libnl 2.0
Modules | Defines | Enumerations

Traffic Control

Routing Family

Modules

 Queueing Classes
 Classifiers
 Packet Location Aliasing
 

Packet Location Aliasing.


 Queueing Disciplines

Defines

#define RTNL_TC_RTABLE_SIZE   256
 Number of entries in a transmission time lookup table.

Enumerations

enum  rtnl_tc_stats_id {
  RTNL_TC_PACKETS, RTNL_TC_BYTES, RTNL_TC_RATE_BPS, RTNL_TC_RATE_PPS,
  RTNL_TC_QLEN, RTNL_TC_BACKLOG, RTNL_TC_DROPS, RTNL_TC_REQUEUES,
  RTNL_TC_OVERLIMITS, __RTNL_TC_STATS_MAX
}
 

TC statistics identifiers.

More...

Utilities

int rtnl_tc_calc_txtime (int bufsize, int rate)
 Calculate time required to transmit buffer at a specific rate.
int rtnl_tc_calc_bufsize (int txtime, int rate)
 Calculate buffer size able to transmit in a specific time and rate.
int rtnl_tc_calc_cell_log (int cell_size)
 Calculate the binary logarithm for a specific cell size.

Rate Tables

int rtnl_tc_build_rate_table (uint32_t *dst, uint8_t mpu, uint8_t overhead, int cell, int rate)
 Compute a transmission time lookup table.

Traffic Control Handle Translations

char * rtnl_tc_handle2str (uint32_t handle, char *buf, size_t len)
 Convert a traffic control handle to a character string (Reentrant).
int rtnl_tc_str2handle (const char *name, uint32_t *res)
 Convert a charactering strint to a traffic control handle.

Enumeration Type Documentation

Enumerator:
RTNL_TC_PACKETS 

Packets seen.

RTNL_TC_BYTES 

Bytes seen.

RTNL_TC_RATE_BPS 

Current bits/s (rate estimator)

RTNL_TC_RATE_PPS 

Current packet/s (rate estimator)

RTNL_TC_QLEN 

Queue length.

RTNL_TC_BACKLOG 

Backlog length.

RTNL_TC_DROPS 

Packets dropped.

RTNL_TC_REQUEUES 

Number of requeues.

RTNL_TC_OVERLIMITS 

Number of overlimits.

Definition at line 27 of file tc.h.


Function Documentation

int rtnl_tc_calc_txtime ( int  bufsize,
int  rate 
)
Parameters:
bufsizeSize of buffer to be transmited in bytes.
rateTransmit rate in bytes per second.

Calculates the number of micro seconds required to transmit a specific buffer at a specific transmit rate.

\[ txtime=\frac{bufsize}{rate}10^6 \]

Returns:
Required transmit time in micro seconds.

Definition at line 375 of file tc.c.

Referenced by rtnl_qdisc_tbf_set_peakrate(), rtnl_qdisc_tbf_set_rate(), and rtnl_tc_build_rate_table().

int rtnl_tc_calc_bufsize ( int  txtime,
int  rate 
)
Parameters:
txtimeAvailable transmit time in micro seconds.
rateTransmit rate in bytes per second.

Calculates the size of the buffer that can be transmitted in a specific time period at a specific transmit rate.

\[ bufsize=\frac{{txtime} \times {rate}}{10^6} \]

Returns:
Size of buffer in bytes.

Definition at line 398 of file tc.c.

int rtnl_tc_calc_cell_log ( int  cell_size)
Parameters:
cell_sizeSize of cell, must be a power of two.
Returns:
Binary logirhtm of cell size or a negative error code.

Definition at line 412 of file tc.c.

Referenced by rtnl_tc_build_rate_table().

int rtnl_tc_build_rate_table ( uint32_t *  dst,
uint8_t  mpu,
uint8_t  overhead,
int  cell,
int  rate 
)
Parameters:
dstDestination buffer of RTNL_TC_RTABLE_SIZE uint32_t[].
mpuMinimal size of a packet at all times.
overheadOverhead to be added to each packet.
cellSize of cell, i.e. size of step between entries in bytes.
rateRate in bytes per second.

Computes a table of RTNL_TC_RTABLE_SIZE entries specyfing the transmission times for various packet sizes, e.g. the transmission time for a packet of size pktsize could be looked up:

 txtime = table[pktsize >> log2(cell)];

Definition at line 446 of file tc.c.

References rtnl_tc_calc_cell_log(), rtnl_tc_calc_txtime(), and RTNL_TC_RTABLE_SIZE.

char* rtnl_tc_handle2str ( uint32_t  handle,
char *  buf,
size_t  len 
)
Parameters:
handletraffic control handle
bufdestination buffer
lenbuffer length

Converts a tarffic control handle to a character string in the form of MAJ:MIN and stores it in the specified destination buffer.

Returns:
The destination buffer or the type encoded in hexidecimal form if no match was found.

Definition at line 485 of file tc.c.

int rtnl_tc_str2handle ( const char *  name,
uint32_t *  res 
)
Parameters:
nametraffic control handle as character string
resdestination buffer

Converts the provided character string specifying a traffic control handle to the corresponding numeric value.

The handle must be provided in one of the following formats:

  • root
  • none
  • XXXX:
  • :YYYY
  • XXXX:YYYY
  • XXXXYYYY
Returns:
0 on success or a negative error code

Definition at line 520 of file tc.c.