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