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fix shebang/magic decoding

This commit is contained in:
tg 2014-11-25 22:46:58 +00:00
parent 93448bdf66
commit 2f26836ed1
1 changed files with 39 additions and 38 deletions
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77
exec.c
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@ -23,7 +23,7 @@
#include "sh.h"
__RCSID("$MirOS: src/bin/mksh/exec.c,v 1.138 2014/11/25 21:13:24 tg Exp $");
__RCSID("$MirOS: src/bin/mksh/exec.c,v 1.139 2014/11/25 22:46:58 tg Exp $");
#ifndef MKSH_DEFAULT_EXECSHELL
#define MKSH_DEFAULT_EXECSHELL "/bin/sh"
@ -854,10 +854,8 @@ scriptexec(struct op *tp, const char **ap)
{
const char *sh;
#ifndef MKSH_SMALL
unsigned char *cp;
/* 64 == MAXINTERP in MirBSD <sys/param.h> */
char buf[64];
int fd;
unsigned char buf[68];
#endif
union mksh_ccphack args, cap;
@ -871,33 +869,35 @@ scriptexec(struct op *tp, const char **ap)
#ifndef MKSH_SMALL
if ((fd = open(tp->str, O_RDONLY | O_BINARY)) >= 0) {
/* read first MAXINTERP octets from file */
if (read(fd, buf, sizeof(buf)) <= 0)
/* read error -> no good */
buf[0] = '\0';
unsigned char *cp;
unsigned short m;
ssize_t n;
/* read first couple of octets from file */
n = read(fd, buf, sizeof(buf) - 1);
close(fd);
/* read error or short read? */
if (n < 5)
goto nomagic;
/* terminate buffer */
buf[n] = '\0';
/* skip UTF-8 Byte Order Mark, if present */
cp = (unsigned char *)buf;
if ((cp[0] == 0xEF) && (cp[1] == 0xBB) && (cp[2] == 0xBF))
cp += 3;
/* save begin of shebang for later */
fd = (char *)cp - buf; /* either 0 or (if BOM) 3 */
cp = buf + (n = ((buf[0] == 0xEF) && (buf[1] == 0xBB) &&
(buf[2] == 0xBF)) ? 3 : 0);
/* scan for newline (or CR) or NUL _before_ end of buffer */
while ((size_t)((char *)cp - buf) < sizeof(buf))
if (*cp == '\0' || *cp == '\n' || *cp == '\r') {
*cp = '\0';
break;
} else
++cp;
/* scan for newline or NUL (end of buffer) */
while (*cp && *cp != '\n')
++cp;
/* if the shebang line is longer than MAXINTERP, bail out */
if ((size_t)((char *)cp - buf) >= sizeof(buf))
if (!*cp)
goto noshebang;
/* replace newline by NUL */
*cp = '\0';
/* restore begin of shebang position (buf+0 or buf+3) */
cp = (unsigned char *)(buf + fd);
/* bail out if read error (above) or no shebang */
cp = buf + n;
/* bail out if no shebang magic found */
if ((cp[0] != '#') || (cp[1] != '!'))
goto noshebang;
@ -923,23 +923,24 @@ scriptexec(struct op *tp, const char **ap)
if (*cp)
*tp->args-- = (char *)cp;
}
goto nomagic;
noshebang:
cp = (unsigned char *)buf;
if (cp[0] == 0x7F && cp[1] == 'E' && cp[2] == 'L' &&
cp[3] == 'F')
m = buf[0] << 8 | buf[1];
if (m == 0x7F45 && buf[2] == 'L' && buf[3] == 'F')
errorf("%s: not executable: %d-bit ELF file", tp->str,
32 * cp[4]);
fd = cp[0] << 8 | cp[1];
if ((fd == /* OMAGIC */ 0407) ||
(fd == /* NMAGIC */ 0410) ||
(fd == /* ZMAGIC */ 0413) ||
(fd == /* QMAGIC */ 0314) ||
(fd == /* ECOFF_I386 */ 0x4C01) ||
(fd == /* ECOFF_M68K */ 0x0150 || fd == 0x5001) ||
(fd == /* ECOFF_SH */ 0x0500 || fd == 0x0005) ||
(fd == /* "MZ" */ 0x4D5A) ||
(fd == /* gzip */ 0x1F8B))
errorf("%s: not executable: magic %04X", tp->str, fd);
32 * buf[4]);
if ((m == /* OMAGIC */ 0407) ||
(m == /* NMAGIC */ 0410) ||
(m == /* ZMAGIC */ 0413) ||
(m == /* QMAGIC */ 0314) ||
(m == /* ECOFF_I386 */ 0x4C01) ||
(m == /* ECOFF_M68K */ 0x0150 || m == 0x5001) ||
(m == /* ECOFF_SH */ 0x0500 || m == 0x0005) ||
(m == /* "MZ" */ 0x4D5A) ||
(m == /* gzip */ 0x1F8B) || (m == /* .Z */ 0x1F9D))
errorf("%s: not executable: magic %04X", tp->str, m);
nomagic:
;
}
#endif
args.ro = tp->args;