blob: 86c7a20d39b2ed65e76ae07ae394d236ae73be03 [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 Renker410e27a2008-09-09 13:27:22 +020026int sysctl_dccp_feat_sequence_window = DCCPF_INITIAL_SEQUENCE_WINDOW;
27int sysctl_dccp_feat_rx_ccid = DCCPF_INITIAL_CCID;
28int sysctl_dccp_feat_tx_ccid = DCCPF_INITIAL_CCID;
Gerrit Renker410e27a2008-09-09 13:27:22 +020029int sysctl_dccp_feat_send_ack_vector = DCCPF_INITIAL_SEND_ACK_VECTOR;
30int sysctl_dccp_feat_send_ndp_count = DCCPF_INITIAL_SEND_NDP_COUNT;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070031
Gerrit Renker02fa4602008-11-23 16:07:53 -080032u64 dccp_decode_value_var(const u8 *bf, const u8 len)
Gerrit Renker410e27a2008-09-09 13:27:22 +020033{
Gerrit Renker02fa4602008-11-23 16:07:53 -080034 u64 value = 0;
Gerrit Renker410e27a2008-09-09 13:27:22 +020035
Gerrit Renker02fa4602008-11-23 16:07:53 -080036 if (len >= DCCP_OPTVAL_MAXLEN)
37 value += ((u64)*bf++) << 40;
38 if (len > 4)
39 value += ((u64)*bf++) << 32;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070040 if (len > 3)
Gerrit Renker02fa4602008-11-23 16:07:53 -080041 value += ((u64)*bf++) << 24;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070042 if (len > 2)
Gerrit Renker02fa4602008-11-23 16:07:53 -080043 value += ((u64)*bf++) << 16;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070044 if (len > 1)
Gerrit Renker02fa4602008-11-23 16:07:53 -080045 value += ((u64)*bf++) << 8;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070046 if (len > 0)
47 value += *bf;
48
49 return value;
50}
51
Gerrit Renker8b819412007-12-13 12:29:24 -020052/**
53 * dccp_parse_options - Parse DCCP options present in @skb
54 * @sk: client|server|listening dccp socket (when @dreq != NULL)
55 * @dreq: request socket to use during connection setup, or NULL
56 */
57int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq,
58 struct sk_buff *skb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070059{
60 struct dccp_sock *dp = dccp_sk(sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070061 const struct dccp_hdr *dh = dccp_hdr(skb);
62 const u8 pkt_type = DCCP_SKB_CB(skb)->dccpd_type;
Gerrit Renker410e27a2008-09-09 13:27:22 +020063 u64 ackno = DCCP_SKB_CB(skb)->dccpd_ack_seq;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070064 unsigned char *options = (unsigned char *)dh + dccp_hdr_len(skb);
65 unsigned char *opt_ptr = options;
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -030066 const unsigned char *opt_end = (unsigned char *)dh +
67 (dh->dccph_doff * 4);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070068 struct dccp_options_received *opt_recv = &dp->dccps_options_received;
69 unsigned char opt, len;
Ingo Molnar3ed7cc02008-11-25 16:57:30 -080070 unsigned char *uninitialized_var(value);
Arnaldo Carvalho de Melo1c14ac02005-09-09 02:32:01 -030071 u32 elapsed_time;
Gerrit Renker76fd1e82007-10-24 10:46:58 -020072 __be32 opt_val;
Andrea Bittauafe00252006-03-20 17:43:56 -080073 int rc;
74 int mandatory = 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070075
76 memset(opt_recv, 0, sizeof(*opt_recv));
77
David S. Millerfb950492006-03-20 22:36:01 -080078 opt = len = 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070079 while (opt_ptr != opt_end) {
80 opt = *opt_ptr++;
81 len = 0;
82 value = NULL;
83
84 /* Check if this isn't a single byte option */
85 if (opt > DCCPO_MAX_RESERVED) {
86 if (opt_ptr == opt_end)
Gerrit Renkerfaf61c332008-08-23 13:28:27 +020087 goto out_nonsensical_length;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070088
89 len = *opt_ptr++;
Gerrit Renkerfaf61c332008-08-23 13:28:27 +020090 if (len < 2)
91 goto out_nonsensical_length;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -070092 /*
93 * Remove the type and len fields, leaving
94 * just the value size
95 */
96 len -= 2;
97 value = opt_ptr;
98 opt_ptr += len;
99
100 if (opt_ptr > opt_end)
Gerrit Renkerfaf61c332008-08-23 13:28:27 +0200101 goto out_nonsensical_length;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700102 }
103
Gerrit Renker8b819412007-12-13 12:29:24 -0200104 /*
Gerrit Renker410e27a2008-09-09 13:27:22 +0200105 * CCID-Specific Options (from RFC 4340, sec. 10.3):
106 *
107 * Option numbers 128 through 191 are for options sent from the
108 * HC-Sender to the HC-Receiver; option numbers 192 through 255
109 * are for options sent from the HC-Receiver to the HC-Sender.
110 *
Gerrit Renker8b819412007-12-13 12:29:24 -0200111 * CCID-specific options are ignored during connection setup, as
112 * negotiation may still be in progress (see RFC 4340, 10.3).
Gerrit Renker65907a42008-06-11 11:19:09 +0100113 * The same applies to Ack Vectors, as these depend on the CCID.
Gerrit Renker410e27a2008-09-09 13:27:22 +0200114 *
Gerrit Renker8b819412007-12-13 12:29:24 -0200115 */
Gerrit Renker410e27a2008-09-09 13:27:22 +0200116 if (dreq != NULL && (opt >= 128 ||
Gerrit Renker65907a42008-06-11 11:19:09 +0100117 opt == DCCPO_ACK_VECTOR_0 || opt == DCCPO_ACK_VECTOR_1))
Gerrit Renker8b819412007-12-13 12:29:24 -0200118 goto ignore_option;
119
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700120 switch (opt) {
121 case DCCPO_PADDING:
122 break;
Andrea Bittauafe00252006-03-20 17:43:56 -0800123 case DCCPO_MANDATORY:
124 if (mandatory)
125 goto out_invalid_option;
Arnaldo Carvalho de Melo6df94242006-03-20 22:06:02 -0800126 if (pkt_type != DCCP_PKT_DATA)
127 mandatory = 1;
Andrea Bittauafe00252006-03-20 17:43:56 -0800128 break;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700129 case DCCPO_NDP_COUNT:
Gerrit Renker5b5d0e72008-07-13 11:51:40 +0100130 if (len > 6)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700131 goto out_invalid_option;
132
133 opt_recv->dccpor_ndp = dccp_decode_value_var(value, len);
Gerrit Renker5b5d0e72008-07-13 11:51:40 +0100134 dccp_pr_debug("%s opt: NDP count=%llu\n", dccp_role(sk),
135 (unsigned long long)opt_recv->dccpor_ndp);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700136 break;
Gerrit Renker410e27a2008-09-09 13:27:22 +0200137 case DCCPO_CHANGE_L:
138 /* fall through */
139 case DCCPO_CHANGE_R:
140 if (pkt_type == DCCP_PKT_DATA)
Gerrit Renkercf863142007-12-13 12:48:19 -0200141 break;
Gerrit Renker410e27a2008-09-09 13:27:22 +0200142 if (len < 2)
143 goto out_invalid_option;
144 rc = dccp_feat_change_recv(sk, opt, *value, value + 1,
145 len - 1);
146 /*
147 * When there is a change error, change_recv is
148 * responsible for dealing with it. i.e. reply with an
149 * empty confirm.
150 * If the change was mandatory, then we need to die.
151 */
152 if (rc && mandatory)
153 goto out_invalid_option;
154 break;
155 case DCCPO_CONFIRM_L:
156 /* fall through */
157 case DCCPO_CONFIRM_R:
158 if (pkt_type == DCCP_PKT_DATA)
159 break;
160 if (len < 2) /* FIXME this disallows empty confirm */
161 goto out_invalid_option;
162 if (dccp_feat_confirm_recv(sk, opt, *value,
163 value + 1, len - 1))
164 goto out_invalid_option;
165 break;
166 case DCCPO_ACK_VECTOR_0:
167 case DCCPO_ACK_VECTOR_1:
168 if (dccp_packet_without_ack(skb)) /* RFC 4340, 11.4 */
169 break;
170
171 if (dccp_msk(sk)->dccpms_send_ack_vector &&
172 dccp_ackvec_parse(sk, skb, &ackno, opt, value, len))
173 goto out_invalid_option;
Andrea Bittauafe00252006-03-20 17:43:56 -0800174 break;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700175 case DCCPO_TIMESTAMP:
176 if (len != 4)
177 goto out_invalid_option;
Gerrit Renkerb4d4f7c2007-12-13 12:37:19 -0200178 /*
179 * RFC 4340 13.1: "The precise time corresponding to
180 * Timestamp Value zero is not specified". We use
181 * zero to indicate absence of a meaningful timestamp.
182 */
Gerrit Renker76fd1e82007-10-24 10:46:58 -0200183 opt_val = get_unaligned((__be32 *)value);
Gerrit Renkerb4d4f7c2007-12-13 12:37:19 -0200184 if (unlikely(opt_val == 0)) {
185 DCCP_WARN("Timestamp with zero value\n");
186 break;
187 }
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700188
Gerrit Renkerb4d4f7c2007-12-13 12:37:19 -0200189 if (dreq != NULL) {
190 dreq->dreq_timestamp_echo = ntohl(opt_val);
191 dreq->dreq_timestamp_time = dccp_timestamp();
192 } else {
193 opt_recv->dccpor_timestamp =
194 dp->dccps_timestamp_echo = ntohl(opt_val);
195 dp->dccps_timestamp_time = dccp_timestamp();
196 }
Gerrit Renker09dbc382006-11-14 12:57:34 -0200197 dccp_pr_debug("%s rx opt: TIMESTAMP=%u, ackno=%llu\n",
Gerrit Renkerb4d4f7c2007-12-13 12:37:19 -0200198 dccp_role(sk), ntohl(opt_val),
David S. Millerf6ccf552005-08-09 20:27:14 -0700199 (unsigned long long)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700200 DCCP_SKB_CB(skb)->dccpd_ack_seq);
201 break;
202 case DCCPO_TIMESTAMP_ECHO:
Ian McDonald1bc09862005-08-20 00:23:43 -0300203 if (len != 4 && len != 6 && len != 8)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700204 goto out_invalid_option;
205
Gerrit Renker76fd1e82007-10-24 10:46:58 -0200206 opt_val = get_unaligned((__be32 *)value);
207 opt_recv->dccpor_timestamp_echo = ntohl(opt_val);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700208
Gerrit Renker09dbc382006-11-14 12:57:34 -0200209 dccp_pr_debug("%s rx opt: TIMESTAMP_ECHO=%u, len=%d, "
Gerrit Renkerf73f7092007-04-20 13:56:47 -0700210 "ackno=%llu", dccp_role(sk),
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300211 opt_recv->dccpor_timestamp_echo,
David S. Millerf6ccf552005-08-09 20:27:14 -0700212 len + 2,
213 (unsigned long long)
Ian McDonald1bc09862005-08-20 00:23:43 -0300214 DCCP_SKB_CB(skb)->dccpd_ack_seq);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700215
Gerrit Renker76fd1e82007-10-24 10:46:58 -0200216 value += 4;
Ian McDonald1bc09862005-08-20 00:23:43 -0300217
Gerrit Renker76fd1e82007-10-24 10:46:58 -0200218 if (len == 4) { /* no elapsed time included */
Gerrit Renkerf73f7092007-04-20 13:56:47 -0700219 dccp_pr_debug_cat("\n");
Arnaldo Carvalho de Melo1c14ac02005-09-09 02:32:01 -0300220 break;
Gerrit Renkerf73f7092007-04-20 13:56:47 -0700221 }
Arnaldo Carvalho de Melo1c14ac02005-09-09 02:32:01 -0300222
Gerrit Renker76fd1e82007-10-24 10:46:58 -0200223 if (len == 6) { /* 2-byte elapsed time */
224 __be16 opt_val2 = get_unaligned((__be16 *)value);
225 elapsed_time = ntohs(opt_val2);
226 } else { /* 4-byte elapsed time */
227 opt_val = get_unaligned((__be32 *)value);
228 elapsed_time = ntohl(opt_val);
229 }
Arnaldo Carvalho de Melo1c14ac02005-09-09 02:32:01 -0300230
Gerrit Renkerdcad8562007-10-04 14:44:01 -0700231 dccp_pr_debug_cat(", ELAPSED_TIME=%u\n", elapsed_time);
Gerrit Renkerf73f7092007-04-20 13:56:47 -0700232
Arnaldo Carvalho de Melo1c14ac02005-09-09 02:32:01 -0300233 /* Give precedence to the biggest ELAPSED_TIME */
234 if (elapsed_time > opt_recv->dccpor_elapsed_time)
235 opt_recv->dccpor_elapsed_time = elapsed_time;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700236 break;
237 case DCCPO_ELAPSED_TIME:
Gerrit Renkerc86ab2b2007-11-21 10:13:53 -0200238 if (dccp_packet_without_ack(skb)) /* RFC 4340, 13.2 */
239 break;
Ian McDonald1bc09862005-08-20 00:23:43 -0300240
Gerrit Renker76fd1e82007-10-24 10:46:58 -0200241 if (len == 2) {
242 __be16 opt_val2 = get_unaligned((__be16 *)value);
243 elapsed_time = ntohs(opt_val2);
Gerrit Renkerc86ab2b2007-11-21 10:13:53 -0200244 } else if (len == 4) {
Gerrit Renker76fd1e82007-10-24 10:46:58 -0200245 opt_val = get_unaligned((__be32 *)value);
246 elapsed_time = ntohl(opt_val);
Gerrit Renkerc86ab2b2007-11-21 10:13:53 -0200247 } else {
248 goto out_invalid_option;
Gerrit Renker76fd1e82007-10-24 10:46:58 -0200249 }
Arnaldo Carvalho de Melo1c14ac02005-09-09 02:32:01 -0300250
251 if (elapsed_time > opt_recv->dccpor_elapsed_time)
252 opt_recv->dccpor_elapsed_time = elapsed_time;
Ian McDonald1bc09862005-08-20 00:23:43 -0300253
Gerrit Renker09dbc382006-11-14 12:57:34 -0200254 dccp_pr_debug("%s rx opt: ELAPSED_TIME=%d\n",
255 dccp_role(sk), elapsed_time);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700256 break;
Gerrit Renker410e27a2008-09-09 13:27:22 +0200257 case 128 ... 191: {
258 const u16 idx = value - options;
259
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300260 if (ccid_hc_rx_parse_options(dp->dccps_hc_rx_ccid, sk,
Gerrit Renker410e27a2008-09-09 13:27:22 +0200261 opt, len, idx,
262 value) != 0)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700263 goto out_invalid_option;
Gerrit Renker410e27a2008-09-09 13:27:22 +0200264 }
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700265 break;
Gerrit Renker410e27a2008-09-09 13:27:22 +0200266 case 192 ... 255: {
267 const u16 idx = value - options;
268
Arnaldo Carvalho de Melo7690af32005-08-13 20:34:54 -0300269 if (ccid_hc_tx_parse_options(dp->dccps_hc_tx_ccid, sk,
Gerrit Renker410e27a2008-09-09 13:27:22 +0200270 opt, len, idx,
271 value) != 0)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700272 goto out_invalid_option;
Gerrit Renker410e27a2008-09-09 13:27:22 +0200273 }
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700274 break;
275 default:
Gerrit Renker59348b12006-11-20 18:39:23 -0200276 DCCP_CRIT("DCCP(%p): option %d(len=%d) not "
277 "implemented, ignoring", sk, opt, len);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700278 break;
YOSHIFUJI Hideakic9eaf172007-02-09 23:24:38 +0900279 }
Gerrit Renker8b819412007-12-13 12:29:24 -0200280ignore_option:
Andrea Bittauafe00252006-03-20 17:43:56 -0800281 if (opt != DCCPO_MANDATORY)
282 mandatory = 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700283 }
284
Arnaldo Carvalho de Melo6df94242006-03-20 22:06:02 -0800285 /* mandatory was the last byte in option list -> reset connection */
286 if (mandatory)
287 goto out_invalid_option;
288
Gerrit Renkerfaf61c332008-08-23 13:28:27 +0200289out_nonsensical_length:
290 /* RFC 4340, 5.8: ignore option and all remaining option space */
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700291 return 0;
292
293out_invalid_option:
294 DCCP_INC_STATS_BH(DCCP_MIB_INVALIDOPT);
Gerrit Renker410e27a2008-09-09 13:27:22 +0200295 DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_OPTION_ERROR;
296 DCCP_WARN("DCCP(%p): invalid option %d, len=%d", sk, opt, len);
Gerrit Renkereac77262008-08-23 13:28:27 +0200297 DCCP_SKB_CB(skb)->dccpd_reset_data[0] = opt;
298 DCCP_SKB_CB(skb)->dccpd_reset_data[1] = len > 0 ? value[0] : 0;
299 DCCP_SKB_CB(skb)->dccpd_reset_data[2] = len > 1 ? value[1] : 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700300 return -1;
301}
302
Arnaldo Carvalho de Melob61fafc2006-03-20 21:25:11 -0800303EXPORT_SYMBOL_GPL(dccp_parse_options);
304
Gerrit Renker02fa4602008-11-23 16:07:53 -0800305void dccp_encode_value_var(const u64 value, u8 *to, const u8 len)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700306{
Gerrit Renker02fa4602008-11-23 16:07:53 -0800307 if (len >= DCCP_OPTVAL_MAXLEN)
308 *to++ = (value & 0xFF0000000000ull) >> 40;
309 if (len > 4)
310 *to++ = (value & 0xFF00000000ull) >> 32;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700311 if (len > 3)
312 *to++ = (value & 0xFF000000) >> 24;
313 if (len > 2)
314 *to++ = (value & 0xFF0000) >> 16;
315 if (len > 1)
316 *to++ = (value & 0xFF00) >> 8;
317 if (len > 0)
318 *to++ = (value & 0xFF);
319}
320
Gerrit Renker5b5d0e72008-07-13 11:51:40 +0100321static inline u8 dccp_ndp_len(const u64 ndp)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700322{
Gerrit Renker5b5d0e72008-07-13 11:51:40 +0100323 if (likely(ndp <= 0xFF))
324 return 1;
325 return likely(ndp <= USHORT_MAX) ? 2 : (ndp <= UINT_MAX ? 4 : 6);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700326}
327
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800328int dccp_insert_option(struct sock *sk, struct sk_buff *skb,
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700329 const unsigned char option,
330 const void *value, const unsigned char len)
331{
332 unsigned char *to;
333
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800334 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len + 2 > DCCP_MAX_OPT_LEN)
335 return -1;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700336
337 DCCP_SKB_CB(skb)->dccpd_opt_len += len + 2;
338
339 to = skb_push(skb, len + 2);
340 *to++ = option;
341 *to++ = len + 2;
342
343 memcpy(to, value, len);
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800344 return 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700345}
346
347EXPORT_SYMBOL_GPL(dccp_insert_option);
348
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800349static int dccp_insert_option_ndp(struct sock *sk, struct sk_buff *skb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700350{
351 struct dccp_sock *dp = dccp_sk(sk);
Gerrit Renker5b5d0e72008-07-13 11:51:40 +0100352 u64 ndp = dp->dccps_ndp_count;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700353
354 if (dccp_non_data_packet(skb))
355 ++dp->dccps_ndp_count;
356 else
357 dp->dccps_ndp_count = 0;
358
359 if (ndp > 0) {
360 unsigned char *ptr;
361 const int ndp_len = dccp_ndp_len(ndp);
362 const int len = ndp_len + 2;
363
364 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800365 return -1;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700366
367 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
368
369 ptr = skb_push(skb, len);
370 *ptr++ = DCCPO_NDP_COUNT;
371 *ptr++ = len;
372 dccp_encode_value_var(ndp, ptr, ndp_len);
373 }
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800374
375 return 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700376}
377
378static inline int dccp_elapsed_time_len(const u32 elapsed_time)
379{
Ian McDonaldb1c9fe72005-08-18 20:45:29 -0300380 return elapsed_time == 0 ? 0 : elapsed_time <= 0xFFFF ? 2 : 4;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700381}
382
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800383int dccp_insert_option_elapsed_time(struct sock *sk, struct sk_buff *skb,
384 u32 elapsed_time)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700385{
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700386 const int elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
387 const int len = 2 + elapsed_time_len;
388 unsigned char *to;
389
Ian McDonald1bc09862005-08-20 00:23:43 -0300390 if (elapsed_time_len == 0)
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800391 return 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700392
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800393 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
394 return -1;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700395
396 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
397
398 to = skb_push(skb, len);
399 *to++ = DCCPO_ELAPSED_TIME;
400 *to++ = len;
401
Ian McDonald1bc09862005-08-20 00:23:43 -0300402 if (elapsed_time_len == 2) {
Andrea Bittau60fe62e2006-03-20 19:23:32 -0800403 const __be16 var16 = htons((u16)elapsed_time);
Ian McDonald1bc09862005-08-20 00:23:43 -0300404 memcpy(to, &var16, 2);
405 } else {
Andrea Bittau60fe62e2006-03-20 19:23:32 -0800406 const __be32 var32 = htonl(elapsed_time);
Ian McDonald1bc09862005-08-20 00:23:43 -0300407 memcpy(to, &var32, 4);
408 }
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700409
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800410 return 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700411}
412
Arnaldo Carvalho de Melod4b81ff2005-08-23 21:51:36 -0700413EXPORT_SYMBOL_GPL(dccp_insert_option_elapsed_time);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700414
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800415int dccp_insert_option_timestamp(struct sock *sk, struct sk_buff *skb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700416{
Gerrit Renker4c70f382007-09-25 22:40:13 -0700417 __be32 now = htonl(dccp_timestamp());
Ian McDonald1bc09862005-08-20 00:23:43 -0300418 /* yes this will overflow but that is the point as we want a
419 * 10 usec 32 bit timer which mean it wraps every 11.9 hours */
420
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800421 return dccp_insert_option(sk, skb, DCCPO_TIMESTAMP, &now, sizeof(now));
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700422}
423
Arnaldo Carvalho de Melod4b81ff2005-08-23 21:51:36 -0700424EXPORT_SYMBOL_GPL(dccp_insert_option_timestamp);
425
Gerrit Renkerb4d4f7c2007-12-13 12:37:19 -0200426static int dccp_insert_option_timestamp_echo(struct dccp_sock *dp,
427 struct dccp_request_sock *dreq,
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800428 struct sk_buff *skb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700429{
Andrea Bittau60fe62e2006-03-20 19:23:32 -0800430 __be32 tstamp_echo;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700431 unsigned char *to;
Gerrit Renkerb4d4f7c2007-12-13 12:37:19 -0200432 u32 elapsed_time, elapsed_time_len, len;
433
434 if (dreq != NULL) {
435 elapsed_time = dccp_timestamp() - dreq->dreq_timestamp_time;
436 tstamp_echo = htonl(dreq->dreq_timestamp_echo);
437 dreq->dreq_timestamp_echo = 0;
438 } else {
439 elapsed_time = dccp_timestamp() - dp->dccps_timestamp_time;
440 tstamp_echo = htonl(dp->dccps_timestamp_echo);
441 dp->dccps_timestamp_echo = 0;
442 }
443
Arnaldo Carvalho de Melob0e56782005-09-09 02:38:35 -0300444 elapsed_time_len = dccp_elapsed_time_len(elapsed_time);
445 len = 6 + elapsed_time_len;
446
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800447 if (DCCP_SKB_CB(skb)->dccpd_opt_len + len > DCCP_MAX_OPT_LEN)
448 return -1;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700449
450 DCCP_SKB_CB(skb)->dccpd_opt_len += len;
451
452 to = skb_push(skb, len);
453 *to++ = DCCPO_TIMESTAMP_ECHO;
454 *to++ = len;
455
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700456 memcpy(to, &tstamp_echo, 4);
457 to += 4;
Andrea Bittauafe00252006-03-20 17:43:56 -0800458
Ian McDonald1bc09862005-08-20 00:23:43 -0300459 if (elapsed_time_len == 2) {
Andrea Bittau60fe62e2006-03-20 19:23:32 -0800460 const __be16 var16 = htons((u16)elapsed_time);
Ian McDonald1bc09862005-08-20 00:23:43 -0300461 memcpy(to, &var16, 2);
462 } else if (elapsed_time_len == 4) {
Andrea Bittau60fe62e2006-03-20 19:23:32 -0800463 const __be32 var32 = htonl(elapsed_time);
Ian McDonald1bc09862005-08-20 00:23:43 -0300464 memcpy(to, &var32, 4);
465 }
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700466
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800467 return 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700468}
469
Gerrit Renkerd3710562008-11-23 16:09:11 -0800470/**
471 * dccp_insert_option_mandatory - Mandatory option (5.8.2)
472 * Note that since we are using skb_push, this function needs to be called
473 * _after_ inserting the option it is supposed to influence (stack order).
474 */
475int dccp_insert_option_mandatory(struct sk_buff *skb)
476{
477 if (DCCP_SKB_CB(skb)->dccpd_opt_len >= DCCP_MAX_OPT_LEN)
478 return -1;
479
480 DCCP_SKB_CB(skb)->dccpd_opt_len++;
481 *skb_push(skb, 1) = DCCPO_MANDATORY;
482 return 0;
483}
484
Gerrit Renker8c862c22008-11-23 16:10:23 -0800485/**
486 * dccp_insert_fn_opt - Insert single Feature-Negotiation option into @skb
487 * @type: %DCCPO_CHANGE_L, %DCCPO_CHANGE_R, %DCCPO_CONFIRM_L, %DCCPO_CONFIRM_R
488 * @feat: one out of %dccp_feature_numbers
489 * @val: NN value or SP array (preferred element first) to copy
490 * @len: true length of @val in bytes (excluding first element repetition)
491 * @repeat_first: whether to copy the first element of @val twice
492 * The last argument is used to construct Confirm options, where the preferred
493 * value and the preference list appear separately (RFC 4340, 6.3.1). Preference
494 * lists are kept such that the preferred entry is always first, so we only need
495 * to copy twice, and avoid the overhead of cloning into a bigger array.
496 */
497int dccp_insert_fn_opt(struct sk_buff *skb, u8 type, u8 feat,
498 u8 *val, u8 len, bool repeat_first)
Gerrit Renker48290072008-09-04 07:30:19 +0200499{
Gerrit Renker8c862c22008-11-23 16:10:23 -0800500 u8 tot_len, *to;
Gerrit Renker48290072008-09-04 07:30:19 +0200501
Gerrit Renker8c862c22008-11-23 16:10:23 -0800502 /* take the `Feature' field and possible repetition into account */
503 if (len > (DCCP_SINGLE_OPT_MAXLEN - 2)) {
504 DCCP_WARN("length %u for feature %u too large\n", len, feat);
Gerrit Renkercf9ddf72008-09-04 07:30:19 +0200505 return -1;
506 }
Gerrit Renkercf9ddf72008-09-04 07:30:19 +0200507
Gerrit Renker8c862c22008-11-23 16:10:23 -0800508 if (unlikely(val == NULL || len == 0))
509 len = repeat_first = 0;
510 tot_len = 3 + repeat_first + len;
Gerrit Renker410e27a2008-09-09 13:27:22 +0200511
Gerrit Renker8c862c22008-11-23 16:10:23 -0800512 if (DCCP_SKB_CB(skb)->dccpd_opt_len + tot_len > DCCP_MAX_OPT_LEN) {
513 DCCP_WARN("packet too small for feature %d option!\n", feat);
514 return -1;
515 }
516 DCCP_SKB_CB(skb)->dccpd_opt_len += tot_len;
517
518 to = skb_push(skb, tot_len);
Andrea Bittauafe00252006-03-20 17:43:56 -0800519 *to++ = type;
Gerrit Renker8c862c22008-11-23 16:10:23 -0800520 *to++ = tot_len;
Andrea Bittauafe00252006-03-20 17:43:56 -0800521 *to++ = feat;
522
Gerrit Renker8c862c22008-11-23 16:10:23 -0800523 if (repeat_first)
524 *to++ = *val;
Andrea Bittauafe00252006-03-20 17:43:56 -0800525 if (len)
526 memcpy(to, val, len);
Gerrit Renker410e27a2008-09-09 13:27:22 +0200527
528 dccp_pr_debug("%s(%s (%d), ...), length %d\n",
529 dccp_feat_typename(type),
530 dccp_feat_name(feat), feat, len);
531 return 0;
532}
533
Gerrit Renkeraf3b8672007-12-13 12:38:11 -0200534/* The length of all options needs to be a multiple of 4 (5.8) */
535static void dccp_insert_option_padding(struct sk_buff *skb)
536{
537 int padding = DCCP_SKB_CB(skb)->dccpd_opt_len % 4;
538
539 if (padding != 0) {
540 padding = 4 - padding;
541 memset(skb_push(skb, padding), 0, padding);
542 DCCP_SKB_CB(skb)->dccpd_opt_len += padding;
543 }
544}
545
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800546int dccp_insert_options(struct sock *sk, struct sk_buff *skb)
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700547{
548 struct dccp_sock *dp = dccp_sk(sk);
Gerrit Renker410e27a2008-09-09 13:27:22 +0200549 struct dccp_minisock *dmsk = dccp_msk(sk);
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700550
551 DCCP_SKB_CB(skb)->dccpd_opt_len = 0;
552
Gerrit Renker410e27a2008-09-09 13:27:22 +0200553 if (dmsk->dccpms_send_ndp_count &&
554 dccp_insert_option_ndp(sk, skb))
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800555 return -1;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700556
Gerrit Renker8b7b6c72008-12-01 23:29:30 -0800557 if (DCCP_SKB_CB(skb)->dccpd_type != DCCP_PKT_DATA) {
558
559 /* Feature Negotiation */
560 if (dccp_feat_insert_opts(dp, NULL, skb))
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800561 return -1;
Gerrit Renker8b7b6c72008-12-01 23:29:30 -0800562
563 if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_REQUEST) {
564 /*
565 * Obtain RTT sample from Request/Response exchange.
566 * This is currently used in CCID 3 initialisation.
567 */
568 if (dccp_insert_option_timestamp(sk, skb))
569 return -1;
570
571 } else if (dmsk->dccpms_send_ack_vector &&
572 dccp_ackvec_pending(dp->dccps_hc_rx_ackvec) &&
573 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 Renkeraf3b8672007-12-13 12:38:11 -0200599 if (dreq->dreq_timestamp_echo != 0 &&
600 dccp_insert_option_timestamp_echo(NULL, dreq, skb))
601 return -1;
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800602
Gerrit Renkeraf3b8672007-12-13 12:38:11 -0200603 dccp_insert_option_padding(skb);
Arnaldo Carvalho de Melo2d0817d2006-03-20 22:32:06 -0800604 return 0;
Arnaldo Carvalho de Melo7c657872005-08-09 20:14:34 -0700605}