/* Routines to maintain a list of online users.
*
* IRC Services is copyright (c) 1996-2007 Andrew Church.
* E-mail: <achurch@achurch.org>
* Parts written by Andrew Kempe and others.
* This program is free but copyrighted software; see the file COPYING for
* details.
*/
#include "services.h"
#include "modules.h"
#include "hash.h"
/*************************************************************************/
/* Maximum number of tries to randomly select a new guest nick when the
* first one chosen is in use before giving up.
*/
#define MAKEGUESTNICK_TRIES 1000
/*************************************************************************/
void add_user(User *user); /* to avoid "no prototype" warning */
void del_user(User *user); /* same */
DEFINE_HASH(user, User, nick)
int32 usercnt = 0, opcnt = 0, maxusercnt = 0;
time_t maxusertime;
static int cb_check = -1;
static int cb_create = -1;
static int cb_servicestamp_change = -1;
static int cb_nickchange1 = -1;
static int cb_nickchange2 = -1;
static int cb_delete = -1;
static int cb_mode = -1;
static int cb_chan_part = -1;
static int cb_chan_kick = -1;
/*************************************************************************/
int user_init(int ac, char **av)
{
cb_check = register_callback(NULL, "user check");
cb_create = register_callback(NULL, "user create");
cb_servicestamp_change=register_callback(NULL,"user servicestamp change");
cb_nickchange1 = register_callback(NULL, "user nickchange (before)");
cb_nickchange2 = register_callback(NULL, "user nickchange (after)");
cb_delete = register_callback(NULL, "user delete");
cb_mode = register_callback(NULL, "user MODE");
cb_chan_part = register_callback(NULL, "channel PART");
cb_chan_kick = register_callback(NULL, "channel KICK");
if (cb_check < 0 || cb_create < 0 || cb_servicestamp_change < 0
|| cb_nickchange1 < 0 || cb_nickchange2 < 0 || cb_delete < 0
|| cb_mode < 0 || cb_chan_part < 0 || cb_chan_kick < 0
) {
log("user_init: register_callback() failed\n");
return 0;
}
return 1;
}
/*************************************************************************/
void user_cleanup(void)
{
User *u;
for (u = first_user(); u; u = next_user())
del_user(u);
unregister_callback(NULL, cb_chan_kick);
unregister_callback(NULL, cb_chan_part);
unregister_callback(NULL, cb_mode);
unregister_callback(NULL, cb_delete);
unregister_callback(NULL, cb_nickchange2);
unregister_callback(NULL, cb_nickchange1);
unregister_callback(NULL, cb_servicestamp_change);
unregister_callback(NULL, cb_create);
unregister_callback(NULL, cb_check);
}
/*************************************************************************/
/************************* User list management **************************/
/*************************************************************************/
/* Allocate a new User structure, fill in basic values, link it to the
* overall list, and return it. Always successful.
*/
static User *new_user(const char *nick)
{
User *user;
user = scalloc(sizeof(User), 1);
if (!nick)
nick = "";
strscpy(user->nick, nick, NICKMAX);
add_user(user);
usercnt++;
if (usercnt > maxusercnt) {
maxusercnt = usercnt;
maxusertime = time(NULL);
if (LogMaxUsers)
log("user: New maximum user count: %d", maxusercnt);
}
return user;
}
/*************************************************************************/
/* Change the nickname of a user, and move pointers as necessary. */
static void change_user_nick(User *user, const char *nick)
{
del_user(user);
strscpy(user->nick, nick, NICKMAX);
add_user(user);
}
/*************************************************************************/
/* Remove and free a User structure. */
static void delete_user(User *user)
{
struct u_chanlist *c, *c2;
struct u_chaninfolist *ci, *ci2;
usercnt--;
if (is_oper(user))
opcnt--;
free(user->username);
free(user->host);
free(user->ipaddr);
free(user->realname);
free(user->fakehost);
free(user->id_nicks);
LIST_FOREACH_SAFE (c, user->chans, c2) {
chan_deluser(user, c->chan);
free(c);
}
LIST_FOREACH_SAFE (ci, user->id_chans, ci2)
free(ci);
#define next snext
#define prev sprev
if (user->server)
LIST_REMOVE(user, user->server->userlist);
#undef next
#undef prev
del_user(user);
free(user);
}
/*************************************************************************/
/*************************************************************************/
/* Remove a user on QUIT/KILL. Calls the user delete callback and then
* deletes the User structure.
*/
void quit_user(User *user, const char *quitmsg, int is_kill)
{
call_callback_3(NULL, cb_delete, user, quitmsg, is_kill);
delete_user(user);
}
/*************************************************************************/
/* Return statistics. Pointers are assumed to be valid. */
void get_user_stats(long *nusers, long *memuse)
{
long count = 0, mem = 0;
User *user;
struct u_chanlist *uc;
struct u_chaninfolist *uci;
for (user = first_user(); user; user = next_user()) {
count++;
mem += sizeof(*user);
if (user->username)
mem += strlen(user->username)+1;
if (user->host)
mem += strlen(user->host)+1;
if (user->realname)
mem += strlen(user->realname)+1;
LIST_FOREACH (uc, user->chans)
mem += sizeof(*uc);
LIST_FOREACH (uci, user->id_chans)
mem += sizeof(*uci);
}
*nusers = count;
*memuse = mem;
}
/*************************************************************************/
/************************* Internal routines *****************************/
/*************************************************************************/
/* Part a user from a channel given the user's u_chanlist entry for the
* channel. */
static void part_channel_uc(User *user, struct u_chanlist *uc, int callback,
const char *param)
{
call_callback_3(NULL, callback, uc->chan, user, param);
chan_deluser(user, uc->chan);
LIST_REMOVE(uc, user->chans);
free(uc);
}
/*************************************************************************/
/************************* Message handlers ******************************/
/*************************************************************************/
/* Handle a server NICK command. Parameters must be in the following order.
* av[0] = nick
* If a new user:
* av[1] = hop count
* av[2] = signon time
* av[3] = username
* av[4] = hostname
* av[5] = server
* av[6] = real name
* av[7] = services stamp (if ac >= 8; NULL if none)
* av[8] = IP address (if ac >= 9; NULL if unknown)
* av[9..] available for protocol module use
* Else:
* av[1] = time of change
* Return 1 if message was accepted, 0 if rejected (AKILL/session limit).
*/
int do_nick(const char *source, int ac, char **av)
{
User *user;
if (!*source) {
/* This is a new user; create a User structure for it. */
if (debug)
log("debug: new user: %s", av[0]);
/* We used to ignore the ~ which a lot of ircd's use to indicate no
* identd response. That caused channel bans to break, so now we
* just take what the server gives us. People are still encouraged
* to read the RFCs and stop doing anything to usernames depending
* on the result of an identd lookup.
*/
/* First check whether the user should be allowed on. */
if (call_callback_2(NULL, cb_check, ac, av))
return 0;
/* User was accepted; allocate User structure and fill it in. */
user = new_user(av[0]);
user->my_signon = time(NULL);
user->signon = strtotime(av[2], NULL);
user->username = sstrdup(av[3]);
user->host = sstrdup(av[4]);
user->server = get_server(av[5]);
user->realname = sstrdup(av[6]);
if (ac >= 8 && av[7])
user->servicestamp = strtoul(av[7], NULL, 10);
else
user->servicestamp = (uint32)user->signon;
if (ac >= 9 && av[8])
user->ipaddr = sstrdup(av[8]);
else
user->ipaddr = NULL;
#define next snext
#define prev sprev
if (user->server)
LIST_INSERT(user, user->server->userlist);
#undef next
#undef prev
call_callback_3(NULL, cb_create, user, ac, av);
if (ac >= 8 && av[7] && !user->servicestamp) {
/* A servicestamp was provided, but it was zero, so assign one.
* Note that we use a random value for the initial Services
* stamp instead of the current time for the following reason:
*
* Suppose you have a network with an average of more than one
* new user per second; for the sake of argument, assume there
* are an average of 1.3 new users per second. If the initial
* Services stamp is T, the current time, then in 100 seconds
* (i.e. at T+100) the Services stamp will have gone to T+130.
* (In reality, it would jump much higher on the initial net
* burst when no users have Services stamps, but that does not
* affect this argument.)
*
* If Services is now restarted, clearing the last used stamp
* value, then assuming 5 seconds for restart, Services will
* receive a network burst at T+105. However! While most of
* the users will already have Services stamps, any new users
* (as well as any users which connect after the network burst)
* will be assigned new Services stamps starting with the
* default value of the current time, in this case T+105. But
* other users _already_ have Services stamp values in the
* range T+105 to T+130 from the previous run--thus you have
* Services stamp collisions, and all the security problems
* that go with them.
*
* Obviously, this possibility does not disappear entirely by
* using a random initial value, but it becomes much more
* unlikely.
*
* Note that Unreal 3.1.1 upper-bounds values at 2^31-1, so we
* limit ourselves to 31 bits here, even though our field is
* unsigned.
*/
static int32 servstamp = 0;
if (servstamp == 0)
servstamp = (rand() & 0x7FFFFFFF) | 1;
user->servicestamp = servstamp++;
if (servstamp <= 0)
servstamp = 1;
call_callback_1(NULL, cb_servicestamp_change, user);
}
} else {
/* An old user changing nicks. */
char oldnick[NICKMAX];
user = get_user(source);
if (!user) {
log("user: NICK from nonexistent nick %s: %s", source,
merge_args(ac, av));
return 0;
}
if (debug)
log("debug: %s changes nick to %s", source, av[0]);
strscpy(oldnick, user->nick, NICKMAX);
call_callback_2(NULL, cb_nickchange1, user, av[0]);
/* Flush out all mode changes; necessary to avoid desynch (otherwise
* we can't find the user when the mode goes out later). The IRC
* servers will take care of translating the old nick to the new one */
set_cmode(NULL, NULL);
change_user_nick(user, av[0]);
call_callback_2(NULL, cb_nickchange2, user, oldnick);
}
return 1;
}
/*************************************************************************/
/* Handle a JOIN command.
* av[0] = channels to join
*/
void do_join(const char *source, int ac, char **av)
{
User *user;
char *s, *t;
user = get_user(source);
if (!user) {
log("user: JOIN from nonexistent user %s: %s", source,
merge_args(ac, av));
return;
}
t = av[0];
while (*(s=t)) {
t = s + strcspn(s, ",");
if (*t)
*t++ = 0;
if (debug)
log("debug: %s joins %s", source, s);
if (*s == '0')
part_all_channels(user);
else
join_channel(user, s, 0);
}
}
/*************************************************************************/
/* Handle a PART command.
* av[0] = channels to leave
* av[1] = reason (optional)
*/
void do_part(const char *source, int ac, char **av)
{
User *user;
char *s, *t;
user = get_user(source);
if (!user) {
log("user: PART from nonexistent user %s: %s", source,
merge_args(ac, av));
return;
}
t = av[0];
while (*(s=t)) {
t = s + strcspn(s, ",");
if (*t)
*t++ = 0;
if (debug)
log("debug: %s leaves %s", source, s);
if (!part_channel(user, s, cb_chan_part, av[1])) {
log("user: do_part: no channel record for %s on %s (bug?)",
user->nick, av[0]);
}
}
}
/*************************************************************************/
/* Handle a KICK command.
* av[0] = channel
* av[1] = nick(s) being kicked
* av[2] = reason
* When called internally to remove a single user (no "," in av[1]) from a
* channel, callers may assume that the contents of the argument strings
* will not be modified.
*/
void do_kick(const char *source, int ac, char **av)
{
User *user;
char *s, *t;
t = av[1];
while (*(s=t)) {
t = s + strcspn(s, ",");
if (*t)
*t++ = 0;
user = get_user(s);
if (!user) {
log("user: KICK for nonexistent user %s on %s: %s", s, av[0],
merge_args(ac-2, av+2));
continue;
}
if (debug)
log("debug: kicking %s from %s", s, av[0]);
if (!part_channel(user, av[0], cb_chan_kick, av[2])) {
log("user: do_kick: no channel record for %s on %s (bug?)",
user->nick, av[0]);
}
}
}
/*************************************************************************/
/* Handle a MODE command for a user.
* av[0] = nick to change mode for
* av[1] = modes
*/
void do_umode(const char *source, int ac, char **av)
{
User *user;
char *modestr, *s;
int add = 1; /* 1 if adding modes, 0 if deleting */
user = get_user(av[0]);
if (!user) {
log("user: MODE %s for nonexistent nick %s from %s: %s", av[1],
av[0], source, merge_args(ac, av));
return;
}
if (debug)
log("debug: Changing mode for %s to %s", av[0], av[1]);
modestr = s = av[1];
av += 2;
ac -= 2;
while (*s) {
char modechar = *s++;
int32 flag;
int params;
if (modechar == '+') {
add = 1;
continue;
} else if (modechar == '-') {
add = 0;
continue;
} else if (add < 0) {
continue;
}
flag = mode_char_to_flag(modechar, MODE_USER);
if (!flag)
continue;
if (flag == MODE_INVALID)
flag = 0;
params = mode_char_to_params(modechar, MODE_USER);
params = (params >> (add*8)) & 0xFF;
if (ac < params) {
log("user: MODE %s %s: missing parameter(s) for %c%c",
user->nick, modestr, add ? '+' : '-', modechar);
break;
}
if (call_callback_4(NULL, cb_mode, user, modechar, add, av) <= 0) {
if (modechar == 'o') {
if (add)
opcnt++;
else
opcnt--;
}
if (add)
user->mode |= flag;
else
user->mode &= ~flag;
}
av += params;
ac -= params;
}
}
/*************************************************************************/
/* Handle a QUIT command.
* av[0] = reason
* When called internally, callers may assume that the contents of the
* argument string will not be modified.
*/
void do_quit(const char *source, int ac, char **av)
{
User *user;
user = get_user(source);
if (!user) {
log("user: QUIT from nonexistent user %s: %s", source,
merge_args(ac, av));
return;
}
if (debug)
log("debug: %s quits", source);
quit_user(user, av[0], 0);
}
/*************************************************************************/
/* Handle a KILL command.
* av[0] = nick being killed
* av[1] = reason
* When called internally, callers may assume that the contents of the
* argument strings will not be modified.
*/
void do_kill(const char *source, int ac, char **av)
{
User *user;
user = get_user(av[0]);
if (!user)
return;
if (debug)
log("debug: %s killed", av[0]);
quit_user(user, av[1], 1);
}
/*************************************************************************/
/*************************************************************************/
/* Join a user to a channel. Return a pointer to the channel record if the
* join succeeded, NULL otherwise.
*/
Channel *join_channel(User *user, const char *channel, int32 modes)
{
Channel *c = chan_adduser(user, channel, modes);
struct u_chanlist *uc;
if (!c)
return NULL;
uc = smalloc(sizeof(*uc));
LIST_INSERT(uc, user->chans);
uc->chan = c;
return c;
}
/*************************************************************************/
/* Part a user from a channel. */
int part_channel(User *user, const char *channel, int callback,
const char *param)
{
struct u_chanlist *uc;
LIST_SEARCH(user->chans, chan->name, channel, irc_stricmp, uc);
if (uc)
part_channel_uc(user, uc, callback, param);
return uc != NULL;
}
/*************************************************************************/
/* Part a user from all channels s/he is in. Assumes cb_chan_part and an
* empty parameter. */
void part_all_channels(User *user)
{
struct u_chanlist *uc, *nextuc;
LIST_FOREACH_SAFE (uc, user->chans, nextuc)
part_channel_uc(user, uc, cb_chan_part, "");
}
/*************************************************************************/
/*************************************************************************/
/* Various check functions. All of these return false/NULL if any
* parameter is NULL. */
/*************************************************************************/
/* Is the given user an oper? */
int is_oper(const User *user)
{
return user != NULL && (user->mode & UMODE_o);
}
/*************************************************************************/
/* Is the given user on the given channel? Return the Channel * for the
* channel if so, NULL if not.
*/
Channel *is_on_chan(const User *user, const char *chan)
{
struct u_chanlist *c;
if (!user || !chan)
return NULL;
LIST_SEARCH(user->chans, chan->name, chan, irc_stricmp, c);
return c ? c->chan : NULL;
}
/*************************************************************************/
/* Is the given user a channel operator on the given channel? */
int is_chanop(const User *user, const char *chan)
{
Channel *c = chan ? get_channel(chan) : NULL;
struct c_userlist *cu;
if (!user || !chan || !c)
return 0;
LIST_SEARCH(c->users, user->nick, user->nick, irc_stricmp, cu);
return cu != NULL && (cu->mode & CUMODE_o) != 0;
}
/*************************************************************************/
/* Is the given user voiced (channel mode +v) on the given channel? */
int is_voiced(const User *user, const char *chan)
{
Channel *c = chan ? get_channel(chan) : NULL;
struct c_userlist *cu;
if (!user || !chan || !c)
return 0;
LIST_SEARCH(c->users, user->nick, user->nick, irc_stricmp, cu);
return cu != NULL && (cu->mode & CUMODE_v) != 0;
}
/*************************************************************************/
/*************************************************************************/
/* Does the user's usermask match the given mask (either nick!user@host or
* just user@host)? Also checks fakehost where supported.
*/
int match_usermask(const char *mask, const User *user)
{
char *mask2 = sstrdup(mask);
char *nick, *username, *host;
int match_user, match_host, result;
if (strchr(mask2, '!')) {
nick = strtok(mask2, "!");
username = strtok(NULL, "@");
} else {
nick = NULL;
username = strtok(mask2, "@");
}
host = strtok(NULL, "");
if (!host) {
free(mask2);
return 0;
}
match_user = match_wild_nocase(username, user->username);
match_host = match_wild_nocase(host, user->host);
if (user->fakehost)
match_host |= match_wild_nocase(host, user->fakehost);
if (nick) {
result = match_wild_nocase(nick, user->nick) &&
match_user && match_host;
} else {
result = match_user && match_host;
}
free(mask2);
return result;
}
/*************************************************************************/
/* Split a usermask up into its constitutent parts. Returned strings are
* malloc()'d, and should be free()'d when done with. Returns "*" for
* missing parts. Assumes `mask' is a non-empty string.
*/
void split_usermask(const char *mask, char **nick, char **user, char **host)
{
char *mask2 = sstrdup(mask);
char *mynick, *myuser, *myhost;
mynick = mask2;
myuser = strchr(mask2, '!');
myhost = myuser ? strchr(myuser, '@') : NULL;
if (myuser)
*myuser++ = 0;
if (myhost)
*myhost++ = 0;
/* Handle special case: mask == user@host */
if (mynick && !myuser && strchr(mynick, '@')) {
mynick = NULL;
myuser = mask2;
myhost = strchr(mask2, '@');
if (myhost) /* Paranoia */
*myhost++ = 0;
}
if (!mynick || !*mynick)
mynick = (char *)"*";
if (!myuser || !*myuser)
myuser = (char *)"*";
if (!myhost || !*myhost)
myhost = (char *)"*";
*nick = sstrdup(mynick);
*user = sstrdup(myuser);
*host = sstrdup(myhost);
free(mask2);
}
/*************************************************************************/
/* Given a user, return a mask that will most likely match any address the
* user will have from that location. For IP addresses, wildcards the last
* octet of the address (e.g. 10.1.1.1 -> 10.1.1.*); for named addresses,
* wildcards the leftmost part of the name unless the name only contains
* two parts. The returned character string is malloc'd and should be
* free'd when done with.
*
* Where supported, uses the fake host instead of the real one if
* use_fakehost is nonzero.
*/
char *create_mask(User *u, int use_fakehost)
{
char *mask, *s, *end, *host;
host = u->host;
if (use_fakehost && u->fakehost)
host = u->fakehost;
/* Get us a buffer the size of the username plus hostname. The result
* will never be longer than this (and will often be shorter), thus we
* can use strcpy() and sprintf() safely.
*/
end = mask = smalloc(strlen(u->username) + strlen(host) + 2);
end += sprintf(end, "%s@", u->username);
if (strspn(host, "0123456789.") == strlen(host)
&& (s = strchr(host, '.'))
&& (s = strchr(s+1, '.'))
&& (s = strchr(s+1, '.'))
&& ( !strchr(s+1, '.'))) { /* IP addr */
s = sstrdup(host);
*strrchr(s, '.') = 0;
sprintf(end, "%s.*", s);
free(s);
} else {
if ((s = strchr(host+1, '.')) && strchr(s+1, '.')) {
s = sstrdup(s-1);
*s = '*';
} else {
s = sstrdup(host);
}
strcpy(end, s); /* safe: see above */
free(s);
}
return mask;
}
/*************************************************************************/
/*************************************************************************/
/* Create a new guest nick using GuestNickPrefix and a unique series of
* digits, and return it. The returned nick is stored in a static buffer
* and will be overwritten at the next call.
*
* At present, we simply use a rollover counter attached to the nick,
* initialized to a random value. This provides for uniqueness as long as
* Services is not restarted and a reasonable chance of uniqueness even
* when Services is restarted (unless you have a long prefix and a short
* maximum nick length; however, this routine will make sure at least 4
* digits are available, possibly by shortening the prefix).
*
* Note that initializing the counter based on the current time would be a
* bad idea, since if more than one user per second (on average) connected
* to the network, duplicate nicks would be almost guaranteed if Services
* restarted.
*/
char *make_guest_nick(void)
{
static char nickbuf[NICKMAX+1]; /* +1 to check for overrun */
static uint32 counter = 0; /* Unique suffix counter */
int tries; /* Tries to find an unused nick */
int prefixlen; /* Length of nick prefix */
uint32 suffixmod; /* Modulo for suffix counter */
int i;
/* Sanity checks on nick prefix length */
prefixlen = strlen(GuestNickPrefix);
if (protocol_nickmax <= 4) {
/* This violates RFC1459 as well as common sense, so just blow
* ourselves out of the water. */
fatal("make_guest_nick(): protocol_nickmax too small (%d)",
protocol_nickmax);
} else if (prefixlen+4 > protocol_nickmax) {
/* Reserve at least 4 digits for the suffix */
prefixlen = protocol_nickmax-4;
log("warning: make_guest_nick(): GuestNickPrefix too long,"
" shortening to %d characters", prefixlen);
GuestNickPrefix[prefixlen] = 0;
}
/* Calculate number of digits available for suffix -> suffix modulo */
i = protocol_nickmax - prefixlen;
if (i < 10) {
suffixmod = 1;
while (i-- > 0)
suffixmod *= 10;
} else {
suffixmod = 0; /* no modulo */
}
/* Actually generate the nick. If the nick already exists, generate a
* new one, and repeat until finding an unused nick or trying too many
* times. If we try too many times, we just kill the last one we end
* up with. */
tries = 0;
for (;;) {
if (counter == 0) /* initialize to random the first time */
counter = rand();
if (suffixmod) /* strip down to right number of digits */
counter %= suffixmod;
if (counter == 0) /* if rand() gave us 0 or N*suffixmod... */
counter = 1; /* ... use 1 instead */
i = snprintf(nickbuf, sizeof(nickbuf), "%s%u", GuestNickPrefix, counter);
if (i > protocol_nickmax) {
log("BUG: make_guest_nick() generated %s but nickmax == %d!",
nickbuf, protocol_nickmax);
nickbuf[protocol_nickmax] = 0;
}
if (!get_user(nickbuf)) /* done if user not found */
break;
/* Increment try count, and break out if it's too much */
if (++tries >= MAKEGUESTNICK_TRIES) {
kill_user(NULL, nickbuf, "Guest nicks may not be used");
break;
}
/* Reset counter to 0 to use a new random number */
counter = 0;
}
/* Increment the unique suffix counter modulo suffixmod, and avoid 0
* (which would cause a reset to a random value) */
counter++;
if (counter == suffixmod) /* because suffixmod==0 if no modulo */
counter = 1;
/* Return the nick */
return nickbuf;
};
/*************************************************************************/
/* Return nonzero if the given nickname can potentially be a guest nickname
* (i.e. a nickname that could be generated by make_guest_nick()), zero if
* not. Currently this means a nickname consisting of GuestNickPrefix
* followed by between 1 and 10 digits inclusive.
*/
int is_guest_nick(const char *nick)
{
int prefixlen = strlen(GuestNickPrefix);
int nicklen = strlen(nick);
return nicklen >= prefixlen+1 && nicklen <= prefixlen+10
&& irc_strnicmp(nick, GuestNickPrefix, prefixlen) == 0
&& strspn(nick+prefixlen, "1234567890") == nicklen-prefixlen;
}
/*************************************************************************/
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