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postgres/src/backend/utils/adt/acl.c

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/*-------------------------------------------------------------------------
*
* acl.c--
* Basic access control list data structures manipulation routines.
*
* Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/utils/adt/acl.c,v 1.4 1996/11/06 06:49:34 scrappy Exp $
*
*-------------------------------------------------------------------------
*/
#include <ctype.h>
#include <string.h>
#include "postgres.h"
#include "utils/acl.h"
#include "catalog/pg_user.h"
#include "utils/syscache.h"
#include "utils/palloc.h"
#include "miscadmin.h"
static char *getid(char *s, char *n);
static int32 aclitemeq(AclItem *a1, AclItem *a2);
static int32 aclitemgt(AclItem *a1, AclItem *a2);
#define ACL_IDTYPE_GID_KEYWORD "group"
#define ACL_IDTYPE_UID_KEYWORD "user"
/*
* getid
* Consumes the first alphanumeric string (identifier) found in string
* 's', ignoring any leading white space.
*
* RETURNS:
* the string position in 's' that points to the next non-space character
* in 's'. Also:
* - loads the identifier into 'name'. (If no identifier is found, 'name'
* contains an empty string).
*/
static char *
getid(char *s, char *n)
{
unsigned len;
char *id;
Assert(s && n);
while (isspace(*s))
++s;
for (id = s, len = 0; isalnum(*s); ++len, ++s)
;
if (len > sizeof(NameData))
elog(WARN, "getid: identifier cannot be >%d characters",
sizeof(NameData));
if (len > 0)
memmove(n, id, len);
n[len] = '\0';
while (isspace(*s))
++s;
return(s);
}
/*
* aclparse
* Consumes and parses an ACL specification of the form:
* [group|user] [A-Za-z0-9]*[+-=][rwaR]*
* from string 's', ignoring any leading white space or white space
* between the optional id type keyword (group|user) and the actual
* ACL specification.
*
* This routine is called by the parser as well as aclitemin(), hence
* the added generality.
*
* RETURNS:
* the string position in 's' immediately following the ACL
* specification. Also:
* - loads the structure pointed to by 'aip' with the appropriate
* UID/GID, id type identifier and mode type values.
* - loads 'modechg' with the mode change flag.
*/
char *
aclparse(char *s, AclItem *aip, unsigned *modechg)
{
HeapTuple htp;
char name[NAMEDATALEN+1];
extern AclId get_grosysid();
Assert(s && aip && modechg);
aip->ai_idtype = ACL_IDTYPE_UID;
s = getid(s, name);
if (*s != ACL_MODECHG_ADD_CHR &&
*s != ACL_MODECHG_DEL_CHR &&
*s != ACL_MODECHG_EQL_CHR)
{ /* we just read a keyword, not a name */
if (!strcmp(name, ACL_IDTYPE_GID_KEYWORD)) {
aip->ai_idtype = ACL_IDTYPE_GID;
} else if (strcmp(name, ACL_IDTYPE_UID_KEYWORD)) {
elog(WARN, "aclparse: bad keyword, must be [group|user]");
}
s = getid(s, name); /* move s to the name beyond the keyword */
if (name[0] == '\0')
elog(WARN, "aclparse: a name must follow the [group|user] keyword");
}
if (name[0] == '\0')
aip->ai_idtype = ACL_IDTYPE_WORLD;
switch (*s) {
case ACL_MODECHG_ADD_CHR: *modechg = ACL_MODECHG_ADD; break;
case ACL_MODECHG_DEL_CHR: *modechg = ACL_MODECHG_DEL; break;
case ACL_MODECHG_EQL_CHR: *modechg = ACL_MODECHG_EQL; break;
default: elog(WARN, "aclparse: mode change flag must use \"%s\"",
ACL_MODECHG_STR);
}
aip->ai_mode = ACL_NO;
while (isalpha(*++s)) {
switch (*s) {
case ACL_MODE_AP_CHR: aip->ai_mode |= ACL_AP; break;
case ACL_MODE_RD_CHR: aip->ai_mode |= ACL_RD; break;
case ACL_MODE_WR_CHR: aip->ai_mode |= ACL_WR; break;
case ACL_MODE_RU_CHR: aip->ai_mode |= ACL_RU; break;
default: elog(WARN, "aclparse: mode flags must use \"%s\"",
ACL_MODE_STR);
}
}
switch (aip->ai_idtype) {
case ACL_IDTYPE_UID:
htp = SearchSysCacheTuple(USENAME, PointerGetDatum(name),
0,0,0);
if (!HeapTupleIsValid(htp))
elog(WARN, "aclparse: non-existent user \"%s\"", name);
aip->ai_id = ((Form_pg_user) GETSTRUCT(htp))->usesysid;
break;
case ACL_IDTYPE_GID:
aip->ai_id = get_grosysid(name);
break;
case ACL_IDTYPE_WORLD:
aip->ai_id = ACL_ID_WORLD;
break;
}
#ifdef ACLDEBUG_TRACE
elog(DEBUG, "aclparse: correctly read [%x %d %x], modechg=%x",
aip->ai_idtype, aip->ai_id, aip->ai_mode, *modechg);
#endif
return(s);
}
/*
* makeacl
* Allocates storage for a new Acl with 'n' entries.
*
* RETURNS:
* the new Acl
*/
Acl *
makeacl(int n)
{
Acl *new_acl;
Size size;
if (n < 0)
elog(WARN, "makeacl: invalid size: %d\n", n);
size = ACL_N_SIZE(n);
if (!(new_acl = (Acl *) palloc(size)))
elog(WARN, "makeacl: palloc failed on %d\n", size);
memset((char *) new_acl, 0, size);
new_acl->size = size;
new_acl->ndim = 1;
new_acl->flags = 0;
ARR_LBOUND(new_acl)[0] = 0;
ARR_DIMS(new_acl)[0] = n;
return(new_acl);
}
/*
* aclitemin
* Allocates storage for, and fills in, a new AclItem given a string
* 's' that contains an ACL specification. See aclparse for details.
*
* RETURNS:
* the new AclItem
*/
AclItem *
aclitemin(char *s)
{
unsigned modechg;
AclItem *aip;
if (!s)
elog(WARN, "aclitemin: null string");
aip = (AclItem *) palloc(sizeof(AclItem));
if (!aip)
elog(WARN, "aclitemin: palloc failed");
s = aclparse(s, aip, &modechg);
if (modechg != ACL_MODECHG_EQL)
elog(WARN, "aclitemin: cannot accept anything but = ACLs");
while (isspace(*s))
++s;
if (*s)
elog(WARN, "aclitemin: extra garbage at end of specification");
return(aip);
}
/*
* aclitemout
* Allocates storage for, and fills in, a new null-delimited string
* containing a formatted ACL specification. See aclparse for details.
*
* RETURNS:
* the new string
*/
char *
aclitemout(AclItem *aip)
{
register char *p;
char *out;
HeapTuple htp;
unsigned i;
static AclItem default_aclitem = { ACL_ID_WORLD,
ACL_IDTYPE_WORLD,
ACL_WORLD_DEFAULT };
extern char *int2out();
char *tmpname;
if (!aip)
aip = &default_aclitem;
p = out = palloc(strlen("group =arwR ") + 1 + NAMEDATALEN);
if (!out)
elog(WARN, "aclitemout: palloc failed");
*p = '\0';
switch (aip->ai_idtype) {
case ACL_IDTYPE_UID:
htp = SearchSysCacheTuple(USESYSID, ObjectIdGetDatum(aip->ai_id),
0,0,0);
if (!HeapTupleIsValid(htp)) {
char *tmp = int2out(aip->ai_id);
elog(NOTICE, "aclitemout: usesysid %d not found",
aip->ai_id);
(void) strcat(p, tmp);
pfree(tmp);
} else
(void) strncat(p, (char *) &((Form_pg_user)
GETSTRUCT(htp))->usename,
sizeof(NameData));
break;
case ACL_IDTYPE_GID:
(void) strcat(p, "group ");
tmpname = get_groname(aip->ai_id);
(void) strncat(p, tmpname, NAMEDATALEN);
pfree(tmpname);
break;
case ACL_IDTYPE_WORLD:
break;
default:
elog(WARN, "aclitemout: bad ai_idtype: %d", aip->ai_idtype);
break;
}
while (*p)
++p;
*p++ = '=';
for (i = 0; i < N_ACL_MODES; ++i)
if ((aip->ai_mode >> i) & 01)
*p++ = ACL_MODE_STR[i];
*p = '\0';
return(out);
}
/*
* aclitemeq
* aclitemgt
* AclItem equality and greater-than comparison routines.
* Two AclItems are equal iff they are both NULL or they have the
* same identifier (and identifier type).
*
* RETURNS:
* a boolean value indicating = or >
*/
static int32
aclitemeq(AclItem *a1, AclItem *a2)
{
if (!a1 && !a2)
return(1);
if (!a1 || !a2)
return(0);
return(a1->ai_idtype == a2->ai_idtype && a1->ai_id == a2->ai_id);
}
static int32
aclitemgt(AclItem *a1, AclItem *a2)
{
if (a1 && !a2)
return(1);
if (!a1 || !a2)
return(0);
return((a1->ai_idtype > a2->ai_idtype) ||
(a1->ai_idtype == a2->ai_idtype && a1->ai_id > a2->ai_id));
}
Acl *
aclownerdefault(AclId ownerid)
{
Acl *acl;
AclItem *aip;
acl = makeacl(2);
aip = ACL_DAT(acl);
aip[0].ai_idtype = ACL_IDTYPE_WORLD;
aip[0].ai_id = ACL_ID_WORLD;
aip[0].ai_mode = ACL_WORLD_DEFAULT;
aip[1].ai_idtype = ACL_IDTYPE_UID;
aip[1].ai_id = ownerid;
aip[1].ai_mode = ACL_OWNER_DEFAULT;
return(acl);
}
Acl *
acldefault()
{
Acl *acl;
AclItem *aip;
acl = makeacl(1);
aip = ACL_DAT(acl);
aip[0].ai_idtype = ACL_IDTYPE_WORLD;
aip[0].ai_id = ACL_ID_WORLD;
aip[0].ai_mode = ACL_WORLD_DEFAULT;
return(acl);
}
Acl *
aclinsert3(Acl *old_acl, AclItem *mod_aip, unsigned modechg)
{
Acl *new_acl;
AclItem *old_aip, *new_aip;
unsigned src, dst, num;
if (!old_acl || ACL_NUM(old_acl) < 1) {
new_acl = makeacl(0);
return(new_acl);
}
if (!mod_aip) {
new_acl = makeacl(ACL_NUM(old_acl));
memmove((char *) new_acl, (char *) old_acl, ACL_SIZE(old_acl));
return(new_acl);
}
num = ACL_NUM(old_acl);
old_aip = ACL_DAT(old_acl);
/*
* Search the ACL for an existing entry for 'id'. If one exists,
* just modify the entry in-place (well, in the same position, since
* we actually return a copy); otherwise, insert the new entry in
* sort-order.
*/
/* find the first element not less than the element to be inserted */
for (dst = 0; dst < num && aclitemgt(mod_aip, old_aip+dst); ++dst)
;
if (dst < num && aclitemeq(mod_aip, old_aip+dst)) {
/* modify in-place */
new_acl = makeacl(ACL_NUM(old_acl));
memmove((char *) new_acl, (char *) old_acl, ACL_SIZE(old_acl));
new_aip = ACL_DAT(new_acl);
src = dst;
} else {
new_acl = makeacl(num + 1);
new_aip = ACL_DAT(new_acl);
if (dst == 0) { /* start */
elog(WARN, "aclinsert3: insertion before world ACL??");
} else if (dst >= num) { /* end */
memmove((char *) new_aip,
(char *) old_aip,
num * sizeof(AclItem));
} else { /* middle */
memmove((char *) new_aip,
(char *) old_aip,
dst * sizeof(AclItem));
memmove((char *) (new_aip+dst+1),
(char *) (old_aip+dst),
(num - dst) * sizeof(AclItem));
}
new_aip[dst].ai_id = mod_aip->ai_id;
new_aip[dst].ai_idtype = mod_aip->ai_idtype;
num++; /* set num to the size of new_acl */
src = 0; /* world entry */
}
switch (modechg) {
case ACL_MODECHG_ADD: new_aip[dst].ai_mode =
old_aip[src].ai_mode | mod_aip->ai_mode;
break;
case ACL_MODECHG_DEL: new_aip[dst].ai_mode =
old_aip[src].ai_mode & ~mod_aip->ai_mode;
break;
case ACL_MODECHG_EQL: new_aip[dst].ai_mode =
mod_aip->ai_mode;
break;
}
/* if the newly added entry has no permissions, delete it from
the list. For example, this helps in removing entries for users who
no longer exists...*/
for (dst = 1; dst < num; dst++) {
if (new_aip[dst].ai_mode == 0) {
int i;
for (i=dst+1; i<num; i++) {
new_aip[i-1].ai_id = new_aip[i].ai_id;
new_aip[i-1].ai_idtype = new_aip[i].ai_idtype;
new_aip[i-1].ai_mode = new_aip[i].ai_mode;
}
ARR_DIMS(new_acl)[0] = num -1 ;
break;
}
}
return(new_acl);
}
/*
* aclinsert
*
*/
Acl *
aclinsert(Acl *old_acl, AclItem *mod_aip)
{
return(aclinsert3(old_acl, mod_aip, ACL_MODECHG_EQL));
}
Acl *
aclremove(Acl *old_acl, AclItem *mod_aip)
{
Acl *new_acl;
AclItem *old_aip, *new_aip;
unsigned dst, old_num, new_num;
if (!old_acl || ACL_NUM(old_acl) < 1) {
new_acl = makeacl(0);
return(new_acl);
}
if (!mod_aip) {
new_acl = makeacl(ACL_NUM(old_acl));
memmove((char *) new_acl, (char *) old_acl, ACL_SIZE(old_acl));
return(new_acl);
}
old_num = ACL_NUM(old_acl);
old_aip = ACL_DAT(old_acl);
for (dst = 0; dst < old_num && !aclitemeq(mod_aip, old_aip+dst); ++dst)
;
if (dst >= old_num) { /* not found or empty */
new_acl = makeacl(ACL_NUM(old_acl));
memmove((char *) new_acl, (char *) old_acl, ACL_SIZE(old_acl));
} else {
new_num = old_num - 1;
new_acl = makeacl(ACL_NUM(old_acl) - 1);
new_aip = ACL_DAT(new_acl);
if (dst == 0) { /* start */
elog(WARN, "aclremove: removal of the world ACL??");
} else if (dst == old_num - 1) {/* end */
memmove((char *) new_aip,
(char *) old_aip,
new_num * sizeof(AclItem));
} else { /* middle */
memmove((char *) new_aip,
(char *) old_aip,
dst * sizeof(AclItem));
memmove((char *) (new_aip+dst),
(char *) (old_aip+dst+1),
(new_num - dst) * sizeof(AclItem));
}
}
return(new_acl);
}
int32
aclcontains(Acl *acl, AclItem *aip)
{
unsigned i, num;
AclItem *aidat;
if (!acl || !aip || ((num = ACL_NUM(acl)) < 1))
return(0);
aidat = ACL_DAT(acl);
for (i = 0; i < num; ++i)
if (aclitemeq(aip, aidat+i))
return(1);
return(0);
}
/* parser support routines */
/*
* aclmakepriv
* make a acl privilege string out of an existing privilege string
* and a new privilege
*
* does not add duplicate privileges
*
* the CALLER is reponsible for free'ing the string returned
*/
char*
aclmakepriv(char* old_privlist, char new_priv)
{
char* priv;
int i;
int l;
Assert(strlen(old_privlist)<5);
priv = malloc(5); /* at most "rwaR" */;
if (old_privlist == NULL || old_privlist[0] == '\0') {
priv[0] = new_priv;
priv[1] = '\0';
return priv;
}
strcpy(priv,old_privlist);
l = strlen(old_privlist);
if (l == 4) { /* can't add any more privileges */
return priv;
}
/* check to see if the new privilege is already in the old string */
for (i=0;i<l;i++) {
if (priv[i] == new_priv)
break;
}
if (i == l) { /* we really have a new privilege*/
priv[l] = new_priv;
priv[l+1] = '\0';
}
return priv;
}
/*
* aclmakeuser
* user_type must be "A" - all users
* "G" - group
* "U" - user
*
* concatentates the two strings together with a space in between
*
* this routine is used in the parser
*
* the CALLER is responsible for freeing the memory allocated
*/
char*
aclmakeuser(char* user_type, char* user)
{
char* user_list;
user_list = malloc(strlen(user) + 3);
sprintf(user_list, "%s %s", user_type, user);
return user_list;
}
/*
* makeAclStmt:
* this is a helper routine called by the parser
* create a ChangeAclStmt
* we take in the privilegs, relation_name_list, and grantee
* as well as a single character '+' or '-' to indicate grant or revoke
*
* returns a new ChangeACLStmt*
*
* this routines works by creating a old-style changle acl string and
* then calling aclparse;
*/
ChangeACLStmt*
makeAclStmt(char* privileges, List* rel_list, char* grantee,
char grant_or_revoke)
{
ChangeACLStmt *n = makeNode(ChangeACLStmt);
char str[MAX_PARSE_BUFFER];
n->aclitem = (AclItem*)palloc(sizeof(AclItem));
/* the grantee string is "G <group_name>", "U <user_name>", or "ALL" */
if (grantee[0] == 'G') /* group permissions */
{
sprintf(str,"%s %s%c%s",
ACL_IDTYPE_GID_KEYWORD,
grantee+2, grant_or_revoke,privileges);
}
else if (grantee[0] == 'U') /* user permission */
{
sprintf(str,"%s %s%c%s",
ACL_IDTYPE_UID_KEYWORD,
grantee+2, grant_or_revoke,privileges);
}
else /* all permission */
{
sprintf(str,"%c%s",
grant_or_revoke,privileges);
}
n->relNames = rel_list;
aclparse(str, n->aclitem, (unsigned*)&n->modechg);
return n;
}
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