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STRUCT TID_AMPDU_RX(9) Internals STRUCT TID_AMPDU_RX(9)

NAME

struct_tid_ampdu_rx - TID aggregation information (Rx).

SYNOPSIS

struct tid_ampdu_rx {
  struct rcu_head rcu_head;
  spinlock_t reorder_lock;
  u64 reorder_buf_filtered;
  struct sk_buff_head * reorder_buf;
  unsigned long * reorder_time;
  struct timer_list session_timer;
  struct timer_list reorder_timer;
  unsigned long last_rx;
  u16 head_seq_num;
  u16 stored_mpdu_num;
  u16 ssn;
  u16 buf_size;
  u16 timeout;
  u8 dialog_token;
  bool auto_seq;
  bool removed;
};

MEMBERS

rcu_head
RCU head used for freeing this struct
reorder_lock
serializes access to reorder buffer, see below.
reorder_buf_filtered
bitmap indicating where there are filtered frames in the reorder buffer that should be ignored when releasing frames
reorder_buf
buffer to reorder incoming aggregated MPDUs. An MPDU may be an A-MSDU with individually reported subframes.
reorder_time
jiffies when skb was added
session_timer
check if peer keeps Tx-ing on the TID (by timeout value)
reorder_timer
releases expired frames from the reorder buffer.
last_rx
jiffies of last rx activity
head_seq_num
head sequence number in reordering buffer.
stored_mpdu_num
number of MPDUs in reordering buffer
ssn
Starting Sequence Number expected to be aggregated.
buf_size
buffer size for incoming A-MPDUs
timeout
reset timer value (in TUs).
dialog_token
dialog token for aggregation session
auto_seq
used for offloaded BA sessions to automatically pick head_seq_and and ssn.
removed
this session is removed (but might have been found due to RCU)

DESCRIPTION

This structure's lifetime is managed by RCU, assignments to the array holding it must hold the aggregation mutex.
The reorder_lock is used to protect the members of this struct, except for timeout, buf_size and dialog_token, which are constant across the lifetime of the struct (the dialog token being used only for debugging).

AUTHOR

Johannes Berg <johannes@sipsolutions.net>
Author.

COPYRIGHT

January 2017 Kernel Hackers Manual 4.8.