Hi Gerrit, On Tue, Jun 24, 2008 at 3:36 PM, Gerrit Renker <gerrit@xxxxxxxxxxxxxx> wrote: > Hi Michael (cc-ed to list), > > as per earlier conversation, I have sat down and assembled a udplite.7 > manpage. Thanks for that! > I have checked it against the conventions (in particular spelling) > mentioned in man-pages(7) and it seems ok. Yes, it looks good. > Since I am rather a groff-newbie, I'd welcome suggestions to improve the > format, the content seems now stable (after a few iterations). The groff was fine. I made a few light edits to the page. I also added some comments to the page with some "FIXME(gr)" pointing to places where I think some work is needed. (I will later pick up the FIXMEs you had already put in the page, when the glibc support appears.) Could you take a look at these? The modified page is inline below. Thanks, Michael ============== .\" FIXME(gr) we need a license for this page. .\" The one I tend to favor is shown in the capabilities.7 page, .\" but others are also used in man-pages (e.g., GPL, BSD). .TH UDPLITE 7 2008-06-23 "Linux" "Linux Programmer's Manual" .SH NAME udplite \- Lightweight User Datagram Protocol .SH SYNOPSIS .B #include <sys/socket.h> .br .\" FIXME: see #defines under `BUGS', .\" when glibc supports this, add .\" #include <netinet/udplite.h> .sp .B s = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDPLITE); .SH DESCRIPTION This is an implementation of the Lightweight User Datagram Protocol (UDP-Lite), as described in RFC\ 3828. UDP-Lite is an extension of UDP (RFC\ 768) to support variable-length checksums. This has advantages for some types of multimedia transport, since it makes it possible to reuse partly damaged frames (with few bit errors). .\" FIXME(gr) is "reuse" the right word in the previous sentence? .\" Reading the RFC suggests to me that a better wording might be: .\" .\" This has advantages for some types of multimedia transport that .\" may be able to make use of slightly damaged datagrams, .\" rather than having them discarded by lower layer protocols. The variable-length checksum coverage is set via a .BR setsockopt (2) option. If this option is not set, the only difference to UDP is in using a different IP protocol identifier (IANA number 136). The UDP-Lite implementation is a full extension of .BR udp (7), i.e., it shares the same API and API behaviour, and in addition offers two socket options to control the checksum coverage. .SS "Address Format" UDP-Litev4 uses the .I sockaddr_in address format described in .BR ip (7). UDP-Litev6 uses the .I sockaddr_in6 address format described in .BR ipv6 (7). .SS "Socket Options" To set or get a UDP-Lite socket option, call .BR getsockopt (2) to read or .BR setsockopt (2) to write the option with the option level argument set to .BR IPPROTO_UDPLITE . In addition, all .B IPPROTO_UDP socket options are valid on a UDP-Lite socket. See .BR udp (7) for more information. The following two options are specific to UDP-Lite. .TP .BR UDPLITE_SEND_CSCOV This option sets the sender checksum coverage and takes an .B int as argument, with a checksum coverage value in the range 0..2^16-1. A value of 0 means that the entire datagram is always covered, values from 1-7 are illegal (RFC\ 3828, 3.1) and are rounded up to the minimum coverage of 8. With regard to IPv6 jumbograms (RFC\ 2675), the UDP-Litev6 checksum coverage is limited to the first 2^16-1 octets, as per RFC\ 3828, 3.5. Higher values are therefore not supported. .\" FIXME(gr) If higher values are specified, what happens? .\" If they are silently ignored, probably we should explicitly .\" say so here. .TP .BR UDPLITE_RECV_CSCOV This is the receiver-side analogue and uses uses the same argument format and value range as .BR UDPLITE_SEND_CSCOV . This option is not required to enable traffic with partial checksum coverage. Its function is that of a traffic filter: when enabled, it instructs the kernel to drop all packets which have a coverage .I less than the specified coverage value. .\" FIXME: SO_NO_CHECK exists and is supported by UDPv4, but is .\" commented out in socket(7), hence also here ??? .\".PP .\"Since UDP-Lite mandates checksums, checksumming can not be disabled .\"via the .\".B SO_NO_CHECK .\"option from .\".BR socket (7). .SH ERRORS All errors documented for .BR udp (7) may be returned. UDP-Lite does not add further errors. When the value of .B UDPLITE_RECV_CSCOV exceeds the actual coverage, incoming packets are silently dropped, but may generate a warning message in the system log. .SH BUGS .\" FIXME: remove this section once glibc supports UDP-Lite Where glibc support is missing, the following definitions are needed: .in +4n .nf #define IPPROTO_UDPLITE 136 .\" The following two are defined in the kernel in linux/net/udplite.h #define UDPLITE_SEND_CSCOV 10 #define UDPLITE_RECV_CSCOV 11 .fi .in .SH FILES .I /proc/net/snmp .br .IR /proc/net/snmp6 .\" FIXME(gr) .\" Could you add some discussion of the UDPLITE-specific .\" info in these files? .SH VERSIONS UDP-Litev4/v6 first appeared in Linux 2.6.20. .SH "SEE ALSO" .BR udp (7), .BR ip (7), .BR ipv6 (7), .BR socket (7) RFC\ 3828 for the Lightweight User Datagram Protocol (UDP-Lite) .br .I Documentation/networking/udplite.txt -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
