sic.c

   1 /* (C)opyright MMV-MMVI Anselm R. Garbe <garbeam at gmail dot com>
   2  * (C)opyright MMV-MMVI Nico Golde <nico at ngolde dot de>
   3  * See LICENSE file for license details.
   4  */
   5 #include <errno.h>
   6 #include <netdb.h>
   7 #include <netinet/in.h>
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <string.h>
  11 #include <time.h>
  12 #include <unistd.h>
  13 #include <sys/socket.h>
  14 #include <sys/time.h>
  15
  16 #define PINGTIMEOUT 300
  17 #define MAXMSG 4096
  18
  19 enum { Tnick, Tuser, Tcmd, Tchan, Targ, Ttext, Tlast };
  20
  21 static char *server = "irc.oftc.net";
  22 static unsigned short port = 6667;
  23 static char *nick = NULL;
  24 static char *fullname = NULL;
  25 static char *password = NULL;
  26
  27 static char bufin[MAXMSG], bufout[MAXMSG];
  28 static char channel[256];
  29 static int srv;
  30 static time_t trespond;
  31
  32 static int
  33 getline(int fd, unsigned int len, char *buf) {
  34         unsigned int i = 0;
  35         char c;
  36
  37         do {
  38                 if(read(fd, &c, sizeof(char)) != sizeof(char))
  39                         return -1;
  40                 buf[i++] = c;
  41         }
  42         while(c != '\n' && i < len);
  43         buf[i - 1] = 0;
  44         return 0;
  45 }
  46
  47 static void
  48 pout(char *channel, char *msg) {
  49         static char timestr[18];
  50         time_t t = time(0);
  51
  52         strftime(timestr, sizeof timestr, "%F %R", localtime(&t));
  53         fprintf(stdout, "%-8.8s: %s %s\n", channel, timestr, msg);
  54 }
  55
  56 static void
  57 privmsg(char *channel, char *msg) {
  58         snprintf(bufout, sizeof bufout, "<%s> %s", nick, msg);
  59         pout(channel, bufout);
  60         snprintf(bufout, sizeof bufout, "PRIVMSG %s :%s\r\n", channel, msg);
  61         write(srv, bufout, strlen(bufout));
  62 }
  63
  64 static void
  65 parsein(char *msg) {
  66         char *p;
  67
  68         if(msg[0] == 0)
  69                 return;
  70         if(msg[0] != ':') {
  71                 privmsg(channel, msg);
  72                 return;
  73         }
  74         if(!strncmp(msg + 1, "j ", 2) && (msg[3] == '#'))
  75                 snprintf(bufout, sizeof bufout, "JOIN %s\r\n", &msg[3]);
  76         else if(!strncmp(msg + 1, "l ", 2))
  77                 snprintf(bufout, sizeof bufout, "PART %s :sic - 300 LOC are too much!\r\n", &msg[3]);
  78         else if(!strncmp(msg + 1, "m ", 2)) {
  79                 if((p = strchr(&msg[3], ' ')))
  80                         *(p++) = 0;
  81                 privmsg(&msg[3], p);
  82                 return;
  83         }
  84         else if(!strncmp(msg + 1, "s ", 2)) {
  85                 strncpy(channel, &msg[3], sizeof channel);
  86                 return;
  87         }
  88         else if(!strncmp(msg + 1, "t ", 2)) {
  89                 if((p = strchr(&msg[3], ' ')))
  90                         *(p++) = 0;
  91                 snprintf(bufout, sizeof bufout, "TOPIC %s :%s\r\n", &msg[3], p);
  92         }
  93         else
  94                 snprintf(bufout, sizeof bufout, "%s\r\n", &msg[1]);
  95         write(srv, bufout, strlen(bufout));
  96 }
  97
  98 static unsigned int
  99 tokenize(char **result, unsigned int reslen, char *str, char delim) {
 100         char *p, *n;
 101         unsigned int i = 0;
 102
 103         if(!str)
 104                 return 0;
 105         for(n = str; *n == delim; n++);
 106         p = n;
 107         for(i = 0; *n != 0;) {
 108                 if(i == reslen)
 109                         return i;
 110                 if(*n == delim) {
 111                         *n = 0;
 112                         if(strlen(p))
 113                                 result[i++] = p;
 114                         p = ++n;
 115                 } else
 116                         n++;
 117         }
 118         if((i < reslen) && (p < n) && strlen(p))
 119                 result[i++] = p;
 120         return i;       /* number of tokens */
 121 }
 122
 123 static void
 124 parsesrv(char *msg) {
 125         char *argv[Tlast], *cmd, *p;
 126         int i;
 127
 128         if(!msg || !(*msg))
 129                 return;
 130         for(i = 0; i < Tlast; i++)
 131                 argv[i] = NULL;
 132         /* <bufout>  ::= [':' <prefix> <SPACE> ] <command> <params> <crlf>
 133          * <prefix>   ::= <servername> | <nick> [ '!' <user> ] [ '@' <server> ]
 134          * <command>  ::= <letter> { <letter> } | <number> <number> <number>
 135          * <SPACE>    ::= ' ' { ' ' }
 136          * <params>   ::= <SPACE> [ ':' <trailing> | <middle> <params> ]
 137          * <middle>   ::= <Any *non-empty* sequence of octets not including SPACE
 138          * or NUL or CR or LF, the first of which may not be ':'>
 139          * <trailing> ::= <Any, possibly *empty*, sequence of octets not including NUL or CR or LF>
 140          * <crlf>     ::= CR LF
 141          */
 142         if(msg[0] == ':') { /* check prefix */
 143                 if (!(p = strchr(msg, ' ')))
 144                         return;
 145                 *p = 0;
 146                 for(++p; *p == ' '; p++);
 147                 cmd = p;
 148                 argv[Tnick] = &msg[1];
 149                 if((p = strchr(msg, '!'))) {
 150                         *p = 0;
 151                         argv[Tuser] = ++p;
 152                 }
 153         } else
 154                 cmd = msg;
 155         /* remove CRLFs */
 156         for(p = cmd; p && *p != 0; p++)
 157                 if(*p == '\r' || *p == '\n')
 158                         *p = 0;
 159         if((p = strchr(cmd, ':'))) {
 160                 *p = 0;
 161                 argv[Ttext] = ++p;
 162         }
 163
 164         if(!strncmp("PRIVMSG", cmd, 7) || !strncmp("PING", cmd, 4)) {
 165                 if(tokenize(&argv[Tcmd], Tlast - Tcmd, cmd, ' ') != Tlast - Tcmd)
 166                         return;
 167                 if(!strncmp("PRIVMSG", argv[Tcmd], 8)) {
 168                         snprintf(bufout, sizeof bufout, "<%s> %s",
 169                                         argv[Tnick], argv[Ttext] ? argv[Ttext] : "");
 170                         pout(argv[Tchan], bufout);
 171                 }
 172                 else if(!strncmp("PING", argv[Tcmd], 5)) {
 173                         snprintf(bufout, sizeof bufout, "PONG %s\r\n", argv[Ttext]);
 174                         write(srv, bufout, strlen(bufout));
 175                 }
 176                 return;
 177         }
 178         snprintf(bufout, sizeof bufout, "-!- %s", cmd);
 179         pout(server, bufout);
 180 }
 181
 182 int
 183 main(int argc, char *argv[]) {
 184         int i;
 185         struct timeval tv;
 186         struct hostent *hp;
 187         static struct sockaddr_in addr;  /* initially filled with 0's */
 188         char ping[256];
 189         fd_set rd;
 190
 191         nick = fullname = getenv("USER");
 192         for(i = 1; i < argc; i++)
 193                 if(!strncmp(argv[i], "-s", 3)) {
 194                         if(++i < argc) server = argv[i];
 195                 }
 196                 else if(!strncmp(argv[i], "-p", 3)) {
 197                         if(++i < argc) port = (unsigned short)atoi(argv[i]);
 198                 }
 199                 else if(!strncmp(argv[i], "-n", 3)) {
 200                         if(++i < argc) nick = argv[i];
 201                 }
 202                 else if(!strncmp(argv[i], "-k", 3)) {
 203                         if(++i < argc) password = argv[i];
 204                 }
 205                 else if(!strncmp(argv[i], "-f", 3)) {
 206                         if(++i < argc) fullname = argv[i];
 207                 }
 208                 else if(!strncmp(argv[i], "-v", 3)) {
 209                         fputs("sic-"VERSION", (C)opyright MMVI Anselm R. Garbe\n", stdout);
 210                         exit(EXIT_SUCCESS);
 211                 }
 212                 else {
 213                         fputs("usage: sic [-s server] [-p port] [-n nick]"
 214                                         " [-k keyword] [-f fullname] [-v]\n", stderr);
 215                         exit(EXIT_FAILURE);
 216                 }
 217
 218         /* init */
 219         if((srv = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
 220                 fprintf(stderr, "sic: cannot connect server '%s'\n", server);
 221                 exit(EXIT_FAILURE);
 222         }
 223         if (NULL == (hp = gethostbyname(server))) {
 224                 fprintf(stderr, "sic: cannot resolve hostname '%s'\n", server);
 225                 exit(EXIT_FAILURE);
 226         }
 227         addr.sin_family = AF_INET;
 228         addr.sin_port = htons(port);
 229         memcpy(&addr.sin_addr, hp->h_addr, hp->h_length);
 230         if(connect(srv, (struct sockaddr *) &addr, sizeof(struct sockaddr_in))) {
 231                 close(srv);
 232                 fprintf(stderr, "sic: cannot connect server '%s'\n", server);
 233                 exit(EXIT_FAILURE);
 234         }
 235         /* login */
 236         if(password)
 237                 snprintf(bufout, sizeof bufout,
 238                                 "PASS %s\r\nNICK %s\r\nUSER %s localhost %s :%s\r\n",
 239                                 password, nick, nick, server, fullname);
 240         else
 241                 snprintf(bufout, sizeof bufout, "NICK %s\r\nUSER %s localhost %s :%s\r\n",
 242                                  nick, nick, server, fullname);
 243         write(srv, bufout, strlen(bufout));
 244         snprintf(ping, sizeof ping, "PING %s\r\n", server);
 245         channel[0] = 0;
 246         setbuf(stdout, NULL); /* unbuffered stdout */
 247
 248         for(;;) { /* main loop */
 249                 FD_ZERO(&rd);
 250                 FD_SET(0, &rd);
 251                 FD_SET(srv, &rd);
 252                 tv.tv_sec = 120;
 253                 tv.tv_usec = 0;
 254                 i = select(srv + 1, &rd, 0, 0, &tv);
 255                 if(i < 0) {
 256                         if(errno == EINTR)
 257                                 continue;
 258                         perror("sic: error on select()");
 259                         exit(EXIT_FAILURE);
 260                 } else if(i == 0) {
 261                         if(time(NULL) - trespond >= PINGTIMEOUT) {
 262                                 pout(server, "-!- sic shutting down: parse timeout");
 263                                 exit(EXIT_FAILURE);
 264                         }
 265                         write(srv, ping, strlen(ping));
 266                         continue;
 267                 }
 268                 if(FD_ISSET(srv, &rd)) {
 269                         if(getline(srv, sizeof bufin, bufin) == -1) {
 270                                 perror("sic: remote server closed connection");
 271                                 exit(EXIT_FAILURE);
 272                         }
 273                         parsesrv(bufin);
 274                         trespond = time(NULL);
 275                 }
 276                 if(FD_ISSET(0, &rd)) {
 277                         if(getline(0, sizeof bufin, bufin) == -1) {
 278                                 perror("sic: broken pipe");
 279                                 exit(EXIT_FAILURE);
 280                         }
 281                         parsein(bufin);
 282                 }
 283         }
 284         return 0;
 285 }