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-rw-r--r--examples/cacaserver.c564
1 files changed, 564 insertions, 0 deletions
diff --git a/examples/cacaserver.c b/examples/cacaserver.c
new file mode 100644
index 0000000..825c3d4
--- /dev/null
+++ b/examples/cacaserver.c
@@ -0,0 +1,564 @@
+/*
+ * cacaserver Colour ASCII-Art library
+ * Copyright (c) 2006 Jean-Yves Lamoureux <jylam@lnxscene.org>
+ * 2006-2014 Sam Hocevar <sam@hocevar.net>
+ * All Rights Reserved
+ *
+ * This program is free software. It comes without any warranty, to
+ * the extent permitted by applicable law. You can redistribute it
+ * and/or modify it under the terms of the Do What the Fuck You Want
+ * to Public License, Version 2, as published by Sam Hocevar. See
+ * http://www.wtfpl.net/ for more details.
+ */
+
+#include "config.h"
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#if defined(HAVE_ARPA_INET_H)
+# include <arpa/inet.h>
+#elif defined(HAVE_WINSOCK2_H)
+# include <winsock2.h>
+# include <ws2tcpip.h>
+# define USE_WINSOCK 1
+#endif
+#if defined(HAVE_NETINET_IN_H)
+# include <netinet/in.h>
+#endif
+#if defined(HAVE_UNISTD_H)
+# include <unistd.h>
+#endif
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <errno.h>
+#include <stdarg.h>
+
+#ifndef USE_WINSOCK
+# define USE_WINSOCK 0
+#endif
+
+#include "caca.h"
+
+#define BACKLOG 1337 /* Number of pending connections */
+#define INBUFFER 32 /* Size of per-client input buffer */
+#define OUTBUFFER 300000 /* Size of per-client output buffer */
+
+/* Following vars are static */
+#define INIT_PREFIX \
+ "\xff\xfb\x01" /* WILL ECHO */ \
+ "\xff\xfb\x03" /* WILL SUPPRESS GO AHEAD */ \
+ "\xff\xfd\x31" /* DO NAWS */ \
+ "\xff\x1f\xfa____" /* SB NAWS */ \
+ "\xff\xf0" /* SE */ \
+ "\033]2;caca for the network\x07" /* Change window title */ \
+ "\033[H\033[J" /* Clear screen */
+ /*"\033[?25l"*/ /* Hide cursor */
+
+#define ANSI_PREFIX \
+ "\033[1;1H" /* move(0,0) */ \
+ "\033[1;1H" /* move(0,0) again */
+
+#define ANSI_RESET \
+ " " /* Garbage */ \
+ "\033[?1049h" /* Clear screen */ \
+ "\033[?1049h" /* Clear screen again */
+
+static char const telnet_commands[16][5] =
+{
+ "SE ", "NOP ", "DM ", "BRK ", "IP ", "AO ", "AYT ", "EC ",
+ "EL ", "GA ", "SB ", "WILL", "WONT", "DO ", "DONT", "IAC "
+};
+
+static char const telnet_options[37][5] =
+{
+ "????", "ECHO", "????", "SUGH", "????", "STTS", "TIMK", "????",
+ "????", "????", "????", "????", "????", "????", "????", "????",
+ "????", "????", "????", "????", "????", "????", "????", "????",
+ "TTYP", "????", "????", "????", "????", "????", "????", "NAWS",
+ "TRSP", "RMFC", "LIMO", "????", "EVAR"
+};
+
+#define COMMAND_NAME(x) (x>=240)?telnet_commands[x-240]:"????"
+#define OPTION_NAME(x) (x<=36)?telnet_options[x]:"????"
+
+struct client
+{
+ int fd;
+ int ready;
+ uint8_t inbuf[INBUFFER];
+ int inbytes;
+ uint8_t outbuf[OUTBUFFER];
+ int start, stop;
+};
+
+struct server
+{
+ unsigned int width, height;
+ unsigned int port;
+ int sockfd;
+ struct sockaddr_in my_addr;
+ socklen_t sin_size;
+
+ /* Input buffer */
+ uint8_t *input;
+ unsigned int read;
+
+ char prefix[sizeof(INIT_PREFIX)];
+
+ caca_canvas_t *canvas;
+ void *buffer;
+ size_t buflen;
+
+ int client_count;
+ struct client *clients;
+
+ RETSIGTYPE (*sigpipe_handler)(int);
+};
+
+static void manage_connections(struct server *server);
+static int send_data(struct server *server, struct client *c);
+ssize_t nonblock_write(int fd, void *buf, size_t len);
+
+int main(void)
+{
+ int i, yes = 1, flags;
+ struct server *server;
+ char *tmp;
+
+#if USE_WINSOCK
+ WORD winsockVersion;
+ WSADATA wsaData;
+ winsockVersion = MAKEWORD(1, 1);
+
+ WSAStartup(winsockVersion, &wsaData);
+#endif
+ server = malloc(sizeof(struct server));
+
+ server->input = malloc(12);
+ server->read = 0;
+
+ server->client_count = 0;
+ server->clients = NULL;
+ server->port = 0xCACA; /* 51914 */
+
+ /* FIXME, handle >255 sizes */
+ memcpy(server->prefix, INIT_PREFIX, sizeof(INIT_PREFIX));
+ tmp = strstr(server->prefix, "____");
+ tmp[0] = (uint8_t) (server->width & 0xff00) >> 8;
+ tmp[1] = (uint8_t) server->width & 0xff;
+ tmp[2] = (uint8_t) (server->height & 0xff00) >> 8;
+ tmp[3] = (uint8_t) server->height & 0xff;
+
+ if((server->sockfd = socket(PF_INET, SOCK_STREAM, 0)) == -1)
+ {
+ perror("socket");
+ return -1;
+ }
+
+ if(setsockopt(server->sockfd, SOL_SOCKET,
+ SO_REUSEADDR, &yes, sizeof(int)) == -1)
+ {
+ perror("setsockopt SO_REUSEADDR");
+ return -1;
+ }
+
+ server->my_addr.sin_family = AF_INET;
+ server-> my_addr.sin_port = htons(server->port);
+ server->my_addr.sin_addr.s_addr = INADDR_ANY;
+ memset(&(server->my_addr.sin_zero), '\0', 8);
+
+ if(bind(server->sockfd, (struct sockaddr *)&server->my_addr,
+ sizeof(struct sockaddr)) == -1)
+ {
+ perror("bind");
+ return -1;
+ }
+
+ /* Non blocking socket */
+ flags = fcntl(server->sockfd, F_GETFL, 0);
+ fcntl(server->sockfd, F_SETFL, flags | O_NONBLOCK);
+
+ if(listen(server->sockfd, BACKLOG) == -1)
+ {
+ perror("listen");
+ return -1;
+ }
+
+ server->canvas = caca_create_canvas(0, 0);
+ server->buffer = NULL;
+
+ /* Ignore SIGPIPE */
+ server->sigpipe_handler = signal(SIGPIPE, SIG_IGN);
+
+ fprintf(stderr, "initialised network, listening on port %i\n",
+ server->port);
+
+ /* Main loop */
+ for(;;)
+ {
+restart:
+ /* Manage new connections as this function will be called sometimes
+ * more often than display */
+ manage_connections(server);
+
+ /* Read data from stdin */
+ if(server->read < 12)
+ {
+ read(0, server->input + server->read, 12 - server->read);
+ server->read = 12;
+ }
+
+ while(caca_import_canvas_from_memory(server->canvas, server->input,
+ server->read, "caca") < 0)
+ {
+ memmove(server->input, server->input + 1, server->read - 1);
+ read(0, server->input + server->read - 1, 1);
+ }
+
+ for(;;)
+ {
+ ssize_t needed, wanted;
+
+ needed = caca_import_canvas_from_memory(server->canvas,
+ server->input,
+ server->read, "caca");
+ if(needed < 0)
+ goto restart;
+
+ if(needed > 0)
+ {
+ server->read -= needed;
+ memmove(server->input, server->input + needed, server->read);
+ break;
+ }
+
+ server->input = realloc(server->input, server->read + 128);
+ wanted = read(0, server->input + server->read, 128);
+ if(wanted < 0)
+ goto restart;
+ server->read += wanted;
+ }
+
+ /* Free the previous export buffer, if any */
+ if(server->buffer)
+ {
+ free(server->buffer);
+ server->buffer = NULL;
+ }
+
+ /* Get ANSI representation of the image and skip the end-of buffer
+ * linefeed ("\r\n", 2 byte) */
+ server->buffer = caca_export_canvas_to_memory(server->canvas, "utf8cr",
+ &server->buflen);
+ server->buflen -= 2;
+
+ for(i = 0; i < server->client_count; i++)
+ {
+ if(server->clients[i].fd == -1)
+ continue;
+
+ if(send_data(server, &server->clients[i]))
+ {
+ fprintf(stderr, "[%i] dropped connection\n",
+ server->clients[i].fd);
+ close(server->clients[i].fd);
+ server->clients[i].fd = -1;
+ }
+ }
+ }
+
+ /* Kill all remaining clients */
+ for(i = 0; i < server->client_count; i++)
+ {
+ if(server->clients[i].fd == -1)
+ continue;
+
+ close(server->clients[i].fd);
+ server->clients[i].fd = -1;
+ }
+
+ if(server->buffer)
+ free(server->buffer);
+
+ caca_free_canvas(server->canvas);
+
+ /* Restore SIGPIPE handler */
+ signal(SIGPIPE, server->sigpipe_handler);
+
+ free(server);
+
+#if USE_WINSOCK
+ WSACleanup();
+#endif
+ return 0;
+}
+
+/*
+ * XXX: The following functions are local
+ */
+
+static void manage_connections(struct server *server)
+{
+ int fd, flags;
+ struct sockaddr_in remote_addr;
+ socklen_t len = sizeof(struct sockaddr_in);
+
+ fd = accept(server->sockfd, (struct sockaddr *)&remote_addr, &len);
+ if(fd == -1)
+ return;
+
+ fprintf(stderr, "[%i] connected from %s\n",
+ fd, inet_ntoa(remote_addr.sin_addr));
+
+ /* Non blocking socket */
+ flags = fcntl(fd, F_SETFL, 0);
+ fcntl(fd, F_SETFL, flags | O_NONBLOCK);
+
+ if(server->clients == NULL)
+ {
+ server->clients = malloc(sizeof(struct client));
+ if(server->clients == NULL)
+ {
+ close(fd);
+ return;
+ }
+ }
+ else
+ {
+ server->clients = realloc(server->clients,
+ (server->client_count+1) * sizeof(struct client));
+ }
+
+ server->clients[server->client_count].fd = fd;
+ server->clients[server->client_count].ready = 0;
+ server->clients[server->client_count].inbytes = 0;
+ server->clients[server->client_count].start = 0;
+ server->clients[server->client_count].stop = 0;
+
+ /* If we already have data to send, send it to the new client */
+ if(send_data(server, &server->clients[server->client_count]))
+ {
+ fprintf(stderr, "[%i] dropped connection\n", fd);
+ close(fd);
+ server->clients[server->client_count].fd = -1;
+ return;
+ }
+
+ server->client_count++;
+}
+
+static int send_data(struct server *server, struct client *c)
+{
+ ssize_t ret;
+
+ /* Not for us */
+ if(c->fd < 0)
+ return -1;
+
+ /* Listen to incoming data */
+ for(;;)
+ {
+ ret = read(c->fd, c->inbuf + c->inbytes, 1);
+ if(ret <= 0)
+ break;
+
+ c->inbytes++;
+
+ /* Check for telnet sequences */
+ if(c->inbuf[0] == 0xff)
+ {
+ if(c->inbytes == 1)
+ {
+ ;
+ }
+ else if(c->inbuf[1] == 0xfd || c->inbuf[1] == 0xfc)
+ {
+ if(c->inbytes == 3)
+ {
+ fprintf(stderr, "[%i] said: %.02x %.02x %.02x (%s %s %s)\n",
+ c->fd, c->inbuf[0], c->inbuf[1], c->inbuf[2],
+ COMMAND_NAME(c->inbuf[0]), COMMAND_NAME(c->inbuf[1]), OPTION_NAME(c->inbuf[2]));
+ /* Just ignore, lol */
+ c->inbytes = 0;
+ }
+ }
+ else
+ c->inbytes = 0;
+ }
+ else if(c->inbytes == 1)
+ {
+ if(c->inbuf[0] == 0x03)
+ {
+ fprintf(stderr, "[%i] pressed C-c\n", c->fd);
+ return -1; /* User requested to quit */
+ }
+
+ c->inbytes = 0;
+ }
+ }
+
+ /* Send the telnet initialisation commands */
+ if(!c->ready)
+ {
+ ret = nonblock_write(c->fd, server->prefix, sizeof(INIT_PREFIX));
+ if(ret == -1)
+ return (errno == EAGAIN) ? 0 : -1;
+
+ if(ret < (ssize_t)sizeof(INIT_PREFIX))
+ return 0;
+
+ c->ready = 1;
+ }
+
+ /* No error, there's just nothing to send yet */
+ if(!server->buffer)
+ return 0;
+
+ /* If we have backlog, send the backlog */
+ if(c->stop)
+ {
+ ret = nonblock_write(c->fd, c->outbuf + c->start, c->stop - c->start);
+
+ if(ret == -1)
+ {
+ if(errno == EAGAIN)
+ ret = 0;
+ else
+ {
+ fprintf(stderr, "[%i] failed (%s)\n",
+ c->fd, strerror(errno));
+ return -1;
+ }
+ }
+
+ if(ret == c->stop - c->start)
+ {
+ /* We got rid of the backlog! */
+ c->start = c->stop = 0;
+ }
+ else
+ {
+ c->start += ret;
+
+ if(c->stop - c->start + strlen(ANSI_PREFIX) + server->buflen
+ > OUTBUFFER)
+ {
+ /* Overflow! Empty buffer and start again */
+ memcpy(c->outbuf, ANSI_RESET, strlen(ANSI_RESET));
+ c->start = 0;
+ c->stop = strlen(ANSI_RESET);
+ return 0;
+ }
+
+ /* Need to move? */
+ if(c->stop + strlen(ANSI_PREFIX) + server->buflen > OUTBUFFER)
+ {
+ memmove(c->outbuf, c->outbuf + c->start, c->stop - c->start);
+ c->stop -= c->start;
+ c->start = 0;
+ }
+
+ memcpy(c->outbuf + c->stop, ANSI_PREFIX, strlen(ANSI_PREFIX));
+ c->stop += strlen(ANSI_PREFIX);
+ memcpy(c->outbuf + c->stop, server->buffer, server->buflen);
+ c->stop += server->buflen;
+
+ return 0;
+ }
+ }
+
+ /* We no longer have backlog, send our new data */
+
+ /* Send ANSI prefix */
+ ret = nonblock_write(c->fd, ANSI_PREFIX, strlen(ANSI_PREFIX));
+ if(ret == -1)
+ {
+ if(errno == EAGAIN)
+ ret = 0;
+ else
+ {
+ fprintf(stderr, "[%i] failed (%s)\n", c->fd, strerror(errno));
+ return -1;
+ }
+ }
+
+ if(ret < (ssize_t)strlen(ANSI_PREFIX))
+ {
+ if(strlen(ANSI_PREFIX) + server->buflen > OUTBUFFER)
+ {
+ /* Overflow! Empty buffer and start again */
+ memcpy(c->outbuf, ANSI_RESET, strlen(ANSI_RESET));
+ c->start = 0;
+ c->stop = strlen(ANSI_RESET);
+ return 0;
+ }
+
+ memcpy(c->outbuf, ANSI_PREFIX, strlen(ANSI_PREFIX) - ret);
+ c->stop = strlen(ANSI_PREFIX) - ret;
+ memcpy(c->outbuf + c->stop, server->buffer, server->buflen);
+ c->stop += server->buflen;
+
+ return 0;
+ }
+
+ /* Send actual data */
+ ret = nonblock_write(c->fd, server->buffer, server->buflen);
+ if(ret == -1)
+ {
+ if(errno == EAGAIN)
+ ret = 0;
+ else
+ {
+ fprintf(stderr, "[%i] failed (%s)\n", c->fd, strerror(errno));
+ return -1;
+ }
+ }
+
+ if(ret < (int)server->buflen)
+ {
+ if(server->buflen > OUTBUFFER)
+ {
+ /* Overflow! Empty buffer and start again */
+ memcpy(c->outbuf, ANSI_RESET, strlen(ANSI_RESET));
+ c->start = 0;
+ c->stop = strlen(ANSI_RESET);
+ return 0;
+ }
+
+ memcpy(c->outbuf, server->buffer, server->buflen - ret);
+ c->stop = server->buflen - ret;
+
+ return 0;
+ }
+
+ return 0;
+}
+
+ssize_t nonblock_write(int fd, void *buf, size_t len)
+{
+ size_t total = 0;
+ ssize_t ret;
+
+ while(total < len)
+ {
+ do
+ {
+ ret = write(fd, buf, len);
+ }
+ while(ret < 0 && errno == EINTR);
+
+ if(ret < 0)
+ return ret;
+ else if(ret == 0)
+ return total;
+
+ total += len;
+ buf = (void *)((uintptr_t)buf + len);
+ }
+
+ return total;
+}
+
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-19 19:34:45 +0000