rohc_comp_rfc3095.h File Reference
Generic framework for RFC3095-based compression profiles such as IP-only, UDP, UDP-Lite, ESP, and RTP profiles. More...
#include "rohc_comp_internals.h"#include "rohc_packets.h"#include "schemes/comp_list.h"#include "ip.h"#include "crc.h"#include <stdlib.h>
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Data Structures | |
| struct | ipv4_header_info |
| Store information about an IPv4 header between the different compressions of IP packets. More... | |
| struct | ipv6_header_info |
| Store information about an IPv6 header between the different compressions of IP packets. More... | |
| struct | ip_header_info |
| Store information about an IP (IPv4 or IPv6) header between the different compressions of IP packets. More... | |
| struct | generic_tmp_vars |
| Structure that contains variables that are used during one single compression of packet. More... | |
| struct | rohc_comp_rfc3095_ctxt |
| The generic decompression context for RFC3095-based profiles. More... | |
Functions | |
| bool | rohc_comp_rfc3095_create (struct rohc_comp_ctxt *const context, 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. | |
| void | rohc_comp_rfc3095_destroy (struct rohc_comp_ctxt *const context) |
| Destroy the context. | |
| 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. | |
| 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. | |
| 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. | |
| 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. | |
| void | rohc_comp_rfc3095_decide_state (struct rohc_comp_ctxt *const context) |
| Decide the state that should be used for the next packet. | |
| 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. | |
| 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? | |
| static bool | no_outer_ip_id_bits_required (const struct rohc_comp_rfc3095_ctxt *const ctxt) |
| Does the outer IP header require to transmit no non-random IP-ID bit? | |
| static bool | is_outer_ip_id_bits_possible (const struct rohc_comp_rfc3095_ctxt *const ctxt, const size_t max_ip_id_bits_nr) |
| May the outer IP header transmit the required non-random IP-ID bits? | |
| static bool | no_inner_ip_id_bits_required (const struct rohc_comp_rfc3095_ctxt *const ctxt) |
| Does the inner IP header require to transmit no non-random IP-ID bit? | |
| static bool | is_inner_ip_id_bits_possible (const struct rohc_comp_rfc3095_ctxt *const ctxt, const size_t max_ip_id_bits_nr) |
| May the inner IP header transmit the required non-random IP-ID bits? | |
| static size_t | get_nr_ipv4_non_rnd (const struct rohc_comp_rfc3095_ctxt *const ctxt) |
| How many IP headers are IPv4 headers with non-random IP-IDs ? | |
| static size_t | get_nr_ipv4_non_rnd_with_bits (const struct rohc_comp_rfc3095_ctxt *const ctxt) |
| How many IP headers are IPv4 headers with non-random IP-IDs and some bits to transmit ? | |
Detailed Description
Generic framework for RFC3095-based compression profiles such as IP-only, UDP, UDP-Lite, ESP, and RTP profiles.
Function Documentation
| 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
| static size_t get_nr_ipv4_non_rnd | ( | const struct rohc_comp_rfc3095_ctxt *const | ctxt | ) | [inline, static] |
How many IP headers are IPv4 headers with non-random IP-IDs ?
- Parameters:
-
ctxt The generic decompression context
- Returns:
- The number of IPv4 headers with non-random IP-ID fields
| static size_t get_nr_ipv4_non_rnd_with_bits | ( | const struct rohc_comp_rfc3095_ctxt *const | ctxt | ) | [inline, static] |
How many IP headers are IPv4 headers with non-random IP-IDs and some bits to transmit ?
- Parameters:
-
ctxt The generic decompression context
- Returns:
- The number of IPv4 headers with non-random IP-ID fields and some bits to transmit
| static bool is_inner_ip_id_bits_possible | ( | const struct rohc_comp_rfc3095_ctxt *const | ctxt, | |
| const size_t | max_ip_id_bits_nr | |||
| ) | [inline, static] |
May the inner IP header transmit the required non-random IP-ID bits?
- Parameters:
-
ctxt The generic decompression context max_ip_id_bits_nr The maximum number of IP-ID bits that may be transmitted
- Returns:
- true if the required IP-ID bits may be transmitted, false otherwise
| static bool is_outer_ip_id_bits_possible | ( | const struct rohc_comp_rfc3095_ctxt *const | ctxt, | |
| const size_t | max_ip_id_bits_nr | |||
| ) | [inline, static] |
May the outer IP header transmit the required non-random IP-ID bits?
- Parameters:
-
ctxt The generic decompression context max_ip_id_bits_nr The maximum number of IP-ID bits that may be transmitted
- Returns:
- true if the required IP-ID bits may be transmitted, false otherwise
| static bool no_inner_ip_id_bits_required | ( | const struct rohc_comp_rfc3095_ctxt *const | ctxt | ) | [inline, static] |
Does the inner IP header require to transmit no non-random IP-ID bit?
- Parameters:
-
ctxt The generic decompression context
- Returns:
- true if no required inner IP-ID bit shall be transmitted, false otherwise
| static bool no_outer_ip_id_bits_required | ( | const struct rohc_comp_rfc3095_ctxt *const | ctxt | ) | [inline, static] |
Does the outer IP header require to transmit no non-random IP-ID bit?
- Parameters:
-
ctxt The generic decompression context
- Returns:
- true if no required outer IP-ID bit shall be transmitted, false otherwise
| 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
| bool rohc_comp_rfc3095_create | ( | struct rohc_comp_ctxt *const | context, | |
| 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_shift The shift parameter (p) to use for encoding SN with W-LSB packet The packet given to initialize the new context
- Returns:
- bool if successful, false otherwise
| 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
| 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
| 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.
1. parse uncompressed packet (done in rohc_compress4)
2. detect changes between the new uncompressed packet and the context
3. decide new compressor state
4. determine how many bytes are required for every field
5. decide which packet to send
6. code the ROHC header
7. copy the packet payload (done in rohc_compress4)
8. 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
| 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
| 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
| 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
