blob: 9bce31886bda4e285d89e0f5d8d344956f01ce00 [file] [log] [blame]
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -07001/*
2 * net/dccp/options.c
3 *
4 * An implementation of the DCCP protocol
Ian McDonald1bc09862005-08-20 00:23:43 -03005 * Copyright (c) 2005 Aristeu Sergio Rozanski Filho <aris@cathedrallabs.org>
6 * Copyright (c) 2005 Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Ian McDonalde6bccd32006-08-26 19:01:30 -07007 * Copyright (c) 2005 Ian McDonald <ian.mcdonald@jandi.co.nz>
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -07008 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License
11 * as published by the Free Software Foundation; either version
12 * 2 of the License, or (at your option) any later version.
13 */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070014#include <linux/dccp.h>
15#include <linux/module.h>
16#include <linux/types.h>
Gerrit Renker76fd1e82007-10-24 10:46:58 -020017#include <asm/unaligned.h>
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070018#include <linux/kernel.h>
19#include <linux/skbuff.h>
20
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -070021#include "ackvec.h"
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070022#include "ccid.h"
23#include "dccp.h"
Andrea Bittauafe00252006-03-20 17:43:56 -080024#include "feat.h"
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070025
Gerrit Renker02fa4602008-11-23 16:07:53 -080026u64 dccp_decode_value_var(const u8 *bf, const u8 len)
Gerrit Renker410e27a2008-09-09 13:27:22 +020027{
Gerrit Renker02fa4602008-11-23 16:07:53 -080028 u64 value = 0;
Gerrit Renker410e27a2008-09-09 13:27:22 +020029
Gerrit Renker02fa4602008-11-23 16:07:53 -080030 if (len >= DCCP_OPTVAL_MAXLEN)
31 value += ((u64)*bf++) << 40;
32 if (len > 4)
33 value += ((u64)*bf++) << 32;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070034 if (len > 3)
Gerrit Renker02fa4602008-11-23 16:07:53 -080035 value += ((u64)*bf++) << 24;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070036 if (len > 2)
Gerrit Renker02fa4602008-11-23 16:07:53 -080037 value += ((u64)*bf++) << 16;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070038 if (len > 1)
Gerrit Renker02fa4602008-11-23 16:07:53 -080039 value += ((u64)*bf++) << 8;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070040 if (len > 0)
41 value += *bf;
42
43 return value;
44}
45
Gerrit Renker8b819412007-12-13 12:29:24 -020046/**
47 * dccp_parse_options - Parse DCCP options present in @skb
48 * @sk: client|server|listening dccp socket (when @dreq != NULL)
49 * @dreq: request socket to use during connection setup, or NULL
50 */
51int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq,
52 struct sk_buff *skb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070053{
54 struct dccp_sock *dp = dccp_sk(sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070055 const struct dccp_hdr *dh = dccp_hdr(skb);
56 const u8 pkt_type = DCCP_SKB_CB(skb)->dccpd_type;
57 unsigned char *options = (unsigned char *)dh + dccp_hdr_len(skb);
58 unsigned char *opt_ptr = options;
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -030059 const unsigned char *opt_end = (unsigned char *)dh +
60 (dh->dccph_doff * 4);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070061 struct dccp_options_received *opt_recv = &dp->dccps_options_received;
62 unsigned char opt, len;
Ingo Molnar3ed7cc02008-11-25 16:57:30 -080063 unsigned char *uninitialized_var(value);
Arnaldo Carvalho de Melo1c14ac02005-09-09 02:32:01 -030064 u32 elapsed_time;
Gerrit Renker76fd1e82007-10-24 10:46:58 -020065 __be32 opt_val;
Andrea Bittauafe00252006-03-20 17:43:56 -080066 int rc;
67 int mandatory = 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070068
69 memset(opt_recv, 0, sizeof(*opt_recv));
70
David S. Millerfb950492006-03-20 22:36:01 -080071 opt = len = 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070072 while (opt_ptr != opt_end) {
73 opt = *opt_ptr++;
74 len = 0;
75 value = NULL;
76
77 /* Check if this isn't a single byte option */
78 if (opt > DCCPO_MAX_RESERVED) {
79 if (opt_ptr == opt_end)
Gerrit Renkerfaf61c332008-08-23 13:28:27 +020080 goto out_nonsensical_length;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070081
82 len = *opt_ptr++;
Gerrit Renkerfaf61c332008-08-23 13:28:27 +020083 if (len < 2)
84 goto out_nonsensical_length;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070085 /*
86 * Remove the type and len fields, leaving
87 * just the value size
88 */
89 len -= 2;
90 value = opt_ptr;
91 opt_ptr += len;
92
93 if (opt_ptr > opt_end)
Gerrit Renkerfaf61c332008-08-23 13:28:27 +020094 goto out_nonsensical_length;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070095 }
96
Gerrit Renker8b819412007-12-13 12:29:24 -020097 /*
Gerrit Renker8b819412007-12-13 12:29:24 -020098 * CCID-specific options are ignored during connection setup, as
99 * negotiation may still be in progress (see RFC 4340, 10.3).
Gerrit Renker65907a42008-06-11 11:19:09 +0100100 * The same applies to Ack Vectors, as these depend on the CCID.
Gerrit Renker8b819412007-12-13 12:29:24 -0200101 */
Gerrit Renkera18213d2010-09-19 20:08:00 +0200102 if (dreq != NULL && (opt >= DCCPO_MIN_RX_CCID_SPECIFIC ||
Gerrit Renker65907a42008-06-11 11:19:09 +0100103 opt == DCCPO_ACK_VECTOR_0 || opt == DCCPO_ACK_VECTOR_1))
Gerrit Renker8b819412007-12-13 12:29:24 -0200104 goto ignore_option;
105
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700106 switch (opt) {
107 case DCCPO_PADDING:
108 break;
Andrea Bittauafe00252006-03-20 17:43:56 -0800109 case DCCPO_MANDATORY:
110 if (mandatory)
111 goto out_invalid_option;
Arnaldo Carvalho de Melo6df94242006-03-20 22:06:02 -0800112 if (pkt_type != DCCP_PKT_DATA)
113 mandatory = 1;
Andrea Bittauafe00252006-03-20 17:43:56 -0800114 break;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700115 case DCCPO_NDP_COUNT:
Gerrit Renker5b5d0e72008-07-13 11:51:40 +0100116 if (len > 6)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700117 goto out_invalid_option;
118
119 opt_recv->dccpor_ndp = dccp_decode_value_var(value, len);
Gerrit Renker5b5d0e72008-07-13 11:51:40 +0100120 dccp_pr_debug("%s opt: NDP count=%llu\n", dccp_role(sk),
121 (unsigned long long)opt_recv->dccpor_ndp);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700122 break;
Gerrit Renkerb1ad0042008-12-01 23:33:18 -0800123 case DCCPO_CHANGE_L ... DCCPO_CONFIRM_R:
124 if (pkt_type == DCCP_PKT_DATA) /* RFC 4340, 6 */
Gerrit Renkercf863142007-12-13 12:48:19 -0200125 break;
Dan Rosenberga2948652011-05-06 03:27:18 +0000126 if (len == 0)
127 goto out_invalid_option;
Gerrit Renkere77b8362008-12-01 23:32:35 -0800128 rc = dccp_feat_parse_options(sk, dreq, mandatory, opt,
129 *value, value + 1, len - 1);
130 if (rc)
131 goto out_featneg_failed;
Gerrit Renker410e27a2008-09-09 13:27:22 +0200132 break;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700133 case DCCPO_TIMESTAMP:
134 if (len != 4)
135 goto out_invalid_option;
Gerrit Renkerb4d4f7c2007-12-13 12:37:19 -0200136 /*
137 * RFC 4340 13.1: "The precise time corresponding to
138 * Timestamp Value zero is not specified". We use
139 * zero to indicate absence of a meaningful timestamp.
140 */
Gerrit Renker76fd1e82007-10-24 10:46:58 -0200141 opt_val = get_unaligned((__be32 *)value);
Gerrit Renkerb4d4f7c2007-12-13 12:37:19 -0200142 if (unlikely(opt_val == 0)) {
143 DCCP_WARN("Timestamp with zero value\n");
144 break;
145 }
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700146
Gerrit Renkerb4d4f7c2007-12-13 12:37:19 -0200147 if (dreq != NULL) {
148 dreq->dreq_timestamp_echo = ntohl(opt_val);
149 dreq->dreq_timestamp_time = dccp_timestamp();
150 } else {
151 opt_recv->dccpor_timestamp =
152 dp->dccps_timestamp_echo = ntohl(opt_val);
153 dp->dccps_timestamp_time = dccp_timestamp();
154 }
Gerrit Renker09dbc382006-11-14 12:57:34 -0200155 dccp_pr_debug("%s rx opt: TIMESTAMP=%u, ackno=%llu\n",
Gerrit Renkerb4d4f7c2007-12-13 12:37:19 -0200156 dccp_role(sk), ntohl(opt_val),
David S. Millerf6ccf552005-08-09 20:27:14 -0700157 (unsigned long long)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700158 DCCP_SKB_CB(skb)->dccpd_ack_seq);
Gerrit Renkerecdfbda2010-10-11 20:41:13 +0200159 /* schedule an Ack in case this sender is quiescent */
160 inet_csk_schedule_ack(sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700161 break;
162 case DCCPO_TIMESTAMP_ECHO:
Ian McDonald1bc09862005-08-20 00:23:43 -0300163 if (len != 4 && len != 6 && len != 8)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700164 goto out_invalid_option;
165
Gerrit Renker76fd1e82007-10-24 10:46:58 -0200166 opt_val = get_unaligned((__be32 *)value);
167 opt_recv->dccpor_timestamp_echo = ntohl(opt_val);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700168
Gerrit Renker09dbc382006-11-14 12:57:34 -0200169 dccp_pr_debug("%s rx opt: TIMESTAMP_ECHO=%u, len=%d, "
Gerrit Renkerf73f7092007-04-20 13:56:47 -0700170 "ackno=%llu", dccp_role(sk),
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300171 opt_recv->dccpor_timestamp_echo,
David S. Millerf6ccf552005-08-09 20:27:14 -0700172 len + 2,
173 (unsigned long long)
Ian McDonald1bc09862005-08-20 00:23:43 -0300174 DCCP_SKB_CB(skb)->dccpd_ack_seq);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700175
Gerrit Renker76fd1e82007-10-24 10:46:58 -0200176 value += 4;
Ian McDonald1bc09862005-08-20 00:23:43 -0300177
Gerrit Renker76fd1e82007-10-24 10:46:58 -0200178 if (len == 4) { /* no elapsed time included */
Gerrit Renkerf73f7092007-04-20 13:56:47 -0700179 dccp_pr_debug_cat("\n");
Arnaldo Carvalho de Melo1c14ac02005-09-09 02:32:01 -0300180 break;
Gerrit Renkerf73f7092007-04-20 13:56:47 -0700181 }
Arnaldo Carvalho de Melo1c14ac02005-09-09 02:32:01 -0300182
Gerrit Renker76fd1e82007-10-24 10:46:58 -0200183 if (len == 6) { /* 2-byte elapsed time */
184 __be16 opt_val2 = get_unaligned((__be16 *)value);
185 elapsed_time = ntohs(opt_val2);
186 } else { /* 4-byte elapsed time */
187 opt_val = get_unaligned((__be32 *)value);
188 elapsed_time = ntohl(opt_val);
189 }
Arnaldo Carvalho de Melo1c14ac02005-09-09 02:32:01 -0300190
Gerrit Renkerdcad8562007-10-04 14:44:01 -0700191 dccp_pr_debug_cat(", ELAPSED_TIME=%u\n", elapsed_time);
Gerrit Renkerf73f7092007-04-20 13:56:47 -0700192
Arnaldo Carvalho de Melo1c14ac02005-09-09 02:32:01 -0300193 /* Give precedence to the biggest ELAPSED_TIME */
194 if (elapsed_time > opt_recv->dccpor_elapsed_time)
195 opt_recv->dccpor_elapsed_time = elapsed_time;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700196 break;
197 case DCCPO_ELAPSED_TIME:
Gerrit Renkerc86ab2b2007-11-21 10:13:53 -0200198 if (dccp_packet_without_ack(skb)) /* RFC 4340, 13.2 */
199 break;
Ian McDonald1bc09862005-08-20 00:23:43 -0300200
Gerrit Renker76fd1e82007-10-24 10:46:58 -0200201 if (len == 2) {
202 __be16 opt_val2 = get_unaligned((__be16 *)value);
203 elapsed_time = ntohs(opt_val2);
Gerrit Renkerc86ab2b2007-11-21 10:13:53 -0200204 } else if (len == 4) {
Gerrit Renker76fd1e82007-10-24 10:46:58 -0200205 opt_val = get_unaligned((__be32 *)value);
206 elapsed_time = ntohl(opt_val);
Gerrit Renkerc86ab2b2007-11-21 10:13:53 -0200207 } else {
208 goto out_invalid_option;
Gerrit Renker76fd1e82007-10-24 10:46:58 -0200209 }
Arnaldo Carvalho de Melo1c14ac02005-09-09 02:32:01 -0300210
211 if (elapsed_time > opt_recv->dccpor_elapsed_time)
212 opt_recv->dccpor_elapsed_time = elapsed_time;
Ian McDonald1bc09862005-08-20 00:23:43 -0300213
Gerrit Renker09dbc382006-11-14 12:57:34 -0200214 dccp_pr_debug("%s rx opt: ELAPSED_TIME=%d\n",
215 dccp_role(sk), elapsed_time);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700216 break;
Gerrit Renkera18213d2010-09-19 20:08:00 +0200217 case DCCPO_MIN_RX_CCID_SPECIFIC ... DCCPO_MAX_RX_CCID_SPECIFIC:
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300218 if (ccid_hc_rx_parse_options(dp->dccps_hc_rx_ccid, sk,
Gerrit Renker4874c132010-09-19 20:06:50 +0200219 pkt_type, opt, value, len))
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700220 goto out_invalid_option;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700221 break;
Gerrit Renker7e87fe82010-11-14 17:26:13 +0100222 case DCCPO_ACK_VECTOR_0:
223 case DCCPO_ACK_VECTOR_1:
224 if (dccp_packet_without_ack(skb)) /* RFC 4340, 11.4 */
225 break;
226 /*
227 * Ack vectors are processed by the TX CCID if it is
228 * interested. The RX CCID need not parse Ack Vectors,
229 * since it is only interested in clearing old state.
230 * Fall through.
231 */
Gerrit Renkera18213d2010-09-19 20:08:00 +0200232 case DCCPO_MIN_TX_CCID_SPECIFIC ... DCCPO_MAX_TX_CCID_SPECIFIC:
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300233 if (ccid_hc_tx_parse_options(dp->dccps_hc_tx_ccid, sk,
Gerrit Renker4874c132010-09-19 20:06:50 +0200234 pkt_type, opt, value, len))
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700235 goto out_invalid_option;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700236 break;
237 default:
Gerrit Renker59348b12006-11-20 18:39:23 -0200238 DCCP_CRIT("DCCP(%p): option %d(len=%d) not "
239 "implemented, ignoring", sk, opt, len);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700240 break;
YOSHIFUJI Hideakic9eaf172007-02-09 23:24:38 +0900241 }
Gerrit Renker8b819412007-12-13 12:29:24 -0200242ignore_option:
Andrea Bittauafe00252006-03-20 17:43:56 -0800243 if (opt != DCCPO_MANDATORY)
244 mandatory = 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700245 }
246
Arnaldo Carvalho de Melo6df94242006-03-20 22:06:02 -0800247 /* mandatory was the last byte in option list -> reset connection */
248 if (mandatory)
249 goto out_invalid_option;
250
Gerrit Renkerfaf61c332008-08-23 13:28:27 +0200251out_nonsensical_length:
252 /* RFC 4340, 5.8: ignore option and all remaining option space */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700253 return 0;
254
255out_invalid_option:
256 DCCP_INC_STATS_BH(DCCP_MIB_INVALIDOPT);
Gerrit Renkere77b8362008-12-01 23:32:35 -0800257 rc = DCCP_RESET_CODE_OPTION_ERROR;
258out_featneg_failed:
259 DCCP_WARN("DCCP(%p): Option %d (len=%d) error=%u\n", sk, opt, len, rc);
260 DCCP_SKB_CB(skb)->dccpd_reset_code = rc;
Gerrit Renkereac77262008-08-23 13:28:27 +0200261 DCCP_SKB_CB(skb)->dccpd_reset_data[0] = opt;
262 DCCP_SKB_CB(skb)->dccpd_reset_data[1] = len > 0 ? value[0] : 0;
263 DCCP_SKB_CB(skb)->dccpd_reset_data[2] = len > 1 ? value[1] : 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700264 return -1;
265}
266
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800267EXPORT_SYMBOL_GPL(dccp_parse_options);
268
Gerrit Renker02fa4602008-11-23 16:07:53 -0800269void dccp_encode_value_var(const u64 value, u8 *to, const u8 len)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700270{
Gerrit Renker02fa4602008-11-23 16:07:53 -0800271 if (len >= DCCP_OPTVAL_MAXLEN)
272 *to++ = (value & 0xFF0000000000ull) >> 40;
273 if (len > 4)
274 *to++ = (value & 0xFF00000000ull) >> 32;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700275 if (len > 3)
276 *to++ = (value & 0xFF000000) >> 24;
277 if (len > 2)
278 *to++ = (value & 0xFF0000) >> 16;
279 if (len > 1)
280 *to++ = (value & 0xFF00) >> 8;
281 if (len > 0)
282 *to++ = (value & 0xFF);
283}
284
Gerrit Renker5b5d0e72008-07-13 11:51:40 +0100285static inline u8 dccp_ndp_len(const u64 ndp)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700286{
Gerrit Renker5b5d0e72008-07-13 11:51:40 +0100287 if (likely(ndp <= 0xFF))
288 return 1;
Alexey Dobriyan4be929b2010-05-24 14:33:03 -0700289 return likely(ndp <= USHRT_MAX) ? 2 : (ndp <= UINT_MAX ? 4 : 6);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700290}
291
Gerrit Renkera7d13fb2010-06-22 01:14:34 +0000292int dccp_insert_option(struct sk_buff *skb, const unsigned char option,
293 const void *value, const unsigned char len)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700294{
295 unsigned char *to;
296
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800297 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 2 > DCCP_MAX_OPT_LEN)
298 return -1;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700299
300 DCCP_SKB_CB(skb)->dccpd_opt_len += len + 2;
301
302 to = skb_push(skb, len + 2);
303 *to++ = option;
304 *to++ = len + 2;
305
306 memcpy(to, value, len);
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800307 return 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700308}
309
310EXPORT_SYMBOL_GPL(dccp_insert_option);
311
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800312static int dccp_insert_option_ndp(struct sock *sk, struct sk_buff *skb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700313{
314 struct dccp_sock *dp = dccp_sk(sk);
Gerrit Renker5b5d0e72008-07-13 11:51:40 +0100315 u64 ndp = dp->dccps_ndp_count;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700316
317 if (dccp_non_data_packet(skb))
318 ++dp->dccps_ndp_count;
319 else
320 dp->dccps_ndp_count = 0;
321
322 if (ndp > 0) {
323 unsigned char *ptr;
324 const int ndp_len = dccp_ndp_len(ndp);
325 const int len = ndp_len + 2;
326
327 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800328 return -1;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700329
330 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
331
332 ptr = skb_push(skb, len);
333 *ptr++ = DCCPO_NDP_COUNT;
334 *ptr++ = len;
335 dccp_encode_value_var(ndp, ptr, ndp_len);
336 }
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800337
338 return 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700339}
340
341static inline int dccp_elapsed_time_len(const u32 elapsed_time)
342{
Ian McDonaldb1c9fe72005-08-18 20:45:29 -0300343 return elapsed_time == 0 ? 0 : elapsed_time <= 0xFFFF ? 2 : 4;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700344}
345
stephen hemminger1f4f0f62010-10-05 04:24:09 +0000346static int dccp_insert_option_timestamp(struct sk_buff *skb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700347{
Gerrit Renker4c70f382007-09-25 22:40:13 -0700348 __be32 now = htonl(dccp_timestamp());
Ian McDonald1bc09862005-08-20 00:23:43 -0300349 /* yes this will overflow but that is the point as we want a
350 * 10 usec 32 bit timer which mean it wraps every 11.9 hours */
351
Gerrit Renkera7d13fb2010-06-22 01:14:34 +0000352 return dccp_insert_option(skb, DCCPO_TIMESTAMP, &now, sizeof(now));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700353}
354
Gerrit Renkerb4d4f7c2007-12-13 12:37:19 -0200355static int dccp_insert_option_timestamp_echo(struct dccp_sock *dp,
356 struct dccp_request_sock *dreq,
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800357 struct sk_buff *skb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700358{
Andrea Bittau60fe62e2006-03-20 19:23:32 -0800359 __be32 tstamp_echo;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700360 unsigned char *to;
Gerrit Renkerb4d4f7c2007-12-13 12:37:19 -0200361 u32 elapsed_time, elapsed_time_len, len;
362
363 if (dreq != NULL) {
364 elapsed_time = dccp_timestamp() - dreq->dreq_timestamp_time;
365 tstamp_echo = htonl(dreq->dreq_timestamp_echo);
366 dreq->dreq_timestamp_echo = 0;
367 } else {
368 elapsed_time = dccp_timestamp() - dp->dccps_timestamp_time;
369 tstamp_echo = htonl(dp->dccps_timestamp_echo);
370 dp->dccps_timestamp_echo = 0;
371 }
372
Arnaldo Carvalho de Melob0e56782005-09-09 02:38:35 -0300373 elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
374 len = 6 + elapsed_time_len;
375
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800376 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
377 return -1;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700378
379 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
380
381 to = skb_push(skb, len);
382 *to++ = DCCPO_TIMESTAMP_ECHO;
383 *to++ = len;
384
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700385 memcpy(to, &tstamp_echo, 4);
386 to += 4;
Andrea Bittauafe00252006-03-20 17:43:56 -0800387
Ian McDonald1bc09862005-08-20 00:23:43 -0300388 if (elapsed_time_len == 2) {
Andrea Bittau60fe62e2006-03-20 19:23:32 -0800389 const __be16 var16 = htons((u16)elapsed_time);
Ian McDonald1bc09862005-08-20 00:23:43 -0300390 memcpy(to, &var16, 2);
391 } else if (elapsed_time_len == 4) {
Andrea Bittau60fe62e2006-03-20 19:23:32 -0800392 const __be32 var32 = htonl(elapsed_time);
Ian McDonald1bc09862005-08-20 00:23:43 -0300393 memcpy(to, &var32, 4);
394 }
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700395
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800396 return 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700397}
398
Gerrit Renker7d870932010-11-10 21:21:02 +0100399static int dccp_insert_option_ackvec(struct sock *sk, struct sk_buff *skb)
400{
401 struct dccp_sock *dp = dccp_sk(sk);
402 struct dccp_ackvec *av = dp->dccps_hc_rx_ackvec;
Gerrit Renkerd83447f2010-11-14 17:25:46 +0100403 struct dccp_skb_cb *dcb = DCCP_SKB_CB(skb);
Gerrit Renkerb3d14bf2010-11-10 21:21:35 +0100404 const u16 buflen = dccp_ackvec_buflen(av);
Gerrit Renker7d870932010-11-10 21:21:02 +0100405 /* Figure out how many options do we need to represent the ackvec */
Gerrit Renkerb3d14bf2010-11-10 21:21:35 +0100406 const u8 nr_opts = DIV_ROUND_UP(buflen, DCCP_SINGLE_OPT_MAXLEN);
407 u16 len = buflen + 2 * nr_opts;
Gerrit Renker7d870932010-11-10 21:21:02 +0100408 u8 i, nonce = 0;
409 const unsigned char *tail, *from;
410 unsigned char *to;
411
Gerrit Renkerd83447f2010-11-14 17:25:46 +0100412 if (dcb->dccpd_opt_len + len > DCCP_MAX_OPT_LEN) {
413 DCCP_WARN("Lacking space for %u bytes on %s packet\n", len,
414 dccp_packet_name(dcb->dccpd_type));
Gerrit Renker7d870932010-11-10 21:21:02 +0100415 return -1;
Gerrit Renkerd83447f2010-11-14 17:25:46 +0100416 }
417 /*
418 * Since Ack Vectors are variable-length, we can not always predict
419 * their size. To catch exception cases where the space is running out
420 * on the skb, a separate Sync is scheduled to carry the Ack Vector.
421 */
422 if (len > DCCPAV_MIN_OPTLEN &&
423 len + dcb->dccpd_opt_len + skb->len > dp->dccps_mss_cache) {
424 DCCP_WARN("No space left for Ack Vector (%u) on skb (%u+%u), "
425 "MPS=%u ==> reduce payload size?\n", len, skb->len,
426 dcb->dccpd_opt_len, dp->dccps_mss_cache);
427 dp->dccps_sync_scheduled = 1;
428 return 0;
429 }
430 dcb->dccpd_opt_len += len;
Gerrit Renker7d870932010-11-10 21:21:02 +0100431
432 to = skb_push(skb, len);
Gerrit Renkerb3d14bf2010-11-10 21:21:35 +0100433 len = buflen;
Gerrit Renker7d870932010-11-10 21:21:02 +0100434 from = av->av_buf + av->av_buf_head;
435 tail = av->av_buf + DCCPAV_MAX_ACKVEC_LEN;
436
437 for (i = 0; i < nr_opts; ++i) {
438 int copylen = len;
439
440 if (len > DCCP_SINGLE_OPT_MAXLEN)
441 copylen = DCCP_SINGLE_OPT_MAXLEN;
442
443 /*
444 * RFC 4340, 12.2: Encode the Nonce Echo for this Ack Vector via
445 * its type; ack_nonce is the sum of all individual buf_nonce's.
446 */
447 nonce ^= av->av_buf_nonce[i];
448
449 *to++ = DCCPO_ACK_VECTOR_0 + av->av_buf_nonce[i];
450 *to++ = copylen + 2;
451
452 /* Check if buf_head wraps */
453 if (from + copylen > tail) {
454 const u16 tailsize = tail - from;
455
456 memcpy(to, from, tailsize);
457 to += tailsize;
458 len -= tailsize;
459 copylen -= tailsize;
460 from = av->av_buf;
461 }
462
463 memcpy(to, from, copylen);
464 from += copylen;
465 to += copylen;
466 len -= copylen;
467 }
468 /*
469 * Each sent Ack Vector is recorded in the list, as per A.2 of RFC 4340.
470 */
Gerrit Renkerd83447f2010-11-14 17:25:46 +0100471 if (dccp_ackvec_update_records(av, dcb->dccpd_seq, nonce))
Gerrit Renker7d870932010-11-10 21:21:02 +0100472 return -ENOBUFS;
473 return 0;
474}
475
Gerrit Renkerd3710562008-11-23 16:09:11 -0800476/**
477 * dccp_insert_option_mandatory - Mandatory option (5.8.2)
478 * Note that since we are using skb_push, this function needs to be called
479 * _after_ inserting the option it is supposed to influence (stack order).
480 */
481int dccp_insert_option_mandatory(struct sk_buff *skb)
482{
483 if (DCCP_SKB_CB(skb)->dccpd_opt_len >= DCCP_MAX_OPT_LEN)
484 return -1;
485
486 DCCP_SKB_CB(skb)->dccpd_opt_len++;
487 *skb_push(skb, 1) = DCCPO_MANDATORY;
488 return 0;
489}
490
Gerrit Renker8c862c22008-11-23 16:10:23 -0800491/**
492 * dccp_insert_fn_opt - Insert single Feature-Negotiation option into @skb
493 * @type: %DCCPO_CHANGE_L, %DCCPO_CHANGE_R, %DCCPO_CONFIRM_L, %DCCPO_CONFIRM_R
494 * @feat: one out of %dccp_feature_numbers
495 * @val: NN value or SP array (preferred element first) to copy
496 * @len: true length of @val in bytes (excluding first element repetition)
497 * @repeat_first: whether to copy the first element of @val twice
Ben Hutchings2c530402012-07-10 10:55:09 +0000498 *
Gerrit Renker8c862c22008-11-23 16:10:23 -0800499 * The last argument is used to construct Confirm options, where the preferred
500 * value and the preference list appear separately (RFC 4340, 6.3.1). Preference
501 * lists are kept such that the preferred entry is always first, so we only need
502 * to copy twice, and avoid the overhead of cloning into a bigger array.
503 */
504int dccp_insert_fn_opt(struct sk_buff *skb, u8 type, u8 feat,
505 u8 *val, u8 len, bool repeat_first)
Gerrit Renker48290072008-09-04 07:30:19 +0200506{
Gerrit Renker8c862c22008-11-23 16:10:23 -0800507 u8 tot_len, *to;
Gerrit Renker48290072008-09-04 07:30:19 +0200508
Gerrit Renker8c862c22008-11-23 16:10:23 -0800509 /* take the `Feature' field and possible repetition into account */
510 if (len > (DCCP_SINGLE_OPT_MAXLEN - 2)) {
511 DCCP_WARN("length %u for feature %u too large\n", len, feat);
Gerrit Renkercf9ddf72008-09-04 07:30:19 +0200512 return -1;
513 }
Gerrit Renkercf9ddf72008-09-04 07:30:19 +0200514
Gerrit Renker8c862c22008-11-23 16:10:23 -0800515 if (unlikely(val == NULL || len == 0))
Rusty Russell3db1cd52011-12-19 13:56:45 +0000516 len = repeat_first = false;
Gerrit Renker8c862c22008-11-23 16:10:23 -0800517 tot_len = 3 + repeat_first + len;
Gerrit Renker410e27a2008-09-09 13:27:22 +0200518
Gerrit Renker8c862c22008-11-23 16:10:23 -0800519 if (DCCP_SKB_CB(skb)->dccpd_opt_len + tot_len > DCCP_MAX_OPT_LEN) {
520 DCCP_WARN("packet too small for feature %d option!\n", feat);
521 return -1;
522 }
523 DCCP_SKB_CB(skb)->dccpd_opt_len += tot_len;
524
525 to = skb_push(skb, tot_len);
Andrea Bittauafe00252006-03-20 17:43:56 -0800526 *to++ = type;
Gerrit Renker8c862c22008-11-23 16:10:23 -0800527 *to++ = tot_len;
Andrea Bittauafe00252006-03-20 17:43:56 -0800528 *to++ = feat;
529
Gerrit Renker8c862c22008-11-23 16:10:23 -0800530 if (repeat_first)
531 *to++ = *val;
Andrea Bittauafe00252006-03-20 17:43:56 -0800532 if (len)
533 memcpy(to, val, len);
Gerrit Renker410e27a2008-09-09 13:27:22 +0200534 return 0;
535}
536
Gerrit Renkeraf3b8672007-12-13 12:38:11 -0200537/* The length of all options needs to be a multiple of 4 (5.8) */
538static void dccp_insert_option_padding(struct sk_buff *skb)
539{
540 int padding = DCCP_SKB_CB(skb)->dccpd_opt_len % 4;
541
542 if (padding != 0) {
543 padding = 4 - padding;
544 memset(skb_push(skb, padding), 0, padding);
545 DCCP_SKB_CB(skb)->dccpd_opt_len += padding;
546 }
547}
548
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800549int dccp_insert_options(struct sock *sk, struct sk_buff *skb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700550{
551 struct dccp_sock *dp = dccp_sk(sk);
552
553 DCCP_SKB_CB(skb)->dccpd_opt_len = 0;
554
Gerrit Renker4098dce2008-12-08 01:18:37 -0800555 if (dp->dccps_send_ndp_count && dccp_insert_option_ndp(sk, skb))
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800556 return -1;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700557
Gerrit Renker8b7b6c72008-12-01 23:29:30 -0800558 if (DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATA) {
559
560 /* Feature Negotiation */
561 if (dccp_feat_insert_opts(dp, NULL, skb))
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800562 return -1;
Gerrit Renker8b7b6c72008-12-01 23:29:30 -0800563
564 if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_REQUEST) {
565 /*
566 * Obtain RTT sample from Request/Response exchange.
Gerrit Renker59b80802010-06-22 01:14:35 +0000567 * This is currently used for TFRC initialisation.
Gerrit Renker8b7b6c72008-12-01 23:29:30 -0800568 */
Gerrit Renkera7d13fb2010-06-22 01:14:34 +0000569 if (dccp_insert_option_timestamp(skb))
Gerrit Renker8b7b6c72008-12-01 23:29:30 -0800570 return -1;
571
Gerrit Renkerb3d14bf2010-11-10 21:21:35 +0100572 } else if (dccp_ackvec_pending(sk) &&
Gerrit Renker8b7b6c72008-12-01 23:29:30 -0800573 dccp_insert_option_ackvec(sk, skb)) {
574 return -1;
575 }
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700576 }
577
Arnaldo Carvalho de Melo507d37c2005-09-09 02:30:07 -0300578 if (dp->dccps_hc_rx_insert_options) {
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800579 if (ccid_hc_rx_insert_options(dp->dccps_hc_rx_ccid, sk, skb))
580 return -1;
Arnaldo Carvalho de Melo507d37c2005-09-09 02:30:07 -0300581 dp->dccps_hc_rx_insert_options = 0;
582 }
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700583
Gerrit Renkerb4d4f7c2007-12-13 12:37:19 -0200584 if (dp->dccps_timestamp_echo != 0 &&
585 dccp_insert_option_timestamp_echo(dp, NULL, skb))
586 return -1;
587
Gerrit Renkeraf3b8672007-12-13 12:38:11 -0200588 dccp_insert_option_padding(skb);
589 return 0;
590}
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700591
Gerrit Renkeraf3b8672007-12-13 12:38:11 -0200592int dccp_insert_options_rsk(struct dccp_request_sock *dreq, struct sk_buff *skb)
593{
594 DCCP_SKB_CB(skb)->dccpd_opt_len = 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700595
Gerrit Renker8b7b6c72008-12-01 23:29:30 -0800596 if (dccp_feat_insert_opts(NULL, dreq, skb))
597 return -1;
598
Gerrit Renker59b80802010-06-22 01:14:35 +0000599 /* Obtain RTT sample from Response/Ack exchange (used by TFRC). */
600 if (dccp_insert_option_timestamp(skb))
601 return -1;
602
Gerrit Renkeraf3b8672007-12-13 12:38:11 -0200603 if (dreq->dreq_timestamp_echo != 0 &&
604 dccp_insert_option_timestamp_echo(NULL, dreq, skb))
605 return -1;
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800606
Gerrit Renkeraf3b8672007-12-13 12:38:11 -0200607 dccp_insert_option_padding(skb);
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800608 return 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700609}