X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/tripe/blobdiff_plain/808702d218ba5999dbc8cef769a79d1fb9be1e63..3cdc3f3a27e8c4f4fe692009d868c773d298a68c:/doc/tripe-admin.5

diff --git a/doc/tripe-admin.5 b/doc/tripe-admin.5
index f762692e..d39866e0 100644
--- a/doc/tripe-admin.5
+++ b/doc/tripe-admin.5
@@ -45,34 +45,125 @@ provides information requested in the command.  An
 .B OK
 response contains no further data.  A
 .B FAIL
-code is followed by a human-readable explanation of why the command
+code is followed by a machine-readable explanation of why the command
 failed.
 .PP
-In addition, there are two types of asynchronous `responses', which
+In addition, there are three types of asynchronous messages which
 aren't associated with any particular command.  The
 .B WARN
-response contains a human-readable message warning of an error
+message contains a machine-readable message warning of an error
 encountered while processing a command, unexpected or unusual behaviour
 by a peer, or a possible attack by an adversary.  Under normal
 conditions, the server shouldn't emit any warnings.  The
 .B TRACE
-response contains a human-readable tracing message containing diagnostic
+message contains a human-readable tracing message containing diagnostic
 information.  Trace messages are controlled using the
 .B \-T
 command-line option to the server, or the
 .B TRACE
 administration command (see below).  Support for tracing can be disabled
 when the package is being configured, and may not be available in your
-version.
-.SS "Command reference"
+version.  Finally, the
+.B NOTE
+message is a machine-readable notification about some routine but
+interesting event such as creation or destruction of peers.
+.PP
+The presence of asynchronous messages can be controlled using the
+.B WATCH
+command.
+.SS "Network addresses"
+A network address is a sequence of words.  The first is a token
+identifying the network address family.  The length of an address and
+the meanings of the subsequent words depend on the address family.
+Address family tokens are not case-sensitive on input; on output, they
+are always in upper-case.
+.PP
+At present, only one address family is understood.
+.TP
+.BI "INET " address " " port
+An Internet socket, naming an IPv4 address and UDP port.  On output, the
+address is always in numeric dotted-quad form, and the port is given as
+a plain number.  On input, DNS hostnames and symbolic port names are
+permitted.  Name resolution does not block the main server, but will
+block the requesting client.  This hopefully makes life simpler for
+stupid clients.  Complex clients which don't wish to be held up can open
+extra connections or do the resolution themselves.)
+.PP
+If, on input, no recognised address family token is found, the following
+words are assumed to represent an
+.B INET
+address.
+.SH "COMMAND REFERENCE"
 The commands provided are:
 .TP
+.BI "ADD " peer " " address\fR...
+Adds a new peer.  The peer is given the name
+.IR peer ;
+the peer's public key is assumed to be in the file
+.B keyring.pub
+(or whatever alternative file was specified in the
+.B \-K
+option on the command line).  The
+.I address
+is the network address (see above for the format) at which the peer can
+be contacted.
+.TP
+.BI "ADDR " peer
+Emits an
+.B INFO
+line reporting the IP address and port number stored for
+.IR peer .
+.TP
+.B "DAEMON"
+Causes the server to disassociate itself from its terminal and become a
+background task.  This only works once.  A warning is issued.
+.TP
 .B "HELP"
 Causes the server to emit an
 .B INFO
 line for each command it supports.  Each line lists the command name,
 followed by the names of the arguments.  This may be helpful as a memory
 aid for interactive use, or for program clients probing for features.
+.TP 
+.BI "IFNAME " peer
+Emits an
+.B INFO
+line containing the name of the network interface used to collect IP
+packets which are to be encrypted and sent to
+.IR peer .
+Used by configuration scripts so that they can set up routing tables
+appropriately after adding new peers.
+.TP
+.BI "KILL " peer
+Causes the server to forget all about
+.IR peer .
+All keys are destroyed, and no more packets are sent.  No notification
+is sent to the peer: if it's important that the peer be notified, you
+must think of a way to do that yourself.
+.TP
+.B "LIST"
+For each currently-known peer, an
+.B INFO
+line is written containing the peer's name, as given to
+.BR ADD .
+.TP
+.B "PORT"
+Emits an
+.B INFO
+line containing just the number of the UDP port used by the
+.B tripe
+server.  If you've allowed your server to allocate a port dynamically,
+this is how to find out which one it chose.
+.TP
+.B "QUIT"
+Instructs the server to exit immediately.  A warning is sent.
+.TP
+.BI "STATS " peer
+Emits a number of
+.B INFO
+lines, each containing one or more statistics in the form
+.IB name = value \fR.
+The statistics-gathering is experimental and subject to change.
 .TP
 .BR "TRACE " [\fIoptions\fP]
 A trace argument consists of a string of letters (listed below)
@@ -145,72 +236,435 @@ without one of
 .B x
 or
 .BR m .
+.TP
+.B A
+All of the above.
 .RE
 .TP
-.B "PORT"
-Emits an
+.BR "WATCH " [\fIoptions\fP]
+Enables or disables asynchronous messages
+.IR "for the current connection only" .
+This command has no effect on other connections.  A watch argument
+consists of a string of letters (listed below) selecting message types,
+optionally interspersed with
+.RB ` + '
+to enable, or
+.RB ` \- '
+to disable, the subsequently listed types, similar to
+.B trace
+above.  The default watch state for the connection the server opens
+automatically on stdin/stdout is to show warnings and trace messages;
+other connections show no asynchronous messages.  (This is done in order
+to guarantee that a program reading the server's stdout does not miss
+any warnings.)
+.RS
+.PP
+Currently, the following watch options are supported:
+.TP
+.B t
+.B TRACE
+messages.
+.TP
+.B n
+.B NOTE
+messages.
+.TP
+.B w
+.B WARN
+messages.
+.TP
+.B a
+All of the above.
+.RE
+.TP
+.B "VERSION"
+Causes the server to emit an
 .B INFO
-line containing just the number of the UDP port used by the
+line stating its software version, as two words: the server name, and
+its version string.  The server name
 .B tripe
-server.  If you've allowed your server to allocate a port dynamically,
-this is how to find out which one it chose.
+is reserved to the Straylight/Edgeware implementation.
+.SH "ERROR MESSAGES"
+The following
+.B FAIL
+messages are sent to clients as a result of errors during command
+processing.
 .TP
-.B "DAEMON"
-Causes the server to disassociate itself from its terminal and become a
-background task.  This only works once.  A warning is issued.
+.BI "already-daemon"
+(For
+.BR DAEMON .)
+The
+.B tripe
+server is already running as a daemon.
 .TP
-.B "LIST"
-For each currently-known peer, an
-.B INFO
-line is written containing the peer's name, as given to
-.BR ADD .
-.TP 
-.BI "IFNAME " peer
-Emits an
-.B INFO
-line containing the name of the network interface used to collect IP
-packets which are to be encrypted and sent to
-.IR peer .
-Used by configuration scripts so that they can set up routing tables
-appropriately after adding new peers.
+.BI "bad-syntax \-\- " message
+(For any command.)  The command couldn't be understood: e.g., the number
+of arguments was wrong.
 .TP
-.BI "ADDR " peer
-Emits an
-.B INFO
-line reporting the IP address and port number stored for
+.BI "bad-trace-option " char
+(For
+.BR TRACE .)
+An unknown trace option was requested.
+.TP
+.BI "bad-watch-option " char
+(For
+.BR WATCH .)
+An unknown watch option was requested.
+.TP
+.BI "daemon-error \-\- " message
+(For
+.BR DAEMON .)
+An error occurred during the attempt to become a daemon, as reported by
+.IR message .
+.TP
+.BI "invalid-port " number
+(For
+.BR ADD .)
+The given port number is out of range.
+.TP
+.BI "peer-create-fail " peer
+(For
+.BR ADD .)
+Adding
+.I peer
+failed for some reason.  A warning should have been emitted explaining
+why.
+.TP
+.BI "peer-exists " peer
+(For
+.BR ADD .)
+There is already a peer named
 .IR peer .
 .TP
-.BI "STATS " peer
-Emits a number of
-.B INFO
-lines, each containing one or more statistics in the form
-.IB name = value \fR.
-The statistics-gathering is experimental and subject to change.
+.BI "resolve-error " hostname
+(For
+.BR ADD .)
+The DNS name
+.I hostname
+could not be resolved.
+.TP
+.BI "resolver-timeout " hostname
+(For
+.BR ADD .)
+The DNS name
+.I hostname
+took too long to resolve.
+.TP
+.BI "unknown-command " token
+The command
+.B token
+was not recognised.
+.TP
+.BI "unknown-peer " name
+(For
+.BR ADDR ,
+.BR IFNAME ,
+.BR KILL ,
+and
+.BR STATS .)
+There is no peer called
+.IR name .
+.TP
+.BI "unknown-service " service
+(For
+.BR ADD .)
+The service name
+.I service
+couldn't be found in 
+.BR /etc/services .
+.SH "NOTIFICATIONS"
+The following notifications are sent to clients who request them.
+.TP
+.BI "ADD " peer " " address \fR...
+A new peer has been added.  The peer's name is
+.I peer
+and its network address is
+.IR address .
+.TP
+.BI "DAEMON"
+The server has forked off into the sunset and become a daemon.
 .TP
 .BI "KILL " peer
-Causes the server to forget all about
-.IR peer .
-All keys are destroyed, and no more packets are sent.  No notification
-is sent to the peer: if it's important that the peer be notified, you
-must think of a way to do that yourself.
+The peer
+.I peer
+has been killed.
 .TP
-.BI "ADD " "peer addr port"
-Adds a new peer.  The peer is given the name
-.IR peer ;
-the peer's public key is assumed to be in the file
-.B keyring.pub
-(or whatever alternative file was specified in the
-.B \-K
-option on the command line).  The peer's
+.BI "KXDONE " peer
+Key exchange with
+.I peer
+finished successfully.
+.TP
+.BI "KXSTART " peer
+Key exchange with
+.I peer
+has begun or restarted.  If key exchange keeps failing, this message
+will be repeated periodically.
+.SH "WARNINGS"
+There are many possible warnings.  They are categorized according to
+their first tokens.
+.SS "ABORT warnings"
+These all indicate that the
 .B tripe
-implementation may be contacted at the given UDP port and IP address.
+server has become unable to continue.  If enabled, the server will dump
+core in its configuration directory.
 .TP
-.B "QUIT"
-Instructs the server to exit immediately.  A warning is sent.
+.BI "ABORT repeated-select-errors"
+The main event loop is repeatedly failing.  If the server doesn't quit,
+it will probably waste all available CPU doing nothing.
+.SS "ADMIN warnings"
+These indicate a problem with the administration socket interface.
+.TP
+.BI "ADMIN accept-error \-\- " message
+There was an error while attempting to accept a connection from a new
+client.
+.TP
+.BI "ADMIN client-read-error \-\- " message
+There was an error sending data to a client.  The connection to the
+client has been closed.
+.SS "KEYMGMT warnings"
+These indicate a problem with the keyring files, or the keys stored in
+them.
+.TP
+.BI "KEYMGMT bad-private-key \-\- " message
+The private key could not be read, or failed a consistency check.  If
+there was a problem with the file, usually there will have been
+.B key-file-error
+warnings before this.
+.TP
+.BI "KEYMGMT bad-public-keyring \-\- " message
+The public keyring couldn't be read.  Usually, there will have been 
+.B key-file-error
+warnings before this.
+.TP
+.BI "KEYMGMT key-file-error " file ":" line " \-\- " message
+Reports a specific error with the named keyring file.  This probably
+indicates a bug in
+.BR key (1).
+.TP
+.BI "KEYMGMT public-key " tag " " tokens\fR...
+These messages all indicate a problem with the public key named
+.IR tag .
+.TP
+.BI "KEYMGMT public-key " tag " algorithm-mismatch"
+The algorithms specified on the public key don't match the ones for our
+private key.  All the peers in a network have to use the same
+algorithms.
+.TP
+.BI "KEYMGMT public-key " tag " bad \-\- " message
+The public key couldn't be read, or is invalid.
+.TP
+.BI "KEYMGMT public-key " tag " bad-public-group-element"
+The public key is invalid.  This may indicate a malicious attempt to
+introduce a bogus key.
+.TP
+.BI "KEYMGMT public-key " tag " bad-algorithm-selection"
+The algorithms listed on the public key couldn't be understood.  The
+algorithm selection attributes are probably malformed and need fixing.
+.TP
+.BI "KEYMGMT public-key " tag " incorrect-group"
+The public key doesn't use the same group as our private key.  All the
+peers in a network have to use the same group.
+.TP
+.BI "KEYMGMT public-key " tag " not-found"
+The public key for peer
+.I tag
+wasn't in the public keyring.
+.TP
+.BI "KEYMGMT public-key " tag " unknown-type"
+The type of the public key isn't understood.  Maybe you need to upgrade
+your copy of
+.BR tripe .
+(Even if you do, you'll have to regenerate your keys.)
+.SS "KX warnings"
+These indicate problems during key-exchange.  Many indicate either a bug
+in the server (either yours or the remote one), or some kind of attack
+in progress.  All name a
+.I peer
+as the second token: this is the peer the packet is apparently from,
+though it may have been sent by an attacker instead.
+.PP
+In the descriptions below,
+.I msgtoken
+is one of the tokens
+.BR pre-challenge ,
+.BR cookie ,
+.BR challenge ,
+.BR reply ,
+.BR switch-rq ,
+or
+.BR switch-ok .
+.TP
+.BI "KX " peer " bad-expected-reply-log"
+The challenges
+.B tripe
+uses in its protocol contain a check value which proves that the
+challenge is honest.  This message indicates that the check value
+supplied is wrong: someone is attempting to use bogus challenges to
+persuade your
+.B tripe
+server to leak private key information.  No chance!
+.TP
+.BI "KX " peer " decrypt-failed \fR[\fBreply\fR|\fBswitch-ok\fR]"
+A symmetrically-encrypted portion of a key-exchange message failed to
+decrypt.
+.TP
+.BI "KX " peer " invalid " msgtoken
+A key-exchange message was malformed.  This almost certainly indicates a
+bug somewhere.
+.TP
+.BI "KX " peer " incorrect \fR[\fBcookie\fR|\fBswitch-rq\fR|\fBswitch-ok\fR]"
+A message didn't contain the right magic data.  This may be a replay of
+some old exchange, or random packets being sent in an attempt to waste
+CPU.
+.TP
+.BI "KX " peer " public-key-expired"
+The peer's public key has expired.  It's maintainer should have given
+you a replacement before now.
+.TP
+.BI "KX " peer " sending-cookie"
+We've received too many bogus pre-challenge messages.  Someone is trying
+to flood us with key-exchange messages and make us waste CPU on doing
+hard asymmetric crypto sums.
+.TP
+.BI "KX " peer " unexpected " msgtoken
+The message received wasn't appropriate for this stage of the key
+exchange process.  This may mean that one of our previous packets got
+lost.  For 
+.BR pre-challenge ,
+it may simply mean that the peer has recently restarted.
+.TP
+.BI "KX " peer " unknown-challenge"
+The peer is asking for an answer to a challenge which we don't know
+about.  This may mean that we've been inundated with challenges from
+some malicious source
+.I who can read our messages
+and discarded the valid one.
+.TP
+.BI "KX " peer " unknown-message 0x" nn
+An unknown key-exchange message arrived.
+.SS "PEER warnings"
+These are largely concerned with management of peers and the low-level
+details of the network protocol.  The second word is usually the name of
+a peer, or 
+.RB ` \- '
+if none is relevant.
+.TP
+.BI "PEER \- unexpected-source " address\fR...
+A packet arrived from
+.I address
+(a network address \(en see above), but no peer is known at that
+address.  This may indicate a misconfiguration, or simply be a result of
+one end of a connection being set up before the other.
+.TP
+.BI "PEER " peer " bad-packet no-type"
+An empty packet arrived.  This is very strange.
+.TP
+.BI "PEER " peer " bad-packet unknown-category 0x" nn
+The message category
+.I nn
+(in hex) isn't understood.  Probably a strange random packet from
+somewhere; could be an unlikely bug.
+.TP
+.BI "PEER " peer " bad-packet unknown-type 0x" nn
+The message type
+.I nn
+(in hex) isn't understood.  Probably a strange random packet from
+somewhere; could be an unlikely bug.
+.TP
+.BI "PEER " peer " decrypt-failed"
+An encrypted IP packet failed to decrypt.  It may have been mangled in
+transit, or may be a very old packet from an expired previous session
+key.  There is usually a considerable overlap in the validity periods of
+successive session keys, so this shouldn't occur unless the key exchange
+takes ages or fails.
+.TP
+.BI "PEER " peer " packet-build-failed"
+There wasn't enough space in our buffer to put the packet we wanted to
+send.  Shouldn't happen.
+.TP
+.BI "PEER \- socket-read-error \-\- " message
+An error occurred trying to read an incoming packet.
+.TP
+.BI "PEER " peer " socket-write-error \-\- " message
+An error occurred attempting to send a network packet.  We lost that
+one.
+.SS "SERVER warnings"
+These indicate problems concerning the server process as a whole.
+.TP
+.BI "SERVER ignore signal " name
+A signal arrived, but the server ignored it.  Currently this happens for
+.B SIGHUP
+because that's a popular way of telling daemons to re-read their
+configuration files.  Since
+.B tripe
+re-reads its keyrings automatically and has no other configuration
+files, it's not relevant, but it seemed better to ignore the signal than
+let the server die.
+.TP
+.BI "SERVER quit signal " \fR[\fInn\fR|\fIname\fR]
+A signal arrived and
+.B tripe
+is going to quit.
+.TP
+.BI "SERVER quit admin-request"
+A client of the administration interface issued a
+.B QUIT
+command.
+.TP
+.BI "SERVER select-error \-\- " message
+An error occurred in the server's main event loop.  This is bad: if it
+happens too many times, the server will abort.
+.SS "SYMM warnings"
+These are concerned with the symmetric encryption and decryption
+process.
+.TP
+.BI "SYMM replay old-sequence"
+A packet was received with an old sequence number.  It may just have
+been delayed or duplicated, or it may have been an attempt at a replay
+attack.
+.TP
+.BI "SYMM replay duplicated-sequence"
+A packet was received with a sequence number we've definitely seen
+before.  It may be an accidental duplication because the 'net is like
+that, or a deliberate attempt at a replay.
+.SS "TUN warnings"
+These concern the workings of the system-specific tunnel driver.  The
+second word is the name of the tunnel interface in question, or
+.RB ` \- '
+if none.
+.TP
+.BI "TUN \- bsd no-tunnel-devices"
+The driver couldn't find an available tunnel device.  Maybe if you
+create some more 
+.BI /dev/tun nn
+files, it will work.
+.TP
+.BI "TUN - open-error " device " \-\- " message
+An attempt to open the tunnel device file
+.I device
+failed.
+.TP
+.BI "TUN " ifname " read-error \-\- " message
+Reading from the tunnel device failed.
+.TP
+.BI "TUN \- linux config-error \-\- " message
+Configuring the Linux TUN/TAP interface failed.
+.TP
+.BI "TUN \- unet config-error \-\- " message
+Configuring the Linux Unet interface failed.  Unet is obsolete and
+shouldn't be used any more.
+.TP
+.BI "TUN \- unet getinfo-error \-\- " message
+Reading information about the Unet interface failed.  Unet is obsolete
+and shouldn't be used any more.
+.TP
+.BI "TUN \- unet ifname-too-long \-\- " message
+The Unet interface's name overflowed, so we couldn't read it properly.
+Unet is obsolete and shouldn't be used any more.
 .SH "SEE ALSO"
 .BR tripectl (1),
 .BR tripe (8).
 .PP
-.IR "The Trivial IP Encryption Protocol" ,
+.IR "The Trivial IP Encryption Protocol" .
 .SH "AUTHOR"
 Mark Wooding, <mdw@nsict.org>