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1 /*
2  * Copyright 2011 Daniel Drown
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  * dump.c - print various headers for debugging
17  */
18 #include "dump.h"
19 
20 #include <arpa/inet.h>
21 #include <linux/icmp.h>
22 #include <linux/if_tun.h>
23 #include <netinet/icmp6.h>
24 #include <netinet/in.h>
25 #include <netinet/ip.h>
26 #include <netinet/ip6.h>
27 #include <netinet/ip_icmp.h>
28 #include <netinet/tcp.h>
29 #include <netinet/udp.h>
30 #include <stdint.h>
31 #include <stdio.h>
32 #include <stdlib.h>
33 
34 #include "checksum.h"
35 #include "clatd.h"
36 #include "debug.h"
37 #include "logging.h"
38 
39 #if CLAT_DEBUG
40 
41 /* print ip header */
dump_ip(struct iphdr * header)42 void dump_ip(struct iphdr *header) {
43   u_int16_t frag_flags;
44   char addrstr[INET6_ADDRSTRLEN];
45 
46   frag_flags = ntohs(header->frag_off);
47 
48   printf("IP packet\n");
49   printf("header_len = %x\n", header->ihl);
50   printf("version = %x\n", header->version);
51   printf("tos = %x\n", header->tos);
52   printf("tot_len = %x\n", ntohs(header->tot_len));
53   printf("id = %x\n", ntohs(header->id));
54   printf("frag: ");
55   if (frag_flags & IP_RF) {
56     printf("(RF) ");
57   }
58   if (frag_flags & IP_DF) {
59     printf("DF ");
60   }
61   if (frag_flags & IP_MF) {
62     printf("MF ");
63   }
64   printf("offset = %x\n", frag_flags & IP_OFFMASK);
65   printf("ttl = %x\n", header->ttl);
66   printf("protocol = %x\n", header->protocol);
67   printf("checksum = %x\n", ntohs(header->check));
68   inet_ntop(AF_INET, &header->saddr, addrstr, sizeof(addrstr));
69   printf("saddr = %s\n", addrstr);
70   inet_ntop(AF_INET, &header->daddr, addrstr, sizeof(addrstr));
71   printf("daddr = %s\n", addrstr);
72 }
73 
74 /* print ip6 header */
dump_ip6(struct ip6_hdr * header)75 void dump_ip6(struct ip6_hdr *header) {
76   char addrstr[INET6_ADDRSTRLEN];
77 
78   printf("ipv6\n");
79   printf("version = %x\n", header->ip6_vfc >> 4);
80   printf("traffic class = %x\n", header->ip6_flow >> 20);
81   printf("flow label = %x\n", ntohl(header->ip6_flow & 0x000fffff));
82   printf("payload len = %x\n", ntohs(header->ip6_plen));
83   printf("next header = %x\n", header->ip6_nxt);
84   printf("hop limit = %x\n", header->ip6_hlim);
85 
86   inet_ntop(AF_INET6, &header->ip6_src, addrstr, sizeof(addrstr));
87   printf("source = %s\n", addrstr);
88 
89   inet_ntop(AF_INET6, &header->ip6_dst, addrstr, sizeof(addrstr));
90   printf("dest = %s\n", addrstr);
91 }
92 
93 /* print icmp header */
dump_icmp(struct icmphdr * icmp)94 void dump_icmp(struct icmphdr *icmp) {
95   printf("ICMP\n");
96 
97   printf("icmp.type = %x ", icmp->type);
98   if (icmp->type == ICMP_ECHOREPLY) {
99     printf("echo reply");
100   } else if (icmp->type == ICMP_ECHO) {
101     printf("echo request");
102   } else {
103     printf("other");
104   }
105   printf("\n");
106   printf("icmp.code = %x\n", icmp->code);
107   printf("icmp.checksum = %x\n", ntohs(icmp->checksum));
108   if (icmp->type == ICMP_ECHOREPLY || icmp->type == ICMP_ECHO) {
109     printf("icmp.un.echo.id = %x\n", ntohs(icmp->un.echo.id));
110     printf("icmp.un.echo.sequence = %x\n", ntohs(icmp->un.echo.sequence));
111   }
112 }
113 
114 /* print icmp6 header */
dump_icmp6(struct icmp6_hdr * icmp6)115 void dump_icmp6(struct icmp6_hdr *icmp6) {
116   printf("ICMP6\n");
117   printf("type = %x", icmp6->icmp6_type);
118   if (icmp6->icmp6_type == ICMP6_ECHO_REQUEST) {
119     printf("(echo request)");
120   } else if (icmp6->icmp6_type == ICMP6_ECHO_REPLY) {
121     printf("(echo reply)");
122   }
123   printf("\n");
124   printf("code = %x\n", icmp6->icmp6_code);
125 
126   printf("checksum = %x\n", icmp6->icmp6_cksum);
127 
128   if ((icmp6->icmp6_type == ICMP6_ECHO_REQUEST) || (icmp6->icmp6_type == ICMP6_ECHO_REPLY)) {
129     printf("icmp6_id = %x\n", icmp6->icmp6_id);
130     printf("icmp6_seq = %x\n", icmp6->icmp6_seq);
131   }
132 }
133 
134 /* print udp header */
dump_udp_generic(const struct udphdr * udp,uint32_t temp_checksum,const uint8_t * payload,size_t payload_size)135 void dump_udp_generic(const struct udphdr *udp, uint32_t temp_checksum, const uint8_t *payload,
136                       size_t payload_size) {
137   uint16_t my_checksum;
138 
139   temp_checksum = ip_checksum_add(temp_checksum, udp, sizeof(struct udphdr));
140   temp_checksum = ip_checksum_add(temp_checksum, payload, payload_size);
141   my_checksum   = ip_checksum_finish(temp_checksum);
142 
143   printf("UDP\n");
144   printf("source = %x\n", ntohs(udp->source));
145   printf("dest = %x\n", ntohs(udp->dest));
146   printf("len = %x\n", ntohs(udp->len));
147   printf("check = %x (mine %x)\n", udp->check, my_checksum);
148 }
149 
150 /* print ipv4/udp header */
dump_udp(const struct udphdr * udp,const struct iphdr * ip,const uint8_t * payload,size_t payload_size)151 void dump_udp(const struct udphdr *udp, const struct iphdr *ip, const uint8_t *payload,
152               size_t payload_size) {
153   uint32_t temp_checksum;
154   temp_checksum = ipv4_pseudo_header_checksum(ip, sizeof(*udp) + payload_size);
155   dump_udp_generic(udp, temp_checksum, payload, payload_size);
156 }
157 
158 /* print ipv6/udp header */
dump_udp6(const struct udphdr * udp,const struct ip6_hdr * ip6,const uint8_t * payload,size_t payload_size)159 void dump_udp6(const struct udphdr *udp, const struct ip6_hdr *ip6, const uint8_t *payload,
160                size_t payload_size) {
161   uint32_t temp_checksum;
162   temp_checksum = ipv6_pseudo_header_checksum(ip6, sizeof(*udp) + payload_size, IPPROTO_UDP);
163   dump_udp_generic(udp, temp_checksum, payload, payload_size);
164 }
165 
166 /* print tcp header */
dump_tcp_generic(const struct tcphdr * tcp,const uint8_t * options,size_t options_size,uint32_t temp_checksum,const uint8_t * payload,size_t payload_size)167 void dump_tcp_generic(const struct tcphdr *tcp, const uint8_t *options, size_t options_size,
168                       uint32_t temp_checksum, const uint8_t *payload, size_t payload_size) {
169   uint16_t my_checksum;
170 
171   temp_checksum = ip_checksum_add(temp_checksum, tcp, sizeof(struct tcphdr));
172   if (options) {
173     temp_checksum = ip_checksum_add(temp_checksum, options, options_size);
174   }
175   temp_checksum = ip_checksum_add(temp_checksum, payload, payload_size);
176   my_checksum   = ip_checksum_finish(temp_checksum);
177 
178   printf("TCP\n");
179   printf("source = %x\n", ntohs(tcp->source));
180   printf("dest = %x\n", ntohs(tcp->dest));
181   printf("seq = %x\n", ntohl(tcp->seq));
182   printf("ack = %x\n", ntohl(tcp->ack_seq));
183   printf("d_off = %x\n", tcp->doff);
184   printf("res1 = %x\n", tcp->res1);
185 #ifdef __BIONIC__
186   printf("CWR = %x\n", tcp->cwr);
187   printf("ECE = %x\n", tcp->ece);
188 #else
189   printf("CWR/ECE = %x\n", tcp->res2);
190 #endif
191   printf("urg = %x  ack = %x  psh = %x  rst = %x  syn = %x  fin = %x\n", tcp->urg, tcp->ack,
192          tcp->psh, tcp->rst, tcp->syn, tcp->fin);
193   printf("window = %x\n", ntohs(tcp->window));
194   printf("check = %x [mine %x]\n", tcp->check, my_checksum);
195   printf("urgent = %x\n", tcp->urg_ptr);
196 
197   if (options) {
198     size_t i;
199 
200     printf("options: ");
201     for (i = 0; i < options_size; i++) {
202       printf("%x ", *(options + i));
203     }
204     printf("\n");
205   }
206 }
207 
208 /* print ipv4/tcp header */
dump_tcp(const struct tcphdr * tcp,const struct iphdr * ip,const uint8_t * payload,size_t payload_size,const uint8_t * options,size_t options_size)209 void dump_tcp(const struct tcphdr *tcp, const struct iphdr *ip, const uint8_t *payload,
210               size_t payload_size, const uint8_t *options, size_t options_size) {
211   uint32_t temp_checksum;
212 
213   temp_checksum = ipv4_pseudo_header_checksum(ip, sizeof(*tcp) + options_size + payload_size);
214   dump_tcp_generic(tcp, options, options_size, temp_checksum, payload, payload_size);
215 }
216 
217 /* print ipv6/tcp header */
dump_tcp6(const struct tcphdr * tcp,const struct ip6_hdr * ip6,const uint8_t * payload,size_t payload_size,const uint8_t * options,size_t options_size)218 void dump_tcp6(const struct tcphdr *tcp, const struct ip6_hdr *ip6, const uint8_t *payload,
219                size_t payload_size, const uint8_t *options, size_t options_size) {
220   uint32_t temp_checksum;
221 
222   temp_checksum =
223     ipv6_pseudo_header_checksum(ip6, sizeof(*tcp) + options_size + payload_size, IPPROTO_TCP);
224   dump_tcp_generic(tcp, options, options_size, temp_checksum, payload, payload_size);
225 }
226 
227 /* generic hex dump */
logcat_hexdump(const char * info,const uint8_t * data,size_t len)228 void logcat_hexdump(const char *info, const uint8_t *data, size_t len) {
229   char output[MAXDUMPLEN * 3 + 2];
230   size_t i;
231 
232   output[0] = '\0';
233   for (i = 0; i < len && i < MAXDUMPLEN; i++) {
234     snprintf(output + i * 3, 4, " %02x", data[i]);
235   }
236   output[len * 3 + 3] = '\0';
237 
238   logmsg(ANDROID_LOG_WARN, "info %s len %d data%s", info, len, output);
239 }
240 
dump_iovec(const struct iovec * iov,int iov_len)241 void dump_iovec(const struct iovec *iov, int iov_len) {
242   int i;
243   char *str;
244   for (i = 0; i < iov_len; i++) {
245     asprintf(&str, "iov[%d]: ", i);
246     logcat_hexdump(str, iov[i].iov_base, iov[i].iov_len);
247     free(str);
248   }
249 }
250 #endif  // CLAT_DEBUG
251