new upstream libsysio snapshot (20041101)

[fs/lustre-release.git] / libsysio / src / access.c

diff --git a/libsysio/src/access.c b/libsysio/src/access.c
index 9d2664f..6b92f64 100644 (file)
--- a/libsysio/src/access.c
+++ b/libsysio/src/access.c
@@ -44,53 +44,35 @@
 #include <stdlib.h>
 #include <errno.h>
 #include <unistd.h>
+#include <assert.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <sys/queue.h>
 
 #include "sysio.h"
+#include "inode.h"
 #include "sysio-symbols.h"
 
-int
-SYSIO_INTERFACE_NAME(access)(const char *path, int amode)
+/*
+ * Check given access type on given inode.
+ */
+static int
+_sysio_check_permission(struct inode *ino,
+                       uid_t uid, gid_t gid,
+                       gid_t gids[], size_t ngids,
+                       int amode)
 {
-       gid_t   *list, *entry;
-       size_t  n;
-       int     err = 0;
-       unsigned mask, mode;
-       struct stat stbuf;
-       SYSIO_INTERFACE_DISPLAY_BLOCK;
-
-       SYSIO_INTERFACE_ENTER;
-       err = 0;
+       mode_t  mask;
+       struct intnl_stat *stat;
 
        /*
         * Check amode.
         */
        if ((amode & (R_OK|W_OK|X_OK)) != amode)
-               SYSIO_INTERFACE_RETURN(-1, -EINVAL);
+               return -EINVAL;
 
-       n = getgroups(0, NULL);
-       list = NULL;
-       if (n) {
-               list = malloc(n * sizeof(gid_t));
-               if (!list) {
-                       err = -ENOMEM;
-                       goto out;
-               }
-       }
-       err = getgroups(n, list);
-       if (err != (int ) n)
-               goto out;
-
-       err = SYSIO_INTERFACE_NAME(stat)(path, &stbuf);
-       if (err) {
-               err = -errno;
-               goto out;
-       }
        if (!amode)
-               SYSIO_INTERFACE_RETURN(0, 0);
-
+               return 0;
 
        mask = 0;
        if (amode & R_OK)
@@ -100,29 +82,91 @@ SYSIO_INTERFACE_NAME(access)(const char *path, int amode)
        if (amode & X_OK)
                mask |= S_IXUSR;
 
-       mode = stbuf.st_mode;
-       if (stbuf.st_uid == getuid() && (mode & mask) == mask) 
-               goto out;
+       stat = &ino->i_stbuf;
+       if (stat->st_uid == uid && (stat->st_mode & mask) == mask) 
+               return 0;
 
        mask >>= 3;
-       if (stbuf.st_gid == getgid() && (mode & mask) == mask)
-               goto out;
+       if (stat->st_gid == gid && (stat->st_mode & mask) == mask)
+               return 0;
 
-       entry = list;
-       while (n--)
-               if (stbuf.st_gid == *entry++ && (mode & mask) == mask)
-                       goto out;
+       while (ngids) {
+               ngids--;
+               if (stat->st_gid == *gids++ && (stat->st_mode & mask) == mask)
+                       return 0;
+       }
 
        mask >>= 3;
-       if ((mode & mask) == mask)
-               goto out;
+       if ((stat->st_mode & mask) == mask)
+               return 0;
+
+       return -EACCES;
+}
+
+/*
+ * Determine if a given access is permitted to a give file.
+ */
+int
+_sysio_permitted(struct inode *ino, int amode)
+{
+       int     err;
+       gid_t   *gids;
+       int     n;
+       void    *p;
 
-       err = -EACCES;
+       err = 0;
+       gids = NULL;
+       for (;;) {
+               n = getgroups(0, NULL);
+               if (!n)
+                       break;
+               p = realloc(gids, n * sizeof(gid_t));
+               if (!p && gids) {
+                       err = -ENOMEM;
+                       break;
+               }
+               gids = p;
+               err = getgroups(n, gids);
+               if (err < 0) {
+                       if (errno == EINVAL)
+                               continue;
+                       err = -errno;
+                       break;
+               }
+               err =
+                   _sysio_check_permission(ino,
+                                           geteuid(), getegid(),
+                                           gids, (size_t )n,
+                                           amode);
+               break;
+       }
+       if (!gids)
+               return err;
+       free(gids);
+       return err;
+}
+
+int
+SYSIO_INTERFACE_NAME(access)(const char *path, int amode)
+{
+       struct intent intent;
+       int     err;
+       struct pnode *pno;
+
+       SYSIO_INTERFACE_DISPLAY_BLOCK;
 
-out:
-       if (list)
-               free(list);
+       SYSIO_INTERFACE_ENTER;
 
+       INTENT_INIT(&intent, INT_GETATTR, NULL, NULL);
+       err = _sysio_namei(_sysio_cwd, path, 0, &intent, &pno);
+       if (err)
+               SYSIO_INTERFACE_RETURN(-1, err);
+       err =
+           _sysio_check_permission(pno->p_base->pb_ino,
+                                   getuid(), getgid(),
+                                   NULL, 0,
+                                   amode);
+       P_RELE(pno);
        SYSIO_INTERFACE_RETURN(err ? -1 : 0, err);
 }