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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 Renkerb9aaac12008-09-04 07:30:19 +020026u64 dccp_decode_value_var(const u8 *bf, const u8 len)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070027{
Gerrit Renkerb9aaac12008-09-04 07:30:19 +020028 u64 value = 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070029
Gerrit Renkerb9aaac12008-09-04 07:30:19 +020030 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 Renkerb9aaac12008-09-04 07:30:19 +020035 value += ((u64)*bf++) << 24;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070036 if (len > 2)
Gerrit Renkerb9aaac12008-09-04 07:30:19 +020037 value += ((u64)*bf++) << 16;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070038 if (len > 1)
Gerrit Renkerb9aaac12008-09-04 07:30:19 +020039 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;
Andrea Bittaubdf13d22006-11-24 13:02:42 -020057 u64 ackno = DCCP_SKB_CB(skb)->dccpd_ack_seq;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070058 unsigned char *options = (unsigned char *)dh + dccp_hdr_len(skb);
59 unsigned char *opt_ptr = options;
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -030060 const unsigned char *opt_end = (unsigned char *)dh +
61 (dh->dccph_doff * 4);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070062 struct dccp_options_received *opt_recv = &dp->dccps_options_received;
63 unsigned char opt, len;
64 unsigned char *value;
Arnaldo Carvalho de Melo1c14ac02005-09-09 02:32:01 -030065 u32 elapsed_time;
Gerrit Renker76fd1e82007-10-24 10:46:58 -020066 __be32 opt_val;
Andrea Bittauafe00252006-03-20 17:43:56 -080067 int rc;
68 int mandatory = 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070069
70 memset(opt_recv, 0, sizeof(*opt_recv));
71
David S. Millerfb950492006-03-20 22:36:01 -080072 opt = len = 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070073 while (opt_ptr != opt_end) {
74 opt = *opt_ptr++;
75 len = 0;
76 value = NULL;
77
78 /* Check if this isn't a single byte option */
79 if (opt > DCCPO_MAX_RESERVED) {
80 if (opt_ptr == opt_end)
Gerrit Renkerfaf61c332008-08-23 13:28:27 +020081 goto out_nonsensical_length;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070082
83 len = *opt_ptr++;
Gerrit Renkerfaf61c332008-08-23 13:28:27 +020084 if (len < 2)
85 goto out_nonsensical_length;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070086 /*
87 * Remove the type and len fields, leaving
88 * just the value size
89 */
90 len -= 2;
91 value = opt_ptr;
92 opt_ptr += len;
93
94 if (opt_ptr > opt_end)
Gerrit Renkerfaf61c332008-08-23 13:28:27 +020095 goto out_nonsensical_length;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070096 }
97
Gerrit Renker8b819412007-12-13 12:29:24 -020098 /*
Gerrit Renker8b819412007-12-13 12:29:24 -020099 * CCID-specific options are ignored during connection setup, as
100 * negotiation may still be in progress (see RFC 4340, 10.3).
Gerrit Renker65907a42008-06-11 11:19:09 +0100101 * The same applies to Ack Vectors, as these depend on the CCID.
Gerrit Renker8b819412007-12-13 12:29:24 -0200102 */
Gerrit Renkerf10ecae2008-09-04 07:30:19 +0200103 if (dreq != NULL && (opt >= DCCPO_MIN_RX_CCID_SPECIFIC ||
Gerrit Renker65907a42008-06-11 11:19:09 +0100104 opt == DCCPO_ACK_VECTOR_0 || opt == DCCPO_ACK_VECTOR_1))
Gerrit Renker8b819412007-12-13 12:29:24 -0200105 goto ignore_option;
106
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700107 switch (opt) {
108 case DCCPO_PADDING:
109 break;
Andrea Bittauafe00252006-03-20 17:43:56 -0800110 case DCCPO_MANDATORY:
111 if (mandatory)
112 goto out_invalid_option;
Arnaldo Carvalho de Melo6df94242006-03-20 22:06:02 -0800113 if (pkt_type != DCCP_PKT_DATA)
114 mandatory = 1;
Andrea Bittauafe00252006-03-20 17:43:56 -0800115 break;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700116 case DCCPO_NDP_COUNT:
Gerrit Renker5b5d0e72008-07-13 11:51:40 +0100117 if (len > 6)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700118 goto out_invalid_option;
119
120 opt_recv->dccpor_ndp = dccp_decode_value_var(value, len);
Gerrit Renker5b5d0e72008-07-13 11:51:40 +0100121 dccp_pr_debug("%s opt: NDP count=%llu\n", dccp_role(sk),
122 (unsigned long long)opt_recv->dccpor_ndp);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700123 break;
Gerrit Renkerd2150b72008-09-04 07:30:19 +0200124 case DCCPO_CHANGE_L ... DCCPO_CONFIRM_R:
125 if (pkt_type == DCCP_PKT_DATA) /* RFC 4340, 6 */
Gerrit Renkercf863142007-12-13 12:48:19 -0200126 break;
Gerrit Renker5a146b92008-09-04 07:30:19 +0200127 rc = dccp_feat_parse_options(sk, dreq, mandatory, opt,
128 *value, value + 1, len - 1);
129 if (rc)
130 goto out_featneg_failed;
Andrea Bittauafe00252006-03-20 17:43:56 -0800131 break;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700132 case DCCPO_ACK_VECTOR_0:
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700133 case DCCPO_ACK_VECTOR_1:
Gerrit Renkerc86ab2b2007-11-21 10:13:53 -0200134 if (dccp_packet_without_ack(skb)) /* RFC 4340, 11.4 */
Arnaldo Carvalho de Meloe5a6de92006-03-20 22:30:51 -0800135 break;
Gerrit Renkerb235dc42008-09-04 07:30:19 +0200136 if (dp->dccps_hc_rx_ackvec != NULL &&
Andrea Bittaubdf13d22006-11-24 13:02:42 -0200137 dccp_ackvec_parse(sk, skb, &ackno, opt, value, len))
Arnaldo Carvalho de Meloae31c332005-09-18 00:17:51 -0700138 goto out_invalid_option;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700139 break;
140 case DCCPO_TIMESTAMP:
141 if (len != 4)
142 goto out_invalid_option;
Gerrit Renkerb4d4f7c2007-12-13 12:37:19 -0200143 /*
144 * RFC 4340 13.1: "The precise time corresponding to
145 * Timestamp Value zero is not specified". We use
146 * zero to indicate absence of a meaningful timestamp.
147 */
Gerrit Renker76fd1e82007-10-24 10:46:58 -0200148 opt_val = get_unaligned((__be32 *)value);
Gerrit Renkerb4d4f7c2007-12-13 12:37:19 -0200149 if (unlikely(opt_val == 0)) {
150 DCCP_WARN("Timestamp with zero value\n");
151 break;
152 }
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700153
Gerrit Renkerb4d4f7c2007-12-13 12:37:19 -0200154 if (dreq != NULL) {
155 dreq->dreq_timestamp_echo = ntohl(opt_val);
156 dreq->dreq_timestamp_time = dccp_timestamp();
157 } else {
158 opt_recv->dccpor_timestamp =
159 dp->dccps_timestamp_echo = ntohl(opt_val);
160 dp->dccps_timestamp_time = dccp_timestamp();
161 }
Gerrit Renker09dbc382006-11-14 12:57:34 -0200162 dccp_pr_debug("%s rx opt: TIMESTAMP=%u, ackno=%llu\n",
Gerrit Renkerb4d4f7c2007-12-13 12:37:19 -0200163 dccp_role(sk), ntohl(opt_val),
David S. Millerf6ccf552005-08-09 20:27:14 -0700164 (unsigned long long)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700165 DCCP_SKB_CB(skb)->dccpd_ack_seq);
Gerrit Renker2975abd2008-09-04 07:30:19 +0200166 /* schedule an Ack in case this sender is quiescent */
167 inet_csk_schedule_ack(sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700168 break;
169 case DCCPO_TIMESTAMP_ECHO:
Ian McDonald1bc09862005-08-20 00:23:43 -0300170 if (len != 4 && len != 6 && len != 8)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700171 goto out_invalid_option;
172
Gerrit Renker76fd1e82007-10-24 10:46:58 -0200173 opt_val = get_unaligned((__be32 *)value);
174 opt_recv->dccpor_timestamp_echo = ntohl(opt_val);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700175
Gerrit Renker09dbc382006-11-14 12:57:34 -0200176 dccp_pr_debug("%s rx opt: TIMESTAMP_ECHO=%u, len=%d, "
Gerrit Renkerf73f7092007-04-20 13:56:47 -0700177 "ackno=%llu", dccp_role(sk),
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300178 opt_recv->dccpor_timestamp_echo,
David S. Millerf6ccf552005-08-09 20:27:14 -0700179 len + 2,
180 (unsigned long long)
Ian McDonald1bc09862005-08-20 00:23:43 -0300181 DCCP_SKB_CB(skb)->dccpd_ack_seq);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700182
Gerrit Renker76fd1e82007-10-24 10:46:58 -0200183 value += 4;
Ian McDonald1bc09862005-08-20 00:23:43 -0300184
Gerrit Renker76fd1e82007-10-24 10:46:58 -0200185 if (len == 4) { /* no elapsed time included */
Gerrit Renkerf73f7092007-04-20 13:56:47 -0700186 dccp_pr_debug_cat("\n");
Arnaldo Carvalho de Melo1c14ac02005-09-09 02:32:01 -0300187 break;
Gerrit Renkerf73f7092007-04-20 13:56:47 -0700188 }
Arnaldo Carvalho de Melo1c14ac02005-09-09 02:32:01 -0300189
Gerrit Renker76fd1e82007-10-24 10:46:58 -0200190 if (len == 6) { /* 2-byte elapsed time */
191 __be16 opt_val2 = get_unaligned((__be16 *)value);
192 elapsed_time = ntohs(opt_val2);
193 } else { /* 4-byte elapsed time */
194 opt_val = get_unaligned((__be32 *)value);
195 elapsed_time = ntohl(opt_val);
196 }
Arnaldo Carvalho de Melo1c14ac02005-09-09 02:32:01 -0300197
Gerrit Renkerdcad8562007-10-04 14:44:01 -0700198 dccp_pr_debug_cat(", ELAPSED_TIME=%u\n", elapsed_time);
Gerrit Renkerf73f7092007-04-20 13:56:47 -0700199
Arnaldo Carvalho de Melo1c14ac02005-09-09 02:32:01 -0300200 /* Give precedence to the biggest ELAPSED_TIME */
201 if (elapsed_time > opt_recv->dccpor_elapsed_time)
202 opt_recv->dccpor_elapsed_time = elapsed_time;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700203 break;
204 case DCCPO_ELAPSED_TIME:
Gerrit Renkerc86ab2b2007-11-21 10:13:53 -0200205 if (dccp_packet_without_ack(skb)) /* RFC 4340, 13.2 */
206 break;
Ian McDonald1bc09862005-08-20 00:23:43 -0300207
Gerrit Renker76fd1e82007-10-24 10:46:58 -0200208 if (len == 2) {
209 __be16 opt_val2 = get_unaligned((__be16 *)value);
210 elapsed_time = ntohs(opt_val2);
Gerrit Renkerc86ab2b2007-11-21 10:13:53 -0200211 } else if (len == 4) {
Gerrit Renker76fd1e82007-10-24 10:46:58 -0200212 opt_val = get_unaligned((__be32 *)value);
213 elapsed_time = ntohl(opt_val);
Gerrit Renkerc86ab2b2007-11-21 10:13:53 -0200214 } else {
215 goto out_invalid_option;
Gerrit Renker76fd1e82007-10-24 10:46:58 -0200216 }
Arnaldo Carvalho de Melo1c14ac02005-09-09 02:32:01 -0300217
218 if (elapsed_time > opt_recv->dccpor_elapsed_time)
219 opt_recv->dccpor_elapsed_time = elapsed_time;
Ian McDonald1bc09862005-08-20 00:23:43 -0300220
Gerrit Renker09dbc382006-11-14 12:57:34 -0200221 dccp_pr_debug("%s rx opt: ELAPSED_TIME=%d\n",
222 dccp_role(sk), elapsed_time);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700223 break;
Gerrit Renkerf10ecae2008-09-04 07:30:19 +0200224 case DCCPO_MIN_RX_CCID_SPECIFIC ... DCCPO_MAX_RX_CCID_SPECIFIC:
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300225 if (ccid_hc_rx_parse_options(dp->dccps_hc_rx_ccid, sk,
Gerrit Renker3306c782008-09-04 07:30:19 +0200226 pkt_type, opt, value, len))
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700227 goto out_invalid_option;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700228 break;
Gerrit Renkerf10ecae2008-09-04 07:30:19 +0200229 case DCCPO_MIN_TX_CCID_SPECIFIC ... DCCPO_MAX_TX_CCID_SPECIFIC:
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300230 if (ccid_hc_tx_parse_options(dp->dccps_hc_tx_ccid, sk,
Gerrit Renker3306c782008-09-04 07:30:19 +0200231 pkt_type, opt, value, len))
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700232 goto out_invalid_option;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700233 break;
234 default:
Gerrit Renker59348b12006-11-20 18:39:23 -0200235 DCCP_CRIT("DCCP(%p): option %d(len=%d) not "
236 "implemented, ignoring", sk, opt, len);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700237 break;
YOSHIFUJI Hideakic9eaf172007-02-09 23:24:38 +0900238 }
Gerrit Renker8b819412007-12-13 12:29:24 -0200239ignore_option:
Andrea Bittauafe00252006-03-20 17:43:56 -0800240 if (opt != DCCPO_MANDATORY)
241 mandatory = 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700242 }
243
Arnaldo Carvalho de Melo6df94242006-03-20 22:06:02 -0800244 /* mandatory was the last byte in option list -> reset connection */
245 if (mandatory)
246 goto out_invalid_option;
247
Gerrit Renkerfaf61c332008-08-23 13:28:27 +0200248out_nonsensical_length:
249 /* RFC 4340, 5.8: ignore option and all remaining option space */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700250 return 0;
251
252out_invalid_option:
253 DCCP_INC_STATS_BH(DCCP_MIB_INVALIDOPT);
Gerrit Renker5a146b92008-09-04 07:30:19 +0200254 rc = DCCP_RESET_CODE_OPTION_ERROR;
255out_featneg_failed:
256 DCCP_WARN("DCCP(%p): Option %d (len=%d) error=%u\n", sk, opt, len, rc);
257 DCCP_SKB_CB(skb)->dccpd_reset_code = rc;
Gerrit Renkereac77262008-08-23 13:28:27 +0200258 DCCP_SKB_CB(skb)->dccpd_reset_data[0] = opt;
259 DCCP_SKB_CB(skb)->dccpd_reset_data[1] = len > 0 ? value[0] : 0;
260 DCCP_SKB_CB(skb)->dccpd_reset_data[2] = len > 1 ? value[1] : 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700261 return -1;
262}
263
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800264EXPORT_SYMBOL_GPL(dccp_parse_options);
265
Gerrit Renkerb9aaac12008-09-04 07:30:19 +0200266void dccp_encode_value_var(const u64 value, u8 *to, const u8 len)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700267{
Gerrit Renkerb9aaac12008-09-04 07:30:19 +0200268 if (len >= DCCP_OPTVAL_MAXLEN)
269 *to++ = (value & 0xFF0000000000ull) >> 40;
270 if (len > 4)
271 *to++ = (value & 0xFF00000000ull) >> 32;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700272 if (len > 3)
273 *to++ = (value & 0xFF000000) >> 24;
274 if (len > 2)
275 *to++ = (value & 0xFF0000) >> 16;
276 if (len > 1)
277 *to++ = (value & 0xFF00) >> 8;
278 if (len > 0)
279 *to++ = (value & 0xFF);
280}
281
Gerrit Renker5b5d0e72008-07-13 11:51:40 +0100282static inline u8 dccp_ndp_len(const u64 ndp)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700283{
Gerrit Renker5b5d0e72008-07-13 11:51:40 +0100284 if (likely(ndp <= 0xFF))
285 return 1;
286 return likely(ndp <= USHORT_MAX) ? 2 : (ndp <= UINT_MAX ? 4 : 6);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700287}
288
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800289int dccp_insert_option(struct sock *sk, struct sk_buff *skb,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700290 const unsigned char option,
291 const void *value, const unsigned char len)
292{
293 unsigned char *to;
294
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800295 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 2 > DCCP_MAX_OPT_LEN)
296 return -1;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700297
298 DCCP_SKB_CB(skb)->dccpd_opt_len += len + 2;
299
300 to = skb_push(skb, len + 2);
301 *to++ = option;
302 *to++ = len + 2;
303
304 memcpy(to, value, len);
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800305 return 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700306}
307
308EXPORT_SYMBOL_GPL(dccp_insert_option);
309
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800310static int dccp_insert_option_ndp(struct sock *sk, struct sk_buff *skb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700311{
312 struct dccp_sock *dp = dccp_sk(sk);
Gerrit Renker5b5d0e72008-07-13 11:51:40 +0100313 u64 ndp = dp->dccps_ndp_count;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700314
315 if (dccp_non_data_packet(skb))
316 ++dp->dccps_ndp_count;
317 else
318 dp->dccps_ndp_count = 0;
319
320 if (ndp > 0) {
321 unsigned char *ptr;
322 const int ndp_len = dccp_ndp_len(ndp);
323 const int len = ndp_len + 2;
324
325 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800326 return -1;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700327
328 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
329
330 ptr = skb_push(skb, len);
331 *ptr++ = DCCPO_NDP_COUNT;
332 *ptr++ = len;
333 dccp_encode_value_var(ndp, ptr, ndp_len);
334 }
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800335
336 return 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700337}
338
339static inline int dccp_elapsed_time_len(const u32 elapsed_time)
340{
Ian McDonaldb1c9fe72005-08-18 20:45:29 -0300341 return elapsed_time == 0 ? 0 : elapsed_time <= 0xFFFF ? 2 : 4;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700342}
343
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800344int dccp_insert_option_elapsed_time(struct sock *sk, struct sk_buff *skb,
345 u32 elapsed_time)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700346{
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700347 const int elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
348 const int len = 2 + elapsed_time_len;
349 unsigned char *to;
350
Ian McDonald1bc09862005-08-20 00:23:43 -0300351 if (elapsed_time_len == 0)
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800352 return 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700353
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800354 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
355 return -1;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700356
357 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
358
359 to = skb_push(skb, len);
360 *to++ = DCCPO_ELAPSED_TIME;
361 *to++ = len;
362
Ian McDonald1bc09862005-08-20 00:23:43 -0300363 if (elapsed_time_len == 2) {
Andrea Bittau60fe62e2006-03-20 19:23:32 -0800364 const __be16 var16 = htons((u16)elapsed_time);
Ian McDonald1bc09862005-08-20 00:23:43 -0300365 memcpy(to, &var16, 2);
366 } else {
Andrea Bittau60fe62e2006-03-20 19:23:32 -0800367 const __be32 var32 = htonl(elapsed_time);
Ian McDonald1bc09862005-08-20 00:23:43 -0300368 memcpy(to, &var32, 4);
369 }
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700370
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800371 return 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700372}
373
Arnaldo Carvalho de Melod4b81ff2005-08-23 21:51:36 -0700374EXPORT_SYMBOL_GPL(dccp_insert_option_elapsed_time);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700375
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800376int dccp_insert_option_timestamp(struct sock *sk, struct sk_buff *skb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700377{
Gerrit Renker4c70f382007-09-25 22:40:13 -0700378 __be32 now = htonl(dccp_timestamp());
Ian McDonald1bc09862005-08-20 00:23:43 -0300379 /* yes this will overflow but that is the point as we want a
380 * 10 usec 32 bit timer which mean it wraps every 11.9 hours */
381
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800382 return dccp_insert_option(sk, skb, DCCPO_TIMESTAMP, &now, sizeof(now));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700383}
384
Arnaldo Carvalho de Melod4b81ff2005-08-23 21:51:36 -0700385EXPORT_SYMBOL_GPL(dccp_insert_option_timestamp);
386
Gerrit Renkerb4d4f7c2007-12-13 12:37:19 -0200387static int dccp_insert_option_timestamp_echo(struct dccp_sock *dp,
388 struct dccp_request_sock *dreq,
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800389 struct sk_buff *skb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700390{
Andrea Bittau60fe62e2006-03-20 19:23:32 -0800391 __be32 tstamp_echo;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700392 unsigned char *to;
Gerrit Renkerb4d4f7c2007-12-13 12:37:19 -0200393 u32 elapsed_time, elapsed_time_len, len;
394
395 if (dreq != NULL) {
396 elapsed_time = dccp_timestamp() - dreq->dreq_timestamp_time;
397 tstamp_echo = htonl(dreq->dreq_timestamp_echo);
398 dreq->dreq_timestamp_echo = 0;
399 } else {
400 elapsed_time = dccp_timestamp() - dp->dccps_timestamp_time;
401 tstamp_echo = htonl(dp->dccps_timestamp_echo);
402 dp->dccps_timestamp_echo = 0;
403 }
404
Arnaldo Carvalho de Melob0e56782005-09-09 02:38:35 -0300405 elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
406 len = 6 + elapsed_time_len;
407
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800408 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
409 return -1;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700410
411 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
412
413 to = skb_push(skb, len);
414 *to++ = DCCPO_TIMESTAMP_ECHO;
415 *to++ = len;
416
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700417 memcpy(to, &tstamp_echo, 4);
418 to += 4;
Andrea Bittauafe00252006-03-20 17:43:56 -0800419
Ian McDonald1bc09862005-08-20 00:23:43 -0300420 if (elapsed_time_len == 2) {
Andrea Bittau60fe62e2006-03-20 19:23:32 -0800421 const __be16 var16 = htons((u16)elapsed_time);
Ian McDonald1bc09862005-08-20 00:23:43 -0300422 memcpy(to, &var16, 2);
423 } else if (elapsed_time_len == 4) {
Andrea Bittau60fe62e2006-03-20 19:23:32 -0800424 const __be32 var32 = htonl(elapsed_time);
Ian McDonald1bc09862005-08-20 00:23:43 -0300425 memcpy(to, &var32, 4);
426 }
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700427
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800428 return 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700429}
430
Gerrit Renkerd0440ee2008-09-04 07:30:19 +0200431/**
432 * dccp_insert_option_mandatory - Mandatory option (5.8.2)
433 * Note that since we are using skb_push, this function needs to be called
434 * _after_ inserting the option it is supposed to influence (stack order).
435 */
436int dccp_insert_option_mandatory(struct sk_buff *skb)
437{
438 if (DCCP_SKB_CB(skb)->dccpd_opt_len >= DCCP_MAX_OPT_LEN)
439 return -1;
440
441 DCCP_SKB_CB(skb)->dccpd_opt_len++;
442 *skb_push(skb, 1) = DCCPO_MANDATORY;
443 return 0;
444}
445
Gerrit Renkercf9ddf72008-09-04 07:30:19 +0200446/**
447 * dccp_insert_fn_opt - Insert single Feature-Negotiation option into @skb
448 * @type: %DCCPO_CHANGE_L, %DCCPO_CHANGE_R, %DCCPO_CONFIRM_L, %DCCPO_CONFIRM_R
449 * @feat: one out of %dccp_feature_numbers
450 * @val: NN value or SP array (preferred element first) to copy
451 * @len: true length of @val in bytes (excluding first element repetition)
452 * @repeat_first: whether to copy the first element of @val twice
453 * The last argument is used to construct Confirm options, where the preferred
454 * value and the preference list appear separately (RFC 4340, 6.3.1). Preference
455 * lists are kept such that the preferred entry is always first, so we only need
456 * to copy twice, and avoid the overhead of cloning into a bigger array.
457 */
458int dccp_insert_fn_opt(struct sk_buff *skb, u8 type, u8 feat,
459 u8 *val, u8 len, bool repeat_first)
Andrea Bittauafe00252006-03-20 17:43:56 -0800460{
Gerrit Renkercf9ddf72008-09-04 07:30:19 +0200461 u8 tot_len, *to;
Andrea Bittauafe00252006-03-20 17:43:56 -0800462
Gerrit Renkercf9ddf72008-09-04 07:30:19 +0200463 /* take the `Feature' field and possible repetition into account */
464 if (len > (DCCP_SINGLE_OPT_MAXLEN - 2)) {
465 DCCP_WARN("length %u for feature %u too large\n", len, feat);
Andrea Bittauafe00252006-03-20 17:43:56 -0800466 return -1;
467 }
468
Gerrit Renkercf9ddf72008-09-04 07:30:19 +0200469 if (unlikely(val == NULL || len == 0))
470 len = repeat_first = 0;
471 tot_len = 3 + repeat_first + len;
Andrea Bittauafe00252006-03-20 17:43:56 -0800472
Gerrit Renkercf9ddf72008-09-04 07:30:19 +0200473 if (DCCP_SKB_CB(skb)->dccpd_opt_len + tot_len > DCCP_MAX_OPT_LEN) {
474 DCCP_WARN("packet too small for feature %d option!\n", feat);
475 return -1;
476 }
477 DCCP_SKB_CB(skb)->dccpd_opt_len += tot_len;
478
479 to = skb_push(skb, tot_len);
Andrea Bittauafe00252006-03-20 17:43:56 -0800480 *to++ = type;
Gerrit Renkercf9ddf72008-09-04 07:30:19 +0200481 *to++ = tot_len;
Andrea Bittauafe00252006-03-20 17:43:56 -0800482 *to++ = feat;
483
Gerrit Renkercf9ddf72008-09-04 07:30:19 +0200484 if (repeat_first)
485 *to++ = *val;
Andrea Bittauafe00252006-03-20 17:43:56 -0800486 if (len)
487 memcpy(to, val, len);
Andrea Bittauafe00252006-03-20 17:43:56 -0800488 return 0;
489}
490
Gerrit Renkeraf3b8672007-12-13 12:38:11 -0200491/* The length of all options needs to be a multiple of 4 (5.8) */
492static void dccp_insert_option_padding(struct sk_buff *skb)
493{
494 int padding = DCCP_SKB_CB(skb)->dccpd_opt_len % 4;
495
496 if (padding != 0) {
497 padding = 4 - padding;
498 memset(skb_push(skb, padding), 0, padding);
499 DCCP_SKB_CB(skb)->dccpd_opt_len += padding;
500 }
501}
502
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800503int dccp_insert_options(struct sock *sk, struct sk_buff *skb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700504{
505 struct dccp_sock *dp = dccp_sk(sk);
506
507 DCCP_SKB_CB(skb)->dccpd_opt_len = 0;
508
Gerrit Renker68e074b2008-09-04 07:30:19 +0200509 if (dp->dccps_send_ndp_count && dccp_insert_option_ndp(sk, skb))
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800510 return -1;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700511
Gerrit Renkerf8a644c2008-09-04 07:30:19 +0200512 if (DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATA) {
513
514 /* Feature Negotiation */
515 if (dccp_feat_insert_opts(dp, NULL, skb))
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800516 return -1;
Gerrit Renkerf8a644c2008-09-04 07:30:19 +0200517
518 if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_REQUEST) {
519 /*
520 * Obtain RTT sample from Request/Response exchange.
521 * This is currently used in CCID 3 initialisation.
522 */
523 if (dccp_insert_option_timestamp(sk, skb))
524 return -1;
525
Gerrit Renkerb235dc42008-09-04 07:30:19 +0200526 } else if (dp->dccps_hc_rx_ackvec != NULL &&
Gerrit Renkerf8a644c2008-09-04 07:30:19 +0200527 dccp_ackvec_pending(dp->dccps_hc_rx_ackvec) &&
528 dccp_insert_option_ackvec(sk, skb)) {
529 return -1;
530 }
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700531 }
532
Arnaldo Carvalho de Melo507d37c2005-09-09 02:30:07 -0300533 if (dp->dccps_hc_rx_insert_options) {
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800534 if (ccid_hc_rx_insert_options(dp->dccps_hc_rx_ccid, sk, skb))
535 return -1;
Arnaldo Carvalho de Melo507d37c2005-09-09 02:30:07 -0300536 dp->dccps_hc_rx_insert_options = 0;
537 }
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700538
Gerrit Renkerb4d4f7c2007-12-13 12:37:19 -0200539 if (dp->dccps_timestamp_echo != 0 &&
540 dccp_insert_option_timestamp_echo(dp, NULL, skb))
541 return -1;
542
Gerrit Renkeraf3b8672007-12-13 12:38:11 -0200543 dccp_insert_option_padding(skb);
544 return 0;
545}
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700546
Gerrit Renkeraf3b8672007-12-13 12:38:11 -0200547int dccp_insert_options_rsk(struct dccp_request_sock *dreq, struct sk_buff *skb)
548{
549 DCCP_SKB_CB(skb)->dccpd_opt_len = 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700550
Gerrit Renkerf8a644c2008-09-04 07:30:19 +0200551 if (dccp_feat_insert_opts(NULL, dreq, skb))
552 return -1;
553
Gerrit Renkeraf3b8672007-12-13 12:38:11 -0200554 if (dreq->dreq_timestamp_echo != 0 &&
555 dccp_insert_option_timestamp_echo(NULL, dreq, skb))
556 return -1;
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800557
Gerrit Renkeraf3b8672007-12-13 12:38:11 -0200558 dccp_insert_option_padding(skb);
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800559 return 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700560}