0359a12ead
was always curthread and totally unuseful. Tested by: Giovanni Trematerra <giovanni dot trematerra at gmail dot com>
256 lines
8.6 KiB
C
256 lines
8.6 KiB
C
/*-
|
|
* Copyright (c) 1993, David Greenman
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
__FBSDID("$FreeBSD$");
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/vnode.h>
|
|
#include <sys/proc.h>
|
|
#include <sys/sbuf.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/sysproto.h>
|
|
#include <sys/exec.h>
|
|
#include <sys/imgact.h>
|
|
#include <sys/kernel.h>
|
|
|
|
#if BYTE_ORDER == LITTLE_ENDIAN
|
|
#define SHELLMAGIC 0x2123 /* #! */
|
|
#else
|
|
#define SHELLMAGIC 0x2321
|
|
#endif
|
|
|
|
/*
|
|
* At the time of this writing, MAXSHELLCMDLEN == PAGE_SIZE. This is
|
|
* significant because the caller has only mapped in one page of the
|
|
* file we're reading. This code should be changed to know how to
|
|
* read in the second page, but I'm not doing that just yet...
|
|
*/
|
|
#if MAXSHELLCMDLEN > PAGE_SIZE
|
|
#error "MAXSHELLCMDLEN is larger than a single page!"
|
|
#endif
|
|
|
|
/**
|
|
* Shell interpreter image activator. An interpreter name beginning at
|
|
* imgp->args->begin_argv is the minimal successful exit requirement.
|
|
*
|
|
* If the given file is a shell-script, then the first line will start
|
|
* with the two characters `#!' (aka SHELLMAGIC), followed by the name
|
|
* of the shell-interpreter to run, followed by zero or more tokens.
|
|
*
|
|
* The interpreter is then started up such that it will see:
|
|
* arg[0] -> The name of interpreter as specified after `#!' in the
|
|
* first line of the script. The interpreter name must
|
|
* not be longer than MAXSHELLCMDLEN bytes.
|
|
* arg[1] -> *If* there are any additional tokens on the first line,
|
|
* then we add a new arg[1], which is a copy of the rest of
|
|
* that line. The copy starts at the first token after the
|
|
* interpreter name. We leave it to the interpreter to
|
|
* parse the tokens in that value.
|
|
* arg[x] -> the full pathname of the script. This will either be
|
|
* arg[2] or arg[1], depending on whether or not tokens
|
|
* were found after the interpreter name.
|
|
* arg[x+1] -> all the arguments that were specified on the original
|
|
* command line.
|
|
*
|
|
* This processing is described in the execve(2) man page.
|
|
*/
|
|
|
|
/*
|
|
* HISTORICAL NOTE: From 1993 to mid-2005, FreeBSD parsed out the tokens as
|
|
* found on the first line of the script, and setup each token as a separate
|
|
* value in arg[]. This extra processing did not match the behavior of other
|
|
* OS's, and caused a few subtle problems. For one, it meant the kernel was
|
|
* deciding how those values should be parsed (wrt characters for quoting or
|
|
* comments, etc), while the interpreter might have other rules for parsing.
|
|
* It also meant the interpreter had no way of knowing which arguments came
|
|
* from the first line of the shell script, and which arguments were specified
|
|
* by the user on the command line. That extra processing was dropped in the
|
|
* 6.x branch on May 28, 2005 (matching __FreeBSD_version 600029).
|
|
*/
|
|
int
|
|
exec_shell_imgact(imgp)
|
|
struct image_params *imgp;
|
|
{
|
|
const char *image_header = imgp->image_header;
|
|
const char *ihp, *interpb, *interpe, *maxp, *optb, *opte, *fname;
|
|
int error, offset;
|
|
size_t length, clength;
|
|
struct vattr vattr;
|
|
struct sbuf *sname;
|
|
|
|
/* a shell script? */
|
|
if (((const short *) image_header)[0] != SHELLMAGIC)
|
|
return(-1);
|
|
|
|
/*
|
|
* Don't allow a shell script to be the shell for a shell
|
|
* script. :-)
|
|
*/
|
|
if (imgp->interpreted)
|
|
return(ENOEXEC);
|
|
|
|
imgp->interpreted = 1;
|
|
|
|
/*
|
|
* At this point we have the first page of the file mapped.
|
|
* However, we don't know how far into the page the contents are
|
|
* valid -- the actual file might be much shorter than the page.
|
|
* So find out the file size.
|
|
*/
|
|
error = VOP_GETATTR(imgp->vp, &vattr, imgp->proc->p_ucred);
|
|
if (error)
|
|
return (error);
|
|
|
|
/*
|
|
* Copy shell name and arguments from image_header into a string
|
|
* buffer. Remember that the caller has mapped only the
|
|
* first page of the file into memory.
|
|
*/
|
|
clength = (vattr.va_size > PAGE_SIZE) ? PAGE_SIZE : vattr.va_size;
|
|
|
|
maxp = &image_header[clength];
|
|
ihp = &image_header[2];
|
|
|
|
/*
|
|
* Find the beginning and end of the interpreter_name. If the
|
|
* line does not include any interpreter, or if the name which
|
|
* was found is too long, we bail out.
|
|
*/
|
|
while (ihp < maxp && ((*ihp == ' ') || (*ihp == '\t')))
|
|
ihp++;
|
|
interpb = ihp;
|
|
while (ihp < maxp && ((*ihp != ' ') && (*ihp != '\t') && (*ihp != '\n')
|
|
&& (*ihp != '\0')))
|
|
ihp++;
|
|
interpe = ihp;
|
|
if (interpb == interpe)
|
|
return (ENOEXEC);
|
|
if ((interpe - interpb) >= MAXSHELLCMDLEN)
|
|
return (ENAMETOOLONG);
|
|
|
|
/*
|
|
* Find the beginning of the options (if any), and the end-of-line.
|
|
* Then trim the trailing blanks off the value. Note that some
|
|
* other operating systems do *not* trim the trailing whitespace...
|
|
*/
|
|
while (ihp < maxp && ((*ihp == ' ') || (*ihp == '\t')))
|
|
ihp++;
|
|
optb = ihp;
|
|
while (ihp < maxp && ((*ihp != '\n') && (*ihp != '\0')))
|
|
ihp++;
|
|
opte = ihp;
|
|
while (--ihp > optb && ((*ihp == ' ') || (*ihp == '\t')))
|
|
opte = ihp;
|
|
|
|
if (imgp->args->fname != NULL) {
|
|
fname = imgp->args->fname;
|
|
sname = NULL;
|
|
} else {
|
|
sname = sbuf_new_auto();
|
|
sbuf_printf(sname, "/dev/fd/%d", imgp->args->fd);
|
|
sbuf_finish(sname);
|
|
fname = sbuf_data(sname);
|
|
}
|
|
|
|
/*
|
|
* We need to "pop" (remove) the present value of arg[0], and "push"
|
|
* either two or three new values in the arg[] list. To do this,
|
|
* we first shift all the other values in the `begin_argv' area to
|
|
* provide the exact amount of room for the values added. Set up
|
|
* `offset' as the number of bytes to be added to the `begin_argv'
|
|
* area, and 'length' as the number of bytes being removed.
|
|
*/
|
|
offset = interpe - interpb + 1; /* interpreter */
|
|
if (opte > optb) /* options (if any) */
|
|
offset += opte - optb + 1;
|
|
offset += strlen(fname) + 1; /* fname of script */
|
|
length = (imgp->args->argc == 0) ? 0 :
|
|
strlen(imgp->args->begin_argv) + 1; /* bytes to delete */
|
|
|
|
if (offset - length > imgp->args->stringspace) {
|
|
if (sname != NULL)
|
|
sbuf_delete(sname);
|
|
return (E2BIG);
|
|
}
|
|
|
|
bcopy(imgp->args->begin_argv + length, imgp->args->begin_argv + offset,
|
|
imgp->args->endp - (imgp->args->begin_argv + length));
|
|
|
|
offset -= length; /* calculate actual adjustment */
|
|
imgp->args->begin_envv += offset;
|
|
imgp->args->endp += offset;
|
|
imgp->args->stringspace -= offset;
|
|
|
|
/*
|
|
* If there was no arg[0] when we started, then the interpreter_name
|
|
* is adding an argument (instead of replacing the arg[0] we started
|
|
* with). And we're always adding an argument when we include the
|
|
* full pathname of the original script.
|
|
*/
|
|
if (imgp->args->argc == 0)
|
|
imgp->args->argc = 1;
|
|
imgp->args->argc++;
|
|
|
|
/*
|
|
* The original arg[] list has been shifted appropriately. Copy in
|
|
* the interpreter name and options-string.
|
|
*/
|
|
length = interpe - interpb;
|
|
bcopy(interpb, imgp->args->buf, length);
|
|
*(imgp->args->buf + length) = '\0';
|
|
offset = length + 1;
|
|
if (opte > optb) {
|
|
length = opte - optb;
|
|
bcopy(optb, imgp->args->buf + offset, length);
|
|
*(imgp->args->buf + offset + length) = '\0';
|
|
offset += length + 1;
|
|
imgp->args->argc++;
|
|
}
|
|
|
|
/*
|
|
* Finally, add the filename onto the end for the interpreter to
|
|
* use and copy the interpreter's name to imgp->interpreter_name
|
|
* for exec to use.
|
|
*/
|
|
error = copystr(fname, imgp->args->buf + offset, imgp->args->stringspace,
|
|
&length);
|
|
|
|
if (error == 0)
|
|
error = copystr(imgp->args->begin_argv, imgp->interpreter_name,
|
|
MAXSHELLCMDLEN, &length);
|
|
|
|
if (sname != NULL)
|
|
sbuf_delete(sname);
|
|
return (error);
|
|
}
|
|
|
|
/*
|
|
* Tell kern_execve.c about it, with a little help from the linker.
|
|
*/
|
|
static struct execsw shell_execsw = { exec_shell_imgact, "#!" };
|
|
EXEC_SET(shell, shell_execsw);
|