sic.c

   1 /*
   2  * (C)opyright MMV-MMVI Anselm R. Garbe <garbeam at gmail dot com>
   3  * (C)opyright MMV-MMVI Nico Golde <nico at ngolde dot de>
   4  * See LICENSE file for license details.
   5  */
   6
   7 #include <errno.h>
   8 #include <netdb.h>
   9 #include <netinet/in.h>
  10 #include <stdio.h>
  11 #include <stdlib.h>
  12 #include <string.h>
  13 #include <sys/socket.h>
  14 #include <time.h>
  15
  16 #define PINGTIMEOUT 300
  17 #define MAXMSG 4096
  18
  19 enum { Tnick, Tuser, Tcmd, Tchan, Targ, Ttext, Tlast };
  20
  21 /* CUSTOMIZE */
  22 static const char *ping = "PING irc.oftc.net\r\n";
  23 static const char *host = "irc.oftc.net";
  24 static const int port = 6667;
  25 static const char *nick = "arg";
  26 static const char *fullname = "Anselm R. Garbe";
  27 static const char *password = NULL;
  28
  29 static char bufin[MAXMSG], bufout[MAXMSG];
  30 static char channel[256];
  31 static int srv;
  32 static time_t trespond;
  33
  34 static int
  35 getline(int fd, unsigned int len, char *buf)
  36 {
  37         unsigned int i = 0;
  38         char c;
  39         do {
  40                 if(read(fd, &c, sizeof(char)) != sizeof(char))
  41                         return -1;
  42                 buf[i++] = c;
  43         }
  44         while(c != '\n' && i < len);
  45         buf[i - 1] = 0;
  46         return 0;
  47 }
  48
  49 static void
  50 pout(char *channel, char *msg)
  51 {
  52         static char timestr[18];
  53         time_t t = time(0);
  54
  55         strftime(timestr, sizeof(timestr), "%a %R", localtime(&t));
  56         fprintf(stdout, "%s: %s %s\n", channel, timestr, msg);
  57 }
  58
  59 static void
  60 privmsg(char *channel, char *msg)
  61 {
  62         snprintf(bufout, sizeof(bufout), "<%s> %s", nick, msg);
  63         pout(channel, bufout);
  64         snprintf(bufout, sizeof(bufout), "PRIVMSG %s :%s\r\n", channel, msg);
  65         write(srv, bufout, strlen(bufout));
  66 }
  67
  68 static void
  69 parsein(char *msg)
  70 {
  71         char *p;
  72
  73         if((p = strchr(msg, ' ')))
  74                 *(p++) = 0;
  75         if(msg[0] != '/' && msg[0] != 0) {
  76                 privmsg(channel, p);
  77                 return;
  78         }
  79         if((p = strchr(&msg[3], ' ')))
  80                 *(p++) = 0;
  81         switch (msg[1]) {
  82         case 'j':
  83                 if(msg[3] == '#')
  84                         snprintf(bufout, sizeof(bufout), "JOIN %s\r\n", &msg[3]);
  85                 else if(p) {
  86                         privmsg(&msg[3], p + 1);
  87                         return;
  88                 }
  89                 break;
  90         case 'l':
  91                 if(p)
  92                         snprintf(bufout, sizeof(bufout), "PART %s :%s\r\n", &msg[3], p);
  93                 else
  94                         snprintf(bufout, sizeof(bufout), "PART %s :sic\r\n", &msg[3]);
  95                 break;
  96         case 'm':
  97                 privmsg(msg, p);
  98                 break;
  99         case 's':
 100                 strncpy(channel, msg, sizeof(channel));
 101                 break;
 102         case 't':
 103                 snprintf(bufout, sizeof(bufout), "TOPIC %s :%s\r\n", &msg[3], p);
 104                 break;
 105         default:
 106                 snprintf(bufout, sizeof(bufout), "%s\r\n", &msg[1]);
 107                 break;
 108         }
 109         write(srv, bufout, strlen(bufout));
 110 }
 111
 112 static unsigned int
 113 tokenize(char **result, unsigned int reslen, char *str, char delim)
 114 {
 115         char *p, *n;
 116         unsigned int i = 0;
 117
 118         if(!str)
 119                 return 0;
 120         for(n = str; *n == delim; n++);
 121         p = n;
 122         for(i = 0; *n != 0;) {
 123                 if(i == reslen)
 124                         return i;
 125                 if(*n == delim) {
 126                         *n = 0;
 127                         if(strlen(p))
 128                                 result[i++] = p;
 129                         p = ++n;
 130                 } else
 131                         n++;
 132         }
 133         if((i < reslen) && (p < n) && strlen(p))
 134                 result[i++] = p;
 135         return i;       /* number of tokens */
 136 }
 137
 138 static void
 139 parsesrv(char *msg)
 140 {
 141         char *argv[Tlast], *cmd, *p;
 142         int i;
 143         if(!msg || !(*msg))
 144                 return;
 145
 146         for(i = 0; i < Tlast; i++)
 147                 argv[i] = NULL;
 148
 149         /*
 150            <bufout>  ::= [':' <prefix> <SPACE> ] <command> <params> <crlf>
 151            <prefix>   ::= <servername> | <nick> [ '!' <user> ] [ '@' <host> ]
 152            <command>  ::= <letter> { <letter> } | <number> <number> <number>
 153            <SPACE>    ::= ' ' { ' ' }
 154            <params>   ::= <SPACE> [ ':' <trailing> | <middle> <params> ]
 155            <middle>   ::= <Any *non-empty* sequence of octets not including SPACE
 156            or NUL or CR or LF, the first of which may not be ':'>
 157            <trailing> ::= <Any, possibly *empty*, sequence of octets not including NUL or CR or LF>
 158            <crlf>     ::= CR LF
 159          */
 160         if(msg[0] == ':') { /* check prefix */
 161                 p = strchr(msg, ' ');
 162                 *p = 0;
 163                 for(++p; *p == ' '; p++);
 164                 cmd = p;
 165                 argv[Tnick] = &msg[1];
 166                 if((p = strchr(msg, '!'))) {
 167                         *p = 0;
 168                         argv[Tuser] = ++p;
 169                 }
 170         } else
 171                 cmd = msg;
 172
 173         /* remove CRLFs */
 174         for(p = cmd; p && *p != 0; p++)
 175                 if(*p == '\r' || *p == '\n')
 176                         *p = 0;
 177
 178         if((p = strchr(cmd, ':'))) {
 179                 *p = 0;
 180                 argv[Ttext] = ++p;
 181         }
 182         tokenize(&argv[Tcmd], Tlast - Tcmd, cmd, ' ');
 183
 184         if(!strncmp("PONG", argv[Tcmd], 5)) {
 185                 return;
 186         } else if(!strncmp("PING", argv[Tcmd], 5)) {
 187                 snprintf(bufout, sizeof(bufout), "PONG %s\r\n", argv[Ttext]);
 188                 write(srv, bufout, strlen(bufout));
 189                 return;
 190         } else if(!argv[Tnick] || !argv[Tuser]) {       /* server command */
 191                 snprintf(bufout, sizeof(bufout), "%s", argv[Ttext] ? argv[Ttext] : "");
 192                 pout((char *)host, bufout);
 193                 return;
 194         } else if(!strncmp("ERROR", argv[Tcmd], 6))
 195                 snprintf(bufout, sizeof(bufout), "-!- error %s",
 196                                 argv[Ttext] ? argv[Ttext] : "unknown");
 197         else if(!strncmp("JOIN", argv[Tcmd], 5)) {
 198                 if(argv[Ttext]!=NULL){
 199                         p = strchr(argv[Ttext], ' ');
 200                 if(p)
 201                         *p = 0;
 202                 }
 203                 argv[Tchan] = argv[Ttext];
 204                 snprintf(bufout, sizeof(bufout), "-!- %s(%s) has joined %s",
 205                                 argv[Tnick], argv[Tuser], argv[Ttext]);
 206         } else if(!strncmp("PART", argv[Tcmd], 5)) {
 207                 snprintf(bufout, sizeof(bufout), "-!- %s(%s) has left %s",
 208                                 argv[Tnick], argv[Tuser], argv[Tchan]);
 209         } else if(!strncmp("MODE", argv[Tcmd], 5))
 210                 snprintf(bufout, sizeof(bufout), "-!- %s changed mode/%s -> %s %s",
 211                                 argv[Tnick], argv[Tcmd + 1],
 212                                 argv[Tcmd + 2], argv[Tcmd + 3]);
 213         else if(!strncmp("QUIT", argv[Tcmd], 5))
 214                 snprintf(bufout, sizeof(bufout), "-!- %s(%s) has quit \"%s\"",
 215                                 argv[Tnick], argv[Tuser],
 216                                 argv[Ttext] ? argv[Ttext] : "");
 217         else if(!strncmp("NICK", argv[Tcmd], 5))
 218                 snprintf(bufout, sizeof(bufout), "-!- %s changed nick to %s",
 219                                 argv[Tnick], argv[Ttext]);
 220         else if(!strncmp("TOPIC", argv[Tcmd], 6))
 221                 snprintf(bufout, sizeof(bufout), "-!- %s changed topic to \"%s\"",
 222                                 argv[Tnick], argv[Ttext] ? argv[Ttext] : "");
 223         else if(!strncmp("KICK", argv[Tcmd], 5))
 224                 snprintf(bufout, sizeof(bufout), "-!- %s kicked %s (\"%s\")",
 225                                 argv[Tnick], argv[Targ],
 226                                 argv[Ttext] ? argv[Ttext] : "");
 227         else if(!strncmp("NOTICE", argv[Tcmd], 7))
 228                 snprintf(bufout, sizeof(bufout), "-!- \"%s\")",
 229                                 argv[Ttext] ? argv[Ttext] : "");
 230         else if(!strncmp("PRIVMSG", argv[Tcmd], 8)) snprintf(bufout, sizeof(bufout), "<%s> %s",
 231                                 argv[Tnick], argv[Ttext] ? argv[Ttext] : "");
 232         if(!argv[Tchan] || !strncmp(argv[Tchan], nick, strlen(nick)))
 233                 pout(argv[Tnick], bufout);
 234         else
 235                 pout(argv[Tchan], bufout);
 236 }
 237
 238 int
 239 main(int argc, char *argv[])
 240 {
 241         int i;
 242         struct timeval tv;
 243         struct hostent *hp;
 244         struct sockaddr_in addr = { 0 };
 245         fd_set rd;
 246
 247         for(i = 1; (i < argc) && (argv[i][0] == '-'); i++) {
 248                 switch (argv[i][1]) {
 249                 default:
 250                         fputs("usage: sic [-v]\n", stderr);
 251                         exit(EXIT_FAILURE);
 252                         break;
 253                 case 'v':
 254                         fputs("sic-"VERSION", (C)opyright MMVI Anselm R. Garbe\n", stdout);
 255                         exit(EXIT_SUCCESS);
 256                         break;
 257                 }
 258         }
 259
 260         /* init */
 261         if((srv = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
 262                 fprintf(stderr, "sic: cannot connect server '%s'\n", host);
 263                 exit(EXIT_FAILURE);
 264         }
 265         hp = gethostbyname(host);
 266         addr.sin_family = AF_INET;
 267         addr.sin_port = htons(port);
 268         bcopy(hp->h_addr, &addr.sin_addr, hp->h_length);
 269         if(connect(srv, (struct sockaddr *) &addr, sizeof(struct sockaddr_in))) {
 270                 close(srv);
 271                 fprintf(stderr, "sic: cannot connect server '%s'\n", host);
 272                 exit(EXIT_FAILURE);
 273         }
 274
 275         /* login */
 276         if(password)
 277                 snprintf(bufout, sizeof(bufout),
 278                                 "PASS %s\r\nNICK %s\r\nUSER %s localhost %s :%s\r\n",
 279                                 password, nick, nick, host, fullname ? fullname : nick);
 280         else
 281                 snprintf(bufout, sizeof(bufout), "NICK %s\r\nUSER %s localhost %s :%s\r\n",
 282                                  nick, nick, host, fullname ? fullname : nick);
 283         write(srv, bufout, strlen(bufout));
 284
 285         channel[0] = 0;
 286         setbuf(stdout, NULL); /* unbuffered stdout */
 287         for(;;) {
 288                 FD_ZERO(&rd);
 289                 FD_SET(0, &rd);
 290                 FD_SET(srv, &rd);
 291                 tv.tv_sec = 120;
 292                 tv.tv_usec = 0;
 293                 i = select(srv + 1, &rd, 0, 0, &tv);
 294                 if(i < 0) {
 295                         if(errno == EINTR)
 296                                 continue;
 297                         perror("sic: error on select()");
 298                         exit(EXIT_FAILURE);
 299                 } else if(i == 0) {
 300                         if(time(NULL) - trespond >= PINGTIMEOUT) {
 301                                 pout((char *)host, "-!- sic shutting down: parseing timeout");
 302                                 exit(EXIT_FAILURE);
 303                         }
 304                         write(srv, ping, strlen(ping));
 305                         continue;
 306                 }
 307                 if(FD_ISSET(srv, &rd)) {
 308                         if(getline(srv, sizeof(bufin), bufin) == -1) {
 309                                 perror("sic: remote host closed connection");
 310                                 exit(EXIT_FAILURE);
 311                         }
 312                         parsesrv(bufin);
 313                         trespond = time(NULL);
 314                 }
 315                 if(FD_ISSET(0, &rd)) {
 316                         if(getline(0, sizeof(bufin), bufin) == -1) {
 317                                 perror("sic: broken pipe");
 318                                 exit(EXIT_FAILURE);
 319                         }
 320                         parsein(bufin);
 321                 }
 322         }
 323
 324         return 0;
 325 }