1 /* 2 * Copyright (c) 2004 Apple Computer, Inc. 3 * Copyright (c) 2005 Robert N. M. Watson 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of 15 * its contributors may be used to endorse or promote products derived 16 * from this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR 22 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 26 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 27 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 28 * POSSIBILITY OF SUCH DAMAGE. 29 * 30 * $P4: //depot/projects/trustedbsd/openbsm/libbsm/bsm_mask.c#13 $ 31 */ 32 33 #include <sys/types.h> 34 35 #include <config/config.h> 36 #ifdef HAVE_FULL_QUEUE_H 37 #include <sys/queue.h> 38 #else /* !HAVE_FULL_QUEUE_H */ 39 #include <compat/queue.h> 40 #endif /* !HAVE_FULL_QUEUE_H */ 41 42 #include <bsm/libbsm.h> 43 44 #include <pthread.h> 45 #include <stdlib.h> 46 #include <string.h> 47 48 /* MT-Safe */ 49 static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER; 50 static int firsttime = 1; 51 52 /* 53 * XXX ev_cache, once created, sticks around until the calling program exits. 54 * This may or may not be a problem as far as absolute memory usage goes, but 55 * at least there don't appear to be any leaks in using the cache. 56 * 57 * XXXRW: Note that despite (mutex), load_event_table() could race with 58 * other consumers of the getauevents() API. 59 */ 60 struct audit_event_map { 61 char ev_name[AU_EVENT_NAME_MAX]; 62 char ev_desc[AU_EVENT_DESC_MAX]; 63 struct au_event_ent ev; 64 LIST_ENTRY(audit_event_map) ev_list; 65 }; 66 static LIST_HEAD(, audit_event_map) ev_cache; 67 68 static struct audit_event_map * 69 audit_event_map_alloc(void) 70 { 71 struct audit_event_map *aemp; 72 73 aemp = malloc(sizeof(*aemp)); 74 if (aemp == NULL) 75 return (aemp); 76 bzero(aemp, sizeof(*aemp)); 77 aemp->ev.ae_name = aemp->ev_name; 78 aemp->ev.ae_desc = aemp->ev_desc; 79 return (aemp); 80 } 81 82 static void 83 audit_event_map_free(struct audit_event_map *aemp) 84 { 85 86 free(aemp); 87 } 88 89 /* 90 * When reading into the cache fails, we need to flush the entire cache to 91 * prevent it from containing some but not all records. 92 */ 93 static void 94 flush_cache(void) 95 { 96 struct audit_event_map *aemp; 97 98 /* XXX: Would assert 'mutex'. */ 99 100 while ((aemp = LIST_FIRST(&ev_cache)) != NULL) { 101 LIST_REMOVE(aemp, ev_list); 102 audit_event_map_free(aemp); 103 } 104 } 105 106 static int 107 load_event_table(void) 108 { 109 struct audit_event_map *aemp; 110 struct au_event_ent *ep; 111 112 /* 113 * XXX: Would assert 'mutex'. 114 * Loading of the cache happens only once; dont check if cache is 115 * already loaded. 116 */ 117 LIST_INIT(&ev_cache); 118 setauevent(); /* Rewind to beginning of entries. */ 119 do { 120 aemp = audit_event_map_alloc(); 121 if (aemp == NULL) { 122 flush_cache(); 123 return (-1); 124 } 125 ep = getauevent_r(&aemp->ev); 126 if (ep != NULL) 127 LIST_INSERT_HEAD(&ev_cache, aemp, ev_list); 128 else 129 audit_event_map_free(aemp); 130 } while (ep != NULL); 131 return (1); 132 } 133 134 /* 135 * Read the event with the matching event number from the cache. 136 */ 137 static struct au_event_ent * 138 read_from_cache(au_event_t event) 139 { 140 struct audit_event_map *elem; 141 142 /* XXX: Would assert 'mutex'. */ 143 144 LIST_FOREACH(elem, &ev_cache, ev_list) { 145 if (elem->ev.ae_number == event) 146 return (&elem->ev); 147 } 148 149 return (NULL); 150 } 151 152 /* 153 * Check if the audit event is preselected against the preselection mask. 154 */ 155 int 156 au_preselect(au_event_t event, au_mask_t *mask_p, int sorf, int flag) 157 { 158 struct au_event_ent *ev; 159 au_class_t effmask = 0; 160 161 if (mask_p == NULL) 162 return (-1); 163 164 165 pthread_mutex_lock(&mutex); 166 if (firsttime) { 167 firsttime = 0; 168 if ( -1 == load_event_table()) { 169 pthread_mutex_unlock(&mutex); 170 return (-1); 171 } 172 } 173 switch (flag) { 174 case AU_PRS_REREAD: 175 flush_cache(); 176 if (load_event_table() == -1) { 177 pthread_mutex_unlock(&mutex); 178 return (-1); 179 } 180 ev = read_from_cache(event); 181 break; 182 case AU_PRS_USECACHE: 183 ev = read_from_cache(event); 184 break; 185 default: 186 ev = NULL; 187 } 188 if (ev == NULL) { 189 pthread_mutex_unlock(&mutex); 190 return (-1); 191 } 192 if (sorf & AU_PRS_SUCCESS) 193 effmask |= (mask_p->am_success & ev->ae_class); 194 if (sorf & AU_PRS_FAILURE) 195 effmask |= (mask_p->am_failure & ev->ae_class); 196 pthread_mutex_unlock(&mutex); 197 if (effmask != 0) 198 return (1); 199 return (0); 200 } 201