Mini Shell
/*
* Copyright 2019-2021 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the Apache License 2.0 (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include <string.h>
#include <stdarg.h>
#include <openssl/bio.h>
#include <openssl/safestack.h>
#include "opt.h"
static BIO *bio_in = NULL;
static BIO *bio_out = NULL;
static BIO *bio_err = NULL;
/*-
* This program sets up a chain of BIO_f_filter() on top of bio_out, how
* many is governed by the user through -n. It allows the user to set the
* indentation for each individual filter using -i and -p. Then it reads
* text from bio_in and prints it out through the BIO chain.
*
* The filter index is counted from the source/sink, i.e. index 0 is closest
* to it.
*
* Example:
*
* $ echo foo | ./bio_prefix_text -n 2 -i 1:32 -p 1:FOO -i 0:3
* FOO foo
* ^^^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
* | |
* | +------ 32 spaces from filter 1
* +-------------------------- 3 spaces from filter 0
*/
static size_t amount = 0;
static BIO **chain = NULL;
typedef enum OPTION_choice {
OPT_ERR = -1,
OPT_EOF = 0,
OPT_AMOUNT,
OPT_INDENT,
OPT_PREFIX
} OPTION_CHOICE;
static const OPTIONS options[] = {
{ "n", OPT_AMOUNT, 'p', "Amount of BIO_f_prefix() filters" },
/*
* idx is the index to the BIO_f_filter chain(), where 0 is closest
* to the source/sink BIO. If idx isn't given, 0 is assumed
*/
{ "i", OPT_INDENT, 's', "Indentation in form '[idx:]indent'" },
{ "p", OPT_PREFIX, 's', "Prefix in form '[idx:]prefix'" },
{ NULL }
};
int opt_printf_stderr(const char *fmt, ...)
{
va_list ap;
int ret;
va_start(ap, fmt);
ret = BIO_vprintf(bio_err, fmt, ap);
va_end(ap);
return ret;
}
static int run_pipe(void)
{
char buf[4096];
while (!BIO_eof(bio_in)) {
size_t bytes_in;
size_t bytes_out;
if (!BIO_read_ex(bio_in, buf, sizeof(buf), &bytes_in))
return 0;
bytes_out = 0;
while (bytes_out < bytes_in) {
size_t bytes;
if (!BIO_write_ex(chain[amount - 1], buf, bytes_in, &bytes))
return 0;
bytes_out += bytes;
}
}
return 1;
}
static int setup_bio_chain(const char *progname)
{
BIO *next = NULL;
size_t n = amount;
chain = OPENSSL_zalloc(sizeof(*chain) * n);
if (chain != NULL) {
size_t i;
next = bio_out;
BIO_up_ref(next); /* Protection against freeing */
for (i = 0; n > 0; i++, n--) {
BIO *curr = BIO_new(BIO_f_prefix());
if (curr == NULL)
goto err;
chain[i] = BIO_push(curr, next);
if (chain[i] == NULL)
goto err;
next = chain[i];
}
}
return chain != NULL;
err:
/* Free the chain we built up */
BIO_free_all(next);
OPENSSL_free(chain);
return 0;
}
static void cleanup(void)
{
if (chain != NULL) {
BIO_free_all(chain[amount - 1]);
OPENSSL_free(chain);
}
BIO_free_all(bio_in);
BIO_free_all(bio_out);
BIO_free_all(bio_err);
}
static int setup(void)
{
OPTION_CHOICE o;
char *arg;
char *colon;
char *endptr;
size_t idx, indent;
const char *progname = opt_getprog();
bio_in = BIO_new_fp(stdin, BIO_NOCLOSE | BIO_FP_TEXT);
bio_out = BIO_new_fp(stdout, BIO_NOCLOSE | BIO_FP_TEXT);
bio_err = BIO_new_fp(stderr, BIO_NOCLOSE | BIO_FP_TEXT);
#ifdef __VMS
bio_out = BIO_push(BIO_new(BIO_f_linebuffer()), bio_out);
bio_err = BIO_push(BIO_new(BIO_f_linebuffer()), bio_err);
#endif
OPENSSL_assert(bio_in != NULL);
OPENSSL_assert(bio_out != NULL);
OPENSSL_assert(bio_err != NULL);
while ((o = opt_next()) != OPT_EOF) {
switch (o) {
case OPT_AMOUNT:
arg = opt_arg();
amount = strtoul(arg, &endptr, 10);
if (endptr[0] != '\0') {
BIO_printf(bio_err,
"%s: -n argument isn't a decimal number: %s",
progname, arg);
return 0;
}
if (amount < 1) {
BIO_printf(bio_err, "%s: must set up at least one filter",
progname);
return 0;
}
if (!setup_bio_chain(progname)) {
BIO_printf(bio_err, "%s: failed setting up filter chain",
progname);
return 0;
}
break;
case OPT_INDENT:
if (chain == NULL) {
BIO_printf(bio_err, "%s: -i given before -n", progname);
return 0;
}
arg = opt_arg();
colon = strchr(arg, ':');
idx = 0;
if (colon != NULL) {
idx = strtoul(arg, &endptr, 10);
if (endptr[0] != ':') {
BIO_printf(bio_err,
"%s: -i index isn't a decimal number: %s",
progname, arg);
return 0;
}
colon++;
} else {
colon = arg;
}
indent = strtoul(colon, &endptr, 10);
if (endptr[0] != '\0') {
BIO_printf(bio_err,
"%s: -i value isn't a decimal number: %s",
progname, arg);
return 0;
}
if (idx >= amount) {
BIO_printf(bio_err, "%s: index (%zu) not within range 0..%zu",
progname, idx, amount - 1);
return 0;
}
if (BIO_set_indent(chain[idx], (long)indent) <= 0) {
BIO_printf(bio_err, "%s: failed setting indentation: %s",
progname, arg);
return 0;
}
break;
case OPT_PREFIX:
if (chain == NULL) {
BIO_printf(bio_err, "%s: -p given before -n", progname);
return 0;
}
arg = opt_arg();
colon = strchr(arg, ':');
idx = 0;
if (colon != NULL) {
idx = strtoul(arg, &endptr, 10);
if (endptr[0] != ':') {
BIO_printf(bio_err,
"%s: -p index isn't a decimal number: %s",
progname, arg);
return 0;
}
colon++;
} else {
colon = arg;
}
if (idx >= amount) {
BIO_printf(bio_err, "%s: index (%zu) not within range 0..%zu",
progname, idx, amount - 1);
return 0;
}
if (BIO_set_prefix(chain[idx], colon) <= 0) {
BIO_printf(bio_err, "%s: failed setting prefix: %s",
progname, arg);
return 0;
}
break;
default:
case OPT_ERR:
return 0;
}
}
return 1;
}
int main(int argc, char **argv)
{
int rv = EXIT_SUCCESS;
opt_init(argc, argv, options);
rv = (setup() && run_pipe()) ? EXIT_SUCCESS : EXIT_FAILURE;
cleanup();
return rv;
}
Zerion Mini Shell 1.0