mirror of
https://gitlab.freedesktop.org/pulseaudio/pulseaudio.git
synced 2025-11-10 13:29:58 -05:00
core: Add thread-safe group info functions with dynamic buffers
Provides getgrgid, getgrnam, getpwuid & getpwnam replacements that are thread safe (a la getgrgid_r() and friends) that internally handle allocating big-enough buffers to avoid ERANGE errors on large users or groups.
This commit is contained in:
Ted Percival
Lennart Poettering
parent
9d1cc133f3
commit
15eb03a5b3
6 changed files with 643 additions and 115 deletions
376
src/pulsecore/usergroup.c
Normal file
376
src/pulsecore/usergroup.c
Normal file
|
|
@ -0,0 +1,376 @@
|
|||
/***
|
||||
This file is part of PulseAudio.
|
||||
|
||||
Copyright 2009 Ted Percival
|
||||
|
||||
PulseAudio is free software; you can redistribute it and/or modify
|
||||
it under the terms of the GNU Lesser General Public License as
|
||||
published by the Free Software Foundation; either version 2.1 of the
|
||||
License, or (at your option) any later version.
|
||||
|
||||
PulseAudio is distributed in the hope that it will be useful, but
|
||||
WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
||||
Lesser General Public License for more details.
|
||||
|
||||
You should have received a copy of the GNU Lesser General Public
|
||||
License along with PulseAudio; if not, write to the Free Software
|
||||
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
|
||||
USA.
|
||||
***/
|
||||
|
||||
#ifdef HAVE_CONFIG_H
|
||||
#include <config.h>
|
||||
#endif
|
||||
|
||||
#include <sys/types.h>
|
||||
#include <errno.h>
|
||||
|
||||
#ifdef HAVE_PWD_H
|
||||
#include <pwd.h>
|
||||
#endif
|
||||
|
||||
#ifdef HAVE_GRP_H
|
||||
#include <grp.h>
|
||||
#endif
|
||||
|
||||
#include <pulse/xmalloc.h>
|
||||
#include <pulsecore/macro.h>
|
||||
|
||||
#include "usergroup.h"
|
||||
|
||||
#ifdef HAVE_GRP_H
|
||||
|
||||
/* Returns a suitable starting size for a getgrnam_r() or getgrgid_r() buffer,
|
||||
plus the size of a struct group.
|
||||
*/
|
||||
static size_t starting_getgr_buflen(void) {
|
||||
size_t full_size;
|
||||
long n;
|
||||
#ifdef _SC_GETGR_R_SIZE_MAX
|
||||
n = sysconf(_SC_GETGR_R_SIZE_MAX);
|
||||
#else
|
||||
n = -1;
|
||||
#endif
|
||||
if (n <= 0)
|
||||
n = 512;
|
||||
|
||||
full_size = (size_t) n + sizeof(struct group);
|
||||
|
||||
if (full_size < (size_t) n) /* check for integer overflow */
|
||||
return (size_t) n;
|
||||
|
||||
return full_size;
|
||||
}
|
||||
|
||||
/* Returns a suitable starting size for a getpwnam_r() or getpwuid_r() buffer,
|
||||
plus the size of a struct passwd.
|
||||
*/
|
||||
static size_t starting_getpw_buflen(void) {
|
||||
long n;
|
||||
size_t full_size;
|
||||
|
||||
#ifdef _SC_GETPW_R_SIZE_MAX
|
||||
n = sysconf(_SC_GETPW_R_SIZE_MAX);
|
||||
#else
|
||||
n = -1;
|
||||
#endif
|
||||
if (n <= 0)
|
||||
n = 512;
|
||||
|
||||
full_size = (size_t) n + sizeof(struct passwd);
|
||||
|
||||
if (full_size < (size_t) n) /* check for integer overflow */
|
||||
return (size_t) n;
|
||||
|
||||
return full_size;
|
||||
}
|
||||
|
||||
/* Given a memory allocation (*bufptr) and its length (*buflenptr),
|
||||
double the size of the allocation, updating the given buffer and length
|
||||
arguments. This function should be used in conjunction with the pa_*alloc
|
||||
and pa_xfree functions.
|
||||
|
||||
Unlike realloc(), this function does *not* retain the original buffer's
|
||||
contents.
|
||||
|
||||
Returns 0 on success, nonzero on error. The error cause is indicated by
|
||||
errno.
|
||||
*/
|
||||
static int expand_buffer_trashcontents(void **bufptr, size_t *buflenptr) {
|
||||
size_t newlen;
|
||||
|
||||
if (!bufptr || !*bufptr || !buflenptr) {
|
||||
errno = EINVAL;
|
||||
return -1;
|
||||
}
|
||||
|
||||
newlen = *buflenptr * 2;
|
||||
|
||||
if (newlen < *buflenptr) {
|
||||
errno = EOVERFLOW;
|
||||
return -1;
|
||||
}
|
||||
|
||||
/* Don't bother retaining memory contents; free & alloc anew */
|
||||
pa_xfree(*bufptr);
|
||||
|
||||
*bufptr = pa_xmalloc(newlen);
|
||||
*buflenptr = newlen;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
#ifdef HAVE_GETGRGID_R
|
||||
/* Thread-safe getgrgid() replacement.
|
||||
Returned value should be freed using pa_getgrgid_free() when the caller is
|
||||
finished with the returned group data.
|
||||
|
||||
API is the same as getgrgid(), errors are indicated by a NULL return;
|
||||
consult errno for the error cause (zero it before calling).
|
||||
The returned value must be freed using pa_xfree().
|
||||
*/
|
||||
struct group *pa_getgrgid_malloc(gid_t gid) {
|
||||
size_t buflen, getgr_buflen;
|
||||
int err;
|
||||
void *buf;
|
||||
void *getgr_buf;
|
||||
struct group *result = NULL;
|
||||
|
||||
buflen = starting_getgr_buflen();
|
||||
buf = pa_xmalloc(buflen);
|
||||
|
||||
getgr_buflen = buflen - sizeof(struct group);
|
||||
getgr_buf = (char *)buf + sizeof(struct group);
|
||||
|
||||
while ((err = getgrgid_r(gid, (struct group *)buf, getgr_buf,
|
||||
getgr_buflen, &result)) == ERANGE)
|
||||
{
|
||||
if (expand_buffer_trashcontents(&buf, &buflen))
|
||||
break;
|
||||
|
||||
getgr_buflen = buflen - sizeof(struct group);
|
||||
getgr_buf = (char *)buf + sizeof(struct group);
|
||||
}
|
||||
|
||||
if (err || !result) {
|
||||
result = NULL;
|
||||
if (buf) {
|
||||
pa_xfree(buf);
|
||||
buf = NULL;
|
||||
}
|
||||
}
|
||||
|
||||
pa_assert(result == buf || result == NULL);
|
||||
|
||||
return result;
|
||||
}
|
||||
|
||||
void pa_getgrgid_free(struct group *grp) {
|
||||
pa_xfree(grp);
|
||||
}
|
||||
|
||||
#else /* !HAVE_GETGRGID_R */
|
||||
|
||||
struct group *pa_getgrgid_malloc(gid_t gid) {
|
||||
return getgrgid(gid);
|
||||
}
|
||||
|
||||
void pa_getgrgid_free(struct group *grp) {
|
||||
/* nothing */
|
||||
return;
|
||||
}
|
||||
|
||||
#endif /* !HAVE_GETGRGID_R */
|
||||
|
||||
#ifdef HAVE_GETGRNAM_R
|
||||
/* Thread-safe getgrnam() function.
|
||||
Returned value should be freed using pa_getgrnam_free() when the caller is
|
||||
finished with the returned group data.
|
||||
|
||||
API is the same as getgrnam(), errors are indicated by a NULL return;
|
||||
consult errno for the error cause (zero it before calling).
|
||||
The returned value must be freed using pa_xfree().
|
||||
*/
|
||||
struct group *pa_getgrnam_malloc(const char *name) {
|
||||
size_t buflen, getgr_buflen;
|
||||
int err;
|
||||
void *buf;
|
||||
void *getgr_buf;
|
||||
struct group *result = NULL;
|
||||
|
||||
buflen = starting_getgr_buflen();
|
||||
buf = pa_xmalloc(buflen);
|
||||
|
||||
getgr_buflen = buflen - sizeof(struct group);
|
||||
getgr_buf = (char *)buf + sizeof(struct group);
|
||||
|
||||
while ((err = getgrnam_r(name, (struct group *)buf, getgr_buf,
|
||||
getgr_buflen, &result)) == ERANGE)
|
||||
{
|
||||
if (expand_buffer_trashcontents(&buf, &buflen))
|
||||
break;
|
||||
|
||||
getgr_buflen = buflen - sizeof(struct group);
|
||||
getgr_buf = (char *)buf + sizeof(struct group);
|
||||
}
|
||||
|
||||
if (err || !result) {
|
||||
result = NULL;
|
||||
if (buf) {
|
||||
pa_xfree(buf);
|
||||
buf = NULL;
|
||||
}
|
||||
}
|
||||
|
||||
pa_assert(result == buf || result == NULL);
|
||||
|
||||
return result;
|
||||
}
|
||||
|
||||
void pa_getgrnam_free(struct group *group) {
|
||||
pa_xfree(group);
|
||||
}
|
||||
|
||||
#else /* !HAVE_GETGRNAM_R */
|
||||
|
||||
struct group *pa_getgrnam_malloc(const char *name) {
|
||||
return getgrnam(name);
|
||||
}
|
||||
|
||||
void pa_getgrnam_free(struct group *group) {
|
||||
/* nothing */
|
||||
return;
|
||||
}
|
||||
|
||||
#endif /* HAVE_GETGRNAM_R */
|
||||
|
||||
#endif /* HAVE_GRP_H */
|
||||
|
||||
#ifdef HAVE_PWD_H
|
||||
|
||||
#ifdef HAVE_GETPWNAM_R
|
||||
/* Thread-safe getpwnam() function.
|
||||
Returned value should be freed using pa_getpwnam_free() when the caller is
|
||||
finished with the returned passwd data.
|
||||
|
||||
API is the same as getpwnam(), errors are indicated by a NULL return;
|
||||
consult errno for the error cause (zero it before calling).
|
||||
The returned value must be freed using pa_xfree().
|
||||
*/
|
||||
struct passwd *pa_getpwnam_malloc(const char *name) {
|
||||
size_t buflen, getpw_buflen;
|
||||
int err;
|
||||
void *buf;
|
||||
void *getpw_buf;
|
||||
struct passwd *result = NULL;
|
||||
|
||||
buflen = starting_getpw_buflen();
|
||||
buf = pa_xmalloc(buflen);
|
||||
|
||||
getpw_buflen = buflen - sizeof(struct passwd);
|
||||
getpw_buf = (char *)buf + sizeof(struct passwd);
|
||||
|
||||
while ((err = getpwnam_r(name, (struct passwd *)buf, getpw_buf,
|
||||
getpw_buflen, &result)) == ERANGE)
|
||||
{
|
||||
if (expand_buffer_trashcontents(&buf, &buflen))
|
||||
break;
|
||||
|
||||
getpw_buflen = buflen - sizeof(struct passwd);
|
||||
getpw_buf = (char *)buf + sizeof(struct passwd);
|
||||
}
|
||||
|
||||
if (err || !result) {
|
||||
result = NULL;
|
||||
if (buf) {
|
||||
pa_xfree(buf);
|
||||
buf = NULL;
|
||||
}
|
||||
}
|
||||
|
||||
pa_assert(result == buf || result == NULL);
|
||||
|
||||
return result;
|
||||
}
|
||||
|
||||
void pa_getpwnam_free(struct passwd *passwd) {
|
||||
pa_xfree(passwd);
|
||||
}
|
||||
|
||||
#else /* !HAVE_GETPWNAM_R */
|
||||
|
||||
struct passwd *pa_getpwnam_malloc(const char *name) {
|
||||
return getpwnam(name);
|
||||
}
|
||||
|
||||
void pa_getpwnam_free(struct passwd *passwd) {
|
||||
/* nothing */
|
||||
return;
|
||||
}
|
||||
|
||||
#endif /* !HAVE_GETPWNAM_R */
|
||||
|
||||
#ifdef HAVE_GETPWUID_R
|
||||
/* Thread-safe getpwuid() function.
|
||||
Returned value should be freed using pa_getpwuid_free() when the caller is
|
||||
finished with the returned group data.
|
||||
|
||||
API is the same as getpwuid(), errors are indicated by a NULL return;
|
||||
consult errno for the error cause (zero it before calling).
|
||||
The returned value must be freed using pa_xfree().
|
||||
*/
|
||||
struct passwd *pa_getpwuid_malloc(uid_t uid) {
|
||||
size_t buflen, getpw_buflen;
|
||||
int err;
|
||||
void *buf;
|
||||
void *getpw_buf;
|
||||
struct passwd *result = NULL;
|
||||
|
||||
buflen = starting_getpw_buflen();
|
||||
buf = pa_xmalloc(buflen);
|
||||
|
||||
getpw_buflen = buflen - sizeof(struct passwd);
|
||||
getpw_buf = (char *)buf + sizeof(struct passwd);
|
||||
|
||||
while ((err = getpwuid_r(uid, (struct passwd *)buf, getpw_buf,
|
||||
getpw_buflen, &result)) == ERANGE)
|
||||
{
|
||||
if (expand_buffer_trashcontents(&buf, &buflen))
|
||||
break;
|
||||
|
||||
getpw_buflen = buflen - sizeof(struct passwd);
|
||||
getpw_buf = (char *)buf + sizeof(struct passwd);
|
||||
}
|
||||
|
||||
if (err || !result) {
|
||||
result = NULL;
|
||||
if (buf) {
|
||||
pa_xfree(buf);
|
||||
buf = NULL;
|
||||
}
|
||||
}
|
||||
|
||||
pa_assert(result == buf || result == NULL);
|
||||
|
||||
return result;
|
||||
}
|
||||
|
||||
void pa_getpwuid_free(struct passwd *passwd) {
|
||||
pa_xfree(passwd);
|
||||
}
|
||||
|
||||
#else /* !HAVE_GETPWUID_R */
|
||||
|
||||
struct passwd *pa_getpwuid_malloc(uid_t uid) {
|
||||
return getpwuid(uid);
|
||||
}
|
||||
|
||||
void pa_getpwuid_free(struct passwd *passwd) {
|
||||
/* nothing */
|
||||
return;
|
||||
}
|
||||
|
||||
#endif /* !HAVE_GETPWUID_R */
|
||||
|
||||
#endif /* HAVE_PWD_H */
|
||||
Loading…
Add table
Add a link
Reference in a new issue