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[unix-history] / usr / src / sys / kern / sys_generic.c

/*      sys_generic.c   5.13    82/09/06        */

#include "../h/param.h"
#include "../h/systm.h"
#include "../h/dir.h"
#include "../h/user.h"
#include "../h/tty.h"
#include "../h/file.h"
#include "../h/inode.h"
#include "../h/buf.h"
#include "../h/proc.h"
#include "../h/inline.h"
#include "../h/conf.h"
#include "../h/socket.h"
#include "../h/socketvar.h"
#include "../h/fs.h"
#ifdef MUSH
#include "../h/quota.h"
#include "../h/share.h"
#else
#define CHARGE(nothing)
#endif
#include "../h/descrip.h"
#include "../h/uio.h"

/*
* Read system call.
*/
read()
{
       register struct a {
               int     fdes;
               char    *cbuf;
               unsigned count;
       } *uap = (struct a *)u.u_ap;
       struct uio auio;
       struct iovec aiov;

       aiov.iov_base = (caddr_t)uap->cbuf;
       aiov.iov_len = uap->count;
       auio.uio_iov = &aiov;
       auio.uio_iovcnt = 1;
       rwuio(&auio, UIO_READ);
}

readv()
{
       register struct a {
               int     fdes;
               struct  iovec *iovp;
               int     iovcnt;
       } *uap = (struct a *)u.u_ap;
       struct uio auio;
       struct iovec aiov[16];          /* XXX */

       if (uap->iovcnt <= 0 || uap->iovcnt > sizeof(aiov)/sizeof(aiov[0])) {
               u.u_error = EINVAL;
               return;
       }
       auio.uio_iov = aiov;
       auio.uio_iovcnt = uap->iovcnt;
       if (copyin((caddr_t)uap->iovp, (caddr_t)aiov,
           (unsigned)(uap->iovcnt * sizeof (struct iovec)))) {
               u.u_error = EFAULT;
               return;
       }
       rwuio(&auio, UIO_READ);
}

/*
* Write system call
*/
write()
{
       register struct a {
               int     fdes;
               char    *cbuf;
               int     count;
       } *uap = (struct a *)u.u_ap;
       struct uio auio;
       struct iovec aiov;

       auio.uio_iov = &aiov;
       auio.uio_iovcnt = 1;
       aiov.iov_base = uap->cbuf;
       aiov.iov_len = uap->count;
       rwuio(&auio, UIO_WRITE);
}

writev()
{
       register struct a {
               int     fdes;
               struct  iovec *iovp;
               int     iovcnt;
       } *uap = (struct a *)u.u_ap;
       struct uio auio;
       struct iovec aiov[16];          /* XXX */

       if (uap->iovcnt <= 0 || uap->iovcnt > sizeof(aiov)/sizeof(aiov[0])) {
               u.u_error = EINVAL;
               return;
       }
       auio.uio_iov = aiov;
       auio.uio_iovcnt = uap->iovcnt;
       if (copyin((caddr_t)uap->iovp, (caddr_t)aiov,
           (unsigned)(uap->iovcnt * sizeof (struct iovec)))) {
               u.u_error = EFAULT;
               return;
       }
       rwuio(&auio, UIO_WRITE);
}

rwuio(uio, rw)
       register struct uio *uio;
       enum uio_rw rw;
{
       struct a {
               int     fdes;
       };
       register struct file *fp;
       register struct iovec *iov;
       register struct inode *ip;
       int i, count;

       GETF(fp, ((struct a *)u.u_ap)->fdes);
       if ((fp->f_flag&(rw==UIO_READ ? FREAD : FWRITE)) == 0) {
               u.u_error = EBADF;
               return;
       }
       uio->uio_resid = 0;
       uio->uio_segflg = 0;
       iov = uio->uio_iov;
       for (i = 0; i < uio->uio_iovcnt; i++) {
               if (iov->iov_len < 0) {
                       u.u_error = EINVAL;
                       return;
               }
               uio->uio_resid += iov->iov_len;
               if (uio->uio_resid < 0) {
                       u.u_error = EINVAL;
                       return;
               }
       }
       count = uio->uio_resid;
       if ((u.u_procp->p_flag&SNUSIG) && setjmp(u.u_qsav)) {
               if (uio->uio_resid == count)
                       u.u_eosys = RESTARTSYS;
       } else if (fp->f_type == DTYPE_SOCKET) {
               int sosend(), soreceive();
               u.u_error = 
                   (*(rw==UIO_READ?soreceive:sosend))
                     (fp->f_socket, (struct sockaddr *)0, uio);
       } else {
               ip = fp->f_inode;
               uio->uio_offset = fp->f_offset;
               if ((ip->i_mode&IFMT) == IFREG) {
                       ilock(ip);
                       u.u_error = rwip(ip, uio, rw);
                       iunlock(ip);
               } else
                       u.u_error = rwip(ip, uio, rw);
               fp->f_offset += count - uio->uio_resid;
       }
       u.u_r.r_val1 = count - uio->uio_resid;
}

rdwri(rw, ip, base, len, offset, segflg, aresid)
       struct inode *ip;
       caddr_t base;
       int len, offset, segflg;
       int *aresid;
       enum uio_rw rw;
{
       struct uio auio;
       struct iovec aiov;
       int error;

       auio.uio_iov = &aiov;
       auio.uio_iovcnt = 1;
       aiov.iov_base = base;
       aiov.iov_len = len;
       auio.uio_resid = len;
       auio.uio_offset = offset;
       auio.uio_segflg = segflg;
       error = rwip(ip, &auio, rw);
       if (aresid)
               *aresid = auio.uio_resid;
       else
               if (auio.uio_resid)
                       error = EIO;
       return (error);
}

rwip(ip, uio, rw)
       register struct inode *ip;
       register struct uio *uio;
       enum uio_rw rw;
{
       dev_t dev = (dev_t)ip->i_rdev;
       struct buf *bp;
       struct fs *fs;
       daddr_t lbn, bn;
       register int on, type;
       register unsigned n;
       int size;
       long bsize;
       extern int mem_no;
       int error = 0;

       if (rw != UIO_READ && rw != UIO_WRITE)
               panic("rwip");
       if (uio->uio_offset < 0 &&
           ((ip->i_mode&IFMT) != IFCHR || mem_no != major(dev)))
               return (EINVAL); if (rw == UIO_READ)
               ip->i_flag |= IACC;
       type = ip->i_mode&IFMT;
       if (type == IFCHR) {
#ifdef QUOTA
               register c = uio->uio_resid;
#endif
               if (rw == UIO_READ)
                       (*cdevsw[major(dev)].d_read)(dev, uio);
               else {
                       ip->i_flag |= IUPD|ICHG;
                       (*cdevsw[major(dev)].d_write)(dev, uio);
               }
               CHARGE(sc_tio * (c - uio->uio_resid));
               return (u.u_error);
       }
       if (rw == UIO_WRITE && type == IFREG &&
           uio->uio_offset + uio->uio_resid >
             u.u_rlimit[RLIMIT_FSIZE].rlim_cur) {
               psignal(u.u_procp, SIGXFSZ);
               return (EMFILE);
       }
       if (type != IFBLK) {
               dev = ip->i_dev;
               fs = ip->i_fs;
               bsize = fs->fs_bsize;
       } else
               bsize = BLKDEV_IOSIZE;
       do {
               lbn = uio->uio_offset / bsize;
               on = uio->uio_offset % bsize;
               n = MIN((unsigned)(bsize - on), uio->uio_resid);
               if (type != IFBLK) {
                       if (rw == UIO_READ) {
                               int diff = ip->i_size - uio->uio_offset;
                               if (diff <= 0)
                                       return (0);
                               if (diff < n)
                                       n = diff;
                       }
                       bn = fsbtodb(fs,
                           bmap(ip, lbn, rw == UIO_WRITE ? B_WRITE: B_READ, (int)(on+n)));
                       if (u.u_error || rw == UIO_WRITE && (long)bn<0)
                               return (u.u_error);
                       if (rw == UIO_WRITE && uio->uio_offset + n > ip->i_size &&
                          (type == IFDIR || type == IFREG || type == IFLNK))
                               ip->i_size = uio->uio_offset + n;
                       size = blksize(fs, ip, lbn);
               } else {
                       bn = lbn * (BLKDEV_IOSIZE/DEV_BSIZE);
                       rablock = bn + (BLKDEV_IOSIZE/DEV_BSIZE);
                       rasize = size = bsize;
               }
               if (rw == UIO_READ) {
                       if ((long)bn<0) {
                               bp = geteblk(size);
                               clrbuf(bp);
                       } else if (ip->i_lastr + 1 == lbn)
                               bp = breada(dev, bn, size, rablock, rasize);
                       else
                               bp = bread(dev, bn, size);
                       ip->i_lastr = lbn;
               } else {
                       int i, count;

                       count = howmany(size, DEV_BSIZE);
                       for (i = 0; i < count; i += CLSIZE)
                               if (mfind(dev, bn + i))
                                       munhash(dev, bn + i);
                       if (n == bsize) 
                               bp = getblk(dev, bn, size);
                       else
                               bp = bread(dev, bn, size);
               }
               n = MIN(n, size - bp->b_resid);
               if (bp->b_flags & B_ERROR) {
                       error = EIO;
                       brelse(bp);
                       goto bad;
               }
               u.u_error =
                   uiomove(bp->b_un.b_addr+on, (u_int)n, rw, uio);
               if (rw == UIO_READ) {
                       if (n + on == bsize || uio->uio_offset == ip->i_size)
                               bp->b_flags |= B_AGE;
                       brelse(bp);
               } else {
                       if ((ip->i_mode&IFMT) == IFDIR)
                               bwrite(bp);
                       else if (n + on == bsize) {
                               bp->b_flags |= B_AGE;
                               bawrite(bp);
                       } else
                               bdwrite(bp);
                       ip->i_flag |= IUPD|ICHG;
                       if (u.u_ruid != 0)
                               ip->i_mode &= ~(ISUID|ISGID);
               }
       } while (u.u_error == 0 && uio->uio_resid > 0 && n != 0);
bad:
       return (error);
}

uiomove(cp, n, rw, uio)
       register caddr_t cp;
       register int n;
       enum uio_rw rw;
       register struct uio *uio;
{
       register struct iovec *iov;
       int error;
       u_int cnt;

       while (n > 0 && uio->uio_resid) {
               iov = uio->uio_iov;
               cnt = iov->iov_len;
               if (cnt == 0) {
                       uio->uio_iov++;
                       uio->uio_iovcnt--;
                       continue;
               }
               if (cnt > n)
                       cnt = n;
               switch (uio->uio_segflg) {

               case 0:
               case 2:
                       if (rw == UIO_READ)
                               error = copyout(cp, iov->iov_base, cnt);
                       else
                               error = copyin(iov->iov_base, cp, cnt);
                       if (error)
                               return (error);
                       break;

               case 1:
                       if (rw == UIO_READ)
                               bcopy((caddr_t)cp, iov->iov_base, cnt);
                       else
                               bcopy(iov->iov_base, (caddr_t)cp, cnt);
                       break;
               }
               iov->iov_base += cnt;
               iov->iov_len -= cnt;
               uio->uio_resid -= cnt;
               uio->uio_offset += cnt;
               cp += cnt;
               n -= cnt;
       }
       return (error);
}

/*
* Give next character to user as result of read.
*/
ureadc(c, uio)
       register int c;
       register struct uio *uio;
{
       register struct iovec *iov;

again:
       if (uio->uio_iovcnt == 0)
               panic("ureadc");
       iov = uio->uio_iov;
       if (iov->iov_len <= 0 || uio->uio_resid <= 0) {
               uio->uio_iovcnt--;
               uio->uio_iov++;
               goto again;
       }
       switch (uio->uio_segflg) {

       case 0:
               if (subyte(iov->iov_base, c) < 0)
                       return (EFAULT);
               break;

       case 1:
               *iov->iov_base = c;
               break;

       case 2:
               if (suibyte(iov->iov_base, c) < 0)
                       return (EFAULT);
               break;
       }
       iov->iov_base++;
       iov->iov_len--;
       uio->uio_resid--;
       uio->uio_offset++;
       return (0);
}

/*
* Get next character written in by user from uio.
*/
uwritec(uio)
       struct uio *uio;
{
       register struct iovec *iov;
       register int c;

again:
       if (uio->uio_iovcnt <= 0 || uio->uio_resid <= 0)
               panic("uwritec");
       iov = uio->uio_iov;
       if (iov->iov_len == 0) {
               uio->uio_iovcnt--;
               uio->uio_iov++;
               goto again;
       }
       switch (uio->uio_segflg) {

       case 0:
               c = fubyte(iov->iov_base);
               break;

       case 1:
               c = *iov->iov_base & 0377;
               break;

       case 2:
               c = fuibyte(iov->iov_base);
               break;
       }
       if (c < 0)
               return (-1);
       iov->iov_base++;
       iov->iov_len--;
       uio->uio_resid--;
       uio->uio_offset++;
       return (c & 0377);
}

/*
* Ioctl system call
* Check legality, execute common code,
* and switch out to individual device routine.
*/
ioctl()
{
       register struct file *fp;
       struct a {
               int     fdes;
               int     cmd;
               caddr_t cmarg;
       } *uap;
       register int com;
       register u_int size;
       char data[IOCPARM_MASK+1];

       uap = (struct a *)u.u_ap;
       if ((fp = getf(uap->fdes)) == NULL)
               return;
       if ((fp->f_flag & (FREAD|FWRITE)) == 0) {
               u.u_error = EBADF;
               return;
       }
       com = uap->cmd;

#ifndef NOCOMPAT
       /*
        * Map old style ioctl's into new for the
        * sake of backwards compatibility (sigh).
        */
       if ((com&~0xffff) == 0) {
               com = mapioctl(com);
               if (com == 0) {
                       u.u_error = EINVAL;
                       return;
               }
       }
#endif
       if (com == FIOCLEX) {
               u.u_pofile[uap->fdes] |= EXCLOSE;
               return;
       }
       if (com == FIONCLEX) {
               u.u_pofile[uap->fdes] &= ~EXCLOSE;
               return;
       }

       /*
        * Interpret high order word to find
        * amount of data to be copied to/from the
        * user's address space.
        */
       size = (com &~ (IOC_INOUT|IOC_VOID)) >> 16;
       if (size > sizeof (data)) {
               u.u_error = EFAULT;
               return;
       }
       if (com&IOC_IN && size) {
               if (copyin(uap->cmarg, (caddr_t)data, (u_int)size)) {
                       u.u_error = EFAULT;
                       return;
               }
       } else
               *(caddr_t *)data = uap->cmarg;
       /*
        * Zero the buffer on the stack so the user
        * always gets back something deterministic.
        */
       if ((com&IOC_OUT) && size)
               bzero((caddr_t)data, size);

       if (fp->f_type == DTYPE_SOCKET)
               soioctl(fp->f_socket, com, data);
       else {
               register struct inode *ip = fp->f_inode;
               int fmt = ip->i_mode & IFMT;
               dev_t dev;

               if (fmt != IFCHR) {
                       if (com == FIONREAD && (fmt == IFREG || fmt == IFDIR)) {
                               *(off_t *)data = ip->i_size - fp->f_offset;
                               goto returndata;
                       }
                       if (com != FIONBIO && com != FIOASYNC)
                               u.u_error = ENOTTY;
                       return;
               }
               dev = ip->i_rdev;
               u.u_r.r_val1 = 0;
               if ((u.u_procp->p_flag&SNUSIG) && setjmp(u.u_qsav)) {
                       u.u_eosys = RESTARTSYS;
                       return;
               }
               (*cdevsw[major(dev)].d_ioctl)(dev, com, data, 0);
       }

returndata:
       /*
        * Copy any data to user, size was
        * already set and checked above.
        */
       if (u.u_error == 0 && (com&IOC_OUT))
               if (size && copyout(data, uap->cmarg, (u_int)size))
                       u.u_error = EFAULT;
}

/*
* Do nothing specific version of line
* discipline specific ioctl command.
*/
/*ARGSUSED*/
nullioctl(tp, cmd, data, flags)
       struct tty *tp;
       char *data;
       int flags;
{

#ifdef lint
       tp = tp; data = data; flags = flags;
#endif
       return (cmd);
}

ostty()
{

}

ogtty()
{

}