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-rw-r--r--man7/raw.742
1 files changed, 21 insertions, 21 deletions
diff --git a/man7/raw.7 b/man7/raw.7
index ab43dd4..65cdbe0 100644
--- a/man7/raw.7
+++ b/man7/raw.7
@@ -5,7 +5,7 @@
.\"
.\" $Id: raw.7,v 1.6 1999/06/05 10:32:08 freitag Exp $
.\"
-.TH raw 7 2023-07-15 "Linux man-pages 6.05.01"
+.TH raw 7 2023-10-31 "Linux man-pages 6.7"
.SH NAME
raw \- Linux IPv4 raw sockets
.SH SYNOPSIS
@@ -18,17 +18,17 @@ raw \- Linux IPv4 raw sockets
Raw sockets allow new IPv4 protocols to be implemented in user space.
A raw socket receives or sends the raw datagram not
including link level headers.
-.PP
+.P
The IPv4 layer generates an IP header when sending a packet unless the
.B IP_HDRINCL
socket option is enabled on the socket.
When it is enabled, the packet must contain an IP header.
For receiving, the IP header is always included in the packet.
-.PP
+.P
In order to create a raw socket, a process must have the
.B CAP_NET_RAW
capability in the user namespace that governs its network namespace.
-.PP
+.P
All packets or errors matching the
.I protocol
number specified
@@ -39,7 +39,7 @@ see the IANA list of assigned protocol numbers at
.UE
and
.BR getprotobyname (3).
-.PP
+.P
A protocol of
.B IPPROTO_RAW
implies enabled
@@ -61,7 +61,7 @@ Packet ID:Filled in when zero
Total Length:Always filled in
.TE
.RE
-.PP
+.P
If
.B IP_HDRINCL
is specified and the IP header has a nonzero destination address, then
@@ -71,7 +71,7 @@ When
is specified, the destination address should refer to a local interface,
otherwise a routing table lookup is done anyway but gatewayed routes
are ignored.
-.PP
+.P
If
.B IP_HDRINCL
isn't set, then IP header options can be set on raw sockets with
@@ -79,12 +79,12 @@ isn't set, then IP header options can be set on raw sockets with
see
.BR ip (7)
for more information.
-.PP
+.P
Starting with Linux 2.2, all IP header fields and options can be set using
IP socket options.
This means raw sockets are usually needed only for new
protocols or protocols with no user interface (like ICMP).
-.PP
+.P
When a packet is received, it is passed to any raw sockets which have
been bound to its protocol before it is passed to other protocol handlers
(e.g., kernel protocol modules).
@@ -123,7 +123,7 @@ protocol.
The value has a bit set for each ICMP message type which
should be filtered out.
The default is to filter no ICMP messages.
-.PP
+.P
In addition, all
.BR ip (7)
.B IPPROTO_IP
@@ -178,7 +178,7 @@ and
.B ICMP_FILTER
are new in Linux 2.2.
They are Linux extensions and should not be used in portable programs.
-.PP
+.P
Linux 2.0 enabled some bug-to-bug compatibility with BSD in the
raw socket code when the
.B SO_BSDCOMPAT
@@ -202,7 +202,7 @@ When turned off, raw sockets will fragment outgoing packets
that exceed the interface MTU.
However, disabling it is not recommended
for performance and reliability reasons.
-.PP
+.P
A raw socket can be bound to a specific local address using the
.BR bind (2)
call.
@@ -211,7 +211,7 @@ In addition, a raw socket can be bound to a specific network device using
.BR SO_BINDTODEVICE ;
see
.BR socket (7).
-.PP
+.P
An
.B IPPROTO_RAW
socket is send only.
@@ -222,28 +222,28 @@ socket with the
protocol.
Note that packet sockets don't reassemble IP fragments,
unlike raw sockets.
-.PP
+.P
If you want to receive all ICMP packets for a datagram socket,
it is often better to use
.B IP_RECVERR
on that particular socket; see
.BR ip (7).
-.PP
+.P
Raw sockets may tap all IP protocols in Linux, even
protocols like ICMP or TCP which have a protocol module in the kernel.
In this case, the packets are passed to both the kernel module and the raw
socket(s).
This should not be relied upon in portable programs, many other BSD
socket implementation have limitations here.
-.PP
+.P
Linux never changes headers passed from the user (except for filling
in some zeroed fields as described for
.BR IP_HDRINCL ).
This differs from many other implementations of raw sockets.
-.PP
+.P
Raw sockets are generally rather unportable and should be avoided in
programs intended to be portable.
-.PP
+.P
Sending on raw sockets should take the IP protocol from
.IR sin_port ;
this ability was lost in Linux 2.2.
@@ -251,12 +251,12 @@ The workaround is to use
.BR IP_HDRINCL .
.SH BUGS
Transparent proxy extensions are not described.
-.PP
+.P
When the
.B IP_HDRINCL
option is set, datagrams will not be fragmented and are limited to
the interface MTU.
-.PP
+.P
Setting the IP protocol for sending in
.I sin_port
got lost in Linux 2.2.
@@ -272,7 +272,7 @@ call is always used.
.BR capabilities (7),
.BR ip (7),
.BR socket (7)
-.PP
+.P
.B RFC\ 1191
for path MTU discovery.
.B RFC\ 791