The Tor Browser: netwerk/sctp/src/netinet/sctp_header.h@ac0c01689b40 (annotated)

netwerk/sctp/src/netinet/sctp_header.h@ac0c01689b40 (annotated)

netwerk/sctp/src/netinet/sctp_header.h

Thu, 15 Jan 2015 15:59:08 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 15 Jan 2015 15:59:08 +0100
branch: TOR_BUG_9701
changeset 10: ac0c01689b40
permissions: -rwxr-xr-x

Implement a real Private Browsing Mode condition by changing the API/ABI;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

 /*-
  * Copyright (c) 2001-2007, by Cisco Systems, Inc. All rights reserved.
  * Copyright (c) 2008-2012, by Randall Stewart. All rights reserved.
  * Copyright (c) 2008-2012, by Michael Tuexen. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  * a) Redistributions of source code must retain the above copyright notice,
  *    this list of conditions and the following disclaimer.
  *
  * b) Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in
  *    the documentation and/or other materials provided with the distribution.
  *
  * c) Neither the name of Cisco Systems, Inc. nor the names of its
  *    contributors may be used to endorse or promote products derived
  *    from this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  * THE POSSIBILITY OF SUCH DAMAGE.
  */
 #ifdef __FreeBSD__
 #include <sys/cdefs.h>
 __FBSDID("$FreeBSD: head/sys/netinet/sctp_header.h 240198 2012-09-07 13:36:42Z tuexen $");
 #endif
 #ifndef _NETINET_SCTP_HEADER_H_
 #define _NETINET_SCTP_HEADER_H_
 #if defined(__Windows__) && !defined(__Userspace_os_Windows)
 #include <packon.h>
 #endif
 #if !defined(__Userspace_os_Windows)
 #include <sys/time.h>
 #endif
 #include <netinet/sctp.h>
 #include <netinet/sctp_constants.h>
 #if !defined(__Userspace_os_Windows)
 #define SCTP_PACKED __attribute__((packed))
 #else
 #pragma pack (push, 1)
 #define SCTP_PACKED
 #endif
 /*
  * Parameter structures
  */
 struct sctp_ipv4addr_param {
 	struct sctp_paramhdr ph;/* type=SCTP_IPV4_PARAM_TYPE, len=8 */
 	uint32_t addr;		/* IPV4 address */
 } SCTP_PACKED;
 #define SCTP_V6_ADDR_BYTES 16
 struct sctp_ipv6addr_param {
 	struct sctp_paramhdr ph;/* type=SCTP_IPV6_PARAM_TYPE, len=20 */
 	uint8_t addr[SCTP_V6_ADDR_BYTES];	/* IPV6 address */
 } SCTP_PACKED;
 /* Cookie Preservative */
 struct sctp_cookie_perserve_param {
 	struct sctp_paramhdr ph;/* type=SCTP_COOKIE_PRESERVE, len=8 */
 	uint32_t time;		/* time in ms to extend cookie */
 } SCTP_PACKED;
 #define SCTP_ARRAY_MIN_LEN 1
 /* Host Name Address */
 struct sctp_host_name_param {
 	struct sctp_paramhdr ph;/* type=SCTP_HOSTNAME_ADDRESS */
 	char name[SCTP_ARRAY_MIN_LEN];		/* host name */
 } SCTP_PACKED;
 /*
  * This is the maximum padded size of a s-a-p
  * so paramheadr + 3 address types (6 bytes) + 2 byte pad = 12
  */
 #define SCTP_MAX_ADDR_PARAMS_SIZE 12
 /* supported address type */
 struct sctp_supported_addr_param {
 	struct sctp_paramhdr ph;/* type=SCTP_SUPPORTED_ADDRTYPE */
 	uint16_t addr_type[2];	/* array of supported address types */
 } SCTP_PACKED;
 /* ECN parameter */
 struct sctp_ecn_supported_param {
 	struct sctp_paramhdr ph;/* type=SCTP_ECN_CAPABLE */
 } SCTP_PACKED;
 /* heartbeat info parameter */
 struct sctp_heartbeat_info_param {
 	struct sctp_paramhdr ph;
 	uint32_t time_value_1;
 	uint32_t time_value_2;
 	uint32_t random_value1;
 	uint32_t random_value2;
 	uint8_t addr_family;
 	uint8_t addr_len;
 	/* make sure that this structure is 4 byte aligned */
 	uint8_t padding[2];
 	char address[SCTP_ADDRMAX];
 } SCTP_PACKED;
 /* draft-ietf-tsvwg-prsctp */
 /* PR-SCTP supported parameter */
 struct sctp_prsctp_supported_param {
 	struct sctp_paramhdr ph;
 } SCTP_PACKED;
 /* draft-ietf-tsvwg-addip-sctp */
 struct sctp_asconf_paramhdr {	/* an ASCONF "parameter" */
 	struct sctp_paramhdr ph;/* a SCTP parameter header */
 	uint32_t correlation_id;/* correlation id for this param */
 } SCTP_PACKED;
 struct sctp_asconf_addr_param {	/* an ASCONF address parameter */
 	struct sctp_asconf_paramhdr aph;	/* asconf "parameter" */
 	struct sctp_ipv6addr_param addrp;	/* max storage size */
 } SCTP_PACKED;
 struct sctp_asconf_tag_param {	/* an ASCONF NAT-Vtag parameter */
 	struct sctp_asconf_paramhdr aph;	/* asconf "parameter" */
         uint32_t local_vtag;
         uint32_t remote_vtag;
 } SCTP_PACKED;
 struct sctp_asconf_addrv4_param {	/* an ASCONF address (v4) parameter */
 	struct sctp_asconf_paramhdr aph;	/* asconf "parameter" */
 	struct sctp_ipv4addr_param addrp;	/* max storage size */
 } SCTP_PACKED;
 #define SCTP_MAX_SUPPORTED_EXT 256
 struct sctp_supported_chunk_types_param {
 	struct sctp_paramhdr ph;/* type = 0x8008  len = x */
 	uint8_t chunk_types[];
 } SCTP_PACKED;
 /*
  * Structures for DATA chunks
  */
 struct sctp_data {
 	uint32_t tsn;
 	uint16_t stream_id;
 	uint16_t stream_sequence;
 	uint32_t protocol_id;
 	/* user data follows */
 } SCTP_PACKED;
 struct sctp_data_chunk {
 	struct sctp_chunkhdr ch;
 	struct sctp_data dp;
 } SCTP_PACKED;
 /*
  * Structures for the control chunks
  */
 /* Initiate (INIT)/Initiate Ack (INIT ACK) */
 struct sctp_init {
 	uint32_t initiate_tag;	/* initiate tag */
 	uint32_t a_rwnd;	/* a_rwnd */
 	uint16_t num_outbound_streams;	/* OS */
 	uint16_t num_inbound_streams;	/* MIS */
 	uint32_t initial_tsn;	/* I-TSN */
 	/* optional param's follow */
 } SCTP_PACKED;
 #define SCTP_IDENTIFICATION_SIZE 16
 #define SCTP_ADDRESS_SIZE 4
 #if defined(__Userspace__)
 #define SCTP_RESERVE_SPACE 5
 #else
 #define SCTP_RESERVE_SPACE 6
 #endif
 /* state cookie header */
 struct sctp_state_cookie {	/* this is our definition... */
 	uint8_t identification[SCTP_IDENTIFICATION_SIZE];/* id of who we are */
 	struct timeval time_entered;	/* the time I built cookie */
 	uint32_t cookie_life;	/* life I will award this cookie */
 	uint32_t tie_tag_my_vtag;	/* my tag in old association */
 	uint32_t tie_tag_peer_vtag;	/* peers tag in old association */
 	uint32_t peers_vtag;	/* peers tag in INIT (for quick ref) */
 	uint32_t my_vtag;	/* my tag in INIT-ACK (for quick ref) */
 	uint32_t address[SCTP_ADDRESS_SIZE];	/* 4 ints/128 bits */
 	uint32_t addr_type;	/* address type */
 	uint32_t laddress[SCTP_ADDRESS_SIZE];	/* my local from address */
 	uint32_t laddr_type;	/* my local from address type */
 	uint32_t scope_id;	/* v6 scope id for link-locals */
 	uint16_t peerport;	/* port address of the peer in the INIT */
 	uint16_t myport;	/* my port address used in the INIT */
 	uint8_t ipv4_addr_legal;/* Are V4 addr legal? */
 	uint8_t ipv6_addr_legal;/* Are V6 addr legal? */
 #if defined(__Userspace__)
 	uint8_t conn_addr_legal;
 #endif
 	uint8_t local_scope;	/* IPv6 local scope flag */
 	uint8_t site_scope;	/* IPv6 site scope flag */
 	uint8_t ipv4_scope;	/* IPv4 private addr scope */
 	uint8_t loopback_scope;	/* loopback scope information */
 	uint8_t reserved[SCTP_RESERVE_SPACE];    /* Align to 64 bits */
 	/*
 	 * at the end is tacked on the INIT chunk and the INIT-ACK chunk
 	 * (minus the cookie).
 	 */
 } SCTP_PACKED;
 /* Used for NAT state error cause */
 struct sctp_missing_nat_state {
 	uint16_t cause;
 	uint16_t length;
         uint8_t data[];
 } SCTP_PACKED;
 struct sctp_inv_mandatory_param {
 	uint16_t cause;
 	uint16_t length;
 	uint32_t num_param;
 	uint16_t param;
 	/*
 	 * We include this to 0 it since only a missing cookie will cause
 	 * this error.
 	 */
 	uint16_t resv;
 } SCTP_PACKED;
 struct sctp_unresolv_addr {
 	uint16_t cause;
 	uint16_t length;
 	uint16_t addr_type;
 	uint16_t reserved;	/* Only one invalid addr type */
 } SCTP_PACKED;
 /* state cookie parameter */
 struct sctp_state_cookie_param {
 	struct sctp_paramhdr ph;
 	struct sctp_state_cookie cookie;
 } SCTP_PACKED;
 struct sctp_init_chunk {
 	struct sctp_chunkhdr ch;
 	struct sctp_init init;
 } SCTP_PACKED;
 struct sctp_init_msg {
 	struct sctphdr sh;
 	struct sctp_init_chunk msg;
 } SCTP_PACKED;
 /* ... used for both INIT and INIT ACK */
 #define sctp_init_ack		sctp_init
 #define sctp_init_ack_chunk	sctp_init_chunk
 #define sctp_init_ack_msg	sctp_init_msg
 /* Selective Ack (SACK) */
 struct sctp_gap_ack_block {
 	uint16_t start;		/* Gap Ack block start */
 	uint16_t end;		/* Gap Ack block end */
 } SCTP_PACKED;
 struct sctp_sack {
 	uint32_t cum_tsn_ack;	/* cumulative TSN Ack */
 	uint32_t a_rwnd;	/* updated a_rwnd of sender */
 	uint16_t num_gap_ack_blks;	/* number of Gap Ack blocks */
 	uint16_t num_dup_tsns;	/* number of duplicate TSNs */
 	/* struct sctp_gap_ack_block's follow */
 	/* uint32_t duplicate_tsn's follow */
 } SCTP_PACKED;
 struct sctp_sack_chunk {
 	struct sctp_chunkhdr ch;
 	struct sctp_sack sack;
 } SCTP_PACKED;
 struct sctp_nr_sack {
 	uint32_t cum_tsn_ack;	/* cumulative TSN Ack */
 	uint32_t a_rwnd;	/* updated a_rwnd of sender */
 	uint16_t num_gap_ack_blks;	/* number of Gap Ack blocks */
 	uint16_t num_nr_gap_ack_blks;	/* number of NR Gap Ack blocks */
 	uint16_t num_dup_tsns;	/* number of duplicate TSNs */
 	uint16_t reserved;	/* not currently used*/
 	/* struct sctp_gap_ack_block's follow */
 	/* uint32_t duplicate_tsn's follow */
 } SCTP_PACKED;
 struct sctp_nr_sack_chunk {
 	struct sctp_chunkhdr ch;
 	struct sctp_nr_sack nr_sack;
 } SCTP_PACKED;
 /* Heartbeat Request (HEARTBEAT) */
 struct sctp_heartbeat {
 	struct sctp_heartbeat_info_param hb_info;
 } SCTP_PACKED;
 struct sctp_heartbeat_chunk {
 	struct sctp_chunkhdr ch;
 	struct sctp_heartbeat heartbeat;
 } SCTP_PACKED;
 /* ... used for Heartbeat Ack (HEARTBEAT ACK) */
 #define sctp_heartbeat_ack		sctp_heartbeat
 #define sctp_heartbeat_ack_chunk	sctp_heartbeat_chunk
 /* Abort Asssociation (ABORT) */
 struct sctp_abort_chunk {
 	struct sctp_chunkhdr ch;
 	/* optional error cause may follow */
 } SCTP_PACKED;
 struct sctp_abort_msg {
 	struct sctphdr sh;
 	struct sctp_abort_chunk msg;
 } SCTP_PACKED;
 /* Shutdown Association (SHUTDOWN) */
 struct sctp_shutdown_chunk {
 	struct sctp_chunkhdr ch;
 	uint32_t cumulative_tsn_ack;
 } SCTP_PACKED;
 /* Shutdown Acknowledgment (SHUTDOWN ACK) */
 struct sctp_shutdown_ack_chunk {
 	struct sctp_chunkhdr ch;
 } SCTP_PACKED;
 /* Operation Error (ERROR) */
 struct sctp_error_chunk {
 	struct sctp_chunkhdr ch;
 	/* optional error causes follow */
 } SCTP_PACKED;
 /* Cookie Echo (COOKIE ECHO) */
 struct sctp_cookie_echo_chunk {
 	struct sctp_chunkhdr ch;
 	struct sctp_state_cookie cookie;
 } SCTP_PACKED;
 /* Cookie Acknowledgment (COOKIE ACK) */
 struct sctp_cookie_ack_chunk {
 	struct sctp_chunkhdr ch;
 } SCTP_PACKED;
 /* Explicit Congestion Notification Echo (ECNE) */
 struct old_sctp_ecne_chunk {
 	struct sctp_chunkhdr ch;
 	uint32_t tsn;
 } SCTP_PACKED;
 struct sctp_ecne_chunk {
 	struct sctp_chunkhdr ch;
 	uint32_t tsn;
 	uint32_t num_pkts_since_cwr;
 } SCTP_PACKED;
 /* Congestion Window Reduced (CWR) */
 struct sctp_cwr_chunk {
 	struct sctp_chunkhdr ch;
 	uint32_t tsn;
 } SCTP_PACKED;
 /* Shutdown Complete (SHUTDOWN COMPLETE) */
 struct sctp_shutdown_complete_chunk {
 	struct sctp_chunkhdr ch;
 } SCTP_PACKED;
 /* Oper error holding a stale cookie */
 struct sctp_stale_cookie_msg {
 	struct sctp_paramhdr ph;/* really an error cause */
 	uint32_t time_usec;
 } SCTP_PACKED;
 struct sctp_adaptation_layer_indication {
 	struct sctp_paramhdr ph;
 	uint32_t indication;
 } SCTP_PACKED;
 struct sctp_cookie_while_shutting_down {
 	struct sctphdr sh;
 	struct sctp_chunkhdr ch;
 	struct sctp_paramhdr ph;/* really an error cause */
 } SCTP_PACKED;
 struct sctp_shutdown_complete_msg {
 	struct sctphdr sh;
 	struct sctp_shutdown_complete_chunk shut_cmp;
 } SCTP_PACKED;
 /*
  * draft-ietf-tsvwg-addip-sctp
  */
 /* Address/Stream Configuration Change (ASCONF) */
 struct sctp_asconf_chunk {
 	struct sctp_chunkhdr ch;
 	uint32_t serial_number;
 	/* lookup address parameter (mandatory) */
 	/* asconf parameters follow */
 } SCTP_PACKED;
 /* Address/Stream Configuration Acknowledge (ASCONF ACK) */
 struct sctp_asconf_ack_chunk {
 	struct sctp_chunkhdr ch;
 	uint32_t serial_number;
 	/* asconf parameters follow */
 } SCTP_PACKED;
 /* draft-ietf-tsvwg-prsctp */
 /* Forward Cumulative TSN (FORWARD TSN) */
 struct sctp_forward_tsn_chunk {
 	struct sctp_chunkhdr ch;
 	uint32_t new_cumulative_tsn;
 	/* stream/sequence pairs (sctp_strseq) follow */
 } SCTP_PACKED;
 struct sctp_strseq {
 	uint16_t stream;
 	uint16_t sequence;
 } SCTP_PACKED;
 struct sctp_forward_tsn_msg {
 	struct sctphdr sh;
 	struct sctp_forward_tsn_chunk msg;
 } SCTP_PACKED;
 /* should be a multiple of 4 - 1 aka 3/7/11 etc. */
 #define SCTP_NUM_DB_TO_VERIFY 31
 struct sctp_chunk_desc {
 	uint8_t chunk_type;
 	uint8_t data_bytes[SCTP_NUM_DB_TO_VERIFY];
 	uint32_t tsn_ifany;
 } SCTP_PACKED;
 struct sctp_pktdrop_chunk {
 	struct sctp_chunkhdr ch;
 	uint32_t bottle_bw;
 	uint32_t current_onq;
 	uint16_t trunc_len;
 	uint16_t reserved;
 	uint8_t data[];
 } SCTP_PACKED;
 /**********STREAM RESET STUFF ******************/
 struct sctp_stream_reset_out_request {
 	struct sctp_paramhdr ph;
 	uint32_t request_seq;	/* monotonically increasing seq no */
 	uint32_t response_seq;	/* if a response, the resp seq no */
 	uint32_t send_reset_at_tsn;	/* last TSN I assigned outbound */
 	uint16_t list_of_streams[];	/* if not all list of streams */
 } SCTP_PACKED;
 struct sctp_stream_reset_in_request {
 	struct sctp_paramhdr ph;
 	uint32_t request_seq;
 	uint16_t list_of_streams[];	/* if not all list of streams */
 } SCTP_PACKED;
 struct sctp_stream_reset_tsn_request {
 	struct sctp_paramhdr ph;
 	uint32_t request_seq;
 } SCTP_PACKED;
 struct sctp_stream_reset_response {
 	struct sctp_paramhdr ph;
 	uint32_t response_seq;	/* if a response, the resp seq no */
 	uint32_t result;
 } SCTP_PACKED;
 struct sctp_stream_reset_response_tsn {
 	struct sctp_paramhdr ph;
 	uint32_t response_seq;	/* if a response, the resp seq no */
 	uint32_t result;
 	uint32_t senders_next_tsn;
 	uint32_t receivers_next_tsn;
 } SCTP_PACKED;
 struct sctp_stream_reset_add_strm {
   struct sctp_paramhdr ph;
   uint32_t request_seq;
   uint16_t number_of_streams;
   uint16_t reserved;
 } SCTP_PACKED;
 #define SCTP_STREAM_RESET_RESULT_NOTHING_TO_DO   0x00000000 /* XXX: unused */
 #define SCTP_STREAM_RESET_RESULT_PERFORMED       0x00000001
 #define SCTP_STREAM_RESET_RESULT_DENIED          0x00000002
 #define SCTP_STREAM_RESET_RESULT_ERR__WRONG_SSN  0x00000003 /* XXX: unused */
 #define SCTP_STREAM_RESET_RESULT_ERR_IN_PROGRESS 0x00000004
 #define SCTP_STREAM_RESET_RESULT_ERR_BAD_SEQNO   0x00000005
 #define SCTP_STREAM_RESET_RESULT_IN_PROGRESS     0x00000006 /* XXX: unused */
 /*
  * convience structures, note that if you are making a request for specific
  * streams then the request will need to be an overlay structure.
  */
 struct sctp_stream_reset_tsn_req {
 	struct sctp_chunkhdr ch;
 	struct sctp_stream_reset_tsn_request sr_req;
 } SCTP_PACKED;
 struct sctp_stream_reset_resp {
 	struct sctp_chunkhdr ch;
 	struct sctp_stream_reset_response sr_resp;
 } SCTP_PACKED;
 /* respone only valid with a TSN request */
 struct sctp_stream_reset_resp_tsn {
 	struct sctp_chunkhdr ch;
 	struct sctp_stream_reset_response_tsn sr_resp;
 } SCTP_PACKED;
 /****************************************************/
 /*
  * Authenticated chunks support draft-ietf-tsvwg-sctp-auth
  */
 /* Should we make the max be 32? */
 #define SCTP_RANDOM_MAX_SIZE 256
 struct sctp_auth_random {
 	struct sctp_paramhdr ph;/* type = 0x8002 */
 	uint8_t random_data[];
 } SCTP_PACKED;
 struct sctp_auth_chunk_list {
 	struct sctp_paramhdr ph;/* type = 0x8003 */
 	uint8_t chunk_types[];
 } SCTP_PACKED;
 struct sctp_auth_hmac_algo {
 	struct sctp_paramhdr ph;/* type = 0x8004 */
 	uint16_t hmac_ids[];
 } SCTP_PACKED;
 struct sctp_auth_chunk {
 	struct sctp_chunkhdr ch;
 	uint16_t shared_key_id;
 	uint16_t hmac_id;
 	uint8_t hmac[];
 } SCTP_PACKED;
 struct sctp_auth_invalid_hmac {
 	struct sctp_paramhdr ph;
 	uint16_t hmac_id;
 	uint16_t padding;
 } SCTP_PACKED;
 /*
  * we pre-reserve enough room for a ECNE or CWR AND a SACK with no missing
  * pieces. If ENCE is missing we could have a couple of blocks. This way we
  * optimize so we MOST likely can bundle a SACK/ECN with the smallest size
  * data chunk I will split into. We could increase throughput slightly by
  * taking out these two but the  24-sack/8-CWR i.e. 32 bytes I pre-reserve I
  * feel is worth it for now.
  */
 #ifndef SCTP_MAX_OVERHEAD
 #ifdef INET6
 #define SCTP_MAX_OVERHEAD (sizeof(struct sctp_data_chunk) + \
 			   sizeof(struct sctphdr) + \
 			   sizeof(struct sctp_ecne_chunk) + \
 			   sizeof(struct sctp_sack_chunk) + \
 			   sizeof(struct ip6_hdr))
 #define SCTP_MED_OVERHEAD (sizeof(struct sctp_data_chunk) + \
 			   sizeof(struct sctphdr) + \
 			   sizeof(struct ip6_hdr))
 #define SCTP_MIN_OVERHEAD (sizeof(struct ip6_hdr) + \
 			   sizeof(struct sctphdr))
 #else
 #define SCTP_MAX_OVERHEAD (sizeof(struct sctp_data_chunk) + \
 			   sizeof(struct sctphdr) + \
 			   sizeof(struct sctp_ecne_chunk) + \
 			   sizeof(struct sctp_sack_chunk) + \
 			   sizeof(struct ip))
 #define SCTP_MED_OVERHEAD (sizeof(struct sctp_data_chunk) + \
 			   sizeof(struct sctphdr) + \
 			   sizeof(struct ip))
 #define SCTP_MIN_OVERHEAD (sizeof(struct ip) + \
 			   sizeof(struct sctphdr))
 #endif /* INET6 */
 #endif /* !SCTP_MAX_OVERHEAD */
 #define SCTP_MED_V4_OVERHEAD (sizeof(struct sctp_data_chunk) + \
 			      sizeof(struct sctphdr) + \
 			      sizeof(struct ip))
 #define SCTP_MIN_V4_OVERHEAD (sizeof(struct ip) + \
 			      sizeof(struct sctphdr))
 #if defined(__Windows__)
 #include <packoff.h>
 #endif
 #if defined(__Userspace_os_Windows)
 #pragma pack ()
 #endif
 #undef SCTP_PACKED
 #endif				/* !__sctp_header_h__ */

The Tor Browser / annotate

netwerk/sctp/src/netinet/sctp_header.h@ac0c01689b40 (annotated)

netwerk/sctp/src/netinet/sctp_header.h