4.1cBSD/usr/src/games/compat/unixtraps.c
#
static char sccsid[] = " unixtraps.c 4.1 82/05/12 ";
/* Function to execute version 6 and version 7 UNIX system calls from
* compatability mode on UNIX-32V.
* Art Wetzel August 1979
*/
#include <stdio.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/stat.h>
#ifdef V6UNIX
#ifdef TRACE
#define RTSNAME "/../../../../usr/local/v6trc"
#else
#define RTSNAME "/../../../../usr/local/v6run"
#endif
#include "unix6sys.h"
#ifdef TRACE
#include "unix6sysn.h"
#endif
#endif
#ifdef V7UNIX
#ifdef TRACE
#define RTSNAME "/../../../../usr/local/v7trc"
#else
#define RTSNAME "/../../../../usr/local/v7run"
#endif
#include "unix7sys.h"
#ifdef TRACE
#include "unix7sysn.h"
#endif
#endif
#include "defs.h"
#define CARRY 1
#define MAXSARGS 25
#ifdef V6UNIX
#define ARGVLEN 512
#define ENVLEN 0
#endif
#ifdef V7UNIX
#define ARGVLEN 5120
#define ENVLEN 1000
#endif
char argvs[ARGVLEN+ENVLEN];
int args[MAXSARGS];
/* 32v type stat structure */
extern struct stat stat32v;
/* place for times data so we can reverse the longs */
struct timebuf {
long t1;
long t2;
long t3;
long t4;
} timebuf;
/* place for pipe file descriptors */
int pipes[2];
/* wait status */
int wstatus;
#ifdef V6UNIX
/* version 6 style stat structure */
struct v6nod {
dev_t majmin;
ino_t inumber;
unsigned short flags;
unsigned char nlinks;
unsigned char uid;
unsigned char gid;
unsigned char size0;
unsigned short size1;
unsigned short addr[8];
long actime;
long modtime;
} *v6stat;
#endif
/* do the trap stuff for the trap with code */
dotrap(code) int code; {
register unsigned short *argp, *savp, *savep;
register int i, j, indirflg;
register char *avp, *oavp;
extern sigcatch();
extern errno;
/* clear out condition codes of psl */
psl &= ~017;
/* special case of indirect sys call */
if(code == 0) {
/* remember this was indirect */
indirflg = 1;
/* point to args */
argp = (unsigned short *)*(pc++);
/* code for indirect sys call */
code = *argp++;
/* is it legit */
if(code>>8 != TRAPS) {
fprintf(stderr,"Bad indirect sys call at 0x%x\n",pc-2);
pc++;
/* set carry flag */
psl |= CARRY;
regs[0] = -1;
return(-1);
}
code &= 0377;
}
else {
/* remember this was not indirect */
indirflg = 0;
/* point to args */
argp = pc;
}
/* check if code too high or bad sys code */
if(code >= NSYSTRAPS || sysargs[code][0] == ILLSYS) {
fprintf(stderr,"Unimplimented trap %d at 0x%x\n",code,argp);
/* set carry bit */
psl |= CARRY;
regs[0] = -1;
return(-1);
}
/* copy args to known locations */
i=0;
for(j=0; j<sysargs[code][0]; j++) args[i++] = regs[j];
for(j=0; j<(sysargs[code][1]); j++) args[i++] = *argp++;
#ifdef TRACE
fprintf(stderr,"pid %d ",getpid());
if(indirflg) fprintf(stderr,"indirect ");
fprintf(stderr,"%s (%d) from 0%o with %d args",sysnames[code],code,pc-1,i);
for(j=0; j<i; j++)
fprintf(stderr," 0%o",args[j]);
if(code==OPEN||code==STAT||code==CREAT||code==EXEC||code==UNLNK||code==LINK||code==CHDIR||code==MKNOD)
fprintf(stderr," (%s)",args[0]);
#ifdef V7UNIX
if(code==EXECE)
fprintf(stderr," (%s)",args[0]);
#endif
if(code==LINK)
fprintf(stderr," (%s)",args[1]);
#endif
/* go do whatever sys call it is */
switch(code) {
case FORK:
/* indirect forks return pids on both sides - must do here */
/* this is possibly a bug in 32V */
i = fork();
break;
case WAIT:
i = wait(&wstatus);
args[0] = i;
args[1] = wstatus;
break;
case EXEC:
#ifdef V7UNIX
case EXECE:
#endif
/*
* have to do a lot of junk here to fix up an argv
* for execute since (1) the pdp-11 argv consists of 16
* bit pointers and (2) the argv itself is in the
* pdp-11 program space where it would get clobbered
* when a new program is read in and before its
* argv is set up.
*/
avp = &argvs[0];
savp = (unsigned short *)args[1];
#ifdef V6UNIX
for(i=1; args[i] = *savp++; i++)
if(args[i] == 0177777) break;
#ifdef TRACE
else fprintf(stderr,"argv[%d]%s ",i-1,args[i]);
#endif
#endif
#ifdef V7UNIX
savep = (unsigned short *)args[2];
for(i=1; args[i] = *savp++; i++)
#ifdef TRACE
fprintf(stderr,"argv[%d]%s ",i-1,args[i]);
#else
;
#endif
#endif
if(stat(args[0], &stat32v)) {
/* return error here if file does not exist */
#ifdef TRACE
fprintf(stderr," does not exist\n");
#endif
i = -1;
break;
}
/* must have execute permission */
if(stat32v.st_mode & (S_IEXEC>>6)) goto experm;
if(stat32v.st_mode & (S_IEXEC>>3)) {
if(stat32v.st_gid == getegid()) goto experm;
if(geteuid() == 0) goto experm;
}
if(stat32v.st_mode & S_IEXEC) {
if(stat32v.st_uid == geteuid()) goto experm;
if(geteuid() == 0) goto experm;
}
/* return failure if no exec permision allowed */
i = -1;
experm:
/* can't exec a directory */
if(stat32v.st_mode & S_IFDIR)
i = -1;
if(i == -1) break;
args[i] = 0;
for(j=0; j<i; j++) {
oavp = (char *)args[j];
args[j] = (int)avp;
while(*avp++ = *oavp++) ;
}
#ifdef V7UNIX
if(code == EXECE) {
for(j = ++i; args[j] = *savep++; j++) ;
for( ; j>i; j--) {
oavp = (char *)args[j];
args[j] = (int)avp;
while(*avp++ = *oavp++) ;
}
}
#endif
/* SETUID and SETGID files must be started with a fresh RTS */
if(stat32v.st_mode & S_ISGID || stat32v.st_mode & S_ISUID) {
/* should add a check here for good magic # in header */
args[1] = args[0];
args[0] = (int)RTSNAME;
#ifdef TRACE
fprintf(stderr," SETUID-GID");
#endif
if(args[i])
i = execve(args[0], &args[0], &args[i]);
else
i = execv(args[0], &args[0]);
fprintf(stderr,"can't exec %s\n",RTSNAME);
break;
}
i = execute(args[0], &args[1], &args[i]);
/* shouldn't get here if exec works */
break;
case SEEK:
#ifdef V6UNIX
/* fix up negative offsets */
if(args[2] != 0 && args[2] != 3)
if(args[1] >= 32768) args[1] -= 65536;
if(args[2] <= 2)
i = lseek(args[0], args[1], args[2]);
else
i = lseek(args[0], args[1]*512, args[2]-3);
if(i != -1) i = 0;
#endif
#ifdef V7UNIX
i = lseek(args[0], (args[1]<<16)|(args[2]&0177777), args[3]);
#endif
break;
#ifdef V6UNIX
case MKNOD:
/* version 6 uses allocated bit which means regular file here */
if(args[1] & S_IFBLK)
args[1] &= ~S_IFREG;
i = mknod(args[0], args[1], args[2]);
break;
#endif
case PIPE:
i = pipe(pipes);
args[0] = pipes[0];
args[1] = pipes[1];
break;
#ifdef V6UNIX
case TELL:
i = lseek(args[0], 0L, 1);
break;
#endif
case STAT:
case FSTAT:
/* do the syscall to a local stat buffer */
i = syscall(code, args[0], &stat32v);
/* reverse the longs */
stat32v.st_size = longrev(stat32v.st_size);
stat32v.st_atime = longrev(stat32v.st_atime);
stat32v.st_mtime = longrev(stat32v.st_mtime);
stat32v.st_ctime = longrev(stat32v.st_ctime);
#ifdef V7UNIX
/* copy out otherwise unchanged stat buffer */
/* in two pieces with st_size as the breaking point */
/* note that st_rdev is a short but due to alingnmemt */
/* problems the rest of the structure is out of sync */
j = (int)((char *)(&stat32v.st_size)-(char *)(&stat32v.st_dev));
bcopy(&stat32v, args[1], j);
bcopy(&stat32v.st_size, args[1]+j-2, sizeof(struct stat)-j);
#endif
#ifdef V6UNIX
/* point to user area as v6stat structure */
v6stat = (struct v6nod *)args[1];
/* copy out piece by piece */
v6stat->majmin = stat32v.st_dev;
v6stat->inumber = stat32v.st_ino;
v6stat->flags = stat32v.st_mode;
v6stat->nlinks = (unsigned char)stat32v.st_nlink;
v6stat->uid = (unsigned char)stat32v.st_uid;
v6stat->gid = (unsigned char)stat32v.st_gid;
/* note size already reversed */
v6stat->size0 = (unsigned char)(stat32v.st_size & 0377);
v6stat->size1 = (unsigned short)(stat32v.st_size>>16);
v6stat->actime = stat32v.st_atime;
v6stat->modtime = stat32v.st_mtime;
/* patch up flags */
/* for now just set 100000 bit if not a plain file */
if(v6stat->flags & 060000)
v6stat->flags |= 0100000;
#endif
break;
case TIMES:
i = times(&timebuf);
timebuf.t2 = longrev(timebuf.t2) + timebuf.t1;
timebuf.t3 = longrev(timebuf.t3);
timebuf.t4 = longrev(timebuf.t4);
bcopy(&timebuf.t2,args[0],sizeof(struct timebuf)-sizeof(long));
break;
#ifdef V6UNIX
case SLEEP:
/* do a sleep function - what about pwb which has alarm? */
sleep(args[0]);
break;
#endif
case GETUID:
args[0] = getuid();
args[1] = geteuid();
#ifdef V6UNIX
i = args[1]<<8 | args[0];
#endif
break;
case GETGID:
args[0] = getgid();
args[1] = getegid();
#ifdef V6UNIX
i = args[1]<<8 | args[0];
#endif
break;
#ifdef V6UNIX
case SETUID:
case SETGID:
/* uids and gids are 8 bits in version 6 */
i = syscall(code,args[0]&0377);
break;
#endif
case SIG:
/* if it is a good signal code */
if(args[0] <= NSIG) {
/* get the current signal value */
i = sigvals[args[0]];
/* reset the signal to the new value */
sigvals[args[0]] = args[1];
/* actually do signal except don't reset SIGILL */
if(args[0] != SIGILL) {
if(args[1] == (int)SIG_DFL || args[1] & (int)SIG_IGN) {
if((int)signal(args[0],args[1]) == -1)
i = -1;
} else {
if((int)signal(args[0], sigcatch) == -1)
i = -1;
}
}
}
else i = -1;
break;
case BRK:
/* brk is successful unless we run over the stack */
i = 0;
if(args[0] >= regs[6]) i = -1;
break;
#ifdef V6UNIX
case PWBSYS:
/* ignore pwbsys for now */
switch(args[2]) {
case UNAME:
#ifdef TRACE
fprintf(stderr,"UNAME with %d %d\n",args[0],args[1]);
#endif
strcpy(args[0],"pwbname");
i = 0;
break;
case UDATA:
#ifdef TRACE
fprintf(stderr,"UDATA with %d %d\n",args[0],args[1]);
#endif
i = 0;
break;
case USTAT:
fprintf(stderr,"USTAT with %d %d\n",args[0],args[1]);
i = 0;
break;
case UTIME:
fprintf(stderr,"UTIME with %d %d\n",args[0],args[1]);
i = 0;
break;
default:
fprintf(stderr,"bad PWBSYS %d\n",args[3]);
i = -1;
break;
}
break;
#endif
default:
/*
* Many sys calls are easily done here since most
* system call codes are the same on version 6 and 7 UNIX
* as they are here.
*/
i = syscall(code,args[0],args[1],args[2],args[3],args[4]);
#ifdef V6UNIX
/* allow read write access to created files for(IDIS v6 mod) */
if(code==CREAT) {
/* get actual file mode after create */
fstat(i, &stat32v);
close(i);
/* ensure read/write access to owner */
chmod(args[0], 0644);
i = open(args[0], 2);
/* change mode back the way it was */
chmod(args[0], stat32v.st_mode);
}
#endif
break;
}
#ifdef TRACE
fprintf(stderr," sys val -> 0%o\n",i);
#endif
/* set carry bit if sys error */
if(i == -1)
psl |= CARRY;
/* if not an indirect sys call, adjust the pc */
if(indirflg == 0)
pc = argp;
/* do alternate return on one side of fork */
if(code == FORK && i != 0)
pc++;
/* do the various return value formats */
switch(sysargs[code][2]) {
case NORMRET:
/* normal case only one return value in r0 */
regs[0] = i;
break;
case LONGRET:
/* return a long in r0 - r1 as in time */
regs[1] = i;
regs[0] = i >> 16;
break;
case TWORET:
/* return two ints in r0 - r1 as in pipe */
if(i == -1)
regs[0] = i;
else {
regs[1] = args[1];
regs[0] = args[0];
}
break;
}
if(i== -1)
regs[0] = errno;
}
long longrev(l) long l; {
/* function to reverse the halves of a long */
union {
long lng;
short s[2];
} u;
register short t;
u.lng = l;
t = u.s[0];
u.s[0] = u.s[1];
u.s[1] = t;
return(u.lng);
}