procattr.c

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/*
 * AppArmor security module
 *
 * This file contains AppArmor /proc/<pid>/attr/ interface functions
 *
 * Copyright (C) 1998-2008 Novell/SUSE
 * Copyright 2009-2010 Canonical Ltd.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation, version 2 of the
 * License.
 */

#include "include/apparmor.h"
#include "include/context.h"
#include "include/policy.h"
#include "include/domain.h"
#include "include/procattr.h"


int aa_getprocattr(struct aa_profile *profile, char **string)
{
    char *str;
    int len = 0, mode_len = 0, ns_len = 0, name_len;
    const char *mode_str = profile_mode_names[profile->mode];
    const char *ns_name = NULL;
    struct aa_namespace *ns = profile->ns;
    struct aa_namespace *current_ns = __aa_current_profile()->ns;
    char *s;

    if (!aa_ns_visible(current_ns, ns))
        return -EACCES;

    ns_name = aa_ns_name(current_ns, ns);
    ns_len = strlen(ns_name);

    /* if the visible ns_name is > 0 increase size for : :// seperator */
    if (ns_len)
        ns_len += 4;

    /* unconfined profiles don't have a mode string appended */
    if (!unconfined(profile))
        mode_len = strlen(mode_str) + 3;    /* + 3 for _() */

    name_len = strlen(profile->base.hname);
    len = mode_len + ns_len + name_len + 1;     /* + 1 for \n */
    s = str = kmalloc(len + 1, GFP_KERNEL);     /* + 1 \0 */
    if (!str)
        return -ENOMEM;

    if (ns_len) {
        /* skip over prefix current_ns->base.hname and separating // */
        sprintf(s, ":%s://", ns_name);
        s += ns_len;
    }
    if (unconfined(profile))
        /* mode string not being appended */
        sprintf(s, "%s\n", profile->base.hname);
    else
        sprintf(s, "%s (%s)\n", profile->base.hname, mode_str);
    *string = str;

    /* NOTE: len does not include \0 of string, not saved as part of file */
    return len;
}

static char *split_token_from_name(int op, char *args, u64 * token)
{
    char *name;

    *token = simple_strtoull(args, &name, 16);
    if ((name == args) || *name != '^') {
        AA_ERROR("%s: Invalid input '%s'", op_table[op], args);
        return ERR_PTR(-EINVAL);
    }

    name++;         /* skip ^ */
    if (!*name)
        name = NULL;
    return name;
}

int aa_setprocattr_changehat(char *args, size_t size, int test)
{
    char *hat;
    u64 token;
    const char *hats[16];       /* current hard limit on # of names */
    int count = 0;

    hat = split_token_from_name(OP_CHANGE_HAT, args, &token);
    if (IS_ERR(hat))
        return PTR_ERR(hat);

    if (!hat && !token) {
        AA_ERROR("change_hat: Invalid input, NULL hat and NULL magic");
        return -EINVAL;
    }

    if (hat) {
        /* set up hat name vector, args guaranteed null terminated
         * at args[size] by setprocattr.
         *
         * If there are multiple hat names in the buffer each is
         * separated by a \0.  Ie. userspace writes them pre tokenized
         */
        char *end = args + size;
        for (count = 0; (hat < end) && count < 16; ++count) {
            char *next = hat + strlen(hat) + 1;
            hats[count] = hat;
            hat = next;
        }
    }

    AA_DEBUG("%s: Magic 0x%llx Hat '%s'\n",
         __func__, token, hat ? hat : NULL);

    return aa_change_hat(hats, count, token, test);
}

int aa_setprocattr_changeprofile(char *fqname, bool onexec, int test)
{
    char *name, *ns_name;

    name = aa_split_fqname(fqname, &ns_name);
    return aa_change_profile(ns_name, name, onexec, test);
}

int aa_setprocattr_permipc(char *fqname)
{
    /* TODO: add ipc permission querying */
    return -ENOTSUPP;
}