diff options
| -rw-r--r-- | src/nyancat.c | 344 |
1 files changed, 196 insertions, 148 deletions
diff --git a/src/nyancat.c b/src/nyancat.c index 33f8522..1bc0294 100644 --- a/src/nyancat.c +++ b/src/nyancat.c @@ -59,6 +59,7 @@ #include <time.h> #include <setjmp.h> #include <sys/ioctl.h> +#include <getopt.h> #ifndef TIOCGWINSZ #include <termios.h> @@ -236,6 +237,17 @@ void send_command(int cmd, int opt) { } } +void usage(char * argv[]) { + printf( + "Terminal Nyancat\n" + "\n" + "usage: %s [-h] [-t] [-i] \n" + "\n" + " -i --intro \033[3mShow the introduction / about informaiton at startup.\033[0m\n" + " -t --telnet \033[3mTelnet mode.\033[0m\n", + " -h --help \033[3mShow this help message.\033[0m\n", + argv[0]); +} int main(int argc, char ** argv) { @@ -249,126 +261,160 @@ int main(int argc, char ** argv) { char sb[1024] = {0}; char sb_len = 0; - if (argc > 1) { - if (!strcmp(argv[1], "-t")) { - /* Yes, I know, lame way to get arguments, whatever, we only want one of them. */ - telnet = 1; + char show_intro = 0; + + /* Long option names */ + static struct option long_opts[] = { + {"help", no_argument, 0, 'h'}, + {"telnet", no_argument, 0, 't'}, + {"intro", no_argument, 0, 'i'}, + {0,0,0,0} + }; + + /* Process arguments */ + int index, c; + while ((c = getopt_long(argc, argv, "hit", long_opts, &index)) != -1) { + if (!c) { + if (long_opts[index].flag == 0) { + c = long_opts[index].val; + } + } + switch (c) { + case 'i': /* Show introduction */ + show_intro = 1; + break; + case 't': /* Expect telnet bits */ + telnet = 1; + break; + case 'h': /* Show help and exit */ + usage(argv); + exit(0); + break; + default: + break; + } + } - /* Set the default options */ - set_options(); + if (telnet) { + /* Telnet mode */ - /* Let the client know what we're using */ - for (option = 0; option < 256; option++) { - if (telnet_options[option]) { - send_command(telnet_options[option], option); - fflush(stdout); - } + /* Intro is implied by telnet mode, so override whatever was asked for. */ + show_intro = 1; + + /* Set the default options */ + set_options(); + + /* Let the client know what we're using */ + for (option = 0; option < 256; option++) { + if (telnet_options[option]) { + send_command(telnet_options[option], option); + fflush(stdout); } - for (option = 0; option < 256; option++) { - if (telnet_willack[option]) { - send_command(telnet_willack[option], option); - fflush(stdout); - } + } + for (option = 0; option < 256; option++) { + if (telnet_willack[option]) { + send_command(telnet_willack[option], option); + fflush(stdout); } + } - /* Set the alarm handler to execute the longjmp */ - signal(SIGALRM, SIGALRM_handler); - - /* Negotiate options */ - if (!setjmp(environment)) { - /* We will stop handling options after one second */ - alarm(1); - - /* Let's do this */ - while (!feof(stdin) && done < 2) { - /* Get either IAC (start command) or a regular character (break, unless in SB mode) */ - unsigned char i = getchar(); - unsigned char opt = 0; - if (i == IAC) { - /* If IAC, get the command */ - i = getchar(); - switch (i) { - case SE: - /* End of extended option mode */ - sb_mode = 0; - if (sb[0] == TTYPE) { - /* This was a response to the TTYPE command, meaning - * that this should be a terminal type */ - alarm(0); - strcpy(term, &sb[2]); - done++; - } - else if (sb[0] == NAWS) { - /* This was a response to the NAWS command, meaning - * that this should be a window size */ - alarm(0); - terminal_width = sb[2]; - done++; - } - break; - case NOP: - /* No Op */ - send_command(NOP, 0); - fflush(stdout); - break; - case WILL: - case WONT: - /* Will / Won't Negotiation */ - opt = getchar(); - if (!telnet_willack[opt]) { - /* We default to WONT */ - telnet_willack[opt] = WONT; - } - send_command(telnet_willack[opt], opt); - fflush(stdout); - if ((i == WILL) && (opt == TTYPE)) { - /* WILL TTYPE? Great, let's do that now! */ - printf("%c%c%c%c%c%c", IAC, SB, TTYPE, SEND, IAC, SE); - fflush(stdout); - } - break; - case DO: - case DONT: - /* Do / Don't Negotation */ - opt = getchar(); - if (!telnet_options[opt]) { - /* We default to DONT */ - telnet_options[opt] = DONT; - } - send_command(telnet_options[opt], opt); - if (opt == ECHO) { - /* We don't really need this, as we don't accept input, but, - * in case we do in the future, set our echo mode */ - do_echo = (i == DO); - } + /* Set the alarm handler to execute the longjmp */ + signal(SIGALRM, SIGALRM_handler); + + /* Negotiate options */ + if (!setjmp(environment)) { + /* We will stop handling options after one second */ + alarm(1); + + /* Let's do this */ + while (!feof(stdin) && done < 2) { + /* Get either IAC (start command) or a regular character (break, unless in SB mode) */ + unsigned char i = getchar(); + unsigned char opt = 0; + if (i == IAC) { + /* If IAC, get the command */ + i = getchar(); + switch (i) { + case SE: + /* End of extended option mode */ + sb_mode = 0; + if (sb[0] == TTYPE) { + /* This was a response to the TTYPE command, meaning + * that this should be a terminal type */ + alarm(0); + strcpy(term, &sb[2]); + done++; + } + else if (sb[0] == NAWS) { + /* This was a response to the NAWS command, meaning + * that this should be a window size */ + alarm(0); + terminal_width = sb[2]; + done++; + } + break; + case NOP: + /* No Op */ + send_command(NOP, 0); + fflush(stdout); + break; + case WILL: + case WONT: + /* Will / Won't Negotiation */ + opt = getchar(); + if (!telnet_willack[opt]) { + /* We default to WONT */ + telnet_willack[opt] = WONT; + } + send_command(telnet_willack[opt], opt); + fflush(stdout); + if ((i == WILL) && (opt == TTYPE)) { + /* WILL TTYPE? Great, let's do that now! */ + printf("%c%c%c%c%c%c", IAC, SB, TTYPE, SEND, IAC, SE); fflush(stdout); - break; - case SB: - /* Begin Extended Option Mode */ - sb_mode = 1; - sb_len = 0; - memset(sb, 0, 1024); - break; - case IAC: - /* IAC IAC? That's probably not right. */ - done = 2; - break; - default: - break; - } - } else if (sb_mode) { - /* Extended Option Mode -> Accept character */ - if (sb_len < 1023) { - /* Append this character to the SB string, - * but only if it doesn't put us over - * our limit; honestly, we shouldn't hit - * the limit, as we're only collecting characters - * for a terminal type or window size, but better safe than - * sorry (and vulernable). - */ - sb[sb_len] = i; - sb_len++; - } + } + break; + case DO: + case DONT: + /* Do / Don't Negotation */ + opt = getchar(); + if (!telnet_options[opt]) { + /* We default to DONT */ + telnet_options[opt] = DONT; + } + send_command(telnet_options[opt], opt); + if (opt == ECHO) { + /* We don't really need this, as we don't accept input, but, + * in case we do in the future, set our echo mode */ + do_echo = (i == DO); + } + fflush(stdout); + break; + case SB: + /* Begin Extended Option Mode */ + sb_mode = 1; + sb_len = 0; + memset(sb, 0, 1024); + break; + case IAC: + /* IAC IAC? That's probably not right. */ + done = 2; + break; + default: + break; + } + } else if (sb_mode) { + /* Extended Option Mode -> Accept character */ + if (sb_len < 1023) { + /* Append this character to the SB string, + * but only if it doesn't put us over + * our limit; honestly, we shouldn't hit + * the limit, as we're only collecting characters + * for a terminal type or window size, but better safe than + * sorry (and vulernable). + */ + sb[sb_len] = i; + sb_len++; } } } @@ -379,7 +425,7 @@ int main(int argc, char ** argv) { char * nterm = getenv("TERM"); if (nterm) strcpy(term, nterm); - + /* Also get the number of columns */ struct winsize w; ioctl(0, TIOCGWINSZ, &w); @@ -390,7 +436,7 @@ int main(int argc, char ** argv) { for (k = 0; k < strlen(term); ++k) { term[k] = tolower(term[k]); } - + /* We don't want terminals wider than 80 columns */ if(terminal_width > 80) terminal_width = 80; @@ -548,39 +594,41 @@ int main(int argc, char ** argv) { /* Clear the screen */ printf("\033[H\033[2J\033[?25l"); - /* Display the MOTD */ - int countdown_clock = 5; - for (k = 0; k < countdown_clock; ++k) { - newline(3); - printf(" \033[1mNyancat Telnet Server\033[0m"); - newline(2); - printf(" written and run by \033[1;32mKevin Lange\033[1;34m @kevinlange\033[0m"); - newline(2); - printf(" If things don't look right, try:"); - newline(1); - printf(" TERM=fallback telnet ..."); - newline(2); - printf(" Or on Windows:"); - newline(1); - printf(" telnet -t vtnt ..."); - newline(2); - printf(" Problems? I am also a webserver:"); - newline(1); - printf(" \033[1;34mhttp://miku.acm.uiuc.edu\033[0m"); - newline(2); - printf(" This is a telnet server, remember your escape keys!"); - newline(1); - printf(" \033[1;31m^]quit\033[0m to exit"); - newline(2); - printf(" Starting in %d... \n", countdown_clock-k); - - fflush(stdout); - usleep(400000); - printf("\033[H"); /* Reset cursor */ - } + if (show_intro) { + /* Display the MOTD */ + int countdown_clock = 5; + for (k = 0; k < countdown_clock; ++k) { + newline(3); + printf(" \033[1mNyancat Telnet Server\033[0m"); + newline(2); + printf(" written and run by \033[1;32mKevin Lange\033[1;34m @kevinlange\033[0m"); + newline(2); + printf(" If things don't look right, try:"); + newline(1); + printf(" TERM=fallback telnet ..."); + newline(2); + printf(" Or on Windows:"); + newline(1); + printf(" telnet -t vtnt ..."); + newline(2); + printf(" Problems? I am also a webserver:"); + newline(1); + printf(" \033[1;34mhttp://miku.acm.uiuc.edu\033[0m"); + newline(2); + printf(" This is a telnet server, remember your escape keys!"); + newline(1); + printf(" \033[1;31m^]quit\033[0m to exit"); + newline(2); + printf(" Starting in %d... \n", countdown_clock-k); - /* Clear the screen again */ - printf("\033[H\033[2J\033[?25l"); + fflush(stdout); + usleep(400000); + printf("\033[H"); /* Reset cursor */ + } + + /* Clear the screen again */ + printf("\033[H\033[2J\033[?25l"); + } /* Store the start time */ time_t start, current; |