int
__copy_grp (const struct group srcgrp, const size_t buflen,
struct group *destgrp, char *destbuf, char **endptr)
{
size_t i;
size_t c = 0;
size_t len;
size_t memcount;
char **members = NULL;
/* Copy the GID. */
destgrp->gr_gid = srcgrp.gr_gid;
/* Copy the name. */
len = strlen (srcgrp.gr_name) + 1;
BUFCHECK (len);
memcpy (&destbuf[c], srcgrp.gr_name, len);
destgrp->gr_name = &destbuf[c];
c += len;
/* Copy the password. */
len = strlen (srcgrp.gr_passwd) + 1;
BUFCHECK (len);
memcpy (&destbuf[c], srcgrp.gr_passwd, len);
destgrp->gr_passwd = &destbuf[c];
c += len;
/* Count all of the members. */
for (memcount = 0; srcgrp.gr_mem[memcount]; memcount++)
;
/* Allocate a temporary holding area for the pointers to the member
contents, including space for a NULL-terminator. */
members = malloc (sizeof (char *) * (memcount + 1));
if (members == NULL)
return ENOMEM;
/* Copy all of the group members to destbuf and add a pointer to each of
them into the 'members' array. */
for (i = 0; srcgrp.gr_mem[i]; i++)
{
len = strlen (srcgrp.gr_mem[i]) + 1;
BUFCHECK (len);
memcpy (&destbuf[c], srcgrp.gr_mem[i], len);
members[i] = &destbuf[c];
c += len;
}
members[i] = NULL;
/* Align for pointers. We can't simply align C because we need to
align destbuf[c]. */
if ((((uintptr_t)destbuf + c) & (__alignof__(char **) - 1)) != 0)
{
uintptr_t mis_align = ((uintptr_t)destbuf + c) & (__alignof__(char **) - 1);
c += __alignof__(char **) - mis_align;
}
/* Copy the pointers from the members array into the buffer and assign them
to the gr_mem member of destgrp. */
destgrp->gr_mem = (char **) &destbuf[c];
len = sizeof (char *) * (memcount + 1);
BUFCHECK (len);
memcpy (&destbuf[c], members, len);
c += len;
free (members);
members = NULL;
/* Save the count of members at the end. */
BUFCHECK (sizeof (size_t));
memcpy (&destbuf[c], &memcount, sizeof (size_t));
c += sizeof (size_t);
if (endptr)
*endptr = destbuf + c;
return 0;
}
int
__copy_grp (const struct group srcgrp, const size_t buflen,
struct group *destgrp, char *destbuf, char **endptr)
{
size_t i;
size_t c = 0;
size_t len;
size_t memcount;
char **members = NULL;
/* Copy the GID */
destgrp->gr_gid = srcgrp.gr_gid;
/* Copy the name */
len = sizeof(char) * (strlen (srcgrp.gr_name) + 1);
BUFCHECK(len);
memcpy (&destbuf[c], srcgrp.gr_name, len);
destgrp->gr_name = &destbuf[c];
c += len;
/* Copy the password */
len = sizeof(char) * (strlen (srcgrp.gr_passwd) + 1);
BUFCHECK(len);
memcpy (&destbuf[c], srcgrp.gr_passwd, len);
destgrp->gr_passwd = &destbuf[c];
c += len;
/* Count all of the members */
for (memcount = 0; srcgrp.gr_mem[memcount]; memcount++)
;
/* Allocate a temporary holding area for the pointers to the member
* contents, including space for a NULL-terminator.
*/
members = malloc (sizeof(char *) * (memcount + 1));
if (!members)
return ENOMEM;
/* Copy all of the group members to destbuf and add a pointer to each of
* them into the 'members' array.
*/
for (i = 0; srcgrp.gr_mem[i]; i++)
{
len = sizeof(char) * (strlen (srcgrp.gr_mem[i]) + 1);
BUFCHECK(len);
memcpy (&destbuf[c], srcgrp.gr_mem[i], len);
members[i] = &destbuf[c];
c += len;
}
members[i] = NULL;
/* Copy the pointers from the members array into the buffer and assign them
* to the gr_mem member of destgrp.
*/
destgrp->gr_mem = (char **) &destbuf[c];
len = sizeof(char *) * (memcount + 1);
BUFCHECK(len);
memcpy (&destbuf[c], members, len);
c += len;
free (members);
members = NULL;
/* Save the count of members at the end */
BUFCHECK(sizeof(size_t));
memcpy (&destbuf[c], &memcount, sizeof(size_t));
c += sizeof(size_t);
if (endptr)
{
*endptr = destbuf + c;
}
return 0;
}
/* Check that the name, GID and passwd fields match, then
copy in the gr_mem array. */
int
__merge_grp (struct group *savedgrp, char *savedbuf, char *savedend,
size_t buflen, struct group *mergegrp, char *mergebuf)
{
size_t c, i, len;
size_t savedmemcount;
size_t memcount;
size_t membersize;
char **members = NULL;
/* We only support merging members of groups with identical names and
GID values. If we hit this case, we need to overwrite the current
buffer with the saved one (which is functionally equivalent to
treating the new lookup as NSS_STATUS_NOTFOUND). */
if (mergegrp->gr_gid != savedgrp->gr_gid
|| strcmp (mergegrp->gr_name, savedgrp->gr_name))
return __copy_grp (*savedgrp, buflen, mergegrp, mergebuf, NULL);
/* Get the count of group members from the last sizeof (size_t) bytes in the
mergegrp buffer. */
savedmemcount = *(size_t *) (savedend - sizeof (size_t));
/* Get the count of new members to add. */
for (memcount = 0; mergegrp->gr_mem[memcount]; memcount++)
;
/* Create a temporary array to hold the pointers to the member values from
both the saved and merge groups. */
membersize = savedmemcount + memcount + 1;
members = malloc (sizeof (char *) * membersize);
if (members == NULL)
return ENOMEM;
/* Copy in the existing member pointers from the saved group
Note: this is not NULL-terminated yet. */
memcpy (members, savedgrp->gr_mem, sizeof (char *) * savedmemcount);
/* Back up into the savedbuf until we get back to the NULL-terminator of the
group member list. (This means walking back savedmemcount + 1 (char *) pointers
and the member count value.
The value of c is going to be the used length of the buffer backed up by
the member count and further backed up by the size of the pointers. */
c = savedend - savedbuf
- sizeof (size_t)
- sizeof (char *) * (savedmemcount + 1);
/* Add all the new group members, overwriting the old NULL-terminator while
adding the new pointers to the temporary array. */
for (i = 0; mergegrp->gr_mem[i]; i++)
{
len = strlen (mergegrp->gr_mem[i]) + 1;
BUFCHECK (len);
memcpy (&savedbuf[c], mergegrp->gr_mem[i], len);
members[savedmemcount + i] = &savedbuf[c];
c += len;
}
/* Add the NULL-terminator. */
members[savedmemcount + memcount] = NULL;
/* Align for pointers. We can't simply align C because we need to
align savedbuf[c]. */
if ((((uintptr_t)savedbuf + c) & (__alignof__(char **) - 1)) != 0)
{
uintptr_t mis_align = ((uintptr_t)savedbuf + c) & (__alignof__(char **) - 1);
c += __alignof__(char **) - mis_align;
}
/* Copy the member array back into the buffer after the member list and free
the member array. */
savedgrp->gr_mem = (char **) &savedbuf[c];
len = sizeof (char *) * membersize;
BUFCHECK (len);
memcpy (&savedbuf[c], members, len);
c += len;
free (members);
members = NULL;
/* Finally, copy the results back into mergebuf, since that's the buffer
that we were provided by the caller. */
return __copy_grp (*savedgrp, buflen, mergegrp, mergebuf, NULL);
}
/* Check that the name, GID and passwd fields match, then
* copy in the gr_mem array.
*/
int
__merge_grp (struct group *savedgrp, char *savedbuf, char *savedend,
size_t buflen, struct group *mergegrp, char *mergebuf)
{
size_t c, i, len;
size_t savedmemcount;
size_t memcount;
size_t membersize;
char **members = NULL;
if (mergegrp->gr_gid != savedgrp->gr_gid
|| strcmp (mergegrp->gr_name, savedgrp->gr_name))
{
/* We only support merging members of groups with identical names and
* GID values. If we hit this case, we need to overwrite the current
* buffer with the saved one (which is functionally equivalent to
* treating the new lookup as NSS_STATUS NOTFOUND.
*/
return __copy_grp (*savedgrp, buflen, mergegrp, mergebuf, NULL);
}
/* Get the count of group members from the last sizeof(size_t) bytes in the
* mergegrp buffer.
*/
savedmemcount = (size_t) *(savedend - sizeof(size_t));
/* Get the count of new members to add */
for (memcount = 0; mergegrp->gr_mem[memcount]; memcount++)
;
/* Create a temporary array to hold the pointers to the member values from
* both the saved and merge groups
*/
membersize = savedmemcount + memcount + 1;
members = malloc (sizeof(char *) * membersize);
if (!members)
return ENOMEM;
/* Copy in the existing member pointers from the saved group
* Note: this is not NULL-terminated yet.
*/
memcpy (members, savedgrp->gr_mem, sizeof(char *) * savedmemcount);
/* Back up into the savedbuf until we get back to the NULL-terminator of the
* group member list. (This means walking back savedmemcount + 1 (char *) pointers
* and the member count value.
*/
c = savedend - savedbuf /* Get the used length of the buffer */
- sizeof(size_t) /* Back up past the member count */
- sizeof(char *) * (savedmemcount + 1); /* Back up past pointers */
/* Add all the new group members, overwriting the old NULL-terminator while
* adding the new pointers to the temporary array.
*/
for (i = 0; mergegrp->gr_mem[i]; i++)
{
len = sizeof(char) * (strlen (mergegrp->gr_mem[i]) + 1);
BUFCHECK(len);
memcpy (&savedbuf[c], mergegrp->gr_mem[i], len);
members[savedmemcount + i] = &savedbuf[c];
c += len;
}
/* Add the NULL-terminator */
members[savedmemcount + memcount] = NULL;
/* Copy the member array back into the buffer after the member list and free
* the member array
*/
savedgrp->gr_mem = (char **) &savedbuf[c];
len = sizeof(char *) * membersize;
BUFCHECK(len);
memcpy (&savedbuf[c], members, len);
c += len;
free (members);
members = NULL;
/* Finally, copy the results back into mergebuf, since that's the buffer
* that we were provided by the caller.
*/
return __copy_grp (*savedgrp, buflen, mergegrp, mergebuf, NULL);
}
