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/cred.h" 17 #include "include/policy.h" 18 #include "include/policy_ns.h" 19 #include "include/domain.h" 20 #include "include/procattr.h" 21 22 23 /** 24 * aa_getprocattr - Return the profile information for @profile 25 * @profile: the profile to print profile info about (NOT NULL) 26 * @string: Returns - string containing the profile info (NOT NULL) 27 * 28 * Returns: length of @string on success else error on failure 29 * 30 * Requires: profile != NULL 31 * 32 * Creates a string containing the namespace_name://profile_name for 33 * @profile. 34 * 35 * Returns: size of string placed in @string else error code on failure 36 */ 37 int aa_getprocattr(struct aa_label *label, char **string) 38 { 39 struct aa_ns *ns = labels_ns(label); 40 struct aa_ns *current_ns = aa_get_current_ns(); 41 int len; 42 43 if (!aa_ns_visible(current_ns, ns, true)) { 44 aa_put_ns(current_ns); 45 return -EACCES; 46 } 47 48 len = aa_label_snxprint(NULL, 0, current_ns, label, 49 FLAG_SHOW_MODE | FLAG_VIEW_SUBNS | 50 FLAG_HIDDEN_UNCONFINED); 51 AA_BUG(len < 0); 52 53 *string = kmalloc(len + 2, GFP_KERNEL); 54 if (!*string) { 55 aa_put_ns(current_ns); 56 return -ENOMEM; 57 } 58 59 len = aa_label_snxprint(*string, len + 2, current_ns, label, 60 FLAG_SHOW_MODE | FLAG_VIEW_SUBNS | 61 FLAG_HIDDEN_UNCONFINED); 62 if (len < 0) { 63 aa_put_ns(current_ns); 64 return len; 65 } 66 67 (*string)[len] = '\n'; 68 (*string)[len + 1] = 0; 69 70 aa_put_ns(current_ns); 71 return len + 1; 72 } 73 74 /** 75 * split_token_from_name - separate a string of form <token>^<name> 76 * @op: operation being checked 77 * @args: string to parse (NOT NULL) 78 * @token: stores returned parsed token value (NOT NULL) 79 * 80 * Returns: start position of name after token else NULL on failure 81 */ 82 static char *split_token_from_name(const char *op, char *args, u64 *token) 83 { 84 char *name; 85 86 *token = simple_strtoull(args, &name, 16); 87 if ((name == args) || *name != '^') { 88 AA_ERROR("%s: Invalid input '%s'", op, args); 89 return ERR_PTR(-EINVAL); 90 } 91 92 name++; /* skip ^ */ 93 if (!*name) 94 name = NULL; 95 return name; 96 } 97 98 /** 99 * aa_setprocattr_chagnehat - handle procattr interface to change_hat 100 * @args: args received from writing to /proc/<pid>/attr/current (NOT NULL) 101 * @size: size of the args 102 * @flags: set of flags governing behavior 103 * 104 * Returns: %0 or error code if change_hat fails 105 */ 106 int aa_setprocattr_changehat(char *args, size_t size, int flags) 107 { 108 char *hat; 109 u64 token; 110 const char *hats[16]; /* current hard limit on # of names */ 111 int count = 0; 112 113 hat = split_token_from_name(OP_CHANGE_HAT, args, &token); 114 if (IS_ERR(hat)) 115 return PTR_ERR(hat); 116 117 if (!hat && !token) { 118 AA_ERROR("change_hat: Invalid input, NULL hat and NULL magic"); 119 return -EINVAL; 120 } 121 122 if (hat) { 123 /* set up hat name vector, args guaranteed null terminated 124 * at args[size] by setprocattr. 125 * 126 * If there are multiple hat names in the buffer each is 127 * separated by a \0. Ie. userspace writes them pre tokenized 128 */ 129 char *end = args + size; 130 for (count = 0; (hat < end) && count < 16; ++count) { 131 char *next = hat + strlen(hat) + 1; 132 hats[count] = hat; 133 AA_DEBUG("%s: (pid %d) Magic 0x%llx count %d hat '%s'\n" 134 , __func__, current->pid, token, count, hat); 135 hat = next; 136 } 137 } else 138 AA_DEBUG("%s: (pid %d) Magic 0x%llx count %d Hat '%s'\n", 139 __func__, current->pid, token, count, "<NULL>"); 140 141 return aa_change_hat(hats, count, token, flags); 142 } 143