Root/security/apparmor/procattr.c

1/*
2 * AppArmor security module
3 *
4 * This file contains AppArmor /proc/<pid>/attr/ interface functions
5 *
6 * Copyright (C) 1998-2008 Novell/SUSE
7 * Copyright 2009-2010 Canonical Ltd.
8 *
9 * This program is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU General Public License as
11 * published by the Free Software Foundation, version 2 of the
12 * License.
13 */
14
15#include "include/apparmor.h"
16#include "include/context.h"
17#include "include/policy.h"
18#include "include/domain.h"
19
20
21/**
22 * aa_getprocattr - Return the profile information for @profile
23 * @profile: the profile to print profile info about (NOT NULL)
24 * @string: Returns - string containing the profile info (NOT NULL)
25 *
26 * Returns: length of @string on success else error on failure
27 *
28 * Requires: profile != NULL
29 *
30 * Creates a string containing the namespace_name://profile_name for
31 * @profile.
32 *
33 * Returns: size of string placed in @string else error code on failure
34 */
35int aa_getprocattr(struct aa_profile *profile, char **string)
36{
37    char *str;
38    int len = 0, mode_len = 0, ns_len = 0, name_len;
39    const char *mode_str = profile_mode_names[profile->mode];
40    const char *ns_name = NULL;
41    struct aa_namespace *ns = profile->ns;
42    struct aa_namespace *current_ns = __aa_current_profile()->ns;
43    char *s;
44
45    if (!aa_ns_visible(current_ns, ns))
46        return -EACCES;
47
48    ns_name = aa_ns_name(current_ns, ns);
49    ns_len = strlen(ns_name);
50
51    /* if the visible ns_name is > 0 increase size for : :// seperator */
52    if (ns_len)
53        ns_len += 4;
54
55    /* unconfined profiles don't have a mode string appended */
56    if (!unconfined(profile))
57        mode_len = strlen(mode_str) + 3; /* + 3 for _() */
58
59    name_len = strlen(profile->base.hname);
60    len = mode_len + ns_len + name_len + 1; /* + 1 for \n */
61    s = str = kmalloc(len + 1, GFP_KERNEL); /* + 1 \0 */
62    if (!str)
63        return -ENOMEM;
64
65    if (ns_len) {
66        /* skip over prefix current_ns->base.hname and separating // */
67        sprintf(s, ":%s://", ns_name);
68        s += ns_len;
69    }
70    if (unconfined(profile))
71        /* mode string not being appended */
72        sprintf(s, "%s\n", profile->base.hname);
73    else
74        sprintf(s, "%s (%s)\n", profile->base.hname, mode_str);
75    *string = str;
76
77    /* NOTE: len does not include \0 of string, not saved as part of file */
78    return len;
79}
80
81/**
82 * split_token_from_name - separate a string of form <token>^<name>
83 * @op: operation being checked
84 * @args: string to parse (NOT NULL)
85 * @token: stores returned parsed token value (NOT NULL)
86 *
87 * Returns: start position of name after token else NULL on failure
88 */
89static char *split_token_from_name(int op, char *args, u64 * token)
90{
91    char *name;
92
93    *token = simple_strtoull(args, &name, 16);
94    if ((name == args) || *name != '^') {
95        AA_ERROR("%s: Invalid input '%s'", op_table[op], args);
96        return ERR_PTR(-EINVAL);
97    }
98
99    name++; /* skip ^ */
100    if (!*name)
101        name = NULL;
102    return name;
103}
104
105/**
106 * aa_setprocattr_chagnehat - handle procattr interface to change_hat
107 * @args: args received from writing to /proc/<pid>/attr/current (NOT NULL)
108 * @size: size of the args
109 * @test: true if this is a test of change_hat permissions
110 *
111 * Returns: %0 or error code if change_hat fails
112 */
113int aa_setprocattr_changehat(char *args, size_t size, int test)
114{
115    char *hat;
116    u64 token;
117    const char *hats[16]; /* current hard limit on # of names */
118    int count = 0;
119
120    hat = split_token_from_name(OP_CHANGE_HAT, args, &token);
121    if (IS_ERR(hat))
122        return PTR_ERR(hat);
123
124    if (!hat && !token) {
125        AA_ERROR("change_hat: Invalid input, NULL hat and NULL magic");
126        return -EINVAL;
127    }
128
129    if (hat) {
130        /* set up hat name vector, args guaranteed null terminated
131         * at args[size] by setprocattr.
132         *
133         * If there are multiple hat names in the buffer each is
134         * separated by a \0. Ie. userspace writes them pre tokenized
135         */
136        char *end = args + size;
137        for (count = 0; (hat < end) && count < 16; ++count) {
138            char *next = hat + strlen(hat) + 1;
139            hats[count] = hat;
140            hat = next;
141        }
142    }
143
144    AA_DEBUG("%s: Magic 0x%llx Hat '%s'\n",
145         __func__, token, hat ? hat : NULL);
146
147    return aa_change_hat(hats, count, token, test);
148}
149
150/**
151 * aa_setprocattr_changeprofile - handle procattr interface to changeprofile
152 * @fqname: args received from writting to /proc/<pid>/attr/current (NOT NULL)
153 * @onexec: true if change_profile should be delayed until exec
154 * @test: true if this is a test of change_profile permissions
155 *
156 * Returns: %0 or error code if change_profile fails
157 */
158int aa_setprocattr_changeprofile(char *fqname, bool onexec, int test)
159{
160    char *name, *ns_name;
161
162    name = aa_split_fqname(fqname, &ns_name);
163    return aa_change_profile(ns_name, name, onexec, test);
164}
165
166int aa_setprocattr_permipc(char *fqname)
167{
168    /* TODO: add ipc permission querying */
169    return -ENOTSUPP;
170}
171

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