source: libcaca/trunk/src/cacaserver.c @ 721

Last change on this file since 721 was 721, checked in by Sam Hocevar, 14 years ago
  • Sanity check in cacaserver.c.
  • Property svn:keywords set to Id
File size: 13.6 KB
Line 
1/*
2 *  cacaserver    Colour ASCII-Art library
3 *  Copyright (c) 2006 Jean-Yves Lamoureux <jylam@lnxscene.org>
4 *                2006 Sam Hocevar <sam@zoy.org>
5 *                All Rights Reserved
6 *
7 *  This program is free software; you can redistribute it and/or
8 *  modify it under the terms of the Do What The Fuck You Want To
9 *  Public License, Version 2, as published by Sam Hocevar. See
10 *  http://sam.zoy.org/wtfpl/COPYING for more details.
11 */
12
13#include "config.h"
14
15#include <stdio.h>
16#include <string.h>
17#include <stdlib.h>
18#include <sys/types.h>
19#include <sys/socket.h>
20#include <arpa/inet.h>
21#include <fcntl.h>
22#include <signal.h>
23#include <errno.h>
24
25#include "cucul.h"
26#include "caca.h"
27
28#include "config.h"
29
30#if defined(HAVE_UNISTD_H)
31#   include <unistd.h>
32#endif
33
34#include <stdarg.h>
35
36#include "caca.h"
37#include "cucul.h"
38
39#define BACKLOG 1337     /* Number of pending connections */
40#define INBUFFER 32      /* Size of per-client input buffer */
41#define OUTBUFFER 300000 /* Size of per-client output buffer */
42
43/* Following vars are static */
44#define INIT_PREFIX \
45    "\xff\xfb\x01"     /* WILL ECHO */ \
46    "\xff\xfb\x03"     /* WILL SUPPRESS GO AHEAD */ \
47    "\xff\xfd\x31"     /* DO NAWS */ \
48    "\xff\x1f\xfa____" /* SB NAWS */ \
49    "\xff\xf0"         /* SE */  \
50    "\x1b]2;caca for the network\x07" /* Change window title */ \
51    "\x1b[H\x1b[J" /* Clear screen */
52    /*"\x1b[?25l"*/ /* Hide cursor */
53
54#define ANSI_PREFIX \
55    "\x1b[1;1H" /* move(0,0) */ \
56    "\x1b[1;1H" /* move(0,0) again */
57
58#define ANSI_RESET \
59    "    " /* Garbage */ \
60    "\x1b[?1049h" /* Clear screen */ \
61    "\x1b[?1049h" /* Clear screen again */
62
63static char const telnet_commands[16][5] =
64{
65    "SE  ", "NOP ", "DM  ", "BRK ", "IP  ", "AO  ", "AYT ", "EC  ",
66    "EL  ", "GA  ", "SB  ", "WILL", "WONT", "DO  ", "DONT", "IAC "
67};
68
69static char const telnet_options[37][5] =
70{
71    "????", "ECHO", "????", "SUGH", "????", "STTS", "TIMK", "????",
72    "????", "????", "????", "????", "????", "????", "????", "????",
73    "????", "????", "????", "????", "????", "????", "????", "????",
74    "TTYP", "????", "????", "????", "????", "????", "????", "NAWS",
75    "TRSP", "RMFC", "LIMO", "????", "EVAR"
76};
77
78#define COMMAND_NAME(x) (x>=240)?telnet_commands[x-240]:"????"
79#define OPTION_NAME(x) (x<=36)?telnet_options[x]:"????"
80
81struct client
82{
83    int fd;
84    int ready;
85    uint8_t inbuf[INBUFFER];
86    int inbytes;
87    uint8_t outbuf[OUTBUFFER];
88    int start, stop;
89};
90
91struct server
92{
93    unsigned int width, height;
94    unsigned int port;
95    int sockfd;
96    struct sockaddr_in my_addr;
97    socklen_t sin_size;
98
99    /* Input buffer */
100    uint8_t *input;
101    unsigned int read;
102
103    char prefix[sizeof(INIT_PREFIX)];
104
105    cucul_t *qq;
106    struct cucul_export *ex;
107
108    int client_count;
109    struct client *clients;
110
111    RETSIGTYPE (*sigpipe_handler)(int);
112};
113
114static void manage_connections(struct server *server);
115static int send_data(struct server *server, struct client *c);
116ssize_t nonblock_write(int fd, void *buf, size_t len);
117
118int main(void)
119{
120    int i, yes = 1, flags;
121    struct server *server;
122    char *tmp;
123
124#ifdef HAVE_WINDOWS_H
125        WORD winsockVersion;
126        WSADATA wsaData;
127        winsockVersion = MAKEWORD(1, 1);
128
129        WSAStartup(winsockVersion, &wsaData);
130#endif
131    server = malloc(sizeof(struct server));
132
133    server->input = malloc(12);
134    server->read = 0;
135
136    server->client_count = 0;
137    server->clients = NULL;
138    server->port = 0xCACA; /* 51914 */
139
140    /* FIXME, handle >255 sizes */
141    memcpy(server->prefix, INIT_PREFIX, sizeof(INIT_PREFIX));
142    tmp = strstr(server->prefix, "____");
143    tmp[0] = (unsigned char) (server->width & 0xff00) >> 8;
144    tmp[1] = (unsigned char) server->width & 0xff;
145    tmp[2] = (unsigned char) (server->height & 0xff00) >> 8;
146    tmp[3] = (unsigned char) server->height & 0xff;
147
148    if((server->sockfd = socket(PF_INET, SOCK_STREAM, 0)) == -1)
149    {
150        perror("socket");
151        return -1;
152    }
153
154    if(setsockopt(server->sockfd, SOL_SOCKET,
155                  SO_REUSEADDR, &yes, sizeof(int)) == -1)
156    {
157        perror("setsockopt SO_REUSEADDR");
158        return -1;
159    }
160
161    server->my_addr.sin_family = AF_INET;
162    server-> my_addr.sin_port = htons(server->port);
163    server->my_addr.sin_addr.s_addr = INADDR_ANY;
164    memset(&(server->my_addr.sin_zero), '\0', 8);
165
166    if(bind(server->sockfd, (struct sockaddr *)&server->my_addr,
167             sizeof(struct sockaddr)) == -1)
168    {
169        perror("bind");
170        return -1;
171    }
172
173    /* Non blocking socket */
174    flags = fcntl(server->sockfd, F_GETFL, 0);
175    fcntl(server->sockfd, F_SETFL, flags | O_NONBLOCK);
176
177    if(listen(server->sockfd, BACKLOG) == -1)
178    {
179        perror("listen");
180        return -1;
181    }
182
183    server->qq = NULL;
184    server->ex = NULL;
185
186    /* Ignore SIGPIPE */
187    server->sigpipe_handler = signal(SIGPIPE, SIG_IGN);
188
189    fprintf(stderr, "initialised network, listening on port %i\n",
190                    server->port);
191
192    /* Main loop */
193    for(;;)
194    {
195        uint8_t *buf = server->input;
196        uint32_t width, height;
197        unsigned int size;
198
199        /* Manage new connections as this function will be called sometimes
200         * more often than display */
201        manage_connections(server);
202
203        /* Read data from stdin */
204        read(0, buf, 12);
205
206        while(buf[0] != 'C' && buf[1] != 'A' && buf[2] != 'C' && buf[3] != 'A')
207        {
208            memmove(buf, buf + 1, 11);
209            read(0, buf + 11, 1);
210        }
211
212        width = ((uint32_t)buf[4] << 24) | ((uint32_t)buf[5] << 16)
213              | ((uint32_t)buf[6] << 8) | (uint32_t)buf[7];
214        height = ((uint32_t)buf[8] << 24) | ((uint32_t)buf[9] << 16)
215               | ((uint32_t)buf[10] << 8) | (uint32_t)buf[11];
216
217        size = 12 + width * height * 5 + 4;
218        buf = server->input = realloc(server->input, size);
219        read(0, buf + 12, size - 12);
220
221        /* Free the previous canvas, if any */
222        if(server->qq)
223            cucul_free(server->qq);
224
225        server->qq = cucul_load(buf, size);
226
227        if(!server->qq)
228            continue; /* Load error */
229
230        /* Free the previous export buffer, if any */
231        if(server->ex)
232        {
233            cucul_free_export(server->ex);
234            server->ex = NULL;
235        }
236
237        /* Get ANSI representation of the image and skip the end-of buffer
238         * linefeed ("\r\n\0", 3 bytes) */
239        server->ex = cucul_create_export(server->qq, "ansi");
240        server->ex->size -= 3;
241
242        for(i = 0; i < server->client_count; i++)
243        {
244            if(server->clients[i].fd == -1)
245                continue;
246
247            if(send_data(server, &server->clients[i]))
248            {
249                fprintf(stderr, "client %i dropped connection\n",
250                                server->clients[i].fd);
251                close(server->clients[i].fd);
252                server->clients[i].fd = -1;
253            }
254        }
255    }
256
257    /* Kill all remaining clients */
258    for(i = 0; i < server->client_count; i++)
259    {
260        if(server->clients[i].fd == -1)
261            continue;
262
263        close(server->clients[i].fd);
264        server->clients[i].fd = -1;
265    }
266
267    if(server->ex)
268        cucul_free_export(server->ex);
269
270    /* Restore SIGPIPE handler */
271    signal(SIGPIPE, server->sigpipe_handler);
272
273    free(server);
274
275#ifdef HAVE_WINDOWS_H
276    WSACleanup();
277#endif
278    return 0;
279}
280
281/*
282 * XXX: The following functions are local
283 */
284
285static void manage_connections(struct server *server)
286{
287    int fd, flags;
288    struct sockaddr_in remote_addr;
289    socklen_t len = sizeof(struct sockaddr_in);
290
291    fd = accept(server->sockfd, (struct sockaddr *)&remote_addr, &len);
292    if(fd == -1)
293        return;
294
295    fprintf(stderr, "client %i connected from %s\n",
296                    fd, inet_ntoa(remote_addr.sin_addr));
297
298    /* Non blocking socket */
299    flags = fcntl(fd, F_SETFL, 0);
300    fcntl(fd, F_SETFL, flags | O_NONBLOCK);
301
302    if(server->clients == NULL)
303    {
304        server->clients = malloc(sizeof(struct client));
305        if(server->clients == NULL)
306            return;
307    }
308    else
309    {
310        server->clients = realloc(server->clients,
311                            (server->client_count+1) * sizeof(struct client));
312    }
313
314    server->clients[server->client_count].fd = fd;
315    server->clients[server->client_count].ready = 0;
316    server->clients[server->client_count].inbytes = 0;
317    server->clients[server->client_count].start = 0;
318    server->clients[server->client_count].stop = 0;
319
320    /* If we already have data to send, send it to the new client */
321    if(send_data(server, &server->clients[server->client_count]))
322    {
323        fprintf(stderr, "client %i dropped connection\n", fd);
324        close(fd);
325        server->clients[server->client_count].fd = -1;
326        return;
327    }
328
329    server->client_count++;
330}
331
332static int send_data(struct server *server, struct client *c)
333{
334    ssize_t ret;
335
336    /* Not for us */
337    if(c->fd < 0)
338        return -1;
339
340    /* Listen to incoming data */
341    for(;;)
342    {
343        ret = read(c->fd, c->inbuf + c->inbytes, 1);
344        if(ret <= 0)
345            break;
346
347        c->inbytes++;
348
349        /* Check for telnet sequences */
350        if(c->inbuf[0] == 0xff)
351        {
352            if(c->inbytes == 1)
353            {
354                ;
355            }
356            else if(c->inbuf[1] == 0xfd || c->inbuf[1] == 0xfc)
357            {
358                if(c->inbytes == 3)
359                {
360                    fprintf(stderr, "client %i said: %.02x %.02x %.02x (%s %s %s)\n",
361                            c->fd, c->inbuf[0], c->inbuf[1], c->inbuf[2],
362                            COMMAND_NAME(c->inbuf[0]), COMMAND_NAME(c->inbuf[1]), OPTION_NAME(c->inbuf[2]));
363                    /* Just ignore, lol */
364                    c->inbytes = 0;
365                }
366            }
367            else
368                c->inbytes = 0;
369        }
370        else if(c->inbytes == 1)
371        {
372            if(c->inbuf[0] == 0x03)
373            {
374                fprintf(stderr, "client %i pressed C-c\n", c->fd);
375                return -1; /* User requested to quit */
376            }
377
378            c->inbytes = 0;
379        }
380    }
381
382    /* Send the telnet initialisation commands */
383    if(!c->ready)
384    {
385        ret = nonblock_write(c->fd, server->prefix, sizeof(INIT_PREFIX));
386        if(ret == -1)
387            return (errno == EAGAIN) ? 0 : -1;
388
389        if(ret < (ssize_t)sizeof(INIT_PREFIX))
390            return 0;
391
392        c->ready = 1;
393    }
394
395    /* No error, there's just nothing to send yet */
396    if(!server->ex)
397        return 0;
398
399    /* If we have backlog, send the backlog */
400    if(c->stop)
401    {
402        ret = nonblock_write(c->fd, c->outbuf + c->start, c->stop - c->start);
403
404        if(ret == -1)
405        {
406            if(errno == EAGAIN)
407                ret = 0;
408            else
409                return -1;
410        }
411
412        if(ret == c->stop - c->start)
413        {
414            /* We got rid of the backlog! */
415            c->start = c->stop = 0;
416        }
417        else
418        {
419            c->start += ret;
420
421            if(c->stop - c->start + strlen(ANSI_PREFIX) + server->ex->size
422                > OUTBUFFER)
423            {
424                /* Overflow! Empty buffer and start again */
425                memcpy(c->outbuf, ANSI_RESET, strlen(ANSI_RESET));
426                c->start = 0;
427                c->stop = strlen(ANSI_RESET);
428                return 0;
429            }
430
431            /* Need to move? */
432            if(c->stop + strlen(ANSI_PREFIX) + server->ex->size > OUTBUFFER)
433            {
434                memmove(c->outbuf, c->outbuf + c->start, c->stop - c->start);
435                c->stop -= c->start;
436                c->start = 0;
437            }
438
439            memcpy(c->outbuf + c->stop, ANSI_PREFIX, strlen(ANSI_PREFIX));
440            c->stop += strlen(ANSI_PREFIX);
441            memcpy(c->outbuf + c->stop, server->ex->buffer, server->ex->size);
442            c->stop += server->ex->size;
443
444            return 0;
445        }
446    }
447
448    /* We no longer have backlog, send our new data */
449
450    /* Send ANSI prefix */
451    ret = nonblock_write(c->fd, ANSI_PREFIX, strlen(ANSI_PREFIX));
452    if(ret == -1)
453    {
454        if(errno == EAGAIN)
455            ret = 0;
456        else
457            return -1;
458    }
459
460    if(ret < (ssize_t)strlen(ANSI_PREFIX))
461    {
462        if(strlen(ANSI_PREFIX) + server->ex->size > OUTBUFFER)
463        {
464            /* Overflow! Empty buffer and start again */
465            memcpy(c->outbuf, ANSI_RESET, strlen(ANSI_RESET));
466            c->start = 0;
467            c->stop = strlen(ANSI_RESET);
468            return 0;
469        }
470
471        memcpy(c->outbuf, ANSI_PREFIX, strlen(ANSI_PREFIX) - ret);
472        c->stop = strlen(ANSI_PREFIX) - ret;
473        memcpy(c->outbuf + c->stop, server->ex->buffer, server->ex->size);
474        c->stop += server->ex->size;
475
476        return 0;
477    }
478
479    /* Send actual data */
480    ret = nonblock_write(c->fd, server->ex->buffer, server->ex->size);
481    if(ret == -1)
482    {
483        if(errno == EAGAIN)
484            ret = 0;
485        else
486            return -1;
487    }
488
489    if(ret < (int)server->ex->size)
490    {
491        if(server->ex->size > OUTBUFFER)
492        {
493            /* Overflow! Empty buffer and start again */
494            memcpy(c->outbuf, ANSI_RESET, strlen(ANSI_RESET));
495            c->start = 0;
496            c->stop = strlen(ANSI_RESET);
497            return 0;
498        }
499
500        memcpy(c->outbuf, server->ex->buffer, server->ex->size - ret);
501        c->stop = server->ex->size - ret;
502
503        return 0;
504    }
505
506    return 0;
507}
508
509ssize_t nonblock_write(int fd, void *buf, size_t len)
510{
511    size_t total = 0;
512    ssize_t ret;
513
514    while(total < len)
515    {
516        do
517        {
518            ret = write(fd, buf, len);
519        }
520        while(ret < 0 && errno == EINTR);
521
522        if(ret < 0)
523            return ret;
524        else if(ret == 0)
525            return total;
526
527        total += len;
528        buf = (void *)((uintptr_t)buf + len);
529    }
530
531    return total;
532}
533
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