ROHC compression context for the IP-only profile. More...

#include "c_ip.h"
#include "rohc_traces.h"
#include "config.h"
#include <string.h>

Include dependency graph for c_ip.c:

Functions
int	c_ip_check_context (const struct c_context context, const struct ip_packet ip)
	Check if an IP packet belongs to the context.
rohc_packet_t	c_ip_decide_FO_packet (const struct c_context *context)
	Decide which packet to send when in First Order (FO) state.
rohc_packet_t	c_ip_decide_SO_packet (const struct c_context *context)
	Decide which packet to send when in Second Order (SO) state.
uint32_t	c_ip_get_next_sn (const struct c_context context, const struct ip_packet outer_ip, const struct ip_packet *inner_ip)
	Determine the SN value for the next packet.
int	c_ip_code_ir_remainder (const struct c_context context, unsigned char const dest, int counter)
	Code the remainder header for the IR or IR-DYN packets.
Variables
struct c_profile	c_ip_profile
	Define the compression part of the IP-only profile as described in the RFC 3843.

Detailed Description

ROHC compression context for the IP-only profile.

Author:: Didier Barvaux <didier.barvaux@toulouse.viveris.com>; The hackers from ROHC for Linux

Function Documentation

int c_ip_check_context	(	const struct c_context *	context,
		const struct ip_packet *	ip
	)

Check if an IP packet belongs to the context.

Conditions are:

the number of IP headers must be the same as in context
IP version of the two IP headers must be the same as in context
IP packets must not be fragmented
the source and destination addresses of the two IP headers must match the ones in the context
IPv6 only: the Flow Label of the two IP headers must match the ones 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
ip	The IP packet to check

Returns:: 1 if the IP packet belongs to the context, 0 if it does not belong to the context and -1 if the profile cannot compress it or an error occurs

References ipv4_hdr::daddr, ip_header_info::info, c_generic_context::ip2_flags, ipv6_hdr::ip6_dst, ipv6_hdr::ip6_src, c_generic_context::ip_flags, ip_get_inner_packet(), ip_get_protocol(), ip_get_version(), IPV4, ipv4_get_daddr(), ipv4_get_saddr(), IPV6, IPV6_ADDR_CMP, ipv6_get_daddr(), IPV6_GET_FLOW_LABEL, ipv6_get_flow_label(), ipv6_get_saddr(), c_generic_context::is_ip2_initialized, c_generic_context::next_header_proto, ipv4_header_info::old_ip, ipv6_header_info::old_ip, rohc_debugf, ROHC_IPPROTO_IPIP, ROHC_IPPROTO_IPV6, ipv4_hdr::saddr, c_context::specific, ip_header_info::v4, ip_header_info::v6, version, and ip_header_info::version.

int c_ip_code_ir_remainder	(	const struct c_context *	context,
		unsigned char *const	dest,
		int	counter
	)

Code the remainder header for the IR or IR-DYN packets.


 Remainder of IR/IR-DYN packet (5.7.7.1):

      0   1   2   3   4   5   6   7
    +---+---+---+---+---+---+---+---+
 1  |             SN                |  2 octets if not RTP
    +---+---+---+---+---+---+---+---+

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

References rohc_debugf, sn, c_generic_context::sn, and c_context::specific.

Referenced by c_udp_create(), and c_udp_lite_create().

rohc_packet_t c_ip_decide_FO_packet ( const struct c_context * context )

Decide which packet to send when in First Order (FO) state.

Packets that can be used are the IR-DYN and UO-2 packets.

See also:: decide_packet

Parameters:

context The compression context

Returns:: The packet type among PACKET_IR_DYN and PACKET_UOR_2

References generic_tmp_vars::nr_of_ip_hdr, generic_tmp_vars::nr_sn_bits, PACKET_IR_DYN, PACKET_UOR_2, rohc_debugf, generic_tmp_vars::send_dynamic, generic_tmp_vars::send_static, c_context::specific, and c_generic_context::tmp.

Referenced by c_udp_create(), and c_udp_lite_create().

rohc_packet_t c_ip_decide_SO_packet ( const struct c_context * context )

Decide which packet to send when in Second Order (SO) state.

Packets that can be used are the UO-0, UO-1 and UO-2 (with or without extensions) packets.

See also:: decide_packet

Parameters:

context The compression context

Returns:: The packet type among PACKET_UO_0, PACKET_UO_1 and PACKET_UOR_2

References ip_header_info::info, c_generic_context::ip2_flags, c_generic_context::ip_flags, IPV4, generic_tmp_vars::nr_ip_id_bits, generic_tmp_vars::nr_ip_id_bits2, generic_tmp_vars::nr_of_ip_hdr, generic_tmp_vars::nr_sn_bits, PACKET_IR_DYN, PACKET_UO_0, PACKET_UO_1, PACKET_UOR_2, ipv4_header_info::rnd, rohc_debugf, c_context::specific, c_generic_context::tmp, ip_header_info::v4, and ip_header_info::version.

Referenced by c_udp_create(), and c_udp_lite_create().

uint32_t c_ip_get_next_sn	(	const struct c_context *	context,
		const struct ip_packet *	outer_ip,
		const struct ip_packet *	inner_ip
	)

Determine the SN value for the next packet.

Profile SN is an internal increasing 16-bit number.

Parameters:

context	The compression context
outer_ip	The outer IP header
inner_ip	The inner IP header if it exists, NULL otherwise

Returns:: The SN

References c_generic_context::sn, and c_context::specific.

Referenced by c_udp_create(), and c_udp_lite_create().

Variable Documentation

struct c_profile c_ip_profile

Initial value:

{
        0,                  
        NULL,               
        ROHC_PROFILE_IP,    
        "IP / Compressor",  
        rohc_ip_ctxt_create,
        c_generic_destroy,
        c_ip_check_context,
        c_generic_encode,
        c_generic_feedback,
}

Define the compression part of the IP-only profile as described in the RFC 3843.

Functions

Variables

Detailed Description

Function Documentation

Variable Documentation