1 /** @addtogroup MCD_MCDIMPL_DAEMON_SRV
2 * @{
3 * @file
4 *
5 * Connection data.
6 *
7 * <!-- Copyright Giesecke & Devrient GmbH 2009 - 2012 -->
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. The name of the author may not be used to endorse or promote
18 * products derived from this software without specific prior
19 * written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
22 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
23 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
25 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
27 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
29 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
30 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
31 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 */
33 #include <stdlib.h>
34 #include <unistd.h>
35 #include <assert.h>
36 #include <cstring>
37 #include <errno.h>
38 #include <stdio.h>
39 #include <sys/socket.h>
40 #include <linux/netlink.h>
41
42 #include "NetlinkConnection.h"
43
44 #include "log.h"
45
46
hashConnection(pid_t pid,uint32_t seq)47 uint64_t hashConnection(
48 pid_t pid,
49 uint32_t seq
50 )
51 {
52 return (((uint64_t)seq) << 32) | (uint64_t)pid;
53 }
54
55
56 //------------------------------------------------------------------------------
NetlinkConnection(void)57 NetlinkConnection::NetlinkConnection(
58 void
59 ) : Connection(),
60 dataLeft(0),
61 manager(NULL)
62 {
63 detached = false;
64 dataMsg = NULL;
65 dataStart = NULL;
66 dataLen = 0;
67
68
69 selfPid = getpid();
70 peerPid = 0;
71 sequenceMagic = 0;
72 hash = hashConnection(peerPid, sequenceMagic);
73 }
74
75
76 //------------------------------------------------------------------------------
NetlinkConnection(NetlinkConnectionManager * manager,int socketDescriptor,uint32_t pid,uint32_t seq)77 NetlinkConnection::NetlinkConnection(
78 NetlinkConnectionManager *manager,
79 int socketDescriptor,
80 uint32_t pid,
81 uint32_t seq
82 ): Connection(),
83 dataLeft(0),
84 manager(manager)
85 {
86 detached = false;
87 dataMsg = NULL;
88 dataStart = NULL;
89 dataLen = 0;
90
91 this->socketDescriptor = socketDescriptor;
92 selfPid = getpid();
93 peerPid = pid;
94 sequenceMagic = seq;
95 hash = hashConnection(pid, seq);
96 }
97
98
99 //------------------------------------------------------------------------------
~NetlinkConnection(void)100 NetlinkConnection::~NetlinkConnection(
101 void
102 )
103 {
104 LOG_I("%s: destroy connection for PID 0x%X", __FUNCTION__, peerPid);
105 socketDescriptor = -1;
106 free(dataMsg);
107
108 if (manager) {
109 manager->removeConnection(hash);
110 }
111 }
112
113
114 //------------------------------------------------------------------------------
connect(const char * dest)115 bool NetlinkConnection::connect(
116 const char *dest
117 )
118 {
119 struct sockaddr_nl addr;
120 bool ret = false;
121
122 assert(NULL != dest);
123
124 LOG_I("%s: Connecting to SEQ 0x%X", __FUNCTION__, MC_DAEMON_PID);
125 do {
126 if ((socketDescriptor = socket(PF_NETLINK, SOCK_DGRAM, MC_DAEMON_NETLINK)) < 0) {
127 LOG_E("%s: Can't open netlink socket - errno: %d(%s)",
128 __FUNCTION__, errno, strerror(errno));
129 break;
130 }
131 memset(&addr, 0, sizeof(addr));
132 addr.nl_family = AF_NETLINK;
133 addr.nl_pid = selfPid; /* self pid */
134 addr.nl_groups = 0; /* not in mcast groups */
135
136 if (bind(socketDescriptor, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
137 LOG_E("%s: bind() failed - errno: %d(%s)", __FUNCTION__, errno, strerror(errno));
138 close(socketDescriptor);
139
140 // Set invalid socketDescriptor
141 socketDescriptor = -1;
142 break;
143 }
144 ret = true;
145
146
147 } while (false);
148
149 return ret;
150 }
151
152
153 //------------------------------------------------------------------------------
handleMessage(struct nlmsghdr * nlh)154 void NetlinkConnection::handleMessage(
155 struct nlmsghdr *nlh
156 )
157 {
158 dataMutex.lock();
159 /* Takeover the buffer */
160 dataMsg = nlh;
161 dataLen = NLMSG_PAYLOAD(dataMsg, 0);
162 dataStart = static_cast<uint8_t *>(NLMSG_DATA(dataMsg));
163 dataMutex.unlock();
164 dataLeft.signal();
165 }
166
167 //------------------------------------------------------------------------------
readData(void * buffer,uint32_t len)168 size_t NetlinkConnection::readData(
169 void *buffer,
170 uint32_t len
171 )
172 {
173 return readData(buffer, len, -1);
174 }
175
176
177 //------------------------------------------------------------------------------
readData(void * buffer,uint32_t len,int32_t timeout)178 size_t NetlinkConnection::readData(
179 void *buffer,
180 uint32_t len,
181 int32_t timeout
182 )
183 {
184 size_t ret = -1;
185 assert(NULL != buffer);
186
187 if (!dataLeft.wait(timeout)) {
188 return -2;
189 }
190 dataMutex.lock();
191 // No data left?? Could we get this far?
192 if (dataLen <= 0) {
193 dataMutex.unlock();
194 return -2;
195 }
196
197 //LOG_I("%s: reading connection data %u, connection data left %u",
198 // __FUNCTION__, len, dataLen);
199
200 assert(dataStart != NULL);
201
202 // trying to read more than the left data
203 if (len > dataLen) {
204 ret = dataLen;
205 memcpy(buffer, dataStart, dataLen);
206 dataLen = 0;
207 } else {
208 ret = len;
209 memcpy(buffer, dataStart, len);
210 dataLen -= len;
211 dataStart += len;
212 }
213
214 if (dataLen == 0) {
215 dataStart = NULL;
216 free(dataMsg);
217 dataMsg = NULL;
218 } else {
219 // Still some data left
220 dataLeft.signal();
221 }
222 dataMutex.unlock();
223
224 //LOG_I("%s: read %u", __FUNCTION__, ret);
225 return ret;
226 }
227
228 //------------------------------------------------------------------------------
writeData(void * buffer,uint32_t len)229 size_t NetlinkConnection::writeData(
230 void *buffer,
231 uint32_t len
232 )
233 {
234 size_t ret;
235 struct sockaddr_nl dest_addr;
236 struct nlmsghdr *nlh = NULL;
237 struct iovec iov;
238 struct msghdr msg;
239
240 assert(NULL != buffer);
241 assert(-1 != socketDescriptor);
242
243 //LOG_I("%s: send data %u to PID %u", __FUNCTION__, len, sequenceMagic);
244
245 memset(&dest_addr, 0, sizeof(dest_addr));
246 dest_addr.nl_family = AF_NETLINK;
247 dest_addr.nl_pid = peerPid;
248 dest_addr.nl_groups = 0; /* unicast */
249
250 nlh = (struct nlmsghdr *)malloc(
251 NLMSG_SPACE(len));
252 /* Fill the netlink message header */
253 nlh->nlmsg_len = NLMSG_SPACE(len);
254 nlh->nlmsg_pid = selfPid;
255 nlh->nlmsg_flags = NLM_F_REQUEST;
256 nlh->nlmsg_seq = sequenceMagic;
257
258 /* Fill in the netlink message payload */
259 memcpy(NLMSG_DATA(nlh), buffer, len);
260
261 iov.iov_base = (void *)nlh;
262 iov.iov_len = nlh->nlmsg_len;
263 msg.msg_name = (void *)&dest_addr;
264 msg.msg_namelen = sizeof(dest_addr);
265 msg.msg_iov = &iov;
266 msg.msg_iovlen = 1;
267 msg.msg_control = NULL;
268 msg.msg_controllen = 0;
269
270 ret = sendmsg(socketDescriptor, &msg, 0);
271 if (ret != NLMSG_SPACE(len)) {
272 LOG_E( "%s: could no send all data, ret=%d, errno: %d(%s)",
273 __FUNCTION__, ret, errno, strerror(errno));
274 ret = -1;
275 } else {
276 /* The whole message sent also includes the header, so make sure to
277 * return only the number of payload data sent, not everything */
278 ret = len;
279 }
280
281 free(nlh);
282
283 return ret;
284 }
285
286 /** @} */
287