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author | The Android Open Source Project | 2009-03-03 20:29:04 -0600 |
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committer | The Android Open Source Project | 2009-03-03 20:29:04 -0600 |
commit | e54eebbf1a908d65ee8cf80bab62821c05666d70 (patch) | |
tree | 4b825dc642cb6eb9a060e54bf8d69288fbee4904 /libnetutils/packet.c | |
parent | a1e1c1b106423de09bc918502e7a51d4ffe5a4ae (diff) | |
download | platform-system-core-e54eebbf1a908d65ee8cf80bab62821c05666d70.tar.gz platform-system-core-e54eebbf1a908d65ee8cf80bab62821c05666d70.tar.xz platform-system-core-e54eebbf1a908d65ee8cf80bab62821c05666d70.zip |
auto import from //depot/cupcake/@135843
Diffstat (limited to 'libnetutils/packet.c')
-rw-r--r-- | libnetutils/packet.c | 239 |
1 files changed, 0 insertions, 239 deletions
diff --git a/libnetutils/packet.c b/libnetutils/packet.c deleted file mode 100644 index 9388345c7..000000000 --- a/libnetutils/packet.c +++ /dev/null | |||
@@ -1,239 +0,0 @@ | |||
1 | /* | ||
2 | * Copyright 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 | |||
17 | #include <stdlib.h> | ||
18 | #include <unistd.h> | ||
19 | #include <sys/uio.h> | ||
20 | #include <sys/socket.h> | ||
21 | #include <netinet/in.h> | ||
22 | #include <netinet/ip.h> | ||
23 | #include <netinet/udp.h> | ||
24 | #include <linux/if_packet.h> | ||
25 | #include <linux/if_ether.h> | ||
26 | #include <errno.h> | ||
27 | |||
28 | #ifdef ANDROID | ||
29 | #define LOG_TAG "DHCP" | ||
30 | #include <cutils/log.h> | ||
31 | #else | ||
32 | #include <stdio.h> | ||
33 | #include <string.h> | ||
34 | #define LOGD printf | ||
35 | #define LOGW printf | ||
36 | #endif | ||
37 | |||
38 | #include "dhcpmsg.h" | ||
39 | |||
40 | int fatal(); | ||
41 | |||
42 | int open_raw_socket(const char *ifname, uint8_t *hwaddr, int if_index) | ||
43 | { | ||
44 | int s, flag; | ||
45 | struct sockaddr_ll bindaddr; | ||
46 | |||
47 | if((s = socket(PF_PACKET, SOCK_DGRAM, htons(ETH_P_IP))) < 0) { | ||
48 | return fatal("socket(PF_PACKET)"); | ||
49 | } | ||
50 | |||
51 | memset(&bindaddr, 0, sizeof(bindaddr)); | ||
52 | bindaddr.sll_family = AF_PACKET; | ||
53 | bindaddr.sll_protocol = htons(ETH_P_IP); | ||
54 | bindaddr.sll_halen = ETH_ALEN; | ||
55 | memcpy(bindaddr.sll_addr, hwaddr, ETH_ALEN); | ||
56 | bindaddr.sll_ifindex = if_index; | ||
57 | |||
58 | if (bind(s, (struct sockaddr *)&bindaddr, sizeof(bindaddr)) < 0) { | ||
59 | return fatal("Cannot bind raw socket to interface"); | ||
60 | } | ||
61 | |||
62 | return s; | ||
63 | } | ||
64 | |||
65 | static uint32_t checksum(void *buffer, unsigned int count, uint32_t startsum) | ||
66 | { | ||
67 | uint16_t *up = (uint16_t *)buffer; | ||
68 | uint32_t sum = startsum; | ||
69 | uint32_t upper16; | ||
70 | |||
71 | while (count > 1) { | ||
72 | sum += *up++; | ||
73 | count -= 2; | ||
74 | } | ||
75 | if (count > 0) { | ||
76 | sum += (uint16_t) *(uint8_t *)up; | ||
77 | } | ||
78 | while ((upper16 = (sum >> 16)) != 0) { | ||
79 | sum = (sum & 0xffff) + upper16; | ||
80 | } | ||
81 | return sum; | ||
82 | } | ||
83 | |||
84 | static uint32_t finish_sum(uint32_t sum) | ||
85 | { | ||
86 | return ~sum & 0xffff; | ||
87 | } | ||
88 | |||
89 | int send_packet(int s, int if_index, struct dhcp_msg *msg, int size, | ||
90 | uint32_t saddr, uint32_t daddr, uint32_t sport, uint32_t dport) | ||
91 | { | ||
92 | struct iphdr ip; | ||
93 | struct udphdr udp; | ||
94 | struct iovec iov[3]; | ||
95 | uint32_t udpsum; | ||
96 | uint16_t temp; | ||
97 | struct msghdr msghdr; | ||
98 | struct sockaddr_ll destaddr; | ||
99 | |||
100 | ip.version = IPVERSION; | ||
101 | ip.ihl = sizeof(ip) >> 2; | ||
102 | ip.tos = 0; | ||
103 | ip.tot_len = htons(sizeof(ip) + sizeof(udp) + size); | ||
104 | ip.id = 0; | ||
105 | ip.frag_off = 0; | ||
106 | ip.ttl = IPDEFTTL; | ||
107 | ip.protocol = IPPROTO_UDP; | ||
108 | ip.check = 0; | ||
109 | ip.saddr = saddr; | ||
110 | ip.daddr = daddr; | ||
111 | ip.check = finish_sum(checksum(&ip, sizeof(ip), 0)); | ||
112 | |||
113 | udp.source = htons(sport); | ||
114 | udp.dest = htons(dport); | ||
115 | udp.len = htons(sizeof(udp) + size); | ||
116 | udp.check = 0; | ||
117 | |||
118 | /* Calculate checksum for pseudo header */ | ||
119 | udpsum = checksum(&ip.saddr, sizeof(ip.saddr), 0); | ||
120 | udpsum = checksum(&ip.daddr, sizeof(ip.daddr), udpsum); | ||
121 | temp = htons(IPPROTO_UDP); | ||
122 | udpsum = checksum(&temp, sizeof(temp), udpsum); | ||
123 | temp = udp.len; | ||
124 | udpsum = checksum(&temp, sizeof(temp), udpsum); | ||
125 | |||
126 | /* Add in the checksum for the udp header */ | ||
127 | udpsum = checksum(&udp, sizeof(udp), udpsum); | ||
128 | |||
129 | /* Add in the checksum for the data */ | ||
130 | udpsum = checksum(msg, size, udpsum); | ||
131 | udp.check = finish_sum(udpsum); | ||
132 | |||
133 | iov[0].iov_base = (char *)&ip; | ||
134 | iov[0].iov_len = sizeof(ip); | ||
135 | iov[1].iov_base = (char *)&udp; | ||
136 | iov[1].iov_len = sizeof(udp); | ||
137 | iov[2].iov_base = (char *)msg; | ||
138 | iov[2].iov_len = size; | ||
139 | memset(&destaddr, 0, sizeof(destaddr)); | ||
140 | destaddr.sll_family = AF_PACKET; | ||
141 | destaddr.sll_protocol = htons(ETH_P_IP); | ||
142 | destaddr.sll_ifindex = if_index; | ||
143 | destaddr.sll_halen = ETH_ALEN; | ||
144 | memcpy(destaddr.sll_addr, "\xff\xff\xff\xff\xff\xff", ETH_ALEN); | ||
145 | |||
146 | msghdr.msg_name = &destaddr; | ||
147 | msghdr.msg_namelen = sizeof(destaddr); | ||
148 | msghdr.msg_iov = iov; | ||
149 | msghdr.msg_iovlen = sizeof(iov) / sizeof(struct iovec); | ||
150 | msghdr.msg_flags = 0; | ||
151 | msghdr.msg_control = 0; | ||
152 | msghdr.msg_controllen = 0; | ||
153 | return sendmsg(s, &msghdr, 0); | ||
154 | } | ||
155 | |||
156 | int receive_packet(int s, struct dhcp_msg *msg) | ||
157 | { | ||
158 | int nread; | ||
159 | int is_valid; | ||
160 | struct dhcp_packet { | ||
161 | struct iphdr ip; | ||
162 | struct udphdr udp; | ||
163 | struct dhcp_msg dhcp; | ||
164 | } packet; | ||
165 | int dhcp_size; | ||
166 | uint32_t sum; | ||
167 | uint16_t temp; | ||
168 | uint32_t saddr, daddr; | ||
169 | |||
170 | nread = read(s, &packet, sizeof(packet)); | ||
171 | if (nread < 0) { | ||
172 | return -1; | ||
173 | } | ||
174 | /* | ||
175 | * The raw packet interface gives us all packets received by the | ||
176 | * network interface. We need to filter out all packets that are | ||
177 | * not meant for us. | ||
178 | */ | ||
179 | is_valid = 0; | ||
180 | if (nread < (int)(sizeof(struct iphdr) + sizeof(struct udphdr))) { | ||
181 | #if VERBOSE | ||
182 | LOGD("Packet is too small (%d) to be a UDP datagram", nread); | ||
183 | #endif | ||
184 | } else if (packet.ip.version != IPVERSION || packet.ip.ihl != (sizeof(packet.ip) >> 2)) { | ||
185 | #if VERBOSE | ||
186 | LOGD("Not a valid IP packet"); | ||
187 | #endif | ||
188 | } else if (nread < ntohs(packet.ip.tot_len)) { | ||
189 | #if VERBOSE | ||
190 | LOGD("Packet was truncated (read %d, needed %d)", nread, ntohs(packet.ip.tot_len)); | ||
191 | #endif | ||
192 | } else if (packet.ip.protocol != IPPROTO_UDP) { | ||
193 | #if VERBOSE | ||
194 | LOGD("IP protocol (%d) is not UDP", packet.ip.protocol); | ||
195 | #endif | ||
196 | } else if (packet.udp.dest != htons(PORT_BOOTP_CLIENT)) { | ||
197 | #if VERBOSE | ||
198 | LOGD("UDP dest port (%d) is not DHCP client", ntohs(packet.udp.dest)); | ||
199 | #endif | ||
200 | } else { | ||
201 | is_valid = 1; | ||
202 | } | ||
203 | |||
204 | if (!is_valid) { | ||
205 | return -1; | ||
206 | } | ||
207 | |||
208 | /* Seems like it's probably a valid DHCP packet */ | ||
209 | /* validate IP header checksum */ | ||
210 | sum = finish_sum(checksum(&packet.ip, sizeof(packet.ip), 0)); | ||
211 | if (sum != 0) { | ||
212 | LOGW("IP header checksum failure (0x%x)", packet.ip.check); | ||
213 | return -1; | ||
214 | } | ||
215 | /* | ||
216 | * Validate the UDP checksum. | ||
217 | * Since we don't need the IP header anymore, we "borrow" it | ||
218 | * to construct the pseudo header used in the checksum calculation. | ||
219 | */ | ||
220 | dhcp_size = ntohs(packet.udp.len) - sizeof(packet.udp); | ||
221 | saddr = packet.ip.saddr; | ||
222 | daddr = packet.ip.daddr; | ||
223 | nread = ntohs(packet.ip.tot_len); | ||
224 | memset(&packet.ip, 0, sizeof(packet.ip)); | ||
225 | packet.ip.saddr = saddr; | ||
226 | packet.ip.daddr = daddr; | ||
227 | packet.ip.protocol = IPPROTO_UDP; | ||
228 | packet.ip.tot_len = packet.udp.len; | ||
229 | temp = packet.udp.check; | ||
230 | packet.udp.check = 0; | ||
231 | sum = finish_sum(checksum(&packet, nread, 0)); | ||
232 | packet.udp.check = temp; | ||
233 | if (temp != sum) { | ||
234 | LOGW("UDP header checksum failure (0x%x should be 0x%x)", sum, temp); | ||
235 | return -1; | ||
236 | } | ||
237 | memcpy(msg, &packet.dhcp, dhcp_size); | ||
238 | return dhcp_size; | ||
239 | } | ||