NetBSD/usr.bin/vi/ex/ex_init.c

420 lines
10 KiB
C

/* $NetBSD: ex_init.c,v 1.8 2001/03/31 11:37:50 aymeric Exp $ */
/*-
* Copyright (c) 1992, 1993, 1994
* The Regents of the University of California. All rights reserved.
* Copyright (c) 1992, 1993, 1994, 1995, 1996
* Keith Bostic. All rights reserved.
*
* See the LICENSE file for redistribution information.
*/
#include "config.h"
#ifndef lint
static const char sccsid[] = "@(#)ex_init.c 10.26 (Berkeley) 8/12/96";
#endif /* not lint */
#include <sys/param.h>
#include <sys/types.h> /* XXX: param.h may not have included types.h */
#include <sys/queue.h>
#include <sys/stat.h>
#include <bitstring.h>
#include <fcntl.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "../common/common.h"
#include "tag.h"
#include "pathnames.h"
enum rc { NOEXIST, NOPERM, RCOK };
static enum rc exrc_isok __P((SCR *, struct stat *, char *, int, int));
static int ex_run_file __P((SCR *, char *));
/*
* ex_screen_copy --
* Copy ex screen.
*
* PUBLIC: int ex_screen_copy __P((SCR *, SCR *));
*/
int
ex_screen_copy(orig, sp)
SCR *orig, *sp;
{
EX_PRIVATE *oexp, *nexp;
/* Create the private ex structure. */
CALLOC_RET(orig, nexp, EX_PRIVATE *, 1, sizeof(EX_PRIVATE));
sp->ex_private = nexp;
/* Initialize queues. */
CIRCLEQ_INIT(&nexp->tq);
TAILQ_INIT(&nexp->tagfq);
LIST_INIT(&nexp->cscq);
if (orig == NULL) {
} else {
oexp = EXP(orig);
if (oexp->lastbcomm != NULL &&
(nexp->lastbcomm = strdup(oexp->lastbcomm)) == NULL) {
msgq(sp, M_SYSERR, NULL);
return(1);
}
if (ex_tag_copy(orig, sp))
return (1);
}
return (0);
}
/*
* ex_screen_end --
* End a vi screen.
*
* PUBLIC: int ex_screen_end __P((SCR *));
*/
int
ex_screen_end(sp)
SCR *sp;
{
EX_PRIVATE *exp;
int rval;
if ((exp = EXP(sp)) == NULL)
return (0);
rval = 0;
/* Close down script connections. */
if (F_ISSET(sp, SC_SCRIPT) && sscr_end(sp))
rval = 1;
if (argv_free(sp))
rval = 1;
if (exp->ibp != NULL)
free(exp->ibp);
if (exp->lastbcomm != NULL)
free(exp->lastbcomm);
if (ex_tag_free(sp))
rval = 1;
/* Free private memory. */
free(exp);
sp->ex_private = NULL;
return (rval);
}
/*
* ex_optchange --
* Handle change of options for ex.
*
* PUBLIC: int ex_optchange __P((SCR *, int, char *, u_long *));
*/
int
ex_optchange(sp, offset, str, valp)
SCR *sp;
int offset;
char *str;
u_long *valp;
{
switch (offset) {
case O_TAGS:
return (ex_tagf_alloc(sp, str));
}
return (0);
}
/*
* ex_exrc --
* Read the EXINIT environment variable and the startup exrc files,
* and execute their commands.
*
* PUBLIC: int ex_exrc __P((SCR *));
*/
int
ex_exrc(sp)
SCR *sp;
{
struct stat hsb, lsb;
char *p, path[MAXPATHLEN];
/*
* Source the system, environment, $HOME and local .exrc values.
* Vi historically didn't check $HOME/.exrc if the environment
* variable EXINIT was set. This is all done before the file is
* read in, because things in the .exrc information can set, for
* example, the recovery directory.
*
* !!!
* While nvi can handle any of the options settings of historic vi,
* the converse is not true. Since users are going to have to have
* files and environmental variables that work with both, we use nvi
* versions of both the $HOME and local startup files if they exist,
* otherwise the historic ones.
*
* !!!
* For a discussion of permissions and when what .exrc files are
* read, see the comment above the exrc_isok() function below.
*
* !!!
* If the user started the historic of vi in $HOME, vi read the user's
* .exrc file twice, as $HOME/.exrc and as ./.exrc. We avoid this, as
* it's going to make some commands behave oddly, and I can't imagine
* anyone depending on it.
*/
switch (exrc_isok(sp, &hsb, _PATH_SYSEXRC, 1, 0)) {
case NOEXIST:
case NOPERM:
break;
case RCOK:
if (ex_run_file(sp, _PATH_SYSEXRC))
return (1);
break;
}
/* Run the commands. */
if (EXCMD_RUNNING(sp->gp))
(void)ex_cmd(sp);
if (F_ISSET(sp, SC_EXIT | SC_EXIT_FORCE))
return (0);
if ((p = getenv("NEXINIT")) != NULL) {
if (ex_run_str(sp, "NEXINIT", p, strlen(p), 1, 0))
return (1);
} else if ((p = getenv("EXINIT")) != NULL) {
if (ex_run_str(sp, "EXINIT", p, strlen(p), 1, 0))
return (1);
} else if ((p = getenv("HOME")) != NULL && *p) {
(void)snprintf(path, sizeof(path), "%s/%s", p, _PATH_NEXRC);
switch (exrc_isok(sp, &hsb, path, 0, 1)) {
case NOEXIST:
(void)snprintf(path,
sizeof(path), "%s/%s", p, _PATH_EXRC);
if (exrc_isok(sp,
&hsb, path, 0, 1) == RCOK && ex_run_file(sp, path))
return (1);
break;
case NOPERM:
break;
case RCOK:
if (ex_run_file(sp, path))
return (1);
break;
}
}
/* Run the commands. */
if (EXCMD_RUNNING(sp->gp))
(void)ex_cmd(sp);
if (F_ISSET(sp, SC_EXIT | SC_EXIT_FORCE))
return (0);
/* Previous commands may have set the exrc option. */
if (O_ISSET(sp, O_EXRC)) {
switch (exrc_isok(sp, &lsb, _PATH_NEXRC, 0, 0)) {
case NOEXIST:
if (exrc_isok(sp, &lsb, _PATH_EXRC, 0, 0) == RCOK &&
(lsb.st_dev != hsb.st_dev ||
lsb.st_ino != hsb.st_ino) &&
ex_run_file(sp, _PATH_EXRC))
return (1);
break;
case NOPERM:
break;
case RCOK:
if ((lsb.st_dev != hsb.st_dev ||
lsb.st_ino != hsb.st_ino) &&
ex_run_file(sp, _PATH_NEXRC))
return (1);
break;
}
/* Run the commands. */
if (EXCMD_RUNNING(sp->gp))
(void)ex_cmd(sp);
if (F_ISSET(sp, SC_EXIT | SC_EXIT_FORCE))
return (0);
}
return (0);
}
/*
* ex_run_file --
* Set up a file of ex commands to run.
*/
static int
ex_run_file(sp, name)
SCR *sp;
char *name;
{
ARGS *ap[2], a;
EXCMD cmd;
ex_cinit(&cmd, C_SOURCE, 0, OOBLNO, OOBLNO, 0, ap);
ex_cadd(&cmd, &a, name, strlen(name));
return (ex_source(sp, &cmd));
}
/*
* ex_run_str --
* Set up a string of ex commands to run.
*
* PUBLIC: int ex_run_str __P((SCR *, char *, char *, size_t, int, int));
*/
int
ex_run_str(sp, name, str, len, ex_flags, nocopy)
SCR *sp;
char *name, *str;
size_t len;
int ex_flags, nocopy;
{
GS *gp;
EXCMD *ecp;
gp = sp->gp;
if (EXCMD_RUNNING(gp)) {
CALLOC_RET(sp, ecp, EXCMD *, 1, sizeof(EXCMD));
LIST_INSERT_HEAD(&gp->ecq, ecp, q);
} else
ecp = &gp->excmd;
F_INIT(ecp,
ex_flags ? E_BLIGNORE | E_NOAUTO | E_NOPRDEF | E_VLITONLY : 0);
if (nocopy)
ecp->cp = str;
else
if ((ecp->cp = v_strdup(sp, str, len)) == NULL)
return (1);
ecp->clen = len;
if (name == NULL)
ecp->if_name = NULL;
else {
if ((ecp->if_name = v_strdup(sp, name, strlen(name))) == NULL)
return (1);
ecp->if_lno = 1;
F_SET(ecp, E_NAMEDISCARD);
}
return (0);
}
/*
* exrc_isok --
* Check a .exrc file for source-ability.
*
* !!!
* Historically, vi read the $HOME and local .exrc files if they were owned
* by the user's real ID, or the "sourceany" option was set, regardless of
* any other considerations. We no longer support the sourceany option as
* it's a security problem of mammoth proportions. We require the system
* .exrc file to be owned by root, the $HOME .exrc file to be owned by the
* user's effective ID (or that the user's effective ID be root) and the
* local .exrc files to be owned by the user's effective ID. In all cases,
* the file cannot be writeable by anyone other than its owner.
*
* In O'Reilly ("Learning the VI Editor", Fifth Ed., May 1992, page 106),
* it notes that System V release 3.2 and later has an option "[no]exrc".
* The behavior is that local .exrc files are read only if the exrc option
* is set. The default for the exrc option was off, so, by default, local
* .exrc files were not read. The problem this was intended to solve was
* that System V permitted users to give away files, so there's no possible
* ownership or writeability test to ensure that the file is safe.
*
* POSIX 1003.2-1992 standardized exrc as an option. It required the exrc
* option to be off by default, thus local .exrc files are not to be read
* by default. The Rationale noted (incorrectly) that this was a change
* to historic practice, but correctly noted that a default of off improves
* system security. POSIX also required that vi check the effective user
* ID instead of the real user ID, which is why we've switched from historic
* practice.
*
* We initialize the exrc variable to off. If it's turned on by the system
* or $HOME .exrc files, and the local .exrc file passes the ownership and
* writeability tests, then we read it. This breaks historic 4BSD practice,
* but it gives us a measure of security on systems where users can give away
* files.
*/
static enum rc
exrc_isok(sp, sbp, path, rootown, rootid)
SCR *sp;
struct stat *sbp;
char *path;
int rootown, rootid;
{
enum { ROOTOWN, OWN, WRITER } etype;
uid_t euid;
int nf1, nf2;
char *a, *b, buf[MAXPATHLEN];
/* Check for the file's existence. */
if (stat(path, sbp))
return (NOEXIST);
/* Check ownership permissions. */
euid = geteuid();
if (!(rootown && sbp->st_uid == 0) &&
!(rootid && euid == 0) && sbp->st_uid != euid) {
etype = rootown ? ROOTOWN : OWN;
goto denied;
}
/* Check writeability. */
if (sbp->st_mode & (S_IWGRP | S_IWOTH)) {
etype = WRITER;
goto denied;
}
return (RCOK);
denied: a = msg_print(sp, path, &nf1);
if (strchr(path, '/') == NULL && getcwd(buf, sizeof(buf)) != NULL) {
b = msg_print(sp, buf, &nf2);
switch (etype) {
case ROOTOWN:
msgq(sp, M_ERR,
"125|%s/%s: not sourced: not owned by you or root",
b, a);
break;
case OWN:
msgq(sp, M_ERR,
"126|%s/%s: not sourced: not owned by you", b, a);
break;
case WRITER:
msgq(sp, M_ERR,
"127|%s/%s: not sourced: writeable by a user other than the owner", b, a);
break;
}
if (nf2)
FREE_SPACE(sp, b, 0);
} else
switch (etype) {
case ROOTOWN:
msgq(sp, M_ERR,
"128|%s: not sourced: not owned by you or root", a);
break;
case OWN:
msgq(sp, M_ERR,
"129|%s: not sourced: not owned by you", a);
break;
case WRITER:
msgq(sp, M_ERR,
"130|%s: not sourced: writeable by a user other than the owner", a);
break;
}
if (nf1)
FREE_SPACE(sp, a, 0);
return (NOPERM);
}