /* |
| 76 | * Only data packets should come through with skb->sk |
| 77 | * set. |
| 78 | */ |
| 79 | WARN_ON(skb->sk); |
| 80 | skb_set_owner_w(skb, sk); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 81 | break; |
| 82 | } |
Arnaldo Carvalho de Melo | 2411772 | 2005-08-21 05:40:16 -0300 | [diff] [blame] | 83 | |
| 84 | dcb->dccpd_seq = dp->dccps_gss; |
Arnaldo Carvalho de Melo | 2d0817d | 2006-03-20 22:32:06 -0800 | [diff] [blame] | 85 | |
| 86 | if (dccp_insert_options(sk, skb)) { |
| 87 | kfree_skb(skb); |
| 88 | return -EPROTO; |
| 89 | } |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 90 | |
| 91 | skb->h.raw = skb_push(skb, dccp_header_size); |
| 92 | dh = dccp_hdr(skb); |
Herbert Xu | fda0fd6 | 2005-10-14 16:38:49 +1000 | [diff] [blame] | 93 | |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 94 | /* Build DCCP header and checksum it. */ |
| 95 | memset(dh, 0, dccp_header_size); |
| 96 | dh->dccph_type = dcb->dccpd_type; |
| 97 | dh->dccph_sport = inet->sport; |
| 98 | dh->dccph_dport = inet->dport; |
| 99 | dh->dccph_doff = (dccp_header_size + dcb->dccpd_opt_len) / 4; |
| 100 | dh->dccph_ccval = dcb->dccpd_ccval; |
| 101 | /* XXX For now we're using only 48 bits sequence numbers */ |
| 102 | dh->dccph_x = 1; |
| 103 | |
| 104 | dp->dccps_awh = dp->dccps_gss; |
| 105 | dccp_hdr_set_seq(dh, dp->dccps_gss); |
| 106 | if (set_ack) |
| 107 | dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), ackno); |
| 108 | |
| 109 | switch (dcb->dccpd_type) { |
| 110 | case DCCP_PKT_REQUEST: |
Arnaldo Carvalho de Melo | 7690af3 | 2005-08-13 20:34:54 -0300 | [diff] [blame] | 111 | dccp_hdr_request(skb)->dccph_req_service = |
Arnaldo Carvalho de Melo | 67e6b62 | 2005-09-16 16:58:40 -0700 | [diff] [blame] | 112 | dp->dccps_service; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 113 | break; |
| 114 | case DCCP_PKT_RESET: |
Arnaldo Carvalho de Melo | 7690af3 | 2005-08-13 20:34:54 -0300 | [diff] [blame] | 115 | dccp_hdr_reset(skb)->dccph_reset_code = |
| 116 | dcb->dccpd_reset_code; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 117 | break; |
| 118 | } |
| 119 | |
Arnaldo Carvalho de Melo | 57cca05 | 2005-12-13 23:16:16 -0800 | [diff] [blame] | 120 | icsk->icsk_af_ops->send_check(sk, skb->len, skb); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 121 | |
Arnaldo Carvalho de Melo | 7ad07e7 | 2005-08-23 21:50:06 -0700 | [diff] [blame] | 122 | if (set_ack) |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 123 | dccp_event_ack_sent(sk); |
| 124 | |
| 125 | DCCP_INC_STATS(DCCP_MIB_OUTSEGS); |
| 126 | |
Herbert Xu | 49c5bfa | 2005-10-18 12:03:28 +1000 | [diff] [blame] | 127 | memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); |
Arnaldo Carvalho de Melo | 57cca05 | 2005-12-13 23:16:16 -0800 | [diff] [blame] | 128 | err = icsk->icsk_af_ops->queue_xmit(skb, 0); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 129 | if (err <= 0) |
| 130 | return err; |
| 131 | |
| 132 | /* NET_XMIT_CN is special. It does not guarantee, |
| 133 | * that this packet is lost. It tells that device |
| 134 | * is about to start to drop packets or already |
| 135 | * drops some packets of the same priority and |
| 136 | * invokes us to send less aggressively. |
| 137 | */ |
| 138 | return err == NET_XMIT_CN ? 0 : err; |
| 139 | } |
| 140 | return -ENOBUFS; |
| 141 | } |
| 142 | |
| 143 | unsigned int dccp_sync_mss(struct sock *sk, u32 pmtu) |
| 144 | { |
Arnaldo Carvalho de Melo | d83d846 | 2005-12-13 23:26:10 -0800 | [diff] [blame] | 145 | struct inet_connection_sock *icsk = inet_csk(sk); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 146 | struct dccp_sock *dp = dccp_sk(sk); |
Arnaldo Carvalho de Melo | d83d846 | 2005-12-13 23:26:10 -0800 | [diff] [blame] | 147 | int mss_now = (pmtu - icsk->icsk_af_ops->net_header_len - |
Arnaldo Carvalho de Melo | 57cca05 | 2005-12-13 23:16:16 -0800 | [diff] [blame] | 148 | sizeof(struct dccp_hdr) - sizeof(struct dccp_hdr_ext)); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 149 | |
| 150 | /* Now subtract optional transport overhead */ |
Arnaldo Carvalho de Melo | d83d846 | 2005-12-13 23:26:10 -0800 | [diff] [blame] | 151 | mss_now -= icsk->icsk_ext_hdr_len; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 152 | |
| 153 | /* |
| 154 | * FIXME: this should come from the CCID infrastructure, where, say, |
| 155 | * TFRC will say it wants TIMESTAMPS, ELAPSED time, etc, for now lets |
| 156 | * put a rough estimate for NDP + TIMESTAMP + TIMESTAMP_ECHO + ELAPSED |
| 157 | * TIME + TFRC_OPT_LOSS_EVENT_RATE + TFRC_OPT_RECEIVE_RATE + padding to |
| 158 | * make it a multiple of 4 |
| 159 | */ |
| 160 | |
| 161 | mss_now -= ((5 + 6 + 10 + 6 + 6 + 6 + 3) / 4) * 4; |
| 162 | |
| 163 | /* And store cached results */ |
Arnaldo Carvalho de Melo | d83d846 | 2005-12-13 23:26:10 -0800 | [diff] [blame] | 164 | icsk->icsk_pmtu_cookie = pmtu; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 165 | dp->dccps_mss_cache = mss_now; |
| 166 | |
| 167 | return mss_now; |
| 168 | } |
| 169 | |
Arnaldo Carvalho de Melo | f21e68c | 2005-12-13 23:24:16 -0800 | [diff] [blame] | 170 | EXPORT_SYMBOL_GPL(dccp_sync_mss); |
| 171 | |
Arnaldo Carvalho de Melo | c530cfb | 2005-08-29 02:15:54 -0300 | [diff] [blame] | 172 | void dccp_write_space(struct sock *sk) |
| 173 | { |
| 174 | read_lock(&sk->sk_callback_lock); |
| 175 | |
| 176 | if (sk->sk_sleep && waitqueue_active(sk->sk_sleep)) |
| 177 | wake_up_interruptible(sk->sk_sleep); |
| 178 | /* Should agree with poll, otherwise some programs break */ |
| 179 | if (sock_writeable(sk)) |
| 180 | sk_wake_async(sk, 2, POLL_OUT); |
| 181 | |
| 182 | read_unlock(&sk->sk_callback_lock); |
| 183 | } |
| 184 | |
Arnaldo Carvalho de Melo | d6809c1 | 2005-08-27 03:06:35 -0300 | [diff] [blame] | 185 | /** |
| 186 | * dccp_wait_for_ccid - Wait for ccid to tell us we can send a packet |
| 187 | * @sk: socket to wait for |
| 188 | * @timeo: for how long |
| 189 | */ |
| 190 | static int dccp_wait_for_ccid(struct sock *sk, struct sk_buff *skb, |
| 191 | long *timeo) |
| 192 | { |
| 193 | struct dccp_sock *dp = dccp_sk(sk); |
| 194 | DEFINE_WAIT(wait); |
| 195 | long delay; |
| 196 | int rc; |
| 197 | |
| 198 | while (1) { |
| 199 | prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE); |
| 200 | |
Ian McDonald | 97e5848 | 2006-08-26 19:16:45 -0700 | [diff] [blame] | 201 | if (sk->sk_err) |
Arnaldo Carvalho de Melo | d6809c1 | 2005-08-27 03:06:35 -0300 | [diff] [blame] | 202 | goto do_error; |
| 203 | if (!*timeo) |
| 204 | goto do_nonblock; |
| 205 | if (signal_pending(current)) |
| 206 | goto do_interrupted; |
| 207 | |
| 208 | rc = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb, |
| 209 | skb->len); |
| 210 | if (rc <= 0) |
| 211 | break; |
| 212 | delay = msecs_to_jiffies(rc); |
| 213 | if (delay > *timeo || delay < 0) |
| 214 | goto do_nonblock; |
| 215 | |
| 216 | sk->sk_write_pending++; |
| 217 | release_sock(sk); |
| 218 | *timeo -= schedule_timeout(delay); |
| 219 | lock_sock(sk); |
| 220 | sk->sk_write_pending--; |
| 221 | } |
| 222 | out: |
| 223 | finish_wait(sk->sk_sleep, &wait); |
| 224 | return rc; |
| 225 | |
| 226 | do_error: |
| 227 | rc = -EPIPE; |
| 228 | goto out; |
| 229 | do_nonblock: |
| 230 | rc = -EAGAIN; |
| 231 | goto out; |
| 232 | do_interrupted: |
| 233 | rc = sock_intr_errno(*timeo); |
| 234 | goto out; |
| 235 | } |
| 236 | |
Ian McDonald | 97e5848 | 2006-08-26 19:16:45 -0700 | [diff] [blame] | 237 | static void dccp_write_xmit_timer(unsigned long data) { |
| 238 | struct sock *sk = (struct sock *)data; |
| 239 | struct dccp_sock *dp = dccp_sk(sk); |
| 240 | |
| 241 | bh_lock_sock(sk); |
| 242 | if (sock_owned_by_user(sk)) |
| 243 | sk_reset_timer(sk, &dp->dccps_xmit_timer, jiffies+1); |
| 244 | else |
| 245 | dccp_write_xmit(sk, 0); |
| 246 | bh_unlock_sock(sk); |
| 247 | sock_put(sk); |
| 248 | } |
| 249 | |
| 250 | void dccp_write_xmit(struct sock *sk, int block) |
Arnaldo Carvalho de Melo | 27258ee | 2005-08-09 20:30:56 -0700 | [diff] [blame] | 251 | { |
Ian McDonald | 97e5848 | 2006-08-26 19:16:45 -0700 | [diff] [blame] | 252 | struct dccp_sock *dp = dccp_sk(sk); |
| 253 | struct sk_buff *skb; |
| 254 | long timeo = 30000; /* If a packet is taking longer than 2 secs |
| 255 | we have other issues */ |
| 256 | |
| 257 | while ((skb = skb_peek(&sk->sk_write_queue))) { |
| 258 | int err = 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] | 259 | skb->len); |
| 260 | |
Ian McDonald | 97e5848 | 2006-08-26 19:16:45 -0700 | [diff] [blame] | 261 | if (err > 0) { |
| 262 | if (!block) { |
| 263 | sk_reset_timer(sk, &dp->dccps_xmit_timer, |
| 264 | msecs_to_jiffies(err)+jiffies); |
| 265 | break; |
| 266 | } else |
| 267 | err = dccp_wait_for_ccid(sk, skb, &timeo); |
| 268 | if (err) { |
| 269 | printk(KERN_CRIT "%s:err at dccp_wait_for_ccid" |
| 270 | " %d\n", __FUNCTION__, err); |
| 271 | dump_stack(); |
| 272 | } |
| 273 | } |
Arnaldo Carvalho de Melo | 27258ee | 2005-08-09 20:30:56 -0700 | [diff] [blame] | 274 | |
Ian McDonald | 97e5848 | 2006-08-26 19:16:45 -0700 | [diff] [blame] | 275 | skb_dequeue(&sk->sk_write_queue); |
| 276 | if (err == 0) { |
| 277 | struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb); |
| 278 | const int len = skb->len; |
Arnaldo Carvalho de Melo | 27258ee | 2005-08-09 20:30:56 -0700 | [diff] [blame] | 279 | |
Ian McDonald | 97e5848 | 2006-08-26 19:16:45 -0700 | [diff] [blame] | 280 | if (sk->sk_state == DCCP_PARTOPEN) { |
| 281 | /* See 8.1.5. Handshake Completion */ |
| 282 | inet_csk_schedule_ack(sk); |
| 283 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, |
Arnaldo Carvalho de Melo | 27258ee | 2005-08-09 20:30:56 -0700 | [diff] [blame] | 284 | inet_csk(sk)->icsk_rto, |
| 285 | DCCP_RTO_MAX); |
Ian McDonald | 97e5848 | 2006-08-26 19:16:45 -0700 | [diff] [blame] | 286 | dcb->dccpd_type = DCCP_PKT_DATAACK; |
| 287 | } else if (dccp_ack_pending(sk)) |
| 288 | dcb->dccpd_type = DCCP_PKT_DATAACK; |
| 289 | else |
| 290 | dcb->dccpd_type = DCCP_PKT_DATA; |
Arnaldo Carvalho de Melo | 27258ee | 2005-08-09 20:30:56 -0700 | [diff] [blame] | 291 | |
Ian McDonald | 97e5848 | 2006-08-26 19:16:45 -0700 | [diff] [blame] | 292 | err = dccp_transmit_skb(sk, skb); |
| 293 | ccid_hc_tx_packet_sent(dp->dccps_hc_tx_ccid, sk, 0, len); |
| 294 | if (err) { |
| 295 | printk(KERN_CRIT "%s:err from " |
| 296 | "ccid_hc_tx_packet_sent %d\n", |
| 297 | __FUNCTION__, err); |
| 298 | dump_stack(); |
| 299 | } |
| 300 | } else |
| 301 | kfree(skb); |
| 302 | } |
Arnaldo Carvalho de Melo | 27258ee | 2005-08-09 20:30:56 -0700 | [diff] [blame] | 303 | } |
| 304 | |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 305 | int dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb) |
| 306 | { |
Arnaldo Carvalho de Melo | 57cca05 | 2005-12-13 23:16:16 -0800 | [diff] [blame] | 307 | 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] | 308 | return -EHOSTUNREACH; /* Routing failure or similar. */ |
| 309 | |
| 310 | return dccp_transmit_skb(sk, (skb_cloned(skb) ? |
| 311 | pskb_copy(skb, GFP_ATOMIC): |
| 312 | skb_clone(skb, GFP_ATOMIC))); |
| 313 | } |
| 314 | |
| 315 | struct sk_buff *dccp_make_response(struct sock *sk, struct dst_entry *dst, |
| 316 | struct request_sock *req) |
| 317 | { |
| 318 | struct dccp_hdr *dh; |
Arnaldo Carvalho de Melo | 67e6b62 | 2005-09-16 16:58:40 -0700 | [diff] [blame] | 319 | struct dccp_request_sock *dreq; |
Arnaldo Carvalho de Melo | 118b2c9 | 2006-03-20 22:31:09 -0800 | [diff] [blame] | 320 | const u32 dccp_header_size = sizeof(struct dccp_hdr) + |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 321 | sizeof(struct dccp_hdr_ext) + |
| 322 | sizeof(struct dccp_hdr_response); |
Arnaldo Carvalho de Melo | 118b2c9 | 2006-03-20 22:31:09 -0800 | [diff] [blame] | 323 | 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] | 324 | GFP_ATOMIC); |
| 325 | if (skb == NULL) |
| 326 | return NULL; |
| 327 | |
| 328 | /* Reserve space for headers. */ |
Arnaldo Carvalho de Melo | 118b2c9 | 2006-03-20 22:31:09 -0800 | [diff] [blame] | 329 | skb_reserve(skb, sk->sk_prot->max_header); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 330 | |
| 331 | skb->dst = dst_clone(dst); |
| 332 | skb->csum = 0; |
| 333 | |
Arnaldo Carvalho de Melo | 67e6b62 | 2005-09-16 16:58:40 -0700 | [diff] [blame] | 334 | dreq = dccp_rsk(req); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 335 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESPONSE; |
Arnaldo Carvalho de Melo | 67e6b62 | 2005-09-16 16:58:40 -0700 | [diff] [blame] | 336 | DCCP_SKB_CB(skb)->dccpd_seq = dreq->dreq_iss; |
Arnaldo Carvalho de Melo | 2d0817d | 2006-03-20 22:32:06 -0800 | [diff] [blame] | 337 | |
| 338 | if (dccp_insert_options(sk, skb)) { |
| 339 | kfree_skb(skb); |
| 340 | return NULL; |
| 341 | } |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 342 | |
| 343 | skb->h.raw = skb_push(skb, dccp_header_size); |
| 344 | |
| 345 | dh = dccp_hdr(skb); |
| 346 | memset(dh, 0, dccp_header_size); |
| 347 | |
| 348 | dh->dccph_sport = inet_sk(sk)->sport; |
| 349 | dh->dccph_dport = inet_rsk(req)->rmt_port; |
Arnaldo Carvalho de Melo | 7690af3 | 2005-08-13 20:34:54 -0300 | [diff] [blame] | 350 | dh->dccph_doff = (dccp_header_size + |
| 351 | DCCP_SKB_CB(skb)->dccpd_opt_len) / 4; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 352 | dh->dccph_type = DCCP_PKT_RESPONSE; |
| 353 | dh->dccph_x = 1; |
Arnaldo Carvalho de Melo | 67e6b62 | 2005-09-16 16:58:40 -0700 | [diff] [blame] | 354 | dccp_hdr_set_seq(dh, dreq->dreq_iss); |
| 355 | dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dreq->dreq_isr); |
| 356 | dccp_hdr_response(skb)->dccph_resp_service = dreq->dreq_service; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 357 | |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 358 | DCCP_INC_STATS(DCCP_MIB_OUTSEGS); |
| 359 | return skb; |
| 360 | } |
| 361 | |
Arnaldo Carvalho de Melo | f21e68c | 2005-12-13 23:24:16 -0800 | [diff] [blame] | 362 | EXPORT_SYMBOL_GPL(dccp_make_response); |
| 363 | |
Arnaldo Carvalho de Melo | 017487d | 2006-03-20 19:25:24 -0800 | [diff] [blame] | 364 | static struct sk_buff *dccp_make_reset(struct sock *sk, struct dst_entry *dst, |
| 365 | const enum dccp_reset_codes code) |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 366 | |
| 367 | { |
| 368 | struct dccp_hdr *dh; |
| 369 | struct dccp_sock *dp = dccp_sk(sk); |
Arnaldo Carvalho de Melo | 118b2c9 | 2006-03-20 22:31:09 -0800 | [diff] [blame] | 370 | const u32 dccp_header_size = sizeof(struct dccp_hdr) + |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 371 | sizeof(struct dccp_hdr_ext) + |
| 372 | sizeof(struct dccp_hdr_reset); |
Arnaldo Carvalho de Melo | 118b2c9 | 2006-03-20 22:31:09 -0800 | [diff] [blame] | 373 | 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] | 374 | GFP_ATOMIC); |
| 375 | if (skb == NULL) |
| 376 | return NULL; |
| 377 | |
| 378 | /* Reserve space for headers. */ |
Arnaldo Carvalho de Melo | 118b2c9 | 2006-03-20 22:31:09 -0800 | [diff] [blame] | 379 | skb_reserve(skb, sk->sk_prot->max_header); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 380 | |
| 381 | skb->dst = dst_clone(dst); |
| 382 | skb->csum = 0; |
| 383 | |
| 384 | dccp_inc_seqno(&dp->dccps_gss); |
| 385 | |
| 386 | DCCP_SKB_CB(skb)->dccpd_reset_code = code; |
| 387 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_RESET; |
| 388 | DCCP_SKB_CB(skb)->dccpd_seq = dp->dccps_gss; |
Arnaldo Carvalho de Melo | 2d0817d | 2006-03-20 22:32:06 -0800 | [diff] [blame] | 389 | |
| 390 | if (dccp_insert_options(sk, skb)) { |
| 391 | kfree_skb(skb); |
| 392 | return NULL; |
| 393 | } |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 394 | |
| 395 | skb->h.raw = skb_push(skb, dccp_header_size); |
| 396 | |
| 397 | dh = dccp_hdr(skb); |
| 398 | memset(dh, 0, dccp_header_size); |
| 399 | |
| 400 | dh->dccph_sport = inet_sk(sk)->sport; |
| 401 | dh->dccph_dport = inet_sk(sk)->dport; |
Arnaldo Carvalho de Melo | 7690af3 | 2005-08-13 20:34:54 -0300 | [diff] [blame] | 402 | dh->dccph_doff = (dccp_header_size + |
| 403 | DCCP_SKB_CB(skb)->dccpd_opt_len) / 4; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 404 | dh->dccph_type = DCCP_PKT_RESET; |
| 405 | dh->dccph_x = 1; |
| 406 | dccp_hdr_set_seq(dh, dp->dccps_gss); |
| 407 | dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), dp->dccps_gsr); |
| 408 | |
| 409 | dccp_hdr_reset(skb)->dccph_reset_code = code; |
Arnaldo Carvalho de Melo | 017487d | 2006-03-20 19:25:24 -0800 | [diff] [blame] | 410 | inet_csk(sk)->icsk_af_ops->send_check(sk, skb->len, skb); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 411 | |
| 412 | DCCP_INC_STATS(DCCP_MIB_OUTSEGS); |
| 413 | return skb; |
| 414 | } |
| 415 | |
Arnaldo Carvalho de Melo | 017487d | 2006-03-20 19:25:24 -0800 | [diff] [blame] | 416 | int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code) |
| 417 | { |
| 418 | /* |
| 419 | * FIXME: what if rebuild_header fails? |
| 420 | * Should we be doing a rebuild_header here? |
| 421 | */ |
| 422 | int err = inet_sk_rebuild_header(sk); |
| 423 | |
| 424 | if (err == 0) { |
| 425 | struct sk_buff *skb = dccp_make_reset(sk, sk->sk_dst_cache, |
| 426 | code); |
| 427 | if (skb != NULL) { |
| 428 | memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); |
| 429 | err = inet_csk(sk)->icsk_af_ops->queue_xmit(skb, 0); |
| 430 | if (err == NET_XMIT_CN) |
| 431 | err = 0; |
| 432 | } |
| 433 | } |
| 434 | |
| 435 | return err; |
| 436 | } |
| 437 | |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 438 | /* |
| 439 | * Do all connect socket setups that can be done AF independent. |
| 440 | */ |
| 441 | static inline void dccp_connect_init(struct sock *sk) |
| 442 | { |
Arnaldo Carvalho de Melo | f21e68c | 2005-12-13 23:24:16 -0800 | [diff] [blame] | 443 | struct dccp_sock *dp = dccp_sk(sk); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 444 | struct dst_entry *dst = __sk_dst_get(sk); |
| 445 | struct inet_connection_sock *icsk = inet_csk(sk); |
| 446 | |
| 447 | sk->sk_err = 0; |
| 448 | sock_reset_flag(sk, SOCK_DONE); |
| 449 | |
| 450 | dccp_sync_mss(sk, dst_mtu(dst)); |
| 451 | |
Arnaldo Carvalho de Melo | f21e68c | 2005-12-13 23:24:16 -0800 | [diff] [blame] | 452 | dccp_update_gss(sk, dp->dccps_iss); |
| 453 | /* |
| 454 | * SWL and AWL are initially adjusted so that they are not less than |
| 455 | * the initial Sequence Numbers received and sent, respectively: |
| 456 | * SWL := max(GSR + 1 - floor(W/4), ISR), |
| 457 | * AWL := max(GSS - W' + 1, ISS). |
| 458 | * These adjustments MUST be applied only at the beginning of the |
| 459 | * connection. |
| 460 | */ |
| 461 | dccp_set_seqno(&dp->dccps_awl, max48(dp->dccps_awl, dp->dccps_iss)); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 462 | |
| 463 | icsk->icsk_retransmits = 0; |
Ian McDonald | 97e5848 | 2006-08-26 19:16:45 -0700 | [diff] [blame] | 464 | init_timer(&dp->dccps_xmit_timer); |
| 465 | dp->dccps_xmit_timer.data = (unsigned long)sk; |
| 466 | dp->dccps_xmit_timer.function = dccp_write_xmit_timer; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 467 | } |
| 468 | |
| 469 | int dccp_connect(struct sock *sk) |
| 470 | { |
| 471 | struct sk_buff *skb; |
| 472 | struct inet_connection_sock *icsk = inet_csk(sk); |
| 473 | |
| 474 | dccp_connect_init(sk); |
| 475 | |
Arnaldo Carvalho de Melo | 118b2c9 | 2006-03-20 22:31:09 -0800 | [diff] [blame] | 476 | 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] | 477 | if (unlikely(skb == NULL)) |
| 478 | return -ENOBUFS; |
| 479 | |
| 480 | /* Reserve space for headers. */ |
Arnaldo Carvalho de Melo | 118b2c9 | 2006-03-20 22:31:09 -0800 | [diff] [blame] | 481 | skb_reserve(skb, sk->sk_prot->max_header); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 482 | |
| 483 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_REQUEST; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 484 | skb->csum = 0; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 485 | |
Herbert Xu | 48918a4 | 2005-10-30 11:20:59 +1100 | [diff] [blame] | 486 | dccp_skb_entail(sk, skb); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 487 | dccp_transmit_skb(sk, skb_clone(skb, GFP_KERNEL)); |
| 488 | DCCP_INC_STATS(DCCP_MIB_ACTIVEOPENS); |
| 489 | |
| 490 | /* Timer for repeating the REQUEST until an answer. */ |
Arnaldo Carvalho de Melo | 27258ee | 2005-08-09 20:30:56 -0700 | [diff] [blame] | 491 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, |
| 492 | icsk->icsk_rto, DCCP_RTO_MAX); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 493 | return 0; |
| 494 | } |
| 495 | |
Arnaldo Carvalho de Melo | f21e68c | 2005-12-13 23:24:16 -0800 | [diff] [blame] | 496 | EXPORT_SYMBOL_GPL(dccp_connect); |
| 497 | |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 498 | void dccp_send_ack(struct sock *sk) |
| 499 | { |
| 500 | /* If we have been reset, we may not send again. */ |
| 501 | if (sk->sk_state != DCCP_CLOSED) { |
Arnaldo Carvalho de Melo | 118b2c9 | 2006-03-20 22:31:09 -0800 | [diff] [blame] | 502 | struct sk_buff *skb = alloc_skb(sk->sk_prot->max_header, |
| 503 | GFP_ATOMIC); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 504 | |
| 505 | if (skb == NULL) { |
| 506 | inet_csk_schedule_ack(sk); |
| 507 | inet_csk(sk)->icsk_ack.ato = TCP_ATO_MIN; |
Arnaldo Carvalho de Melo | 7690af3 | 2005-08-13 20:34:54 -0300 | [diff] [blame] | 508 | inet_csk_reset_xmit_timer(sk, ICSK_TIME_DACK, |
| 509 | TCP_DELACK_MAX, |
| 510 | DCCP_RTO_MAX); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 511 | return; |
| 512 | } |
| 513 | |
| 514 | /* Reserve space for headers */ |
Arnaldo Carvalho de Melo | 118b2c9 | 2006-03-20 22:31:09 -0800 | [diff] [blame] | 515 | skb_reserve(skb, sk->sk_prot->max_header); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 516 | skb->csum = 0; |
| 517 | DCCP_SKB_CB(skb)->dccpd_type = DCCP_PKT_ACK; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 518 | dccp_transmit_skb(sk, skb); |
| 519 | } |
| 520 | } |
| 521 | |
| 522 | EXPORT_SYMBOL_GPL(dccp_send_ack); |
| 523 | |
| 524 | void dccp_send_delayed_ack(struct sock *sk) |
| 525 | { |
| 526 | struct inet_connection_sock *icsk = inet_csk(sk); |
| 527 | /* |
| 528 | * FIXME: tune this timer. elapsed time fixes the skew, so no problem |
| 529 | * with using 2s, and active senders also piggyback the ACK into a |
| 530 | * DATAACK packet, so this is really for quiescent senders. |
| 531 | */ |
| 532 | unsigned long timeout = jiffies + 2 * HZ; |
| 533 | |
| 534 | /* Use new timeout only if there wasn't a older one earlier. */ |
| 535 | if (icsk->icsk_ack.pending & ICSK_ACK_TIMER) { |
| 536 | /* If delack timer was blocked or is about to expire, |
| 537 | * send ACK now. |
| 538 | * |
| 539 | * FIXME: check the "about to expire" part |
| 540 | */ |
| 541 | if (icsk->icsk_ack.blocked) { |
| 542 | dccp_send_ack(sk); |
| 543 | return; |
| 544 | } |
| 545 | |
| 546 | if (!time_before(timeout, icsk->icsk_ack.timeout)) |
| 547 | timeout = icsk->icsk_ack.timeout; |
| 548 | } |
| 549 | icsk->icsk_ack.pending |= ICSK_ACK_SCHED | ICSK_ACK_TIMER; |
| 550 | icsk->icsk_ack.timeout = timeout; |
| 551 | sk_reset_timer(sk, &icsk->icsk_delack_timer, timeout); |
| 552 | } |
| 553 | |
Arnaldo Carvalho de Melo | e92ae93 | 2005-08-17 03:10:59 -0300 | [diff] [blame] | 554 | void dccp_send_sync(struct sock *sk, const u64 seq, |
| 555 | const enum dccp_pkt_type pkt_type) |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 556 | { |
| 557 | /* |
| 558 | * We are not putting this on the write queue, so |
| 559 | * dccp_transmit_skb() will set the ownership to this |
| 560 | * sock. |
| 561 | */ |
Arnaldo Carvalho de Melo | 118b2c9 | 2006-03-20 22:31:09 -0800 | [diff] [blame] | 562 | 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] | 563 | |
| 564 | if (skb == NULL) |
| 565 | /* FIXME: how to make sure the sync is sent? */ |
| 566 | return; |
| 567 | |
| 568 | /* Reserve space for headers and prepare control bits. */ |
Arnaldo Carvalho de Melo | 118b2c9 | 2006-03-20 22:31:09 -0800 | [diff] [blame] | 569 | skb_reserve(skb, sk->sk_prot->max_header); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 570 | skb->csum = 0; |
Arnaldo Carvalho de Melo | e92ae93 | 2005-08-17 03:10:59 -0300 | [diff] [blame] | 571 | DCCP_SKB_CB(skb)->dccpd_type = pkt_type; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 572 | DCCP_SKB_CB(skb)->dccpd_seq = seq; |
| 573 | |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 574 | dccp_transmit_skb(sk, skb); |
| 575 | } |
| 576 | |
Arnaldo Carvalho de Melo | b61fafc | 2006-03-20 21:25:11 -0800 | [diff] [blame] | 577 | EXPORT_SYMBOL_GPL(dccp_send_sync); |
| 578 | |
Arnaldo Carvalho de Melo | 7690af3 | 2005-08-13 20:34:54 -0300 | [diff] [blame] | 579 | /* |
| 580 | * Send a DCCP_PKT_CLOSE/CLOSEREQ. The caller locks the socket for us. This |
| 581 | * cannot be allowed to fail queueing a DCCP_PKT_CLOSE/CLOSEREQ frame under |
| 582 | * any circumstances. |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 583 | */ |
Arnaldo Carvalho de Melo | 7ad07e7 | 2005-08-23 21:50:06 -0700 | [diff] [blame] | 584 | void dccp_send_close(struct sock *sk, const int active) |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 585 | { |
| 586 | struct dccp_sock *dp = dccp_sk(sk); |
| 587 | struct sk_buff *skb; |
Al Viro | 7d877f3 | 2005-10-21 03:20:43 -0400 | [diff] [blame] | 588 | const gfp_t prio = active ? GFP_KERNEL : GFP_ATOMIC; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 589 | |
Arnaldo Carvalho de Melo | 7ad07e7 | 2005-08-23 21:50:06 -0700 | [diff] [blame] | 590 | skb = alloc_skb(sk->sk_prot->max_header, prio); |
| 591 | if (skb == NULL) |
| 592 | return; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 593 | |
| 594 | /* Reserve space for headers and prepare control bits. */ |
| 595 | skb_reserve(skb, sk->sk_prot->max_header); |
| 596 | skb->csum = 0; |
Arnaldo Carvalho de Melo | 7690af3 | 2005-08-13 20:34:54 -0300 | [diff] [blame] | 597 | DCCP_SKB_CB(skb)->dccpd_type = dp->dccps_role == DCCP_ROLE_CLIENT ? |
| 598 | DCCP_PKT_CLOSE : DCCP_PKT_CLOSEREQ; |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 599 | |
Arnaldo Carvalho de Melo | 7ad07e7 | 2005-08-23 21:50:06 -0700 | [diff] [blame] | 600 | if (active) { |
Ian McDonald | 97e5848 | 2006-08-26 19:16:45 -0700 | [diff] [blame] | 601 | dccp_write_xmit(sk, 1); |
Herbert Xu | 48918a4 | 2005-10-30 11:20:59 +1100 | [diff] [blame] | 602 | dccp_skb_entail(sk, skb); |
Arnaldo Carvalho de Melo | 7ad07e7 | 2005-08-23 21:50:06 -0700 | [diff] [blame] | 603 | dccp_transmit_skb(sk, skb_clone(skb, prio)); |
Ian McDonald | 97e5848 | 2006-08-26 19:16:45 -0700 | [diff] [blame] | 604 | /* FIXME do we need a retransmit timer here? */ |
Arnaldo Carvalho de Melo | 7ad07e7 | 2005-08-23 21:50:06 -0700 | [diff] [blame] | 605 | } else |
| 606 | dccp_transmit_skb(sk, skb); |
Arnaldo Carvalho de Melo | 7c65787 | 2005-08-09 20:14:34 -0700 | [diff] [blame] | 607 | } |