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Commit | Line | Data |
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d9a17c07 | 1 | /* Byte Stream Connection Server Example |
688903eb | 2 | Copyright (C) 1991-2018 Free Software Foundation, Inc. |
d9a17c07 RM |
3 | |
4 | This program is free software; you can redistribute it and/or | |
5 | modify it under the terms of the GNU General Public License | |
6 | as published by the Free Software Foundation; either version 2 | |
7 | of the License, or (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, if not, see <http://www.gnu.org/licenses/>. | |
16 | */ | |
17 | ||
28f540f4 RM |
18 | #include <stdio.h> |
19 | #include <errno.h> | |
20 | #include <stdlib.h> | |
21 | #include <unistd.h> | |
22 | #include <sys/types.h> | |
23 | #include <sys/socket.h> | |
24 | #include <netinet/in.h> | |
25 | #include <netdb.h> | |
26 | ||
27 | #define PORT 5555 | |
28 | #define MAXMSG 512 | |
29 | ||
30 | int | |
31 | read_from_client (int filedes) | |
32 | { | |
33 | char buffer[MAXMSG]; | |
34 | int nbytes; | |
35 | ||
36 | nbytes = read (filedes, buffer, MAXMSG); | |
37 | if (nbytes < 0) | |
38 | { | |
39 | /* Read error. */ | |
40 | perror ("read"); | |
41 | exit (EXIT_FAILURE); | |
42 | } | |
43 | else if (nbytes == 0) | |
44 | /* End-of-file. */ | |
45 | return -1; | |
46 | else | |
47 | { | |
48 | /* Data read. */ | |
49 | fprintf (stderr, "Server: got message: `%s'\n", buffer); | |
50 | return 0; | |
51 | } | |
52 | } | |
53 | ||
54 | int | |
55 | main (void) | |
56 | { | |
001426b8 | 57 | extern int make_socket (uint16_t port); |
28f540f4 RM |
58 | int sock; |
59 | fd_set active_fd_set, read_fd_set; | |
60 | int i; | |
61 | struct sockaddr_in clientname; | |
62 | size_t size; | |
63 | ||
64 | /* Create the socket and set it up to accept connections. */ | |
65 | sock = make_socket (PORT); | |
66 | if (listen (sock, 1) < 0) | |
67 | { | |
68 | perror ("listen"); | |
69 | exit (EXIT_FAILURE); | |
70 | } | |
71 | ||
72 | /* Initialize the set of active sockets. */ | |
73 | FD_ZERO (&active_fd_set); | |
74 | FD_SET (sock, &active_fd_set); | |
75 | ||
76 | while (1) | |
77 | { | |
78 | /* Block until input arrives on one or more active sockets. */ | |
79 | read_fd_set = active_fd_set; | |
80 | if (select (FD_SETSIZE, &read_fd_set, NULL, NULL, NULL) < 0) | |
81 | { | |
82 | perror ("select"); | |
83 | exit (EXIT_FAILURE); | |
84 | } | |
85 | ||
86 | /* Service all the sockets with input pending. */ | |
87 | for (i = 0; i < FD_SETSIZE; ++i) | |
88 | if (FD_ISSET (i, &read_fd_set)) | |
89 | { | |
90 | if (i == sock) | |
91 | { | |
92 | /* Connection request on original socket. */ | |
93 | int new; | |
94 | size = sizeof (clientname); | |
95 | new = accept (sock, | |
96 | (struct sockaddr *) &clientname, | |
97 | &size); | |
98 | if (new < 0) | |
99 | { | |
100 | perror ("accept"); | |
101 | exit (EXIT_FAILURE); | |
102 | } | |
103 | fprintf (stderr, | |
104 | "Server: connect from host %s, port %hd.\n", | |
105 | inet_ntoa (clientname.sin_addr), | |
106 | ntohs (clientname.sin_port)); | |
107 | FD_SET (new, &active_fd_set); | |
108 | } | |
109 | else | |
110 | { | |
111 | /* Data arriving on an already-connected socket. */ | |
112 | if (read_from_client (i) < 0) | |
113 | { | |
114 | close (i); | |
115 | FD_CLR (i, &active_fd_set); | |
116 | } | |
117 | } | |
118 | } | |
119 | } | |
120 | } |