ii.c

   1 /* (C)opyright MMV-MMVI Anselm R. Garbe <garbeam at gmail dot com>
   2  * (C)opyright MMV-MMXI Nico Golde <nico at ngolde dot de>
   3  * See LICENSE file for license details. */
   4 #include <errno.h>
   5 #include <netdb.h>
   6 #include <netinet/in.h>
   7 #include <stdio.h>
   8 #include <stdlib.h>
   9 #include <limits.h>
  10 #include <fcntl.h>
  11 #include <string.h>
  12 #include <signal.h>
  13 #include <sys/stat.h>
  14 #include <sys/socket.h>
  15 #include <ctype.h>
  16 #include <time.h>
  17 #include <unistd.h>
  18
  19 #ifndef PIPE_BUF /* FreeBSD don't know PIPE_BUF */
  20 #define PIPE_BUF 4096
  21 #endif
  22 #define PING_TIMEOUT 300
  23 #define SERVER_PORT 6667
  24 enum { TOK_NICKSRV = 0, TOK_USER, TOK_CMD, TOK_CHAN, TOK_ARG, TOK_TEXT, TOK_LAST };
  25
  26 typedef struct Channel Channel;
  27 struct Channel {
  28         int fd;
  29         char *name;
  30         Channel *next;
  31 };
  32
  33 static int irc;
  34 static time_t last_response;
  35 static Channel *channels = NULL;
  36 static char *host = "irc.freenode.net";
  37 static char nick[32] = "anonymous";     /* might change while running */
  38 static char path[_POSIX_PATH_MAX];
  39 static char message[PIPE_BUF]; /* message buf used for communication */
  40
  41 static void usage() {
  42         fprintf(stderr, "%s",
  43                         "ii - irc it - " VERSION "\n"
  44                         "(C)opyright MMV-MMVI Anselm R. Garbe\n"
  45                         "(C)opyright MMV-MMXI Nico Golde\n"
  46                         "usage: ii [-i <irc dir>] [-s <host>] [-p <port>]\n"
  47                         "          [-n <nick>] [-k <password>] [-f <fullname>]\n"
  48                         "          [-d <directory>]\n");
  49         exit(EXIT_SUCCESS);
  50 }
  51
  52 static char *striplower(char *s) {
  53         char *p = NULL;
  54         for(p = s; p && *p; p++) {
  55                 if(*p == '/') *p = '_';
  56                 *p = tolower(*p);
  57         }
  58         return s;
  59 }
  60
  61 /* creates directories top-down, if necessary */
  62 static void create_dirtree(const char *dir) {
  63         char tmp[256];
  64         char *p = NULL;
  65         size_t len;
  66
  67         snprintf(tmp, sizeof(tmp),"%s",dir);
  68         len = strlen(tmp);
  69         if(tmp[len - 1] == '/')
  70                 tmp[len - 1] = 0;
  71         for(p = tmp + 1; *p; p++)
  72                 if(*p == '/') {
  73                         *p = 0;
  74                         mkdir(tmp, S_IRWXU);
  75                         *p = '/';
  76                 }
  77         mkdir(tmp, S_IRWXU);
  78 }
  79
  80 static int get_filepath(char *filepath, size_t len, char *channel, char *file) {
  81         if(channel) {
  82                 if(!snprintf(filepath, len, "%s/%s", path, channel))
  83                         return 0;
  84                 create_dirtree(filepath);
  85                 return snprintf(filepath, len, "%s/%s/%s", path, channel, file);
  86         }
  87         return snprintf(filepath, len, "%s/%s", path, file);
  88 }
  89
  90 static void create_filepath(char *filepath, size_t len, char *channel, char *suffix) {
  91         if(!get_filepath(filepath, len, striplower(channel), suffix)) {
  92                 fprintf(stderr, "%s", "ii: path to irc directory too long\n");
  93                 exit(EXIT_FAILURE);
  94         }
  95 }
  96
  97 static int open_channel(char *name) {
  98         static char infile[256];
  99         create_filepath(infile, sizeof(infile), name, "in");
 100         if(access(infile, F_OK) == -1)
 101                 mkfifo(infile, S_IRWXU);
 102         return open(infile, O_RDONLY | O_NONBLOCK, 0);
 103 }
 104
 105 static void add_channel(char *cname) {
 106         Channel *c;
 107         int fd;
 108         char *name = striplower(cname);
 109
 110         for(c = channels; c; c = c->next)
 111                 if(!strcmp(name, c->name))
 112                         return; /* already handled */
 113
 114         fd = open_channel(name);
 115         if(fd == -1) {
 116                 printf("ii: exiting, cannot create in channel: %s\n", name);
 117                 exit(EXIT_FAILURE);
 118         }
 119         c = calloc(1, sizeof(Channel));
 120         if(!c) {
 121                 perror("ii: cannot allocate memory");
 122                 exit(EXIT_FAILURE);
 123         }
 124         if(!channels) channels = c;
 125         else {
 126                 c->next = channels;
 127                 channels = c;
 128         }
 129         c->fd = fd;
 130         c->name = strdup(name);
 131 }
 132
 133 static void rm_channel(Channel *c) {
 134         Channel *p;
 135         if(channels == c) channels = channels->next;
 136         else {
 137                 for(p = channels; p && p->next != c; p = p->next);
 138                 if(p->next == c)
 139                         p->next = c->next;
 140         }
 141         free(c->name);
 142         free(c);
 143 }
 144
 145 static void login(char *key, char *fullname) {
 146         if(key) snprintf(message, PIPE_BUF,
 147                                 "PASS %s\r\nNICK %s\r\nUSER %s localhost * :%s\r\n", key,
 148                                 nick, nick, fullname ? fullname : nick);
 149         else snprintf(message, PIPE_BUF, "NICK %s\r\nUSER %s localhost * :%s\r\n",
 150                                 nick, nick, fullname ? fullname : nick);
 151         write(irc, message, strlen(message));   /* login */
 152 }
 153
 154 static int tcpopen(unsigned short port) {
 155         int fd;
 156         struct sockaddr_in sin;
 157         struct hostent *hp = gethostbyname(host);
 158
 159         memset(&sin, 0, sizeof(struct sockaddr_in));
 160         if(!hp) {
 161                 perror("ii: cannot retrieve host information");
 162                 exit(EXIT_FAILURE);
 163         }
 164         sin.sin_family = AF_INET;
 165         memcpy(&sin.sin_addr, hp->h_addr, hp->h_length);
 166         sin.sin_port = htons(port);
 167         if((fd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
 168                 perror("ii: cannot create socket");
 169                 exit(EXIT_FAILURE);
 170         }
 171         if(connect(fd, (const struct sockaddr *) &sin, sizeof(sin)) < 0) {
 172                 perror("ii: cannot connect to host");
 173                 exit(EXIT_FAILURE);
 174         }
 175         return fd;
 176 }
 177
 178 static size_t tokenize(char **result, size_t reslen, char *str, char delim) {
 179         char *p = NULL, *n = NULL;
 180         size_t i;
 181
 182         if(!str)
 183                 return 0;
 184         for(n = str; *n == ' '; n++);
 185         p = n;
 186         for(i = 0; *n != 0;) {
 187                 if(i == reslen)
 188                         return 0;
 189                 if(i > TOK_CHAN - TOK_CMD && strtol(result[0], NULL, 10) > 0) delim=':'; /* workaround non-RFC compliant messages */
 190                 if(*n == delim) {
 191                         *n = 0;
 192                         result[i++] = p;
 193                         p = ++n;
 194                 } else
 195                         n++;
 196         }
 197         if(i<reslen && p < n && strlen(p))
 198                 result[i++] = p;
 199         return i;                               /* number of tokens */
 200 }
 201
 202 static void print_out(char *channel, char *buf) {
 203         static char outfile[256], server[256], buft[18];
 204         FILE *out = NULL;
 205         time_t t = time(0);
 206
 207         if(channel) snprintf(server, sizeof(server), "-!- %s", channel);
 208         if(strstr(buf, server)) channel="";
 209         create_filepath(outfile, sizeof(outfile), channel, "out");
 210         if(!(out = fopen(outfile, "a"))) return;
 211         if(channel && channel[0]) add_channel(channel);
 212
 213         strftime(buft, sizeof(buft), "%F %R", localtime(&t));
 214         fprintf(out, "%s %s\n", buft, buf);
 215         fclose(out);
 216 }
 217
 218 static void proc_channels_privmsg(char *channel, char *buf) {
 219         snprintf(message, PIPE_BUF, "<%s> %s", nick, buf);
 220         print_out(channel, message);
 221         snprintf(message, PIPE_BUF, "PRIVMSG %s :%s\r\n", channel, buf);
 222         write(irc, message, strlen(message));
 223 }
 224
 225 static void proc_channels_input(Channel *c, char *buf) {
 226         char *p = NULL;
 227
 228         if(buf[0] != '/' && buf[0] != 0) {
 229                 proc_channels_privmsg(c->name, buf);
 230                 return;
 231         }
 232         message[0] = '\0';
 233         if(buf[2] == ' ' || buf[2] == '\0') switch (buf[1]) {
 234                 case 'j':
 235                         if(buf[3] != ' '){
 236                                 p = strchr(&buf[3], ' ');
 237                                 if(p) *p = 0;
 238                         }
 239                         if((buf[3]=='#')||(buf[3]=='&')||(buf[3]=='+')||(buf[3]=='!')){
 240                                 if(p) snprintf(message, PIPE_BUF, "JOIN %s %s\r\n", &buf[3], p + 1); /* password protected channel */
 241                                 else snprintf(message, PIPE_BUF, "JOIN %s\r\n", &buf[3]);
 242                                 add_channel(&buf[3]);
 243                         }
 244                         else {
 245                                 if(p && buf[3] != ' '){
 246                                         add_channel(&buf[3]);
 247                                         proc_channels_privmsg(&buf[3], p + 1);
 248                                 }
 249                                 return;
 250                         }
 251                         break;
 252                 case 't':
 253                         if(buf[3] != ' '){
 254                                 p = strchr(&buf[3], ' ');
 255                                 if(p) *p = 0;
 256                         }
 257                         if((buf[3]=='#')||(buf[3]=='&')||(buf[3]=='+')||(buf[3]=='!')){
 258                                 if(p) snprintf(message, PIPE_BUF, "TOPIC %s :%s\r\n", &buf[3], p + 1);
 259                                 else snprintf(message, PIPE_BUF, "TOPIC %s\r\n", &buf[3]);
 260                         }
 261                         else {
 262                                 if(c->name[0] == 0) return;
 263                                 if(strlen(buf)>3) snprintf(message, PIPE_BUF, "TOPIC %s :%s\r\n", c->name, &buf[3]);
 264                                 else snprintf(message, PIPE_BUF, "TOPIC %s\r\n", c->name);
 265                         }
 266                         break;
 267                 case 'a':
 268                         if(strlen(buf)>3){
 269                                 snprintf(message, PIPE_BUF, "-!- %s is away \"%s\"", nick, &buf[3]);
 270                                 print_out(c->name, message);
 271                                 snprintf(message, PIPE_BUF, "AWAY :%s\r\n", &buf[3]);
 272                         } else snprintf(message, PIPE_BUF, "AWAY\r\n");
 273                         break;
 274                 case 'n':
 275                         if(strlen(buf)>3){
 276                                 snprintf(nick, sizeof(nick),"%s", &buf[3]);
 277                                 snprintf(message, PIPE_BUF, "NICK %s\r\n", &buf[3]);
 278                         }
 279                         break;
 280                 case 'l':
 281                         if(c->name[0] == 0) return;
 282                         if(strlen(buf)>3) snprintf(message, PIPE_BUF, "PART %s :%s\r\n", c->name, &buf[3]);
 283                         else snprintf(message, PIPE_BUF, "PART %s\r\n", c->name);
 284                         write(irc, message, strlen(message));
 285                         close(c->fd);
 286                         rm_channel(c);
 287                         return;
 288                         break;
 289                 default:
 290                         snprintf(message, PIPE_BUF, "%s\r\n", &buf[1]);
 291                         break;
 292         } else
 293                 snprintf(message, PIPE_BUF, "%s\r\n", &buf[1]);
 294
 295         if (message[0] != '\0')
 296                 write(irc, message, strlen(message));
 297 }
 298
 299 static void proc_server_cmd(char *buf) {
 300         char *argv[TOK_LAST], *cmd = NULL, *p = NULL;
 301         int i;
 302
 303         if(!buf || *buf=='\0')
 304                 return;
 305
 306         for(i = 0; i < TOK_LAST; i++)
 307                 argv[i] = NULL;
 308         /* <message>  ::= [':' <prefix> <SPACE> ] <command> <params> <crlf>
 309            <prefix>   ::= <servername> | <nick> [ '!' <user> ] [ '@' <host> ]
 310            <command>  ::= <letter> { <letter> } | <number> <number> <number>
 311            <SPACE>    ::= ' ' { ' ' }
 312            <params>   ::= <SPACE> [ ':' <trailing> | <middle> <params> ]
 313            <middle>   ::= <Any *non-empty* sequence of octets not including SPACE
 314            or NUL or CR or LF, the first of which may not be ':'>
 315            <trailing> ::= <Any, possibly *empty*, sequence of octets not including NUL or CR or LF>
 316            <crlf>     ::= CR LF */
 317
 318         if(buf[0] == ':') {             /* check prefix */
 319                 if (!(p = strchr(buf, ' '))) return;
 320                 *p = 0;
 321                 for(++p; *p == ' '; p++);
 322                 cmd = p;
 323                 argv[TOK_NICKSRV] = &buf[1];
 324                 if((p = strchr(buf, '!'))) {
 325                         *p = 0;
 326                         argv[TOK_USER] = ++p;
 327                 }
 328         } else
 329                 cmd = buf;
 330
 331         /* remove CRLFs */
 332         for(p = cmd; p && *p != 0; p++)
 333                 if(*p == '\r' || *p == '\n')
 334                         *p = 0;
 335
 336         if((p = strchr(cmd, ':'))) {
 337                 *p = 0;
 338                 argv[TOK_TEXT] = ++p;
 339         }
 340
 341         tokenize(&argv[TOK_CMD], TOK_LAST - TOK_CMD, cmd, ' ');
 342
 343         if(!argv[TOK_CMD] || !strncmp("PONG", argv[TOK_CMD], 5)) {
 344                 return;
 345         } else if(!strncmp("PING", argv[TOK_CMD], 5)) {
 346                 snprintf(message, PIPE_BUF, "PONG %s\r\n", argv[TOK_TEXT]);
 347                 write(irc, message, strlen(message));
 348                 return;
 349         } else if(!argv[TOK_NICKSRV] || !argv[TOK_USER]) {      /* server command */
 350                 snprintf(message, PIPE_BUF, "%s%s", argv[TOK_ARG] ? argv[TOK_ARG] : "", argv[TOK_TEXT] ? argv[TOK_TEXT] : "");
 351                 print_out(0, message);
 352                 return;
 353         } else if(!strncmp("ERROR", argv[TOK_CMD], 6))
 354                 snprintf(message, PIPE_BUF, "-!- error %s", argv[TOK_TEXT] ? argv[TOK_TEXT] : "unknown");
 355         else if(!strncmp("JOIN", argv[TOK_CMD], 5)) {
 356                 if(argv[TOK_TEXT] != NULL){
 357                         p = strchr(argv[TOK_TEXT], ' ');
 358                         if(p)
 359                                 *p = 0;
 360                 }
 361                 argv[TOK_CHAN] = argv[TOK_TEXT];
 362                 snprintf(message, PIPE_BUF, "-!- %s(%s) has joined %s", argv[TOK_NICKSRV], argv[TOK_USER], argv[TOK_TEXT]);
 363         } else if(!strncmp("PART", argv[TOK_CMD], 5)) {
 364                 snprintf(message, PIPE_BUF, "-!- %s(%s) has left %s", argv[TOK_NICKSRV], argv[TOK_USER], argv[TOK_CHAN]);
 365         } else if(!strncmp("MODE", argv[TOK_CMD], 5))
 366                 snprintf(message, PIPE_BUF, "-!- %s changed mode/%s -> %s %s", argv[TOK_NICKSRV], argv[TOK_CMD + 1] ? argv[TOK_CMD + 1] : "" , argv[TOK_CMD + 2]? argv[TOK_CMD + 2] : "", argv[TOK_CMD + 3] ? argv[TOK_CMD + 3] : "");
 367         else if(!strncmp("QUIT", argv[TOK_CMD], 5))
 368                 snprintf(message, PIPE_BUF, "-!- %s(%s) has quit \"%s\"", argv[TOK_NICKSRV], argv[TOK_USER], argv[TOK_TEXT] ? argv[TOK_TEXT] : "");
 369         else if(!strncmp("NICK", argv[TOK_CMD], 5))
 370                 snprintf(message, PIPE_BUF, "-!- %s changed nick to %s", argv[TOK_NICKSRV], argv[TOK_TEXT]);
 371         else if(!strncmp("TOPIC", argv[TOK_CMD], 6))
 372                 snprintf(message, PIPE_BUF, "-!- %s changed topic to \"%s\"", argv[TOK_NICKSRV], argv[TOK_TEXT] ? argv[TOK_TEXT] : "");
 373         else if(!strncmp("KICK", argv[TOK_CMD], 5))
 374                 snprintf(message, PIPE_BUF, "-!- %s kicked %s (\"%s\")", argv[TOK_NICKSRV], argv[TOK_ARG], argv[TOK_TEXT] ? argv[TOK_TEXT] : "");
 375         else if(!strncmp("NOTICE", argv[TOK_CMD], 7))
 376                 snprintf(message, PIPE_BUF, "-!- \"%s\")", argv[TOK_TEXT] ? argv[TOK_TEXT] : "");
 377         else if(!strncmp("PRIVMSG", argv[TOK_CMD], 8))
 378                 snprintf(message, PIPE_BUF, "<%s> %s", argv[TOK_NICKSRV], argv[TOK_TEXT] ? argv[TOK_TEXT] : "");
 379         if(!argv[TOK_CHAN] || !strncmp(argv[TOK_CHAN], nick, strlen(nick)))
 380                 print_out(argv[TOK_NICKSRV], message);
 381         else
 382                 print_out(argv[TOK_CHAN], message);
 383 }
 384
 385 static int read_line(int fd, size_t res_len, char *buf) {
 386         size_t i = 0;
 387         char c = 0;
 388         do {
 389                 if(read(fd, &c, sizeof(char)) != sizeof(char))
 390                         return -1;
 391                 buf[i++] = c;
 392         }
 393         while(c != '\n' && i < res_len);
 394         buf[i - 1] = 0;                 /* eliminates '\n' */
 395         return 0;
 396 }
 397
 398 static void handle_channels_input(Channel *c) {
 399         static char buf[PIPE_BUF];
 400         if(read_line(c->fd, PIPE_BUF, buf) == -1) {
 401                 close(c->fd);
 402                 int fd = open_channel(c->name);
 403                 if(fd != -1)
 404                         c->fd = fd;
 405                 else
 406                         rm_channel(c);
 407                 return;
 408         }
 409         proc_channels_input(c, buf);
 410 }
 411
 412 static void handle_server_output() {
 413         static char buf[PIPE_BUF];
 414         if(read_line(irc, PIPE_BUF, buf) == -1) {
 415                 perror("ii: remote host closed connection");
 416                 exit(EXIT_FAILURE);
 417         }
 418         proc_server_cmd(buf);
 419 }
 420
 421 static void run() {
 422         Channel *c;
 423         int r, maxfd;
 424         fd_set rd;
 425         struct timeval tv;
 426         char ping_msg[17] = "PING localhost\r\n";
 427
 428         for(;;) {
 429                 FD_ZERO(&rd);
 430                 maxfd = irc;
 431                 FD_SET(irc, &rd);
 432                 for(c = channels; c; c = c->next) {
 433                         if(maxfd < c->fd)
 434                                 maxfd = c->fd;
 435                         FD_SET(c->fd, &rd);
 436                 }
 437
 438                 tv.tv_sec = 120;
 439                 tv.tv_usec = 0;
 440                 r = select(maxfd + 1, &rd, 0, 0, &tv);
 441                 if(r < 0) {
 442                         if(errno == EINTR)
 443                                 continue;
 444                         perror("ii: error on select()");
 445                         exit(EXIT_FAILURE);
 446                 } else if(r == 0) {
 447                         if(time(NULL) - last_response >= PING_TIMEOUT) {
 448                                 print_out(NULL, "-!- ii shutting down: ping timeout");
 449                                 exit(EXIT_FAILURE);
 450                         }
 451                         write(irc, ping_msg, strlen(ping_msg));
 452                         continue;
 453                 }
 454                 if(FD_ISSET(irc, &rd)) {
 455                         handle_server_output();
 456                         last_response = time(NULL);
 457                 }
 458                 for(c = channels; c; c = c->next)
 459                         if(FD_ISSET(c->fd, &rd))
 460                                 handle_channels_input(c);
 461         }
 462 }
 463
 464 int main(int argc, char *argv[]) {
 465         int i;
 466         unsigned short port = SERVER_PORT;
 467         char *key = NULL, *fullname = NULL, *dir = NULL;
 468         char prefix[_POSIX_PATH_MAX] = "irc";
 469
 470         if (argc <= 1 || (argc == 2 && argv[1][0] == '-' && argv[1][1] == 'h')) usage();
 471
 472         for(i = 1; (i + 1 < argc) && (argv[i][0] == '-'); i++) {
 473                 switch (argv[i][1]) {
 474                         case 'i': snprintf(prefix,sizeof(prefix),"%s", argv[++i]); break;
 475                         case 's': host = argv[++i]; break;
 476                         case 'p': port = strtol(argv[++i], NULL, 10); break;
 477                         case 'n': snprintf(nick,sizeof(nick),"%s", argv[++i]); break;
 478                         case 'k': key = argv[++i]; break;
 479                         case 'f': fullname = argv[++i]; break;
 480                         case 'd': dir = argv[++i]; break;
 481                         default: usage(); break;
 482                 }
 483         }
 484         irc = tcpopen(port);
 485         if(!snprintf(path, sizeof(path), "%s/%s", prefix, dir ? dir : host)) {
 486                 fprintf(stderr, "%s", "ii: path to irc directory too long\n");
 487                 exit(EXIT_FAILURE);
 488         }
 489         create_dirtree(path);
 490
 491         add_channel(""); /* master channel */
 492         login(key, fullname);
 493         run();
 494
 495         return 0;
 496 }