libsmack: add a common function for opening long and short label file

Added internal function 'open_smackfs_file()' to open long label
file and as a fallback short label file. This can be used for
load, access and cipso files.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

diff --git a/libsmack/libsmack.c b/libsmack/libsmack.c
index 8e88d47..15414fd 100644 (file)
--- a/libsmack/libsmack.c
+++ b/libsmack/libsmack.c
@@ -98,6 +98,8 @@ struct smack_cipso {
        struct cipso_mapping *last;
 };
 
        struct cipso_mapping *last;
 };
 

+static int open_smackfs_file(const char *long_name, const char *short_name,
+                            int *use_long);

 static int accesses_apply(struct smack_accesses *handle, int clear);
 static int accesses_print(struct smack_accesses *handle, int clear,
                          int load_fd, int change_fd, int use_long, int add_lf);
 static int accesses_apply(struct smack_accesses *handle, int clear);
 static int accesses_print(struct smack_accesses *handle, int clear,
                          int load_fd, int change_fd, int use_long, int add_lf);


@@ -280,27 +282,20 @@ int smack_have_access(const char *subject, const char *object,
        int code;
        int ret;
        int fd;
        int code;
        int ret;
        int fd;

-       int access2 = 1;
+       int use_long = 1;

 
        if (smackfs_mnt_dirfd < 0)
                return -1;
 
 
        if (smackfs_mnt_dirfd < 0)
                return -1;
 

-       fd = openat(smackfs_mnt_dirfd, "access2", O_RDWR);
-       if (fd < 0) {
-               if (errno != ENOENT)
-                       return -1;
-               
-               fd = openat(smackfs_mnt_dirfd, "access", O_RDWR);
-               if (fd < 0)
-                       return -1;
-               access2 = 0;
-       }
+       fd = open_smackfs_file("access2", "access", &use_long);
+       if (fd < 0)
+               return -1;

 
        if ((code = str_to_access_code(access_type)) < 0)
                return -1;
        access_code_to_str(code, str);
 
 
        if ((code = str_to_access_code(access_type)) < 0)
                return -1;
        access_code_to_str(code, str);
 

-       if (access2)
+       if (use_long)

                ret = snprintf(buf, LOAD_LEN + 1, KERNEL_LONG_FORMAT,
                               subject, object, str);
        else
                ret = snprintf(buf, LOAD_LEN + 1, KERNEL_LONG_FORMAT,
                               subject, object, str);
        else


@@ -600,26 +595,41 @@ int smack_revoke_subject(const char *subject)
        return (ret < 0) ? -1 : 0;
 }
 
        return (ret < 0) ? -1 : 0;
 }
 

+static int open_smackfs_file(const char *long_name, const char *short_name,
+                            int *use_long)
+{
+       int fd;
+
+       fd = openat(smackfs_mnt_dirfd, long_name, O_WRONLY);
+       if (fd < 0) {
+               if (errno != ENOENT)
+                       return -1;
+
+               fd = openat(smackfs_mnt_dirfd, short_name, O_WRONLY);
+               if (fd < 0)
+                       return -1;
+
+               *use_long = 0;
+               return fd;
+       }
+
+       *use_long = 1;
+       return fd;
+}
+

 static int accesses_apply(struct smack_accesses *handle, int clear)
 {
        int ret;
        int load_fd;
        int change_fd;
 static int accesses_apply(struct smack_accesses *handle, int clear)
 {
        int ret;
        int load_fd;
        int change_fd;

-       int load2 = 1;
+       int use_long = 1;

 
        if (smackfs_mnt_dirfd < 0)
                return -1;
 
 
        if (smackfs_mnt_dirfd < 0)
                return -1;
 

-       load_fd = openat(smackfs_mnt_dirfd, "load2", O_WRONLY);
-       if (load_fd < 0) {
-               if (errno != ENOENT)
-                       return -1;
-               /* fallback */
-               load_fd = openat(smackfs_mnt_dirfd, "load", O_WRONLY);
-               if (load_fd < 0)
-                       return -1;
-               load2 = 0;
-       }
+       load_fd = open_smackfs_file("load2", "load", &use_long);
+       if (load_fd < 0)
+               return -1;

 
        change_fd = openat(smackfs_mnt_dirfd, "change-rule", O_WRONLY);
        /* Try to continue if the file doesn't exist, we might not need it. */
 
        change_fd = openat(smackfs_mnt_dirfd, "change-rule", O_WRONLY);
        /* Try to continue if the file doesn't exist, we might not need it. */


@@ -628,7 +638,7 @@ static int accesses_apply(struct smack_accesses *handle, int clear)
                goto err_out;
        }
 
                goto err_out;
        }
 

-       ret = accesses_print(handle, clear, load_fd, change_fd, load2, 0);
+       ret = accesses_print(handle, clear, load_fd, change_fd, use_long, 0);

 
 err_out:
        if (load_fd >= 0)
 
 err_out:
        if (load_fd >= 0)