/* (C)opyright MMV-MMVI Anselm R. Garbe <garbeam at gmail dot com>

* (C)opyright MMV-MMXI Nico Golde <nico at ngolde dot de>

* See LICENSE file for license details. */

#include <errno.h>

#include <netdb.h>

#include <sys/types.h>

#include <sys/stat.h>

#include <sys/socket.h>

#include <sys/select.h>

#include <netinet/in.h>

#include <stdio.h>

#include <stdlib.h>

#include <limits.h>

#include <fcntl.h>

#include <string.h>

#include <pwd.h>

#include <signal.h>

#include <ctype.h>

#include <time.h>

#include <unistd.h>

#include <openssl/rand.h>

#include <openssl/ssl.h>

#include <openssl/err.h>

#ifndef PIPE_BUF /* FreeBSD don't know PIPE_BUF */

#define PIPE_BUF 4096

#endif

#define PING_TIMEOUT 300

#define SERVER_PORT 6667

#define SSL_SERVER_PORT 6697

#define WRITE(con, mes, len) (use_ssl ? SSL_write(irc->sslHandle, mes, len) : write(con->irc, mes, len))

#define READ(fd, buf, size) (from_server && use_ssl ? SSL_read(irc->sslHandle, buf, size) : read(fd, buf, size))

typedef struct {

int irc;

SSL *sslHandle;

SSL_CTX *sslContext;

} conn;

enum { TOK_NICKSRV = 0, TOK_USER, TOK_CMD, TOK_CHAN, TOK_ARG, TOK_TEXT, TOK_LAST };

typedef struct Channel Channel;

struct Channel {

};

conn *irc;

static int use_ssl;

static time_t last_response;

static Channel *channels = NULL;

static char *host = "irc.freenode.net";

static char nick[32]; /* might change while running */

static char path[_POSIX_PATH_MAX];

static char message[PIPE_BUF]; /* message buf used for communication */

static void usage() {

fputs("ii - irc it - " VERSION "\n"

"(C)opyright MMV-MMVI Anselm R. Garbe\n"

"(C)opyright MMV-MMXI Nico Golde\n"

"usage: ii [-i <irc dir>] [-s <host>] [-p <port>] [-e ssl]\n"

" [-n <nick>] [-k <password>] [-f <fullname>]\n", stderr);

exit(EXIT_FAILURE);

}

static char *striplower(char *s) {

char *p = NULL;

for(p = s; p && *p; p++) {

if(*p == '/') *p = ',';

*p = tolower(*p);

}

return s;

}

/* creates directories top-down, if necessary */

static void create_dirtree(const char *dir) {

char tmp[256];

char *p = NULL;

size_t len;

snprintf(tmp, sizeof(tmp),"%s",dir);

len = strlen(tmp);

if(tmp[len - 1] == '/')

tmp[len - 1] = 0;

for(p = tmp + 1; *p; p++)

if(*p == '/') {

*p = 0;

mkdir(tmp, S_IRWXU);

*p = '/';

}

mkdir(tmp, S_IRWXU);

}

static int get_filepath(char *filepath, size_t len, char *channel, char *file) {

if(channel) {

if(!snprintf(filepath, len, "%s/%s", path, channel))

return 0;

create_dirtree(filepath);

return snprintf(filepath, len, "%s/%s/%s", path, channel, file);

}

return snprintf(filepath, len, "%s/%s", path, file);

}

static void create_filepath(char *filepath, size_t len, char *channel, char *suffix) {

if(!get_filepath(filepath, len, striplower(channel), suffix)) {

fputs("ii: path to irc directory too long\n", stderr);

exit(EXIT_FAILURE);

}

}

static int open_channel(char *name) {

static char infile[256];

create_filepath(infile, sizeof(infile), name, "in");

if(access(infile, F_OK) == -1)

mkfifo(infile, S_IRWXU);

return open(infile, O_RDONLY | O_NONBLOCK, 0);

}

static void add_channel(char *cname) {

Channel *c;

int fd;

char *name = striplower(cname);

for(c = channels; c; c = c->next)

if(!strcmp(name, c->name))

return; /* already handled */

fd = open_channel(name);

if(fd == -1) {

printf("ii: exiting, cannot create in channel: %s\n", name);

exit(EXIT_FAILURE);

}

c = calloc(1, sizeof(Channel));

if(!c) {

perror("ii: cannot allocate memory");

exit(EXIT_FAILURE);

}

if(!channels) channels = c;

else {

c->next = channels;

channels = c;

}

c->fd = fd;

c->name = strdup(name);

}

static void rm_channel(Channel *c) {

Channel *p;

if(channels == c) channels = channels->next;

else {

for(p = channels; p && p->next != c; p = p->next);

if(p->next == c)

p->next = c->next;

}

free(c->name);

free(c);

}

static void login(char *key, char *fullname) {

if(key) snprintf(message, PIPE_BUF,

"PASS %s\r\nNICK %s\r\nUSER %s localhost %s :%s\r\n", key,

nick, nick, host, fullname ? fullname : nick);

else snprintf(message, PIPE_BUF, "NICK %s\r\nUSER %s localhost %s :%s\r\n",

nick, nick, host, fullname ? fullname : nick);

WRITE(irc, message, strlen(message)); /* login */

}

conn *tcpopen(unsigned short port) {

int fd;

conn *c;

struct sockaddr_in sin;

struct hostent *hp = gethostbyname(host);

memset(&sin, 0, sizeof(struct sockaddr_in));

if(!hp) {

perror("ii: cannot retrieve host information");

exit(EXIT_FAILURE);

}

sin.sin_family = AF_INET;

memcpy(&sin.sin_addr, hp->h_addr, hp->h_length);

sin.sin_port = htons(port);

if((fd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {

perror("ii: cannot create socket");

exit(EXIT_FAILURE);

}

if(connect(fd, (const struct sockaddr *) &sin, sizeof(sin)) < 0) {

perror("ii: cannot connect to host");

exit(EXIT_FAILURE);

}

c = malloc(sizeof(conn));

c->irc = fd;

if(use_ssl) {

c->sslHandle = NULL;

c->sslContext = NULL;

SSL_load_error_strings();

SSL_library_init();

c->sslContext = SSL_CTX_new(SSLv23_client_method());

if(c->sslContext == NULL)

ERR_print_errors_fp(stderr);

c->sslHandle = SSL_new(c->sslContext);

if(!SSL_set_fd(c->sslHandle, c->irc)

|| (SSL_connect(c->sslHandle) != 1))

ERR_print_errors_fp(stderr);

}

return c;

}

static size_t tokenize(char **result, size_t reslen, char *str, char delim) {

char *p = NULL, *n = NULL;

size_t i;

if(!str)

return 0;

for(n = str; *n == ' '; n++);

p = n;

for(i = 0; *n != 0;) {

if(i == reslen)

return 0;

if(i > TOK_CHAN - TOK_CMD && strtol(result[0], NULL, 10) > 0) delim=':'; /* workaround non-RFC compliant messages */

if(*n == delim) {

*n = 0;

result[i++] = p;

p = ++n;

} else

n++;

}

if(i<reslen && p < n && strlen(p))

result[i++] = p;

return i; /* number of tokens */

}

static void print_out(char *channel, char *buf) {

static char outfile[256], server[256], buft[18];

FILE *out = NULL;

time_t t = time(0);

if(channel) snprintf(server, sizeof(server), "-!- %s", channel);

if(strstr(buf, server)) channel="";

create_filepath(outfile, sizeof(outfile), channel, "out");

if(!(out = fopen(outfile, "a"))) return;

if(channel && channel[0]) add_channel(channel);

strftime(buft, sizeof(buft), "%F %R", localtime(&t));

fprintf(out, "%s %s\n", buft, buf);

fclose(out);

}

static void proc_channels_privmsg(char *channel, char *buf) {

snprintf(message, PIPE_BUF, "<%s> %s", nick, buf);

print_out(channel, message);

snprintf(message, PIPE_BUF, "PRIVMSG %s :%s\r\n", channel, buf);

WRITE(irc, message, strlen(message));

}

static void proc_channels_input(Channel *c, char *buf) {

/* static char infile[256]; */

char *p = NULL;

if(buf[0] != '/' && buf[0] != 0) {

proc_channels_privmsg(c->name, buf);

return;

}

message[0] = '\0';

if(buf[2] == ' ' || buf[2] == '\0') switch (buf[1]) {

case 'j':

p = strchr(&buf[3], ' ');

if(p) *p = 0;

if((buf[3]=='#')||(buf[3]=='&')||(buf[3]=='+')||(buf[3]=='!')){

if(p) snprintf(message, PIPE_BUF, "JOIN %s %s\r\n", &buf[3], p + 1); /* password protected channel */

else snprintf(message, PIPE_BUF, "JOIN %s\r\n", &buf[3]);

add_channel(&buf[3]);

}

else if(p){

add_channel(&buf[3]);

proc_channels_privmsg(&buf[3], p + 1);

return;

}

break;

case 't':

if(strlen(buf)>=3) snprintf(message, PIPE_BUF, "TOPIC %s :%s\r\n", c->name, &buf[3]);

break;

case 'a':

if(strlen(buf)>=3){

snprintf(message, PIPE_BUF, "-!- %s is away \"%s\"", nick, &buf[3]);

print_out(c->name, message);

}

if(buf[2] == 0 || strlen(buf)<3) /* or used to make else part safe */

snprintf(message, PIPE_BUF, "AWAY\r\n");

else

snprintf(message, PIPE_BUF, "AWAY :%s\r\n", &buf[3]);

break;

case 'n':

if(strlen(buf)>=3){

snprintf(nick, sizeof(nick),"%s", &buf[3]);

snprintf(message, PIPE_BUF, "NICK %s\r\n", &buf[3]);

}

break;

case 'l':

if(c->name[0] == 0)

return;

if(buf[2] == ' ' && strlen(buf)>=3)

snprintf(message, PIPE_BUF, "PART %s :%s\r\n", c->name, &buf[3]);

else

snprintf(message, PIPE_BUF,

"PART %s :ii - 500 SLOC are too much\r\n", c->name);

WRITE(irc, message, strlen(message));

close(c->fd);

/*create_filepath(infile, sizeof(infile), c->name, "in");

unlink(infile); */

rm_channel(c);

return;

break;

default:

snprintf(message, PIPE_BUF, "%s\r\n", &buf[1]);

break;

}

else

snprintf(message, PIPE_BUF, "%s\r\n", &buf[1]);

if (message[0] != '\0')

WRITE(irc, message, strlen(message));

}

static void proc_server_cmd(char *buf) {

char *argv[TOK_LAST], *cmd = NULL, *p = NULL;

int i;

if(!buf || *buf=='\0')

return;

for(i = 0; i < TOK_LAST; i++)

argv[i] = NULL;

/* <message> ::= [':' <prefix> <SPACE> ] <command> <params> <crlf>

<prefix> ::= <servername> | <nick> [ '!' <user> ] [ '@' <host> ]

<command> ::= <letter> { <letter> } | <number> <number> <number>

<SPACE> ::= ' ' { ' ' }

<params> ::= <SPACE> [ ':' <trailing> | <middle> <params> ]

<middle> ::= <Any *non-empty* sequence of octets not including SPACE

or NUL or CR or LF, the first of which may not be ':'>

<trailing> ::= <Any, possibly *empty*, sequence of octets not including NUL or CR or LF>

<crlf> ::= CR LF */

if(buf[0] == ':') { /* check prefix */

if (!(p = strchr(buf, ' '))) return;

*p = 0;

for(++p; *p == ' '; p++);

cmd = p;

argv[TOK_NICKSRV] = &buf[1];

if((p = strchr(buf, '!'))) {

*p = 0;

argv[TOK_USER] = ++p;

}

} else

cmd = buf;

/* remove CRLFs */

for(p = cmd; p && *p != 0; p++)

if(*p == '\r' || *p == '\n')

*p = 0;

if((p = strchr(cmd, ':'))) {

*p = 0;

argv[TOK_TEXT] = ++p;

}

tokenize(&argv[TOK_CMD], TOK_LAST - TOK_CMD, cmd, ' ');

if(!argv[TOK_CMD] || !strncmp("PONG", argv[TOK_CMD], 5)) {

return;

} else if(!strncmp("PING", argv[TOK_CMD], 5)) {

snprintf(message, PIPE_BUF, "PONG %s\r\n", argv[TOK_TEXT]);

WRITE(irc, message, strlen(message));

return;

} else if(!argv[TOK_NICKSRV] || !argv[TOK_USER]) { /* server command */

snprintf(message, PIPE_BUF, "%s%s", argv[TOK_ARG] ? argv[TOK_ARG] : "", argv[TOK_TEXT] ? argv[TOK_TEXT] : "");

print_out(0, message);

return;

} else if(!strncmp("ERROR", argv[TOK_CMD], 6))

snprintf(message, PIPE_BUF, "-!- error %s", argv[TOK_TEXT] ? argv[TOK_TEXT] : "unknown");

else if(!strncmp("JOIN", argv[TOK_CMD], 5)) {

if (argv[TOK_TEXT] != NULL)

argv[TOK_CHAN] = argv[TOK_TEXT];

snprintf(message, PIPE_BUF, "-!- %s(%s) has joined %s", argv[TOK_NICKSRV], argv[TOK_USER], argv[TOK_CHAN]);

} else if(!strncmp("PART", argv[TOK_CMD], 5)) {

snprintf(message, PIPE_BUF, "-!- %s(%s) has left %s", argv[TOK_NICKSRV], argv[TOK_USER], argv[TOK_CHAN]);

} else if(!strncmp("MODE", argv[TOK_CMD], 5))

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] : "");

else if(!strncmp("QUIT", argv[TOK_CMD], 5))

snprintf(message, PIPE_BUF, "-!- %s(%s) has quit \"%s\"", argv[TOK_NICKSRV], argv[TOK_USER], argv[TOK_TEXT] ? argv[TOK_TEXT] : "");

else if(!strncmp("NICK", argv[TOK_CMD], 5))

snprintf(message, PIPE_BUF, "-!- %s changed nick to %s", argv[TOK_NICKSRV], argv[TOK_TEXT]);

else if(!strncmp("TOPIC", argv[TOK_CMD], 6))

snprintf(message, PIPE_BUF, "-!- %s changed topic to \"%s\"", argv[TOK_NICKSRV], argv[TOK_TEXT] ? argv[TOK_TEXT] : "");

else if(!strncmp("KICK", argv[TOK_CMD], 5))

snprintf(message, PIPE_BUF, "-!- %s kicked %s (\"%s\")", argv[TOK_NICKSRV], argv[TOK_ARG], argv[TOK_TEXT] ? argv[TOK_TEXT] : "");

else if(!strncmp("NOTICE", argv[TOK_CMD], 7))

snprintf(message, PIPE_BUF, "-!- \"%s\")", argv[TOK_TEXT] ? argv[TOK_TEXT] : "");

else if(!strncmp("PRIVMSG", argv[TOK_CMD], 8))

snprintf(message, PIPE_BUF, "<%s> %s", argv[TOK_NICKSRV], argv[TOK_TEXT] ? argv[TOK_TEXT] : "");

if(!argv[TOK_CHAN] || !strncmp(argv[TOK_CHAN], nick, strlen(nick)))

print_out(argv[TOK_NICKSRV], message);

else

print_out(argv[TOK_CHAN], message);

}

static int read_line(int fd, size_t res_len, char *buf, int from_server) {

size_t i = 0;

char c = 0;

do {

if(READ(fd, &c, sizeof(char)) != sizeof(char))

return -1;

buf[i++] = c;

}

while(c != '\n' && i < res_len);

buf[i - 1] = 0; /* eliminates '\n' */

return 0;

}

static void handle_channels_input(Channel *c) {

static char buf[PIPE_BUF];

if(read_line(c->fd, PIPE_BUF, buf, 0) == -1) {

close(c->fd);

int fd = open_channel(c->name);

if(fd != -1)

c->fd = fd;

else

rm_channel(c);

return;

}

proc_channels_input(c, buf);

}

static void handle_server_output() {

static char buf[PIPE_BUF];

if(read_line(irc->irc, PIPE_BUF, buf, 1) == -1) {

perror("ii: remote host closed connection");

exit(EXIT_FAILURE);

}

proc_server_cmd(buf);

}

static void run() {

Channel *c;

int r, maxfd;

fd_set rd;

struct timeval tv;

char ping_msg[512];

snprintf(ping_msg, sizeof(ping_msg), "PING %s\r\n", host);

for(;;) {

FD_ZERO(&rd);

maxfd = irc->irc;

FD_SET(irc->irc, &rd);

for(c = channels; c; c = c->next) {

if(maxfd < c->fd)

maxfd = c->fd;

FD_SET(c->fd, &rd);

}

tv.tv_sec = 120;

tv.tv_usec = 0;

r = select(maxfd + 1, &rd, 0, 0, &tv);

if(r < 0) {

if(errno == EINTR)

continue;

perror("ii: error on select()");

exit(EXIT_FAILURE);

} else if(r == 0) {

if(time(NULL) - last_response >= PING_TIMEOUT) {

print_out(NULL, "-!- ii shutting down: ping timeout");

exit(EXIT_FAILURE);

}

WRITE(irc, ping_msg, strlen(ping_msg));

continue;

}

if(FD_ISSET(irc->irc, &rd)) {

handle_server_output();

last_response = time(NULL);

}

for(c = channels; c; c = c->next)

if(FD_ISSET(c->fd, &rd))

handle_channels_input(c);

}

}

int main(int argc, char *argv[]) {

int i;

unsigned short port = SERVER_PORT;

struct passwd *spw = getpwuid(getuid());

char *key = NULL, *fullname = NULL;

char prefix[_POSIX_PATH_MAX];

if(!spw) {

fputs("ii: getpwuid() failed\n", stderr);

exit(EXIT_FAILURE);

}

snprintf(nick, sizeof(nick), "%s", spw->pw_name);

snprintf(prefix, sizeof(prefix),"%s/irc", spw->pw_dir);

if (argc <= 1 || (argc == 2 && argv[1][0] == '-' && argv[1][1] == 'h')) usage();

for(i = 1; (i + 1 < argc) && (argv[i][0] == '-'); i++) {

switch (argv[i][1]) {

case 'i': snprintf(prefix,sizeof(prefix),"%s", argv[++i]); break;

case 's': host = argv[++i]; break;

case 'p': port = strtol(argv[++i], NULL, 10); break;

case 'n': snprintf(nick,sizeof(nick),"%s", argv[++i]); break;

case 'k': key = getenv(argv[++i]); break;

case 'e': use_ssl = 1; ++i; break;

case 'f': fullname = argv[++i]; break;

default: usage(); break;

}

}

if(use_ssl)

port = port == SERVER_PORT ? SSL_SERVER_PORT : port;

irc = tcpopen(port);

if(!snprintf(path, sizeof(path), "%s/%s", prefix, host)) {

fputs("ii: path to irc directory too long\n", stderr);

exit(EXIT_FAILURE);

}

create_dirtree(path);

add_channel(""); /* master channel */

login(key, fullname);

run();

return EXIT_SUCCESS;

}