-execv()
-{
- ((struct execa *)u.u_ap)->envp = NULL;
- execve();
-}
-
-execve()
-{
- register nc;
- register char *cp;
- register struct buf *bp;
- register struct execa *uap;
- int na, ne, ucp, ap, c;
- int indir, uid, gid;
- char *sharg;
- struct inode *ip;
- swblk_t bno;
- char cfname[MAXCOMLEN + 1];
- char cfarg[SHSIZE];
- int resid;
-
- if ((ip = namei(uchar, LOOKUP, 1)) == NULL)
- return;
- bno = 0;
- bp = 0;
- indir = 0;
- uid = u.u_uid;
- gid = u.u_gid;
- if (ip->i_mode & ISUID)
- uid = ip->i_uid;
- if (ip->i_mode & ISGID)
- gid = ip->i_gid;
-
- again:
- if (access(ip, IEXEC))
- goto bad;
- if ((u.u_procp->p_flag&STRC) && access(ip, IREAD))
- goto bad;
- if ((ip->i_mode & IFMT) != IFREG ||
- (ip->i_mode & (IEXEC|(IEXEC>>3)|(IEXEC>>6))) == 0) {
- u.u_error = EACCES;
- goto bad;
- }
-
- /*
- * Read in first few bytes of file for segment sizes, ux_mag:
- * 407 = plain executable
- * 410 = RO text
- * 413 = demand paged RO text
- * Also an ASCII line beginning with #! is
- * the file name of a ``shell'' and arguments may be prepended
- * to the argument list if given here.
- *
- * SHELL NAMES ARE LIMITED IN LENGTH.
- *
- * ONLY ONE ARGUMENT MAY BE PASSED TO THE SHELL FROM
- * THE ASCII LINE.
- */
- u.u_exdata.ux_shell[0] = 0; /* for zero length files */
- u.u_error = rdwri(UIO_READ, ip, (caddr_t)&u.u_exdata, sizeof (u.u_exdata),
- 0, 1, &resid);
- if (u.u_error)
- goto bad;
- u.u_count = resid;
-#ifndef lint
- if (u.u_count > sizeof(u.u_exdata) - sizeof(u.u_exdata.Ux_A) &&
- u.u_exdata.ux_shell[0] != '#') {
- u.u_error = ENOEXEC;
- goto bad;
- }
-#endif
- switch (u.u_exdata.ux_mag) {
-
- case 0407:
- u.u_exdata.ux_dsize += u.u_exdata.ux_tsize;
- u.u_exdata.ux_tsize = 0;
- break;
-
- case 0413:
- case 0410:
- if (u.u_exdata.ux_tsize == 0) {
- u.u_error = ENOEXEC;
- goto bad;
- }
- break;
-
- default:
- if (u.u_exdata.ux_shell[0] != '#' ||
- u.u_exdata.ux_shell[1] != '!' ||
- indir) {
- u.u_error = ENOEXEC;
- goto bad;
- }
- cp = &u.u_exdata.ux_shell[2]; /* skip "#!" */
- while (cp < &u.u_exdata.ux_shell[SHSIZE]) {
- if (*cp == '\t')
- *cp = ' ';
- else if (*cp == '\n') {
- *cp = '\0';
- break;
- }
- cp++;
- }
- if (*cp != '\0') {
- u.u_error = ENOEXEC;
- goto bad;
- }
- cp = &u.u_exdata.ux_shell[2];
- while (*cp == ' ')
- cp++;
- u.u_dirp = cp;
- while (*cp && *cp != ' ')
- cp++;
- sharg = NULL;
- if (*cp) {
- *cp++ = '\0';
- while (*cp == ' ')
- cp++;
- if (*cp) {
- bcopy((caddr_t)cp, (caddr_t)cfarg, SHSIZE);
- sharg = cfarg;
- }
- }
- if (u.u_dent.d_namlen > MAXCOMLEN)
- u.u_dent.d_namlen = MAXCOMLEN;
- bcopy((caddr_t)u.u_dent.d_name, (caddr_t)cfname,
- (unsigned)(u.u_dent.d_namlen + 1));
- cfname[MAXCOMLEN] = 0;
- indir = 1;
- iput(ip);
- ip = namei(schar, LOOKUP, 1);
- if (ip == NULL)
- return;
- goto again;
- }
-
- /*
- * Collect arguments on "file" in swap space.
- */
- na = 0;
- ne = 0;
- nc = 0;
- uap = (struct execa *)u.u_ap;
- if ((bno = rmalloc(argmap, (long)ctod(clrnd((int)btoc(NCARGS))))) == 0) {
- swkill(u.u_procp, "exece");
- goto bad;
- }
- if (bno % CLSIZE)
- panic("execa rmalloc");
- if (uap->argp) for (;;) {
- ap = NULL;
- if (indir && (na == 1 || na == 2 && sharg))
- ap = (int)uap->fname;
- else if (uap->argp) {
- ap = fuword((caddr_t)uap->argp);
- uap->argp++;
- }
- if (ap==NULL && uap->envp) {
- uap->argp = NULL;
- if ((ap = fuword((caddr_t)uap->envp)) == NULL)
- break;
- uap->envp++;
- ne++;
- }
- if (ap == NULL)
- break;
- na++;
- if (ap == -1)
- u.u_error = EFAULT;
- do {
- if (nc >= NCARGS-1)
- u.u_error = E2BIG;
- if (indir && na == 2 && sharg != NULL)
- c = *sharg++ & 0377;
- else if ((c = fubyte((caddr_t)ap++)) < 0)
- u.u_error = EFAULT;
- if (u.u_error) {
- if (bp)
- brelse(bp);
- bp = 0;
- goto badarg;
- }
- if (nc % (CLSIZE*NBPG) == 0) {
- if (bp)
- bdwrite(bp);
- bp = getblk(argdev, bno + ctod(nc / NBPG),
- CLSIZE*NBPG);
- cp = bp->b_un.b_addr;
- }
- nc++;
- *cp++ = c;
- } while (c > 0);
- }
- if (bp)
- bdwrite(bp);
- bp = 0;
- nc = (nc + NBPW-1) & ~(NBPW-1);
- if (indir) {
- u.u_dent.d_namlen = strlen(cfname);
- bcopy((caddr_t)cfname, (caddr_t)u.u_dent.d_name,
- (unsigned)(u.u_dent.d_namlen + 1));
- }
- getxfile(ip, nc + (na+4)*NBPW, uid, gid);
- if (u.u_error) {
-badarg:
- for (c = 0; c < nc; c += CLSIZE*NBPG) {
- bp = baddr(argdev, bno + ctod(c / NBPG), CLSIZE*NBPG);
- if (bp) {
- bp->b_flags |= B_AGE; /* throw away */
- bp->b_flags &= ~B_DELWRI; /* cancel io */
- brelse(bp);
- bp = 0;
- }
- }
- goto bad;
- }
-
- /*
- * copy back arglist
- */
- ucp = USRSTACK - nc - NBPW;
- ap = ucp - na*NBPW - 3*NBPW;
- u.u_ar0[SP] = ap;
- (void) suword((caddr_t)ap, na-ne);
- nc = 0;
- for (;;) {
- ap += NBPW;
- if (na==ne) {
- (void) suword((caddr_t)ap, 0);
- ap += NBPW;
- }
- if (--na < 0)
- break;
- (void) suword((caddr_t)ap, ucp);
- do {
- if (nc % (CLSIZE*NBPG) == 0) {
- if (bp)
- brelse(bp);
- bp = bread(argdev, bno + ctod(nc / NBPG),
- CLSIZE*NBPG);
- bp->b_flags |= B_AGE; /* throw away */
- bp->b_flags &= ~B_DELWRI; /* cancel io */
- cp = bp->b_un.b_addr;
- }
- (void) subyte((caddr_t)ucp++, (c = *cp++));
- nc++;
- } while(c&0377);
- }
- (void) suword((caddr_t)ap, 0);
- setregs();
-bad:
- if (bp)
- brelse(bp);
- if (bno)
- rmfree(argmap, (long)ctod(clrnd((int) btoc(NCARGS))), bno);
- iput(ip);
-}
projects / unix-history / blobdiff