ii.c

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