Generic framework for RFC3095-based compression profiles such as IP-only, UDP, UDP-Lite, ESP, and RTP profiles. More...

#include "rohc_comp_rfc3095.h"
#include "c_rtp.h"
#include "rohc_traces.h"
#include "rohc_traces_internal.h"
#include "rohc_debug.h"
#include "rohc_packets.h"
#include "rohc_utils.h"
#include "rohc_bit_ops.h"
#include "schemes/cid.h"
#include "schemes/ip_id_offset.h"
#include "schemes/comp_list_ipv6.h"
#include "sdvl.h"
#include "crc.h"
#include <stdint.h>
#include <string.h>
#include <assert.h>
#include "config.h"

Include dependency graph for rohc_comp_rfc3095.c:

Macros
#define	MOD_TOS 0x0001

#define	MOD_TTL 0x0010

#define	MOD_PROTOCOL 0x0020

#define	MOD_IPV6_EXT_LIST_STRUCT 0x0002

#define	MOD_IPV6_EXT_LIST_CONTENT 0x0004

#define	MOD_ERROR 0x0008

Functions
static void	ip_header_info_new (struct ip_header_info const header_info, const struct ip_packet const ip, const size_t list_trans_nr, const size_t wlsb_window_width, rohc_trace_callback2_t trace_cb, void *const trace_cb_priv, const int profile_id)
	Initialize the IP header info stored in the context. More...

static void	ip_header_info_free (struct ip_header_info *const header_info)
	Reset the given IP header info. More...

static void	c_init_tmp_variables (struct generic_tmp_vars *const tmp_vars)
	Initialize all temporary variables stored in the context. More...

static rohc_packet_t	decide_packet (struct rohc_comp_ctxt *const context)
	Decide which packet to send when in the different states. More...

static rohc_ext_t	decide_extension_uor2 (const struct rohc_comp_ctxt *const context, const size_t nr_innermost_ip_id_bits, const size_t nr_outermost_ip_id_bits)
	Decide what extension shall be used in the UOR-2 packet (non-RTP). More...

static rohc_ext_t	decide_extension_uor2rtp (const struct rohc_comp_ctxt *const context, const size_t nr_innermost_ip_id_bits, const size_t nr_outermost_ip_id_bits)
	Decide what extension shall be used in the UOR-2 packet (RTP). More...

static rohc_ext_t	decide_extension_uor2ts (const struct rohc_comp_ctxt *const context, const size_t nr_innermost_ip_id_bits, const size_t nr_outermost_ip_id_bits)
	Decide what extension shall be used in the UO-1-ID/UOR-2 packet. More...

static rohc_ext_t	decide_extension_uor2id (const struct rohc_comp_ctxt *const context, const size_t nr_innermost_ip_id_bits, const size_t nr_outermost_ip_id_bits)
	Decide what extension shall be used in the UOR-2-ID packet. More...

static rohc_ext_t	decide_extension_uo1id (const struct rohc_comp_ctxt *const context, const size_t nr_innermost_ip_id_bits, const size_t nr_outermost_ip_id_bits)
	Decide what extension shall be used in the UO-1-ID packet. More...

static int	code_packet (struct rohc_comp_ctxt const context, const struct net_pkt const uncomp_pkt, uint8_t *const rohc_pkt, const size_t rohc_pkt_max_len)
	Build the ROHC packet to send. More...

static int	code_IR_packet (struct rohc_comp_ctxt const context, const struct net_pkt const uncomp_pkt, uint8_t *const rohc_pkt, const size_t rohc_pkt_max_len)
	Build the IR packet. More...

static int	code_IR_DYN_packet (struct rohc_comp_ctxt const context, const struct net_pkt const uncomp_pkt, uint8_t *const rohc_pkt, const size_t rohc_pkt_max_len)
	Build the IR-DYN packet. More...

static int	rohc_code_static_part (const struct rohc_comp_ctxt const context, const struct net_pkt const uncomp_pkt, uint8_t *const rohc_pkt, int counter)
	Build the static part of the IR packet. More...

static int	rohc_code_static_ip_part (const struct rohc_comp_ctxt const context, struct ip_header_info const header_info, const struct ip_packet const ip, uint8_t const dest, int counter)
	Build the static part of one IP header for the IR packet. More...

static int	code_ipv4_static_part (const struct rohc_comp_ctxt const context, struct ip_header_info const header_info, const struct ip_packet const ip, uint8_t const dest, int counter)
	Build the IPv4 static part of the IR packet. More...

static int	code_ipv6_static_part (const struct rohc_comp_ctxt const context, struct ip_header_info const header_info, const struct ip_packet const ip, uint8_t const dest, int counter)
	Build the IPv6 static part of the IR packet. More...

static int	rohc_code_dynamic_part (const struct rohc_comp_ctxt const context, const struct net_pkt const uncomp_pkt, uint8_t *const rohc_pkt, int counter)
	Build the dynamic part of the IR and IR-DYN packets. More...

static int	rohc_code_dynamic_ip_part (const struct rohc_comp_ctxt const context, const unsigned int hdr_pos, struct ip_header_info const header_info, const struct ip_packet const ip, uint8_t const dest, int counter)
	Build the dynamic part of one IP header for the IR/IR-DYN packets. More...

static int	code_ipv4_dynamic_part (const struct rohc_comp_ctxt const context, struct ip_header_info const header_info, const struct ip_packet const ip, uint8_t const dest, int counter)
	Build the IPv4 dynamic part of the IR and IR-DYN packets. More...

static int	code_ipv6_dynamic_part (const struct rohc_comp_ctxt const context, const unsigned int hdr_pos, struct ip_header_info const header_info, const struct ip_packet const ip, uint8_t const dest, int counter)
	Build the IPv6 dynamic part of the IR and IR-DYN packets. More...

static int	code_uo_remainder (struct rohc_comp_ctxt const context, const struct net_pkt const uncomp_pkt, uint8_t *const dest, int counter)
	Build the tail of the UO packet. More...

static int	code_UO0_packet (struct rohc_comp_ctxt const context, const struct net_pkt const uncomp_pkt, uint8_t *const rohc_pkt, const size_t rohc_pkt_max_len)
	Build the UO-0 packet. More...

static int	rohc_comp_rfc3095_build_uo1_pkt (struct rohc_comp_ctxt const context, const struct net_pkt const uncomp_pkt, uint8_t *const rohc_pkt, const size_t rohc_pkt_max_len)
	Build the UO-1 packet for the non-RTP profiles. More...

static int	rohc_comp_rfc3095_build_uo1rtp_pkt (struct rohc_comp_ctxt const context, const struct net_pkt const uncomp_pkt, uint8_t *const rohc_pkt, const size_t rohc_pkt_max_len)
	Build the UO-1 packet for the RTP profiles. More...

static int	rohc_comp_rfc3095_build_uo1ts_pkt (struct rohc_comp_ctxt const context, const struct net_pkt const uncomp_pkt, uint8_t *const rohc_pkt, const size_t rohc_pkt_max_len)
	Build the UO-1-TS packet. More...

static int	rohc_comp_rfc3095_build_uo1id_pkt (struct rohc_comp_ctxt const context, const struct net_pkt const uncomp_pkt, uint8_t *const rohc_pkt, const size_t rohc_pkt_max_len)
	Build the UO-1-ID packet. More...

static int	code_UO2_packet (struct rohc_comp_ctxt const context, const struct net_pkt const uncomp_pkt, uint8_t *const rohc_pkt, const size_t rohc_pkt_max_len)
	Build the UO-2 packet. More...

static int	code_UOR2_bytes (const struct rohc_comp_ctxt const context, const rohc_ext_t extension, uint8_t const f_byte, uint8_t const s_byte, uint8_t const t_byte)
	Code some fields of the UOR-2 packet. More...

static int	code_UOR2_RTP_bytes (const struct rohc_comp_ctxt const context, const rohc_ext_t extension, uint8_t const f_byte, uint8_t const s_byte, uint8_t const t_byte)
	Code some fields of the UOR-2-RTP packet. More...

static int	code_UOR2_TS_bytes (const struct rohc_comp_ctxt const context, const rohc_ext_t extension, uint8_t const f_byte, uint8_t const s_byte, uint8_t const t_byte)
	Code some fields of the UOR-2-TS packet. More...

static int	code_UOR2_ID_bytes (const struct rohc_comp_ctxt const context, const rohc_ext_t extension, uint8_t const f_byte, uint8_t const s_byte, uint8_t const t_byte)
	Code some fields of the UOR-2-ID packet. More...

static int	code_EXT0_packet (const struct rohc_comp_ctxt const context, uint8_t const dest, int counter)
	Build the extension 0 of the UO-2 packet. More...

static int	code_EXT1_packet (const struct rohc_comp_ctxt const context, uint8_t const dest, int counter)
	Build the extension 1 of the UO-2 packet. More...

static int	code_EXT2_packet (const struct rohc_comp_ctxt const context, uint8_t const dest, int counter)
	Build the extension 2 of the UO-2 packet. More...

static int	code_EXT3_packet (struct rohc_comp_ctxt const context, const struct net_pkt const uncomp_pkt, uint8_t *const dest, int counter)
	Build the extension 3 of the UO* packet types. More...

static int	code_EXT3_rtp_packet (struct rohc_comp_ctxt const context, const struct net_pkt const uncomp_pkt, uint8_t *const dest, int counter)
	Build the extension 3 of the UO-2 packet. More...

static int	code_EXT3_nortp_packet (struct rohc_comp_ctxt const context, const struct net_pkt const uncomp_pkt, uint8_t *const dest, int counter)
	Build the extension 3 of the UO-2 packet. More...

static int	rtp_header_flags_and_fields (const struct rohc_comp_ctxt const context, const struct ip_packet const ip, uint8_t *const dest, int counter)

static int	header_flags (const struct rohc_comp_ctxt const context, struct ip_header_info const header_info, const unsigned short changed_f, const struct ip_packet const ip, const int ip2_or_I2, uint8_t const dest, int counter)
	Build inner or outer IP header flags. More...

static int	header_fields (const struct rohc_comp_ctxt const context, struct ip_header_info const header_info, const unsigned short changed_f, const struct ip_packet const ip, const int I, const ip_header_pos_t ip_hdr_pos, uint8_t const dest, int counter)
	Build inner or outer IP header fields. More...

static uint8_t	compute_uo_crc (struct rohc_comp_ctxt const context, const struct net_pkt const uncomp_pkt, const rohc_crc_type_t crc_type, const uint8_t crc_init, const uint8_t *const crc_table)
	Compute the CRC for a UO* packet. More...

static void	update_context (struct rohc_comp_ctxt const context, const struct net_pkt const uncomp_pkt)
	Update the compression context with the successfully compressed packet. More...

static void	update_context_ip_hdr (struct ip_header_info const ip_flags, const struct ip_packet const ip)
	Update the IP information with the IP header. More...

static bool	rohc_comp_rfc3095_detect_changes (struct rohc_comp_ctxt const context, const struct net_pkt const uncomp_pkt)
	Detect changes between packet and context. More...

static int	changed_static_both_hdr (struct rohc_comp_ctxt const context, const struct net_pkt const uncomp_pkt)
	Check if the static parts of the context changed in any of the two IP headers. More...

static int	changed_static_one_hdr (struct rohc_comp_ctxt const context, const unsigned short changed_fields, struct ip_header_info const header_info)
	Check if the static part of the context changed in the new IP packet. More...

static int	changed_dynamic_both_hdr (struct rohc_comp_ctxt const context, const struct net_pkt const uncomp_pkt)
	Check if the dynamic parts of the context changed in any of the two IP headers. More...

static int	changed_dynamic_one_hdr (struct rohc_comp_ctxt const context, const unsigned short changed_fields, struct ip_header_info const header_info, const struct ip_packet *const ip)
	Check if the dynamic part of the context changed in the IP packet. More...

static unsigned short	detect_changed_fields (const struct rohc_comp_ctxt const context, struct ip_header_info const header_info, const struct ip_packet *const ip)
	Find the IP fields that changed between the profile and a new IP packet. More...

static bool	is_field_changed (const unsigned short changed_fields, const unsigned short check_field)
	Check if a specified IP field has changed. More...

static void	detect_ip_id_behaviours (struct rohc_comp_ctxt const context, const struct net_pkt const uncomp_pkt)
	Detect the behaviour of the IP-ID fields of the IPv4 headers. More...

static void	detect_ip_id_behaviour (const struct rohc_comp_ctxt const context, struct ip_header_info const header_info, const struct ip_packet *const ip)
	Detect the behaviour of the IP-ID field of the given IPv4 header. More...

static bool	encode_uncomp_fields (struct rohc_comp_ctxt const context, const struct net_pkt const uncomp_pkt)
	Encode uncompressed fields with the corresponding encoding scheme. More...

static void	rohc_get_innermost_ipv4_non_rnd (const struct rohc_comp_ctxt const context, ip_header_pos_t const pos, size_t const nr_bits, uint16_t const offset)
	Determine the number of IP-ID bits and the IP-ID offset of the innermost IPv4 header with non-random IP-ID. More...

static void	rohc_comp_rfc3095_get_ext3_I_flags (const struct rohc_comp_ctxt const context, const struct net_pkt const uncomp_pkt, const rohc_packet_t packet_type, const size_t nr_ip_id_bits, const size_t nr_ip_id_bits2, ip_header_pos_t const innermost_ipv4_non_rnd, uint8_t const I, uint8_t *const I2)
	Determine the values of the I and I2 flags for UO* extension 3. More...

static bool	rohc_comp_rfc3095_feedback_2 (struct rohc_comp_ctxt const context, const uint8_t const packet, const size_t packet_len, const uint8_t *const feedback_data, const size_t feedback_data_len)
	Update the profile when FEEDBACK-2 is received. More...

static void	rohc_comp_rfc3095_feedback_ack (struct rohc_comp_ctxt *const context, const uint32_t sn_bits, const size_t sn_bits_nr, const bool sn_not_valid)
	Perform the required actions after the reception of a positive ACK. More...

bool	rohc_comp_rfc3095_create (struct rohc_comp_ctxt const context, const size_t sn_bits_nr, const rohc_lsb_shift_t sn_shift, const struct net_pkt const packet)
	Create a new context and initialize it thanks to the given IP packet. More...

void	rohc_comp_rfc3095_destroy (struct rohc_comp_ctxt *const context)
	Destroy the context. More...

bool	rohc_comp_rfc3095_check_profile (const struct rohc_comp const comp, const struct net_pkt const packet)
	Check if the given packet corresponds to an IP-based profile. More...

int	rohc_comp_rfc3095_encode (struct rohc_comp_ctxt const context, const struct net_pkt const uncomp_pkt, uint8_t const rohc_pkt, const size_t rohc_pkt_max_len, rohc_packet_t const packet_type, size_t *const payload_offset)
	Encode an IP packet according to a pattern decided by several different factors. More...

bool	rohc_comp_rfc3095_feedback (struct rohc_comp_ctxt const context, const enum rohc_feedback_type feedback_type, const uint8_t const packet, const size_t packet_len, const uint8_t *const feedback_data, const size_t feedback_data_len)
	Update the profile when feedback is received. More...

void	rohc_comp_rfc3095_decide_state (struct rohc_comp_ctxt *const context)
	Decide the state that should be used for the next packet. More...

rohc_ext_t	decide_extension (const struct rohc_comp_ctxt *const context)
	Decide what extension shall be used in the UO-1-ID/UOR-2 packet. More...

void	rohc_get_ipid_bits (const struct rohc_comp_ctxt const context, size_t const nr_innermost_bits, size_t *const nr_outermost_bits)
	Get the number of non-random outer/inner IP-ID bits. More...

bool	rohc_comp_rfc3095_is_sn_possible (const struct rohc_comp_rfc3095_ctxt *const rfc3095_ctxt, const size_t bits_nr, const size_t add_bits_nr)
	Are the given SN field sizes possible? More...

Detailed Description

Generic framework for RFC3095-based compression profiles such as IP-only, UDP, UDP-Lite, ESP, and RTP profiles.

Author: Didier Barvaux didie.nosp@m.r.ba.nosp@m.rvaux.nosp@m.@tou.nosp@m.louse.nosp@m..viv.nosp@m.eris..nosp@m.com; Didier Barvaux didie.nosp@m.r@ba.nosp@m.rvaux.nosp@m..org; David Moreau from TAS; Emmanuelle Pechereau epech.nosp@m.erea.nosp@m.u@tou.nosp@m.lous.nosp@m.e.viv.nosp@m.eris.nosp@m..com

Macro Definition Documentation

◆ MOD_ERROR

#define MOD_ERROR 0x0008

A flag to indicate that an errror occurred

◆ MOD_IPV6_EXT_LIST_CONTENT

#define MOD_IPV6_EXT_LIST_CONTENT 0x0004

A flag to indicate that the content of the IPv6 extension headers list changed in IP header

◆ MOD_IPV6_EXT_LIST_STRUCT

#define MOD_IPV6_EXT_LIST_STRUCT 0x0002

A flag to indicate that the structure of the IPv6 extension headers list changed in IP header

◆ MOD_PROTOCOL

#define MOD_PROTOCOL 0x0020

A flag to indicate that the IPv4 Protocol field changed in IP header

◆ MOD_TOS

#define MOD_TOS 0x0001

A flag to indicate that IPv4 Type Of Service field changed in IP header

◆ MOD_TTL

#define MOD_TTL 0x0010

A flag to indicate that IPv4 Time To Live field changed in IP header

Function Documentation

◆ c_init_tmp_variables()

static void c_init_tmp_variables ( struct generic_tmp_vars *const tmp_vars )

static

Initialize all temporary variables stored in the context.

Parameters

tmp_vars The temporary variables to initialize

◆ changed_dynamic_both_hdr()

static int changed_dynamic_both_hdr	(	struct rohc_comp_ctxt *const	context,
		const struct net_pkt *const	uncomp_pkt
	)

static

Check if the dynamic parts of the context changed in any of the two IP headers.

Parameters

context	The compression context
uncomp_pkt	The uncompressed packet

Returns: The number of dynamic fields that changed

◆ changed_dynamic_one_hdr()

static int changed_dynamic_one_hdr	(	struct rohc_comp_ctxt *const	context,
		const unsigned short	changed_fields,
		struct ip_header_info *const	header_info,
		const struct ip_packet *const	ip
	)

static

Check if the dynamic part of the context changed in the IP packet.

The fields classified as CHANGING by RFC need to be checked for change. The fields are:

the TOS, IP-ID and TTL fields for IPv4,
the TC and HL fields for IPv6.

The IP-ID changes are managed outside of this function.

Although classified as STATIC, the IPv4 Don't Fragment flag is not part of the static initialization, but of the dynamic initialization. It needs to be checked for change.

Other flags are checked for change for IPv4. There are IP-ID related flags:

RND: is the IP-ID random?
NBO: is the IP-ID in Network Byte Order?
SID: is the IP-ID static?

Parameters

context	The compression context
changed_fields	The fields that changed, created by the function changed_fields
header_info	The header info stored in the profile
ip	The header of the new IP packet

Returns: The number of fields that changed

◆ changed_static_both_hdr()

static int changed_static_both_hdr	(	struct rohc_comp_ctxt *const	context,
		const struct net_pkt *const	uncomp_pkt
	)

static

Check if the static parts of the context changed in any of the two IP headers.

Parameters

context	The compression context
uncomp_pkt	The uncompressed packet

Returns: The number of static fields that changed

◆ changed_static_one_hdr()

static int changed_static_one_hdr	(	struct rohc_comp_ctxt *const	context,
		const unsigned short	changed_fields,
		struct ip_header_info *const	header_info
	)

static

Check if the static part of the context changed in the new IP packet.

The fields classified as STATIC-DEF by RFC do not need to be checked for change. These fields are constant for all packets in a stream (ie. a profile context). So, the Source Address and Destination Address fields are not checked for change for both IPv4 and IPv6. The Flow Label is not checked for IPv6.

Although not classified as STATIC-DEF, the Version field is the same for all packets in a stream (ie. a profile context) and therefore does not need to be checked for change neither for IPv4 nor IPv6.

Although classified as STATIC, the IPv4 Don't Fragment flag is not part of the static initialization, but of the dynamic initialization.

Summary:

For IPv4, check the Protocol field for change.
For IPv6, check the Next Header field for change.

Parameters

context	The compression context
changed_fields	The fields that changed, created by the function changed_fields
header_info	The header info stored in the profile

Returns: The number of fields that changed

◆ code_EXT0_packet()

static int code_EXT0_packet	(	const struct rohc_comp_ctxt *const	context,
		uint8_t *const	dest,
		int	counter
	)

static

Build the extension 0 of the UO-2 packet.

 Extension 0 for non-RTP profiles (5.11.4):

    +---+---+---+---+---+---+---+---+
 1  | 0   0 |    SN     |   IP-ID   |
    +---+---+---+---+---+---+---+---+

 Extension 0 for RTP profile (5.7.5):

    +---+---+---+---+---+---+---+---+
 1  | 0   0 |    SN     |    +T     |
    +---+---+---+---+---+---+---+---+

 if T = 0 -> +T = IP-ID
          -> -T = TS

 if T = 1 -> +T = TS
          -> -T = IP-ID

 no T bit -> +T = -T = TS

Parameters

context	The compression context
dest	The rohc-packet-under-build buffer
counter	The current position in the rohc-packet-under-build buffer

Returns: The new position in the rohc-packet-under-build buffer if successful, -1 otherwise

◆ code_EXT1_packet()

static int code_EXT1_packet	(	const struct rohc_comp_ctxt *const	context,
		uint8_t *const	dest,
		int	counter
	)

static

Build the extension 1 of the UO-2 packet.

 Extension 1 for non-RTP profiles (5.11.4):

    +---+---+---+---+---+---+---+---+
 1  | 0   1 |    SN     |   IP-ID   |
    +---+---+---+---+---+---+---+---+
 2  |             IP-ID             |
    +---+---+---+---+---+---+---+---+

 Extension 1 for RTP profile (5.7.5):

    +---+---+---+---+---+---+---+---+
 1  | 0   1 |    SN     |    +T     |
    +---+---+---+---+---+---+---+---+
 2  |               -T              |
    +---+---+---+---+---+---+---+---+

 if T = 0 -> +T = IP-ID
          -> -T = TS

 if T = 1 -> +T = TS
          -> -T = IP-ID

 no T bit -> +T = -T = TS

Parameters

context	The compression context
dest	The rohc-packet-under-build buffer
counter	The current position in the rohc-packet-under-build buffer

Returns: The new position in the rohc-packet-under-build buffer if successful, -1 otherwise

◆ code_EXT2_packet()

static int code_EXT2_packet	(	const struct rohc_comp_ctxt *const	context,
		uint8_t *const	dest,
		int	counter
	)

static

Build the extension 2 of the UO-2 packet.

 Extension 2 for non-RTP profiles (5.11.4):

    +---+---+---+---+---+---+---+---+
 1  | 1   0 |    SN     |   IP-ID2  |
    +---+---+---+---+---+---+---+---+
 2  |            IP-ID2             |
    +---+---+---+---+---+---+---+---+
 3  |             IP-ID             |
    +---+---+---+---+---+---+---+---+

 IP-ID2 is for outer IP-ID field

 Extension 2 for RTP profile (5.7.5):

    +---+---+---+---+---+---+---+---+
 1  | 1   0 |    SN     |     +T    |
    +---+---+---+---+---+---+---+---+
 2  |               +T              |
    +---+---+---+---+---+---+---+---+
 3  |               -T              |
    +---+---+---+---+---+---+---+---+

 if T = 0 -> +T = IP-ID
          -> -T = TS

 if T = 1 -> +T = TS
          -> -T = IP-ID

 no T bit -> +T = -T = TS

Parameters

context	The compression context
dest	The rohc-packet-under-build buffer
counter	The current position in the rohc-packet-under-build buffer

Returns: The new position in the rohc-packet-under-build buffer if successful, -1 otherwise

◆ code_EXT3_nortp_packet()

static int code_EXT3_nortp_packet	(	struct rohc_comp_ctxt *const	context,
		const struct net_pkt *const	uncomp_pkt,
		uint8_t *const	dest,
		int	counter
	)

static

Build the extension 3 of the UO-2 packet.

 Extension 3 for non-RTP profiles (5.7.5 & 5.11.4):

       0     1     2     3     4     5     6     7
    +-----+-----+-----+-----+-----+-----+-----+-----+
 1  |  1     1  |  S  |   Mode    |  I  | ip  | ip2 |
    +-----+-----+-----+-----+-----+-----+-----+-----+
 2  |            Inner IP header flags        |     |  if ip = 1
    +-----+-----+-----+-----+-----+-----+-----+-----+
 3  |            Outer IP header flags              |  if ip2 = 1
    +-----+-----+-----+-----+-----+-----+-----+-----+
 4  |                      SN                       |  if S = 1
    +-----+-----+-----+-----+-----+-----+-----+-----+
    |                                               |
 5  /            Inner IP header fields             /  variable,
    |                                               |  if ip = 1
    +-----+-----+-----+-----+-----+-----+-----+-----+
 6  |                     IP-ID                     |  2 octets, if I = 1
    +-----+-----+-----+-----+-----+-----+-----+-----+
    |                                               |
 7  /            Outer IP header fields             /  variable,
    |                                               |  if ip2 = 1
    +-----+-----+-----+-----+-----+-----+-----+-----+

Parameters

context	The compression context
uncomp_pkt	The uncompressed packet to encode
dest	The rohc-packet-under-build buffer
counter	The current position in the rohc-packet-under-build buffer

Returns: The new position in the rohc-packet-under-build buffer if successful, -1 otherwise

◆ code_EXT3_packet()

static int code_EXT3_packet	(	struct rohc_comp_ctxt *const	context,
		const struct net_pkt *const	uncomp_pkt,
		uint8_t *const	dest,
		int	counter
	)

static

Build the extension 3 of the UO* packet types.

Parameters

context	The compression context
uncomp_pkt	The uncompressed packet to encode
dest	The rohc-packet-under-build buffer
counter	The current position in the rohc-packet-under-build buffer

Returns: The new position in the rohc-packet-under-build buffer if successful, -1 otherwise

◆ code_EXT3_rtp_packet()

static int code_EXT3_rtp_packet	(	struct rohc_comp_ctxt *const	context,
		const struct net_pkt *const	uncomp_pkt,
		uint8_t *const	dest,
		int	counter
	)

static

Build the extension 3 of the UO-2 packet.

 Extension 3 for RTP profile (5.7.5):

       0     1     2     3     4     5     6     7
    +-----+-----+-----+-----+-----+-----+-----+-----+
 1  |  1     1  |  S  |R-TS | Tsc |  I  | ip  | rtp |
    +-----+-----+-----+-----+-----+-----+-----+-----+
 2  |            Inner IP header flags        | ip2 |  if ip = 1
    +-----+-----+-----+-----+-----+-----+-----+-----+
 3  |            Outer IP header flags              |  if ip2 = 1
    +-----+-----+-----+-----+-----+-----+-----+-----+
 4  |                      SN                       |  if S = 1
    +-----+-----+-----+-----+-----+-----+-----+-----+
    |                                               |
 5  /                      TS                       / 1-4 octets, if R-TS = 1
    |                                               |
    +-----+-----+-----+-----+-----+-----+-----+-----+
    |                                               |
 6  /            Inner IP header fields             /  variable,
    |                                               |  if ip = 1
    +-----+-----+-----+-----+-----+-----+-----+-----+
 7  |                     IP-ID                     |  2 octets, if I = 1
    +-----+-----+-----+-----+-----+-----+-----+-----+
    |                                               |
 8  /            Outer IP header fields             /  variable,
    |                                               |  if ip2 = 1
    +-----+-----+-----+-----+-----+-----+-----+-----+
    |                                               |  variable,
 9  /          RTP Header flags and fields          /  if rtp = 1
    |                                               |
    +-----+-----+-----+-----+-----+-----+-----+-----+

Parameters

context	The compression context
uncomp_pkt	The uncompressed packet to encode
dest	The rohc-packet-under-build buffer
counter	The current position in the rohc-packet-under-build buffer

Returns: The new position in the rohc-packet-under-build buffer if successful, -1 otherwise

◆ code_ipv4_dynamic_part()

static int code_ipv4_dynamic_part	(	const struct rohc_comp_ctxt *const	context,
		struct ip_header_info *const	header_info,
		const struct ip_packet *const	ip,
		uint8_t *const	dest,
		int	counter
	)

static

Build the IPv4 dynamic part of the IR and IR-DYN packets.

 Dynamic part IPv4 (5.7.7.4):

    +---+---+---+---+---+---+---+---+
 1  |        Type of Service        |
   +---+---+---+---+---+---+---+---+
 2  |         Time to Live          |
    +---+---+---+---+---+---+---+---+
 3  /        Identification         /   2 octets, sent verbatim
    +---+---+---+---+---+---+---+---+
 4  | DF|RND|NBO|SID|       0       |
    +---+---+---+---+---+---+---+---+
 5  / Generic extension header list /  variable length
    +---+---+---+---+---+---+---+---+

Parameters

context	The compression context
header_info	The IP header info stored in the profile
ip	The IPv4 header the dynamic part is built for
dest	The rohc-packet-under-build buffer
counter	The current position in the rohc-packet-under-build buffer

Returns: The new position in the rohc-packet-under-build buffer

◆ code_ipv4_static_part()

static int code_ipv4_static_part	(	const struct rohc_comp_ctxt *const	context,
		struct ip_header_info *const	header_info,
		const struct ip_packet *const	ip,
		uint8_t *const	dest,
		int	counter
	)

static

Build the IPv4 static part of the IR packet.

 Static part IPv4 (5.7.7.4):

    +---+---+---+---+---+---+---+---+
 1  |  Version = 4  |       0       |
    +---+---+---+---+---+---+---+---+
 2  |           Protocol            |
    +---+---+---+---+---+---+---+---+
 3  /        Source Address         /   4 octets
    +---+---+---+---+---+---+---+---+
 4  /      Destination Address      /   4 octets
    +---+---+---+---+---+---+---+---+

Parameters

context	The compression context
header_info	The IP header info stored in the profile
ip	The IPv4 header the static part is built for
dest	The rohc-packet-under-build buffer
counter	The current position in the rohc-packet-under-build buffer

Returns: The new position in the rohc-packet-under-build buffer

◆ code_ipv6_dynamic_part()

static int code_ipv6_dynamic_part	(	const struct rohc_comp_ctxt *const	context,
		const unsigned int	hdr_pos,
		struct ip_header_info *const	header_info,
		const struct ip_packet *const	ip,
		uint8_t *const	dest,
		int	counter
	)

static

Build the IPv6 dynamic part of the IR and IR-DYN packets.

 Dynamic part IPv6 (5.7.7.3):

    +---+---+---+---+---+---+---+---+
 1  |         Traffic Class         |   1 octet
    +---+---+---+---+---+---+---+---+
 2  |           Hop Limit           |   1 octet
    +---+---+---+---+---+---+---+---+
 3  / Generic extension header list /   variable length
    +---+---+---+---+---+---+---+---+

Parameters

context	The compression context
hdr_pos	The position of the IP header: 1 for the outer header or 2 for the inner IP header
header_info	The IP header info stored in the profile
ip	The IPv6 header the dynamic part is built for
dest	The rohc-packet-under-build buffer
counter	The current position in the rohc-packet-under-build buffer

Returns: The new position in the rohc-packet-under-build buffer, -1 in case of error

◆ code_ipv6_static_part()

static int code_ipv6_static_part	(	const struct rohc_comp_ctxt *const	context,
		struct ip_header_info *const	header_info,
		const struct ip_packet *const	ip,
		uint8_t *const	dest,
		int	counter
	)

static

Build the IPv6 static part of the IR packet.

 Static part IPv6 (5.7.7.3):

    +---+---+---+---+---+---+---+---+
 1  |  Version = 6  |Flow Label(msb)|   1 octet
    +---+---+---+---+---+---+---+---+
 2  /        Flow Label (lsb)       /   2 octets
    +---+---+---+---+---+---+---+---+
 3  |          Next Header          |   1 octet
    +---+---+---+---+---+---+---+---+
 4  /        Source Address         /   16 octets
    +---+---+---+---+---+---+---+---+
 5  /      Destination Address      /   16 octets
    +---+---+---+---+---+---+---+---+

Parameters

context	The compression context
header_info	The IP header info stored in the profile
ip	The IPv6 header the static part is built for
dest	The rohc-packet-under-build buffer
counter	The current position in the rohc-packet-under-build buffer

Returns: The new position in the rohc-packet-under-build buffer

◆ code_IR_DYN_packet()

static int code_IR_DYN_packet	(	struct rohc_comp_ctxt *const	context,
		const struct net_pkt *const	uncomp_pkt,
		uint8_t *const	rohc_pkt,
		const size_t	rohc_pkt_max_len
	)

static

Build the IR-DYN packet.

 IR-DYN packet (5.7.7.2):

      0   1   2   3   4   5   6   7
     --- --- --- --- --- --- --- ---
 1  :         Add-CID octet         : if for small CIDs and CID != 0
    +---+---+---+---+---+---+---+---+
 2  | 1   1   1   1   1   0   0   0 | IR-DYN packet type
    +---+---+---+---+---+---+---+---+
    :                               :
 3  /     0-2 octets of CID info    / 1-2 octets if for large CIDs
    :                               :
    +---+---+---+---+---+---+---+---+
 4  |            Profile            | 1 octet
    +---+---+---+---+---+---+---+---+
 5  |              CRC              | 1 octet
    +---+---+---+---+---+---+---+---+
    |                               |
 6  /         Dynamic chain         / variable length
    |                               |
    +---+---+---+---+---+---+---+---+
 7  |             SN                | 2 octets if not RTP nor ESP
    +---+---+---+---+---+---+---+---+
    :                               :
    /           Payload             / variable length
    :                               :
     - - - - - - - - - - - - - - - -

Parameters

context	The compression context
uncomp_pkt	The uncompressed packet to encode
rohc_pkt	OUT: The ROHC packet
rohc_pkt_max_len	The maximum length of the ROHC packet

Returns: The length of the ROHC packet if successful, -1 otherwise

◆ code_IR_packet()

static int code_IR_packet	(	struct rohc_comp_ctxt *const	context,
		const struct net_pkt *const	uncomp_pkt,
		uint8_t *const	rohc_pkt,
		const size_t	rohc_pkt_max_len
	)

static

Build the IR packet.

 IR packet (5.7.7.1):

      0   1   2   3   4   5   6   7
     --- --- --- --- --- --- --- ---
 1  |         Add-CID octet         |  if for small CIDs and CID != 0
    +---+---+---+---+---+---+---+---+
 2  | 1   1   1   1   1   1   0 | D |
    +---+---+---+---+---+---+---+---+
    |                               |
 3  /    0-2 octets of CID info     /  1-2 octets if for large CIDs
    |                               |
    +---+---+---+---+---+---+---+---+
 4  |            Profile            |  1 octet
    +---+---+---+---+---+---+---+---+
 5  |              CRC              |  1 octet
    +---+---+---+---+---+---+---+---+
    |                               |
 6  |         Static chain          |  variable length
    |                               |
    +---+---+---+---+---+---+---+---+
    |                               |
 7  |         Dynamic chain         |  present if D = 1, variable length
    |                               |
    +---+---+---+---+---+---+---+---+
 8  |             SN                |  2 octets if not RTP nor ESP
    +---+---+---+---+---+---+---+---+
    |                               |
    |           Payload             |  variable length
    |                               |
     - - - - - - - - - - - - - - - -

Parameters

context	The compression context
uncomp_pkt	The uncompressed packet to encode
rohc_pkt	OUT: The ROHC packet
rohc_pkt_max_len	The maximum length of the ROHC packet

Returns: The length of the ROHC packet if successful, -1 otherwise

◆ code_packet()

int code_packet	(	struct rohc_comp_ctxt *const	context,
		const struct net_pkt *const	uncomp_pkt,
		uint8_t *const	rohc_pkt,
		const size_t	rohc_pkt_max_len
	)

static

Build the ROHC packet to send.

Parameters

context	The compression context
uncomp_pkt	The uncompressed packet to encode
rohc_pkt	OUT: The ROHC packet
rohc_pkt_max_len	The maximum length of the ROHC packet

Returns: The length of the ROHC packet if successful, -1 otherwise

◆ code_UO0_packet()

static int code_UO0_packet	(	struct rohc_comp_ctxt *const	context,
		const struct net_pkt *const	uncomp_pkt,
		uint8_t *const	rohc_pkt,
		const size_t	rohc_pkt_max_len
	)

static

Build the UO-0 packet.

      0   1   2   3   4   5   6   7
     --- --- --- --- --- --- --- ---
 1  :         Add-CID octet         :
    +---+---+---+---+---+---+---+---+
 2  |   first octet of base header  |
    +---+---+---+---+---+---+---+---+
    :                               :
 3  /   0, 1, or 2 octets of CID    /
    :                               :
    +---+---+---+---+---+---+---+---+

 UO-0 (5.7.1)

      0   1   2   3   4   5   6   7
    +---+---+---+---+---+---+---+---+
 2  | 0 |      SN       |    CRC    |
    +===+===+===+===+===+===+===+===+

Parameters

context	The compression context
uncomp_pkt	The uncompressed packet to encode
rohc_pkt	OUT: The ROHC packet
rohc_pkt_max_len	The maximum length of the ROHC packet

Returns: The length of the ROHC packet if successful, -1 otherwise

◆ code_UO2_packet()

static int code_UO2_packet	(	struct rohc_comp_ctxt *const	context,
		const struct net_pkt *const	uncomp_pkt,
		uint8_t *const	rohc_pkt,
		const size_t	rohc_pkt_max_len
	)

static

Build the UO-2 packet.

      0   1   2   3   4   5   6   7
     --- --- --- --- --- --- --- ---
 1  :         Add-CID octet         :
    +---+---+---+---+---+---+---+---+
 2  |   first octet of base header  |
    +---+---+---+---+---+---+---+---+
    :                               :
 3  /   0, 1, or 2 octets of CID    /
    :                               :
    +---+---+---+---+---+---+---+---+

 UOR-2 (5.11.3):

      0   1   2   3   4   5   6   7
    +---+---+---+---+---+---+---+---+
 2  | 1   1   0 |        SN         |
    +===+===+===+===+===+===+===+===+
 5  | X |            CRC            |
    +---+---+---+---+---+---+---+---+

 UOR-2-RTP (5.7.4):

      0   1   2   3   4   5   6   7
    +---+---+---+---+---+---+---+---+
 2  | 1   1   0 |        TS         |
    +===+===+===+===+===+===+===+===+
 4  | TS| M |       SN              |
    +---+---+---+---+---+---+---+---+
 5  | X |            CRC            |
    +---+---+---+---+---+---+---+---+

 UOR-2-TS (5.7.4):

      0   1   2   3   4   5   6   7
    +---+---+---+---+---+---+---+---+
 2  | 1   1   0 |        TS         |
    +===+===+===+===+===+===+===+===+
 4  |T=1| M |          SN           |
    +---+---+---+---+---+---+---+---+
 5  | X |           CRC             |
    +---+---+---+---+---+---+---+---+

 UOR-2-ID (5.7.4):

      0   1   2   3   4   5   6   7
    +---+---+---+---+---+---+---+---+
 2  | 1   1   0 |      IP-ID        |
    +===+===+===+===+===+===+===+===+
 4  |T=0| M |          SN           |
    +---+---+---+---+---+---+---+---+
 5  | X |           CRC             |
    +---+---+---+---+---+---+---+---+

    +---+---+---+---+---+---+---+---+
    :                               :
 6  /           Extension           /
    :                               :
     --- --- --- --- --- --- --- ---

 X: X = 0 indicates that no extension is present;
    X = 1 indicates that an extension is present.

 T: T = 0 indicates format UOR-2-ID;
    T = 1 indicates format UOR-2-TS.

Parameters

context	The compression context
uncomp_pkt	The uncompressed packet to encode
rohc_pkt	OUT: The ROHC packet
rohc_pkt_max_len	The maximum length of the ROHC packet

Returns: The length of the ROHC packet if successful, -1 otherwise

◆ code_uo_remainder()

static int code_uo_remainder	(	struct rohc_comp_ctxt *const	context,
		const struct net_pkt *const	uncomp_pkt,
		uint8_t *const	dest,
		int	counter
	)

static

Build the tail of the UO packet.

 The general format for the UO packets is:

      0   1   2   3   4   5   6   7
     --- --- --- --- --- --- --- ---
 1  :         Add-CID octet         :                    |
    +---+---+---+---+---+---+---+---+                    |
 2  |   first octet of base header  |                    |
    +---+---+---+---+---+---+---+---+                    |
    :                               :                    |
 3  /   0, 1, or 2 octets of CID    /                    |
    :                               :                    |
    +---+---+---+---+---+---+---+---+                    |
 4  /   remainder of base header    /                    |
    +---+---+---+---+---+---+---+---+                    |
    :                               :                    |
 5  /           Extension           /                    |
    :                               :                    |
     --- --- --- --- --- --- --- ---                     |
    :                               :                    |
 6  +   IP-ID of outer IPv4 header  +
    :                               :     (see section 5.7 or [RFC-3095])
     --- --- --- --- --- --- --- ---
 7  /    AH data for outer list     /                    |
     --- --- --- --- --- --- --- ---                     |
    :                               :                    |
 8  +         GRE checksum          +                    |
    :                               :                    |
     --- --- --- --- --- --- --- ---                     |
    :                               :                    |
 9  +   IP-ID of inner IPv4 header  +                    |
    :                               :                    |
     --- --- --- --- --- --- --- ---                     |
 10 /    AH data for inner list     /                    |
     --- --- --- --- --- --- --- ---                     |
    :                               :                    |
 11 +         GRE checksum          +                    |
    :                               :                    |
     --- --- --- --- --- --- --- ---
    :            List of            :
 12 /        Dynamic chains         /  variable, given by static chain
    :   for additional IP headers   :  (includes no SN)
     --- --- --- --- --- --- --- ---

     --- --- --- --- --- --- --- ---
    :                               :  RTP/UDP profiles only [RFC-3095]
 13 +         UDP Checksum          +  2 octets,
    :                               :  if context(UDP Checksum) != 0
     --- --- --- --- --- --- --- ---

Parts 7, 8, 10, 11 and 12 are not supported. Parts 1, 2, 3, 4 and 5 are built in packet-specific functions. Parts 6 and 9 are built in this function. Part 13 is built in profile-specific function.

Parameters

context	The compression context
uncomp_pkt	The uncompressed packet to encode
dest	The rohc-packet-under-build buffer
counter	The current position in the rohc-packet-under-build buffer

Returns: The new position in the rohc-packet-under-build buffer

◆ code_UOR2_bytes()

static int code_UOR2_bytes	(	const struct rohc_comp_ctxt *const	context,
		const rohc_ext_t	extension,
		uint8_t *const	f_byte,
		uint8_t *const	s_byte,
		uint8_t *const	t_byte
	)

static

Code some fields of the UOR-2 packet.

This function is called by code_UO2_packet. It should not be called directly.

See also: code_UO2_packet

 UOR-2 (5.11.3):

      0   1   2   3   4   5   6   7
    +---+---+---+---+---+---+---+---+
 2  | 1   1   0 |        SN         |
    +===+===+===+===+===+===+===+===+
 5  | X |            CRC            |
    +---+---+---+---+---+---+---+---+

Parameters

context	The compression context
extension	The extension that will be appended to the packet
f_byte	IN/OUT: The first byte of the UOR-2 packet
s_byte	IN/OUT: Not used by the UOR-2 packet
t_byte	IN/OUT: The second byte of the UOR-2 packet

Returns: 1 if successful, 0 otherwise

◆ code_UOR2_ID_bytes()

static int code_UOR2_ID_bytes	(	const struct rohc_comp_ctxt *const	context,
		const rohc_ext_t	extension,
		uint8_t *const	f_byte,
		uint8_t *const	s_byte,
		uint8_t *const	t_byte
	)

static

Code some fields of the UOR-2-ID packet.

This function is called by code_UO2_packet. It should not be called directly.

See also: code_UO2_packet

 UOR-2-ID (5.7.4):

      0   1   2   3   4   5   6   7
    +---+---+---+---+---+---+---+---+
 2  | 1   1   0 |      IP-ID        |
    +===+===+===+===+===+===+===+===+
 4  |T=0| M |          SN           |
    +---+---+---+---+---+---+---+---+
 5  | X |           CRC             |
    +---+---+---+---+---+---+---+---+

Parameters

context	The compression context
extension	The extension that will be appended to the packet
f_byte	IN/OUT: The first byte of the UOR-2-ID packet
s_byte	IN/OUT: The second byte of the UOR-2-ID packet
t_byte	IN/OUT: The third byte of the UOR-2-ID packet

Returns: 1 if successful, 0 otherwise

◆ code_UOR2_RTP_bytes()

static int code_UOR2_RTP_bytes	(	const struct rohc_comp_ctxt *const	context,
		const rohc_ext_t	extension,
		uint8_t *const	f_byte,
		uint8_t *const	s_byte,
		uint8_t *const	t_byte
	)

static

Code some fields of the UOR-2-RTP packet.

This function is called by code_UO2_packet. It should not be called directly.

See also: code_UO2_packet

 UOR-2-RTP (5.7.4):

      0   1   2   3   4   5   6   7
    +---+---+---+---+---+---+---+---+
 2  | 1   1   0 |        TS         |
    +===+===+===+===+===+===+===+===+
 4  | TS| M |       SN              |
    +---+---+---+---+---+---+---+---+
 5  | X |            CRC            |
    +---+---+---+---+---+---+---+---+

Parameters

context	The compression context
extension	The extension that will be appended to the packet
f_byte	IN/OUT: The first byte of the UOR-2-RTP packet
s_byte	IN/OUT: The second byte of the UOR-2-RTP packet
t_byte	IN/OUT: The third byte of the UOR-2-RTP packet

Returns: 1 if successful, 0 otherwise

◆ code_UOR2_TS_bytes()

static int code_UOR2_TS_bytes	(	const struct rohc_comp_ctxt *const	context,
		const rohc_ext_t	extension,
		uint8_t *const	f_byte,
		uint8_t *const	s_byte,
		uint8_t *const	t_byte
	)

static

Code some fields of the UOR-2-TS packet.

This function is called by code_UO2_packet. It should not be called directly.

See also: code_UO2_packet

 UOR-2-TS (5.7.4):

      0   1   2   3   4   5   6   7
    +---+---+---+---+---+---+---+---+
 2  | 1   1   0 |        TS         |
    +===+===+===+===+===+===+===+===+
 4  |T=1| M |          SN           |
    +---+---+---+---+---+---+---+---+
 5  | X |           CRC             |
    +---+---+---+---+---+---+---+---+

Parameters

context	The compression context
extension	The extension that will be appended to the packet
f_byte	IN/OUT: The first byte of the UOR-2-TS packet
s_byte	IN/OUT: The second byte of the UOR-2-TS packet
t_byte	IN/OUT: The third byte of the UOR-2-TS packet

Returns: 1 if successful, 0 otherwise

◆ compute_uo_crc()

static uint8_t compute_uo_crc	(	struct rohc_comp_ctxt *const	context,
		const struct net_pkt *const	uncomp_pkt,
		const rohc_crc_type_t	crc_type,
		const uint8_t	crc_init,
		const uint8_t *const	crc_table
	)

static

Compute the CRC for a UO* packet.

Parameters

context	The compression context to update
uncomp_pkt	The uncompressed packet to encode
crc_type	The type of CRC to compute
crc_init	The initial value of the CRC
crc_table	The table of pre-computed CRC

Returns: The computed CRC

◆ decide_extension()

rohc_ext_t decide_extension ( const struct rohc_comp_ctxt *const context )

Decide what extension shall be used in the UO-1-ID/UOR-2 packet.

Extensions 0, 1 & 2 are IPv4 only because of the IP-ID.

Parameters

context The compression context

Returns: The extension code among ROHC_EXT_NONE, ROHC_EXT_0, ROHC_EXT_1 and ROHC_EXT_3 if successful, ROHC_EXT_UNKNOWN otherwise

◆ decide_extension_uo1id()

static rohc_ext_t decide_extension_uo1id	(	const struct rohc_comp_ctxt *const	context,
		const size_t	nr_innermost_ip_id_bits,
		const size_t	nr_outermost_ip_id_bits
	)

static

Decide what extension shall be used in the UO-1-ID packet.

Extensions 0, 1 & 2 are IPv4 only because of the IP-ID.

Parameters

context	The compression context
nr_innermost_ip_id_bits	The number of IP-ID bits of the innermost IPv4 header
nr_outermost_ip_id_bits	The number of IP-ID bits of the outermost IPv4 header

Returns: The extension code among ROHC_EXT_NONE, ROHC_EXT_0, ROHC_EXT_1 and ROHC_EXT_3

◆ decide_extension_uor2()

static rohc_ext_t decide_extension_uor2	(	const struct rohc_comp_ctxt *const	context,
		const size_t	nr_innermost_ip_id_bits,
		const size_t	nr_outermost_ip_id_bits
	)

static

Decide what extension shall be used in the UOR-2 packet (non-RTP).

Extensions 0, 1 & 2 are IPv4 only because of the IP-ID.

Parameters

context	The compression context
nr_innermost_ip_id_bits	The number of IP-ID bits of the innermost IPv4 header
nr_outermost_ip_id_bits	The number of IP-ID bits of the outermost IPv4 header

Returns: The extension code among ROHC_EXT_NONE, ROHC_EXT_0, ROHC_EXT_1 and ROHC_EXT_3

◆ decide_extension_uor2id()

static rohc_ext_t decide_extension_uor2id	(	const struct rohc_comp_ctxt *const	context,
		const size_t	nr_innermost_ip_id_bits,
		const size_t	nr_outermost_ip_id_bits
	)

static

Decide what extension shall be used in the UOR-2-ID packet.

Extensions 0, 1 & 2 are IPv4 only because of the IP-ID.

Parameters

context	The compression context
nr_innermost_ip_id_bits	The number of IP-ID bits of the innermost IPv4 header
nr_outermost_ip_id_bits	The number of IP-ID bits of the outermost IPv4 header

Returns: The extension code among ROHC_EXT_NONE, ROHC_EXT_0, ROHC_EXT_1 and ROHC_EXT_3

◆ decide_extension_uor2rtp()

static rohc_ext_t decide_extension_uor2rtp	(	const struct rohc_comp_ctxt *const	context,
		const size_t	nr_innermost_ip_id_bits,
		const size_t	nr_outermost_ip_id_bits
	)

static

Decide what extension shall be used in the UOR-2 packet (RTP).

Extensions 0, 1 & 2 are IPv4 only because of the IP-ID.

Parameters

context	The compression context
nr_innermost_ip_id_bits	The number of IP-ID bits of the innermost IPv4 header
nr_outermost_ip_id_bits	The number of IP-ID bits of the outermost IPv4 header

Returns: The extension code among ROHC_EXT_NONE, ROHC_EXT_0, ROHC_EXT_1 and ROHC_EXT_3

◆ decide_extension_uor2ts()

static rohc_ext_t decide_extension_uor2ts	(	const struct rohc_comp_ctxt *const	context,
		const size_t	nr_innermost_ip_id_bits,
		const size_t	nr_outermost_ip_id_bits
	)

static

Decide what extension shall be used in the UO-1-ID/UOR-2 packet.

Extensions 0, 1 & 2 are IPv4 only because of the IP-ID.

Parameters

context	The compression context
nr_innermost_ip_id_bits	The number of IP-ID bits of the innermost IPv4 header
nr_outermost_ip_id_bits	The number of IP-ID bits of the outermost IPv4 header

Returns: The extension code among ROHC_EXT_NONE, ROHC_EXT_0, ROHC_EXT_1 and ROHC_EXT_3

◆ decide_packet()

static rohc_packet_t decide_packet ( struct rohc_comp_ctxt *const context )

static

Decide which packet to send when in the different states.

In IR state, IR packets are used. In FO and SO, the profile-specific functions are called if they are defined, otherwise IR packets are used.

Parameters

context The compression context

Returns

The packet type among ROHC_PACKET_IR, ROHC_PACKET_IR_DYN, ROHC_PACKET_UO_0, ROHC_PACKET_UO_1* and ROHC_PACKET_UOR_2* in case of success
ROHC_PACKET_UNKNOWN in case of failure

◆ detect_changed_fields()

static unsigned short detect_changed_fields	(	const struct rohc_comp_ctxt *const	context,
		struct ip_header_info *const	header_info,
		const struct ip_packet *const	ip
	)

static

Find the IP fields that changed between the profile and a new IP packet.

Only some fields are checked for change in the compression process, so only check these ones to avoid useless work. The fields to check are: TOS/TC, TTL/HL and Protocol/Next Header.

Parameters

context	The compression context
header_info	The header info stored in the profile
ip	The header of the new IP packet

Returns: The bitpattern that indicates which field changed

◆ detect_ip_id_behaviour()

static void detect_ip_id_behaviour	(	const struct rohc_comp_ctxt *const	context,
		struct ip_header_info *const	header_info,
		const struct ip_packet *const	ip
	)

static

Detect the behaviour of the IP-ID field of the given IPv4 header.

Detect how the IP-ID field behave:

constant,
increase in Network Bit Order (NBO),
increase in Little Endian,
randomly.

Parameters

context	The compression context
header_info	The header info stored in the profile
ip	One IPv4 header

◆ detect_ip_id_behaviours()

static void detect_ip_id_behaviours	(	struct rohc_comp_ctxt *const	context,
		const struct net_pkt *const	uncomp_pkt
	)

static

Detect the behaviour of the IP-ID fields of the IPv4 headers.

Detect how the IP-ID fields behave:

constant (not handled yet),
increase in Network Bit Order (NBO),
increase in Little Endian,
randomly.

Parameters

context	The compression context
uncomp_pkt	The uncompressed packet

◆ encode_uncomp_fields()

static bool encode_uncomp_fields	(	struct rohc_comp_ctxt *const	context,
		const struct net_pkt *const	uncomp_pkt
	)

static

Encode uncompressed fields with the corresponding encoding scheme.

Parameters

context	The compression context
uncomp_pkt	The uncompressed packet to encode

Returns: true in case of success, false otherwise

◆ header_fields()

static int header_fields	(	const struct rohc_comp_ctxt *const	context,
		struct ip_header_info *const	header_info,
		const unsigned short	changed_f,
		const struct ip_packet *const	ip,
		const int	I,
		const ip_header_pos_t	ip_hdr_pos,
		uint8_t *const	dest,
		int	counter
	)

static

Build inner or outer IP header fields.

This function is used to code the IP header fields of the extension 3 of the UO-2 packet. The function is called twice (one for inner IP header and one for outer IP header) with different arguments.

See also: code_EXT3_packet

    +-----+-----+-----+-----+-----+-----+-----+-----+
 1  |         Type of Service/Traffic Class         |  if TOS = 1
     ..... ..... ..... ..... ..... ..... ..... .....
 2  |         Time to Live/Hop Limit                |  if TTL = 1
     ..... ..... ..... ..... ..... ..... ..... .....
 3  |         Protocol/Next Header                  |  if PR = 1
     ..... ..... ..... ..... ..... ..... ..... .....
 4  /         IP extension headers                  /  variable, if IPX = 1
     ..... ..... ..... ..... ..... ..... ..... .....

 For outer IP-ID:
     ..... ..... ..... ..... ..... ..... ..... .....
 5  |                  IP-ID                        |  2 octets,
     ..... ..... ..... ..... ..... ..... ..... .....    if I2 = 1

Part 4 is not supported.

Parameters

context	The compression context
header_info	The header info stored in the profile
changed_f	The fields that changed, created by the function changed_fields
ip	One inner or outer IP header
I	The I flag of the IP header
ip_hdr_pos	The position of the IP header
dest	The rohc-packet-under-build buffer
counter	The current position in the rohc-packet-under-build buffer

Returns: The new position in the rohc-packet-under-build buffer

See also: changed_fields

◆ header_flags()

static int header_flags	(	const struct rohc_comp_ctxt *const	context,
		struct ip_header_info *const	header_info,
		const unsigned short	changed_f,
		const struct ip_packet *const	ip,
		const int	ip2_or_I2,
		uint8_t *const	dest,
		int	counter
	)

static

Build inner or outer IP header flags.

This function is used to code the IP header fields of the extension 3 of the UO-2 packet. The function is called twice (one for inner IP header and one for outer IP header) with different arguments.

See also: code_EXT3_packet

 Header flags for IP and UDP profiles (5.11.4):

 For inner flags:

    +-----+-----+-----+-----+-----+-----+-----+-----+
 1  |            Inner IP header flags        |     |  if ip = 1
    | TOS | TTL | DF  | PR  | IPX | NBO | RND | ip2 |  ip2 = 0 if non-RTP
    +-----+-----+-----+-----+-----+-----+-----+-----+

 or for outer flags:

    +-----+-----+-----+-----+-----+-----+-----+-----+
 2  |            Outer IP header flags              |
    | TOS2| TTL2| DF2 | PR2 |IPX2 |NBO2 |RND2 |  I2 |  if ip2 = 1
    +-----+-----+-----+-----+-----+-----+-----+-----+

Parameters

context	The compression context
header_info	The header info stored in the profile
changed_f	The fields that changed, created by the function changed_fields
ip	One inner or outer IP header
ip2_or_I2	Whether the ip2 (inner, RTP only) or I2 (outer) flag is set or not
dest	The rohc-packet-under-build buffer
counter	The current position in the rohc-packet-under-build buffer

Returns: The new position in the rohc-packet-under-build buffer

See also: changed_fields

◆ ip_header_info_free()

static void ip_header_info_free ( struct ip_header_info *const header_info )

static

Reset the given IP header info.

Parameters

header_info The IP header info to reset

◆ ip_header_info_new()

static void ip_header_info_new	(	struct ip_header_info *const	header_info,
		const struct ip_packet *const	ip,
		const size_t	list_trans_nr,
		const size_t	wlsb_window_width,
		rohc_trace_callback2_t	trace_cb,
		void *const	trace_cb_priv,
		const int	profile_id
	)

static

Initialize the IP header info stored in the context.

Parameters

header_info	The IP header info to initialize
ip	The IP header
list_trans_nr	The number of uncompressed transmissions for list compression (L)
wlsb_window_width	The width of the W-LSB sliding window for IPv4 IP-ID (must be > 0)
trace_cb	The function to call for printing traces
trace_cb_priv	An optional private context, may be NULL
profile_id	The ID of the associated compression profile

◆ is_field_changed()

static bool is_field_changed	(	const unsigned short	changed_fields,
		const unsigned short	check_field
	)

static

Check if a specified IP field has changed.

Parameters

changed_fields	The fields that changed, created by the function changed_fields
check_field	The field for which to check a change

Returns: 1 if the field changed, 0 if not

See also: changed_fields

◆ rohc_code_dynamic_ip_part()

static int rohc_code_dynamic_ip_part	(	const struct rohc_comp_ctxt *const	context,
		const unsigned int	hdr_pos,
		struct ip_header_info *const	header_info,
		const struct ip_packet *const	ip,
		uint8_t *const	dest,
		int	counter
	)

static

Build the dynamic part of one IP header for the IR/IR-DYN packets.

Parameters

context	The compression context
hdr_pos	The position of the IP header: 1 for the outer header or 2 for the inner IP header
header_info	The IP header info stored in the profile
ip	The IP header the dynamic part is built for
dest	The rohc-packet-under-build buffer
counter	The current position in the rohc-packet-under-build buffer

Returns: The new position in the rohc-packet-under-build buffer, -1 in case of error

◆ rohc_code_dynamic_part()

static int rohc_code_dynamic_part	(	const struct rohc_comp_ctxt *const	context,
		const struct net_pkt *const	uncomp_pkt,
		uint8_t *const	rohc_pkt,
		int	counter
	)

static

Build the dynamic part of the IR and IR-DYN packets.

Parameters

context	The compression context
uncomp_pkt	The uncompressed packet to encode
rohc_pkt	The rohc-packet-under-build buffer
counter	The current position in the rohc-packet-under-build buffer

Returns: The new position in the rohc-packet-under-build buffer

◆ rohc_code_static_ip_part()

static int rohc_code_static_ip_part	(	const struct rohc_comp_ctxt *const	context,
		struct ip_header_info *const	header_info,
		const struct ip_packet *const	ip,
		uint8_t *const	dest,
		int	counter
	)

static

Build the static part of one IP header for the IR packet.

Parameters

context	The compression context
header_info	The IP header info stored in the profile
ip	The IP header the static part is built for
dest	The rohc-packet-under-build buffer
counter	The current position in the rohc-packet-under-build buffer

Returns: The new position in the rohc-packet-under-build buffer

◆ rohc_code_static_part()

static int rohc_code_static_part	(	const struct rohc_comp_ctxt *const	context,
		const struct net_pkt *const	uncomp_pkt,
		uint8_t *const	rohc_pkt,
		int	counter
	)

static

Build the static part of the IR packet.

Parameters

context	The compression context
uncomp_pkt	The uncompressed packet to encode
rohc_pkt	The rohc-packet-under-build buffer
counter	The current position in the rohc-packet-under-build buffer

Returns: The new position in the rohc-packet-under-build buffer

◆ rohc_comp_rfc3095_build_uo1_pkt()

static int rohc_comp_rfc3095_build_uo1_pkt	(	struct rohc_comp_ctxt *const	context,
		const struct net_pkt *const	uncomp_pkt,
		uint8_t *const	rohc_pkt,
		const size_t	rohc_pkt_max_len
	)

static

Build the UO-1 packet for the non-RTP profiles.

The UO-1 packet type cannot be used if there is no IPv4 header in the context or if value(RND) and value(RND2) are both 1.

      0   1   2   3   4   5   6   7
     --- --- --- --- --- --- --- ---
 1  :         Add-CID octet         :
    +---+---+---+---+---+---+---+---+
 2  |   first octet of base header  |
    +---+---+---+---+---+---+---+---+
    :                               :
 3  /   0, 1, or 2 octets of CID    /
    :                               :
    +---+---+---+---+---+---+---+---+

 UO-1 (5.11.3):

      0   1   2   3   4   5   6   7
    +---+---+---+---+---+---+---+---+
 2  | 1   0 |         IP-ID         |
    +===+===+===+===+===+===+===+===+
 4  |        SN         |    CRC    |
    +---+---+---+---+---+---+---+---+

Parameters

	context	The compression context
	uncomp_pkt	The uncompressed packet to encode
[out]	rohc_pkt	The ROHC packet
	rohc_pkt_max_len	The maximum length of the ROHC packet

Returns: The length of the ROHC packet if successful, -1 otherwise

◆ rohc_comp_rfc3095_build_uo1id_pkt()

static int rohc_comp_rfc3095_build_uo1id_pkt	(	struct rohc_comp_ctxt *const	context,
		const struct net_pkt *const	uncomp_pkt,
		uint8_t *const	rohc_pkt,
		const size_t	rohc_pkt_max_len
	)

static

Build the UO-1-ID packet.

The UO-1-ID packet type cannot be used if there is no IPv4 header in the context or if value(RND) and value(RND2) are both 1.

      0   1   2   3   4   5   6   7
     --- --- --- --- --- --- --- ---
 1  :         Add-CID octet         :
    +---+---+---+---+---+---+---+---+
 2  |   first octet of base header  |
    +---+---+---+---+---+---+---+---+
    :                               :
 3  /   0, 1, or 2 octets of CID    /
    :                               :
    +---+---+---+---+---+---+---+---+

 UO-1-ID (5.7.3):

      0   1   2   3   4   5   6   7
    +---+---+---+---+---+---+---+---+
 2  | 1   0 |T=0|      IP-ID        |
    +===+===+===+===+===+===+===+===+
 4  | X |      SN       |    CRC    |
    +---+---+---+---+---+---+---+---+

 X: X = 0 indicates that no extension is present;
    X = 1 indicates that an extension is present.

 T: T = 0 indicates format UO-1-ID;
    T = 1 indicates format UO-1-TS.

Parameters

	context	The compression context
	uncomp_pkt	The uncompressed packet to encode
[out]	rohc_pkt	The ROHC packet
	rohc_pkt_max_len	The maximum length of the ROHC packet

Returns: The length of the ROHC packet if successful, -1 otherwise

◆ rohc_comp_rfc3095_build_uo1rtp_pkt()

static int rohc_comp_rfc3095_build_uo1rtp_pkt	(	struct rohc_comp_ctxt *const	context,
		const struct net_pkt *const	uncomp_pkt,
		uint8_t *const	rohc_pkt,
		const size_t	rohc_pkt_max_len
	)

static

Build the UO-1 packet for the RTP profiles.

The UO-1 packet type cannot be used if there is no IPv4 header in the context or if value(RND) and value(RND2) are both 1.

      0   1   2   3   4   5   6   7
     --- --- --- --- --- --- --- ---
 1  :         Add-CID octet         :
    +---+---+---+---+---+---+---+---+
 2  |   first octet of base header  |
    +---+---+---+---+---+---+---+---+
    :                               :
 3  /   0, 1, or 2 octets of CID    /
    :                               :
    +---+---+---+---+---+---+---+---+

 UO-1 (5.7.3):

      0   1   2   3   4   5   6   7
    +---+---+---+---+---+---+---+---+
 2  | 1   0 |          TS           |
    +===+===+===+===+===+===+===+===+
 4  | M |      SN       |    CRC    |
    +---+---+---+---+---+---+---+---+

Parameters

	context	The compression context
	uncomp_pkt	The uncompressed packet to encode
[out]	rohc_pkt	The ROHC packet
	rohc_pkt_max_len	The maximum length of the ROHC packet

Returns: The length of the ROHC packet if successful, -1 otherwise

◆ rohc_comp_rfc3095_build_uo1ts_pkt()

static int rohc_comp_rfc3095_build_uo1ts_pkt	(	struct rohc_comp_ctxt *const	context,
		const struct net_pkt *const	uncomp_pkt,
		uint8_t *const	rohc_pkt,
		const size_t	rohc_pkt_max_len
	)

static

Build the UO-1-TS packet.

      0   1   2   3   4   5   6   7
     --- --- --- --- --- --- --- ---
 1  :         Add-CID octet         :
    +---+---+---+---+---+---+---+---+
 2  |   first octet of base header  |
    +---+---+---+---+---+---+---+---+
    :                               :
 3  /   0, 1, or 2 octets of CID    /
    :                               :
    +---+---+---+---+---+---+---+---+

 UO-1-TS (5.7.3):

      0   1   2   3   4   5   6   7
    +---+---+---+---+---+---+---+---+
 2  | 1   0 |T=1|        TS         |
    +===+===+===+===+===+===+===+===+
 4  | M |      SN       |    CRC    |
    +---+---+---+---+---+---+---+---+

 T: T = 0 indicates format UO-1-ID;
    T = 1 indicates format UO-1-TS.

Parameters

	context	The compression context
	uncomp_pkt	The uncompressed packet to encode
[out]	rohc_pkt	The ROHC packet
	rohc_pkt_max_len	The maximum length of the ROHC packet

Returns: The length of the ROHC packet if successful, -1 otherwise

◆ rohc_comp_rfc3095_check_profile()

bool rohc_comp_rfc3095_check_profile	(	const struct rohc_comp *const	comp,
		const struct net_pkt *const	packet
	)

Check if the given packet corresponds to an IP-based profile.

Conditions are:

the version of the outer IP header is 4 or 6
if the outer IP header is IPv4, it does not contain options
the outer IP header is not an IP fragment
if there are at least 2 IP headers, the version of the inner IP header is 4 or 6
if there are at least 2 IP headers and if the inner IP header is IPv4, it does not contain options
if there are at least 2 IP headers, the inner IP header is not an IP fragment

This function is one of the functions that must exist in one profile for the framework to work.

Parameters

comp	The ROHC compressor
packet	The packet to check

Returns

Whether the IP packet corresponds to the profile:

true if the IP packet corresponds to the profile,
false if the IP packet does not correspond to the profile

◆ rohc_comp_rfc3095_create()

bool rohc_comp_rfc3095_create	(	struct rohc_comp_ctxt *const	context,
		const size_t	sn_bits_nr,
		const rohc_lsb_shift_t	sn_shift,
		const struct net_pkt *const	packet
	)

Create a new context and initialize it thanks to the given IP packet.

Parameters

context	The compression context
sn_bits_nr	The maximum number of bits used for SN
sn_shift	The shift parameter (p) to use for encoding SN with W-LSB
packet	The packet given to initialize the new context

Returns: true if successful, false otherwise

◆ rohc_comp_rfc3095_decide_state()

void rohc_comp_rfc3095_decide_state ( struct rohc_comp_ctxt *const context )

Decide the state that should be used for the next packet.

The three states are:

Initialization and Refresh (IR),
First Order (FO),
Second Order (SO).

Parameters

context The compression context

◆ rohc_comp_rfc3095_destroy()

void rohc_comp_rfc3095_destroy ( struct rohc_comp_ctxt *const context )

Destroy the context.

This function is one of the functions that must exist in one profile for the framework to work.

Parameters

context The compression context

◆ rohc_comp_rfc3095_detect_changes()

static bool rohc_comp_rfc3095_detect_changes	(	struct rohc_comp_ctxt *const	context,
		const struct net_pkt *const	uncomp_pkt
	)

static

Detect changes between packet and context.

Parameters

context	The compression context to compare
uncomp_pkt	The uncompressed packet to compare

Returns: true if changes were successfully detected, false if a problem occurred

◆ rohc_comp_rfc3095_encode()

int rohc_comp_rfc3095_encode	(	struct rohc_comp_ctxt *const	context,
		const struct net_pkt *const	uncomp_pkt,
		uint8_t *const	rohc_pkt,
		const size_t	rohc_pkt_max_len,
		rohc_packet_t *const	packet_type,
		size_t *const	payload_offset
	)

Encode an IP packet according to a pattern decided by several different factors.

parse uncompressed packet (done in rohc_compress4)
detect changes between the new uncompressed packet and the context
decide new compressor state
determine how many bytes are required for every field
decide which packet to send
code the ROHC header
copy the packet payload (done in rohc_compress4)
update the context with the new headers

This function is one of the functions that must exist in one profile for the framework to work.

Parameters

context	The compression context
uncomp_pkt	The uncompressed packet to encode
rohc_pkt	OUT: The ROHC packet
rohc_pkt_max_len	The maximum length of the ROHC packet
packet_type	OUT: The type of ROHC packet that is created
payload_offset	OUT: The offset for the payload in the IP packet

Returns: The length of the ROHC packet if successful, -1 otherwise

◆ rohc_comp_rfc3095_feedback()

bool rohc_comp_rfc3095_feedback	(	struct rohc_comp_ctxt *const	context,
		const enum rohc_feedback_type	feedback_type,
		const uint8_t *const	packet,
		const size_t	packet_len,
		const uint8_t *const	feedback_data,
		const size_t	feedback_data_len
	)

Update the profile when feedback is received.

This function is one of the functions that must exist in one profile for the framework to work.

Parameters

context	The compression context
feedback_type	The feedback type
packet	The whole feedback packet with CID bits
packet_len	The length of the whole feedback packet with CID bits
feedback_data	The feedback data without the CID bits
feedback_data_len	The length of the feedback data without the CID bits

Returns: true if the feedback was successfully handled, false if the feedback could not be taken into account

◆ rohc_comp_rfc3095_feedback_2()

static bool rohc_comp_rfc3095_feedback_2	(	struct rohc_comp_ctxt *const	context,
		const uint8_t *const	packet,
		const size_t	packet_len,
		const uint8_t *const	feedback_data,
		const size_t	feedback_data_len
	)

static

Update the profile when FEEDBACK-2 is received.

Parameters

context	The compression context
packet	The whole feedback packet with CID bits
packet_len	The length of the whole feedback packet with CID bits
feedback_data	The feedback data without the CID bits
feedback_data_len	The length of the feedback data without the CID bits

Returns: true if the feedback was successfully handled, false if the feedback could not be taken into account

◆ rohc_comp_rfc3095_feedback_ack()

static void rohc_comp_rfc3095_feedback_ack	(	struct rohc_comp_ctxt *const	context,
		const uint32_t	sn_bits,
		const size_t	sn_bits_nr,
		const bool	sn_not_valid
	)

static

Perform the required actions after the reception of a positive ACK.

Parameters

context	The compression context that received a positive ACK
sn_bits	The LSB bits of the acknowledged SN
sn_bits_nr	The number of LSB bits of the acknowledged SN
sn_not_valid	Whether the received SN may be considered as valid or not

◆ rohc_comp_rfc3095_get_ext3_I_flags()

static void rohc_comp_rfc3095_get_ext3_I_flags	(	const struct rohc_comp_ctxt *const	context,
		const struct net_pkt *const	uncomp_pkt,
		const rohc_packet_t	packet_type,
		const size_t	nr_ip_id_bits,
		const size_t	nr_ip_id_bits2,
		ip_header_pos_t *const	innermost_ipv4_non_rnd,
		uint8_t *const	I,
		uint8_t *const	I2
	)

static

Determine the values of the I and I2 flags for UO* extension 3.

Parameters

	context	The compression context
	uncomp_pkt	The uncompressed packet to encode
	packet_type	The type of packet that is being built
	nr_ip_id_bits	The number of IP-ID bits for the first IP header
	nr_ip_id_bits2	The number of IP-ID bits for the second IP header (if any)
[out]	innermost_ipv4_non_rnd	The position of the innermost IPv4 header with a non-random IP-ID field
[out]	I	The value of the I flag in UO extension 3, ie. whether the innermost IPv4 header with a non-random IP-ID needs to transmit some IP-ID bits
[out]	I2	The value of the I2 flag in UO extension 3, ie. whether the 2nd innermost IPv4 header with a non-random IP-ID needs to transmit some IP-ID bits

◆ rohc_comp_rfc3095_is_sn_possible()

bool rohc_comp_rfc3095_is_sn_possible	(	const struct rohc_comp_rfc3095_ctxt *const	rfc3095_ctxt,
		const size_t	bits_nr,
		const size_t	add_bits_nr
	)

Are the given SN field sizes possible?

Parameters

rfc3095_ctxt	The compression context
bits_nr	The base number of SN bits
add_bits_nr	The additional number of SN bits

Returns: true if the SN field is usable, false if not

◆ rohc_get_innermost_ipv4_non_rnd()

static void rohc_get_innermost_ipv4_non_rnd	(	const struct rohc_comp_ctxt *const	context,
		ip_header_pos_t *const	pos,
		size_t *const	nr_bits,
		uint16_t *const	offset
	)

static

Determine the number of IP-ID bits and the IP-ID offset of the innermost IPv4 header with non-random IP-ID.

Parameters

context	The compression context
pos	OUT: The position of the header
nr_bits	OUT: the number of IP-ID bits of the found header
offset	OUT: the IP-ID offset of the found header

◆ rohc_get_ipid_bits()

void rohc_get_ipid_bits	(	const struct rohc_comp_ctxt *const	context,
		size_t *const	nr_innermost_bits,
		size_t *const	nr_outermost_bits
	)

Get the number of non-random outer/inner IP-ID bits.

Parameters

context	The compression context
nr_innermost_bits	OUT: the maximum number of IP-ID bits for the innermost IPv4 header
nr_outermost_bits	OUT: the maximum number of IP-ID bits for the outermost IP header

◆ rtp_header_flags_and_fields()

static int rtp_header_flags_and_fields	(	const struct rohc_comp_ctxt *const	context,
		const struct ip_packet *const	ip,
		uint8_t *const	dest,
		int	counter
	)

static

◆ update_context()

static void update_context	(	struct rohc_comp_ctxt *const	context,
		const struct net_pkt *const	uncomp_pkt
	)

static

Update the compression context with the successfully compressed packet.

Parameters

context	The compression context to update
uncomp_pkt	The uncompressed packet that updates the context

◆ update_context_ip_hdr()

static void update_context_ip_hdr	(	struct ip_header_info *const	ip_flags,
		const struct ip_packet *const	ip
	)

static

Update the IP information with the IP header.

Parameters

ip_flags	The IP context to update
ip	The uncompressed IP header that updates the context

Macros

Functions

Detailed Description

Macro Definition Documentation

◆ MOD_ERROR

◆ MOD_IPV6_EXT_LIST_CONTENT

◆ MOD_IPV6_EXT_LIST_STRUCT

◆ MOD_PROTOCOL

◆ MOD_TOS

◆ MOD_TTL

Function Documentation

◆ c_init_tmp_variables()

◆ changed_dynamic_both_hdr()

◆ changed_dynamic_one_hdr()

◆ changed_static_both_hdr()

◆ changed_static_one_hdr()

◆ code_EXT0_packet()

◆ code_EXT1_packet()

◆ code_EXT2_packet()

◆ code_EXT3_nortp_packet()

◆ code_EXT3_packet()

◆ code_EXT3_rtp_packet()

◆ code_ipv4_dynamic_part()

◆ code_ipv4_static_part()

◆ code_ipv6_dynamic_part()

◆ code_ipv6_static_part()

◆ code_IR_DYN_packet()

◆ code_IR_packet()

◆ code_packet()

◆ code_UO0_packet()

◆ code_UO2_packet()

◆ code_uo_remainder()

◆ code_UOR2_bytes()

◆ code_UOR2_ID_bytes()

◆ code_UOR2_RTP_bytes()

◆ code_UOR2_TS_bytes()

◆ compute_uo_crc()

◆ decide_extension()

◆ decide_extension_uo1id()

◆ decide_extension_uor2()

◆ decide_extension_uor2id()

◆ decide_extension_uor2rtp()

◆ decide_extension_uor2ts()

◆ decide_packet()

◆ detect_changed_fields()

◆ detect_ip_id_behaviour()

◆ detect_ip_id_behaviours()

◆ encode_uncomp_fields()

◆ header_fields()

◆ header_flags()

◆ ip_header_info_free()

◆ ip_header_info_new()

◆ is_field_changed()

◆ rohc_code_dynamic_ip_part()

◆ rohc_code_dynamic_part()

◆ rohc_code_static_ip_part()

◆ rohc_code_static_part()

◆ rohc_comp_rfc3095_build_uo1_pkt()

◆ rohc_comp_rfc3095_build_uo1id_pkt()

◆ rohc_comp_rfc3095_build_uo1rtp_pkt()

◆ rohc_comp_rfc3095_build_uo1ts_pkt()

◆ rohc_comp_rfc3095_check_profile()

◆ rohc_comp_rfc3095_create()

◆ rohc_comp_rfc3095_decide_state()

◆ rohc_comp_rfc3095_destroy()

◆ rohc_comp_rfc3095_detect_changes()

◆ rohc_comp_rfc3095_encode()

◆ rohc_comp_rfc3095_feedback()

◆ rohc_comp_rfc3095_feedback_2()

◆ rohc_comp_rfc3095_feedback_ack()

◆ rohc_comp_rfc3095_get_ext3_I_flags()

◆ rohc_comp_rfc3095_is_sn_possible()

◆ rohc_get_innermost_ipv4_non_rnd()

◆ rohc_get_ipid_bits()

◆ rtp_header_flags_and_fields()

◆ update_context()

◆ update_context_ip_hdr()