Return to arguments.c CVS log

Up to [local] / src / usr.bin / tmux

Don't blindly increase offsets by the return value of snprintf, if there
wasn't enough space this will go off the end. Instead clamp to the
available space. Fixes crash reported by Julien Rebetez.

/* $OpenBSD: arguments.c,v 1.9 2014/04/11 19:35:54 nicm Exp $ */

/*
 * Copyright (c) 2010 Nicholas Marriott <nicm@users.sourceforge.net>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
 * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>

#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "tmux.h"

/*
 * Manipulate command arguments.
 */

struct args_entry	*args_find(struct args *, u_char);

RB_GENERATE(args_tree, args_entry, entry, args_cmp);

/* Arguments tree comparison function. */
int
args_cmp(struct args_entry *a1, struct args_entry *a2)
{
	return (a1->flag - a2->flag);
}

/* Create an arguments set with no flags. */
struct args *
args_create(int argc, ...)
{
	struct args	*args;
	va_list		 ap;
	int		 i;

	args = xcalloc(1, sizeof *args);

	args->argc = argc;
	if (argc == 0)
		args->argv = NULL;
	else
		args->argv = xcalloc(argc, sizeof *args->argv);

	va_start(ap, argc);
	for (i = 0; i < argc; i++)
		args->argv[i] = xstrdup(va_arg(ap, char *));
	va_end(ap);

	return (args);
}

/* Find a flag in the arguments tree. */
struct args_entry *
args_find(struct args *args, u_char ch)
{
	struct args_entry	entry;

	entry.flag = ch;
	return (RB_FIND(args_tree, &args->tree, &entry));
}

/* Parse an argv and argc into a new argument set. */
struct args *
args_parse(const char *template, int argc, char **argv)
{
	struct args	*args;
	int		 opt;

	args = xcalloc(1, sizeof *args);

	optreset = 1;
	optind = 1;

	while ((opt = getopt(argc, argv, template)) != -1) {
		if (opt < 0)
			continue;
		if (opt == '?' || strchr(template, opt) == NULL) {
			args_free(args);
			return (NULL);
		}
		args_set(args, opt, optarg);
	}
	argc -= optind;
	argv += optind;

	args->argc = argc;
	args->argv = cmd_copy_argv(argc, argv);

	return (args);
}

/* Free an arguments set. */
void
args_free(struct args *args)
{
	struct args_entry	*entry;
	struct args_entry	*entry1;

	cmd_free_argv(args->argc, args->argv);

	RB_FOREACH_SAFE(entry, args_tree, &args->tree, entry1) {
		RB_REMOVE(args_tree, &args->tree, entry);
		free(entry->value);
		free(entry);
	}

	free(args);
}

/* Print a set of arguments. */
size_t
args_print(struct args *args, char *buf, size_t len)
{
	size_t		 	 off, used;
	int			 i;
	const char		*quotes;
	struct args_entry	*entry;

	/* There must be at least one byte at the start. */
	if (len == 0)
		return (0);
	off = 0;

	/* Process the flags first. */
	buf[off++] = '-';
	RB_FOREACH(entry, args_tree, &args->tree) {
		if (entry->value != NULL)
			continue;

		if (off == len - 1) {
			buf[off] = '\0';
			return (len);
		}
		buf[off++] = entry->flag;
		buf[off] = '\0';
	}
	if (off == 1)
		buf[--off] = '\0';

	/* Then the flags with arguments. */
	RB_FOREACH(entry, args_tree, &args->tree) {
		if (entry->value == NULL)
			continue;

		if (off >= len) {
			/* snprintf will have zero terminated. */
			return (len);
		}

		if (strchr(entry->value, ' ') != NULL)
			quotes = "\"";
		else
			quotes = "";
		used = xsnprintf(buf + off, len - off, "%s-%c %s%s%s",
		    off != 0 ? " " : "", entry->flag, quotes, entry->value,
		    quotes);
		if (used > len - off)
			used = len - off;
		off += used;
	}

	/* And finally the argument vector. */
	for (i = 0; i < args->argc; i++) {
		if (off >= len) {
			/* snprintf will have zero terminated. */
			return (len);
		}

		if (strchr(args->argv[i], ' ') != NULL)
			quotes = "\"";
		else
			quotes = "";
		used = xsnprintf(buf + off, len - off, "%s%s%s%s",
		    off != 0 ? " " : "", quotes, args->argv[i], quotes);
		if (used > len - off)
			used = len - off;
		off += used;
	}

	return (off);
}

/* Return if an argument is present. */
int
args_has(struct args *args, u_char ch)
{
	return (args_find(args, ch) == NULL ? 0 : 1);
}

/* Set argument value in the arguments tree. */
void
args_set(struct args *args, u_char ch, const char *value)
{
	struct args_entry	*entry;

	/* Replace existing argument. */
	if ((entry = args_find(args, ch)) != NULL) {
		free(entry->value);
		entry->value = NULL;
	} else {
		entry = xcalloc(1, sizeof *entry);
		entry->flag = ch;
		RB_INSERT(args_tree, &args->tree, entry);
	}

	if (value != NULL)
		entry->value = xstrdup(value);
}

/* Get argument value. Will be NULL if it isn't present. */
const char *
args_get(struct args *args, u_char ch)
{
	struct args_entry	*entry;

	if ((entry = args_find(args, ch)) == NULL)
		return (NULL);
	return (entry->value);
}

/* Convert an argument value to a number. */
long long
args_strtonum(struct args *args, u_char ch, long long minval, long long maxval,
    char **cause)
{
	const char		*errstr;
	long long 	 	 ll;
	struct args_entry	*entry;

	if ((entry = args_find(args, ch)) == NULL) {
		*cause = xstrdup("missing");
		return (0);
	}

	ll = strtonum(entry->value, minval, maxval, &errstr);
	if (errstr != NULL) {
		*cause = xstrdup(errstr);
		return (0);
	}

	*cause = NULL;
	return (ll);
}