OpenSolaris_b135/cmd/streams/strcmd/strchg.c
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2005 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
#pragma ident "%Z%%M% %I% %E% SMI" /* SVr4.0 1.6 */
/*
* Streams Command strchg: change the configuration of the
* stream associated with stdin.
*
* USAGE: strchg -h module1[,module2,module3 ...]
* or: strchg -p
* or: strchg -p -a
* or: strchg -p -u module
* or: strchg -f file
*
* -h pusHes the named module(s) onto the stdin stream
* -p poPs the topmost module from the stdin stream
* -p -a poPs All modules
* -p -u module poPs all modules Up to, but not including, the named module
* -f file reads a list of modules from the named File, pops all modules,
* then pushes the list of modules
*
* RETURNS:
* 0 SUCCESS it worked
* 1 ERR_USAGE bad invocation
* 2 ERR_MODULE bad module name(s)
* 3 ERR_STDIN an ioctl or stat on the stdin stream failed
* 4 ERR_MEM couldn't allocate memory
* 5 ERR_OPEN couldn't open file in -f opt
* 6 ERR_PERM not owner or superuser
*
*/
#include <stdio.h>
#include <sys/stropts.h>
#include <sys/termio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#define FALSE 0
#define TRUE 1
#define SUCCESS 0
#define FAILURE 1
#define NMODULES 16 /* "reasonable" # of modules to push */
/* (can push more if you like) */
#define MAXMODULES 2048 /* max # of modules to push */
#define OPTLIST "af:h:pu:"
#define USAGE "Usage:\t%s -h module1[,module2 ... ]\n\t%s -f file"\
"\n\t%s -p [-a | -u module ]\n"
#define ERR_USAGE 1 /* bad invocation */
#define ERR_MODULE 2 /* bad module name(s) or too many modules */
#define ERR_STDIN 3 /* an ioctl or stat on stdin failed */
#define ERR_MEM 4 /* couldn't allocate memory */
#define ERR_OPEN 5 /* couldn't open file in -f opt */
#define ERR_PERM 6 /* not owner or superuser */
#define STDIN 0
static char *Cmd_namep; /* how was it invoked? */
static struct str_mlist Oldmods[NMODULES]; /* modlist for Oldlist */
static struct str_list Oldlist; /* original modules */
static int pop_modules(int);
static int push_module(const char *);
static int more_modules(struct str_list *, int);
static void restore(int, int);
int
main(int argc, char **argv)
{
char buf[BUFSIZ]; /* input buffer */
char *file_namep; /* file from -f opt */
char *modnamep; /* mods from -h or -u opt */
char *modp; /* for walking thru modnamep */
FILE *fp; /* file pointer for -f file */
int i; /* loop index and junk var */
int j; /* loop index and junk var */
int euid; /* effective uid */
short error; /* TRUE if usage error */
short fromfile; /* TRUE if -f file */
short is_a_tty; /* TRUE if TCGETA succeeds */
short pop; /* TRUE if -p */
short popall; /* TRUE if -p -a */
short popupto; /* TRUE if -p -u module */
short push; /* TRUE if -h mod1[,mod2 ...] */
struct str_mlist newmods[NMODULES]; /* mod list for new list */
struct stat stats; /* stream stats */
struct str_list newlist; /* modules to be pushed */
struct termio termio; /* save state of tty */
/*
* init
*/
Cmd_namep = argv[0];
error = fromfile = is_a_tty = pop = popall = popupto = push = FALSE;
Oldlist.sl_modlist = Oldmods;
Oldlist.sl_nmods = NMODULES;
newlist.sl_modlist = newmods;
newlist.sl_nmods = NMODULES;
/*
* only owner and root can change stream configuration
*/
if ((euid = geteuid()) != 0) {
if (fstat(0, &stats) < 0) {
perror("fstat");
(void) fprintf(stderr, "%s: fstat of stdin failed\n",
Cmd_namep);
return (ERR_STDIN);
}
if (euid != stats.st_uid) {
(void) fprintf(stderr,
"%s: not owner of stdin\n", Cmd_namep);
return (ERR_PERM);
}
}
/*
* parse args
*/
if (argc == 1) {
(void) fprintf(stderr, USAGE, Cmd_namep, Cmd_namep, Cmd_namep);
return (ERR_USAGE);
}
while (!error && (i = getopt(argc, argv, OPTLIST)) != -1) {
switch (i) {
case 'a': /* pop All */
if (fromfile || popupto || push)
error = TRUE;
else
popall = TRUE;
break;
case 'f': /* read from File */
if (pop || push)
error = TRUE;
else {
fromfile = TRUE;
file_namep = optarg;
}
break;
case 'h': /* pusH */
if (fromfile || pop)
error = TRUE;
else {
push = TRUE;
modnamep = optarg;
}
break;
case 'p': /* poP */
if (fromfile || push)
error = TRUE;
else
pop = TRUE;
break;
case 'u': /* pop Upto */
if (fromfile || popall || push)
error = TRUE;
else {
popupto = TRUE;
modnamep = optarg;
}
break;
default:
(void) fprintf(stderr,
USAGE, Cmd_namep, Cmd_namep, Cmd_namep);
return (ERR_USAGE);
/*NOTREACHED*/
}
}
if (error || optind < argc) {
(void) fprintf(stderr, USAGE, Cmd_namep, Cmd_namep, Cmd_namep);
return (ERR_USAGE);
}
if (!pop && (popall || popupto)) {
(void) fprintf(stderr,
"%s: -p option must be used with -a or -u to pop modules\n",
Cmd_namep);
(void) fprintf(stderr, USAGE, Cmd_namep, Cmd_namep, Cmd_namep);
return (ERR_USAGE);
}
/*
* Save state so can restore if something goes wrong
* (If are only going to push modules, don't need to
* save original module list for restore.)
*/
if (fromfile || pop) {
/*
* get number of modules on stream
* allocate more room if needed
*/
if ((i = ioctl(STDIN, I_LIST, NULL)) < 0) {
perror("I_LIST");
(void) fprintf(stderr,
"%s: I_LIST ioctl failed\n", Cmd_namep);
return (ERR_STDIN);
}
if (i > Oldlist.sl_nmods &&
more_modules(&Oldlist, i) != SUCCESS)
return (ERR_MEM);
/*
* get list of modules on stream
*/
Oldlist.sl_nmods = i;
if (ioctl(STDIN, I_LIST, &Oldlist) < 0) {
perror("I_LIST");
(void) fprintf(stderr,
"%s: I_LIST ioctl failed\n", Cmd_namep);
return (ERR_STDIN);
}
/*
* The following attempts to avoid leaving a
* terminal line that does not respond to anything
* if the strchg -h or -f options failed due to
* specifying invalid module names for pushing
*/
if (ioctl(STDIN, TCGETA, &termio) >= 0)
is_a_tty = TRUE;
}
/*
* push modules on stream
*/
if (push) {
/*
* pull mod names out of comma-separated list
*/
for (i = 0, modp = strtok(modnamep, ",");
modp != NULL; ++i, modp = strtok(NULL, ",")) {
if (push_module(modp) == FAILURE) {
/* pop the 'i' modules we just added */
restore(i, 0);
return (ERR_STDIN);
}
}
return (SUCCESS);
}
/*
* read configuration from a file
*/
if (fromfile) {
if ((fp = fopen(file_namep, "r")) == NULL) {
perror("fopen");
(void) fprintf(stderr,
"%s: could not open file '%s'\n",
Cmd_namep, file_namep);
return (ERR_OPEN);
}
/*
* read file and construct a new strlist
*/
i = 0;
while (fgets(buf, BUFSIZ, fp) != NULL) {
if (buf[0] == '#')
continue; /* skip comments */
/*
* skip trailing newline, trailing and leading
* whitespace
*/
if ((modp = strtok(buf, " \t\n")) == NULL)
continue; /* blank line */
(void) strncpy(newlist.sl_modlist[i].l_name,
modp, FMNAMESZ);
++i;
if ((modp = strtok(NULL, " \t\n")) != NULL) {
/*
* bad format
* should only be one name per line
*/
(void) fprintf(stderr,
"%s: error on line %d in file %s: "
"multiple module names??\n",
Cmd_namep, i, file_namep);
return (ERR_MODULE);
}
if (i > newlist.sl_nmods)
if (more_modules(&newlist, i) != SUCCESS)
return (ERR_MEM);
}
newlist.sl_nmods = i;
/*
* If an empty file, exit silently
*/
if (i == 0)
return (SUCCESS);
/*
* Pop all modules currently on the stream.
*/
if ((i = pop_modules(Oldlist.sl_nmods - 1))
!= (Oldlist.sl_nmods - 1)) {
/* put back whatever we've popped */
restore(0, i);
return (ERR_STDIN);
}
/*
* Push new modules
*/
for (i = newlist.sl_nmods - 1; i >= 0; --i) {
if (push_module(newlist.sl_modlist[i].l_name) ==
FAILURE) {
/*
* pop whatever new modules we've pushed
* then push old module list back on
*/
restore((newlist.sl_nmods - 1 - i),
(Oldlist.sl_nmods - 1));
/*
* If the stream is a tty line, at least try
* to set the state to what it was before.
*/
if (is_a_tty &&
ioctl(STDIN, TCSETA, &termio) < 0) {
perror("TCSETA");
(void) fprintf(stderr,
"%s: WARNING: Could not restore "
"the states of the terminal line "
"discipline\n", Cmd_namep);
}
return (ERR_STDIN);
}
}
return (SUCCESS);
} /* end if-fromfile */
/*
* pop all modules (except driver)
*/
if (popall) {
if (Oldlist.sl_nmods > 1) {
if ((i = pop_modules(Oldlist.sl_nmods - 1)) !=
(Oldlist.sl_nmods - 1)) {
restore(0, i);
return (ERR_STDIN);
}
}
return (SUCCESS);
}
/*
* pop up to (but not including) a module
*/
if (popupto) {
/*
* check that the module is in fact on the stream
*/
for (i = 0; i < Oldlist.sl_nmods; ++i)
if (strncmp(Oldlist.sl_modlist[i].l_name, modnamep,
FMNAMESZ) == 0)
break;
if (i == Oldlist.sl_nmods) {
/* no match found */
(void) fprintf(stderr, "%s: %s not found on stream\n",
Cmd_namep, modnamep);
return (ERR_MODULE);
}
if ((j = pop_modules(i)) != i) {
/* put back whatever we've popped */
restore(0, j);
return (ERR_STDIN);
}
return (SUCCESS);
}
/*
* pop the topmost module
*/
if (pop) {
if (Oldlist.sl_nmods > 1)
if (pop_modules(1) != 1)
/* no need to restore */
return (ERR_STDIN);
return (SUCCESS);
}
return (SUCCESS);
}
/*
* pop_module(n) pop 'n' modules from stream
*
* returns # of modules popped
*/
static int
pop_modules(int num_modules)
{
int i;
for (i = 0; i < num_modules; i++) {
if (ioctl(STDIN, I_POP, 0) < 0) {
perror("I_POP");
(void) fprintf(stderr,
"%s: I_POP ioctl failed\n", Cmd_namep);
return (i);
}
}
return (i);
}
/*
* push_module(modnamep) pushes 'modnamep' module on stream
*
* returns SUCCESS or FAILURE
*/
static int
push_module(const char *modnamep)
{
if (ioctl(STDIN, I_PUSH, modnamep) < 0) {
perror("I_PUSH");
(void) fprintf(stderr,
"%s: I_PUSH ioctl of %s failed\n", Cmd_namep, modnamep);
return (FAILURE);
}
return (SUCCESS);
}
/*
* restore(npop, npush) restore original state of stream
*
* pops 'npop' modules, then pushes the topmost 'npush' modules from
* Oldlist
*
*/
static void
restore(int npop, int npush)
{
int i;
if ((i = pop_modules(npop)) != npop) {
(void) fprintf(stderr,
"%s: WARNING: could not restore state of stream\n",
Cmd_namep);
return;
}
if (npush >= Oldlist.sl_nmods) { /* "cannot" happen */
(void) fprintf(stderr,
"%s: internal logic error in restore\n", Cmd_namep);
(void) fprintf(stderr,
"%s: WARNING: could not restore state of stream\n",
Cmd_namep);
return;
}
for (i = npush - 1; i >= 0; --i) {
if (push_module(Oldlist.sl_modlist[i].l_name) == FAILURE) {
(void) fprintf(stderr,
"%s: WARNING: could not restore state of stream\n",
Cmd_namep);
return;
}
}
}
/*
* more_modules(listp, n) allocate space for 'n' modules in 'listp'
*
* returns: SUCCESS or FAILURE
*/
static int
more_modules(struct str_list *listp, int n)
{
int i;
struct str_mlist *modp;
if (n > MAXMODULES) {
(void) fprintf(stderr,
"%s: too many modules (%d) -- max is %d\n",
Cmd_namep, n, MAXMODULES);
return (FAILURE);
}
if ((modp = calloc(n, sizeof (struct str_mlist))) == NULL) {
perror("calloc");
(void) fprintf(stderr,
"%s: failed to allocate space for module list\n",
Cmd_namep);
return (FAILURE);
}
for (i = 0; i < listp->sl_nmods; ++i)
(void) strncpy(modp[i].l_name, listp->sl_modlist[i].l_name,
FMNAMESZ);
listp->sl_nmods = n;
listp->sl_modlist = modp;
return (SUCCESS);
}