user_namespaces.7: Minor wording fix to recently added text

[thirdparty/man-pages.git] / man2 / connect.2

diff --git a/man2/connect.2 b/man2/connect.2
index c1e731ce003bbe0c9f85a7003b5d7bd20d56c06d..679b0fec5035773f11b1f529c03205a09d2f087a 100644 (file)
--- a/man2/connect.2
+++ b/man2/connect.2
@@ -64,7 +64,7 @@
 .\" Modified 1998, 1999 by Andi Kleen
 .\" Modified 2004-06-23 by Michael Kerrisk <mtk.manpages@gmail.com>
 .\"
-.TH CONNECT 2 2008-12-03 "Linux" "Linux Programmer's Manual"
+.TH CONNECT 2 2019-03-06 "Linux" "Linux Programmer's Manual"
 .SH NAME
 connect \- initiate a connection on a socket
 .SH SYNOPSIS
@@ -72,7 +72,7 @@ connect \- initiate a connection on a socket
 .BR "#include <sys/types.h>" "          /* See NOTES */"
 .br
 .B #include <sys/socket.h>
-.sp
+.PP
 .BI "int connect(int " sockfd ", const struct sockaddr *" addr ,
 .BI "            socklen_t " addrlen );
 .fi
@@ -94,11 +94,11 @@ is determined by the address space of the socket
 see
 .BR socket (2)
 for further details.
-
+.PP
 If the socket
 .I sockfd
 is of type
-.B SOCK_DGRAM
+.BR SOCK_DGRAM ,
 then
 .I addr
 is the address to which datagrams are sent by default, and the only
@@ -149,36 +149,50 @@ firewall rule.
 .B EADDRINUSE
 Local address is already in use.
 .TP
+.B EADDRNOTAVAIL
+(Internet domain sockets)
+The socket referred to by
+.I sockfd
+had not previously been bound to an address and,
+upon attempting to bind it to an ephemeral port,
+it was determined that all port numbers in the ephemeral port range
+are currently in use.
+See the discussion of
+.I /proc/sys/net/ipv4/ip_local_port_range
+in
+.BR ip (7).
+.TP
 .B EAFNOSUPPORT
 The passed address didn't have the correct address family in its
 .I sa_family
 field.
 .TP
 .B EAGAIN
-No more free local ports or insufficient entries in the routing cache.
-For
-.B AF_INET
-see the description of
-.I /proc/sys/net/ipv4/ip_local_port_range
-.BR ip (7)
-for information on how to increase the number of local ports.
+For nonblocking UNIX domain sockets, the socket is nonblocking, and the
+connection cannot be completed immediately.
+For other socket families, there are insufficient entries in the routing cache.
 .TP
 .B EALREADY
 The socket is nonblocking and a previous connection attempt has not yet
 been completed.
 .TP
 .B EBADF
-The file descriptor is not a valid index in the descriptor table.
+.I sockfd
+is not a valid open file descriptor.
 .TP
 .B ECONNREFUSED
-No-one listening on the remote address.
+A
+.BR connect ()
+on a stream socket found no one listening on the remote address.
 .TP
 .B EFAULT
 The socket structure address is outside the user's address space.
 .TP
 .B EINPROGRESS
-The socket is nonblocking and the connection cannot be completed
-immediately.
+The socket is nonblocking and the connection cannot be completed immediately.
+(UNIX domain sockets failed with
+.BR EAGAIN
+instead.)
 It is possible to
 .BR select (2)
 or
@@ -214,7 +228,14 @@ The socket is already connected.
 Network is unreachable.
 .TP
 .B ENOTSOCK
-The file descriptor is not associated with a socket.
+The file descriptor
+.I sockfd
+does not refer to a socket.
+.TP
+.B EPROTOTYPE
+The socket type does not support the requested communications protocol.
+This error can occur, for example,
+on an attempt to connect a UNIX domain datagram socket to a stream socket.
 .TP
 .B ETIMEDOUT
 Timeout while attempting connection.
@@ -223,9 +244,9 @@ busy to accept new connections.
 Note that for IP sockets the timeout may
 be very long when syncookies are enabled on the server.
 .SH CONFORMING TO
-SVr4, 4.4BSD, (the
-.BR connect ()
-function first appeared in 4.2BSD), POSIX.1-2001.
+POSIX.1-2001, POSIX.1-2008, SVr4, 4.4BSD,
+.RB (connect ()
+first appeared in 4.2BSD).
 .\" SVr4 documents the additional
 .\" general error codes
 .\" .BR EADDRNOTAVAIL ,
@@ -239,22 +260,22 @@ function first appeared in 4.2BSD), POSIX.1-2001.
 .\" It also
 .\" documents many additional error conditions not described here.
 .SH NOTES
-POSIX.1-2001 does not require the inclusion of
+POSIX.1 does not require the inclusion of
 .IR <sys/types.h> ,
 and this header file is not required on Linux.
 However, some historical (BSD) implementations required this header
 file, and portable applications are probably wise to include it.
-
-The third argument of
-.BR connect ()
-is in reality an
-.I int
-(and this is what 4.x BSD and libc4 and libc5 have).
-Some POSIX confusion resulted in the present
-.IR socklen_t ,
-also used by glibc.
-See also
+.PP
+For background on the
+.I socklen_t
+type, see
 .BR accept (2).
+.PP
+If
+.BR connect ()
+fails, consider the state of the socket as unspecified.
+Portable applications should close the socket and create a new one for
+reconnecting.
 .SH EXAMPLE
 An example of the use of
 .BR connect ()