Files
sudo/plugins/sudoers/rcstr.c
Todd C. Miller 90995c0acf Add simple reference-counted string allocator and use it for passing
around references to the sudoers path.  This lets us avoid making
copies of the sudoers path for the errorfile as well as each Defaults
entry.
2016-11-11 16:18:27 -07:00

101 lines
2.3 KiB
C

/*
* Copyright (c) 2016 Todd C. Miller <Todd.Miller@courtesan.com>
*
* 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 <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#ifdef HAVE_STRING_H
# include <string.h>
#endif /* HAVE_STRING_H */
#ifdef HAVE_STRINGS_H
# include <strings.h>
#endif /* HAVE_STRINGS_H */
#include "sudoers.h"
/* Trivial reference-counted strings. */
struct rcstr {
int refcnt;
char str[1]; /* actually bigger */
};
/*
* Allocate a reference-counted string and copy src to it.
* Returns the newly-created string with a refcnt of 1.
*/
char *
rcstr_dup(const char *src)
{
size_t len = strlen(src);
char *dst;
debug_decl(rcstr_dup, SUDOERS_DEBUG_UTIL)
dst = rcstr_alloc(len);
memcpy(dst, src, len);
dst[len] = '\0';
debug_return_ptr(dst);
}
char *
rcstr_alloc(size_t len)
{
struct rcstr *rcs;
debug_decl(rcstr_dup, SUDOERS_DEBUG_UTIL)
/* Note: sizeof(struct rcstr) includes space for the NUL */
rcs = malloc(sizeof(struct rcstr) + len);
if (rcs == NULL)
return NULL;
rcs->refcnt = 1;
rcs->str[0] = '\0';
debug_return_ptr(rcs->str);
}
char *
rcstr_addref(const char *s)
{
struct rcstr *rcs;
debug_decl(rcstr_dup, SUDOERS_DEBUG_UTIL)
if (s == NULL)
debug_return_ptr(NULL);
rcs = __containerof(s, struct rcstr, str);
rcs->refcnt++;
debug_return_ptr(rcs->str);
}
void
rcstr_delref(const char *s)
{
struct rcstr *rcs;
debug_decl(rcstr_dup, SUDOERS_DEBUG_UTIL)
if (s != NULL) {
rcs = __containerof(s, struct rcstr, str);
if (--rcs->refcnt == 0) {
rcs->str[0] = '\0';
free(rcs);
}
}
debug_return;
}