servers/pfs/main.c

   1 #include "fs.h"
   2 #include <assert.h>
   3 #include <signal.h>
   4 #include <minix/dmap.h>
   5 #include <minix/driver.h>
   6 #include <minix/endpoint.h>
   7 #include <minix/rs.h>
   8 #include <minix/vfsif.h>
   9 #include <sys/types.h>
  10 #include <pwd.h>
  11 #include "buf.h"
  12 #include "inode.h"
  13 #include "uds.h"
  14
  15 static void get_work(message *m_in);
  16
  17 /* SEF functions and variables. */
  18 static void sef_local_startup(void);
  19 static int sef_cb_init_fresh(int type, sef_init_info_t *info);
  20 static void sef_cb_signal_handler(int signo);
  21
  22 /*===========================================================================*
  23  *                              main                                         *
  24  *===========================================================================*/
  25 int main(int argc, char *argv[])
  26 {
  27 /* This is the main routine of this service. The main loop consists of
  28  * three major activities: getting new work, processing the work, and
  29  * sending the reply. The loop never terminates, unless a panic occurs.
  30  */
  31   int ind, do_reply, transid;
  32   message pfs_m_in;
  33   message pfs_m_out;
  34
  35   /* SEF local startup. */
  36   env_setargs(argc, argv);
  37   sef_local_startup();
  38
  39   while(!unmountdone || !exitsignaled) {
  40         endpoint_t src;
  41
  42         do_reply = 1;
  43         /* Wait for request message. */
  44         get_work(&pfs_m_in);
  45
  46         transid = TRNS_GET_ID(pfs_m_in.m_type);
  47         pfs_m_in.m_type = TRNS_DEL_ID(pfs_m_in.m_type);
  48         if (pfs_m_in.m_type == 0) {
  49                 assert(!IS_VFS_FS_TRANSID(transid));
  50                 pfs_m_in.m_type = transid;
  51                 transid = 0;
  52         } else
  53                 assert(IS_VFS_FS_TRANSID(transid) || transid == 0);
  54
  55         src = pfs_m_in.m_source;
  56         caller_uid = INVAL_UID; /* To trap errors */
  57         caller_gid = INVAL_GID;
  58         req_nr = pfs_m_in.m_type;
  59
  60         if (IS_DEV_RQ(req_nr)) {
  61                 ind = req_nr - DEV_RQ_BASE;
  62                 if (ind < 0 || ind >= DEV_CALL_VEC_SIZE) {
  63                         printf("pfs: bad DEV request %d\n", req_nr);
  64                         pfs_m_out.m_type = EINVAL;
  65                 } else {
  66                         int result;
  67                         result = (*dev_call_vec[ind])(&pfs_m_in, &pfs_m_out);
  68                         if (pfs_m_out.REP_STATUS == SUSPEND ||
  69                             result == SUSPEND) {
  70                                 /* Nothing to tell, so not replying */
  71                                 do_reply = 0;
  72                         }
  73                 }
  74         } else if (IS_VFS_RQ(req_nr)) {
  75                 ind = req_nr - VFS_BASE;
  76                 if (ind < 0 || ind >= FS_CALL_VEC_SIZE) {
  77                         printf("pfs: bad FS request %d\n", req_nr);
  78                         pfs_m_out.m_type = EINVAL;
  79                 } else {
  80                         pfs_m_out.m_type =
  81                                 (*fs_call_vec[ind])(&pfs_m_in, &pfs_m_out);
  82                 }
  83         } else {
  84                 printf("pfs: bad request %d\n", req_nr);
  85                 pfs_m_out.m_type = EINVAL;
  86         }
  87
  88         if (do_reply) {
  89                 if (IS_VFS_RQ(req_nr) && IS_VFS_FS_TRANSID(transid)) {
  90                         pfs_m_out.m_type = TRNS_ADD_ID(pfs_m_out.m_type,
  91                                                         transid);
  92                 }
  93                 reply(src, &pfs_m_out);
  94         }
  95   }
  96   return(OK);
  97 }
  98
  99 /*===========================================================================*
 100  *                             sef_local_startup                             *
 101  *===========================================================================*/
 102 static void sef_local_startup()
 103 {
 104   /* Register init callbacks. */
 105   sef_setcb_init_fresh(sef_cb_init_fresh);
 106   sef_setcb_init_restart(sef_cb_init_fail);
 107
 108   /* No live update support for now. */
 109
 110   /* Register signal callbacks. */
 111   sef_setcb_signal_handler(sef_cb_signal_handler);
 112
 113   /* Let SEF perform startup. */
 114   sef_startup();
 115 }
 116
 117 /*===========================================================================*
 118  *                          sef_cb_init_fresh                                *
 119  *===========================================================================*/
 120 static int sef_cb_init_fresh(int type, sef_init_info_t *info)
 121 {
 122 /* Initialize the pipe file server. */
 123   int i;
 124   struct passwd *pw;
 125
 126   /* Initialize main loop parameters. */
 127   exitsignaled = 0;     /* No exit request seen yet. */
 128   busy = 0;             /* Server is not 'busy' (i.e., inodes in use). */
 129
 130   /* Init inode table */
 131   for (i = 0; i < NR_INODES; ++i) {
 132         inode[i].i_count = 0;
 133   }
 134
 135   init_inode_cache();
 136   uds_init();
 137   buf_pool();
 138
 139
 140   /* Drop root privileges */
 141   if ((pw = getpwnam(SERVICE_LOGIN)) == NULL) {
 142         printf("PFS: unable to retrieve uid of SERVICE_LOGIN, "
 143                 "still running as root");
 144   } else if (setuid(pw->pw_uid) != 0) {
 145         panic("unable to drop privileges");
 146   }
 147
 148   SELF_E = getprocnr();
 149
 150   return(OK);
 151 }
 152
 153 /*===========================================================================*
 154  *                         sef_cb_signal_handler                             *
 155  *===========================================================================*/
 156 static void sef_cb_signal_handler(int signo)
 157 {
 158   /* Only check for termination signal, ignore anything else. */
 159   if (signo != SIGTERM) return;
 160
 161
 162   exitsignaled = 1;
 163 }
 164
 165 /*===========================================================================*
 166  *                              get_work                                     *
 167  *===========================================================================*/
 168 static void get_work(m_in)
 169 message *m_in;                          /* pointer to message */
 170 {
 171   int r, srcok = 0, status;
 172   endpoint_t src;
 173
 174   do {
 175         /* wait for a message */
 176         if ((r = sef_receive_status(ANY, m_in, &status)) != OK)
 177                 panic("sef_receive_status failed: %d", r);
 178         src = m_in->m_source;
 179
 180         if(src == VFS_PROC_NR) {
 181                 srcok = 1;              /* Normal FS request. */
 182         } else
 183                 printf("PFS: unexpected source %d\n", src);
 184   } while(!srcok);
 185 }
 186
 187
 188 /*===========================================================================*
 189  *                              reply                                        *
 190  *===========================================================================*/
 191 void reply(who, m_out)
 192 endpoint_t who;
 193 message *m_out;                         /* report result */
 194 {
 195   if (OK != send(who, m_out))   /* send the message */
 196         printf("PFS(%d) was unable to send reply\n", SELF_E);
 197 }