1 #include <rtthread.h>
2 #include <sys/socket.h>
3
4 #ifdef SAL_USING_POSIX
5 #include <sys/select.h> // only dfs_net
6 #include <dfs_posix.h>
7 #else
8 #define read lwip_read
9 #define write lwip_write
10 #endif /* SAL_USING_POSIX */
11
12 #include "netdb.h"
13
14 #define MAX_SERV 32 /* Maximum number of chargen services. Don't need too many */
15 #define CHARGEN_THREAD_NAME "chargen"
16 #if RT_THREAD_PRIORITY_MAX == 32
17 #define CHARGEN_PRIORITY 20 /* Really low priority */
18 #else
19 #define CHARGEN_PRIORITY 200 /* Really low priority */
20 #endif
21 #define CHARGEN_THREAD_STACKSIZE 1024
22 struct charcb
23 {
24 struct charcb *next;
25 int socket;
26 struct sockaddr_in cliaddr;
27 socklen_t clilen;
28 char nextchar;
29 };
30
31 static struct charcb *charcb_list = 0;
32 static int do_read(struct charcb *p_charcb);
33 static void close_chargen(struct charcb *p_charcb);
34 extern int select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, struct timeval *timeout);
35
36 /**************************************************************
37 * void chargen_thread(void *arg)
38 *
39 * chargen task. This server will wait for connections on well
40 * known TCP port number: 19. For every connection, the server will
41 * write as much data as possible to the tcp port.
42 **************************************************************/
chargen_thread(void * arg)43 static void chargen_thread(void *arg)
44 {
45 int listenfd;
46 struct sockaddr_in chargen_saddr;
47 fd_set readset;
48 fd_set writeset;
49 int i, maxfdp1;
50 struct charcb *p_charcb;
51
52 /* First acquire our socket for listening for connections */
53 listenfd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
54 LWIP_ASSERT("chargen_thread(): Socket create failed.", listenfd >= 0);
55 memset(&chargen_saddr, 0, sizeof(chargen_saddr));
56 chargen_saddr.sin_family = AF_INET;
57 chargen_saddr.sin_addr.s_addr = htonl(INADDR_ANY);
58 chargen_saddr.sin_port = htons(19); // Chargen server port
59
60 if (bind(listenfd, (struct sockaddr *) &chargen_saddr, sizeof(chargen_saddr)) == -1)
61 LWIP_ASSERT("chargen_thread(): Socket bind failed.", 0);
62
63 /* Put socket into listening mode */
64 if (listen(listenfd, MAX_SERV) == -1)
65 LWIP_ASSERT("chargen_thread(): Listen failed.", 0);
66
67
68 /* Wait forever for network input: This could be connections or data */
69 for (;;)
70 {
71 maxfdp1 = listenfd + 1;
72
73 /* Determine what sockets need to be in readset */
74 FD_ZERO(&readset);
75 FD_ZERO(&writeset);
76 FD_SET(listenfd, &readset);
77 for (p_charcb = charcb_list; p_charcb; p_charcb = p_charcb->next)
78 {
79 if (maxfdp1 < p_charcb->socket + 1)
80 maxfdp1 = p_charcb->socket + 1;
81 FD_SET(p_charcb->socket, &readset);
82 FD_SET(p_charcb->socket, &writeset);
83 }
84
85 /* Wait for data or a new connection */
86 i = select(maxfdp1, &readset, &writeset, 0, 0);
87
88 if (i == 0) continue;
89
90 /* At least one descriptor is ready */
91 if (FD_ISSET(listenfd, &readset))
92 {
93 /* We have a new connection request!!! */
94 /* Lets create a new control block */
95 p_charcb = (struct charcb *)rt_calloc(1, sizeof(struct charcb));
96 if (p_charcb)
97 {
98 p_charcb->socket = accept(listenfd,
99 (struct sockaddr *) &p_charcb->cliaddr,
100 &p_charcb->clilen);
101 if (p_charcb->socket < 0)
102 rt_free(p_charcb);
103 else
104 {
105 /* Keep this tecb in our list */
106 p_charcb->next = charcb_list;
107 charcb_list = p_charcb;
108 p_charcb->nextchar = 0x21;
109 }
110 }
111 else
112 {
113 /* No memory to accept connection. Just accept and then close */
114 int sock;
115 struct sockaddr cliaddr;
116 socklen_t clilen;
117
118 sock = accept(listenfd, &cliaddr, &clilen);
119 if (sock >= 0)
120 closesocket(sock);
121 }
122 }
123
124 /* Go through list of connected clients and process data */
125 for (p_charcb = charcb_list; p_charcb; p_charcb = p_charcb->next)
126 {
127 if (FD_ISSET(p_charcb->socket, &readset))
128 {
129 /* This socket is ready for reading. This could be because someone typed
130 * some characters or it could be because the socket is now closed. Try reading
131 * some data to see. */
132 if (do_read(p_charcb) < 0)
133 break;
134 }
135
136 if (FD_ISSET(p_charcb->socket, &writeset))
137 {
138 char line[80];
139 char setchar = p_charcb->nextchar;
140
141 for (i = 0; i < 59; i++)
142 {
143 line[i] = setchar;
144 if (++setchar == 0x7f)
145 setchar = 0x21;
146 }
147
148 line[i] = 0;
149 strcat(line, "\n\r");
150 if (write(p_charcb->socket, line, strlen(line)) < 0)
151 {
152 close_chargen(p_charcb);
153 break;
154 }
155
156 if (++p_charcb->nextchar == 0x7f)
157 p_charcb->nextchar = 0x21;
158 }
159 }
160 }
161 }
162
163 /**************************************************************
164 * void close_chargen(struct charcb *p_charcb)
165 *
166 * Close the socket and remove this charcb from the list.
167 **************************************************************/
close_chargen(struct charcb * p_charcb)168 static void close_chargen(struct charcb *p_charcb)
169 {
170 struct charcb *p_search_charcb;
171
172 /* Either an error or tcp connection closed on other
173 * end. Close here */
174 closesocket(p_charcb->socket);
175
176 /* Free charcb */
177 if (charcb_list == p_charcb)
178 charcb_list = p_charcb->next;
179 else
180 for (p_search_charcb = charcb_list; p_search_charcb; p_search_charcb = p_search_charcb->next)
181 {
182 if (p_search_charcb->next == p_charcb)
183 {
184 p_search_charcb->next = p_charcb->next;
185 break;
186 }
187 }
188
189 rt_free(p_charcb);
190 }
191
192 /**************************************************************
193 * void do_read(struct charcb *p_charcb)
194 *
195 * Socket definitely is ready for reading. Read a buffer from the socket and
196 * discard the data. If no data is read, then the socket is closed and the
197 * charcb is removed from the list and freed.
198 **************************************************************/
do_read(struct charcb * p_charcb)199 static int do_read(struct charcb *p_charcb)
200 {
201 char buffer[80];
202 int readcount;
203
204 /* Read some data */
205 readcount = read(p_charcb->socket, &buffer, 80);
206 if (readcount <= 0)
207 {
208 close_chargen(p_charcb);
209 return -1;
210 }
211 return 0;
212 }
213
chargen_init(void)214 void chargen_init(void)
215 {
216 rt_thread_t chargen;
217
218 chargen = rt_thread_create(CHARGEN_THREAD_NAME,
219 chargen_thread, RT_NULL,
220 CHARGEN_THREAD_STACKSIZE,
221 CHARGEN_PRIORITY, 5);
222 if (chargen != RT_NULL) rt_thread_startup(chargen);
223 }
224 #ifdef RT_USING_FINSH
225 #include <finsh.h>
chargen()226 void chargen()
227 {
228 chargen_init();
229 }
230 FINSH_FUNCTION_EXPORT(chargen, start chargen server);
231 #endif
232