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.TH VENTI-SERVER 2
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.SH NAME
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vtsrvhello, vtlisten, vtgetreq, vtrespond \- Venti server
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.SH SYNOPSIS
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.PP
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.ft L
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#include <u.h>
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.br
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#include <libc.h>
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.br
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#include <venti.h>
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.ta +\w'\fLVtReq* 'u
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.PP
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.ft L
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.nf
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typedef struct VtReq
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{
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	VtFcall tx;
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	VtFcall rx;
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	...
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} VtReq;
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.PP
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.B
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int	vtsrvhello(VtConn *z)
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.PP
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.B
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VtSrv*	vtlisten(char *addr)
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.PP
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.B
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VtReq*	vtgetreq(VtSrv *srv)
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.PP
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.B
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void	vtrespond(VtReq *req)
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.SH DESCRIPTION
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These routines execute the server side of the
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.IR venti (6)
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protocol.
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.PP
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.I Vtsrvhello
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executes the server side of the initial
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.B hello
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transaction.
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It sets
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.IB z -> uid
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with the user name claimed by the other side.
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Each new connection must be initialized by running
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.I vtversion
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and then
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.IR vtsrvhello .
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The framework below takes care of this detail automatically;
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.I vtsrvhello
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is provided for programs that do not use the functions below.
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.PP
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.IR Vtlisten ,
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.IR vtgetreq ,
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and
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.I vtrespond
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provide a simple framework for writing Venti servers.
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.PP
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.I Vtlisten
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announces at the network address
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.IR addr ,
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returning a fresh
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.B VtSrv
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structure representing the service.
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.PP
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.I Vtgetreq
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waits for and returns
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the next
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.BR read ,
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.BR write ,
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.BR sync ,
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or
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.B ping
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request from any client connected to
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the service
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.IR srv .
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.B Hello
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and
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.B goodbye
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messages are handled internally and not returned to the client.
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The interface does not distinguish between the
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different clients that may be connected at any given time.
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The request can be found in the
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.I tx
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field of the returned
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.BR VtReq .
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.PP
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Once a request has been served and a response stored in
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.IB r ->rx \fR,
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the server should call
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.IR vtrespond
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to send the response to the client.
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.I Vtrespond
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frees the structure
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.I r
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as well as the packets
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.IB r ->tx.data
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and
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.IB r ->rx.data \fR.
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.SH EXAMPLE
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.B /sys/src/cmd/venti
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contains two simple Venti servers
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.B ro.c
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and
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.B devnull.c
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written using these routines.
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.I Ro
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is a read-only Venti proxy (it rejects
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.B write
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requests).
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.I Devnull
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is a dangerous write-only Venti server: it discards all
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blocks written to it and returns error on all reads.
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.SH SOURCE
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.B /sys/src/libventi
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.SH SEE ALSO
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.IR venti (2),
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.IR venti-conn (2),
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.IR venti-packet (2),
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.IR venti (6),
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.IR venti (8)