Capitalization in .SS sections across pages (and sometimes even
within a single page) is wildly inconsistent. Make it consistent.
Capitalize first word in heading, but otherwise use lower case,
except where English usage (e.g., proper nouns) or programming
language requirements (e.g., identifier names) dictate otherwise.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
POSIX.1-2008 TC1 clarified this, so that O_CLOEXEC,
O_DIRECTORY, and O_NOFOLLOW are also in this list.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
I misapplied Vince's patch, so that his name was not recorded
as the author in the git log. We can at least fix it in the
manual changelog.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Problem:
When connect(2) is executed, the local port number may duplicate.
How reproducible:
When using parameter "net.ipv4.ip_local_port_range", a client may use
the same port to connect to the different sessions on the localhost.
Steps to Reproduce:
1.Change "net.ipv4.ip_local_port_range".
[Example]
net.ipv4.ip_local_port_range = 32768 32770
2.Connect to any two ports of LISTEN by telnet command.
[Example]
# netstat -antp | grep LISTEN
tcp 0 0 0.0.0.0:139 0.0.0.0:* LISTEN 2828/smbd
tcp 0 0 0.0.0.0:21 0.0.0.0:* LISTEN 2800/vsftpd
#
# telnet 127.0.0.1 139
# telnet 127.0.0.1 21
# telnet 127.0.0.1 21
3.Duplication of a local transmission port.
[Example]
# netstat -antp
tcp 0 0 127.0.0.1:32769 127.0.0.1:139 ESTABLISHED 18147/telnet
tcp 0 0 127.0.0.1:32769 127.0.0.1:21 ESTABLISHED 18157/telnet
Actual results:
The local port number may duplicate.
Expected results:
The local port number doesn't duplicate.
Additional info:
[Investigation]
"man 7 ip" contains following text:
-----------------------------------------------------------------
When listen(2) or connect(2) are called on an unbound socket, it
is automatically bound to a random free port with the local
address set to INADDR_ANY.
-----------------------------------------------------------------
Although indicated as "it is automatically bound to a random free
port", the port number which is not free like in a reproduce
procedure may be bound. Therefore, based on the description of
this "man 7 ip", it can be judged that it is bug to use the local
port where the process duplicated.
--- Comment by Leitner, Flavio on 2/7/2012 2:55 PM ---
It's allowed to have multiple tasks using the same port (as a
result of calling connect(2)) as long as the other connection
information (4-tuple) differs to resolve the conflict. Thus,
it must be an unique 4-tuple consisting of source and
destination IP addresses and port numbers to not conflict.
In the example, the dest port is different.
tcp 0 0 127.0.0.1:32769 127.0.0.1:139 ESTABLISHED 18147/telnet
tcp 0 0 127.0.0.1:32769 127.0.0.1:21 ESTABLISHED 18157/telnet
Reported-by: Peter Schiffer <pschiffe@redhat.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
POSIX deliberately leaves this case open, so the man
page should be less specific about what happens.
See http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=533232
Reported-by: Zack Weinberg <zackw@panix.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Michael Kerrisk