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scall1.c
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scall1.c
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/**************************************************
UZI (Unix Z80 Implementation) Kernel: scall1.c
***************************************************/
/*LINTLIBRARY*/
#include "unix.h"
#include "extern.h"
/*******************************************
open(name, flag)
char *name;
register int16 flag;
*********************************************/
#define name (char *)udata.u_argn1
#define flag (int16)udata.u_argn
_open()
{
int16 uindex;
register int16 oftindex;
register inoptr ino;
register int16 perm;
inoptr n_open();
if (flag < 0 || flag > 2)
{
udata.u_error = EINVAL;
return (-1);
}
if ((uindex = uf_alloc()) == -1)
return (-1);
if ((oftindex = oft_alloc()) == -1)
goto nooft;
ifnot (ino = n_open(name,NULLINOPTR))
goto cantopen;
of_tab[oftindex].o_inode = ino;
perm = getperm(ino);
if (((flag == O_RDONLY || flag == O_RDWR) && !(perm & OTH_RD)) ||
((flag == O_WRONLY || flag == O_RDWR) && !(perm & OTH_WR)))
{
udata.u_error = EPERM;
goto cantopen;
}
if (getmode(ino) == F_DIR &&
(flag == O_WRONLY || flag == O_RDWR))
{
udata.u_error = EISDIR;
goto cantopen;
}
if (isdevice(ino) && d_open((int)ino->c_node.i_addr[0]) != 0)
{
udata.u_error = ENXIO;
goto cantopen;
}
udata.u_files[uindex] = oftindex;
of_tab[oftindex].o_ptr.o_offset = 0;
of_tab[oftindex].o_ptr.o_blkno = 0;
of_tab[oftindex].o_access = flag;
return (uindex);
cantopen:
oft_deref(oftindex); /* This will call i_deref() */
nooft:
udata.u_files[uindex] = -1;
return (-1);
}
#undef name
#undef flag
/*********************************************
close(uindex)
int16 uindex;
**********************************************/
#define uindex (int16)udata.u_argn
_close()
{
return(doclose(uindex));
}
#undef uindex
doclose(uindex)
int16 uindex;
{
register int16 oftindex;
inoptr ino;
inoptr getinode();
ifnot(ino = getinode(uindex))
return(-1);
oftindex = udata.u_files[uindex];
if (isdevice(ino)
/* && ino->c_refs == 1 && of_tab[oftindex].o_refs == 1 */ )
d_close((int)(ino->c_node.i_addr[0]));
udata.u_files[uindex] = -1;
oft_deref(oftindex);
return(0);
}
/****************************************
creat(name, mode)
char *name;
int16 mode;
*****************************************/
#define name (char *)udata.u_argn1
#define mode (int16)udata.u_argn
_creat()
{
register inoptr ino;
register int16 uindex;
register int16 oftindex;
inoptr parent;
register int16 j;
inoptr n_open();
inoptr newfile();
parent = NULLINODE;
if ((uindex = uf_alloc()) == -1)
return (-1);
if ((oftindex = oft_alloc()) == -1)
return (-1);
if (ino = n_open(name,&parent)) /* The file exists */
{
i_deref(parent);
if (getmode(ino) == F_DIR)
{
i_deref(ino);
udata.u_error = EISDIR;
goto nogood;
}
ifnot (getperm(ino) & OTH_WR)
{
i_deref(ino);
udata.u_error = EACCES;
goto nogood;
}
if (getmode(ino) == F_REG)
{
/* Truncate the file to zero length */
f_trunc(ino);
/* Reset any oft pointers */
for (j=0; j < OFTSIZE; ++j)
if (of_tab[j].o_inode == ino)
of_tab[j].o_ptr.o_blkno = of_tab[j].o_ptr.o_offset = 0;
}
}
else
{
if (parent && (ino = newfile(parent,name)))
/* Parent was derefed in newfile */
{
ino->c_node.i_mode = (F_REG | (mode & MODE_MASK & ~udata.u_mask));
setftime(ino, A_TIME|M_TIME|C_TIME);
/* The rest of the inode is initialized in newfile() */
wr_inode(ino);
}
else
{
/* Doesn't exist and can't make it */
if (parent)
i_deref(parent);
goto nogood;
}
}
udata.u_files[uindex] = oftindex;
of_tab[oftindex].o_ptr.o_offset = 0;
of_tab[oftindex].o_ptr.o_blkno = 0;
of_tab[oftindex].o_inode = ino;
of_tab[oftindex].o_access = O_WRONLY;
return (uindex);
nogood:
oft_deref(oftindex);
return (-1);
}
#undef name
#undef mode
/********************************************
pipe(fildes)
int fildes[];
*******************************************/
#define fildes (int *)udata.u_argn
_pipe()
{
register int16 u1, u2, oft1, oft2;
register inoptr ino;
inoptr i_open();
if ((u1 = uf_alloc()) == -1)
goto nogood2;
if ((oft1 = oft_alloc()) == -1)
goto nogood2;
udata.u_files[u1] = oft1;
if ((u2 = uf_alloc()) == -1)
goto nogood;
if ((oft2 = oft_alloc()) == -1)
{
oft_deref(oft1);
goto nogood;
}
ifnot (ino = i_open(ROOTDEV, 0))
{
oft_deref(oft1);
oft_deref(oft2);
goto nogood;
}
udata.u_files[u2] = oft2;
of_tab[oft1].o_ptr.o_offset = 0;
of_tab[oft1].o_ptr.o_blkno = 0;
of_tab[oft1].o_inode = ino;
of_tab[oft1].o_access = O_RDONLY;
of_tab[oft2].o_ptr.o_offset = 0;
of_tab[oft2].o_ptr.o_blkno = 0;
of_tab[oft2].o_inode = ino;
of_tab[oft2].o_access = O_WRONLY;
++ino->c_refs;
ino->c_node.i_mode = F_PIPE | 0777; /* No permissions necessary on pipes */
ino->c_node.i_nlink = 0; /* a pipe is not in any directory */
*fildes = u1;
*(fildes+1) = u2;
return (0);
nogood:
udata.u_files[u1] = -1;
nogood2:
return(-1);
}
#undef fildes
/********************************************
link(name1, name2)
char *name1;
char *name2;
*********************************************/
#define name1 (char *)udata.u_argn1
#define name2 (char *)udata.u_argn
_link()
{
register inoptr ino;
register inoptr ino2;
inoptr parent2;
char *filename();
inoptr n_open();
ifnot (ino = n_open(name1,NULLINOPTR))
return(-1);
if (getmode(ino) == F_DIR && !super())
{
udata.u_error = EPERM;
goto nogood;
}
/* Make sure file2 doesn't exist, and get its parent */
if (ino2 = n_open(name2,&parent2))
{
i_deref(ino2);
i_deref(parent2);
udata.u_error = EEXIST;
goto nogood;
}
ifnot (parent2)
goto nogood;
if (ino->c_dev != parent2->c_dev)
{
i_deref(parent2);
udata.u_error = EXDEV;
goto nogood;
}
if (ch_link(parent2,"",filename(name2),ino) == 0)
goto nogood;
/* Update the link count. */
++ino->c_node.i_nlink;
wr_inode(ino);
setftime(ino, C_TIME);
i_deref(parent2);
i_deref(ino);
return(0);
nogood:
i_deref(ino);
return(-1);
}
#undef name1
#undef name2
/**********************************************************
unlink(path)
char *path;
**************************************************/
#define path (char *)udata.u_argn
_unlink()
{
register inoptr ino;
inoptr pino;
char *filename();
inoptr i_open();
inoptr n_open();
ino = n_open(path,&pino);
ifnot (pino && ino)
{
udata.u_error = ENOENT;
return (-1);
}
if (getmode(ino) == F_DIR && !super())
{
udata.u_error = EPERM;
goto nogood;
}
/* Remove the directory entry */
if (ch_link(pino,filename(path),"",NULLINODE) == 0)
goto nogood;
/* Decrease the link count of the inode */
ifnot (ino->c_node.i_nlink--)
{
ino->c_node.i_nlink += 2;
warning("_unlink: bad nlink");
}
setftime(ino, C_TIME);
i_deref(pino);
i_deref(ino);
return(0);
nogood:
i_deref(pino);
i_deref(ino);
return(-1);
}
#undef path
/*****************************************************
read(d, buf, nbytes)
int16 d;
char *buf;
uint16 nbytes;
**********************************************/
#define d (int16)udata.u_argn2
#define buf (char *)udata.u_argn1
#define nbytes (uint16)udata.u_argn
_read()
{
register inoptr ino;
inoptr rwsetup();
/* Set up u_base, u_offset, ino; check permissions, file num. */
if ((ino = rwsetup(1)) == NULLINODE)
return (-1); /* bomb out if error */
readi(ino);
updoff();
return (udata.u_count);
}
#undef d
#undef buf
#undef nbytes
/***********************************
write(d, buf, nbytes)
int16 d;
char *buf;
uint16 nbytes;
***********************************/
#define d (int16)udata.u_argn2
#define buf (char *)udata.u_argn1
#define nbytes (uint16)udata.u_argn
_write()
{
register inoptr ino;
off_t *offp;
inoptr rwsetup();
/* Set up u_base, u_offset, ino; check permissions, file num. */
if ((ino = rwsetup(0)) == NULLINODE)
return (-1); /* bomb out if error */
writei(ino);
updoff();
return (udata.u_count);
}
#undef d
#undef buf
#undef nbytes
inoptr
rwsetup(rwflag)
int rwflag;
{
register inoptr ino;
register struct oft *oftp;
inoptr getinode();
udata.u_base = (char *)udata.u_argn1; /* buf */
udata.u_count = (uint16)udata.u_argn; /* nbytes */
if ((ino = getinode(udata.u_argn2)) == NULLINODE)
return (NULLINODE);
oftp = of_tab + udata.u_files[udata.u_argn2];
if (oftp->o_access == (rwflag ? O_WRONLY : O_RDONLY))
{
udata.u_error = EBADF;
return (NULLINODE);
}
setftime(ino, rwflag ? A_TIME : (A_TIME | M_TIME | C_TIME));
/* Initialize u_offset from file pointer */
udata.u_offset.o_blkno = oftp->o_ptr.o_blkno;
udata.u_offset.o_offset = oftp->o_ptr.o_offset;
return (ino);
}
readi(ino)
register inoptr ino;
{
register uint16 amount;
register uint16 toread;
register blkno_t pblk;
register char *bp;
int dev;
int ispipe;
char *bread();
char *zerobuf();
blkno_t bmap();
dev = ino->c_dev;
ispipe = 0;
switch (getmode(ino))
{
case F_DIR:
case F_REG:
/* See of end of file will limit read */
toread = udata.u_count =
ino->c_node.i_size.o_blkno-udata.u_offset.o_blkno >= 64 ?
udata.u_count :
min(udata.u_count,
512*(ino->c_node.i_size.o_blkno-udata.u_offset.o_blkno) +
(ino->c_node.i_size.o_offset-udata.u_offset.o_offset));
goto loop;
case F_PIPE:
ispipe = 1;
while (psize(ino) == 0)
{
if (ino->c_refs == 1) /* No writers */
break;
/* Sleep if empty pipe */
psleep(ino);
}
toread = udata.u_count = min(udata.u_count, psize(ino));
goto loop;
case F_BDEV:
toread = udata.u_count;
dev = *(ino->c_node.i_addr);
loop:
while (toread)
{
if ((pblk = bmap(ino, udata.u_offset.o_blkno, 1)) != NULLBLK)
bp = bread(dev, pblk, 0);
else
bp = zerobuf();
bcopy(bp+udata.u_offset.o_offset, udata.u_base,
(amount = min(toread, 512 - udata.u_offset.o_offset)));
brelse(bp);
udata.u_base += amount;
addoff(&udata.u_offset, amount);
if (ispipe && udata.u_offset.o_blkno >= 18)
udata.u_offset.o_blkno = 0;
toread -= amount;
if (ispipe)
{
addoff(&(ino->c_node.i_size), -amount);
wakeup(ino);
}
}
break;
case F_CDEV:
udata.u_count = cdread(ino->c_node.i_addr[0]);
if (udata.u_count != -1)
addoff(&udata.u_offset, udata.u_count);
break;
default:
udata.u_error = ENODEV;
}
}
/* Writei (and readi) need more i/o error handling */
writei(ino)
register inoptr ino;
{
register uint16 amount;
register uint16 towrite;
register char *bp;
int ispipe;
blkno_t pblk;
int created; /* Set by bmap if newly allocated block used */
int dev;
char *zerobuf();
char *bread();
blkno_t bmap();
dev = ino->c_dev;
switch (getmode(ino))
{
case F_BDEV:
dev = *(ino->c_node.i_addr);
case F_DIR:
case F_REG:
ispipe = 0;
towrite = udata.u_count;
goto loop;
case F_PIPE:
ispipe = 1;
while ((towrite = udata.u_count) > (16*512) - psize(ino))
{
if (ino->c_refs == 1) /* No readers */
{
udata.u_count = -1;
udata.u_error = EPIPE;
ssig(udata.u_ptab, SIGPIPE);
return;
}
/* Sleep if empty pipe */
psleep(ino);
}
/* Sleep if empty pipe */
goto loop;
loop:
while (towrite)
{
amount = min(towrite, 512 - udata.u_offset.o_offset);
if ((pblk = bmap(ino, udata.u_offset.o_blkno, 0)) == NULLBLK)
break; /* No space to make more blocks */
/* If we are writing an entire block, we don't care
about its previous contents */
bp = bread(dev, pblk, (amount == 512));
bcopy(udata.u_base, bp+udata.u_offset.o_offset, amount);
bawrite(bp);
udata.u_base += amount;
addoff(&udata.u_offset, amount);
if(ispipe)
{
if (udata.u_offset.o_blkno >= 18)
udata.u_offset.o_blkno = 0;
addoff(&(ino->c_node.i_size), amount);
/* Wake up any readers */
wakeup(ino);
}
towrite -= amount;
}
/* Update size if file grew */
ifnot (ispipe)
{
if ( udata.u_offset.o_blkno > ino->c_node.i_size.o_blkno ||
(udata.u_offset.o_blkno == ino->c_node.i_size.o_blkno &&
udata.u_offset.o_offset > ino->c_node.i_size.o_offset))
{
ino->c_node.i_size.o_blkno = udata.u_offset.o_blkno;
ino->c_node.i_size.o_offset = udata.u_offset.o_offset;
ino->c_dirty = 1;
}
}
break;
case F_CDEV:
udata.u_count = cdwrite(ino->c_node.i_addr[0]);
if (udata.u_count != -1)
addoff(&udata.u_offset, udata.u_count);
break;
default:
udata.u_error = ENODEV;
}
}
min(a, b)
int a, b;
{
return ( a < b ? a : b);
}
psize(ino)
inoptr ino;
{
return (512*ino->c_node.i_size.o_blkno+ino->c_node.i_size.o_offset);
}
addoff(ofptr, amount)
off_t *ofptr;
int amount;
{
if (amount >= 0)
{
ofptr->o_offset += amount % 512;
if (ofptr->o_offset >= 512)
{
ofptr->o_offset -= 512;
++ofptr->o_blkno;
}
ofptr->o_blkno += amount/512;
}
else
{
ofptr->o_offset -= (-amount) % 512;
if (ofptr->o_offset < 0)
{
ofptr->o_offset += 512;
--ofptr->o_blkno;
}
ofptr->o_blkno -= (-amount)/512;
}
}
updoff()
{
register off_t *offp;
/* Update current file pointer */
offp = &of_tab[udata.u_files[udata.u_argn2]].o_ptr;
offp->o_blkno = udata.u_offset.o_blkno;
offp->o_offset = udata.u_offset.o_offset;
}
/****************************************
seek(file,offset,flag)
int16 file;
uint16 offset;
int16 flag;
*****************************************/
#define file (int16)udata.u_argn2
#define offset (uint16)udata.u_argn1
#define flag (int16)udata.u_argn
_seek()
{
register inoptr ino;
register int16 oftno;
register uint16 retval;
inoptr getinode();
if ((ino = getinode(file)) == NULLINODE)
return(-1);
if (getmode(ino) == F_PIPE)
{
udata.u_error = ESPIPE;
return(-1);
}
oftno = udata.u_files[file];
if (flag <= 2)
retval = of_tab[oftno].o_ptr.o_offset;
else
retval = of_tab[oftno].o_ptr.o_blkno;
switch(flag)
{
case 0:
of_tab[oftno].o_ptr.o_blkno = 0;
of_tab[oftno].o_ptr.o_offset = offset;
break;
case 1:
of_tab[oftno].o_ptr.o_offset += offset;
break;
case 2:
of_tab[oftno].o_ptr.o_blkno = ino->c_node.i_size.o_blkno;
of_tab[oftno].o_ptr.o_offset = ino->c_node.i_size.o_offset + offset;
break;
case 3:
of_tab[oftno].o_ptr.o_blkno = offset;
break;
case 4:
of_tab[oftno].o_ptr.o_blkno += offset;
break;
case 5:
of_tab[oftno].o_ptr.o_blkno = ino->c_node.i_size.o_blkno + offset;
break;
default:
udata.u_error = EINVAL;
return(-1);
}
while ((unsigned)of_tab[oftno].o_ptr.o_offset >= 512)
{
of_tab[oftno].o_ptr.o_offset -= 512;
++of_tab[oftno].o_ptr.o_blkno;
}
return((int16)retval);
}
#undef file
#undef offset
#undef flag
/************************************
chdir(dir)
char *dir;
************************************/
#define dir (char *)udata.u_argn
_chdir()
{
register inoptr newcwd;
inoptr n_open();
ifnot (newcwd = n_open(dir,NULLINOPTR))
return(-1);
if (getmode(newcwd) != F_DIR)
{
udata.u_error = ENOTDIR;
i_deref(newcwd);
return(-1);
}
i_deref(udata.u_cwd);
udata.u_cwd = newcwd;
return(0);
}
#undef dir
/*************************************
mknod(name,mode,dev)
char *name;
int16 mode;
int16 dev;
***************************************/
#define name (char *)udata.u_argn2
#define mode (int16)udata.u_argn1
#define dev (int16)udata.u_argn
_mknod()
{
register inoptr ino;
inoptr parent;
inoptr n_open();
inoptr newfile();
udata.u_error = 0;
ifnot (super())
{
udata.u_error = EPERM;
return(-1);
}
if (ino = n_open(name,&parent))
{
udata.u_error = EEXIST;
goto nogood;
}
ifnot (parent)
{
udata.u_error = ENOENT;
goto nogood3;
}
ifnot (ino = newfile(parent,name))
goto nogood2;
/* Initialize mode and dev */
ino->c_node.i_mode = mode & ~udata.u_mask;
ino->c_node.i_addr[0] = isdevice(ino) ? dev : 0;
setftime(ino, A_TIME|M_TIME|C_TIME);
wr_inode(ino);
i_deref(ino);
return (0);
nogood:
i_deref(ino);
nogood2:
i_deref(parent);
nogood3:
return (-1);
}
#undef name
#undef mode
#undef dev
/****************************************
sync()
***************************************/
_sync()
{
register j;
register inoptr ino;
register char *buf;
char *bread();
/* Write out modified inodes */
for (ino=i_tab; ino < i_tab+ITABSIZE; ++ino)
if ((ino->c_refs) > 0 && ino->c_dirty != 0)
{
wr_inode(ino);
ino->c_dirty = 0;
}
/* Write out modified super blocks */
/* This fills the rest of the super block with garbage. */
for (j=0; j < NDEVS; ++j)
{
if (fs_tab[j].s_mounted == SMOUNTED && fs_tab[j].s_fmod)
{
fs_tab[j].s_fmod = 0;
buf = bread(j, 1, 1);
bcopy((char *)&fs_tab[j], buf, 512);
bfree(buf, 2);
}
}
bufsync(); /* Clear buffer pool */
}
/****************************************
access(path,mode)
char *path;
int16 mode;
****************************************/
#define path (char *)udata.u_argn1
#define mode (int16)udata.u_argn
_access()
{
register inoptr ino;
register int16 euid;
register int16 egid;
register int16 retval;
inoptr n_open();
if ((mode & 07) && !*(path))
{
udata.u_error = ENOENT;
return (-1);
}
/* Temporarily make eff. id real id. */
euid = udata.u_euid;
egid = udata.u_egid;
udata.u_euid = udata.u_ptab->p_uid;
udata.u_egid = udata.u_gid;
ifnot (ino = n_open(path,NULLINOPTR))
{
retval = -1;
goto nogood;
}
retval = 0;
if (~getperm(ino) & (mode&07))
{
udata.u_error = EPERM;
retval = -1;
}
i_deref(ino);
nogood:
udata.u_euid = euid;
udata.u_egid = egid;