X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;f=src%2Fmans%2Foping.pod;h=19d45042f6d237c451fb4649b6d75bce60bd6368;hb=ee13385b1c68103b7d57a745ee8a1ae908406df6;hp=6005b0011f396db802bd6fd4192e067bf69e11ed;hpb=12b51be67146bf5619acb1110b54c291fcca6652;p=liboping.git diff --git a/src/mans/oping.pod b/src/mans/oping.pod index 6005b00..19d4504 100644 --- a/src/mans/oping.pod +++ b/src/mans/oping.pod @@ -66,10 +66,142 @@ Set the outgoing network device to use. Instead of specifying hostnames on the command line, read them from I. If I is B<->, read from C. -If the real user ID (as returned by L) and the effective user ID (as +If I is installed with the SetUID-bit, it will set the effective UID to +the real UID before opening the file. In the special (but common) case that +I is owned by the super-user (UIDE0), this means that privileges +are temporarily dropped before opening the file, in order to prevent users from +reading arbitrary files on the system. + +If your system doesn't provide I (this was an optional +feature before POSIXE2001), the behavior is different because it is not +possible to I drop privileges. The alternative behavior is: If the +real user ID (as returned by L) and the effective user ID (as returned by L) differ, the only argument allowed for this option is -"-" (i.Ee. standard input). This is meant to avoid security issues when -I is installed with the SUID-bit. +"-" (i.e. standard input). + +=item B<-Q> I + +Specify the I (QoS) for outgoing packets. This is a +somewhat tricky option, since the meaning of the bits in the IPv4 header has +been revised several times. + +The currently recommended method is I which is used in +IPv6 headers as well. There are shortcuts for various predefined +I (PHBs): + +=over 4 + +=item B + +Selects the I behavior. This is the default behavior. + +=item B + +Selects the I (EF) per-hop behavior, as defined in +I3246>. This PHB is characterised by low delay, low loss and low +jitter, i.e. high priority traffic. + +=item B + +Selects the I (VA) per-hop behavior, as defined in +I5865>. This traffic class is meant for I (VoIP) +traffic which uses I (CAC) for reserving network +capacity. + +=item BII

+ +Selects one of 12Edifferentiated services code points (DSCPs), which are +organized in four I with three I each. Therefore, I +must be a number betweenE1 throughE4 and I

must be a number +betweenE1 throughE3, for example "af13", "af22" and "af41". In each +class, the lower priority number takes precedence over the higher priority +number. + +=item BI + +Selects one of the eight I PHBs. I is a number +betweenE0 throughE7. The class selectors have been defined to be +compatible to the I field in the IPv4 header as defined in +I791>. Please note that "cs0" is synonymous to "be". + +=back + +The old definition of the same bits in the IPv4 header was as I (ToS) field, specified in I1349>. It defined four possible +values which have appropriate aliases. Please note that this use of the bits is +B and the meaning is limited to IPv4! + +=over 4 + +=item B + +Minimize delay + +=item B + +Maximize throughput + +=item B + +Maximize reliability + +=item B + +Minimize monetary cost + +=back + +Alternatively, you can also specify the byte manually. You can use either a +decimal number (0-255), a hexadecimal number (0x00-0xff) or an octal number +(00-0377) using the usual "0x" and "0" prefixes for hexadecimal and octal +respectively. + +The printed lines will contain information about the QoS field of received +packets if either a non-standard QoS setting was used on outgoing packets or if +the QoS byte of incoming packets is not zero. In other words, the QoS +information is omitted if both, the outgoing and the incoming QoS bytes are +zero. The received byte is always interpreted as +I (DSCP) and +I (ECN), even if the deprecated +I (ToS) aliases were used to specify the bits of outgoing +packets. + +=item B<-u>|B<-U> + +I B<-u> forces UTF-8 output, B<-U> disables UTF-8 output. If +neither is given, the codeset is automatically determined from the locale. + +=item B<-P> I + +Configures the latency percentile to report. I must be a number +between zero and 100, exclusively in both cases. In general, defaults to B<95>. +If B<-c> is given and a number less than 20, this would be the same as the +maximum. In this case the default is chosen so that it excludes the maximum, +e.g. if B<-cE5> is given, the default is I<80>. + +The calculated percentile has roughly millisecond precision. If precision is of +importance, read on for a more detailed explanation. In order to calculate the +percentile without keeping all replies in memory, I divides the +I (the B<-i> option) in 1000 "buckets". Each bucket counts the number +of packets received in the represented time. That means that the precision +decreases if the interval is increased, because each bucket represents a larger +(fraction of the) response time. The code looks for the first bucket +representing at least I responses and returns the upper-bound latency +represented by that bucket. Since the represented percentage may be larger than +the configured percentile, this algorithm I the actual percentile +by at most 1000th of I. + +=item B<-Z> I + +If any hosts have a drop rate higher than I, where I is a +number between zero and 100 inclusively, exit with a non-zero exit status. +Since it is not possible to have a higher drop rate than 100%, passing this +limit will effectively disable the feature (the default). Setting the option to +zero means that the exit status will only be zero if I replies for I +hosts have been received. + +The exit status will indicate the number of hosts with more than I +packets lost, up to a number of 255 failing hosts. =back @@ -95,7 +227,7 @@ L, L, L =head1 AUTHOR -liboping is written by Florian octo Forster Eocto at verplant.orgE. +liboping is written by Florian "octo" Forster Eff at octo.itE. Its homepage can be found at L. -(c) 2005-2010 by Florian octo Forster. +Copyright (c) 2005-2011 by Florian "octo" Forster.