minix/servers/pfs/main.c
2012-03-25 21:58:14 +02:00

197 lines
5.3 KiB
C

#include "fs.h"
#include <assert.h>
#include <signal.h>
#include <minix/dmap.h>
#include <minix/driver.h>
#include <minix/endpoint.h>
#include <minix/rs.h>
#include <minix/vfsif.h>
#include <sys/types.h>
#include <pwd.h>
#include "buf.h"
#include "inode.h"
#include "uds.h"
static void get_work(message *m_in);
/* SEF functions and variables. */
static void sef_local_startup(void);
static int sef_cb_init_fresh(int type, sef_init_info_t *info);
static void sef_cb_signal_handler(int signo);
/*===========================================================================*
* main *
*===========================================================================*/
int main(int argc, char *argv[])
{
/* This is the main routine of this service. The main loop consists of
* three major activities: getting new work, processing the work, and
* sending the reply. The loop never terminates, unless a panic occurs.
*/
int ind, do_reply, transid;
message pfs_m_in;
message pfs_m_out;
/* SEF local startup. */
env_setargs(argc, argv);
sef_local_startup();
while(!unmountdone || !exitsignaled) {
endpoint_t src;
do_reply = 1;
/* Wait for request message. */
get_work(&pfs_m_in);
transid = TRNS_GET_ID(pfs_m_in.m_type);
pfs_m_in.m_type = TRNS_DEL_ID(pfs_m_in.m_type);
if (pfs_m_in.m_type == 0) {
assert(!IS_VFS_FS_TRANSID(transid));
pfs_m_in.m_type = transid;
transid = 0;
} else
assert(IS_VFS_FS_TRANSID(transid) || transid == 0);
src = pfs_m_in.m_source;
caller_uid = INVAL_UID; /* To trap errors */
caller_gid = INVAL_GID;
req_nr = pfs_m_in.m_type;
if (IS_DEV_RQ(req_nr)) {
ind = req_nr - DEV_RQ_BASE;
if (ind < 0 || ind >= DEV_CALL_VEC_SIZE) {
printf("pfs: bad DEV request %d\n", req_nr);
pfs_m_out.m_type = EINVAL;
} else {
int result;
result = (*dev_call_vec[ind])(&pfs_m_in, &pfs_m_out);
if (pfs_m_out.REP_STATUS == SUSPEND ||
result == SUSPEND) {
/* Nothing to tell, so not replying */
do_reply = 0;
}
}
} else if (IS_VFS_RQ(req_nr)) {
ind = req_nr - VFS_BASE;
if (ind < 0 || ind >= FS_CALL_VEC_SIZE) {
printf("pfs: bad FS request %d\n", req_nr);
pfs_m_out.m_type = EINVAL;
} else {
pfs_m_out.m_type =
(*fs_call_vec[ind])(&pfs_m_in, &pfs_m_out);
}
} else {
printf("pfs: bad request %d\n", req_nr);
pfs_m_out.m_type = EINVAL;
}
if (do_reply) {
if (IS_VFS_RQ(req_nr) && IS_VFS_FS_TRANSID(transid)) {
pfs_m_out.m_type = TRNS_ADD_ID(pfs_m_out.m_type,
transid);
}
reply(src, &pfs_m_out);
}
}
return(OK);
}
/*===========================================================================*
* sef_local_startup *
*===========================================================================*/
static void sef_local_startup()
{
/* Register init callbacks. */
sef_setcb_init_fresh(sef_cb_init_fresh);
sef_setcb_init_restart(sef_cb_init_fail);
/* No live update support for now. */
/* Register signal callbacks. */
sef_setcb_signal_handler(sef_cb_signal_handler);
/* Let SEF perform startup. */
sef_startup();
}
/*===========================================================================*
* sef_cb_init_fresh *
*===========================================================================*/
static int sef_cb_init_fresh(int type, sef_init_info_t *info)
{
/* Initialize the pipe file server. */
int i;
struct passwd *pw;
/* Initialize main loop parameters. */
exitsignaled = 0; /* No exit request seen yet. */
busy = 0; /* Server is not 'busy' (i.e., inodes in use). */
/* Init inode table */
for (i = 0; i < NR_INODES; ++i) {
inode[i].i_count = 0;
}
init_inode_cache();
uds_init();
buf_pool();
/* Drop root privileges */
if ((pw = getpwnam(SERVICE_LOGIN)) == NULL) {
printf("PFS: unable to retrieve uid of SERVICE_LOGIN, "
"still running as root");
} else if (setuid(pw->pw_uid) != 0) {
panic("unable to drop privileges");
}
SELF_E = getprocnr();
return(OK);
}
/*===========================================================================*
* sef_cb_signal_handler *
*===========================================================================*/
static void sef_cb_signal_handler(int signo)
{
/* Only check for termination signal, ignore anything else. */
if (signo != SIGTERM) return;
exitsignaled = 1;
}
/*===========================================================================*
* get_work *
*===========================================================================*/
static void get_work(m_in)
message *m_in; /* pointer to message */
{
int r, srcok = 0, status;
endpoint_t src;
do {
/* wait for a message */
if ((r = sef_receive_status(ANY, m_in, &status)) != OK)
panic("sef_receive_status failed: %d", r);
src = m_in->m_source;
if(src == VFS_PROC_NR) {
srcok = 1; /* Normal FS request. */
} else
printf("PFS: unexpected source %d\n", src);
} while(!srcok);
}
/*===========================================================================*
* reply *
*===========================================================================*/
void reply(who, m_out)
endpoint_t who;
message *m_out; /* report result */
{
if (OK != send(who, m_out)) /* send the message */
printf("PFS(%d) was unable to send reply\n", SELF_E);
}