1 /*
2  * Copyright (C) 2008 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 #include <errno.h>
17 #include <string.h>
18 #include <stdlib.h>
19 
20 #define LOG_TAG "FrameworkListener"
21 
22 #include <cutils/log.h>
23 
24 #include <sysutils/FrameworkListener.h>
25 #include <sysutils/FrameworkCommand.h>
26 #include <sysutils/SocketClient.h>
27 
28 static const int CMD_BUF_SIZE = 1024;
29 
30 #define UNUSED __attribute__((unused))
31 
FrameworkListener(const char * socketName,bool withSeq)32 FrameworkListener::FrameworkListener(const char *socketName, bool withSeq) :
33                             SocketListener(socketName, true, withSeq) {
34     init(socketName, withSeq);
35 }
36 
FrameworkListener(const char * socketName)37 FrameworkListener::FrameworkListener(const char *socketName) :
38                             SocketListener(socketName, true, false) {
39     init(socketName, false);
40 }
41 
FrameworkListener(int sock)42 FrameworkListener::FrameworkListener(int sock) :
43                             SocketListener(sock, true) {
44     init(NULL, false);
45 }
46 
init(const char * socketName UNUSED,bool withSeq)47 void FrameworkListener::init(const char *socketName UNUSED, bool withSeq) {
48     mCommands = new FrameworkCommandCollection();
49     errorRate = 0;
50     mCommandCount = 0;
51     mWithSeq = withSeq;
52 }
53 
onDataAvailable(SocketClient * c)54 bool FrameworkListener::onDataAvailable(SocketClient *c) {
55     char buffer[CMD_BUF_SIZE];
56     int len;
57 
58     len = TEMP_FAILURE_RETRY(read(c->getSocket(), buffer, sizeof(buffer)));
59     if (len < 0) {
60         SLOGE("read() failed (%s)", strerror(errno));
61         return false;
62     } else if (!len)
63         return false;
64    if(buffer[len-1] != '\0')
65         SLOGW("String is not zero-terminated");
66 
67     int offset = 0;
68     int i;
69 
70     for (i = 0; i < len; i++) {
71         if (buffer[i] == '\0') {
72             /* IMPORTANT: dispatchCommand() expects a zero-terminated string */
73             dispatchCommand(c, buffer + offset);
74             offset = i + 1;
75         }
76     }
77 
78     return true;
79 }
80 
registerCmd(FrameworkCommand * cmd)81 void FrameworkListener::registerCmd(FrameworkCommand *cmd) {
82     mCommands->push_back(cmd);
83 }
84 
dispatchCommand(SocketClient * cli,char * data)85 void FrameworkListener::dispatchCommand(SocketClient *cli, char *data) {
86     FrameworkCommandCollection::iterator i;
87     int argc = 0;
88     char *argv[FrameworkListener::CMD_ARGS_MAX];
89     char tmp[CMD_BUF_SIZE];
90     char *p = data;
91     char *q = tmp;
92     char *qlimit = tmp + sizeof(tmp) - 1;
93     bool esc = false;
94     bool quote = false;
95     bool haveCmdNum = !mWithSeq;
96 
97     memset(argv, 0, sizeof(argv));
98     memset(tmp, 0, sizeof(tmp));
99     while(*p) {
100         if (*p == '\\') {
101             if (esc) {
102                 if (q >= qlimit)
103                     goto overflow;
104                 *q++ = '\\';
105                 esc = false;
106             } else
107                 esc = true;
108             p++;
109             continue;
110         } else if (esc) {
111             if (*p == '"') {
112                 if (q >= qlimit)
113                     goto overflow;
114                 *q++ = '"';
115             } else if (*p == '\\') {
116                 if (q >= qlimit)
117                     goto overflow;
118                 *q++ = '\\';
119             } else {
120                 cli->sendMsg(500, "Unsupported escape sequence", false);
121                 goto out;
122             }
123             p++;
124             esc = false;
125             continue;
126         }
127 
128         if (*p == '"') {
129             if (quote)
130                 quote = false;
131             else
132                 quote = true;
133             p++;
134             continue;
135         }
136 
137         if (q >= qlimit)
138             goto overflow;
139         *q = *p++;
140         if (!quote && *q == ' ') {
141             *q = '\0';
142             if (!haveCmdNum) {
143                 char *endptr;
144                 int cmdNum = (int)strtol(tmp, &endptr, 0);
145                 if (endptr == NULL || *endptr != '\0') {
146                     cli->sendMsg(500, "Invalid sequence number", false);
147                     goto out;
148                 }
149                 cli->setCmdNum(cmdNum);
150                 haveCmdNum = true;
151             } else {
152                 if (argc >= CMD_ARGS_MAX)
153                     goto overflow;
154                 argv[argc++] = strdup(tmp);
155             }
156             memset(tmp, 0, sizeof(tmp));
157             q = tmp;
158             continue;
159         }
160         q++;
161     }
162 
163     *q = '\0';
164     if (argc >= CMD_ARGS_MAX)
165         goto overflow;
166     argv[argc++] = strdup(tmp);
167 #if 0
168     for (int k = 0; k < argc; k++) {
169         SLOGD("arg[%d] = '%s'", k, argv[k]);
170     }
171 #endif
172 
173     if (quote) {
174         cli->sendMsg(500, "Unclosed quotes error", false);
175         goto out;
176     }
177 
178     if (errorRate && (++mCommandCount % errorRate == 0)) {
179         /* ignore this command - let the timeout handler handle it */
180         SLOGE("Faking a timeout");
181         goto out;
182     }
183 
184     for (i = mCommands->begin(); i != mCommands->end(); ++i) {
185         FrameworkCommand *c = *i;
186 
187         if (!strcmp(argv[0], c->getCommand())) {
188             if (c->runCommand(cli, argc, argv)) {
189                 SLOGW("Handler '%s' error (%s)", c->getCommand(), strerror(errno));
190             }
191             goto out;
192         }
193     }
194     cli->sendMsg(500, "Command not recognized", false);
195 out:
196     int j;
197     for (j = 0; j < argc; j++)
198         free(argv[j]);
199     return;
200 
201 overflow:
202     LOG_EVENT_INT(78001, cli->getUid());
203     cli->sendMsg(500, "Command too long", false);
204     goto out;
205 }
206