term% cat index.txt VENTI-CONN(2) System Calls Manual VENTI-CONN(2)
NAME
VtConn, vtconn, vtdial, vtfreeconn, vtsend, vtrecv, vtversion, vtdebug,
vthangup - Venti network connections
SYNOPSIS
#include <u.h>
#include <libc.h>
#include <venti.h>
typedef struct VtConn {
int debug;
char *version;
char *uid;
char *sid;
char addr[256];
...
} VtConn;
VtConn* vtconn(int infd, int outfd)
VtConn* vtdial(char *addr)
int vtversion(VtConn *z)
int vtsend(VtConn *z, Packet *p)
Packet* vtrecv(VtConn *z)
void vtrecvproc(void *z)
void vtsendproc(void *z)
void vtdebug(VtConn *z, char *fmt, ...)
void vthangup(VtConn *z)
void vtfreeconn(VtConn *z)
extern int chattyventi;/* default 0 */
DESCRIPTION
A VtConn structure represents a connection to a Venti server (when used
by a client) or to a client (when used by a server). It contains the
following user-visible fields: debug, a flag enabling debugging prints;
version, the protocol version in use; uid, the (unverified) name of the
client; sid, the (unverified) name of the server; and addr, the network
address of the remote side.
Vtconn initializes a new connection structure using file descriptors
infd and outfd (which may be the same) for reading and writing. Vtdial
dials the given network address (see dial(2)) and returns a correspond‐
ing connection. If addr is nil, the environment variable venti will be
used if set; if not, the address tcp!$venti!venti will be used. It re‐
turns nil if the connection cannot be established.
Vtversion exchanges version information with the remote side as de‐
scribed in venti(6). The negotiated version is stored in z->version.
Vtsend writes a packet (see venti-packet(2)) on the connection z. The
packet p should be a formatted Venti message as might be returned by
vtfcallpack; vtsend will add the two-byte length field (see venti(6))
at the begnning. Vtsend frees p, even on error.
Vtrecv reads a packet from the connection z. Analogous to vtsend, the
data read from the connection must start with a two-byte length, but
the returned packet will omit them.
By default, vtsend and vtrecv block until the packet can be written or
read from the network. In a threaded program (see thread(2)), this may
not be desirable. If the caller arranges for vtsendproc and vtrecvproc
to run in their own procs (typically by calling proccreate), then vt‐
send and vtrecv will yield the proc in which they are run to other
threads when waiting on the network. The void* argument to vtsendproc
and vtrecvproc must be the connection structure z.
Vtdebug prints the formatted message to standard error when z->debug is
set. Otherwise it is a no-op.
Vthangup hangs up a connection. It closes the associated file descrip‐
tors and shuts down send and receive procs if they have been started.
Future calls to vtrecv or vtsend will return errors. Additional calls
to vthangup will have no effect.
Vtfreeconn frees the connection structure, hanging it up first if nec‐
essary.
If the global variable chattyventi is set, the library prints all Venti
RPCs to standard error as they are sent or received.
SOURCE
/sys/src/libventi
SEE ALSO
venti(1), venti(2), venti-client(2), venti-packet(2), venti-server(2),
venti(6)
DIAGNOSTICS
Routines that return pointers return nil on error. Routines returning
integers return 0 on success, -1 on error. All routines set errstr on
error.
VENTI-CONN(2)