ROHC compression/decompression library: tcp.h Source File

00001 /*
00002  * Copyright 2012,2013,2014 Didier Barvaux
00003  * Copyright 2013 Viveris Technologies
00004  * Copyright 2012 WBX
00005  *
00006  * This library is free software; you can redistribute it and/or
00007  * modify it under the terms of the GNU Lesser General Public
00008  * License as published by the Free Software Foundation; either
00009  * version 2.1 of the License, or (at your option) any later version.
00010  *
00011  * This library is distributed in the hope that it will be useful,
00012  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00013  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00014  * Lesser General Public License for more details.
00015  *
00016  * You should have received a copy of the GNU Lesser General Public
00017  * License along with this library; if not, write to the Free Software
00018  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
00019  */
00020 
00021 /**
00022  * @file   tcp.h
00023  * @brief  TCP header description.
00024  * @author FWX <rohc_team@dialine.fr>
00025  * @author Didier Barvaux <didier@barvaux.org>
00026  * @author Didier Barvaux <didier.barvaux@toulouse.viveris.com>
00027  */
00028 
00029 #ifndef ROHC_PROTOCOLS_TCP_H
00030 #define ROHC_PROTOCOLS_TCP_H
00031 
00032 #include <stdint.h>
00033 #include <assert.h>
00034 
00035 #ifdef __KERNEL__
00036 #  include <endian.h>
00037 #else
00038 #  include "config.h" /* for WORDS_BIGENDIAN */
00039 #endif
00040 
00041 
00042 /* See RFC4996 page 37-40 */
00043 
00044 #define ROHC_PACKET_TYPE_IR      0xFD
00045 #define ROHC_PACKET_TYPE_IR_DYN  0xF8
00046 
00047 
00048 /************************************************************************
00049  * Limits                                                               *
00050  ************************************************************************/
00051 
00052 /**
00053  * @brief The maximum number of IP headers supported by the TCP profile
00054  *
00055  * The limit value was chosen arbitrarily. It should handle most real-life case
00056  * without hurting performances nor memory footprint.
00057  */
00058 #define ROHC_TCP_MAX_IP_HDRS        10U
00059 
00060 
00061 /**
00062  * @brief The maximum number of IP extension header supported by the TCP profile
00063  *
00064  * The limit value was chosen arbitrarily. It should handle most real-life case
00065  * without hurting performances nor memory footprint.
00066  */
00067 #define ROHC_TCP_MAX_IP_EXT_HDRS    20U
00068 
00069 
00070 /**
00071  * @brief The largest index that may be used to identify one TCP option
00072  *
00073  * The ROHC standard defines that one TCP option is identified by an index. It
00074  * also defines that index is in range [0 ; 15].
00075  */
00076 #define MAX_TCP_OPTION_INDEX 15U
00077 
00078 
00079 /**
00080  * @brief The maximum of TCP options supported by the TCP protocol
00081  *
00082  * One TCP header may contain up to 40 bytes of options, so it may contain
00083  * up 40 1-byte options.
00084  *
00085  * @see ROHC_TCP_OPTS_MAX
00086  */
00087 #define ROHC_TCP_OPTS_MAX_PROTO  40U
00088 
00089 
00090 /**
00091  * @brief The maximum of TCP options supported by the TCP profile
00092  *
00093  * One TCP header may contain up to 40 bytes of options, so it may contain
00094  * up 40 1-byte options, so the ROHC (de)compressors should expect such TCP
00095  * packets. However the m field in the compressed list of TCP options (see
00096  * RFC 6846, section 6.3.3 for more details) cannot be larger than 15, so
00097  * restrict the number of TCP options that value. One TCP packet with more
00098  * than 15 TCP options will be compressed with the IP-only profile.
00099  *
00100  * @see ROHC_TCP_OPTS_MAX_PROTO
00101  */
00102 #define ROHC_TCP_OPTS_MAX  15U
00103 
00104 
00105 
00106 /************************************************************************
00107  * Uncompressed TCP base header                                         *
00108  ************************************************************************/
00109 
00110 /**
00111  * @brief The TCP base header without options
00112  *
00113  * See RFC4996 page 72/73
00114  */
00115 struct tcphdr
00116 {
00117         uint16_t src_port;
00118         uint16_t dst_port;
00119         uint32_t seq_num;
00120         uint32_t ack_num;
00121 #if WORDS_BIGENDIAN == 1
00122         uint8_t data_offset:4;
00123         uint8_t res_flags:4;
00124         uint8_t ecn_flags:2;
00125         uint8_t urg_flag:1;
00126         uint8_t ack_flag:1;
00127         uint8_t psh_flag:1;
00128         uint8_t rsf_flags:3;
00129 #else
00130         uint8_t res_flags:4;
00131         uint8_t data_offset:4;
00132         uint8_t rsf_flags:3;
00133         uint8_t psh_flag:1;
00134         uint8_t ack_flag:1;
00135         uint8_t urg_flag:1;
00136         uint8_t ecn_flags:2;
00137 #endif
00138         uint16_t window;
00139         uint16_t checksum;
00140         uint16_t urg_ptr;
00141         uint8_t options[0];          /**< The beginning of the TCP options */
00142 } __attribute__((packed));
00143 
00144 
00145 /* The RSF flags */
00146 #define RSF_RST_ONLY  0x04
00147 #define RSF_SYN_ONLY  0x02
00148 #define RSF_FIN_ONLY  0x01
00149 #define RSF_NONE      0x00
00150 
00151 
00152 
00153 /************************************************************************
00154  * Uncompressed TCP options                                             *
00155  ************************************************************************/
00156 
00157 /** The different TCP options */
00158 typedef enum
00159 {
00160         TCP_OPT_EOL       = 0U,  /**< The End of Option List (EOL) TCP option */
00161         TCP_OPT_NOP       = 1U,  /**< The No OPeration (NOP) TCP option */
00162         TCP_OPT_MSS       = 2U,  /**< The Maximum Segment Size (MSS) TCP option */
00163 #define TCP_OLEN_MSS         4U
00164         TCP_OPT_WS        = 3U,  /**< The Window Scale (WS) TCP option */
00165 #define TCP_OLEN_WS          3U
00166         TCP_OPT_SACK_PERM = 4U,  /**< The SACK Permitted TCP option */
00167 #define TCP_OLEN_SACK_PERM   2U
00168         TCP_OPT_SACK      = 5U,  /**< The Selective ACKnowledgement (SACK) TCP option */
00169         TCP_OPT_TS        = 8U,  /**< The TimeStamp (TS) TCP option */
00170 #define TCP_OLEN_TS         10U
00171         TCP_OPT_MAX       = 255U /**< The maximum TCP option */
00172 
00173 } rohc_tcp_option_type_t;
00174 
00175 
00176 #define TCP_INDEX_NOP          0U
00177 #define TCP_INDEX_EOL          1U
00178 #define TCP_INDEX_MSS          2U
00179 #define TCP_INDEX_WS           3U
00180 #define TCP_INDEX_TS           4U
00181 #define TCP_INDEX_SACK_PERM    5U
00182 #define TCP_INDEX_SACK         6U
00183 #define TCP_INDEX_GENERIC7     7U
00184 #define TCP_INDEX_GENERIC8     8U
00185 #define TCP_INDEX_GENERIC9     9U
00186 #define TCP_INDEX_GENERIC10   10U
00187 #define TCP_INDEX_GENERIC11   11U
00188 #define TCP_INDEX_GENERIC12   12U
00189 #define TCP_INDEX_GENERIC13   13U
00190 #define TCP_INDEX_GENERIC14   14U
00191 #define TCP_INDEX_GENERIC15   15U
00192 
00193 
00194 /**
00195  * @brief The Selective Acknowlegment TCP option
00196  *
00197  * See RFC2018 for TCP Selective Acknowledgement Options
00198  * See RFC4996 page 66
00199  */
00200 typedef struct
00201 {
00202         uint32_t block_start;
00203         uint32_t block_end;
00204 } __attribute__((packed)) sack_block_t;
00205 
00206 
00207 /** The maximum number of SACK blocks in the TCP SACK option */
00208 #define TCP_SACK_BLOCKS_MAX_NR  4U
00209 
00210 
00211 /** The Timestamp option of the TCP header */
00212 struct tcp_option_timestamp
00213 {
00214         uint32_t ts;        /**< The timestamp value */
00215         uint32_t ts_reply;  /**< The timestamp echo reply value */
00216 } __attribute__((packed));
00217 
00218 
00219 
00220 /************************************************************************
00221  * Compressed IPv4 header                                               *
00222  ************************************************************************/
00223 
00224 /**
00225  * @brief The IPv4 static part
00226  *
00227  * See RFC4996 page 62
00228  */
00229 typedef struct
00230 {
00231 #if WORDS_BIGENDIAN == 1
00232         uint8_t version_flag:1;
00233         uint8_t reserved:7;
00234 #else
00235         uint8_t reserved:7;
00236         uint8_t version_flag:1;
00237 #endif
00238         uint8_t protocol;
00239         uint32_t src_addr;
00240         uint32_t dst_addr;
00241 } __attribute__((packed)) ipv4_static_t;
00242 
00243 
00244 /** The different IP-ID behaviors */
00245 typedef enum
00246 {
00247         IP_ID_BEHAVIOR_SEQ       = 0, /**< IP-ID increases */
00248         IP_ID_BEHAVIOR_SEQ_SWAP  = 1, /**< IP-ID increases in little endian */
00249         IP_ID_BEHAVIOR_RAND      = 2, /**< IP-ID is random */
00250         IP_ID_BEHAVIOR_ZERO      = 3, /**< IP-ID is constant zero */
00251 } tcp_ip_id_behavior_t;
00252 
00253 
00254 /**
00255  * @brief The IPv4 dynamic part without IP-ID field
00256  *
00257  * See RFC4996 page 62
00258  */
00259 typedef struct
00260 {
00261 #if WORDS_BIGENDIAN == 1
00262         uint8_t reserved:5;
00263         uint8_t df:1;
00264         uint8_t ip_id_behavior:2;
00265         uint8_t dscp:6;
00266         uint8_t ip_ecn_flags:2;
00267 #else
00268         uint8_t ip_id_behavior:2;
00269         uint8_t df:1;
00270         uint8_t reserved:5;
00271         uint8_t ip_ecn_flags:2;
00272         uint8_t dscp:6;
00273 #endif
00274         uint8_t ttl_hopl;
00275 } __attribute__((packed)) ipv4_dynamic1_t;
00276 
00277 
00278 /**
00279  * @brief The IPv4 dynamic part with IP-ID field
00280  *
00281  * See RFC4996 page 62
00282  */
00283 typedef struct
00284 {
00285 #if WORDS_BIGENDIAN == 1
00286         uint8_t reserved:5;
00287         uint8_t df:1;
00288         uint8_t ip_id_behavior:2;
00289         uint8_t dscp:6;
00290         uint8_t ip_ecn_flags:2;
00291 #else
00292         uint8_t ip_id_behavior:2;
00293         uint8_t df:1;
00294         uint8_t reserved:5;
00295         uint8_t ip_ecn_flags:2;
00296         uint8_t dscp:6;
00297 #endif
00298         uint8_t ttl_hopl;
00299         uint16_t ip_id;
00300 } __attribute__((packed)) ipv4_dynamic2_t;
00301 
00302 
00303 
00304 /************************************************************************
00305  * Compressed IPv6 base header and its extension headers                *
00306  ************************************************************************/
00307 
00308 /** The static part of IPv6 option header */
00309 typedef struct
00310 {
00311         uint8_t next_header;
00312         uint8_t length;
00313 } __attribute__((packed)) ip_opt_static_t;
00314 
00315 
00316 /** The static part of IPv6 Destination option header */
00317 typedef struct
00318 {
00319         uint8_t next_header;
00320         uint8_t length;
00321 } __attribute__((packed)) ip_dest_opt_static_t;
00322 
00323 
00324 /** The static part of IPv6 Hop-by-Hop option header */
00325 typedef struct
00326 {
00327         uint8_t next_header;
00328         uint8_t length;
00329 } __attribute__((packed)) ip_hop_opt_static_t;
00330 
00331 
00332 /** The static part of IPv6 Routing option header */
00333 typedef struct
00334 {
00335         uint8_t next_header;
00336         uint8_t length;
00337         uint8_t value[1];
00338 } __attribute__((packed)) ip_rout_opt_static_t;
00339 
00340 
00341 /**
00342  * @brief The IPv6 static part, null flow_label encoded with 1 bit
00343  *
00344  * See RFC4996 page 58
00345  */
00346 typedef struct
00347 {
00348 #if WORDS_BIGENDIAN == 1
00349         uint8_t version_flag:1;
00350         uint8_t reserved1:2;
00351         uint8_t flow_label_enc_discriminator:1;
00352         uint8_t reserved2:4;
00353 #else
00354         uint8_t reserved2:4;
00355         uint8_t flow_label_enc_discriminator:1;
00356         uint8_t reserved1:2;
00357         uint8_t version_flag:1;
00358 #endif
00359         uint8_t next_header;
00360         uint32_t src_addr[4];
00361         uint32_t dst_addr[4];
00362 } __attribute__((packed)) ipv6_static1_t;
00363 
00364 
00365 /**
00366  * @brief The IPv6 static part, flow_label encoded with 1+20 bits
00367  *
00368  * See RFC4996 page 59
00369  */
00370 typedef struct
00371 {
00372 #if WORDS_BIGENDIAN == 1
00373         uint8_t version_flag:1;
00374         uint8_t reserved:2;
00375         uint8_t flow_label_enc_discriminator:1;
00376         uint8_t flow_label1:4;
00377 #else
00378         uint8_t flow_label1:4;
00379         uint8_t flow_label_enc_discriminator:1;
00380         uint8_t reserved:2;
00381         uint8_t version_flag:1;
00382 #endif
00383         uint16_t flow_label2;
00384         uint8_t next_header;
00385         uint32_t src_addr[4];
00386         uint32_t dst_addr[4];
00387 } __attribute__((packed)) ipv6_static2_t;
00388 
00389 
00390 /**
00391  * @brief The IPv6 dynamic part
00392  *
00393  * See RFC4996 page 59
00394  */
00395 typedef struct
00396 {
00397 #if WORDS_BIGENDIAN == 1
00398         uint8_t dscp:6;
00399         uint8_t ip_ecn_flags:2;
00400 #else
00401         uint8_t ip_ecn_flags:2;
00402         uint8_t dscp:6;
00403 #endif
00404         uint8_t ttl_hopl;
00405 } __attribute__((packed)) ipv6_dynamic_t;
00406 
00407 
00408 
00409 /************************************************************************
00410  * Compressed TCP header and its options                                *
00411  ************************************************************************/
00412 
00413 /**
00414  * @brief The TCP static part
00415  *
00416  * See RFC4996 page 73/74
00417  */
00418 typedef struct
00419 {
00420         uint16_t src_port;          /**< irregular(16)                          [ 16 ] */
00421         uint16_t dst_port;          /**< irregular(16)                          [ 16 ] */
00422 } __attribute__((packed)) tcp_static_t;
00423 
00424 
00425 /**
00426  * @brief The TCP dynamic part
00427  *
00428  * See RFC4996 page 73/74
00429  */
00430 typedef struct
00431 {
00432 #if WORDS_BIGENDIAN == 1
00433         uint8_t ecn_used:1;         /**< one_bit_choice                         [ 1 ] */
00434         uint8_t ack_stride_flag:1;  /**< irregular(1)                           [ 1 ] */
00435         uint8_t ack_zero:1;         /**< irregular(1)                           [ 1 ] */
00436         uint8_t urp_zero:1;         /**< irregular(1)                           [ 1 ] */
00437         uint8_t tcp_res_flags:4;    /**< irregular(4)                           [ 4 ] */
00438 
00439         uint8_t tcp_ecn_flags:2;    /**< irregular(2)                           [ 2 ] */
00440         uint8_t urg_flag:1;         /**< irregular(1)                           [ 1 ] */
00441         uint8_t ack_flag:1;         /**< irregular(1)                           [ 1 ] */
00442         uint8_t psh_flag:1;         /**< irregular(1)                           [ 1 ] */
00443         uint8_t rsf_flags:3;        /**< irregular(3)                           [ 3 ] */
00444 #else
00445         uint8_t tcp_res_flags:4;
00446         uint8_t urp_zero:1;
00447         uint8_t ack_zero:1;
00448         uint8_t ack_stride_flag:1;
00449         uint8_t ecn_used:1;
00450 
00451         uint8_t rsf_flags:3;
00452         uint8_t psh_flag:1;
00453         uint8_t ack_flag:1;
00454         uint8_t urg_flag:1;
00455         uint8_t tcp_ecn_flags:2;
00456 #endif
00457         uint16_t msn;               /**< irregular(16)                          [ 16 ] */
00458         uint32_t seq_num;           /**< irregular(32)                          [ 32 ] */
00459 
00460         /* variable fields:
00461          *   zero_or_irreg(ack_zero.CVALUE, 32)                                 [ 0, 32 ]
00462          *   irregular(16)                                                      [ 16 ]
00463          *   irregular(16)                                                      [ 16 ]
00464          *   zero_or_irreg(urp_zero.CVALUE, 16)                                 [ 0, 16 ]
00465          *   static_or_irreg(ack_stride_flag.CVALUE, 16)                        [ 0, 16 ]
00466          *   list_tcp_options                                                   [ VARIABLE ]
00467          */
00468 
00469 } __attribute__((packed)) tcp_dynamic_t;
00470 
00471 
00472 /**
00473  * @brief The Common compressed packet format
00474  *
00475  * See RFC4996 page 80/81
00476  */
00477 typedef struct
00478 {
00479 #if WORDS_BIGENDIAN == 1
00480 
00481         uint8_t discriminator:7;         /**< '1111101'                         [ 7 ] */
00482         uint8_t ttl_hopl_outer_flag:1;   /**< compressed_value(1,
00483                                                                                                            ttl_irregular_chain_flag)   [ 1 ] */
00484 
00485         uint8_t ack_flag:1;              /**< irregular(1)                      [ 1 ] */
00486         uint8_t psh_flag:1;              /**< irregular(1)                      [ 1 ] */
00487         uint8_t rsf_flags:2;             /**< rsf_index_enc                     [ 2 ] */
00488         uint8_t msn:4;                   /**< lsb(4, 4)                         [ 4 ] */
00489 
00490         uint8_t seq_indicator:2;         /**< irregular(2)                      [ 2 ] */
00491         uint8_t ack_indicator:2;         /**< irregular(2)                      [ 2 ] */
00492         uint8_t ack_stride_indicator:1;  /**< irregular(1)                      [ 1 ] */
00493         uint8_t window_indicator:1;      /**< irregular(1)                      [ 1 ] */
00494         uint8_t ip_id_indicator:1;       /**< irregular(1)                      [ 1 ] */
00495         uint8_t urg_ptr_present:1;       /**< irregular(1)                      [ 1 ] */
00496 
00497         uint8_t reserved:1;              /**< compressed_value(1, 0)            [ 1 ] */
00498         uint8_t ecn_used:1;              /**< one_bit_choice                    [ 1 ] */
00499         uint8_t dscp_present:1;          /**< irregular(1)                      [ 1 ] */
00500         uint8_t ttl_hopl_present:1;      /**< irregular(1)                      [ 1 ] */
00501         uint8_t list_present:1;          /**< irregular(1)                      [ 1 ] */
00502         uint8_t ip_id_behavior:2;        /**< ip_id_behavior_choice(true)       [ 2 ] */
00503         uint8_t urg_flag:1;              /**< irregular(1)                      [ 1 ] */
00504 
00505         uint8_t df:1;                    /**< dont_fragment(version.UVALUE)     [ 1 ] */
00506         uint8_t header_crc:7;            /**< crc7(THIS.UVALUE,THIS.ULENGTH)    [ 7 ] */
00507 
00508 #else
00509 
00510         uint8_t ttl_hopl_outer_flag:1;
00511         uint8_t discriminator:7;
00512 
00513         uint8_t msn:4;
00514         uint8_t rsf_flags:2;
00515         uint8_t psh_flag:1;
00516         uint8_t ack_flag:1;
00517 
00518         uint8_t urg_ptr_present:1;
00519         uint8_t ip_id_indicator:1;
00520         uint8_t window_indicator:1;
00521         uint8_t ack_stride_indicator:1;
00522         uint8_t ack_indicator:2;
00523         uint8_t seq_indicator:2;
00524 
00525         uint8_t urg_flag:1;
00526         uint8_t ip_id_behavior:2;
00527         uint8_t list_present:1;
00528         uint8_t ttl_hopl_present:1;
00529         uint8_t dscp_present:1;
00530         uint8_t ecn_used:1;
00531         uint8_t reserved:1;
00532 
00533         uint8_t header_crc:7;
00534         uint8_t df:1;
00535 
00536 #endif
00537 
00538         /* variable fields:
00539          *   variable_length_32_enc(seq_indicator.CVALUE)                       [ 0, 8, 16, 32 ]
00540          *   variable_length_32_enc(ack_indicator.CVALUE)                       [ 0, 8, 16, 32 ]
00541          *   static_or_irreg(ack_stride_indicator.CVALUE, 16)                   [ 0, 16 ]
00542          *   static_or_irreg(window_indicator.CVALUE, 16)                       [ 0, 16 ]
00543          *   optional_ip_id_lsb(ip_id_behavior.UVALUE,ip_id_indicator.CVALUE)   [ 0, 8, 16 ]
00544          *   static_or_irreg(urg_ptr_present.CVALUE, 16)                        [ 0, 16 ]
00545          *   dscp_enc-dscp_present.CVALUE)                                      [ 0, 8 ]
00546          *   static_or_irreg(ttl_hopl_present.CVALUE, 8)                        [ 0, 8 ]
00547          *   tcp_list_presence_enc(list_present.CVALUE)                         [ VARIABLE ]
00548          *   irregular chain                                                    [ VARIABLE ]
00549          */
00550 
00551 } __attribute__((packed)) co_common_t;
00552 
00553 
00554 /**
00555  * @brief The rnd_1 compressed packet format
00556  *
00557  * Send LSBs of sequence number
00558  * See RFC4996 page 81
00559  */
00560 typedef struct
00561 {
00562 #if WORDS_BIGENDIAN == 1
00563         uint8_t discriminator:6;    /**< '101110'                               [  6 ] */
00564         uint8_t seq_num1:2;         /**< lsb(18, 65535)                         [ 18 ] */
00565         uint16_t seq_num2;          /**< sequel of \e seq_num1                  [  - ] */
00566         uint8_t msn:4;              /**< lsb(4, 4)                              [  4 ] */
00567         uint8_t psh_flag:1;         /**< irregular(1)                           [  1 ] */
00568         uint8_t header_crc:3;       /**< crc3(THIS.UVALUE, THIS.ULENGTH)        [  3 ] */
00569 #else
00570         uint8_t seq_num1:2;
00571         uint8_t discriminator:6;
00572         uint16_t seq_num2;
00573         uint8_t header_crc:3;
00574         uint8_t psh_flag:1;
00575         uint8_t msn:4;
00576 #endif
00577         /* irregular chain                                                      [ VARIABLE ] */
00578 } __attribute__((packed)) rnd_1_t;
00579 
00580 
00581 /**
00582  * @brief The rnd_2 compressed packet format
00583  *
00584  * Send scaled sequence number LSBs
00585  * See RFC4996 page 81
00586  */
00587 typedef struct
00588 {
00589 #if WORDS_BIGENDIAN == 1
00590         uint8_t discriminator:4;    /**< '1100'                                 [ 4 ] */
00591         uint8_t seq_num_scaled:4;   /**< lsb(4, 7)                              [ 4 ] */
00592         uint8_t msn:4;              /**< lsb(4, 4)                              [ 4 ] */
00593         uint8_t psh_flag:1;         /**< irregular(1)                           [ 1 ] */
00594         uint8_t header_crc:3;       /**< crc3(THIS.UVALUE, THIS.ULENGTH)        [ 3 ] */
00595 #else
00596         uint8_t seq_num_scaled:4;
00597         uint8_t discriminator:4;
00598         uint8_t header_crc:3;
00599         uint8_t psh_flag:1;
00600         uint8_t msn:4;
00601 #endif
00602         /* irregular chain                                                      [ VARIABLE ] */
00603 } __attribute__((packed)) rnd_2_t;
00604 
00605 
00606 /**
00607  * @brief The rnd_3 compressed packet format
00608  *
00609  * Send acknowledgment number LSBs
00610  * See RFC4996 page 81
00611  */
00612 typedef struct
00613 {
00614 #if WORDS_BIGENDIAN == 1
00615         uint16_t discriminator:1;   /**< '0'                                    [  4 ] */
00616         uint8_t ack_num1:7;         /**< lsb(15, 8191)                          [ 15 ] */
00617         uint8_t ack_num2;           /**< sequel of \e ack_num1                  [  - ] */
00618         uint8_t msn:4;              /**< lsb(4, 4)                              [  4 ] */
00619         uint8_t psh_flag:1;         /**< irregular(1)                           [  1 ] */
00620         uint8_t header_crc:3;       /**< crc3(THIS.UVALUE, THIS.ULENGTH)        [  3 ] */
00621 #else
00622         uint8_t ack_num1:7;
00623         uint8_t discriminator:1;
00624         uint8_t ack_num2:8;
00625         uint8_t header_crc:3;
00626         uint8_t psh_flag:1;
00627         uint8_t msn:4;
00628 #endif
00629         /* irregular chain                                                      [ VARIABLE ] */
00630 } __attribute__((packed)) rnd_3_t;
00631 
00632 
00633 /**
00634  * @brief The rnd_4 compressed packet format
00635  *
00636  * Send acknowlegment number scaled
00637  * See RFC4996 page 81
00638  */
00639 typedef struct
00640 {
00641 #if WORDS_BIGENDIAN == 1
00642         uint8_t discriminator:4;    /**< '1101'                                 [ 4 ] */
00643         uint8_t ack_num_scaled:4;   /**< lsb(4, 3)                              [ 4 ] */
00644         uint8_t msn:4;              /**< lsb(4, 4)                              [ 4 ] */
00645         uint8_t psh_flag:1;         /**< irregular(1)                           [ 1 ] */
00646         uint8_t header_crc:3;       /**< crc3(THIS.UVALUE, THIS.ULENGTH)        [ 3 ] */
00647 #else
00648         uint8_t ack_num_scaled:4;
00649         uint8_t discriminator:4;
00650         uint8_t header_crc:3;
00651         uint8_t psh_flag:1;
00652         uint8_t msn:4;
00653 #endif
00654         /* irregular chain                                                      [ VARIABLE ] */
00655 } __attribute__((packed)) rnd_4_t;
00656 
00657 
00658 /**
00659  * @brief The rnd_5 compressed packet format
00660  *
00661  * Send ACK and sequence number
00662  * See RFC4996 page 82
00663  */
00664 typedef struct
00665 {
00666 #if WORDS_BIGENDIAN == 1
00667         uint8_t discriminator:3;    /**< '100'                                  [  3 ] */
00668         uint8_t psh_flag:1;         /**< irregular(1)                           [  1 ] */
00669         uint8_t msn:4;              /**< lsb(4, 4)                              [  4 ] */
00670         uint32_t header_crc:3;      /**< crc3(THIS.UVALUE, THIS.ULENGTH)        [  3 ] */
00671         uint32_t seq_num1:5;        /**< lsb(14, 8191)                          [ 14 ] */
00672         uint32_t seq_num2:8;        /**< sequel of \e seq_num1                  [  - ] */
00673         uint32_t seq_num3:1;        /**< sequel of \e seq_num1 and \e seq_num2  [  - ] */
00674         uint32_t ack_num1:7;        /**< lsb(15, 8191)                          [ 15 ] */
00675         uint32_t ack_num2:8;        /**< sequel of \e ack_num1                  [  - ] */
00676 #else
00677         uint8_t msn:4;
00678         uint8_t psh_flag:1;
00679         uint8_t discriminator:3;
00680         uint8_t seq_num1:5;
00681         uint8_t header_crc:3;
00682         uint8_t seq_num2;
00683         uint8_t ack_num1:7;
00684         uint8_t seq_num3:1;
00685         uint8_t ack_num2;
00686 #endif
00687         /* irregular chain                                                      [ VARIABLE ] */
00688 } __attribute__((packed)) rnd_5_t;
00689 
00690 
00691 /**
00692  * @brief The rnd_6 compressed packet format
00693  *
00694  * Send both ACK and scaled sequence number LSBs
00695  * See RFC4996 page 82
00696  */
00697 typedef struct
00698 {
00699 #if WORDS_BIGENDIAN == 1
00700         uint8_t discriminator:4;    /**< '1010'                                 [ 4 ] */
00701         uint8_t header_crc:3;       /**< crc3(THIS.UVALUE, THIS.ULENGTH)        [ 3 ] */
00702         uint8_t psh_flag:1;         /**< irregular(1)                           [ 1 ] */
00703 #else
00704         uint8_t psh_flag:1;
00705         uint8_t header_crc:3;
00706         uint8_t discriminator:4;
00707 #endif
00708         uint16_t ack_num;           /**< lsb(16, 16383)                         [ 16 ] */
00709 #if WORDS_BIGENDIAN == 1
00710         uint8_t msn:4;              /**< lsb(4, 4)                              [ 4 ] */
00711         uint8_t seq_num_scaled:4;   /**< lsb(4, 7)                              [ 4 ] */
00712 #else
00713         uint8_t seq_num_scaled:4;
00714         uint8_t msn:4;
00715 #endif
00716         /* irregular chain                                                      [ VARIABLE ] */
00717 } __attribute__((packed)) rnd_6_t;
00718 
00719 
00720 /**
00721  * @brief The rnd_7 compressed packet format
00722  *
00723  * Send ACK and window
00724  * See RFC4996 page 82
00725  */
00726 typedef struct
00727 {
00728 #if WORDS_BIGENDIAN == 1
00729         uint8_t discriminator:6;    /**< '101111'                               [ 6 ] */
00730         uint8_t ack_num1:2;         /**< lsb(18, 65535)                         [ 18 ] */
00731         uint16_t ack_num2;          /**< sequel of \e ack_num1                  [ - ]*/
00732 #else
00733         uint8_t ack_num1:2;
00734         uint8_t discriminator:6;
00735         uint16_t ack_num2;
00736 #endif
00737         uint16_t window;            /**< irregular(16)                          [ 16 ] */
00738 #if WORDS_BIGENDIAN == 1
00739         uint8_t msn:4;              /**< lsb(4, 4)                              [ 4 ] */
00740         uint8_t psh_flag:1;         /**< irregular(1)                           [ 1 ] */
00741         uint8_t header_crc:3;       /**< crc3(THIS.UVALUE, THIS.ULENGTH)        [ 3 ] */
00742 #else
00743         uint8_t header_crc:3;
00744         uint8_t psh_flag:1;
00745         uint8_t msn:4;
00746 #endif
00747         /* irregular chain                                                      [ VARIABLE ] */
00748 } __attribute__((packed)) rnd_7_t;
00749 
00750 
00751 /**
00752  * @brief The rnd_8 compressed packet format
00753  *
00754  * Can send LSBs of TTL, RSF flags, change ECN behavior and options list
00755  * See RFC4996 page 82
00756  */
00757 typedef struct
00758 {
00759 #if WORDS_BIGENDIAN == 1
00760         uint8_t discriminator:5;    /**< '10110'                                [ 5 ] */
00761         uint8_t rsf_flags:2;        /**< rsf_index_enc                          [ 2 ] */
00762         uint8_t list_present:1;     /**< irregular(1)                           [ 1 ] */
00763         uint16_t header_crc:7;      /**< crc7(THIS.UVALUE, THIS.ULENGTH)        [ 7 ] */
00764         uint16_t msn1:1;            /**< lsb(4, 4)                              [ 4 ] */
00765         uint16_t msn2:3;            /**< sequel of \e msn1                      [ - ] */
00766         uint16_t psh_flag:1;        /**< irregular(1)                           [ 1 ] */
00767         uint16_t ttl_hopl:3;        /**< lsb(3, 3)                              [ 3 ] */
00768         uint16_t ecn_used:1;        /**< one_bit_choice                         [ 1 ] */
00769 #else
00770         uint8_t list_present:1;
00771         uint8_t rsf_flags:2;
00772         uint8_t discriminator:5;
00773         uint8_t msn1:1;
00774         uint8_t header_crc:7;
00775         uint8_t ecn_used:1;
00776         uint8_t ttl_hopl:3;
00777         uint8_t psh_flag:1;
00778         uint8_t msn2:3;
00779 #endif
00780         uint16_t seq_num;           /**< lsb(16, 65535)                         [ 16 ] */
00781         uint16_t ack_num;           /**< lsb(16, 16383)                         [ 16 ] */
00782         uint8_t options[0];         /**< tcp_list_presence_enc(list_present.CVALUE)
00783                                                                                 [ VARIABLE ] */
00784         /* irregular chain                                                      [ VARIABLE ] */
00785 } __attribute__((packed)) rnd_8_t;
00786 
00787 
00788 /**
00789  * @brief The seq_1 compressed packet format
00790  *
00791  * Send LSBs of sequence number
00792  * See RFC4996 page 83
00793  */
00794 typedef struct
00795 {
00796 #if WORDS_BIGENDIAN == 1
00797         uint8_t discriminator:4;    /**< '1010'                                 [ 4 ] */
00798         uint8_t ip_id:4;            /**< ip_id_lsb(ip_id_behavior.UVALUE, 4, 3) [ 4 ] */
00799 #else
00800         uint8_t ip_id:4;
00801         uint8_t discriminator:4;
00802 #endif
00803         uint16_t seq_num;           /**< lsb(16, 32767)                         [ 16 ] */
00804 #if WORDS_BIGENDIAN == 1
00805         uint8_t msn:4;              /**< lsb(4, 4)                              [ 4 ] */
00806         uint8_t psh_flag:1;         /**< irregular(1)                           [ 1 ] */
00807         uint8_t header_crc:3;       /**< crc3(THIS.UVALUE, THIS.ULENGTH)        [ 3 ] */
00808 #else
00809         uint8_t header_crc:3;
00810         uint8_t psh_flag:1;
00811         uint8_t msn:4;
00812 #endif
00813         /* irregular chain                                                      [ VARIABLE ] */
00814 } __attribute__((packed)) seq_1_t;
00815 
00816 
00817 /**
00818  * @brief The seq_2 compressed packet format
00819  *
00820  * Send scaled sequence number LSBs
00821  * See RFC4996 page 83
00822  */
00823 typedef struct
00824 {
00825 #if WORDS_BIGENDIAN == 1
00826         uint16_t discriminator:5;   /**< '11010'                                [ 5 ] */
00827         uint16_t ip_id1:3;          /**< ip_id_lsb(ip_id_behavior.UVALUE, 7, 3) [ 7 ] */
00828         uint16_t ip_id2:4;          /**< sequel of ip_id1                       [ - ] */
00829         uint16_t seq_num_scaled:4;  /**< lsb(4, 7)                              [ 4 ] */
00830         uint8_t msn:4;              /**< lsb(4, 4)                              [ 4 ] */
00831         uint8_t psh_flag:1;         /**< irregular(1)                           [ 1 ] */
00832         uint8_t header_crc:3;       /**< crc3(THIS.UVALUE, THIS.ULENGTH)        [ 3 ] */
00833 #else
00834         uint8_t ip_id1:3;
00835         uint8_t discriminator:5;
00836         uint8_t seq_num_scaled:4;
00837         uint8_t ip_id2:4;
00838         uint8_t header_crc:3;
00839         uint8_t psh_flag:1;
00840         uint8_t msn:4;
00841 #endif
00842         /* irregular chain                                                      [ VARIABLE ] */
00843 } __attribute__((packed)) seq_2_t;
00844 
00845 
00846 /**
00847  * @brief The seq_3 compressed packet format
00848  *
00849  * Send acknowledgment number LSBs
00850  * See RFC4996 page 83
00851  */
00852 typedef struct
00853 {
00854 #if WORDS_BIGENDIAN == 1
00855         uint8_t discriminator:4;    /**< '1001'                                 [  4 ] */
00856         uint8_t ip_id:4;            /**< ip_id_lsb(ip_id_behavior.UVALUE, 4, 3) [  4 ] */
00857 #else
00858         uint8_t ip_id:4;
00859         uint8_t discriminator:4;
00860 #endif
00861         uint16_t ack_num;           /**< lsb(16, 16383)                         [ 16 ] */
00862 #if WORDS_BIGENDIAN == 1
00863         uint8_t msn:4;              /**< lsb(4, 4)                              [  4 ] */
00864         uint8_t psh_flag:1;         /**< irregular(1)                           [  1 ] */
00865         uint8_t header_crc:3;       /**< crc3(THIS.UVALUE, THIS.ULENGTH)        [  3 ] */
00866 #else
00867         uint8_t header_crc:3;
00868         uint8_t psh_flag:1;
00869         uint8_t msn:4;
00870 #endif
00871         /* irregular chain                                                      [ VARIABLE ] */
00872 } __attribute__((packed)) seq_3_t;
00873 
00874 
00875 /**
00876  * @brief The seq_4 compressed packet format
00877  *
00878  * Send scaled acknowledgment number scaled
00879  * See RFC4996 page 84
00880  */
00881 typedef struct
00882 {
00883 #if WORDS_BIGENDIAN == 1
00884         uint8_t discriminator:1;    /**< '0'                                    [ 1 ] */
00885         uint8_t ack_num_scaled:4;   /**< lsb(4, 3)                              [ 4 ] */
00886         uint8_t ip_id:3;            /**< ip_id_lsb(ip_id_behavior.UVALUE, 3, 1) [ 3 ] */
00887         uint8_t msn:4;              /**< lsb(4, 4)                              [ 4 ] */
00888         uint8_t psh_flag:1;         /**< irregular(1)                           [ 1 ] */
00889         uint8_t header_crc:3;       /**< crc3(THIS.UVALUE, THIS.ULENGTH)        [ 3 ] */
00890 #else
00891         uint8_t ip_id:3;
00892         uint8_t ack_num_scaled:4;
00893         uint8_t discriminator:1;
00894         uint8_t header_crc:3;
00895         uint8_t psh_flag:1;
00896         uint8_t msn:4;
00897 #endif
00898         /* irregular chain                                                      [ VARIABLE ] */
00899 } __attribute__((packed)) seq_4_t;
00900 
00901 
00902 /**
00903  * @brief The seq_5 compressed packet format
00904  *
00905  * Send ACK and sequence number
00906  * See RFC4996 page 84
00907  */
00908 typedef struct
00909 {
00910 #if WORDS_BIGENDIAN == 1
00911         uint8_t discriminator:4;    /**< '1000'                                 [  4 ] */
00912         uint8_t ip_id:4;            /**< ip_id_lsb(ip_id_behavior.UVALUE, 4, 3) [  4 ] */
00913 #else
00914         uint8_t ip_id:4;
00915         uint8_t discriminator:4;
00916 #endif
00917         uint16_t ack_num;           /**< lsb(16, 16383)                         [ 16 ] */
00918         uint16_t seq_num;           /**< lsb(16, 32767)                         [ 16 ] */
00919 #if WORDS_BIGENDIAN == 1
00920         uint8_t msn:4;              /**< lsb(4, 4)                              [  4 ] */
00921         uint8_t psh_flag:1;         /**< irregular(1)                           [  1 ] */
00922         uint8_t header_crc:3;       /**< crc3(THIS.UVALUE, THIS.ULENGTH)        [  3 ] */
00923 #else
00924         uint8_t header_crc:3;
00925         uint8_t psh_flag:1;
00926         uint8_t msn:4;
00927 #endif
00928         /* irregular chain                                                      [ VARIABLE ] */
00929 } __attribute__((packed)) seq_5_t;
00930 
00931 
00932 /**
00933  * @brief The seq_6 compressed packet format
00934  *
00935  * Send both ACK and scaled sequence number LSBs
00936  * See RFC4996 page 84
00937  */
00938 typedef struct
00939 {
00940 #if WORDS_BIGENDIAN == 1
00941         uint16_t discriminator:5;   /**< '11011'                                [  5 ] */
00942         uint16_t seq_num_scaled1:3; /**< lsb(4, 7)                              [  4 ] */
00943         uint16_t seq_num_scaled2:1; /**< sequel of \e seq_num_scaled1           [  4 ] */
00944         uint16_t ip_id:7;           /**< ip_id_lsb(ip_id_behavior.UVALUE, 7, 3) [  7 ] */
00945 #else
00946         uint8_t seq_num_scaled1:3;
00947         uint8_t discriminator:5;
00948         uint8_t ip_id:7;
00949         uint8_t seq_num_scaled2:1;
00950 #endif
00951         uint16_t ack_num;           /**< lsb(16, 16383)                         [ 16 ] */
00952 #if WORDS_BIGENDIAN == 1
00953         uint8_t msn:4;              /**< lsb(4, 4)                              [ 4 ] */
00954         uint8_t psh_flag:1;         /**< irregular(1)                           [ 1 ] */
00955         uint8_t header_crc:3;       /**< crc3(THIS.UVALUE, THIS.ULENGTH)        [ 3 ] */
00956 #else
00957         uint8_t header_crc:3;
00958         uint8_t psh_flag:1;
00959         uint8_t msn:4;
00960 #endif
00961         /* irregular chain                                                      [ VARIABLE ] */
00962 } __attribute__((packed)) seq_6_t;
00963 
00964 
00965 /**
00966  * @brief The seq_7 compressed packet format
00967  *
00968  * Send ACK and window
00969  * See RFC4996 page 85
00970  */
00971 typedef struct
00972 {
00973 #if WORDS_BIGENDIAN == 1
00974         uint8_t discriminator:4;    /**< '1100'                                 [  4 ] */
00975         uint8_t window1:4;          /**< lsb(15, 16383)                         [ 15 ] */
00976         uint8_t window2;            /**< sequel of \e window1                   [  - ] */
00977         uint8_t window3:3;          /**< sequel of \e window1 and \e window2    [  - ] */
00978         uint8_t ip_id:5;            /**< ip_id_lsb(ip_id_behavior.UVALUE, 5, 3) [  5 ] */
00979         uint16_t ack_num;           /**< lsb(16, 32767)                         [ 16 ] */
00980         uint8_t msn:4;              /**< lsb(4, 4)                              [  4 ] */
00981         uint8_t psh_flag:1;         /**< irregular(1)                           [  1 ] */
00982         uint8_t header_crc:3;       /**< crc3(THIS.UVALUE, THIS.ULENGTH)        [  3 ] */
00983 #else
00984         uint8_t window1:4;
00985         uint8_t discriminator:4;
00986         uint8_t window2;
00987         uint8_t ip_id:5;
00988         uint8_t window3:3;
00989         uint16_t ack_num;
00990         uint8_t header_crc:3;
00991         uint8_t psh_flag:1;
00992         uint8_t msn:4;
00993 #endif
00994         /* irregular chain                                                      [ VARIABLE ] */
00995 } __attribute__((packed)) seq_7_t;
00996 
00997 
00998 /**
00999  * @brief The seq_8 compressed packet format
01000  *
01001  * Can send LSBs of TTL, RSF flags, change ECN behavior, and options list
01002  * See RFC4996 page 85
01003  */
01004 typedef struct
01005 {
01006 #if WORDS_BIGENDIAN == 1
01007         uint8_t discriminator:4;    /**< '1011'                                 [  4 ] */
01008         uint8_t ip_id:4;            /**< ip_id_lsb(ip_id_behavior.UVALUE, 4, 3) [  4 ] */
01009         uint8_t list_present:1;     /**< irregular(1)                           [  1 ] */
01010         uint8_t header_crc:7;       /**< crc7(THIS.UVALUE, THIS.ULENGTH)        [  7 ] */
01011         uint8_t msn:4;              /**< lsb(4, 4)                              [  4 ] */
01012         uint8_t psh_flag:1;         /**< irregular(1)                           [  1 ] */
01013         uint8_t ttl_hopl:3;         /**< lsb(3, 3)                              [  3 ] */
01014         uint8_t ecn_used:1;         /**< one_bit_choice                         [  1 ] */
01015         uint8_t ack_num1:7;         /**< lsb(15, 8191)                          [ 15 ] */
01016         uint8_t ack_num2;           /**< sequel of \e ack_num1                  [  - ] */
01017         uint8_t rsf_flags:2;        /**< rsf_index_enc                          [  2 ] */
01018         uint8_t seq_num1:6;         /**< lsb(14, 8191)                          [ 14 ] */
01019         uint8_t seq_num2;           /**< sequel of \e seq_num1                  [  - ] */
01020 #else
01021         uint8_t ip_id:4;
01022         uint8_t discriminator:4;
01023         uint8_t header_crc:7;
01024         uint8_t list_present:1;
01025         uint8_t ttl_hopl:3;
01026         uint8_t psh_flag:1;
01027         uint8_t msn:4;
01028         uint8_t ack_num1:7;
01029         uint8_t ecn_used:1;
01030         uint8_t ack_num2;
01031         uint8_t seq_num1:6;
01032         uint8_t rsf_flags:2;
01033         uint8_t seq_num2:8;
01034 #endif
01035         uint8_t options[0];       /**< tcp_list_presence_enc(list_present.CVALUE)
01036                                                                               [ VARIABLE ] */
01037         /* irregular chain                                                    [ VARIABLE ] */
01038 } __attribute__((packed)) seq_8_t;
01039 
01040 
01041 
01042 /************************************************************************
01043  * Helper functions                                                     *
01044  ************************************************************************/
01045 
01046 static inline char * tcp_ip_id_behavior_get_descr(const tcp_ip_id_behavior_t ip_id_behavior)
01047         __attribute__((warn_unused_result, const));
01048 
01049 static inline char * tcp_opt_get_descr(const uint8_t opt_type)
01050         __attribute__((warn_unused_result, const));
01051 
01052 
01053 /**
01054  * @brief Get a string that describes the given IP-ID behavior
01055  *
01056  * @param behavior  The type of the option to get a description for
01057  * @return          The description of the option
01058  */
01059 static inline char * tcp_ip_id_behavior_get_descr(const tcp_ip_id_behavior_t behavior)
01060 {
01061         switch(behavior)
01062         {
01063                 case IP_ID_BEHAVIOR_SEQ:
01064                         return "sequential";
01065                 case IP_ID_BEHAVIOR_SEQ_SWAP:
01066                         return "sequential swapped";
01067                 case IP_ID_BEHAVIOR_RAND:
01068                         return "random";
01069                 case IP_ID_BEHAVIOR_ZERO:
01070                         return "constant zero";
01071                 default:
01072                         return "unknown IP-ID behavior";
01073         }
01074 }
01075 
01076 
01077 /**
01078  * @brief Get a string that describes the given option type
01079  *
01080  * @param opt_type  The type of the option to get a description for
01081  * @return          The description of the option
01082  */
01083 static inline char * tcp_opt_get_descr(const uint8_t opt_type)
01084 {
01085         switch(opt_type)
01086         {
01087                 case TCP_OPT_EOL:
01088                         return "EOL";
01089                 case TCP_OPT_NOP:
01090                         return "NOP";
01091                 case TCP_OPT_MSS:
01092                         return "MSS";
01093                 case TCP_OPT_WS:
01094                         return "Window Scale";
01095                 case TCP_OPT_SACK_PERM:
01096                         return "SACK permitted";
01097                 case TCP_OPT_SACK:
01098                         return "SACK";
01099                 case TCP_OPT_TS:
01100                         return "Timestamp";
01101                 default:
01102                         return "generic";
01103         }
01104 }
01105 
01106 
01107 #endif /* ROHC_PROTOCOLS_TCP_H */
01108