1 /*
2 * Copyright (C) 2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <ctype.h>
18 #include <endian.h>
19 #include <errno.h>
20 #include <limits.h>
21 #include <stdarg.h>
22 #include <stdlib.h>
23 #include <sys/prctl.h>
24 #include <sys/uio.h>
25 #include <syslog.h>
26
27 #include <private/android_filesystem_config.h>
28 #include <private/android_logger.h>
29
30 #include "libaudit.h"
31 #include "LogAudit.h"
32 #include "LogKlog.h"
33
34 #define KMSG_PRIORITY(PRI) \
35 '<', \
36 '0' + LOG_MAKEPRI(LOG_AUTH, LOG_PRI(PRI)) / 10, \
37 '0' + LOG_MAKEPRI(LOG_AUTH, LOG_PRI(PRI)) % 10, \
38 '>'
39
LogAudit(LogBuffer * buf,LogReader * reader,int fdDmesg)40 LogAudit::LogAudit(LogBuffer *buf, LogReader *reader, int fdDmesg) :
41 SocketListener(getLogSocket(), false),
42 logbuf(buf),
43 reader(reader),
44 fdDmesg(fdDmesg),
45 initialized(false) {
46 static const char auditd_message[] = { KMSG_PRIORITY(LOG_INFO),
47 'l', 'o', 'g', 'd', '.', 'a', 'u', 'd', 'i', 't', 'd', ':',
48 ' ', 's', 't', 'a', 'r', 't', '\n' };
49 write(fdDmesg, auditd_message, sizeof(auditd_message));
50 }
51
onDataAvailable(SocketClient * cli)52 bool LogAudit::onDataAvailable(SocketClient *cli) {
53 if (!initialized) {
54 prctl(PR_SET_NAME, "logd.auditd");
55 initialized = true;
56 }
57
58 struct audit_message rep;
59
60 rep.nlh.nlmsg_type = 0;
61 rep.nlh.nlmsg_len = 0;
62 rep.data[0] = '\0';
63
64 if (audit_get_reply(cli->getSocket(), &rep, GET_REPLY_BLOCKING, 0) < 0) {
65 SLOGE("Failed on audit_get_reply with error: %s", strerror(errno));
66 return false;
67 }
68
69 logPrint("type=%d %.*s",
70 rep.nlh.nlmsg_type, rep.nlh.nlmsg_len, rep.data);
71
72 return true;
73 }
74
logPrint(const char * fmt,...)75 int LogAudit::logPrint(const char *fmt, ...) {
76 if (fmt == NULL) {
77 return -EINVAL;
78 }
79
80 va_list args;
81
82 char *str = NULL;
83 va_start(args, fmt);
84 int rc = vasprintf(&str, fmt, args);
85 va_end(args);
86
87 if (rc < 0) {
88 return rc;
89 }
90
91 char *cp;
92 while ((cp = strstr(str, " "))) {
93 memmove(cp, cp + 1, strlen(cp + 1) + 1);
94 }
95
96 bool info = strstr(str, " permissive=1") || strstr(str, " policy loaded ");
97 if ((fdDmesg >= 0) && initialized) {
98 struct iovec iov[3];
99 static const char log_info[] = { KMSG_PRIORITY(LOG_INFO) };
100 static const char log_warning[] = { KMSG_PRIORITY(LOG_WARNING) };
101
102 iov[0].iov_base = info ? const_cast<char *>(log_info)
103 : const_cast<char *>(log_warning);
104 iov[0].iov_len = info ? sizeof(log_info) : sizeof(log_warning);
105 iov[1].iov_base = str;
106 iov[1].iov_len = strlen(str);
107 iov[2].iov_base = const_cast<char *>("\n");
108 iov[2].iov_len = 1;
109
110 writev(fdDmesg, iov, sizeof(iov) / sizeof(iov[0]));
111 }
112
113 pid_t pid = getpid();
114 pid_t tid = gettid();
115 uid_t uid = AID_LOGD;
116 log_time now;
117
118 static const char audit_str[] = " audit(";
119 char *timeptr = strstr(str, audit_str);
120 if (timeptr
121 && ((cp = now.strptime(timeptr + sizeof(audit_str) - 1, "%s.%q")))
122 && (*cp == ':')) {
123 memcpy(timeptr + sizeof(audit_str) - 1, "0.0", 3);
124 memmove(timeptr + sizeof(audit_str) - 1 + 3, cp, strlen(cp) + 1);
125 //
126 // We are either in 1970ish (MONOTONIC) or 2015+ish (REALTIME) so to
127 // differentiate without prejudice, we use 1980 to delineate, earlier
128 // is monotonic, later is real.
129 //
130 # define EPOCH_PLUS_10_YEARS (10 * 1461 / 4 * 24 * 60 * 60)
131 if (now.tv_sec < EPOCH_PLUS_10_YEARS) {
132 LogKlog::convertMonotonicToReal(now);
133 }
134 } else {
135 now.strptime("", ""); // side effect of setting CLOCK_REALTIME
136 }
137
138 static const char pid_str[] = " pid=";
139 char *pidptr = strstr(str, pid_str);
140 if (pidptr && isdigit(pidptr[sizeof(pid_str) - 1])) {
141 cp = pidptr + sizeof(pid_str) - 1;
142 pid = 0;
143 while (isdigit(*cp)) {
144 pid = (pid * 10) + (*cp - '0');
145 ++cp;
146 }
147 tid = pid;
148 logbuf->lock();
149 uid = logbuf->pidToUid(pid);
150 logbuf->unlock();
151 memmove(pidptr, cp, strlen(cp) + 1);
152 }
153
154 // log to events
155
156 size_t l = strlen(str);
157 size_t n = l + sizeof(android_log_event_string_t);
158
159 bool notify = false;
160
161 android_log_event_string_t *event = static_cast<android_log_event_string_t *>(malloc(n));
162 if (!event) {
163 rc = -ENOMEM;
164 } else {
165 event->header.tag = htole32(AUDITD_LOG_TAG);
166 event->type = EVENT_TYPE_STRING;
167 event->length = htole32(l);
168 memcpy(event->data, str, l);
169
170 rc = logbuf->log(LOG_ID_EVENTS, now, uid, pid, tid,
171 reinterpret_cast<char *>(event),
172 (n <= USHRT_MAX) ? (unsigned short) n : USHRT_MAX);
173 free(event);
174
175 if (rc >= 0) {
176 notify = true;
177 }
178 }
179
180 // log to main
181
182 static const char comm_str[] = " comm=\"";
183 const char *comm = strstr(str, comm_str);
184 const char *estr = str + strlen(str);
185 char *commfree = NULL;
186 if (comm) {
187 estr = comm;
188 comm += sizeof(comm_str) - 1;
189 } else if (pid == getpid()) {
190 pid = tid;
191 comm = "auditd";
192 } else {
193 logbuf->lock();
194 comm = commfree = logbuf->pidToName(pid);
195 logbuf->unlock();
196 if (!comm) {
197 comm = "unknown";
198 }
199 }
200
201 const char *ecomm = strchr(comm, '"');
202 if (ecomm) {
203 ++ecomm;
204 l = ecomm - comm;
205 } else {
206 l = strlen(comm) + 1;
207 ecomm = "";
208 }
209 n = (estr - str) + strlen(ecomm) + l + 2;
210
211 char *newstr = static_cast<char *>(malloc(n));
212 if (!newstr) {
213 rc = -ENOMEM;
214 } else {
215 *newstr = info ? ANDROID_LOG_INFO : ANDROID_LOG_WARN;
216 strlcpy(newstr + 1, comm, l);
217 strncpy(newstr + 1 + l, str, estr - str);
218 strcpy(newstr + 1 + l + (estr - str), ecomm);
219
220 rc = logbuf->log(LOG_ID_MAIN, now, uid, pid, tid, newstr,
221 (n <= USHRT_MAX) ? (unsigned short) n : USHRT_MAX);
222 free(newstr);
223
224 if (rc >= 0) {
225 notify = true;
226 }
227 }
228
229 free(commfree);
230 free(str);
231
232 if (notify) {
233 reader->notifyNewLog();
234 if (rc < 0) {
235 rc = n;
236 }
237 }
238
239 return rc;
240 }
241
log(char * buf)242 int LogAudit::log(char *buf) {
243 char *audit = strstr(buf, " audit(");
244 if (!audit) {
245 return 0;
246 }
247
248 *audit = '\0';
249
250 int rc;
251 char *type = strstr(buf, "type=");
252 if (type) {
253 rc = logPrint("%s %s", type, audit + 1);
254 } else {
255 rc = logPrint("%s", audit + 1);
256 }
257 *audit = ' ';
258 return rc;
259 }
260
getLogSocket()261 int LogAudit::getLogSocket() {
262 int fd = audit_open();
263 if (fd < 0) {
264 return fd;
265 }
266 if (audit_setup(fd, getpid()) < 0) {
267 audit_close(fd);
268 fd = -1;
269 }
270 return fd;
271 }
272