minix/lib/libsffs/main.c
David van Moolenbroek ef7b484e5c Create SFFS library out of HGFS
This Shared Folders File System library (libsffs) now contains all the
file system logic originally in HGFS. The actual HGFS server code is
now a stub that passes on all the work to libsffs. The libhgfs library
is changed accordingly.
2012-04-09 18:08:26 +02:00

154 lines
4.1 KiB
C

/* This file contains the SFFS initialization code and message loop.
*
* The entry points into this file are:
* sffs_init initialization
* sffs_signal signal handler
* sffs_loop main message loop
*
* Created:
* April 2009 (D.C. van Moolenbroek)
*/
#include "inc.h"
/*===========================================================================*
* sffs_init *
*===========================================================================*/
int sffs_init(char *name, const struct sffs_table *table,
struct sffs_params *params)
{
/* Initialize this file server. Called at startup time.
*/
int i;
/* Make sure that the given path prefix doesn't end with a slash. */
i = strlen(params->p_prefix);
while (i > 0 && params->p_prefix[i - 1] == '/') i--;
params->p_prefix[i] = 0;
state.s_mounted = FALSE;
state.s_signaled = FALSE;
sffs_name = name;
sffs_table = table;
sffs_params = params;
return OK;
}
/*===========================================================================*
* sffs_signal *
*===========================================================================*/
void sffs_signal(int signo)
{
/* Only check for termination signal, ignore anything else. */
if (signo != SIGTERM) return;
/* We can now terminate if we have also been unmounted. */
state.s_signaled = TRUE;
if (state.s_mounted) {
dprintf(("%s: got SIGTERM, still mounted\n", sffs_name));
} else {
dprintf(("%s: got SIGTERM, shutting down\n", sffs_name));
/* Break out of the main loop, giving the main program the chance to
* perform further cleanup. This causes sef_receive() to return with
* an EINTR error code.
*/
sef_cancel();
}
}
/*===========================================================================*
* get_work *
*===========================================================================*/
static int get_work(who_e)
endpoint_t *who_e;
{
/* Receive a request message from VFS. Return TRUE if a new message is ready
* to be processed, or FALSE if sef_stop() was called from the signal handler.
*/
int r;
if ((r = sef_receive(ANY, &m_in)) != OK) {
if (r != EINTR)
panic("receive failed: %d", r);
return FALSE;
}
*who_e = m_in.m_source;
return TRUE;
}
/*===========================================================================*
* send_reply *
*===========================================================================*/
static void send_reply(err, transid)
int err; /* resulting error code */
int transid;
{
/* Send a reply message to the requesting party, with the given error code.
*/
int r;
m_out.m_type = err;
if (IS_VFS_FS_TRANSID(transid)) {
/* If a transaction ID was set, reset it */
m_out.m_type = TRNS_ADD_ID(m_out.m_type, transid);
}
if ((r = send(m_in.m_source, &m_out)) != OK)
printf("%s: send failed (%d)\n", sffs_name, r);
}
/*===========================================================================*
* sffs_loop *
*===========================================================================*/
void sffs_loop(void)
{
/* The main function of this file server. After initializing, loop, receiving
* one request from VFS at a time, processing it, and sending a reply back to
* VFS. Termination occurs when we both have been unmounted and have received
* a termination signal.
*/
endpoint_t who_e;
int call_nr, err, transid;
while (state.s_mounted || !state.s_signaled) {
if (!get_work(&who_e))
continue; /* Recheck running conditions */
transid = TRNS_GET_ID(m_in.m_type);
m_in.m_type = TRNS_DEL_ID(m_in.m_type);
if (m_in.m_type == 0) {
assert(!IS_VFS_FS_TRANSID(transid));
m_in.m_type = transid; /* Backwards compat. */
transid = 0;
} else
assert(IS_VFS_FS_TRANSID(transid));
call_nr = m_in.m_type;
if (who_e != VFS_PROC_NR) {
continue;
}
if (state.s_mounted || call_nr == REQ_READSUPER) {
call_nr -= VFS_BASE;
dprintf(("%s: call %d\n", sffs_name, call_nr));
if (call_nr >= 0 && call_nr < NREQS) {
err = (*call_vec[call_nr])();
} else {
err = ENOSYS;
}
dprintf(("%s: call %d result %d\n", sffs_name, call_nr, err));
}
else err = EINVAL;
send_reply(err, transid);
}
}