[PATCH v10 0/5] Retry SYNs for inbound connections

[Yumei Huang <yuhuang@redhat.com>]

When a client connects, SYN would be sent to guest only once. If the
guest is not connected or ready at that time, the connection will be
reset in 10s. These patches introduce the SYN retry mechanism using
the similar backoff timeout as linux kernel. Also update the data
retransmission timeout using the backoff timeout.

v10:
    - Update read_file() to check buf_size first
    - Improve debug message in read_file_integer()
    - Replace RTO_MAX_MS_DEFAULT with RTO_MAX_DEFAULT
    - Wording fixes

v9:
    - Squash the patch of adding parameter c to tcp_timer_ctl() into the
      later one
    - Fix the cppcheck error
    - Update the return values of read_file(), remove the error message
      of it and add check for buf_size
    - Rename RTO_INIT_ACK to RTO_INIT_AFTER_SYN_RETRIES
    - Round up rto_max, fix the conversion in subtraction
    - Some other minor fixes related to wording
    
v8:
    - Remove the TCP_/tcp_ suffix from certain macro and struct member names
    - Add parameter struct ctx *c to tcp_timer_ctl()
    - Modify rto_max type from size_t to int
    - Clamp syn_retries and syn_linear_timeouts with MAX_SYNCNT(127)
    - Some other minor fixes related to wording and formatting

v7:
    - Update read_file() and read_file_integer()
    - Rename tcp_syn_params_init() to tcp_get_rto_params()
    - Modify the implementation of the timeout assignment
    - Add a patch to clamp the retry timeout

Yumei Huang (5):
  tcp: Rename "retrans" to "retries"
  util: Introduce read_file() and read_file_integer() function
  tcp: Resend SYN for inbound connections
  tcp: Update data retransmission timeout
  tcp: Clamp the retry timeout

 tcp.c      | 107 +++++++++++++++++++++++++++++++++++++++--------------
 tcp.h      |   6 +++
 tcp_conn.h |  13 ++++---
 util.c     |  91 +++++++++++++++++++++++++++++++++++++++++++++
 util.h     |   1 +
 5 files changed, 185 insertions(+), 33 deletions(-)

-- 
2.51.1