vtsrvhello, vtlisten, vtgetreq, vtrespond – Venti server


#include <u.h>
#include <libc.h>
#include <venti.h>

typedef struct VtReq { VtFcall tx; VtFcall rx; ... } VtReq;

int vtsrvhello(VtConn *z)

VtSrv* vtlisten(char *addr)

VtReq* vtgetreq(VtSrv *srv)

void vtrespond(VtReq *req)


These routines execute the server side of the venti(6) protocol.

Vtsrvhello executes the server side of the initial hello transaction. It sets z->uid with the user name claimed by the other side. Each new connection must be initialized by running vtversion and then vtsrvhello. The framework below takes care of this detail automatically; vtsrvhello is provided for programs that do not use the functions below.

Vtlisten, vtgetreq, and vtrespond provide a simple framework for writing Venti servers.

Vtlisten announces at the network address addr, returning a fresh VtSrv structure representing the service.

Vtgetreq waits for and returns the next read, write, sync, or ping request from any client connected to the service srv. Hello and goodbye messages are handled internally and not returned to the client. The interface does not distinguish between the different clients that may be connected at any given time. The request can be found in the tx field of the returned VtReq.

Once a request has been served and a response stored in r->rx, the server should call vtrespond to send the response to the client. Vtrespond frees the structure r as well as the packets r-> and r->


/sys/src/cmd/venti contains two simple Venti servers ro.c and devnull.c written using these routines. Ro is a read-only Venti proxy (it rejects write requests). Devnull is a dangerous write-only Venti server: it discards all blocks written to it and returns error on all reads.




venti(2), venti-conn(2), venti-packet(2), venti(6), venti(8)