plugins/sudoers/rationalize.c - main - githubmirror/sudo

plugins/sudoers/rationalize.c

60 строк2 KB

Todd C. Miller

find_path: collapse extra "/" and "./" components in the command path

18 мар 2026, 15:54

18 мар 2026, 15:544b3a5e7

/*
 * SPDX-License-Identifier: ISC
 *
 * Copyright (c) 2026 Todd C. Miller <Todd.Miller@sudo.ws>
 *
 * 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 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 <config.h>

#include <string.h>

#include <sudoers.h>

/*
 * Rationalize a path by removing consecutive '/' and "/./" path elements.
 */
char *
rationalize_path(char *path)
{
    char *cp, *ep, *path_end;
    debug_decl(rationalize_path, SUDOERS_DEBUG_UTIL);

    path_end = path + strlen(path);
    for (cp = path; *cp != '\0';) {
	if (cp[0] == '/') {
	    /* Collapse consecutive '/' characters. */
	    if (cp[1] == '/') {
		for (ep = cp + 1; ep[1] == '/'; ep++)
		    continue;

		/* The size argument includes the terminating NUL byte. */
		memmove(cp, ep, (size_t)(path_end - ep) + 1);
		continue;
	    }

	    /* Remove "/./" in path or "/." at path_end. */
	    if (cp[1] == '.' && (cp[2] == '/' || cp[2] == '\0')) {
		/* /./foo -> /foo OR /foo/. -> /foo */
		ep = cp + 2;

		/* The size argument includes the terminating NUL byte. */
		memmove(cp, ep, (size_t)(path_end - ep) + 1);
		continue;
	    }
	}
	cp++;
    }
    debug_return_str(path);
}